Are sufficient statistics sufficient? A gambling example is presented in which the players use the Minimum Variance Unbiased Estimator to estimate a parameter while you use another estimator. Your winnings are significant. The properties of your estimator are discussed and its derivation given.

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

exponential distribution
compound decision


Selection of programme slots of television channels for giving advertisement: A graph theoretic approach The present paper aims at developing a linear time algorithm to find a solution to the maximum weight 1 colouring problem for an interval graph with interval weight. This algorithm has been applied to solve the problem that involves selecting different programme slots telecast on different television channels in a day so as to reach the maximum number of viewers. It is shown that all programmes of all television channels can be modelled as a weighted interval graph with interval numbers as weights. The programme slots are taken as the vertices of the graph and if the time durations of two programme slots have non-empty intersection, the corresponding vertices are considered to be connected by an edge. The number of viewers of a programme is taken as the weight of the vertex. In reality, the number of viewers of a programme is not a fixed one; generally, it lies in an interval. Thus, the weights of the vertices are taken as interval numbers. We assume that a company sets the objective of selecting the popular programme in different channels so as to make its commercial advertisement reach the maximum number of viewers. However, the constraint imposed is that all selected programmes are mutually exclusive in respect of time scheduling. The objective of the paper is, therefore, to helps the companies to select the programme slots, which are mutually exclusive with respect to the time schedule of telecasting time, in such a way that the total number of viewers of the selected programme slots rises to the optimum level. It is shown that the solution of this problem is obtained by solving the maximum weight colouring problem on an interval graph. An algorithm is designed to solve this optimization problem using O(n) time, where n represents the total number of programmes of all channels.

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


Metaheuristic algorithms for approximate solution to ordinary differential equations of longitudinal fins having various profiles Approximate solutions to ordinary differential equations (ODEs) in engineering. Fourier series with the aid of metaheuristics used as suggested approximate method. The GA, PSO and HS are utilized for optimization purposes. Obtained approximate solutions by the proposed method confirm the results by others. Proposed approach offers acceptable accuracy for a wide range of ODEs.

O O O B I 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 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

metaheuristics
approximate solution
fourier series
longitudinal fins

analytical solution
weighted residual function


Compositional approach applied to loop specialization An optimizing compiler cannot generate one best code pattern for all input data. There is no 'one optimization fits all' inputs. To attain high performance for a large range of inputs, it is therefore desirable to resort to some kind of specialization. Data specialization significantly improves the performance delivered by the compiler-generated codes. Specialization is, however, limited by code expansion and introduces a time overhead for the selection of the appropriate version. We propose a new method to specialize the code at the assembly level for loop structures. Our specialization scheme focuses on different ranges of loop trip count and combines all these versions into a code that switches smoothly from one to the other while the iteration count increases. Hence, the resulting code achieves the same level of performance than each version on its specific iteration interval. We illustrate the benefit of our method on the SPEC benchmarks with detailed experimental results. Copyright (c) 2008 John Wiley & Sons, Ltd.

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

loop optimization
code specialization
instruction level parallelism
instruction scheduling


A global remote laboratory experimentation network and the experiment service provider business model This paper presents results from the IST KAII Trial project ReLAX-Remotc LAboratory eXperimentation trial (IST 1999-20827), and contributes with a framework for a global remote laboratory experimentation network supported by a new business model. The paper presents this new Experiment Service Provider business model that aims at bringing physical experimentation back into the learning arena, where remotely operable laboratory experiments used in advanced education and training schemes are made available to a global education and training market in industry and academia. The business model is based on an approach where individual experiment owners offer remote access to their high-quality laboratory facilities to users around the world. The usage can be for research, education, on-the-job training etc. The access to these facilities is offered via an independent operating company-the Experiment Service Provider. The Experiment Service Provider offers eCommerce services like booking, access control, invoicing, dispute resolution, quality control, customer evaluation services and a unified Lab Portal.

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


VTBuilder: a tool for the assembly of multi isoform transcriptomes Within many research areas, such as transcriptomics, the millions of short DNA fragments (reads) produced by current sequencing platforms need to be assembled into transcript sequences before they can be utilized. Despite recent advances in assembly software, creating such transcripts from read data harboring isoform variation remains challenging. This is because current approaches fail to identify all variants present or they create chimeric transcripts within which relationships between co-evolving sites and other evolutionary factors are disrupted. We present VTBuilder, a tool for constructing non-chimeric transcripts from read data that has been sequenced from sources containing isoform complexity.

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

de novo
contigs
next generation sequencing
java
chimeras
haplotypes
non-chimeric


Modal Knowledge and Game Semirings The aim of algebraic logic is to compact series of small steps of general logical inference into larger (in)equational steps. Algebraic structures that have proved very useful in this context are modal semirings and modal Kleene algebras. We show that they can also model knowledge and belief logics as well as games without additional effort; many of the standard logical properties are theorems rather than axioms in this setting. As examples of the first area, we treat the classical puzzles of the Wise Men and the Muddy Children. Moreover, we show possibilities of handling knowledge update and revision algebraically. For the area of games, we generalize the well-known connection between game logic and dynamic logic to the setting of modal semirings and link it to predicate transformer semantics, in particular to demonic refinement algebra. We think that our study provides evidence that modal semirings are capable of handling a wide variety of (multi-)modal logics in a uniform algebraic fashion.

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 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

modal logic
epistemic logic
game algebra
semiring


The emotion paradox in the aging brain This paper reviews age differences in emotion processing and how they may relate to age-related changes in the brain. Compared with younger adults, older adults react less to negative situations, ignore irrelevant negative stimuli better, and remember relatively more positive than negative information. Older adults ability to insulate their thoughts and emotional reactions from negative situations is likely due to a number of factors, such as being less influenced by interoceptive cues, selecting different emotion regulation strategies, having less age-related decline in prefrontal regions associated with emotional control than in other prefrontal regions, and engaging in emotion regulation strategies as a default mode in their everyday lives. Healthy older adults avoidance of processing negative stimuli may contribute to their well-maintained emotional well-being. However, when cardiovascular disease leads to additional prefrontal white matter damage, older adults have fewer cognitive control mechanisms available to regulate their emotions, making them more vulnerable to depression. In general, although age-related changes in the brain help shape emotional experience, shifts in preferred strategies and goal priorities are also important influences.

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 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

fmri
ventromedial prefrontal cortex
amygdala


A multi-agent architecture with cooperative fuzzy control for a mobile robot The challenges of robotics have led the researchers to develop control architectures composed of distributed, independent and asynchronous behaviors. One way to approach decentralization is through cooperative control, since it allows the development of complex behavior based on several controllers combined to achieve the desired result. Robots, however, require high-level cognitive capacities, and multi-agent architectures provide the appropriate level of abstraction to define them. This article describes a multi-agent architecture combined with cooperative control developed within the agent. The experiments were carried out on an ActivMedia Pioneer 2DX mobile robot. (c) 2007 Elsevier 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

multi-agent architectures
mobile robotics
fuzzy logic
distributed coordination


Why, when and how to use augmented reality agents (AuRAs) Over the last number of years, multiple research projects have begun to create augmented reality (AR) applications that use augmented reality agents, or AuRAs, as their principle interaction and development paradigm. This paper aims to address this new and distinct field of AuRAs by asking three questions: why should AuRAs be researched, when are they a useful paradigm, and how can they be developed? The first question explores the motivation behind applying AuRAs to AR. Specifically, it investigates whether AuRAs are purely an interaction paradigm, or whether they can also serve as a development paradigm, by outlining in which circumstances it is appropriate for a project to use AuRAs and where their addition would only add unnecessary complexity. A navigational experiment, performed in simulated AR, explores the second question of when AuRAs can be a useful concept in AR applications. Results from this experiment suggest that an embodied virtual character allows for faster navigation along a shorter route than directional arrows or marking the target with an AR bubble. An exploration of the limitations of the simulated AR environment illuminates how faithfully the experiment recreated the environmental challenges that AuRAs can help to address. Finally, the question of how to develop such applications is addressed through the introduction of the agent factory augmented reality toolkit that allows the rapid prototyping of such applications. Results from a usability study on the toolkit are also presented.

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

multi-agent systems
virtual reality
ar simulation
interaction techniques


Fuzzy analysis of statistical evidence Bayesian classifiers are effective methods for pattern classification, although their assumptions on the belief structure among attributes are not always justified. In this paper, we introduce a new classification method based on the possibility measure, which does not require a precise belief model and, in a sense, it includes the Bayesian classifiers as special cases. This new classification method uses the fuzzy operators to aggregate attributes information (evidence) and it is referred to as fuzzy analysis of statistical evidence (FASE). FASE has several nice properties. It is noise tolerant, it can handle missing values with ease, and it can extract statistical patterns from the data and represent them by knowledge of beliefs, which, in turn, are propositions for an expert system. Thus, from pattern classification to expert systems, FASE provides a linkage from inductive reasoning to deductive reasoning.

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


Motion synthesis through 1D affine matching We present the study of a data-driven motion synthesis approach based on a 1D affine image-matching equation. We start by deriving the relevant properties of the exact matching operator, such as the existence of a singular point. Next, we approximate such operator by the Greens function of a second-order differential equation, finding that it leads to a more compelling motion impression, due to the incorporation of blur. We then proceed to show that, by judicious choice of the matching parameters, the 1D affine Greens filter allows the simulation of a broad class of effects, such as zoom-in and zoom-out, and of complex nonrigid motions such as that of a pulsating heart.

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


An information security governance framework Information security culture develops in an organization due to certain actions taken by the organization. Management implements information security components, such as policies and technical security measures with which employees interact and that they include in their working procedures. Employees develop certain perceptions and exhibit behavior, such as the reporting of security incidents or sharing of passwords, which could either contribute or be a threat to the securing of information assets. To inculcate an acceptable level of information security culture, the organization must govern information security effectively by implementing all the required information security components. This article evaluates four approaches towards information security governance frameworks in order to arrive at a complete list of information security components. The information security components are used to compile a new comprehensive Information Security Governance framework. The proposed governance framework can be used by organizations to ensure they are governing information security from a holistic perspective, thereby minimising risk and cultivating an acceptable level of information security culture.

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

information security culture
information security behavior


Sediment transport mechanics upstream of an orifice Mechanics of sediment transport, maximum scour depth, and scoured volume upstream of a circular orifice was explored under constant head condition. A high-speed camera was used to investigate the sediment transport mechanism. It was found that sediment transport had two distinct phases. In the first phase, the sediment transport was due to excess bed shear stress and occurred within an area that was elliptical in shape, and the mobilized sediment was transported out of the orifice. In the second stage, vortices appear in the area that was scoured during the first phase. The sediment particles were lifted up into the main flow by these vortices, which were then transported out of the orifice by the main flow. The scour depth and scoured volume were found to be dependent on sediment size and head over the orifice.

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

sediment transport mode
scour hole
orifices
visualization
high-speed camera


Spurious responses suppression of parallel coupled-lines microstrip bandpass filters: Comparison and improvements of planar approaches In this paper, three methods to reject the first spurious harmonic in parallel-coupled microstrip filters are investigated. The authors proposed an extension of these approaches to also suppress the second unwanted passbands while keeping the initial passband practically unchanged. Then, two of these techniques are combined to achieve a wider upper stopband. Indeed, the sinusoidal perturbation technique is well combined with overcoupled end sections to reject the first three spurious passbands of an order three filter. A comparison of simulations and experimental results is made, with a discussion on each method efficiency and possible applications to higher order filters. (C) 2006 Wiley Periodicals, Inc.

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

band-pass filters
parallel coupled microstrip lines
spurious-harmonic suppression
optimization


Unique sink orientations of grids We introduce unique sink orientations of grids as digraph models for many well-studied problems, including linear programming over products of simplices, generalized linear complementarity problems over P-matrices (PGLCP), and simple stochastic games. We investigate the combinatorial structure of such orientations and develop randomized algorithms for finding the sink. We show that the orientations arising from PGLCP satisfy the Holt-Klee condition known to hold for polytope digraphs, and we give the first expected linear-time algorithms for solving PGLCP with a fixed number of blocks.

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


Emergence and predictors of alcohol reference displays on Facebook during the first year of college Displayed Facebook alcohol references often emerge during the first year of college. Displayed alcohol content prior to college was uncommon and linked to drinking. Predictors of alcohol displays included university and number of Facebook friends. Displayed alcohol references often increase with alcohol-themed campus events. Universities could create alcohol prevention messages as Facebook advertisements.

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


summarizing application performance from a components perspective In the era of distributed development, it is common for large applications to be assembled from multiple component layers that are developed by different development teams. Layered applications have deep call paths and numerous invocations (average call stack depth of up to 75, and upto 35 million invocations in the applications we studied) making summarization of performance problems a critical issue. Summarization of performance by classes, methods, invocations or packages is usually inadequate because they are often at the wrong level of granularity. We propose a technique that uses thresholding and filtering to identify a small set of interesting method invocations in components deemed interesting by the user. We show the utility of this technique with a set of 7 real-life applications, where the technique was used to identify a small set (10-93) of expensive invocations which accounted for 82-99\% of the overall performance costs of the application. Our experience shows that this type of characterization can help quickly isolate the specific parts of a large system that can benefit most from performance tuning.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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 analysis
regression
blame assignment
segmented cumulative costs


Hopf bifurcation analysis for a model of single genetic negative feedback autoregulatory system with delay ? In this paper, we deal with a model of single genetic negative feedback autoregulatory system with delay. Choosing the transcriptional rate k as the bifurcation parameter, we demonstrate that the Hopf bifurcation would occur when k exceeds a critical value. By using the normal form theory and center manifold argument, we derive the explicit formulas which determine the bifurcation direction and the stability of bifurcated periodic solution. In order to illustrate our theoretical analysis, a numerical simulation is also included in the end.

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


Estrogens and Antiestrogens as Etiological Factors and Therapeutics for Prostate Cancer Mounting evidence supports a key role played by estrogen or estrogen in synergy with an androgen, in the pathogenesis of prostate cancer (PCa). New experimental data suggest that this process could begin as early as prenatal life. During adulthood, estrogen carcinogenicity is believed to be mediated by the combined effects of hormone-induced, unscheduled cell proliferation and bioactivation of estrogens to genotoxic carcinogens. Increased bioavailability of estrogen through age-dependent increases in conversion from androgen could also be a contributing factor. Individual variations and race-/ethnic-based differences in circulating or locally formed estrogens or in tissue estrogen responsiveness may explain differential PCa risk among individuals or different populations. Estrogen receptor (ER)-? and ER-? are the main mediators of estrogen action in the prostate. However, ER-? is the first ER subtype expressed in the fetal prostate. During cancer development, ER-? expression is first lost as tumors progress into high grade in the primary site. Yet, its reexpression occurs in all metastatic cases of PCa. A change in cytosine methylation in a regulatory CpG island located in the proximal promoter of ER-? may constitute an on/off switch for reversible regulation of ER-? expression. A variety of estrogenic/antiestrogenic/selective estrogen receptor modulator (SERM)-like compounds have been shown to use non-ERE pathways, such as tethering of ER-? to NF-?B binding proteins, Sp2, or Ap1 for gene transactivation. These findings open new avenues for drug design that now focuses on developing a new generation of estrogen-based PCa therapies with maximal proapoptotic action but few or no side effects

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 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 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

selective estrogen receptor modulator
(serm)
nuclear receptor coregulators
dna methylation
developmental reprogramming
licorice
apigenin
phytoestrogen
apoptosis
oxidative stress
genomic damages
prostate cancer risk
hormonal therapy


Fast equilibration of coarse-grained polymeric liquids The study of macromolecular systems may require large computer simulations that are too time consuming and resource intensive to execute in full atomic detail. The integral equation coarse-graining approach by Guenza and co-workers enables the exploration of longer time and spatial scales without sacrificing thermodynamic consistency, by approximating collections of atoms using analytically-derived soft-sphere potentials. Because coarse-grained (CG) characterizations evolve polymer systems far more efficiently than the corresponding united atom (UA) descriptions, we can feasibly equilibrate a CG system to a reasonable geometry, then transform back to the UA description for a more complete equilibration. Automating the transformation between the two different representations simultaneously exploits CG efficiency and UA accuracy. By iteratively mapping back and forth between CG and UA, we can quickly guide the simulation towards a configuration that would have taken many more time steps within the UA representation alone. Accomplishing this feat requires a diligent workflow for managing input/output coordinate data between the different steps, deriving the potential at runtime, and inspecting convergence. In this paper, we present a lightweight workflow environment that accomplishes such fast equilibration without user intervention. The workflow supports automated mapping between the CG and UA descriptions in an iterative, scalable, and customizable manner. We describe this technique, examine its feasibility, and analyze its correctness.

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

atomistic simulation
coarse-graining
scientific workflows
lammps


a bandwidth analysis of reliable multicast transport protocols Multicast is an efficient communication technique to save bandwidth for group communication purposes. A number of protocols have been proposed in the past to provide a reliable multicast service. Briefly classified, they can be distinguished into sender-initiated, receiver-initiated and tree-based approaches. In this paper, an analytical bandwidth evaluation of generic reliable multicast protocols is presented. Of particular importance are new classes with aggregated acknowledgments. In contrast to other approaches, these classes provide reliability not only in case of message loss but also in case of node failures. Our analysis is based on a realistic system model, including data packet and control packet loss, asynchronous local clocks and imperfect scope-limited local groups. Our results show that hierarchical approaches are superior. They provide higher throughput as well as lower bandwidth consumption. Relating to protocols with aggregated acknowledgments, the analysis shows only little additional bandwidth overhead and therefore high throughput rates.

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

tree-based receiver-initiated sender-initiated aak


Optimizations for Risk-Aware Secure Supply Chain Master Planning Supply chain master planning strives for optimally aligned production, warehousing and transportation decisions across a multiple number of partners. Its execution in practice is limited by business partners' reluctance to share their vital business data. Secure Multi-Party Computation (SMC) can be used to make such collaborative computations privacy-preserving by applying cryptographic techniques. Thus, computation becomes acceptable in practice, but the performance of SMC remains critical for real world-sized problems. We assess the disclosure risk of the input and output data and then apply a protection level appropriate for the risk under the assumption that SMC at lower protection levels can be performed faster. This speeds up the secure computation and enables significant improvements in the supply chain.

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

linear programming
privacy
security and protection


Global sensitivity analysis of the joint kinematics during gait to the parameters of a lower limb multi-body model Sensitivity analysis is a typical part of biomechanical models evaluation. For lower limb multi-body models, sensitivity analyses have been mainly performed on musculoskeletal parameters, more rarely on the parameters of the joint models. This study deals with a global sensitivity analysis achieved on a lower limb multi-body model that introduces anatomical constraints at the ankle, tibiofemoral, and patellofemoral joints. The aim of the study was to take into account the uncertainty of parameters (e.g. 2.5cm on the positions of the skin markers embedded in the segments, 5 on the orientation of hinge axis, 2.5mm on the origin and insertion of ligaments) using statistical distributions and propagate it through a multi-body optimisation method used for the computation of joint kinematics from skin markers during gait. This will allow us to identify the most influential parameters on the minimum of the objective function of the multi-body optimisation (i.e. the sum of the squared distances between measured and model-determined skin marker positions) and on the joint angles and displacements. To quantify this influence, a Fourier-based algorithm of global sensitivity analysis coupled with a Latin hypercube sampling is used. This sensitivity analysis shows that some parameters of the motor constraints, that is to say the distances between measured and model-determined skin marker positions, and the kinematic constraints are highly influencing the joint kinematics obtained from the lower limb multi-body model, for example, positions of the skin markers embedded in the shank and pelvis, parameters of the patellofemoral hinge axis, and parameters of the ankle and tibiofemoral ligaments. The resulting standard deviations on the joint angles and displacements reach 36 and 12mm. Therefore, personalisation, customisation or identification of these most sensitive parameters of the lower limb multi-body models may be considered as essential.

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

latin hypercube sampling
kinematic constraints
gait
joint angles

monte carlo simulation
parameters sensitivity
joint displacements


An automated satellite image classification design using object-oriented segmentation algorithms: A move towards standardization Numerous segmentation algorithms have been developed, many of them highly specific and only applicable to a reduced class of problems and image data. Without an additional source of knowledge, automatic image segmentation based on low level image features seemed unlikely to succeed in extracting semantic objects in generic images. A new region-merging segmentation technique has recently been developed which incorporates the spectral and textural properties of the objects to be detected and also their different size and behaviour at different stages of scale, respectively. Linking this technique with the FAO Land Cover Land Use classification system resulted in the development of an automated, standardized classification methodology. Testing on Landsat and Aster images resulted in mutually exclusive classes with clear and unambiguous class definitions. The error matrix based on field samples showed overall accuracy values of 92% for Aster image and 89% for Landsat. The KIA values were 88% for Aster images and 84% for the Landsat image.

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

object-orientation
land use and land cover
automation


A system for the static analysis of XPath XPath is the standard language for navigating XML documents and returning a set of matching nodes. We present a sound and complete decision procedure for containment of XPath queries, as well as other related XPath decision problems such as satisfiability, equivalence, overlap, and coverage. The considered XPath fragment covers most of the language features used in practice. Specifically, we propose a unifying logic for XML, namely, the alternation-free modal mu-calculus with converse. We show how to translate major XML concepts such as XPath and regular XML types (including DTDs) into this logic. Based on these embeddings, we show how XPath decision problems, in the presence or absence of XML types, can be solved using a decision procedure for mu-calculus satisfiability. We provide a complexity analysis of our system together with practical experiments to illustrate the efficiency of the approach for realistic scenarios.

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

algorithms languages standardization theory query


the challenges in creating tools for improving the software development lifecycle Creating successful software systems for end user applications is a complex task. It is often proposed that tools can be built for development teams to help them do their job more efficiently and to help them communicate with their team members. The success of these tools relies on how well the technical community that builds software tools understands the needs of the technical community that uses these tools. How can we effectively apply a user centered design approach to building these tools?

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 B I I O O O O O

software development
user centered design


Some results on Lagrangians of hypergraphs The Lagrangian of a hypergraph has been a useful tool in hypergraph extremal problems. In most applications, we need an upper bound for the Lagrangian of a hypergraph. Frankl and Fredi conjectured that the r r -graph with m m edges formed by taking the first m m sets in the colex ordering of N(r) N ( r ) has the largest Lagrangian of all r r -graphs with m m edges. Talbot in Talbot (2002) provided some evidences for Frankl and Fredis conjecture. In this paper, we prove that the r r -graph with m m edges formed by taking the first m m sets in the colex ordering of N(r) N ( r ) has the largest Lagrangian of all r r -uniform graphs on t t vertices with m m edges when m = t r ? p where 0?p?t?r 0 ? p ? t ? r under some conditions. As an implication, we also derive that Frankl and Fredis conjecture holds for 3-uniform graphs with m = t 3 ? p edges where 0?p?4 0 ? p ? 4 .

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

lagrangians of r r -graphs r r r r r
extremal problems in hypergraphs


extracting urban patterns from location-based social networks Social networks attract lots of new users every day and absorb from them information about events and facts happening in the real world. The exploitation of this information can help identifying mobility patterns that occur in an urban environment as well as produce services to take advantage of social commonalities between people. In this paper we set out to address the problem of extracting urban patterns from fragments of multiple and sparse people life traces, as they emerge from the participation to social network. To investigate this challenging task, we analyzed 13 millions Twitter posts (3 GB) of data in New York. Then we test upon this data a probabilistic topic models approach to automatically extract urban patterns from location-based social network data. We find that the extracted patterns can identify hotspots in the city, and recognize a number of major crowd behaviors that recur over time and space in the urban scenario.

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

spatio-temporal data mining
social dynamics


Development of working competence items for mechatronics with graphical monitoring and control The purpose of this study was to identify the working competence items which considered important for mechatronics with graphical monitoring and control for industry requirements. The data were collected by document analysis, expert interview, and Delphi technique surveys. The Delphi technique involved three questionnaire surveys of field experts and scholars followed by Kendall coefficient of concordance analysis to evaluate the Chi-Square value and examine the consistency of respondent opinions to check the items whether reach the level of significance. Further, a KolmogorovSmirnov one-sample test examined working competence items using 31 items divided into 7 domains. The survey items were selected according to consensus opinions of 10 experts by Delphi survey technique. The findings of this study provide guidelines for assessing professional working competence for mechatronics by applying graphical monitoring and control systems. The research findings reveal the practical competency requirements for students in a technology institute program, and a relevant curriculum is suggested. 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 20: 8892, 2012

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

graphical monitoring and control
mechatronics
delphi technique


Modified T vacation policy for an M/G/1 queueing system with an unreliable server and startup This paper studies the vacation policy of an M/G/1 queueing system with an unreliable server and startup. After all the customers are served in the queue exhaustively, the server deactivates and takes at most J vacations of constant time length T repeatedly until at least one customer is found waiting in the queue upon returning from a vacation. If at least one customer presents in the system when the server returns from a vacation, then the server reactivates and requires a startup time before providing the service. On the other hand, if no customers arrive by the end of the J(th) vacation, the server remains dormant in the system until at least one customer arrives. We will call the policy modified T vacation policy. Furthermore, it is assumed that the server breaks down according to a Poisson process and his repair time has a general distribution. We analyze the system characteristics for this model. (c) 2005 Elsevier Ltd. All rights reserved.

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

queue
startup
unreliable
vacation policy


Dynamic neural networks for modeling and control of nonlinear systems This paper considers the design of a dynamic neural network (DNN) for modeling of a class of nonlinear systems for the purpose of real-time control. The primary contribution of the paper is in developing a DNN estimator with a stable training technique for on-line modeling of unknown (black box) dynamic nonlinear systems. The DNN acts as a generic model of the system, which can be trained on-line and, hence, can be utilized for the implementation of an adaptive model-based control strategy. The training of the network is based on a novel scheme that arranges the outputs of the hidden layer of the DNN into a set of basis functions. This allows for the derivation of a stable rule for the training of the DNN's weights and does not require random initialization of the weights.

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

nonlinear systems
dynamic neural networks

on-line system modeling
model-based adaptive control


Fabrication of a two-step Ni stamp for blind via hole application on PWB This study examined imprint lithography with a two-step Ni stamp to solve the laser process problems and simultaneously form a blind via and layer pattern. The Ni stamp was fabricated by electroplating on a dry-etched Si mold, made from a SOI (silicon on insulator) wafer, and pattern replication. For the pattern transfer of the Ni stamp, hot embossing was performed on SU8-coated BT and Si wafer substrates. The residual layer was of a uniform thickness with an embossed shape of acceptable squareness.

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 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


A polynomial representation of the Diffie-Hellman mapping Let F-q be the finite field of order q and gamma be an element of F-q of order d. The construction of an explicit polynomial f(X) is an element of F-q [X] of degree less than or equal to d - 1 with the property f (gamma(i)) = gamma(i2) for 0 less than or equal to i less than or equal to d - 1 is described. In particular the exact degree and sparsity of f are determined.

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

diffie-hellman cryptosystem
polynomial interpolation


The Hahn decomposition theorem for fuzzy measures and applications We deal with measures on Delta -l-semigroups, in particular on MV-algebras. Examples of such measures are T-infinity-valuations on clans of fuzzy sets. We first provide the Hahn decomposition theorem for measures on Delta -l-semigroups. This is then used to obtain a representation theorem for such measures, which itself is a basic tool in the proof of Liapounoff type theorems. (C) 2001 Elsevier Science 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 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

t-infinity-valuation on clans of fuzzy sets


Optimizing the simultaneous management of blood pressure and cholesterol for type 2 diabetes patients We model the simultaneous control of blood pressure and cholesterol for patients with type 2 diabetes. We present a trade-off analysis between costs and quality-adjusted life years. We compare optimal guidelines to current treatment guidelines. Results indicate that coordination of treatment can reduce costs while improving length and quality of life.

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 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

or in medicine
markov decision process
blood pressure treatment
cholesterol treatment


A study of the role of user-centered design methods in design team projects User-centered approaches to design can guide teams toward an understanding of users and aid teams in better posing design problems. This paper investigates the role of user-centered design approaches in design process and outcome within the context of design team projects. The value of interaction with users is examined at several stages throughout the design process. The influence of user-centered design on the performance of design teams is also explored. Results suggest that the quantity of interactions with users and time spent interacting with users alone is not linked with better design outcome, but that iterative evaluation of concepts by users may be of particular value to design prototypes. Suggestions are made based on the reflections from the authors after conducting this study.

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

design pedagogy
product design
user-centered design


Dynamic service placement and replication framework to enhance service availability using team formation algorithm The motivation of this work is to reduce the complexity in managing and administering services in the ever growing distributed environment via automated service placement and replication with team formation algorithm. The team formation algorithm is designed in a way that it would continuously search for resources with better performance and pool resources together to achieve better availability. The main intention of this work is not to replace the human administrators but to provide a better alternative in managing services in dynamic distributed environment. Instructions from the administrators are still required but at a different level. Administrators are freed from making low level decisions such as to decide the actual placement of the services and design the failover capabilities for each of the services. The evaluation results showed that the framework is capable of managing resources according to the requirements given by administrator, even during in the event of multiple consecutive resources failure. The proposed solution had the probability of 72.1% of its services that are still available after 83.3% of the available resources were shut down while conventional failover solution using three redundant units had only the probability of 40.8% of services that are still available.

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

autonomic computing
resource selection
resource management


An MCR-weighted protocol for multipoint-to-point communication over ABR service In this paper, we propose an available bit rate (ABR) algorithm which can work with multipoint-to-point (mpt-to-pt) as well as with point-to-point (pt-to-pt) connections. The algorithm is an extension to the MCR-weighted maxmin algorithm [Y. Hou, H. Tzeng, S. Panwar, IEEE GLOBCOM, 1997, pp. 492497], which allocates rates to users in proportion to their MCR requirements. This paper shows how source-level information can be compensated for in order to achieve a performance comparable to that of the pt-to-pt algorithm. This is achieved by combining the current cell rate (CCR) and minimum cell rate (MCR) values of all merged connections hierarchically at each merging point and inserting the aggregate values in the outgoing FRM cells. However, we propose to combine the bottlenecked information only in order to avoid mixing the rates of bottlenecked and non-bottlenecked sources. The same switch algorithm used for the pt-to-pt case can therefore still run on the VC level. A simulation study is conducted under different network configurations. Results show that the algorithm produces an oscillation-free allocation vector with almost the same convergence time of the pt-to-pt algorithm. The results also indicate that the additional buffer requirements due to packet level service is minimal.

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

atm
multipoint-to-point
traffic management


Automatic 3D face recognition from depth and intensity Gabor features As is well known, traditional 2D face recognition based on optical (intensity or color) images faces many challenges, such as illumination, expression, and pose variation. In fact, the human face generates not only 2D texture information but also 3D shape information. In this paper, we investigate what contributions depth and intensity information makes to face recognition when expression and pose variations are taken into account, and we propose a novel system for combining depth and intensity information to improve face recognition systems. In our system, local features described by Gabor wavelets are extracted from depth and intensity images, which are obtained from 3D data after fine alignment. Then a novel hierarchical selecting scheme embedded in linear discriminant analysis (LDA) and AdaBoost learning is proposed to select the most effective and most robust features and to construct a strong classifier. Experiments are performed on the CASIA 3D face database and the FRGC V2.0 database, two data sets with complex variations, including expressions, poses and long time lapses between two scans. Experimental results demonstrate the promising performance of the proposed method. In our system, all processes are performed automatically, thus providing a prototype of automatic face recognition combining depth and intensity information. (C) 2009 Elsevier Ltd. All rights reserved.

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

feature sampling
depth gabor images
feature selection
fusion


Elastic Tubes: Modeling Elastic Deformation of Hollow Tubes The Cosserat theory of elastic rods has been used in a wide range of application domains to model and simulate the elastic deformation of thin rods. It is physically accurate and its implementations are efficient for interactive simulation. However, one requirement of using Cosserat rod theory is that the tubular object must have rigid cross-sections that are small compared to its length. This requirement make it difficult for the approach to model elastic deformation of rods with large, non-rigid cross-sections that can change shape during rod deformation, in particular, hollow tubes. Our approach achieves this task using a hybrid model that binds a mesh elastically to a reference Cosserat rod. The mesh represents the surface of the hollow tube while the reference rod models bending, twisting, shearing and stretching of the tube. The cross-sections of the tube may take on any arbitrary shape. The binding is established by a mapping between mesh vertices and the rod's directors. Deformation of the elastic tube is accomplished in two phases. First, the reference rod is deformed according to Cosserat theory. Next, the mesh is deformed using Laplacian deformation according to its mapping to the rod and its surface elastic energy. This hybrid approach allows the tube to deform in a physically correct manner in relation to the bending, twisting, shearing, and stretching of the reference rod. It also allows the surface to deform realistically and efficiently according to surface elastic energy and the shape of the reference rod. In this way, the deformation of elastic hollow tubes with large, non-rigid cross-sections can be simulated accurately and efficiently.

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

elastic tubes
cosserat rod theory
laplacian deformation


Robots in the kitchen: Exploiting ubiquitous sensing and actuation Our goal is to develop intelligent service robots that operate in standard human environments, automating common tasks. In pursuit of this goal, we follow the ubiquitous robotics paradigm, in which intelligent perception and control, are combined with ubiquitous computing. By exploiting sensors and effectors in its environment, a robot can perform more complex tasks without becoming overly complex itself. Following this insight, we have developed a service robot that operates autonomously in a sensor-equipped kitchen. The robot learns from demonstration, and performs sophisticated tasks, in concert with the network of devices in its environment. We report on the design, implementation, and usage of this system, which is freely available for use, and improvement by others, in the research community.

O O O O O O O O O O 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

sensor network
software infrastructure
reusable code


A conservative scheme for the relativistic Vlasov-Maxwell system A new scheme for numerical integration of the 1D2V relativistic Vlasov-Maxwell system is proposed. Assuming that all particles in a cell of the phase space move with the same velocity as that of the particle located at the center of the cell at the beginning of each time step, we successfully integrate the system with no artificial loss of particles. Furthermore, splitting the equations into advection and interaction parts, the method conserves the sum of the kinetic energy of particles and the electromagnetic energy. Three test problems, the gyration of particles, the Weibel instability, and the wakefield acceleration, are solved by using our scheme. We confirm that our scheme can reproduce analytical results of the problems. Though we deal with the 1D2V relativistic Vlasov-Maxwell system, Our method can be applied to the 2D3V and 3D3V cases. (C) 2009 Elsevier Inc. All rights reserved.

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

relativistic vlasov-maxwell system
plasma instability
laser-plasma interaction


On the influence of deformation rate and cooling media on the static strain aging of a warm-rolled low carbon steel An investigation was performed on the static strain aging behavior of warm-rolled low carbon steel during a nearly 1-year aging period, from the view point concerning with influence of changing the deformation speed and cooling media. Mechanical response of the examined material during aging period was evaluated through variations occurred in strength and hardness of the warm-deformed steel. It was shown that changing the rolling speed as well as cooling rate, may result in the occurrence of different metallurgical phenomena, consequently altering the aging kinetics of the material. It was also found that by increasing rolling speed, an increase in the value of hardness and UTS takes place, while changing the cooling rate to a higher value can cause a more considerable variation in the mechanical behavior of warm-rolled samples throughout the aging period. From the industrial point of view, the experiments conducted in this work is in agreement with the practical conditions of high temperature rolling processes with long interpass times, such as Steckel rolling process.

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

static strain aging
rolling speed
cooling rate


Hypergraph-partitioning-based decomposition for parallel sparse-matrix vector multiplication In this work, we show that the standard graph-partitioning-based decomposition of sparse matrices does not reflect the actual communication volume requirement for parallel matrix-vector multiplication. We propose two computational hypergraph models which avoid this crucial deficiency of the graph model. The proposed models reduce the decomposition problem to the well-known hypergraph partitioning problem. The recently proposed successful multilevel framework is exploited to develop a multilevel hypergraph partitioning tool PaToH for the experimental verification of our proposed hypergraph models. Experimental results on a wide range of realistic sparse test matrices confirm the validity of the proposed hypergraph models. In the decomposition of the test matrices, the hypergraph models using PaToH and hMeTiS result in up to 63 percent less communication volume (30 to 38 percent less on the average) than the graph model using MeTiS, while PaToH is only 1.3-2.3 times slower than MeTiS on the average.

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

matrix multiplication
parallel processing
matrix decomposition
computational graph model
graph partitioning
computational hypergraph model


Orthogonal Component Analysis: A Fast Dimensionality Reduction Algorithm Most existing dimensionality reduction algorithms have two disadvantages: their computational cost is high and they cannot estimate the intrinsic dimension of the original dataset by themselves. To deal with these problems, in this paper we propose a fast linear dimensionality reduction method named Orthogonal Component Analysis (OCA). While avoiding solving eigenproblem and matrix inverse problem, OCA successfully achieves high-speed orthogonal component extraction. By proposing an adaptive threshold scheme, OCA is able to estimate the dimension of the feature space automatically. Meanwhile, the algorithm is guaranteed to be numerical stable. In the experiments, OCA is compared with several typical dimensionality reduction algorithms. The experimental results demonstrate that as a universal algorithm, OCA is efficient and effective.

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

dimensionality reduction
orthogonal component

intrinsic dimension estimation
high-speed component learning


Score distributions for Pseudo Relevance Feedback Relevance-Based Language Models, commonly known as Relevance Models, are successful approaches to explicitly introduce the concept of relevance in the statistical language modelling framework of Information Retrieval. These models achieve state-of-the-art retrieval performance in the Pseudo Relevance Feedback task. It is known that one of the factors that more affect to the Pseudo Relevance Feedback robustness is the selection for some queries of harmful expansion terms. In order to minimise this effect in these methods a crucial point is to reduce the number of non-relevant documents in the pseudo relevant set. In this paper, we propose an original approach to tackle this problem. We try to automatically determine for each query how many documents we should select as pseudo-relevant set. For achieving this objective we will study the score distributions of the initial retrieval and trying to discern in base of their distribution between relevant and non-relevant documents. Evaluation of our proposal showed important improvements in terms of robustness.

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 B I 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 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

information retrieval
pseudo relevance feedback

score distribution
pseudo relevance feedback set
relevance model


Systemic Thromboembolism in Inflammatory Bowel Disease: Mechanisms and Clinical Applications Abstract: Systemic thromboembolism is an extraintestinal manifestation of inflammatory bowel disease (IBD), and an important cause of patient morbidity and mortality. The underlying basis for the hypercoagulable state in IBD is complex, and involves altered activity of all three components that govern hemostasis: platelets, fibrinolysis, and the coagulation cascade. Currently, there are no distinct guidelines for treating or preventing thromboembolic (TE) events in IBD patients compared with the general population. However, the prothrombotic state in IBD stems, at least in part, from several modifiable factors, such as hyperhomocysteinemia and an active inflammatory state. In this review we summarize the mechanisms that favor thrombosis in IBD, and the principles that need to be applied for the primary and secondary prevention of TE in this selected group of patients.

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 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 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

thrombosis
hypercoagulable state
inflammatory bowel disease


A numerical scheme based on compact integrated-RBFs and AdamsBashforth/CrankNicolson algorithms for diffusion and unsteady fluid flow problems This paper presents a high-order approximation scheme based on compact integrated radial basis function (CIRBF) stencils and second-order AdamsBashforth/CrankNicolson algorithms for solving time-dependent problems in one and two space dimensions. We employ CIRBF stencils, where the RBF approximations are locally constructed through integration and expressed in terms of nodal values of the function and its derivatives, to discretise the spatial derivatives in the governing equation. We adopt the AdamsBashforth and CrankNicolson algorithms, which are second-order accurate, to discretise the temporal derivatives. The performance of the proposed scheme is investigated numerically through the solution of several test problems, including heat transfer governed by the diffusion equation, shock wave propagation and shock-like solution governed by the Burgers' equation, and torsionally oscillating lid-driven cavity flow governed by the NavierStokes equation in the primitive variables. Numerical experiments show that the proposed scheme is stable and high-order accurate in reference to the exact solution of analytic test problems and achieves a good agreement with published results for other test problems.

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

time-dependent problems
compact integrated-rbf stencils
high-order approximations


Mining Bucket Order-Preserving SubMatrices in Gene Expression Data The Order-Preserving SubMatrices (OPSMs) are employed to discover significant biological associations between genes and experiment conditions. Herein, we propose a new relaxed OPSM model by considering the linearity relaxation, which is called the Bucket OPSM (BOPSM) model. An efficient method called APRIBOPSM is developed to exhaustively mine such BOPSM patterns. We further generalize the BOPSM model by incorporating the similarity relaxation strategy. We develop a generalized BOPSM model called GeBOPSM and adopt a pattern growing method called SEEDGROWTH to mine GeBOPSM patterns. Informally, the SEEDGROWTH algorithm adopts two different growing strategies on rows and columns in order to expand a seed BOPSM into a maximal GeBOPSM pattern. We conduct a series of experiments using both synthetic and biological datasets to study the effectiveness of our proposed relaxed models and the efficiency of the relevant mining methods. The BOPSM model is shown to be able to capture the characteristics of noisy OPSM patterns, and is superior to the strict counterparts. APRIBOPSM is also significantly more efficient than OPC-Tree, which is the state-of-the-art OPSM mining method. Compared to all the current relaxed OPSM models, the GeBOPSM model achieves the best performance in terms of the number of mined quality patterns.

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

linearity relaxation
similarity relaxation
opsm

order-preserving submatrix
biclustering
bucket order


using statistical testing in the evaluation of retrieval experiments The standard strategies for evaluation based on precision and recall are examined and their relative advantages and disadvantages are discussed. In particular, it is suggested that relevance feedback be evaluated from the perspective of the user. A number of different statistical tests are described for determining if differences in performance between retrieval methods are significant. These tests have often been ignored in the past because most are based on an assumption of normality which is not strictly valid for the standard performance measures. However, one can test this assumption using simple diagnostic plots, and if it is a poor approximation, there are a number of non-parametric alternatives.

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

strategies test approximation performance retrieval evaluation user

precise
statistics
method
performance measurement
parametric
standardization
experience
relation
relevance-feedback
normalization


An Empirical Analysis of the Relationship Between IT Training Sources and IT Value Information technology (IT) training has been identified as a key factor for the success of IT applications and the most frequently applied coping mechanism to handle changing IT. However, there is a question as to how IT training has to be conducted to obtain desired outcomes (higher levels of IT value). This paper analyses the presence of IT training sources used by firms and examines the influence on IT business value. Here, IT training is studied according to three IT training sources: in-house IT training, outside IT training, and self IT training by employees. In addition, differences in IT training sources are analysed according to two contingency factors: business size and business industry. Results show a positive relationship between IT training sources (outside and self IT training) and IT business value and confirm that IT training sources are positively related to business size and differ moderately by business industry.

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

information technology
training
it value
business value


A robust optimization approach for dynamic traffic signal control with emission considerations Traffic signal optimization with emission considerations is formulated as a math program. The LWR model is employed to describe traffic and capture queue spillback. A macroscopic relationship between emission rate and link occupancy is uncovered. We use robust optimization to explicitly reformulate emission constraints into linear forms. The resulting mixed integer linear program can be efficiently solved.

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

signal control
emission
robust optimization
mixed integer linear program


A hybrid genetic algorithm with adaptive diversity management for a large class of vehicle routing problems with time-windows The paper presents an efficient Hybrid Genetic Search with Advanced Diversity Control for a large class of time-constrained vehicle routing problems, introducing several new features to manage the temporal dimension. New move evaluation techniques are proposed, accounting for penalized infeasible solutions with respect to time-window and duration constraints, and allowing to evaluate moves from any classical neighbourhood based on arc or node exchanges in amortized constant time. Furthermore, geometric and structural problem decompositions are developed to address efficiently large problems. The proposed algorithm outperforms all current state-of-the-art approaches on classical literature benchmark instances for any combination of periodic, multi-depot, site-dependent, and duration-constrained vehicle routing problem with time windows.

O B I I O O B I 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 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 B I

vehicle routing problems
time windows
hybrid genetic algorithm
diversity management


A Structured Approach for Designing Collaboration Experiences for Virtual Worlds While 3D virtual worlds are more frequently being used as interactive environments for collaboration, there is still no structured approach developed specifically for the combined design of 3D virtual environments and the collaborative activities in them. We argue that formalizing both the structural elements of virtual worlds and aspects of collaborative work or collaborative learning helps to develop fruitful collaborative work and learning experiences. As such, we present the avatar-based collaboration framework (ABC framework). Based on semiotics theory, the framework puts the collaborating groups into the center of the design and emphasizes the use of distinct features of 3D virtual worlds for use in collaborative learning environments and activities. In developing the framework, we have drawn from best practices in instructional design and game design, research in HCl, and findings and observations from our own empirical research that investigates collaboration patterns in virtual worlds. Along with the framework, we present a case study of its first application for a global collaborative learning project. This paper particularly addresses virtual world designers, educators, meeting facilitators, and other practitioners by thoroughly describing the process of creating rich collaboration and collaborative learning experiences for virtual worlds with the ABC framework.

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 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 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 B I O O O O

group collaboration
embodied collaboration
presence
design science research
online collaboration
immersion


Assessment of Protein Allergenicity For the safety evaluation of genetically engineered crops, the potential allergenicity of the newly introduced protein(s) has become an important issue. There is, however, no universal and reliable test system for the evaluation of the allergic sensitizing ability of food proteins. Therefore, there is a growing interest in the development of animal models. This paper summarizes the results of a promising food allergy model developed in Brown Norway (BN) rats. The results demonstrate that BN rats can be sensitized via the relevant oral route of exposure. Daily gavage dosing of the animals with several food proteins, without the use of adjuvants, resulted in significant antigen-specific IgE responses. In addition, the profile of allergens recognized by the immune system of the BN rat, appeared comparable to the profile of allergens recognized by allergic humans. Besides oral sensitization, local and systemic immune-mediated effects, such as increased gastrointestinal permeability, decreased breathing frequency, and decreased blood pressure, could also be observed in the sensitized animals after an oral challenge. All together, these observations suggest that this BN rat model might provide a suitable animal model to study the allergenicity of food proteins in humans.

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

protein allergenicity
genetically engineered crops
animal models
ige

brown norway rats
passive
cutaneous anaphylaxis testing


Generating rules from examples of human multiattribute decision making should be simple How many prototypes or clusters are needed to predict real world human multiattribute subjective decision making? Although subjective decision making problems occur daily in our life, they have received relatively little attention in artificial intelligence, machine learning and data mining communities. We claim that for most problems, a simple set of rules derived by a nearest neighbor algorithm is the appropriate approach. A simple version of a nearest neighbor model is tested and compared with two other well-established classification methods: neural networks and classifications and regression trees (CART). The results of the experiments show that the simple nearest neighbor method provides very accurate predictions while using very few prototypes or clusters. Although not always the best in accuracy, the differences are sufficiently slight to not warrant greater complexity in deriving rules. Our research on the effectiveness of parsimonious rule sets suggests that decision trees with more than 710 branches are not needed for capturing most human multiattribute decision-making problems, and minimal time or memory resources should be used to generate decision making rules.

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

neural networks
nearest neighbor
data mining

classification and regression trees
exemplar-based learning
clustering
human multiattribute decision-making


diagnosing mobile applications in the wild There are a lot of applications that run on modern mobile operating systems. Inevitably, some of these applications fail in the hands of users. Diagnosing a failure to identify the culprit, or merely reproducing that failure in the lab is difficult. To get insight into this problem, we interviewed developers of five mobile applications and analyzed hundreds of trouble tickets. We find that support for diagnosing unexpected application behavior is lacking across major mobile platforms. Even when developers implement heavy-weight logging during controlled trials, they do not discover many dependencies that are then stressed in the wild. They are also not well-equipped to understand how to monitor the large number of dependencies without impacting the phone's limited resources such as CPU and battery. Based on these findings, we argue for three fundamental changes to failure reporting on mobile phones. The first is spatial spreading , which exploits the large number of phones in the field by spreading the monitoring work across them. The second is statistical inference , which builds a conditional distribution model between application behavior and its dependencies in the presence of partial information. The third is adaptive sampling , which dynamically varies what each phone monitors, to adapt to both the varying population of phones and what is being learned about each failure. We propose a system called MobiBug that combines these three techniques to simplify the task of diagnosing mobile applications.

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


Predictive RANS simulations via Bayesian Model-Scenario Averaging The turbulence closure model is the dominant source of error in most Reynolds-Averaged NavierStokes simulations, yet no reliable estimators for this error component currently exist. Here we develop a stochastic, a posteriori error estimate, calibrated to specific classes of flow. It is based on variability in model closure coefficients across multiple flow scenarios, for multiple closure models. The variability is estimated using Bayesian calibration against experimental data for each scenario, and Bayesian Model-Scenario Averaging (BMSA) is used to collate the resulting posteriors, to obtain a stochastic estimate of a Quantity of Interest (QoI) in an unmeasured (prediction) scenario. The scenario probabilities in BMSA are chosen using a sensor which automatically weights those scenarios in the calibration set which are similar to the prediction scenario. The methodology is applied to the class of turbulent boundary-layers subject to various pressure gradients. For all considered prediction scenarios the standard-deviation of the stochastic estimate is consistent with the measurement ground truth. Furthermore, the mean of the estimate is more consistently accurate than the individual model predictions.

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

bayesian model averaging
bayesian model-scenario averaging
rans models
model inadequacy
uncertainty quantification
boundary-layers
error estimation


Modelling the initial shear stiffness of unsaturated soils as a function of the coupled effects of the void ratio and the degree of saturation Existing models for predicting the small strain behaviour of unsaturated soil are not capable of predicting the initial shear stiffness during suction reduction under normally consolidated conditions. This problem has been addressed in the present study by combining an existing elastoplastic model and recent experimental data to provide a new model for the initial shear stiffness. The model, which is similar to that typically adopted for saturated soils, uses the average skeleton stress and an additional function of the degree of saturation. This new model not only captures the behaviour of the new experimental results, but it also describes a unique relationship between saturated and unsaturated soils.

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

initial shear stiffness
unsaturated soils
modelling
average skeleton stress


panel on role engineering Due to its exibility, ease of administration and intuitiveness, role-based access control (RBAC) is now part of most operating systems and application software. As a result of its commercial success, it has become a standard to implementing access control in many of today's organizations. However, deploying RBAC requires one to first identify an accurate and complete set of roles, and assign users to roles and permissions to roles. This process, known as role engineering [3], has been identified as one of the costliest components in realizing RBAC [7]. Although the problem of role engineering has been studied since early nineties, a recent surge in interest can be seen equally from academic and industry communities. The primary focus of this panel is to have an in-depth discussion of this problem along several dimensions. The panelists, drawn from both academia and industry, include Gail Ahn (University of North Carolina, Charlotte), Vijay Atluri (Rutgers University), Edward Coyne (Science Applications International Corporation), William Horne (Hewlett-Packard), Axel Kern (Beta Systems), Sylvia Osborn (University of Western Ontario) and Andreas Schaad (SAP Labs), who are experts in role engineering. The first dimension of discussions will be on the different means of approaching the role engineering problem, which basically include top-down and bottom-up approaches. Under the top-down approach, roles are defined by carefully analyzing and decomposing business processes into smaller units in a functionally independent manner. These functional units are then associated with permissions on information systems. Coyne [3] is the first to describe the role engineering problem, and to present the concepts of the top-down approach. Later, several top-down approaches have been proposed [6, 1, 12, 14, 15, 11, 5, 8, 2]. In contrast, the bottom-up approach utilizes the existing permission assignments to formulate roles. Recently, several solutions have been proposed in this direction [9, 13, 18, 16, 17, 4, 10]. It may also be advantageous to use a hybrid approach, which is a mixture of the top-down and the bottom-up approaches. The focus of the discussion will be on the pragmatics of applying these classes of solutions in real world situations. Another dimension of discussion will be on the past experiences and current practices employed by organizations in dealing with the role engineering problem, as well as on the opinions of the panelists on the expected practices in future. Yet another dimension is to tackle this problem from a formal perspective and examine the different variants of the problem. These include devising a minimal but complete and good set of roles, minimal number of user-to-role and role-permission assignments, weaker notions of devising minimal roles [16], and the like. The discussions include formal versus practical solutions, their limitations and issues needing further investigation.

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


Spectral clustering with discriminant cuts Recently, many k-way spectral clustering algorithms have been proposed, satisfying one or both of the following requirements: between-cluster similarities are minimized and within-cluster similarities are maximized. In this paper, a novel graph-based spectral clustering algorithm called discriminant cut (Dcut) is proposed, which first builds the affinity matrix of a weighted graph and normalizes it with the corresponding regularized Laplacian matrix, then partitions the vertices into k parts. Dcut has several advantages. First, it is derived from graph partition and has a straightforward geometrical explanation. Second, it emphasizes the above requirements simultaneously. Besides, it is computationally feasible because the NP-hard intractable graph cut problem can be relaxed into a mild eigenvalue decomposition problem. Toy-data and real-data experimental results show that Dcut is pronounced comparing with other spectral clustering methods. (C) 2011 Elsevier B.V. All rights reserved.

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

spectral clustering
discriminant cut
graph cut


Non parametric, self organizing, scalable modeling of spatiotemporal inputs: The sign language paradigm Modeling and recognizing spatiotemporal, as opposed to static input, is a challenging task since it incorporates input dynamics as part of the problem. The vast majority of existing methods tackle the problem as an extension of the static counterpart, using dynamics, such as input derivatives, at feature level and adopting artificial intelligence and machine learning techniques originally designed for solving problems that do not specifically address the temporal aspect. The proposed approach deals with temporal and spatial aspects of the spatiotemporal domain in a discriminative as well as coupling manner. Self Organizing Maps (SOM) model the spatial aspect of the problem and Markov models its temporal counterpart. Incorporation of adjacency, both in training and classification, enhances the overall architecture with robustness and adaptability. The proposed scheme is validated both theoretically, through an error propagation study, and experimentally, on the recognition of individual signs, performed by different, native Greek Sign Language users. Results illustrate the architectures superiority when compared to Hidden Markov Model techniques and variations both in terms of classification performance and computational cost.

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

spatiotemporal pattern recognition
probabilistic
sign language recognition


Aggregative quantification for regression The problem of estimating the class distribution (or prevalence) for a new unlabelled dataset (from a possibly different distribution) is a very common problem which has been addressed in one way or another in the past decades. This problem has been recently reconsidered as a new task in data mining, renamed quantification when the estimation is performed as an aggregation (and possible adjustment) of a single-instance supervised model (e.g., a classifier). However, the study of quantification has been limited to classification, while it is clear that this problem also appears, perhaps even more frequently, with other predictive problems, such as regression. In this case, the goal is to determine a distribution or an aggregated indicator of the output variable for a new unlabelled dataset. In this paper, we introduce a comprehensive new taxonomy of quantification tasks, distinguishing between the estimation of the whole distribution and the estimation of some indicators (summary statistics), for both classification and regression. This distinction is especially useful for regression, since predictions are numerical values that can be aggregated in many different ways, as in multi-dimensional hierarchical data warehouses. We focus on aggregative quantification for regression and see that the approaches borrowed from classification do not work. We present several techniques based on segmentation which are able to produce accurate estimations of the expected value and the distribution of the output variable. We show experimentally that these methods especially excel for the relevant scenarios where training and test distributions dramatically differ.

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

quantification segmentation distribution aggregation

regression quantification
probability estimation


A stochastic model for the evolution of the Web Recently several authors have proposed stochastic models of the growth of the Web graph that give rise to power-law distributions. These models are based on the notion of preferential attachment leading to the rich get richer phenomenon. However, these models fail to explain several distributions arising from empirical results, due to the fact that the predicted exponent is not consistent with the data. To address this problem, we extend the evolutionary model of the Web graph by including a non-preferential component, and we view the stochastic process in terms of an urn transfer model. By making this extension, we can now explain a wider variety of empirically discovered power-law distributions provided the exponent is greater than two. These include: the distribution of incoming links, the distribution of outgoing links, the distribution of pages in a Web site and the distribution of visitors to a Web site. A by-product of our results is a formal proof of the convergence of the standard stochastic model (first proposed by Simon).

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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 splitting extrapolation for solving nonlinear elliptic equations with d-quadratic finite elements ? Nonlinear elliptic partial differential equations are important to many large scale engineering and science problems. For this kind of equations, this article discusses a splitting extrapolation which possesses a high order of accuracy, a high degree of parallelism, less computational complexity and more flexibility than Richardson extrapolation. According to the problems, some domain decompositions are constructed and some independent mesh parameters are designed. Multi-parameter asymptotic expansions are proved for the errors of approximations. Based on the expansions, splitting extrapolation formulas are developed to compute approximations with high order of accuracy on a globally fine grid. Because these formulas only require us to solve a set of smaller discrete subproblems on different coarser grids in parallel instead of on the globally fine grid, a large scale multidimensional problem is turned into a set of smaller discrete subproblems. Additionally, this method is efficient for solving interface problems.

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


human-computer discourse in the design of a pascal tutor An effective human-computer discourse system requires more than a clever grammar or a rich knowledge base. It needs knowledge about the user and his understanding of the domain in order to produce a relevant and coherent discourse. We describe MENO, a prototype tutor for elementary PASCAL, which uses a set of speech patterns modelled after complex human discourse and a richly annotated knowledge base to produce a flexible interactive system for the user.

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

speech
order
interactive system
prototype
design
human
discourse
knowledge
user
grammar

understandability
systems
computation
flexibility
relevance
complexity
effect
knowledge base
coherence
pattern