ppxscal/embedding_network huggingface dataset:
Parallel black box $$\mathcal {H}$$-LU preconditioning for elliptic boundary value problems
Authors: Lars Grasedyck, Ronald Kriemann, Sabine Le Borne
Venue: Computing and Visualization in Science (2008)

Hierarchical ($$\mathcal {H}$$-) matrices provide a data-sparse way to approximate fully populated matrices. The two basic steps in the construction of an $$\mathcal {H}$$-matrix are (a) the hierarchical construction of a matrix block partition, and (b) the blockwise approximation of matrix data by low rank matrices. In the context of finite element discretisations of elliptic boundary value problems, $$\mathcal {H}$$-matrices can be used for the construction of preconditioners such as approximate $$\mathcal {H}$$-LU factors. In this paper, we develop a new black box approach to construct the necessary partition. This new approach is based on the matrix graph of the sparse stiffness matrix and no longer requires geometric data associated with the indices like the standard clustering algorithms. The black box clustering and a subsequent $$\mathcal {H}$$-LU factorisation have been implemented in parallel, and we provide numerical results in which the resulting black box $$\mathcal {H}$$-LU factorisation is used as a preconditioner in the iterative solution of the discrete (three-dimensional) convection-diffusion equation.
Optimal horizons for a one-parameter family of unbiased FIR filters
Authors: Yuriy S. Shmaliy, Jorge Munoz-Diaz, Luis Arceo-Miquel
Venue: Digital Signal Processing (2008)

In this paper, we find the optimal horizons and sampling intervals, both in the sense of the minimum mean square error (MSE), for a one-parameter family of the discrete-time unbiased finite impulse response (FIR) filters. On a horizon of N"l points in the nearest past, the FIR and the model k-state are represented with the l-degree and m-degree polynomials, respectively. The noise-free state space model is observed in the presence of zero-mean noise of an arbitrary distribution and covariance. The approach is based on the following. The FIR filter produces an unbiased estimate if l>=m. In order to reduce the noise, N"l needs to be increased. The model fits the increased horizon with a higher degree polynomial, m>l. Minimization of the mean square error for m>l gives the optimal horizon and sampling interval. Justification is provided for the global positioning system (GPS)-based measurements of the first state of a local crystal clock provided in the presence of uniformly distributed sawtooth noise induced by the GPS timing receiver.
Tool, tutor, environment or resource: Exploring metaphors for digital technology and pedagogy using activity theory
Authors: Ian Stevenson
Venue: Computers Education (2008)

Describing digital technologies as tool, tutor, environment or resource in pedagogical contexts is common, and this paper examines the metaphorical nature of these descriptions and their implications for digitally-based teaching and learning practices. To compare the metaphors, the paper first develops a model of pedagogy derived from Activity Theory. It explores the implications of these metaphors in practical situations by examining a set of 60 digitally-based activities, collected as part of a snapshot survey of a representative sample of maintained schools in England, to draw out their pedagogical characteristics. In conclusion the paper discusses the issues raised by the analysis for the relationship between use of digital technologies and learners' attainments, and the efficacy of the model that has been developed.
Communication Security between a Computer and a Hardware Token
Authors: H. Karen Lu, Asad Ali
Venue: Proceedings of the Third International Conference on Systems (2008)

Hardware security tokens are gradually gaining popularity as tools for strong online authentication and secure storage of personal information. The security services they offer protect online service providers as well as consumers. These tokens are small embedded systems that typically have little or no human interface themselves. They work with software on the host computer for human interface and for interaction with programs on the computer or over the Internet. Since these security tokens typically provide cryptographic services and secure storage, the security of communication between the token and the host computer is a critical piece of the overall security framework. The design of this piece is a challenging task. It requires solving multiple problems, such as ensuring that the hardware token only talks with a legitimate host application; exchanging encryption keys; and minimizing the impact on communication performance. This paper presents our solutions to these problems. These solutions are applicable in a variety of hardware security tokens.
Rule-based reasoning about qualitative spatiotemporal relations
Authors: Clemens Holzmann
Venue: Proceedings of the 5th international workshop on Middleware for pervasive and ad-hoc computing: held at the ACM/IFIP/USENIX 8th International Middleware Conference (2007)

This paper is about a novel rule-based approach for reasoning about qualitative spatiotemporal relations among technology-rich autonomous objects, to which we refer to as artifacts. The objective of our work is to provide means for defining spatiotemporal constraints - i.e. logical combinations of spatial relations to artifacts at certain time intervals - at a high level of abstraction, and to recognize relative situations therewith. Such constraints are defined with rules that infer high-level relationships for newly recognized situations, which in turn can be used in other constraints. At any time, the history of known relationships can be queried in order to trigger predefined actions. We decided for qualitative abstractions of both spatial and temporal relationships, as they reflect the semantics of natural language terms and thus facilitate dealing with relationships at the application programming level. The core concepts of this reasoning approach are presented, and the implementation of a middleware for spatiotemporal reasoning as well as evaluation results are discussed.
Third-order generalization: A new approach to categorizing higher-order generalization
Authors: Richard Neville
Venue: Neurocomputing (2008)

Generalization, in its most basic form, is an artificial neural network's (ANN's) ability to automatically classify data that were not seen during training. This paper presents a framework in which generalization in ANNs is quantified and different types of generalization are viewed as orders. The ordering of generalization is a means of categorizing different behaviours. These orders enable generalization to be evaluated in a detailed and systematic way. The approach used is based on existing definitions which are augmented in this paper. The generalization framework is a hierarchy of categories which directly aligns an ANN's ability to perform table look-up, interpolation, extrapolation, and hyper-extrapolation tasks. The framework is empirically validated. Validation is undertaken with three different types of regression task: (1) a one-to-one (o-o) task, f(x):x"i->y"j; (2) the second, in its f(x):{x"i,x"i"+"1,...}->y"j formulation, maps a many-to-one (m-o) task; and (3) the third f(x):x"i->{y"j,y"j"+"1,...} a one-to-many (o-m) task. The first and second are assigned to feedforward nets, while the third, due to its complexity, is assigned to a recurrent neural net. Throughout the empirical work, higher-order generalization is validated with reference to the ability of a net to perform symmetrically related or isomorphic functions generated using symmetric transformations (STs) of a net's weights. The transformed weights of a base net (BN) are inherited by a derived net (DN). The inheritance is viewed as the reuse of information. The overall framework is also considered in the light of alignment to neural models; for example, which order (or level) of generalization can be performed by which specific type of neuron model. The complete framework may not be applicable to all neural models; in fact, some orders may be special cases which apply only to specific neuron models. This is, indeed, shown to be the case. Lower-order generalization is viewed as a general case and is applicable to all neuron models, whereas higher-order generalization is a particular or special case. This paper focuses on initial results; some of the aims have been demonstrated and amplified through the experimental work.
A high-resolution integrated hydrology-hydrodynamic model of the Barataria Basin system
Authors: Masamichi Inoue, Dongho Park, Dubravko Justic, William J. Wiseman,  Jr.
Venue: Environmental Modelling Software (2008)

An attempt was made to build a model that can simulate salinity variations in Barataria Basin, and can ultimately be used for managing day-to-day operation of freshwater diversion aimed to rebuild coastal wetland in the surrounding area near the Mississippi River delta. A high-resolution (O (100m)) integrated hydrology-hydrodynamic model of the Barataria Basin has been developed to simulate the local hydrological cycle over the surrounding drainage basin and hydrodynamics within the basin. A hydrological model of local runoff from the surrounding drainage basin is coupled to a two-dimensional depth-integrated hydrodynamic model of the basin. The integrated model is forced by observed tides coming from the Gulf of Mexico, local wind, rainfall and evaporation over the model domain. The model can be used to simulate salinity changes in response to a variety of climactic conditions including drought and flood. For management purposes, the integrated model can be useful in simulating salinity alterations associated with the introduction of freshwater diversions.
A Modular Calculus for the Average Cost of Data Structuring, 1 edition
Authors: Michel Schellekens
Venue:  (2008)

A Modular Calculus for the Average Cost of Data Structuring introduces MOQA, a new domain-specific programming language which guarantees the average-case time analysis of its programs to be modular.Time in this context refers to a broad notion of cost, which can be used to estimate the actual running time, but also other quantitative information such as power consumption, while modularity means that the average time of a program can be easily computed from the times of its constituents--something that no programming language of this scope has been able to guarantee so far. MOQA principles can be incorporated in any standard programming language. MOQA supports tracking of data and their distributions throughout computations, based on the notion of random bag preservation. This allows a unified approach to average-case time analysis, and resolves fundamental bottleneck problems in the area. The main techniques are illustrated in an accompanying Flash tutorial, where the visual nature of this method can provide new teaching ideas for algorithms courses. This volume, with forewords by Greg Bollella and Dana Scott, presents novel programs based on the new advances in this area, including the first randomness-preserving version of Heapsort. Programs are provided, along with derivations of their average-case time, to illustrate the radically different approach to average-case timing. The automated static timing tool applies the Modular Calculus to extract the average-case running time of programs directly from their MOQA code. A Modular Calculus for the Average Cost of Data Structuring is designed for a professional audience composed of researchers and practitioners in industry, with an interest in algorithmic analysis and also static timing and power analysis--areas of growing importance. It is also suitable as an advanced-level text or reference book for students in computer science, electrical engineering and mathematics. Michel Schellekens obtained his PhD from Carnegie Mellon University, following which he worked as a Marie Curie Fellow at Imperial College London. Currently he is an Associate Professor at the Department of Computer Science in University College Cork - National University of Ireland, Cork, where he leads the Centre for Efficiency-Oriented Languages (CEOL) as a Science Foundation Ireland Principal Investigator.
Singular Points Detection Based on Zero-Pole Model in Fingerprint Images
Authors: Lingling Fan, Shuguang Wang, Hongfa Wang, Tiande Guo
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2008)

An algorithm is proposed which combines Zero-pole Model and Hough Transform(HT) to detect singular points. Orientation of singular points is defined on basis of Zero-pole Model which can further explain the practicability of Zero-pole Model. Contrary to orientation field generation, detection of singular points is simplified to determine the parameters of Zero-pole Model. HT uses rather global information of fingerprint images to detect singular points. This makes our algorithm more robust to noise than methods which only use local information. As Zero-pole Model may have a little warp from actual fingerprint orientation field, Poincare index is used to make position adjustment in neighborhood of the detected candidate singular points. Experimental results show that our algorithm performs well and fast enough for real time application in database NIST-4.
Timing yield driven clock skew scheduling considering non-Gaussian distributions of critical path delays
Authors: Yi Wang, Wai-Shing Luk, Xuan Zeng, Jun Tao, Changhao Yan, Jiarong Tong, Wei Cai, Jia Ni
Venue: Proceedings of the 45th annual Design Automation Conference (2008)

In nanometer technologies, process variations possess growing nonlinear impacts on circuit performance, which causes critical path delays of combinatorial circuits variate randomly with non-Gaussian distribution. In this paper, we propose a novel clock skew scheduling methodology that optimizes timing yield by handling non-Gaussian distributions of critical path delays. Firstly a general formulation of the optimization problem is proposed, which covers most of the previous formulations and indicates their limitations with statistical interpretations. Then a generalized minimum balancing algorithm is proposed for effectively solving the skew scheduling problem. Experimental results show that the proposed method significantly outperforms some representative methods previously proposed for yield optimization, and could obtain timing yield improvements up to 33.6% and averagely 17.7%.
Structuring and designing web information system for stroke care: a Malaysian perspective
Authors: Noor Hafizah Hassan, Mohd Hairul Nizam Md Nasir, Sri Hastuti Kurniawan
Venue: Issue 91 (June 2008) (2008)

The rapid development of information technology is a powerful instrument for organizational problem-solving to help with establishing general information systems behavior. The choice of medium is important to insure the success of message delivery. The Internet plays an important role in providing information in a timely manner and in a way that can reach a large geographical area. Internet/web systems mean that business, government, or consumers can access the information (Walter and Scott, 2006). Nowadays, an important use of the Internet is to spread information with an emphasis on health. For more than thirty years, clinicians, health service researchers and others have been investigating the use of advanced telecommunications and information technologies to improve healthcare as mentioned by Hawkey et al. (2007). Health information includes stroke and cancer awareness to inform the public about how to detect and cope with situations related to these two diseases.
A characterization of Hash P by arithmetic straight line programs
Authors: L. Babai, L. Fortnow
Venue: Proceedings of the 31st Annual Symposium on Foundations of Computer Science (1990)

Hash P functions are characterized by certain straight-line programs of multivariate polynomials. The power of this characterization is illustrated by a number of consequences. These include a somewhat simplified proof of S. Toda's (1989) theorem that PH contained in P/sup Hash P/, as well as an infinite class of potentially inequivalent checkable functions.
Dealing with P2P semantic heterogeneity through query expansion and interpretation
Authors: Anthony Ventresque, Sylvie Cazalens, Philippe Lamarre, Patrick Valduriez
Venue: Proceedings of the 2008 international workshop on Data management in peer-to-peer systems (2008)

In P2P systems where query initiators and information providers do not necessarily share the same ontology, semantic interoperability generally relies on ontology matching or schema mappings. Information exchange is then not only enabled by the established correspondences (the "shared" parts of the ontologies) but, in some sense, limited to them. Then, to what extent the "unshared" parts can also contribute to and improve information exchange? In this paper, we address this question by considering a system where documents and queries are represented by semantic vectors. We propose a specific query expansion step at the query initiator's side and a query interpretation step at the document provider's. Through these steps, unshared concepts contribute to evaluate the relevance of documents wrt. a given query. Our experiments show that our method enables to correctly evaluate the relevance of a document even if concepts of a query are not shared. In some cases, we are able to find up to 90% of the documents that would be selected when all the central concepts are shared.
Hybrid statecharts to model continuous and discrete behavior in engineering systems
Authors: J. A. Ferreira
Venue: Proceedings of the 4th WSEAS International Conference on Applied Mathematics and Computer Science (2005)

Some of the mathematical difficulties when modeling and simulate engineering systems arrive from the different time scales of the several components involved. However, in some situations, the behavior of fast components in the system may be modeled with instantaneous changes. This lead to a variable structure DAEs with their activity governed by a set of events. This paper explores the use of the Hybrid Statecharts graphical formalism to describe systems with continuous and discrete behavior. Being a multi level formalism, the Statecharts hierarchy mechanisms are particularly important to model complex systems as are normally the case of engineering systems. Throughout the article examples are presented trying to evidence the Statecharts formalism capabilities to describe hybrid behavior.
A parallel genetic algorithm to discover patterns in genetic markers that indicate predisposition to multifactorial disease
Authors: Tobias Rausch, Alun Thomas, Nicola J. Camp, Lisa A. Cannon-Albright, Julio C. Facelli
Venue: Computers in Biology and Medicine (2008)

This paper describes a novel algorithm to analyze genetic linkage data using pattern recognition techniques and genetic algorithms (GA). The method allows a search for regions of the chromosome that may contain genetic variations that jointly predispose individuals for a particular disease. The method uses correlation analysis, filtering theory and genetic algorithms to achieve this goal. Because current genome scans use from hundreds to hundreds of thousands of markers, two versions of the method have been implemented. The first is an exhaustive analysis version that can be used to visualize, explore, and analyze small genetic data sets for two marker correlations; the second is a GA version, which uses a parallel implementation allowing searches of higher-order correlations in large data sets. Results on simulated data sets indicate that the method can be informative in the identification of major disease loci and gene-gene interactions in genome-wide linkage data and that further exploration of these techniques is justified. The results presented for both variants of the method show that it can help genetic epidemiologists to identify promising combinations of genetic factors that might predispose to complex disorders. In particular, the correlation analysis of IBD expression patterns might hint to possible gene-gene interactions and the filtering might be a fruitful approach to distinguish true correlation signals from noise.
D. Liu and X. Zhu, Erratum to: &ldquo;Fractional chromatic number and circular chromatic number for distance graphs with large clique size&rdquo;. Journal of Graph Theory47(2) 2004, 129&ndash;146
Authors: Daphne Der-Fen Liu, Xuding Zhu
Venue: Journal of Graph Theory (2005)

The original article to which this Erratum refers was published in Journal of Graph Theory 47:129&ndash;146,2004.
Modeling expert finding as an absorbing random walk
Authors: Pavel Serdyukov, Henning Rode, Djoerd Hiemstra
Venue: Proceedings of the 31st annual international ACM SIGIR conference on Research and development in information retrieval (2008)

We introduce a novel approach to expert finding based on multi-step relevance propagation from documents to related candidates. Relevance propagation is modeled with an absorbing random walk. The evaluation on the two official Enterprise TREC data sets demonstrates the advantage of our method over the state-of-the-art method based on one-step propagation.
Semantic Web for E-Government Service Delivery Integration
Authors: Farzad Sanati, Jie Lu
Venue: Proceedings of the Fifth International Conference on Information Technology: New Generations (2008)

Repeatability is one of the most fundamental components of any methodology or framework in any engineering discipline. Many research projects attempting to formulate some modelling strategies as the new technologies and development techniques are being proposed in Service Oriented Architecture (SOA) domain. In absence of a documented best common practice of design and modelling techniques for e-service composition, it would be greatly beneficial to discover such common practices and describe the detail specifications of a repeatable methodology for e-service composition projects. This paper will discuss some proposed e-government integration models, and then it will introduce some e-service integration practices and classifications of e-service composition strategies. The main contribution of this paper is to propose detailed specifications of a repeatable methodology for e-service composition projects. This methodology called E-service Integration Methodology (E-SIM) is a repeatable process, clearly defining all the tasks and activities of its process to provide effective management control over all these tasks and activities. This paper also will use E-SIM to model a simplified e-service integration solution as a proof of concept.
Querying Imprecise Data in Sensor Databases
Authors: Z. M. Ma, Li Yan
Venue: Proceedings of the The Ninth International Conference on Mobile Data Management (2008)

Sensors are used to monitor some physical phenomena such as contamination, climate, building, and so on. The sensors collect and communicate their readings to the sensor databases for making decisions and answering various user queries. Due to continuous changes and possible errors in these values, the data values recorded in sensor databases may differ from the actual status. Queries using these values can yield incorrect and misleading answers. In order to manage the imprecision between the actual sensor value and the database value, the framework representing imprecision of sensor data has been proposed, in which each data value is represented as an interval. In this paper, we examine the situation when answer imprecision can be represented qualitatively and quantitatively. In particular, we propose two new kinds of imprecise queries called Top-k imprecise query and imprecise threshold query. Also, we investigate techniques for evaluating the qualitative and quantitative queries.