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  • optimization
  • 1985-1989  (32)
  • 1970-1974
  • 1950-1954
  • 1945-1949
  • 1
    ISSN: 1572-9443
    Keywords: Effective service time ; age dependent service interruptions ; database systems ; failures ; recovery ; rollback ; checkpoints ; optimization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract A stochastic model is developed describing a service system subject to inhomogeneous Poisson interruptions with age dependent interruption periods. By studying the probabilistic flow of the underlying multivariate Markov process, the Laplace transform of the effective service time is explicitly obtained. For general renewal interruptions, only the expected effective service time is derived. As an application, an optimal checkpoint policy is examined for database management. It is shown that an optimal policy maximizing the ergodic availability of the database is to implement a checkpoint as soon as the cumulative uptime of the database reaches a prespecified constantk *. A computational procedure is then developed for findingk * and numerical results are exhibited.
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  • 2
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    Cellular and molecular life sciences 45 (1989), S. 1024-1029 
    ISSN: 1420-9071
    Keywords: Anaerobic filter ; computer control ; optimization ; sugar refinery
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An anaerobic filter system with a volume of 11 l fed with wastewater from the Swiss sugar refinery in Frauenfeld was established on a laboratory scale. It provided a filter performance of over 8 kg COD·m−3·d−1 with an efficiency of at least 70%. A 600–1 pilot plant system in the factory gave a degradation efficiency of 70% when fed with 28 kg COD·m−3·d−1 and yielded 0.34 m3 methane/kg COD, demonstrating that the scaling-up of the anaerobic filter had been successful. The rapidly-varying concentrations of organic materials in the wasterwater required the constant control of the wastewater flow to the system. A control program was developed for a small computer using an empirical model simulating the operator. By varying the influx rate of the wastewater to the anaerobic filter the computer kept the system at an optimal organic load. The results obtained were equivalent to those obtained by permanent control of the system by an operator.
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  • 3
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    Mathematical geology 21 (1989), S. 221-232 
    ISSN: 1573-8868
    Keywords: Fracture hydrology ; network ; optimization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Mathematics
    Notes: Abstract Numerically generated discrete fracture networks are used to simulate the flow of water through rock fractures. The fractures are modeled as random assemblages of conductive elements in a nonconductive matrix. Because large numbers of fractures often are needed to represent fractured rock adequately, minimizing the required computer time and memory is crucial. For steady-state flow, any portion of the mesh that is linked to the rest of the mesh by only one point is a dead end and does not contribute to water flow. The removal of such dead-end clusters simplifies the mesh and therefore speeds up computation, without changing its response. An algorithm for removing these dead ends is described in detail. Its effectiveness is discussed with regard to the connectivity of a network.
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  • 4
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    Water resources management 3 (1989), S. 107-128 
    ISSN: 1573-1650
    Keywords: Unit hydrograph ; instantaneous unit hydrograph ; identification ; probability density function ; probability distribution function ; method of moments ; optimization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract Unit hydrograph identification by the parametric approach is based on the assumption of a proper analytical form for its shape, using a limited number of parameters. This paper presents various suitable analytical forms for the instantaneous unit hydrograph, originated from known probability density functions or transformations of them. Analytical expressions for the moments of area of these form versus their definition parameters are theoretically derived. The relation between moments and specific shape characteristics are also examined. Two different methods of parameter estimation are studied, the first being the well-known method of moments, while the second is based on the minimization of the integral error between derived and recorded flood hydrographs. The above tasks are illustrated with application examples originated from case studies of catchments in Greece.
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  • 5
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    Journal of optimization theory and applications 63 (1989), S. 309-332 
    ISSN: 1573-2878
    Keywords: Dynamic ship positioning ; Kalman filtering ; optimization ; linear optimal control
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract The design of a dynamic positioning system for a multiplymoored vessel with active winches and thrusters is presented. The proposed positioning system is based on the Kalman filter and linear optimal control. Its peculiarity is that it contains a scheme which allocates dynamically the control forces between moorings and thrusters. The allocation policy tries to minimize the energy of the control by maintaining the average propeller thrust near to zero. The efficacy of the scheme is illustrated by numerical simulations.
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  • 6
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    Journal of optimization theory and applications 62 (1989), S. 139-150 
    ISSN: 1573-2878
    Keywords: Optimality conditions ; value function ; mathematical programming ; generalized gradients ; optimization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract The B-gradients are a convex set of generalized gradients contained in Clarke's generalized gradients. These gradients retain many of the nice properties of Clarke's generalized gradients. In this paper, necessary conditions for optimality in finite-dimensional perturbed optimization problems are given. A calmness condition is used for a constraint qualification.
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  • 7
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    Journal of optimization theory and applications 62 (1989), S. 405-417 
    ISSN: 1573-2878
    Keywords: Robust stability ; robustness ; optimization ; uncertain systems
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract In this paper, the problem of robustness bounds of Hurwitz and Schur polynomials is addressed. For weightedL 2-norm perturbations of a Hurwitz polynomialp(s) or a Schur polynomialp(z), a new method is developed for calculating the maximal perturbation bound under which stability is preserved. We show that such a robustness bound is related to the minimum of a rational function. The new method is superior to the previous one developed by Soh, Berger, and Dabke in Ref. 1. Our approach also provides solutions for the perturbation polynomial δp(s) or δp(z) with minimal coefficient norm which causep(s)+δp(s) orp(z)+δp(z) to be unstable.
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  • 8
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    Evolutionary ecology 3 (1989), S. 343-359 
    ISSN: 1573-8477
    Keywords: Evolution ; exploitation ; fisheries ; Gadus morhua ; life history ; optimization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Age-specific exploitation of a natural population acts as a selective force on genetic variation in life history traits. Evolution arising from this selection may bring about evolutionary changes in the total yield which the population is able to sustain. An analysis of this process is given for a harvested population with densitydependent recruitment, in which selection of life history traits by cropping is independent of density and frequency. Evolution of the total yield depends on an interplay between the yield from an individual over the course of its life and recruitment; whether the total yield increases or decreases depends on the properties of particular populations. Evolution brought about by harvesting does not, in general, lead to the maximization of the total yield. Nonetheless, by appropriate choice of an age-specific harvest pattern, it is possible in principle to select the life history which gives the maximum total yield following evolution; this harvest pattern is called the ‘evolutionarily stable optimal harvesting strategy’ (ESOHS). Results of the analysis are illustrated with data on the Arcto-Norwegian cod.
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  • 9
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    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 1 (1989), S. 27-37 
    ISSN: 0899-0042
    Keywords: mutarotation ; sugars ; carbohydrates ; isomeric ; separation ; temperature effects ; selectvity ; optimization ; hemiacetal ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A brief review of sugar stereochemistry is given. The separation of 84 different pairs of anomers was accomplished on both α- and β-cyclodextrin columns. Five different mobile phases were evaluated. The separation of anomers temperature, flow rate, and so on. The separation of anomers that mutarotate is somewhat more difficult than those that do not. Prior knowledge as to the rate of mutaroation is useful so that the chromatographic conditions can be arranged to minimize any deleterious effects on the separation.
    Additional Material: 7 Ill.
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  • 10
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    Computational economics 1 (1988), S. 3-19 
    ISSN: 1572-9974
    Keywords: Decision theory ; optimization ; file search ; algorithm design
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Economics
    Notes: Abstract We investigate the relationship between algorithm construction and optimal decision processes. We provide a sufficient condition, a linear ordering over the experiment set, for when we can efficiently use an optimization approach for selecting a decision strategy. We demonstrate the linear ordering condition within the context of the file search problem; however, any problem whose representation satisfies the linear ordering condition is amenable to the optimization approach.
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  • 11
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    Journal of scientific computing 3 (1988), S. 233-260 
    ISSN: 1573-7691
    Keywords: Computational aerodynamics ; transonic flow ; inverse problem ; wing design ; optimization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Conclusion The purpose of the last three sections is to demonstrate by representative examples that control theory can be used to formulate computationally feasible procedures for aerodynamic design. The cost of each iteration is of the same order as two flow solutions, since the adjoint equation is of comparable complexity to the flow equation, and the remaining auxiliary equations could be solved quite inexpensively. Provided, therefore, that one can afford the cost of a moderate number of flow solutions, procedures of this type can be used to derive improved designs. The approach is quite general, not limited to particular choices of the coordinate transformation or cost function, which might in fact contain measures of other criteria of performance such as lift and drag. For the sake of simplicity certain complicating factors, such as the need to include a special term in the mapping function to generate a corner at the trailing edge, have been suppressed from the present analysis. Also it remains to explore the numerical implementation of the design procedures proposed in this paper.
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  • 12
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    Water resources management 2 (1988), S. 209-219 
    ISSN: 1573-1650
    Keywords: Hydroelectric power ; operating policy ; optimization ; probabilistic dynamic programming ; Shiroro Dam
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract Reservoir water release policies are computed for the Shiroro Dam hydroelectric power scheme in Northern Nigeria, using a probabilistic dynamic programming model. The state variable is the reservoir storage volume, while the uncertain nature of the inflow process is accounted for in the model by considering different possible inflow volumes and their inflow probabilities. Simulation of the reservoir operations with the derived policies show that on the average the hydrosystem has acceptable reliability when two units are in use, at 45% design power plant factor. At 70% power plant factor, which is the desired optimum for the power system in Nigeria, system failures are frequent and, in most cases, severe. For normal operation of the Shiroro Dam hydroelectric power system, two or three generating units, running at 40–50% power plant factor is recommended.
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  • 13
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    Mathematical methods of operations research 32 (1988), S. 271-297 
    ISSN: 1432-5217
    Keywords: Quadratic programming ; optimization ; conjugate directions ; decomposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Economics
    Description / Table of Contents: Zusammenfassung Unter Benutzung von konjungierten Richtungen wird eine Methode zur Lösung von konvexen, quadratischen Optimierungsproblemen entwickelt. Der Algorithmus erzeugt eine Folge von zulässigen Lösungen und endet nach einer endlichen Anzahl von Iterationen. Erweiterungen des Algorithmus für nichtkonvexe und für große strukturierte quadratische Optimierungsprobleme werden diskutiert.
    Notes: Abstract By using conjugate directions a method for solving convex quadratic programming problems is developed. The algorithm generates a sequence of feasible solutions and terminates after a finite number of iterations. Extensions of the algorithm for nonconvex and large structured quadratic programming problems are discussed.
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  • 14
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    Journal of optimization theory and applications 59 (1988), S. 39-43 
    ISSN: 1573-2878
    Keywords: Nonlinear algebraic equations ; conjugate direction methods ; optimization ; projection algorithms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract In this paper, it is shown that, when two subclasses of algorithms in the ABSg family are applied to a set of nonlinear algebraic equations, then the convergence is superlinear. The conditions for the theorem to be true are essentially the same as those that apply to the Newton method.
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  • 15
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    Annals of operations research 8 (1987), S. 351-362 
    ISSN: 1572-9338
    Keywords: Response surface methodology ; simulation ; optimization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Economics
    Notes: Abstract Managing the volume of experimental and/or simulation data required for large-scale design studies can be a significant problem. This paper describes a method for dealing with this problem, using response surface methodology. The method involves (1) determining a summary parameterization of the response of the underlying process mechanism generating the data, in order to characterize this response in terms of a manageable set of performance measures, and (2) deriving a model of the data, in order to summarize the dependence of the performance measures on selected predictor or design variables. The method is illustrated by its application to a problem in vehicle collision research.
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  • 16
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    Water resources management 1 (1987), S. 241-254 
    ISSN: 1573-1650
    Keywords: Groundwater management ; optimization ; uncertainty analysis ; reliability ; multiple-objective analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract Like any other resources planning and management, groundwater management is performed in a stochastic environment in which the system itself involves a number of random elements. Consequences as a result of decisions made based on analyses are not certain. This paper presents a management model using the chance-constrained framework which explicitly considers the random nature of aquifer properties. The model enables the derivation of an optimal groundwater management policy that would satisfy required operation performance reliability. Furthermore, the chance-constrained model is extended to the multi-objective optimization framework in which a tradeoff between total water supply pumpage and system performance reliability is explicitly considered. The models are applied to a hypothetical example of a steady, nonuniform, homogeneous confined aquifer.
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  • 17
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    Water resources management 1 (1987), S. 255-266 
    ISSN: 1573-1650
    Keywords: Reservoir operation ; optimization ; dynamic programming ; water resources planning
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract Optimization of long-term operation of real-world reservoir systems by dynamic programming has been studied. Computer time requirements make it necessary to use iterative methods in the case of multi-reservoir systems. State-incremental dynamic programming provides a reasonable rate of convergence for serial systems when initial policies are suitably chosen. A new method is proposed that combines dynamic programming with successive approximations and state-incremental dynamic programming. Incremental sequential dynamic programming is especially useful for systems of complex configuration which cannot be optimized with other iterative methods due to very slow convergence. Choices of initial policy, state increment, and the number of states to be considered in each iteration are investigated in two case studies.
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  • 18
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    Irrigation and drainage systems 1 (1987), S. 195-204 
    ISSN: 1573-0654
    Keywords: agricultural technologies ; optimization ; simulation ; system ; water management ; water quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The system approach and combination of simulation and optimization models to the problems of water quality in public water supply basins influenced by agricultural activities, drainage, irrigation and soil conservation are presented. The methodological aspects of the problem are analysed.
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  • 19
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    Journal of optimization theory and applications 55 (1987), S. 377-390 
    ISSN: 1573-2878
    Keywords: Stochastic programming ; probabilistic constrained problems ; chance constrained problems ; duality ; optimization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract In this paper, the two problems inf{inf{cx:x ∈R n,A 1 x≥y,A 2 x≥b}:y ∈ suppF ⊂R m,F(y)≥p} and sup{inf{uy:y ∈ suppF ⊂R m,F(y)≥p}+vb:uA 1+vA 2=c, (u,v≥0} are investigated, whereA 1,A 2,b,c are given matrices and vectors of finite dimension,F is the joint probability distribution of the random variables β1,...,β m, and 0〈p〈1. The first problem was introduced as the deterministic equivalent and the second problem was introduced as the dual of the probabilistic constrained linear programming problem inf{cx:P(A 1 x≥β)≥p,A 2 x≥b}.b}. Properties of the sets and the functions involved in the two problems and regularity conditions of optimality are discussed.
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  • 20
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    Human ecology 14 (1986), S. 415-435 
    ISSN: 1572-9915
    Keywords: prehistoric hunting ; optimization ; Tehuacan Valley
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Ethnic Sciences
    Notes: Abstract Previous analyses of faunal remains from highland Mesoamerican sites have viewed implied changes in animal exploitation patterns as a secondary consequence of early agricultural practices. This paper argues that faunal data from the Tehuacan Valley, when interpreted within an optimization framework provide evidence for the alteration of optimal meat harvesting strategies through time by communities responding to a variety of socioenvironmental factors: seasonal and long-term availability of game, access to domestic meat resources, human meat demand levels, and scheduling constraints.
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  • 21
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    Journal of optimization theory and applications 49 (1986), S. 289-317 
    ISSN: 1573-2878
    Keywords: Control theory ; disturbances ; stochastic processes ; production and inventory smoothing ; optimization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract A comprehensible and unified system control approach is presented to solve a class of production/inventory smoothing problems. A nonstationary, non-Gaussian, finite-time linear optimal solution with an attractive computation scheme is obtained for a general quadratic and linear cost structure. A complete solution to a classical production/inventory control problem is given as an example. A general solution to the discrete-time optimal regulator with arbitrary but known disturbance is provided and discussed in detail. A computationally attractive closed-loop suboptimal scheme is presented for problems with constraints or nonquadratic costs. Implementation and interpretation of the results are discussed.
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  • 22
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    Annals of operations research 5 (1985), S. 599-612 
    ISSN: 1572-9338
    Keywords: Microcomputers ; spreadsheets ; linear programming ; optimization ; software
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Economics
    Notes: Abstract This paper discusses the advantages of using spreadsheets for problem specification and report generation in optimization projects. It summarizes some of the mathematical programming software which is compatible with popular spreadsheets. A small production planning problem is used to illustrate the steps in input and processing of the results. Two programs are compared in detail.
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  • 23
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    Annals of operations research 5 (1985), S. 613-630 
    ISSN: 1572-9338
    Keywords: Microcomputers ; computer programs ; mathematical programming ; software ; optimization ; management science ; operations research
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Economics
    Notes: Abstract This paper provides a summary of some OR/MS software for microcomputers. Lists of packages in many management science techniques are included. A bibliography of other papers is also included. We also summarize the general features of packages in each category. Finally, we mention a few sources to help the reader keep up with the developments in this area.
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  • 24
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    Journal of fusion energy 4 (1985), S. 315-319 
    ISSN: 1572-9591
    Keywords: optimization ; SENRI ; blanket ; tritium ; breeding ; energy multiplication ; molten salt ; nonbreeding ; hybrid ; support ratio
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Neutronic calculations were performed to optimize the SENRI blanket in terms of energy multiplication as well as tritium breeding ratio. The blanket employs a thick (∼ 64-cm) Li layer as breeder/coolant. Three approaches were taken here to achieve the goal: (1) reduction of6Li in the lithium, (ii) replacement of the Li layer by a molten-salt (flibe) layer, and (iii) shipment of excess tritium to a nonbreeding blanket. It was found that the excess tritium produced in the SENRI blanket could be used effectively to obtain additional power by fueling a nonbreeding D-T reactor.
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  • 25
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    European biophysics journal 12 (1985), S. 115-119 
    ISSN: 1432-1017
    Keywords: tRNA cycle ; optimization ; elongation rate ; codon frequency ; tRNA synthetase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract With the aid of a kinetic model, we have investigated how the adaptation between the various components of the tRNA cycle and the codon frequencies affects the rate of protein synthesis. Depending on the relative amounts of total tRNA, synthetase and ribosomes, the optimal correlations vary between a situation where all tRNA species are either present in equal amounts or are present in amounts proportional to the square-root of the corresponding codon frequencies, and a situation where the amounts of the different tRNA species present are linearly proportional to the codon frequencies.
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  • 26
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    Mathematical geology 17 (1985), S. 195-208 
    ISSN: 1573-8868
    Keywords: geostatistics ; covariance estimation ; optimization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Mathematics
    Notes: Abstract The parameters of covariance functions (or variograms) of regionalized variables must be determined before linear unbiased estimation can be applied. This work examines the problem of minimum-variance unbiased quadratic estimation of the parameters of ordinary or generalized covariance functions of regionalized variables. Attention is limited to covariance functions that are linear in the parameters and the normality assumption is invoked when fourth moments of the data need to be calculated. The main contributions of this work are (1) it shows when and in what sense minimum-variance unbiased quadratic estimation can be achieved, and (2) it yields a well-founded, practicable, and easy-to-automate methodology for the estimation of parameters of covariance functions. Results of simulation studies are very encouraging.
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  • 27
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    Journal of pharmacokinetics and pharmacodynamics 13 (1985), S. 515-540 
    ISSN: 1573-8744
    Keywords: models ; data analysis ; regression ; least squares ; estimation ; identifiability ; optimization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract This is the second in a series of tutorial articles discussing the analysis of pharmacokinetic data using parametric models. In this article the basic issue is how to estimate the parameters of such models. Primary emphasis is placed on point estimates of the parameters of the structural (pharmacokinetic) model. All the estimation methods discussed are least squares (LS) methods: ordinary least squares, weighted least squares, iteratively reweighted least squares, and extended least squares. The choice of LS method depends on the variance model. Some discussion is also provided of computer methods used to find the LS estimates, identifiability, and robust LS-based estimation methods.
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  • 28
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    Geotechnical and geological engineering 3 (1985), S. 295-310 
    ISSN: 1573-1529
    Keywords: Off-highway trucks ; optimization ; horsepower ; productivity ; haulage cost
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Summary Critical equipment characteristics are isolated and analysed by traditional operations research techniques, using off-highway trucks as an archetype. A computer search technique has been developed, employing various production and cost analyses. With this model, the optimum combination of horsepower, capacity, velocity, and total cost can be found, minimizing haulage cost per ton. Horsepower is treated as the most important characteristic. An example of the program's use and interpretation of its results conclude the paper. The optimization is useful as an aid to off-highway truck selection, evaluation, and design. Model limitations are offered and advantages to its use are given.
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  • 29
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    Acta applicandae mathematicae 4 (1985), S. 115-137 
    ISSN: 1572-9036
    Keywords: 82A05 ; 90C39 ; Macromolecular structure ; dynamic programming ; optimization ; statistical mechanics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract Recent advances in DNA and protein-sequencing technologies have made an increasing number of primary structures available for theoretical investigations. The prediction of a higher-order protein, and nucleic acid structure in particular, is an area where computational approaches will be able to complement the lack of experimental observations. We review some of the problems related to structure predictions: sequence homology searches, secondary structure prediction in RNAs, and regular structure prediction in proteins. The first two are mathematically well-defined problems, for it is not usually necessary to consider long-range interactions. The solution to a smaller segment is a part of the solution to the entire sequence. Thus, the problem can be solved by dynamic programming algorithms. The prediction of protein structures poses a more complex combinatorial problem, as illustrated in our statistical mechanical treatment. A promising approximation is to calculate locally optimal structures stabilized by relatively short-range interactions, and then to include longer-range effects as interactions between the locally optimal structures.
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    Journal of fusion energy 4 (1985), S. 389-394 
    ISSN: 1572-9591
    Keywords: D-D reactor ; optimization ; blanket/shield ; SWAN ; energy gain ; atomic displacement ; perturbation theory ; D2O coolant ; neutron multiplier
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Position-dependent optimization calculations have been carried out on a D-D fusion reactor blanket/shield to maximize the energy gain in the blanket and to minimize the atomic displacement rate of the copper stabilizer in the superconducting magnet. The results obtained by using the optimization code SWAN indicate (1) the advantage of D2O coolant over H2O coolant with respect to increasing the energy gain, and (2) the difference in the optimal shield distributions between D-T and D-D neutron sources. The possibility of improving both the energy gain and radiation shielding characteristics is also discussed.
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    Human ecology 13 (1985), S. 485-510 
    ISSN: 1572-9915
    Keywords: hunting ; game depletion ; optimization ; ritual ; tortoises
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Ethnic Sciences
    Notes: Abstract Several investigators cite population control, frequent settlement relocation, trekking, expansion of diet breadth, and food taboos as strategic responses to game depletion by indigenous populations living in interfluvial zones of lowland South America. The Ka'apor Indians of the interfluvial forest of northern Maranhão, Brazil, employ other means of optimizing hunting efficiency, partly based on ritual. Menstruating women, pubescent girls, and parents of newborns can consume meat only of the tortoise (Gochelone denticulata), the first prey species to be hunted out of an area. Tortoise capture requires, on average, one full day of hunting. This means that the full potential of hunting pressure does not materialize near the settlement. Meat productivity is unusually high even near old settlements. I argue that ritual tortoise hunting helps to regulate environmental utilization, to maintain a sustained yield of meat protein, and to expand the catchment area gradually.
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  • 32
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    Journal of optimization theory and applications 45 (1985), S. 101-112 
    ISSN: 1573-2878
    Keywords: Delay systems ; optimization ; block pulse functions ; linear systems
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract The concept of coefficient shift matrix is introduced to represent delay variables in block pulse series. The optimal control of a linear delay system with quadratic performance index is then studied via block pulse functions, which convert the problems into the minimization of a quadratic form with linear algebraic equation constraints. The solution of the two-point boundary-value problem with both delay and advanced arguments is circumvented. The control variable obtained is piecewise constant.
    Type of Medium: Electronic Resource
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