On-line algorithms for computing mean and variance of interval data, and their use in intelligent systems When we have only interval ranges [ x ? i , x i ] of sample values x1,,xn, what is the interval [ V ? , V ] of possible values for the variance V of these values? There are quadratic time algorithms for computing the exact lower bound V on the variance of interval data, and for computing V under reasonable easily verifiable conditions. The problem is that in real life, we often make additional measurements. In traditional statistics, if we have a new measurement result, we can modify the value of variance in constant time. In contrast, previously known algorithms for processing interval data required that, once a new data point is added, we start from the very beginning. In this paper, we describe new algorithms for statistical processing of interval data, algorithms in which adding a data point requires only O(n) computational steps.

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


Principles for designing data-/compute-intensive distributed applications and middleware systems for heterogeneous environments The nature of distributed systems is constantly and steadily changing as the hardware and software landscape evolves. Porting applications and adapting existing middleware systems to ever changing computational platforms has become increasingly complex and expensive. Therefore, the design of applications, as well as the design of next generation middleware systems, must follow a set of guiding principles in order to insure long-term survivability without costly re-engineering. From our practical experience, the key determinants to success in this endeavor are adherence to the following principles: (1) Design for change; (2) Provide for storage subsystem I/O coordination; (3) Employ workload partitioning and load balancing techniques; (4) Employ caching; (5) Schedule the workload; and (6) Understand the workload. In order to support these principles, we have collected extensive experimental results comparing three middleware systems targeted at data- and compute-intensive applications implemented by our research group during the course of the last decade, on a single data- and compute-intensive application. The main contribution of this work is the analysis of a level playing field, where we discuss and quantify how adherence to these guiding principles impacts overall system throughput and response time.

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

middleware systems
heterogeneous environments

data-/compute-intensive applications
computational science applications


The use of mixtures for dealing with non-normal regression errors In many situations, the distribution of the error terms of a linear regression model departs significantly from normality. It is shown, through a simulation study, that an effective strategy to deal with these situations is fitting a regression model based on the assumption that the error terms follow a mixture of normal distributions. The main advantage, with respect to the usual approach based on the least-squares method is a greater precision of the parameter estimates and confidence intervals. For the parameter estimation we make use of the EM algorithm, while confidence intervals are constructed through a bootstrap method.

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

kurtosis
location-scale mixtures
normal probability plot
residual analysis
skewness
switching regression


Genetic evolution of nonlinear material constitutive models Material constitutive model is highly nonlinear and multimodal in the large parameter space. A genetic evolution algorithm is thus proposed for its recognition. The nonlinear stressstrain relationship presented by several added multinomials, whose structure is not simplified, is automatically recognized from global response information, e.g., load vs. reflection data, obtained from a structure test through genetic evolution in global space. Nonlinear finite element analysis is used as a bridge to build a relationship between stressstrain data and loaddeflection information. The potential of the proposed method is demonstrated by applying it to the macro-mechanical modeling of nonlinear behavior in advanced composite materials. A nonlinear material model for the ply is recognized using experimental results on a lamina plate [(45)6]s to be a modification of HahnTsai model [H.T. Hahn, S.W. Tsai, J. Compos. Mater. (1973) (7) 102]. The obtained nonlinear constitutive model is subsequently used to predict nonlinear behaviors of the [(30)6]s and [(0/45)4]s plates. The results are satisfying. This modeling procedure can be used as a method to guide to improve analysis of nonlinear behavior and damage of composite materials.

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

genetic algorithm
constitutive equations


A review on Gabor wavelets for face recognition Due to the robustness of Gabor features against local distortions caused by variance of illumination, expression and pose, they have been successfully applied for face recognition. The Facial Recognition Technology (FERET) evaluation and the recent Face Verification Competition (FVC2004) have seen the top performance of Gabor feature based methods. This paper aims to give a detailed survey of state of the art 2D face recognition algorithms using Gabor wavelets for feature extraction. Existing problems are covered and possible solutions are suggested.

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


On the ideals of secant varieties of Segre varieties We establish basic techniques for determining the ideals of secant varieties of Segre varieties. We solve a conjecture of Garcia, Stillman, and Sturmfels on the generators of the ideal of the first secant variety in the case of three factors and solve the conjecture set-theoretically for an arbitrary number of factors. We determine the low degree components of the ideals of secant varieties of small dimension in a few cases.

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

algebraic complexity
segre variety
border rank


BEM for dynamic analysis using compact supported radial basis functions This paper presents a novel dynamic modelling of structures. The main idea of the present formulation is to re-formulate the dual reciprocity method (DRM) using compact supported radial basis functions (CS RBF). The fictitious displacement and traction particular solution kernels are derived, for the first time, for four classes of CS RBF. Additional complementary solutions are derived to replace the particular solutions outside the zone of the compact radius (?). The continuity of the two solutions and their derivatives up to the third derivatives are ensured along the circumference of the compact supported edge circle. The present formulation is general, as proved validity for modelling structures bounded by interior and exterior domains (structures in infinite domains) which have never been studied previously using the DRM.

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


The construction of possibility measures from samples on T-semi-partitions We address the (generalized) extension problem for possibility measures: given a map defined on a family of(fuzzy) sets, is it possible to extend it to a (generalized) possibility measure? The extension problem for possibility measures is known to be equivalent to a system of sup-T equations, with T a t-norm. A key role is played by the greatest solution (of type inf-J, with J a border implicator). When the family of sets considered is a semi-partition, another important solution (of type sup-T, with T a t-norm) can be identified. In the treatment of the generalized possibilistic extension problem, we show that a fuzzification of the greatest solution also plays a central role. On the other hand, an immediate fuzzification of the sup-T type solution is investigated. General necessary and sufficient conditions for this fuzzification to be a solution are established. This fuzzification is then further discussed in the case of a T-semi-partition or a T-partition. Finally, we investigate possible criteria for extendability, inspired by Wang's classical criterion of P-consistency. (C) 1998 Elsevier Science Inc. All rights reserved.

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

possibilistic extension problem
possibility measure

p-consistency
sup-t equation
t-semi-partition


New exponential convergence on SICNNs with time-varying leakage delays and neutral type distributed delays This paper is concerned with a shunting inhibitory cellular neural networks (SICNNs) with time-varying leakage delays and neutral type continuously distributed delays. Some criteria are established for the existence and global exponential stability of pseudo almost periodic solutions for the addressed model with pseudo almost periodic coefficients and delays. Moreover, without assuming pseudo almost periodicity on coefficients and delays, a novel criterion is also given to ensure that all solutions of the considered neural networks converge exponentially to zero vector, which is new and complement previously known results.

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


an instructional design of open source networking laboratory and curriculum Computer Networking is one of the most challenging subjects to learn and to teach in an efficient way. On one hand, students may find the topic too technical and dry when presented. On the other hand, most IT instructors still primarily use lectures as the exclusive means to teach. As stated in SIGITE Computing Curricula, it is strongly recommended to incorporate hands-on lab components into teaching as they help students apply the theory to solve real-world problems. In this paper, we designed and implemented open source lab and curriculum that cover a set of learning outcomes recommended by SIGITE IT computing curricula. The design is guided by one of most commonly used instructional design models - Dick and Carey model. This research is aimed at producing students that can configure, maintain and troubleshoot the network from a "hands-on" perspective. In addition, the labs developed in this research, which map the SIGITE IT model curricula, will be helpful in the efforts to pursue ABET accreditation

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


Complex patterns We outline some results of our current research on developing a methodology for solving problems of spatio-temporal reasoning. We consider classifiers for complex concepts in spatio-temporal reasoning that are constructed hierarchically. We emphasise the fact that the construction of such hierarchical classifiers should be supported by domain knowledge. Approximate reasoning networks (AR networks) are proposed for approximation of reasoning schemes expressed in natural language. Such reasoning schemes are extracted from knowledge bases representing domain knowledge. This approach makes it possible to induce classifiers for complex concepts by constructing them along schemes of reasoning extracted from domain knowledge.

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

complex object
concept approximation
pattern
rough sets
spatio-temporal reasoning
classifier
network of classifiers


A MatrixMatrix Multiplication methodology for single/multi-core architectures using SIMD In this paper, a new methodology for speeding up MatrixMatrix Multiplication using Single Instruction Multiple Data unit, at one and more cores having a shared cache, is presented. This methodology achieves higher execution speed than ATLAS state of the art library (speedup from 1.08 up to 3.5), by decreasing the number of instructions (load/store and arithmetic) and the data cache accesses and misses in the memory hierarchy. This is achieved by fully exploiting the software characteristics (e.g. data reuse) and hardware parameters (e.g. data caches sizes and associativities) as one problem and not separately, giving high quality solutions and a smaller search space.

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

matrixmatrix multiplication
data cache
simd

cache associativity
multi-core
memory management


Interaction in asynchronous discussion forums: peer facilitation techniques Peer facilitation is proposed as a solution to counter limited interaction in asynchronous online discussions. However, there is a lack of empirical research on online peer facilitation. This study identifies, through cross-case comparison of two graduate-level blended courses attended by Asian Pacific students, the actual peer facilitation techniques that could encourage online interaction. Analyses of interviews and online discussion transcripts suggest that techniques such as showing appreciation and considering others' viewpoints encourage online interaction. However, instructors intending to incorporate peer-facilitated online discussions should also consider the influence of factors such as the design of the online discussion activity and learners' cultural background as some participants could consider challenging others' ideas culturally inappropriate and need to be encouraged through techniques such as general invitation to contribute. Facilitators might also re-consider the use of certain traditionally recommended strategies such as directing an online message at specific participants to encourage responses. This study suggests that doing so could sometimes backfire and discourage online contributions.

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

interaction
peer facilitation techniques

asynchronous online discussion forums
knowledge construction
participation
student facilitators


Soil-pipe interaction due to tunnelling: Assessment of Winkler modulus for underground pipelines One of the key problems in the implementation of Winkler models to analyze tunnelling effects on existing pipelines lies in the assessment of subgrade modulus under external soil displacement. In this paper, an expression of the Winkler subgrade modulus for a pipeline buried at arbitrary depth and subjected to free soil displacement with arbitrary curve shape is given. Using superposition principle and the Fourier integral, the subgrade modulus of an infinite beam resting on the surface of an elastic half space and buried infinitely are obtained respectively. Then the influence of embedment depth is estimated based on Mindlin and Kelvin solution. The validity of the proposed subgrade modulus is verified by comparison with the results from an elastic continuum solution and two centrifuge model tests for the responses of buried pipeline due to nearby tunnelling. Thereafter, parametric studies are shown to assess the accuracy of the proposed subgrade modulus by comparing with an elastic continuum solution in homogeneous and non-homogeneous soil stratum and the amount of error is estimated. (c) 2012 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 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

tunnel excavation
underground pipeline
soil movement


Generalized Jeffreys rule of conditioning and evidence combining rule for a priori probabilistic knowledge in conditional evidence theory In Bayesian probabilistic approach for uncertain reasoning, one basic assumption is that a priori knowledge about the uncertain variable is modeled by a probability distribution. When new evidence representable by a constant set is available, the Bayesian conditioning is used to update a priori knowledge. In the conventional D-S evidence theory, all bodies of evidence about the uncertain variable are imprecise and uncertain. All bodies of evidence are combined by so-called Dempsters rule of combination to achieve a combined body of evidence without considering a priori knowledge. From our point of view, when identifying the true value of an uncertain variable, Bayesian approach and evidence theory can cooperate to deal with uncertain reasoning. Firstly all imprecise and uncertain bodies of evidence about the uncertain variable are fused to achieve a combined evidence based on a priori knowledge, then the a posteriori probability distribution is achieved from a priori probability distribution by conditioning on the combined evidence. In this paper we firstly deal with the knowledge updating problem where a priori knowledge is represented by a probability distribution and new evidence is represented by a random set. Then we review the conditional evidence theory which resolves the knowledge combining problem based on a priori probabilistic knowledge. Finally we discuss the close relationship between knowledge updating procedure and knowledge combining procedure presented in this paper. We show that a posteriori probability conditioned on fused body of evidence satisfies the Bayesian parallel combination rule.

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

random set
knowledge updating
knowledge combining
generalized jeffreys rule
bayesian parallel combination rule
conditional evidence theory

conditioned combination rule
target identification


Many-to-One Throughput Capacity of IEEE 802.11 Multihop Wireless Networks This paper investigates the many-to-one throughput capacity (and by symmetry, one-to-many throughput capacity) of IEEE 802.11 multihop networks, in which many sources send data to a sink. An example of a practical scenario is that of a multihop mesh network connecting source and relay nodes to an Internet gateway. In the trivial case where all source nodes are just one hop from the sink, the system throughput can approach L(s), where L(s) is the throughput capacity of an isolated link consisting of just one transmitter and one receiver. In the nontrivial case where some source nodes are more than one hop away, one can still achieve a system throughput of L(s) by sacrificing and starving the non-one-hop source nodes-however, this degenerates to an unacceptable trivial solution. We could approach the problem by the following partitioning: preallocate some link capacity aL(s) (0 <= a <= 1) at the sink to the one-hop source nodes and then determine the throughput for the source nodes that are two or more hops away based on the remaining capacity L = (1 - a)L(s). The throughput of the one-hop nodes will be around aL(s). This paper investigates the extent to which the remaining capacity L can be used efficiently by the source traffic that is two or more hops away. We find that for such source traffic, a throughput of L is not achievable under 802.11. We introduce the notion of "canonical networks," a general class of regularly structured networks that allow us to investigate the system throughput by varying the distances between nodes and other operating parameters. When all links have equal length, we show that 2L/3 is the upper bound for general networks, including random topologies and canonical networks. When the links are allowed to have different lengths, we show that the throughput capacity of canonical networks has an analytical upper bound of 3L/4. The tightness of the bound is confirmed by simulations of 802.11 canonical networks, in which we obtain simulated throughputs of 0.74L when the source nodes are two hops away and 0.69L when the source nodes are many hops away. We conjecture that 3L/4 is also the upper bound for general networks. Our simulations show that 802.11 networks with random topologies operated with AODV routing typically achieve throughputs far below 3L/4. Fortunately, by properly selecting routes near the gateway (or by properly positioning the relay nodes leading to the gateway) to fashion after the structure of canonical networks, the throughput can be improved by more than 150 percent: indeed, in a dense network, deactivating some of the relay nodes near the sink can lead to a higher throughput.

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

wireless mesh networks
many-to-one
one-to-many
data-gathering networks
802.11
wi-fi


An examination of how a cross-section of academics use computer technology when writing academic papers A cross-section of 361 faculty, graduate and undergraduate students completed a survey that assessed computer availability, experience, attitudes toward computers, and use of computers while engaged in academic writing. Overall, computers served as a tool for all participants, however, undergraduates in the math and computer science areas were more comfortable with computers than others. Experience with computers increased with academic level, suggesting that academics currently use, and have been using, computers throughout their careers. Generally, there were few differences as a function of discipline or gender. Participants indicated different reasons for using computers during the process of writing academic papers relative to written/hard copies. Their responses indicate that these two formats may facilitate the writing process in unique ways. Rather than viewing continued use of hard copy as a transitional period to more extensive computer use, it may be that hard copy offers cognitive supports that may not be available in computer writing software. (C) 2002 Elsevier Science Ltd. All rights reserved.

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

post-secondary education
adult learning
teaching/learning strategies
media in education


Computer attitude scales: How relevant today? Since the increase in the use of computers as learning tools, there have been many scales developed that can measure various aspects of computer attitude. The aim of this study is to examine the relevance of a number of these scales and determine whether they are still appropriate for use today. Four computer attitude scales, which are used widely, are assessed. It was found that the scales are reliable. However, the degree of predictive validity for each scale varied and the various underlying constructs appear to reflect different aspects of attitude. In addition, these constructs had changed since the original creation of the scales. This suggests that the traditional style of computer attitude scale is no longer as relevant as when first developed, and judicious selection and care need to be exercised over their use and the interpretation of findings.

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


a framework for the performance analysis of concurrent b-tree algorithms Many concurrent B-tree algorithms have been proposed, but they have not yet been satisfactorily analyzed. When transaction processing systems require high levels of concurrency, a restrictive serialization technique on the B-tree index can cause a bottleneck. In this paper, we present a framework for constructing analytical performance models of concurrent B-tree algorithms. The models can predict the response time and maximum throughput. We analyze three algorithms: Naive Lock-coupling, Optimistic Descent, and the Lehman-Yao algorithm. The analyses are validated by simulations of the algorithms on actual B-trees. Simple and instructive rules of thumb for predicting performance are also derived. We apply the analyses to determine the effect of database recovery on B-tree concurrency.

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

framework
recovery
systems
performance
response time
concurrency
throughput
algorithm
paper
transaction
database
effect
rules
predict

tree
indexing
simulation
performance model
couples
process
trees
model
performance analysis
locking


Evaluating the performance of geographical locations within scientific networks using an aggregation-randomization-re-sampling approach (ARR) Knowledge creation and dissemination in science and technology systems are perceived as prerequisites for socioeconomic development. The efficiency of creating new knowledge is considered to have a geographical component, that is, some regions are more capable in terms of scientific knowledge production than others. This article presents a method of using a network representation of scientific interaction to assess the relative efficiency of regions with diverse boundaries in channeling knowledge through a science system. In a first step, a weighted aggregate of the betweenness centrality is produced from empirical data (aggregation). The subsequent randomization of this empirical network produces the necessary null model for significance testing and normalization (randomization). This step is repeated to provide greater confidence about the results (re-sampling). The results are robust estimates for the relative regional efficiency of brokering knowledge, which is discussed along with cross-sectional and longitudinal empirical examples. The network representation acts as a straightforward metaphor of conceptual ideas from economic geography and neighboring disciplines. However, the procedure is not limited to centrality measures, nor is it limited to geographical aggregates. Therefore, it offers a wide range of applications for scientometrics and beyond.

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


An incident information management framework based on data integration, data mining, and multi-criteria decision making An effective incident information management system needs to deal with several challenges. It must support heterogeneous distributed incident data, allow decision makers (DMs) to detect anomalies and extract useful knowledge, assist DMs in evaluating the risks and selecting an appropriate alternative during an incident, and provide differentiated services to satisfy the requirements of different incident management phases. To address these challenges, this paper proposes an incident information management framework that consists of three major components. The first component is a high-level data integration module in which heterogeneous data sources are integrated and presented in a uniform format. The second component is a data mining module that uses data mining methods to identify useful patterns and presents a process to provide differentiated services for pre-incident and post-incident information management. The third component is a multi-criteria decision-making (MCDM) module that utilizes MCDM methods to assess the current situation, find the satisfactory solutions, and take appropriate responses in a timely manner. To validate the proposed framework, this paper conducts a case study on agrometeorological disasters that occurred in China between 1997 and 2001. The case study demonstrates that the combination of data mining and MCDM methods can provide objective and comprehensive assessments of incident risks.

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

incident information management
data integration
data mining

multiple criteria decision making
decision support system


A butterfly effect: highly insecticidal resistance caused by only a conservative residue mutated of drosophila melanogaster acetylcholinesterase Acetylcholinesterase (AChE) and its mutation recently emerged as a significant research area, due to its resistance against organophosphate and carbamate insecticides. Residue G265, which is always a conservative residue, mutated to A265 is the most frequent mutant of AChE in Drosophila populations. However, only this mutation caused a 'butterfly effect' that gives high insecticidal resistance. Herein, the models of sensitive strain (Dm-S) and the resistance strain (Dm-R) were constructed, to give a total of 2000 ps molecular dynamics simulation and to reveal the insecticidal resistance mechanism, with implied, the active gorge of Dm-R was much less flexible than that of Dm-S. The "back door" channel was widened to accelerate the detoxication against insecticides by the conformation changing of W83 and I161. All the distances (S238-H480, S238-G150, S238-G151, Y71-M153) in Dm-R became smaller than those in Dm-S, which may deeply influence the binding between the insecticides and DmAChE.

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

dmache
insecticidal resistance
molecular dynamics


a high fidelity atm traffic and network simulator The design of an ATM traffic and network (ATM-TN) simulator which characterizes cell level network behavior is presented. The simulator incorporates three classes of ATM traffic source models: an aggregate ethernet model, an MPEG model and a World Wide Webb transactions model. Six classes of ATM switch architectures are modeled including output buffered, shared memory buffered and cross bar switch models, and then multistage switches which can be built from these three basic models. The ATM-TN simulator can be used to characterize arbitrary ATM networks with dynamic multimedia traffic loads. Call set up and tear down via ATM signaling is implemented in addition to the various types of cell traffic streams generated by voice, video and data. The simulator is built on a simple, efficient simulation language called SimKit which is capable of supporting both fast sequential and parallel execution. Parallel execution is supported using WarpKit, an optimistically synchronized kernel that is aimed at shared memory multiprocessor platforms such as the Silicon Graphics Powerchallenge and Sun Spare 1000 series machines. The paper outlines general requirements for ATM traffic and network simulation, presents an ATM-TN simulator architecture, describes its major components and discusses the major issues associated with cell level ATM modeling and simulation.

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

requirements
network
voice
video
simulation
signaling
design
general
graphics
paper
model
traffic
ethernet
shared memory
parallel
aggregate
behavior
architecture
dynamic
language
types
multimedia
data
switch

platform
efficiency
synchronization
association
network simulation
modeling and simulation
component
shared memory multiprocessors
transaction
class


Assessment of potential-based fluid finite elements for seismic analysis of dam-reservoir systems This paper assesses the use of a potential-based fluid finite element formulation to investigate earthquake excited dam-reservoir systems. The mathematical background of the analytical and numerical techniques is presented in a unified format. Frequency and time-domain analyses are conducted to validate the potential-based finite element formulation. A case study of a typical dam-reservoir system subjected to earthquake loading is presented. The dynamic response of the system is discussed to illustrate the effects of fluid-structure interaction and reservoir bottom absorption. The validated potential-based fluid elements and boundary conditions are shown to perform adequately for practical seismic analysis of dam-reservoir systems. (C) 2008 Elsevier Ltd. All rights reserved.

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

fluid-structure interaction
dam safety
earthquake engineering
frequency-domain response
time-domain response


An improved particle swarm optimization for exponential stabilization of a singular linear time-varying system This paper derives an optimization problem for exponential stabilization condition of a singular linear time-varying system governed by the second-order vector differential equations and proposes an improved particle swarm optimization (PSO) method, called the adaptive fuzzy PSO with a constriction factor (AFPSO-cf) algorithm, for solving the optimization problem of exponential stabilization. The proposed AFPSO-cf algorithm adaptively adjusts the accelerating coefficients of PSO by using the fuzzy set theory to improve global searching ability of controller parameters. Compared with the standard particle swarm optimization (SPSO), the PSO with a constriction factor (PSO-cf), the Quadratic Interpolation PSO (QIPSO), the unified PSO (UPSO), the fully informed particle swarm (FIPS) and the comprehensive learning PSO (CLPSO) algorithms, the experiment results show that the proposed method significantly performs better than those algorithms. (C) 2011 Elsevier Ltd. All rights reserved.

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

second-order singular system
time-varying system


Fast Insertion-Based Optimization of Bounding Volume Hierarchies We present an algorithm for fast optimization of bounding volume hierarchies (BVH) for efficient ray tracing. We perform selective updates of the hierarchy driven by the cost model derived from the surface area heuristic. In each step, the algorithm updates a fraction of the hierarchy nodes to minimize the overall hierarchy cost. The updates are realized by simple operations on the tree nodes: removal, search and insertion. Our method can quickly reduce the cost of the hierarchy constructed by the traditional techniques, such as the surface area heuristic. We evaluate the properties of the proposed method on fourteen test scenes of different complexity including individual objects and architectural scenes. The results show that our method can improve a BVH initially constructed with the surface area heuristic by up to 27% and a BVH constructed with the spatial median split by up to 88%.

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


mining frequent itemsets in time-varying data streams Mining frequent itemsets in data streams is beneficial to many real-world applications but is also a challenging task since data streams are unbounded and have high arrival rates. Moreover, the distribution of data streams can change over time, which makes the task of maintaining frequent itemsets even harder. In this paper, we propose a false-negative oriented algorithm, called TWIM, that can find most of the frequent itemsets, detect distribution changes, and update the mining results accordingly. Experimental results show that our algorithm performs as good as other false-negative algorithms on data streams without distribution change, and has the ability to detect changes over time-varying data streams in -time with a high accuracy rate.

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


Cumulative distribution function of a geometric Poisson distribution The geometric Poisson distribution (also called Plya-Aeppli) is a particular case of the compound Poisson distribution. We propose to express the general term of this distribution through a recurrence formula leading to a linear algorithm for the computation of its cumulative distribution function. Practical implementation with a special care for numerical computations is proposed and validated. The article ends with an example of application of these results for the computation of pattern statistics in biological sequences modelized by a Markov model.

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

polya-aeppli
confluent hypergeometric function
kummer


Cross-validation approximation in functional linear regression Cross-validation has been widely used in the context of statistical linear models and multivariate data analysis. Recently, technological advancements give possibility of collecting new types of data that are in the form of curves. Statistical procedures for analysing these data, which are of infinite dimension, have been provided by functional data analysis. In functional linear regression, using statistical smoothing, estimation of slope and intercept parameters is generally based on functional principal components analysis (FPCA), that allows for finite-dimensional analysis of the problem. The estimators of the slope and intercept parameters in this context, proposed by Hall and Hosseini-Nasab [On properties of functional principal components analysis, J. R. Stat. Soc. Ser. B: Stat. Methodol. 68 (2006), pp. 109-126], are based on FPCA, and depend on a smoothing parameter that can be chosen by cross-validation. The cross-validation criterion, given there, is time-consuming and hard to compute. In this work, we approximate this cross-validation criterion by such another criterion so that we can turn to a multivariate data analysis tool in some sense. Then, we evaluate its performance numerically. We also treat a real dataset, consisting of two variables; temperature and the amount of precipitation, and estimate the regression coefficients for the former variable in a model predicting the latter one.

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

cross-validation
eigenfunction
eigenvalue
stochastic expansion
65c60
68u20


Subjective Quality Evaluation via Paired Comparison: Application to Scalable Video Coding Scalable video coding is a powerful solution for content delivery in many interactive multimedia services due to its adaptability to varying terminal and network constraints. In order to successfully exploit such adaptability, it is necessary to understand users' preference among various scalability options and consequently develop an optimal bit rate adaptation strategy. In this paper, we present a study of subjective quality assessment of scalable video coding, which investigates the influence of the combination of scalability options on perceived quality with the goal of providing guidelines for an adaptive strategy that selects the optimal combination for a given bandwidth constraint. In particular, the study is based on paired comparison of stimuli that is suitable for our goal due to its simplicity and easiness. We propose a new method, called Paired Evaluation via Analysis of Reliability (PEAR), which analyzes paired comparison results and produces not only quality scores but also intuitive measures of confidence of the scores for significance analysis. Results and analysis of extensive subjective tests for two different scalable video codecs and high definition contents are described, from which general consistent conclusions are drawn. The video and subjective data used in the paper are publicly available to the research community.(1)

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

bradley-terry model
content distribution
multimedia quality assessment
subjective test


Comparison of semi-analytical and FEM solutions in a certain magnetic fluid dynamics problem Purpose - To provide a new semi-analytical procedure which is much faster than FEM and for this reason can be applied in a reconstruction of an interface between two conducting fluids (magnetic fluid dynamics problem) by means of magnetic field tomography. Design/methodology/approach - Three approaches are compared: a simple analytical solution (AS1), a modified semi-analytical solution (AS2), and the finite element method solution. The modified semi-analytical approach takes into account an information about azimuthal spatial harmonics received from the Fourier analysis of magnetic flux density distributions calculated by FEM. AS1 and AS2 have been compared for different modes of the interface using FEM solution as a reference. Findings - It is shown that for small perturbations the AS2 in every case provides smaller errors than AS1 although for some modes (14,24) the quality of the solution is still not satisfactory. Originality/value - This paper describes a new technique for the analysis of electromagnetic field which can be also applied in other problems.

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


Privacy protection in pervasive systems: State of the art and technical challenges Pervasive and mobile computing applications are dramatically increasing the amount of personal data released to service providers as well as to third parties. Data includes geographical and indoor positions of individuals, their movement patterns as well as sensor-acquired data that may reveal individuals physical conditions, habits, and, in general, information that may lead to undesired consequences like unsolicited advertisement or more serious ones like discrimination and stalking. In this survey paper, at first we consider representative classes of pervasive applications, and identify the requirements they impose in terms of privacy and trade-off with service quality. Then, we review the most prominent privacy preservation approaches, we discuss and summarize them in terms of the requirements. Finally, we take a more holistic view of the privacy problem by discussing other aspects that turn out to be crucial for the widespread adoption of privacy enhancing technologies. We discuss technical challenges like the need for tools augmenting the awareness of individuals and to capture their privacy preferences, as well as legal and economic challenges. Indeed, on one side privacy solutions must comply to ethical and legal requirements, and not prevent profitable business models, while on the other side it is unlikely that privacy preserving solutions will become practical and effective without new regulations.

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


Combination of partially non-distinct beliefs: The cautious-adaptive rule The combination rule is critical in an evidence based fusion process. The conjunctive rule is most common eventhough when the cognitive independence - distinctness - assumption is often questionable. A new combination rule is tested here in both discrete and continuous cases, accounting for a partial non-distinctness between evidences. It is based on 'generalized discounting', that we define for separable basic belief assignments (bbas) or basic belief densities (bbds), to be applied to the source correlation derived from the cautious rule. This correlation can be specified in both considered cases of consonant bbas/bbds (as proposed by Dubois et al.) and separable bbas/bbds (as proposed by Denceux). Then, the so-called 'cautious-adaptive' rule varies between the conjunctive rule and the cautious one, depending on the discounting level. In the Gaussian case with standard deviation a, the evidence non-distinctness will be parameterized by a factor Q is an element of [0, 1] dividing sigma. It leads to the generalized discounting needed in the cautious-adaptive formulation. (C) 2009 Elsevier Inc. All rights reserved.

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

evidence theory
separable belief
consonant belief


QoS management in educational digital library environments Advances in multimedia computing technologies offer new approaches to the support of computer-assisted education and training within many application domains. Novel interactive presentation tools can be built to enhance traditional teaching methods with more active learning. Since a variety of user expectations are possible in such an environment, research must address the incorporation of these factors into presentation tools. During an interactive learning/training process, presentation tools must be able to handle various types of delays. A flexibly adjustable quality of service (QoS) should thus be supported. In this paper, we investigate a framework and systematic strategies for supporting the continuous and synchronized retrieval and presentation of multimedia data streams in a client/server distributed multimedia environment for educational digital libraries. Specifically, we establish a practical framework for specifying multimedia objects, tasks, schedules, and synchronization constraints between media streams. We identify the QoS parameters critical to the support of multimedia presentations for learning and training activities. Based on the proposed framework and QoS specifications, we develop presentation scheduling and buffer management strategies which can enforce the specified QoS requirements in an educational digital library environment.

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

multimedia
synchronization
digital libraries


Towards a standard Arabic information processing vocabulary (Reprinted from Computer Standards and Interfaces, vol 7, pg 343-348, 1988) This paper is concerned with the development of a standard Arabic information processing vocabulary. It has been considered that the development of such a vocabulary does not only involve the translation of information processing terms into Arabic, but it also includes the provision of standard definitions for them. The paper establishes the necessary ground for the required plan by reviewing the special features of the information processing terms, and how they have been dealt with by various institutions and individuals, both internationally, and within the Arab world. The proposed plan consists of several tasks, and considers the necessity of obtaining pan-Arab recognition of the target vocabulary, and the importance of cooperation with international efforts. (C) 1999 Elsevier Science B.V. All rights reserved.

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

information processing
standards
vocabulary
terms
definitions


List version of L (d,s)-labelings Let G = (V, E) be a simple graph, and for all v is an element of V, let L(v) be a list of colors assigned to v. We shall assume throughout that the colors are natural numbers. For nonnegative integers d, s, define chi(d, s)(l) (G) to be the smallest integer k such that for every list assignment with vertical bar L(v)vertical bar = k for all v is an element of V one can choose a color c(v) is an element of L(v) for every vertex in such a way that vertical bar c(v) - c(w)vertical bar >= d for all vw is an element of E and vertical bar c(v) - c(w)vertical bar >= s for all pairs v, w of vertices having distance 2 in G. For a given list assignment such a coloring c is called an L(d, s)-list labeling. We prove a general bound for chi(d, s)(l)(G) depending on the maximum degree of G. Furthermore, we study this parameter for trees, and also for the particular classes of paths and stars. Polynomial algorithms are designed for deciding whether a given list assignment admits an L (d, s) -list labeling on paths (for a given s unrestricted) and on trees (for s = 1). (c) 2005 Elsevier B.V. All rights reserved.

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

channel assignment problem
l(d,s)-labeling
list coloring


Computing highly accurate or exact P P -values using importance sampling Especially for discrete data, standard first order P P -values can suffer from poor accuracy, even for quite large sample sizes. Moreover, different test statistics can give practically different results. There are several approaches to computing P P -values which do not suffer these defects, such as parametric bootstrap P P -values or the partially maximised P P -values ofBerger and Boos (1994). Both these methods require computing the exact tail probability of the approximate P P -value as a function of the nuisance parameter/s, known as the significance profile. For most practical problems, this is not computationally feasible. I develop an importance sampling approach to this problem. A major advantage is that significance can be simultaneously estimated at a grid of nuisance parameter values, without the need for smoothing away the simulation noise. The theory is fully developed for generalised linear models. The importance distribution is selected from the same generalised linear model family but with parameters biased towards an optimal point on the boundary of the tail-set. For logistic regression at least, standard guidelines for selecting the importance distribution can fail quite badly and a conceptually simple alternative algorithm for selecting these parameters is developed. This may have application to importance sampling more generally.

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


Understanding software project risk: a cluster analysis Understanding software project risk can help in reducing the incidence of failure. Building on prior work, software project risk was conceptualized along six dimensions. A questionnaire was built and 507 software project managers were surveyed. A cluster analysis was then performed to identify aspects of low, medium, and high risk projects. An examination of risk dimensions across the levels revealed that even low risk projects have a high level of complexity risk. For high risk projects, the risks associated with requirements, planning and control, and the organization become more obvious. The influence of project scope, sourcing practices, and strategic orientation on project risk dimensions was also examined. Results suggested that project scope affects all dimensions of risk, whereas sourcing practices and strategic orientation had a more limited impact. A conceptual model of project risk and performance was presented.

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

software project risk
cluster analysis
scope


Cepstrum derived from differentiated power spectrum for robust speech recognition ? In this paper, cepstral features derived from the differential power spectrum (DPS) are proposed for improving the robustness of a speech recognizer in presence of background noise. These robust features are computed from the speech signal of a given frame through the following four steps. First, the short-time power spectrum of speech signal is computed from the speech signal through the fast Fourier transform algorithm. Second, DPS is obtained by differentiating the power spectrum with respect to frequency. Third, the magnitude of DPS is projected from linear frequency to the mel scale and smoothed by a filter bank. Finally, the outputs of the filter bank are transformed to cepstral coefficients by the discrete cosine transform after a nonlinear transformation. It is shown that this new feature set can be decomposed as the superposition of the standard cepstrum and its nonlinearly liftered counterpart. While a linear lifter has no effect on the continuous density hidden Markov model based speech recognition, we show that the proposed feature set embedded with a nonlinear liftering transformation is quite effective for robust speech recognition. For this, we conduct a number of speech recognition experiments (including isolated word recognition, connected digits recognition, and large vocabulary continuous speech recognition) in various operating environments and compare the DPS features with the standard mel-frequency cepstral coefficient features used with cepstral mean normalization and spectral subtraction techniques.

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

robust speech recognition
hidden markov model
differential power spectrum
cepstral mean normalization
spectral subtraction


Lagrangian support vector regression via unconstrained convex minimization In this paper, a simple reformulation of the Lagrangian dual of the 2-norm support vector regression (SVR) is proposed as an unconstrained minimization problem. This formulation has the advantage that its objective function is strongly convex and further having only m m variables, where m m is the number of input data points. The proposed unconstrained Lagrangian SVR (ULSVR) is solvable by computing the zeros of its gradient. However, since its objective function contains the non-smooth plus function, two approaches are followed to solve the proposed optimization problem: (i) by introducing a smooth approximation, generate a slightly modified unconstrained minimization problem and solve it; (ii) solve the problem directly by applying generalized derivative. Computational results obtained on a number of synthetic and real-world benchmark datasets showing similar generalization performance with much faster learning speed in accordance with the conventional SVR and training time very close to least squares SVR clearly indicate the superiority of ULSVR solved by smooth and generalized derivative approaches.

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

smooth approximation
support vector regression
unconstrained convex minimization


On fair and optimal multi-source IP-multicast We investigate the problem of maximizing multicast throughput under a fairness constraint. Multiple server nodes wish to communicate to their intended set of client nodes over a shared network infrastructure. Our goal is to devise distributed algorithms to construct multicast sessions, one for each server node, such that (a) the network infrastructure is optimally utilized and (b) the network resources are fairly distributed between multicast sessions, i.e., no individual session claims more than a prescribed share of the network bandwidth resources. We are particularly interested in multi-tree multicast strategies in which every multicast session may contain many multicast trees. We show how the use of multiple trees increases network throughput and the load distribution in the network. We propose a class of round-robin algorithms that are based on successive selection of multicast trees for each multicast session, in a loosely cooperative, yet distributed fashion. Our best algorithm, the Cooperative Shortest Path Tree Packing (CSPTP) algorithm, performs well in a variety of scenarios, ranging from very sparse to dense applications. Through extensive simulations on random networks, we compare the performance of our algorithms with those commonly used in IP-multicast as well as theoretical upper bounds derived from network coding formulations. We show that the CSPTP can improve the throughput, and often achieves about 90% of the theoretical upper bound.

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

ip multicast
steiner tree packing
minimum weight trees
optimal throughput
resource distribution


Novel floating inductance and FDNR simulators employing CCII+s In this paper, a floating inductance and frequency-dependent negative resistance (FDNR) depending on the passive element selection is presented. The proposed circuit employs only plus-type second-generation current conveyors (CCII+s) as active elements, together with two resistors and two capacitors for realizing floating inductance and FDNR. Both of the capacitors in the floating inductance realization are grounded. Also, electronically tunable floating FDNR is obtained with the proposed circuit. The nonideality effects of the current conveyors on the proposed circuit are given. The proposed circuit is used in a low-pass ladder filter, and simulated with SPICE to exhibit its performance.

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


The effect of the mean particle size on the dynamic behaviour of catalyzed olefin polymerization fluidized bed reactors Recent developments in modelling gas-phase catalyzed olefin fluidized bed polymerization reactors are critically examined in order to quantify the effect of the mean particle size on the dynamic behaviour of the FBR A comprehensive population balance model is developed to investigate the effect of particle size distribution in gasphase fluidized bed olefin polymerization reactors. To assess the impact of mean particle size on the dynamic behaviour of an FBR, a new bubble-growth model is proposed. Simulation results show that model predictions are strongly influenced by the choice of the mean particle diameter, since its values dramatically affects the main fluidization parameters (e.g., solids terminal velocity, maximum stable bubble size, minimum fluidization velocity and the heat and mass transfer coefficients) in the bed. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.

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

fluidized bed reactor
population balances


DEA cross-efficiency evaluation based on Pareto improvement We propose a cross-efficiency evaluation approach based on Pareto improvement. Our approach generates Pareto-optimal cross efficiencies for the DMUs. Our approach has good power of improving the cross-efficiencies of the DMUs. The cross-efficiency of each DMU will be equal to its self-evaluated efficiency. The cross-efficiencies of all DMUs can be generated by only a common set of weights.

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

data envelopment analysis (dea)
cross-efficiency evaluation
pareto-optimal cross efficiencies


The Cuidado music browser: an end-to-end electronic music distribution system The IST project Cuidado, which ran from January 2001 to December 2003, produced the first entirely automatic chain for extracting and exploiting musical metadata for browsing music. The Sony CSL laboratory is primarily interested in the context of popular music browsing in large-scale catalogues. First, we are interested in human-centred issues related to browsing Popular Music. Popular here means that the music accessed to is widely distributed, and known to many listeners. Second, we consider popular browsing of music, i.e., making music accessible to non-specialists (music lovers), and allowing sharing of musical tastes and information within communities, departing from the usual, single user view of digital libraries. This research project covers all areas of the music-to-listener chain, from music descriptiondescriptor extraction from the music signal, or data mining techniquessimilarity based access and novel music retrieval methods such as automatic sequence generation, and user interface issues. This paper describes the scientific and technical issues at stake, and the results obtained.

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

similarity
cultural metadata
acoustic metadata
editorial metadata


Work Item Tagging: Communicating Concerns in Collaborative Software Development In collaborative software development projects, work items are used as a mechanism to coordinate tasks and track shared development work. In this paper, we explore how "tagging," a lightweight social computing mechanism, is used to communicate matters of concern in the management of development tasks. We present the results from two empirical studies over 36 and 12 months, respectively, on how tagging has been adopted and what role it plays in the development processes of several professional development projects with more than 1,000 developers in total. Our research shows that the tagging mechanism was eagerly adopted by the teams, and that it has become a significant part of many informal processes. Different kinds of tags are used by various stakeholders to categorize and organize work items. The tags are used to support finding of tasks, articulation work, and information exchange. Implicit and explicit mechanisms have evolved to manage the tag vocabulary. Our findings indicate that lightweight informal tool support, prevalent in the social computing domain, may play an important role in improving team-based software development practices.

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

tagging
software development
articulation work
work items


The optimal group consensus deviation measure for multiplicative preference relations Consistency and consensus measures are two important procedures employed in group decision making with multiplicative preference relations (MPRs). In this paper, we first establish the concept of individual consistency deviation degree between the original MPR and its optimal estimation. Then we develop a group consensus deviation degree optimization model (GCO Model) by minimizing the weighted arithmetic average of individual consistency deviation degrees. Our established theorems enlist the conditions for the existence of the optimal solution, the satisfactory solution, and non-inferior solution to the GCO Model. These results also provide an existence condition of redundant MPR in group decision making. Additionally, we show that the optimal value function of the GCO Model converges to 0, which implies that the consensus degree of DMs converges as the number of the decision makers increases indefinitely.

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

group decision making
group consensus
satisfactory solution


Robust Object Tracking with Online Multiple Instance Learning In this paper, we address the problem of tracking an object in a video given its location in the first frame and no other information. Recently, a class of tracking techniques called "tracking by detection" has been shown to give promising results at real-time speeds. These methods train a discriminative classifier in an online manner to separate the object from the background. This classifier bootstraps itself by using the current tracker state to extract positive and negative examples from the current frame. Slight inaccuracies in the tracker can therefore lead to incorrectly labeled training examples, which degrade the classifier and can cause drift. In this paper, we show that using Multiple Instance Learning (MIL) instead of traditional supervised learning avoids these problems and can therefore lead to a more robust tracker with fewer parameter tweaks. We propose a novel online MIL algorithm for object tracking that achieves superior results with real-time performance. We present thorough experimental results (both qualitative and quantitative) on a number of challenging video clips.

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 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


A numerical algorithm for the construction of efficient quadrature rules in two and higher dimensions We present a numerical algorithm for the construction of efficient, high-order quadratures in two and higher dimensions. Quadrature rules constructed via this algorithm possess positive weights and interior nodes, resembling the Gaussian quadratures in one dimension. In addition, rules can be generated with varying degrees of symmetry, adaptable to individual domains. We illustrate the performance of our method with numerical examples, and report quadrature rules for polynomials on triangles, squares, and cubes, up to degree 50. These formulae are near optimal in the number of nodes used, and many of them appear to be new.

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

multivariate integration
gaussian quadrature
triangle
square
cube
point elimination method
least squares newtons method


Robust modeling for multivariate calibration transfer by the successive projections algorithm The use of the Successive Projections Algorithm (VSPA) to select variables for building robust transferable Multiple Linear Regression (MLR) models is investigated. The robustness requirement is explicitly taken into account by introducing some spectra acquired by the slave instrument in the validation set that guides VSPA selection. The transfer samples are selected by the classic Kennard-Stone (KS) algorithm or a modified version of VSPA (SSPA) that operates across the rows of the instrumental response matrix, instead of the columns. The proposed approach was tested in two data sets, each set consisting of spectra obtained by infrared spectrometry in two different instruments. The first data set consists of gasoline spectra, which are employed to predict the distillation temperature at which 90% of the sample has evaporated (T 90%). The second data set consists of corn spectra, which are employed for moisture determination. The robust MLR models were compared to a PLS model employing Piecewise Direct Standardization (PDS) to correct the slave spectra. In both data sets, the mean prediction errors at the slave instrument for the robust VSPA-MLR and the PLS-PDS models were comparable, and slightly better for VSPA-MLR. The proposed approach appears to be a valid alternative to the commonly used PLS-PDS technique. (c) 2004 Elsevier B.V. All rights reserved.

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

multivariate calibration transfer
robust modeling
successive projections algorithm
piecewise direct standardization

ft-ir spectrometry
kennard-stone algorithm


A new subspace method for blind estimation of selective MIMO-STBC channels In this paper, a new technique for the blind estimation of frequency and/or time-selective multiple-input multiple-output (MIMO) channels under space-time block coding (STBC) transmissions is presented. The proposed method relies on a basis expansion model (BEM) of the MIMO channel, which reduces the number of parameters to be estimated, and includes many practical STBC-based transmission scenarios, such as STBC-orthogonal frequency division multiplexing (OFDM), space-frequency block coding (SFBC), time-reversal STBC, and time-varying STBC encoded systems. Inspired by the unconstrained blind maximum likelihood (UML) decoder, the proposed criterion is a subspace method that efficiently exploits all the information provided by the STBC structure, as well as by the reduced-rank representation of the MIMO channel. The method, which is independent of the specific signal constellation, is able to blindly recover the MIMO channel within a small number of available blocks at the receiver side. In fact, for some particular cases of interest such as orthogonal STBC-OFDM schemes, the proposed technique blindly identifies the channel using just one data block. The complexity of the proposed approach reduces to the solution of a generalized eigenvalue (GEV) problem and its computational cost is linear in the number of sub-channels. An identifiability analysis and some numerical examples illustrating the performance of the proposed algorithm are also provided. Copyright (C) 2009 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 O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

orthogonal frequency division multiplexing (ofdm)


Three-block bi-focal PLS (3BIF-PLS) and its application in QSAR When X and Y are multivariate, the two-block partial least squares (PLS) method is often used. In this paper, we outline an extension addressing a special case of the three-block (X/Y/Z) problem, where Z sits "under" Y. We have called this approach three-block bi-focal PLS (3BIF-PLS). It views the X/Y relationship as the dominant problem, and seeks to use the additional information in Z in order to improve the interpretation of the Y-part of the X/Y association. Two data sets are used to illustrate 3BIF-PLS. Example I relates to single point mutants of haloalkane dehalogenase from Sphingomonas paucimobilis UT26 and their ability to transform halogenated hydrocarbons, some of which are found as organic pollutants in soil. Example II deals with soil remediation capability of bacteria. Whole bacterial communities are monitored over time using "DNA-fingerprinting" technology to see how pollution affects population composition. Since the data sets are large, hierarchical multivariate modelling is invoked to compress data prior to 3BIF-PLS analysis. It is concluded that the 3BIF-PLS approach works well. The paper contains a discussion of pros and cons of the method, and hints at further developmental opportunities.

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

two-block pls
three-block pls
hierarchical modelling


Spikes that count: rethinking spikiness in neurally embedded systems Spiky neural networks are widely used in neural modeling, due to their biological relevance and high computational power. In this paper we investigate the usage of spiking dynamics in embedded artificial neural networks, that serve as a control mechanism for evolved autonomous agents performing a counting task. The synaptic weights and spiking dynamics are evolved using a genetic algorithm. We compare evolved spiky networks with evolved McCullochPitts networks, while confronting new questions about the nature of spikiness and its contribution to the neurocontroller's processing. We show that in a memory-dependent task, network solutions that incorporate spiking dynamics can be less complex and easier to evolve than networks involving McCullochPitts neurons. We identify and rigorously characterize two distinct properties of spiking dynamics in embedded agents: spikiness dynamic influence and spikiness functional contribution.

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

evolutionary computation
neurocontroller analysis


exploiting statistical correlations for proactive prediction of program behaviors This paper presents a finding and a technique on program behavior prediction. The finding is that surprisingly strong statistical correlations exist among the behaviors of different program components (e.g., loops) and among different types of program level behaviors (e.g., loop trip-counts versus data values). Furthermore, the correlations can be beneficially exploited: They help resolve the proactivity-adaptivity dilemma faced by existing program behavior predictions, making it possible to gain the strengths of both approaches--the large scope and earliness of offline-profiling--based predictions, and the cross-input adaptivity of runtime sampling-based predictions. The main technique contributed by this paper centers on a new concept, seminal behaviors. Enlightened by the existence of strong correlations among program behaviors, we propose a regression based framework to automatically identify a small set of behaviors that can lead to accurate prediction of other behaviors in a program. We call these seminal behaviors. By applying statistical learning techniques, the framework constructs predictive models that map from seminal behaviors to other behaviors, enabling proactive and cross-input adaptive prediction of program behaviors. The prediction helps a commercial compiler, the IBM XL C compiler, generate code that runs up to 45\% faster (5\%-13\% on average), demonstrating the large potential of correlation-based techniques for program optimizations.

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


VSPLIT: A Cross-Layer Architecture for V2I TCP Services Over 802.11 This article proposes VSPLIT, a new architecture based on TCP cross-layering and splitting techniques for optimizing the transport layer performance in vehicular networks for Internet-based Vehicle-to-Infrastructure (V2I) communications. Our architecture mainly pretends to enhance the performance of TCP handovers in 802.11 networks. VSPLIT includes a cross-layer TCP protocol, called VSPLIT-TCP, that adapts the congestion control during the handover, learning the new characteristics of the network after the handover using the mechanisms provided by the IEEE 802.21 Media Independent Handover (MIH) services. VSPLIT has been implemented and tested in the NS-3 simulator. We include the some of the most interesting performance evaluation results, which show a good performance of our proposal for the intended scenario.

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


Toward structural sparsity: an explicit \(\ell _{2}/\ell _0\) approach As powerful tools, machine learning and data mining techniques have been widely applied in various areas. However, in many real-world applications, besides establishing accurate black box predictors, we are also interested in white box mechanisms, such as discovering predictive patterns in data that enhance our understanding of underlying physical, biological and other natural processes. For these purposes, sparse representation and its variations have been one of the focuses. More recently, structural sparsity has attracted increasing attentions. In previous research, structural sparsity was often achieved by imposing convex but non-smooth norms such as \({\ell _{2}/\ell _{1}}\) and group \({\ell _{2}/\ell _{1}}\) norms. In this paper, we present the explicit \({\ell _2/\ell _0}\) and group \({\ell _2/\ell _0}\) norm to directly approach the structural sparsity. To tackle the problem of intractable \({\ell _2/\ell _0}\) optimizations, we develop a general Lipschitz auxiliary function that leads to simple iterative algorithms. In each iteration, optimal solution is achieved for the induced subproblem and a guarantee of convergence is provided. Furthermore, the local convergent rate is also theoretically bounded. We test our optimization techniques in the multitask feature learning problem. Experimental results suggest that our approaches outperform other approaches in both synthetic and real-world data sets.

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


ANALYSIS OF THE AVERAGE EXECUTION TIME FOR A SELF-STABILIZING LEADER ELECTION ALGORITHM This paper focuses on the self-stabilizing leader election algorithm of Xu and Srimani [10] that finds a leader in a tree graph. The worst case execution time for this algorithm is O(N(4)), where N is the number of nodes in the tree. We show that the average execution time for this algorithm, assuming two different scenarios, is much lower than O(N(4)). In the first scenario, the algorithm assumes an equiprobable daemon and it only privileges a single node at a time. The average execution time for this case is O(N(2)). For the second case, the algorithm can privilege multiple nodes at a time. We eliminate the daemon from this algorithm by making random choices to avoid interference between neighboring nodes. The execution time for this case is O(N). We also show that for specific tree graphs, these results reduce even more.

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

average execution time analysis
self-stabilization


An optimal QoS-based Web service selection scheme Quality-of-service (QoS) in Web services encompasses various non-functional issues such as performance, dependability and security, etc. As more and more Web services become available, QoS capability is becoming a decisive factor to distinguishing services. This study proposes an efficient service selection scheme to help service requesters select services by considering two different contexts: single QoS-based service discovery and QoS-based optimization of service composition. Based on QoS measurement metrics, this study proposes multiple criteria decision making and integer programming approaches to select the optimal service. Experimental results show that the scheme is not only efficient, but also works well for complicated scenarios.

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


A Majorize-Minimize Subspace Approach for l(2)-l(0) Image Regularization In this work, we consider a class of differentiable criteria for sparse image computing problems, where a nonconvex regularization is applied to an arbitrary linear transform of the target image. As special cases, it includes edge-preserving measures or frame-analysis potentials commonly used in image processing. As shown by our asymptotic results, the l(2) - l(0) penalties we consider may be employed to provide approximate solutions to l(0) penalized optimization problems. One of the advantages of the proposed approach is that it allows us to derive an efficient majorize-minimize subspace algorithm. The convergence of the algorithm is investigated by using recent results in nonconvex optimization. The fast convergence properties of the proposed optimization method are illustrated through image processing examples. In particular, its effectiveness is demonstrated on several data recovery problems.

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truncated quadratic function
edge preservation
sparse representations
majorize-minimize algorithms
inverse problems
denoising
deblurring
reconstruction
kurdyka-lojasiewicz inequality


efficient longest executable path search for programs with complex flows and pipeline effects Current development tools for embedded real-time systems do not efficiently support the timing aspect. The most important timing parameter for scheduling and system analysis is the Worst-Case Execution Time (WCET) of a program.This paper presents a fast and effective WCET calculation method that takes account of low-level machine aspects like pipelining and caches, and high-level program flow like loops and infeasible paths. The method is more efficient than previous path-based approaches, and can easily handle complex programs. By separating the low-level from the high-level analysis, the method is easy to retarget.Experiments confirm that speed does not sacrifice precision, and that programs with extreme numbers of potential execution paths can be analyzed quickly.

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

embedded systems
pipeline timing
hard real-time


On the efficiency of semi-implicit and semi-Lagrangian spectral methods for the calculation of incompressible flows Classical semi-implicit backward Euler/Adams-Baskforth time discretizations of the Navier-Stokes equations induce, for high-Reynolds number flows, severe restrictions on the time step. Such restrictions can be relaxed by using semi-lagrangian schemes essentially based on splitting the full problem into an explicit transport step and an implicit diffusion step. In comparison with the standard characteristics method, the semi-lagrangian method has the advantage of being much less CPU time consuming where spectral methods are concerned. This paper is devoted to the comparison of the 'semi-implicit' and 'semi-Lagrangian' approaches, in terms of stability, accuracy and computational efficiency. Numerical results on the advection equation, Burger's equation and finally two- and three-dimensional Navier-Stokes equations, using spectral elements or a collocation method, are provided. Copyright (C) 2001 John Wiley & Sons, Ltd.

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

high-reynolds number flows
navier-stokes equations
semi-lagrangian methods


Absolute and specific measures of research group excellence A desirable goal of scientific management is to introduce, if it exists, a simple and reliable way to measure the scientific excellence of publicly funded research institutions and universities to serve as a basis for their ranking and financing. While citation-based indicators and metrics are easily accessible, they are far from being universally accepted as way to automate or inform evaluation processes or to replace evaluations based on peer review. Here we consider absolute measurements of research excellence at an amalgamated, institutional level and specific measures of research excellence as performance per head. Using biology research institutions in the UK as a test case, we examine the correlations between peer review-based and citation-based measures of research excellence on these two scales. We find that citation-based indicators are very highly correlated with peer-evaluated measures of group strength, but are poorly correlated with group quality. Thus, and almost paradoxically, our analysis indicates that citation counts could possibly form a basis for deciding on, how to fund research institutions, but they should not be used as a basis for ranking them in terms of quality.

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scientometrics
scientific evaluation
higher education


DIPS: an efficient pointer swizzling strategy for incremental uncaching environments Pointer swizzling improves the performance of OODBMSs by reducing the number of table lookups. However, the object replacement incurs the unswizzling overhead. In this paper, we propose a new pointer swizzling strategy, the dynamic indirect pointer swizzling (DIPS). DIPS dynamically applies pointer swizzling techniques in order to reduce the overhead of unswizzling. DIPS uses the temporal locality information which is gathered by the object buffer manager. The information is used to select the object to whose pointers the pointer swizzling techniques are applied and to dynamically bind the pointer swizzling techniques using the virtual function mechanism. We show the efficiency of the proposed strategy through experiments over various object buffer sizes and workloads.

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databases
persistent objects
smart pointers


power allocation associated with optimal cooperation level determination for half-duplex coded cooperative systems In this paper, we have developed two power allocation strategies in a half-duplex coded cooperative scheme under the transmit rate and the total power constraints, respectively. We further analyzed the effect of cooperation level and determined the optimal cooperation level based on these power allocation strategies.

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 B I O

coded cooperation
half-duplex
optimization of cooperation level


An ROBDD-Based Combinatorial Method for the Evaluation of Yield of Defect-Tolerant Systems-on-Chip In this paper, we develop a combinatorial method for the evaluation of the functional yield of defect-tolerant systems-on-chip (SoC). The method assumes that random manufacturing defects are produced according to a model in which defects cause the failure of given components of the system following a distribution common to all defects. The distribution of the number of defects is arbitrary. The yield is obtained by conditioning on the number of defects that result in the failure of some component and performing recursive computations over a reduced ordered binary decision diagram (ROBDD) representation of the fault-tree function of the system. The method has excellent error control. Numerical experiments seem to indicate that the method is efficient and, with some exceptions, allows the analysis with affordable computational resources of systems with very large numbers of components.

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combinatorial method
manufacturing defects
yield

reduced ordered binary decision diagram (robdd)