Item difficulty estimation: An auspicious collaboration between data and judgment The evolution from static to dynamic electronic learning environments has stimulated the research on adaptive item sequencing. A prerequisite for adaptive item sequencing, in which the difficulty of the item is constantly matched to the ability level of the learner, is to have items with a known difficulty level. The difficulty level can be estimated by means of the item response theory (IRT). However, the requirement of a large sample size for calibrating items based on IRT models is not easily met in many practical learning situations. The aim of this paper is to search for relatively simple and fast alternative estimation methods and to review the accuracy of these methods as compared to IRT-based calibration in one single setting, and this for various sample sizes. Using real data, six alternative estimation methods are compared next to IRT-based calibration: proportion correct, learner feedback, expert rating, one-to-many comparison (learner), one-to-many comparison (expert) and the Elo rating system. Results indicate that proportion correct has the strongest relation with IRT-based difficulty estimates, followed by learner feedback, the Elo rating system, expert rating and finally one-to-many comparison. Learner feedback and one-to-many comparison (learner) provide stable estimates even with a small sample size. IRT, proportion correct and the Elo rating system provide reliable estimates, especially with a sample size of 200-250 learners. The alternative estimation methods can be utilized for adaptive item sequencing when IRT-based calibration does not yet provide reliable estimates or can be used as a prior in a Bayesian estimation method. (C) 2011 Elsevier Ltd. All rights reserved.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

distance education and telelearning
intelligent tutoring systems
cooperative/collaborative learning
evaluation methodologies


An ultra-large-scale simulation framework ? Many modern systems involve complex interactions between a large number of diverse entities that constitute these systems. Unfortunately, these large, complex systems frequently defy analysis by conventional analytical methods and their study is generally performed using simulation models. Further aggravating the situation, detailed simulations of large systems will frequently require days, weeks, or even months of computer time and lead to scaled down studies. These scaled down studies may be achieved by the creation of smaller, representative, models and/or by analysis with short duration simulation exercises. Unfortunately, scaled down simulation studies will frequently fail to exhibit behaviors of the full-scale system under study. Consequently, better simulation infrastructure is needed to support the analysis of ultra-large (models containing over 1 million components)-scale models. Simulation support for ultra-large-scale simulation models must be achieved using low-cost commodity computer systems. The expense of custom or high-end parallel systems prevent their widespread use. Consequently, we have developed an Ultra-large-Scale Simulation Framework (USSF). This paper presents the issues involved in the design and development of USSF. Parallel simulation techniques are used to enable optimal time versus resource tradeoffs in USSF. The techniques employed in the framework to reduce and regulate the memory requirements of the simulations are described. The API needed for model development is illustrated. The results obtained from the experiments conducted using various system models with two parallel simulation kernels (comparing a conventional approach with USSF) are also presented.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

large-scale modeling
parallel and distributed simulation
time warp simulation
unsynchronized simulation


Efficient management of transient station failures in linear radio communication networks with bases ? Given a communication network undergoing a transient component failure, a swap algorithm provides the maintenance of the network functionality by means of a minimum number of adjustments. Swap algorithms have recently received growing attention for managing transient failures in classic wired networks, due to their practical usefulness. In this paper, we propose efficient swap algorithms to guarantee survivability in a linear radio communication network undergoing transient station failures. More precisely, given an optimal range assignment for a set of n stations with bases spread on a line, and a bounded number of hops h , we show that, as a consequence of a single non-base station failure, the network survivability can always be guaranteed through a minimum number of adjustments, i.e., by updating either of one station in O(hlogn) O ( h log n ) time, or two stations in O(n) O ( n ) time, or three stations in O(hn) O ( hn ) time, all using O(n) O ( n ) space, depending on the structure of the network around the failed station. Furthermore, our swap algorithms identifies the best network reconfiguration in terms of the additional required power.

O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O


Hybrid video quality prediction: reviewing video quality measurement for widening application scope A tremendous number of objective video quality measurement algorithms have been developed during the last two decades. Most of them either measure a very limited aspect of the perceived video quality or they measure broad ranges of quality with limited prediction accuracy. This paper lists several perceptual artifacts that may be computationally measured in an isolated algorithm and some of the modeling approaches that have been proposed to predict the resulting quality from those algorithms. These algorithms usually have a very limited application scope but have been verified carefully. The paper continues with a review of some standardized and well-known video quality measurement algorithms that are meant for a wide range of applications, thus have a larger scope. Their individual artifacts prediction accuracy is usually lower but some of them were validated to perform sufficiently well for standardization. Several difficulties and shortcomings in developing a general purpose model with high prediction performance are identified such as a common objective quality scale or the behavior of individual indicators when confronted with stimuli that are out of their prediction scope. The paper concludes with a systematic framework approach to tackle the development of a hybrid video quality measurement in a joint research collaboration.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

video quality assessment
human visual system
hybrid model development
perceptual indicators
quality of experience


Haptic rendering method based on generalized penetration depth computation We studied the 6-DoF haptic rendering method by using generalized penetration depth computation. We use a filter method to reduce the instability problem in the haptic rendering. We use the direction control method to make the force feedback the same as in the physical world. The method is simple and effective. It can increase the stability of the haptic system.

B I O O O B I I O O O O O B I O O O B I I O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

haptic rendering
generalized penetration depth


Online monitoring and fault identification of mean shifts in bivariate processes using decision tree learning techniques With modern data collection system and computers used for on-line process monitoring and fault identification in manufacturing processes, it is common to monitor more than one correlated process variables simultaneously. The main problems in most multivariate control charts (e.g., T (2) charts, MCUSUM charts, MEWMA charts) are that they cannot give direct information on which variable or subset of variables caused the out-of-control signals. A Decision Tree (DT) learning based model for bivariate process mean shift monitoring and fault identification is proposed in this paper under the assumption of constant variance-covariance matrix. Two DT classifiers based on the C5.0 algorithm are built, one for process monitoring and the other for fault identification. Simulation results show that the proposed model can not only detect the mean shifts but also give information on the variable or subset of variables that cause the out-of-control signals and its/their deviate directions. Finally a bivariate process example is presented and compared with the results of an existing model.

O O O B I O O O O O O O B I I O O O O O O O O O O O B I O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O

decision tree learning
bivariate process
process monitoring
fault identification

statistical process control
average run length


Ambient media today and tomorrow Ambient media are novel, and this new media form alters our daily-living experience in many ways. Ambient media refer to media environments that are embedded throughout the natural space where people are following their daily activities. These digital media environments become part of the living space and altering our daily-living experience in many ways. The goal of this article is to elaborate the status of ambient media today and to forecast how ambient media will develop in the next decade. It clearly identifies megatrends and develops scenarios (e. g., ambient-assisted living) for the future. These scenarios shall shed light on the potentials and give a glimpse on the potential future development of embedding digital objects into the daily living space. This paper is based on a future wheel approach and on an analysis of the results of an expert workshop. The article concludes with a discussion of the results and an evaluation of the impact of each scenario.

B I O O O B I O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

ubiquitous computation
pervasive computation
human-computer-interaction
ambient assisted living
iptv
shape shifting media
user experience
smart environments
smart cities
smart urban environments


Aspects of predicative algebraic set theory, II: Realizability One of the main goals of this paper is to give a construction of realizability models for predicative constructive set theories in a predicative metatheory. We will use the methods of algebraic set theory, in particular the results on exact completion from van den Berg and Moerdijk (2008) [5]. Thus, the principal results of our paper are concerned with the construction of an extension of a category with small maps by a category of assemblies, again equipped with a class of maps, and to show that this extension construction preserves those axioms for a class of maps necessary to produce models of the relevant set theories in the exact completion of this category of assemblies. (C) 2010 Elsevier B.V. All rights reserved.

O O O O O O O B O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

constructive set theory
categorical logic


Trilateral Teleoperation of Adaptive Fuzzy Force/Motion Control for Nonlinear Teleoperators With Communication Random Delays In this paper, an adaptive fuzzy control scheme is proposed for hybrid motion/force of trilateral teleoperation systems with a dual-master-single-slave configuration under stochastic time-varying delays in communication channels. Different from previous works on bilateral teleoperation systems, this paper addresses dual-master trilateral control of a single holonomic-constrained robotic manipulator, where the communication delays are modeled as multiple Markov chains, and the motion/force controls are investigated under consideration of unsymmetric stochastic time-varying delays and system dynamical uncertainties. Using partial feedback linearization, the whole trilateral teleoperation system, which consists of both master and slave manipulator dynamics, is transformed into three subsystems. By integrating Markov jump systems to handle random delays, adaptive fuzzy control strategies are developed for the nonlinear teleoperators with modeling uncertainties and external disturbances by using the approximation property of the fuzzy logic systems (FLSs). It is proven that the trilateral teleoperation system is stochastically stable in mean square under specific linear matrix inequality (LMI) conditions, and all the signals of the resulting closed-loop system are uniformly bounded. The proposed scheme is validated by extensive simulations.

O O O O O O O O O B O O B I O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O B I O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

fuzzy control
random delays
teleoperators


Fractal image compression using visual-based particle swarm optimization Fractal image compression is promising both theoretically and practically. The encoding speed of the traditional full search method is a key factor rendering the fractal image compression unsuitable for real-time applications. In this paper, particle swarm optimization (PSO) method by utilizing the visual information of the edge property is proposed, which can speedup the encoder and preserve the image quality. Instead of the full search, a direction map is built according to the edge-type of image blocks, which directs the particles in the swarm to regions consisting of candidates of higher similarity. Therefore, the searching space is reduced and the speedup can be achieved. Also, since the strategy is performed according to the edge property, better visual effect can be preserved. Experimental results show that the visual-based particle swarm optimization speeds up the encoder 125 times faster with only 0.89dB decay of image quality in comparison to the full search method.

B I I O O B I I B I I O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O

fractal image compression
particle swarm optimization


low-cost router microarchitecture for on-chip networks On-chip networks are critical to the scaling of future multi-core processors. The challenge for on-chip network is to reduce the cost including power consumption and area while providing high performance such as low latency and high bandwidth. Although much research in on-chip network have focused on improving the performance of on-chip networks, they have often relied on a router microarchitecture adopted from off-chip networks. As a result, the on-chip network architecture will not scale properly because of design complexity. In this paper, we propose a low-cost, on-chip network router microarchitecture which is different from the commonly assumed baseline router microarchitecture. We reduce the cost of on-chip networks by partitioning the crossbar, prioritizing packets in flight to simplify arbitration, and reducing the amount of buffers. We show that by introducing intermediate buffers to decouple the routing in the x and the y dimensions, high performance can be achieved with the proposed, low-cost router microarchitecture. By removing the complexity of a baseline router microarchitecture, the low-cost router microarchitecture can also approach the ideal latency in on-chip networks. However, the prioritized switch arbitration simplifies the router but creates starvation for some nodes. We show how delaying the rate credits are returned upstream can be used to implement a distributed, starvation avoidance mechanism to provide fairness. Our evaluations show that the proposed low-cost router can reduce the area by 37\% and the power consumption by 45\% compared with a baseline router microarchitecture that achieves a similar throughput.

O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O B O O O O O O O O O B I O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O B O O O B I O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O


offering cs1 on-line reducing campus resource demand while improving the learning environment Multimedia-rich Web interfaces offer an increasingly attractive option for teaching distance and large-scale courses. We explore our experience of publishing CS1 to over 200 students and the resulting student performance. Our approach included streaming QuickTime audio and video synchronized with animated PowerPoint slides; in addition, a "Frequently Asked Questions" (FAQ) list was compiled from previous students' questions and made available. We demonstrate that the on-line lecture material enhanced students' learning of those enrolled in the traditional, lecture-based sections and those enrolled in the on-line section. The process is cost-effective, scalable, and affords use in other disciplines beyond CS1. Our future research is also discussed.

O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O

empirical analysis
streaming media
on-line learning
large-scale courses
distance education


A knowledge-based, concept-oriented view generation system for clinical data Information overload is a well-known problem for clinicians who must review large amounts of data in patient records. Concept-oriented views, which organize patient data around clinical concepts such as diagnostic strategies and therapeutic goals, may offer a solution to the problem of information overload. However, although concept-oriented views are desirable, they are difficult to create and maintain. We have developed a general-purpose, knowledge-based. approach to the generation of concept-oriented views and have developed a system to Ile test our approach. The system creates concept-oriented views through automated identification of relevant patient data. The knowledge in the system is represented by both a semantic network and rules. The key relevant data identification function is accomplished by a rule-based traversal of the semantic network. This paper focuses on the design and implementation of the system; an evaluation of the system is reported separately. (C) 2001 Academic Press.

O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

concept-oriented view
knowledge-based system
relevant patient data identification


A partially structure-preserving algorithm for the permanents of adjacency matrices of fullerenes A partially structure-preserving method for sparse symmetric matrices is proposed. Computational results on the permanents of adjacency matrices arising from molecular chemistry are presented. The largest adjacency matrix of fullerenes computed before is that of C-60 with a cost of several hours on supercomputers, while only about 6 min on an Intel Pentium PC (1.8 GHz) with our method. Further numerical computations are given for larger fullerenes and other adjacency matrices with n = 60, 80. This shows that our method is promising for problems from molecular chemistry. (C) 2004 Elsevier B.V. All rights reserved.

O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O B I O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O

permanent of matrix
structure-preserving algorithm


Fast, precise flattening of cubic Bezier path and offset curves We present two related algorithms for flattening (generating polyline approximations for) curves associated with planar cubic Bezier segments. One flattens the path curve, and the other flattens the left and right offset curves. The algorithm for flattening path curves yields an average of 67% of the vertices generated by recursive subdivision, while maintaining flatness to within 4% of the specified value, and runs 37% faster. The algorithm for flattening offset curves generates 70% of the vertices as the methods based on recursive subdivision, such that 94% of all subsegments fall within 20% of the flatness criterion. This latter code runs as fast as recursive subdivision. (c) 2005 Elsevier Ltd. All rights reserved.

O O B O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Evaluation of interoperability protocols in repositories of electronic theses and dissertations Purpose - The purpose of this study is to evaluate the status of eight interoperability protocols within repositories of electronic theses and dissertations (ETDs) as an introduction to further studies on feasibility of deploying these protocols in upcoming areas of interoperability. Design/methodology/approach - Three surveys of 266 ETD repositories, 15 common ETD management software solutions, and 136 ETD experts were conducted in order to appraise the protocols. These protocols were evaluated in four categories of aggregation, syndication, distributed search, and publishing protocols. Findings - This study revealed that, despite its drawbacks, Protocol for Metadata Harvesting (PMH) is still the most utilized interoperability protocol within ETD providers, ETD software developers, and implementers, followed by ATOM and Object Reuse and Exchange (ORE) protocols. However, in all competitive areas related to performance and functionality, ORE surpasses other protocols. It was also found that the three protocols of ATOM, PMH, and ORE could be used interchangeably in the most used cases of interoperability protocols in repositories. Practical implications - In this research, a combination of methods was employed to evaluate the status of protocols, from the perspectives of data providers, software providers, and implementers. Practitioners may use these methods to assess other protocols in terms of effectiveness and efficiency. Originality/value - The conduct of this study has involved three types of surveys, through which different aspects of interoperability protocols are evaluated. Prior to the conduct of this study, there has yet any study focusing on the same topic, which has adopted the multi-method that has been adopted in this study.

O O B I O O O B I I I O O O O O O O O O O O O O O B I O O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

interoperability protocols
electronic theses and dissertations

transmission control protocol/internet protocols


Compression of ultraviolet-visible spectrum with recurrent neural network Data compression method based on the recurrent neural network (RNN) of the dynamical system approach was proposed and applied to ultraviolet-visible (UV-VIS) spectra. RNN schemes with different network size were studied and their performance was evaluated by using both synthetic and experimental data. It was found that the storage space of the spectral information under study could be reduced significantly by using the proposed RNN method with duality spectra regenerated from the compressed data. Furthermore, the method was found to perform as good as the wavelet, transform (WT) in data compression and in some cases, even better. (C) 2000 Elsevier Science B.V. All rights reserved.

O O O O O B I I O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

spectral compression
ultraviolet-visible spectrum


A Systems Engineering Perspective on Proposal Management Mastering proposal management is key to the very survival of organizations that capture and execute contracts to supply products or services. Systems engineering plays a central role in proposal management for complex systems by often leading the technical effort. This paper provides an alternative perspective to the existing acquisition-focused literature by examining proposal management from the supplier perspective. This paper identifies proposal stakeholders and defines objectives that can be used to evaluate success from each stakeholder's perspective. A high-level process model is identified that describes steps in the proposal process and the corresponding role of systems engineering. This paper also introduces a detailed process model for defining the proposed system solution. A more thorough understanding of proposal stakeholder roles, associated objectives, and the proposal process can help supplier organizations devise more effective strategies for responding to proposal opportunities.

O B I O O B O O B O O O O O O O O O O O O O O O O O O O B I O O O O O B O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O B O O O O O O O O O O O O O O O O O O B O O O O O O O B O O O O O O B I O O O O O O O B O O O O O O O O O O O B O O O O O O B O O O O O O O O O O O O B O


classification-enhanced ranking Many have speculated that classifying web pages can improve a search engine's ranking of results. Intuitively results should be more relevant when they match the class of a query. We present a simple framework for classification-enhanced ranking that uses clicks in combination with the classification of web pages to derive a class distribution for the query. We then go on to define a variety of features that capture the match between the class distributions of a web page and a query, the ambiguity of a query, and the coverage of a retrieved result relative to a query's set of classes. Experimental results demonstrate that a ranker learned with these features significantly improves ranking over a competitive baseline. Furthermore, our methodology is agnostic with respect to the classification space and can be used to derive query classes for a variety of different taxonomies.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Estimating Relative Camera Motion from the Antipodal-Epipolar Constraint This paper introduces a novel antipodal-epipolar constraint on relative camera motion. By using antipodal points, which are available in large Field-of-View cameras, the translational and rotational motions of a camera are geometrically decoupled, allowing them to be separately estimated as two problems in smaller dimensions. We present a new formulation based on discrete camera motions, which works over a larger range of motions compared to previous differential techniques using antipodal points. The use of our constraints is demonstrated with two robust and practical algorithms, one based on RANSAC and the other based on Hough-like voting. As an application of the motion decoupling property, we also present a new structure-from-motion algorithm that does not require explicitly estimating rotation (it uses only the translation found with our methods). Finally, experiments involving simulations and real image sequences will demonstrate that our algorithms perform accurately and robustly, with some advantages over the state-of-the-art.

O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

multiview geometry
epipolar constraint
structure and motion
hough
robust estimation


Bayesian winner-take-all reconstruction of intermediate views from stereoscopic images This paper presents a new algorithm for the reconstruction of intermediate views from a pair of still stereoscopic images. The algorithm is designed to address the issue of blur caused by linear filtering often employed in such reconstruction, The proposed algorithm is block-based and to reconstruct the intermediate views employs nonlinear disparity-compensated filtering by means of a winner-take-all strategy. The reconstructed image is modeled as a tiling by fixed-size blocks coming from various positions (disparity compensation) of either the left or right images, while the tiling map itself is modeled by a binary decision field. In addition to that, an observation model relating the left and right images via a disparity field, and a disparity field model are used, All models are probabilistic and are combined into a maximum a posteriori probability criterion. The intermediate intensities, disparities and the binary decision field are estimated jointly using the expectation-maximization algorithm, The new approach is compared experimentally on complex natural images with a reference block-based algorithm employing linear filtering, Although the improvements are localized and often subtle, they demonstrate that a high-quality intermediate view reconstruction for complex scenes is feasible.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O

stereoscopic and three-dimensional imaging


A hierarchical Nave Bayes model for approximate identity matching ? Organizations often manage identity information for their customers, vendors, and employees. Identity management is critical to various organizational practices ranging from customer relationship management to crime investigation. The task of searching for a specific identity is difficult because disparate identity information may exist due to the issues related to unintentional errors and intentional deception. In this paper we propose a hierarchical Nave Bayes model that improves existing identity matching techniques in terms of searching effectiveness. Experiments show that our proposed model performs significantly better than the exact-match based matching technique. With 50% training instances labeled, the proposed semi-supervised learning achieves a performance comparable to the fully supervised record comparison algorithm. The semi-supervised learning greatly reduces the efforts of manually labeling training instances without significant performance degradation.

O B I I I O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

identity management
hierarchical nave bayes model

em algorithm
entity matching
semi-supervised learning


POLARIZATION ENTANGLEMENT CONCENTRATIONS WITH LESS-HYPERENTANGLED PHOTON PAIRS IN MULTIPLE DEGREES OF FREEDOM We demonstrate two entanglement concentration protocols (ECPs) for photon pairs in less-hyperentanglement, the simultaneous entanglement in multiple degrees of freedom. Using these ECPs, some maximally entangled states in polarization can be reconstructed deterministically from less-hyperentangled ones shared between remote participants. Both of the success probabilities are 100% in principle, and they do not require additional single photons. The former is implemented with the passive linear optics, which is achievable with current technology. The later adopts the cross-Kerr nonlinearity media to complete this task, which can increase the efficiency of the entanglement concentration process since it does not require the sophisticated single-photon detectors for measurements. The two ECPs are useful for practical long-distance quantum communication due to the fact that the entangled state in either the spatial degree of freedom or the frequency degree of freedom suffers little from channel noise in optical fiber.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

quantum entanglement
quantum information
quantum communications
entanglement purification
bell states


Two FETI-based heterogeneous time step coupling methods for Newmark and ? ? -schemes derived from the energy method The purpose of this paper is to describe a general methodology to obtain multi-time step coupling methods for different time-integration schemes (Newmark, HHT-? ? , WBZ-? ? , CH-? ? ) on the basis of energetic considerations. The general framework of the FETI method is considered for building the heterogeneous time step coupling methods by ensuring the gluing of subdomains with Lagrange multipliers. The proposed methods for coupling subdomains with different time integration schemes and time steps (fine and large time steps), are based on the pseudo-energy measure as introduced by Hughes in the so-called energy method employed for proving the stability of implicitexplicit algorithms. Assuming a given variation of the Lagrange multipliers over the large time step, kinematic conditions are derived by ensuring the zero pseudo-energy at the interface. Two methods will be derived in this paper. The first new method, for which the interface problem involving the Lagrange multipliers is solved at the large time scale, can handle the popular dissipative ? ? -schemes (HHT-? ? , WBZ-? ? , CH-? ? ); in the particular case of the Newmark schemes, the new method matches with the PH method proposed by Prakash and Hjelmstad. The second new method is based at the micro time scale. It can be viewed as an extension of the method proposed by Gravouil and Combescure (GC method) for the coupling of the ? ? -schemes. Nonetheless, like the GC method, the new micro-time-based method turns out to be dissipative when non-dissipative second-order accurate schemes are involved, and looses one order of accuracy.

O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

structural dynamics
heterogeneous time integrators
hybrid multi-time methods
energy conserving methods


Three new metrics to measure the convergence of metaheuristics towards the Pareto frontier and the aesthetic of a set of solutions in biobjective optimization In this paper, some new quality metrics concerning the evaluation of performances of biobjective optimization methods relating to the generation of the Pareto frontier are presented. A new metric for the calculation of the running speed of a multiobjective optimization method is also presented. These metrics are tested on two biobjective scalarization functions (Weighted sum and Tchebychev aggregation of objective functions) handled by a metaheuristic (Simulated Annealing).

O O O O O O O O B O O O O O O O O O O O O O B I O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O

multiobjective optimization
biobjective optimization
metaheuristics


Object-space visibility ordering for point-based and volume rendering This paper presents a method to accelerate algorithms that need a correct and complete visibility ordering of their data for rendering. The technique works by pre-sorting primitives in object-space using three lists (one for each axis: X, Y and Z), and then combining the lists using graphics hardware by rendering each list to a texture and merging the textures in the end. We validate our algorithm by applying it to the splatting technique using several types of rendering, including point-based rendering and volume rendering. We also detail our hardware implementation for volume rendering using point sprites.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

1.3.3 computer graphics : picture/image generation-viewing algorithms


Optimisation of a tubular linear machine with permanent magnets for wave energy extraction Purpose - The purpose of this paper is to optimise the cost-based performance of a tubular linear generator and to minimise cogging forces. Design/methodology/approach - Optimisation of a tubular linear generator with longitudinal flux topology has been undertaken using a finite element method. The computational models used have been verified experimentally. Findings - The use of an oversized stator linear generator design as opposed to an oversized translator design has the potential to increase the output electromotive force per unit material cost by 25 per cent for slotless iron core topologies and approximately 14 per cent for air core topologies. For cogging force minimisation, optimisation of the length of the stator core is an effective technique for both oversized stator and oversized translator constructions. Comparisons of magnet materials also indicate that the higher cost of rare earth magnets to ferrites is compensated by their superior specific performances. Originality/value - In this paper, a broader range of design parameters than in previous investigations has been optimised for the slotless iron core and air core topologies. The result relating to cogging force reduction and cost savings (in particular) has the potential to make direct drive wave energy extraction a more competitive technology in terms of reliability and cost.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Local margin based semi-supervised discriminant embedding for visual recognition Most manifold learning algorithms adopt the k nearest neighbors function to construct the adjacency graph. However, severe bias may be introduced in this case if the samples are not uniformly distributed in the ambient space. In this paper a semi-supervised dimensionality reduction method is proposed to alleviate this problem. Based on the notion of local margin, we simultaneously maximize the separability between different classes and estimate the intrinsic geometric structure of the data by both the labeled and unlabeled samples. For high-dimensional data, a discriminant subspace is derived via maximizing the cumulative local margins. Experimental results on high-dimensional classification tasks demonstrate the efficacy of our algorithm.

O B O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

dimensionality reduction
margin
manifold learning


the implementation of the bsp parallel computing model on the integrade grid middleware InteGrade is an object-oriented grid middleware infrastructure whose goal is to leverage existing computational resources in organizations. Rather than relying on dedicated hardware such as reserved clusters, InteGrade focuses on using desktops in users' offices, machines in computer laboratories, shared workstations, as well as dedicated clusters. In this paper, we describe the support for the execution of highly coupled parallel applications on top of InteGrade. The paper describes the implementation of the middleware to support BSP parallel applications (with global synchronization points), and presents experimental results.

O O O O B B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O

parallel computing library
grid computing


Finding Alternative Shortest Paths in Spatial Networks Shortest path query is one of the most fundamental queries in spatial network databases. There exist algorithms that can process shortest path queries in real time. However, many complex applications require more than just the calculation of a single shortest path. For example, one of the common ways to determine the importance (or price) of a vertex or an edge in spatial network is to use Vickrey pricing, which intuitively values the vertex upsilon (or edge e) based on how much harder for travelling from the sources to the destinations without using upsilon (or e). In such cases, the alternative shortest paths without using upsilon (or e) are required. In this article, we propose using a precomputation based approach for both single pair alternative shortest path and all pairs shortest paths processing. To compute the alternative shortest path between a source and a destination efficiently, a naive way is to precompute and store all alternative shortest paths between every pair of vertices avoiding every possible vertex (or edge), which requires O(n(4)) space. Currently, the state of the art approach for reducing the storage cost is to choose a subset of the vertices as center points, and only store the single-source alternative shortest paths from those center points. Such approach has the space complexity of O(n(2) log n). We propose a storage scheme termed iSPQF, which utilizes shortest path quadtrees by observing the relationships between each avoiding vertex and its corresponding alternative shortest paths. We have reduced the space complexity from the naive O(n(4)) (or the state of the art O(n(2) log n)) to O(min(gamma, L)n(1.5)) with comparable query performance of O(K), where K is the number of vertices in the returned paths, L is the diameter of the spatial network, and gamma is a value that depends on the structure of the spatial network, which is empirically estimated to be 40 for real road networks. Experiments on real road networks have shown that the space cost of the proposed iSPQF is scalable, and both the algorithms based on iSPQF are efficient.

O O B I O B I O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O

algorithms
performance
spatial networks
shortest paths


Comparison of time series using subsampling Existing procedures for the comparison of stationary time series are based on tests which require either model estimation or spectral estimation. In most cases these procedures are applicable to pairs of time series that are assumed to be generated independently of each other. A procedure that is based on subsampling techniques, and is free from either model or spectral estimation is proposed. It is applicable to pairs of time series that may or may not be assumed to be independently generated. This procedure for which consistency is established, involves the use of a test based on the Euclidean distance between the autocorrelation functions of two time series. The performance of the test is evaluated using a Monte Carlo study. This study reveals that the test performs reasonably well and is competitive with existing procedures for the comparison of stationary time series. The test is applied to a set of observed financial time series.

B O O O O O O O O O B O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O B I I O O O O O O O O O O O O


Optimal Design of the Power-Delivery Network for Multiple Voltage-Island System-on-Chips This paper introduces techniques for power-efficient design of power-delivery network (PDN) in multiple voltage-island system-on-chip (SoC) designs. The first technique is targeted to SoC designs with static-voltage assignment, while the second technique is pertinent to SoC designs with dynamic-voltage scaling (DVS) capability. Conventionally, a single-level configuration of dc-dc converters, where exactly one converter resides between the power source and each load, is used to deliver currents at appropriate voltage levels to different loads on the chip. In the presence of DVS capability, each dc-dc converter in this network should be able to adjust its output voltage. In the first part of this paper, it is shown that, in a SoC design with static-voltage assignment, a multilevel tree topology of suitably chosen dc-dc converters between the power source and loads can result in higher power efficiency in the PDN. The problem is formulated as a combinatorial problem and is efficiently solved by dynamic programming. In the second part of this paper, a new technique is presented to design the PDN for a SoC design to support DVS. In this technique, the PDN is composed of two layers. In the first layer, dc-dc converters with fixed output voltages are used to generate all voltage levels that are needed by different loads in the SoC design. In the second layer of the PDN, a power-switch network is used to dynamically connect the power-supply terminals of each load to the appropriate dc-dc converter output in the first layer. Experimental results demonstrate the efficacy of both techniques.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

dc-dc converter
energy efficiency
low-power design
power-delivery network (pdn)
system-on-chip (soc)
voltage island
voltage regulator


SECURE SMART CARD BASED PASSWORD AUTHENTICATION SCHEME WITH USER ANONYMITY Recently, a smart card based authentication and key agreement scheme preserving the user anonymity was proposed by Wang, Juang and Lei, that is designed to provide users with secure activities in ubiquitous computing environments. The authors proved that their scheme delivers important security properties and functionalities, such as without maintaining password/verification tables, freedom on password selection and alteration, mutual authentication, user anonymity, no time synchronization problem, key agreement implementation, forgery attack resistance and computation efficiency. However, we show that Wang et al.'s scheme has potential security flaws, which enable malicious attackers to counterfeit an application server to spoof the victim client and damage the security of session key and the property of user anonymity. In this paper, we propose an enhanced version of Wang et al.'s scheme to remedy these flaws. The proposed scheme not only ensures the merits of their scheme but also enhances the security of their scheme without raising any computation cost.

O B I O B I O O B I O O B I O O O O O O O O B I O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

password authentication
smart card
ubiquitous computing environments
user anonymity


Integrated buffer and route management in a DTN with message ferry Unlike normal wireless ad hoc networks, end-to-end connection may not exist in DTNs Thus, the Message Ferrying (MF) scheme has been proposed as a strategy for providing connectivity in disruption tolerant network (DTN)s, where a set of nodes called ferries are responsible for carrying messages for all nodes in the networks. In such store- and-forward networks, buffers at ferry and regular nodes become critical resources and need to be allocated fairly among different users. In this paper, we propose a max-min fairness model for a DTN with a message ferry. Based on this model, we propose a buffer allocation scheme that can achieve fairness among different sessions. We also design an integrated buffer and routing management scheme called buffer efficient routing scheme (BERS). Via simulations, we demonstrate that our fair buffer allocation scheme assigns buffers fairly to different sessions. Our simulation studies also show that BERS can achieve higher session throughput and lower packet delivery latency than the only-store-and-forward routing scheme that is typically used in a message ferry system.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

buffer management
ferry route design
performance evaluation


Preamble-based channel estimation in OFDM/OQAM systems: A review Filter bank-based multicarrier communications (FBMC) have recently attracted increased interest in both wired (e.g., xDSL, PLC) and wireless (e.g., cognitive radio) applications, due to their enhanced flexibility, higher spectral efficiency, and better spectral containment compared to conventional OFDM. A particular type of FBMC, the so-called FBMC/OQAM or OFDM/OQAM system, consisting of pulse shaped OFDM carrying offset QAM (OQAM) symbols, has received increasing attention due to, among other features, its higher spectral efficiency and implementation simplicity. It suffers, however, from an imaginary inter-carrier/inter-symbol interference that complicates signal processing tasks such as channel estimation. This paper focuses on channel estimation for OFDM/OQAM systems based on a known preamble. A review of the existing preamble structures and associated channel estimation methods is given, for both single- (SISO) and multiple-antenna (MIMO) systems. The various preambles are compared via simulations in both mildly and highly frequency selective channels.

O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O B I O O O O O O O B O O O O O B O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O

orthogonal frequency division multiplexing (ofdm)


Understanding student attitudes of mobile phone features: Rethinking adoption through conjoint, cluster and SEM analyses Young adults have been labelled as one of the most important segments for mobile phones, however there is little empirical evidence to indicate how these young adults value the feature richness of their devices. This research presents a richer view of mobile phone user preferences and perceptions by applying methodologies from the marketing and information systems domains. Conjoint analysis provides insights into how students value various mobile phone applications and tools. Cluster analysis extracts salient and homogenous consumer segments from the conjoint analysis output. Structural equation modelling then explores how antecedents to attitude may differ by the elicited consumer segments.

O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O B I O O O O O O O B I O O O B I O O O O O O O O B I O O O O O O O O O B O O O O O O O

mobile phone
attitude
conjoint analysis
cluster analysis


A combined QM and MM investigation into guanine quadruplexes This paper reports on the application of quantum mechanical (QM) energy calculations, QM optimisations and MD simulations to explore the stability of a human telomeric guanine quadruplex, containing potassium and sodium cations. G-quadruplexes are of great biological interest as it has been suggested that they offer a novel path to cancer inhibition. By understanding the stability and geometry of these DNA features gives us the ability to design ligands which can bind and stabilise the G-quadruplex. There are significant structural differences between the potassium containing crystal structure of human telomeric G-quadruplex and the sodium containing NMR structure; in this paper, we investigate the energetics and dynamics of the potassium derived crystal structure and a model for the sodium containing structure. QM investigations upon the 12 G-quadruplex core, extracted from the human potassium quadruplex crystal structure, indicate that replacement of the potassium cations with sodium yields an energetically more favourable structure. However, attempts to geometry optimise both structures at the QM level proved unsuccessful, the structure of the partially optimised potassium containing G-quadruplex retains significant structural integrity with respect to the original crystal structure, whilst the sodium containing G-quadruplex shows significant structural distortion. QM investigation of the 12 G-quadruplex core containing no cations unsurprisingly yields a highly unfavourable energetic structure. MD simulations on the complete quadruplex structure, containing potassium cations, yields a remarkably stable structure after 4ns of simulation, the most significant deviation from the original crystal structure being the loss of the capping potassium cation from the structure. MD simulation of the sodium containing quadruplex for 4ns show significant structural reorganisation compared with the original potassium containing crystal structure.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


A scalable P2P platform for the knowledge grid The Knowledge Grid needs to operate with a scalable platform to provide large-scale intelligent services. A key function of such a platform is to efficiently support various complex queries in a dynamic large-scale network environment. This paper proposes a platform to support index-based path queries by incorporating a semantic overlay with an underlying structured P2P network that provides object location and management services. Various distributed indexing structures can be dynamically formed by publishing semantic objects as indexing nodes. Queries are forwarded along the chains of semantic object pointers to search for objects. We investigate the deployment of a scalable distributed trie index for broadcast queries on key strings, propose a decentralized load balancing method for solving the problem of uneven load distribution incurred by heterogeneity of loads and node capacities and by the distributed trie index, and give an approach for improving the availability of the semantic overlay and its trie index. Experiments demonstrate the scalability of the proposed platform.

O O O O O O B I O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O B I O O O O O O O O O O O O

semantic overlay
knowledge grid
distributed trie index
load balancing


Global and polynomial-time convergence of an infeasible-interior-point algorithm using inexact computation In this paper, we propose an infeasible-interior-point algorithm for solving a primal-dual linear programming problem. The algorithm uses inexact computations for solving a linear system of equations at each iteration. Under a very mild assumption on the inexactness we show that the algorithm finds an approximate solution of the linear program whenever the primal-dual linear programming problem is feasible. The assumption on the inexact computation is satisfied ii the approximation to the solution of the linear system is just a little bit "better" than the trivial approximation 0.

O O O B O O O O O B I O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O

linear programming problem
convergence
inexact computation


An estimation of the sensitivity of numerical error norm using adjoint model A posteriori estimation of the numerical error sensitivity to the local truncation error is addressed using adjoint model endowed with the information on the error field. The numerical error is estimated from the solution of the linear tangent model (LTM) or from a Richardson extrapolation. The local truncation error used in the LTM is obtained by the action of a high-order finite-difference stencil on the field computed by the main (low-order accuracy) algorithm. Copyright (C) 2009 John Wiley & Sons, Ltd.

O O O O B O B I I O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

adjoint problem
a posteriori error estimation


Engaging online learners: The impact of Web-based learning technology on college student engagement Widespread use of the Web and other Internet technologies in postsecondary education has exploded in the last 15 years. Using a set of items developed by the National Survey of Student Engagement (NSSE), the researchers utilized the hierarchical linear model (HLM) and multiple regressions to investigate the impact of Web-based learning technology on student engagement and self-reported learning outcomes in face-to-face and online learning environments. The results show a general positive relationship between the use the learning technology and student engagement and learning outcomes. We also discuss the possible impact on minority and part-time students as they are more likely to enroll in online courses. (C) 2009 Elsevier Ltd. All rights reserved.

O O O O O O O O O O B O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B B O O O O O O O O O O O O O O O O O O O O O B O O O O O O O B I O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Real-time Large-deformation Substructuring This paper shows a method to extend 3D nonlinear elasticity model reduction to open-loop multi-level reduced deformable structures. Given a volumetric mesh, we decompose the mesh into several subdomains, build a reduced deformable model for each domain, and connect the domains using inertia coupling. This makes model reduction deformable simulations much more versatile: localized deformations can be supported without prohibitive computational costs, parts can be re-used and precomputation times shortened. Our method does not use constraints, and can handle large domain rigid body motion in addition to large deformations, due to our derivation of the gradient and Hessian of the rotation matrix in polar decomposition. We show real-time examples with multi-level domain hierarchies and hundreds of reduced degrees of freedom.

O O O O O O O O O O O B I B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Filtering segmentation cuts for digit string recognition In this paper we propose a method to evaluate segmentation cuts for handwritten touching digits. The idea of this method is to work as a filter in segmentation-based recognition system. This kind of system usually rely on over-segmentation methods, where several segmentation hypotheses are created for each touching group of digits and then assessed by a general-purpose classifier. The novelty of the proposed methodology lies in the fact that unnecessary segmentation cuts can be identified without any attempt of classification by a general-purpose classifier, reducing the number of paths in a segmentation graph, what can consequently lead to a reduction in computational cost. An cost-based approach using ROC (receiver operating characteristics) was deployed to optimize the filter. Experimental results show that the filter can eliminate up to 83% of the unnecessary segmentation hypothesis and increase the overall performance of the system.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

handwriting recognition handwriting recognition handwriting recognition handwriting recognition

segmentation segmentation segmentation segmentation segmentation segmentation segmentation

filtering filtering filtering filtering filtering filtering filtering


Performance of miniload systems with two-class storage To increase throughput, the higher turnover items are often stored near the input/output point of a miniload system. We analyze the performance of such a miniload with a square-in-time rack containing two storage zones: high turnover and low turnover. First, we derive the distribution of the dual command travel time. System performance measures such as the throughput depend upon the distribution of the dual command travel time and the distribution of pick times. We work out the details and obtain closed-form expressions for throughput for two important families of pick time distributions: deterministic and exponential. Finally, we investigate how the size of the high turnover region affects throughput.

O O B O O O O O O O O O O O O O O O O O O O O B O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

applied probability
order picking
class based storage
automated storage/retrieval systems


WS-Naming: location migration, replication, and failure transparency support for Web Services Naming transparencies, i.e. abstracting the name and binding of the entity being used from the endpoints that are actually doing the work, are used in distributed systems to simplify application development by hiding the complexity of the environment. In this paper, we demonstrate how to apply traditional distributed systems naming and binding techniques in the Web Services realm. Specifically, we show how the WS-Naming profile on WS-Addressing Endpoint References can be used for identity, transparent failover, replication, and migration. We begin with a discussion of the traditional distributed systems transparencies. We then present four detailed use cases. Next, we provide a brief background on both WS-Addressing and WS-Naming. Finally, we show how WS-Naming can be used to provide transparent implementations of our use cases. Copyright (C) 2009 John Wiley & Sons, Ltd.

O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


an organic model for detecting cyber-events Cyber entities in many ways mimic the behavior of organic systems. Individuals or groups compete for limited resources using a variety of strategies, the most effective of which are reused and refined in later 'generations'. Traditionally this behavior has made detection of malicious entities very difficult because 1) recognition systems are often built on exact matching to a pattern that can only be 'learned' after a malicious entity reveals itself and 2) the enormous volume and variation in benign entities is an overwhelming source of previously unseen entities that often confound detectors. To turn the tables of complexity on the would-be attackers, we have developed a method for mapping the sequence of behaviors in which cyber entities engage to strings of text and analyze these strings using modified bioinformatics algorithms. Bioinformatics algorithms optimize the alignment between text strings even in the presence of mismatches, insertions or deletions and do not require an a priori definition of the patterns one is seeking. Nor do they require any type of exact matching. This allows the data itself to suggest meaningful patterns that are conserved between cyber entities. We demonstrate this method on data generated from live network traffic. The impact of this approach is that it can rapidly calculate similarity measures of previously unseen cyber entities in terms of well-characterized entities. These measures may also be used to organize large collections of data into families, making it possible to identify motifs indicative of each family.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


On the fairness characteristics of FAST TCP Fairness of competing transmission control protocol (TCP) flows is an integral and indispensable part of transport protocol design for next-generation, high-bandwidth-delay product networks. It is not just a protocol-intrinsic property but it could also have severe impact on quality of experience (QoE). In this paper, we revisit FAST TCP fairness behavior based on a comprehensive performance evaluation study. We demonstrate that FAST TCP with proper parameter settings can always achieve fair behavior with HighSpeed TCP and Scalable TCP. We also show that this behavior is a rather robust property of the protocol concerning different traffic mix or network topology. The dynamic behavior of reaching the fair equilibrium state can be different, which is demonstrated in the paper. Our study also emphasizes the important need for finding a dynamic sensitive fairness metric for performance evaluation of transport protocols for next-generation, high-bandwidth-delay product networks.

O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Vibration control of beam-plates with bonded piezoelectric sensors and actuators This paper studies vibration control of beam-plates with bonded piezoelectric sensors and actuators. Basic equations for piezoelectric sensors and actuators are presented. The equation of motion for a beam-plate structure bonded with pairs of piezoelectric sensors or actuators is derived by using the Hamilton's principle, and a finite element method is used for the analysis. A control algorithm based on Lyapunov energy function is studied. Numerical results are presented for illustrative purposes. (C) 1999 Civil-Comp Ltd and Elsevier Science Ltd. All rights reserved.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

beam plate structure
intelligent structure
piezoelectric material
lyapunov stability


A learning automata based scheduling solution to the dynamic point coverage problem in wireless sensor networks The dynamic point coverage problem in wireless sensor networks is to detect some moving target points in the area of the network using as few sensor nodes as possible. One way to deal with this problem is to schedule sensor nodes in such a way that a node is activated only at the times a target point is in its sensing region. In this paper we propose SALA, a scheduling algorithm based on learning automata, to deal with the problem of dynamic point coverage. In SALA each node in the network is equipped with a set of learning automata. The learning automata residing in each node try to learn the maximum sleep duration for the node in such a way that the detection rate of target points by the node does not degrade dramatically. This is done using the information obtained about the movement patterns of target points while passing throughout the sensing region of the nodes. We consider two types of target points; events and moving objects. Events are assumed to occur periodically or based on a Poisson distribution and moving objects are assumed to have a static movement path which is repeated periodically with a randomly selected velocity. In order to show the performance of SALA, some experiments have been conducted. The experimental results show that SALA outperforms the existing methods such as LEACH, GAF, PEAS and PW in terms of energy consumption.

O B I O B O O O B I I O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O B I O O O O O O B I I O O O O O O O O O O O O O B I O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

dynamic point coverage
scheduling
learning automata


Weighted feature extraction with a functional data extension ? Dimensionality reduction has proved to be a beneficial tool in learning problems. Two of the main advantages provided by dimensionality reduction are interpretation and generalization. Typically, dimensionality reduction is addressed in two separate ways: variable selection and feature extraction. However, in the recent years there has been a growing interest in developing combined schemes such as feature extraction with built-in feature selection. In this paper, we look at dimensionality reduction as a rank-deficient problem that embraces variable selection and feature extraction, simultaneously. From our analysis, we derive a weighting algorithm that is able to select and linearly transform variables by fixing the dimensionality of the space where a relevance criterion is evaluated. This step enforces sparseness on the resulting weights. Our main goal is dimensionality reduction for classification problems. Namely, we introduce modified versions of principal component analysis (PCA) by expectation maximization (EM) and linear regularized discriminant analysis (RDA). Finally, we propose a simple extension of WRDA that deals with functional features. In this case, observations are described by a set of functions defined over the same domain. Methods were put to test on artificial and real data sets showing high levels of generalization even for small sized training samples.

O B I O O O O O O B I O O O O O O O O O O O O O O O O O B I O O O O O B I O O O O O O O O O B I O O O O O O O O O O O O O O O O O B I O O B I O O O O O O B I O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O B I I O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

dimensionality reduction
feature selection
feature extraction
principal component analysis
regularized discriminant analysis


Decision making with imprecise parameters We analyze the impact of imprecise parameters on performance of an uncertainty-modeling tool presented in this paper. In particular, we present a reliable and efficient uncertainty-modeling tool, which enables dynamic capturing of interval-valued clusters representations sets and functions using well-known pattern recognition and machine learning algorithms. We mainly deal with imprecise learning parameters in identifying uncertainty intervals of membership value distributions and imprecise functions. In the experiments, we use the proposed system as a decision support tool for a production line process. Simulation results indicate that in comparison to benchmark methods such as well-known type-1 and type-2 system modeling tools, and statistical machine-learning algorithms, proposed interval-valued imprecise system modeling tool is more robust with less error. (C) 2010 Elsevier Inc. All rights reserved.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

interval-valued membership functions and imprecise functions


Triangulation of points, lines and conics The problem of reconstructing 3D scene features from multiple views with known camera motion and given image correspondences is considered. This is a classical and one of the most basic geometric problems in computer vision and photogrammetry. Yet, previous methods fail to guarantee optimal reconstructions-they are either plagued by local minima or rely on a non-optimal cost-function. A common framework for the triangulation problem of points, lines and conics is presented. We define what is meant by an optimal triangulation based on statistical principles and then derive an algorithm for computing the globally optimal solution. The method for achieving the global minimum is based on convex and concave relaxations for both fractionals and monomials. The performance of the method is evaluated on real image data.

B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Cutaneous Basophilia in the Resistance of Goats to Amblyomma cajennense Nymphs after Repeated Infestations The acquisition of resistance in goats against Amblyomma cajennense after repeated infestations and the role of inflammatory cells in this mechanism were investigated. Ten naive goats aged 6 months were distributed into two groups: test (n= 5), infested thrice at 30-day intervals; and control (n= 5), infested once. Nymphs (n= 115 per animal per infestation) were released inside alimentary chambers glued to the animal's dorsum and the following biological parameters were evaluated: yielding rate, nymphal engorgement weight, engorgement period, ecdise rate, and ecdise period. Skin fragments of tick bite sites were collected at 24, 48, 72, and 120 h post attachment for histopathology and inflammatory cells counts. The engorgement weight decreased significantly (P < 0.05) from the first infestation onward; nymphs weighed 41.7% and 37.1% less after the second and third infestations, respectively, as compared to those collected after the first infestation (12.55 mg 3.21). Furthermore, the ecdise period increased significantly (P < 0.05) in the third infestation (18 days 2.83) in comparison with the first infestation (15 days 0.82) and the ecdise rate was significantly lower after the second infestation (71.91% 17.38) in comparison with the first infestation (96.89% 3.38). There were no significant differences with regard to both the engorgement period and yielding rate. A cutaneous basophilia was evidenced between 48 and 72 h (P < 0.05) after both the second and third infestations. We conclude that goats develop resistance against nymphs of A. cajennense and that basophils may play an important role in such a mechanism.

B I O O O O B O B I B O O O O O O O O B O B I O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O B O O O B O O O O O O O O O O O O O O O

amblyomma cajennense
biological parameters
cutaneous basophilia
goats
nymphs


Rough neural expert systems The knowledge acquisition process is a crucial stage in the technology of expert systems. However, this process is not well defined. One of the promising structured sources of learning can be found in the recent work on neural network technology. A neural network can serve as a knowledge base of expert systems that does classification tasks. Another way of learning is by using the rough set as a new mathematical tool to deal with uncertain and imprecise data. Two methods based on rough set analysis were developed and merged with the integration of neural networks and expert systems, forming a new hybrid architecture of expert systems called a rough neural expert system. The first method works as a pre-processor for neural networks within the architecture, and it is called a pre-processing rough engine, while the second one was added to the architecture for building a new structure of inference engine called a rough neural inference engine. Consequently, a new architecture of knowledge base was designed. This new architecture was based on the connectionist of neural networks and the reduction of rough set analysis. The performance of the proposed system was evaluated by an application to the field of medical diagnosis using a real example of hepatitis diseases. The results indicate that the new methods have improved the inference procedures of the expert systems, and have showed that this new architecture has some properties over the conventional architectures of expert systems.

O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

knowledge acquisition process
rough set analysis
neural network


GRAONTO: A graph-based approach for automatic construction of domain ontology Extracting domain knowledge and taking its full advantage has been an important way to reducing costs and accelerating processes in domain-related applications. Domain ontology, providing a common and unambiguous understanding of a domain for both the users and the system to communicate with each other via a set of representational primitives, has been proposed as an important and natural approach to represent domain knowledge. Most domain knowledge about domain entities with their properties and relationships is embodied in document collections. Thus, extracting ontologies from these documents is an important means of ontology construction. In this paper, a graph-based approach for automatic construction of domain ontology from domain corpus, named GRAONTO, has been proposed. First, each document in the collection is represented by a graph. After the generation of document graphs, random walk term weighting is employed to estimate the relevance of the information of a term to the corpus from both local and global perspectives. Next, the MCL (Markov Clustering) algorithm is used to disambiguate terms with different meanings and group similar terms to produce concepts. Next, an improved gSpan algorithm constrained by both vertices and informativeness is exploited to find arbitrary latent relations among these concepts. Finally, the domain ontology is output in the OWL format. For ontology evaluation purposes, a method for adaptive adjustment of concepts and relations with respect to its practical effectiveness is conceived. Evaluation experiments show that GRAONTO is a promising approach for domain ontology construction. (C) 2011 Elsevier Ltd. All rights reserved.

O O O O O B I I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

document graph
graph clustering
frequent subgraph mining
informative subgraph


Existence results for an evolution problem with fractional nonlocal conditions A second-order abstract problem involving derivatives of non-integer order in the nonlinearity as well as in the nonlocal conditions is considered. This problem covers many situations arising in real world phenomena and extends the case of integer order to the case of non-integer order. We establish the existence of mild solutions. Under extra appropriate sufficient assumptions on the nonlinearity and on the initial data these mild solutions are shown to be classical.

O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O B I O O O O O

fractional nonlocal conditions
mild solutions

cauchy problem
cosine family
fractional derivative
second-order abstract problem


towards automatic derivation of a product performance model from a uml software product line model Software Product Line (SPL) engineering is a software development approach that takes advantage of the commonality and variability between products from a family, and supports the generation of specific products by reusing a set of core family assets. This paper proposes a UML model transformation approach for software product lines to derive a performance model for a specific product. The input to the proposed technique, the "source model", is a UML model of a SPL with performance annotations, which uses two separate profiles: a "product line" profile from literature for specifying the commonality and variability between products, and the MARTE profile recently standardized by OMG for performance annotations. The source model is generic and therefore its performance annotations must be parameterized. The proposed derivation of a performance model for a concrete product requires two steps: a) the transformation of a SPL model to a UML model with performance annotations for a given product, and b) the transformation of the outcome of the first step into a performance model. This paper focuses on the first step, whereas the second step will use the PUMA transformation approach of annotated UML models to performance models, developed in previous work. The output of the first step, named "target model", is a UML model with MARTE annotations, where the variability expressed in the SPL model has been analyzed and bound to a specific product, and the generic performance annotations have been bound to concrete values for the product. The proposed technique is illustrated with an e-commerce case study.

O O O O O O O O O O B B I I O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B B I O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O B O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

model transformation
software product line
marte
uml


Rate-distortion optimized tree-structured compression algorithms for piecewise polynomial images This paper presents novel coding algorithms based on tree-structured segmentation, which achieve the correct asymptotic rate-distortion (R-D) behavior for a simple class of signals, known as piecewise polynomials, by using an R-D based prune and join scheme. For the one-dimensional case, our scheme is based on binary-tree segmentation of the signal. This scheme approximates the signal segments using polynomial models and utilizes an R-D optimal bit allocation strategy among the different signal segments. The scheme further encodes similar neighbors jointly to achieve the correct exponentially decaying R-D behavior (D (R) similar to c(0)2-(c1 R)), thus improving over classic wavelet schemes. We also prove that the computational complexity of the scheme is of O (N log N). We then show the extension of this scheme to the two-dimensional case using a quadtree. This quadtree-coding scheme also achieves an exponentially decaying R-D behavior, for the polygonal image model composed of a white polygon-shaped object against a uniform black background, with low computational cost of O (N log N). Again, the key is an R-D optimized prune and join strategy. Finally, we conclude with numerical results, which show that the proposed quadtree-coding scheme outperforms JPEG2000 by about 1 dB for real images, like cameraman, at low rates of around 0.15 bpp.

O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

binary tree
neighbor joining
piecewise polynomial functions
pruning
rate-distortion
tree-structured segmentation


On link layer denial of service in data wireless LANs In this paper, we investigate the resiliency to jamming of data protocols, such as IP, over WLAN. We show that, on existing WLAN, an adversary can successfully jam data packets at a very low energy cost. Such attacks allow a set of adversary nodes disseminated over an area to prevent communication, partition an ad hoc network or force packets to be routed over adversary chosen paths. The ratio of the jamming pulses duration to the transmission duration can be as low as 10(-4). We investigate and analyze the performance of combining a cryptographic interleaver with various coding schemes to improve the robustness of wireless LANs for IP packets transmission [1]. A concatenated code that is simple to decode and can maintain a low frame error rate (FER) under a jamming effort ratio of 15%. We argue that LDPC codes will be very suitable to prevent this type of jamming. We investigate the theoretical limits by analyzing the performance derived from upper bounds on binary error-control codes. We also propose an efficient anti-jamming technique for IEEE802.11b based on Reed-Solomon codes. Copyright (c) 2004 John Wiley & Sons, Ltd.

O B I B I I O O O O O O O O O O O O B O O O O O O O B O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

denial of service
jamming
link layer
wlan

error control codes
ieee802.11
interleaving
wireless networks


monitoring, accounting and automated decision support for the alice experiment based on the monalisa framework The successful administration of a global Data Grid system requires collecting and storing relevant monitoring information, using it to show the status and the trends of the entire system. The collected information is further used in developing the higher-level services and components of the distributed system to provide a degree of automated operational decisions, in order to maintain and optimize the work-flow through the entire system. In this paper we present the architecture of the monitoring system, developed within the MonALISA framework, for the ALICE Grid. The system uses flexible mechanisms for collecting, aggregating, storing and presenting monitoring information both in near real-time or history charts, in global or specific views, being able to generate alerts or take automated decisions based on it.

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Multi-channel information seeking: a fuzzy conceptual model Information seeking is a fluid and situation dependent activity where a seeker's actions are influenced by access to information, perceived quality (or information fit) and trust in the information source. All of these factors combined create an ever-changing information-seeking environment. Generally, traditional models and survey methodologies capture a "snapshot in time" of a particular information-seeking activity, but fail to capture the multivalent influences of things such as chance, frequency of encounters, strength of source or the introduction of new or multiple influencers. Using the tool of fuzzy control systems, a new conceptual model is introduced that not only diagrams the influences on the information seeker, but also provides a framework to devise (or refine existing) communications strategies.

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Adaptive Isotopic Approximation of Nonsingular Curves: the Parameterizability and Nonlocal Isotopy Approach We consider domain subdivision algorithms for computing isotopic approximations of a nonsingular algebraic curve. The curve is given by a polynomial equation f(X,Y)=0. Two algorithms in this area are from Snyder (1992) SIGGRAPH Comput. Graphics, 26(2), 121 and Plantinga and Vegter (2004) In Proc. Eurographics Symposium on Geometry Processing, pp. 245-254. We introduce a new algorithm that combines the advantages of these two algorithms: like Snyder, we use the parameterizability criterion for subdivision, and like Plantinga and Vegter, we exploit nonlocal isotopy. We further extend our algorithm in two important and practical directions: first, we allow subdivision cells to be rectangles with arbitrary but bounded aspect ratios. Second, we extend the input domains to be regions R (0) with arbitrary geometry and which might not be simply connected. Our algorithm halts as long as the curve has no singularities in the region, and intersects the boundary of R (0) transversally. Our algorithm is practical and easy to implement exactly. We report some very encouraging experimental results, showing that our algorithms can be much more efficient than the algorithms of Plantinga-Vegter and Snyder.

O O O O O O O B O O B O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

isotopy
parameterizability
subdivision algorithms

meshing
curve approximation
topological correctness
exact algorithms


Decentralized H-infinity Filter Design for Discrete-Time Interconnected Fuzzy Systems This paper describes a decentralized H-infinity filter design for discrete-time interconnected fuzzy systems based on piecewise-quadratic Lyapunov functions. The systems consist of J discrete-time interconnected Takagi-Sugeno (T-S) fuzzy subsystems, and a decentralized H-infinity filter is designed for each subsystem. It is shown that the stability of the overall filtering-error system with H-infinity performance can be established if a piecewise-quadratic Lyapunov function can be constructed. Moreover, the parameters of filters can be obtained by solving a set of linear matrix inequalities that are numerically feasible. Two simulation examples are given to show the effectiveness of the proposed approach.

B O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

h-infinity filter
interconnected fuzzy system
linear matrix inequalities (lmis)
takagi-sugeno (t-s) model


A multi-objective particle swarm optimization for project selection problem Selecting the most appropriate projects out of a given set of investment proposals is recognized as a critical issue for which the decision maker takes several aspects into consideration. Since many of these aspects may be conflicting, the problem is rendered as a multi-objective one. Consequently, we consider a multi-objective project selection problem in this study where total benefits are to be maximized while total risk and total coat must be minimized, simultaneously. Since solving an NP-hard problem becomes demanding as the number of projects grows, a multi-objective particle swarm with new selection regimes for global best and personal best for swarm members is designed to find the locally Pareto-optimal frontier and is compared with a salient multi-objective genetic algorithm, i.e. SPEAII, based on some comparison metrics with random instances.

O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

multi-objective particle swarm
multi-objective genetic algorithm