from operational semantics to abstract machines: preliminary results The operational semantics of functional programming languages is frequently presented using inference rules within simple meta-logics. Such presentations of semantics can be high-level and perspicuous since meta-logics often handle numerous syntactic details in a declarative fashion. This is particularly true of the meta-logic we consider here, which includes simply typed &lgr;-terms, quantification at higher types, and &bgr; -conversion. Evaluation of functional programming languages is also often presented using low-level descriptions based on abstract machines: simple term rewriting systems in which few high-level features are present. In this paper, we illustrate how a high-level description of evaluation using inference rules can be systematically transformed into a low-level abstract machine by removing dependencies on high-level features of the meta-logic until the resulting inference rules are so simple that they can be immediately identified as specifying an abstract machine. In particular, we present in detail the transformation of two inference rules specifying call-by-name evaluation of the untyped &lgr;-calculus into the Krivine machine, a stack-based abstract machine that implements such evaluation. The initial specification uses the meta-logic's &bgr; -conversion to perform substitutions. The resulting machine uses de Bruijn numerals and closures instead of formal substitution. We also comment on a similar construction of a simplified SECD machine implementing call-by-value evaluation. This approach to abstract machine construction provides a semantics-directed method for motivating, proving correct, and extending such abstract machines.

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

present
dependencies
method
term rewriting
systems
inference
operational semantics
types
paper
rules
evaluation
functional programming

value formalism abstract-machine abstraction motivation semantic language direct logic feature conversation


Scheduling efficiency of resource information aggregation in grid networks We consider information aggregation as a method for reducing the information exchanged in a Grid network and used by the resource manager in order to make scheduling decisions. In this way, information is summarized across nodes and sensitive or detailed information can be kept private, while resources are still publicly available for use. We present a general framework for information aggregation, trying to identify issues that relate to aggregation in Grids. In this context, we describe a number of techniques, including single point and intra-domain aggregation, define appropriate grid-specific domination relations and operators for aggregating static and dynamic resource information, and discuss resource selection optimization functions. The quality of an aggregation scheme is measured both by its effects on the efficiency of the schedulers decisions and also by the reduction it brings on the amount of resource information recorded, a tradeoff that we examine in detail. Simulation experiments demonstrate that the proposed schemes achieve significant information reduction, either in the amount of information exchanged, or in the frequency of the updates, while at the same time maintaining most of the value of the original information as expressed by a stretch factor metric we introduce.

B O O O B I 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 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 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 B I O O O

grid networks
information aggregation
scheduling
stretch factor


B-RAAM: A connectionist model which develops holistic internal representations of symbolic structures Connectionist models have been criticized as seemingly! unable to represent data structures thought necessary to support symbolic processing. However, a class of model-recursive auto-associative memory (RAAM)-has been demonstrated to be capable of encoding/decoding compositionally such symbolic structures as trees, lists and stacks. Despite RAAM's appeal, a number of shortcomings are apparent. These include: the large number of epochs often required to train RAAM models; the size of encoded representation (and, therefore, of hidden layer) needed; a bias in the (fed-back) representation for more recently-presented information; and a cumulative error effect that results from recursively processing the encoded pattern during decoding. In this paper, the RAAM model is modified to form a new encoder/decoder, called bi-coded RAAM (B-RAAM). In bicoding, there ave two mechanisms for holding contextual information: the first is hidden-to-input layer feedback as in RAAM but extended with a delay line; the second is an output layer which expands dynamically to hold the concatenation of past input symbols. A comprehensive series of experiments is described which demonstrates the superiority of B-RAAM over RAAM in terms of fewer training epochs, smaller hidden layer, improved ability to represent long-term rime dependencies and reduction of the cumulative error effect during decoding.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O 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 B 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 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-raam
recurrent neural networks
auto-associator


Single View Reflectance Capture using Multiplexed Scattering and Time-of-flight Imaging This paper introduces the concept of time-of-flight reflectance estimation, and demonstrates a new technique that allows a camera to rapidly acquire reflectance properties of objects from a single viewpoint, over relatively long distances and without encircling equipment. We measure material properties by indirectly illuminating an object by a laser source, and observing its reflected light indirectly using a time-of-flight camera. The configuration collectively acquires dense angular, but low spatial sampling, within a limited solid angle range - all from a single viewpoint. Our ultra-fast imaging approach captures space-time "streak images" that can separate out different bounces of light based on path length. Entanglements arise in the streak images mixing signals from multiple paths if they have the same total path length. We show how reflectances can be recovered by solving for a linear system of equations and assuming parametric material models; fitting to lower dimensional reflectance models enables us to disentangle measurements. We demonstrate proof-of-concept results of parametric reflectance models for homogeneous and discretized heterogeneous patches, both using simulation and experimental hardware. As compared to lengthy or highly calibrated BRDF acquisition techniques, we demonstrate a device that can rapidly, on the order of seconds, capture meaningful reflectance information. We expect hardware advances to improve the portability and speed of this device.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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 photography
multipath light transport
reflectance acquisition
global illumination
time of flight


Evaluation of statistical and multiple-hypothesis tracking for video traffic surveillance Conventional tracking methods encounter difficulties as the number of objects, clutter, and sensors increase, because of the requirement for data association. Statistical tracking, based on the concept of network tomography, is an alternative that avoids data association. It estimates the number of trips made from one region to another in a scene based on interregion boundary traffic counts accumulated over time. It is not necessary to track an object through a scene to determine when an object crosses a boundary. This paper describes statistical tracing and presents an evaluation based on the estimation of pedestrian and vehicular traffic intensities at an intersection over a period of 1 month. We compare the results with those from a multiple-hypothesis tracker and manually counted ground-truth estimates.

O O O O O B 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 B 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


Gas-kinetic numerical studies of three-dimensional complex flows on spacecraft re-entry The gas-kinetic numerical algorithm solving the Boltzmann model equation is extended and developed to study the three-dimensional hypersonic flows of spacecraft re-entry into the atmosphere in perfect gas. In this study, the simplified velocity distribution function equation for various flow regimes is presented on the basis of the kinetic BoltzmannShakhov model. The discrete velocity ordinate technique and numerical quadrature methods, such as the Gauss quadrature formulas with the weight function 2/?1/2exp(?V2) and the GaussLegendre numerical quadrature rule, are studied to resolve the barrier in simulating complex flows from low Mach numbers to hypersonic problems. Specially, the gas-kinetic finite-difference scheme is constructed for the computation of three-dimensional flow problems, which directly captures the time evolution of the molecular velocity distribution function. The gas-kinetic boundary conditions and numerical procedures are studied and implemented by directly acting on the velocity distribution function. The HPF (high performance fortran) parallel implementation technique for the gas-kinetic numerical method is developed and applied to study the hypersonic flows around three-dimensional complex bodies. The main purpose of the current research is to provide a way to extend the gas-kinetic numerical algorithm to the flow computation of three-dimensional complex hypersonic problems with high Mach numbers. To verify the current method and simulate gas transport phenomena covering various flow regimes, the three-dimensional hypersonic flows around sphere and spacecraft shape with different Knudsen numbers and Mach numbers are studied by HPF parallel computing. Excellent results have been obtained for all examples computed.

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 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 B I I 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

velocity distribution function
boltzmann model equation

kinetic theory of gases
discrete velocity ordinate method
finite-difference computation
three-dimensional complex flow
spacecraft re-entry


Image warping for retargeting garments among arbitrary poses We address the problem of warping 2D images of garments onto target mannequins of arbitrary poses. The motivation for this work is to enable an online shopper to drag and drop selected articles of clothing onto a single mannequin to configure and visualize outfits. Such a capability requires each garment to be available in a pose that is consistent with the target mannequin. A2D deformation system is proposed, which enables a designer to quickly deform images of clothing onto a target shape with both fine and coarse controls over the deformation. This system has retargeted thousands of images for retailers to establish virtual dressing rooms for their online customers.

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

shape deformation
moving least squares
as-rigid-as-possible shape manipulation


Partitions of graphs into small and large sets Let G G be a graph on n n vertices. We call a subset A A of the vertex set V(G) V ( G ) k k -small if, for every vertex v?A v ? A , deg(v)?n?|A|+k deg ( v ) ? n ? | A | + k . A subset B?V(G) B ? V ( G ) is called k k -large if, for every vertex u?B u ? B , deg(u)?|B|?k?1 deg ( u ) ? | B | ? k ? 1 . Moreover, we denote by ?k(G) ? k ( G ) the minimum integer t t such that there is a partition of V(G) V ( G ) into t k -small sets, and by ?k(G) ? k ( G ) the minimum integer t t such that there is a partition of V(G) V ( G ) into t k -large sets. In this paper, we will show tight connections between k k -small sets, respectively k k -large sets, and the k k -independence number, the clique number and the chromatic number of a graph. We shall develop greedy algorithms to compute in linear time both ?k(G) ? k ( G ) and ?k(G) ? k ( G ) and prove various sharp inequalities concerning these parameters, which we will use to obtain refinements of the CaroWei Theorem, Turns Theorem and the HansenZheng Theorem among other things.

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

k k -small set k k k k k
k k -large set k k k k k
k k -independence k k k k k


Speaking in noise: How does the Lombard effect improve acoustic contrasts between speech and ambient noise? ? We investigate how speakers can improve their segregation from a background noise. Lombard speech is explored in realistic conditions (interactive game, loudspeakers). Speakers maintain a positive SNR in noise and boost their energy around 3kHz. They enhance the modulation of their speech in f0 and intensity. When possible, they specifically adjust f0 and F1 to minima of the noise spectrum.

O O B 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 B B I 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

production
speech audibility
auditory detection
energetic masking


On the probability of generating a lattice We study the problem of determining the probability that m vectors selected uniformly at random from the intersection of the full-rank lattice ? in Rn R n and the window [0,B)n [ 0 , B ) n generate ? when B is chosen to be appropriately large. This problem plays an important role in the analysis of the success probability of quantum algorithms for solving the Discrete Logarithm Problem in infrastructures obtained from number fields and also for computing fundamental units of number fields. We provide the first complete and rigorous proof that 2n+1 2 n + 1 vectors suffice to generate ? with constant probability (provided that B is chosen to be sufficiently large in terms of n and the covering radius of ? and the last n+1 n + 1 vectors are sampled from a slightly larger window). Based on extensive computer simulations, we conjecture that only n+1 n + 1 vectors sampled from one window suffice to generate ? with constant success probability. If this conjecture is true, then a significantly better success probability of the above quantum algorithms can be guaranteed.

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

random generation of lattice
riemann zeta function
infrastructure
analysis of quantum algorithm


Designing DCCP: Congestion control without reliability Fast-growing Internet applications like streaming media and telephony prefer timeliness to reliability, making TCP a poor fit. Unfortunately, UDP, the natural alternative, lacks congestion control. High-bandwidth UDP applications must implement congestion control themselves-a difficult task-or risk rendering congested networks unusable. We set out to ease the safe deployment of these applications by designing a congestion-controlled unreliable transport protocol. The outcome, the Datagram Congestion Control Protocol or DCCP, adds to a UDP-like foundation the minimum mechanisms necessary to support congestion control. We thought those mechanisms would resemble TCP's, but without reliability and, especially, cumulative acknowledgements, we had to reconsider almost every aspect of TCP's design. The resulting protocol sheds light on how congestion control interacts with unreliable transport, how modem network constraints impact protocol design, and how TCP's reliable bytestream semantics intertwine with its other mechanisms, including congestion control.

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

design
dccp
congestion control
streaming media
tcp

standardization
transport protocols
unreliable transfer
internet telephony


Embedded software verification in hardwaresoftware codesign Concurrent Embedded Real-Time Software (CERTS) is intrinsically different from traditional, sequential, independent, and temporally unconstrained software. The verification of software is more complex than hardware due to inherent flexibilities (dynamic behavior) that incur a multitude of possible system states. The verification of CERTS is all the more difficult due to its concurrency and embeddedness. The work presented here shows how the complexity of CERTS verification can be reduced significantly through answering common engineering questions such as when, where, and how one must verify embedded software. First, a new Schedule-Verify-Map strategy is proposed to answer the when question. Second, verification under system concurrency is proposed to answer the where question. Finally, a complete symbolic model checking procedure is proposed for CERTS verification. Several application examples illustrate the usefulness of our technique in increasing verification scalability.

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

embedded software
symbolic model checking

software verification
system/process concurrency
quasi-static scheduling
software synthesis


The Hausdorff fuzzy metric on compact sets We propose a method for constructing a Hausdorff fuzzy metric on the set of the nonempty compact subsets of a given fuzzy metric space (in the sense of George and Veeramani). We discuss several important properties as completeness, completion and precompactness. Some illustrative examples are given. (C) 2003 Elsevier B.V. All rights reserved.

B I I 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 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

continuous t-norm
compact subset
complete
precompact
completable


Conservative occlusion culling for urban visualization using a slice-wise data structure In this paper, we propose a framework for urban visualization using a conservative from-region visibility algorithm based on occluder shrinking. The visible geometry in a typical urban walkthrough mainly consists of partially visible buildings. Occlusion-culling algorithms, in which the granularity is buildings, process these partially visible buildings as if they are completely visible. To address the problem of partial visibility, we propose a data structure, called slice-wise data structure, that represents buildings in terms of slices parallel to the coordinate axes. We observe that the visible parts of the objects usually have simple shapes. This observation establishes the base for occlusion-culling where the occlusion granularity is individual slices. The proposed slice-wise data structure has minimal storage requirements. We also propose to shrink general 3D occluders in a scene to find volumetric occlusion. Empirical results show that significant increase in frame rates and decrease in the number of processed polygons can be achieved using the proposed slice-wise occlusion-culling as compared to an occlusion-culling method where the granularity is individual buildings.

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 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

space subdivision
octree
occlusion-culling
minkowski difference
from-region visibility
visibility processing


On Byzantine generals with alternative plans This paper proposes a variation of the Byzantine generals problem (or Byzantine consensus). Each general has a set of good plans and a set of bad plans. The problem is to make all loyal generals agree on a good plan proposed by a loyal general, and never on a bad plan.

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

distributed computing
fault tolerance
byzantine faults
agreement


Short proofs are narrow - Resolution made simple The width of a Resolution proof is defined to be the maximal number of literals in any clause of the proof. In this paper, we relate proof width to proof length (=size), in both general Resolution, and its tree-like variant. The following consequences of these relations reveal width as a crucial "resource" of Resolution proofs. In one direction, the relations allow us to give simple, unified proofs for almost all known exponential lower bounds on size of resolution proofs, as well as several interesting new ones. They all follow from width lower bounds, and we show how these follow from natural expansion property of clauses of the input tautology. In the other direction, the width-size relations naturally suggest a simple dynamic programming procedure for automated theorem proving-one which simply searches for small width proofs. This relation guarantees that the running time land thus the size of the produced proof) is at most quasi-polynomial in the smallest tree-like proof. This algorithm is never much worse than any of the recursive automated provers (such as DLL) used in practice. In contrast, we present a family of tautologies on which it is exponentially faster.

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


Resource allocation with proportional rate fairness in orthogonal frequency division multiple access relay networks We address the problem of subchannel and transmission power allocation in orthogonal frequency division multiple access relay networks with an aim to maximize the sum rate and maintain proportional rate fairness among users. Because the formulated problem is a mixed-integer nonlinear optimization problem with an extremely high computational complexity, we propose a low-complexity suboptimal algorithm, which is a two-step separated subchannel and power allocation algorithm. In the first step, subchannels are allocated to each user, whereas in the second step, the optimal power allocation is carried out on the basis of the given subchannel allocation and the nonlinear interval Gauss-Seidel method. Simulation results have demonstrated that the proposed algorithm can achieve a good trade-off between the efficiency and the fairness compared with two other existing relevant algorithms. In particular, the proposed algorithm can always achieve 100% fairness under various conditions. Copyright (c) 2012 John Wiley & Sons, Ltd.

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

resource allocation
relay networks
proportional rate fairness


Video recommendation based on multi-modal information and multiple kernel Collaborative Filter (CF) algorithms often suffer from data sparsity and item cold start problem, for the user-item matrix is insufficient and extremely sparse especially when new item is added to recommendation system. These two problems also exist in video recommendation process. We propose two methods to solve them by incorporating multimodal information and multiple kernel together. To solve item cold start problem, we learn a user taste hyper-plane by using multiple kernel SVM to represent the user taste, which is further used to predict the recommendation of new added videos. We combine the different user taste hyper-plane similarity and the traditional cosine similarity with a trade-off between them to address the data sparse problem. Experimental results show that our proposed algorithm can alleviate the data sparsity and item cold start problems.

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

multi-modal information
collaborative filtering


Managing workload in humanrobot interaction: A review of empirical studies Working with artificial agents is a challenging endeavor, often imposing high levels of workload on human operators who work within these socio-technical systems. We seek to understand these workload demands through examining the literature in major content areas of humanrobot interaction. As research on HRI continues to explore a host of issues with operator workload, there is a need to synthesize the extant literature to determine its current state and to guide future research. Within HRI socio-technical systems, we reviewed the empirical literature on operator information processing and action execution. Using multiple resource theory (MRT; Wickens, 2002) as a guiding framework, we organized this review by the operator perceptual and responding demands which are routinely manipulated in HRI studies. We also reviewed the utility of different interventions for reducing the strain on the perceptual system (e.g., multimodal displays) and responses (e.g., automation). Our synthesis of the literature demonstrates that much is known about how to decrease operator workload, but there are specific gaps in knowledge due to study operations and methodology. This work furthers our understanding of workload in complex environments such as those found when working with robots. Principles and propositions are provided for those interested in decreasing operator workload in applied settings and also for future research.

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

performance teleoperation perception display


Using an intelligent agent to classify competitor behavior and develop an effective E-market counterstrategy Internet markets allow online sellers to rapidly update prices. By employing intelligent software agents known as pricebots, the re-pricing process can be streamlined and automated. Developing the pricebot repricing logic requires an understanding of the optimal pricing strategy in relation to competitors' strategies. We use simulation to construct a decision table of the most effective counterstrategy for several competitor strategy combinations. We then design a neural network for classifying the strategies of the competition, which allows us to look up the optimal counterstrategy in the decision table. Our findings indicate that a pricebot armed with the decision table and neural network classifier can recognize when the market is such that no entrant can gain a profit advantage beyond the profit achieved at a common price floor, and in other cases where higher profits are possible, the agent is able to achieve statistically significant profit improvements over the no-pricebot case. (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 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


A simulation tool for combined rail/road transport in intermodal terminals A simulation model of the flow of intermodal terminal units (ITUs) among and within inland intermodal terminals is presented. The intermodal terminals are interconnected by rail corridors. Each terminal serves a user catchment area via a road network. The terminal is modelled as a set of platforms, which are served by a number of gantry cranes and front lifters. The user of the simulation model defines the structure of the terminal and the train and truck arrival scenarios. The train arrivals are defined in a train timetable, while the patterns of truck arrivals for ITU delivery and pick-up can be either statistically modelled or given as a deterministic input. The simulator can be used to simulate both a single terminal and a rail network, that is, two or more interconnected terminals. During the simulation, various statistics are gathered to assess the performance of the terminal equipment, the ITU residence time, and the terminal throughput. The simulation software has been implemented as a discrete-event simulation model, using MODSIM III as development tool. The simulator tool has been developed as part of the Platform project, funded by the Directorate General VII of the European Community. (C) 2002 IMACS. Published by Elsevier Science B.V. 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

intermodal transport
intermodal terminal simulation


Low-Resolution Face Tracker Robust to Illumination Variations In many practical video surveillance applications, the faces acquired by outdoor cameras are of low resolution and are affected by uncontrolled illumination. Although significant efforts have been made to facilitate face tracking or illumination normalization in unconstrained videos, the approaches developed may not be effective in video surveillance applications. This is because: 1) a low-resolution face contains limited information, and 2) major changes in illumination on a small region of the face make the tracking ineffective. To overcome this problem, this paper proposes to perform tracking in an illumination-insensitive feature space, called the gradient logarithm field (GLF) feature space. The GLF feature mainly depends on the intrinsic characteristics of a face and is only marginally affected by the lighting source. In addition, the GLF feature is a global feature and does not depend on a specific face model, and thus is effective in tracking low-resolution faces. Experimental results show that the proposed GLF-based tracker works well under significant illumination changes and outperforms many state-of-the-art tracking algorithms.

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

face tracking
gradient logarithm field
illumination variations


Quantum Error Correction Beyond the Bounded Distance Decoding Limit In this paper, we consider quantum error correction over depolarizing channels with nonbinary low-density parity-check codes defined over Galois field of size. The proposed quantum error correcting codes are based on the binary quasi-cyclic Calderbank, Shor, and Steane (CSS) codes. The resulting quantum codes outperform the best known quantum codes and surpass the performance limit of the bounded distance decoder. By increasing the size of the underlying Galois field, i.e.,, the error floors are considerably improved.

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

calderbank, shor, and steane (css) codes


Differentiation Pathways in Human Embryonic Stem Cell-Derived Cardiomyocytes Abstract: Human embryonic stem (hES) cells are pluripotent cell lines derived from the inner cell mass of the blastocyst-stage embryo. These unique cell lines can be propagated in the undifferentiated state in culture, while retaining the capacity to differentiate into derivatives of all three germ layers, including cardiomyocytes. The derivation of the hES cell lines presents a powerful tool to explore the early events of cardiac progenitor cell specification and differentiation, and it also provides a novel cell source for the emerging field of cardiovascular regenerative medicine. A spontaneous differentiation system of these stem cells to cardiomyocytes was established and the generated myocytes displayed molecular, structural, and functional properties of early-stage heart cells. In order to follow the in vitro differentiation process, the temporal expression of signaling molecules and transcription factors governing early cardiac differentiation was examined throughout the process. A characteristic pattern was noted recapitulating the normal in vivo cardiac differentiation scheme observed in other model systems. This review discusses the known pathways involved in cardiac specification and the possible factors that may be used to enhance cardiac differentiation of hES cells, as well as the steps required to fully harness the enormous potential of these unique cells.

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


The interplay of optimization and machine learning research The fields of machine learning and mathematical programming are increasingly intertwined. Optimization problems lie at the heart of most machine learning approaches. The Special Topic on Machine Learning and Large Scale Optimization examines this interplay. Machine learning researchers have embraced the advances in mathematical programming allowing new types of models to be pursued. The special topic includes models using quadratic, linear, second-order cone, semi-definite, and semi-infinite programs. We observe that the qualities of good optimization algorithms from the machine learning and optimization perspectives can be quite different. Mathematical programming puts a premium on accuracy, speed, and robustness. Since generalization is the bottom line in machine learning and training is normally done off-line, accuracy and small speed improvements are of little concern in machine learning. Machine learning prefers simpler algorithms that work in reasonable computational time for specific classes of problems. Reducing machine learning problems to well-explored mathematical programming classes with robust general purpose optimization codes allows machine learning researchers to rapidly develop new techniques. In turn, machine learning presents new challenges to mathematical programming. The special issue include papers from two primary themes: novel machine learning models and novel optimization approaches for existing models. Many papers blend both themes, making small changes in the underlying core mathematical program that enable the develop of effective new algorithms.

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

machine learning
mathematical programming


hw/sw partitioning techniques for multi-mode multi-task embedded applications An embedded system is called a multi-mode embedded system if it performs multiple applications by dynamically reconfiguring the system functionality. Further, the embedded system is called a multi-mode multi-task embedded system if it additionally supports multiple tasks to be executed in a mode. In this paper, we address an important HW/SW partitioning problem, that is, HW/SW partitioning of multi-mode multi-task embedded applications with timing constraints of tasks. The objective of the optimization problem is to find a minimal total system cost of allocation/mapping of processing resources to functional modules in tasks together with a schedule that satisfies the timing constraints. The key success of solving the problem is closely related to the degree of the amount of utilization of the potential parallelism among the executions of modules. However, due to an inherently excessively large search space of the parallelism, and to make the task of schedulabilty analysis easy, the prior HW/SW partitioning methods have not been able to fully exploit the potential parallel execution of modules. To overcome the limitation, we propose a set of comprehensive HW/SW partitioning techniques which solve the three subproblems of the partitioning problem simultaneously : (1) allocation of processing resources ,(2) mapping the processing resources to the modules in tasks , and (3) determining an execution schedule of modules . Specifically, based on a precise measurement on the parallel execution and schedulability of modules, we develop a stepwise refinement partitioning technique for single-mode multi-task applications, which aims to solve the subproblems 1, 2 and 3 effectively in an integrated fashion. The proposed techniques is then extended to solve the HW/SW partitioning problem of multi-mode multi-task applications (i.e., to find a globally optimized allocation/mapping of processing resources with feasible execution schedule of modules).

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


Models and temporal logical specifications for timed component connectors Component-based software engineering advocates construction of software systems through composition of coordinated autonomous components. Significant benefits of this approach include software reuse, simpler and faster construction, enhanced reliability, and dramatic reductions in the complexity of construction of provably correct critical systems, many of which involve real-time concerns. Effective, flexible component composition by itself still poses a challenge today and yet the special nature of real-time constraints makes component-based construction of real-time systems even more demanding. The coordination language Reo supports compositional system construction through connectors that exogenously coordinate the interactions among the constituent components which unawarely comprise a complex system, into a coherent collaboration. The simple, yet surprisingly rich, calculus of channel composition that underlies Reo offers a flexible framework for compositional construction of coordinating component connectors with real-time properties. In this paper, we present an operational semantics for the channel-based component connectors of Reo in terms of Timed Constraint Automata and introduce a temporal-logic for specification and verification of their real-time properties.

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

coordination
composition
reo
constraint automata

real-time
timed automata
linear temporal logic
timed data streams


towards a jitting vm for prolog execution Most Prolog implementations are implemented in low-level languages such as C and are based on a variation of the WAM instruction set, which enhances their performance but makes them hard to write. In addition, many of the more dynamic features of Prolog (like assert), despite their popularity, are not well supported. We present a high-level continuation-based Prolog interpreter based on the PyPy project. The PyPy project makes it possible to easily and efficiently implement dynamic languages. It provides tools that automatically generate a just-in-time compiler for a given interpreter of the target language, by using partial evaluation techniques. The resulting Prolog implementation is surprisingly efficient: it clearly outperforms existing interpreters of Prolog in high-level languages such as Java. Moreover, on some benchmarks, our system outperforms state-of-the-art WAM-based Prolog implementations. Our paper aims to show that declarative languages such as Prolog can indeed benefit from having a just-in-time compiler and that PyPy can form the basis for implementing programming languages other than Python.

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


Static tiling for heterogeneous computing platforms In the framework of fully permutable loops, tiling has been extensively studied as a source-to-source program transformation. However, little work has been devoted to the mapping and scheduling of the tiles on physical processors. Moreover, targeting heterogeneous computing platforms has to the best of our knowledge, never been considered. In this paper we extend static tiling techniques to the context of limited computational resources with different-speed processors. In particular, we present efficient scheduling and mapping strategies that are asymptotically optimal. The practical usefulness of these strategies is fully demonstrated by MPI experiments on a heterogeneous network of workstations. (C) 1999 Elsevier Science B.V. All rights reserved.

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

communication-computation overlap
limited resources
different-speed processors
heterogeneous networks


Combining designed experiments with several blocks of spectroscopic data Two varieties of a new method of analysis are introduced and tested against a standard PLS method. The method is developed for situations where experimental design is combined with spectroscopic measurements at several points in an industrial process. The method is a combination of ordinary least squares (OLS) and PLS and is called LS-PLS. The purpose of the methodology is to extract relevant information from spectroscopic measurements without having to calibrate the instrument against external reference measurements first. We compare the LS-PLS variants with a straight forward PLS modeling of all the available variables and demonstrate that the LS-PLS method give results that are easier to interpret, The methods are compared by computer simulations based on real data from a cheese making experiment. (c) 2007 Elsevier B.V. All rights reserved.

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

process modeling
spectroscopy
nir
ft-ir
ls-pls
multiblock methods


Energy Detection Approach for Spectrum Sensing in Cognitive Radio Systems with the Use of Random Sampling In radiomobile contexte, radio frequency spectrum is a ressource that needs to be used with appropriate efficiency. This can be achieved by the mean of spectrum sensing operation. This function consists to analyze the occupancy of the radio frequency spectrum in order to detect which bands are unused. This concept is largely appreciated in cognitive radio where more flexibility is required to adapt to the communication environment. Different techniques are presented in the literature. In this paper, we are interested by the application of the energy detector method for spectrum sensing. This application is performed in cognitive radio systems with the use of random sampling. The performance of this approach is evaluated in term of its receiver operating characteristic curve and compared to the uniform sampling case.

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

cognitive radio
energy detector
random sampling
spectrum sensing


Perceived performance effects of ICT in manufacturing SMEs Purpose - The purpose of this paper is to investigate whether information and communication technologies (ICT) resources, including investment and use of specific types of ICT as well as innovative work practices, have a positive impact on several dimensions of firm performance, taking into account both direct and indirect effects and both short and long-term effects. Design/methodology/approach - An empirical study using data from a sample of 267 Spanish manufacturing SMEs was conducted. Path analysis was used to study direct and indirect ICT impacts and OLS regression was the estimation method employed. Findings - The findings show a positive relationship between ICT adoption and all the measures of perceived performance analyzed, although the impact is not always immediate since the lag effects and length differ according to the type of ICT. Managers' perceptions of ICT impact are related to the adoption of new work practices but the effects also depend positively on the number of years since new work practices were implemented. ICT impact on final performance (market share and profits and margin) takes place mainly indirectly through the improvement of internal and external communication, as well as through operational performance. Research limitations/implications - The main limitations of the research stem from the specific geographical context under consideration and restrictions relating to the cross-sectional nature of the data. Practical implications - The results reveal the wide scope of the benefits of ICT adoption in SMEs and point to the need for persistence in use so as to obtain good results in some areas. They also stress the positive effects of adopting ICTs together with organizational innovation. Originality/value - This research extends the scope of the analysis of ICT payoff literature by analyzing direct and indirect effects and by focusing on a broad range of technologies, a variety of performance measures and several time lags to study ICT adoption impacts in SMEs.

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

communication technologies
new work practices
firm performance
payoff


Neural bistability and amplification mediated by NMDA receptors: Analysis of stationary equations The macroscopic current/voltage relationship of NMDA receptor ion channels is nonmonotonic under physiological conditions, which can give rise to bistable and amplifying/facilitatory behavior in neurons and neural structures, supporting significant computational primitives. Conditions under which bistable regimes of operation prevail, and also general amplifying properties associated with active NMDA receptors, are examined in a single compartment enclosed by a cell membrane, and subsequently in cable-like dendrites under varying boundary conditions. Methodology consists of numerical and mathematical analyses of stationary versions of equations governing the electrical behavior of these systems. Bistability mediated by NMDA receptors requires interaction with other conductances in the membrane or cytoplasm, with particular importance attached to membrane potassium conductance, especially that of inward-rectifying potassium channels. A corollary conclusion is that coactivation of GABAB synaptic receptors or SK channels is a computationally powerful and sometimes necessary adjunct condition for NMDA receptor-mediated bistability. Neural multistability due to dendritic bistability is considered, including the case of closely coupled dendrites. The characteristics of coactivation-dependent facilitation, and amplifying states in which NMDA receptor activation boosts the efficacy of other classes of synapses, are also described. Coactive inward-rectifying potassium channels are found to significantly affect the characteristics of such amplification.

O B 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 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 B O O O B I 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 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

nmda receptor
bistability
gabab
sk channels


Vaidurya: A multiple-ontology, concept-based, context-sensitive clinical-guideline search engine We designed and implemented a generic search engine (Vaidurya), as part of our Digital clinical-Guideline Library (DeGeL) framework. Two search methods were implemented in addition to full-text search: (1) concept-based search, which relies on pre-indexing the guidelines in a clinically meaningful fashion, and (2) context-sensitive search, which relies on first semi-structuring the guidelines according to a given ontology, then searching for terms within specific labeled text segments. The Vaidurya engine is fully functional and is used within the DeGeL system. We describe the Vaidurya ontological and algorithmic framework; we also briefly summarize the results of a detailed evaluation in the clinical-guideline domain, demonstrating that both concept-based and context-sensitive ontology-independent search are highly feasible and significantly improve on free text search retrieval performance. We conclude by analyzing the limitations and advantages of the approach, and the steps that we have started to take to extend it based on user feedback.

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

information retrieval
medical informatics
clinical practice guidelines
concept-based search
context-sensitive search
digital libraries


Topographic visualization of prefix propagation in the Internet We propose a new metaphor for the visualization of prefixes propagation in the Internet. Such a metaphor is based on the concept of topographic map and allows to put in evidence the relative importance of the Internet Service Providers (ISPs) involved in the routing of the prefix. Based on the new metaphor we propose an algorithm for computing layouts and experiment with such algorithm on a test suite taken from the real Internet. The paper extends the visualization approach of the BGPlay service, which is an Internet routing monitoring tool widely used by ISP operators.

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

interdomain routing
internet visualization
graph drawing
spring embedder


A privacy-enhancing model for location-based personalized recommendations To receive personalized recommendation, users of a location-based service (e.g., a Location-Based Social Network, LBSN) have to provide personal information and preferences to the location-based service. However, detailed personal information could be used to identify the users, and hence compromise user privacy. In this paper, we consider an untrusted third party recommendation service used by the location-based service that may attempt to identify the sender of a recommendation query from the query log or may publish the query log. To protect user identity, anonymization must be done online before a query reaches the recommendation service. This is different from the usual offline scenario where a trusted recommendation service will receive all unanonymized queries and the focus is to anonymize the collected query log. We propose the notion of online anonymity to formalize this online requirement. The challenge for providing online anonymity is dealing with unknown and dynamic location-based service users who can get online and offline at any time. We define this problem, discuss its implications and differences from the problems in the literature, and propose a solution. Our experimental study shows that it is feasible to achieve personalized recommendation while preserve user privacy.

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


Molecular modeling of the GABA(c) receptor ligand-binding domain We have constructed a molecular model of the ligand-binding domain of the GABA(C) receptor, which is a member of the Cys-loop ligand-gated ion channel family. The extracellular domains of these receptors share similar sequence homology (20%) with Limnaea acetylcholine-binding protein for which an X-ray crystal structure is available. We used this structure as a template for homology modeling of the GABA(C) receptor extracellular domain using FUGUE and MODELLER software. FlexX was then used to dock GABA into the receptor ligand-binding site, resulting in three alternative energetically favorable orientations. Residues located no more than 5 angstrom from the docked GABA were identified for each model; of these, three were found to be common to all models with 14 others present only in certain models. Using data from experimental studies, we propose that the most likely orientation of GABA is with its amine close to Y198, and its carboxylate close to R104. These studies have therefore provided a model of the ligand-binding domain, which will be useful for both GABA(C) and GABA(A) receptor studies, and have also yielded an experimentally testable hypothesis of the location of GABA in the binding pocket.

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

gaba(rho) receptor
rho receptor
ligand-gated ion channel
cys-loop receptor
neurotransmitter binding site
ligand docking


Increasing the discriminatory power of DEA in the presence of the sample heterogeneity with cluster analysis and decision trees Data envelopment analysis (DEA) is a widely used non-parametric data analytic tool discriminatory power of which is dependent on the homogeneity of the domain of the sample. In many real-life cases, however, the sample of the decision making units (DMU) could consist of two or more naturally occurring subsets, thus exhibiting clear signs of heterogeneity. In such situations, the discriminatory power of DEA is limited, for the nature of the relative efficiency of a DMU is likely to be influenced by its membership in a particular subset of the sample. In this study, we propose a three-step methodology allowing for increasing the discriminatory power of DEA in the presence of the heterogeneity of the sample. In the first phase, we use cluster analysis (CA) in order to test for the presence of the naturally occurring subsets in the sample. In the second phase DEA is used to calculate the relative efficiencies of the DMUs, as well as averaged relative efficiencies of each subset identified in the previous phase. Finally, we utilize decision tree (DT) induction in order to inquire into the subset-specific nature of the relative efficiencies of the DMUs in the sample. Illustrative example is provided.

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

data envelopment analysis
heterogeneity
homogeneity

clustering
decision tree induction
data mining


Towards the fast and robust optimal design of wireless body area networks Wireless body area networks are wireless sensor networks whose adoption has recently emerged and spread in important healthcare applications, such as the remote monitoring of health conditions of patients. A major issue associated with the deployment of such networks is represented by energy consumption: in general, the batteries of the sensors cannot be easily replaced and recharged, so containing the usage of energy by a rational design of the network and of the routing is crucial. Another issue is represented by traffic uncertainty: body sensors may produce data at a variable rate that is not exactly known in advance, for example because the generation of data is event-driven. Neglecting traffic uncertainty may lead to wrong design and routing decisions, which may compromise the functionality of the network and have very bad effects on the health of the patients. In order to address these issues, in this work we propose the first robust optimization model for jointly optimizing the topology and the routing in body area networks under traffic uncertainty. Since the problem may result challenging even for a state-of-the-art optimization solver, we propose an original optimization algorithm that exploits suitable linear relaxations to guide a randomized fixing of the variables, supported by an exact large variable neighborhood search. Experiments on realistic instances indicate that our algorithm performs better than a state-of-the-art solver, fast producing solutions associated with improved optimality gaps.

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

body area networks
wireless sensor networks
robust optimization
traffic uncertainty

integer linear programming
metaheuristics


A bibliometric approach demonstrates the impact of a social care data set on research and policy The National Minimum Dataset for Social Care (NMDS-SC) has provided detailed data since 2006 on the workforce for adult social care services in England. In 2012, the organisation responsible for the data set commissioned an evaluation into the impact of the data set on researchers and policymakers.

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

bibliometrics
qualitative evaluation
research impact


Robust location transportation problems under uncertain demands In robust optimization, the multi-stage context (or dynamic decision-making) assumes that the information is revealed in stages. So, part of the decisions must be taken before knowing the real values of the uncertain parameters, and another part, called recourse decisions, is taken when the information is known. In this paper, we are interested in a robust version of the location transportation problem with an uncertain demand using a 2-stage formulation. The obtained robust formulation is a convex (not linear) program, and we apply a cutting plane algorithm to exactly solve the problem. At each iteration, we have to solve an NP-hard recourse problem in an exact way, which is time-consuming. Here, we go further in the analysis of the recourse problem of the location transportation problem. In particular, we propose a mixed integer program formulation to solve the quadratic recourse problem and we define a tight bound for this reformulation. We present an extensive computation analysis of the 2-stage robust location transportation problem. The proposed tight bound allows us to solve large size instances.

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

robust optimization
location transportation problem

interval uncertainty
convex optimization
mixed integer linear programming


A new ant colony optimization-based algorithm for range query answering problem in relational schema-based P2P database systems Nowadays, peer-to-peer database systems (P2PDBSs) aiming at data sharing in the Web have become very popular. Due to the absence of global knowledge about data placement in unstructured P2P networks, query processing and answering is a challenging problem in such systems. This process is provided by query routing and is an optimization problem whose goal is to find the maximum results with spending a predetermined cost. With the aim of improving the efficiency of range query answering algorithm in relational schema-based P2PDBSs, the present study, for the first time, adapts the ant colony metaphor with range query answering problem in relational schema-based P2P systems and proposes a new algorithm using the ant colony optimization approach in which the researchers use histogram data structure and apply both positive and negative feedbacks, dynamic learning rate, and local heuristic mechanisms and show that the proposed algorithm gives better results than the comparative greedy-based method. The experimental tests indicate that in the best case, the average number of traveled links for finding one answer (i.e., cost-to-answers ratio) is decreased almost by half in contrast to that of greedy-based algorithm. Furthermore, the achieved results indicate that the proposed algorithm is completely flexible with the users requests, i.e., more query answers or less query response time, and the algorithm parameters can be properly set to meet the users requests.

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

relational schema-based p2p database system


Bayesian analysis of the Logit model and comparison of two MetropolisHastings strategies We examine some Markov chain Monte Carlo (MCMC) methods for a generalized non-linear regression model, the Logit model. It is first shown that MCMC algorithms may be used since the posterior is proper under the choice of non-informative priors. Then two non-standard MCMC methods are compared: a MetropolisHastings algorithm with a bivariate normal proposal resulting from an approximation, and a MetropolisHastings algorithm with an adaptive proposal. The results presented here are illustrated by simulations, and show the good behavior of both methods, and superior performances of the method with an adaptive proposal in terms of convergence to the stationary distribution and exploration of the posterior distribution surface.

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

markov chain monte carlo
metropolishastings algorithm

bayesian statistic
adaptive algorithm
stationarity
convergence assessment


Classification by restricted random walks We define a random walk in a data set of a metric space. In order that the random walk depends on the pattern of the data, restrictions are imposed during its generation. Since such a restricted random walk investigates only a local subset of the data, a series of random walks has to be realized for describing the entire data set. An agglomerative graph-related classification method is introduced whose hierarchy is based on these restricted random walks. It is demonstrated on various examples that this new technique is able to detect efficiently clusters of different shapes without specifying the number of groups in advance.

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

stochastic classification
hierarchical clustering


Adaptive load shedding and regional protection The requirement for improved efficiency whilst maintaining system security necessitates the development of improved system analysis approaches and the development of advanced emergency control technologies. Load shedding is a type of emergency control that is designed to ensure system stability by curtailing system load to match generation supply. This paper presents a new adaptive load shedding scheme that provides emergency protection against excess frequency decline, whilst minimizing the risk of line overloading. The proposed load shedding scheme uses the local frequency rate information to adapt the load shedding behaviour to suit the size and location of the experienced disturbance. The proposed scheme is tested in simulation on a 3-region, 10-generator sample system and shows good performance.

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


Expectation Propagation for microarray data classification Microarray experiments are a very promising tool for early diagnosis and disease treatment. The datasets obtained in these experiments typically consist of a small number of instances and a large number of covariates, most of which are irrelevant for discrimination. These characteristics pose severe difficulties for standard learning algorithms. A Bayesian approach can be useful to overcome these problems and produce more accurate and robust predictions. However, exact Bayesian inference is computationally costly and in many cases infeasible. In practice, some form of approximation has to be made. In this paper we consider a Bayesian linear model for microarray data classification based on a prior distribution that favors sparsity in the model coefficients. Expectation Propagation (EP) is then used to perform approximate inference as an alternative to computationally more expensive methods, such as Markov Chain Monte Carlo (MCMC) sampling. The model considered is evaluated on 15 microarray datasets and compared with other state-of-the-art classification algorithms. These experiments show that the Bayesian model trained with EP performs well on the datasets investigated and is also useful to identify relevant genes for subsequent analysis.

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 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 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

microarray data
bayesian inference
expectation propagation


Generation of various rhythms by thalamic neural network model Experimental investigations of the brain revealed that a variety type of rhythms arises in the thalamic region, from slow oscillations (0.54Hz) to very fast oscillations (up to 350 Hz), depending on the value of injected current. In order to explain how these neurons can generate such interesting rhythms, we connect 100 model neurons randomly by a Heaviside function. We observe that this network model can produce a variety of rhythms, ranging from slow oscillations (about 2.5Hz) to very high frequencies (up to 180Hz). Using 2D plots of firing neurons, we show that the neural network model produces different chaotic and regular wave activities.

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 B I O O O O O O O O

brain rhythms
brain waves
synchronization


A Convertible Multi-Authenticated Encryption scheme for group communications ? Recently, Wu et al. proposed a Convertible Multi-Authenticated Encryption (CMAE) scheme, which allows a signing group with multiple signers to generate a multi-authenticated ciphertext signature on the chosen message so that only a designated verifier can recover and verify the message. In case of later dispute, the verifier can convert the multi-authenticated ciphertext signature into an ordinary one that can be verified by anyone. In this study, a CMAE scheme for group communications is proposed. This is presented by first reviewing the concepts of group-oriented encryption schemes and the merits of Wu et al.s scheme. This shows that not only can a multi-authenticated ciphertext signature be generated by a signing group, but also the message can be recovered and verified by a verifying group with multiple verifiers. The security of the proposed scheme is based solely on the DDH problem, which provides higher security confidence than using the CDH problem in Wu et al.s CMAE scheme.

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

authenticated encryption
cryptography
diffiehellman problem
group-oriented encryption
message recovery signature
multi-signature


supporting peer learning with ad-hoc communities Research in learning and competence development shows the benefits of peer support and access to peers' solutions for learning and understanding. We propose a concept for task-focused knowledge exchange in a learner network using a digital learning environment that supports creation of ad-hoc (sub)communities by matching learning opportunities. Structural results from Social Network Analysis (SNA) are incorporated in the derived models of community-based learning in (sub)communities. The approach, research questions and the planned evaluation setup are described.

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

learning communities
ergm
peer reviews
knowledge sharing


accelerating sql database operations on a gpu with cuda Prior work has shown dramatic acceleration for various database operations on GPUs, but only using primitives that are not part of conventional database languages such as SQL. This paper implements a subset of the SQLite command processor directly on the GPU. This dramatically reduces the effort required to achieve GPU acceleration by avoiding the need for database programmers to use new programming languages such as CUDA or modify their programs to use non-SQL libraries. This paper focuses on accelerating SELECT queries and describes the considerations in an efficient GPU implementation of the SQLite command processor. Results on an NVIDIA Tesla C1060 achieve speedups of 20-70X depending on the size of the result set.

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


processing first-order queries under limited access patterns We study the problem of answering queries over sources with limited access patterns. Given a first-order query Q, the problem is to decide whether there is an equivalent query which can be executed observing the access patterns restrictions. If so, we say that Q is feasible. We define feasible for first-order queries---previous definitions handled only some existential cases---and characterize the complexity of many first-order query classes. For each of them, we show that deciding feasibility is as hard as deciding containment. Since feasibility is undecidable in many cases and hard to decide in some others, we also define an approximation to it which can be computed in NP for any first-order query and in P for unions of conjunctive queries with negation. Finally, we outline a practical overall strategy for processing first-order queries under limited access patterns.

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

approximation
conjunctive queries
queries
complexity
access
practical
query

order strategies definition process class pattern container


Simulation and fault detection of three-phase induction motors Computer simulation of electric motor operation is particularly useful for gaining an insight into their dynamic behaviour and electro-mechanical interaction. A suitable model enables motor faults to be simulated and the change in corresponding parameters to be predicted without physical experimentation. This paper presents both a theoretical and experimental analysis of asymmetric stator and rotor faults in induction machines. A three-phase induction motor was simulated and operated under normal healthy operation, with one broken rotor bar and with voltage imbalances between phases of supply. The results illustrate good agreement between both simulated and experimental results. (C) 2002 IMACS. Published by Elsevier Science B.V. All rights reserved.

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

fault simulation
mathematical models
condition monitoring


Classification-based vehicle detection in high-resolution satellite images In this study, we have looked into the problem of vehicle detection in high-resolution satellite images. Based on the input from the local road authorities, we have focused not only on highways, but also on inner city roads, where more clutter is expected. The study site is the city of Oslo, Norway. To do vehicle detection in these areas, we propose an automatic approach, consisting of a segmentation step, followed by two stages of object classification. In the process, we utilize multispectral images, panchromatic images and a road network. The approach has been tested on Quickbird images, and the results that are obtained have been compared with manual counts and classifications.

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

quickbird
vehicle detection
classification


Keyphrase extraction through query performance prediction Previous research shows that keyphrases are useful tools in document retrieval and navigation. While these point to a relation between keyphrases and document retrieval performance, no other work uses this relationship to identify keyphrases of a given document. This work aims to establish a link between the problems of query performance prediction (QPP) and keyphrase extraction. To this end, features used in QPP are evaluated in keyphrase extraction using a naive Bayes classifier. Our experiments indicate that these features improve the effectiveness of keyphrase extraction in documents of different length. More importantly, commonly used features of frequency and first position in text perform poorly on shorter documents, whereas QPP features are more robust and achieve better results.

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

keyphrase extraction
query performance prediction


Plaintext awareness in identity-based key encapsulation The notion of plaintext awareness (\({\mathsf{PA}}\)) has many applications in public key cryptography: it offers unique, stand-alone security guarantees for public key encryption schemes, has been used as a sufficient condition for proving indistinguishability against adaptive chosen-ciphertext attacks (\({\mathsf{IND}\hbox {-}{\mathsf{CCA}}}\)), and can be used to construct privacy-preserving protocols such as deniable authentication. Unlike many other security notions, plaintext awareness is very fragile when it comes to differences between the random oracle and standard models; for example, many implications involving \({\mathsf{PA}}\) in the random oracle model are not valid in the standard model and vice versa. Similarly, strategies for proving \({\mathsf{PA}}\) of schemes in one model cannot be adapted to the other model. Existing research addresses \({\mathsf{PA}}\) in detail only in the public key setting. This paper gives the first formal exploration of plaintext awareness in the identity-based setting and, as initial work, proceeds in the random oracle model. The focus is laid mainly on identity-based key encapsulation mechanisms (IB-KEMs), for which the paper presents the first definitions of plaintext awareness, highlights the role of \({\mathsf{PA}}\) in proof strategies of \({\mathsf{IND}\hbox {-}{\mathsf{CCA}}}\) security, and explores relationships between \({\mathsf{PA}}\) and other security properties. On the practical side, our work offers the first, highly efficient, general approach for building IB-KEMs that are simultaneously plaintext-aware and \({\mathsf{IND}\hbox {-}{\mathsf{CCA}}}\)-secure. Our construction is inspired by the Fujisaki-Okamoto (FO) transform, but demands weaker and more natural properties of its building blocks. This result comes from a new look at the notion of \(\gamma \)-uniformity that was inherent in the original FO transform. We show that for IB-KEMs (and PK-KEMs), this assumption can be replaced with a weaker computational notion, which is in fact implied by one-wayness. Finally, we give the first concrete IB-KEM scheme that is \({\mathsf{PA}}\) and \({\mathsf{IND}\hbox {-}{\mathsf{CCA}}}\)-secure by applying our construction to a popular IB-KEM and optimizing it for better performance.

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

identity-based encryption
key encapsulation mechanism
generic transformation


Anchorperson extraction for Picture in Picture news video Picture in Picture news video is one typical kind of video sequences, where some regions undergo the moving camera and the others undergo the static camera. Actually it is a very difficult for computer to distinguish whether the motion is caused by the moving objects themselves or the moving camera, thus extracting anchorperson from this kind of video becomes a challenging vision task. To our knowledge, it is the first time to address this kind of application. Change detection is implemented to achieve fast, automatic and robust anchorperson extraction with the aid of a simple anchorperson model, which is initialized once in the first frame. The experiment results demonstrate our performance.

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

multiple motion video
video segmentation


enhancing topic tracking with temporal information In this paper, we propose a new strategy with time granularity reasoning for utilizing temporal information in topic tracking. Compared with previous ones, our work has four distinguished characteristics. Firstly, we try to determine a set of topic times for a target topic from the given on-topic stories. It helps to avoid the negative influence from other irrelevant times. Secondly, we take into account time granularity variance when deciding whether a coreference relationship exists between two times. Thirdly, both publication time and times presented in texts are considered. Finally, as time is only one attribute of a topic, we increase the similarity between a story and a target topic only when they are related not only temporally but also semantically. Experiments on two TDT corpora show that our method makes good use of temporal information in news stories.

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


Sweep-line algorithm for constrained Delaunay triangulation This paper introduces a new algorithm for constrained Delaunay triangulation, which is built upon sets of points and constraining edges. It has various applications in geographical information system (GIS), for example, iso-lines triangulation or the triangulation of polygons in land cadastre. The presented algorithm uses a sweep-line paradigm combined with Lawson's legalisation. An advancing front moves by following the sweep-line. It separates the triangulated and non-triangulated regions of interest. Our algorithm simultaneously triangulates points and constraining edges and thus avoids consuming location of those triangles containing constraining edges, as used by other approaches. The implementation of the algorithm is also considerably simplified by introducing two additional artificial points. Experiments show that the presented algorithm is among the fastest constrained Delaunay triangulation algorithms available at the moment.

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

algorithm
constrained delaunay triangulation


reinforcement learning for active model selection In many practical Machine Learning tasks, there are costs associated with acquiring the feature values of training instances, as well as a hard learning budget which limits the number of feature values that can be purchased. In this budgeted learning scenario, it is important to use an effective "data acquisition policy", that specifies how to spend the budget acquiring training data to produce an accurate classifier. This paper examines a simplified version of this problem, "active model selection" [10]. As this is a Markov decision problem, we consider applying reinforcement learning (RL) techniques to learn an effective spending policy. Despite extensive training, our experiments on various versions of the problem show that the performance of RL techniques is inferior to existing, simpler spending policies.

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


Enhancement of wireless positioning in outdoor suburban NLOS environment using hybrid-network-GPS systems This article will introduce a method for locating mobile stations (MSs) in outdoor suburban non-line-of-sight (NLOS) environment. The measurements used to locate the MS are taken from three base stations and a satellite. Such a setup of measurements is named the hybrid-network-GPS system. The proposed method uses constraint nonlinear optimization to minimize the NLOS error. The problem is simplified to three independent nonlinear equations of three unknowns, then it is solved to find the MS location. Numerical simulations are introduced to assess the performance of the proposed method compared with other positioning algorithms.

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Binary self-dual codes with automorphisms of composite order In this paper, we present some results concerning a decomposition of binary self-dual codes having an automorphism of an order which is the product of two odd prime numbers. These results are applied to construct self-dual [72, 36, 121 codes with an automorphism of order 15. Furthermore, it is proved that the automorphism group of a putative binary extremal self-dual [72, 36, 16] code contains at most 28 nontrivial types of automorphisms of odd order. A complete list of these possible types of automorphisms is presented.

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On multiroute maximum flows in networks Let G = (N, A) be a network with a designated source node s, a designated sink node t, and a finite integral capacity uij on each arc (i, j) is an element of A. An elementary K-flow is a flow of K units from s to t such that the flow on each arc is 0 or 1. A K-route flow is a flow from s to t that may be expressed as a nonnegative linear sum of elementary K-flows. In this paper, we show how to determine a maximum K-route flow as a sequence of O(min {log (nU), K}) maximum-flow problems. This improves upon the algorithm by Kishimoto, which solves this problem as a sequence of K maximum-flow problems. In addition, we have simplified and extended some of the basic theory. We also discuss the application of our technique to Birkhoff's theorem and a scheduling problem. (C) 2001 John Wiley Sons, Inc.

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Efficient compiler and run-time support for parallel irregular reductions ? Many scientific applications are comprised of irregular reductions on large data sets. In shared-memory parallel programs, these irregular reductions are typically computed in parallel using replicated buffers, then combined using synchronization. We develop LocalWrite, a new technique which partitions irregular reductions so that each processor computes values only for locally assigned data, eliminating the need for buffers or synchronized writes. Computation is replicated if its results are needed on multiple processors. We experimentally evaluate its performance for three irregular codes on a software DSM running on a distributed-memory multiprocessor and two shared-memory multiprocessors while varying connectivity, locality, and adaptivity. Results show LocalWrite improves performance significantly compared to using replicated buffers, and can match or exceed explicit message-passing gather/scatter for applications with low locality or high adaptivity.

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parallelizing compilers
locality optimizations
irregular computations


Self-learning complex neuro-fuzzy system with complex fuzzy sets and its application to adaptive image noise canceling In this paper we propose a new self-learning complex neuro-fuzzy system (CNFS) using complex fuzzy sets (CFSs). We design a class of Gaussian complex fuzzy sets for the proposed approach. This new computing model is applied to the problem of adaptive image noise canceling (AINC), where images are corrupted additively by unknown noise and the proposed CNFS is used to adaptively perform the task of image restoration. The proposed CNFS is focused on improving image quality with additive noise. The knowledge base of CNFS is composed of TakagiSugeno fuzzy IfThen rules, whose premises are described by CFSs. CFS is an advanced fuzzy set, which is described by a complex-valued membership function in the unit disc of the complex plane. The utility of CFSs can enhance the non-linear functional mapping ability of the CNFS, because CFSs can carry more information into fuzzy inference computing as well as more degrees of freedom for the adaption flexibility of CNFS. For optimal estimation of the parameters of CNFS, we devise a hybrid PSORLSE optimization method, which combines the well-known particle swarm optimization (PSO) method and the famous recursive least squares estimation (RLSE) method. Iteratively, the PSO is used to evolve the premise parameters of CNFS, based on which the RLSE is used to update the consequent parameters. The PSORLSE method is very efficient for fast learning. For AINC application, the proposed CNFS is used to mimic the behavior of unknown noise channel, so that corrupted images may be adaptively restored as close to its original version as possible. Several images are used to test the proposed approach, whose experimental results are compared to other approaches. The experimental results indicate that the proposed approach outperforms the compared approaches. Excellent performance for image restoration by the proposed approach has been observed.

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pso
rlse
adaptive image noise canceling
image restoration

complex fuzzy set
complex neuro-fuzzy system
machine learning


Efficiently implementable algebra for distributed in-network spatial analysis Existing sensor network query processors (SNQPs) have demonstrated that in-network processing is an effective and efficient means of interacting with wireless sensor networks (WSNs) for data collection tasks. Inspired by these findings, this article investigates the question as to whether spatial analysis over WSNs can be built upon established distributed query processing techniques, but, here, emphasis is on the spatial aspects of sensed data, which are not adequately addressed in the existing SNQPs. By spatial analysis, we mean the ability to detect topological relationships between spatially referenced entities (e.g. whether mist intersects a vineyard or is disjoint from it) and to derive representations grounded on such relationships (e.g. the geometrical extent of that part of a vineyard that is covered by mist). To support the efficient representation, querying and manipulation of spatial data, we use an algebraic approach. We revisit a previously proposed centralized spatial algebra comprising a set of spatial data types and a comprehensive collection of operations. We have redefined and re-conceptualized the algebra for distributed evaluation and shown that it can be efficiently implemented for in-network execution. This article provides rigorous, formal definitions of the spatial data types, points, lines and regions, together with spatial-valued and topological operations over them. The article shows how the algebra can be used to characterize complex and expressive topological relationships between spatial entities and spatial phenomena that, due to their dynamic, evolving nature, cannot be represented a priori.

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wireless sensor networks
spatial algebra

in-network processing
distributed spatial analysis