A feature-based matching scheme: MPCD and robust matching strategy This paper presents a scheme that matches interest point features detected on two images taken from different points of view. To accomplish this objective, we jointly consider the corner detection and matching problems. Firstly, a new multi-scale Plessey corner detector (MPCD) is used to detect the interest points. Secondly, the geometric constraint between two images is exploited, based on which we propose a new energy function that can approximate 2D affine transformation in a more efficient way. Only a small set of corners with the highest accuracy and robustness are considered in the first stage, consequently, a small data space is provided to the robust algorithm in the second stage reducing the computation time. Therefore, more information can be incorporated into our scheme based on corner detection and matching phases. We compare our method using the proposed MPCD with two standard corner detectors based on image matching. We also evaluate our proposed matching strategy against Zhengyous method [Deriche, R., Zhang, Z., Luong, Q.-T., Faugeras, O., 1994. Robust recovery of the epipolar geometry for an uncalibrated stereo rig. In: European Conference on Computer Vision, Stockholm, Sweden, pp. 567576]. Our scheme provides a new viewpoint and better results for the traditional feature matching problem.

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


3D facial model exaggeration builder for small or large sized model manufacturing An action figure is a small human-shaped object used as a toy for children or artistic collection. In the past, the creation of action figures required intense manual effort. An initial trial to automate the process using recent scanning technology failed to yield figures with market appeal because the resulting action figures did not have sufficiently life-like shapes and expressions. The limiting factor which was not considered during this trial is the loss of individual characteristics resulting from either an increase or reduction in scale. We provide novel techniques for creating an exaggerated human face that retains all of the skin detail in the 3D scanned model, which will allow more characteristic figures to be easily created at any scale, thereby saving money and time during manufacturing. While traditional 3D printing applications utilize rigid models acquired using computer-aided design, our method demonstrates that deformable models (such as a human face) obtained from scanners are also suitable.

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

3d graphics
virtual faces
3d skin
mesh parameterization


Development of robust intelligent tracking control system for uncertain nonlinear systems using H-infinity control technique In this paper, a robust intelligent tracking control (RITC) system employs an adaptive output recurrent cerebellar model articulation controller (ORCMAC) is developed for uncertain nonlinear system to achieve H-infinity tracking performance. The proposed dynamic structure of ORCMAC has superior capability in efficient learning mechanism and dynamic response. Temporal relations are embedded in conventional cerebellar model articulation controller (CMAC) by adding feedback connections between the output space and input space, so that the ORCMAC captures the system dynamic. In the RITC design, the Taylor linearization technique is employed to increase the learning ability of ORCMAC and the on-line adaptive laws are derived based on the Lyapunov stability analysis, the sliding mode control methodology and the H-infinity control technique so that the stability of the closed-loop system and H-infinity tracking performance can be guaranteed. Finally, the proposed control system is applied to control an inverted pendulum system, a Van der Pol oscillator and a Genesio chaotic system. Simulation results demonstrate that the proposed control scheme can achieve favorable tracking performances for the uncertain nonlinear systems with unknown dynamic functions and under the occurrence of external disturbance. (C) 2010 Elsevier B. V. All rights reserved.

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

output recurrent cerebellar model
sliding mode control

robust control
intelligent control
adaptive control
articulation controller (orcmac)
h-infinity control technique


Frequency dependence of the cardiac threshold to alternating current between 10 Hz and 160 Hz It is still unclear what fundamental criteria influence the ability of alternating current (AC) to induce ventricular fibrillation (VF) in vivo. As the VF threshold has a bowl-shaped relationship with frequency (showing a minimum threshold at some frequency), similar to the nervous system, one proposed model has assumed that the mechanisms underlying AC stimulation of nerves are at work for VF induction. More recent work has suggested a second approach, whereby a simple RC-like model is sufficient to understand the cardiac AC stimulation threshold's frequency dependence, suggesting that some unarticulated mechanism is at work for VF. The paper directly tests these two models. In 12 intact dogs and 20 intact guinea pigs, DC pulses were used to stimulate AC square and AC sine waves at 70, 20, 40, 80 and 160 Hz. All electrodes were endocardial, with the return electrode being on a paw or thorax. It was found that, for square and sine wave stimulation in both dogs and guinea pigs, the stimulation threshold increased monotonically with frequency from 10 Hz up to 160 Hz (p < 0.01 for dogs and guinea pigs). Between 80 and 160 Hz, the AC stimulation threshold doubled, exactly as predicted by an RC model. It was concluded that the AC stimulation threshold is not bowl-shaped and is best understood with an RC model. As the VF threshold does exhibit a bowl-shape with frequency, as opposed to the stimulation threshold which does not, the VF induction frequency dependence must have different origins.

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

ac leakage currents
medical device safety


EQ-sequences for coding floorplans A floorplan specifies the layout of modules in very large scale integration (VLSI) design, and a new code, called the EQ-sequence, for representing a floorplan is presented in this paper. The EQ-sequence is based on a Q-sequence. The EQ-sequence can preserve the adjacent relationships of rooms on a floorplan, but the Q-sequence cannot. The algorithms for encoding, moving and decoding of an EQ-sequence are introduced. With the EQ-sequence, we can check whether two modules abut each other on a floorplan. It has been proved that any floorplan of n rooms is uniquely encoded by an EQ-sequence and any EQ-sequence is uniquely decoded to a floorplan, both in O(n) time.

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


a systematic method for functional unit power estimation in microprocessors We present a new method for mathematically estimating the active unit power of functional units in modern microprocessors such as the Pentium 4 family. Our method leverages the phasic behavior in power consumption of programs, and captures as many power phases as possible to form a linear system of equations such that the functional unit power can be solved. Our experiment results on a real Pentium 4 processor show that power estimations attained as such agree with the measured power very well, with deviations less than 5\% only.

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

processor
method
power consumption
behavior
functional
power

program
activation
estimates
microprocessor
systems
families
experience
performance counter
power estimation


a comparison of sentence retrieval techniques Identifying redundant information in sentences is useful for several applications such as summarization, document provenance, detecting text reuse and novelty detection. The task of identifying redundant information in sentences is defined as follows: Given a query sentence the task is to retrieve sentences from a given collection that express all or some subset of the information present in the query sentence. Sentence retrieval techniques rank sentences based on some measure of their similarity to a query. The effectiveness of such techniques depends on the similarity measure used to rank sentences. An effective retrieval model should be able to handle low word overlap between query and candidate sentences and go beyond just word overlap. Simple language modeling techniques like query likelihood retrieval have outperformed TF-IDF and word overlap based methods for ranking sentences. In this paper, we compare the performance of sentence retrieval using different language modeling techniques for the problem of identifying redundant information.

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

task
reuse
applications
performance
novelty detection
paper
summarization
language modeling
text
retrieval
similarity
query
ranking

measurement
sentece retrieval
redundancy
collect
informal
comparisons
method
proven
documentation
effect
retrieval model
similarity measure


Transnational strategic alliances in the telecommunications industry The global marketplace in the 1990s demands that multinational companies have access to an increasingly sophisticated, seamless communications network. Transnational strategic alliances (TSAs) are a way of meeting these needs in the context of limited available resources. The current map of TSAs in telecom industry is dominated by five groups of players; WorldPartners, Concert, Global One, Unisource, and C&W. Firms select the type of alliance depending on their relative positions with respect to size, profitability, capital structure, and R&D capability. The critical issues in TSAs are trade reciprocity, legal environment, and financing. Although competition is the flip side of the coin in strategic alliances, managing this duality effectively is a key to the success of the alliances.

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

worldpartners
concert
global one
unisource

transnational strategic alliances (tsas)


Virtual world teaching, experiential learning, and assessment: An interdisciplinary communication course in Second Life While many reports espouse the potential impact that 3-D virtual worlds are expected to have on teaching and learning in higher education in a few years, there are few empirical studies that inform instructional design and learning assessment in virtual worlds. This study explores the nature and process of learning in Second Life in a graduate interdisciplinary communication course in fall 2007. Literature suggests that 3-D virtual worlds can be well suited for experiential learning environments. In this study, the actual instructional effectiveness of Second Life as an experiential learning environment for interdisciplinary communication is empirically examined using mixed research methods of journal content analysis, surveys, focus group, and virtual world snapshots and video. (C) 2009 Elsevier Ltd. All rights reserved.

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

virtual reality
computer-mediated communication
interdisciplinary projects
interactive learning environments
cooperative/collaborative learning


A computational study of a nonlinear minsum facility location problem A discrete location problem with nonlinear objective is addressed. A set of p plants is to be open to serve a given set of clients. Together with the locations, the number p of facilities is also a decision variable. The objective is to minimize the total cost, represented as the transportation cost between clients and plants, plus an increasing nonlinear function of p. Two Lagrangean relaxations are considered to derive lower bounds. Dual information is also used to design a core heuristic. Computational results are given, showing that nearly optimal solutions are obtained in short running times.

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

p-median problem
lagrangean relaxation
nonlinear integer programming


PROJECT RELIABILITY GROWTH MODEL BASED ON CURVES OF ACCUMULATED COMMUNICATION TOPICS FOR SOFTWARE DEVELOPMENT New trends in software development, such as agile software development, have a difficulty in conventional document-based management. Executable software has a higher priority than development documents such as detail design documents and formal bug reports. If managers depend on development reports in order to determine the project progress and the product quality, they will miss the opportunity of determining the progress and quality in agile software development. Therefore, we proposed a project reliability growth model for determining the project state without development documents. This model is based on conventional software reliability growth models. The parameters related to bugs are replaced with communication topic parameters. The concept and procedure of the model are the same as those of the software reliability growth model. By applying this model to open source projects, it is possible to detect a significant change in the project state without development documents.

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 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


understanding software approaches for gpgpu reliability Even though graphics processors (GPUs) are becoming increasingly popular for general purpose computing, current (and likely near future) generations of GPUs do not provide hardware support for detecting soft/hard errors in computation logic or memory storage cells since graphics applications are inherently fault tolerant. As a result, if an error occurs in GPUs during program execution, the results could be silently corrupted, which is not acceptable for general purpose computations. To improve the fidelity of general purpose computation on GPUs (GPGPU), we investigate software approaches to perform redundant execution. In particular, we propose and study three different, application-level techniques. The first technique simply executes the GPU kernel program twice, and thus achieves roughly half of the throughput of a non-redundant execution. The next two techniques interleave redundant execution with the original code in different ways to take advantage of the parallelism between the original code and its redundant copy. Furthermore, we evaluate the benefits of providing hardware support, including ECC/parity protection to on-chip and off-chip memories, for each of the software techniques. Interestingly, our findings, based on six commonly used applications, indicate that the benefits of complex software approaches are both application and architecture dependent. The simple approach, which executes the kernel twice, is often sufficient and may even outperform the complex ones. Moreover, we argue that the cost is not justified to protect memories with ECC/parity bits.

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


A NEW BICLUSTERING ALGORITHM BASED ON ASSOCIATION RULE MINING Clustering has been applied in a wide variety of disciplines and has also been utilized in many scientific areas. Usually, clustering algorithms construct either clusters of rows or clusters of columns of the input data matrix. Biclustering is a methodology where biclusters are formed by both a subset of rows and a subset of columns, such that objects represented by the first are the most similar to each other when compared over the latter. In this paper, we introduce a new biclustering technique, based on association rule mining, which can support different well-known biclustering models proposed in the literature. Experimental tests demonstrate the accuracy and efficiency of the proposed technique with respect to well known related ones.

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

biclustering
clustering
association rule mining


Accurate Model-Based Reconstruction Algorithm for Three-Dimensional Optoacoustic Tomography In many practical optoacoustic imaging implementations, dimensionality of the tomographic problem is commonly reduced into two dimensions or 1-D scanning geometries in order to simplify technical implementation, improve imaging speed or increase signal-to-noise ratio. However, this usually comes at a cost of significantly reduced quality of the tomographic data, out-of-plane image artifacts, and overall loss of image contrast and spatial resolution. Quantitative optoacoustic image reconstruction implies therefore collection of point 3-D (volumetric) data from as many locations around the object as possible. Here, we propose and validate an accurate model-based inversion algorithm for 3-D optoacoustic image reconstruction. Superior performance versus commonly-used backprojection inversion algorithms is showcased by numerical simulations and phantom experiments.

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

model-based reconstruction
photoacoustic tomography
three-dimensional imaging


Testing Taxonomies: Beyond Card Sorting EDITOR'S SUMMARY

index language construction
evaluation
information architecture
cognitive models


Computer Interaction Analysis: Toward an Empirical Approach to Understanding User Practice and Eye Gaze in GUI-Based Interaction Todays personal computers enable complex forms of user interaction. Unlike older mainframe computers that required batch processing, personal computers enable real-time user control on a one-to-one basis. Such user interaction involves mixed initiative, logic, language and pointing gestures, features reminiscent of interaction with another human. Yet there are also major differences between computer interaction and human interaction, such as computers inability to stray from scripts or to adapt to the idiosyncrasies of particular recipients or situations. Given these similarities and differences, can we study computer interaction using methods similar to those for studying human interaction? If so, are the findings from the analysis of human interaction also useful in understanding computer interaction? In this paper, we explore these questions and outline a novel methodological approach for examining human-computer interaction, which we call computer interaction analysis. We build on earlier approaches to human interaction with a computer and adapt them to the latest technologies for computer screen capture and eye tracking. In doing so, we propose a new transcription notation scheme that is designed to represent the interweaving streams of input actions, display events and eye movements. Finally we demonstrate the approach with concrete examples involving the phenomena of placeholding, repair and referential practices.

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

computer interaction analysis
eye tracking

ethnomethodology
conversation analysis
human computer interaction
web search


Selecting feature subset for high dimensional data via the propositional FOIL rules Feature interaction is an important issue in feature subset selection. However, most of the existing algorithms only focus on dealing with irrelevant and redundant features. In this paper, a propositional FOIL rule based algorithm FRFS, which not only retains relevant features and excludes irrelevant and redundant ones but also considers feature interaction, is proposed for selecting feature subset for high dimensional data. FRFS first merges the features appeared in the antecedents of all FOIL rules, achieving a candidate feature subset which excludes redundant features and reserves interactive ones. Then, it identifies and removes irrelevant features by evaluating features in the candidate feature subset with a new metric CoverRatio, and obtains the final feature subset. The efficiency and effectiveness of FRFS are extensively tested upon both synthetic and real world data sets, and it is compared with other six representative feature subset selection algorithms, including CFS, FCBF, Consistency, Relief-F, INTERACT, and the rule-based FSBAR, in terms of the number of selected features, runtime and the classification accuracies of the four well-known classifiers including Naive Bayes, C4.5, PART and IB1 before and after feature selection. The results on the five synthetic data sets show that FRFS can effectively identify irrelevant and redundant features while reserving interactive ones. The results on the 35 real world high dimensional data sets demonstrate that compared with other six feature selection algorithms, FRFS cannot only efficiently reduce the feature space, but also can significantly improve the performance of the four well-known classifiers.

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

feature subset selection
feature interaction
propositional foil rule


Modeling user context with applications to media retrieval In this paper, we develop a theoretical understanding of multi-sensory knowledge and user context and their inter-relationships. This is used to develop a generic representation framework for multi-sensory knowledge and context. A representation framework for context can have a significant impact on media applications that dynamically adapt to user needs. There are three key contributions of this work: (a) theoretical analysis, (b) representation framework and (c) experimental validation. Knowledge is understood to be a dynamic set of multi-sensory facts with three key properties - multi-sensory, emergent and dynamic. Context is the dynamic subset of knowledge that affects the communication between entities. We develop a graph based, multi-relational representation framework for knowledge, and model its temporal dynamics using a linear dynamical system. Our approach results in a stable and convergent system. We applied our representation framework to a image retrieval system with a large collection of photographs from everyday events. Our experimental validation with the retrieval evaluated against two reference algorithms indicates that our context based approach provides significant gains in real-world usage scenarios.

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


An adaptive protocol for real-time fax communications over Internet Internet faring allows users from different locations to exchange fax documents without incurring the high costs associated with international toll charges. This paper proposes a protocol, Adaptive Internet Fax Protocol (AIFP) which provides a basic framework for Internet fax transmission. It comprises three secondary protocols, which take care of issues like capability exchange, change of data socket, network load feedback and data transfer. AIFP is able to facilitate real-time fax transmission over unreliable Internet and make delivery confirmation possible. In a heavy jitter network, AIFP is able to provide at least session mode transmission albeit not real time. (C) 2001 Elsevier Science B.V. All rights reserved.

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

internet faxing
adaptive fax communication
real-time transmission


Adaptive finite element computational fluid dynamics using an anisotropic error estimator The aim of this paper is to present the results on finite element adaptive strategies for computational fluid dynamics (CFD) problems with singularities arising from shock phenomena and/or discontinuous boundary data. The adaptive analysis is based on an optimal-mesh-adaptive strategy which is employed to refine the mesh, stretch and orient the elements in such a way that, along the adaptation process, the mesh becomes aligned with the discontinuities. This mesh adaptation process yields improved results in locating regions of rapid or abrupt variations of the variables, whose location is not known a priori. On the other hand, the proposed mesh adaptation process is generated by minimizing, for a given number of elements in the mesh, a new anisotropic error estimator based on local directional interpolation error and recovering of the second derivatives of the finite element solution. Several adaptive mesh-refinement solutions for interpolation problems are presented in order to show that the proposed optimal adaptive strategy using this anisotropic error estimator recovers optimal and/or superconvergent rates. Finally, applications of this approach to CFD problems are also presented in order to show the computational performance of the proposed optimal adaptive procedure.

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

error estimator
adaptive analysis
computational fluid dynamics


Comparisons of some improving strategies on MOPSO for multi-objective (r,Q) inventory system This paper presents comparisons of some recent improving strategies on multi-objective particle swarm optimization (MOPSO) algorithm which is based on Pareto dominance for handling multiple objective in continuous review stochastic inventory control system. The complexity of considering conflict objectives such as cost minimization and service level maximization in the real-world inventory control problem needs to employ more exact optimizers generating more diverse and better non-dominated solutions of a reorder point and order size system. At first, we apply the original MOPSO employed for the multi-objective inventory control problem. Then we incorporate the mutation operator to maintain diversity in the swarm and explore all the search space into the MOPSO. Next we change the leader selection strategy used that called geographically-based system (Grids) and instead of that, crowding distance factor is also applied to select the global optimal particle as a leader. Also we use ?-dominance concept to bound archive size and maintain more diversity and convergence in the MOPSO for optimizing the inventory control problem. Finally, the MOPSO algorithms created using these strategies are evaluated and compared with each other in terms of some performance metrics taken from the literature. The results indicate that these strategies have significant influences on computational time, convergence, and diversity of generated Pareto optimal solutions.

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


building common ground and reciprocity through social network games Social network games (SNG) are an extremely popular and rapidly growing application of social network sites (SNS). But are SNGs really social? A survey based on a social cognitive theory approach to uses and gratifications revealed that people are motivated to play the game to create common ground, reciprocate, cope, and pass time. People play SNGs to create common ground for future social interaction rather than seeking direct social interaction in the game. Customization was strongly correlated with social motivations; in particular, use of avatar customization was different from use of space customization. Reciprocity was facilitated more by the design of the game than social motives.

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

space customization
uses and gratifications
avatar customization
common ground
reciprocity
customization

social network game
gifting
social computing
asynchronous
virtual goods
game motivations
social network site
online game


a technique for translating states between database schemata Consider two database schemata modeling the same reality. Given a state of the first schema, we can ask what information it provides about the state of the second schema. It turns out that this information can be represented by a table similar to a tableau of Aho, Sagiv and Ullman. We show a simple method to construct this table, by using results developed for tables of this type in the context of representing incomplete information in relational databases. We also consider a closely related notion of equivalence of database schemata, briefly sketching a method to test two schemata for equivalence.

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

context
tables
schema
incomplete information
method
test
database
sketching


reliable real-time foreground detection for video surveillance applications Foreground segmentation is usually needed as an initial step in video surveillance applications. Background subtraction is typically used to segment moving regions by comparing each new frame to a model of the scene background. We present a segmentation algorithm that works in real-time and efficiently extracts foreground objects from indoor and outdoor scenes that may contain small environment motions. The model adapts quickly to changes in the video which enables very sensitive detection of moving targets. The evaluation performed shows that this approach reliably extracts the foreground with very low false alarms and false misses.

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

foreground segmentation
video surveillance


an overview of bloom BLOOM is a system for doing software understanding through visualization. It provides facilities for static and dynamic data collection. It offers a wide range of data analyses. It includes a visual query language for specifying what information should be visualized. All these are used in conjunction with a back end that supports a variety of 2D and 3D visualization strategies.

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

data 3d software strategies visualization dynamic

query languages
understandability
systems
informal
data collection


The user model-based summarize and refine approach improves information presentation in spoken dialog systems A common task for spoken dialog systems (SDS) is to help users select a suitable option (e.g., flight, hotel, and restaurant) from the set of options available. As the number of options increases, the system must have strategies for generating summaries that enable the user to browse the option space efficiently and successfully. In the user-model based summarize and refine approach (UMSR, Demberg and Moore, 2006), options are clustered to maximize utility with respect to a user model, and linguistic devices such as discourse cues and adverbials are used to highlight the trade-offs among the presented items. In a Wizard-of-Oz experiment, we show that the UMSR approach leads to improvements in task success, efficiency, and user satisfaction compared to an approach that clusters the available options to maximize coverage of the domain (Polifroni et al., 2003). In both a laboratory experiment and a web-based experimental paradigm employing the Amazon Mechanical Turk platform, we show that the discourse cues in UMSR summaries help users compare different options and choose between options, even though they do not improve verbatim recall. This effect was observed for both written and spoken stimuli.

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

information presentation
spoken dialog systems


ISRAM: information security risk analysis method Continuously changing nature of technological environment has been enforcing to revise the process of information security risk analysis accordingly. A number of quantitative and qualitative risk analysis methods have been proposed by researchers and vendors. The purpose of these methods is to analyze today's information security risks properly. Some of these methods are supported by a software package. In this study, a survey based quantitative approach is proposed to analyze security risks of information technologies by taking current necessities into consideration. The new method is named as Information Security Risk Analysis Method (ISRAM). Case study has shown that ISRAM yields consistent results in a reasonable time period by allowing the participation of the manager and staff of the organization.

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

quantitative risk analysis
paper-based risk analysis
risk model


Usability of multiviewpoint images for spatial interaction in projection-based display systems In a common application scenario, large screen projection-based stereoscopic display systems are not used by a single user alone, but are shared by a small group of people. Using multiviewpoint images for multiuser interaction does not require special hardware and scales transparently with the number of colocated users in a system. We present a qualitative and quantitative study comparing usability and interaction performance for multiviewpoint images to non-head-tracked and head-tracked interaction for raycasting selection and in-hand object manipulation. Results show that while direct first-person interaction in projection-based displays without head-tracking is difficult or even completely impractical, interaction with multiviewpoint images can produce similar or even better performance than fully head-tracked interaction. For ray-casting selection, interaction with multiviewpoint images is actually up to 10 percent faster than head-tracked interaction. For in-hand object manipulation in a simple docking task, multiviewpoint interaction performs only about 6 percent slower than fully head-tracked interaction.

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

collaborative computing
usability testing
virtual reality


Efficient classifiers for multi-class classification problems Classification problems have become more complex and intricate in modern applications in the face of continuous data explosion. In addition to great quantities of features and large numbers of instances, modern classification applications are continuously developed with multiple classes (objectives). The ever-increasing growth in data quantity and computation complexity has largely deteriorated the performance and accuracy of classification models. In order to deal with such situations, multivariate statistical analyses are adopted in this paper. Multivariate statistical analyses have two advantages. First, they can explore the relationships between variables and find the most characterizing features of the observed data. Second, they can solve problems which are stalled by high dimensionality. In this paper, the first advantage is applied to the selection of relevant features and the second is employed to generate the multivariate classifier. Experimental results show that our model can significantly improve classification training time by combining a compact subset of relevant features without the loss of accuracy in multi-class classification problems. In addition, the discrimination degree of our classifier outperforms other conventional classifiers.

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

multivariate analysis
multi-class problems
feature evaluation
feature selection
feature extraction
inductive learning


FINE-GRAINED AND LAYERED OBJECT RECOGNITION This paper presents a novel research on promoting the performance and enriching the functionalities of object recognition. Instead of simply fitting various data to a few predefined semantic object categories, we propose to generate proper results for different object instances based on their actual visual appearances. The results can be fine-grained and layered categorization along with absolute or relative localization. We present a generic model based on structured prediction and an efficient online learning algorithm to solve it. Experiments on a new benchmark dataset demonstrate the effectiveness of our model and its superiority against traditional recognition methods.

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

object recognition
structured prediction
online learning

fine-grained and layered recognition
object detection


The exact values of the optimal average information ratio of perfect secret-sharing schemes for tree-based access structures A perfect secret-sharing scheme is a method of distributing a secret among a set of participants such that only qualified subsets of participants can recover the secret and the joint shares of the participants in any unqualified subset is statistically independent of the secret. The set of all qualified subsets is called the access structure of the scheme. In a graph-based access structure, each vertex of a graph \(G\) represents a participant and each edge of \(G\) represents a minimal qualified subset. The information ratio of a perfect secret-sharing scheme is defined as the ratio between the maximum length of the share given to a participant and the length of the secret. The average information ratio is the ratio between the average length of the shares given to the participants and the length of the secret. The infimum of the (average) information ratios of all possible perfect secret-sharing schemes realizing a given access structure is called the (average) information ratio of the access structure. Very few exact values of the (average) information ratio of infinite families of access structures are known. Csirmaz and Tardos have found the information ratio of all trees. Based on their method, we develop our approach to determining the exact values of the average information ratio of access structures based on trees.

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


State-morphism pseudo-effect algebras The notion of a state-morphism on pseudo-effect algebras is introduced, and pseudo-effect algebras with distinguished state-morphisms are studied under the name state-morphism pseudo-effect algebras (SMPEAs). It is shown that every SMPEA admits a representation as a (total) state-morphism algebra, and some results from the general theory of state-morphism algebras (that is, algebras endowed with a distinguished idempotent endomorphism called a state-morphism), recently developed by Botur and Dvure?enskij, can be applied. In particular, it is shown that under suitable conditions, a SMPEA can be embedded into a so-called diagonal one, realized by a direct product of the SMPEA with itself endowed with a suitable natural state-morphism.

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

state operator
state-morphism
pseudo effect algebra
riesz congruence
normal riesz ideal


sub-document queries over xml with xsqirrel This paper describes XSQirrel, a new XML query language that transforms a document into a sub-document, i.e. a tree where the root-to-leaf paths are a subset of the root-to-leaf paths from the original document.We show that this type of queries is extremely useful for various applications (e.g. web services) and that the currently existing query languages are poorly equipped to express, reason and evaluate such queries. In particular, we emphasize the need to be able to compose such queries. We present the XSQirrel language with its syntax, semantics and two language specific operators, union and composition.For the evaluation of the language, we leverage well established query technologies by translating XSQirrel expressions into XPath programs, XQuery queries or XSLT stylesheets.We provide some experimental results that compare our various evaluation strategies. We also show the runtime benefits of query composition over sequential evaluation.

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


agent dependability as an architectural issue The paper demonstrates how a layered reference architecture for software agents provides a framework for a dependability model that allows to associate the sources of failures and the ensuing error handling with a specific layer, thus integrating dependability directly into the design of agents.

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

layered software architecture
multiagent system


Automated rapid prototyping of TUG specifications using Prolog A prototype is usually built quickly and cheaply to explore poorly understood user requirements in the front-end of the software development life cycle. There are several techniques to construct a prototype such as fourth generation languages, functional and logic programming languages, and simulation techniques. Despite their benefits, these techniques do not directly support formal user requirements and specifications. In this paper, a formal specification language, called TUG, is presented to support an automatic derivation of a prototype in Prolog from a specification in the language via a set of transformation rules. The work described in this paper is distinct from existing rapid prototyping techniques. There is a close correspondence between TUG and Prolog that makes the process of transformation relatively mechanical. The process also allows specifiers not to consider low-level details at implementation such as selection of data structures and algorithms due to the features of the TUG specification language and the Prolog programming language. In addition, rederivation of a prototype in Prolog from a TUG specification is also avoided whenever the specification is modified. A Change Request Script is used to update the prototype in response to the revised specification. The prototype construction and specification acquisition are integrated to handle the construction of user requirements. The formality of the TUG specification language improves the quality of the description of user requirements. Rapid prototyping from the specification via software transformations improves the understanding of user requirements in a cost effective way.

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

formality
formal specification language
rapid prototyping
tug


Readout of Higher-Level Processing in the Discharge of Superior Colliculus Neurons Abstract: The discharge of neurons in the deeper layers of the superior colliculus (SC) was studied while monkeys performed two visual discrimination tasks that required different amounts of cognitive processing. In a search paradigm the animal's task was to saccade to the location of an odd-colored stimulus located in an array of distractors of uniform color (pop-out visual search). The visual stimuli remained on the screen as the discrimination process distinguished target from distractors. In a choice response task the color of a central cue signaled which stimulus from a previously presented array of colored stimuli was to be the target of a saccade. The stimulus array was turned off well before the central cue was presented. Most neurons showed activity aligned on both the visual input and the motor response in single-target tasks. Many of these same neurons showed additional discharge that was correlated with the required higher-level decision processes in both of these more natural visual tasks. In the case of pop-out search the SC has been shown to be functionally involved in the decision processes. The cue-aligned activity in SC in the choice response task is surprising because no transient visual stimulus appeared in the response field of the neuron.

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

saccades
frontal eye fields
choice response paradigm


An accurate mathematical performance model of partially adaptive routing in binary n-cube multiprocessors Although several analytical models have been proposed in the literature for different interconnection networks with different routing algorithms, there is only one work [M. Ould-Khaoua, An approximate performance model for partially adaptive routing algorithm in hypercubes, Microprocessors and Microsystems 23 (1999) 185-190] dealing with partially adaptive routing. It is not accurate enough especially in heavy traffic regions due to the rough approximation of assuming equal traffic rate over network channels. We show, however, such an approximation can greatly affect the accuracy of the model. This paper proposes an accurate analytical model to predict the average message latency in wormhole hypercube networks using partially adaptive routing. Our model accurately formulates the traffic rate over individual network channels and the results obtained from simulation experiments confirm that the proposed model exhibits a significant accuracy for various network sizes and under different operating conditions even in moderate to heavy traffic regions, the regions for which the model in [M. Ould-Khaoua, An approximate performance model for partially adaptive routing algorithm in hypercubes, Microprocessors and Microsystems 23 (1999) 185-190] fails to exhibit acceptable accuracy. (C) 2007 Elsevier Ltd. All rights reserved.

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

interconnection networks
hypercube
partially adaptive routing
message latency

multicomputers
p-cube algorithm
wormhole switching
performance evaluation


Structural theorems for symbolic summation Starting with Karr's structural theorem for summation-the discrete version of Liouville's structural theorem for integration-we work out crucial properties of the underlying difference fields. This leads to new and constructive structural theorems for symbolic summation. E.g., these results can be applied for harmonic sums which arise frequently in particle physics.

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

structural theorems
symbolic summation
difference fields

symbolic integration
liouville's theorem


New algorithms for computing the least trimmed squares regression estimator The outlier detection in multiple linear regression is a difficult problem because of the masking effect. A procedure that works successfully uses residuals based on a high breakdown estimator. The least trimmed squares (LTS) estimator, which was proposed by Rousseeuw (J. Amer. Statist. Assoc. 79 (1984)), is a high breakdown estimator. In this paper we propose two algorithms to compute the LTS estimator. The first algorithm is probabilistic and is based on an exchange procedure. The second algorithm is exact and based on a branch-and-bound technique that guarantees global optimality without exhaustive evaluation. We discuss the implementation of these algorithms using orthogonal decomposition procedures and propose several accelerations. The application of the new algorithms to real and simulated data sets shows that they significantly reduce the computational cost with respect to the algorithms previously described in the literature.

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 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

least trimmed squares
multiple linear regression

outliers
high breakdown point
branch and bound
exchange algorithm


Registration of MR and CT images of the liver: comparison of voxel similarity and surface based registration algorithms The purpose of this work was to determine the feasibility and efficacy of retrospective registration of MR and CT images of the liver. The open-source ITK Insight Software package developed by the National Library of Medicine (USA) contains a multi-resolution, voxel-similarity-based registration algorithm which we selected as our baseline registration method. For comparison we implemented a multi-scale surface fitting technique based on the head-and-hat algorithm. Registration accuracy was assessed using the mean displacement of automatically selected point landmarks. The ITK voxel-similarity-based registration algorithm performed better than the surface-based approach with mean misregistration in the range of 7.78.4?mm for CTCT registration, 8.2?mm for MRMR registration, and 14.018.9?mm for MRCT registration compared to mean misregistration from the surface-based technique in the range of 9.611.1?mm for CTCT registration, 9.212.4?mm for MRMR registration, and 15.219.0?mm for MRCT registration.

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

magnetic resonance imaging
computed tomography
image registration


experiencing aspects of games programming in an introductory computer graphics class Our computer graphics (CG) programming class uses games development as a means to help students understand CG concepts. Many students mistakenly thought this CG class was a games programming class. We present a simple frame-work for discussing games programming classes. Based on the framework, the paper describes our efforts in integrating competencies associated with games programming into our CG programming class. Our results show that the resulting class maintains the integrity of the original CG class while allowing students to develop projects with more interesting games features.

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 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


Intracortical vs. thalamocortical processing of spatial working memory Working memory processes contain not only maintenance but manipulation of the working memory contents. The system of the mediodorsal (MD) nucleus and the prefrontal cortex is considered to contribute to some aspects of the working memory processes. This article studies computationally the characteristics of the integrated cortical and thalamocortical system. The model circuit is operated in the thalamocortical mode, in which the thalamocortical inputs can control the cortical working memory representation. Our simulation shows that transient excitatory inputs to the MD relay cells can erase the working memory representation through the intracortical processes, especially the cross-directional inhibition.

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

intracortical
spatial working memory
thalamocortical


robust moving least-squares fitting with sharp features We introduce a robust moving least-squares technique for reconstructing a piecewise smooth surface from a potentially noisy point cloud. We use techniques from robust statistics to guide the creation of the neighborhoods used by the moving least squares (MLS) computation. This leads to a conceptually simple approach that provides a unified framework for not only dealing with noise, but also for enabling the modeling of surfaces with sharp features.Our technique is based on a new robust statistics method for outlier detection: the forward-search paradigm. Using this powerful technique, we locally classify regions of a point-set to multiple outlier-free smooth regions. This classification allows us to project points on a locally smooth region rather than a surface that is smooth everywhere, thus defining a piecewise smooth surface and increasing the numerical stability of the projection operator. Furthermore, by treating the points across the discontinuities as outliers, we are able to define sharp features. One of the nice features of our approach is that it automatically disregards outliers during the surface-fitting phase.

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


Mechanised wire-wise verification of Handel-C synthesis The compilation of Handel-C programs into net-list descriptions of hardware components has been extensively used in commercial tools but never formally verified. In this paper, we first introduce an extension of the compilation schema that allows the synthesis of the prioritised choice construct. Then we present a variation of the existing semantic model for Handel-C compilation that is amenable to mechanical proof and detailed enough for analysing properties of the hardware generated. We use this model to prove the correctness of the wiring schema used to interconnect the components at the hardware level and propagate control signals among them. Finally, we present the most interesting aspects of the mechanisation of the model and the correctness proofs in the HOL theorem prover.

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

handel-c synthesis
denotational semantics
mechanical verification


LEARNING OLIGOPOLISTIC COMPETITION IN ELECTRICITY AUCTIONS This paper addresses the problem of auction markets efficiency within the context of recently liberalized electricity markets. Two different auction mechanisms, i.e., the uniform and the discriminatory price setting rules, have been employed worldwide in designing electricity markets. In this paper, we study the relative efficiency of the two auction mechanisms in the framework of the learning-in-games approach. The behavior of electricity suppliers are modeled by means of an adaptive learning algorithm and the demand is assumed to be constant and inelastic, according to a common hypothesis in electricity market modeling. Computational experiments results are interpreted according game theoretical solutions, i.e., Nash equilibria and Pareto optima. Different economic scenarios corresponding to a duopoly and a tripoly competition with different level of demand are considered. Results show that in the proposed conditions, sellers learn to play competitive strategies, which correspond to Nash equilibria. Finally, this study establishes that, in the presented computational setting and economic scenarios, the discriminatory auction mechanism results more efficient than the uniform auction one.

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

agent-based computational economics
game theory
oligopolistic theory
design economics


Mesoscale modelling of concrete tensile failure mechanism at high strain rates At mesoscale, concrete may be regarded as a three-phase composite consisting of coarse aggregate, mortar matrix and interfacial transition zone (ITZ) between the aggregate and the mortar matrix. In the present paper, mesoscale model is adopted to analyze the dynamic tensile behaviour of concrete at high strain rates; especially, the effects of the ITZ on the failure properties are analyzed. In the mesoscale model, to simplify the problem, the shape of the coarse aggregate is assumed to be circular and the ITZ zone is modelled as a thin boundary layer around the aggregate. Dynamic material properties and continuum damage mechanics theory are employed to simulate the material behaviour of the three phases. Numerical simulation of the concrete samples under tension at different strain rates are carried out. Different aggregate size, different aggregate distribution and different material properties are considered. Strain rate effect is also analyzed. From the numerical results, it is found that the dynamic failure (crack) pattern is highly affected by the aggregate distribution. It is also found that the properties of the interfacial transition zone significantly influence the failure mechanism and the tensile strength of concrete.

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

concrete
strain rate
mesoscale model
aggregate


a comparison of social bookmarking with traditional search Social bookmarking systems allow users to store links to internet resources on a web page. As social bookmarking systems are growing in popularity, search algorithms have been developed that transfer the idea of link-based rankings in the Web to a social bookmarking system's data structure. These rankings differ from traditional search engine rankings in that they incorporate the rating of users. In this study, we compare search in social bookmarking systems with traditionalWeb search. In the first part, we compare the user activity and behaviour in both kinds of systems, as well as the overlap of the underlying sets of URLs. In the second part,we compare graph-based and vector space rankings for social bookmarking systems with commercial search engine rankings. Our experiments are performed on data of the social bookmarking system Del.icio.us and on rankings and log data from Google, MSN, and AOL. We will show that part of the difference between the systems is due to different behaviour (e. g., the concatenation of multi-word lexems to single terms in Del.icio.us), and that real-world events may trigger similar behaviour in both kinds of systems. We will also show that a graph-based ranking approach on folksonomies yields results that are closer to the rankings of the commercial search engines than vector space retrieval, and that the correlation is high in particular for the domains that are well covered by the social bookmarking system.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O B O O O O O O O O O O O B I 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-based 3D medical image visualization framework for biomedical engineering education Medical imaging is one of the major fields in the multi-disciplinary curriculum of biomedical engineering (BME). Biomedical engineers from different backgrounds need to understand biology in order to be able to develop effective equipment to improve healthcare diagnosis through medical images. Visualization tools are important in the learning process to improve biomedical engineer's understanding of medical imagery. In this work, we design a web-based 3D medical image visualization framework that can be used to improve medical image understanding in biology and anatomy. Our proposed framework provides not only 3D visualization, but also 3D reconstruction for medical images. This paper describes the design framework and the technology integration, as well as the implementation details. The developed system has been used as an educational tool prototype in a BME department. In order to evaluate the tool's usability, we tested it with BME students as well as doctors. We compared a conventional 2D visualization application and our proposed method with regard to system efficiency and user satisfaction. The 3D system generally demonstrated better performance and a higher level of satisfaction. The students were able to use our 3D tool to study 2D images effectively without prior background knowledge in anatomy. 2011 Wiley Periodicals, Inc. Comput Appl Eng Educ 22:216226, 2014; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.20548

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

medical image visualization
3d visualization
3d reconstruction


Parallel sets: Interactive exploration and visual analysis of categorical data Categorical data dimensions appear in many real-world data sets, but few visualization methods exist that properly deal with them. Parallel Sets are a new method for the visualization and interactive exploration of categorical data that shows data frequencies instead of the individual data points. The method is based on the axis layout of parallel coordinates, with boxes representing the categories and parallelograms between the axes showing the relations between categories. In addition to the visual representation, we designed a rich set of interactions. Parallel Sets allow the user to interactively remap the data to new categorizations and, thus, to consider more data dimensions during exploration and analysis than usually possible. At the same time, a metalevel, semantic representation of the data is built. Common procedures, like building the cross product of two or more dimensions, can be performed automatically, thus complementing the interactive visualization. We demonstrate Parallel Sets by analyzing a large CRM data set, as well as investigating housing data from two US states.

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

information visualization
interaction
nominal data
multivariate data


Understanding and managing taxonomies as economic goods and services EDITOR'S SUMMARY

economics of information
costs
index language construction
information production


Globally flexible functional forms: The neural distance function ? The output distance function is a key concept in economics. However, its empirical estimation often violates properties dictated by neoclassical production theory. In this paper, we introduce the neural distance function (NDF) which constitutes a global approximation to any arbitrary production technology with multiple outputs given by a neural network (NN) specification. The NDF imposes all theoretical properties such as monotonicity, curvature and homogeneity, for all economically admissible values of outputs and inputs. Fitted to a large data set for all US commercial banks (19892000), the NDF explains a very high proportion of the variance of output while keeping the number of parameters to a minimum and satisfying the relevant theoretical properties. All measures such as total factor productivity (TFP) and technical efficiency (TE) are computed routinely. Next, the NDF is compared with the Translog popular specification and is found to provide very satisfactory results as it possesses the properties thought as desirable in neoclassical production theory in a way not matched by its competing specification.

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

output distance function
translog
technical efficiency


Scientific Application Demands on a Reconfigurable Functional Unit Interface Modern scientific applications are large, complex, and highly parallel they are commonly executed on supercomputers with tens of thousands of processors. Yet these applications still commonly require weeks or even months to execute. Thus, single-thread performance remains a concern for highly parallel scientific applications. Adding a reconfigurable accelerator to each CPU could improve system performance; however, scientific applications have design constraints that differ from most application domains commonly accelerated by reconfigurable logic. In this article, we discuss the constraints imposed by scientific applications on the computation model, the accelerator architecture, and the accelerator's communication interface with the CPU. Based on these constraints and application analysis, we have previously proposed adding a Reconfigurable Functional Unit (RFU) to accelerate integer graphs that calculate complex memory addresses. In this work, we now propose a flexible multi-instruction interface technique that allows dataflow graphs implemented on the RFU to access a large number of inputs and outputs with minor CPU datapath modifications. We present an in-depth examination of the performance effects of different communication interfaces that use this technique, and select one that best matches the needs of Sandia's scientific applications. Although RFU execution overall improves performance, we also isolate two key negative performance effects introduced by aggregating CPU instructions into dataflow graphs: delayed issue and graph serialization. Finally, to demonstrate the marketability of an RFU beyond scientific applications, we reanalyze the proposed interfaces using the SPEC-fp benchmark suite. We show that although choosing an interface based on SPEC-fp needs is detrimental to Sandia application performance, choosing an interface based on Sandia demands works well for more general-purpose applications.

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

design
performance
communication interfaces
scientific applications


Hierarchical structuring of layout problems in an interactive evolutionary layout system This paper focuses on computer-based generative methods for layout problems in architecture and urban planning with special regard for the hierarchical structuring of layout elements. The generation of layouts takes place using evolutionary algorithms, which are used to optimize the arrangement of elements in terms of overlapping within a given boundary and the topological relations between them. In this paper, the approach is extended by a data structure that facilitates the hierarchical organization of layout elements making it possible to structure and organize larger layout problems into subsets that can be solved in parallel. An important aspect for the applicability of such a system in the design process is an appropriate means of user interaction. This depends largely on the calculation speed of the system and the variety of viable solutions. These properties are evaluated for hierarchical as well as for nonhierarchical structured layout problems.

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

evolutionary algorithms
hierarchical structuring


Component system identification and state-space model synthesis A scheme for synthesis of subsystem state-space models to be used for analysis of dynamic behaviour of built-up structures is presented. Using measurements on each component, subsystem models are identified adopting contemporary system identification methods. The subsystem state-space models are transformed into a coupling form, at which kinematic constraints and equilibrium conditions for the interfaces are introduced. The procedure is applied to a plane frame structure, which is built up of two components. It is found that the non-trivial model order determination constitutes a crucial step in the process. If the model order is incorrect at subsystem level, the synthesized model may radically fail to describe the properties of the built-up structure. It is also found that the identified subsystem models need to satisfy certain physically motivated constraints, e.g. reciprocity and passivity. Different approaches and methods to aid the model order determination and the estimation of physically consistent state-space models at subsystem level are discussed.

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

state-space models
modal identification
experimental modal analysis
component synthesis


Dynamic two-stage image retrieval from large multimedia databases Content-based image retrieval (CBIR) with global features is notoriously noisy, especially for image queries with low percentages of relevant images in a collection. Moreover, CBIR typically ranks the whole collection, which is inefficient for large databases. We experiment with a method for image retrieval from multimedia databases, which improves both the effectiveness and efficiency of traditional CBIR by exploring secondary media. We perform retrieval in a two-stage fashion: first rank by a secondary medium, and then perform CBIR only on the top-K items. Thus, effectiveness is improved by performing CBIR on a 'better' subset. Using a relatively 'cheap' first stage, efficiency is also improved via the fewer CBIR operations performed. Our main novelty is that K is dynamic, i.e. estimated per query to optimize a predefined effectiveness measure. We show that our dynamic two-stage method can be significantly more effective and robust than similar setups with static thresholds previously proposed. In additional experiments using local feature derivatives in the visual stage instead of global, such as the emerging visual codebook approach, we find that two-stage does not work very well. We attribute the weaker performance of the visual codebook to the enhanced visual diversity produced by the textual stage which diminishes codebook's advantage over global features. Furthermore, we compare dynamic two-stage retrieval to traditional score-based fusion of results retrieved visually and textually. We find that fusion is also significantly more effective than single-medium baselines. Although, there is no clear winner between two-stage and fusion, the methods exhibit different robustness features; nevertheless, two-stage retrieval provides efficiency benefits over fusion. (C) 2012 Elsevier Ltd. All rights reserved.

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

multimodal retrieval
multimedia retrieval


Soft-decision decoding of Reed-Muller codes: Recursive lists Recursive list decoding is considered for Reed-Muller (RM) codes. The algorithm repeatedly relegates itself to the shorter RM codes by recalculating the posterior probabilities of their symbols. Intermediate decodings are only performed when these recalculations reach the trivial RM codes. In turn, the updated lists of most plausible codewords are used in subsequent decodings. The algorithm is further improved by using permutation techniques on code positions and by eliminating the most error-prone information bits. Simulation results show that for all RM codes of length 256 and many subcodes of length 512, these algorithms approach maximum-likelihood (ML) performance within a margin of 0.1 dB. As a result, we present tight experimental bounds on ML performance for these codes.

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

maximum-likelihood (ml) performance
plotkin construction
reed-muller (rm) codes


Evaluating shakedown under proportional loading by non-linear static analysis A lower bound method for calculating shakedown loads under proportional loading by static non-linear finite element analysis is presented. Stress fields obtained by static analysis and stress superposition are substituted into Melans lower bound shakedown theorem. The proposed method is applied to two sample problems: a thick cylinder under internal pressure and a square plate with a central hole under proportional biaxial loading. The results indicate that the method gives accurate lower bound shakedown loads for these problems.

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

plasticity
cyclic loading
incremental plastic collapse
ratchetting


a multimodal pervasive framework for ambient assisted living The increasing need to access information everywhere and at any time leads us to believe that future user interfaces, through which users interact with pervasive computing systems, must address both device and modality independence. The pervasive computing paradigm sees almost every object in the everyday environment as a system able to communicate with users and other systems in their own languages. The interaction between users and systems is therefore typically multimodal. The main challenge of multimodal interaction, that is also the main topic of this paper, lies in developing a framework that is able to process information derived from whatever input modalities, giving these inputs an appropriate representation and integrating these individual representations into a joint semantic interpretation. A description of this multimodal pervasive framework will be given in this paper, along with some details of its application in Ambient Assisted Living and the usability test that was implemented to validate its effectiveness.

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

framework architecture
multimodal languages
pervasive systems


COMPARISON OF ICTAL AND INTERICTAL EEG SIGNALS USING FRACTAL FEATURES The feature analysis of epileptic EEG is very significant in diagnosis of epilepsy. This paper introduces two nonlinear features derived from fractal geometry for epileptic EEG analysis. The features of blanket dimension and fractal intercept are extracted to characterize behavior of EEG activities, and then their discriminatory power for ictal and interictal EEGs are compared by means of statistical methods. It is found that there is significant difference of the blanket dimension and fractal intercept between interictal and ictal EEGs, and the difference of the fractal intercept feature between interictal and ictal EEGs is more noticeable than the blanket dimension feature. Furthermore, these two fractal features at multi-scales are combined with support vector machine (SVM) to achieve accuracies of 97.58% for ictal and interictal EEG classification and 97.13% for normal, ictal and interictal EEG classification.

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

nonlinear features
blanket dimension
fractal intercept


Monochromatic and Bichromatic Reverse Top-k Queries Nowadays, most applications return to the user a limited set of ranked results based on the individual user's preferences, which are commonly expressed through top-k queries. From the perspective of a manufacturer, it is imperative that her products appear in the highest ranked positions for many different user preferences, otherwise the product is not visible to potential customers. In this paper, we define a novel query type, namely the reverse top-k query, that covers this requirement: "Given a potential product, which are the user preferences that make this product belong to the top-k query result set?." Reverse top-k queries are essential for manufacturers to assess the impact of their products in the market based on the competition. We formally define reverse top-k queries and introduce two versions of the query, monochromatic and bichromatic. First, we provide a geometric interpretation of the monochromatic reverse top-k query to acquire an intuition of the solution space. Then, we study in detail the case of bichromatic reverse top-k query, and we propose two techniques for query processing, namely an efficient threshold-based algorithm and an algorithm based on materialized reverse top-k views. Our experimental evaluation demonstrates the efficiency of our techniques.

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


Embedding Access Control Policy in Web Service Path Composition Algorithm Web services accomplish requirements, which are complicated functions. To apply web services for a requirement, it should be decomposed into sub-functions for web services. After the decomposition, web services are selected to compose paths. During composition, secure access of web services should be considered. This paper proposes a two-leveled web service access control policy and a web service composition algorithm. We embed the policy in the algorithm. The upper level access control policy uses attributes and credentials to filter out the web services that cannot be invoked by a requester. The lower level policy compares the credit level numbers of web services with the security level numbers of arguments to evaluate the possibility of leaking the arguments. The possibility facilitates evaluating the successfulness of executing a path. After access control, the composition algorithm composes multiple paths.

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

access control policy
web service composition
information flow


Stability of longest-queue-first scheduling in linear wireless networks with multihop traffic and one-hop interference We consider the stability of the longest-queue-first (LQF) scheduling policy in wireless networks with multihop traffic under the one-hop interference model. Although it is well known that the back-pressure algorithm achieves the maximal stability, its computational complexity is prohibitively high. In this paper, we consider LQF, a low-complexity scheduling algorithm, which has been shown to have near-optimal throughput performance in many networks with single-hop traffic flows. We are interested in the performance of LQF for multihop traffic flows. In this scenario, the coupling between queues due to multihop traffic flows makes the local-pooling-factor analysis difficult to perform. Using the fluid-limit techniques, we show that LQF achieves the maximal stability for linear networks with multihop traffic and a single destination on the boundary of the network under the one-hop interference model.

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

stability
linear networks
multihop traffic


Immunotherapy with interleukin-2: A study based on mathematical modeling The role of interleukin-2 (IL-2) in tumor dynamics is illustrated through mathematical modeling, using delay differential equations with a discrete time delay (a modified version of the Kirshner-Panetta model). Theoretical analysis gives an expression for the discrete time delay and the length of the time delay to preserve stability. Numerical analysis shows that interleukin-2 alone can cause the tumor cell population to regress.

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

effector cells
tumor cells
interleukin-2


A synergistic model-driven approach for persistence modeling with UML The Model Driven Development (MDD) approach proposes that models (and model-to-model transformations) play the main role on system development. However, there is not a consensual notation to model persistence based upon object-relational mapping frameworks: while UML lacks specific resources for persistence modeling, the entity-relationship model does not make reference to the dynamic concepts existing in UML. This paper proposes MD-JPA, a UML profile for persistence modeling based on the well-known Java Persistence API 2 (JPA) standard for object-relational mapping, pursuing the modeling of transient and persistent elements in a more coherent and synergistic way. This paper describes the main characteristics of MD-JPA as well as the way that models that adopt such profile can them be used to generate a Java implementation by the application of the proposed model transformations on a MDD approach. Finally, an open source tool was developed to make the results of this work available to the community.

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

object-relational mapping
unified modeling language profile
model transformation
java persistence api


role updating for assignments The role-based access control (RBAC) has significantly simplified the management of users and permissions in computing systems. In dynamic environments, systems are usually undergoing changes, whereas the associated user-role, role-role and role-permission relations need to be updated accordingly in order to reflect the systems' evolutions. However, such updating process is generally complicated as the resulting system state is expected to meet necessary constraints. This paper presents an approach for assisting administrators with the update task: using this approach, it is possible to check, in an automatic way, whether a required update is achievable or not, and if so, a reference model will be produced. In light of this model, administrators could fulfill the changes to RBAC systems. We propose a formalization of the update approach, investigate its properties, and develop an updating algorithm based on model checking techniques. Our experimental results demonstrate the effectiveness of our approach.

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


A fixed-charge transportation problem in two-stage supply chain network in Gaussian type-2 fuzzy environments This paper presents two mathematical models representing imprecise capacitated fixed-charge transportation problems for a two-stage supply chain network in Gaussian fuzzy type-2 environment. It is a two-stage transportation process from a manufacturing center to m potential distribution centers (DCs) and then from DCs to business centers of n retailers with particular demands. Retailers are situated at some distances apart. Here unit transportation costs, fixed charges, availabilities, and demands are imprecise and represented by Gaussian type-2 fuzzy numbers. The proposed models are formulated as profit maximization problems in such a way that some DCs are selected in order to satisfy the demands at all retailers. The type-2 fuzziness has been removed by using generalized credibility measure developed with the help of CV-based reduction method and hence the models are reduced to chance constrained programming problems with different credibility labels. The deterministic models are then solved using both genetic algorithm (GA) based on Roulette wheel selection, arithmetic crossover with uniform mutation and modified particle swarm optimization (PSO), where the position of each particle is adjusted according to its own experience and that of its neighbors. Finally models are illustrated with some numerical data. Some sensitivity analyses on the proposed models are presented.

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

supply chain
genetic algorithm
particle swarm optimization

fixed-charge transportation
gaussian fuzzy type-2 variables


Continuous Learning of Compiler Heuristics Optimizing programs to exploit the underlying hardware architecture is an important task. Much research has been done on enabling compilers to find the best set of code optimizations that can build the fastest and less resource-hungry executable for a given program. A common approach is iterative compilation, sometimes enriched by machine learning techniques. This provides good results, but requires extremely long compilation times and an initial training phase lasting even for days or weeks. We present long-term learning, a new algorithm that allows the compiler user to improve the performance of compiled programs with reduced compilation times with respect to iterative compilation, and without an initial training phase. Our algorithm does not just build good programs: it acquires knowledge every time a program is compiled and it uses such knowledge to learn compiler heuristics, without the need for an expert to manually define them. The heuristics are evolved during every compilation, by evaluating their effect on the generated programs. We present implementations of long-term learning on top of two different compilers, and experimental data gathered on multiple hardware configurations showing its effectiveness.

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

performance
iterative compilation
machine learning


applying genetic algorithms to economy market using iterated prisoner's dilemma This paper investigates the use of Genetic Algorithms (GA) to evolve cooperative agents in a competitive market environment using Iterated Prisoner's Dilemma (IPD). Our study seeks to follow Axelrod's research of computer simulations of the IPD game which is generally regarded as a benchmark for the studies on evolution of cooperation. However, we are of the opinion that his work was a little restrictive and lack of a genuine real-world component. In this paper, we report on a simulation study that attempts to bridge the gap by applying GA to a market model. We examine how well GA could perform against the IPD strategies, and explore the strategic interactions among the agents that represent firms in a coevolving population. We also report on the influence of the genetic operators on the performance of GA. Our experimental results show that cooperation can be evolved in such non-cooperative environment using GA. We conclude that with proper tuning of parameters, GA could be extremely useful for optimizing the outcome of an economy market.

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

iterated prisoner's dilemma
strategy optimization