On optimizing JacobiDavidson method for calculating eigenvalues in low dimensional structures using eight band kp model The paper presents two ways of improving the JacobiDavidson method for calculating the eigenvalues and eigenvectors described by eight-band kp model for quantum dots and other low dimensional structures. First, the method is extended by the application of time reversal symmetry operator. This extension allows efficient calculations of the twofold degeneracy present in the multiband kp model and other interior eigenvalues. Second, the preconditioner for the indefinite matrix which comes from the discretization of the eight band kp Hamiltonian is presented. The construction of this preconditioner is based on physical considerations about energy band structure in the kp model. On the basis of two real examples, it is shown that the preconditioner can significantly shorten the time needed to calculate the interior eigenvalues, despite the fact that the memory usage of the preconditioner and Hamiltionian is comparable. Finally, some technical details for implementing the eight band kp Hamiltonian and the eigensolver are provided.

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

jacobidavidson method
eight band kp model
low dimensional structures


Lognormal and Weibull accelerated life test plans under distribution misspecification In this article, we derive expressions for the asymptotic distribution of maximum likelihood estimators of model parameters in accelerated life tests (ALTs) when the model distribution is misspecified. We investigate results for two popular models, namely, the lognormal and Weibull Arrhenius-type ALT models. We propose test plan criteria based on asymptotic bias (ABias) and asymptotic mean squared error (AMSE) to derive ALT test plans. We derive 4:2:1 allocation plans that minimize either ABiaS(2) or AMSE. These criteria provide control over estimation bias and variance when the model distribution is misspecified.

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

asymptotic mean square error
optimal test plans
relative efficiency
type i censoring


DEVELOPMENTAL SIZE ESTIMATION FOR OBJECT-ORIENTED SOFTWARE BASED ON ANALYSIS MODEL Software size estimation at the early analysis phase of software development lifecycle is crucial for predicting the associated effort and cost. Analysis phase captures the functionality addressed in the software to be developed in object-oriented software development life-cycle. Unified modeling language captures the functionality of the software at the analysis phase based on use case model. This paper proposes a new method named as use case model function point to estimate the size of the object-oriented software at the analysis phase itself. While this approach is based on use case model, it also adapts the function point analysis technique to use case model. The various features such as actors, use cases, relationship, external reference, flows, and messages are extracted from use case model. Eleven rules have been derived as guidelines to identify the use case model components. The function point analysis components are appropriately mapped to use case model components and the complexity based on the weightage is specified to calculate use case model function point. This proposed size estimation approach has been evaluated with the object-oriented software developed in our software engineering laboratory to assess its ability to predict the developmental size. The results are empirically analysed based on statistical correlation for substantiating the proposed estimation method.

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

object-oriented software
software estimation


Developing a variables repetitive group sampling plan based on process capability index C (pk) with unknown mean and variance In this paper, variables repetitive group sampling plans are developed based on the process capability index C-pk when the quality characteristic follows a normal distribution with unknown mean and variance. The sampling plan parameters such as the sample size and the acceptance constant are determined to minimize the average sample number. Symmetric and asymmetric cases, in percent defectives due to two specification limits, are dealt with for specified combinations of acceptable quality level and limiting quality level. Tables are provided and examples are given to use proposed plans in practice.

O O O B I I 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 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

repetitive group sampling
process capability index

upper and lower specifications limits
operating characteristics curve


Novel Signal Transduction Pathways Although the precise etiology of inflammatory bowel disease still remains unclear, considerable progress has been made in the identification of novel signal transduction pathways that elucidate the immunopathogenesis involved in the perpetuation of the inflammatory process. Augmented T cell resistance against apoptosis is regarded as a pivotal factor in the pathogenesis, as it impairs mucosal homeostasis and leads to unrestrained accumulation of activated T cells, which subsequently lead to the amplification of the inflammatory response. Therefore novel therapeutic strategies aim at restoring mucosal T cell susceptibility to apoptosis through targeting of signal transduction pathways that are elemental for augmented resistance of T lymphocytes against apoptosis. For example, a newly developed humanized anti-IL-6R monoclonal antibody that induces intestinal T cell apoptosis showed clinical efficacy in patients with active Crohn`s disease. Moreover, recent data that relate the immunosuppressive effects of azathioprine in inflammatory bowel disease to its apoptosis-inducing potential, have important implications for the design of a more specific therapeutic approach.The examination of these novel signal transduction pathways has elucidated the pathogenetic mechanisms involved in inflammatory bowel disease and gives hope for the development of new strategies that may result in a more effective and less toxic therapeutic procedure

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

inflammatory bowel disease
signal transduction
apoptosis
azathioprine


AN MS-DOS PROGRAM FOR CERTAIN COMPUTATIONS FOR THE WECHSLER ADULT INTELLIGENCE SCALE - REVISED A compiled program for MS-DOS computers is described. The program computes four useful measures for the Wechsler Adult Intelligence Scale - Revised (WAIS-R). It will estimate the subject's premorbid Verbal, Performance, and Full-Scale IQs from demographic data. It will prorate the sum of the Verbal or Performance scaled scores when less than the full number of subtests are administered. It will compute the deviation of each age-scaled score from either the Verbal or Performance mean, indicating the reliablity and abnormality of all differences. For those subtests which differ significantly from the appropriate mean score, the program briefly describes the subject's relative strengths and weaknesses. Finally, the program will compute the difference between the Verbal and Performance IQs, indicating the reliability and abnormality of the difference.

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

wais-r microcomputer ms-dos psychologist


Geodesic Image and Video Editing This article presents a new, unified technique to perform general edge-sensitive editing operations on n-dimensional images and videos efficiently. The first contribution of the article is the introduction of a Generalized Geodesic Distance Transform (GGDT), based on soft masks. This provides a unified framework to address several edge-aware editing operations. Diverse tasks such as denoising and nonphotorealistic rendering are all dealt with fundamentally the same, fast algorithm. Second, a new Geodesic Symmetric Filter (GSF) is presented which imposes contrast-sensitive spatial smoothness into segmentation and segmentation-based editing tasks (cutout, object highlighting, colorization, panorama stitching). The effect of the filter is controlled by two intuitive, geometric parameters. In contrast to existing techniques, the GSF filter is applied to real-valued pixel likelihoods (soft masks), thanks to GGDTs and it can be used for both interactive and automatic editing. Complex object topologies are dealt with effortlessly. Finally, the parallelism of GGDTs enables us to exploit modern multicore CPU architectures as well as powerful new GPUs, thus providing great flexibility of implementation and deployment. Our technique operates on both images and videos, and generalizes naturally to n-dimensional data. The proposed algorithm is validated via quantitative and qualitative comparisons with existing, state-of-the-art approaches. Numerous results on a variety of image and video editing tasks further demonstrate the effectiveness of our method.

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

image and video
segmentation
nonphotorealistic rendering
geodesic distance
denoising

algorithms
restoration
geodestic segmentation
tooning


Digital Error Corrector for Phase Lead-Compensated Buck Converter in DVS Applications Modern low-power system on a chip needs direct current converter with dynamic voltage scaling (DVS) ability for core power supply. The converter output should be accurate voltage across the full load current and voltage scaling range. An integrated buck converter for DVS application is proposed in this brief. Voltage mode phase lead compensation is implemented in the converter, with much smaller passive components than conventional type-III compensation. To improve accuracy, the output voltage error accompanied with load current and reference voltage caused by finite loop gain in analog control loop is corrected by the digital error corrector. The output voltage is compared by two comparators whose threshold voltage is about 10 mV above and below the reference voltage, respectively. The duty cycle is slightly adjusted by finite state machine according to outputs of the two comparators. Experimental results show that the converter is well regulated over an output range of 0.7-1.8 V, with step voltage of 25 mV. When load current suddenly changes between 170 and 500 mA, the overshoot and undershoot voltage are 32 and 50 mV, respectively. Load regulation is maintained about 1% throughout the full load range. The voltage error is within +/- 10 mV in the voltage scaling range.

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

buck converter
digital error corrector
phase lead compensation


Street-based topological representations and analyses for predicting traffic flow in GIS It is well received in the space syntax community that traffic flow is significantly correlated to a morphological property of streets, which are represented by axial lines, forming a so called axial map. The correlation co-efficient (R 2) approaches 0.8 and even a higher value according to the space syntax literature. In this paper, we study the same issue using the Hong Kong street network and the Hong Kong Annual Average Daily Traffic datasets, and find surprisingly that street-based topological representations (or street-street topologies) tend to be better representations than the axial map. In other words, vehicle flow is correlated to a morphological property of streets better than that of axial lines. Based on the finding, we suggest the street-based topological representations as an alternative GIS representation, and the topological analyses as a new analytical means for geographic knowledge discovery.

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

street-based topological representation
topological analysis


secure communication for ad-hoc, federated groups Ad-hoc federated groups are getting increasingly popular as means of addressing collaborative tasks that require information sharing. However, in some application scenarios, the security of the shared information is vital. Managing the communication security of such groups in an efficient way is a difficult task. This paper presents an architecture that enables secure communication for ad-hoc, cross-organisational groups. Our architecture covers group admission control, group key management and secure group communication. The groups in question are expected to be ad-hoc groups where the potential participants have no prior knowledge of each other and thus federation mechanisms need to be used to establish group admission rights. In order to handle group admission we use the SAML and XACML standards, for group key management we use the TGDH protocol. Our approach thus supports decentralised management of the most important tasks in secure group communication using an integrated approach based on established security standards. We have also produced a demo implementation to show the feasibility of our architecture. This research was pursued as part of the TrustDis project funded by the Swedish Governmental Agency for Innovation Systems (Vinnova).

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

authorization
access control
tree-based group
diffie-hellman


More Than a Number: Unexpected Benefits of Return on Investment Analysis In 20102011, University of Colorado (CU) librarians implemented a multi-campus pilot study to measure the institutional value of library resources used by faculty in their research. The study incorporated quantitative methods including return on investment (ROI), cost benefit analysis (CBA), and citation analysis of journal articles published by faculty; and qualitative methodologies such as in-person interviews with faculty. The study resulted in a CU ROI model that can be used to measure faculty perceptions of value and the economic benefits of electronic journal collections for faculty research in terms of ROI. The CU ROI methodology provides outcomes beyond a single ROI number and led to unexpected benefits for informing collection development decisions and strategies.

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

return on investment
cost benefit analysis


Efficient FIB caching using minimal non-overlapping prefixes ? The size of the global Routing Information Base (RIB) has been increasing at an alarming rate. As a direct effect, the size of the global Forwarding Information Base (FIB) has experienced rapid growth. This increase raises serious concerns for Internet Service Providers (ISPs) as the FIB memory in line cards is much more expensive than regular memory modules, so frequently increasing this memory capacity for all the routers is prohibitively costly to an ISP. Previous research on Internet traffic indicates that a very small number of popular prefixes receive most of the Internets traffic, making caching a possible solution to reduce the FIB size. However, FIB caching may cause a cache-hiding problem where a packets longest-prefix match in the cache differs from that in the full FIB, and thus the packet will be forwarded to the wrong next hop. Motivated by these observations, we propose an efficient FIB caching scheme that stores only non-overlapping FIB entries into the fast memory (i.e., a FIB cache), while storing the complete FIB in slow memory. Our caching scheme achieves a considerably higher hit ratio than previous approaches while preventing the cache-hiding problem. It can also handle cache misses, cache replacement, and routing updates efficiently. Moreover, we have implemented the proposed caching scheme using the OpenFlow platform, which allows a local or remote route controller to manage routes in the cache. We use real traffic of a regional ISP and a Tier1 ISP to carry out our experiments. Our simulation results show that with only 20K prefixes in the cache (5.28% of the actual FIB size), the hit ratio of our scheme is higher than 99.95%. Our OpenFlow implementation achieves a hit ratio near 99.94%, which approaches the performance of the simulated results.

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


the dawn at my back Interactive multimedia narrative in CD/DVD-ROMs and game design offers choice and non-linearity as communication signifiers. The viewer chooses where to go in an interactive design, viewing content in a non-traditional, non-linear fashion. However the content is totally controlled by the author, not the reader. The content is pre-determined while the viewer controls the viewing path in real time. The Dawn At My Back: Memoir of a Black Texas Upbringing outlines three parallel stories of a mother, a daughter, and a society by detailing racism's impact on each element. The concept is to design a combination Book/DVD-ROM/Website that allows the reader direct interaction with the narrative. This project expands on the idea that interactivity is a dialogue between viewer and story by encouraging the book's reader to become a DVD-ROM user and website co-author.

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

interactive art
storytelling
reader (user experience)
autobiography


The effects of individualismcollectivism cultural orientation on eWOM information We explore how individualistic culture affects readers information credibility. Individualistic culture has positive moderate effect with information sidedness. Individualistic culture has negative moderate effect with information consistency. Individualistic culture has negative moderate effect with information rating.

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

espoused culture
elaboration likelihood model


Accessibility and acceptance of responsive virtual human technology as a survey interviewer training tool Research on survey non-response suggests that advanced communication and listening skills are among the best strategies telephone interviewers can employ for obtaining survey participation, allowing them to identify and address respondents concerns immediately with appropriate, tailored language. Yet training on interaction skills is typically insufficient, relying on role-playing or passive learning through lecture and videos. What is required is repetitive, structured practice in a realistic work environment. This research examines acceptance by trainees of an application based on responsive virtual human technology (RVHT) as a tool for teaching refusal avoidance skills to telephone interviewers. The application tested here allows interviewers to practice confronting common objections offered by reluctant sample members. Trainee acceptance of the training tool as a realistic simulation of real life interviewing situations is the first phase in evaluating the overall effectiveness of the RVHT approach. Data were gathered from two sources structured debrief questionnaires administered to users of the application, and observations of users by researchers and instructors. The application was tested with a group of approximately 50 telephone interviewers of varying skill and experience levels. The research presents findings from these acceptance evaluations and discusses users experiences with and perceived effectiveness of the virtual training tool.

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

technology-based training
virtual reality
speech processing
survey research


Cubic polynomial patches through geodesics We consider patches that contain any given 3D polynomial curve as a pregeodesic (i.e.geodesic up to reparametrization). A curve is a pregeodesic if and only if its rectifying plane coincides with the tangent plane to the surface, we use this fact to construct ruled cubic patches through pregeodesics and bicubic patches through pairs of pregeodesics. We also discuss the G1 G 1 connection of (1,k) ( 1 , k ) patches with abutting pregeodesics.

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


managing duplicates in a web archive Crawlers harvest the web by iteratively downloading documents referenced by URLs. It is frequent to find different URLs that refer to the same document, leading crawlers to download duplicates. Hence, web archives built through incremental crawls waste space storing these documents. In this paper, we study the existence of duplicates within a web archive and discuss strategies to eliminate them at storage level during the crawl. We present a storage system architecture that addresses the requirements of web archives and detail its implementation and evaluation. The system is now supporting an archive for the Portuguese web replacing previous NFS-based storage servers. Experimental results showed that the elimination of duplicates can improve storage throughput. The web storage system outperformed NFS based storage by 68\% in read operations and by 50\% in write operations. 1

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

requirements
storage system
strategies
crawl
space
web
architecture
storage
implementation
throughput
paper
read
evaluation
incremental

web archival
experimentation
systems
operability
documentation
writing
server
archival
management


Fuzzy class theory The paper introduces a simple, yet powerful axiomatization of Zadeh's notion of fuzzy set, based on formal fuzzy logic. The presented formalism is strong enough to serve as foundations of a large part of fuzzy mathematics. Its essence is elementary fuzzy set theory, cast as two-sorted first-order theory over fuzzy logic, which is generalized to simple type theory. We show a reduction of the elementary fuzzy set theory to fuzzy propositional calculus and a general method of fuzzification of classical mathematical theories within this formalism. In this paper we restrict ourselves to set relations and operations that are definable without any structure on the universe of objects presupposed; however, we also demonstrate how to add structure to the universe of discourse within our framework. (c) 2005 Elsevier B.V. All rights reserved.

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

foundations of fuzzy mathematics
lti logic
higher-order fuzzy logic
fuzzy type theory
multi-sorted fuzzy logic


Quantifier elimination by cylindrical algebraic decomposition based on regular chains ? A quantifier elimination algorithm by cylindrical algebraic decomposition based on regular chains is presented. The main idea is to refine a complex cylindrical tree until the signs of polynomials appearing in the tree are sufficient to distinguish the true and false cells. We report an implementation of our algorithm in the RegularChains library in Maple and illustrate its effectiveness by examples.

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

quantifier elimination
cylindrical algebraic decomposition
regular chains


O(2)ABA: A novel high-performance predictable circuit architecture for the deep submicron era Current VLSI design techniques focus on four major goals: higher integration, faster speed, lower power, and shorter time-to-market. These goals have been accomplished mainly by deep submicron (DSM) technology along with voltage scaling. However, scaling down of feature size causes larger interwire capacitance which results in large crosstalk between interconnects. In this paper, we propose a novel predictable circuit architecture, named "optimized overlaying array-based architecture" (O(2)ABA), especially suited for the deep submicron regime. O(2)ABA achieves reduction in crosstalk by considering the current directions and by reducing interwire capacitance. The introduction of "unit cell" leads to regularity, which makes the performance predictable even before layout, and shortens design time. O(2)ABA is compared with other design styles, such as custom design and standard cell approach, in terms of coupling capacitance, area, and delay.

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

crosstalk
deep submicron
regularity
unit cell

array-based
delay fault
dynamic circuit
predictability
signal integrity


Natural Language based On-demand Service Composition The widespread of Web services in the ubiquitous computing era and the impossibility to predict a priori all possible user needs generates the necessity for on-demand service composition. Natural language is one of the the easiest ways for a user to express what he expects regarding a service. Two main problems need to be solved in order to create a composite service to satisfy the user: a)retrieval of relevant services and b) orchestration/composition of the selected services in order to fulfill the user request. We solve the first problem by using semantic concepts associated with the services and we define a conceptual distance to measure the similarity between the user request and a service configuration. Retrieved services are composed, based on aspect oriented templates called Aspects of Assembly. We have tested our application in an environment for pervasive computing called Ubiquarium, where our system composes a service according to the user request described by a sentence. The implementation is based on the WComp middleware that enables us to use regular Web services but also Web services for devices.

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

natural language
service composition
middleware
templates


Uncertainty distribution and independence of uncertain processes Uncertain process is a sequence of uncertain variables indexed by time. This paper presents a concept of uncertainty distribution for describing uncertain process. Some sufficient and necessary conditions are also proved for uncertainty distribution and inverse uncertainty distribution of uncertain process. Finally, this paper proposes an independence definition of uncertain processes and shows some mathematical properties of it.

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

uncertain process
uncertainty distribution


Model-based clustering in gene expression microarrays: An application to breast cancer data In microarray studies, the application of clustering techniques is often used to derive meaningful insights into the data. In the past, hierarchical methods have been the primary clustering tool employed to perform this task. The hierarchical algorithms have been mainly applied heuristically to these cluster analysis problems. Further, a major limitation of these methods is their inability to determine the number of clusters. Thus there is a need for a model-based approach to these. clustering problems. To this end, McLachlan et al. [7] developed a mixture model-based algorithm (EMMIX-GENE) for the clustering of tissue samples. To further investigate the EMMIX-GENE procedure as a model-based -approach, we present a case study involving the application of EMMIX-GENE to the breast cancer data as studied recently in van 't Veer et al. [10]. Our analysis considers the problem of clustering the tissue samples on the basis of the genes which is a non-standard problem because the number of genes greatly exceed the number of tissue samples. We demonstrate how EMMIX-GENE can be useful in reducing the initial set of genes down to a more computationally manageable size. The results from this analysis also emphasise the difficulty associated with the task of separating two tissue groups on the basis of a particular subset of genes. These results also shed light on why supervised methods have such a high misallocation error rate for the breast cancer data.

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


Credit-based source-adaptive multilayered video multicast ? Spatial and temporal variations in network bandwidth constraints constitute serious challenges to the multicast distribution of real-time video content. This paper presents a video multicast algorithm that combines multilayered video encoding with feedback-based source adaptation in order to address varying bandwidth constraints in a multicast tree. The proposed algorithm uses a novel credit-based, hop-by-hop multicast flow control mechanism in conjunction with explicit rate congestion feedback. It achieves nearly optimal network utilization at the expense of packet losses that are isolated to low priority video content. The responsiveness, bandwidth utilization, scalability, video quality and fairness of the proposed mechanism are evaluated through simulations, and results suggest that the proposed mechanism is capable of providing a high quality video service in the presence of varying bandwidth constraints.

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

video multicast
multilayered video encoding


Computing isolated roots of sparse polynomial systems in affine space We present a symbolic probabilistic algorithm to compute the isolated roots in C(n) of sparse polynomial equation systems. As some already known numerical algorithms solving this task, our procedure is based on polyhedral deformations and homotopies, but it amounts to solving a smaller number of square systems of equations and in fewer variables. The output of the algorithm is a geometric resolution of a finite set of points including the isolated roots of the system. The complexity is polynomial in the size of the combinatorial structure of the system supports up to a pre-processing yielding the mixed cells in a subdivision of the family of these supports. (C) 2010 Elsevier B.V. All rights reserved.

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

sparse polynomial systems
algorithms
complexity


COLREGs-based collision avoidance strategies for unmanned surface vehicles The aim of this paper is to report the preliminary development of an automatic collision avoidance technique for unmanned marine craft based on standardised rules, COLREGs, defined by the International Maritime Organisation. It is noted that all marine surface vessels are required to adhere to COLREGs at all times in order to minimise or eliminate the risk of collisions. The approach presented is essentially a reactive path planning algorithm which provides feedback to the autopilot of an unmanned vessel or the human captain of a manned ship for steering the craft safely. The proposed strategy consists of waypoint guidance by line-of-sight coupled with a manual biasing scheme. This is applied to the dynamic model of an unmanned surface vehicle. A simple PID autopilot is incorporated to ensure that the vessel adheres to the generated seaway. It is shown through simulations that the resulting scheme is able to generate viable trajectories in the presence of both stationary and dynamic obstacles. Rules 8 and 14 of the COLREGs, which apply to the amount of manoeuvre and to a head-on scenario respectively are simulated. A comparison is also made with an offline or deliberative grid-based path planning algorithm which has been modified to generate COLREGs-compliant routes. (c) 2011 Elsevier Ltd. All rights reserved.

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

obstacle detection and avoidance
navigation
guidance and control


evaluating invariances in document layout functions With the development of variable-data-driven digital presses where each document printed is potentially unique there is a need for pre-press optimization to identify material that is invariant from document to document. In this way rasterisation can be confined solely to those areas which change between successive documents thereby alleviating a potential performance bottleneck.Given a template document specified in terms of layout functions, where actual data is bound at the last possible moment before printing, we look at deriving and exploiting the invariant properties of layout functions from their formal specifications. We propose future work on generic extraction of invariance from such properties for certain classes of layout functions.

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


towards persistence-based reconstruction in euclidean spaces Manifold reconstruction has been extensively studied for the last decade or so, especially in two and three dimensions. Recent advances in higher dimensions have led to new methods to reconstruct large classes of compact subsets of R d . However, the complexities of these methods scale up exponentially with d , making them impractical in medium or high dimensions, even on data sets of low intrinsic dimensionality. In this paper, we introduce a novel approach that stands in-between classical reconstruction and topological estimation, and whose complexity scales up with the intrinsic dimension of the data. Our algorithm combines two paradigms: greedy refinement, and topological persistence. Given a point cloud in R d , we build a set of landmarks iteratively, while maintaining a nested pair of abstract complexes, whose images in R d lie close to the data, and whose persistent homology eventually coincides with the homology of the underlying shape. When the data points are densely sampled from a smooth m -submanifold X of R d , our method retrieves the homology of X in time at most c ( m ) n 5 , where n is the size of the input and c ( m ) is a constant depending solely on m . To prove the correctness of our algorithm, we investigate on ?ech, Rips, and witness complex filtrations in Euclidean spaces. More precisely, we show how previous results on unions of balls can be transposed to ?ech filtrations, and from there to Rips and witness complex filtrations. Finally, investigating further on witness complexes, we quantify a conjecture of Carlsson and de Silva, which states that witness complex filtrations should have cleaner persistence barcodes than ?ech or Rips filtrations, at least on smooth submanifolds of Euclidean spaces.

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

witness complex
persistent homology
manifold reconstruction


Technoliteracy and learning: An analysis of the quality of knowledge in electronic representations of understanding Recent educational research from a socio-cognitive perspective has validated students' collaborative engagement with new technologies and heightened understanding of influential factors shaping the effectiveness of peer interactions, learning contexts and computer interfaces for enhancing learning. This paper focuses on an analysis of the complexity of knowledge in student-designed, electronically created texts for what they might reveal about learning with technology. It reports on a study with 17-year-old female students whose collaborative learning process in subject English was mediated by the creation of electronic concept maps and Web files to represent their developing understanding. To analyse these electronic texts, evaluative criteria templates were developed from the Structure of Observed Learning Outcomes (SOLO) taxonomy, integrating levels of understanding with the distinctive characteristics of multimodal text production. Findings indicated not just the incremental acquisition of conceptual understanding equated with cognitive change but that the level of understanding might also be positively influenced by the students' length of exposure to computer-mediated learning practices. As well, the criteria templates have emerged as useful evaluative tools for classroom assessment or further research when analysis of the level of complexity of student-created, electronic artefacts is required. (c) 2005 Elsevier Ltd. All rights reserved.

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 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

technoliteracy
collaborative learning process

computer-mediated learning
evaluation tools for e-learning
electronic representation of learning


On equalization for Direct Sequence-Ultra Wideband system using Received Response code sequence This paper proposes a combination of novel Received Response (RR) sequence at the transmitter and Matched Filter-Equalizer-RAKE (MF-EQZ-RAKE) combining scheme receiver system for Direct Sequence-Ultra Wideband (DS-UWB) multipath channel model. When binary code sequence such as M sequence is used, there is a possibility of generating extra Inter-Symbol Interference (ISI) in the UWB system. Therefore, it is quite a challenging task to collect the energy efficiently although RAKE reception method is applied at the receiver. The main purpose of the proposed system is to overcome the performance degradation for UWB transmission due to the occurrence of Inter-Symbol Interference (ISI) during high speed transmission of ultra short pulses in a multipath channel. The proposed system improves the system performance by improving the RAKE reception performance using RR sequence and suppressing the ISI effect with the equalizer. Simulation results verify that significant improvement can be obtained by the proposed system especially in UWB multipath channel models such as channel CM4 that suffered severe ISI effect.

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

direct sequence-ultra wideband (ds-uwb)
inter-symbol interference (isi)


Parametric Monte Carlo studies of rock slopes based on the HoekBrown failure criterion Probabilistic evaluation of slope failures is increasingly seen as the most appropriate framework for accounting for uncertainties in design. This paper performs reliability assessments for rock slopes based on the latest version of the HoekBrown failure criterion. The purpose of this study is to demonstrate the use of a new form of stability number for rock slope designs that has been recently developed from finite element upper and lower bound limit analysis methods, and to provide guidance for its use in probabilistic assessments. The analyses show that by using this newly proposed stability number, the probability of failure (Pf) obtained from case studies agrees well with the true state of the slope. In addition, this paper details a procedure to determine the magnitude of safety factor required for rock slope design.

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

safety factor
limit analysis
stability number
probability


Modified CC-LR algorithm with three diverse feature sets for motor imagery tasks classification in EEG based braincomputer interface Motor imagery (MI) tasks classification provides an important basis for designing braincomputer interface (BCI) systems. If the MI tasks are reliably distinguished through identifying typical patterns in electroencephalography (EEG) data, a motor disabled people could communicate with a device by composing sequences of these mental states. In our earlier study, we developed a cross-correlation based logistic regression (CC-LR) algorithm for the classification of MI tasks for BCI applications, but its performance was not satisfactory. This study develops a modified version of the CC-LR algorithm exploring a suitable feature set that can improve the performance. The modified CC-LR algorithm uses the C3 electrode channel (in the international 1020 system) as a reference channel for the cross-correlation (CC) technique and applies three diverse feature sets separately, as the input to the logistic regression (LR) classifier. The present algorithm investigates which feature set is the best to characterize the distribution of MI tasks based EEG data. This study also provides an insight into how to select a reference channel for the CC technique with EEG signals considering the anatomical structure of the human brain. The proposed algorithm is compared with eight of the most recently reported well-known methods including the BCI III Winner algorithm. The findings of this study indicate that the modified CC-LR algorithm has potential to improve the identification performance of MI tasks in BCI systems. The results demonstrate that the proposed technique provides a classification improvement over the existing methods tested.

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

braincomputer interface (bci)
electroencephalogram (eeg)
cross-correlation
feature extraction


Missing pattern discovery In this paper, we study the missing patterns problem: Find the shortest pair of patterns that do not occur close to each other in a given text, i.e., the distance between their occurrences is always greater than a given threshold ?. We present various solutions to this problem, as well as to the case where the patterns in the pair are required to be of the same length. This work is motivated by optimizing the sensitivity of PCR. Experiments show that our algorithm is practical enough to handle human genome data.

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

polymerase chain reaction (pcr)
suffix trees


Power-aware node deployment in wireless sensor networks Wireless sensor networks (WSNs) have attracted intense interest due to their extensible capability. In this paper, we attempt to answer a fundamental but practical question: "how should we deploy, these nodes?" In most current designs, sensor nodes are randomly or uniformly distributed because of their simplicity. However, the node deployment has a great impact on the performance of WSNs. Instead of maintaining the coverage for some snapshots of a WSN, it is essential that we can provide a continuous coverage in the whole lifecycle of the WSN. We will exhibit the weakness of the uniform distribution by disclosing the fatal sink routing-hole problem. To address this problem, we propose a non-uniform, power-aware distribution scheme. Our analysis and simulation results show that the power-aware deployment scheme can significantly improve the long-term network connectivity, and service quality.

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

wireless sensor networks
node deployment


RRG: redundancy reduced gossip protocol for real-time N-to-N dynamic group communication Real-time group communication is an indispensable part of many interactive multimedia applications over the internet. In scenarios that involve large group sizes, sporadic sources, high user churns, and random network failures, gossip-based protocols can potentially provide advantages over structure-based group communication algorithms in ease of deployment, scalability, and resiliency against churns and failures. In this paper, we propose a novel protocol called Redundancy Reduced Gossip for real-time N-to-N group communication. We show that our proposed protocol can achieve a considerably lower traffic load than conventional push-based gossip protocols and conventional push-pull gossip protocols for the same probability of successful delivery, with higher performance gains in networks with smaller delays. We derive a mathematical model for estimating the frame non-delivery probability and the traffic load from overhead, and demonstrate the general correctness of the model by simulation. We implement a functioning prototype conferencing system using the proposed protocol, completed with functions including NTP synchronization, dynamic group size estimation, redundancy suppression, and other features needed for proper operation. We perform experiments over the campus network and PlanetLab, and the prototype system demonstrates the ability of our protocol to maintain robust performance in real-world network environments.

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

terms real-time distributed
network protocols
network communication
multicast
verification
reliability


Well placement optimization with the covariance matrix adaptation evolution strategy and meta-models The amount of hydrocarbon recovered can be considerably increased by finding optimal placement of non-conventional wells. For that purpose, the use of optimization algorithms, where the objective function is evaluated using a reservoir simulator, is needed. Furthermore, for complex reservoir geologies with high heterogeneities, the optimization problem requires algorithms able to cope with the non-regularity of the objective function. In this paper, we propose an optimization methodology for determining optimal well locations and trajectories based on the covariance matrix adaptation evolution strategy (CMA-ES) which is recognized as one of the most powerful derivative-free optimizers for continuous optimization. In addition, to improve the optimization procedure, two new techniques are proposed: (a) adaptive penalization with rejection in order to handle well placement constraints and (b) incorporation of a meta-model, based on locally weighted regression, into CMA-ES, using an approximate stochastic ranking procedure, in order to reduce the number of reservoir simulations required to evaluate the objective function. The approach is applied to the PUNQ-S3 case and compared with a genetic algorithm (GA) incorporating the Genocop III technique for handling constraints. To allow a fair comparison, both algorithms are used without parameter tuning on the problem, and standard settings are used for the GA and default settings for CMA-ES. It is shown that our new approach outperforms the genetic algorithm: It leads in general to both a higher net present value and a significant reduction in the number of reservoir simulations needed to reach a good well configuration. Moreover, coupling CMA-ES with a meta-model leads to further improvement, which was around 20% for the synthetic case in this study.

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

field development optimization
cma-es
evolution strategies
meta-models


Experience report: Erlang in acoustic ray tracing We investigated the relative merits of C++ and Erlang in the implementation of a parallel acoustic ray tracing algorithm for the U. S. Navy. We found a much smaller learning curve and better debugging environment for parallel Erlang than for pthreads-based C++ programming. Our C++ implementation outperformed the Erlang program by at least 12x. Attempts to use Erlang on the IBM Cell BE microprocessor were frustrated by Erlang's memory footprint.

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


A grapheme-to-phoneme translator for TTS synthesis in Greek In this paper is presented the algorithm of an automatic grapheme-to-phoneme translator for the Greek language. The proposed algorithm is designed to collaborate with a high quality Text-to-Speech synthesis system in Greek. The algorithm assimilates the full reading process of written text as realized by a Greek speaking person. A detailed study of the Greek language's operation, led us to the implementation of an automatic integrated system which describes its phonetic behaviour in an exact and natural way. The software that implements the algorithm has the capability to receive written text from any input (keyboard, file, screen reader, OCR system e.t.c.) and transform it to phonetic form. Afterwards the output of the algorithm is directed to the input of a concatenation-based speech synthesizer and the right pronunciation of any written text is achieved in real-time. During the reading process the software locates and distinguishes Greek written text from any foreign language words, specially written symbols, abbreviations e.t.c... and afterwards manages them in order that the flow of the reading process permits the right perception of the produced spoken messages. The most important qualification of the algorithm is the possibility to incorporate it in other Text-to-Speech synthesis systems of different technology. Finally experimental measurements indicate the successful operation of the algorithm.

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

text-to-speech
natural language processing


On maximal synchronous codes In this paper, we are interested in maximal synchronous codes. More precisely, we prove that we can embed any synchronous code in a maximal one. Moreover, we establish that, for synchronous codes, the notion of maximality in the family of synchronous codes is equivalent to the notion of maximality in the family of codes. (C) 2003 Elsevier B.V. All rights reserved.

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


A Control-Theoretic Approach to Distributed Optimal Configuration of 802.11 WLANs The optimal configuration of the contention parameters of a WLAN depends on the network conditions in terms of number of stations and the traffic they generate. Following this observation, a considerable effort in the literature has been devoted to the design of distributed algorithms that optimally configure the WLAN parameters based on current conditions. In this paper, we propose a novel algorithm that, in contrast to previous proposals which are mostly based on heuristics, is sustained by mathematical foundations from multivariable control theory. A key advantage of the algorithm over existing approaches is that it is compliant with the 802.11 standard and can be implemented with current wireless cards without introducing any changes into the hardware or firmware. We study the performance of our proposal by means of theoretical analysis, simulations, and a real implementation. Results show that the algorithm substantially outperforms previous approaches in terms of throughput and delay.

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

wireless lan
ieee 802.11
dcf
adaptive mac
distributed algorithm


Consciousness, the Brain, and Spacetime Geometry: An Addendum Brain action is both physically controlled and beyond computational simulation. Accordingly, there is a strong case for examining brain organization in a way that specifically seeks out structures in the brain that might plausibly support such putative non-computational action at the ill-understood borderline between quantum and classical physics. Thus, we must seek out structures in the brain where the actual physics that operates at this level could plausibly have important influence on brain action. This is the basis of the Orch-OR model that Stuart Hameroff and I have been proposing, and which he describes in the foregoing article. The case is strongly put forward that the neuronal microtubules play a key role in the required quantum/classical borderline activities which might have an essential relevance to the phenomenon of consciousness. The exploration of such deeper level of neuronal structure and function is very much a continuation of the line of work so wonderfully initiated by Cajal.

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

non-computability
orch-or model
quantum-classical borderline
measurement problem
quantum non-locality
binding problem


Effect of diffusion on a two-species eco-epidemiological model This paper deals with the stabilizing effect of diffusion on a prey-predator system where the prey population is infected by a microparasite. The predator functional response is a concave-type function. Conditions for the local as well as global stability of the model without diffusion are derived in terms of system parameters. It is also shown that an unstable equilibrium of the model without diffusion can be made stable by increasing the diffusion coefficients appropriately.

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

eco-epidemic model
uniform steady state
asymptotic stability


on iterative intelligent medical search Searching for medical information on the Web has become highly popular, but it remains a challenging task because searchers are often uncertain about their exact medical situations and unfamiliar with medical terminology. To address this challenge, we have built an intelligent medical Web search engine called iMed, which uses medical knowledge and an interactive questionnaire to help searchers form queries. This paper focuses on iMed's iterative search advisor, which integrates medical and linguistic knowledge to help searchers improve search results iteratively. Such an iterative process is common for general Web search, and especially crucial for medical Web search, because searchers often miss desired search results due to their limited medical knowledge and the task's inherent difficulty. iMed's iterative search advisor helps the searcher in several ways. First, relevant symptoms and signs are automatically suggested based on the searcher's description of his situation. Second, instead of taking for granted the searcher's answers to the questions, iMed ranks and recommends alternative answers according to their likelihoods of being the correct answers. Third, related MeSH medical phrases are suggested to help the searcher refine his situation description. We demonstrate the effectiveness of iMed's iterative search advisor by evaluating it using real medical case records and USMLE medical exam questions.

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

medical knowledge
intelligent medical web search engine

medical query
language model
iterative search process


An approach for the integration of swarm intelligence in MAS: An engineering perspective For more than 20years, researchers have designed models in order to describe swarm intelligence and apply the resulting techniques to complex problems. However, there is still a gap between these models and current MAS methodologies. The goal of this paper is to propose a principled and methodological approach for the engineering of systems based upon swarm intelligence. The constraints are, on the one hand, to enable the analysis, design and implementation of such systems; and, on the other hand, to formally analyze and verify properties of resulting systems. The principles of the approach are based, on the one hand, on requirement driven activities that produce goals to be fulfilled by the system of interest and, on the other, hand on an ontological modeling of the problem domain. This ontological modeling conceptualizes the phenomenon one seek to imitate and thus allows it understanding. The produced ontology is refined through the methodology activities down to organizational models.

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

agents
swarming systems
agent-oriented software engineering


polylogarithmic inapproximability We provide the first hardness result of a polylogarithmic approximation ratio for a natural NP-hard optimization problem. We show that for every fixed ?>0 , the GROUP-STEINER-TREE problem admits no efficient log 2-? k approximation, where k denotes the number of groups (or, alternatively, the input size), unless NP has quasi polynomial Las-Vegas algorithms. This hardness result holds even for input graphs which are Hierarchically Well-Separated Trees , introduced by Bartal [FOCS, 1996]. For these trees (and also for general trees), our bound is nearly tight with the log-squared approximation currently known. Our results imply that for every fixed ?>0 , the DIRECTED-STEINER TREE problem admits no log 2-? n --approximation, where n is the number of vertices in the graph, under the same complexity assumption.

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

integrality ratio
hardness of approximation
approximation algorithms
steiner tree


A boundary integral method for multiple circular inclusions in an elastic half-plane This paper presents a numerical method for solving the problem of an isotropic elastic half-plane containing a large number of randomly distributed, non-overlapping, perfectly bonded circular elastic inclusions. The boundary of the half-plane is assumed to be traction free and a uniform far-field stress acts parallel to that boundary. In general, the inclusions may have different elastic properties and sizes. The analysis is based on a numerical solution of a complex singular integral equation with the unknown tractions at each circular boundary approximated by a truncated complex Fourier series. A system of linear algebraic equations is obtained by using a Taylor series expansion. The resulting numerical method allows one to calculate the elastic fields everywhere in the matrix and inside the inclusions. Numerical examples are included to demonstrate the effectiveness of the approach.

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 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

complex singular integral equation
multiple circular inclusions


New existence of homoclinic orbits for a second-order Hamiltonian system ? By using the Mountain Pass Theorem and the Symmetric Mountain Pass Theorem, we establish some existence criteria to guarantee that the second-order Hamiltonian system u ? ( t ) ? a ( t ) | u ( t ) | p ? 2 u ( t ) + ? W ( t , u ( t ) ) = 0 has at least one or infinitely many homoclinic orbits, where t ? R , u ? R N , a?C(R,R) a ? C ( R , R ) and W?C1(RRN,R) W ? C 1 ( R R N , R ) are not periodic in t t . Our conditions on the potential W(t,x) W ( t , x ) are rather relaxed.

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

weighted lp l p spaces lp l p lp l p l p


HubLocator: an exact solution method for the multiple allocation hub location problem HubLocator is a new branch-and-bound procedure for the uncapacitated multiple allocation hub location problem. An existing optimal method developed by Klincewicz (Location Sci. 4 (1996) 173) is based on dual ascent and dual adjustment techniques applied to a disaggregated model formulation. These techniques have already successfully been used to solve the closely related simple plant location problem. However, due to the specific structure of the problem at hand, the success of these techniques in reducing the computational effort is rather restricted. Therefore, HubLocator additionally considers an aggregated model formulation enabling us to significantly tighten the lower bounds. Upper bounds which satisfy complementary slackness conditions for some constraints are constructed and improved by means of a simple heuristic procedure. Computational experiments demonstrate that optimal solutions for problems with up to 40 nodes can be found in a reasonable amount of time. Scope and purpose Ground and air transportation networks, postal delivery networks, and computer networks are often configured as hub-and-spoke systems. Traffic between two locations is not transported directly between these locations, but routed via particular switching or consolidation points called hubs. Due to increased traffic on linkages between hubs, larger vehicles can be used or the capacity of existing vehicles can be utilized more efficiently, resulting in smaller per unit transportation costs. The exploitation of scale economies as a result of the reduced number of linkages, which have to be operated in a hub-and-spoke system, compared to a fully interconnected network is an important advantage of this type of system. Designing hub-and-spoke networks deals with the selection of hubs from a given set of potential locations and the routing of traffic. We consider a special type of such a hub location problem and adapt a successful technique developed to find an optimal solution for the well-known simple plant location problem.

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

hub location problem
aggregated model
dual ascent


Folksonomy-based personalized search and ranking in social media services In recent years, social Web users have been overwhelmed by the huge numbers of social media available. Consequentially, users have trouble finding social media suited to their needs. To help such users retrieve useful social media content, we propose a new model of tag-based personalized searches to enhance not only retrieval accuracy but also retrieval coverage. By leveraging social tagging as a preference indicator, we build two models: (i) a latent tag preference model that reflects how a certain user has assigned tags similar to a given tag and (ii) a latent tag annotation model that captures how users have tagged a certain tag to resources similar to a given resource. We then seamlessly map the tags onto items, depending on an individual user's query, to find the most desirable content relevant to the user's needs. Experimental results demonstrate that the proposed method significantly outperforms the state-of-the art algorithms and show our method's feasibility for personalized searches in social media services.

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

folksonomy
social media search
social ranking


Satisfaction-based query replication An automatic and self-adaptable approach for replicating queries in the presence of autonomous participants In large-scale Internet-based distributed systems, participants (consumers and providers) are typically autonomous, i.e. they may have special interests towards queries and other participants. In this context, a way to avoid a participant to voluntarily leave the system is satisfying its interests when allocating queries. However, participants satisfaction may also be negatively affected by the failures of other participants. Query replication is a solution to deal with providers failures, but, it is challenging because of autonomy: it cannot only quickly overload the system, but also it can dissatisfy participants with uninteresting queries. Thus, a natural question arises: should queries be replicated? If so, which ones? and how many times? In this paper, we answer these questions by revisiting query replication from a satisfaction and probabilistic point of view. We propose a new algorithm, called S(b)QR, that decides on-the-fly whether a query should be replicated and at which rate. As replicating a large number of queries might overload the system, we propose a variant of our algorithm, called S(b)QR+. The idea is to voluntarily fail to allocate as many replicas as required by consumers for low critical queries so as to keep resources for high critical queries during query-intensive periods. Our experimental results demonstrate that our algorithms significantly outperform the baseline algorithms from both the performance and satisfaction points of view. We also show that our algorithms automatically adapt to the criticality of queries and different rates of participant failures.

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

query replication
participants satisfaction
autonomous participants

fault-tolerance
self-adaptation
query criticality


On computing the minimum feedback vertex set of a directed graph by contraction operations Finding the minimum feedback vertex set (MFVS) in a graph is an important problem for a variety of computer-aided design (CAD) applications and graph reduction plays an important role in solving this intractable problem. This paper is largely concerned with three new and powerful reduction operations. Each of these operations defines a new class of graphs, strictly larger than the class of contractible graphs [Levy and Low (1988)], in which the MFVS can be found in polynomial-time complexity. Based on these operations, an exact algorithm run on branch and bound manner is developed. This exact algorithm uses a good heuristic to find out an initial solution and a good bounding strategy to prune the solution space. To demonstrate the efficiency of our algorithms, we have implemented our algorithms and applied them to solving the partial scan problem in ISCAS'89 benchmarks. The experimental results show that if our three new contraction operations are applied, 27 out of 31 circuits in ISCAS'89 benchmarks can be fully reduced. Otherwise, only 12 out of 31 can be fully reduced. Furthermore, for all ISCAS'89 benchmarks our exact algorithm can fmd the exact cutsets in less than 3 s (CPU time) on SUN-UltraII workstation. Therefore, the new contraction operations and our algorithms are demonstrated to be very effective in the partial scan application.

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

algorithm
branch and bound
minimum feedback vertex set
partial scan


Structure-Aware Placement Techniques for Designs With Datapaths As technology scales and frequencies increase, a new hybrid design style emerges, wherein designs contain a mixture of random logic and datapath standard-cell components. This paper demonstrates that conventional half-perimeter wirelength driven placers underperform in terms of regularity and Steiner wirelength (StWL) for such hybrid designs. In addition, the quality gap between manual and automatic placement is more pronounced as the designs become more datapath oriented. To effectively handle hybrid designs, this paper proposes a new unified placement flow that simultaneously places random logic and datapath cells. This flow is built on the top of a leading academic force-directed placer and significantly improves the quality of datapath placement while leveraging the speed and flexibility of existing random-logic placement algorithms. It consists of a suite of novel global and detailed placement techniques, collectively called structure-aware placement techniques (SAPT). These techniques effectively integrate alignment constraints into placement, thereby overcoming the deficiencies of existing randomlogic placers when handling designs with embedded datapaths. Compared to other state-of-the-art placers, SAPT improves total StWL by more than 28% and total routing overflow by over six times on the ISPD 2011 datapath benchmark suite. In addition, it improves total StWL by 5.8% on industrial hybrid designs.

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


Use of virtual field trips in teaching introductory geology We designed a series of case studies for Introductory Geology Laboratory courses using computer visualization techniques integrated with traditional laboratory materials. These consist of a comprehensive case study which requires three two-hour long laboratory periods to complete, and several shorter case studies requiring one or two, two-hour laboratory periods. Currently we have prototypes of the Yellowstone National Park, Hawaii volcanoes and the Mid-Atlantic Ridge case studies. The Yellowstone prototype can be used to learn about a wide variety of rocks and minerals, about geothermal activity and hydrology, about volcanic hazards and the hot-spot theory of plate tectonics. The Hawaiian exercise goes into more depth about volcanoes, volcanic rocks and their relationship to plate movements. The Mid-Atlantic Ridge project focuses on formation of new ocean crust and mineral-rich hydrothermal deposits at spreading centers. With new improvements in visualization technology that are making their way to personal computers, we are now closer to the ideal of a virtual field trip. We are currently making scenes of field areas in Hawaii and Yellowstone which allow the student to pan around the area and zoom in on interesting objects. Specific rocks in the scene will be able to be picked up and studied in three dimensions. This technology improves the ability of the computer to present a realistic simulation of the field area and allows the student to have more control over the presentation. This advanced interactive technology is intuitive to control, relatively cheap and easy to add to existing computer programs and documents.

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

virtual field trip
teaching
introductory geology
interactive
field


an analytical approach to floorplan design and optimization An analytical method for general floorplan design and optimization is proposed. This method is based on a mixed integer programming model and application of a standard mathematical software. The method allows arbitrary combinations of rigid and flexible modules. Various objective functions such as chip area, interconnection length, timing delays or any combinations of them are permitted. Routing space is estimated by the global router. Experimental data are provided.

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

software
method
space
design
router
data
routing
timing
general
model
integer programming
global

applications experimentation optimality delay module object standardization interconnect flexibility floorplanning


Comparative analysis of multi-criteria decision making methodologies and implementation of a warehouse location selection problem For the solution of decision making problems with multi criteria, the literature presents many methodologies under the title of decision theory. In this context, AHP, TOPSIS, ELECTRE and Grey Theory are well-known and the most acceptable methodologies. Firstly, in this study; these methodologies are compared in terms of main characteristic of decision theory and thus advantages and disadvantages of these methodologies are offered. Later, the application of these methodologies on the warehouse selection problem, which is one of the main topics of logistics management that has a wide range of applications with multi-criteria decision making methodologies, is presented as a case study which is characterized in retail sector, that maintains high uncertainity and product variety and then how to choose the best warehouse location among many alternatives has been shown.

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

warehouse location selection
topsis
electre
grey theory


generation of tests for programming challenge tasks using evolution algorithms In this paper, an automated method for generation of tests in order to detect inefficient (slow) solutions for programming challenge tasks is proposed. The method is based on genetic algorithms. The proposed method was applied to a task from the Internet problem archive - the Timus Online Judge. For this problem, none of the existed solutions passed the generated set of tests.

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


speed up of test generation using high-level primitives We propose a general methodology to speed up the test generation process for circuits with high-level primitives. Our search procedure is a variation of depth first search that tries to fully exploit the capabilities of a computer to execute complex arithmetic and logical operations. We present techniques for signal value justification, and fault propagation, which are used by our algorithm. We have implemented a dependency-directed backtracking method to speed up our algorithm. This methodology has been applied to six circuits and the results are found to be very encouraging.

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

value
backtracking
method
capabilities
methodology
exploit
variation
process
fault
general
algorithm
test generation
search
propagation
circuits

dependencies signaling computation direct operability complexity


ExpTime tableaux with global state caching for the description logic SHIO We give the first ExpTime(complexity-optimal) tableau decision procedure for checking satisfiability of a knowledge base in the description logic SHIO SHIO , which extends the basic description logic ALC ALC with transitive roles, hierarchies of roles, inverse roles and nominals. Our procedure exploits global state caching and does not use blind (analytic) cuts.

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


The bicompletion of fuzzy quasi-metric spaces Extending the well-known result that every fuzzy metric space, in the sense of Kramosil and Michalek, has a completion which is unique up to isometry, we show that every KM-fuzzy quasi-metric space has a bicompletion which is unique up to isometry, and deduce that for each KM-fuzzy quasi-metric space, the completion of its induced fuzzy metric space coincides with the fuzzy metric space induced by its bicompletion. (C) 2010 Elsevier B.V. All rights reserved.

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


Augmenting platform-based design with synthesis tools Platform-based design faces an essential tension: it wants to reuse previous designs to leverage IP; but new designs must necessarily include work that is not complete or well-characterized. Synthesis and analysis methods axe therefore important elements in platform-based design methodologies. This paper describes two aspects of this problem. First, we consider the first-generation dilemma, in which we must use additional analysis in order to create the first generation of a platform. Second, we describe a synthesis method that creates accelerators for platforms whose clock periods have been optimized for the system characteristics.

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

hardware/software co-design
clock cycle optimization
first-generation dilemma
platform-based design


On the bounded quasi-degrees of c.e. sets We study the degree structure of bQ-reducibility and we prove that for any noncomputable c.e. incomplete bQ-degree a, there exists a nonspeedable bQ-degree incomparable with it. The structure of the -degrees is not elementary equivalent neither to the structure of the -degrees nor to the structure of the -degrees. If c.e. degrees a and b form a minimal pair in the c.e. bQ-degrees, then a and b form a minimal pair in the bQ-degrees. Also, for every simple set S there is a noncomputable nonspeedable set A which is bQ-incomparable with S and bQ-degrees of S and A does not form a minimal pair.

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

computably enumerable sets
nonspeedable sets
bq-degrees
-degrees
-degrees. msc (2010) 03d25
03d30


Linux bugs: Life cycle, resolution and architectural analysis Efforts to improve application reliability can be irrelevant if the reliability of the underlying operating system on which the application resides is not seriously considered. An important first step in improving the reliability of an operating system is to gain insights into why and how the bugs originate, contributions of the different modules to the bugs, their distribution across severities, the different ways in which the bugs may be resolved and the impact of bug severities on their resolution times. To acquire this insight, we conducted an extensive analysis of the publicly available bug data on the Linux kernel over a period of seven years. We also justify and explain the statistical bug occurrence trends observed from the data, using the architecture of the Linux kernel as an anchor. The statistical analysis of the Linux bug data suggests that the Linux kernel may draw significant benefits from the continual reliability improvement efforts of its developers. These efforts, however, are disproportionately targeted towards popular configurations and hardware platforms, due to which the reliability of these configurations may be better than those that are not commonly used. Thus. a key finding of our study is that it may be prudent to restrict to using common configurations and platforms when using open source systems such as Linux in applications with stringent reliability expectations. Finally, our study of the architectural properties of the bugs suggests that the dependence among the modules rather than the unreliabilities of the individual modules is the primary cause of the bugs and their impact on system reliability. (C) 2009 Elsevier B.V. All rights reserved.

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


A comprehensive empirical study of count models for software fault prediction Count models, such as the Poisson regression model, and the negative binomial regression model, can be used to obtain software fault predictions. With the aid of such predictions, the development team can improve the quality of operational software. The zero-inflated, and hurdle count models may be more appropriate when, for a given software system, the number of modules with faults are very few. Related literature lacks quantitative guidance regarding the application of count models for software quality prediction. This study presents a comprehensive empirical investigation of eight count models in the context of software fault prediction. It includes comparative hypothesis testing, model selection, and performance evaluation for the count models with respect to different criteria. The case study presented is that of a full-scale industrial software system. It is observed that the information obtained from hypothesis testing, and model selection techniques was not consistent with the predictive performances of the count models. Moreover, the comparative analysis based on one criterion did not match that of another criterion. However, with respect to a given criterion, the performance of a count model is consistent for both the fit, and test data sets. This ensures that, if a fitted model is considered good based on a given criterion, then the model will yield a good prediction based on the same criterion. The relative performances of the eight models are evaluated based on a one-way ANOVA model, and Tukey's multiple comparison technique. The comparative study is useful in selecting the best count model for estimating the quality of a given software system.

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

anova
count models
hypothesis testing
software quality

information criteria
pearson's chi-square
software metrics
tukey's multiple comparison


Learning to match the schemas of data sources: A multistrategy approach The problem of integrating data from multiple data sources-either on the Internet or within enterprises-has received much attention in the database and AI communities. The focus has been on building data integration systems that provide a uniform query interface to the sources. A key bottleneck in building such systems has been the laborious manual construction of semantic mappings between the query interface and the source schemas. Examples of mappings are "element location maps to address" and "price maps to listed-price". We propose a multistrategy learning approach to automatically find such mappings. The approach applies multiple learner modules, where each module exploits a different type of information either in the schemas of the sources or in their data, then combines the predictions of the modules using a meta-learner. Learner modules employ a variety of techniques, ranging from Naive Bayes and nearest-neighbor classification to entity recognition and information retrieval. We describe the LSD system, which employs this approach to find semantic mappings. To further improve matching accuracy, LSD exploits domain integrity constraints, user feedback, and nested structures in XML data. We test LSD experimentally on several real-world domains. The experiments validate the utility of multistrategy learning for data integration and show that LSD proposes semantic mappings with a high degree of accuracy.

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


Discovering and orienting the edges connected to a target variable in a DAG via a sequential local learning approach Given a target variable and observational data, we propose a sequential learning approach for discovering direct cause and effect variables of the target under the causal network framework. In the approach, we start from the target, sequentially find Markov blankets of variables and learn local structures over Markov blankets until we determine the causes and effects of the target variable. Without constructing a whole network over all variables, we find only a local structure around the target. The main advantage of the proposed sequential approach is that it can greatly reduce CPU time compared with whole network learning approaches for finding the causes and effects of a given target node in a large network. The proposed approach can be applied to predict the effects of external interventions. Theoretically we show the correctness of the approach under the assumptions of faithfulness, causal sufficiency and that independencies are correctly checked. These theoretical results can also be used for learning directed acyclic graphs with latent variables.

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

directed acyclic graph
discover causes and effects
sequential structural learning


Single-channel color image encryption algorithm based on fractional Hartley transform and vector operation A single-channel color image encryption algorithm is proposed by combining fractional Hartley transform (FRHT) with vector operation. The original color image is decomposed into RGB components and the G and B components are encrypted into two phase-only masks ? G and ? B with vector operation, respectively. The R, ? G and ? B are transformed by FRHT and vector operation twice to obtain amplitude, random phase and decryption phase key. The new amplitude combined with the random phase is transformed by FRHT once more and then the result is scrambled by the chaotic scrambling to strengthen the security of the algorithm. The private phase key is dependent on the original image, which makes the proposed encryption algorithm more secure than the linear color image encryption algorithm based on the double random phase encoding in FRHT. Simulation results demonstrate the security and effectiveness of the proposed algorithm.

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

vector operation
fractional hartley transform
image encryption