ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Books
  • Articles  (324)
  • Data
  • Articles: DFG German National Licenses  (324)
  • Chemistry  (243)
  • data mining  (23)
  • automated theorem proving  (21)
  • stability  (19)
  • optimization  (18)
  • 1995-1999  (286)
  • 1975-1979  (38)
  • 1935-1939
  • 1999  (34)
  • 1997  (252)
  • 1983
  • 1978  (37)
  • 1977  (1)
  • 1925
  • Computer Science  (246)
  • Architecture, Civil Engineering, Surveying  (78)
Collection
  • Books
  • Articles  (324)
  • Data
Source
Publisher
Years
  • 1995-1999  (286)
  • 1975-1979  (38)
  • 1935-1939
  • 1980-1984  (39)
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Queueing systems 32 (1999), S. 131-168 
    ISSN: 1572-9443
    Keywords: stability ; positive recurrence ; fluid limit ; polling system ; exhaustive service policy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract We introduce a generalized criterion for the stability of Markovian queueing systems in terms of stochastic fluid limits. We consider an example in which this criterion may be applied: a polling system with two stations and two heterogeneous servers.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Constraints 4 (1999), S. 79-89 
    ISSN: 1572-9354
    Keywords: benchmarks ; radio link frequency assignment ; constraint satisfaction ; optimization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract The problem of radio frequency assignment is to provide communication channels from limited spectral resources whilst keeping to a minimum the interference suffered by those whishing to communicate in a given radio communication network. This problem is a combinatorial (NP-hard) optimization problem. In 1993, the CELAR (the French “Centre d'Electronique de l'Armement”) built a suite of simplified versions of Radio Link Frequency Assignment Problems (RLFAP) starting from data on a real network Roisnel93. Initially designed for assessing the performances of several Constraint Logic Programming languages, these benchmarks have been made available to the public in the framework of the European EUCLID project CALMA (Combinatorial Algorithms for Military Applications). These problems should look very attractive to the CSP community: the problem is simple to represent, all constraints are binary and involve finite domain variables. They nevertheless have some of the flavors of real problems (including large size and several optimization criteria). This paper gives essential facts about the CELAR instances and also introduces the GRAPH instances which were generated during the CALMA project.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Information systems frontiers 1 (1999), S. 259-266 
    ISSN: 1572-9419
    Keywords: data mining ; statistics ; patterns in data ; fitting distributions ; lambda ; beta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Data mining has, in the past, tended to use simplistic statistical methods (or even none at all). In this paper we show by example how cutting edge (but easy to use and comprehend) statistical methods can yield substantial gains in data mining. The role of statistics in IS/IT (information systems and information technology) in general can be substantial, yielding more nearly optimal performance of problems at the emerging frontiers in all their aspects.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1572-9354
    Keywords: overconstrained problems ; constraint satisfaction ; optimization ; soft constraint ; dynamic programming ; branch and bound ; complexity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract In this paper we describe and compare two frameworks for constraint solving where classical CSPs, fuzzy CSPs, weighted CSPs, partial constraint satisfaction, and others can be easily cast. One is based on a semiring, and the other one on a totally ordered commutative monoid. While comparing the two approaches, we show how to pass from one to the other one, and we discuss when this is possible. The two frameworks have been independently introduced in ijcai95,jacm and schiex-ijcai95.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Queueing systems 27 (1997), S. 205-226 
    ISSN: 1572-9443
    Keywords: multiclass queueing networks ; ergodicity ; stability ; performance analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract We develop the use of piecewise linear test functions for the analysis of stability of multiclass queueing networks and their associated fluid limit models. It is found that if an associated LP admits a positive solution, then a Lyapunov function exists. This implies that the fluid limit model is stable and hence that the network model is positive Harris recurrent with a finite polynomial moment. Also, it is found that if a particular LP admits a solution, then the network model is transient.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Queueing systems 33 (1999), S. 293-325 
    ISSN: 1572-9443
    Keywords: stability ; fluid models ; multiclass queueing networks ; piecewise linear Lyapunov functions ; linear Lyapunov functions ; monotone global stability ; static buffer priority disciplines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract This paper studies the stability of a three‐station fluid network. We show that, unlike the two‐station networks in Dai and Vande Vate [18], the global stability region of our three‐station network is not the intersection of its stability regions under static buffer priority disciplines. Thus, the “worst” or extremal disciplines are not static buffer priority disciplines. We also prove that the global stability region of our three‐station network is not monotone in the service times and so, we may move a service time vector out of the global stability region by reducing the service time for a class. We introduce the monotone global stability region and show that a linear program (LP) related to a piecewise linear Lyapunov function characterizes this largest monotone subset of the global stability region for our three‐station network. We also show that the LP proposed by Bertsimas et al. [1] does not characterize either the global stability region or even the monotone global stability region of our three‐station network. Further, we demonstrate that the LP related to the linear Lyapunov function proposed by Chen and Zhang [11] does not characterize the stability region of our three‐station network under a static buffer priority discipline.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Queueing systems 31 (1999), S. 171-206 
    ISSN: 1572-9443
    Keywords: scheduling ; open multiclass queueing networks ; discrete-review policies ; fluid models ; stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract This paper describes a family of discrete-review policies for scheduling open multiclass queueing networks. Each of the policies in the family is derived from what we call a dynamic reward function: such a function associates with each queue length vector q and each job class k a positive value r k (q), which is treated as a reward rate for time devoted to processing class k jobs. Assuming that each station has a traffic intensity parameter less than one, all policies in the family considered are shown to be stable. In such a policy, system status is reviewed at discrete points in time, and at each such point the controller formulates a processing plan for the next review period, based on the queue length vector observed. Stability is proved by combining elementary large deviations theory with an analysis of an associated fluid control problem. These results are extended to systems with class dependent setup times as well as systems with alternate routing and admission control capabilities.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Constraints 4 (1999), S. 101-112 
    ISSN: 1572-9354
    Keywords: sensitivity analysis ; duality ; optimization ; inference
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract The constraint programming community has recently begun to address certain types of optimization problems. These problems tend to be discrete or to have discrete elements. Although sensitivity analysis is well developed for continuous problems, progress in this area for discrete problems has been limited. This paper proposes a general approach to sensitivity analysis that applies to both continuous and discrete problems. In the continuous case, particularly in linear programming, sensitivity analysis can be obtained by solving a dual problem. One way to broaden this result is to generalize the classical idea of a dual to that of an “inference dual,” which can be defined for any optimization problem. To solve the inference dual is to obtain a proof of the optimal value of the problem. Sensitivity analysis can be interpreted as an analysis of the role of each constraint in this proof. This paper shows that traditional sensitivity analysis for linear programming is a special case of this approach. It also illustrates how the approach can work out in a discrete problem by applying it to 0-1 linear programming (linear pseudo-boolean optimization).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Queueing systems 26 (1997), S. 343-363 
    ISSN: 1572-9443
    Keywords: retrial queues ; stability ; ergodicity ; renovation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract We consider the following Type of problems. Calls arrive at a queue of capacity K (which is called the primary queue), and attempt to get served by a single server. If upon arrival, the queue is full and the server is busy, the new arriving call moves into an infinite capacity orbit, from which it makes new attempts to reach the primary queue, until it finds it non-full (or it finds the server idle). If the queue is not full upon arrival, then the call (customer) waits in line, and will be served according to the FIFO order. If λ is the arrival rate (average number per time unit) of calls and μ is one over the expected service time in the facility, it is well known that μ 〉 λ is not always sufficient for stability. The aim of this paper is to provide general conditions under which it is a sufficient condition. In particular, (i) we derive conditions for Harris ergodicity and obtain bounds for the rate of convergence to the steady state and large deviations results, in the case that the inter-arrival times, retrial times and service times are independent i.i.d. sequences and the retrial times are exponentially distributed; (ii) we establish conditions for strong coupling convergence to a stationary regime when either service times are general stationary ergodic (no independence assumption), and inter-arrival and retrial times are i.i.d. exponentially distributed; or when inter-arrival times are general stationary ergodic, and service and retrial times are i.i.d. exponentially distributed; (iii) we obtain conditions for the existence of uniform exponential bounds of the queue length process under some rather broad conditions on the retrial process. We finally present conditions for boundedness in distribution for the case of nonpatient (or non persistent) customers.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Queueing systems 32 (1999), S. 99-130 
    ISSN: 1572-9443
    Keywords: neural network ; inhibition ; stability ; Markov process ; fluid limit ; Harris-recurrence ; transience
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract The subject of the paper is the stability analysis of some neural networks consisting of a finite number of interacting neurons. Following the approach of Dai [5] we use the fluid limit model of the network to derive a sufficient condition for positive Harris-recurrence of the associated Markov process. This improves the main result in Karpelevich et al. [11] and, at the same time, sheds some new light on it. We further derive two different conditions that are sufficient for transience of the state process and illustrate our results by classifying some examples according to positive recurrence or transience.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Queueing systems 32 (1999), S. 195-231 
    ISSN: 1572-9443
    Keywords: window flow control ; TCP ; stability ; multiclass networks ; stationary ergodic point processes ; (max,+)-linear system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract We focus on window flow control as used in packet-switched communication networks. The approach consists in studying the stability of a system where each node on the path followed by the packets of the controlled connection is modeled by a FIFO (First-In-First-Out) queue of infinite capacity which receives in addition some cross traffic represented by an exogenous flow. Under general stochastic assumptions, namely for stationary and ergodic input processes, we show the existence of a maximum throughput allowed by the flow control. Then we establish bounds on the value of this maximum throughput. These bounds, which do not coincide in general, are reached by time-space scalings of the exogenous flows. Therefore, the performance of the window flow control depends not only on the traffic intensity of the cross flows, but also on fine statistical characteristics such as the burstiness of these flows. These results are illustrated by several examples, including the case of a nonmonotone, nonconvex and fractal stability region.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Machine learning 26 (1997), S. 177-211 
    ISSN: 0885-6125
    Keywords: inductive logic programming ; qualitative modelling ; system identification ; PAC learning ; physiological modelling ; cardiovascular system ; data mining ; patient monitoring
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract The automated construction of dynamic system models is an important application area for ILP. We describe a method that learns qualitative models from time-varying physiological signals. The goal is to understand the complexity of the learning task when faced with numerical data, what signal processing techniques are required, and how this affects learning. The qualitative representation is based on Kuipers' QSIM. The learning algorithm for model construction is based on Coiera's GENMODEL. We show that QSIM models are efficiently PAC learnable from positive examples only, and that GENMODEL is an ILP algorithm for efficiently constructing a QSIM model. We describe both GENMOEL which performs RLGG on qualitative states to learn a QSIM model, and the front-end processing and segmenting stages that transform a signal into a set of qualitative states. Next we describe results of experiments on data from six cardiac bypass patients. Useful models were obtained, representing both normal and abnormal physiological states. Model variation across time and across different levels of temporal abstraction and fault tolerance is explored. The assumption made by many previous workers that the abstraction of examples from data can be separated from the learning task is not supported by this study. Firstly, the effects of noise in the numerical data manifest themselves in the qualitative examples. Secondly, the models learned are directly dependent on the initial qualitative abstraction chosen.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Journal of intelligent and robotic systems 19 (1997), S. 39-54 
    ISSN: 1573-0409
    Keywords: extended Jacobian method ; Lagrange multiplier method ; kinematically redundant manipulators ; numerical efficiency ; optimization ; robotics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Several methods have been proposed in the past for resolving the control of kinematically redundant manipulators by optimizing a secondary criterion. The extended Jacobian method constrains the gradient of this criterion to be in the null space of the Jacobian matrix, while the Lagrange multiplier method represents the gradient as being in the row space. In this paper, a numerically efficient form of the Lagrange multiplier method is presented and is compared analytically, computationally, and operationally to the extended Jacobian method. This paper also presents an improved method for tracking algorithmic singularities over previous work.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Journal of intelligent and robotic systems 19 (1997), S. 89-103 
    ISSN: 1573-0409
    Keywords: kinematics ; manipulator ; optimization ; performance criteria ; redundancy ; robot
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A method to simultaneously optimize multiple performance criteria for a redundant manipulator is presented. Preferred formulation requirements for the criteria are discussed, and previously proposed normalization methods are examined. A statistically based variable weighting technique is developed and evaluated. A seven-degree-of-freedom Robotics Research Corporation manipulator is used as a test bed for the multiple criteria optimization scheme.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Journal of intelligent and robotic systems 24 (1999), S. 43-68 
    ISSN: 1573-0409
    Keywords: learning robots ; system organization ; optimization ; physical equation ; look-ut table ; neural networks ; fuzzy controllers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract This paper explores a stepwise learning approach based on a system's decomposition into functional subsystems. Two case studies are examined: a visually guided robot that learns to track a maneuvering object, and a robot that learns to use the information from a force sensor in order to put a peg into a hole. These two applications show the features and advantages of the proposed approach: i) the subsystems naturally arise as functional components of the hardware and software; ii) these subsystems are building blocks of the robot behavior and can be combined in several ways for performing various tasks; iii) this decomposition makes it easier to check the performances and detect the cause of a malfunction; iv) only those subsystems for which a satisfactory solution is not available need to be learned; v) the strategy proposed for coordinating the optimization of all subsystems ensures an improvement at the task-level; vi) the overall system's behavior is significantly improved by the stepwise learning approach.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Journal of intelligent and robotic systems 19 (1997), S. 105-117 
    ISSN: 1573-0409
    Keywords: optimization ; Pontryagin’s maximum principle ; redundant manipulators ; state-space augmentation ; trajectory planning
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The off-line global trajectory planning for kinematically redundant manipulators is formulated as an optimization problem whose solution is obtained by applying the Pontryagin’s Maximum Principle. The state space augmentation method is developed to obtain a set of optimal joint trajectories corresponding to a singularity-free Cartesian path which avoids joint limits and conserves joint configuration in cyclic motion. Results of computer simulation conducted on a three-degree-of-freedom planar manipulator are presented and discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Journal of intelligent and robotic systems 20 (1997), S. 131-155 
    ISSN: 1573-0409
    Keywords: robot adaptive control ; basis function-like networks ; stability ; discrete variable structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Stable neural network-based sampled-data indirect and direct adaptivecontrol approaches, which are the integration of a neural network (NN)approach and the adaptive implementation of the discrete variable structurecontrol, are developed in this paper for the trajectory tracking control ofa robot arm with unknown nonlinear dynamics. The robot arm is assumed tohave an upper and lower bound of its inertia matrix norm and its states areavailable for measurement. The discrete variable structure control servestwo purposes, i.e., one is to force the system states to be within the stateregion in which neural networks are used when the system goes out of neuralcontrol; and the other is to improve the tracking performance within the NNapproximation region. Main theory results for designing stable neuralnetwork-based sampled data indirect and direct adaptive controllers aregiven, and the extension of the proposed control approaches to the compositeadaptive control of a flexible-link robot is discussed. Finally, theeffectiveness of the proposed control approaches is illustrated throughsimulation studies.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Journal of intelligent and robotic systems 24 (1999), S. 125-149 
    ISSN: 1573-0409
    Keywords: planning ; control ; multi-fingered robot hand ; optimization ; internal force ; simulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract In this paper, the problem of controlling multi-fingered robot hands with rolling and sliding contacts is addressed. Several issues are explored. These issues involve the kinematic analysis and modeling, the dynamic analysis and control, and the coordination of a multi-fingered robot hand system. Based on a hand-object system in which the contacts are allowed to both roll and slide, a kinematic model is derived and analyzed. Also, the dynamic model of the hand-object system with relative motion contacts is studied. A control law is proposed to guarantee the asymptotic tracking of the object trajectory together with the desired rolling and/or sliding motions along the surface of the object. A planning approach is then introduced to minimize the contact forces so that the desired motion of the object and the relative motions between the fingers and the object can be achieved. Simulation results which support the theoretical development are presented.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Journal of intelligent and robotic systems 19 (1997), S. 411-436 
    ISSN: 1573-0409
    Keywords: assembly planning ; stability ; robot ; forward ; operations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The paper presents an approach to sequence planning consisting in determining assembly sequences defined in terms of mating and non-mating operations and based on a dynamic expansion of the assembly tree obtained using a knowledge base management system. The planner considers the case of a single-robot assembly workcell. The use of stability and the detailed definition of sequences also by means of several non-mating operations are shown to be powerful instruments in the control of the tree expansion. Forward assembly planning has been chosen, in order to minimize the number of stability checks. Backtracking is avoided by combining precedence relations and stability analysis. Hard and soft constrains are introduced to drive the tree expansion. Hard constraints are precedence relations and stability analysis. All operations are associated to costs, which are used as soft constraints. The operation based approach enables one to manage even non-mating operations and to easily overcome the linearity constraint. Costs enable the planner to manage the association among tools and components. The first section of the paper concerns Stability Analysis that is subdivided into Static and Dynamic Stability Analysis. The former is mainly involved in analyzing gravity effects; the latter is mainly involved in evaluate inertia effects due to manipulation. Stability Analysis is implemented in a simplified form. Fundamental assumptions are: no rotational equilibrium condition is considered; for each reaction force only direction and versus, but not magnitude, are considered; friction is neglected. The second section discusses the structure of the planner and its implementation. The planner is a rule based system. Forward chaining and hypothetical reasoning are the inference strategies used. The knowledge base and the data base of the system are presented and the advantages obtained using a rule based system are discussed. The third section shows two planning examples, showing the performance of the system in a simple case and in an industrial test case, the assembly of a microwave branching filter composed of 26 components.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Journal of intelligent and robotic systems 26 (1999), S. 91-100 
    ISSN: 1573-0409
    Keywords: robots ; neural networks ; adaptiveness ; stability ; approximation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract An indirect adaptive control approach is developed in this paper for robots with unknown nonlinear dynamics using neural networks (NNs). A key property of the proposed approach is that the actual joint angle values in the control law are replaced by the desired joint angles, angle velocities and accelerators, and the bound on the NN reconstruction errors is assumed to be unknown. Main theoretical results for designing such a neuro-controller are given, and the control performance of the proposed controller is verified with simulation studies.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    ISSN: 1432-0770
    Keywords: Key words: Hebbian learning rule ; attractor dynamics ; symmetric connections ; multiplicative normalization ; self-organization ; stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract. While learning and development are well characterized in feedforward networks, these features are more difficult to analyze in recurrent networks due to the increased complexity of dual dynamics – the rapid dynamics arising from activation states and the slow dynamics arising from learning or developmental plasticity. We present analytical and numerical results that consider dual dynamics in a recurrent network undergoing Hebbian learning with either constant weight decay or weight normalization. Starting from initially random connections, the recurrent network develops symmetric or near-symmetric connections through Hebbian learning. Reciprocity and modularity arise naturally through correlations in the activation states. Additionally, weight normalization may be better than constant weight decay for the development of multiple attractor states that allow a diverse representation of the inputs. These results suggest a natural mechanism by which synaptic plasticity in recurrent networks such as cortical and brainstem premotor circuits could enhance neural computation and the generation of motor programs.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Computational economics 13 (1999), S. 103-115 
    ISSN: 1572-9974
    Keywords: optimization ; econometric functions ; nonlinear programming ; evolutionary programming
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Economics
    Notes: Abstract In the present paper we apply a new Genetic Hybrid Algorithm (GHA) to globally minimize a representative set of ill-conditioned econometric/mathematical functions. The genetic algorithm was specifically designed for nonconvex mixed integer nonlinear programming problems and it can be successfully applied to both global and constrained optimization. In previous studies, we have demonstrated the efficiency of the GHA in solving complicated NLP, INLP and MINLP problems. The present study is a continuation of this research, now focusing on a set of highly irregular optimization problems. In this paper we discuss the genetic hybrid algorithm, the nonlinear problems to be solved and present the results of the empirical tests.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    Springer
    Numerical algorithms 14 (1997), S. 343-359 
    ISSN: 1572-9265
    Keywords: progressive interpolation ; stability ; spline ; shape parameters ; geometric continuity ; 41A05 ; 41A15 ; 65D05 ; 65D07
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mathematics
    Notes: Abstract In this paper, we study several interpolating and smoothing methods for data which are known “progressively”. The algorithms proposed are governed by recurrence relations and our principal goal is to study their stability. A recurrence relation will be said stable if the spectral radius of the associated matrix is less than one. The iteration matrices depend on shape parameters which come either from the connection at the knots, or from the nature of the interpolant between two knots. We obtain various stability domains. Moving the parameters inside these domains leads to interesting shape effects.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Springer
    Computational economics 10 (1997), S. 267-277 
    ISSN: 1572-9974
    Keywords: data mining ; forecasting ; genetic algorithms.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Economics
    Notes: Abstract This paper presents an algorithm that permits the search for dependencies among sets of data (univariate or multivariate time-series, or cross-sectional observations). The procedure is modeled after genetic theories and Darwinian concepts, such as natural selection and survival of the fittest. It permits the discovery of equations of the data-generating process in symbolic form. The genetic algorithm that is described here uses parts of equations as building blocks to breed ever better formulas. Apart from furnishing a deeper understanding of the dynamics of a process, the method also permits global predictions and forecasts. The algorithm is successfully tested with artificial and with economic time-series and also with cross-sectional data on the performance and salaries of NBA players during the 94–95 season.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Springer
    Artificial intelligence review 13 (1999), S. 345-364 
    ISSN: 1573-7462
    Keywords: data mining ; document filtering ; exploratory data analysis ; information retrieval ; self-organizing map ; SOM ; text document collection ; WEBSOM
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract New methods that are user-friendly and efficient are needed for guidanceamong the masses of textual information available in the Internet and theWorld Wide Web. We have developed a method and a tool called the WEBSOMwhich utilizes the self-organizing map algorithm (SOM) for organizing largecollections of text documents onto visual document maps. The approach toprocessing text is statistically oriented, computationally feasible, andscalable – over a million text documents have been ordered on a single map.In the article we consider different kinds of information needs and tasksregarding organizing, visualizing, searching, categorizing and filteringtextual data. Furthermore, we discuss and illustrate with examples howdocument maps can aid in these situations. An example is presented wherea document map is utilized as a tool for visualizing and filtering a stream ofincoming electronic mail messages.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Springer
    Applied intelligence 11 (1999), S. 277-284 
    ISSN: 1573-7497
    Keywords: genetic algorithms ; classification ; data mining
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract A common approach to evaluating competing models in a classification context is via accuracy on a test set or on cross-validation sets. However, this can be computationally costly when using genetic algorithms with large datasets and the benefits of performing a wide search are compromised by the fact that estimates of the generalization abilities of competing models are subject to noise. This paper shows that clear advantages can be gained by using samples of the test set when evaluating competing models. Further, that applying statistical tests in combination with Occam's razor produces parsimonious models, matches the level of evaluation to the state of the search and retains the speed advantages of test set sampling.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    ISSN: 1573-7497
    Keywords: discretisation ; data mining ; simulated annealing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract An introduction to the approaches used to discretise continuous database features is given, together with a discussion of the potential benefits of such techniques. These benefits are investigated by applying discretisation algorithms to two large commercial databases; the discretisations yielded are then evaluated using a simulated annealing based data mining algorithm. The results produced suggest that dramatic reductions in problem size may be achieved, yielding improvements in the speed of the data mining algorithm. However, it is also demonstrated under certain circumstances that the discretisation produced may give an increase in problem size or allow overfitting by the data mining algorithm. Such cases, within which often only a small proportion of the database belongs to the class of interest, highlight the need both for caution when producing discretisations and for the development of more robust discretisation algorithms.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    Electronic Resource
    Electronic Resource
    Springer
    Applied intelligence 11 (1999), S. 297-304 
    ISSN: 1573-7497
    Keywords: data mining ; rule discovery ; interest measure ; distinctive features ; characteristic rules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract One strategy for increasing the efficiency of rule discovery in data mining is to target a restricted class of rules, such as exact or almost exact rules, rules with a limited number of conditions, or rules in which each condition, on its own, eliminates a competing outcome class. An algorithm is presented for the discovery of rules in which each condition is a distinctive feature of the outcome class on its right-hand side in the subset of the data set defined by the conditions, if any, which precede it. Such a rule is said to be characteristic for the outcome class. A feature is defined as distinctive for an outcome class if it maximises a well-known measure of rule interest or is unique to the outcome class in the data set. In the special case of data mining which arises when each outcome class is represented by a single instance in the data set, a feature of an object is shown to be distinctive if and only if no other feature is shared by fewer objects in the data set.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    Electronic Resource
    Electronic Resource
    Springer
    International journal of parallel programming 6 (1977), S. 41-54 
    ISSN: 1573-7640
    Keywords: Pattern recognition ; feature selection and extraction ; dimensionality reduction ; data compression ; algorithms ; optimization ; mathematical programming
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract A computational algorithm is presented for the extraction of an optimal single linear feature from several Gaussian pattern classes. The algorithm minimizes the increase in the probability of misclassification in the transformed (feature) space. The general approach used in this procedure was developed in a recent paper by R. J. P. de Figueiredo.(1) Numerical results on the application of this procedure to the remotely sensed data from the Purdue C1 flight line as well asLandsat data are presented. It was found that classification using the optimal single linear feature yielded a value for the probability of misclassification on the order of 30% less than that obtained by using the best single untransformed feature. The optimal single linear feature gave performance results comparable to those obtained by using the two features which maximized the average divergence. Also discussed are improvements in classification results using this method when the size of the training set is small.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    Springer
    Journal of scientific computing 12 (1997), S. 361-369 
    ISSN: 1573-7691
    Keywords: Alternating-direction implicit ; difference scheme ; stability ; convergence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract A new alternating-direction implicit (ADI) scheme for solving three-dimensional parabolic differential equations has been developed based on the idea of regularized difference scheme. It is unconditionally stable and second-order accurate. Further, it overcomes the drawback of the Douglas scheme and is to be very well to simulate fast transient phenomena and to efficiently capture steady state solutions of parabolic differential equations. Numerical example is illustrated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Springer
    Neural processing letters 10 (1999), S. 267-271 
    ISSN: 1573-773X
    Keywords: recurrent neural networks ; stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract In this paper, we point out that the conditions given in [1] are sufficient but unnecessary for the global asymptotically stable equilibrium of a class of delay differential equations. Instead, we prove that under weaker conditions, it is still global asymptotically stable.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    Electronic Resource
    Electronic Resource
    Springer
    Artificial intelligence review 11 (1997), S. 193-225 
    ISSN: 1573-7462
    Keywords: lazy learning ; model selection ; cross validation ; optimization ; attribute selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Given a set of models and some training data, we would like to find the model that best describes the data. Finding the model with the lowest generalization error is a computationally expensive process, especially if the number of testing points is high or if the number of models is large. Optimization techniques such as hill climbing or genetic algorithms are helpful but can end up with a model that is arbitrarily worse than the best one or cannot be used because there is no distance metric on the space of discrete models. In this paper we develop a technique called “racing” that tests the set of models in parallel, quickly discards those models that are clearly inferior and concentrates the computational effort on differentiating among the better models. Racing is especially suitable for selecting among lazy learners since training requires negligible expense, and incremental testing using leave-one-out cross validation is efficient. We use racing to select among various lazy learning algorithms and to find relevant features in applications ranging from robot juggling to lesion detection in MRI scans.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    ISSN: 1573-7462
    Keywords: CancerLit ; concept spaces ; data mining ; Hopfield net ; information retrieval ; Kohonen net ; medical knowledge ; neural networks
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract This paper discusses several data mining algorithms and techniques thatwe have developed at the University of Arizona Artificial Intelligence Lab.We have implemented these algorithms and techniques into severalprototypes, one of which focuses on medical information developed incooperation with the National Cancer Institute (NCI) and the University ofIllinois at Urbana-Champaign. We propose an architecture for medicalknowledge information systems that will permit data mining across severalmedical information sources and discuss a suite of data mining tools that weare developing to assist NCI in improving public access to and use of theirexisting vast cancer information collections.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    Electronic Resource
    Electronic Resource
    Springer
    Journal of intelligent information systems 9 (1997), S. 57-81 
    ISSN: 1573-7675
    Keywords: Feature subset selection ; data mining ; simulated annealing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract An overview of the principle feature subset selection methods isgiven. We investigate a number of measures of feature subset quality, usinglarge commercial databases. We develop an entropic measure, based upon theinformation gain approach used within ID3 and C4.5 to build trees, which isshown to give the best performance over our databases. This measure is usedwithin a simple feature subset selection algorithm and the technique is usedto generate subsets of high quality features from the databases. A simulatedannealing based data mining technique is presented and applied to thedatabases. The performance using all features is compared to that achievedusing the subset selected by our algorithm. We show that a substantialreduction in the number of features may be achieved together with animprovement in the performance of our data mining system. We also present amodification of the data mining algorithm, which allows it to simultaneouslysearch for promising feature subsets and high quality rules. The effect ofvarying the generality level of the desired pattern is alsoinvestigated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    Electronic Resource
    Electronic Resource
    Springer
    Journal of intelligent information systems 9 (1997), S. 33-56 
    ISSN: 1573-7675
    Keywords: combinatorial pattern matching ; data mining ; sequential pattern ; suffix tree ; update
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Most daily and scientific data are sequential in nature. Discoveringimportant patterns from such data can benefit the user and scientist bypredicting coming activities, interpreting recurring phenomena, extractingoutstanding similarities and differences for close attention, compressingdata, and detecting intrusion. We consider the following incrementaldiscovery problem for large and dynamic sequential data. Suppose thatpatterns were previously discovered and materialized. An update is made tothe sequential database. An incremental discovery will take advantage ofdiscovered patterns and compute only the change by accessing the affectedpart of the database and data structures. In addition to patterns, thestatistics and position information of patterns need to be updated to allowfurther analysis and processing on patterns. We present an efficientalgorithm for the incremental discovery problem. The algorithm is applied tosequential data that honors several sequential patterns modeling weatherchanges in Singapore. The algorithm finds what it is supposed to find.Experiments show that for small updates and large databases, the incrementaldiscovery algorithm runs in time independent of the data size.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    Electronic Resource
    Electronic Resource
    Springer
    Journal of scientific computing 12 (1997), S. 215-231 
    ISSN: 1573-7691
    Keywords: Transport models ; shallow water ; splitting methods ; stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract We investigate the use of splitting methods for the numerical integration of three-dimensional transport-chemistry models. In particular, we investigate various possibilities for the time discretization that can take advantage of the parallelization and vectorization facilities offered by multi-processor vector computers. To suppress wiggles in the numerical solution, we use third-order, upwind-biased discretization of the advection terms, resulting in a five-point coupling in each direction. As an alternative to the usual splitting functions, such as co-ordinate splitting or operator splitting, we consider a splitting function that is based on a three-coloured hopscotch-type splitting in the horizontal direction, whereas full coupling is retained in the vertical direction. Advantages of this splitting function are the easy application of domain decomposition techniques and unconditional stability in the vertical, which is an important property for transport in shallow water. The splitting method is obtained by combining the hopscotch-type splitting function with various second-order splitting formulae from the literature. Although some of the resulting methods are highly accurate, their stability behaviour (due to horizontal advection) is quite poor. Therefore we also discuss several new splitting formulae with the aim to improve the stability characteristics. It turns out that this is possible indeed, but the price to pay is a reduction of the accuracy. Therefore, such methods are to be preferred if accuracy is less crucial than stability; such a situation is frequently encountered in solving transport problems. As part of the project TRUST (Transport and Reactions Unified by Splitting Techniques), preliminary versions of the schemes are implemented on the Cray C98 4256 computer and are available for benchmarking.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    Electronic Resource
    Springer
    Journal of scientific computing 12 (1997), S. 353-360 
    ISSN: 1573-7691
    Keywords: Alternating-direction implicit ; difference scheme ; stability ; convergence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract A generalized Peaceman–Rachford alternating-direction implicit (ADI) scheme for solving two-dimensional parabolic differential equations has been developed based on the idea of regularized difference scheme. It is to be very well to simulate fast transient phenomena and to efficiently capture steady state solutions of parabolic differential equations. Numerical example is illustrated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    Springer
    Neural processing letters 5 (1997), S. 69-81 
    ISSN: 1573-773X
    Keywords: data mining ; feature extraction ; information retrieval ; Self-Organizing Map (SOM) ; text analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract WEBSOM is a recently developed neural method for exploring full-text document collections, for information retrieval, and for information filtering. In WEBSOM the full-text documents are encoded as vectors in a document space somewhat like in earlier information retrieval methods, but in WEBSOM the document space is formed in an unsupervised manner using the Self-Organizing Map algorithm. In this article the document representations the WEBSOM creates are shown to be computationally efficient approximations of the results of a certain probabilistic model. The probabilistic model incorporates information about the similarity of use of different words to take into account their semantic relations.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    Electronic Resource
    Springer
    Journal of intelligent information systems 12 (1999), S. 61-73 
    ISSN: 1573-7675
    Keywords: association rules ; knowledge discovery ; data mining
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract We consider the problem of finding association rules in a database with binary attributes. Most algorithms for finding such rules assume that all the data is available at the start of the data mining session. In practice, the data in the database may change over time, with records being added and deleted. At any given time, the rules for the current set of data are of interest. The naive, and highly inefficient, solution would be to rerun the association generation algorithm from scratch following the arrival of each new batch of data. This paper describes the Borders algorithm, which provides an efficient method for generating associations incrementally, from dynamically changing databases. Experimental results show an improved performance of the new algorithm when compared with previous solutions to the problem.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    Electronic Resource
    Electronic Resource
    Springer
    Journal of intelligent information systems 13 (1999), S. 195-234 
    ISSN: 1573-7675
    Keywords: data mining ; knowledge discovery ; machine learning ; knowledge representation ; attribute-oriented generalization ; domain generalization graphs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Attribute-oriented generalization summarizes the information in a relational database by repeatedly replacing specific attribute values with more general concepts according to user-defined concept hierarchies. We introduce domain generalization graphs for controlling the generalization of a set of attributes and show how they are constructed. We then present serial and parallel versions of the Multi-Attribute Generalization algorithm for traversing the generalization state space described by joining the domain generalization graphs for multiple attributes. Based upon a generate-and-test approach, the algorithm generates all possible summaries consistent with the domain generalization graphs. Our experimental results show that significant speedups are possible by partitioning path combinations from the DGGs across multiple processors. We also rank the interestingness of the resulting summaries using measures based upon variance and relative entropy. Our experimental results also show that these measures provide an effective basis for analyzing summary data generated from relational databases. Variance appears more useful because it tends to rank the less complex summaries (i.e., those with few attributes and/or tuples) as more interesting.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Electronic Resource
    Electronic Resource
    Springer
    Journal of intelligent information systems 8 (1997), S. 5-28 
    ISSN: 1573-7675
    Keywords: machine learning ; meta-learning ; scalability ; data mining ; classifiers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract In this paper, wedescribe a general approach to scaling data mining applications thatwe have come to call meta-learning. Meta-Learningrefers to a general strategy that seeks to learn how to combine anumber of separate learning processes in an intelligent fashion. Wedesire a meta-learning architecture that exhibits two key behaviors.First, the meta-learning strategy must produce an accurate final classification system. This means that a meta-learning architecturemust produce a final outcome that is at least as accurate as aconventional learning algorithm applied to all available data.Second, it must be fast, relative to an individual sequential learningalgorithm when applied to massive databases of examples, and operatein a reasonable amount of time. This paper focussed primarily onissues related to the accuracy and efficacy of meta-learning as ageneral strategy. A number of empirical results are presenteddemonstrating that meta-learning is technically feasible in wide-area,network computing environments.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    Electronic Resource
    Springer
    Neural processing letters 10 (1999), S. 211-222 
    ISSN: 1573-773X
    Keywords: constraint satisfaction ; Hopfield network ; neural networks ; optimization ; relaxation procedure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract When solving an optimization problem with a Hopfield network, a solution is obtained after the network is relaxed to an equilibrium state. The relaxation process is an important step in achieving a solution. In this paper, a new procedure for the relaxation process is proposed. In the new procedure, the amplified signal received by a neuron from other neurons is treated as the target value for its activation (output) value. The activation of a neuron is updated directly based on the difference between its current activation and the received target value, without using the updating of the input value as an intermediate step. A relaxation rate is applied to control the updating scale for a smooth relaxation process. The new procedure is evaluated and compared with the original procedure in the Hopfield network through simulations based on 200 randomly generated instances of the 10-city traveling salesman problem. The new procedure reduces the error rate by 34.6% and increases the percentage of valid tours by 194.6% as compared with the original procedure.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    Springer
    Neural processing letters 9 (1999), S. 119-127 
    ISSN: 1573-773X
    Keywords: reinforcement learning ; neurocontrol ; optimization ; polytope algorithm ; pole balancing ; genetic reinforcement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract A new training algorithm is presented for delayed reinforcement learning problems that does not assume the existence of a critic model and employs the polytope optimization algorithm to adjust the weights of the action network so that a simple direct measure of the training performance is maximized. Experimental results from the application of the method to the pole balancing problem indicate improved training performance compared with critic-based and genetic reinforcement approaches.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Electronic Resource
    Electronic Resource
    Springer
    Water resources management 13 (1999), S. 153-170 
    ISSN: 1573-1650
    Keywords: Aquifer management ; infrastructure location ; least-cost design and operation ; optimization ; simulated annealing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract Aquifer systems play an essential role in meeting the ever increasing use of water for different purposes. Proper design and management of such systems should therefore be a very important matter of concern, not only to ensure that water will be available in adequate quantity (and quality) to satisfy demands but also to guarantee that this would be done in an optimal manner. This paper presents a model serving to define which water supply structures (especially pumping equipment and pipes) should be installed in order to minimize the sum of set-up costs and operation costs while satisfying demands, using a heuristic approach based on simulated annealing. Annealing algorithms are random local search optimization algorithms that allow, at least in theory and in probability, the determination of a global optimum of a (possibly constrained) function.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    Electronic Resource
    Electronic Resource
    Springer
    Water resources management 11 (1997), S. 165-184 
    ISSN: 1573-1650
    Keywords: optimization ; linear programming ; simulation ; irrigation planning
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract A methodology is presented for planning the operation of the Fuerte-Carrizo irrigation system in northwest Mexico. The system has two storage dams, two irrigation districts, and water transfer capabilities between both dams. The methodology uses a combination of linear programming (LP) and simulation. The LP model maximizes the net return of the farmers, subject to restrictions of the system, availability of water and land, and water transfer relationships. The simulation model is programmed as a microcomputer interactive package simulating the performance of the system. The methodology has proven to be a useful tool to assist those responsible for the operation of the irrigation system.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Electronic Resource
    Electronic Resource
    Springer
    International journal of computer vision 34 (1999), S. 19-28 
    ISSN: 1573-1405
    Keywords: geodesic active contours ; active surfaces ; Hamiltonian ; snakes ; optimization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Recently, Caselles et al. have shown the equivalence between a classical snake problem of Kass et al. and a geodesic active contour model. The PDE derived from the geodesic problem gives an evolution equation for active contours which is very powerfull for image segmentation since changes of topology are allowed using the level set implementation. However in Caselles' paper the equivalence with classical snake is only shown for 2D images and 1D curves, by using concepts of Hamiltonian theory which have no meanings for active surfaces. This paper propose to examine the notion of equivalence and to revisite Caselles et al. arguments. Then a notion equivalence is introduced and shown for classical snakes and geodesic active contours in the 2D (active contour) and 3D (active surface) case.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 22 (1999), S. 379-396 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; resolution decision procedures ; propositional modal logic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract The paper shows that satisfiability in a range of popular propositional modal systems can be decided by ordinary resolution procedures. This follows from a general result that resolution combined with condensing, and possibly some additional form of normalization, is a decision procedure for the satisfiability problem in certain so-called path logics. Path logics arise from normal propositional modal logics by the optimized functional translation method. The decision result provides an alternative method of proving decidability for modal logics, as well as closely related systems of artificial intelligence. This alone is not interesting. A more far-reaching consequence of the result has practical value, namely, many standard first-order theorem provers that are based on resolution are suitable for facilitating modal reasoning.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 18 (1997), S. 139-162 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; competition ; design
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Running a competition for automated theorem proving (ATP) systems is a difficult and arguable venture. However, the potential benefits of such an event by far outweigh the controversial aspects. The motivations for running the CADE-13 ATP System Competition were to contribute to the evaluation of ATP systems, to stimulate ATP research and system development, and to expose ATP systems to researchers both within and outside the ATP community. This article identifies and discusses the issues that determine the nature of such a competition. Choices and motivated decisions for the CADE-13 competition, with respect to the issues, are given.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 18 (1997), S. 205-210 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; competition ; LINUS ; first-order logic ; hyperlinking ; mate saturation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract LINUS is a theorem prover for clause logic based on hyperlinking. The main new feature of the system is the emphasis on the preference for unit clauses, which are generated as a by-product of the hyperlinking method. The mechanism of unit support also motivates a slightly different interpretation of hyperlinking, namely, as mate saturation. Mate saturation can be viewed as a generalization of unit-resulting resolution that is compatible with any set-of-support strategy. We give a survey on the theoretical background and the architecture of the system, and decribe its performance.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 18 (1997), S. 227-236 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; competition ; Satchmo ; compilation ; incremental evaluation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Compiling Satchmo and Functional Satchmo are two variants of the model generator Satchmo, incorporating enhancements in different directions. Compiling Satchmo is based on the observation that Satchmo (like any model generator or theorem prover) can be seen as an interpreter for a program given as a logical theory, and that this interpretation layer can be avoided by compilation of the theory into a directly executable program. Functional Satchmo is an implementation of Satchmo's calculus in a purely functional language supporting lazy evaluation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 18 (1997), S. 271-286 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; competition ; results
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract The CADE-13 ATP System Competition tested 18 ATP systems on 50 theorems, in five competition categories, with a time limit of 300 seconds imposed on each system run. This article records the results of the competition. Some analysis of these results is given, and interesting points are highlighted.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 18 (1997), S. 171-176 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; competition ; Barcelona ; data structures and algorithms ; implementation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Here we describe the equational theorem prover Barcelona, in its version that participated in the CADE-13 ATP System Competition. The system was built on top of our toolkit of data structures and algorithms for automated deduction in first-order logic with equality and was devised mainly to test the performance of this toolkit.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 18 (1997), S. 189-198 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; competition ; DISCOUNT ; distributed theorem proving ; reactive planning ; learning
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract The DISCOUNT system is a distributed equational theorem prover based on the teamwork method for knowledge-based distribution. It uses an extended version of unfailing Knuth–Bendix completion that is able to deal with arbitrarily quantified goals. DISCOUNT features many different control strategies that cooperate using the teamwork approach. Competition between multiple strategies, combined with reactive planning, results in an adaptation of the whole system to given problems, and thus in a very high degree of independence from user interaction. Teamwork also provides a suitable framework for the use of control strategies based on learning from previous proof experiences. One of these strategies forms the core of the expert global_learn, which is capable of learning from successful proofs of several problems. This expert, running sequentially, was one of the entrants in the competition (DISCOUNT/GL), while a distributed DISCOUNT system running on two workstations was another en trant.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 18 (1997), S. 247-252 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; competition ; SPASS ; sorts ; superposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract This article describes SPASS, Version 0.49, as it was entered in the system competition at CADE-13. SPASS is an automated theorem prover for full first-order logic with equality. It is based on the superposition calculus originally developed by Bachmair and Ganzinger, extended by the sort techniques due to Weidenbach and an inference rule for case analysis.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 18 (1997), S. 259-264 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; competition ; Violet ; resolution ; locking ; term rewriting ; Knuth–Bendix completion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Violet is an easy-to-use theorem prover based on locking resolution, with integrated equality extensions that use term rewriting and Knuth–Bendix completion. Violet participated in the CADE-13 ATP System Competition.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 23 (1999), S. 1-23 
    ISSN: 1573-0670
    Keywords: competition ; automated theorem proving
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract The results of the CADE-15 ATP System Competition (CASC-15) are presented.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 18 (1997), S. 237-246 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; competition ; SETHEO ; E-SETHEO ; first-order logic ; model elimination ; equality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract The model elimination theorem prover SETHEO (version V3.3) and its equational extension E-SETHEO are presented. SETHEO employs sophisticated mechanisms of subgoal selection, elaborate iterative deepening techniques, and local failure caching methods. Its equational counterpart E-SETHEO transforms formulae containing equality (using a variant of Brand's modification method) and processes the output with the standard SETHEO system. This article gives an overview of the theoretical background, the system architecture, and the performance of both systems.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 18 (1997), S. 265-270 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; competition ; Waldmeister ; unfailing Knuth–Bendix completion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Waldmeister is a high-performance theorem prover for unit equational first-order logic. In the making of Waldmeister, we have applied an engineering approach, identifying the critical points with respect to efficiency in time and space. Our logical three-level system model consists of the basic operations on the lowest level, where we put great stress on efficient data structures and algorithms. For the middle level, where the inference steps are aggregated into an inference machine, flexible adjustment has proven essential during experimental evaluation. The top level holds control strategy and reduction ordering. Although at this level only standard strategies are employed, really large proof tasks have been managed in reasonable time.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 18 (1997), S. 105-134 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; Gentzen system ; natural deduction ; unification algorithm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract A natural deduction system was adapted from Gentzen system. It enables valid wffs to be deduced in a very ‘natural’ way. One need not transform a formula into other normal forms. Robinson’s unification algorithm is used to handle clausal formulas. Algorithms for eliminating and introducing quantifiers without Skolemization are presented, and unification theorems for them are proved. A natural deduction automated theorem prover based on the algorithms was implemented. The rules for quantifiers are controlled by the algorithms. The Andrews challenge and the halting problem were proved by the system.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 18 (1997), S. 163-169 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; competition ; procedures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract This article describes the practical procedures that were used to run the CADE-13 ATP System Competition. The article describes the hardware and software environments, the system installation, the soundness testing performed, the preparation of problems for the competition, the choice of the number of problems and the time limit, and the execution of the systems.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 18 (1997), S. 199-204 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; competition ; Gandalf ; resolution ; subsumption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract We give a brief overview of the first-order classical logic component in the Gandalf family of resolution-based automated theorem provers for classical and intuitionistic logics. The main strength of the described version is a sophisticated algorithm for nonunit subsumption.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 18 (1997), S. 221-226 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; competition ; RRTP ; replacement ; instance based theorem prover ; propositional calculus decision procedure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract The Replacement Rule Theorem Prover (RRTP) is an instance-based, refutational, first-order clausal theorem prover. The prover is motivated by the idea of selectively replacing predicates by their definitions, and operates by selecting relevant instances of the input clauses. The relevant instances are grounded, if necessary, and tested for unsatisfiability by using a fast propositional calculus decision procedure.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 18 (1997), S. 253-258 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; competition ; SPTHEO ; parallel search ; static partitioning with slackness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract SPTHEO v3.3 is a parallelization of the sequential first-order theorem prover SETHEO v3.3. The parallelization is based on the SPS-model (Static Partitioning with Slackness) for parallel search, an approach that minimizes the processor-to-processor communication. This model allows efficient computations on hardware with weak communication performance, such as workstation networks. SPTHEO offers the utilization of both OR- and independent-AND parallelism. In this article, a detailed description and evaluation of the OR-parallel part used in the CADE-13 ATP System Competition are given.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 18 (1997), S. 287-296 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; competition ; conclusions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract The CADE-13 ATP System Competition was the first large-scale controlled competition for first-order ATP systems. Many people have commented on various aspects of the competition, including some suggestions for future improvement. These comments, and some discussion of them, are contained in this article. An overview of the major issues that will affect future competitions is given.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 18 (1997), S. 183-188 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; competition ; CLIN-S ; semantics ; hyper-linking ; resolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract CLIN-S is an instance-based, clause-form first-order theorem prover. CLIN-S employs three inference procedures: semantic hyper-linking, which uses semantics to guide the proof search and performs well on non-Horn parts of the proofs involving small literals, rough resolution, which removes large literals in the proofs, and UR resolution, which proves the Horn parts of the proofs. A semantic structure for the input clauses is given as input. During the search for the proof, ground instances of the input clauses are generated and new semantic structures are built based on the input semantics and a model of the ground clause set. A proof is found if the ground clause set is unsatisfiable. In this article, we describe the system architecture and major inference rules used in CLIN-S.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 18 (1997), S. 177-182 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; competition ; CLIN-E ; hyper-linking ; smallest instance first hyper-linking
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Hyper-linking is an instance-based automated theorem proving strategy that uses unification to generate instances of the input clauses. Lee implemented hyper-linking in the automated theorem prover CLIN, which uses a breadth-first strategy for generating instances of clauses via the hyper-link operation. In attempting to add equality support to CLIN, a number of inefficiencies with Lee's breadth-first strategy for generating instances were encountered. An alternative depth-first strategy, referred to as smallest-instance-first hyper-linking, for generating instances via the hyper-link operation was developed to address these inefficiencies. Smallest-instance-first hyper-linking is implemented in the automated theorem prover CLIN-E.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Electronic Resource
    Electronic Resource
    Springer
    Journal of automated reasoning 18 (1997), S. 211-220 
    ISSN: 1573-0670
    Keywords: automated theorem proving ; competition ; Otter ; automated reasoning ; equational deduction ; paramodulation ; resolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract This article discusses the two incarnations of Otter entered in the CADE-13 Automated Theorem Proving System Competition. Also presented are some historical background, a summary of applications that have led to new results in mathematics and logic, and a general discussion of Otter.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    Electronic Resource
    Electronic Resource
    Springer
    Computational optimization and applications 12 (1999), S. 41-51 
    ISSN: 1573-2894
    Keywords: convex programming ; optimization ; duality ; error bounds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Given a single feasible solution $$x_F $$ and a single infeasible solution $$x_I $$ of a mathematical program, we provide an upper bound to the optimal dual value. We assume that $$x_F $$ satisfies a weakened form of the Slater condition. We apply the bound to convex programs and we discuss its relation to Hoffman-like bounds. As a special case, we recover a bound due to Mangasarian [11] on the distance of a point to a convex set specified by inequalities.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    Electronic Resource
    Electronic Resource
    Springer
    Computational optimization and applications 7 (1997), S. 143-158 
    ISSN: 1573-2894
    Keywords: planning under uncertainty ; parallel computing ; optimization ; software
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract We present a computationally efficient implementation of an interior point algorithm for solving large-scale problems arising in stochastic linear programming and robust optimization. A matrix factorization procedure is employed that exploits the structure of the constraint matrix, and it is implemented on parallel computers. The implementation is perfectly scalable. Extensive computational results are reported for a library of standard test problems from stochastic linear programming, and also for robust optimization formulations.The results show that the codes are efficient and stable for problems with thousands of scenarios. Test problems with 130 thousand scenarios, and a deterministic equivalent linear programming formulation with 2.6 million constraints and 18.2 million variables, are solved successfully.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    Electronic Resource
    Electronic Resource
    Springer
    Computational optimization and applications 12 (1999), S. 53-79 
    ISSN: 1573-2894
    Keywords: support vector machines ; linear programming ; classification ; data mining ; machine learning.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract We examine the problem of how to discriminate between objects of three or more classes. Specifically, we investigate how two-class discrimination methods can be extended to the multiclass case. We show how the linear programming (LP) approaches based on the work of Mangasarian and quadratic programming (QP) approaches based on Vapnik's Support Vector Machine (SVM) can be combined to yield two new approaches to the multiclass problem. In LP multiclass discrimination, a single linear program is used to construct a piecewise-linear classification function. In our proposed multiclass SVM method, a single quadratic program is used to construct a piecewise-nonlinear classification function. Each piece of this function can take the form of a polynomial, a radial basis function, or even a neural network. For the k 〉 2-class problems, the SVM method as originally proposed required the construction of a two-class SVM to separate each class from the remaining classes. Similarily, k two-class linear programs can be used for the multiclass problem. We performed an empirical study of the original LP method, the proposed k LP method, the proposed single QP method and the original k QP methods. We discuss the advantages and disadvantages of each approach.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    ISSN: 1573-756X
    Keywords: data cube ; data mining ; aggregation ; summarization ; database ; analysis ; query
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Data analysis applications typically aggregate data across manydimensions looking for anomalies or unusual patterns. The SQL aggregatefunctions and the GROUP BY operator produce zero-dimensional orone-dimensional aggregates. Applications need the N-dimensionalgeneralization of these operators. This paper defines that operator, calledthe data cube or simply cube. The cube operator generalizes the histogram,cross-tabulation, roll-up,drill-down, and sub-total constructs found in most report writers.The novelty is that cubes are relations. Consequently, the cubeoperator can be imbedded in more complex non-procedural dataanalysis programs. The cube operator treats each of the Naggregation attributes as a dimension of N-space. The aggregate ofa particular set of attribute values is a point in this space. Theset of points forms an N-dimensional cube. Super-aggregates arecomputed by aggregating the N-cube to lower dimensional spaces.This paper (1) explains the cube and roll-up operators, (2) showshow they fit in SQL, (3) explains how users can define new aggregatefunctions for cubes, and (4) discusses efficient techniques tocompute the cube. Many of these features are being added to the SQLStandard.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    ISSN: 1573-756X
    Keywords: data mining ; knowledge discovery ; attribute focusing ; basketball ; NBA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Advanced Scout is a PC-based data mining application used by National Basketball Association (NBA)coaching staffs to discover interesting patterns in basketball game data. We describe Advanced Scout software from the perspective of data mining and knowledge discovery. This paper highlights the pre-processing of raw data that the program performs, describes the data mining aspects of the software and how the interpretation of patterns supports the processof knowledge discovery. The underlying technique of attribute focusing asthe basis of the algorithm is also described. The process of pattern interpretation is facilitated by allowing the user to relate patterns to video tape.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    Electronic Resource
    Electronic Resource
    Springer
    Data mining and knowledge discovery 1 (1997), S. 203-224 
    ISSN: 1573-756X
    Keywords: causal discovery ; data mining ; observational data
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract This paper presents a simple, efficient computer-based method for discovering causal relationships from databases that contain observational data. Observational data is passively observed, as contrasted with experimental data. Most of the databases available for data mining are observational. There is great potential for mining such databases to discover causal relationships. We illustrate how observational data can constrain the causal relationships among measured variables, sometimes to the point that we can conclude that one variable is causing another variable. The presentation here is based on a constraint-based approach to causal discovery. A primary purpose of this paper is to present the constraint-based causal discovery method in the simplest possible fashion in order to (1) readily convey the basic ideas that underlie more complex constraint-based causal discovery techniques, and (2) permit interested readers to rapidly program and apply the method to their own databases, as a start toward using more elaborate causal discovery algorithms.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    Electronic Resource
    Electronic Resource
    Springer
    Data mining and knowledge discovery 3 (1999), S. 197-217 
    ISSN: 1573-756X
    Keywords: binary decision tree ; classification ; data mining ; entropy ; Gini index ; impurity ; optimal splitting
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract To find the optimal branching of a nominal attribute at a node in an L-ary decision tree, one is often forced to search over all possible L-ary partitions for the one that yields the minimum impurity measure. For binary trees (L = 2) when there are just two classes a short-cut search is possible that is linear in n, the number of distinct values of the attribute. For the general case in which the number of classes, k, may be greater than two, Burshtein et al. have shown that the optimal partition satisfies a condition that involves the existence of 2 L hyperplanes in the class probability space. We derive a property of the optimal partition for concave impurity measures (including in particular the Gini and entropy impurity measures) in terms of the existence ofL vectors in the dual of the class probability space, which implies the earlier condition. Unfortunately, these insights still do not offer a practical search method when n and k are large, even for binary trees. We therefore present a new heuristic search algorithm to find a good partition. It is based on ordering the attribute's values according to their principal component scores in the class probability space, and is linear in n. We demonstrate the effectiveness of the new method through Monte Carlo simulation experiments and compare its performance against other heuristic methods.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    Electronic Resource
    Electronic Resource
    Springer
    Data mining and knowledge discovery 3 (1999), S. 219-225 
    ISSN: 1573-756X
    Keywords: data mining ; knowledge discovery ; churn prediction application ; predictive modeling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract We describe CHAMP (CHurn Analysis, Modeling, and Prediction), an automated system for modeling cellular customer behavior on a large scale. Using historical data from GTE's data warehouse for cellular phone customers, every month CHAMP identifies churn factors for several geographic regions and updates models to generate churn scores predicting who is likely to churn within the near future. CHAMP is capable of developing customized monthly models and churn scores for over one hundred GTE cellular phone markets totaling over 5 million customers.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    Electronic Resource
    Electronic Resource
    Springer
    Data mining and knowledge discovery 3 (1999), S. 237-261 
    ISSN: 1573-756X
    Keywords: data mining ; parallel processing ; classification ; scalability ; decision trees
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Classification decision tree algorithms are used extensively for data mining in many domains such as retail target marketing, fraud detection, etc. Highly parallel algorithms for constructing classification decision trees are desirable for dealing with large data sets in reasonable amount of time. Algorithms for building classification decision trees have a natural concurrency, but are difficult to parallelize due to the inherent dynamic nature of the computation. In this paper, we present parallel formulations of classification decision tree learning algorithm based on induction. We describe two basic parallel formulations. One is based on Synchronous Tree Construction Approach and the other is based on Partitioned Tree Construction Approach. We discuss the advantages and disadvantages of using these methods and propose a hybrid method that employs the good features of these methods. We also provide the analysis of the cost of computation and communication of the proposed hybrid method. Moreover, experimental results on an IBM SP-2 demonstrate excellent speedups and scalability.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    Electronic Resource
    Electronic Resource
    Springer
    Data mining and knowledge discovery 3 (1999), S. 291-314 
    ISSN: 1573-756X
    Keywords: association rules ; data mining ; data skewness ; workload balance ; parallel mining ; parallel computing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Association rule mining is an important new problem in data mining. It has crucial applications in decision support and marketing strategy. We proposed an efficient parallel algorithm for mining association rules on a distributed share-nothing parallel system. Its efficiency is attributed to the incorporation of two powerful candidate set pruning techniques. The two techniques, distributed and global prunings, are sensitive to two data distribution characteristics: data skewness and workload balance. The prunings are very effective when both the skewness and balance are high. We have implemented FPM on an IBM SP2 parallel system. The performance studies show that FPM outperforms CD consistently, which is a parallel version of the representative Apriori algorithm (Agrawal and Srikant, 1994). Also, the results have validated our observation on the effectiveness of the two pruning techniques with respect to the data distribution characteristics. Furthermore, it shows that FPM has nice scalability and parallelism, which can be tuned for different business applications.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    ISSN: 1573-7578
    Keywords: enterprise integration ; workflow management ; agents interoperation ; heterogeneous databases ; scientific decision support ; data mining
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract The Carnot project was an ambitious research project inheterogeneous databases. It integrated a variety of techniques toaddress a wide range of problems in achieving interoperation inheterogeneous environments. Here we describe some of the majorimplemented applications of this project. These applications concern(a) accessing a legacy scientific database, (b) automating a workflowinvolving legacy systems, (c) cleaning data, and (d) retrievingsemantically appropriate information from structured databases inresponse to text queries. These applications support scientificdecision support, business process management, data integrityenhancement, and analytical decision support, respectively. Theydemonstrate Carnot‘s capabilities for (a) heterogeneous queryprocessing, (b) relaxed transaction and workflow management, (c)knowledge discovery, and (d) heterogeneous resource modelintegration.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Much of the information accumulated on the fire resistance of ‘dividing’ elements can be utilized in the design of buildings for fire safety, if the fire tolerance values are converted into fire resistance. Three methods of conversion, one based on the concept of equal temperature-time areas, the second on the concept of equal maximum temperatures, and the third, Law method, are critically examined and handy conversion tools presented. In the case of the ‘key’ elements of buildings, basing the fire safety design on fire resistance information is not recommended.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 21 (1997), S. 7-16 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The modelling of the spread of fire and its extinguishment still represents a significant challenge. As part of a combined experimental and computational study of fires we have developed a general Computational Fluid Dynamics (CFD) model of fire spread and extinguishment. The primary objective was to produce a flexible computational tool which can be used by engineers and scientists for design or research purposes. The present paper deals with the description and validation of a solid pyrolysis model which has been applied, as a sub-model, in this general computer fire code. The pyrolysis model has been formulated using the heat-balance integral method. The model can be applied to slabs of char forming solids, such as wood, as well as non-charring thermoplastic materials, such as PMMA. Results are compared with analytical solutions, numerical simulations and experimental data. In all cases the integral model performs well. © 1997 by John Wiley & Sons, Ltd.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 21 (1997), S. 17-22 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: An investigation of cone calorimeter test procedures was performed using two types of mattress composites with various specimen preparations and equipment configurations. The objective was to discover suitable procedures for testing mattress composites. Concurrent with this work a much larger and more sophisticated project known as CBUF was underway in Europe. One of CBUF's secondary objectives was to provide an appropriate test protocol for testing upholstered furniture composites, including mattresses. Most of the CBUF protocol was available at the time of this study and a modified form of the specimen preparation technique was used in this investigation. Preliminary tests found unacceptable test performance with some configurations. Subsequent testing examined variations of the established test protocols and other test procedures. The data sample was small, but observations of the data indicate trends that might be attributable to the use of the different procedures. Significantly it was determined that the edge frame used to hold specimens in place during the test does affect the test results. A modified CBUF protocol proved to be the best procedure, but it requires extensive experience with the CBUF specimen preparation method in order to be able to produce satisfactory specimens. © 1997 by John Wiley & Sons, Ltd.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 21 (1997), S. 1-6 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The effect of melting behaviour on upward flame spread of thermoplastic materials when subjected to small ignition sources and considered to suffer no external flux was studied using large-scale tests. For moderate fire conditions the cone calorimeter was utilized, with the sample set in a vertical orientation to study the melting behaviour of the specimens. Under these conditions the results indicate that the melting behaviour significantly affects upward flame spread behaviour. A pool of the melt which formed at the base of the vertically oriented sample tested creates a pool fire which then controls the fire growth and flame spread. In contrast, it was found that some thermoplastic materials which have higher glass transition temperatures or undergo a special pyrolysis process such as depolymerization, intumescing or charring do not experience significant melting behaviour when exposed to the same thermal insult. As a result, they behave very differently in terms of upward flame spread. The study also indicates that the melting behaviour of thermoplastic materials is an important characteristic in fires which should be taken into account in the development of modelling, in particular for upward flame spread models. © 1997 by John Wiley & Sons, Ltd.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 21 (1997), S. 51-51 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: No Abstract
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 21 (1997), S. 33-39 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A series of 37 cigarettes were analysed to develop a model, based on cigarette physical properties, to predict the ignition propensity of the cigarettes towards cellulosic fabrics. The properties used were: cigarette circumference (in mm), tobacco packing density (in g cm-2), paper permeability (in CORESTA units) and the presence or absence of citrate additives in the paper (used independent of concentration, although typical additions range from 0.5 to 0.8 wt%). Two empirical models were developed, one for low and medium paper permeabilities, and one for very high paper permeabilities (above 50 CORESTA units). The latter exceed the paper permeability of most commercial cigarettes, and have medium to high ignition propensities. Thus, they are probably only of interest from the point of view of a mathematical curiosity. The former model, however, addresses cigarettes in the range where commercial cigarettes are potentially viable. The resulting ignition propensities exhibited cover the entire feasible range, from 0% to 100%. Both models predicted the ignition propensities of the tested cigarettes quite well, within an error range which did not exceed 30% for any cigarette. Physical rationales are presented for the effects of the variables used. However, the rationale for the discontinuity in ignition propensity found for the cigarettes with extremely high paper permeability is less clear. One explanation is that there is probably excess oxygen present so that a fuel/oxygen mixture is obtained with a ratio which is less than the lower flammability limits and is too lean to support combustion. However, further analysis of this issue is warranted. The empirical model for low and medium paper permeability cigarettes is potentially useful for developing cigarettes with lower ignition propensity, since it is a practical way of combining the individual properties that most heavily affect cigarette ignition propensity. © 1997 by John Wiley & Sons, Ltd.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 21 (1997), S. 53-65 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Fire hazard assessments must be primarily driven by life safety variables. Concern is often highly focused on toxicity issues, since fire deaths, in the majority of cases, are found (in whole or in part) to be due to toxic gas inhalation. Procedures have recently been published by ISO, wherein the toxicity assessment of fire products is focused primarily on bench-scale testing for toxic potency (the ‘per-gram toxicity’). Yet hazards of products with regards to fire toxicity may be determined much more by their differences in burning rates than by any differences in toxic potency. Burning rates are not assessed in the pertinent standards (ISO 13344 and ISO TR 9122). For most product categories, techniques for predicting full-scale burning rates from bench-scale data are not yet in hand. Thus, today the best means of comparing actual, full-scale toxic fire hazards is the full-scale fire test, equipped with additional gas measuring instrumentation. Such an approach is not among the recommended methods of the international standards, yet it is the only one with innate validity. In the present work, a series of sandwich panel products were tested in a full-scale room configuration. Bench-scale comparison was made to the ISO 5660 Cone Calorimeter and the DIN 53436 tube furnace. The toxic gases were quantified in all cases by chemical analysis. The product which showed the best performance in the full-scale tests (rock wool insulated sandwich panel) did not achieve a good fire toxicity performance due to minimization of toxic potency. Instead, the successful performance was attributed wholly to reduction of burning rate. Bench-scale measurements of toxic potency were shown to lack relevance to reality in such cases where even the full-scale toxic potency is not a determining factor. © 1997 John Wiley & Sons, Ltd.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 21 (1997), S. 179-185 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Zinc hydroxystannate (ZHS), at levels of 2-5 phr, and the hydrated fillers, magnesium hydroxide (MH) and alumina trihydrate (ATH), at levels of 20-50 phr, are effective flame retardants and smoke suppressants for flexible PVC. Novel ZHS-coated hydrated fillers are found to exhibit markedly improved fire-retardant properties, particularly with regard to increasing LOI values, reducing heat release rates and suppressing smoke generation, when compared with conventional uncoated forms. The ZHS coating appears to change the filler particle morphology and there is evidence that the coating is largely retained on the filler surface after melt processing into the PVC. The improved dispersion of the active tin compound in the polymer matrix leads to enhanced fire retardancy and this, in turn, allows significant reductions to be made in overall filler loading, with no loss in flame-retardant or smoke-suppressant performance. © 1997 John Wiley & Sons, Ltd.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 21 (1997), S. 95-105 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: In the EC-sponsored CBUF (Combustion Behaviour of Upholstered Furniture) study three different models were developed for using Cone Calorimeter results to predict full-scale furniture burning. Model I is a correlation-based approach and has the most comprehensive coverage of styles and furniture types. Model II is based on area-convolution. It has been developed, so far, for several of the common upholstered furniture styles. Model III is based on an extension of a thermal flame spread model and is here developed only for mattresses. Models II and III offer the prediction of the burning item's time history, while Model I computes the peak HRR, the time to peak, and several other primary characteristics. The predictability of all three models is good. At present, the models presented do not consider furniture with plastic frames, and only a limited predictability is offered for office-type furnitures items which contain a hard-plastic shell. The models offer a very significant improvement over the existing state of the art. © 1997 John Wiley & Sons, Ltd.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 21 (1997), S. 277-282 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A correlation has been developed between closed-cup flash points and normal boiling points for silicone compounds. In addition, a more general correlation has been developed between these two properties for the general organic compounds, including silicone compounds. The closed-cup flash points can be predicted using empirical equations. The standard errors of estimate are 11.06 and 11.66°C for silicone compounds and general organic compounds (including silicone compounds), respectively. © 1997 John Wiley & Sons, Ltd.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The incorporation of two brominated compounds/antimony trioxide blends into a PP-PE copolymer were studied. Both brominated trimethylphenyl indane (FR 1808) and poly(pentabromobenzyl acrylate) (FR 1025) confer good flame retardancy at 40% loading. A comparison was made with the incorporation of magnesium hydroxide at higher loadings (up to 64%) in the same copolymer. The mineral filler improves both fire resistance and stiffness of the copolymer, nevertheless the high loading causes a dramatic decrease in impact resistance. Moreover, the necessary surface treatment of the filler significantly lowers the maximal tensile strength. In order to maximize both fire resistance and mechanical properties, we combined each brominated flame-retardant system (20% in weight) with magnesium hydroxide or talc (20% in weight). Talc is used as reference. These composites show interesting fire-retardant properties in comparison with the copolymers containing only 40% of the brominated flame-retardant systems. In addition, the mechanical properties are on the whole improved. © 1997 John Wiley & Sons, Ltd.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 21 (1997), S. 271-276 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Results are presented of a project to evaluate the combustibility and surface flammability of building interior finish materials commonly used in Taiwan. The project was conducted at the Fire Laboratory of the Architecture and Building Research Institute in Taipei. Eighteen different wall-covering materials were tested according to Chinese National Standard (CNS) 6532, which is equivalent to Japanese Industry Standard (JIS) 1321, and according to ASTM E 1354-92 (Cone calorimeter). A comparison of test results is presented, and a qualitative relationship is developed between the performance in the two methods. The classification system for degrees of combustibility developed in Canada by Richardson and Brooks was hereby used to group materials based in performance in the ASTM test method. © 1997 John Wiley & Sons, Ltd.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 2 (1978), S. 184-184 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 2 (1978), S. 173-176 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Various celloulosic materials were evaluated for ignitability and flash-fire propensity, using screening test methods developed at the University of San Francisco. Time to ignition, using radiation from a high-temperature radiant source without a pilot flame, appeared to be primarily a function of heat flux and material density, rather than of type of wood or celloulosic board. At heat flux levels from 5.8 to 10.5 W cm-2, time to ignition was shortest for cellulose fiberboard with a density of 0.2225 g ml-1, followed by western red cedar at 0.314 g ml-1, eastern white pine at 0.348 g ml-1, southern yellow pine at 0.422 g ml-1, Douglas fir at 0.565 g ml -1, and longest for hardboard at 0.878 g ml-1. For the cotton and rayon woven-pile upholstery fabrics, time to ignition appeared to increase with increasing fabric weight.For Cellulose insulation treated with boron-containing additives, flash-fire magnitude decreased with increasing additive content. Flash-fire magnitude decreased more that could be accounted for by decreasing weight loss alone, indication reduction in the combustibility of the volatiles produced. Reduction in flash-fire propensity of cotton bating by treatment with boron-containing additives was also observed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The Australian Children's Nightwear Standards have been accepted as the basis of legislation in all States of Australia and by the Commonwealth Government. The standards are based on the philosophy that garment design as well as combustion characteristics of the material is an important consideration in assessing the fire hazard of nightwear. Using this approach a classification system has been devised which place children's nightwear into three categories of potential fire hazard. If a garment cannot be classified then it cannot be legally sold in Australia. The combustion characteristics tested are ease of ignition, rate of flame propagation and surface burn properties. For classification all materials used for children's nightwear must pass the latter test. The design of the standard test methods, criteria for classification and the concepts of safe design were developed by collection data from burns accidents and burnt clothing from accident victims from the burns research unit of a large children's hospital and by the study of the burning behavior of clothing on a manikin. The combustion criteria are not so stringent as to require the use of inherently flame resist materials or the use of flame retardant finishes. This approach in combination with safe design criterial enable commercially available textiles to meet the legislative requirements for children's nightwear. This mean that the nightwear standards are inexpensive to attain and do not require a sophisticated textile technology. A consumer labeling system has been designed to describe the three categories but yet there is no evidence to suggest that this had had any effect in reducing the number of burns accidents - consumers apparently regrading safe nightwear as a low priority. An inconsistent aspect of the calssification system is the incorporation into the standards in 1977 of criteria to prevent the classification of cotton flannelette nightdresses and the incorporation of arbitrary requirements for other nightdress containing cotton. These inconsistencies have been caused fundamentally by a problem which continues to bedevil the writing of good standards in Australia - that is, the lack of nationwide statistics on burns accidents.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 2 (1978), S. 177-183 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A Collaborative Programme of work was carried out by two laboratories to asscess a procedure for identifying paint systems which possess poor ‘in service’ lives by virtue of being repeatedly washed. The small scale surface spread of flame apparatus as described in BS 476 part 7 was used to measure any change in the surface spread of flame characteristic of eight coating system, applied to two substrates, as a result of washing the coated surfaces. The results indicate that both laboratories ranked the paints in the same order and the reproducibility of the proposed washing procedure was good. The most consistent results were obtained when the coating systems were applied to standard hardboard. It is suggested that flame retardant coating system having poor resistance to washing would be identified if a limit of changes of average spread of flame were set at 75 mm. This investigation was carried out in support of the activities of BSI committee PVC/12, Fire Retardant Paints.
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 2 (1978), S. iii 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Silica gel combined with potassium carbonate is an effective fire retardant for a wide variety of common polymers (at mass fraction of only 10% total additive) such as polypropylene, nylon, polymethylmethacrylate, poly(vinyl alcohol), cellulose, and to a lesser extent polystyrene and styrene-acrylonitrile. The peak heat release rate is reduced by up to 68% without significantly increasing the smoke or carbon monoxide levels during the combustion. © 1997 by John Wiley & Sons, Ltd.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 21 (1997), S. 41-49 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Flame-retarded epoxy composites and phenolic composites containing fiberglass, aramid (Kevlar® 49), and graphite fiber-reinforcements were tested using the NASA upward flame propagation test, the controlled-atmosphere cone calorimeter test, and the liquid oxygen (LOX) mechanical impact test. The upward flame propagation test showed that phenolic/graphite had the highest flame resistance and epoxy/graphite had the lowest flame resistance. The controlled-atmosphere cone calorimeter was used to investigate the effect of oxygen concentration and fiber reinforcement on the burning behavior of composites. The LOX mechanical impact test showed that epoxy/fiberglass had the lowest ignition resistance and phenolic/aramid had the highest ignition resistance in LOX. The composites containing epoxy resin and/or aramid fiber reinforcement reacted very violently in LOX upon mechanical impact. © 1997 by John Wiley & Sons, Ltd.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 21 (1997), S. 75-83 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Melamine and its salts added to polyamide 6 (PA-6, nylon 6) improve its fire retardancy as measured by oxygen index and UL94 tests. The mechanism of the fire-retardant action of the additives was studied using thermogravimetry, kinetics of thermal decomposition and characterization of solid residues and evolved high-boiling products. It was found that melamine, melamine oxalate, melamine phthalate and melamine cyanurate facilitate thermal decomposition of PA-6 with increasing evolution of oligomeric chain fragments instead of caprolactam, which is the principal product evolved from the nonfire-retarded PA-6. These additives promote non-combustible flow dripping and help extinguishment of the flame. The observed increase in solid residue from the thermal decomposition of the formulations or the endothermic cooling due to melamine evaporation might give an additional but less important contribution to fire retardancy. In the case of dimelamine phosphate and melamine pyrophosphate, PA-6 reacts with liberated phosphoric acids producing phosphoric esters which give char upon further thermal decomposition. The fire-retardant effect of these two salts is mostly attributed to polymer mass retention and intumescent layer protection mechanisms. © 1997 John Wiley & Sons, Ltd.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 21 (1997), S. 107-114 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The National Building Code of Canada provides architects, engineers and builders with a simple, practical calculation method for assigning fire-resistance ratings to wood-frame and steel-frame wall, floor and roof-ceiling assemblies. It was originally devised in the early 1960s and is commonly known as the Component Additive Method (CAM). A collaborative industry-government research program was carried out recently at the National Research Council Canada to develop new fire-resistance ratings for gypsum-board protected walls. Forintek Canada Corp. and the Canadian Wood Council participated in that program on behalf of Canada's wood industry. As part of the research program, a number of full-size fire-endurance tests were carried out on wood-frame and steel-frame walls. The results of those fire tests have allowed us to revisit those sections of the Component Additive Method which are applicable to light-frame walls lined with gypsum board. © 1997 John Wiley & Sons, Ltd.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 21 (1997), S. 115-121 
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Tests were conducted on two fabrics intended for use in protective clothing: an aramid (used extensively in firefighter gear) and a modified viscose cellulosic fabric. Both were exposed to very high heat (temperatures above 400°C) and their performance as thermal insulators was assessed by the temperature transmitted through the fabric, both in their dry state and after being exposed to a water spray. Both fabrics performed satisfactorily, but the modified viscose fabric improved its thermal insulation properties when damp, while the aramid fabric remained unaffected (or perhaps negatively affected) by the water spray. Overall, the modified viscose fabric seemed a better thermal insulator than the aramid. © 1997 John Wiley & Sons, Ltd.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...