ppxscal/embedding_network huggingface dataset:
Adaptive Geometric Integrators for Hamiltonian Problems with Approximate Scale Invariance
Authors: S. Blanes, C. J. Budd
Venue: SIAM Journal on Scientific Computing (2005)

We consider adaptive geometric integrators for the numerical integration of Hamiltonian systems with greatly varying time scales. A time regularization is considered using either the Sundman or the Poincaré transformation. In the latter case, this gives a new Hamiltonian which is usually separable, but with one of the parts not always exactly solvable. This system can be numerically integrated with a splitting scheme where each part can be computed using a symplectic implicit or explicit method, preserving the qualitative properties of the exact solution. In this case, a backward error analysis for the numerical integration is presented. For a one-dimensional near singular problem, this analysis reveals a strong dependence of the performance of the method with the choice of the monitor function g, which is also observed when using other symmetric nonsymplectic integrators. We also show how this dependence greatly increases with the order of the numerical integrator used. The optimal choice corresponds to the function g, which nearly preserves the scaling invariance of the system. Numerical examples supporting this result are presented. In some cases a canonical transformation can also be considered, making the system more regular or easy to compute, and this is also illustrated with some examples.
Advanced SQL modeling in RDBMS
Authors: Andrew Witkowski, Srikanth Bellamkonda, Tolga Bozkaya, Nathan Folkert, Abhinav Gupta, John Haydu, Lei Sheng, Sankar Subramanian
Venue: ACM Transactions on Database Systems (TODS) (2005)

Commercial relational database systems lack support for complex business modeling. ANSI SQL cannot treat relations as multidimensional arrays and define multiple, interrelated formulas over them, operations which are needed for business modeling. Relational OLAP (ROLAP) applications have to perform such tasks using joins, SQL Window Functions, complex CASE expressions, and the GROUP BY operator simulating the pivot operation. The designated place in SQL for calculations is the SELECT clause, which is extremely limiting and forces the user to generate queries with nested views, subqueries and complex joins. Furthermore, SQL query optimizers are preoccupied with determining efficient join orders and choosing optimal access methods and largely disregard optimization of multiple, interrelated formulas. Research into execution methods has thus far concentrated on efficient computation of data cubes and cube compression rather than on access structures for random, interrow calculations. This has created a gap that has been filled by spreadsheets and specialized MOLAP engines, which are good at specification of formulas for modeling but lack the formalism of the relational model, are difficult to coordinate across large user groups, exhibit scalability problems, and require replication of data between the tool and RDBMS. This article presents an SQL extension called SQL Spreadsheet, to provide array calculations over relations for complex modeling. We present optimizations, access structures, and execution models for processing them efficiently. Special attention is paid to compile time optimization for expensive operations like aggregation. Furthermore, ANSI SQL does not provide a good separation between data and computation and hence cannot support parameterization for SQL Spreadsheets models. We propose two parameterization methods for SQL. One parameterizes ANSI SQL view using subqueries and scalars, which allows passing data to SQL Spreadsheet. Another method presents parameterization of the SQL Spreadsheet formulas. This supports building stand-alone SQL Spreadsheet libraries. These models are then subject to the SQL Spreadsheet optimizations during model invocation time.
Automatic generation of link collections and their visualization
Authors: Osamu Segawa, Jun Kawai, Kazuyuki Sakauchi
Venue: Special interest tracks and posters of the 14th international conference on World Wide Web (2005)

In this paper, we describe a method of generating link collections in a user-specified category by comprehensively collecting existing link collections and analyzing their hyperlink references. Moreover, we propose a visualization method for a bird's-eye view of the generated link collections. Our methods are effective in grasping intuitively the trend of significant sites and keywords in a category.
Dynamic QoS-Aware Coalition Formation
Authors: Luis Nogueira, Luis Miguel Pinho
Venue: Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium (IPDPS'05) - Workshop 2 - Volume 03 (2005)

Users of wireless devices increasingly demand access to multimedia content with specific quality of service requirements. However, different users might tolerate different levels of service, or could be satisfied with different quality combinations choices. We provide semantically rich QoS specification interface for multidimensional QoS provisioning, allowing the user, and applications, to define finegrained service requests. Traditionally, multimedia processing introduces heavy resource requirements on the client side. Our work tries to address this growing demand on resources and performance requirements, by allowing wireless nodes to cooperate with each other, or with wired neighbor nodes, to meet resource allocation requests and handle stringent constraints, opportunistically taking advantage of local network resources and processing power, as nodes move in range of each other, forming a temporary coalition for service execution. We argue that coalition formation is necessary when a single node cannot execute a specific service, and it may also be beneficial when groups perform more efficiently when compared to a single's node performance.
Intrusion-Tolerant Server Architecture for Survivable Services
Authors: Byoung Min Joon
Venue: The Journal of Supercomputing (2005)

Survivable systems are increasingly needed in a wide range of applications. As a step toward realizing survivable systems, this paper presents architecture of intrusion-tolerant servers. It is to deliver intended services transparently to the clients even when a computing node fails due to failures, intrusions, and other threats. In order to deliver only secure results to the client, we need an algorithm to decide agreement on results from replicated servers. For this purpose, a secure and practical decentralized voting algorithm for the architecture is proposed in the paper. Through the experiments on a test-bed, especially, for web services, the approach turned out very effective in terms of extra cost and considered to be able to cope with both confidentiality and integrity attacks.
Applying the Oscillation Test Strategy to FPAA's Configurable Analog Blocks
Authors: Tiago R. Balen, Antonio Q. Andrade,  Jr., Florence Azaïs, Marcelo Lubaszewski, Michel Renovell
Venue: Journal of Electronic Testing: Theory and Applications (2005)

This paper presents the application of the oscillation test methodology as an alternative to test configurable analog blocks of Field Programmable Analog Arrays. The blocks of the device under test are first configured to behave as oscillators. Then, the output frequency and amplitude are observed to obtain the signature of the fault-free circuit. During test, this signature is compared to the actual output signal. Experimental results show the effectiveness of the method in detecting parametric and large deviation faults of the tested components.
ELECTRONIC MAIL STANDARDS: RECONCILING TECHNOLOGY WITH USABILITY
Authors: Nigel Bevan
Venue: ACM SIGCHI Bulletin (1991)

Over the past 20 years electronic mail services have evolved from pioneering in-house facilities to extensively-used national and international networks. Electronic mail is now widely provided by individual companies, commercial mail box services, and internet and associated international research networks. Unfortunately there are currently very limited interconnections between internet and company and commercial services. One of the major objectives of the X.400 international standard is to facilitate such interconnections, and to provide a universal naming scheme. We can look forward to a time when all those failed attempts to send internet mail will be forgotten. With one unique address for each mail user valid worldwide, just type it in and you will be sure your mail will reach its destination. Or will you?
Bridging Separations in Matroids
Authors: Jim Geelen, Petr Hlinený, Geoff Whittle
Venue: SIAM Journal on Discrete Mathematics (2005)

Let (X1,X2) be an exact k-separation of a matroid N. If M is a matroid that contains N as a minor and the k-separation (X1,X2) does not extend to a k-separation in M, then we say that M bridges the k-separation (X1,X2) in N. One would hope that a minor minimal bridge for (X1,X2) would not be much larger than N. Unfortunately there are instances in which one can construct arbitrarily large minor-minimal bridges. We restrict our attention to the class of matroids representable over a fixed finite field and show that here minor-minimal bridges are bounded in size.
Toward a basic framework for webometrics
Authors: Lennart Björneborn, Peter Ingwersen
Venue: Journal of the American Society for Information Science and Technology (2004)

In this article, we define webometrics within the framework of informetric studies and bibliometrics, as belonging to library and information science, and as associated with cybermetrics as a generic subfield. We develop a consistent and detailed link typology and terminology and make explicit the distinction among different Web node levels when using the proposed conceptual framework. As a consequence, we propose a novel diagram notation to fully appreciate and investigate link structures between Web nodes in webometric analyses. We warn against taking the analogy between citation analyses and link analyses too far.
A New Wireless Networking System for Rescue Activities in Disasters " System Overview and Evaluation of Wireless Node
Authors: Makoto Kamegawa, Mai Kawamoto, Tetsuya Shigeyasu, Misako Urakami, Hiroshi Matsuno
Venue: Proceedings of the 19th International Conference on Advanced Information Networking and Applications - Volume 2 (2005)

In recent years, many network systems to provide disaster information have been proposed. However, any network system to provide such real time for rescue activities has not been proposed. Then, this paper proposes a new wireless network system for rescue activities at distressed area. The main feature of our system is, providing sufferes information in real time to the disaster countermeasures office. In order to realize the system, we developed a wireless control station called "ANPI", and the program to share all suffererýs information with all shelters.
Note on starting the Numerov method more accurately by a hybrid formula of order four for an initial-value problem
Authors: S. O. Adee, P. Onumanyi, U. W. Sirisena, Y. A. Yahaya
Venue: Journal of Computational and Applied Mathematics (2005)

In this note we report a hybrid formula of order four for starting the Numerov method applied to the initial--value problem for y'' = f(x, y), over the recently obtained result of order three by two different papers (J. Pure Appl. Sci. 2(2) (2002) 1, Abacus 29(2) (2002) 92), based on two different approaches. We illustrate the accuracy of the methods by two numerical examples.
Refined memorization for vertex cover
Authors: L. Sunil Chandran, Fabrizio Grandoni
Venue: Information Processing Letters (2005)

Memorization is a technique which allows to speed up exponential recursive algorithms at the cost of an exponential space complexity. This technique already leads to the currently fastest algorithm for fixed-parameter vertex cover, whose time complexity is O(1.2832kk1.5 + kn), where n is the number of nodes and k is the size of the vertex cover. Via a refined use of memorization, we obtain an O(1.2759kk1.5 + kn) algorithm for the same problem. We moreover show how to further reduce the complexity to O(1.2745kk4 + kn).
On using flexure-hinge five-bar linkages to develop novel walking mechanisms and small-scale grippers for microrobots
Authors: Guo-Bao Wang, Shi-Gang Wang, Wei Xu
Venue: Journal of Robotic Systems (2004)

This paper presents the micromotion analysis of five-bar linkages and demonstrates the approximate linearity of motion transmission of five-bar mechanisms within a micromotion range. A novel walking mechanism used for a microrobot and a small-scale gripper with a high transmission ratio are introduced, based on the flexure-hinge five-bar mechanism analysis. Results of numerical simulation show the validity of design and analysis on the introduced mechanisms and the feasibility of corresponding thoughts. The presented micromotion-based robot mechanisms are devoid of friction and fitting errors, and particularly suitable for microrobot applications. &copy; 2004 Wiley Periodicals, Inc.
Obtaining Probabilistic Dynamic State Graphs for TPPAL Processes
Authors: Juan J. Pardo, Valentin Valero, M. Carmen Ruiz, Fernando Cuartero, Gregorio Diaz
Venue: Proceedings of the 2005 Australian conference on Software Engineering (2005)

Software engineers work gladly with process algebras, as they are very similar to programming languages. However, graphical models are better in order to understand how a system behaves, and even these graphical models allow us to analyze some properties of the systems. Then, in this paper we present two formalisms for the specification of concurrent systems. On the one hand we present the timed-probabilistic process algebra TPPAL, which is a suitable model for description of systems in which time and probabilities are two important factors to be considered in the description, as it occurs in real-time systems and fault-tolerant systems. Then, the specification written in TPPAL can be automatically translated into a graphical model (the so-called probabilistic dynamic state graphs), which allows us to simulate and evaluate the system. Thus, in this paper we present this translation, which is currently supported by a tool (TPAL).
Fault Recovery Designs for Processor-Embedded Distributed Storage Architectures with I/O-Intensive DB Workloads
Authors: Steve C. Chiu, Alok N. Choudhary, Mahmut T. Kandemir
Venue: Proceedings of the 22nd IEEE / 13th NASA Goddard Conference on Mass Storage Systems and Technologies (2005)

Fault recovery has become an essential capability for systems that process large data-intensive workloads. Processor-embedded distributed storage architectures offload user-level processing to the peripheral from the host servers. Our earlier work investigated the performance benefits of such architectures for disk- and MEMS-based smart storage devices. In this paper, we focus on the issue of fault recovery. We propose recovery schemes for TPC-H based workloads, and evaluate several recovery scenarios applicable to both disk- and MEMS-based smart storage architectures.
Hardware-Assisted Visibility Sorting for Unstructured Volume Rendering
Authors: Steven P. Callahan Milan Ikits, Joao L. D. Comba Claudio T. Silva
Venue: IEEE Transactions on Visualization and Computer Graphics (2005)

Harvesting the power of modern graphics hardware to solve the complex problem of real-time rendering of large unstructured meshes is a major research goal in the volume visualization community. While, for regular grids, texture-based techniques are well-suited for current GPUs, the steps necessary for rendering unstructured meshes are not so easily mapped to current hardware. We propose a novel volume rendering technique that simplifies the CPU-based processing and shifts much of the sorting burden to the GPU, where it can be performed more efficiently. Our hardware-assisted visibility sorting algorithm is a hybrid technique that operates in both object-space and image-space. In object-space, the algorithm performs a partial sort of the 3D primitives in preparation for rasterization. The goal of the partial sort is to create a list of primitives that generate fragments in nearly sorted order. In image-space, the fragment stream is incrementally sorted using a fixed-depth sorting network. In our algorithm, the object-space work is performed by the CPU and the fragment-level sorting is done completely on the GPU. A prototype implementation of the algorithm demonstrates that the fragment-level sorting achieves rendering rates of between one and six million tetrahedral cells per second on an ATI Radeon 9800.
Representing linear algebra algorithms in code: the FLAME application program interfaces
Authors: Paolo Bientinesi, Enrique S. Quintana-Ortí, Robert A. van de Geijn
Venue: ACM Transactions on Mathematical Software (TOMS) (2005)

In this article, we present a number of Application Program Interfaces (APIs) for coding linear algebra algorithms. On the surface, these APIs for the MATLAB M-script and C programming languages appear to be simple, almost trivial, extensions of those languages. Yet with them, the task of programming and maintaining families of algorithms for a broad spectrum of linear algebra operations is greatly simplified. In combination with our Formal Linear Algebra Methods Environment (FLAME) approach to deriving such families of algorithms, dozens of algorithms for a single linear algebra operation can be derived, verified to be correct, implemented, and tested, often in a matter of minutes per algorithm. Since the algorithms are expressed in code much like they are explained in a classroom setting, these APIs become not just a tool for implementing libraries, but also a valuable tool for teaching the algorithms that are incorporated in the libraries. In combination with an extension of the Parallel Linear Algebra Package (PLAPACK) API, the approach presents a migratory path from algorithm to MATLAB implementation to high-performance sequential implementation to parallel implementation. Finally, the APIs are being used to create a repository of algorithms and implementations for linear algebra operations, the FLAME Interface REpository (FIRE), which already features hundreds of algorithms for dozens of commonly encountered linear algebra operations.
Article impact calculated over arbitrary periods: Research Articles
Authors: Tove Faber Frandsen, Ronald Rousseau
Venue: Journal of the American Society for Information Science and Technology (2005)

In this paper we address the various formulations of impact of articles, usually groups of articles as gauged by citations that these articles receive over a certain period of time. The journal impact factor, as published by ISI (Philadelphia, PA), is the best-known example of a formulation of impact of journals (considered as a set of articles) but many others have been defined in the literature. Impact factors have varying publication and citation periods and the chosen length of these periods enables, e.g., a distinction between synchronous and diachronous impact factors. It is shown how an impact factor for the general case can be defined. Two alternatives for a general impact factor are proposed, depending on whether different publication years are seen as a whole, and hence treating each one of them differently, or by operating with citation periods of identical length but allowing each publication period different starting points. &copy; 2005 Wiley Periodicals, Inc.
Firm-like behavior of journals? Scaling properties of their output and impact growth dynamics: Research Articles
Authors: Frank Havemann, Michael Heinz, Roland Wagner-Döbler
Venue: Journal of the American Society for Information Science and Technology (2005)

In the study of growth dynamics of artificial and natural systems, the scaling properties of fluctuations can exhibit information on the underlying processes responsible for the observed macroscopic behavior according to H.E. Stanley and colleagues (Lee, Amaral, Canning, Meyer, & Stanley, 1998; Plerou, Amaral, Gopikrishnan, Meyer, & Stanley, 1999; Stanley et al., 1996). With such an approach, they examined the growth dynamics of firms, of national economies, and of university research fundings and paper output. We investigated the scaling properties of journal output and impact according to the Journal Citation Reports (JCR; ISI, Philadelphia, PA) and find distributions of paper output and of citations near to lognormality. Growth rate distributions are near to Laplace &ldquo;tents,&rdquo; however with a better fit to Subbotin distributions. The width of fluctuations decays with size according to a power law. The form of growth rate distributions seems not to depend on journal size, and conditional probability densities of the growth rates can thus be scaled onto one graph. To some extent even quantitatively, all our results are in agreement with the observations of Stanley and others. Further on, a Matthew effect of journal citations is confirmed. If journals &ldquo;behave&rdquo; like business firms, a better understanding of Bradford's Law as a result of competition among publishing houses, journals, and topics suggests itself. &copy; 2005 Wiley Periodicals, Inc.
Three Dimensional Multi-Valued Design in Nanoscale Integrated Circuits
Authors: Sergey Edward Lyshevski
Venue: Proceedings of the 35th International Symposium on Multiple-Valued Logic (2005)

Novel three-dimensional (3D) nanoscale integrated circuits (nanoICs) are examined in this paper. These nanoICs are synthesized utilizing aggregated 3D neuronal-hypercells (¿-hypercells) with multi-terminal electronic nanodevices. The proposed nanodevices ensure multi-valued inputoutput characteristic that lead to a direct technological solution of multi-valued logic synthesis problem. Super-high-performance computing architectures and memories can be devised (synthesized), designed and optimized. At the system-level, we examine nanoICs as networked aggregated 3D ¿-hypercells. In particular, scalable 3D ¿-hypercell topologies are under consideration. These ¿-hypercells integrate interconnected functional multi-terminal electronic nanodevices that implement logic functions. The proposed nanoICs platform suits the envisioned cognizant computing ensuringpreeminent information processing and immense memory.
Application of Gaussian plume models for air pollution simulation at instantaneous emissions
Authors: N. Kh. Arystanbekova
Venue: Mathematics and Computers in Simulation (2004)

In this paper there is proposed analytical Gaussian model for diagnosis and prognosis of atmospheric pollution level at damage emissions. The models of Gauss are very widely used to estimate local pollution levels. The program complex has been realized on FORTRAN language of high level. The model reads its input data from GIS files and produces its outputs in a format acceptable by GIS.
Error Estimates for the Numerical Approximation of Boundary Semilinear Elliptic Control Problems
Authors: Eduardo Casas, Mariano Mateos, Fredi Tröltzsch
Venue: Computational Optimization and Applications (2005)

We study the numerical approximation of boundary optimal control problems governed by semilinear elliptic partial differential equations with pointwise constraints on the control. The analysis of the approximate control problems is carried out. The uniform convergence of discretized controls to optimal controls is proven under natural assumptions by taking piecewise constant controls. Finally, error estimates are established and some numerical experiments, which confirm the theoretical results, are performed.