ppxscal/embedding_network huggingface dataset:
Maximum trimmed likelihood estimator for multivariate mixed continuous and categorical data
Authors: Tsung-Chi Cheng, Atanu Biswas
Venue: Computational Statistics Data Analysis (2008)

In this article, we apply the maximum trimmed likelihood (MTL) approach [Hadi, A.S., Luceno, A., 1997. Maximum trimmed likelihood estimators: a unified approach, examples, and algorithms. Comput. Statist. Data Anal. 25, 251-272] to obtain the robust estimators of multivariate location and shape, especially for data mixed with continuous and categorical variables. The forward search algorithm [Atkinson, A.C., 1994. Fast very robust methods for the detection of multiple outliers. J. Amer. Statist. Assoc. 89, 1329-1339] is adapted to compute the proposed MTL estimates. A simulation study shows that the proposed estimator outperforms the classical maximum likelihood estimator when outliers exist in data. Real data sets are also used to illustrate the method and results of the detection of the outliers.
Nonmonotone projected gradient methods based on barrier and Euclidean distances
Authors: Alfred Auslender, Paulo J. Silva, Marc Teboulle
Venue: Computational Optimization and Applications (2007)

We consider nonmonotone projected gradient methods based on non-Euclidean distances, which play the role of barrier for a given constraint set. Our basic scheme uses the resulting projection-like maps that produces interior trajectories, and combines it with the recent nonmonotone line search technique originally proposed for unconstrained problems by Zhang and Hager. The combination of these two ideas leads to produce a nonmonotone scheme for constrained nonconvex problems, which is proven to converge to a stationary point. Some variants of this algorithm that incorporate spectral steplength are also studied and compared with classical nonmonotone schemes based on the usual Euclidean projection. To validate our approach, we report on numerical results solving bound constrained problems from the CUTEr library collection.
Higher order models for fuzzy random variables
Authors: Inés Couso, Luciano Sánchez
Venue: Fuzzy Sets and Systems (2008)

A fuzzy random variable is viewed as the imprecise observation of the outcomes in a random experiment. Since randomness and vagueness coexist in the same framework, it seems reasonable to integrate fuzzy random variables into imprecise probabilities theory. Nevertheless, fuzzy random variables are commonly presented in the literature as classical measurable functions associated to a classical probability measure. We present here a higher order possibility model that represents the imprecise information provided by a fuzzy random variable. We compare it with previous classical models in the literature. First, some aspects about the acceptability function associated to a fuzzy random variable are investigated. Secondly, we present three different higher order possibility models, all of them arising in a natural way. We investigate their similarities and differences, and observe that the first one (the fuzzy probability envelope) is the most informative. Finally we compare the fuzzy probability envelope with the (classical) probability measure induced by the fuzzy random variable. We conclude that the classical probability measure does not always contain all relevant information provided by a fuzzy random variable.
A nanoanalytical investigation of elemental distributions in high-k dielectric gate stacks on silicon
Authors: F. T. Docherty, M. MacKenzie, A. J. Craven, D. W. McComb, S. De Gendt, S. McFadzean, C. M. McGilvery
Venue: Microelectronic Engineering (2008)

Two high-k gate stacks with the structure Si/SiO"2/HfO"2/TiN/poly-Si are characterised using nanoanalytical electron microscopy. The effect of two key changes to the processing steps during the fabrication of the stacks is investigated. Electron energy-loss spectroscopy is used to show that the TiN layer has a very similar composition whether it is deposited by PVD or ALD. Spectrum imaging in the electron microscope was used to profile the distribution of elements across the layers in the stack. It was found that when the anneal after HfO"2 deposition is carried out in a NH"3 atmosphere instead of an O"2 atmosphere, there is diffusion of N into the SiO"2 and HfO"2 layers. There is also significant intermixing of the layers at the interfaces for both wafers.
High-Performance Computing in High Schools?
Authors: Tom Murphy
Venue: IEEE Distributed Systems Online (2007)

If high-performance computing in community colleges seems odd, HPC in high schools is even stranger. This article will help readers grok the nature of the author's version of high school HPC.
Adaptive Pre-Filtering Techniques for Colour Image Analysis
Authors: Dana Elena Ilea, Paul F. Whelan
Venue: Proceedings of the International Machine Vision and Image Processing Conference (2007)

One important step in the process of colour image segmentation is to reduce the errors caused by image noise and local colour inhomogeneities. This can be achieved by filtering the data with a smoothing operator that eliminates the noise and the weak textures. In this regard, the aim of this paper is to evaluate the performance of two image smoothing techniques designed for colour images, namely bilateral filtering for edge preserving smoothing and coupled forward and backward anisotropic diffusion scheme (FAB). Both techniques are non-linear and have the purpose of eliminating the image noise, reduce weak textures and artefacts and improve the coherence of colour information. A quantitative comparison between them will be evaluated and also the ability of such techniques to preserve the edge information will be investigated.
Maximizing throughput for optical burst switching networks
Authors: Jikai Li, Chunming Qiao, Jinhui Xu, Dahai Xu
Venue: IEEE/ACM Transactions on Networking (TON) (2007)

In optical burst switching (OBS) networks, a key problem is to schedule as many bursts as possible on wavelength channels so that the throughput is maximized and the burst loss is minimized. Most of the current research on OBS has been concentrated on reducing burst loss in an "average-case" sense, and little effort has been devoted to understanding the worst case performance. Since OBS itself is an open-loop control system, it may exhibit a worst case behavior when adversely synchronized. On the other hand, most commercial systems require an acceptable worst case performance. In this paper, we use competitive analysis to analyze the worst case performance of a large set of scheduling algorithms, called best-effort online scheduling algorithms, for OBS networks and establish a number of interesting upper and lower bounds on the performance of such algorithms. Our analysis shows that the performance of any best-effort online algorithm is closely related to a few factors, such as the range of offset time, maximum-to-minimum burst-length ratio, and the number of data channels. A surprising discovery is that the worst case performance of any best-effort online scheduling algorithm is primarily determined by the maximum-to-minimum burst-length ratio, followed by the range of offset time. Furthermore, if all bursts have the same burst length and offset time, all best-effort online scheduling algorithms generate the same optimal solution, regardless of how different they may look. Our analysis can also be extended to some non-best-effort online scheduling algorithms, such as the well-known Horizon algorithm, and establish similar bounds. Based on the analytic results, we give guidelines for several widely discussed OBS problems, including burst assembly, offset time setting, and scheduling algorithm design, and propose a new channel reservation protocol called virtual fixed offset-time (VFO) to improve the worst case performance. Our simulation shows that VFO can also reduce the average burst loss rate.
Semantic verification in an online fact seeking environment
Authors: Dmitri Roussinov, Ozgur Turetken
Venue: Proceedings of the sixteenth ACM conference on Conference on information and knowledge management (2007)

Many artificial intelligence tasks, such as automated question answering, reasoning or heterogeneous database integration, involve verification of a semantic category (e.g. "coffee" is a drink, "red" is a color, while "steak" is not a drink and "big" is not a color). We present a novel algorithm to automatically validate a semantic category. Contrary to the methods suggested earlier, our approach does not rely on any manually codified knowledge but instead capitalizes on the diversity of topics and word usage on the World Wide Web. We have tested our approach within our online fact-seeking (question answering) environment. When tested on the TREC questions that expect the answer to belong to a specific semantic category, our approach has improved the accuracy by up to 14% depending on the model and metrics used.
Offline untrusted storage with immediate detection of forking and replay attacks
Authors: Marten van Dijk, Jonathan Rhodes, Luis F. G. Sarmenta, Srinivas Devadas
Venue: Proceedings of the 2007 ACM workshop on Scalable trusted computing (2007)

We address the problemof using an untrusted server with only a trusted timestamping device (TTD) to provide trusted storage for a large number of clients, where each client may own and use several different devices that may be offline at different times and may not be able to communicate with each other except through the untrusted server (over an untrusted network). We show how a TTD can be implemented using currently available Trusted Platform Module TPM 1.2 technology without having to assume trust in the BIOS, CPU, or OS of the TPM's server. We show how the TTD can be used to implement tamper-evident storagewhere clients are guaranteed to immediately detect illegitimate modifications to their data (including replay attacks and forking attacks) whenever they wish to perform a critical operation that relies on the freshness and validity of the data. In particular, we introduce and analyze a log-based scheme in which the TTD is used to securely implement a large number of virtual monotonic counters, which can then be used to time-stamp data and provide tamper-evident storage. We present performance results of an actual implementation using PlanetLab and a PC with a TPM 1.2 chip
Threats Analysis and Prevention for Grid and Web Service Security
Authors: Jiancheng Ni, Zhishu Li, Zhonghe Gao, Jirong Sun
Venue: Proceedings of the Eighth ACIS International Conference on Software Engineering, Artificial Intelligence, Networking, and Parallel/Distributed Computing - Volume 03 (2007)

In order to enhance the security level and prevent the threats in Grid interacting with Web service environment, based on discriminating participant actors during the procedure of computation, a new threat classification method is proposed before corresponding threats model is introduced. Furthermore, we illustrate how basic security services and tools should interact with each other to provide an attack-resilient multilayer protection methodology in a service-oriented architecture. As a result, such threats analysis can be further utilized as the basis of proper security services design and operational procedures development.
The Epidemic Threshold of a More General Epidemic Spreading Model for Network Viruses
Authors: Lansheng Han, Shuxia Han, Min Yang
Venue: Proceedings of the Third International Conference on Natural Computation - Volume 02 (2007)

Deferent from the other epidemic models, this paper focus on the different spreading features of network viruses compared with biological viruses such as the connectivity rate of the net is variable and that is also the key factor determining the existence of the threshold. Based on a more general epidemic model of the network viruses we constructed in another paper, this paper presents the solution to the model, and then gets the conclusion: if the speed of viruses' propagation varies with the network connectivity rate and their curing rates are relatively small, then the epidemic thresholds do not exist. For the particular case of the connectivity rate the paper carries out the simulation test and finds it is consistent well with the statistics of the real viruses. Thus the paper replies the two open problems about the epidemic model of computer virus model proposed by White.
Your dinner's calling: supporting family dinnertime activities
Authors: Max Snyder, John Zimmerman, Jodi Forlizzi
Venue: Proceedings of the 2007 conference on Designing pleasurable products and interfaces (2007)

Families want to eat dinner together, but lack the time or resources to achieve their desires. A human-centered research and design process explores dual-income American families to better understand their needs and desires to see if technology can help them achieve their goal of having dinner together more often. Literature review, observations, contextualized interviews, and journaling aided the development of concepts which where validated by families. A conceptual service leveraging the existing family infrastructure of mobile phones and personal computers is also explored through scenarios.
On the Use of Semantic Blocking Techniques for Data Cleansing and Integration
Authors: Jordi Nin, Victor Muntes-Mulero, Norbert Martinez-Bazan, Josep-L. Larriba-Pey
Venue: Proceedings of the 11th International Database Engineering and Applications Symposium (2007)

Record Linkage (RL) is an important component of data cleansing and integration. For years, many efforts have focused on improving the performance of the RL process, either by reducing the number of record comparisons or by reducing the number of attribute comparisons, which reduces the computational time, but very often decreases the quality of the results. However, the real bottleneck of RL is the post-process, where the results have to be reviewed by experts that decide which pairs or groups of records are real links and which are false hits. In this paper, we show that exploiting the relationships (e.g. foreign key) established between one or more data sources, makes it possible to find a new sort of semantic blocking method that improves the number of hits and reduces the amount of review effort.
Significance of sinusoids for myocardial blood circulation
Authors: N. Djavakhishvili
Venue: Technology and Health Care (1997)

As the myocardial capillaries drain tassel-like into the peripheral end of sinusoids, the venous system of the myocardium begins in the sinusoids and plays an important role in the regulation of myocardial circulation. The sinusoids dilate in response to inadequacy of the arterial vascularization and their expansion has been found to be inversely proportional to the blood flow in the coronary arteries. The sinusoids become more dilated and prominent with coronary dilators and reinforcement of myocardial vascularization by cardiopexy techniques, causes the sinusoids to become dilated. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Detecting Double Faults on Term and Literal in Boolean Expressions
Authors: M. F. Lau, Y. Liu, Y. T. Yu
Venue: Proceedings of the Seventh International Conference on Quality Software (2007)

Fault-based testing aims at selecting test cases to guarantee the detection of certain prescribed faults in programs. The detection conditions of single faults have been studied and used in areas like developing test case selection strategies, establishing relationships between faults and investigating the fault coupling effect. It is common, however, for programmers to commit more than one fault. Our previous studies on the detection conditions of faults in Boolean expressions show that (1) some test case selection strategies developed for the detection of single faults can also detect all double faults related to terms, but (2) these strategies cannot guarantee to detect all double faults related to literals. This paper supplements our previous studies and completes our series of analysis of the detection condition of all double fault classes in Boolean expressions. Here we consider the fault detection conditions of combinations of two single faults, in which one is related to term and the other is related to literal. We find that all such faulty expressions, except two, can be detected by some test case selection strategies for single fault detection. Moreover, the two exception faulty expressions can be detected by existing strategies when used together with a supplementary strategy which we earlier developed to detect double literal faults.
Analysis of ratings on trust inference in open environments
Authors: Zhengqiang Liang, Weisong Shi
Venue: Performance Evaluation (2008)

Ratings (also known as recommendations) provide an efficient and effective way to build trust relationship in the human society, by making use of the information from others rather than exclusively relying on one's own direct observations. However, it is uncertain that whether the rating can play the same positive effect in the open computing environment because of differences between the computing world and human society. We envisage that there are two kinds of uncertainties: the uncertainty resulting from rating aggregation algorithms and the uncertainty resulting from other algorithm-independent design factors, which are coined as algorithm uncertainty and factor uncertainty in this paper. The algorithm uncertainty is related to such a problem: are the complex aggregating algorithms necessary? The factor uncertainty refers to how the performance of ratings is affected by all kinds of factors, including trust model design related factors and trust model design independent factors. In this paper, we take an initial step to answer these two uncertainties. First, we study the effect of all factors based on a simple averaging rating algorithm in terms of several proposed performance metrics. Then we compare different rating aggregation algorithms in the same context and platform, focusing on several relevant metrics. The simulation results show that ratings are not always as helpful as what we expected, especially when the system is facing malicious raters and highly dynamic peer behaviors. In certain circumstances, the simple average aggregation algorithm performs better than the complex ones, especially when there are considerable number of bad raters in the system. Considering the system dynamics, the cost of the algorithm design, and the system overhead, we argue that it is not worth putting too much energy on the design of complex rating aggregation schemes for trust inference in open computing environments.
Cognitive Limits of Software Cost Estimation
Authors: Ricardo Valerdi
Venue: Proceedings of the First International Symposium on Empirical Software Engineering and Measurement (2007)

This paper explores the cognitive limits of estimation in the context of software cost estimation. Two heuristics, representativeness and anchoring, motivate two experiments involving psychology students, engineering students, and engineering practitioners. The first experiment, designed to determine if there is a difference in estimating ability in everyday quantities, demonstrates that the three populations estimate with relatively equal accuracy. The results shed light on the distribution of estimates and the process of subjective judgment. The second experiment, designed to explore abilities for estimating the cost of software-intensive systems given incomplete information, shows that predictions by engineering students and practitioners are within 3-12% of each other. The value of this work is in helping better understand how software engineers make decisions based on limited information. The manifestation of the two heuristics is discussed together with the implications for the development of software cost estimation models in light of the findings from the two experiments.
A Coarse-Grained Dynamically Reconfigurable Processing Array (RPA) for Multimedia Application
Authors: Guochang Zhou, Xubang Shen
Venue: Proceedings of the Third International Conference on Natural Computation - Volume 05 (2007)

The accelerating need for higher performance, due to complex and real-time applications, has made reconfigurable architectures the best platform for solving such problems. A novel dynamically reconfigurable processing array (RPA) is proposed in this paper. The interconnection network and reconfigurable processing units(RPUs) of RPA can be dynamically reconfigured to arrange different interconnection networks and support different arithmetic representations and bits wide by the configurable word. The RPA with 8×8 coarse-grained RPUs matrix can be organized as SIMD architecture, as well as MIMD architecture. Through the results of the DCT transform and FIR filter algorithms mapping into RPA, RPA performs the multimedia related operations efficiently. Based on Charter 0.25um process standard cell library, the area of RPA is 7×7mm^2 and the critical path delay is 16 ns.
Building data infrastructure for geo-computation by spatial information grid
Authors: ZhenChun Huang, GuoQing Li, Yi Zeng
Venue: Proceedings of the Sixth International Conference on Grid and Cooperative Computing (2007)

The continuing research on geo-computation purchases more orders to the data infrastructure of geo-computation. It should be distributed, platform-independent, extensible, robust, autonomic, and can on-stop serve the users and applications. In this paper, based on spatial information grid (shortly SIG), a 4-layered data infrastructure which is built up by data nodes, data sources, data agencies, support libraries, and other components is proposed. It adopts an XML based extensible data accessing language as the operating protocol for the data sources and data agencies. Furthermore, some primary data sources and data agencies are designed and implemented; and based on them, a prototype of the data infrastructure is constructed and tested. The test shows that the SIG based data infrastructure can provide different sources, types and formats of spatial information data and make it easier to build up application for geo-computation.
Characterization of layer-2 unique topologies
Authors: Yuri Breitbart, Hassan Gobjuka
Venue: Information Processing Letters (2008)

In this paper we study a layer-2 topology restoration for multisubnet networks. We design a new algorithm for generating such topologies and prove a criterion on a set of input data that guarantees a unique layer-2 topology. Our criterion is easily verifiable in O(n^2) time, where n is the number of internal network nodes.
New Synchronization Scheme between Audio and Video
Authors: Li-feng Qi, He-xin Chen, Yan Zhao
Venue: Proceedings of the Eighth ACIS International Conference on Software Engineering, Artificial Intelligence, Networking, and Parallel/Distributed Computing - Volume 03 (2007)

The synchronization between audio and video during their transmission and playout has become one of key issues of Internet multimedia applications. In this paper, a new scheme for synchronized coding of audio and video is proposed. In the encoder, audio bits are embedded into transformed coefficients of video as hiding signal, and then the hybrid information is encoded simultaneously. In the decoder, the embedded audio bits is extracted from hybrid signal, then audio and video are reconstructed respectively and playout. Experimental results show that, the proposed scheme can achieve synchronization between audio and video exactly.