parallel packet classification using gpu co-processors In the domain of network security, packet filtering for classification purposes is of significant interest. Packet classification provides a mechanism for understanding the composition of packet streams arriving at distinct network interfaces, and is useful in diagnosing threats and uncovering vulnerabilities so as to maximise data integrity and system security. Traditional packet classifiers, such as PCAP, have utilised Control Flow Graphs (CFGs) in representing filter sets, due to both their amenability to optimisation, and their inherent structural applicability to the metaphor of decision-based classification. Unfortunately, CFGs do not map well to cooperative processing implementations, and single-threaded CPU-based implementations have proven too slow for real-time classification against multiple arbitrary filters on next generation networks. In this paper, we consider a novel multithreaded classification algorithm, optimised for execution on GPU co-processors, intended to accelerate classification throughput and maximise processing efficiency in a highly parallel execution context.

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

network telescope
general packet filter
gp-gpu
cuda


A resource-sharing game with relative priorities Motivated by cloud-based computing resources operating with relative priorities, we investigate the strategic interaction between a fixed number of users sharing the capacity of a processor. Each user chooses a payment, which corresponds to his priority level, and submits jobs of variable sizes according to a stochastic process. These jobs have to be completed before some user-specific deadline. They are executed on the processor and receive a share of the capacity that is proportional to the priority level. The users goal is to choose priority levels so as to minimize their own payment, while guaranteeing that their jobs meet their deadlines. We fully characterize the solution of the game for two classes of users and exponential service times. For an arbitrary number of classes and general service times, we develop an approximation based on heavy-traffic and we characterize the solution of the game under the heavy-traffic assumption. Our experiments show that the approximate solution captures accurately the structure of the equilibrium in the original game.

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

pricing
queueing games
heavy-traffic approximation
discriminatory processor-sharing


Entropy/length profiles, bounds on the minimal covering of bipartite graphs, and trellis complexity of nonlinear codes In this paper, the trellis representation of nonlinear codes is studied from a new perspective, We introduce the new concept of entropy/length profile (ELP), This profile can be considered as an extension of the dimension/length profile (DLP) to nonlinear codes, This elaboration of the DLP, the entropy/length profiles, appears to be suitable to the analysis of nonlinear codes, Additionally and independently, we use well-known information-theoretic measures to derive novel bounds on the minimal covering of a bipartite graph by complete subgraphs. We use these bounds in conjunction with the ELP notion to derive both lower and upper bounds on the stale complexity and branch complexity profiles of (nonlinear) block codes represented by any trellis diagram. We lay down no restrictions on the trellis structure, and we do not confine the scope of our results to proper of one-to-one trellises only, The basic lower bound on the state complexity profile implies that the state complexity at any given level cannot be smaller than the mutual information between the past and the future portions of the code at this level under a uniform distribution of the codewords, We also devise a different probabilistic model to prove that the minimum achievable state complexity over all possible trellises is not larger than the maximum value of the above mutual information over all possible probability distributions of the codewords, This approach is pursued further to derive similar bounds on the branch complexity profile, To the best of our knowledge, the proposed upper bounds are the only upper bounds that address nonlinear codes, The novel fewer bounds are tighter than the existing bounds, The new quantities and hounds reduce to well-known results when applied to linear codes.

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

bipartite graphs
mutual information
nonlinear codes
trellis complexity

complete graphs
entropy
entropy/length profiles


A truck loading problem A vehicle with m compartments transports q different products of various sizes from a source to n different destinations. The operational problem is how to load the compartments of the vehicle so that the replenishment time is maximized for a given route of destinations. A mixed integer linear programming model is developed for this class of problems. An investigation of the structure of the model reveals that a subproblem can be obtained in the form of a weighted distribution problem. Consequently, a simple subalgorithm finds an integer solution to this subproblem. The main algorithm bisects the interval of uncertainty until it becomes sufficiently small. There is another subalgorithm to test whether a feasible solution exists in the final interval of uncertainty by solving a Phase I problem. Our numerical experience has shown its computational efficiency and the quality of the solutions obtained. A problem of size 30 can be solved by this method in a fraction of a second. Further, an optimal solution is obtained in 82% of the randomly chosen problems. (C) 2010 Elsevier Ltd. All rights reserved.

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 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

loading problem
weighted distribution problem


A tabu search algorithm for the flowshop scheduling problem with changing neighborhoods Flowshop scheduling deals with the sequencing of a set of jobs that visit a set of machines in the same order. A tabu search procedure is proposed for the flowshop scheduling problem with the makespan minimization criterion. Different from other tabu search procedures, the neighborhood of a solution is generated using a combination of three different exchange mechanisms. This has resulted in a well-diversified search procedure. The performance of the algorithm is tested using Taillard's benchmark problems. The results are compared to recently developed neuro-tabu search and ant colony heuristics. The computational results indicate the effectiveness of the proposed approach. (c) 2007 Elsevier Ltd. All rights reserved.

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

flowshop
scheduling
tabu search
heuristics
neighborhood


TSL: A System for Generating Abstract Interpreters and its Application to Machine-Code Analysis This article describes the design and implementation of a system, called TSL (for Transformer Specification Language), that provides a systematic solution to the problem of creating retargetable tools for analyzing machine code. TSL is a tool generator-that is, a metatool-that automatically creates different abstract interpreters for machine-code instruction sets. The most challenging technical issue that we faced in designing TSL was how to automate the generation of the set of abstract transformers for a given abstract interpretation of a given instruction set. From a description of the concrete operational semantics of an instruction set, together with the datatypes and operations that define an abstract domain, TSL automatically creates the set of abstract transformers for the instructions of the instruction set. TSL advances the state-of-the-art in program analysis because it provides two dimensions of parameterizability: (i) a given analysis component can be retargeted to different instruction sets; (ii) multiple analysis components can be created automatically from a single specification of the concrete operational semantics of the language to be analyzed. TSL is an abstract-transformer-generator generator. The article describes the principles behind TSL, and discusses how one uses TSL to develop different abstract interpreters.

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

algorithms
languages
security
theory
verification
machine-code analysis
dynamic analysis
symbolic analysis
static analysis
dataflow analysis


Characteristic functions and option valuation in a Markov chain market We introduce an approach for valuing some path-dependent options in a discrete-time Markov chain market based on the characteristic function of a vector of occupation times of the chain. A pricing kernel is introduced and analytical formulas for the prices of Asian options and occupation time call options are derived.

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

markov chain market
occupation times
characteristic functions
asian options


Probability-free solutions to the non-stationary newsvendor problem This paper concerns the multi-period newsvendor problem. In this problem, the decision maker has to decide the order quantity of an item in the subsequent period in which the demand is usually unknown. No statistical assumptions are made about the unknown demand. We adopt an online learning method from the field of prediction with expert advice to study the non-stationary newsvendor problem. We propose newsvendor strategies for both real-valued and integer order quantities. Taking the non-stationary strategies that can switch between different order quantities as benchmark, we prove that our proposed strategies can guarantee that the newsvendors cumulative gains are almost as large as those of the best switching strategies with not too many switches. Simple computational experiments are further performed to illustrate the effectiveness of our strategies.

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

distribution-free inventory strategy
switching strategy
weak aggregating algorithm


A neural network approach to multiobjective and multilevel programming problems This study aims at utilizing the dynamic behavior of artificial neural networks (ANNs) to solve multiobjective programming (MOP) and multilevel programming (MLP) problems. The traditional and nontraditional approaches to the MLP are first classified into five categories. Then, based on the approach proposed by Hopfield and Tank [1], the optimization problem is converted into a system of nonlinear differential equations through the use of an energy function and Lagrange multipliers. Finally, the procedure is extended to MOP and MLP problems. To solve the resulting differential equations, a steepest descent search technique is used. This proposed nontraditional algorithm is efficient for solving complex problems, and is especially useful for implementation on a large-scale VLSI, in which the MOP and MLP problems can be solved on a real time basis. To illustrate the approach, several numerical examples are solved and compared. (C) 2004 Elsevier Ltd. All rights reserved.

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

neural network
energy function
multilevel programming
multiobjective programming
dynamic behavior


Calculation of surface energy associated with formation of multiple kinked cracks An energy parameter termed Mc is proposed for calculation of the surface energy associated with formation of multiple kinked cracks in 2-D anisotropic elastic solids. The formulation is based on a path-independent contour integral. The surface energy can be exactly evaluated by Mc when the cracked solids are homogeneously-stressed (i.e., the material characteristic), and effectively approximated when the solids are nonhomogeneously-stressed (i.e., the structural characteristic). It is thus suggested that Mc be possibly used as a fracture parameter that quantitatively measures the degradation of material (e.g. in micromechanics) and/or structural integrity due to irreversible evolution of multiple kinked cracks.

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

multiple kinked cracks
surface energy
material characteristic
structural characteristic


Noise tolerance in a Neocognitron-like network The Neocognitron and its related hierarchical models have been shown to be competitive in recognizing handwritten digits and objects. However, the tolerance of these models to several types of noise can be low. We will start by briefly overviewing some previous results regarding the tolerance of these models. Afterwards, we report the higher noise tolerance of the winner-take-all response in a hierarchical model over related models. We provide an analysis and interpretation of this tolerance under Bayesian decision theory. Finally, we report on how to further improve recognition for extremely noisy patterns.

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 O O O O 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 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

neocognitron
hierarchical model
noise tolerance

winner-take-all
lateral competition
selectivity


Using an E-Health Intervention to Promote the Health of Cancer Survivors With Preexisting Disabling Conditions Although there has been research on the use of e-health for cancer patients and those living with disabilities, no interventions focus on cancer survivors who had a disabling condition prior to their cancer. Therefore, we developed and piloted the feasibility of the online health-promotion program LiveAble. Based on a theoretically driven health-promotion program previously shown to be effective among people with various chronic conditions, LiveAble was adapted to be an e-heath intervention for cancer survivors with preexisting disabilities. Eleven cancer survivors reviewed LiveAble and provided feedback. The participants' average age was 54 years. Most had neuromuscular impairments prior to their cancer; about half were breast cancer survivors. Average scores on the Self-efficacy for Health Practices Scale increased. Participants rated LiveAble useful, attractively presented, and relevant to people with disabilities. Their feedback also suggested areas for change, such as a system that was easier to navigate and more individualized. Only 51% of these participants agreed that LiveAble motivated them to take action to improve their health. To turn information into action, participants may need additional assistance and encouragement. Although preliminary results were promising, future efforts should determine the efficacy of LiveAble with larger and more diverse groups of survivors.

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 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 B I O O B 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 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


Effect of electronic secondary markets on the supply chain We present a model to investigate the competitive implications of electronic secondary markets that promote concurrent selling of new and used goods on a supply chain. In secondary markets where suppliers cannot directly utilize used goods for practicing intertemporal price discrimination and where transaction costs of resales are negligible, the threat of cannibalization of new goods by used goods becomes significant. We examine conditions under which it is optimal for suppliers to operate in such markets, explaining why these markets may not always be detrimental for them. Intuitively, secondary markets provide an active outlet for some high-valuation consumers to sell their used goods. The potential for such resales leads to an increase in consumers' valuation for a new good, leading them to buy an additional new good. Given sufficient heterogeneity in consumers' affinity across multiple suppliers' products, the "market expansion effect" accruing from consumers' cross-product purchase affinity can mitigate the losses incurred by suppliers from the direct "cannibalization effect." We also highlight the strategic role that the used goods commission set by the retailer plays in determining profits for suppliers. We conclude the paper by empirically testing some implications of our model using a unique data set from the online book industry, which has a flourishing secondary market.

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

electronic markets
information goods
market segmentation
quality degradation
used goods markets


Enabling Adaptive Video Streaming for BitTorrent-Like Video Systems BitTorrent (BT) is one of the most efficient file sharing mechanisms in Internet. BitTorrent can distribute large files efficiently by using the shared bandwidth of the downloading peers. Using the rarest file first piece selection algorithm to download the data, BitTorrent's downloaded data pieces are stored in an out-of-order way. Therefore, users can not watch a movie before the whole video file is downloaded. In order to support the video streaming for BitTorrent-based systems, we propose several mechanisms to improve the original BitTorrent protocol: (1) frame selection algorithms named decoding order frame first (DOFF) and rarest I frame first (RIFF); (2) an adaptive streaming retrieval scheme to allocate the available bandwidth adaptively for video streams. The adaptive streaming retrieval scheme periodically checks the streaming buffer to have knowledge of downloaded frames, and then allocates the available bandwidth for adapting frame downloading jobs with DOFF and RIFF frame selection algorithms. As a result, users can have smoother video playout experience than original BitTorrent protocol.

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

peer-to-peer network
rarest first algorithm


Compressed Sensing Signal and Data Acquisition in Wireless Sensor Networks and Internet of Things The emerging compressed sensing (CS) theory can significantly reduce the number of sampling points that directly corresponds to the volume of data collected, which means that part of the redundant data is never acquired. It makes it possible to create standalone and net-centric applications with fewer resources required in Internet of Things (IoT). CS-based signal and information acquisition/compression paradigm combines the non-linear reconstruction algorithm and random sampling on a sparse basis that provides a promising approach to compress signal and data in information systems. This paper investigates how CS can provide new insights into data sampling and acquisition in wireless sensor networks and IoT. First, we briefly introduce the CS theory with respect to the sampling and transmission coordination during the network lifetime through providing a compressed sampling process with low computation costs. Then, a CS-based framework is proposed for IoT, in which the end nodes measure, transmit, and store the sampled data in the framework. Then, an efficient cluster-sparse reconstruction algorithm is proposed for in-network compression aiming at more accurate data reconstruction and lower energy efficiency. Performance is evaluated with respect to network size using datasets acquired by a real-life deployment.

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

compressed sensing (cs)
enterprise systems
industrial informatics
internet of things (iot)
wireless sensor networks (wsns)


Incorporating spectral data into logistic regression model to classify land cover: a case study in Mt. Qomolangma (Everest) National Nature Preserve Only few models for land-cover classification incorporated spectral data into ordinary logistic regression (OL model) in the Mt. Qomolangma (Everest) National Nature Preserve (QNNP) in China. In this study, spectral variables were incorporated into OL model and autologistic regression (AL) model to classify six main land covers. Twelve environmental variables and seven spectral variables of 10,000 stratified random sites in the QNNP were quantified and analyzed; OL model, AL model, OL model with spectral data (OLM model), and AL model with spectral data (ALM model) were estimated. The OLM and ALM models produced better estimates of regression coefficients and significantly improved model performance and overall accuracy for the grassland, sparsely vegetated land, and bare land compared with OL and AL models.

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

logistic regression model
land cover
classification

autologistic regression model
spectral variable
mt. qomolangma national nature preserve


UML-BASED MODELING AND ANALYSIS OF SECURITY THREATS Poor design has been a major source of software security problems. Rigorous and designer-friendly methodologies for modeling and analyzing secure software are highly desirable. A formal method for software development, however, often suffers from a gap between the rigidity of the method and the informal nature of system requirements. To narrow this gap, this paper presents a UML-based framework for modeling and analyzing security threats (i.e. potential security attacks) rigorously and visually. We model the intended functions of a software application with UML statechart diagrams and the security threats with sequence diagrams, respectively. Statechart diagrams are automatically converted into a graph transformation system, which has a well-established theoretical foundation. Method invocations in a sequence diagram of a security threat are interpreted as a sequence of paired graph transformations. Therefore, the analysis of a security threat is conducted through simulating the state transitions from an initial state to a final state triggered by method invocations. In our approach, designers directly work with UML diagrams to visually model system behaviors and security threats while threats can still be rigorously analyzed based on graph transformation.

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


A new approach to visioplasticity in dynamic plane upsetting A new numerical approach to analyze the stress distributions in the plane-strain upsetting process is developed. In this procedure, the generalizing stream function with the velocity parameters used to find the optimal flow pattern is produced first, and then the velocity and strain-rate fields can be obtained. From the strain-rate fields calculated, the stress fields can be found by the constructed slip-lines from CauchyRiemann equations. Along these slip-lines, the stress fields can be calculated easily from Hencky equations. The results show that this method presents a good and reasonable solution compared with the slab method and traditional visioplasticity.

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

gerneralizing stream function
slip-line functions


Computation of 3D queries for ROCS based virtual screens Rapid overlay of chemical structures (ROCS) is a method that aligns molecules based on shape and/or chemical similarity. It is often used in 3D ligand-based virtual screening. Given a query consisting of a single conformation of an active molecule ROCS can generate highly enriched hit lists. Typically the chosen query conformation is a minimum energy structure. Can better enrichment be obtained using conformations other than the minimum energy structure? To answer this question a methodology has been developed called CORAL (COnformational analysis, Rocs ALignment). For a given set of molecule conformations it computes optimized conformations for ROCS screening. It does so by clustering all conformations of a chosen molecule set using pairwise ROCS combo scores. The best representative conformation is that which has the highest average overlap with the rest of the conformations in the cluster. It is these best representative conformations that are then used for virtual screening. CORAL was tested by performing virtual screening experiments with the 40 DUD (Directory of Useful Decoys) data sets. Both CORAL and minimum energy queries were used. The recognition capability of each query was quantified as the area under the ROC curve (AUC). Results show that the CORAL AUC values are on average larger than the minimum energy AUC values. This demonstrates that one can indeed obtain better ROCS enrichments with conformations other than the minimum energy structure. As a result, CORAL analysis can be a valuable first step in virtual screening workflows using ROCS.

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 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 B 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 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 B

ligand-based virtual screening
optimized query conformation
roc curve analysis
statistical significance
virtual screening workflow


security and privacy considerations in digital death Death is an uncomfortable subject for many people, and digital systems are rarely designed to deal with this event. In particular, the wide array of existing digital authentication infrastructure rarely deals with gracefully retiring credentials in a uniform fashion. This research paper highlights an emerging paradigm: gracefully dealing with expired digital identities in a secure, privacy-preserving fashion. It examines the confluence of modern browser technology, cloud services, and human factors involved in managing a person's digital footprint while they live and retiring it when they die. We contemplate a potential approach to dealing with credentials after death by using cloud computing. We consider the reasons that such an approach may actually provide an opportunity for enhancing authentication security by frustrating identity stealing attacks. We note that this paper is not aimed at trivializing the real grief and loss that people feel, but rather an attempt to understand how security and privacy concerns are shaped by the end of life, with the ultimate goal of easing this transition for friends and family.

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

digital end-of-life
cloud identity management
identity containers


The use of a computerized brain atlas to support knowledge-based training in radiology Trainers of radiologists face the particular challenges of teaching normal and abnormal appearance for a variety of imaging modalities, providing access to a large appropriately-indexed case library, and teaching a consistent approach to the reporting of cases. The computer has the potential to address these issues, to supplement conventional teaching of radiology by providing case-based tutoring and diagnostic support based on a large library of images of normal and abnormal anatomy, described in a consistent terminology. The paper presents a new approach to computer-based training in radiology that combines a knowledge-based tutor with an on-line medical atlas. It describes two existing computer systems, the MR Tutor and ATLAS, and discusses the medical, computational, epistemic, and pedagogic issues involved in developing a combined AtlasTutor. Integrating an atlas with a training system could significantly improve the teaching and support offered, but practical difficulties include the need to merge knowledge representations and to incorporate techniques for registering atlas plates on images that exhibit abnormalities. The paper addresses these problems, and concludes by indicating how the AtlasTutor might be employed in practical radiology training.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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-based training
computer-based atlas
knowledge representation
magnetic resonance imaging
neuroradiology


profit-maximizing multicast pricing by approximating fixed points [extended abstract] We describe a fixed point approach for the following stochastic optimization problem: given a multicast tree and probability distributions of user utilities, compute prices to offer the users in order to maximize the expected profit of the service provider. We show that any optimum pricing is a fixed point of an efficiently computable map. In the language of classical numerical analysis, we show that the non-linear Jacobi and Gauss-Seidel methods of coordinate descent are applicable to this problem. We provide proof of convergence to the optimum prices for special cases of utility distributions and tree edge costs.

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 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


Research and performance evaluation of data replication technology in distributed storage systems Replication is a key technology of distributed storage systems. In this paper, an indirect replication algorithm is proposed following the intrinsic characteristic of distributed storage systems and the peer-to-peer model. In the indirect replication algorithm, the data object is partitioned into several data blocks. These data blocks are encoded in order that there is data redundancy between data blocks. Comparing with the traditional replication algorithm, the indirect replication algorithm has less granularity of replication, less bandwidth and storage costs, and provides higher availability, durability, and security. The performance evaluation shows that the encoding and decoding times are proportional to the data size, and that the irregular cascade bipartite graphs are of great advantage in improving the success ratio of data recovery. Finally, if the number of data blocks used to recover the data object is larger than a certain value, the success ratio of data recovery approaches 100%. (c) 2006 Elsevier Ltd. All rights reserved.

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

distributed storage system
data availability
code


Evaporation model for interfacial flows based on a continuum-field representation of the source terms An evaporation model compatible with interface-capturing schemes for vaporliquid flow is presented. The model formulation is largely independent of the specific realization of interface-capturing and relies on a continuum-field representation of the source terms implementable in a broad class of CFD models. In contrast to most other numerical methods for evaporating interfacial flows, the model incorporates an evaporation source-term derived from a physical relationship for the evaporation mass flux. It is shown that especially for microscale evaporation phenomena this implies significant deviations of the interface temperature from the saturation temperature. The mass source-term distribution is derived from the solution of an inhomogeneous Helmholtz equation that contains a free parameter allowing to tune the spatial localization of the source. The evaporation model is implemented into the volume-of-fluid scheme with piecewise linear interface construction. Results are obtained for three analytically or semi-analytically solvable model problems, the first two being one-dimensional Stefan problems, the third a free droplet evaporation problem. In addition, a two-dimensional film boiling problem is considered. Overall, the comparison between the CFD and the (semi)-analytical models shows good agreement. Deviations exist where convective heat transfer due to spurious currents is no longer negligible compared to heat conduction. With regard to the film boiling problem, a similar evaporation pattern as recently identified using a level-set method is found. A major advantage of the developed evaporation model is that it does not refer to intrinsic details of the interface-capturing scheme, but relies on continuum-field quantities that can be computed by virtually any CFD approach.

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

evaporation model
droplet evaporation
film boiling

interfacial flow
volume-of-fluid method
stefan problem


Learning Kernels for Unsupervised Domain Adaptation with Applications to Visual Object Recognition Domain adaptation aims to correct the mismatch in statistical properties between the source domain on which a classifier is trained and the target domain to which the classifier is to be applied. In this paper, we address the challenging scenario of unsupervised domain adaptation, where the target domain does not provide any annotated data to assist in adapting the classifier. Our strategy is to learn robust features which are resilient to the mismatch across domains and then use them to construct classifiers that will perform well on the target domain. To this end, we propose novel kernel learning approaches to infer such features for adaptation. Concretely, we explore two closely related directions. In the first direction, we propose unsupervised learning of a geodesic flow kernel (GFK). The GFK summarizes the inner products in an infinite sequence of feature subspaces that smoothly interpolates between the source and target domains. In the second direction, we propose supervised learning of a kernel that discriminatively combines multiple base GFKs. Those base kernels model the source and the target domains at fine-grained granularities. In particular, each base kernel pivots on a different set of landmarksthe most useful data instances that reveal the similarity between the source and the target domains, thus bridging them to achieve adaptation. Our approaches are computationally convenient, automatically infer important hyper-parameters, and are capable of learning features and classifiers discriminatively without demanding labeled data from the target domain. In extensive empirical studies on standard benchmark recognition datasets, our appraches yield state-of-the-art results compared to a variety of competing methods.

O B O O B I 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 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 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

domain adaptation
kernels
object recognition


Understanding the ways in which design features of educational websites impact upon student learning outcomes in blended learning environments This study investigated the effectiveness, in terms of the attainment of relevant learning outcomes, of the types of learning promoted by educational features commonly incorporated in course management systems. Twenty-one courses with significant use of the Internet, but with face-to-face teaching as the predominant instructional mode, were investigated. Five hundred and ninety-five students taking these 21 courses completed a questionnaire which gave feedback on the extent of use of and quality of implementation of internet features, as well as their perception of the attainment of outcomes relating to approaches to learning, communication skills and understanding of content. A confirmatory factor analysis of scales pertinent to information presentation and constructive dialogue features showed a very poor fit to the data, indicating that the two types of function did not act in concert. Structural equation modelling was used to test instructional models in presage-process-product format for 'information' and 'dialogue' features. The information one showed a marginal fit to the data, but the dialogue one a very good fit. This shows that using the Internet for presenting information in a blended environment does not seem to effectively help students achieve learning outcomes. Using features which promote constructive dialogue and interactive learning activities encourages a deep approach to learning, the development of communication skills and enhanced understanding of content. (C) 2010 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

computer-mediated communication
interactive learning environments
pedagogical issues
teaching/learning strategies


Analysis of composite dynamics of two bifurcating neurons This paper presents pulse-coupled two bifurcating neurons. The single neuron is represented by a spike position map and the coupled neurons can be represented by a composition of the spike position maps. Using the composite map, we can analyze basic bifurcation phenomena and can find some interesting phenomena that are caused by the pulse-coupling and are impossible in the single neuron. Presenting a simple test circuit, typical phenomena are confirmed experimentally.

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

synchronization
chaos
spiking neuron
pulse-coupled neural networks


Object-oriented transformations for extracting aspects In the migration of object-oriented systems towards the aspect technology, after locating fragments of code presenting a crosscutting behavior and before extracting such code to aspects, transformations may be needed in the base program. Such transformations aim to associate crosscutting code to points of the base program that can be captured using the pointcut descriptor model of aspect-oriented languages. In this paper, we present a catalog of object-oriented transformations and demonstrate the importance of such transformations by reporting on a case study involving four systems that have been aspectized using AspectJ.

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

aspect-oriented programming
refactoring
software evolution
program transformation


EULDEP: a program for the Euler deconvolution of magnetic and gravity data Measurements of the geomagnetic field can be used to help determine the structure of the Earth, since rocks often contain magnetic minerals. Measurements of the strength of the Earth's gravitational field can also be used, since the more dense the rocks, the stronger the field. The interpretation of large amounts of data can be aided by automatic interpretation techniques such as Euler deconvolution. This considers the anomalies to be caused by many relatively simple sources (such as dipoles or lines of dipoles) and produces the positions and depths of these sources. This data can then be used as a basis for a more detailed interpretation. The software runs under DOS and is available free via ftp from ftp.cs.wits.ac.za in directory/pub/general/geophys.

O O O O O B B 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 B 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


The Poetics of Purpose Hackles have been raised in biosemiotic circles by T. L. Shorts assertion that semiosis, as defined by Peirce, entails acting for purposes and therefore is not found below the level of the organism (2007a:174177). This paper examines Shorts teleology and theory of purposeful behavior and offers a remedy to the disagreement. Remediation becomes possible when the issue is reframed in the terms of the complexity sciences, which allows intentionality to be understood as the interplay between local and global aspects of a system within a system. What is called acting for purposes is not itself a type of behavior so much as a relationship between a dynamic system that exists for a purpose and its microprocesses that serve purposes. The intentional object of philosophy is recast here as the holistic self-organized dynamics of a system, which exists for the purpose of self-maintenance, and that constrains the parts behaviors, which serve the purpose of forming the system. (A system can be any emergent, e.g. an abiotic form, an adapted species, a self, a conditioned response, thought, or a set of ideas.) The self-organized whole, which is represented to the parts in their own constrained behaviors, assumes the guiding function so long attributed to the mysterious intentional object. If emergent self-causation is not disallowed, creative originality, as well as directionality, becomes part of the definition of purposeful behavior. Thus, key tools used here, required for understanding emergence, come from poetics rather than semoitics. In the microprocesses of self-organization, I find what I call accidental indices and icons which are poetic in the sense that they involve mere metonymic contiguity and metaphoric similarity and which are preferentially selected under constrained conditions allowing radically new connections to habituate into an intentional self-organized system that, not coincidentally, has some of the emergent characteristics of a conventional symbolic system.

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

complexity sciences
poetics
teleology
emergence

biosemiotics
t. l. short
j. p. crutchfield


from adaptation engineering to aspect-oriented context-dependency The evolution of the Web requires to consider an increasing number of context-dependency issues. Therefore, in our research we focus on how to extend a Web application with additional adaptation concerns without having to redesign the entire application. Based on a generic transcoding tool we illustrate here how we can add adaptation functionality to an existing Web application. Furthermore, we consider how an aspect-oriented approach can support the high-level specification of such additional concerns in the design of the Web application.

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 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

web engineering
component-based web engineering
aspect-oriented programming


Modelling systems defined by RTD curves The RTD theory is commonly used for describing flow patterns in a large class of applications, and particularly for ventilated enclosures. Experimental RTD curves are used for modelling these premises with an application in the nuclear industry for predicting the airborne pollutant transfers in order to prevent radiological risk. An approach based on a superstructure involving interlinked elementary flow patterns such as CSTRs, PFRs, recycles and by-passes is implemented. In order to propose a generic and easy to use tool, the associated large-scale MINLP problem is solved by using the GAMS package. After a validation phase on examples with known solutions, a laboratory enclosure, called MELANIE, used in the nuclear industry is modelled. The comparison between experimental RTD curve and the ones obtained from models extracted from superstructures shows good agreement. The superstructure-based solution procedure constitutes an efficient and intermediate way between numerical simulations using CFD codes and experimental determinations of characteristic parameters, which are both difficult to implement in the case of large and cluttered systems which are typical of the nuclear industry. (C) 2008 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 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 O O O O O O O O O O O O O O

air flow patterns
ventilation
residence time distribution
mixed-integer nonlinear programming


Extraction of 3D freeform surfaces as visual landmarks for real-time tracking This work presents a system for the generation of a free-form surface model from video sequences. Although any single centered camera can be applied in the proposed system the approach is demonstrated using fish-eye lenses because of their good properties for tracking. The system is designed to function automatically and to be flexible with respect to size and shape of the reconstructed scene. To minimize geometric assumptions a statistic fusion of dense depth maps is utilized. Special attention is payed to the necessary rectification of the spherical images and the resulting iso-disparity surfaces, which can be exploited in the fusion approach. Before dense depth estimation can be performed the cameras pose parameters are extracted by means of a structure-from-motion (SfM) scheme. In this respect automation of the system is achieved by thorough decision model based on robust statistics and error propagation of projective measurement uncertainties. This leads to a scene-independent set of only a few parameters. All system components are formulated in a general way, making it possible to cope with any single centered projection model, in particular with spherical cameras. In using wide field-of-view cameras the presented system is able to reliably retrieve poses and consistently reconstruct large scenes. A textured triangle mesh constructed on basis of the scenes reconstructed depth, makes the systems results suitable to function as reference models in a GPU driven analysis-by-synthesis framework for real-time tracking.

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

omnidirectional vision
visual scene reconstruction
structure-from-motion


a reassessment of the simultaneous dynamic range of the human visual system The dynamic range of the human visual system should be an important parameter in the design of high dynamic range (HDR) display devices. A good display should at least approximate this range. However, the literature reports a simultaneous dynamic range between 2 and 4 log units of luminance, leaving ambiguity as to what dynamic range HDR display devices should cater for. In this paper we present a sequence of psychophysical experiments, carried out with the aid of a high dynamic range display device, to determine the simultaneous dynamic range of the human visual system under full adaptation to a given background luminance. Our findings show that the human visual system is capable of distinguishing contrasts over a range of 3.7 log units under specific viewing conditions. Further, we show how the dynamic range is affected by stimulus duration, contrast of the stimulus as well as background illumination, thereby accounting for the differences reported in the literature and providing guidance for display design.

O O O O 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 B I 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 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 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 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


Using hybrid alignment for iterative sequence database searches Progressive sequence model refinement by means of iterative searches is an effective technique for high sensitivity database searches and is currently employed in popular tools such as PSI-BLAST and SAM. Recently, a novel alignment algorithm has been proposed that offers features expected to improve the sensitivity of such iterative approaches, specifically a well-characterized theory of its statistics even in the presence of position-specific gap costs. Here, we demonstrate that the new hybrid alignment algorithm is ready to be used as the alignment core of PSI-BLAST. In addition, we evaluate the accuracy of two proposed approaches to edge effect correction in short sequence alignment statistics that turns out to be one of the crucial issues in developing a hybrid-alignment based version of PSI-BLAST. Copyright (C) 2004 John Wiley Sons, Ltd.

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

hybrid algorithm
length correction
psi-blast
mpi


The Effect of Invitation Design on Web Survey Response Rates Web surveys present methodological challenges including lower response rates as compared to other survey methods. The literature on invitations to participate in web surveys builds on previous research suggesting that advance letters are cost-effective means for increasing response rates in mail surveys and interviewer-administered surveys. The efficacy and appropriateness of design elements of invitations to participate in a web survey is not yet well understood. This research reports results of a full-factorial experiment (n = 15,652) of five design elements of web survey invitations-invitation mode, subject line, location of URL link, length of the invitation text, and survey time/effort estimate. There were significant effects of different design elements on response rates. The results suggest that some design elements of invitations may have similar effects across subsets of populations, while others may have different effects on different subsets of potential respondents.

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

internet survey
survey invitation
survey recruitment
response rate
mail invitations
e-mail invitations


a survey on trust management for intelligent transportation system Trust management is a fundamental and critical aspect of any serious application in ITS. However, only a few studies have addressed this important problem. In this paper, we present a survey on trust management for ITS. We first describe the properties of trust, trust metrics and potential attacks against trust management schemes. Existing related works are then reviewed based on the way in which trust management is implemented. Along with the review, we also identify some open research questions for future work, and consequently present a novel idea of trust management implementation.

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 B I 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 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

entity trust
intelligent transportation system (its)
attack prevention
data trust


The independence number for polarity graphs of even order planes In this paper, we use coherent configurations to obtain new upper bounds on the independence number of orthogonal polarity graphs of projective planes of even order. In the case of classical planes of square even order, these bounds differ only by 1 from the size of the largest known independent sets.

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

projective plane
polarity graph
coherent configuration


Partial characterizations of clique-perfect graphs I: Subclasses of claw-free graphs ? A clique-transversal of a graph G is a subset of vertices that meets all the cliques of G. A clique-independent set is a collection of pairwise vertex-disjoint cliques. The clique-transversal number and clique-independence number of G are the sizes of a minimum clique-transversal and a maximum clique-independent set of G, respectively. A graph G is clique-perfect if these two numbers are equal for every induced subgraph of G. The list of minimal forbidden induced subgraphs for the class of clique-perfect graphs is not known. In this paper, we present a partial result in this direction; that is, we characterize clique-perfect graphs by a restricted list of forbidden induced subgraphs when the graph belongs to two different subclasses of claw-free graphs.

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

claw-free graphs
clique-perfect graphs
hereditary clique-helly graphs
line graphs
perfect graphs


Construction of the nearest neighbor embracing graph of a point set This paper gives optimal algorithms for the construction of the Nearest Neighbor Embracing Graph (NNE-graph) of a given point set V of size n in the k-dimensional space (k-D) for k = 2,3. The NNE-graph provides another way of connecting points in a communication network, which has lower expected degree at each point and shorter total length of connections with respect to those using Delaunay triangulation. In fact, the NNE-graph can also be used as a tool to test whether a point set is randomly generated or has some particular properties. We show that in 2-D the NNE-graph can be constructed in optimal Theta(n(2)) time in the worst case. We also present an O(n log n + nd) time algorithm, where d is the Omega(log n)-th largest degree in the utput NNE-graph. The algorithm is optimal when d=O(log n). The algorithm is also sensitive to the structure of the NNE-graph, for instance when d=g.(log n), the number of edges in NNE-graph is bounded by O(gn log n) for any value g with 1 <= g <= n/log n. We finally propose an O(n log n + nd log d*) time algorithm for the problem in 3-D, where d and d* are the Omega(log n/log log n)-th largest vertex degree and the largest vertex degree in the NNE-graph, respectively. The algorithm is optimal when the largest vertex degree of the NNE-graph d* is O(log n/log log n).

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

computational geometry
nearest neighbors
network connections


Web user clustering and Web prefetching using Random Indexing with weight functions Users of a Web site usually perform their interest-oriented actions by clicking or visiting Web pages, which are traced in access log files. Clustering Web user access patterns may capture common user interests to a Web site, and in turn, build user profiles for advanced Web applications, such as Web caching and prefetching. The conventional Web usage mining techniques for clustering Web user sessions can discover usage patterns directly, but cannot identify the latent factors or hidden relationships among users' navigational behaviour. In this paper, we propose an approach based on a vector space model, called Random Indexing, to discover such intrinsic characteristics of Web users' activities. The underlying factors are then utilised for clustering individual user navigational patterns and creating common user profiles. The clustering results will be used to predict and prefetch Web requests for grouped users. We demonstrate the usability and superiority of the proposed Web user clustering approach through experiments on a real Web log file. The clustering and prefetching tasks are evaluated by comparison with previous studies demonstrating better clustering performance and higher prefetching accuracy.

B I I O B I 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 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 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

web user clustering
random indexing
weight functions
web prefetching


An improved priority list and neighborhood search method for unit commitment The built MILP based on priority list can achieve the goal of the priority list method correctly. The presented neighborhood search algorithm can handle the ramp rate constraints efficiently. The proposed method can obtain high-quality solutions for UC with fast convergence rate.

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

improved priority list method
mixed integer linear programming


patterns for web applications This paper presents the preliminary results achieved in introducing a new formalism into the Web business logic layer. New useful and consistent patterns have been defined to support the modelling phase of web applications. The innovation in the use of patterns is extremely important when concepts like solidity, stability and reuse are crucial for the application design. The proposed patterns are graphically modelled using the Unified Modelling Language and formalized using the Object Constraints Language introduced by IBM. The new patterns are suitable for use in a CASE tool, to help developers build web solutions and eliminate inconsistences often present in natural languages.

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

web application
uml
pattern
design pattern


Accurate location estimation of sensor node using received signal strength measurements Received signal strength indications (RSSI) received at multiple anchors decay with distances that the signals have traveled to reach the sensors, so the sensor of unknown node can be uniquely located. By converting the nonlinear equations into linear equations the unconstrained least square calibration (ULSC) and constrained least square calibration (CLSC) algorithms are all algebraic closed-form solutions for RSSI-based wireless localization. The designed ULSC and CLSC algorithms obtain the corresponding best linear unbiased estimator by considering the anchor position uncertainty. The simulations demonstrate the validity of the localization computation method and test the impacts of signal strength noises on localization error. The results also show that the localization error of CLSC algorithm is less than that of ULSC algorithm and more close to the position CramerRao low bound (CRLB) which provides optimal position accuracy.

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

wireless sensor networks
received signal strength indication


The effects of panel arrangement on search performance This study investigated the effects of panel arrangement on search performance. The three variables of this experiment were panel arrangement, movement distance, and icon size. Participants were asked to search for target items within a four stimulus array which included: round, horizontal, square, and vertical panel arrangements. Four movement distances were used: ?1, ?2, ?4, and ?5. Three icon sizes were examined: 20, 24, and 27mm. Exposure duration was adopted as the dependent factor which was also treated as the within-subjects factor. Notably, this study is concerned with the users icon-clicking distance focusing on two distances, namely, the distance between the start position and the first icon on the panel (P1), and the distance between two icons (P2). Results showed that these three factors of panel arrangement, movement distance, and icon size have caused significant effects on the users search performance regarding the two distances mentioned above. Additionally, no difference with regard to search performance was found between the vertical and horizontal arrangements. The results obtained can form design guidelines which are applicable for future humancomputer interface design.

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 B I 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 B I 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

panel arrangement
movement distance
icon size


visual languages for event integration specification We are exploring existing approaches and developing new techniques for visual event-based system integration. We are using domain-specific visual languages with different high-level visual metaphors (including Tool Abstraction, Event-Query-Filter-Action and Spreadsheet) to specify event-handling support and provide backend processing tool support for event integration specification and visualisation of event propagation. We aim to generalise from three exemplar visual event-driven system metaphors and develop a new, generic visual event handling metaphor. From this we will build a visual environment for specifying event-based system integration. The visual metaphor we are developing should adapt the event-based communication model to a wide range of application domains, and also should support complex and intelligent system design and implementation.

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

domain-specific visual language tools
meta-case tools


Experiences in modeling and simulation of computer architectures in DEVS The use of traditional approaches to teach computer organization usually generates misconceptions in the students. The simulated computer ALFA-1 was designed to fill this gap. DEVS was used to attack this complex design of the chosen architecture, allowing for the definition and integration of individual components. DEVS also provided a formal specification framework, which allowed reduction of testing time and improvement of the development process. Using ALFA-1, the students acquired some practice in the design and implementation of hardware components, which is not usually achievable in computer organization courses.

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 B I O

applications of devs methodology
devs models
simulation in education


Small Variance Estimators for Rare Event Probabilities Improving Importance Sampling estimators for rare event probabilities requires sharp approximations of conditional densities. This is achieved for events defined through large exceedances of the empirical mean of summands of a random walk, in the domain of large or moderate deviations. The approximation of conditional density of the trajectory of the random walk is handled on long runs. The length of those runs which is compatible with a given accuracy is discussed; simulated results are presented, which enlight the gain of the present approach over classical Importance Sampling schemes. Detailed algorithms are proposed.

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


The boundedness of Gorman's Superposition method for free vibration analysis of plates Gorman's Superposition method is known as one of the most efficient methods to solve the eigenvalue problems of plates because of its excellent convergence rate. However, there are few published results available that provide sufficient information on its boundedness. Here we have considered the nature of convergence of the eigenvalues for rectangular plates with the following sets of boundary conditions, completely free, fully clamped and cantilever. This paper shows numerically, the boundedness of the Superposition method for undamped vibration problems of rectangular isotropic plates subjected to different boundary conditions. The Superposition method gives upper bound results for eigenvalues of plates if the building blocks used in the Superposition method are subjected to stiffer boundary conditions than those of the original system being modelled. In contrast, the Superposition method yields lower bound results if the boundary conditions of building blocks are more flexible than those of the original system. The results would be useful to estimate the maximum possible error if the other bound can be obtained by another method. (C) 2012 Civil-Comp Ltd and Elsevier Ltd. All rights reserved.

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

superposition method
vibration
upper bound
lower bound


WSPE: a peer-to-peer grid programming environment Grid programming environments are tools designed to isolate users from issues such as heterogeneity, scalability and adaptability, thus simplifying the use of a Grid infrastructure. This paper presents work stealing programming environment (WSPE), a Grid programming environment for Grid-unaware applications. WSPE can be defined as a programming environment, since it is a software tool that presents both a programming model and an execution system. The WSPE consists of a simple programming interface and a fully decentralized runtime system following a peer-to-peer organization, both presented in this paper. It's runtime system employs a new scheduling mechanism, known as round stealing, inspired by the idea of work stealing. The main focus of our work is to research on methods to achieve efficient execution of parallel applications in a Grid computing infrastructure. By simulation, we show that our scheduling mechanism outperforms a more traditional mechanism in a Grid environment. We also demonstrate how an appropriate choice for a network overlay mechanism can further improve the execution efficiency. Copyright (C) 2009 John Wiley & Sons, Ltd.

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 B I B I 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 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 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

grid computing
work stealing
programming environment


Posttraumatic Stress Disorder With Amnesia Following Asphyxiation We describe five cases of traumatic asphyxiation injury, each meeting diagnostic criteria for posttraumatic stress disorder (PTSD) and characterized by a range of postinjury cognitive impairment. Four patients exhibited dense retrograde amnesia, including absence of conscious memory for the traumatic event. Appreciation of these asphyxiation cases, which involve temporally extended trauma exposure, may help resolve arguments regarding the possibility of co-occurrence of PTSD and neurological amnesia based exclusively on observations of much briefer duration events (specifically, motor vehicle crashes). These five cases also provide evidence that cognitive symptoms of PTSD can develop in the absence of conscious memory for the event

B I I O B 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 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 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


The physical, gain-loss model for the stochasticity of the phase velocity of a wind-driven water wave Mathematical-model study of the behavior of a ship in an irregular sea (e.g., the roll motion) includes an analysis of the particular case where the stochastic wind-driven wave is a plane wave, i.e. the wave traveling in one spatial direction. The stochasticity of a wind-driven wave is solely due to the stochasticity of wind. By using the basic physical facts on the water-surface/wind interaction, more specifically, the rates of the gain and loss of the wave energy, the present work derives a dynamical model for the phase velocity of a water wave. The model is a linear ordinary differential equation for the cubed phase velocity. This equation which includes the velocity of wind becomes stochastic when the wind is a stochastic process, for example, is described by the first-order Ito's stochastic differential equation (ISDE). In this case, the water-wave phase velocity appears to be a solution of the second-order ISDE. The derivation of the model implies an analytical relation which explicitly couples the parameters "alpha'' and "beta'' of the well-known Pierson-Moskowitz spectral function. It is shown that the derived relation agrees well with the experimentally obtained values of the parameters. The derived model can be used not only in models for the ship dynamics in a stochastic sea but also in a number of other ocean problems where the prediction of water waves by mere measurement of the wind is an advantage. These problems in particular include the real-time control of the stochastic water load on the ocean structures by sensing the stochastic wind rather than sensing stochastic waves thereby creating an alternative to more complex and expensive methods. (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 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 O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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

wind-driven water surface
elevation of water wave
ito's stochastic differential equation


Stylistics analysis and authorship attribution algorithms based on self-organizing maps The style followed by authors can be thought of as a collection of attributes that defines the stylistics space. Texts from the same author tend to be similar in that space. However, the identification of stylistics spaces has proven to be challenging. Associated with the stylistics space is the authorship attribution task. On it, a text of unknown authorship is presented to a system, and the system is expected to identify the author of the text. Two modules define an authorship attribution algorithm: the stylistics space and a classifier. We present a methodology that includes both, a module that allows the identification of novel stylistics spaces, and a classifier to confront the authorship attribution task from the features that define space. The methodology imbricates feature selection, anomaly detection, classification, and visualization algorithms. We applied the capabilities of self-organizing maps not only for visualization but also for anomaly detection, which defines the basis of the classifier. We compared our authorship attribution algorithm with two existing ones. Our methodology achieved similar or better results under bag-of-words-related stylistics spaces, and it presented the lowest error under a novel stylistics space based on the rate of introduction of new words.

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

authorship attribution
anomaly detection
feature selection

computational stylistics
self-organizing maps


A mixed BEMFEM formulation for layered soilsuperstructure interaction The analysis of soilstructure interaction is a vast field of interest in the area of civil engineering. Any realistic representation of its behaviour is a complex numerical task owing to its extremely variable mechanical behaviour. In this paper a Boundary Element Method formulation (BEM) for the analysis of SSI is presented in which all dependent interactions (superstructure, infrastructure and the supporting soil) are considered. Thus, the soil is treated as an inhomogeneous continuum supported by a rigid and adhesive interface and modelled by BEM using the 3D Kelvin solution. The raft foundation and the superstructure are represented by finite shell and 3D frame elements. In order to estimate the accuracy and the potentiality of the proposed numerical formulation, some examples are validated by comparison with similar approaches, and other simulations are presented, to stress the need to analyse the inhomogeneous soilraft-superstructure system as a whole.

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

mixed boundary element methodfinite element method formulation


The amazing variety of motions of a loaded hoop The subject of loaded hoops, and their ability to hop under certain conditions, received some attention at the turn of the century, inter alia by Tokieda, Pritchett and Theron. In this paper the emphasis is rather on extending the analysis of the motion before the hoop hops, including those cases where the hoop does not hop. The results of numerical simulation based on a classical mechanical model of a loaded hoop is presented. Results show that the motion consists of an amazing variety of alternating phases of rolling and slipping, some of which may be absent. A list of thirty-six possible sequences is included. Phase diagrams are presented to illustrate the relationship between the various slipping and rolling phases, as well as how they depend on the eccentricity, the friction coefficient and the initial angular velocity. (c) 2008 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

classical mechanics
rolling hoops
eccentric hoops


Model-Assisted Adaptive Recovery of Compressed Sensing with Imaging Applications In compressive sensing (CS), a challenge is to find a space in which the signal is sparse and, hence, faithfully recoverable. Since many natural signals such as images have locally varying statistics, the sparse space varies in time/spatial domain. As such, CS recovery should be conducted in locally adaptive signal-dependent spaces to counter the fact that the CS measurements are global and irrespective of signal structures. On the contrary, existing CS reconstruction methods use a fixed set of bases (e.g., wavelets, DCT, and gradient spaces) for the entirety of a signal. To rectify this problem, we propose a new framework for model-guided adaptive recovery of compressive sensing (MARX) and show how a 2-D piecewise autoregressive model can be integrated into the MARX framework to make CS recovery adaptive to spatially varying second order statistics of an image. In addition, MARX offers a mechanism of characterizing and exploiting structured sparsities of natural images, greatly restricting the CS solution space. Simulation results over a wide range of natural images show that the proposed MARX technique can improve the reconstruction quality of existing CS methods by 2-7 dB.

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

adaptive modeling
autoregressive process
compressive sensing (cs)
inverse problem


A parallel multigrid solver for 3D convection and convectiondiffusion problems ? Multigrid algorithms are known to be highly efficient in solving systems of elliptic equations. However, standard multigrid algorithms fail to achieve optimal grid-independent convergence rates in solving non-elliptic problems. In many practical cases, the non-elliptic part of a problem is represented by the convection operator. Downstream marching, when it is viable, is the simplest and most efficient way to solve this operator. However, in a parallel setting, the sequential nature of marching degrades the efficiency of the algorithm. The aim of this paper is to present, evaluate and analyze an alternative highly parallel multigrid method for 3D convection-dominated problems. This method employs semicoarsening, a four-color plane-implicit smoother, and discretization rules allowing the same cross-characteristic interactions on all the grids involved to be maintained. The load imbalance below the critical level is the main source of inefficiency in its parallel implementation. After comparing several strategies to relieve the load imbalance, a hybrid smoother that degrades the convergence properties of the method but improves its granularity has been found to be the best choice. The numerical and parallel properties of the multigrid algorithm with the four-color and hybrid smoothers are studied on SGI Origin 2000 and Cray T3E systems.

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 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

robust multigrid
convection-dominated problems


an assistive robotic agent for pedestrian mobility The goal of this project is to develop a pedestrian mobility aid for the elderly. In order for this type of assistive technology to be useful and accepted by its intended user community, it must enhance the abilities of users, not replace them. This leads to an agent architecture in which the agent must operate without hindering the user's ability to take direct action when they choose. In other words, the agent cannot simply be a proxy for the user's actions. The agent must select its own goals based on observations of its users actions. This is crucial not only because users may have diminished capacity to explain their actions to an agent, but because the ability of the agent to correctly interpret the user's goals is tied to its ability to act while still allowing the user to feel in control. We present a mobility aid, i. e. a wheeled walker, which varies its goals and level of activity based on an estimation of its user's intentions. The assistive agent often takes no action, allowing the user to be fully in control. When the ease or safety of the users travel is threatened, the agent attempts to influence the users motion based on its belief in the users goal. By varying the degree of autonomy, the walker can adjust to the user as their abilities change from day to day, or hour to hour. This prevents the walker from trying to do too much, allowing the user to feel as if they are in control and not being lead.

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


New microstrip radiator feeding by electromagnetic coupling for circular polarization We present a novel feeding system for microstrip radiators which is based on electromagnetic coupling. The effects of the antenna's key design parameters have been studied and discussed. This new feeding system was found to be very simple and useful in the design of flat arrays and reflectarrays using microstrip patches. A novel circularly polarized patch radiator fed from only one input line and based on the proposed feeding system is also presented in this paper. The result of the developed prototype in axial ratio bandwidth is double that obtained with a typical microstrip patch fed from two inputs.

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

circular polarization
electromagnetic coupling
microstrip radiator

perturbation method
photoetching antenna


intelligent information triage In many applications, large volumes of time-sensitive textual information require triage: rapid, approximate prioritization for subsequent action. In this paper, we explore the use of prospective indications of the importance of a time-sensitive document, for the purpose of producing better document filtering or ranking. By prospective, we mean importance that could be assessed by actions that occur in the future. For example, a news story may be assessed (retrospectively) as being important, based on events that occurred after the story appeared, such as a stock price plummeting or the issuance of many follow-up stories. If a system could anticipate (prospectively) such occurrences, it could provide a timely indication of importance. Clearly, perfect prescience is impossible. However, sometimes there is sufficient correlation between the content of an information item and the events that occur subsequently. We describe a process for creating and evaluating approximate information-triage procedures that are based on prospective indications. Unlike many information-retrieval applications for which document labeling is a laborious, manual process, for many prospective criteria it is possible to build very large, labeled, training corpora automatically. Such corpora can be used to train text classification procedures that will predict the (prospective) importance of each document. This paper illustrates the process with two case studies, demonstrating the ability to predict whether a news story will be followed by many, very similar news stories, and also whether the stock price of one or more companies associated with a news story will move significantly following the appearance of that story. We conclude by discussing how the comprehensibility of the learned classifiers can be critical to success.}

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

text classification
news
applications
use
price
correlation
paper
filtering
predict
training
case studies
prioritization
mean
process
future
action
ranking

sensitive
examples
association
intelligence
event
approximation
timing
informal
exploration
label
contention
systems
procedure
classifiation
critic
documentation
comprehension
information retrieval


Motion sequence analysis in the presence of figural cues Addressing how dynamic and figural cues interact in visual sequences. Novel paradigm to dissociate contributions of figural and dynamic cues. Assessment of healthy subjects and those with brain lesions. Empirical results point towards a computational model of visual sequence analysis.

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

form-cues
structure-from-motion
stroke patients


Dedicated hardware for linearly-scaling algorithms in condensed-matter physics The locality of the interactions in a Hamiltonian model gives origin to the linearization of the algorithms expressing the calculation of the interactions. This specific property, often used in condensed matter physics, has originated approximate models which, although preserving most of the physical insights of the parent exact models, display attractive computational properties which has determined their use in several scientific applications. We review the main issues at the basis of the linearization property arising in two different problems in condensed matter physics: the projection method to compute total energies in the Tight Binding approximation and the calculation of the pair-correlation function of weakly interacting bosons, in the Hypernetted-Chain expansion. We also remark how linearized numerical models could be mapped into "Systems of Affine Recurrence Equations" (SARE). The SARE structures revealed to be tractable with recently developed tools for hardware/software automatic synthesis. These tools could be used to purposely design dedicated hardware devices which efficiently perform those numerical calculations. (C) 2001 Elsevier Science B.V. All rights reserved.

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Robust human body segmentation based on part appearance and spatial constraint Human body segmentation in images is desirable in various practical applications, e.g., content-based image retrieval. However, it remains a challenging problem due to various body poses and confusing background. To overcome these difficulties, two properties of human body are explored in this paper, i.e., complementary property and weak structure property. Complementary property means that different human body parts always have the similar appearances. With this property, we propose to construct the Part Appearance Map (PAM). PAM can effectively represent the appearance probability of what a pixel belong to a human body, even for inaccurate human pose obtained by pictorial structure model. Afterward, robust foreground and background seeds are acquired by PAM. To utilize the structure information of human body effectively, we propose a novel graph cuts method spatial constraint based graph cuts (SCGC), which incorporates weak structure property of human body parts into the cost function. The weak structure property constrains the arms, legs and head to appear in limited space under the condition that the location of torso is ascertained. With this property, the SCGC can successfully remove false segmentations by traditional graph cuts methods due to their similar appearances to human body. Experimental results show that the proposed method achieves promising performance and outperforms many state-of-the-art methods over publicly available challenging datasets which contain arbitrary poses.

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

human body segmentation
complementary property
weak structure property

spatial constraint based graph cuts (scgc)


Improving resource location with locally precomputed partial random walks Random walks can be used to search complex networks for a desired resource. To reduce search lengths, we propose a mechanism based on building random walks connecting together partial walks (PW) previously computed at each network node. Resources found in each PW are registered. Searches can then jump over PWs where the resource is not located. However, we assume that perfect recording of resources may be costly, and hence, probabilistic structures like Bloom filters are used. Then, unnecessary hops may come from false positives at the Bloom filters. Two variations of this mechanism have been considered, depending on whether we first choose a PW in the current node and then check it for the resource, or we first check all PWs and then choose one. In addition, PWs can be either simple random walks or self-avoiding random walks. Analytical models are provided to predict expected search lengths and other magnitudes of the resulting four mechanisms. Simulation experiments validate these predictions and allow us to compare these techniques with simple random walk searches, finding very large reductions of expected search lengths.

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Morphable Crowds Crowd simulation has been an important research field due to its diverse range of applications that include film production, military simulation, and urban planning. A challenging problem is to provide simple yet effective control over captured and simulated crowds to synthesize intended group motions. We present a new method that blends existing crowd data to generate a new crowd animation. The new animation can include an arbitrary number of agents, extends for an arbitrary duration, and yields a natural-looking mixture of the input crowd data. The main benefit of this approach is to create new spatio-temporal crowd behavior in an intuitive and predictable manner. It is accomplished by introducing a morphable crowd model that allows us to encode the formations and individual trajectories in crowd data. Then, its original spatiotemporal behavior can be reconstructed and interpolated at an arbitrary scale using our morphable model.

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computer graphics
computer animation
data-driven animation
human motion