Analysis and design of mobile Wireless Social Model Delay Tolerant Networks (DTNs) are characterized by very long delay paths and frequent network partitions, Most existing protocols are based oil simplistic models which differ from real scenarios or real traces which do not allow for sensitivity analysis. In this paper, we analyze the differences between the Social Network (SN) and the Wireless Social Network (W-SN) in terms of the clustering coefficient. characteristic path length, Community size, and membership number. We observe that the clustering coefficient, Community Size and Membership number in the W-SN are bigger than those in the SN, while the character path length in W-SN becomes smaller. And then we propose a new Wireless Social Model (WSM) based Oil Community character. Node in WSM is driven by the alpha-Model and has an equal probability to move to one of his adjacent vertices. We evaluate our model via real traces supplied by Dartmouth College, which shows that our wireless social mobile model offers a good approximation of real movements. (C) 2008 Elsevier B.V. All rights reserved.

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


Computing the null space of finite element problems We present a method for computing the null space of finite element models, including models with equality constraints. The method is purely algebraic; it requires access to the element matrices, but not to the geometry or material properties of the model. Theoretical considerations show that under certain conditions, both the amount of computation and the amount of memory required by our method scale linearly with model size; memory scales linearly but computation scales quadratically with the dimension of the null space. Our experiments confirm this: the method scales extremely well on 3-dimensional model problems. In general, large industrial models do not satisfy all the conditions that the theoretical results assume; however, experimentally the method performs well and outperforms an established method on industrial models, including models with many equality constraints. The accuracy of the computed null vectors is acceptable, but the method is usually less accurate than a more naive (and computationally much more expensive) method.

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

rigid-body motions
linear constraints
singular linear systems
fretsaw preconditioner


Finding the M-best consistent correspondences between 3D symmetric objects ? This paper proposes a novel algorithm that resolves the underlying ambiguity in shape correspondences between symmetric objects. Due to the equivocal nature of symmetry, each part of a symmetric object may have two or more correspondence candidates in another symmetric object, which may induce local inconsistencies in the correspondence of parts or global ambiguities in shape matching. As an effective approach for resolving these symmetric ambiguities, we find multiple probable solutions for consistent shape correspondences between two 3D symmetric objects and let the user select one of them for an application-specific purpose. We formulate the problem of 3D symmetric object correspondences with a Markov Random Field (MRF) and iteratively search multiple solutions by excluding previously found solutions using Linear Programming (LP). The consistency of each solution is provided by four-point correspondences as high-order measurements in our MRF network, with each node corresponding to a point pair and each edge corresponding to a pair of point pairs. By leveraging the properties of the symmetry structure of the 3D object, we further reduce the complexity of our MRF network while efficiently handling high-order measurements. Finally, we evaluate the proposed algorithm using real-world symmetric object datasets.

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 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

surface correspondences
m-best matchings


Measurement of PTHrP, PTHR1, and CaSR Expression Levels in Tissues of Sea Bream (Sparus aurata) Using Quantitative PCR Abstract: A quantitative PCR (Q-PCR) method has been established to measure the mRNA expression levels of parathyroid hormone-related protein (PTHrP), parathyroid hormone receptor type 1 (PTHR1), and calcium-sensing receptor (CaSR) in sea bream (Sparus aurata), using the housekeeping gene, ?-actin, as endogenous control. TaqMan primers and probes were designed using the Primer Express program, according to the published/unpublished sequences of the three target genes and ?-actin of sea bream. Different tissues including gill, kidney, duodenum, hindgut, rectum, liver, heart, brain, pituitary, skin, muscle, and gonad were removed and immediately snap-frozen from three juvenile sea bream (100-150 g) cultured in sea water. The mRNAs were extracted and reverse-transcribed into cDNAs, which were subsequently examined by the ABI 5700 system using an optimized Q-PCR method. Triplicate measures of each sample indicated consistency of the technique. However, the mRNA expression levels for each transcript in these tissues were variable between fish and also relatively low. Nevertheless, this methodology can be used in the future studies of factors that may alter gene expression in these tissues.

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


Studies on the impact of capacitor bank switching on grid connected transformers Switching events in power system generate transients. These transients have unfavorable impact on grid connected EHV transformers due to their complex oscillatory wave shapes embodying wide spectrum of frequencies. One or more of these frequency components can often excite the natural resonant frequencies of the transformer windings while travelling through transformers and may result severe internal voltage amplification and development of abnormal voltage stresses on the transformer insulation. While designing insulation for grid connected EHV transformers, adequate considerations must therefore be given to the voltage stresses which are likely to develop on the insulation during such occurrences of oscillatory transient overvoltages. In this paper, the authors have analyzed the stresses developed in the windings of a 400/220/33kV grid connected transformer operating in the National Power Grid of India by model based studies when natural frequencies of the windings are triggered by oscillatory transient overvoltages originated from deliberate switching of static capacitor banks at substation.

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

emtp
ehv transformer
natural frequency
resonance
voltage stress


Application of a Failure Driven Test Profile in Random Testing Random testing techniques have been extensively used in reliability assessment, as well as in debug testing. When used to assess software reliability, random testing selects test cases based on an operational profile; while in the context of debug testing, random testing often uses a uniform distribution. However, generally neither an operational profile nor a uniform distribution is chosen from the perspective of maximizing the effectiveness of failure detection. Adaptive random testing has been proposed to enhance the failure detection capability of random testing by evenly spreading test cases over the whole input domain. In this paper, we propose a new test profile, which is different from both the uniform distribution, and operational profiles. The aim of the new test profile is to maximize the effectiveness of failure detection. We integrate this new test profile with some existing adaptive random testing algorithms, and develop a family of new random testing algorithms. These new algorithms not only distribute test cases more evenly, but also have better failure detection capabilities than the corresponding original adaptive random testing algorithms. As a consequence, they perform better than the pure random testing.

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

adaptive random testing
operational profile
random testing
test profile
uniform distribution


Residual resources aware distributed admission control mechanism in mobile multi-hop network Without considering current residual resources of the medium, nodes in mobile ad hoc networks (MANETs) admit the data flow arbitrarily, and the quality of service (QoS) of the data flows deteriorates. To release the contending on the resources induced by the overloaded flows, the admission control mechanism can effectively keep the balance between injected data flows and network capacity, and it is viewed as the most important technology in MANET. A novel distributed residual resources aware admission control mechanism is proposed in this paper, where the residual resources and the service rate are studied thoroughly. Considering the medium utilization, frame retransmission and backoff procedure, the passive method is applied to predict the residual resources, and the binomial distribution is utilized to model the medium status; moreover, based on the cooperation between the source node and intermediate nodes, the path meeting the resource demand is probed across the network, and the flows are rejected while the residual resources cannot meet its demand. Results show that the network load can be constrained by our proposed admission control mechanism, and the QoS of the data flows can be guaranteed effectively.

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


A unified approach to detecting spatial outliers Spatial outliers represent locations which are significantly different from their neighborhoods even though they may not be significantly different from the entire population. Identification of spatial outliers can lead to the discovery of unexpected, interesting, and implicit knowledge, such as local instability. In this paper, we first provide a general definition of S-outhers for spatial outliers. This definition subsumes the traditional definitions of spatial outliers. Second, we characterize the computation structure of spatial outlier detection methods and present scalable algorithms. Third, we provide a cost model of the proposed algorithms. Finally, we experimentally evaluate our algorithms using a Minneapolis-St. Paul (Twin Cities) traffic data set.

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

scalable algorithm for outlier detection


A unified approach towards reconstruction of a planar point set The algorithm works for boundary samples as well as dot patterns. Theoretical guarantee has been provided. Extensive experimentation shows that this approach works well.

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

delaunay triangulation
dot pattern
boundary sample


Optimizing queries with expensive video predicates in cloud?environment With the rapid developments in video processing technologies, video data have increased rapidly and become popular in our daily life for both professional and consumer applications such as surveillance, education and entertainment. Because of the increasing processing workload, more and more queries with expensive video predicates are being implemented in a parallel environment for better performance. Such requirements entail that the data management system not only be able to store and access video content, but also be able to optimize queries that have expensive video predicates in an effective and efficient way in a cloud environment. In previous research literatures, parallel and distributed policies and query optimizations in relational database management systems are often based on the disk input/output (I/O) cost of involved operations and network transmission cost. However, for a query that contains expensive video predicates in a cloud environment, the traditional cost estimation model does not work well. Although researchers have proposed some approaches that can solve the problem in certain situations, there are still some unresolved issues, and these approaches need further optimizations. This paper is motivated by a real-world large supermarket business data and video surveillance data management scenario in a parallel environment. By considering the characteristics of video data and their expensive processing, we present methods named operating results buffer and operating results buffer-C for implementing expensive video predicates at simple node, mapping video data and executing expensive video predicates in a cloud environment, which reduce the cost of video data transmission and the invoking times of expensive video predicates. We propose a novel query optimization approach that reconstructs the join order-based estimation for attribute cardinality and computes the total cost with I/O, network and expensive processing. This approach reduces the invoking times of expensive video predicates to a greater degree and gives a better solution for mixed query optimization, which contains traditional data types and large object operations in a cloud environment. Our query performance improves by 30% to 80% compared with existing expensive predicates query optimization methods. Copyright (c) 2011 John Wiley & Sons, Ltd.

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

expensive video predicates
attribute cardinality


He's variational iteration method for treating nonlinear singular boundary value problems This paper applies He's variational iteration method for solving nonlinear singular boundary value problems. The solution process is illustrated and various physically relevant results are obtained. Comparison of the obtained results with exact solutions shows that the method used is an effective and highly promising method for treating various classes of both linear and nonlinear singular boundary value problems. (C) 2010 Elsevier Ltd. All rights reserved.

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


Population-based continuous optimization, probabilistic modelling and mean shift Evolutionary algorithms perform optimization using a population of sample solution points. An interesting development has been to view population-based optimization as the process of evolving an explicit, probabilistic model of the search space. This paper investigates a formal basis for continuous, population-based optimization in terms of a stochastic gradient descent on the Kullback-Leibler divergence between the model probability density and the objective function, represented as an unknown density of assumed form. This leads to an update rule that is related and compared with previous theoretical work, a continuous version of the population-based incremental learning algorithm, and the generalized mean shift clustering framework. Experimental results are presented that demonstrate the dynamics of the new algorithm on a set of simple test problems.

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

probabilistic modelling
mean shift
continuous optimization

estimation of distribution algorithms
population-based incremental learning


An efficient vector finite element method for nonlinear electromagnetic modeling We have developed a mixed Vector Finite Element Method (VFEM) for Maxwells equations with a nonlinear polarization term. The method allows for discretization of complicated geometries with arbitrary order representations of the B and E fields. In this paper we will describe the method and a series of optimizations that significantly reduce the computational cost. Additionally, a series of test simulations will be presented to validate the method. Finally, a nonlinear waveguide mode mixing example is presented and discussed.

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

maxwells equations
finite element method
simulations


A Stochastic Model for Quantitative Security Analyses of Networked Systems Traditional security analyses are often geared toward cryptographic primitives or protocols. Although such analyses are necessary, they cannot address a defender's need for insight into which aspects of a networked system having a significant impact on its security, and how to tune its configurations or parameters so as to improve security. This question is known to be notoriously difficult to answer, and the state of the art is that we know little about it. Toward ultimately addressing this question, this paper presents a stochastic model for quantifying security of networked systems. The resulting model captures two aspects of a networked system: 1) the strength of deployed security mechanisms such as intrusion detection systems and 2) the underlying vulnerability graph, which reflects how attacks may proceed. The resulting model brings the following insights: 1) How should a defender "tune" system configurations (e.g., network topology) so as to improve security? 2) How should a defender "tune" system parameters (e. g., by upgrading which security mechanisms) so as to improve security? 3) Under what conditions is the steady-state number of compromised entities of interest below a given threshold with a high probability? Simulation studies are conducted to confirm the analytic results, and to show the tightness of the bounds of certain important metric that cannot be resolved analytically.

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

security modeling
quantitative security analysis
security metric


Adaptive appearance based face recognition In this paper, we present an adaptive appearance based face recognition framework that combines the efficiency of global approaches and the robustness of local approaches together. The framework uses a novel eye locator to select an appropriate scheme for appearance based recognition. The eye locator first locates eye candidates via a new strength assignment, determined by the dissimilarity between the local appearance of an image point and the appearance of its neighboring points. Then the eye locator applies a simple but flexible model (half-circle snake) to the local context of the eye candidates in order to either refine the location of an eye candidate or discard non-eye candidates. We show the performance of our framework by testing on challenging face datasets containing extreme expressions, severe occlusions, and varied lighting conditions.

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


Perfect present, perfect gift: finding a place for archival consciousness in social theory In 1924, Canadian Dominion Archivist Arthur Doughty (18601936) characterized archives as the gift of one generation to another. This essay takes these words seriously. It sets aside the common habit of thinking of archival work in terms of keeping and preserving and experiments withre-imaginesarchives as a form of gift giving. However, as a growing body of scholarship across numerous disciplines is discovering, gift giving is a complex social act. Thus, construing archives as a form of gift opens up new avenues of critical inquiry into archives unique temporal consciousness and its importance to accounts of the establishment and unmaking of any social order. This article explores the nature of archival consciousness and its place in social theory.

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


A PetrovGalerkin method for solving the generalized regularized long wave (GRLW) equation The generalized regularized long wave (GRLW) equation is solved numerically by the PetrovGalerkin method which uses a linear hat function as the trial function and a quintic B B -spline function as the test function. Product approximation has been used in this method. A linear stability analysis of the scheme shows it to be conditionally stable. Test problems including the single soliton and the interaction of solitons are used to validate the suggested method, which is found to be accurate and efficient. Finally, the Maxwellian initial condition pulse is studied.

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

petrovgalerkin
product approximation
solitons

quintic b b -spline b b b b b
solitary waves


Super efficiencies or super inefficiencies? Insights from a joint computation model for slacks-based measures in DEA The slacks-based measure (SBM) can incorporate input and output slacks that would otherwise be neglected in the classical DEA model. In parallel, the super-efficiency model for SBM (S-SBM) has been developed for the purpose of ranking SBM efficient decision-making units (DMUs). When implementing SBM in conjunction with S-SBM, however, several issues can arise. First, unlike the standard super-efficiency model, S-SBM can only solve for super-efficiency scores but not SBM scores. Second, the S-SBM model may result in weakly efficient reference points. Third, the S-SBM and SBM scores for certain DMUs may be discontinuous with a perturbation to their inputs and outputs, making it hard to interpret and justify the scores in applications and the efficiency scores may be sensitive to small changes/errors in data. Due to this discontinuity, the S-SBM model may overestimate the super-efficiency score. This paper extends the existing SBM approaches and develops a joint model (J-SBM) that addresses the above issues; namely, the J-SBM model can (1) simultaneously compute SBM scores for inefficient DMUs and super-efficiency for efficient DMUs, (2) guarantee the reference points generated by the joint model are Pareto-efficient, and (3) the J-SBM scores of a firm are continuous in the input and output space. Interestingly, the radial DEA efficiency and super-efficiency scores for a DMU are continuous in the inputoutput space. The J-SBM model combines the merits of the radial and SBM models (i.e., continuity and Pareto-efficiency).

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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
slacks-based measure
super-efficiency
pareto-efficiency


efficient type inference for secure information flow This paper describes the design, analysis, and implementation of an efficient algorithm for information flow analysis expressed using a type system. Given a program and an environment of security classes for information accessed by the program, the algorithm checks whether the program is well typed, i.e., there is no information of higher security classes flowing into places of lower security classes according to a lattice of security classes, by inferring the highest or lowest security class as appropriate for each program node. We express the analysis as a set of Datalog-like rules based on the typing and subtyping rules, and we use a systematic method to generate specialized algorithms and data structures directly from the Datalog-like rules. The generated implementation traverses the program multiple times and uses a combination of linked and indexed data structures to represent program nodes, environments, and types. The time complexity of the algorithm is linear in the size of the input program, times the height of the lattice of security classes, plus a small overhead for preprocessing the security classes. This complexity is confirmed through our prototype implementation and experimental evaluation on code generated from high-level specifications for real systems.

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

algorithm
information flow
security
time complexity
type inference


Cell-centered finite volume methods with flexible stencils for diffusion equations on general nonconforming meshes ? A cell-centered finite volume method is presented for discretizing diffusion operator on general nonconforming meshes. The node values are accurately approximated using a new weighted interpolation formula, in which the calculation of the weight is adaptive to both geometric parameters and diffusion coefficients. It follows that an explicit expression, composed of cell-centered unknowns only, is obtained for the discretization of normal flux. Numerical results demonstrate that linear solutions are reproduced exactly on the nonconforming random grids, and that the convergence rate is close to second order for non-linear or discontinuous problems.

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

finite volume method
diffusion equations
nonconforming meshes


O-means: An Optimized Clustering Method for Analyzing Spam Based Attacks In recent years, the number of spam emails has been dramatically increasing and spam is recognized as a serious internet threat. Most recent spam emails are being sent by hots which often operate with others in the form of a botnet, and skillful spammers try to conceal their activities from spam analyzers and spam detection technology. In addition, most spam messages contain URLs that lure spam receivers to malicious Web servers for the purpose of carrying out various cyber attacks such as malware infection, phishing attacks, etc. In order to cope with spam based attacks, there have been many efforts made towards the clustering of spam emails based on similarities between them. The spam clusters obtained from the clustering of spam emails can be used to identify the infrastructure of spam sending systems and malicious Web servers, and how they are grouped and correlate with each other, and to minimize the time needed for analyzing Web pages. Therefore, it is very important to improve the accuracy of the spam clustering as much as possible so as to analyze spam based attacks more accurately. In this paper, we present an optimized spam clustering method, called O-means, based on the K-means clustering method, which is one of the most widely used clustering methods. By examining three weeks of spam gathered in our SMTP server, we observed that the accuracy of the O-means clustering method is about 87% which is superior to the previous clustering methods. In addition, we define 12 statistical features to compare similarity between spam emails, and we determined a set of optimized features which makes the O-means clustering method more effective.

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


ViennaX: a parallel plugin execution framework for scientific computing We present the free open source plugin execution framework ViennaX for modularizing and parallelizing scientific simulations. In general, functionality is abstracted by the notion of a task, which is implemented as a plugin. The plugin system facilitates the utilization of both, already available functionality as well as new implementations. Each task can define arbitrary data dependencies which are used by ViennaX to build a task graph. The framework supports the execution of this dependence graph based on the message passing interface in either a serial or a parallel fashion. The applied modular approach allows for defining highly flexible simulations, as plugins can be easily exchanged. The frameworks general design as well as implementation details are discussed. Applications based on the Mandelbrot set and the solution of a partial differential equation are investigated, and performance results are shown.

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

parallel execution
plugin system software reuse


the jabberwocky programming environment for structured social computing We present Jabberwocky, a social computing stack that consists of three components: a human and machine resource management system called Dormouse, a parallel programming framework for human and machine computation called ManReduce, and a high-level programming language on top of ManReduce called Dog. Dormouse is designed to enable cross-platform programming languages for social computation, so, for example, programs written for Mechanical Turk can also run on other crowdsourcing platforms. Dormouse also enables a programmer to easily combine crowdsourcing platforms or create new ones. Further, machines and people are both first-class citizens in Dormouse, allowing for natural parallelization and control flows for a broad range of data-intensive applications. And finally and importantly, Dormouse includes notions of real identity, heterogeneity, and social structure. We show that the unique properties of Dormouse enable elegant programming models for complex and useful problems, and we propose two such frameworks. ManReduce is a framework for combining human and machine computation into an intuitive parallel data flow that goes beyond existing frameworks in several important ways, such as enabling functions on arbitrary communication graphs between human and machine clusters. And Dog is a high-level procedural language written on top of ManReduce that focuses on expressivity and reuse. We explore two applications written in Dog: bootstrapping product recommendations without purchase data, and expert labeling of medical images.

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


PLANMINE: Predicting plan failures using sequence mining This paper presents the PLANMINE sequence mining algorithm to extract patterns of events that predict failures in databases: of plan executions. New techniques were needed because previous data mining algorithms were overwhelmed by the staggering number of very frequent, but entirely unpredictive patterns that exist in the plan database. This paper combines several techniques fur pruning out unpredictive and redundant patterns which reduce the size of the returned rule set by more than three orders of magnitude. PLANMINE has also been fully integrated into two real-world planning systems. We experimentally evaluate the rules discovered by PLANMINE, and show that they are extremely useful for understanding and improving plans, as well as for building monitors that raise alarms before failures happen.

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


Border-collision bifurcations in a dynamic management game Managerial systems often involve piecewise-linear relations associated with non-negativity conditions or other forms of restrictions to the decision variables. The bifurcations that take place in such systems differ qualitatively from the bifurcations that one can observe in smooth dynamical systems. The present paper provides an analysis of the bifurcation structure of the so-called BEER game, a dynamic management game developed at the Sloan School of Management to illustrate how the structure of a system determines its behavior. We show how the BEER model displays abrupt period-doubling bifurcations, truncated bifurcation cascades, and a variety of the so-called border-collision bifurcations. Particular emphasis is paid to the resonance structure observed in one- and two-sector versions of the model.

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

border-collision
chaos
production-distribution chain


On the sorting-complexity of suffix tree construction The suffix tree of a string is the fundamental data structure of combinatorial pattern matching. We present a recursive technique for building suffix trees that yields optimal algorithms in different computational models. Sorting is an inherent bottleneck in building suffix trees and our algorithms match the sorting lower bound. Specifically, we present the following results. (1) Weiner [1973], who introduced the data structure, gave an optimal O(n)-time algorithm for building the suffix tree of an n-character string drawn from a constant-size alphabet. In the comparison model, there is a trivial n(n log n)-time lower bound based on sorting, and Weiner's algorithm matches this bound. For integer alphabets, the fastest known algorithm is the O(n log n) time comparison-based algorithm, but no super-linear lower bound is known. Closing this gap is the main open question in stringology. We settle this open problem by giving a linear time reduction to sorting for building suffix trees. Since sorting is a lower-bound for building suffix trees, this algorithm is time-optimal in every alphabet model, in particular, for an alphabet consisting of integers in a polynomial range we get the first known linear-time algorithm. (2) All previously known algorithms for building suffix trees exhibit a marked absence of locality of reference, and thus they tend to elicit many page faults (I/Os) when indexing very long strings. They are therefore unsuitable for building suffix trees in secondary storage devices, where I/Os dominate the overall computational cost. We give a linear-I/O reduction to sorting for suffix tree construction. Since sorting is a trivial I/O-lower bound for building suffix trees, our algorithm is I/O-optimal.

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

design
theory
dam model
external-memory data structures
ram model
sorting complexity
suffix array


On dimensionality of embedding space in multidimensional scaling Multidimensional scaling is a technique for exploratory analysis of multidimensional data widely usable in different applications. By means of this technique the image points in a low-dimensional embedding space can be found whose inter-point distances fit the given dissimilarities between the considered objects. In this paper dependence of relative visualization error on the dimensionality of embedding space is investigated. Both artificial and practical data sets have been used. The images in three-dimensional embedding space normally show the structural properties of sets of considered objects with acceptable accuracy, and widening of applications of stereo screens makes three-dimensional visualization very attractive.

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

global optimization
city-block distances


A logical characterization of forward and backward chaining in the inverse method The inverse method is a generalization of resolution that can be applied to non-classical logics. We have recently shown how Andreoli's focusing strategy can be adapted for the inverse method in linear logic. In this paper we introduce the notion of focusing bias for atoms and show that it gives rise to forward and backward chaining, generalizing both hyperresolution (forward) and SLD resolution (backward) on the Horn fragment. A key feature of our characterization is the structural, rather than purely operational, explanation for forward and backward chaining. A search procedure like the inverse method is thus able to perform both operations as appropriate, even simultaneously. We also present experimental results and an evaluation of the practical benefits of biased atoms for a number of examples from different problem domains.

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

inverse method
focusing
sld resolution
hyperresolution


Guest editor's introduction: Agentization and coordination Firstly, some novel understanding about agents and multi-agent systems, in particular, agentization and coordination, is presented to build a consensus. Afterwards, a brief overview is given of the papers that are included in this special issue.

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


Web-based quiz-game-like formative assessment: Development and evaluation This research aims to develop a multiple-choice Web-based quiz-game-like formative assessment system, named GAM-WATA. The unique design of 'Ask-Hint Strategy' turns the Web-based formative assessment into an online quiz game. 'Ask-Hint Strategy' is composed of 'Prune Strategy' and 'Call-in Strategy'. 'Prune Strategy' removes one incorrect option and turns the original 4-option item into a 3-option one. 'Call-in Strategy' provides the rate at which other test takers choose each option when answering a question. This research also compares the effectiveness of three different types of formative assessment in an e-Learning environment: paper-and-pencil test (PPT), normal Web-based test (N-WBT) and GAM-WATA. In total, 165 fifth grade elementary students (from six classes) in central Taiwan participated in this research. The six classes of students were then divided into three groups and each group was randomly assigned one type of formative assessment. Overall results indicate that different types of formative assessment have significant impacts on e-Learning effectiveness and that the e-Learning effectiveness of the students in the GAM-WATA group appears to be better. Students in the GAM-WATA group more actively participate in Web-based formative assessment to do self-assessment than students in the N-WBT group. The effectiveness of formative assessment will not be significantly improved only by replacing the paper-and-pencil test with Web-based test. The strategies included in GAM-WATA are recommended to be taken into consideration when researchers design Web-based formative assessment systems in the future. (c) 2007 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 B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

e-learning
gam-wata
web-based formative assessment
wata system


Two-stage salient region detection by exploiting multiple priors We propose a two-stage salient region detection method by exploiting multiple priors. The image-feature-based saliency map is obtained by combining the isolation and distribution measure. We incorporate into the image-feature-based saliency map a location prior map to emphasize the foci of attention. Experimental results indicate the effectiveness and robustness of our method.

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

location prior
multiple priors
salient region

superpixel isolation
superpxiel distribution
two-stage
image-feature-based
precision/recall rate


Human exposure during operation of GMAW-P welding machines Purpose - The purpose of this paper is to investigate the exposure of human workers to low and high frequency electromagnetic fields during operation of GMAW-P welding machines. Design/methodology/approach - First, a numerical parametric analysis of the current waveform has been performed in Matlab, with reference to the human exposure; then a simulation model of a full welding system has been implemented in Simulink/Matlab. The effect has been numerically quantified accordingly to European Standards EN 50444 and EN 50445. Findings - Contributions to human exposure of specific parts of the current waveform have been evaluated. A new numerical implementation of a full welding system has been done. Practical implications - The paper shows that there could possibly be improvement in the design of current waveforms, with respect to a reduced human exposure of workers to electromagnetic fields. Originality/value - The paper presents a new numerical tool that can be useful since the design phase of a welding system for the evaluation of human exposure of workers to electromagnetic fields.

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

electromagnetic fields
human exposure
current waveform

gas metal arc-welding
gmaw-p welding machine
converter scheme


Vorticitydivergence mass-conserving semi-Lagrangian shallow-water model using the reduced grid on the sphere The semi-Lagrangian semi-implicit shallow water model on the sphere using the reduced latitudelongitude grid is presented. The key feature of the model is the vorticitydivergence formulation on the unstaggered grid. The new algorithm for the reconstruction of wind components from vorticity and divergence is described. The mass-conservative version of the model is developed. The conservative cascade scheme (CCS) by Nair et al. is modified to provide a locally-conservative semi-Lagrangian advection algorithm for the reduced grid. Some numerical advection tests are carried out to demonstrate the accuracy of the CCS with the reduced grid. The CCS-based discretization for the continuity equation and finite-volume Helmholtz problem solver are introduced to guarantee the mass-conservation. The results for shallow water tests on the sphere are presented. The results for different versions of the model are compared. They are also compared with the results for the same tests available in literature. The impact of the reduced grid is analyzed. The mass-conservative version of the model using the reduced grid with up to 20% reduction of grid points number has approximately the same accuracy as its non-conservative counterpart implemented on the regular latitudelongitude grid.

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


On the Way to Large-Scale and High-Resolution Brain-Chip Interfacing Brain-chip-interfaces (BCHIs) are hybrid entities where chips and nerve cells establish a close physical interaction allowing the transfer of information in one or both directions. Typical examples are represented by multi-site-recording chips interfaced to cultured neurons, cultured/acute brain slices, or implanted in vivo. This paper provides an overview on recent achievements in our laboratory in the field of BCHIs leading to enhancement of signals transmission from nerve cells to chip or from chip to nerve cells with an emphasis on in vivo interfacing, either in terms of signal-to-noise ratio or of spatiotemporal resolution. Oxide-insulated chips featuring large-scale and high-resolution arrays of stimulation and recording elements are presented as a promising technology for high spatiotemporal resolution interfacing, as recently demonstrated by recordings obtained from hippocampal slices and brain cortex in implanted animals. Finally, we report on an automated tool for processing and analysis of acquired signals by BCHIs.

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

electrolyte-oxide-semiconductor field effect transistors


Implantation Defects in Infertile Women with Endometriosis The endometrium undergoes characteristic histologic changes during the menstrual cycle as it prepares for embryo implantation. Historic and current data suggest the presence of a defined period of maximal uterine receptivity during the mid-secretory phase occurring between days 7 and 10 postovulation. In recent years, we and others have sought to define biochemical markers of receptivity that might be used to better understand this time of endometrial differentiation. Based on the work with cell adhesion molecules, we have discovered three different integrins that are only coexpressed during this time in the cycle when embryos will successfully implant. By studying the regulation of one of these, the ?v?3 integrin, and its extracellular matrix ligand, osteopontin (OPN), we have defined two separate regulatory pathways that may regulate endometrial receptivity. While ?v?3 expression appears to be stimulated by EGF or heparin-binding EGF, osteopontin is stimulated by progesterone. We now believe the former pathway is a paracrine-mediated signal, while the latter is a direct effect of progesterone on the estrogen-primed endometrial epithelium. In women with endometriosis, it appears that ?v?3 expression is reduced, while OPN expression is unaffected. Interestingly, binding of OPN to the surface epithelium appears quite limited when ?v?3 expression is lacking. Such evidence continues to reinforce the notion that endometrium from some women with endometriosis is dysfunctional and may account for the reduction in cycle fecundity noted in this group of patients.

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

integrins endometrium implantation osteopontin


augmenting human memory using personal lifelogs Memory is a key human facility to support life activities, including social interactions, life management and problem solving. Unfortunately, our memory is not perfect. Normal individuals will have occasional memory problems which can be frustrating, while those with memory impairments can often experience a greatly reduced quality of life. Augmenting memory has the potential to make normal individuals more effective, and those with significant memory problems to have a higher general quality of life. Current technologies are now making it possible to automatically capture and store daily life experiences over an extended period, potentially even over a lifetime. This type of data collection, often referred to as a personal life log (PLL), can include data such as continuously captured pictures or videos from a first person perspective, scanned copies of archival material such as books, electronic documents read or created, and emails and SMS messages sent and received, along with context data of time of capture and access and location via GPS sensors. PLLs offer the potential for memory augmentation. Existing work on PLLs has focused on the technologies of data capture and retrieval, but little work has been done to explore how these captured data and retrieval techniques can be applied to actual use by normal people in supporting their memory. In this paper, we explore the needs for augmenting human memory from normal people based on the psychology literature on mechanisms about memory problems, and discuss the possible functions that PLLs can provide to support these memory augmentation needs. Based on this, we also suggest guidelines for data for capture, retrieval needs and computer-based interface design. Finally we introduce our work-in-process prototype PLL search system in the iCLIPS project to give an example of augmenting human memory with PLLs and computer based interfaces.

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

personal information archives
context-aware retrieval
augmented human memory


Communication patterns during synchronous Web-based military training in problem solving The nature of communication among geographically dispersed groups of learners using text messaging in a military training environment was assessed. A total of 6601 acts of chat were coded into one of three interaction content categories (social, task, or technology-related) and analyzed for frequency and relative change over time. Results indicated shifting patterns of interaction over the 6-month course; while technology concerns gradually diminished, on task discussion peaked in the middle months and social interactions were higher at the start and end of the training. Overall, student chats were categorized as on-task 55%, social 30%, or technology-related 15%. Examples of chats and focus group data indicated that there was an emphasis on fostering student problem solving within the online course.

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

dispersed groups
military
problem solving

computer supported collaborative learning


An ultrawideband SPST switch using defected ground structure low pass filter in 65-nm CMOS technology In this article, we propose a novel concept of applying a defected ground structure low pass filter (DGS LPF) to the design of switches. We highlight that the DGS structure has such advantages as consuming less silicon area and providing another degree of design freedom to optimize the switch performances. To prove the concept, we analyze, design, and characterize a single-pole single-throw (SPST) switch using a DGS LPF in 65-nm CMOS technology. We show that the DGS LPF SPST switch with active size of 125 88 m2 can cover an ultrawideband from DC to 77 GHz. 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:758768, 2015.

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

millimeter-wave integrated circuit
rf switch
hfss


Minimizing False Positives of a Decision Tree Classifier for Intrusion Detection on the Internet Machine learning or data mining technologies are often used in network intrusion detection systems. An intrusion detection system based on machine learning utilizes a classifier to infer the current state from the observed traffic attributes. The problem with learning-based intrusion detection is that it leads to false positives and so incurs unnecessary additional operation costs. This paper investigates a method to decrease the false positives generated by an intrusion detection system that employs a decision tree as its classifier. The paper first points out that the information-gain criterion used in previous studies to select the attributes in the tree-constructing algorithm is not effective in achieving low false positive rates. Instead of the information-gain criterion, this paper proposes a new function that evaluates the goodness of an attribute by considering the significance of error types. The proposed function can successfully choose an attribute that suppresses false positives from the given attribute set and the effectiveness of using it is confirmed experimentally. This paper also examines the more trivial leaf rewriting approach to benchmark the proposed method. The comparison shows that the proposed attribute evaluation function yields better solutions than the leaf rewriting approach.

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

internet
intrusion detection
data mining
machine learning
decision tree


On Generalization Performance and Non-Convex Optimization of Extended nu-Support Vector Machine The nu-support vector classification (nu-SVC) algorithm was shown to work well and provide intuitive interpretations, e.g., the parameter nu roughly specifies the fraction of support vectors. Although nu corresponds to a fraction, it cannot take the entire range between 0 and 1 in its original form. This problem was settled by a non-convex extension of nu-SVC and the extended method was experimentally shown to generalize better than original nu-SVC. However, its good generalization performance and convergence properties of the optimization algorithm have not been studied yet. In this paper, we provide new theoretical insights into these issues and propose a novel nu-SVC algorithm that has guaranteed generalization performance and convergence properties.

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

support vector machine
conditional value-at-risk
e nu-svc
generalization error bound
global optimization


Mobile mapping technology of wind velocity data along highway for traffic safety evaluation Traffic safety of highway vehicles under strong crosswind gust and other hazardous driving conditions has become a pressing issue for modern highway transportation and economy. It is known that the actual wind environment at the typical height of a moving vehicle varies considerably from one segment to another even on the same highway, because of influence of the specific terrain and surroundings. Therefore, accurate crosswind velocity data in both time and spatial domains are needed, for a rational assessment of traffic safety risks for various moving vehicles on highways in windy conditions. In addition to site-specific wind data which can be used for most vehicles, vehicle-specific crosswind velocity is often required for an accurate safety assessment of high-sided vehicles with unique shapes. A mobile mapping technology aiming at collecting site-specific as well as vehicle-specific wind velocity data for traffic safety evaluations was developed. Such technology integrates a 3D sonic anemometer and geospatial video mapping system, mounted on a vehicle driven along highways at a normal (cruising) speed. As a result, both vehicle-specific and general site-specific crosswind velocity can be directly sensed and collected by using a high-sided vehicle or a streamlined car as the test vehicle. A field test of the developed technology with a high-sided truck driven on mountainous sections of the interstate I-70 (in Colorado) was conducted. The crosswind data at six selected feature locations along I-70, representing different roadside environments, was analyzed. Wind-tunnel investigations employing the scaled models of the truck used in the field test as well as a common streamlined sedan car were conducted to evaluate the accuracy and the feasibility of the developed technology.

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


Achieving distributed user access control in sensor networks User access control in sensor networks defines a process of granting user an access right to the stored information. It is essential for future real sensor network deployment in which sensors may provide users with different services in terms of data and resource accesses. A centralized access control mechanism requires the base station to be involved whenever a user requests to get authenticated and access the information stored in the sensor node, which is inefficient, not scalable, and is exposed to many potential attacks along long communication paths. In this paper, we propose a distributed user access control under a realistic adversary model in which sensors can be compromised and user may collude. We split the access control into local authentication conducted by a group of sensors physically close to a user, and a light remote authentication based on the endorsement of the local sensors. We implement the access control protocols on a testbed of TelosB motes. Our analysis and experimental results show that our schemes are feasible for real access control requirements.

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

public key cryptography
elliptic curve cryptography


effective thread management on network processors with compiler analysis Mapping packet processing tasks on network processor micro-engines involves complex tradeoffs that relating to maximizing parallelism and pipelining. Due to an increase in the size of the code store and complexity of the application requirements, network processors are being programmed with heterogeneous threads that may execute code belonging to different tasks on a given micro-engine. Also, most network applications are streaming applications that are typically processed in a pipelined fashion. Thus, the tasks on different micro-engines are pipelined in such a way as to maximize the throughput. Tasks themselves could have different run time performance demands. Traditionally, runtime management involving processor sharing, real-time scheduling etc. is provided by the runtime environment (typically an operating system) using the hardware support for timers and interrupts that allows time slicing the resource amongst the tasks. However, due to stringent performance requirements on network processors (which process packets from very high speed network traffic), neither OS nor hardware mechanisms are typically feasible/available.In this paper, we show that it is very difficult and inefficient for the programmer to meet the constraints of runtime management by coding them statically. Due to the infeasibility of hardware or OS solution (even in the near future), the only choice left is a compiler approach.We propose a complete compiler solution to automatically insert explicit context switch (ctx) instructions provided on the processors so that the execution of programs is better manipulated at runtime to meet their constraints. We show that such an approach is feasible opening new application domains that would need heterogeneous thread programming. Such approaches would in general become important for multi-core processors.

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

cpu scheduling
real-time scheduling
compiler optimizations


Integrated Route Selection, Transponder Placement, Wavelength Assignment, and Restoration in an Advanced ROADM Architecture New reconfigurable optical add-drop (ROADM) architectures based on rapidly tunable transponders and wavelength selective switches are being actively studied in the Defense Advanced Research Projects Agency (DARPA) core optical networks project and elsewhere. They are making new optical network architectures possible, and could change optical network cost structures. This paper focuses on two principal issues arising from these new designs: (i) What should be the relationships between the routing, wavelength assignment, transponder placement, and restoration planning functions for these networks? (ii) How should the new cost structures affect their design? We show for a representative large core network employing shared mesh restoration to offer dynamic wavelength services that integrating these functions and dealing with trade-offs between them using a cost-based methodology can significantly reduce total network cost when compared with non-integrated methods or methods that focus on optimizing specific physical metrics such as wavelength mileage or regenerator counts.

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

optical networks
restoration
roadm
routing
transponder placement
wavelength assignment


A Memetic Algorithm for staff scheduling problem in airport security service The staff scheduling problem is widely studied in Operational Research. Various surveys are available in the literature dealing with this problem which concerns various objectives and various constraints. In this article, we present a staff scheduling problem in airport security service. First, a modeling of the problem, and a representation of solutions are shown. The problem is solved in three steps, days-off scheduling, shift scheduling, and staff assignment. We focus on the last step, by providing a Memetic Algorithm (MA) which merged an Evolutionary Algorithm and Local Search techniques. We propose a chromosome encoding, a crossover operator and a combined neighborhood function, specially dedicated to this staff assignment problem. Besides providing better solutions than software currently used, this algorithm provides up to 50% of improvement from initial feasible solutions. (C) 2013 Elsevier Ltd. All rights reserved.

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


Efficient breadth first search on multi-GPU systems Simple distributed BFS algorithms lead load unbalance among threads. Communication among tasks quickly becomes an issue. We propose a novel technique for mapping threads to data. We perform a pruning operation on the set of edges exchanged at each BFS level. Our implementation can efficiently traverse graphs with billions of nodes.

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

gpu
cuda
distributed algorithm
large graphs
graph 500 benchmark


Molecular Motors Involved in Chromaffin Cell Secretion Neurosecretory cells, including chromaffin cells, possess a mesh of filamentous actin underneath the plasma membrane. It has been proposed that filamentous actin network separates the secretory vesicles into two compartments

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

myosin v
myosin ii
cytoskeleton
exocytosis
f-actin


Runtime support for scalable programming in Java The paper research is concerned with enabling parallel, high-performance computation-in particular development of scientific software in the network-aware programming language, Java. Traditionally, this kind of computing was done in Fortran. Arguably, Fortran is becoming a marginalized language, with limited economic incentive for vendors to produce modern development environments, optimizing compilers for new hardware, or other kinds of associated software expected of by today's programmers. Hence, Java looks like a very promising alternative for the future. The paper will discuss in detail a particular environment called HPJava. HPJava is the environment for parallel programming-especially data-parallel scientific programming-in Java. Our HPJava is based around a small set of language extensions designed to support parallel computation with distributed arrays, plus a set of communication libraries. A high-level communication API, Adlib, is developed as an application level communication library suitable for our HPJava. This communication library supports collective operations on distributed arrays. We include Java Object as one of the Adlib communication data types. So we fully support communication of intrinsic Java types, including primitive types, and Java object types.

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


first workshop on targeting and ranking for online advertising Online advertising is a rapidly growing, multi-billion dollar industry. It has become a significant element of the Web browsing experience. Online advertising providers use sophisticated ad targeting and ranking algorithms with the dual aim of maximizing revenue while providing a superior user experience. As a result, advertising optimization is a very complex research problem, since it combines relevance with user interaction models, advertiser valuations, and commercial constraints. Online advertising integrates a number of core research areas: machine learning, data mining, search, auction theory, and user modeling. This workshop is intended to serve as an open forum for discussion of new ideas and current research in the field of online advertising. We expect that the workshop will promote a community of researchers interested in this area and yield future collaboration and exchanges. The research included should address problems faced by advertisers, end-users, advertising platforms, and the market.

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


Radar and vision data fusion for hybrid adaptive cruise control on highways A system for hybrid adaptive cruise control (HACC) on high-speed roads designed as a combination of a radar-based ACC and visual perception is presented. The system is conceived to run on different performance levels depending on the actual perception capabilities. The advantages of a combination of the two different types of sensors are discussed in comparison to the shortcomings of each single sensor. A description of the visual lane detection and tracking procedure is given, followed by an overview of the vehicle detection, hypothesis generation, and tracking procedure. Enhanced robustness is achieved by cooperative estimation of egomotion and the dynamics of other vehicles using the lane-coordinate system as a common reference. Afterwards, the assignment of vehicles to lanes and the determination of the relevant vehicle for the longitudinal controller is described.

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

dynamic machine vision
road recognition
vehicle recognition


Egypts digital activism and the Dictators Dilemma: An evaluation In recent years academics have used the term Dictators Dilemma to describe the impact of the Internet on undemocratic societies. The Dilemma says that if dictatorial rulers permit increased Internet penetration, they risk overthrow; if they do not, they isolate themselves from the global information economy, causing economic decline. Since Internet penetration world-wide has deepened, the Dilemma implies that dictatorships are bound to fall one by one. But how good is the Dilemma as an analytical device? Not very, this essay argues, using the Egyptian uprising of January 2011 as a case study. By examining the states Internet politics before 2011, the use of the Internet by Egyptian resistance activists, and the power relations that existed after the overthrow of the Dictator, this essay argues that the Dictators Dilemma blinds scholars to what really happens on the ground.

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

social media
egypt
sixth of april youth movement
we are all khalid said
authoritarianism
arab spring


theoretical frameworks for knowledge sharing in a community of practice The aim of this study is to develop an understanding of the factors influencing participants' knowledge-sharing in communities of practice. As the need to create and manage knowledge becomes increasingly more important to organizations, understanding the factors of knowledge sharing behaviors is paramount to success. Prior studies indicate that knowledge sharing takes place at the organizational and the individual level and that the factors that influence knowledge sharing are derived from the theories of social capital and social exchange. Subsequently, this study includes an overview of four theoretical frameworks derived from the theories of social capital and social exchange with the aim of developing an integrative conceptual framework for knowledge sharing.

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


Explicit solutions for the steady state distributions in M/PH/1 queues with workload dependent balking We consider an M/PH/1 queue with balking based on the workload. An arriving customer joins the queue and stays until served only if the system workload is below a fixed level at the time of arrival. The steady state workload distribution in such a system satisfies an integral equation. We derive a differential equation for Phase type service time distribution and we solve it explicitly, with Erlang, Hyper-exponential and Exponential distributions as special cases. We illustrate the results with numerical examples.

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

m/ph/1 queue
workload process
level crossing arguments
call centers


Short-term scheduling of cascade reservoirs using an immune algorithm-based particle swarm optimization This paper presents a new approach for short-term hydropower scheduling of reservoirs using an immune algorithm-based particle swarm optimization (IA-PSO). IA-PSO is employed by coupling the immune information processing mechanism with the particle swarm optimization algorithm in order to achieve a better global solution with less computational effort. With the IA-PSO technique, the hydro-electrical optimization model of reservoirs is formulated as a high-dimensional, dynamic, nonlinear and stochastic global optimization problem of a multi-reservoir hydropower system. The purpose of the proposed methodology is to maximize total hydropower production. Here it is applied to a reservoir system on the Qingjiang River, in the Yangtze watershed, that consists of two reservoirs. The results are compared with the results obtained through conventional operation method, the dynamic programming and the standard PSO algorithm. From the comparative results, it is found that the IA-PSO approach provides the most globally optimum solution at a faster convergence speed.

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


Space complexity vs. query complexity Combinatorial property testing deals with the following relaxation of decision problems: Given a fixed property and an input x, one wants to decide whether x satisfies the property or is "far" from satisfying it. The main focus of property testing is in identifying large families of properties that can be tested with a certain number of queries to the input. In this paper we study the relation between the space complexity of a language and its query complexity. Our main result is that for any space complexity s(n) <= log n there is a language with space complexity O(s(n)) and query complexity 2(Omega(s(n))). Our result has implications with respect to testing languages accepted by certain restricted machines. Alon et al. [FOCS 1999] have shown that any regular language is testable with a constant number of queries. It is well known that any language in space o(log log n) is regular, thus implying that such languages can be so tested. It was previously known that there are languages in space 0(logn) that are not testable with a constant number of queries and Newman [FOCS 2000] raised the question of closing the exponential gap between these two results. A special case of our main result resolves this problem as it implies that there is a language in space 0(log log n) that is not testable with a constant number of queries. It was also previously known that the class of testable properties cannot be extended to all context-free languages. We further show that one cannot even extend the family of testable languages to the class of languages accepted by single counter machines.

O B 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 B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O B O O O O O O O O B O O O O O O O O O O B O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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 Branch-and-Bound procedure to minimize total tardiness on one machine with arbitrary release dates ? In this paper, we present a Branch-and-Bound procedure to minimize total tardiness on one machine with arbitrary release dates. We introduce new lower bounds and we generalize some well-known dominance properties. Our procedure handles instances as large as 500 jobs although some 60 jobs instances remain open. Computational results show that the proposed approach outperforms the best known procedures.

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


Multi-carrier platform for wireless communications. Part 1: High-performance, high-throughput TDMA and DS-CDMA via multi-carrier implementations Multi-carrier technologies in general, and OFDM and MC-CDMA in particular, are quickly becoming an integral part of the wireless landscape. In this first of a two-part survey, the authors present the innovative transmit/receive multi-carrier implementation of TDMA and DS-CDMA systems. Specifically, at the transmit side, the pulse shape (in TDMA) and the chip shape (in DS-CDMA) corresponds to a linear combining of in-phase harmonics (called a CI signal). At the receiver side, traditional time-domain processing (equalization in TDMA and RAKE reception in DS-CDMA) is replaced by innovative frequency based processing. Here, receivers decompose pulse (or chip) shapes into carrier subcomponents and recombine these in a manner achieving both high frequency diversity gain and low MAI. The resulting system outperforms traditional TDMA and DS-CDMA systems by 1014 dB at typical BERs, and, by application of pseudo-orthogonal pulse shapes (chip shapes), is able to double system throughput while maintaining performance gains of up to 8 dB. Copyright 2002 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

orthogonal frequency division multiplexing

multi-carrier code division multiple access

direct sequence code division multiple access


Packing cycles exactly in polynomial time Let G = (V, E) be an undirected graph in which every vertex v. V is assigned a nonnegative integer w(v). A w- packing is a collection P of cycles (repetition allowed) in G such that every v. V is contained at most w(v) times by the members of P. Let = 2|V | + Sigma(v is an element of V)[log(w(v)+ 1)] denote the binary encoding length (input size) of the vector (w(v): v is an element of V)(T). We present an efficient algorithm which finds in O(|V|(8) (2) + |V|(14)) time a w- packing of maximum cardinality in G provided packing and covering cycles inGsatisfy the Z(+)-max-flow min-cut property.

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

polynomial algorithm
min-max relation
maximum cycle packing


Detection and enhancement of line structures in an image by anisotropic diffusion This paper describes a method to enhance line structures in a gray-level image. For this purpose, we blur the image using anisotropic Gaussian filters along the directions of each line structure. In a line structure region the gradients of image gray levels have a uniform direction. To find such line structures, we evaluate the uniformity of the directions of the local gradients. Before this evaluation, we need to smooth out small structures to obtain line directions. We, first, blur the given image by a set of Gaussian filters. The variance of the filter which maximizes the uniformity of the local gradient directions is detected position by position. Then, the line directions in the image are obtained from this blurred image. Finally, we blur the image using an anisotropic filter again along the directions, and enhance every line structure.

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

line structure enhancement
multi-resolution analysis
structure tensor


A novel approach for comparing web sites by using MicroGenres In this paper, a novel approach is introduced to compare web sites by analysing their web page content. Each web page can be expressed as a set of entities called MicroGenres, which in turn are abstractions about design patterns and genres for representing the page content. This description is useful for web page and web site classification and for a deeper insight into the web site?s social context. The web site comparison is useful for extracting patterns which can be used for improving Web search engine effectiveness, the identification of best practices in web site design and of course in the organization of web page content to personalize the web user experience on a web site. The effectiveness of the proposed approach was tested in a real world case, with e-shop web sites showing that a web site can be represented in a high level of abstraction by using MicroGenres, the contents of which can then be compared and given a measure corresponding to web site similarity. This measure is very useful for detecting web communities on the Web, i.e., a group of web sites sharing similar contents, and the result is essential in performing a focused and effective information search as well as minimizing web page retrieval.

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

web design pattern
genre
microgenre
detection


Pore

scale

definition

and

computation

from

tomography

data

During

recent

years

characterisation

capabilities

of

porous

media

have

been

transformed

by

advances

in

computation

and

visualisation

technologies.

It

is

now

possible

to

obtain

detailed

topological

and

hydrodynamic

information

of

porous

media

by

combining

tomographic

and

computational

fluid

dynamic

studies.

Despite

the

existence

of

these

new

capabilities,

the

characterisation

process

itself

is

based

on

the

same

antiquated

experimental

macroscopic

concepts.

We

are

interested

in

an

up-scaling

process

where

we

can

keep

key

information

for

every

pore

size

present

in

the

media

in

order

to

feed

multi-scale

transport

models.

Hydrometallurgical,

environmental,

food,

pharmaceutical

and

chemical

engineering

are

industries

with

process

outcomes

based

on

homogeneous

and

heterogeneous

reactions

and

therefore

sensitive

to

the

reaction

and

transport

processes

happening

at

different

pore

scales.

The

present

work

addresses

a

key

step

in

the

information

up-scaling

process,

i.e.

a

pore

identification

algorithm

similar

to

alternating

sequential

filters.

In

a

preliminary

study,

topological

and

hydrodynamic

variables

are

correlated

with

the

pore

size.

Micrometre

and

millimetre

resolution

tomographies

are

used

to

characterise

the

pore

size

distribution

of

a

packed

column

and

different

rocks.

Finally,

we

compute

the

inter-pore-scale

redistribution

function

which

is

a

measure

of

the

heterogeneity

of

the

media

and

magnitude

needed

in

multi-scale

modelling.

Program

title:

Poresizedist

Catalogue

identifier:

Program

summary

Program

obtainable

from:

CPC

Program

Library,

Queen?s

University,

Belfast,

N.

Ireland

Licensing

provisions:

Standard

CPC

licence,

No.

of

lines

in

distributed

program,

including

test

data,

etc.:

No.

of

bytes

in

distributed

program,

including

test

data,

etc.:

Distribution

format:

tar.gz

Programming

language:

MatLab

Computer:

Desktop

or

Laptop

Operating

system:

Runs

under

MatLab

(tested

in

Linux

and

Windows)

RAM:

Tested

for

problems

up

to

bytes

Classification:

External

routines:

MatLab

Image

Toolbox

Nature

of

problem:

Identify

individual

pores

from

a

foreground

image

representing

void

space.

Solution

method:

Algorithm

based

on

successive

erosions

with

a

shrinking

erosion

disk

diameter.

Restrictions:

The

tomographic

data

must

fit

in

the

available

computer

memory.

The

input

tomographic

data

should

have

the

open

porosity

space

to

characterise

as

foreground.

Unusual

features:

Can

be

used

together

with

the

solution

for

the

fluid

flow

for

obtaining

a

combined

topological-hydrodynamical

characterisation.

Additional

comments:

Our

implementation

was

oriented

for

easy

understanding,

not

computational

speed.

However,

see

section

regarding

memory

implementation

details,

RAM-disk

swapping

strategy

and

parallelisation

for

details.

Running

time:

Typical

running

time:

hours.

Largest

tested

problem

bytes):

day.

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

pore size distribution
porous media
characterisation
upscaling


Point and interval estimation of partial attributable risks from casecontrol data using the R-package pARccs The attributable risk (AR) is an epidemiologic measure quantifying the relationship between an exposure factor and a disease at the population level. In addition to its original use as a one-dimensional parameter the AR is increasingly applied in multifactorial epidemiologic situations when the combined impact of multiple exposure factors has to be partitioned into factor-specific components. We discuss the point and interval estimation of the resulting multidimensional parameter termed partial attributable risk (PAR) and introduce the R-package pARccs, a comprehensive software enabling the application of the methods. pARccs allows for point and interval estimation of PAR from casecontrol data utilizing the non-parametric bootstrap with stratified resampling in combination with the percentile or BCa BC a method to compute confidence intervals. We illustrate the concept of partial attributable risks and the application of the software by an example from a recent casecontrol study on risk factors for melanoma. We also discuss practical aspects of the software application for epidemiologic purposes and its limitations.

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

attributable fraction
confidence interval
epidemiologic methods
sequential attributable risk


Enhanced-interval linear programming An enhanced-interval linear programming (EILP) model and its solution algorithm have been developed that incorporate enhanced-interval uncertainty (e.g., A, B and C) in a linear optimization framework. As a new extension of linear programming, the EILP model has the following advantages. Its solution space is absolutely feasible compared to that of interval linear programming (ILP), which helps to achieve insight into the expected-value-oriented trade-off between system benefits and risks of constraint violations. The degree of uncertainty of its enhanced-interval objective function (EIOF) would be lower than that of ILP model when the solution space is absolutely feasible, and the EIOFs expected value could be used as a criterion for generating the appropriate alternatives, which help decision-makers obtain non-extreme decisions. Moreover, because it can be decomposed into two submodels, EILPs computational requirement is lower than that of stochastic and fuzzy LP models. The results of a numeric example further indicated the feasibility and effectiveness of EILP model. In addition, EI nonlinear programming models, hybrid stochastic or fuzzy EILP models as well as risk-based trade-off analysis for EI uncertainty within decision process can be further developed to improve its applicability.

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

linear programming
optimization
uncertainty
feasibility
solution algorithm


Improvement of the k-means clustering filtering algorithm In this paper, we present a modified filtering algorithm (MFA) by making use of center variations to speed up clustering process. Our method first divides clusters into static and active groups. We use the information of cluster displacements to reject unlikely cluster centers for all nodes in the kd-tree. We reduce the computational complexity of filtering algorithm (FA) through finding candidates for each node mainly from the set of active cluster centers. Two conditions for determining the set of candidate cluster centers for each node from active clusters are developed. Our approach is different from the major available algorithm, which passes no information from one stage of iteration to the next. Theoretical analysis shows that our method can reduce the computational complexity, in terms of the number of distance calculations, of FA at each stage of iteration by a factor of FC/AC, where FC and AC are the numbers of total clusters and active clusters, respectively. Compared with the FA, our algorithm can effectively reduce the computing time and number of distance calculations. It is noted that our proposed algorithm can generate the same clusters as that produced by hard k-means clustering. The superiority of our method is more remarkable when a larger data set with higher dimension is used.

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

k-means clustering
nearest-neighbor search
knowledge discovery


Real-time digitaloptical correlator-systems design The systems design of a real-time hybrid digitaloptical correlator is detailed. Emphasis is on: partitioning of the digital and optical systems such that the efficiency of the optical image train is maximised; and the parallelisation of tasks within the digital sub-system to maximise throughput. The significance of communication bottlenecks are emphasised in the digital system and the constraints this enforces on the initial selection of DSP devices.

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

optical-correlation
fourier image processing
template matching
real-time pattern recognition