Efficient text independent speaker recognition with wavelet feature selection based multilayered neural network using supervised learning algorithm A wavelet packet feature selection derived by using multilayered neural network for speaker identification is described. The concept of a multilayered neural network is without using a gradient method. First, the outputs of each hidden unit are algebraically determined by an error backpropagation method. Then, the weight parameters are determined by using an exponentially weighted least squares method. Our results have shown that this feature selection introduced better performance than the other methods with respect to the percentages of recognition.

O O O B I O B I I 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 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

speaker recognition
wavelet feature selection
neural network


Normal Helly circular-arc graphs and its subclasses A Helly circular-arc model M=(C,A) M = ( C , A ) is a circle C C together with a Helly family A A of arcs of C C . If no arc is contained in any other, then M M is a proper Helly circular-arc model, if every arc has the same length, then M M is a unit Helly circular-arc model, and if there are no two arcs covering the circle, then M M is a normal Helly circular-arc model. A Helly (resp.proper Helly, unit Helly, normal Helly) circular-arc graph is the intersection graph of the arcs of a Helly (resp.proper Helly, unit Helly, normal Helly) circular-arc model. In this article we study these subclasses of Helly circular-arc graphs. We show natural generalizations of several properties of (proper) interval graphs that hold for some of these Helly circular-arc subclasses. Next, we describe characterizations for the subclasses of Helly circular-arc graphs, including forbidden induced subgraphs characterizations. These characterizations lead to efficient algorithms for recognizing graphs within these classes. Finally, we show how these classes of graphs relate with straight and round digraphs.

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

helly circular-arc graphs
proper circular-arc graphs
unit circular-arc graphs
normal circular-arc graphs


collection of bcnet bgp traffic This poster paper describes testbed for collection of BCNET Border Gateway Protocol (BGP) traffic. The BGP traffic was collected using special purpose hardware and software. Preliminary data collection was illustrated using the Wireshark and Walrus graph visualization tools.

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

communication system traffic control
communication networks
communications technology
communication system traffic
protocols
routing protocols


Upper-level scheduling supporting multimedia traffic in cellular data networks ? Wireless data networks such as cdma2000 1x EV-DO and UMTS HSDPA use downlink scheduling that exploits channel fading to increase the system throughput. As future wireless networks will eventually support multimedia and data traffic together, we need a proper criterion for scheduling that can count various service requirements such as delay and packet loss. Although some previous approaches proposed opportunistic schedulers at the lower layer, it has not been investigated well whether they are able to meet explicit QoS defined at the upper layer. Hence, in this paper, we develop a hierarchical scheduling model that considers QoS provisioning and the time-varying channel feature separately. We focus on the upper-level QoS scheduling that supports various traffic classes in a unified manner. Supposing that a user gets some satisfaction or utility when served, we introduce a novel concept of opportunity cost, which is defined as the maximum utility loss among users incurred by serving a particular user at the current turn. We obtain each users net profit by subtracting the opportunity cost from its expected utility, and then select a user with the maximum profit for service. Simulation results reveal that our scheme supports various QoS classes well that are represented by delay and packet loss under various traffic loadings.

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


A methodology for fitting and validating metamodels in simulation1 This paper proposes a methodology that replaces the usual ad hoc approach to metamodeling. This methodology considers validation of a metamodel with respect to both the underlying simulation model and the problem entity. It distinguishes between fitting and validating a metamodel, and covers four types of goal: (i) understanding, (ii) prediction, (iii) optimization, and (iv) verification and validation. The methodology consists of a metamodeling process with 10 steps. This process includes classic design of experiments (DOE) and measuring fit through standard measures such as R-square and cross-validation statistics. The paper extends this DOE to stagewise DOE, and discusses several validation criteria, measures, and estimators. The methodology covers metamodels in general (including neural networks); it also gives a specific procedure for developing linear regression (including polynomial) metamodels for random simulation.

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


on the control dependence in the program dependence graph The program dependence graph, PDG, is used to represent the data and control dependencies between the statements of some program. The data dependencies between the statements are fully understood and they correspond to the definition-use chain. On the other hand the concept of control dependence is not fully explored. In this paper we formalize and analyze the concept or control dependence and present algorithms to find directly the control dependence subgraph of PDG in &Ogr; (N &agr;(N)), where N is the number of statements in the program.

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

program dependence graph
control dependence

leader and non-leader nodes
devoted followers
followers


multimedia content processing through cross-modal association Multimodal information processing has received considerable attention in recent years. The focus of existing research in this area has been predominantly on the use of fusion technology. In this paper, we suggest that cross-modal association can provide a new set of powerful solutions in this area. We investigate different cross-modal association methods using the linear correlation model. We also introduce a novel method for cross-modal association called Cross-modal Factor Analysis (CFA). Our earlier work on Latent Semantic Indexing (LSI) is extended for applications that use off-line supervised training. As a promising research direction and practical application of cross-modal association, cross-modal information retrieval where queries from one modality are used to search for content in another modality using low-level features is then discussed in detail. Different association methods are tested and compared using the proposed cross-modal retrieval system. All these methods achieve significant dimensionality reduction. Among them CFA gives the best retrieval performance. Finally, this paper addresses the use of cross-modal association to detect talking heads. The CFA method achieves 91.1\% detection accuracy, while LSI and Canonical Correlation Analysis (CCA) achieve 66.1\% and 73.9\% accuracy, respectively. As shown by experiments, cross-modal association provides many useful benefits, such as robust noise resistance and effective feature selection. Compared to CCA and LSI, the proposed CFA shows several advantages in analysis performance and feature usage. Its capability in feature selection and noise resistance also makes CFA a promising tool for many multimedia analysis applications.

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

applications
use
association
analysis
performance
correlation
tool
paper
model
practical
robust
search
training
attention
fusion
research
detection
method
accuracy
factor
multimedia
retrieval
feature selection
queries
noise
feature

direct
experience
dimensional reduction
informal
multimodality
cross-modal association
contention
systems
technologies
modal
cross-modal factor analysis (cfa)
cross-modal information retrieval
latent semantic analysis
process
talking head analysis
effect
information retrieval


Imperfect cross-correlation and amplitude balance effects on conventional multiuser decoder with turbo encoding The present work aims to illustrate the improvement that turbo encoding/decoding algorithms can bring to a multiuser detection system, evaluated in terms of bit error rate (BER). Extended simulations have been performed for conventional multiuser detection algorithms and are still under study for other algorithms, like the optimal, the MMSE and the classical MMSE ones. Simulations have been performed in both optimal conditions and imperfect ones, like non-equal power of users and non-zero correlations between them and for different number of users. Several interesting conclusions have been highlighted with respect to parameters influence on overall system performances.

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

imperfect detection conditions
performance evaluation turbo coding


Using the World Wide Web for interactive control of an X-ray diffractometer The web-accessible diffractometer is a Philips APD3520 X-ray diffractometer that can be controlled by anyone on the World Wide Web. More than a simulation, remotely-located users submit operating parameters and receive X-ray diffraction patterns through their web browsers. Using the web to control analytic devices enables expanded equipment use in university curricula, provides a new way to share the cost of equipment purchases and fosters long-distance research and teaching collaborations.

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


ENUMERATED TYPE SEMANTICS FOR THE CALCULUS OF LOOPING SEQUENCES The calculus of looping sequences is a formalism for describing the evolution of biological systems by means of term rewriting rules. In this paper we enrich this calculus with a type discipline which preserves some biological properties depending on the minimum and the maximum number of elements of some type requested by the present elements. The type system enforces these properties and typed reductions guarantee that evolution preserves them. As an example, we model the hemoglobin structure and the equilibrium between cell death and division: typed reductions prevent undesirable behaviors.

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

system biology
predictive modelling
cls
type systems


An algebraic variational multiscalemultigrid method for large-eddy simulation of turbulent variable-density flow at low Mach number An algebraic variational multiscalemultigrid method is proposed for large-eddy simulation of turbulent variable-density flow at low Mach number. Scale-separating operators generated by level-transfer operators from plain aggregation algebraic multigrid methods enable the application of modeling terms to selected scale groups (here, the smaller of the resolved scales) in a purely algebraic way. Thus, for scale separation, no additional discretization besides the basic one is required, in contrast to earlier approaches based on geometric multigrid methods. The proposed method is thoroughly validated via three numerical test cases of increasing complexity: a RayleighTaylor instability, turbulent channel flow with a heated and a cooled wall, and turbulent flow past a backward-facing step with heating. Results obtained with the algebraic variational multiscalemultigrid method are compared to results obtained with residual-based variational multiscale methods as well as reference results from direct numerical simulation, experiments and LES published elsewhere. Particularly, mean and various second-order velocity and temperature results obtained for turbulent channel flow with a heated and a cooled wall indicate the higher prediction quality achievable when adding a small-scale subgrid-viscosity term within the algebraic multigrid framework instead of residual-based terms accounting for the subgrid-scale part of the non-linear convective term.

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

turbulent variable-density flow
large-eddy simulation
finite element method
variational multiscale method


The roles of monitoring and cyberbystanders in reducing sexual abuse Offering a fresh perspective on the bystander effect beyond the conventional street violence scenario, this paper examines mens time reactions to an online sex offence against minors. Study 1 shows that men advised of very high electronic monitoring take more time to intervene than men advised of very low electronic monitoring and non-monitoring, and when they are accompanied by strangers rather than acquaintances. Study 2 extends these findings by demonstrating that computerized surveillance, in contrast to user-assisted surveillance and non-surveillance, has a similar inhibitory effect. Drawing on these two studies, Study 3 suggests that the bystander effect also emerges under high monitoring and when the group size of unknown cyberbystanders is increased. Taken together, it appears that high surveillance and increased numbers of cyberbystanders, the factors unexamined jointly in previous research, inhibit intervention, although not in a linear way, and that the likely reasons for it are erosion of bystanders social bonds, diffusion of personal responsibility and diminished sense of making a difference.

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

bystander effect
sexual abuse
surveillance


Hybrid Chinese term indexing and the 2-Poisson model Retrieval effectiveness depends on both the retrieval model and how terms are extracted and indexed. For Chinese, Japanese and Korea text, there are no spaces to delimit words. Indexing using hybrid terms (i.e. words and bigrarns) was found to be effective and efficient using the 2-Poisson model in NTCIR-III open evaluation workshop. Here, we explore another Okapi weight, BM25, based on the 2-Poisson model and compared their performances with bigram and word indexing strategies. Results show that word indexing is the most efficient in terms of indexing time and storage but hybrid term indexing requires the least amount of retrieval time per query. Without pseudo-relevance feedback (PRF), our BM25 appeared to yield better retrieval effectiveness performance for short queries. With PRF, our implementation of the BM11 weights, which are a simplified version of BM25, with hybrid term indexing remains the most effective combination for retrieval in this study.

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

chinese information retrieval
2-poisson model


Multisource Bayesian sequential binary hypothesis testing problem We consider the problem of testing two simple hypotheses about unknown local characteristics of several independent Brownian motions and compound Poisson processes. All of the processes may be observed simultaneously as long as desired before a final choice between hypotheses is made. The objective is to find a decision rule that identifies the correct hypothesis and strikes the optimal balance between the expected costs of sampling and choosing the wrong hypothesis. Previous work on Bayesian sequential hypothesis testing in continuous time provides a solution when the characteristics of these processes are tested separately. However, the decision of an observer can improve greatly if multiple information sources are available both in the form of continuously changing signals (Brownian motions) and marked count data (compound Poisson processes). In this paper, we combine and extend those previous efforts by considering the problem in its multisource setting. We identify a Bayes optimal rule by solving an optimal stopping problem for the likelihood-ratio process. Here, the likelihood-ratio process is a jump-diffusion, and the solution of the optimal stopping problem admits a two-sided stopping region. Therefore, instead of using the variational arguments (and smooth-fit principles) directly, we solve the problem by patching the solutions of a sequence of optimal stopping problems for the pure diffusion part of the likelihood-ratio process. We also provide a numerical algorithm and illustrate it on several examples.

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

bayesian sequential identification
jump-diffusion processes


Thermodynamics of proteins: Fast folders and sharp transitions Several small globular proteins exhibit a simple two-state folding process (sharp transition). The rather short folding times of proteins (fast folders) indicate that folding is guided through some sequence of contact bindings. We discuss the possibility for reconciling a two-state folding event with a sequential folding process, i.e. a folding pathway in a schematic model of protein folding. We show that both single and multiple folding pathways can lead to an apparent two-state folding from a thermodynamic point of view. We also discuss water interactions in protein folding, leading to cold and warm destabilization of the protein. (C) 2002 Published by Elsevier Science B.V.

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

protein folding
thermodynamics
folding pathway


Being progressive is just a phase: celebrating the uniqueness of progressive aspect under a phase-based analysis The identity of phasal boundaries has mostly been considered in light of minimal CP-TP-vP-VP structures. The question this paper addresses is where the clause-internal phase boundary lies in light of more complex structures in which aspectual projections intervene between TP and vP. Iclaim progressive aspect to be unique amongst aspectual forms in English in that it is part of the clause-internal phase, whilst perfect aspect and all higher functional items are contained within the CP/TP phase. This claim accounts for many peculiar quirks of progressive aspect in English, namely in VP ellipsis, fronting phenomena, idioms and existential constructions. On the theoretical front I argue that this division in the aspectual hierarchy is best understood through a variable approach to phases in which the highest projection within a sub-numeration acts as the phase, irrespective of what that projection is. This denies vP of its exclusivity as the clause-internal phase, and allows the progressive layer to project the phase when present. This approach generally sits in line with the move towards a dynamic understanding of phases, as per Bobaljik and Wurmbrand (2005), Wurmbrand (2012, 2013) and Bokovi? (2013, 2014).

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

progressive aspect
ellipsis
fronting
idioms
existential constructions


Localization and Chemical Characterization of the Audiogenic Stress Pathway Neuronal pathways involved in stress responses to extreme somatosensory stimuli were investigated by immunostaining, viral tract tracing, and experimental brain surgery in rats. Acute audiogenic stress, which elicits an immediate marked elevation in plasma ACTH and corticosterone concentrations, was used as a model. Loud noise (105 dB, 30 min) elicited c-fos activation within neurons in all of the components of the auditory system and stress-sensitive brain nuclei, including corticotropin-releasing hormone-synthesizing parvicellular neurons in the hypothalamic paraventricular nucleus (PVN). c-Fos activation was also seen in the medial paralemniscal nucleus in the pons (MPL) and in the subparafascicular nucleus (SPF) in the midbrain. After injection of neurotropic virus (pseudorabies, Bartha strain) into the PVN, neurons in the MPL and the parvicellular portion of the SPF were retrogradely infected. It has been shown by immunostaining that MPL and SPF neurons express a newly discovered neuropeptide, tuberoinfundibular peptide of 39 residues (TIP39). TIP39 is present in a fine neuronal network in the PVN. Audiogenic stress-elicited c-fos activation in TIP39-containing neurons of the MPL and SPF. TIP39 immunoreactivity disappeared from the PVN after transection of MPL and SPF projections to the nucleus. These observations suggest that TIP39-containing MPL and SPF neurons may participate in mediating audiogenic stress responses.

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

c-fos
tract-tracing
double immunostaining


Low resistivity tungsten for 32nm node MOL contacts and beyond Contact resistance in high performance CMOS devices is a major challenge. The introduction of a novel modified low resistivity tungsten process coupled with a robust, and very conformal, thin atomic layer deposited TiN can reduce contact resistance and provide measurable device benefits with very good electrical yield performance. Key characteristics of the modified tungsten (W) process involve, in part, an aggressively thin nucleation layer and low temperature processing (CA, W, low resistivity, resistance).

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


The relationships among several types of fuzzy automata We discuss the relationships among several types of fuzzy automata in which all fuzzy sets are defined by membership functions whose codomains are a lattice-ordered monoid L. These automata include nondeterministic L-valued finite automata with Lambda-move, nondeterministic L-valued finite automata, deterministic L-valued finite automata, and L-valued finite-state automata. We consider all that come with fuzzy initial states and fuzzy final states or with crisp initial states or crisp final states. Some comparative results concerning the power of fuzzy automata used in the existing literature to recognize fuzzy languages are given systematically. (C) 2005 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

fuzzy automaton
lattice-ordered monoid
fuzzy language
equivalence


a type system for certified binaries A certified binary is a value together with a proof that the value satisfies a given specification. Existing compilers that generate certified code have focused on simple memory and control-flow safety rather than more advanced properties. In this paper, we present a general framework for explicitly representing complex propositions and proofs in typed intermediate and assembly languages. The new framework allows us to reason about certified programs that involve effects while still maintaining decidable typechecking. We show how to integrate an entire proof system (the calculus of inductive constructions) into a compiler intermediate language and how the intermediate language can undergo complex transformations (CPS and closure conversion) while preserving proofs represented in the type system. Our work provides a foundation for the process of automatically generating certified binaries in a typetheoretic framework.

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

type system
certified code
value
framework
language
process
general

program
systems
code
memorialized
compilation
assemblers
typed intermediate languages
control flow
complexity
inductance
effect
conversation
proof-preserving compilation
integrability


leveraging complexity in software for cybersecurity A method for assessing statistically quantifiable improvements in security for software vulnerabilities is presented. Drawing on concepts in complexity theory, undecidability, and previous work in high-reliability systems, we show that ensembles of similar implementations have statistical value even though each by itself is inscrutable. Research questions are identified that may allow practical application of these concepts.

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


Exploring user contributed information in social computing systems: quantity versus quality Purpose - The objective of this paper is to explore empirically the relationship between quantity and quality of user contributed information in online social computing systems, and how these two performance outcomes are associated with user factors. Design/methodology/approach - Drawing from prior research, the paper presents a conceptual model hypothesizing a tradeoff between quality and quantity of user contributed information. In addition quality and quantity are associated with a set of motivational, cognitive, and social factors. The model was tested using data obtained through a web-based survey of 345 users of the Flickr online photo sharing community. Findings - The empirical results support the hypothesized inverse relationship between quantity and quality of user contributed information, moderated by user's tenure in the community. The findings also suggest that a user's quantity of contribution is positively associated with the intrinsic motivation of commitment to the community, whereas quality of contribution is positively associated with the extrinsic motivation of self-development. While users' social embeddedness is associated with quality and quantity of contribution, virtualness of social ties is only associated with quality of contribution. Practical implications - The findings of this study can inform the design and management of online communities, and promote sustained contributions from individual users. Originality/value - This study extends our knowledge of the quality and quantity of user contributed online information by demonstrating the inverse relationship between these two performance outcomes, and that they could be motivated by different user factors.

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

quality
social computing
online communities
quantity
user contributed information


A client-server architecture for remotely controlling a robot using a closed-loop system with a biological neuroprocessor This paper introduces an open-source real-time system that remotely controls a robot using human neuroblastoma cultures and a client-server architecture. Multielectrode array set-ups have been designed for direct culturing of neural cells over silicon or glass substrates, providing the capability simultaneously to stimulate and record populations of neural cells. However, it is very difficult to attach these neural cells to the robot structure due to the special conditions of the biological material. The main objective of this research is to build a client-server system for remotely connecting a robot to a neural culture in a closed-loop experimentation. The robot sensors will feed the biological neuroprocessor, while the neural activity will be used for guiding the robot, controlling in this way the robotic behaviour. (C) 2010 Elsevier B.V. All rights reserved.

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

remote robotic control
cultured neural network
client-server architecture


A Full-Brain, Bootstrapped Analysis of Diffusion Tensor Imaging Robustly Differentiates Parkinson Disease from Healthy Controls There is a compelling need for early, accurate diagnosis of Parkinsons disease (PD). Various magnetic resonance imaging modalities are being explored as an adjunct to diagnosis. A significant challenge in using MR imaging for diagnosis is developing appropriate algorithms for extracting diagnostically relevant information from brain images. In previous work, we have demonstrated that individual subject variability can have a substantial effect on identifying and determining the borders of regions of analysis, and that this variability may impact on prediction accuracy. In this paper we evaluate a new statistical algorithm to determine if we can improve accuracy of prediction using a subjects left-out validation of a DTI analysis. Twenty subjects with PD and 22 healthy controls were imaged to evaluate if a full brain diffusion tensor imaging-fractional anisotropy (DTI-FA) map might be capable of segregating PD from controls. In this paper, we present a new statistical algorithm based on bootstrapping. We compare the capacity of this algorithm to classify the identity of subjects left out of the analysis with the accuracy of other statistical techniques, including standard cluster-thresholding. The bootstrapped analysis approach was able to correctly discriminate the 20 subjects with PD from the 22 healthy controls (area under the receiver operator curve or AUROC 0.90); however the sensitivity and specificity of standard cluster-thresholding techniques at various voxel-specific thresholds were less effective (AUROC 0.720.75). Based on these results sufficient information to generate diagnostically relevant statistical maps may already be collected by current MRI scanners. We present one statistical technique that might be used to extract diagnostically relevant information from a full brain analysis.

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

parkinson disease
diffusion tensor imaging
diagnosis


self-organization methodologies for services placement in future mobile communication networks Ubiquitous access to information and services anywhere, anytime and anyhow at low cost is one of the essential features of future mobile communication networks, which will interconnect a heterogeneity of various systems and be much more dynamic and flexible in terms of changes in access technology, topology, services, etc. In such networks, there will be a need to match resources supply with application demands continuously as these demands are expected to fluctuate over time. This makes an adequate service placement in such networks of a major importance. Handling this issue is the main purpose of our research, which will be carried out in the scope of the International Graduate School on Mobile Communications at Ilmenau University of Technology (www.gs-mobicom.de). The paper proposes a novel distributed and self-organized service placement mechanism that enables minimizing the cost, retaining the Quality of Service (QoS) and balancing the load. Our proposal is called Mobile Agent-assisted Ant Colony Optimization (MA-ACO). The basic idea lies in enhancing the ACO technique with mechanisms from the MA-field, so that the speed, accuracy, and self-organization capabilities are improved. This has been achieved by means of ants carrying a set of MAs as a piece of food. As a replica of a service is created on a node, this node sends ants to put MAs on the 1-hop neighbors capable of hosting the offered service. When the serving cost increases, QoS degrades, etc., ants are sent towards the MAs to collect information about the current status of the network. Based on this information, the hosting node can take an accurate decision. Our approach can cope with dynamic networks, where network topology, load, clients' distribution, etc. often change. Moreover, it has self-healing capabilities since it is able to remove congestion situation, balance the load, etc. As MA-ACO works in a distributed manner, it does not require global knowledge of the network. Our proposal overcomes existing approaches with respect to self-organization capabilities, speed and accuracy.

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

service placement
ant colony optimization


Duality and efficiency computations in the cost efficiency model with price uncertainty The calculation of cost efficiency requires complete and accurate information on the input prices at each decision making unit (DMU). In practice, however, exact knowledge of the relevant prices is difficult to come by, and prices may be subject to variation in the short term. To estimate the cost efficiency while taking price uncertainty into account, cone-ratio DEA models incorporating the available price information as weight restrictions can be applied. However, the literature lacks a clear explanation regarding the exact relationships between these two models. In this paper, through a duality study, we establish both the theoretical properties of these relationships and the characteristics of their efficiency solutions between cone-ratio DEA models and CE models, assuming there are imprecise price data. Based on the duality study, we also develop a new approach and design a lexicographic order algorithm to estimate the lower bounds of the cost efficiency measure. Our computational experiments indicate that the proposed models are robust and that the proposed algorithm is computationally simple.

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

duality
cost efficiency
price uncertainty


using transaction isolation levels for ensuring replicated database consistency in mobile computing environments Replicating databases over several servers is an efficient strategy to improve data availability and to increase transaction throughput rate. However, due to inherent limitations of mobile and other loosely-coupled environments, the replica control protocols responsible for ensuring replicated database consistency should be revisited. This paper proposes a new replica control protocol which guarantees the consistency of replicated databases in a mobile computing environment. The key benefit of the proposed protocol is to ensure consistency by means of the notion of transaction isolation levels without the use of a locking mechanism. Thus, a user may trade the degree of replica consistency for a potential increase in data availability and transaction through-put rate. The proposed protocol uses a read-any/write-any approach and reduces the number of messages exchanged among the replicated servers. Experimental results show the potential efficiency of the proposed approach.

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


The latent process decomposition of cDNA microarray data sets We present a new computational technique (a software implementation, data sets, and supplementary information are available at http://www.enm.bris.ac.uk/lpd/) which enables the probabilistic analysis of cDNA microarray data and we demonstrate its effectiveness in identifying features of biomedical importance. A hierarchical Bayesian model, called Latent Process Decomposition (LPD), is introduced in which each sample in the data set is represented as a combinatorial mixture over a finite set of latent processes, which are expected to correspond to biological processes. Parameters in the model are estimated using efficient variational methods. This type of probabilistic model is most appropriate for the interpretation of measurement data generated by cDNA microarray technology. For determining informative substructure in such data sets, the proposed model has several important advantages over the standard use of dendrograms. First, the ability to objectively assess the optimal number of sample clusters. Second, the ability to represent samples and gene expression levels using a common set of latent variables (dendrograms cluster samples and gene expression values separately which amounts to two distinct reduced space representations). Third, in constrast to standard cluster models, observations are not assigned to a single cluster and, thus, for example, gene expression levels are modeled via combinations of the latent processes identified by the algorithm. We show this new method compares favorably with alternative cluster analysis methods. To illustrate its potential, we apply the proposed technique to several microarray data sets for cancer. For these data sets it successfully decomposes the data into known subtypes and indicates possible further taxonomic subdivision in addition to highlighting, in a wholly unsupervised manner, the importance of certain genes which are known to be medically significant. To illustrate its wider applicability, we also illustrate its performance on a microarray data set for yeast.

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


Artificial-Cellular Computing This paper describes a compelling method to make a wet-computing system based on artificial cell models. The discrete system is inspired by real cell chemical information processing. Liposomes, which are small vesicles of phospholipid bilayer membranes, have been established as the basement architecture of artificial cell models that can safely entrap enzymes, proteins, genes and Substrates. Recently, biochemical reactions Such as the gene expression system are incorporated within the liposome. Such liposome conditions can be "operated" by some specific physico-chemical triggers. Here, the possibility and real examples of the artificial cellular model and their operation as computation elements have been described.

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

artificial cell model
enzyme reaction
lipid bilayer membrane


Combining analytic kernel models for energy-efficient data modeling and classification Energy-efficient computing has now become a key challenge not only for data-center operations, but also for many other energy-driven systems, with the focus on reducing of all energy-related costs, and operational expenses, as well as its corresponding and environmental impacts. However, current intelligent data models are typically performance driven. For instance, most data-driven machine-learning approaches are often known to require high computational cost in order to find the global optima. Designing more accurate intelligent data models to satisfy the market needs will hence lead to a higher likelihood of energy waste due to the increased computational cost. This paper thus introduces an energy-efficient framework for large-scale data modeling and classification/prediction. It can achieve a predictive accuracy comparable to or better than the state-of-the-art machine-learning models, while at the same time, maintaining a low computational cost when dealing with large-scale data. The effectiveness of the proposed approaches has been demonstrated by our experiments with two large-scale KDD data sets: Mtv-1 and Mtv-2.

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

energy-efficient computing
machine learning
a large volume of data


On the Importance of Transition Regions for Automatic Speaker Recognition This letter describes the importance of transition regions, e.g. at phoneme boundaries, for automatic speaker recognition compared with using steady-state regions. Experimental results of automatic speaker identification tasks confirm that transition regions include the most speaker distinctive features. A possible reason for obtaining such results is described in view of articulation, in particular, the degree of freedom of articulators. These results are expected to provide useful information in designing an efficient automatic speaker recognition system.

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


New General Constructions of LCZ Sequence Sets Based on Interleaving Technique and Affine Transformations In this paper, we propose four new general constructions of LCZ/ZCZ sequence sets based on interleaving technique and affine transformations. A larger family of LCZ/ZCZ sequence sets with longer period are generated by these constructions, which are more flexible among the selection of the alphabet size, the period of the sequences and the length of LCZ/ZCZ, compared with those generated by the known constructions. Especially, two families of the newly constructed sequences can achieve or almost achieve the theoretic bound.

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

quasi-synchronous code-division multiple access (qs-cdma)


Statistical functions and procedures in IDL 5.6 and 6.0 This work presents the results of assessing the accuracy of statistical routines as implemented in the IDL platform, versions 5.6 and 6.0 for Windows XP and Linux. This is a complete computing environment for the interactive analysis and visualization of data. IDL integrates a powerful, array-oriented language with numerous mathematical analysis and graphical display techniques (Research Systems Inc., IDL Versions 5.6 for Microsoft Windows, 2003 and 6.0.1 for Linux x86 m32, 2004. URL http://www.rsinc.com). It is shown that, though it is an excellent platform for signal and image processing and analysis, it has flaws when statistical computing is concerned, mainly when dealing with non-linear regression by least squares fitting and, in particular, when computing in single precision floating point.

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

statistical software
numerical computation


Energy-Distortion Tradeoffs in Gaussian Joint Source-Channel Coding Problems The information-theoretic notion of energy efficiency is studied in the context of various joint source-channel coding problems. The minimum transmission energy E(D) required to communicate a source over a noisy channel so that it can be reconstructed within a target distortion D is analyzed. Unlike the traditional joint source-channel coding formalisms, no restrictions are imposed on the number of channel uses per source sample. For single-source memoryless point-to-point channels, E(D) is shown to be equal to the product of the minimum energy per bit E-bmin of the channel and the rate-distortion function R(D) of the source, regardless of whether channel output feedback is available at the transmitter. The primary focus is on Gaussian sources and channels affected by additive white Gaussian noise under quadratic distortion criteria, with or without perfect channel output feedback. In particular, for two correlated Gaussian sources communicated over a Gaussian multiple-access channel, inner and outer bounds on the energy-distortion region are obtained, which coincide in special cases. For symmetric channels, the difference between the upper and lower bounds on energy is shown to be at most a constant even when the lower bound goes to infinity as D -> 0. It is also shown that simple uncoded transmission schemes perform better than the separation-based schemes in many different regimes, both with and without feedback.

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

energy efficiency
feedback
uncoded transmission

information theory
joint source-channel coding
multiple-access channel (mac)
separate source and channel coding


Visualization and analysis of large data collections: a case study applied to confocal microscopy data In this paper we propose an approach in which interactive visualization and analysis are combined with batch tools for the processing of large data collections. Large and heterogeneous data collections are difficult to analyze and pose specific problems to interactive visualization. Application of the traditional interactive processing and visualization approaches as well as batch processing encounter considerable drawbacks for such large and heterogeneous data collections due to the amount and type of data. Computing resources are not sufficient for interactive exploration of the data and automated analysis has the disadvantage that the user has only limited control and feedback on the analysis process. In our approach, an analysis procedure with features and attributes of interest for the analysis is defined interactively. This procedure is used for off-line processing of large collections of data sets. The results of the batch process along with "visual summaries" are used for further analysis. Visualization is not only used for the presentation of the result, but also as a tool to monitor the validity and quality of the operations performed during the batch process. Operations such as feature extraction and attribute calculation of the collected data sets are validated by visual inspection. This approach is illustrated by an extensive case study, in which a collection of confocal microscopy data sets is analyzed.

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

biomedical visualization
features in volume data sets
large data set visualization


Improving pathways to adoption: Putting the right P's in precision agriculture On-the-go yield monitors, proximal plant-canopy and electromagnetic soil sensors, and airborne/satellite remote sensing have all been introduced into mainstream agriculture practice under the auspices of precision agriculture. While these technologies have been shown to provide production and environmental benefits, widespread adoption has been slow. In many cases, new technologies have been produced through developer push rather than user pull. Insufficient attention is paid to well-known technology adoption paradigms and as a consequence, the adoption of precision agriculture technologies is not as great as it could and should be. In precision agriculture there is often a large knowledge gap between developers and users, and not enough effort is being spent on closing this gap. By paying attention to developing of protocols and realistic performance criteria, developers can exert a stronger, positive influence on the rate and breadth of adoption.

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


The Brazilian Experience With the Use of the Shield Wire Line Technology (SWL) for Energy Distribution This paper presents an analysis of the impact of the lightning overvoltages on the operational performance of the energized shield wire line technology (SWL) implemented in two locations of the State of Rondonia, Brazil. The analysis covers the periods of 1996 to 2000 (SWL Jaru) and 1997 to 2002 (SWL Itapua do Oeste), and shows that lightning is responsible for most of the system outages. The paper describes the satisfactory results achieved with the system, showing that the isolation and energization of the shield wires does not deteriorate the lightning performance of the 230 kV transmission lines. Comparisons between the performances of the SWL technology, conventional 34.5 kV lines, and thermal power plants in operation in the same region are also presented. The results demonstrate the technical and economical viability of the SWL technology and show that its application can lead to a postponement of investments.

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

power distribution
power transmission line
operational indexes


How Many Clusters: A Validation Index for Arbitrary-Shaped Clusters Clustering validation indexes are intended to assess the goodness of clustering results. Many methods used to estimate the number of clusters rely on a validation index as a key element to find the correct answer. This paper presents a new validation index based on graph concepts, which has been designed to find arbitrary shaped clusters by exploiting the spatial layout of the patterns and their clustering label. This new clustering index is combined with a solid statistical detection framework, the gap statistic. The resulting method is able to find the right number of arbitrary-shaped clusters in diverse situations, as we show with examples where this information is available. A comparison with several relevant validation methods is carried out using artificial and gene expression data sets. The results are very encouraging, showing that the underlying structure in the data can be more accurately detected with the new clustering index. Our gene expression data results also indicate that this new index is stable under perturbation of the input data.

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


Improving efficiency in business-to-business information transfers: a Web-based solution in the beef sector Internet usage is growing rapidly among agricultural producers and processors, but little attention has been paid to the advantages of agribusiness firms using the Internet as an information exchange with other firms, such as input suppliers. A case study of a beef processor using the Internet to deliver information to input suppliers is presented to illustrate possible information transfer efficiency gains. The prototype information delivery system is a three-tier, Web-based product consisting of data, business logic, and presentation layers. Compared to a traditional clientserver design, the Web-based system is more easily scalable as system demand increases, more easily managed whenever software is updated, more flexible, less costly, and more reliable. An overview of the system's design is provided to facilitate information professionals developing a similar system, which is specific to their business model.

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

internet
information exchange
beef processor


student athletes on facebook Student athletes at U.S. universities are bound by rules affecting their participation in their sport and are highly visible to their fellow students and a larger public of fans. This difference makes them more likely than other students to be sensitive to issues of impression management and use of social network sites (SNSs). In this paper, we show how student athletes at a large university engage with the social network site Facebook compared with their fellow students, including differences in the size of their networks, reported uses of the site, and perceptions about their audience. This work shows that while student athletes have a higher anticipation of being watched, they have similar uses and concerns compared to other students.

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

social network sites
facebook
student athletes


De-embedding method for on-wafer RF CMOS inductor measurements In this work, an accurate de-embedding method for on-wafer RF measurements of CMOS large area devices like the inductors is presented. The method uses distributed and lumped-element models to represent the parasitic elements. The interconnect parasitics are calculated using the transmission line theory. The proposed method is compared to existing de-embedding methods. The validity of the method is checked with the DC resistance value of the interconnects as calculated from the layout and as extracted from measurements, as well as with inductance results of the fabricated inductor, extracted from measurements and from electromagnetic simulations. On-wafer S-parameter measurements have been taken from a test chip up to 20GHz.

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

de-embedding
on-wafer rf cmos measurements
integrated inductors


The MFS for the solution of harmonic boundary value problems with non-harmonic boundary conditions We investigate applications of the method of fundamental solutions (MFS) for the numerical solution of two-dimensional boundary value problems in complex geometries, governed by the Laplace equation and subject to Dirichlet boundary conditions which are not harmonic. Such problems can be very challenging because of the appearance of boundary singularities. We consider several ways of choosing the boundary collocation points as well as the source points in the MFS. We show that with an appropriate such choice the MFS yields highly accurate results.

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 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

method of fundamental solutions
laplace equation


a longitudinal study of how highlighting web content change affects people's web interactions The Web is constantly changing, but most tools used to access Web content deal only with what can be captured at a single instance in time. As a result, Web users may not have a good understanding of the changes that occur. In this paper we show that making Web content change explicitly visible allows people to interact with the Web in new ways. We present a longitudinal study in which 30 people used a Web browser plug-in that caches visited pages and highlights text changes to those pages when revisited. We used a survey to capture their understanding of Web page change and their own revisitation patterns at the beginning of use and after one month. For a majority of the participants, we also logged their Web page visits and associated content change. Exposing change is more valuable to our participants than initially expected, making them aware of how dynamic content they visit is and changing their interactions with it.

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


The effect of user characteristics on search effectiveness in information retrieval This paper investigates the influence of user characteristics (e.g. search experience and cognitive skills) on user effectiveness. A user study was conducted to investigate this effect, 56 participants completed searches for 56 topics using the TREC test collection. Results indicated that participants with search experience and high cognitive skills were more effective than those with less experience and slower perceptual abilities. However, all users rated themselves with the same level of satisfaction with the search results despite the fact they varied substantially in their effectiveness. Therefore, information retrieval evaluators should take these factors into consideration when investigating the impact of system effectiveness on user effectiveness.

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

information retrieval
user characteristics
search effectiveness


Fuzzy clustering analysis for optimizing fuzzy membership functions Fuzzy model identification is an application of fuzzy inference system for identifying unknown functions, for a given set of sampled data. The most important thing for fuzzy identification task is to decide the parameters of membership functions (MFs) used in fuzzy systems. A lot of efforts (Chung and Lee, 1994; Jang, 1993; Sun and Jang, 1993) have been given to initialize the parameters of fuzzy membership functions. However, the problems of parameter identification were not solved formally. Assessments of these algorithms are discussed in the paper. Based on the fuzzy c-means (FCM) Bezdek (1987) clustering algorithm, we propose a heuristic method to calibrate the fuzzy exponent iteratively. A hybrid learning algorithm for refining the system parameters is then presented. Examples are demonstrated to show the effectiveness of the proposed method, comparing with the equalized universe method (EUM) and subtractive clustering method (SCM) Chiu (1994). The simulation results indicate the general applicability of our methods to a wide range of applications. (C) 1999 Elsevier Science B.V. All rights reserved.

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

fuzzy identification
fuzzy membership functions
fcm


A recursive solution to nonunitary joint diagonalization ? Joint diagonalization of a set of matrices is an essential tool in many signal processing applications. This letter is devoted to seeking a recursive solution to nonunitary joint diagonalization. The proposed algorithm recursively minimizes an exponentially windowed least squares (LS) criterion, leading to a computationally cheaper recursive update rule for joint diagonalization. This merit enables us to develop (block) online algorithm for source separation and other applications. Simulation results on synthetic data and blind separation of real speech signals validate the effectiveness of the proposed algorithm.

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

joint diagonalization (jd)
blind source separation (bss)


Rational synthesis of pindolol imprinted polymer by non-covalent protocol based on computational approach Pindolol (PDL) is a potent and specific adrenoreceptor blocking agent. It is widely used in the treatment of hypertension, cardiac arrhythmia and angina pectoris. Molecularly imprinted polymers (MIPs) are synthetic receptors having potential applications in drug delivery systems and devices such as diagnostic sensors. In the present work, ab initio quantum mechanical simulations and computational screening were used to identify functional monomer having best interactions with PDL. A virtual library of 16 functional monomers was built and the possible minimum energy conformation of the monomers and PDL were calculated using Hartree-Fock (HF) method for the synthesis of PDL imprinted polymer. The interaction energy between functional monomer and the template were corrected by means of basis set superposition error (BSSE) in all pre-polymerization complexes. The hydrogen bonding between PDL and functional monomer was evaluated by changes in bond lengths before and after complex formation. The virtual template-monomer complex with highest interaction energy is more stable during the polymerization and leads to high selectivity and specificity toward the template. The interaction energy of PDL was found to be the highest with itaconic acid followed by 4-vinyl pyridine and least with acrylonitrile. Taking a spectroscopic viewpoint, results obtained from analysis of the harmonic infrared spectrum were examined. Red and blue shifts related to the stretching frequencies of either donors or acceptors of protons were identified and compared experimentally. Stoichiometric mole ratio of template to functional monomer was optimized and confirmed by UV visible spectra titrations. The theoretical results were correlated by evaluation of binding parameters of MIPs. The experimental binding results were in good agreement with theoretical computations.

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

bsse
computational approach
hydrogen bonding
molecularly imprinted polymers
pindolol


ClusterTree: Integration of cluster representation and nearest-neighbor search for large data sets with high dimensions In this paper, we introduce the ClusterTree, a new indexing approach to representing clusters generated by any existing clustering approach. A cluster is decomposed into several subclusters and represented as the union of the subclusters. The subclusters can be further decomposed, which isolates the most related groups within the clusters. A ClusterTree is a hierarchy of clusters and subclusters which incorporates the cluster representation into the index structure to achieve effective and efficient retrieval. Our cluster representation is highly adaptive to any kind of cluster. It is well accepted that most existing indexing techniques degrade rapidly as the dimensions increase. The ClusterTree provides a practical solution to index clustered data sets and supports the retrieval of the nearest-neighbors effectively without having to linearly scan the high-dimensional data set. We also discuss an approach to dynamically reconstruct the ClusterTree when new data is added. We present the detailed analysis of this approach and justify it extensively with experiments.

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

nearest-neighbor search
high-dimensional data sets


PHIRST: A distributed architecture for P2P information retrieval Recent progress in peer to peer (P2P) search algorithms has presented viable structured and unstructured approaches for full-text search. We posit that these existing approaches are each best suited for different types of queries. We present PHIRST the first system to facilitate effective full-text search within P2P databases. PHIRST works by effectively leveraging between the relative strengths of these approaches. Similar to structured approaches, agents first publish terms within their stored documents. However, frequent terms are quickly identified and not exhaustively stored, resulting in a significant reduction in the system's storage requirements. During query lookup, agents use unstructured search to compensate for the lack of fully published terms. Additionally, they explicitly weigh between the costs involved in structured and unstructured approaches, allowing for a significant reduction in query costs. Finally, we address how node failures can be effectively addressed through storing multiple copies of selected data. We evaluated the effectiveness of our approach using both real-world and artificial queries. We found that in most situations our approach yields near perfect recall. We discuss the limitations of our system, as well as possible compensatory strategies. (c) 2008 Elsevier B.V. All rights reserved.

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

distributed databases
peer to peer systems


A data structure for representing multi-version texts online The digitisation of cultural heritage and linguistics texts has long been troubled by the problem of how to represent overlapping structures arising from different markup perspectives (overlapping hierarchies) or from different versions of the same work (textual variation). These two problems can be reduced to one by observing that every case of overlapping hierarchies is also a case of textual variation. Overlapping textual structures can be accurately modelled either as a minimally redundant directed graph, or, more practically, as an ordered list of pairs, each containing a set of versions and a fragment of text or data. This pairs-list representation is provably equivalent to the graph representation. It can record texts consisting of thousands of versions or perspectives without becoming overloaded with data, and the most common operations on variant text, e.g. comparison between two versions, can be performed in linear time. This representation also separates variation or other overlapping structures from the document content, leading to a simplification of markup suitable for wiki-like web applications.

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

textual variation
overlapping hierarchies
markup
cultural heritage


The effect of sensor errors on production and energy consumption in greenhouse horticulture The accuracy of sensors used in Dutch greenhouses for climate control has been assessed and the influence of sensor errors on the energy consumption and crop production has been determined using model simulations. It is shown that currently used sensors are prone to errors exceeding current standards set for practice. The extra energy consumption, due to sensor inaccuracy, is mainly caused by the sensors for global radiation and relative humidity. Sensor errors may result in a higher crop production but at the expense of a higher energy consumption resulting in a loss in economic return of the crop production process. Results indicate that sensor maintenance is economically feasible because the resulting energy savings exceed the costs of the maintenance operation. (C) 2011 Elsevier B.V. All rights reserved.

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


Power management in energy harvesting sensor networks Power management is an important concern in sensor networks, because a tethered energy infrastructure is usually not available and an obvious concern is to use the available battery energy efficiently. However, in some of the sensor networking applications, an additional facility is available to ameliorate the energy problem: harvesting energy from the environment. Certain considerations in using an energy harvesting source are fundamentally different from that in using a battery, because, rather than a limit on the maximum energy, it has a limit on the maximum rate at which the energy can be used. Further, the harvested energy availability typically varies with time in a nondeterministic manner. While a deterministic metric, such as residual battery, suffices to characterize the energy availability in the case of batteries, a more sophisticated characterization may be required for a harvesting source. Another issue that becomes important in networked systems with multiple harvesting nodes is that different nodes may have different harvesting opportunity. In a distributed application, the same end-user performance may be achieved using different workload allocations, and resultant energy consumptions at multiple nodes. In this case, it is important to align the workload allocation with the energy availability at the harvesting nodes. We consider the above issues in power management for energy-harvesting sensor networks. We develop abstractions to characterize the complex time varying nature of such sources with analytically tractable models and use them to address key design issues. We also develop distributed methods to efficiently use harvested energy and test these both in simulation and experimentally on an energy-harvesting sensor network, prototyped for this work.

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

experimentation
measurement
theory
adaptive duty cycling
heliomote
lifetime
energy neutrality


stationary solution approximation using a memory-efficient perfect sampling technique The analytical solution of large Markovian models is one of the major challenges in performance evaluation. Structured formalisms provide a modular description to tackle state space explosion by presenting memory-efficient solutions based on tensor algebra and specific software tools implement such solutions using iterative methods. However, even these numerical methods become unsuitable when massively large models are considered, i.e. , models with more than 100 million states. To deal with such classes of models is possible to find approximations of the stationary solution using simulation of long-run trajectories with perfect sampling methods. The use of these methods prevents usual simulation problems such as initial state setup and burn-in time. Unfortunately, the number of produced samples to establish statistically significant solution remains an open problem. This paper analyzes the sampling process in its extent, proposing a memory-efficient stopping criteria based on a numerical tolerance of the measures of interest. Moreover, we present some memory cost estimations for a classical Markovian model in order to demonstrate the gains of the proposed method.

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

san
discrete event simulation
integration functions


On the local quadratic convergence of the primal-dual augmented Lagrangian method We consider a primal-dual augmented Lagrangian (PDAL) method for optimization problems with equality constraints. Each step of the PDAL requires solving the primal-dual (PD) linear system of equations. We show that under the standard second-order optimality condition the PDAL method generates a sequence, which locally converges to the PD solution with quadratic rate.

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

primal-dual system
merit function
quadratic rate of convergence


Flexible robot-based disassembly cell for obsolete TV-sets and monitors Disassembly is a developing field of application for automated components for processing electronic waste. The reasons behind its rapid development are changing legislation in favor of environmental protection because of a globally increasing amount of obsolete electronic products and growing public awareness of environmental problems. A prototype of a flexible robot based disassembly cell for obsolete TV-sets and monitors has been developed at PRIELOG Logistik GmbH and is currently being adapted to the demands of industry. Main parts of this system are a disassembly robot, a handling robot, an intelligent vision system as well as software far highly flexible online planning and control of the disassembly process. A detailed description of the disassembly cell and first results of industrial adaptation are introduced in this work. The results lead to optimized reactive planning algorithms as well as improved sensor systems and the usage of universal and flexible disassembly tools and fixtures. (C) 1999 Elsevier Science Ltd. All rights reserved.

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


FIR Filter Synthesis Based on Interleaved Processing of Coefficient Generation and Multiplier-Block Synthesis An efficient filter synthesis algorithm is proposed to minimize the number of adders required in the design of finite-impulse response filters. Given a specification, a filter can be synthesized by conducting two main steps: coefficient generation and multiplier-block synthesis. While most of previous works have focused on only one of the steps, the proposed algorithm integrates the two steps in an interleaved manner so as to take into account the effect of multiplier-block synthesis in generating coefficients. In addition, the concept of sensitivity is developed to reduce the complexity of computing the variable ranges of coefficients. Experimental results show that the proposed algorithm outperforms previous algorithms in terms of adder cost and takes a relatively short computation time.

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

coefficient sensitivity
common subexpression
finite-impulse response (fir) filter
multiplierless filter


Secure communication in IPTV broadcasting In internet protocol television (IPTV) broadcasting, service providers charge subscribing fee by scrambling the program with conditional access system (CAS) using control words (CWs). A smart card is used to decrypt the CWs and transfer them back to set-top box (STB) to descramble the scrambled program. Secure communication between STB and the smart card is closely related with the benefit of service providers and the legal rights of users. In addition, secure key exchange with mutual authentication in the communication between STB and the smart card is an essential part of secure communication that will significantly improve the security of the system. To provide secure communication with mutual authentication in IPTV broadcasting, there are several schemes. The schemes proposed a secure and efficient method for the communication between STB and the smart card. Unfortunately, the schemes still have some security flaws. In this paper, we review that the previous schemes are vulnerable to several attacks. Further, we recommend some modifications to the schemes to correct these security flaws and present a formal analysis about our improved protocol using a logic based formal method.

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 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 B I 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 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

secure communication
iptv
formal analysis


online identification of learner problem solving strategies using pattern recognition methods Learning and programming environments used in computer science education give feedback to the users by system messages. These are triggered by programming errors and give only "technical" hints without regard to the learners' problem solving process. To adapt the messages not only to the factual but also to the procedural knowledge of the learners, their problem solving strategies have to be identified automatically and in process. This article describes a way to achieve this with the help of pattern recognition methods. Using data from a study with 65 learners aged 12 to 13 using a learning environment for programming, a classification system based on hidden Markov models is trained and integrated in the very same environment. We discuss findings in that data and the performance of the automatic online identification, and present first results using the developed software in class.

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

problem solving strategies
pattern recognition
computer science education

secondary education
tool-based analysis
algorithms


Cryptanalysis of a remote login authentication scheme In this article, we present a cryptanalysis of Wu's proposed efficient remote login authentication scheme which is based on simple geometric properties on the Euclidean plane, We show that the scheme contains pitfalls in the authentication phase. (C) 1999 Elsevier Science B.V. All rights reserved.

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


inspiring blind high school students to pursue computer science with instant messaging chatbots Blind students are an underrepresented group in computer science. In this paper, we describe our experience preparing and leading the computer science track at the National Federation of the Blind Youth Slam. As part of this workshop, fifteen blind high school students created and personalized instant messaging chatbots, a project designed to be completely accessible to blind students. Chatbots enable students to infuse their own personalities into a socially-oriented program that incorporates ideas from artificial intelligence, natural language processing, and web services. We first outline the chatbots project and curriculum, which has wide appeal for all students, and then offer general design principles used to create it that can help ensure the accessibility of future projects. Students created their chatbots using a real programming language and were guided by both blind and sighted mentors. By programming from the start in a supportive environment, our students will gain the confidence to persevere in computer science in the future.

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


Asymptotic analysis of Levy-driven tandem queues We analyze tail asymptotics of a two-node tandem queue with spectrally-positive Levy input. A first focus lies in the tail probabilities of the type P(Q (1) > alpha x, Q(2) > (1-alpha)x), for alpha is an element of (0,1) and x large, and Q(i) denoting the steady-state workload in the ith queue. In case of light-tailed input, our analysis heavily uses the joint Laplace transform of the stationary buffer contents of the first and second queue; the logarithmic asymptotics can be expressed as the solution to a convex programming problem. In case of heavy-tailed input we rely on sample-path methods to derive the exact asymptotics. Then we specialize in the tail asymptotics of the downstream queue, again in case of both light-tailed and heavy-tailed Levy inputs. It is also indicated how the results can be extended to tandem queues with more than two nodes.

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

levy processes
queueing asymptotics
rare events
large deviations
60k25


Simulated annealing applied to test generation: landscape characterization and stopping criteria This paper investigates a measurement approach to support the implementation of Simulated Annealing (SA) applied to test generation. SA, like other metaheuristics, is a generic technique that must be tuned to the testing problem under consideration. Finding an adequate setting of SA parameters, that will offer good performance for the target problem, is known to be difficult. Our measurement approach is intended to guide the implementation choices to be made. It builds upon advanced research on how to characterize search problems and the dynamics of metaheuristic techniques applied to them. Central to this research is the concept of landscape. Existing measures of landscape have mainly been applied to combinatorial problems considered in complexity theory. We show that some of these measures can be useful for testing problems as well. The diameter and autocorrelation are retained to study the adequacy of alternative settings of SA parameters. A new measure, the Generation Rate of Better Solutions (GRBS), is introduced to monitor convergence of the search process and implement stopping criteria. The measurement approach is experimented on various case studies, and allows us to successfully revisit a problem issued from our previous work on testing control systems.

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


Breakdown time statistics of successive failure events in constant voltage-stressed Al2O3/HfO2 nanolaminates Analysis of successive failure events in nanolaminated dielectric films. Characterization of occurrence and interarrival times. Modeling using a nonhomogeneous Poisson process.

O O O O O O O O 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


Symbolic description of intracerebral vessels segmented from magnetic resonance angiograms and evaluation by comparison with X-ray angiograms We describe and evaluate methods that create detailed vessel trees by linking vessels that have been segmented from magnetic resonance angiograms (MRA). The tree-definition process can automatically exclude erroneous vessel segmentations. The parentchild connectivity information provided by our vessel trees is important to both surgical planning and to guidance of endovascular procedures. We evaluated the branch connection accuracy of our 3D vessel trees by asking two neuroradiologists to evaluate 140 parentchild connections comprising seven vascular trees against 17 digital subtraction angiography (DSA) views. Each reviewer rated each connection as (1) Correct, (2) Incorrect, (3) Partially correct (a minor error without clinical significance), or (4) Indeterminate. Analysis was summarized for each evaluator by calculating 95% confidence intervals for both the proportion completely correct and the proportion clinically acceptable (completely or partially correct). In order to protect the overall Type I error rate, alpha-splitting was done using a top down strategy. We additionally evaluated segmentation completeness by examining each slice in 11 MRA datasets in order to determine unlabeled vessels identifiable in cross-section following segmentation. Results indicate that only one vascular parentchild connection was judged incorrect by both reviewers. MRA segmentations appeared complete within MRA resolution limits. We conclude that our methods permit creation of detailed vascular trees from segmented 3D image data. We review the literature and compare other approaches to our own. We provide examples of clinically useful visualizations enabled by our methodology and taken from a visualization program now in clinical use.

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

digital subtraction angiography
segmentation

magnetic resonance angiography
registration


On algorithmically checking whether a Hilbert series comes from a complete intersection It is not possible to determine from the Hilbert series whether a commutative Z-graded Noetherian algebra is a complete intersection. Nevertheless, the Hilbert series of a complete intersection satisfies very stringent conditions and we define a concept CI-type for formal power series, that embodies some of these necessary properties. This definition becomes interesting mainly for algebras that are not standard i.e. not generated in degree 1. For the class of formal power series that occur as the Hilbert series of Z-graded Noetherian Cohen-Macaulay algebras, the main result is a criterion for a series to be of CI-type, that is formulated in terms of properties of truncated power series. Hence it can be used as the basis for an algorithm that provides in a finite number of steps either a rational function expression of the formal power series, or the information that the truncated power series is not of Cl-type. Also sample computations using this algorithm on some non-standard graded invariant algebras are described. (C) 2004 Published by Elsevier Ltd.

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 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 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


Numerical simulation of 3D bubbles rising in viscous liquids using a front tracking method The rise of bubbles in viscous liquids is not only a very common process in many industrial applications, but also an important fundamental problem in fluid physics. An improved numerical algorithm based on the front tracking method, originally proposed by Tryggvason and his co-workers, has been validated against experiments over a wide range of intermediate Reynolds and Bond numbers using an axisymmetric model [J. Hua, J. Lou, Numerical simulation of bubble rising in viscous liquid, J. Comput. Phys. 22 (2007) 769-795]. In the current paper, this numerical algorithm is further extended to simulate 3D bubbles rising in viscous liquids with high Reynolds and Bond numbers and with large density and viscosity ratios representative of the common air-water two-phase flow system. To facilitate the 3D front tracking simulation, mesh adaptation is implemented for both the front mesh on the bubble surface and the background mesh. On the latter mesh, the governing Navier-Stokes equations for incompressible, Newtonian flow are solved in a moving reference frame attached to the rising bubble. Specifically, the equations are solved using a finite volume scheme based on the Semi-Implicit Method for Pressure-Linked Equations (SIMPLE) algorithm, and it appears to be robust even for high Reynolds numbers and high density and viscosity ratios. The 3D bubble surface is tracked explicitly using an adaptive, unstructured triangular mesh. The numerical model is integrated with the software package PARAMESH, a block-based adaptive mesh refinement (AMR) tool developed for parallel computing. PARAMESH allows background mesh adaptation as well as the solution of the governing equations in parallel on a supercomputer. Further, Peskin distribution function is applied to interpolate the variable values between the front and the background meshes. Detailed sensitivity analysis about the numerical modeling algorithm has been performed. The current model has also been applied to simulate a number of cases of 3D gas bubbles rising in viscous liquids, e.g. air bubbles rising in water. Simulation results are compared with experimental observations both in aspect of terminal bubble shapes and terminal bubble velocities. In addition, we applied this model to simulate the interaction between two bubbles rising in a liquid, which illustrated the model's capability in predicting the interaction dynamics of rising bubbles. (C) 2007 Elsevier Inc. All rights reserved.

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

bubble rising
simple algorithm
front tracking method
adaptive mesh refinement
moving reference frame

computational fluid dynamics
incompressible flow
multiphase flow