Numerical solution for an inverse MRI problem using a regularised boundary element method We investigate the reconstruction of a divergence-free surface current distribution from knowledge of the magnetic flux density in a prescribed region of interest in the framework of static electromagnetism. This inverse problem is motivated by the design of gradient coils used in magnetic resonance imaging (MRI) and is formulated using its corresponding integral representation according to potential theory. A constant boundary element method (BEM) which satisfies the continuity equation for the current density, i.e. divergence-free BEM, and was originally proposed by Lemdiasov and Ludwig [A stream function method for gradient coil design. Concepts Magn Reson B Magn Reson Eng 2005;26B:6780], is presented based on geometrical arguments with respect to the linear (flat) triangular boundary elements employed in order to emphasise its possible extension to further higher-order divergence-free interpolations. Since the discretised BEM system is ill-posed and hence the associated least-squares solution may be inaccurate and/or physically meaningless, the Tikhonov regularisation method is employed in order to retrieve accurate and physically correct solutions. A rigorous numerical approximation for the calculation the magnetic energy, which reduces the errors induced by employing the approach of Lemdiasov and Ludwig [A stream function method for gradient coil design. Concepts Magn Reson B Magn Reson Eng 2005;26B:6780], is also proposed.

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

inverse problem
regularisation
electromagnetism
coil design

divergence-free boundary element method (bem)


Color image compression using quantization, thresholding, and edge detection techniques all based on the moment-preserving principle ? A new approach to color image compression with high compression ratios and good quality of reconstructed images using quantization, thresholding, and edge detection all based on the moment-preserving principle is proposed. An input image with 24 bits per pixel is quantized into 8 bits per pixel using a new color quantization method based on the moment-preserving principle. The quantized image is then divided into n n non-overlapping square blocks. Two representative colors for each block are computed by moment-preserving thresholding. A bit-map is then generated, consisting of 0s and 1s indicating whether the block pixels are assigned to the first color or the second according to the Euclidean distance measure. A moment-based edge detector is performed further on the bit-map of each non-uniform block. The two parameters l and ? of a line edge with the equation of x cos ? + y sin ? = l are obtained. The image is finally coded with a codebook of a 256-color palette; a 1-bit indicator for each block which specifies whether the block is uniform or not; an 8-bit color index for a uniform block, or two 8-bit color indices, a 3-bit index for ?, and a 2-bit or 3-bit index for l for a non-uniform block. An average compression ratio of 22.49 or 33.32 can be obtained for 4 4 or 5 5 image blocks, respectively. Experimental results show the feasibility and efficiency of the proposed approach for color image compression.

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

color image compression
color quantization


On q-logistic and related models Numerous types of asymmetrical distributions such as the logistic, Weibull, gamma, and beta distributions have been used for modeling various random phenomena such as those encountered in data engineering, pattern recognition, and reliability assessment studies. Several generalizations of the logistic distribution, and certain related models, are proposed in this paper. The corresponding density functions involve an additional parameter, denoted by q, which allows for increased flexibility for modeling purposes; in fact, the larger this parameter is, the lower the mode of the resulting distribution will be. Generalizations of the type-1 and type-2 beta distributions are introduced, along with their logistic-type counterparts; the moments and cumulants of the latter are also derived. Other extensions are discussed including a q-analog of the generalized type-2 beta model, a q-extended generalized logistic distribution, and q-analogs of generalizations of the Dirichlet distribution. As is shown graphically, the propose univariate distributions can generate a wide array of unimodal or symmetric bimodal curves.

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

dirichlet distribution
logistic distribution

beta distribution
life testing models
skewed distributions


INFLUENCE OF INTER-COMMUNITY LINK STRENGTH ON COMMUNITY NETWORKS This paper mainly discusses how the strength of inter-community links affects the synchronization state of the whole network and the individual community. It is found, when the inter-community link number is neither too small nor too large and the overall coupling strength takes right values, there will be an optimal inter-community link strength value, in which the community networks are in a balance region where the individual community is maximally independent, while the information transmission remains effective among different communities. Combining the result of this paper and that of the number of inter-community links, it is easy to help us find the most effective community networks.

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

inter-community links
connection strength


Learning dynamic algorithm portfolios Algorithm selection can be performed using a model of runtime distribution, learned during a preliminary training phase. There is a trade-off between the performance of model-based algorithm selection, and the cost of learning the model. In this paper, we treat this trade-off in the context of bandit problems. We propose a fully dynamic and online algorithm selection technique, with no separate training phase: all candidate algorithms are run in parallel, while a model incrementally learns their runtime distributions. A redundant set of time allocators uses the partially trained model to propose machine time shares for the algorithms. A bandit problem solver mixes the model-based shares with a uniform share, gradually increasing the impact of the best time allocators as the model improves. We present experiments with a set of SAT solvers on a mixed SAT-UNSAT benchmark; and with a set of solvers for the Auction Winner Determination problem.

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

algorithm selection
algorithm portfolios
bandit problem

online learning
life-long learning
expert advice
survival analysis
satisfiability
constraint programming


an analytical model of the working-set sizes in decision-support systems This paper presents an analytical model to study how working sets scale with database size and other applications parameters in decision-support systems (DSS). The model uses application parameters, that are measured on down-scaled database executions, to predict cache miss ratios for executions of large databases. By applying the model to two database engines and typical DSS queries we find that, even for large databases, the most performance-critical working set is small and is caused by the instructions and private data that are required to access a single tuple. Consequently, its size is not affected by the database size. Surprisingly, database data may also exhibit temporal locality but the size of its working set critically depends on the structure of the query, the method of scanning, and the size and the content of the database.

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

applications cache method structure scale size data temporal queries access paper model database locality query predict

contention
analytic models
decision support system
performance
instruction
critic
scan


deriving abstract transfer functions for analyzing embedded software This paper addresses the problem of creating abstract transfer functions supporting dataflow analyses. Writing these functions by hand is problematic: transfer functions are difficult to understand, difficult to make precise, and difficult to debug. Bugs in transfer functions are particularly serious since they defeat the soundness of any program analysis running on top of them. Furthermore, implementing transfer functions by hand is wasteful because the resulting code is often difficult to reuse in new analyzers and to analyze new languages. We have developed algorithms and tools for deriving transfer functions for the bitwise and unsigned interval abstract domains. The interval domain is standard; in the bitwise domain, values are vectors of three-valued bits. For both domains, important challenges are to derive transfer functions that are sound in the presence of integer overflow, and to derive precise transfer functions for operations whose semantics are a mismatch for the domain (i.e., bit-vector operations in the interval domain and arithmetic operations in the bitwise domain). We can derive transfer functions, and execute them, in time linear in the bitwidth of the operands. These functions are maximally precise in most cases. Our generated transfer functions are parameterized by a bitwidth and are independent of the language being analyzed, and also of the language in which the analyzer is written. Currently, we generate interval and bitwise transfer functions in C and OCaml for analyzing C source code, ARM object code, and AVR object code. We evaluate our derived functions by using them in an interprocedural dataflow analyzer.

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

precise
reuse
domain
object
presence
program analysis
paper
writing
sound
interval
values
code
language
embedded software
dataflow
transfer functions
tools
bugs

challenge
abstract interpretation
static analysis
timing
evaluation
vectorization
abstraction
semantic
operability
source-code
algorithm
debugging


Epigenetics in heart failure Heart failure is one of the main causes of mortality in developed countries and is frequently associated with cardiac hypertrophy. Gene expression reprogramming in cardiac myocytes is a key feature of heart hypertrophy and failure and is characterized by upregulation of fetal genes and decreased expression of some subsets of adult ones. The full picture of signaling events underlying gene transcription in these pathophysiologic states is not completely understood, but recent evidence suggests a major role for epigenetics. This report provides an overview of the mechanisms of epigenetics and how they affect myocardial gene expression during hypertrophy and failure.

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


Development of MEMS integrated into TEM setup to monitor shear deformation, force and stress for nanotribology We fabricated a MEMS device and integrated the device with TEM. We actuated the MEMS device in TEM. The nano junction deformed due to induced shear actuation. We measured a shear force, a shear displacement and a shear stress at the nanoscale.

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


Linear controller analysis and design for systems with input hystereses nonlinearities ? An output feedback control analysis and design framework for linear systems with input hystereses nonlinearities is developed. Specifically, by transforming the hystereses nonlinearities into dissipative inputoutput dynamical operators, dissipativity theory is used to analyze and design linear controllers for systems with hysteretic actuators. The overall framework guarantees partial asymptotic stability of the closed-loop system; that is, asymptotic stability with respect to part of the closed-loop system state associated with the plant and the controller. Furthermore, the remainder of the state associated with the hysteresis dynamics is shown to be semistable; that is, solutions of the hysteretic system converge to Lyapunov stable equilibrium points determined by the system initial conditions.

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 B I 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

hystereses nonlinearities
output feedback
dissipativity theory

preisach model
linear stabilization
semistability
partial stability


The network of faults: a complex network approach to prioritize test cases for regression testing Regression testing is performed to provide confidence that changes in a part of software do not affect other parts of the software. An execution of all existing test cases is the best way to re-establish this confidence. However, regression testing is an expensive processthere might be insufficient resources (e.g., time, workforce) to allow for the re-execution of all test cases. Regression test prioritization techniques attempt to re-order a regression test suite based on some criteria so that highest priority test cases are executed earlier. In this study, we prioritize test cases for regression testing based on the dependency network of faults. In software testing, it is common that some faults are the consequences of other faults (leading faults). Dependent faults can be removed if and only if the leading faults have been removed. Our goal is to prioritize test cases so that test cases that have exposed the leading faults in the system testing phase, are executed first in regression testing. The leading faults are modeled as the most central faults in the fault dependency network. We present ComReg, a test-case prioritization technique based on the dependency network of faults. We model a fault dependency network as a directed graph and identify leading faults to prioritize test cases for regression testing. We use a centrality aggregation technique which considers six network representative centrality metrics to identify leading faults in the fault dependency network. We also discuss the use of fault communities to select an arbitrary percentage of the test cases from a prioritized regression test suite. We conduct a case study that evaluates the effectiveness and applicability of the proposed method. We obtain a fault dependency network from the development of a vocabulary learning software. We found that the fault network is a small-world graph with distinguishable community structure. The leading faults are common in all centralities and a re-ordering of test cases is feasible for regression testing based on those leading faults. Our method outperforms traditional regression testing prioritization techniques in detecting fault dependencies. Our modeling of the network of faults provides insights into the requirement of recognizing fault dependencies while re-ordering regression test suites for both research and practice. The dependency model needs further evaluation and improvement considering relevant resources (e.g., man-hours).

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


Novel energy and SLA efficient resource management heuristics for consolidation of virtual machines in cloud data centers ? A multi criteria resource allocation policy is proposed. A multi criteria policy for determination of underloaded PMs is proposed. A novel holistic resource management procedure is proposed. The results show up to 45% reductions in energy consumption. The results show up to 99% reductions in SLA violation.

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

consolidation
energy consumption
resource allocation


Semantic data modelling and visualisation using Noetica Noetica is a tool for structuring knowledge about concepts and the relationships between them. It differs from typical information systems in that the knowledge it represents is abstract, highly connected, and includes meta-knowledge (knowledge about knowledge). Noetica represents knowledge using a strongly typed graph data model. By providing a rich type system it is possible to represent conceptual information using formalised structures. A class hierarchy provides a basic classification for all objects. This allows for a consistency of representation that is not often found in free semantic networks, and gives the ability to easily extend a knowledge model while retaining its semantics. Visualisation and query tools are provided for this data model. Visualisation can be used to explore complete sets of link-classes, show paths while navigating through the database, or visualise the results of queries. Noetica supports goal-directed queries (a series of user-supplied goals that the system attempts to satisfy in sequence) and pathfinding queries (where the system finds relationships between objects in the database by following links).

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

knowledge representation
graph traversal
data visualisation


A hardware/software partitioning algorithm based on artificial immune principles Hardware/software codesign is the main approach to designing the embedded systems. One of the primary steps of the hardware/software codesign is the hardware/software partitioning. A good partitioning scheme is a tradeoff of some constraints, such as power, size, performance, and so on. Inspired by both negative selection model and evolutionary mechanism of the biological immune system, an evolutionary negative selection algorithm for hardware/software partitioning, namely ENSA-HSP, is proposed in this paper. This ENSA-HSP algorithm is proved to be convergent, and its ability to escape from the local optimum is also analyzed. The experimental results demonstrate that ENSA-HSP is more efficient than traditional evolutionary algorithm. (C) 2007 Elsevier B. V. All rights reserved.

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

evolutionary algorithm
negative selection

artificial immune system
hardware/software partitioning


Mapping Hidden Water Pipelines Using a Mobile Sensor Droplet This study presents several extensions to our previous work on the PipeProbe system, a mobile sensor system for identifying the spatial topology of hidden water pipelines (i.e., non-moldable pipes such as copper and PVC) behind walls or under floors [Lai et al. 2010]. The PipeProbe system works by dropping a tiny wireless sensor capsule into the source of a water pipeline. As the PipeProbe capsule traverses the pipelines, it gathers and transmits pressure and angular velocity readings. Through spatiotemporal analysis of these sensor readings, the proposed algorithm locates all turning points in the pipelines and maps their 3D spatial topology. This study expands upon previous research by developing new sensing techniques that identify variable-diameter pipes and differentiate 90-degree pipe turns from 45-degree pipe bends.

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

design
experimentation
performance
wireless sensor networks
mapping water pipeline
sensor inference
constraint satisfaction


Probabilistic resource allocation in heterogeneous distributed systems with random failures The problem of finding efficient workload distribution techniques is becoming increasingly important today for heterogeneous distributed systems where the availability of compute nodes may change spontaneously over time. Resource-allocation policies designed for such systems should maximize the performance and, at the same time, be robust against failure and recovery of compute nodes. Such a policy, based on the concepts of the Derman-Lieberman-Ross theorem, is proposed in this work, and is applied to a simulated model of a dedicated system composed of a set of heterogeneous image processing servers. Assuming that each image results in a "reward" if its processing is completed before a certain deadline, the goal for the resource allocation policy is to maximize the expected cumulative reward. An extensive analysis was done to study the performance of the proposed policy and compare it with the performance of some existing policies adapted to this environment. Our experiments conducted for various types of task-machine heterogeneity illustrate the potential of our method for solving resource allocation problems in a broad spectrum of distributed systems that experience high failure rates. (C) 2012 Elsevier Inc. All rights reserved.

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


development of an active ankle-foot orthosis for hemiplegic patients In this study, we developed an active ankle-foot orthosis (AAFO) which could control dorsiflexion/plantarflexion of the ankle joint to prevent foot drop and toe drag during walking. To prevent foot slap after initial contact, the ankle joint needs to be actively controlled to minimize forefoot collision with the ground. During late stance, the ankle joint also needs to be controlled to provide toe clearance and to help push-off. 3D gait analyses were performed on a hemiplegic patient under three different gait conditions: gait without AFO(NAFO), gait with the conventional hinged AFO without controlling ankle joint (HAFO), and gait with the developed AFO(AAFO). Results showed that AAFO could prevent not only foot drop by the proper plantarflexion during loading response but also toe drag by sufficient amount of plantarflexion in pre-swing and reasonable dorsiflexion during swing phase, enhancing all temporal gait parameters. The present results indicated that the developed AAFO might have more clinical benefits to treat foot drop and toe drag in hemiplegic patients, comparing with conventional AFOs.

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

3d gait analysis
hemiplegic gait
active ankle-foot-orthosis


Schedule length and reliability-oriented multi-objective scheduling for distributed computing Maximizing system reliability and minimizing schedule length are the two major objectives in scheduling a distributed computing system. These two objectives have been considered separately by most researchers, although more realistically they should be considered simultaneously. This paper addresses the problem by taking a multi-objective approach in scheduling. A Tabu search algorithm is proposed and two lateral interference schemes are used to distribute the Pareto optimal solutions along the Pareto front uniformly. Randomly generated directed acyclic graphs and a real application task graph are used to study the performance of the proposed algorithms. Experimental results show that for this problem lateral interference has no influence on the non-dominated solution number, but does benefit the uniform distribution of non-dominated solutions, irrespective of the computation method used to determine distances between the solutions.

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

multi-objective optimization
distributed computing systems


An energy-aware active smart card Despite recent advances in smart card technology, most modern smart cards continue to rely on card readers for power and clocking, creating a potential security gap. In this paper, we present an energy-aware smart card architecture that operates using an embedded battery and crystal. This low-power VLSI system is continually active and provides enhanced security through periodic internal update when the card is detached from a reader. Our architecture achieves reduced power consumption by deactivating the majority of its circuitry, including an embedded microcontroller, for the vast majority of the card's lifetime. A proof-of-concept prototype implementation of the architecture has been developed including register-transfer-level and gate-level designs which have been synthesized to silicon. To permit extended operation for up to 18 months, critical design logic has been implemented using ultralow-power (adiabatic) circuit techniques.

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 B O O


On the features and challenges of security and privacy in distributed internet of things In the Internet of Things, services can be provisioned using centralized architectures, where central entities acquire, process, and provide information. Alternatively, distributed architectures, where entities at the edge of the network exchange information and collaborate with each other in a dynamic way, can also be used. In order to understand the applicability and viability of this distributed approach, it is necessary to know its advantages and disadvantages not only in terms of features but also in terms of security and privacy challenges. The purpose of this paper is to show that the distributed approach has various challenges that need to be solved, but also various interesting properties and strengths.

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

internet of things
distributed architectures
security


efficient overlap and content reuse detection in blogs and online news articles The use of blogs to track and comment on real world (political, news, entertainment) events is growing. Similarly, as more individuals start relying on the Web as their primary information source and as more traditional media outlets try reaching consumers through alternative venues, the number of news sites on the Web is also continuously increasing. Content-reuse, whether in the form of extensive quotations or content borrowing across media outlets, is very common in blogs and news entries outlets tracking the same real-world event. Knowledge about which web entries re-use content from which others can be an effective asset when organizing these entries for presentation. On the other hand, this knowledge is not cheap to acquire: considering the size of the related space web entries, it is essential that the techniques developed for identifying re-use are fast and scalable. Furthermore, the dynamic nature of blog and news entries necessitates incremental processing for reuse detection. In this paper, we develop a novel qSign algorithm that efficiently and effectively analyze the blogosphere for quotation and reuse identification. Experiment results show that with qSign processing time gains from 10X to 100X are possible while maintaining reuse detection rates of upto 90\%. Furthermore, processing time gains can be pushed multiple orders of magnitude (from 100X to 1000X) for 70\% recall.

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


A numerical and experimental investigation on self-heating effects in viscoelastic dampers It is widely known that the mechanical characteristics of viscoelastic materials are highly dependent upon temperature. In traditional procedures of analysis and design of viscoelastic dampers, uniform, constant temperature is generally assumed. However, this procedure can lead to poor designs or even severe failures since the energy dissipated within the volume of the material leads to temperature rises, which depend on a number of factors such as material properties, load conditions and the geometry of the damping device. This phenomenon, which has been frequently disregarded in the literature, is known as self-heating. In this paper, a hybrid numericalexperimental investigation on the self-heating phenomenon in viscoelastic materials subjected to harmonic loadings is reported. The main goal is the development of a finite-element-based methodology intended to perform the thermoviscoelastic analysis of discrete damping devices such as translational and rotational mounts. Since direct coupling between thermal and structural fields would result in prohibitive computational costs, the problem is solved by assuming weak coupling between both fields and the nonlinear coupled thermal and structural analyses are performed in a sequential iterative scheme, implemented in ANSYS finite element software. In order to put in evidence the self-heating phenomenon and evaluate the accuracy of the modeling procedure, laboratory experiments are carried-out using a translational viscoelastic mount, subjected to shear harmonic loading with various frequency and amplitude values. The numerical and experimental results obtained in terms of the temperature evolutions at different points within the volume of the viscoelastic material are compared. Additionally, an optimization-based procedure is used to identify some unknown thermal parameters intervening in the model. The obtained results confirm that accounting for self-heating can be of capital importance in the design and performance analysis of viscoelastic dampers.

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

viscoelastic damping
thermoviscoelasticity
self-heating
finite elements


Modeling and comparison of candidate selection algorithms in opportunistic routing Opportunistic Routing (OR) has been investigated in recent years as a way to increase the performance of multihop wireless networks by exploiting its broadcast nature. In contrast to traditional routing, where traffic is sent along pre-determined paths, in OR an ordered set of candidates is selected for each next-hop. Upon each transmission, the candidates coordinate such that the most priority one receiving the packet actually forwards it. Most of the research in OR has been addressed to investigate candidate selection algorithms. In this paper we propose a discrete time Markov chain to assess the improvement that may be achieved using opportunistic routing. We use our model to compare a selected group of candidate selection algorithms that have been proposed in the literature. Our main conclusion is that optimality is obtained at a high computational cost, with a performance gain very similar to that of much simpler but non-optimal algorithms. Therefore, we conclude that fast and simple OR candidate selection algorithms may be preferable in dynamic networks, where the candidates sets are likely to be updated frequently.

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

wireless networks
opportunistic routing
markov chain
candidate selection algorithms


Down-regulation of Receptor-mediated Endocytosis Is Reponsible for Senescence-associated Hyporesponsiveness Human diploid fibroblasts (HDF) do not divide indefinitely and eventually lead to an arrest of cell division by a process termed cellular or replicative senescence. Irreversible growth arrest of senescent cells is strongly related to the attenuated response to growth factors. Recently, we reported that up-regulation of caveolin in the senescent cells is responsible for the attenuated response to growth factors. Senescent cells did not phosphorylate Erk-1/2 after EGF stimulation, whereas young cells did. In those senescent cells, we found an increased level of caveolin proteins and strong interactions between caveolin-1 and EGFR. When we overexpressed caveolin-1 in young HDF, the activation of Erk-1/2 on EGF stimulation was significantly suppressed. These results suggest that the hyporesponsiveness of senescent fibroblasts to EGF stimulation might be due to the overexpression of caveolin. In addition, the clathrin-dependent endocytosis system plays the more active and dominant role over the caveolae system. Therefore, we monitored the efficiency of clathrin-dependent receptor-mediated endocytosis in the senescent cells in order to elucidate the exact mode of the attenuated response to growth factors in the senescent cells. Using a transferrin-uptake assay and Western blot analysis of endocytosis-related proteins, we found a significant decrease of amphiphysin-1 in human diploid fibroblasts of multipassages. By adjusting the level of amphiphysin, we could modulate the efficiency of receptor-mediated endocytosis either in young or old cells toward growth factors

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


Solution of 3D singular electrostatics problems using adaptive hp-FEM Purpose - This paper seeks to describe the solution of a simple electrostatic problem using an adaptive hp-FEM and to show the benefits of this approach. Numerical experiments are presented to demonstrate its superiority. Design/methodology/approach - Adaptive hp-FEM is used. In contrast with standard FEM, the automatic adaptivity procedurecan choose from a variety of refinement candidates. An element with over estimated error can be refined in space, or its polynomial degree can be increased. Arbitrary level hanging nodes are allowed, so that no unnecessary refinements are performed in order to keep a mesh regular. Findings Numerical solution of a singular electrostatic problem is presented. From the comparison it can be seen that the hp-FEM outperforms both the standard linear and quadratic elements significantly. The accuracy of an hp-FEM solution would be hard to attain by standard means due to the limited capacity of the computer memory. Originality/value - The paper describes results obtained from an original and innovative implementation of the adaptive hp-FEM.

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

simulation
finite element analysis
meshes


topology guaranteeing manifold reconstruction using distance function to noisy data Given a smooth compact codimension one submanifold S of R k and a compact approximation K of S , we prove that it is possible to reconstruct S and to approximate the medial axis of S with topological guarantees using unions of balls centered on K . We consider two notions of noisy-approximation that generalize sampling conditions introduced by Amenta & al. and Dey & al. Our results are based upon critical point theory for distance functions. For the two approximation conditions, we prove that the connected components of the boundary of unions of balls centered on K are isotopic to S . Our results allow to consider balls of different radii. For the first approximation condition, we also prove that a subset (known as the ? medial axis) of the medial axis of R k \ K is homotopy equivalent to the medial axis of S . We obtain similar results for smooth compact submanifolds S of R k of any codimension.

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


Tactile VR for hand-eye coordination in simulated PTCA Percutaneous transluminal coronary angioplasty (PTCA) is a minimally invasive image-guided technique for treatment of coronary diseases. PTCA procedure requires physicians to have good skills of hand-eye coordination in performing the operation. Training of PTCA thus very much emphasizes skill building for hand-eye coordination. We have been developing virtual reality (VR) technology for medical simulation. In this paper, we will address the issue of VR-based simulation for the enhancement of hand-eye coordination for PTCA operation. Starting from the characterization of PTCA procedure, we examine what roles VR can play in training of PTCA physicians. We then describe a computerized PTCA training system we have developed which is composed of a tactile interface and a visual interface. The system is designed in such a way that real PTCA devices (including catheters and guide-wires) can be used to mimic the requirements of the CathLab. The backend computational engine supporting the real-time and realistic PTCA simulation is also presented. (C) 2004 Elsevier Ltd. All rights reserved.

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

image-guided surgery
hand-eye coordination
tactile and visual interfaces


Exploring student response systems in nursing education Using software products in the classroom can be an effective component in an overall technology integration plan. Choosing the right software for the subject area and classroom, however, can be a formidable task if undertaken without preplanning, In this article, we describe the developing process experienced professionally and personally with the student response system. The Internet and other new digital technologies have changed the way we respond to information. These changes are making an impact on students' learning styles and preferences, How to address this issue might be found in an endeavor that places the student at the center of the learning process and facilitates a more active experience: the interactive student response system. Imagine classrooms where teachers electronically introduce assignments using receivers and students beam information from pocket-sized remote controls. Imagine students working on group projects exchanging information without pen or paper.

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


Analytical spherical-mode-based compensation of mutual coupling in uniform circular arrays for direction-of-arrival estimation An analytical circuit model with a limited number of parameters is presented to describe mutual coupling in uniform circular arrays. The model, which is based on a spherical-mode expansion, provides physical insight into the frequency dependence and the dependence on azimuth and elevation angle of the coupling between antenna elements. It is shown that the number of circuit elements, required to describe the open-circuit voltages and the mutual impedances at the different antenna ports, depends on the overall size of the array and not on the spacing between the antenna elements. Based on this observation, an analytical technique is described to derive a coupling matrix representing the mutual coupling effects. Relying on the phase-mode-based circuit elements, dedicated eigenstructure techniques are developed for direction-of-arrival (DOA) estimation with uniform circular arrays. By considering several synthetic reference scenarios, it is shown that even in the presence of severe mutual coupling, root-MUSIC combined with a limited number of phase-mode components gives very robust DOA estimations for the azimuth angle, when all signals are incident on the array from a fixed elevation angle.

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 I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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

antenna array mutual coupling
array signal processing
mobile communication


GenMin: An enhanced genetic algorithm for global optimization A new method that employs grammatical evolution and a stopping rule for finding the global minimum of a continuous multidimensional, multimodal function is considered. The genetic algorithm used is a hybrid genetic algorithm in conjunction with a local search procedure. We list results from numerical experiments with a series of test functions and we compare with other established global optimization methods. The accompanying software accepts objective functions coded either in Fortran 77 or in C++.

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

genetic algorithm
grammatical evolution
global optimization
stopping rule


the urgency for effective user privacy-education to counter social engineering attacks on secure computer systems Trusted people can fail to be trustworthy when it comes to protecting their aperture of access to secure computer systems due to inadequate education, negligence, and various social pressures. People are often the weakest link in an otherwise secure computer system and, consequently, are targeted for social engineering attacks. Social Engineering is a technique used by hackers or other attackers to gain access to information technology systems by getting the needed information (for example, a username and password) from a person rather than breaking into the system through electronic or algorithmic hacking methods. Such attacks can occur on both a physical and psychological level. The physical setting for these attacks occurs where a victim feels secure: often the workplace, the phone, the trash, and even on-line. Psychology is often used to create a rushed or officious ambiance that helps the social engineer to cajole information about accessing the system from an employee. Data privacy legislation in the United States and international countries that imposes privacy standards and fines for negligent or willful non-compliance increases the urgency to measure the trustworthiness of people and systems. One metric for determining compliance is to simulate, by audit, a social engineering attack upon an organization required to follow data privacy standards. Such an organization commits to protect the confidentiality of personal data with which it is entrusted. This paper presents the results of an approved social engineering audit made without notice within an organization where data security is a concern. Areas emphasized include experiences between the Social Engineer and the audited users, techniques used by the Social Engineer, and other findings from the audit. Possible steps to mitigate exposure to the dangers of Social Engineering through improved user education are reviewed.

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


Bubble-type solutions of nonlinear singular problems The paper describes the set of all solutions of the singular initial problems (p(t)u')' = p(t)f(u), u(0) = B, u'(0) = 0, on the half-line [0, infinity). Here B 0 on (0, infinity), f(L) = 0 for some L > 0 and xf(x) < 0 if x < L, x not equal 0. By means of this result, the existence of a strictly increasing solution of this problem satisfying u(infinity) = L is proved under some additional assumptions. In particular cases this homoclinic solution determines an increasing mass density in centrally symmetric gas bubbles which are surrounded by an external liquid with density L. (C) 2009 Elsevier Ltd. All rights reserved.

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

singular ordinary differential equation of the second order


A novel Bayesian classification for uncertain data Data uncertainty can be caused by numerous factors such as measurement precision limitations, network latency, data staleness and sampling errors. When mining knowledge from emerging applications such as sensor networks or location based services, data uncertainty should be handled cautiously to avoid erroneous results. In this paper, we apply probabilistic and statistical theory on uncertain data and develop a novel method to calculate conditional probabilities of Bayes theorem. Based on that, we propose a novel Bayesian classification algorithm for uncertain data. The experimental results show that the proposed method classifies uncertain data with potentially higher accuracies than the Naive Bayesian approach. It also has a more stable performance than the existing extended Naive Bayesian method.

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

bayes theorem
uncertain data
classification
statistical theory


A flow-based methodology for the calculation of TSO to TSO compensations for cross-border flows In the context of the development of the European internal electricity market, several methods for the tarification of cross-border flows have been proposed. This paper presents a flow-based method for the calculation of TSO to TSO compensations for cross-border flows. The basic principle of this approach is the allocation of the costs of cross-border flows to the TSOs who are responsible for these flows. This method is cost reflective, non-transaction based and compatible with domestic tariffs. It can be applied when limited data are available. Each internal transmission network is then modelled as an aggregated node, called supernode, and the European network is synthesized by a graph of supernodes and arcs, each arc representing all cross-border lines between two adjacent countries. When detailed data are available, the proposed methodology is also applicable to all the nodes and lines of the transmission network. Costs associated with flows transiting through supernodes or network elements are forwarded through the network in a way reflecting how the flows make use of the network. The costs can be charged either towards loads and exports or towards generations and imports. Combination of the two charging directions can also be considered.

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

transmission system operator compensation


Combinatorial and arithmetical properties of infinite words associated with non-simple quadratic parry numbers We study some arithmetical and combinatorial properties of beta-integers for beta being the larger root of the equation x(2) = mx - n, m, n epsilon N, m >= n + 2 >= 3. We determine with the accuracy of +/- 1 the maximal number of beta-fractional positions, which may arise as a result of addition of two beta- integers. For the infinite word u(beta) coding distances between the consecutive beta- integers, we determine precisely also the balance. The word u(beta) is the only fixed point of the morphism A -> A (m-1) B and B -> A (m-n- 1) B. In the case n = 1, the corresponding infinite word u(beta) is sturmian, and, therefore, 1- balanced. On the simplest non- sturmian example with n = 2, we illustrate how closely the balance and the arithmetical properties of beta- integers are related.

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

balance property
arithmetics
expansions
infnite words


Frequency-domain identification of time-varying systems for analysis and prediction of aeroelastic flutter In this paper a different approach to wind tunnel flutter testing is presented. This procedure can now be performed as one continuous test, resulting in a major time saving. Both analysis of the current behaviour of the structure, and prediction towards higher velocities, are important for flight flutter testing, and are dealt with in this paper. The recently developed time-varying weighted non-linear least-squares estimator (TV-WNLS) (Lataire and Pintelon, 2011 [1]) is applied to the aeroelastic flutter problem. Smooth variation of the transfer function coefficients is forced through the TV-WNLS estimator, and the obtained polynomials are used as basis for predicting the damping ratio towards higher velocities. Selection of the model order is based on linear variation of the airspeed and the evaluation of Theodorsen's unsteady aerodynamics for the frozen time-varying aeroelastic system at a certain constant velocity. Therefore, providing a physical justification for the extrapolation of the damping ratio towards higher velocities. The method is applied to wind-tunnel measurements on a cantilevered wing. It is shown that the proposed method outperforms flutter speed prediction by classic damping ratio extrapolation and a non-parametric analysis of the time-varying signal.

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

aeroelasticity
frequency-domain identification
time-varying system
wind tunnel testing


A longitudinal study of state government homepage accessibility in Maryland and the role of web page templates for improving accessibility A longitudinal evaluation of government web site accessibility. The first state-level longitudinal analysis of government web site accessibility. Web page templates tend to result in more accessible sites in state government.

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

web accessibility
policy
disability
compliance
section508


Improved Two-Point Codes on Hermitian Curves One-point codes on the Hermitian curve produce long codes with excellent parameters. Feng and Rao introduced a modified construction that improves the parameters while still using one-point divisors. A separate improvement of the parameters was introduced by Matthews considering the classical construction but with two-point divisors. Those two approaches are combined to describe an elementary construction of two-point improved codes. Upon analysis of their minimum distance and redundancy, it is observed that they improve on the previous constructions for a large range of designed distances.

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

algebraic geometric codes
error-correcting codes
two-point codes


Approaching Throughput-Optimality in Distributed CSMA Scheduling Algorithms With Collisions It was shown recently that carrier sense multiple access (CSMA)-like distributed algorithms can achieve the maximal throughput in wireless networks (and task processing networks) under certain assumptions. One important but idealized assumption is that the sensing time is negligible, so that there is no collision. In this paper, we study more practical CSMA-based scheduling algorithms with collisions. First, we provide a Markov chain model and give an explicit throughput formula that takes into account the cost of collisions and overhead. The formula has a simple form since the Markov chain is "almost" time-reversible. Second, we propose transmission-length control algorithms to approach throughput-optimality in this case. Sufficient conditions are given to ensure the convergence and stability of the proposed algorithms. Finally, we characterize the relationship between the CSMA parameters (such as the maximum packet lengths) and the achievable capacity region.

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

carrier sence multiple access (csma)
convex optimization
distributed scheduling


Mutual benefits of two multicriteria analysis methodologies: A case study for batch plant design This paper presents a MultiObjective Genetic Algorithm (MOGA) optimization framework for batch plant design. For this purpose, two approaches are implemented and compared with respect to three criteria, i.e., investment cost, equipment number and a flexibility indicator based on work in process (the so-called WIP) computed by use of a discrete-event simulation model. The first approach involves a genetic algorithm in order to generate acceptable solutions, from which the best ones are chosen by using a Pareto Sort algorithm. The second approach combines the previous Genetic Algorithm with a multicriteria analysis methodology, i.e., the Electre method in order to find the best solutions. The performances of the two procedures are studied for a large-size problem and a comparison between the procedures is then made.

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

multiobjective optimization
multicriteria decision analysis


How to measure the impact of environmental factors in a nonparametric production model The measurement of technical efficiency allows managers and policy makers to enhance existing differentials and potential improvements across a sample of analyzed units. The next step involves relating the obtained efficiency estimates to some external or environmental factors which may influence the production process, affect the performances and explain the efficiency differentials. Recently introduced conditional efficiency measures (Daraio and Simar, 2005, Daraio and Simar, 2007aandDaraio and Simar, 2007b), including conditional FDH, conditional DEA, conditional order-m and conditional order-?, have rapidly developed into a useful tool to explore the impact of exogenous factors on the performance of Decision Making Units in a nonparametric framework. This paper contributes in a twofold fashion. It first extends previous studies by showing that a careful analysis of both full and partial conditional measures allows the disentangling of the impact of environmental factors on the production process in its two components: impact on the attainable set and/or impact on the distribution of the efficiency scores. The authors investigate these interrelationships, both from an individual and a global perspective. Second, this paper examines the impact of environmental factors on the production process in a new two-stage type approach but using conditional measures to avoid the flaws of the traditional two-stage analysis. This novel approach also provides a measure of inefficiency whitened from the main effect of the environmental factors allowing a ranking of units according to their managerial efficiency, even when facing heterogeneous environmental conditions. The paper includes an illustration on simulated samples and a real data set from the banking industry.

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

conditional efficiency measures
managerial efficiency

data envelopment analysis (dea)
free disposal hull (fdh)
nonparametric frontiers
two-stage efficiency analysis


Gauss map computation for free-form surfaces The Gauss map of a smooth doubly-curved surface characterizes the range of variation of the surface normal as an area on the unit sphere. An algorithm to approximate the Gauss map boundary to any desired accuracy is presented, in the context of a tensor-product polynomial surface patch, r(u, v) for (u, v) is an element of [0, 1] x [0, 1]. Boundary segments of the Gauss map correspond to variations of the normal along the patch boundary or the parabolic lines (loci of vanishing Gaussian curvature) on the surface, To compute the latter, points of vanishing Gaussian curvature are identified with the zero-set of a bivariate polynomial, expressed in the numerically-stable Bernstein basis-the subdivision and variation-diminishing properties then govern an adaptive quadtree decomposition of the (it, v) parameter domain that captures the zero-set of this polynomial to any desired accuracy. Loci on the unit sphere corresponding to the patch boundaries and parabolic lines are trimmed at their mutual or self-intersection points (if any), and the resulting segments are arranged in a graph structure with the segment end-points as nodes. By appropriate traversal of this graph, the Gauss map boundary segments may then be identified in proper order, and extraneous segments (lying in the Gauss map interior) are discarded. The symmetrization of the Gauss map (by identification of antipodal points) and its stereographic projection onto a plane are also discussed. (C) 2001 Elsevier Science B.V. All rights reserved.

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

surface normal
gauss map
gaussian curvature
quadtree decomposition
stereographic projection

free-form surface
parabolic lined
bernstein form


Understanding emotional impact of images using Bayesian multiple kernel learning Affective classification and retrieval of multimedia such as audio, image, and video have become emerging research areas in recent years. The previous research focused on designing features and developing feature extraction methods. Generally, a multimedia content can be represented with different feature representations (i.e., views). However, the most suitable feature representation related to people?s emotions is usually not known a priori. We propose here a novel Bayesian multiple kernel learning algorithm for affective classification and retrieval tasks. The proposed method can make use of different representations simultaneously (i.e., multiview learning) to obtain a better prediction performance than using a single feature representation (i.e., single-view learning) or a subset of features, with the advantage of automatic feature selections. In particular, our algorithm has been implemented within a multilabel setup to capture the correlation between emotions, and the Bayesian formulation enables our method to produce probabilistic outputs for measuring a set of emotions triggered by a single image. As a case study, we perform classification and retrieval experiments with our algorithm for predicting people?s emotional states evoked by images, using generic low-level image features. The empirical results with our approach on the widely-used International Affective Picture System (IAPS) data set outperform several existing methods in terms of classification performance and results interpretability.

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

multiple kernel learning
multiview learning

image emotions
variational approximation
low-level image features


PadLegendre approximants for uncertainty analysis with discontinuous response surfaces A novel uncertainty propagation method for problems characterized by highly non-linear or discontinuous system responses is presented. The approach is based on a PadLegendre (PL) formalism which does not require modifications to existing computational tools (non-intrusive approach) and it is a global method. The paper presents a novel PL method for problems in multiple dimensions, which is non-trivial in the Pad literature. In addition, a filtering procedure is developed in order to minimize the errors introduced in the approximation close to the discontinuities. The numerical examples include fluid dynamic problems characterized by shock waves: a simple dual throat nozzle problem with uncertain initial state, and the turbulent transonic flow over a transonic airfoil where the flight conditions are assumed to be uncertain. Results are presented in terms of statistics of both shock position and strength and are compared to Monte Carlo simulations.

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

uncertainty quantification
padlegendre approximation
gibbs phenomenon
shock capturing
rae2822


The post-Doppler adaptive processing method based on the spatial domain reconstruction Space-time adaptive processing (STAP) has a huge computational complexity and a large training samples requirement, which limit its practical applications. The traditional post-Doppler adaptive processing methods such as factored approach (FA) and extended factored approach (EFA) can significantly reduce the computational complexity and the training sample requirement in adaptive processing, and maintain nearly the same performance as the optimal STAP. However, because training samples are restricted in real-world environments, their performances can be considerably degraded in the large-scale antenna array. To solve this problem, the post-Doppler adaptive processing method based on the spatial domain reconstruction is proposed. In this method, the spatial clutter data after Doppler filtering is reconstructed as a matrix that has close columns and rows. The spatial weights vector in FA or EFA is also re-expressed as the product of two shorter weight vectors. Then the cyclic minimizer is applied to find the desired solution. Experimental results show that the proposed method has the advantages of fast convergence and small training samples requirement. It has greater moving target detection ability especially under the condition for large-scale antenna array and small training samples support than FA and EFA.

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

space-time adaptive processing (stap)
clutter suppression


Nitric Oxide in Liver Diseases Research on the free radical gas, nitric oxide (NO), during the past twenty years is one of the most rapid growing areas in biology. NO seems to play a part in almost every organ and tissue. However, there is considerable controversy and confusion in understanding its role. The liver is one organ that is clearly influenced by NO. Acute versus chronic exposure to NO has been associated with distinct patterns of liver disease. In this paper we review and discuss the involvement of NO in various liver diseases collated from observations by various researchers. Overall, the important factors in determining the beneficial versus harmful effects of NO are the amount, duration, and site of NO production. A low dose of NO serves to maximize blood perfusion, prevent platelet aggregation and thrombosis, and neutralize toxic oxygen radicals in the liver during acute sepsis and reperfusion events. NO also demonstrates antimicrobial and antiapoptosis properties during acute hepatitis infection and other inflammatory processes. However, in the setting of chronic liver inflammation, when a large sustained amount of NO is present, NO might become genotoxic and lead to the development of liver cancer. Additionally, during prolonged ischemia, high levels of NO may have cytotoxic effects leading to severe liver injury. In view of the various possible roles that NO plays, the pharmacologic modulation of NO synthesis is promising in the future treatment of liver diseases, especially with the emergence of selective NO synthase inhibitors and cell-specific NO donors.

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


Experience Transfer for the Configuration Tuning in Large-Scale Computing Systems This paper proposes a new strategy, the experience transfer, to facilitate the management of large-scale computing systems. It deals with the utilization of management experiences in one system (or previous systems) to benefit the same management task in other systems (or current systems). We use the system configuration tuning as a case application to demonstrate all procedures involved in the experience transfer including the experience representation, experience extraction, and experience embedding. The dependencies between system configuration parameters are treated as transferable experiences in the configuration tuning for two reasons: 1) because such knowledge is helpful to the efficiency of the optimal configuration search, and 2) because the parameter dependencies are typically unchanged between two similar systems. We use the Bayesian network to model configuration dependencies and present a configuration tuning algorithm based on the Bayesian network construction and sampling. As a result, after the configuration tuning is completed in the original system, we can obtain a Bayesian network as the by-product which records the dependencies between system configuration parameters. Such a network is then embedded into the tuning process in other similar systems as transferred experiences to improve the configuration search efficiency. Experimental results in a web-based system show that with the help of transferred experiences, the configuration tuning process can be significantly accelerated.

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

distributed systems
knowledge acquisition
knowledge reuse
active sampling


HCV-Related Immunocytoma and Type II Mixed Cryoglobulinemia-Associated Autoantigens Hepatitis C virus (HCV) is a hepatotropic virus causing hepatocellular damage and chronic liver inflammation that progressively can lead to cirrhosis and hepatocellular carcinoma (HCC). HCV is also lymphotropic, as demonstrated by its capacity to replicate in lymphocytes, by the recurrent detection of organ- and non-organ-specific autoantibodies in HCV-infected patients, and by the strong association found between HCV infection and type II mixed cryoglobulinemic syndrome (MC-II). Moreover, accumulating data ascribe an etiopathogenetic role in the development of B cell non-Hodgkin's lymphomas (NHL) to HCV. All these findings account for the profound effect of HCV infection in the host's immune system. The unique virushost interactions that culminate in the generation and sustained production of autoantibodies and cryoglobulins have not been delineated. It appears that chronic antigenic stimulation could cause the emergence of specific B cell clones that produce cryoglobulins; moreover, B cell activation and/or deregulation could originate as a result of HCV binding to CD81 tetraspanin or as a consequence of its ability to replicate in B cells. In a previous study we demonstrated that, in MC-II HCV-positive patients, cryoprecipitated monoclonal IgMs, and B cell receptors (BCR) of overexpanded B cell clones share the same combinatory region. Moreover, these IgMs were reactive against both the Fc region of human IgG and the HCV-NS3 antigen. NS3 and Fc epitopes have been idengified by epitope excision approach. One of the idengified NS3 epitopes has been used to immunize a mouse and the monoclonal antibody obtained showed the same cross-reactivity as patients' IgMs. The characterization of antigenic specificity of this antibody may be useful to idengify antigens that can stimulate B cell proliferation in HCV-infected individuals

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

hepatitis c virus
b cell proliferation
autoantibodies


An efficient incomparable public key encryption scheme Public keys are closely related to the identity of recipients in public key encryption setting. In privacy-sensitive applications of public key encryption, it is desirable to hide the relation between the public key and the identity of the recipient. The main functional approach in the privacy enhanced public key encryption scheme is to give anonymity of the public keys of recipients. In this case, all the users in the system are potential recipients of every ciphertext. Waters, Felten, and Sahai proposed an incomparable public key encryption scheme which guarantees the anonymity of recipients against both eavesdroppers and senders. In their scheme, all the recipients must complete the same amount of computations to identify the ciphertexts which direct to them. In this paper, we focus on reducing the number of computations for the recipients while preserving the security level of Waters et al.s scheme. Our method is to separate the decryption process into two steps, first the recipient determines whether a ciphertext is directed to him or her, and only if the direction is correct, the recipient recovers the corresponding plaintext. This improves the efficiency of the system.

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


Mathematical model for dispersion and diffusion of chemically reactive pollutants from various sources into a boundary layer with dry deposition Purpose - The purpose of this paper is to propose a mathematical model for dispersion and diffusion of chemically reactive primary pollutants emitted from an elevated line sources into a stable atmospheric boundary layer with generalized wind velocity of quadratic function of vertical heights. Design/methodology/approach - The governing partial differential equations are converted into the two-dimensional time dependent partial differential equation by suitable choice of meteorological parameters and non-dimensional variables, which is solved by the multiple inverse Laplace transform through Green's Function technique. Findings - The three different types' sources, viz, continuous, an instantaneous and step-function type sources are studied. The pollutants considered are chemically reactive primary pollutants emitted from the above sources. In many previous works, solutions are obtained through numerical technique or numerical inversion of the Laplace transform; but here, an analytical method is carried out to find the exact solution through multiple inversion of Laplace transform, which yields an effective and accurate solution. Originality/value - The paper describes how the authors obtained exact solutions for the elevated line sources into a stable atmospheric boundary layer arising in the chemically reactive primary pollutants model by inverse Laplace transform through Green's Function technique. The graphical results show that this method is very accurate. The gaseous pollutants converted into particulate matter and settled on surface terrain are also considered in this theoretical model.

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

atmosphere
winds
mathematical modelling
settling velocity
stable boundary layer
instantaneous line source
continuous line source
step-function type source
chemically reactive pollutants
quadratic diffusion coefficient
generalized parabolic wind profile


type invariants for haskell Multi-parameter type classes, functional dependencies, and recently GADTs and open type families open up opportunities to use complex type-level programming to let GHC's type checker verify various properties of your programs. But type-level code is special in that its correctness is crucial to the safety of the program; so except in those cases simple enough for the type checker to see trivially that the code is correct (or harmless), type-level programs need to come with a specification of their properties together with their proof. In this article, we propose an extension to Haskell that allows the specification of invariants for type classes and open type families, together with accompanying evidence that those invariants hold. To accommodate the open nature of type classes and type families, the evidence itself needs to be open and every subcase of the proof can be provided independently from the others.

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


globally synchronized dead-reckoning with local lag for continuous distributed multiplayer games Dead-Reckoning (DR) is an effective method to maintain consistency for Continuous Distributed Multiplayer Games (CDMG) . Since DR can filter most unnecessary state updates and improve the scalability of a system, it is widely used in commercial CDMG. However, DR cannot maintain high consistency, and this constrains its application in highly interactive games. With the help of global synchronization, DR can achieve higher consistency, but it still cannot eliminate before inconsistency . In this paper, a method named Globally Synchronized DR with Local Lag (GS-DR-LL) , which combines local lag and Globally Synchronized DR (GS-DR) , is presented. Performance evaluation shows that GS-DR-LL can effectively decrease before inconsistency, and the effects increase with the lag.

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

dead-reckoning
continuous replicated application
distributed multi-player games


Failure analysis on reflector blackening between lead frame electrodes in LEDs under WHTOL test We report a new blackening failure mode of commercial LEDs. Delamination and corrosive de-flash agent are the root causes of the failure. Reflector cup corrosion and Ag migration are the features of the failure. The effect of the blackening failure to LED performance is estimated.

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

blackening
delamination
failure analysis

electromigration
led reliability
reflector corrosion


Quantifying the value of IT-investments We described a method to quantify the value of investments in software systems. For that, we adopted the classical risk-adjusted discounted cash flow model and geared it towards the field of information technology. This resulted in a scenario-based approach incorporating two IT-specific risks that can substantially influence IT-appraisals. They are requirements creep and time compression. To account for the risk of failed IT-projects and overrun risks we proposed the Weighted Average Cost of Information Technology (WACIT). WACIT adjusts the well-known Weighted Average Cost of Capital, commonly used in discounted cash flow models. We proposed several methods to approximate WACIT ranging from an investment-specific rate to a (company-wide) one inferred from a quantitative IT-portfolio analysis. We illustrated our quantitative IT-investment management approach by way of a published example. For various risk-scenarios, we calculated using this example the impact on the firm's share price, standard economic indicators like NPV, IRR, PBP, ROI, RAROC, and more, in order to come to grips with the appraisal of information technology-the largest production factor of today. (c) 2004 Elsevier B.V. All rights reserved.

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

weighted average cost of information technology (wacit)


Designing competitions between teams of individuals We consider a setting with two teams, each with a number of players. There is an ordering of all players that determines outcome of matches between any two players from the opposing teams. Neither the teams nor the competition designer know this ordering, but each team knows the derived ordering of strengths among its own players. Each team announces an ordering of its players, and the competition designer schedules matches according to the announced orderings. This setting in general allows for two types of manipulations by a team: Misreporting the strength ordering (lack of truthfulness), and deliberately losing a match (moral hazard). We prove necessary and sufficient conditions for a set of competition rules to have the properties that truthful reporting are dominant strategies and maximum effort in matches are Nash equilibrium strategies, and certain fairness conditions are met. Extensions of the original setting are discussed. (C) 2010 Elsevier B.V. All rights reserved.

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

team competition
mechanism design
dominant strategy implementation


Robust hybrid position force control of redundant robots A nonlinear feedback control based on inverse dynamics is proposed for redundant robots with rigid or flexible joints during the execution of constrained motion tasks. Based on constrained system formalism, the presented control scheme achieves simultaneous, independent control of both position and contact force at the robot end-effector, while optimizing an objective function for redundancy resolution. Non-invariance problems are avoided by the use of a special methodology for constraint formulation. Issues related to the practical application of the proposed control algorithms, such as the design of robust controllers, are discussed. The assumed uncertainties are related to the robot as well the environment model. For flexible joint robots, it is also possible to use an inexact model for calculating those feedback variables which cannot be measured directly such as link accelerations and jerks, as well as the contact force time derivatives. The proposed approach is illustrated using an example of a three-link robot operating a moving joystick, with mixed contact conditions. The results of numerical simulation demonstrate the effectiveness of the proposed controllers. (C) 1999 Elsevier Science B.V. All rights reserved.

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

hybrid position force control
flexible joint robots
redundant robots

inverse dynamics control
constrained systems
robustness enhancement


THEME-SEER: a multidimensional exploratory technique to analyze a structural model using an extended covariance criterion In this work, we present a new approach to path modeling based on an extended multiple covariance criterion: system extended multiple covariance (SEMC). SEMC is suitable to measure the quality of any structural equations system. We show why SEMC may be preferred to criteria based on usual covariance of components and also to criteria based on residual sums of squares. We give a pursuit algorithm ensuring that SEMC increases and converges. When one wishes to extract more than one component per variable group, a problem arises of component hierarchy. To solve it, we define a local nesting principle of component models that makes the role of each component statistically clear. We then embed the pursuit algorithm in a more general algorithm that extracts sequences of locally nested models. We finally provide a component backward selection strategy. The technique is applied to cigarette data to model the generation of chemical compounds in smoke through tobacco combustion. Copyright (c) 2012 John Wiley & Sons, Ltd.

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

structural equation exploratory regression


High voltage degradation of GaN High Electron Mobility Transistors on silicon substrate We have electrically stressed GaN High Electron Mobility Transistors on Si substrate at high voltages. We observe a pattern of device degradation that differs markedly from previous reports in GaN-on-SiC HEMTs. Similarly to these devices, the gate leakage current of GaN-on-Si HEMTs increases by several orders of magnitude at a certain critical voltage and this increase is irreversible. However, in contrast with devices on SiC, the critical voltage varies substantially across the wafer, even over short distances, with values as high as 75V being observed. In addition, for voltages below the critical voltage, we observe a prominent degradation in the drain current and the source and drain resistances, something not observed in devices on SiC. This degradation is almost completely recoverable under UV illumination. We attribute these results to the high mismatch that exists between GaN and Si that leads to a large concentration of electrically active traps and a lower and non-uniform initial strain in the AlGaN barrier. This is evidenced by observed correlations between threshold voltage and maximum drain current in fresh devices and their corresponding critical voltages.

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


Development of wavelet de-noising technique for PET images Positron emission tomography (PET) imaging provides the functional information and precise physiological uptake of radioactivity in a patient's body. But the shortcoming of PET is low signal to noise ratio (SNR) due to photon noise. The noise may influence image quality, and cause the mistake of clinical interpretation. The purpose of this research is to develop a wavelet de-noising technique to reduce the noise of PET images. By processing the image through the optimum wavelet parameters we selected, we keep the resolution and contrast but reduce almost half of coefficient of variation in the region of interest of PET images.

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

positron emission tomography
image quality

wavelet transform
de-noising
image filtering


The ArnoldWinther mixed FEM in linear elasticity. Part I: Implementation and numerical verification ? Following some de Rham complex, Arnold and Winther have recently proposed a symmetric mixed finite element method (MFEM) in linear elasticity. This paper describes the implementation of the symmetric MFEM and its 3030 local stress stiffness matrices and studies the implementation of the lowest-order scheme for general boundary conditions. Numerical experiments in model examples in computational mechanics illustrate the robust locking-free convergence behavior and support the theoretically predicted experimental convergence rates.

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

linear elasticity
mixed finite element method
arnoldwinther
implementation
experimental convergence rates


Improved single phase modeling of propylene polymerization in a fluidized bed reactor An improved model for the production of polypropylene in a gas phase fluidized bed reactor was developed. Comparative simulation studies were carried out using the well-mixed, constant bubble size and the improved models. The improved model showed different prediction characteristics of polymer production rate as well as heat and mass transfer behavior as compared to other published models. All the three models showed similar dynamic behavior at the startup conditions but the improved model predicted a narrower safe operation window. Furthermore, the safe ranges of variation of the main operating parameters such as catalyst feed rate and superficial gas velocity calculated by the improved and well mixed models are wider than that obtained by the constant bubble size model. The improved model predicts the monomer conversion per pass through the bed which varies from 0.28 to 5.57% within the practical ranges of superficial gas velocity and catalyst feed rate. (C) 2011 Elsevier Ltd. All rights reserved.

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

polymerization
fluidized bed reactor
polypropylene

mathematical modeling
ziegler-natta catalyst


Medical image fusion based on improved sum-modified-Laplacian Sum-modified-Laplacian (SML) plays an important role in medical image fusion. However, fused rules based on larger SML always lead to fusion image distortion in transform domain image fusion or image information loss in spatial domain image fusion. Combined with average filter and median filter, a new medical image fusion method based on improved SML (ISML) is proposed. First, a basic fused image is gained by ISML, which is used for evaluation of the selection map of medical images. Second, difference images can be obtained by subtracting average image of all sources of medical images. Finally, basic fused image can be refined by difference images. The algorithm can both preserve the information of the source images well and suppress pixel distortion. Experimental results demonstrate that the proposed method outperforms the state-of-the-art medical image fusion methods. 2015 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 25, 206212, 2015

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

medical image fusion
average filter
median filter


Structural optimisation based on the boundary element and level set methods A level set based structural optimisation method is presented. The bi-directional evolutionary optimisation approach is used with BEM. The proposed method provides automatic insertion and merging of holes. NURBS were used to represent the structural geometry segments.

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 B O O O O O O O O

boundary element method
level set method


a reconfigurable cache architecture for energy efficiency On-chip caches often consume a significant fraction of the total processor energy budget. Allowing adaptation to the running workload can significantly lower their energy consumption. In this paper, we present a novel Set and way Management cache Architecture for efficient Run-Time reconfiguration (Smart cache), a cache architecture that allows reconfiguration in both its size and associativity. Results show the energy-delay of the Smart cache is on average 18\% better than state-of-the-art reconfiguration architectures.

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