ALBERT

Description: The paper focuses on a navigation facility, relying on commercial-off-the-shelf (COTS) technology, developed to generate high-accuracy attitude and trajectory measurements in postprocessing. Target performance is cm-level positioning with tenth of degree attitude accuracy. The facility is based on the concept of GPS-aided inertial navigation but comprises carrier-phase differential GPS (CDGPS) processing and attitude estimation based on multiantenna GPS configurations. Expected applications of the system include: (a) performance assessment of integrated navigation systems, developed for general aviation aircraft and medium size unmanned aircraft systems (UAS); (b) generation of reference measurements to evaluate the flight performance of airborne sensors (e.g., radar or laser); and (c) generation of reference trajectory and attitude for improving imaging quality of airborne remote sensing data. The paper describes system architecture, selected algorithms for data processing and integration, and theoretical performance evaluation. Experimental results are also presented confirming the effectiveness of the implemented approach.

Description: The time model of Beidou satellite clocks is analyzed. The general relations of satellite clocks with the system time are studied. The error sources of two-way radio time transfer between satellites and uplink stations are analyzed. The uncertainty of type A is about 0.3 ns in Beidou system. All the satellite clocks in orbit of Beidou satellite navigation system are evaluated by the clock offsets observed by the two-way radio time transfer. The frequency stabilities at a sample time of 10000 s and 1 day for all the satellite clocks are better than . It means that the performance of Beidou satellite clocks in orbit is consistent with the ground test, and the results in orbit are a little better than those in ground vacuum.

Description: This paper presents an extended Kalman filter-based hybrid indoor position estimation technique which is based on integration of fingerprinting and trilateration approach. In this paper, Euclidian distance formula is used for the first time instead of radio propagation model to convert the received signal to distance estimates. This technique combines the features of fingerprinting and trilateration approach in a more simple and robust way. The proposed hybrid technique works in two stages. In the first stage, it uses an online phase of fingerprinting and calculates nearest neighbors (NN) of the target node, while in the second stage it uses trilateration approach to estimate the coordinate without the use of radio propagation model. The distance between calculated NN and detective access points (AP) is estimated using Euclidian distance formula. Thus, distance between NN and APs provides radii for trilateration approach. Therefore, the position estimation accuracy compared to the lateration approach is better. Kalman filter is used to further enhance the accuracy of the estimated position. Simulation and experimental results validate the performance of proposed hybrid technique and improve the accuracy up to 53.64% and 25.58% compared to lateration and fingerprinting approaches, respectively.

Description: Support system for safe driving heavily depends on global navigation satellite system. Pseudoranges between satellites and vehicles are measured to compute vehicles’ positions and their relative positions. In urban areas, however, multipath errors (MPEs) in pseudoranges, caused by obstruction and reflection of roadside buildings, greatly degrade the precision of relative positions. On the other hand, simply removing all reflected signals might lead to a shortage of satellites in fixing positions. In our previous work, we suggested solving this dilemma by cooperative relative positioning (CoRelPos) which exploits spatial correlation of MPEs. In this paper, we collected the trace data of pseudoranges by driving cars in urban areas, analyzed the properties of MPEs (specifically, their dependency on signal strength, elevation angles of satellites, and receivers’ speeds), and highlighted their spatial correlation. On this basis, the CoRelPos scheme is refined by considering the dynamics of MPEs. Evaluation results under practical vehicular scenarios confirm that properties of MPEs can be exploited to improve the precision of relative positions.

Description: This paper examines place inscriptions in Trench Town, Jamaica, and explores the ways these are used to reinforce, shape, or challenge dominant images of this inner-city community. On one hand, Trench Town is like many of its neighbouring communities, characterised by high levels of poverty, unemployment, political and gang violence, derelict buildings, and overcrowded homes. On the other hand, Trench Town is iconic and unique as it is recognised worldwide for being the birth place of reggae music and home to a number of well-known reggae artists including reggae superstar Bob Marley. Today, Trench Town’s landscape is filled with inscriptions reminiscent of its rich cultural past. Linked to this is a conscious effort by its residents to identify themselves with reggae music and to recapture and sustain the positive legacies that have made the community popular. This is manifested in the numerous murals, statues, and graffiti seen throughout the community evoking past images of reggae music icons such as Marley and Tosh alongside renowned black leaders such as Marcus Garvey. These inscriptions are conceived as texts and are seen as part of a broader discourse on issues relating to urban spatial identity, commoditisation, exclusion, struggle, resistance, and change.

Description: We examined the first and final term grade point averages (GPA) for a class of students at a Texas community college to determine how dual enrollment credit influenced GPA. Five statistically significant differences, albeit small effect sizes, were present by gender and by ethnic membership. Dual credit students had higher GPAs than did nondual credit students. Interestingly, dual enrollment did not have a statistically significant influence on GPAs for Asian students or for students after two years at this community college. As such, this study is the first research investigation of which we are aware in which student GPA in the first college semester and at the end of the second year was compared between dual credit and nondual credit students. Implications of our findings and suggestions for future research are provided.

Description: Most diversity management programs in Canada maintain that enhancing workforce diversity is of tremendous significance for business organizations in today’s competitive global urban markets. Since well-meaning diversity management initiatives have been largely ineffective thus far in dealing with workplace discrimination and racism in the Canadian workplace, this paper underscores the need to decenter the focus of diversity management from a business imperative to an antidiscrimination and social justice imperative. Within this latter perspective, the paper examines the strengths and limitations of the antiracism approach that has been implemented in various developed countries in recent years. The antiracism approach is an action-oriented strategy for institutional and systemic change that has at its core the interrogation of privilege, power disparities, and other forms of inequity within the organization. Drawing from the lessons of various initiatives that have utilized this approach, the present paper emphasizes the need for a nuanced antiracism approach in the multicultural Canadian society if diversity management is to attain its goal of greater inclusion of all individuals in informal networks and formal organizational programs.

Description: This paper examines the dynamic spatial and temporal patterns of China’s urban hierarchy from 1950 to 2005. We limit the study to mainland China’s 137 urban agglomerations of 750,000 or more population as of 2005. The paper improves upon a classic approach to measuring shifting ranks within an urban hierarchy by applying advanced spatial analysis techniques. We use a Getis-Ord , a space-time Moran scatter plot, and dynamic LISA paths to examine the regional difference and change for these urban agglomerations. Our study revealed a north-south divide in the changing urban hierarchy of China after 1990. The analysis demonstrated that the spatial and temporal shift of urban dominance in China was closely associated with policy and economic factors. The paper concludes with a discussion of the differences across the six different time periods of change from 1950 to 2005.

Description: Companion animals are very important to people of big cities. In Greece the families which own those animals take them for a walk in the parks and streets of their town but not always with care to not disturb other citizens. Laws and regulations for companion and stray animals are not respected in Greece, although as a result of the Athens Olympics in 2004 the Greek government started to provide funds for the collection, care, and sterilization of stray animals. This paper is a first attempt to record, through the aid of a structured questionnaire, the view of the citizens of the city of Xanthi in northern Greece regarding companion animals and what they do when animals become old. The paper also examines the extent to which the existence of stray and companion animals in parks disturbs the people who visit green areas looking for a place to get a rest or play on the grass. The majority preferred that stray animals are collected off the streets, recorded, treated from parasites, vaccinated, and sterilized and after that are available for adoption or are returned to the area they were found at.

Description: The majority of 3G mobile phones have an integrated GPS chip enabling them to calculate a navigation solution. But to deliver continuous and accurate location information, the satellite tracking process has to be stable and reliable. This is still challenging, for example, in heavy multipath and non-line of sight (NLOS) environments. New families of Galileo and GPS navigation signals, such as Alternate Binary Offset Carrier (AltBOC), Composite Binary Offset Carrier (CBOC), and Time-Multiplex Binary Offset Carrier (TMBOC), will bring potential improvements in the pseudorange calculation, including more signal power, better multipath mitigation capabilities, and overall more robust navigation. However, GNSS signal tracking strategies have to be more advanced in order to profit from the enhanced properties of the new signals.In this paper, a tracking algorithm designed for Galileo E1 CBOC signal that consists of two steps, coarse and fine, with different tracking parameters in each step, is presented and analyzed with respect to tracking accuracy, sensitivity and robustness. The aim of this paper is therefore to provide a full theoretical analysis of the proposed two-step tracking algorithm for Galileo E1 CBOC signals, as well as to confirm the results through simulations as well as using real Galileo satellite data.

Description: The problem of designing robust systems to track global navigation satellite system (GNSS) signals in harsh environments has gained high attention. The classical closed loop architectures, such as phase locked loops, have been used for many years for tracking, but in challenging applications their design procedure becomes intricate. This paper proposes and demonstrates the use of a quasi-open loop architecture to estimate the time varying carrier frequency of GNSS signals. Simulation results show that this scheme provides an additional degree of freedom to the design of the whole architecture. In particular, this additional degree of freedom eases the design of the loop filter in harsh environments.

Description: The well-known Space-Alternating Generalized Expectation Maximisation (SAGE) algorithm has been recently considered for multipath mitigation in Global Navigation Satellite System (GNSS) receivers. However, the implementation of SAGE in a GNSS receiver is a challenging issue due to the numerous number or parameters to be estimated and the important size of the data to be processed. A new implementation of the SAGE algorithm is proposed in this paper in order to reach the same efficiency with a reduced complexity. This paper focuses on the trade-off between complexity and performance thanks to the Cramer Rao bound derivation. Moreover, this paper shows how the proposed algorithm can be integrated with a classical GNSS tracking loop. This solution is thus a very promising approach for multipath mitigation.

Description: This paper studies Bayesian filtering techniques applied to the design of advanced delay tracking loops in GNSS receivers with multipath mitigation capabilities. The analysis includes tradeoff among realistic propagation channel models and the use of a realistic simulation framework. After establishing the mathematical framework for the design and analysis of tracking loops in the context of GNSS receivers, we propose a filtering technique that implements Rao-Blackwellization of linear states and a particle filter for the nonlinear partition and compare it to traditional delay lock loop/phase lock loop-based schemes.

Description: The spatial techniques currently used in accurate time transfer are based on GPS, TWSTFT, and GLONASS. The International Bureau of Weights and Measures (BIPM) is mandated for the generation of Coordinated Universal Time (UTC) which is published monthly in the BIPM Circular T. In 2009, the international Consultative Committee for Time and Frequency (CCTF) recommended the use of multitechniques in time transfer to ensure precision, accuracy, and robustness in UTC. To complement the existing GPS and TWSTFT time links, in November 2009 the first two GLONASS time links were introduced into the UTC worldwide time link network. By November 2011, 6 GLONASS time links are used in the UTC computation. In the frame of the application in the UTC computation, we establish the technical features of GLONASS time transfer: the short- and long-term stabilities, the calibration process, and in particular the impact of the multiple GLONASS frequency biases. We then outline various considerations for future developments, including the uses of P-codes and carrier-phase information.

Description: We examined the first and final term grade point averages (GPA) for a class of students at a Texas community college to determine how dual enrollment credit influenced GPA. Five statistically significant differences, albeit small effect sizes, were present by gender and by ethnic membership. Dual credit students had higher GPAs than did nondual credit students. Interestingly, dual enrollment did not have a statistically significant influence on GPAs for Asian students or for students after two years at this community college. As such, this study is the first research investigation of which we are aware in which student GPA in the first college semester and at the end of the second year was compared between dual credit and nondual credit students. Implications of our findings and suggestions for future research are provided.

Description: While neighbourhood differences in social capital have been mapped, few empirical studies have considered the nexus between specific physical characteristics of communities and social capital. In this study we hypothesised that social capital would be positively associated with a more walkable street network design, but inversely associated with negative experiences and perceptions of neighbourhood environments. Data was gathered through a random cross-sectional telephone survey of adults (

Description: The departure point for this investigation is to highlight the centrality of regulation theory as a praxis in planning enforcement. The value of the conceptual framework is demonstrated by application in the problematic arena of conservation regulatory compliance, where there is currently a dearth of investigation. It is evidenced that this thematic approach provides a lens to scrutinise problematic areas of control and provides a deeper understanding of the difficulties faced by planning enforcement operational practice generally and heritage regimes specifically. The utility of the proposed mechanism is that it remedies the current, well documented, pitfalls of disjointed, piecemeal strategies by providing a framework for robust, coherent decision making not only in planning but in the wider regulatory arena.

Description: A perceived emerging threat to GNSS receivers is posed by a spoofing transmitter that emulates authentic signals but with randomized code phase and Doppler over a small range. Such spoofing signals can result in large navigational solution errors that are passed onto the unsuspecting user with potentially dire consequences. In this paper, a simple and readily implementable processing rule based on CNR estimates of the correlation peaks of the despread GNSS signals is developed expressly for reducing the effectiveness of such a spoofer threat. Consequently, a comprehensive statistical analysis is given to evaluate the effectiveness of the proposed technique in various LOS and NLOS environments. It is demonstrated that the proposed receiver processing is highly effective in both line-of-sight and multipath propagation conditions.

Description: Indoor wireless localisation is a widely sought feature for use in logistics, health, and social networking applications. Low-powered localisation will become important for the next generation of pervasive media applications that operate on mobile platforms. We present an inexpensive and robust context-aware tracking system that can track the position of users in an indoor environment, using a wireless smart meter network. Our context-aware tracking system combines wireless trilateration with a dynamic position tracking model and a probability density map to estimate indoor positions. The localisation network consisted of power meter nodes placed at known positions in a building. The power meter nodes are tracked by mobile nodes which are carried by users to localise their position. We conducted an extensive trial of the context-aware tracking system and performed a comparison analysis with existing localisation techniques. The context-aware tracking system was able to localise a person's indoor position with an average error of 1.21 m.

Description: An episode of relatively thick (till ~3 km) aerosol formation over the urban area of Sofia city was observed by lidar at a wavelength of 1064 nm. The lidar is part of Sofia lidar station at the Institute of Electronics of Bulgarian Academy of Sciences. Analysis of the weather conditions during the measurement period explains the stable persistence of such formation of human-activity aerosol over the town for the days of observation 20, 21, 23, and 24 June, 2011. The estimated top of the Planetary Boundary Layer for the measurement dated 23 June showed unusually high altitude ~2200 m above ground. The results are presented in terms of vertical atmospheric backscatter coefficient profiles and color maps of the aerosol stratification evolution.

Description: Multipath propagation is one of the most difficult error sources to compensate in global navigation satellite systems due to its environment-specific nature. In order to gain a better understanding of its impact on the received signal, the establishment of a theoretical performance limit can be of great assistance. In this paper, we derive the Cramer Rao lower bounds (CRLBs), where in one case, the unknown parameter vector corresponds to any of the three multipath signal parameters of carrier phase, code delay, and amplitude, and in the second case, all possible combinations of joint parameter estimation are considered. Furthermore, we study how various channel parameters affect the computed CRLBs, and we use these bounds to compare the performance of three deconvolution methods: least squares, minimum mean square error, and projection onto convex space. In all our simulations, we employ CBOC modulation, which is the one selected for future Galileo E1 signals.

Description: An unmanned aerial vehicle- (UAV-) based monitoring system is developed as an intermediate system between aerial survey and ground survey. All the measurement tools are mounted on the UAV to acquire detailed information from low altitudes which is different from a satellite or a plane. The monitoring is carried out from the sky, but the spatial and temporal resolutions are freely selected near the ground. In this study, the data is easily acquired with safety and mobility by the utilization of a sensor web. A sensor web is a type of sensor network which is well suited for environmental monitoring. Sensor nodes are spatially distributed and wirelessly communicate with each other. In this study, the UAV-based system is considered as a mobile sensor node. This study proposes a combination of UAV-based monitoring with a ubiquitous sensor network.

Description: Multipath remains a dominant source of ranging errors in Global Navigation Satellite Systems (GNSS), such as the Global Positioning System (GPS) or the future European satellite navigation system Galileo. Multipath is generally considered undesirable in the context of GNSS, since the reception of multipath can make significant distortion to the shape of the correlation function used for time delay estimation. However, some wireless communications techniques exploit multipath in order to provide signal diversity though in GNSS, the major challenge is to effectively mitigate the multipath, since we are interested only in the satellite-receiver transit time offset of the Line-Of-Sight (LOS) signal for the receiver's position estimate. Therefore, the multipath problem has been approached from several directions in order to mitigate the impact of multipath on navigation receivers, including the development of novel signal processing techniques. In this paper, we propose a maximum likelihood-based technique, namely, the Reduced Search Space Maximum Likelihood (RSSML) delay estimator, which is capable of mitigating the multipath effects reasonably well at the expense of increased complexity. The proposed RSSML attempts to compensate the multipath error contribution by performing a nonlinear curve fit on the input correlation function, which finds a perfect match from a set of ideal reference correlation functions with certain amplitude(s), phase(s), and delay(s) of the multipath signal. It also incorporates a threshold-based peak detection method, which eventually reduces the code-delay search space significantly. However, the downfall of RSSML is the memory requirement which it uses to store the reference correlation functions. The multipath performance of other delay-tracking methods previously studied for Binary Phase Shift Keying-(BPSK-) and Sine Binary Offset Carrier- (SinBOC-) modulated signals is also analyzed in closed loop model with the new Composite BOC (CBOC) modulation chosen for Galileo E1 signal. The simulation results show that the RSSML achieves the best multipath mitigation performance in a uniformly distributed two-to-four paths Rayleigh fading channel model for all three modulated signals.

Description: A new approximation for the distribution of the probability ratio in a sequential probability ratio test (SPRT) using noncoherent integration across a full code period is presented. The new approximation is valid for the carrier-to-noise power ratios (C/N0) typically encountered in GPS acquisition (20 dB-Hz ≤ C/N0 ≤ 50 dB-Hz), and it allows accurate theoretical performance analysis of the SPRT to be carried out for signals in this C/N0 range, eliminating the need for lengthy simulations for each scenario under investigation. Thus, the SPRT performance can be readily compared to that of other acquisition strategies for receiver design. Previous approximations in the literature are not valid in the range 20 dB-Hz ≤ C/N0 ≤ 50 dB-Hz.

Description: Satellite navigation technology is becoming essential for civil application. The high-accuracy navigation service is demanded. However, the satellite signal may be exposed to the signal from other systems, which are sharing the same frequency band. This is a potential threat for the performance of navigation devices. The aim of this paper is to present an interference impact assessment in the context of global navigation based on the new modulation Composite Binary Offset Carrier (CBOC) that will be used for Galileo E1 civil signal. The focus is on the analysis of the Galileo CBOC-modulated signal robustness against narrowband interference.

Description: The paper exploits the outlier detection techniques for wireless-sensor-network- (WSN-) based localization problem and proposes an outlier detection scheme to cope with noisy sensor data. The cheap and widely available measurement technique—received signal strength (RSS)—is usually taken into account in the indoor localization system, but the RSS measurements are known to be sensitive to the change of the environment. The paper develops an outlier detection scheme to deal with abnormal RSS data so as to obtain more reliable measurements for localization. The effectiveness of the proposed approach is verified experimentally in an indoor environment.

Description: Using an Unscented Kalman Filter (UKF) as the nonlinear estimator within a Global Positioning System/Inertial Navigation System (GPS/INS) sensor fusion algorithm for attitude estimation, various methods of calculating the matrix square root were discussed and compared. Specifically, the diagonalization method, Schur method, Cholesky method, and five different iterative methods were compared. Additionally, a different method of handling the matrix square root requirement, the square-root UKF (SR-UKF), was evaluated. The different matrix square root calculations were compared based on computational requirements and the sensor fusion attitude estimation performance, which was evaluated using flight data from an Unmanned Aerial Vehicle (UAV). The roll and pitch angle estimates were compared with independently measured values from a high quality mechanical vertical gyroscope. This manuscript represents the first comprehensive analysis of the matrix square root calculations in the context of UKF. From this analysis, it was determined that the best overall matrix square root calculation for UKF applications in terms of performance and execution time is the Cholesky method.

Description: The remote synchronization system for the onboard crystal oscillator (RESSOX) is a remote control method that permits synchronization between a ground station atomic clock and Japanese quasi-zenith satellite system (QZSS) crystal oscillators. To realize the RESSOX of the QZSS, the utilization of navigation signals of QZSS for feedback control is an important issue. Since QZSS transmits seven navigation signals (L1C/A, L1CP, L1CD, L2CM, L2CL, L5Q, and L5I), all combinations of these signals should be evaluated. First, the RESSOX algorithm will be introduced. Next, experimental performance will be demonstrated. If only a single signal is available, ionospheric delay should be input from external measurements. If multiple frequency signals are available, any combination, except for L2 and L5, gives good performance with synchronization error being within two nanoseconds that of RESSOX. The combination of L1CD and L5Q gives the best synchronization performance (synchronization error within 1.14 ns). Finally, in the discussion, comparisons of long-duration performance, computer simulation, and sampling number used in feedback control are considered. Although experimental results do not correspond to the simulation results, the tendencies are similar. For the overlapping Allan deviation of long duration, the stability of 1.23×10−14 at 100,160 s is obtained.

Description: A new framework is presented for multiparticipant coordination of over-the-horizon maneuvering processes. In this framework, geographical information is decentralizedly augmented via the multitude of annotation processes: landmark localization by map builder, connection generation by planner, and GPS tracking by probe vehicles. By integrating the augmentation process on a common satellite image, the subscriber participants reuse the geographics within specific maneuvering context. Based on graph theoretic representation of the multiparticipant augment process, an interactive geographics annotation system was developed and verified within the context of interactive rendezvous and cooperative monitoring.

Description: Automatic dependent surveillance-broadcast (ADS-B) is a system in which aircraft continually transmit their identity and GPS-derived navigational information. ADS-B networks for air traffic monitoring have already been implemented in areas around the world, but ground stations cannot be installed in midocean and are difficult to maintain in the Arctic, leaving a coverage gap for oceanic and high latitude airspace. A potential solution for worldwide tracking of aircraft is through the monitoring of aircraft-transmitted ADS-B signals using satellite-borne receivers. To investigate this possibility, a high altitude balloon experiment was carried out in June 2009 to determine if ADS-B signals can be detected from near space. The Flying Laboratory for the Observation of ADS-B Transmissions (FLOAT) was the first stratospheric platform to collect ADS-B data. The FLOAT mission successfully demonstrated the reception of ADS-B signals from near space, paving the way to the development of a space-based ADS-B system.

Description: The field of satellite navigation has witnessed the advent of a number of new systems and technologies: after the landmark design and development of the Global Positioning System (GPS), a number of new independent Global Navigation Satellite Systems (GNSSs) were or are being developed all over the world: Russia's GLONASS, Europe's GALILEO, and China's BEIDOU-2, to mention a few. In this ever-changing context, the availability of reliable and flexible receivers is becoming a priority for a host of applications, including research, commercial, civil, and military. Flexible means here both easily upgradeable for future needs and/or on-the-fly reprogrammable to adapt to different signal formats. An effective approach to meet these design goals is the software-defined radio (SDR) paradigm. In the last few years, the availability of new processors with high computational power enabled the development of (fully) software receivers whose performance is comparable to or better than that of conventional hardware devices, while providing all the advantages of a flexible and fully configurable architecture. The aim of this tutorial paper is surveying the issue of the general architecture and design rules of a GNSS software receiver, through a comprehensive discussion of some techniques and algorithms, typically applied in simple PC-based receiver implementations.

Description: Inertial navigation problems are often understood as initial value problems. However, there are many applications where boundary value problems naturally arise. In these situations, it has been shown that the finite element method can be efficiently used to compute accurate position and velocity estimates. We will propose that finite element method complemented with Tikhonov regularization—a basic tool for inverse problems—is a powerful combination for further accuracy improvements. The proposed method provides a straightforward way to exploit prior information of various types and is subject to rigorous optimality results. Use and accuracy of the proposed method are demonstrated with examples.

Description: It is a valid way to analyze the space object real-time movement by using distributed satellite earth observation system, which can provide the stereographic image through the collaboration of the satellites. That relative position and pose estimation is one of the key technologies for distributed micro/nanosatellite earth observation system (DMSEOS). In this paper, on the basis of the attitude dynamics of spacecrafts and the theory of machine vision, an autonomous positioning and orientating algorithm for distributed micro/nanosatellites based on dual quaternion and EKF (extended Kalman filtering) is proposed. Firstly, how to represent a line transform unit using dual quaternion is introduced. Then, the feature line point of the line transform unit is defined. And then, on the basis of the attitude dynamics of spacecrafts and the theory of EKF, we build the state and observation equations. Finally, the simulations show that this algorithm is an accurate valid method in positioning and orientating of distributed micro/nanosatellite earth observation system.

Description: Traditionally the relative positioning and attitude determination problem are treated as independent. In this contribution we will investigate the possibilities of using multiantenna (i.e., triple and quadruple) data, not only for attitude determination but also for relative positioning. The methods developed are rigorous and have the additional advantage that they improve ambiguity resolution on the unconstrained baseline(s) and the overall success rate of ambiguity resolution between a number of antennas.

Description: Present land vehicle navigation relies mostly on the Global Positioning System (GPS) that may be interrupted or deteriorated in urban areas. In order to obtain continuous positioning services in all environments, GPS can be integrated with inertial sensors and vehicle odometer using Kalman filtering (KF). For car navigation, low-cost positioning solutions based on MEMS-based inertial sensors are utilized. To further reduce the cost, a reduced inertial sensor system (RISS) consisting of only one gyroscope and speed measurement (obtained from the car odometer) is integrated with GPS. The MEMS-based gyroscope measurement deteriorates over time due to different errors like the bias drift. These errors may lead to large azimuth errors and mitigating the azimuth errors requires robust modeling of both linear and nonlinear effects. Therefore, this paper presents a solution based on Parallel Cascade Identification (PCI) module that models the azimuth errors and is augmented to KF. The proposed augmented KF-PCI method can handle both linear and nonlinear system errors as the linear parts of the errors are modeled inside the KF and the nonlinear and residual parts of the azimuth errors are modeled by PCI. The performance of this method is examined using road test experiments in a land vehicle.

Description: This paper presents an evaluation of several GNSS multicarrier ambiguity (MCAR) resolution techniques for the purpose of attitude determination of low earth orbiting satellites (LEOs). It is based on the outcomes of the study performed by the University of Calgary and financed by the European 6th Framework Programme for Research and Development as part of the research project PROGENY. The existing MCAR literature is reviewed and eight possible variations of the general MCAR processing scheme are identified based on two possible options for the mathematical model of the float solution, two options for the estimation technique used for the float solution, and finally two possible options for the ambiguity resolution process. The two most promising methods, geometry-based filtered cascading and geometry-based filtered LAMBDA, are analysed in detail for two simulated users modelled after polar orbiting LEOs through an extensive covariance simulation. Both the proposed Galileo constellation and Galileo used in conjunction with the GPS constellation are tested and results are presented in terms of probabilities of correct ambiguity resolution and float and fixed solution baseline accuracies. The LAMBDA algorithm is shown to outperform the cascading method, particularly in the single-frequency dual-GNSS system case. Secondly, more frequencies and multiple GNSS always offer improvement, but the single-frequency dual-system case is found to have similar performance to the dual-frequency single-system case.

Description: The remote synchronization system for the onboard crystal oscillator (RESSOX) realizes accurate synchronization between an atomic clock at a ground station and the QZSS onboard crystal oscillator, reduces overall cost and satellite power consumption, as well as onboard weight and volume, and is expected to have a longer lifetime than a system with onboard atomic clocks. Since a QZSS does not yet exist, we have been conducting synchronization experiments using geostationary earth orbit satellites (JCSAT-1B or Intelsat-4) to confirm that RESSOX is an excellent system for timing synchronization. JCSAT-1B, the elevation angle of which is 46.5 degrees at our institute, is little affected by tropospheric delay, whereas Intelsat-4, the elevation angle of which is 7.9 degrees, is significantly affected. The experimental setup and the results of uplink experiments and feedback experiments using mainly Intelsat-4 are presented. The results show that synchronization within 10 ns is realized.

Description: In the face of uncertainties associated with climate change, building adaptive capacity and resilience at the community level emerges as an essential and timely element of local planning. However, key social factors that facilitate the effective building and maintenance of urban resilience are poorly understood. Two groups of US cities differing markedly in their commitment to climate change are contrasted with respect to their planning approaches and actions related to mitigation and adaptation strategies, and also in relation to social features that are believed to enhance adaptive capacity and resilience to climate change. The first group manifests a strong commitment to climate change mitigation and adaptation, and the second group has demonstrated little or no such commitment. These cities are compared with respect to several noteworthy social features, including level of social capital, degree of unconventional thought, and level of cultural diversity. These characteristics are postulated to contribute to the adaptive capacity of communities for dealing with the impacts of climate change. The aim is to determine to what extent there is a relationship between social/cultural structures and urban commitment and planning for climate change that could discriminate between climate change resilient and nonresilient urban areas.

Description: This paper searches to find out of building integrated photovoltaic system designs in Khartoum. It discussed technical issues and designed an integrated of photovoltaic in domestic using, within an urban approach towards sustainability in energy. Photovoltaic systems can be used to develop the solar energy in almost all kinds of applications. Exploiting of solar energy for domestic use is one avenue where the energy produced from the sun is converted into electricity to power most if not all the appliances available at our homes and residences. Building a photovoltaic system is the process of designing, selecting, and calculating the ratings of the equipments employed in the system. This process depends on a range of factors such as geographical location, solar irradiation, and load requirements. I introduce the procedures utilize, in building and selecting the equipments of a grid-connected photovoltaic system based on the Watt-hour demand of 3.8 kw. As a case study, a residence in Khartoum with low-energy consumption is selected.

Description: Studies on quality of life can contribute to a better understanding of situations where socioenvironmental transformations are evident, from environmental, social, cultural, and political perspectives. This paper analyzes the quality of life of the inhabitants of the Moinho rural settlement in the context of the surrounding conditions of environmental degradation. Moinho is located in Nazaré Paulista municipality, which belongs to the Cantareira System Environmental Protected Area (Cantareira EPA), state of São Paulo, Brazil. The methodology used was based on secondary data collection and interviews with local residents. The results explore the interface between the transformation of land use and the growing change of rural life that are greatly influenced by expanding urban sprawl in the region. Over recent decades, changes in the production systems, substitution of agriculture crops, and the impacts of these variables on environmental health and water availability, as well as damage to the Municipal Human Development Index (HDI-M) of its municipalities, are indicators of the region’s present social complexity. This study shows that an improvement in the quality of life has an intimate relationship with the creation of sustainable economic activities and the real participation of the local population in decision making processes.

Description: GPS-dependent positioning, navigation, and timing synchronization procedures have a significant impact on everyday life. Therefore, such a widely used system increasingly becomes an attractive target for illicit exploitation by terrorists and hackers for various motives. As such, spoofing and antispoofing algorithms have become an important research topic within the GPS discipline. This paper will provide a review of recent research in the field of GPS spoofing/anti-spoofing. The vulnerability of GPS to a spoofing attack will be investigated and then different spoofing generation techniques will be discussed. After introducing spoofing signal model, a brief review of recently proposed anti-spoofing techniques and their performance in terms of spoofing detection and spoofing mitigation will be provided. Limitations of anti-spoofing algorithms will be discussed and some methods will be introduced to ameliorate these limitations. In addition, testing the spoofing/anti-spoofing methods is a challenging topic that encounters some limitations due to stringent emission regulations. This paper will also provide a review of different test scenarios that have been adopted for testing anti-spoofing techniques.

Description: Location awareness is a key enabling feature and fundamental challenge in present and future wireless networks. Most existing localization methods rely on existing infrastructure and thus lack the flexibility and robustness necessary for large ad hoc networks. In this paper, we build upon SPAWN (sum-product algorithm over a wireless network), which determines node locations through iterative message passing, but does so at a high computational cost. We compare different message representations for SPAWN in terms of performance and complexity and investigate several types of cooperation based on censoring. Our results, based on experimental data with ultra-wideband (UWB) nodes, indicate that parametric message representation combined with simple censoring can give excellent performance at relatively low complexity.

Description: Owing to their complimentary characteristics, global positioning system (GPS) and inertial navigation system (INS) are integrated, traditionally through Kalman filter (KF), to obtain improved navigational solution. To reduce the overall cost of the system, microelectromechanical system- (MEMS-) based INS is utilized. One of the approaches is to reduce the number of low-cost inertial sensors, decreasing their error contribution which leads to a reduced inertial sensor system (RISS). This paper uses KF to integrate GPS and 3D RISS in a loosely coupled fashion to enhance navigational solution while further improvement is achieved by augmenting it with map matching (MM). The 3D RISS consists of only one gyroscope and two accelerometers along with the vehicle’s built-in odometer. MM limits the error growth during GPS outages by restricting the predicted positions to the road networks. The performance of proposed method is compared with KF-only 3D RISS/GPS integration to demonstrate the efficacy of the proposed technique.

Description: Indoor navigation is challenging due to unavailability of satellites-based signals indoors. Inertial Navigation Systems (INSs) may be used as standalone navigation indoors. However, INS suffers from growing drifts without bounds due to error accumulation. On the other side, the IEEE 802.11 WLAN (WiFi) is widely adopted which prompted many researchers to use it to provide positioning indoors using fingerprinting. However, due to WiFi signal noise and multipath errors indoors, WiFi positioning is scattered and noisy. To benefit from both WiFi and inertial systems, in this paper, two major techniques are applied. First, a low-cost Reduced Inertial Sensors System (RISS) is integrated with WiFi to smooth the noisy scattered WiFi positioning and reduce RISS drifts. Second, a fast feature reduction technique is applied to fingerprinting to identify the WiFi access points with highest discrepancy power to be used for positioning. The RISS/WiFi system is implemented using a fast version of Mixture Particle Filter for state estimation as nonlinear non-Gaussian filtering algorithm. Real experiments showed that drifts of RISS are greatly reduced and the scattered noisy WiFi positioning is significantly smoothed. The proposed system provides smooth indoor positioning of 1 m accuracy 70% of the time outperforming each system individually.

Description: This paper studies the implementation of a novel wireless local positioning system (WLPS) for spacecraft formation flying to maintain high-performance spacecraft relative and absolute position estimation. A WLPS equipped with antenna arrays allows each spacecraft to measure the relative range and coordinate angle(s) of other spacecraft located in its coverage area. The dynamic base station and the transponder of WLPS enable spacecraft to localize each other in the formation. Because the signal travels roundtrip in WLPS, and due to the high spacecraft velocities, the signal transmission time delay reduces the localization performance. This work studies spacecraft formation positions estimation performance assuming that only WLPS is available onboard. The feasibility of estimating the spacecraft absolute position using only one-dimensional antenna array is also investigated. The effect of including GPS measurements in addition to WLPS is studied and compared to a GPS standalone system.

Description: This paper presents a sequential fault detection and identification algorithm for detecting a fault in a vehicle's ultrasonic parking sensors. The algorithm identifies a bias fault in any of the ultrasonic sensors by computing the probability of having that bias fault given a carefully constructed measurement residual that is only a function of the measurement noise and the possible measurement fault. A set of bias hypotheses is assumed and initially given equal alarm probability. It is assumed that only one sensor will acquire a bias at any given time. Once the probability of a hypothesis approaches 1, that hypothesis is declared as the correct hypothesis and the bias associated with the hypothesis is removed from the sensors' reading. The accuracy and convergence characteristics of the proposed algorithm are verified using experimental results. This study is essential to ensure accurate operation of vehicle's ultrasonic parking sensors.

Description: This paper presents an algorithm for the classification of targets based on the fusion of the class information provided by different imaging sensors. The outputs of the different sensors are combined to obtain an accurate estimate of the target class. The performance of each imaging sensor is modelled by means of its confusion matrix (CM), whose elements are the conditional error probabilities in the classification and the conditional correct classification probabilities. These probabilities are used by each sensor to make a decision on the target class. Then, a final decision on the class is made using a suitable fusion rule in order to combine the local decisions provided by the sensors. The overall performance of the classification process is evaluated by means of the “fused” confusion matrix, i.e. the CM pertinent to the final decision on the target class. Two fusion rules are considered: a majority voting (MV) rule and a maximum likelihood (ML) rule. A case study is then presented, where the developed algorithm is applied to three imaging sensors located on a generic air platform: a video camera, an infrared camera (IR), and a spotlight Synthetic Aperture Radar (SAR).

Description: The term inertial navigation is often automatically associated with the term initial value problem. However, there are many applications where it is possible to end up with a boundary value problem (BVP) as well. We show that in case of a BVP, the finite element method that incorporates boundary conditions can be efficiently used to compute position and velocity estimates not prone to accumulation of errors. For further accuracy enhancements, a method of combining inertial measurements with additional constraints is proposed. This way, we can model sensor errors, known to limit the accuracy of the system. The capabilities of the proposed methods are demonstrated with real-life examples.

Description: As part of the GPS modernization, the GPS L1 C/A signal will be augmented by the L1C signal. With this improvement, for the first time, several signals from the same constellation will be available at the same frequency. In this paper, an acquisition method is implemented to combine the GPS L1 C/A and L1C signals before correlation. The combined acquisition succeeds to acquire the signal at low C/N0, whereas the acquisition of the L1C data channel alone fails. Concerning the tracking, a method to combine the GPS L1 C/A and L1C signals before the discriminator is developed. This method shows better performance than the traditional tracking using only one signal. Finally, a Kalman filter to combine the signals in the tracking is developed. It shows better performance than the traditional tracking in all conditions. Since the L1C signal will not be broadcast before 2013, these methods are tested using a software signal simulator.

Description: A real-time algorithm to detect, determine, and validate the cycle-slips for triple-frequency GPS is proposed. The cycle-slip detection is implemented by simultaneously applying two geometry-free phase combinations in order to detect more insensitive cycle-slips, and it is applicable for high data rate applications. The cycle-slip determination adaptively uses the predicted phase data and the code data. LAMBDA technique is applied to search for the cycle-slip candidates. The cycle-slip validation provides strict test criteria to identify the cycle-slip candidates under low phase noise. The reliability of the proposed algorithms is tested in different simulated scenarios.

Description: The carrier-phase-derived delta pseudorange measurements are often used for velocity determination. However, it is a type of integrated measurements with errors strongly related to pseudorange errors at the start and end of the integration interval. Conventional methods circumvent these errors with approximations, which may lead to large velocity estimation errors in high-dynamic applications. In this paper, we employ the extra states to “remember” the pseudorange errors at the start point of the integration interval. Sequential processing is employed for reducing the processing load. Simulations are performed based on a field-collected UAV trajectory. Numerical results show that the correct handling of errors involved in the delta pseudorange measurements is critical for high-dynamic applications. Besides, sequential processing can update different types of measurements without degrading the system estimation accuracy, if certain conditions are met.

Description: The upcoming Galileo global navigation satellite system has a design problem with the cosine-phased BOCc(15, 2.5) modulation of its Public Regulated Service (PRS A-code). This signal needs far more bandwidth than the available 40.92 MHz. The present signal and system specification cannot be expected to deliver design performance under practical operational conditions (noise, receiver phase distortion, and multipath). There would not have been this problem with sine-phased BOC(15, 2.5).

Description: The aim of this study is to analyze the urban land use changes occurred in the central part of Ulaanbaatar, the capital city of Mongolia, from 1930 to 2008 with a 10-year interval using geographical information system (GIS) and very high-resolution remote sensing (RS) data sets. As data sources, a large-scale topographic map, panchromatic and multispectral Quickbird images, and TerraSAR synthetic aperture radar (SAR) data are used. The primary urban land use database is developed using the topographic map of the study area and historical data about buildings. To extract updated land use information from the RS images, Quickbird and TerraSAR images are fused. For the fusion, ordinary and special image fusion techniques are used and the results are compared. For the final land use change analysis and RS image processing, ArcGIS and Erdas imagine systems installed in a PC environment are used. Overall, the study demonstrates that within the last few decades the central part of Ulaanbaatar city is urbanized very rapidly and became very dense.

Description: Motion detection in the fly is extremely fast with low computational requirements. Inspired from the fly's vision system, we focus on a real-time flight control on a miniquadrotor with fast visual feedback. In this work, an elaborated elementary motion detector (EMD) is utilized to detect local optical flow. Combined with novel receptive field templates, the yaw rate of the quadrotor is estimated through a lookup table established with this bioinspired visual sensor. A closed-loop control system with the feedback of yaw rate estimated by EMD is designed. With the motion of the other degrees of freedom stabilized by a camera tracking system, the yaw-rate of the quadrotor during hovering is controlled based on EMD feedback under real-world scenario. The control performance of the proposed approach is compared with that of conventional approach. The experimental results demonstrate the effectiveness of utilizing EMD for quadrotor control.

Description: Global position system (GPS) is being widely used in land vehicles to provide positioning information. However, in urban canyons, rural tree canopies, and tunnels, the GPS satellite signal is usually blocked and there is an interruption in the positioning information. To obtain positioning solution during GPS outages, GPS can be augmented with an inertial navigation system (INS). However, the utilization of full inertial measurement unit (IMU) in land vehicles could be quite expensive despite the use of the microelectromechanical system (MEMS)-based sensors. Contemporary research is focused on reducing the number of inertial sensors inside an IMU. This paper explores a multisensor system (MSS) involving single-axis gyroscope and an odometer to provide full 2D positioning solution in denied GPS environments. Furthermore, a Kalman filter (KF) model is utilized to predict and compensate the position errors of the proposed MSS. The performance of the proposed method is examined by conducting several road tests trajectories using both MEMS and tactical grade inertial sensors. It was found that by using proposed MSS algorithm, the positional inaccuracies caused by GPS signal blockages are adequately compensated and resulting positional information can be used to steer the land vehicles during GPS outages with relatively small position errors.

Description: This paper deals with the spatial implications of the French sanitary policies in early colonial urban Senegal. It focuses on the French politics of residential segregation following the outbreak of the bubonic plague in Dakar in 1914, and their precedents in Saint Louis. These policies can be conceived as most dramatic, resulting in a displacement of a considerable portion of the indigenous population, who did not want or could not afford to build à l’européen, to the margins of the colonial city. Aspects of residential segregation are analysed here through the perspective of cultural history and history of colonial planning and architecture, in contrast to the existing literature on this topic. The latter dilates on the statutory policies of the colonial authorities facing the 1914 plague in Dakar, the plague's sociopolitical implications, and the colonial politics of public health there. In the light of relevant historiography, and a variety of secondary and primary sources, this paper exposes the contradictions that were inherent in the French colonial regime in West Africa. These contradictions were wisely used by the African agency, so that such a seemingly urgent segregationist project was actually never accomplished.

Description: Our study examines a nontraditional engagement process employed by the City of Seattle during neighborhood plan updates. Adapting the trusted advocates model from the public health field, the city hired planning outreach liaisons (POLs) from 13 diverse community groups to solicit input from traditionally underrepresented residents. To explore the efficacy of this approach, we collected data through interviews with residents, neighborhood leaders, community development firm employees, university researchers, and municipal staff; a review of planning documents; observation at planning meetings. We found that the POLs effectively engaged underrepresented groups—including more than 1,200 stakeholders—particularly those characterized as self-organized, centralized or having strong social networks and were important in the advancement of democratic principles. Greater transparency by the city about process goals and constraints, along with strategies to address power issues, may have facilitated better communication and relationship building among the city, newly enfranchised residents, and the “usual suspects.”

Description: The viability of traditional economic development strategies has long been questioned by urban policy scholars; yet traditional strategies remain the norm among city leaders. Traditional concerns emphasize economic and business considerations at the expense of nontraditional community considerations such as quality of life. In this paper, we examine the conditions under which city leaders give weight to nontraditional community concerns when making economic development decisions. Our analysis of the results of a survey conducted of more than 200 leaders in over 150 Texas cities indicates that although traditional economic development concerns remain dominant, certain conditions may exist that allow or compel city leaders to give increased weight to non-traditional community considerations. Conditions revealed by our study include the socioeconomic status of Texas cities and the relative differences in leadership positions and professionalism among city leaders. The paper concludes with a discussion of how our study contributes to the literature about economic development policy and points to avenues for future research on the conditions under which decision-making strategies are pursued by city leaders.

Description: Public housing advocates argue that the nation should expand the federal public housing program as part of an effort to increase the supply of affordable rental housing. This paper examines federal public housing construction in the largest US cities over the period 1937–1967, a period during which the public housing program was the primary program to provide low-income households with affordable rental housing. Public housing is found to depend upon the population level of the city, factors that characterize the housing stock as of 1950, the poverty level in the city, and the size of the nonwhite population in the city. The National Commission on Urban Problems (National commission on urban problems 1968, page 128) found that this supply response meant that “… the great need of the large central cities for housing for poor families was largely unmet.” Changes in racial segregation from 1940 to 1960 are found to be unrelated to public housing construction. While the current situation is different in many respects from circumstances of these earlier decades, a renewed effort to supply public housing might produce similar outcomes.

Description: The local and regional administrations of Valencia, Spain, have been working to position the city, which is the country's third largest in terms of population, as an international destination for luxury tourism through sports mega-events. Valencia's new image as a “mega-events city” has been criticized by citizens and urban-based movements on social and environmental grounds, resulting in various urban conflicts. The aim of this paper is to examine the causes and dynamics of these conflicts in order to understand the discourse and rationales behind the criticism. This will also include an examination of the ways in which these conflicts were managed by the local administration, especially in the months leading up to and during the events, when the city was receiving worldwide media coverage. Researching local print media, we focused on urban conflicts that took place in Valencia between 1995 and 2010. We also looked at the performance of urban-based movements and the administration as conflicting actors. One of the main findings was the strong consensual authoritarianism manifested by the administration and mega-event organizers when making decisions and managing urban conflicts related to mega-events.

Description: Between 2005 and 2007 there were 9071 traffic accidents involving bicycles within London and this paper demonstrates the utility of Geographic Information Systems as a tool for analysing and visualising these occurrences. Through linkage of these spatial locations to a street network dataset it was possible to create a variety of intelligence about the types of street infrastructure where accidents predominantly occur. Additionally, a network routing algorithm was adapted to account for the frequency of accidents within a series of proposed journeys. This pilot routing application compared the quickest route with an accident avoidance weighted route between a series of origins and destinations. The results demonstrated that the routes avoiding areas of high accident volume did not increase journey length significantly; however they did provide a “safer” route based on empirical evidence over the volume of accident locations.

Description: The object of discussion of the current paper is transformations of urban public spaces since Czarist Russia's colonial rule up to the period after the restoration of Lithuania's independence. While reviewing the transformations of public spaces (first and foremost squares) of the country's larger cities, the authors noted that this field is distinguished by extremely contradictory tendencies: on one hand, we are dealing with the urban legacy of previous regime as well as its impact on the “physiognomies” of Lithuanian cities as well as hurried often premature attempts to change the earlier function of public spaces simply by eliminating the symbols of Soviet ideology continued; on the other, a rapid campaign for creating new ideological symbols related to independence was launched, which often involved sacrificing the actual function of public spaces and the artistic quality of monuments. It is noted that similar processes took place in the earlier periods of history: whenever the repertoire of certain visual signs and symbols was exhausted, in urbanistic spaces it would be replaced with the visual symbols of the new era and a new structure of a public space. One more tendency of restructuring public spaces has recently become distinct: under the influence of interests of private capital, part of the former traditional city squares with monuments is being converted into parking lots or other uses changing their functions and meaning.

Description: Contextual research on adolescent offending is primarily based on the idea that residential areas provide a major ecological setting that (indirectly) shapes observed differences in adolescent offending. The social disorganisation/collective efficacy perspective has tried to explain why structural disadvantage of residential areas affects residents' involvement in offending. On the other hand, contextual research has also been conducted within the school setting. This separate contextual approach is problematic as it does not reflect the reality of adolescents' lives. Adolescents are exposed to different ecological settings. They are also exposed to many other settings that may provide opportunities to offend, as outlined in the situational action theory (SAT) of crime causation. This study contributes to the literature on the urban context of offending in three ways. First, the effects of adolescents' residential neighbourhood and school context on adolescent offending are assessed simultaneously. Second, this study elaborates on SAT from a cross-level point of view. Third, this contribution makes use of non-hierarchical multilevel modelling, which is a statistically correct method of testing hypotheses that involve multiple contexts. Our study revealed the existence of small contextual effects of school-level disadvantage, whereas the effect of neighbourhood-level disadvantage is entirely due to neighbourhood composition.

Description: This paper investigates the impact of anthropogenic heat on formation of urban heat island (UHI) and also determines which factors can directly affect energy use in the city. It explores literally the conceptual framework of confliction between anthropogenic heat and urban structure, which produced UHI intensity and affected energy consumption balance. It then discusses how these two factors can be affected and gives implication to the city and then focuses on whether actions should be taken for balancing adaptation and mitigation of UHI effects. It will be concluded by making the three important strategies to minimise the impact of UHI on energy consumption: landscaping, using albedo materials on external surfaces of buildings and urban areas, and promoting natural ventilation.

Description: In agreement with Nested City theory, this paper illustrates how Japan's municipal hierarchy has evolved and remained embedded within that nation's particular historical-political-economic context. It chronicles how municipalities have attained status based upon the role they have played in the country's political, economic, and military history, and, more recently, their population size. It then shows how during the post-war period, the tiers within this urban stratification system were expanded and institutionalized by national laws governing municipalities. Drawing upon more than 100 interviews with local government officials in nine prefectures, it then reveals how a shift in national policy toward decentralization in the late-1990s sparked a race for higher municipal status in Japan's national hierarchy, during the 2000s, and thereby, local power.

Description: Since the 1990s, the intensification of capital accumulation, especially in its financial dimension, has been one of the keystones for the triumph of neoliberalism. Spanish neoliberal policies have focused on the flexibilization of the real estate sector, leading to the specialization in the secondary circuit of accumulation. This has generated a third real estate boom which has been accompanied with an outstanding housing bubble. The Balearic Islands are a paradigmatic case within these logics, tourist specialization being the main trigger of the process. In Palma, the region's capital, neoliberal urban planning policies have been implemented in order to convert it into a “successful city” within the global urban network competition. These policies have led to Palma's uneven geographical development through processes like gentrification, as is the case of the Gerreria, a neighborhood of Palma's city center.

Description: The prevalence of witnessed community violence (WCV) amongst urban populations in the USA is striking. WCV can be harmful to one's psychological health, and for mothers, the consequences may be more far-reaching as their mental health affects parenting and child development. This study used telephone interviews (n = 209) to explore the patterns and covariates of WCV amongst a sample of urban, African American mothers of infants. Mothers reported whether they had witnessed 11 different forms of violence in their current neighborhoods. A latent class analysis revealed two distinct groups of mothers, those with higher versus lower-exposure to WCV. Mothers in the higher-exposure group were more likely to be low-income, to have a high school education or less, and to have higher anxiety scores than those in the lower-exposure group. Depression was not associated with higher exposure to WCV. Distinguishing between higher- and lower-exposure samples can inform the development of targeted prevention and intervention strategies for metropolitan areas.

Description: For many years, effective model-based representations of the dynamics and evolution of urban spatial structure have proved elusive. While some progress has been made through the deployment of spatial interaction models, these approaches have been limited by the difficulty of representing behavioural mechanisms and processes. In this paper, it is demonstrated that evolutionary models grounded in the principles of spatial interaction are compatible with the more novel approaches of agent-based modelling. The incorporation of agents provides a much more flexible means for the representation of behavioural mechanisms. The paper illustrates the way in which three more complicated situations can be handled through the fusion of spatial interaction and agent modelling perspectives. These situations comprise discontinuous evolution (in which structural adjustment takes place in discrete steps, and not as a continuously smooth process); nonequilibrium dynamics (in which the underlying system parameters continue to evolve through time); the incorporation of new decision variables (which we illustrate through the addition of land rents into the model). The conclusion of the paper is that the combination of spatial interaction and agent-based modelling methods provides encouraging prospects for the social simulation of real urban systems.

Description: The purpose of this paper is to assess the classical theoretical propositions of Wirth and Stouffer regarding the independent impact of urban and suburban residency on beliefs about racial inequality. This paper further assesses the impacts of these social locations over a three-decade period. While scholars pose that city size positively impacts behavior, there is debate regarding the impact of these locations over time. Using the General Social Survey, findings demonstrate that while urbanism continues to have an independent impact on beliefs, the impact of suburban residency is much weaker and inconsistent. Analyses of over time trends reveal that the gap between urban and rural residents appears to have increased, with rural residents expressing more intolerant beliefs about the causes of racial inequality over time. These findings are further discussed in a broader theoretical context.

Description: This paper analyzes the governance strategy of the 22@ District in Barcelona in order to assess the factors that explain its success and could support the economic reconversion of Montreal’s future Innovation District (ID), as well as that of other cities. We examine the case of the 22@ District as a former industrial neighbourhood seen as a “model” of urban regeneration and economic revitalization. Our assumption is that the world’s major cities are going through a phase based on the reorganization of central urban areas. Our article evaluates the main factors of urban regeneration in the 22@—district of innovation and it identifies elements of best practices in terms of governance which can be constructive for the “Quartier de l’Innovation” in Montreal and similar projects of other cities. The paper highlights the role of decision makers concerning the process of governance of 22@ and its historic changes, and insists on the the role of socioeconomic actors and territorial factors that could support the level of integration and implementation of Montreal@ID. Our paper highlights the importance of the integration process based on socio-territorial innovations characterizing the Catalan context of 22@ as well as the Innovation District, something useful for other similar initiatives.

Description: We analyse architects and nonarchitects' emotional assessments of different districts in their own city (Valencia, Spain) by applying Kansei engineering techniques. A field study was carried out on a sample of 140 subjects (70 architects and 70 nonarchitects) who were asked to express their opinions on different areas in the city. The set of emotional impressions used by architects and non-architects to describe their sensations was obtained using differential semantics. The semantic space was described by 9 independent axis which explained 62% of the variability. Then, for each collective the set of impressions which influence the final residential or investment area decision was analysed. This relationship was obtained applying linear regression models. The results showed no significant differences between both groups so that the emotional attributes determining the choice of area were very similar for architects and non-architects. Greater discrepancies were found when the purpose of the choice was investment and not residential. Finally a neighbourhood was semantically profiled to represent and compare both collectives' perceptions.

Description: One of the most promising features of the modernized global navigation satellite systems signals is the presence of pilot channels that, being data-transition free, allow for increasing the coherent integration time of the receivers. Generally speaking, the increased integration time allows to better average the thermal noise component, thus improving the postcorrelation SNR of the receiver in the acquisition phase. On the other hand, for a standalone receiver which is not aided or assisted, the acquisition architecture requires that only the pilot channel is processed, at least during the first steps of the procedure. The aim of this paper is to present a detailed investigation on the impact of the code cross-correlation properties in the reception of Galileo E1 Open Service and GPS L1C civil signals. Analytical and simulation results demonstrate that the S-curve of the code synchronization loop can be affected by a bias around the lock point. This effect depends on the code cross-correlation properties and on the receiver setup. Furthermore, in these cases, the sensitivity of the receiver to other error sources might increase, and the paper shows how in presence of an interfering signal the pseudorange bias can be magnified and lead to relevant performance degradation.

Description: Recent research has elucidated the role of talents to explain urban growth differences but it remains to be shown whether urban dynamics, such as human capital and a mixed local population, can be linked to intraurban employment growth. By use of a unique longitudinal database, we track the economic development through the lens of intraurban employment growth of a number of primary urban areas (PUA) in Göteborg, Sweden. Regarding factors influencing employment growth, we find that relative concentrations of human capital protect areas from rising unemployment during severe recession (1990–1993) and recovery (1990–2000) while the composition of skills is beneficial during recovery (1990–2000) and long-term growth (1990–2008). Our findings suggest that neither too high concentrations of creative occupations nor too low ones are beneficial. Thus, human capital drives much of the employment changes in relation to the recession and early transition from manufacturing to service but composition of skills is more relevant for explaining long-term intraurban employment growth.

Description: Radio frequency interference detection and mitigation are becoming of paramount importance due to the increasing number of services and applications based on the position obtained by means of Global Navigation Satellite Systems. A way to cope with such threats is the implementation in the receiver of advanced signal processing algorithm able to raise proper warning or improve the receiver performance. In this paper, we propose a method based on the Wavelet Transform able to split the useful signal from the interfering component in a transformed domain. The wavelet packet decomposition and proper statistical thresholds allow the algorithm to show very good performance in case of multiple pulse interference as well as in the case of narrowband interference, two scenarios in which traditional countermeasures might not be effective.

Description: Neighborhood income and social capital are considered important for child development, but social capital has rarely been measured directly at an aggregate level. We used Canadian data to derive measures of social capital from aggregated parental judgments of neighborhood collective efficacy and neighborhood safety. Measures of neighborhood income came from Census data. Direct measures of preschoolers’ school readiness were predicted from neighborhood-level variables, with regional indicators and household/parental characteristics taken into account. Our findings show that (1) residing in Quebec, being Black, and having a parent who was born outside Canada are positively associated with children’s living in disadvantaged or low collective efficacy neighborhoods as well as with their living in low-income households. (2) Children’s odds of residential mobility were reduced when the origin neighborhood had higher collective efficacy but increased when the family rented rather than owned. (3) Both neighborhood collective efficacy and children’s ever having lived in a poor neighborhood were correlated with receptive vocabulary scores, but results were mixed for other cognitive dimensions. Children of younger mothers scored worse on receptive vocabulary. There were similar patterns for demographic predictors related to visible minority status, sibship size, and birth order. Neighborhood average income had no effect on cognitive outcomes when the region was controlled.

Description: A three-dimensional matrix method is proposed in this paper for Global Navigation Satellite System (GNSS) constellation Intrasatellite Link (ISL) topological design. The rows and columns of proposed matrix contain the information of both constellation orbit planes and satellites in each orbit plane. The third dimension of proposed matrix represents the time sequences during constellation movement. The proposed method has virtues of better advantage of conceptual clarity and computational efficiency, meanwhile, some properties of ISLs in the constellation can be proved easily. At the second part of this paper, a link assignment and optimal routing problem is proposed using three-dimensional topology matrixes, which aimed to minimize the relay hops during the process of data uploading to whole constellation network. Moreover, some practical constrains as antenna beam coverage and relative velocity are considered and analyzed in detail. Finally, some numerical simulations are provided, and the results demonstrated the promising performance of proposed topological method in reduction of computation burden, clear ISL conception, and so forth; the efficiency of provided optimal ISL routing problem is also proved.

Description: The middle of 2007 saw the beginning of a worldwide financial crisis that led to a sharp reduction in investment based on construction and urban development. This new situation is generating a new process, characterised by a slowdown that has almost reached a standstill when compared with the frenzied development of previous decades. In order to analyse these processes, this study examines urban land use changes and the urban growth rate and spatial dynamics of the metropolitan region of Madrid. The analysis has been carried out on a large scale between two periods (2000–2006 and 2006–2009) using a regional land use geodatabase. The results show the changes in the urban land use dynamics that took place over these two periods that could characterise the cities of Mediterranean Europe, where contrarily to the general pattern in Europe built-up areas are combining scattered built-up areas with new aggregated compact developments.

Description: This paper examines the dynamics of economic change in the City of Paterson, New Jersey, from the time of its founding in the late eighteenth century to 1990, with emphasis on the post-1945 era. Analysis shows that from the time of its founding to the first half of the twentieth century, Paterson experienced a period of economic growth followed by economic decline in the 1960s, characterized by major changes in its principal industries of cotton, locomotives, and silk. Economic growth in Paterson up to the early part of the twentieth century is attributable to several locational factors, including the availability of water resources, transportation, labor supply, and markets. Its decline in the post-1945 era is attributable to a combination of local, national, and global economic factors including periods of depression, labor discord, product substitution, decentralization of economic activities, and deindustrialization. Economic decline resulted in a high rate of unemployment, poverty, and urban decay. The most significant effort to reverse urban decline in the city is the urban enterprise zone (UEZ) program. The impacts of this program on economic growth in the city, however, remain inconclusive.

Description: The procedure of determining the initial values of the attitude angles (pitch, roll, and heading) is known as the alignment. Also, it is essential to align an inertial system before the start of navigation. Unless the inertial system is not aligned with the vehicle, the information provided by MEMS (microelectromechanical system) sensors is not useful for navigating the vehicle. At the moment MEMS gyroscopes have poor characteristics and it’s necessary to develop specific algorithms in order to obtain the attitude information of the object. Most of the standard algorithms for the attitude estimation are not suitable when using MEMS inertial sensors. The wavelet technique, the Kalman filter, and the quaternion are not new in navigation data processing. But the joint use of those techniques for MEMS sensor data processing can give some new results. In this paper the performance of a developed algorithm for the attitude estimation using MEMS IMU (inertial measurement unit) is tested. The obtained results are compared with the attitude output of another commercial GPS/IMU device by Xsens. The impact of MEMS sensor measurement noises on an alignment process is analysed. Some recommendations for the Kalman filter algorithm tuning to decrease standard deviation of the attitude estimation are given.

Description: This study explores urban planning office and community influence on land-use decision making in two poverty-stricken but redeveloping neighborhood areas in Chicago. The Department of Planning and Development in this study had marginal impact on land-use decisions due to administrative limitations. Community influence is moderated by the degree to which low-income housing advocates can act directly as developers and produce housing units. The research findings indicate that land-use decisions intended to benefit the low-income resulted not from community-based political conflict but more so from community organization cooperation with political actors.

Description: This paper offers a critical review and interpretation of gentrification in Latin American cities. Applying a flexible methodology, it examines enabling conditions associated with societal regime change and local contingencies to determine its presence, nature, extent, and possibilities. Questioning the uncritical transfer of constructs such as gentrification from the Global North to the Global South, the paper advocates analyses of mediating structures and local conditions to determine their applicability and possible variations. Overall, the review questions the feasibility of self-sustained, large scale gentrification in central areas of the region’s cities today tying it to each city’s level of incorporation into global circuits and the role of local governments. Rather than an orthodox hypothesis testing, this is an exercise in interpretation that calls for nuanced approaches to the study of urban restructuring in cities of the global South.

Description: Vehicle navigation systems usually simply function by calculating the shortest fastest route over a road network. In contrast, pedestrian navigation can have more diverse concerns. Pedestrians are not constrained to road/path networks; their route may involve going into buildings (where accurate satellite locational signals are not available) and they have different priorities, for example, preferring routes that are quieter or more sheltered from the weather. In addition, there are differences in how people are best directed: pedestrians noticing landmarks such as buildings, doors, and steps rather than junctions and sign posts. Landmarks exist both indoors and outdoors. A system has been developed that uses quick response (QR) codes affixed to registered landmarks allowing users to localise themselves with respect to their route and with navigational instructions given in terms of these landmarks. In addition, the system includes images of each landmark helping users to navigate visually in addition to through textual instructions and route maps. The system runs on a mobile device; the users use the device’s camera to register each landmark’s QR code and so update their position (particularly indoors) and progress through the route itinerary.

Description: The GNSS measurements are strongly affected by ionospheric effects, due to the signal propagation through ionosphere; these effects could severely degrade the position; hence, a model to limit or remove the ionospheric error is necessary. The use of several techniques (DGPS, SBAS, and GBAS) reduces the ionospheric effect, but implies the use of expensive devices and/or complex architectures necessary to meet strong requirements in terms of accuracy and reliability for safety critical application. The cheapest and most widespread GNSS devices are single frequency stand-alone receivers able to partially correct this kind of error using suitable models. These algorithms compute the ionospheric delay starting from ionospheric model, which uses parameters broadcast within the navigation messages. NeQuick is a three-dimensional and time-dependent ionospheric model adopted by Galileo, the European GNSS, and developed by International Centre for Theoretical Physics (ICTP) together with Institute for Geophysics, Astrophysics, and Meteorology of the University of Graz. The aim of this paper is the performance assessment in single point positioning of the NeQuick Galileo version provided by ESA and the comparison with respect to the Klobuchar model used for GPS; the analysis is performed in position domain and the errors are examined in terms of RMS and maximum error for the horizontal and vertical components. A deep analysis is also provided for the application of the exanimated model in the first possible Galileo only position fix.

Description: In this investigation, we ascertained the extent to which differences were present in dual credit enrollment by gender and by ethnicity for students () enrolled in a Texas community college from the 2005-2006 through the 2011-2012 academic years. Statistical analyses revealed an increase in the numbers (i.e., from 3,069 to 3,664) and percentages (i.e., from 12.2% to 19.5%) of students who were enrolled in dual credit courses over the time period analyzed. Moreover, higher percentages of women (i.e., 20.8% in the most recent academic year) had enrolled in dual credit courses while in high school than men (i.e., 17.9% in the most recent academic year). Differences were also present as a function of ethnicity, with 33.1% Asian, 25.3% White, 17.4% Hispanic, and 7.5% Black students having been enrolled in dual credit in the most recent academic year. Differences were also revealed by gender for Hispanic and White students, but not for Asian and Black students. Implications of our findings are discussed.

Description: To inform a city-wide youth Violence Prevention Initiative, we explored youth narratives about their exposure to violence to gain insight into their understanding of the causes and effects of violence in their communities. At-risk youth were recruited through street outreach for individual interviews and focus group sessions. Types of experiential violence identified included (1) street, (2) family/interpersonal, (3) school, (4) indirect exposure (e.g., neighborhood crime), and (5) prejudice/discrimination. Reactions ranged from motivating positive effects (resilience, determination to escape) to negative effects (fear, paranoia, and aggression). For some, experiences with violence motivated them to pursue educational achievement and positive lifestyles. Causes of violence were described by participants as existing at a number of different levels (societal, neighborhood, interpersonal, and individual), reflecting a social-ecological perspective. Our findings highlight a need for violence prevention efforts that focus on a broad definition of violence, as well as on the poly-victimization of children and youth. At the same time, our findings highlight the challenges of conducting effective community-based prevention programs in urban settings characterized by spatial inequalities and social exclusion of community residents.

Description: Electric wheelchair is one of the many engines used for the movement of aged and disabled people. This paper introduces an obstacle avoidance using deformable virtual zone (DVZ), particle filter to improve localization and fuzzy controller to join desired target. This controller is developed to increase the independence of disabled and aged people, specifically those who suffer not only disability in the lower limbs but also visual disturbances. To overcome these problems, different perceptive abilities or sensors were introduced. In this context, we developed a control system composed by fuzzy controller to join a target, DVZ method for obstacle avoidance, and particle filter for localization. Also, we present the simulation results of the wheelchair navigation system.

Description: Bursa is one of the cities with high disaster risk and a quality housing problem in Turkey. Urban transformation activities are carried out in order to improve quality of life and create safe living spaces for sustainable urban development. Quality housing production does not signify merely a need to be satisfied quantitatively. Housing and its environment, where physical and social needs of the users are satisfied, should be designed considering local conditions and in a way that they will be suitable for users’ life styles and cultural habits. In this study, the selected study area comprises neighborhoods which are under disaster risk, have been determined as urban transformation areas, and have residents with similar socioeconomic characteristics. With the purpose of improving user satisfaction, this study investigates users’ experience with physical, social, and cultural features of housing and its environment, which identify the quality of housing, and their preferences of new housing units to be produced. Nonprobability sampling method was selected for the field study, and a survey study was conducted. SPSS 17.0 (Statistical Package for Social Sciences) was employed for data entry. In order to generate data for quality housing production, relationships between variables were analyzed with Pearson chi-square test.

Description: Satellite navigation is critical in signal-degraded environments where signals are corrupted and GNSS systems do not guarantee an accurate and continuous positioning. In particular measurements in urban scenario are strongly affected by gross errors, degrading navigation solution; hence a quality check on the measurements, defined as RAIM, is important. Classical RAIM techniques work properly in case of single outlier but have to be modified to take into account the simultaneous presence of multiple outliers. This work is focused on the implementation of random sample consensus (RANSAC) algorithm, developed for computer vision tasks, in the GNSS context. This method is capable of detecting multiple satellite failures; it calculates position solutions based on subsets of four satellites and compares them with the pseudoranges of all the satellites not contributing to the solution. In this work, a modification to the original RANSAC method is proposed and an analysis of its performance is conducted, processing data collected in a static test.

Description: This paper examines the dynamics of economic change in the City of Paterson, New Jersey, from the time of its founding in the late eighteenth century to 1990, with emphasis on the post-1945 era. Analysis shows that from the time of its founding to the first half of the twentieth century, Paterson experienced a period of economic growth followed by economic decline in the 1960s, characterized by major changes in its principal industries of cotton, locomotives, and silk. Economic growth in Paterson up to the early part of the twentieth century is attributable to several locational factors, including the availability of water resources, transportation, labor supply, and markets. Its decline in the post-1945 era is attributable to a combination of local, national, and global economic factors including periods of depression, labor discord, product substitution, decentralization of economic activities, and deindustrialization. Economic decline resulted in a high rate of unemployment, poverty, and urban decay. The most significant effort to reverse urban decline in the city is the urban enterprise zone (UEZ) program. The impacts of this program on economic growth in the city, however, remain inconclusive.

Description: The researchers developed an instrument for measuring student housing quality (SHQ) in Higher Institutions of Learning (HIL) in Ghana. The paper sought to validate the student housing quality scale (SHOQUAL) through factor analysis approach. 700 respondents were sampled from two public HIL in Ghana in a cross-sectional survey that used a self-administered structured questionnaire for data collection. Confirmatory factor fnalysis (CFA) was conducted to detect the underlying latent variables that significantly determine SHQ in Ghanaian HIL. The findings indicate that four emerged SHQ dimensions relevant to the research context were labelled as follows: core facility quality, enabling facility quality, support facility quality, and cost of housing. The constructs in the derived model possess high reliability and validity. Student housing service providers could conveniently use the derived instrument items for measuring SHQ in HIL. Implications are discussed and limitations are noted. The paper contributes to the literature in the areas of models of service quality in student housing management in HIL.

Description: The time model of Beidou satellite clocks is analyzed. The general relations of satellite clocks with the system time are studied. The error sources of two-way radio time transfer between satellites and uplink stations are analyzed. The uncertainty of type A is about 0.3 ns in Beidou system. All the satellite clocks in orbit of Beidou satellite navigation system are evaluated by the clock offsets observed by the two-way radio time transfer. The frequency stabilities at a sample time of 10000 s and 1 day for all the satellite clocks are better than . It means that the performance of Beidou satellite clocks in orbit is consistent with the ground test, and the results in orbit are a little better than those in ground vacuum.

Description: This paper presents an extended Kalman filter-based hybrid indoor position estimation technique which is based on integration of fingerprinting and trilateration approach. In this paper, Euclidian distance formula is used for the first time instead of radio propagation model to convert the received signal to distance estimates. This technique combines the features of fingerprinting and trilateration approach in a more simple and robust way. The proposed hybrid technique works in two stages. In the first stage, it uses an online phase of fingerprinting and calculates nearest neighbors (NN) of the target node, while in the second stage it uses trilateration approach to estimate the coordinate without the use of radio propagation model. The distance between calculated NN and detective access points (AP) is estimated using Euclidian distance formula. Thus, distance between NN and APs provides radii for trilateration approach. Therefore, the position estimation accuracy compared to the lateration approach is better. Kalman filter is used to further enhance the accuracy of the estimated position. Simulation and experimental results validate the performance of proposed hybrid technique and improve the accuracy up to 53.64% and 25.58% compared to lateration and fingerprinting approaches, respectively.

Description: In this investigation, we ascertained the extent to which differences were present in dual credit enrollment by gender and by ethnicity for students () enrolled in a Texas community college from the 2005-2006 through the 2011-2012 academic years. Statistical analyses revealed an increase in the numbers (i.e., from 3,069 to 3,664) and percentages (i.e., from 12.2% to 19.5%) of students who were enrolled in dual credit courses over the time period analyzed. Moreover, higher percentages of women (i.e., 20.8% in the most recent academic year) had enrolled in dual credit courses while in high school than men (i.e., 17.9% in the most recent academic year). Differences were also present as a function of ethnicity, with 33.1% Asian, 25.3% White, 17.4% Hispanic, and 7.5% Black students having been enrolled in dual credit in the most recent academic year. Differences were also revealed by gender for Hispanic and White students, but not for Asian and Black students. Implications of our findings are discussed.

Description: The paper focuses on a navigation facility, relying on commercial-off-the-shelf (COTS) technology, developed to generate high-accuracy attitude and trajectory measurements in postprocessing. Target performance is cm-level positioning with tenth of degree attitude accuracy. The facility is based on the concept of GPS-aided inertial navigation but comprises carrier-phase differential GPS (CDGPS) processing and attitude estimation based on multiantenna GPS configurations. Expected applications of the system include: (a) performance assessment of integrated navigation systems, developed for general aviation aircraft and medium size unmanned aircraft systems (UAS); (b) generation of reference measurements to evaluate the flight performance of airborne sensors (e.g., radar or laser); and (c) generation of reference trajectory and attitude for improving imaging quality of airborne remote sensing data. The paper describes system architecture, selected algorithms for data processing and integration, and theoretical performance evaluation. Experimental results are also presented confirming the effectiveness of the implemented approach.

Description: The aim of our research was to examine how clusters appear and develop in the video game sector. We thus did a comparative study of the video games cluster in Montreal and Los Angeles. This paper shows that concentration of human creativity in arts and in technology is a significant economic localization factor, but cross-fertilization of sectors and public policy also contributes to the understanding of the emergence of clusters in certain urban regions. Thus, political and industrial factors offer an explanation as to why clusters emerge and how they evolve, going beyond the purely geographic or economic factors. In LA as in Montreal, the cross-fertilization with film is important. However, in Montreal, it is the public policy contributing to financing jobs in the Multimedia City and the French language that brought Ubisoft to the city; this contributed to make the city well known in the field, creating a “brand” for the city and thus fuelling the cluster development.

Description: Multiconstellation satellite navigation is critical in signal-degraded environments where signals are strongly corrupted. In this case, the use of a single GNSS system does not guarantee an accurate and continuous positioning. A possible approach to solve this problem is the use of multiconstellation receivers that provide additional measurements and allows robust reliability testing; in this work, a GPS/GLONASS combination is considered. In urban scenario, a modification of the classical RAIM technique is necessary taking into account frequent multiple blunders. The FDE schemes analysed are the “Observation Subset Testing,” “Forward-Backward Method,” and “Danish Method”; they are obtained by combining different basic statistical tests. The considered FDE methods are modified to optimize their behaviour in urban scenario. Specifically a preliminary check is implemented to screen out bad geometries. Moreover, a large blunder could cause multiple test failures; hence, a separability index is implemented to avoid the incorrect exclusion of blunder-free measurements. Testing the RAIM algorithms of GPS/GLONASS combination to verify the benefits relative to GPS only case is a main target of this work too. The performance of these methods is compared in terms of RMS and maximum error for the horizontal and vertical components of position and velocity.

Description: This paper presents principles and praxis of sustainable approach to maintaining targeted “residential regeneration by density” yet achieving innovations in urban form in a contextual scenario of Dhaka City, the capital of Bangladesh. It is evident from the context that Dhaka is experiencing a dramatic transformation in residential density due to demographic changes during the past two decades due the concentration of social, administrative, institutional, recreational, small-scale industries, and associated housing facilities. The transformation is visible in residential built footprint, significantly due to the demand-driven and density-led market, originated from low rise and low density and transforming to high density high rise. This transformation has been consistently threatening social and environmental realm indicated by depletion of garden houses; reduction of public parks; shrinking walkways; deletion of setback for ventilation and sun shade from trees; slowing down mobility; and obstruction of physical and visual permeability. The paper discussed a pragmatic approach that professionals have adopted to control the density and to introduce scopes for innovative urban forms by way of applying floor area ratio (FAR) methods and further discusses the merits of the methodological process of exercising morphology with a set of new building rules without undermining the market demand.

Description: A simple approach to gyro and accelerometer bias estimation is proposed. It does not involve Kalman filtering or similar formal techniques. Instead, it is based on physical intuition and exploits a duality between gimbaled and strapdown inertial systems. The estimation problem is decoupled into two separate stages. At the first stage, inertial system attitude errors are corrected by means of a feedback from an external aid. In the presence of uncompensated biases, the steady-state feedback rebalances those biases and can be used to estimate them. At the second stage, the desired bias estimates are expressed in a closed form in terms of the feedback signal. The estimator has only three tunable parameters and is easy to implement and use. The tests proved the feasibility of the proposed approach for the estimation of low-cost MEMS inertial sensor biases on a moving land vehicle.

Description: Vehicle-to-vehicle relative navigation of a network of vehicles travelling in an urban canyon is assessed using least-squares and Kalman filtering covariance simulation techniques. Between-vehicle differential GPS is compared with differential GPS augmented with between-vehicle ultrawideband range and bearing measurements. The three measurement types are combined using both least-squares and Kalman filtering to estimate the horizontal positions of a network of vehicles travelling in the same direction on a road in a simulated urban canyon. The number of vehicles participating in the network is varied between two and nine while the severity of the urban canyon was varied from 15-to 65-degree elevation mask angles. The effect of each vehicle’s azimuth being known a priori, or unknown is assessed. The resulting relative positions in the network of vehicles are then analysed in terms of horizontal accuracy and statistical reliability of the solution. The addition of both range and bearing measurements provides protection levels on the order of 2 m at almost all times where DGPS alone only rarely has observation redundancy and often exhibits estimated accuracies worse than 200 m. Reliability is further improved when the vehicle azimuth is assumed to be known a priori.

Description: This paper examines the impacts of municipal adjustment strategies on territorial governance in Africa, with specific reference to Senegal, as the result of the action of the World Bank. The paper identifies the process through which the World Bank is reconfiguring the system of actors and changing the local institutional environment to embody its philosophy of governance modernization. The paper shows how the local actor is brought to contribute to the new focus on governance and the reshaping of local institutions, which together comprise a type of urban development that aligns with the tenets of globalization.