ppxscal/embedding_network huggingface dataset:
C++ implementations of numerical methods for solving differential-algebraic equations: design and optimization considerations
Authors: Christopher E. Kees, Cass T. Miller
Venue: ACM Transactions on Mathematical Software (TOMS) (1999)

Object-oriented programming can produce improved implementations of complex numerical methods, but it can also introduce a performance penalty. Since computational simulation often requires intricate and highly efficient codes, the performance penalty of high-level techniques must always be weighed against the improvements they enable. These issues are addressed in a general object-oriented (OO) toolkit for the numerical solution of differential-algebraic equations (DAEs). The toolkit can be configured in several different ways to solve DAE initial-value problems with an adaptive multistep method. It contains a wrapped version of the Fortran 77 code DASPK and a translation of this to C++. Two C++ constructs for assembling the tools are provided, as are two implementations an important DAE test problem. Multiple configurations of the toolkit for DAE test problems are compared in order to assess the performance penalties of C++. The mathematical methods and implementation techniques are discussed in detail in order to provide heuristics for efficient OO scientific programming and to demonstrate the effectiveness of OO techniques in managing complexity and producing better code. The codes were tested on a variety of problems using publicly available Fortran 77 and C++ compilers. Extensive effficiency comparisons are presented in order to isolate computationally inefficient OO techniques. Techniques that caused difficulty in implementation and maintenance are also highlighted. The comparisons demonstrate that the majority of C++'s built-in support for OO programming has a negligible effect on performance, when used at sufficiently high levels, and provides flexible and extensible software for numerical methods.
Credit Risk Assessment Using Statistical and MachineLearning: Basic Methodology and Risk Modeling Applications
Authors: J. Galindo, P. Tamayo
Venue: Computational Economics (2000)

Risk assessment of financial intermediaries is an area of renewed interest due to the financial crises of the 1980's and 90's. An accurate estimation of risk, and its use in corporate or global financial risk models, could be translated into a more efficient use of resources. One important ingredient to accomplish this goal is to find accurate predictors of individual risk in the credit portfolios of institutions. In this context we make a comparative analysis of different statistical and machine learning modeling methods of classification on a mortgage loan data set with the motivation to understand their limitations and potential. We introduced a specific modeling methodology based on the study of error curves. Using state-of-the-art modeling techniques we built more than 9,000 models as part of the study. The results show that CART decision-tree models provide the best estimation for default with an average 8.31% error rate for a training sample of 2,000 records. As a result of the error curve analysis for this model we conclude that if more data were available, approximately 22,000 records, a potential 7.32% error rate could be achieved. Neural Networks provided the second best results with an average error of 11.00%. The K-Nearest Neighbor algorithm had an average error rate of 14.95%. These results outperformed the standard Probit algorithm which attained an average error rate of 15.13%. Finally we discuss the possibilities to use this type of accurate predictive model as ingredients of institutional and global risk models.
An Overhead Specimen Handling System for Variable Workloads
Authors: Arthur A. Eggert, Karen L. Bowers, Gary J. Smulka, Kenneth A. Emmerich, Anita L. Iwanski, Elsa F. Quam
Venue: Journal of Medical Systems (1999)

This unique overhead specimen handling system requires virtually no floor space and only a minimal amount of bench space. It uses state-of-the-art conveyors suspended near the ceiling to transport, log-in and sort blood specimens in standard specimen containers. Specimens placed into the system at bench-level bins are automatically singulated and loaded onto cleated conveyors and lifted to the main conveyor belt near the ceiling. The barcoded labels are then read as the containers are rotated under an optical scanner. The specimens are then diverted to the appropriate branch conveyor and lowered back to the bench level by cleated conveyors. The specimen handling system is rapid and accurate, requires no special containers, allows laboratorians to move unimpeded below it, and is inexpensive by automation standards. Studies show no adverse effect upon the specimens.
A rate-based congestion control scheme for ABR service in ATM networks
Authors: Anna Hać
Venue: International Journal of Network Management (1998)

In this article we describe an improved rate-based congestion control scheme for Available Bit Rate &lpar;ABR&rpar; service in ATM networks. The analytical results are presented and the characteristics of the designed scheme are illustrated by using simulation results. &copy; 1998 John Wiley & Sons, Ltd.
Spectral compression of mesh geometry
Authors: Zachi Karni, Craig Gotsman
Venue: Proceedings of the 27th annual conference on Computer graphics and interactive techniques (2000)

We show how spectral methods may be applied to 3D mesh data to obtain compact representations. This is achieved by projecting the mesh geometry onto an orthonormal basis derived from the mesh topology. To reduce complexity, the mesh is partitioned into a number of balanced submeshes with minimal interaction, each of which are compressed independently. Our methods may be used for compression and progressive transmission of 3D content, and are shown to be vastly superior to existing methods using spatial techniques, if slight loss can be tolerated.
Forgetting Exceptions is Harmful in Language Learning
Authors: Walter Daelemans, Antal Van Den Bosch, Jakub Zavrel
Venue: Machine Learning (1999)

We show that in language learning, contrary to received wisdom, keeping exceptional training instances in memory can be beneficial for generalization accuracy. We investigate this phenomenon empirically on a selection of benchmark natural language processing tasks: grapheme-to-phoneme conversion, part-of-speech tagging, prepositional-phrase attachment, and base noun phrase chunking. In a first series of experiments we combine memory-based learning with training set editing techniques, in which instances are edited based on their typicality and class prediction strength. Results show that editing exceptional instances (with low typicality or low class prediction strength) tends to harm generalization accuracy. In a second series of experiments we compare memory-based learning and decision-tree learning methods on the same selection of tasks, and find that decision-tree learning often performs worse than memory-based learning. Moreover, the decrease in performance can be linked to the degree of abstraction from exceptions (i.e., pruning or eagerness). We provide explanations for both results in terms of the properties of the natural language processing tasks and the learning algorithms.
Primal-Dual Affine-Scaling Algorithms Fail for Semidefinite Programming
Authors: Masakazu Muramatsu, Robert J. Vanderbei
Venue: Mathematics of Operations Research (1999)

In this paper, we give an example of a semidefinite programming problem in which primal-dual affine-scaling algorithms using the HRVW/KSH/M, MT, and AHO directions fail. We prove that each of these algorithms can generate a sequence converging to a non-optimal solution and that, for the AHO direction, even its associated continuous trajectory can converge to a non-optimal point. In contra st with these directions, we show that the primal-dual affine-scaling algorithm using the NT direction for the same semidefinite programming problem always generates a sequence converging to the optimal solution. Both primal and dual problems have interior feasible solutions and unique optimal solutions which satisfy strict complementarity, and are nondegenerate everywhere.
Supremum Operators and Computation of Supremal Elements in System Theory
Authors: S. Hashtrudi Zad, R. H. Kwong, W. M. Wonham
Venue: SIAM Journal on Control and Optimization (1999)

Constrained supremum and supremum operators are introduced to obtain a general procedure for computing supremal elements of upper semilattices. Examples of such elements include supremal (A, B)-invariant subspaces in linear system theory and supremal controllable sublanguages in discrete-event system theory. For some examples, we show that the algorithms available in the literature are special cases of our procedure. Our iterative algorithms may also provide more insight into applications; in the case of supremal controllable subpredicate, the algorithm enables us to derive a lookahead policy for supervisory control of discrete-event systems.
Relationship among copyright holders for use and reuse of digital contents
Authors: Masayuki Kumazawa, Hironori Kamada, Atsushi Yamada, Hiroshi Hoshino, Yahiko Kambayashi, Mukesh Mohania
Venue: Proceedings of the fifth ACM conference on Digital libraries (2000)

Modification and reuse of digital contents, particularly web data, has become easy due to advancement in computer technology. The work created by a person (or a group of persons) can be reused by another person (or group) for different purpose. Thus, there can be multiple copyright holders for the same information. In such scenario, it is important to define the relationship among the copyright holders. There have been some attempts at designing the Electronic Copyright Management System (ECMS) \cite{6,7}. However, this system is used for defining and registering the information of one copyright holder. Another attempt to develop copyright management systems is reported in \cite{indecs}. The key feature of this system is that they have an RDF expression for copyright metadata. When multiple creators take part in creating one content or when contents are created reusing existing contents, it is vital to define the relationship among copyright holders. This relationship should be clarified in order to make proper allocation of profits and protect rights of all the copyright holders. Therefore, a framework is required where the relationship among copyright holders and profit allocations are described. In this paper we outline the main points of such framework. We refer the readers to see \cite{tr-wmu} for a detailed description. The proposed framework also represents copyright processing for multiple rights holders, it gives a framework for realizing transaction systems where reuse for creating new contents is promoted. In this paper we also outline the conceptual model designed for describing copyright information, examining the relationship among rights holders, and modeling charge rules.
MCGS: A Modified Conjugate Gradient Squared Algorithm for Nonsymmetric Linear Systems
Authors: Muthucumaru Maheswaran, Kevin J. Webb, Howard Jay Siegel
Venue: The Journal of Supercomputing (1999)

The conjugate gradient squared (CGS) algorithm is a Krylov subspace algorithm that can be used to obtain fast solutions for linear systems (Ax&equals;b) with complex nonsymmetric, very large, and very sparse coefficient matrices (A). By considering electromagnetic scattering problems as examples, a study of the performance and scalability of this algorithm on two MIMD machines is presented. A modified CGS (MCGS) algorithm, where the synchronization overhead is effectively reduced by a factor of two, is proposed in this paper. This is achieved by changing the computation sequence in the CGS algorithm. Both experimental and theoretical analyses are performed to investigate the impact of this modification on the overall execution time. From the theoretical and experimental analysis it is found that CGS is faster than MCGS for smaller number of processors and MCGS outperforms CGS as the number of processors increases. Based on this observation, a set of algorithms approach is proposed, where either CGS or MGS is selected depending on the values of the dimension of the A matrix (N) and number of processors (P). The set approach provides an algorithm that is more scalable than either the CGS or MCGS algorithms. The experiments performed on a 128-processor mesh Intel Paragon and on a 16-processor IBM SP2 with multistage network indicate that MCGS is approximately 20% faster than CGS.
Vector instruction set support for conditional operations
Authors: J. E. Smith, Greg Faanes, Rabin Sugumar
Venue: Proceedings of the 27th annual international symposium on Computer architecture (2000)

Vector instruction sets are receiving renewed interest because of their applicability to multimedia. Current multimedia instruction sets use short vectors with SIMD implementations, but long vector, pipelined implementations have a number of advantages and arc a logical next step in multimedia ISA development. Support for conditional operations (as occur in loops containing IF statements) is an important aspect of a vector ISA. Seven ISA alternatives for implementing conditional operations are systematically explored. Performance considerations are discussed through evaluation of a typical IF loop over a range of vector lengths and true conditional values. An approach using masked operations is shown to be one of the better methods, especially if its implementation is able to skip over blocks of false mask bits. Additional analyses of complex IF loops and parallel pipeline implementations support the masked operation approach. The paper concludes with a practical implementation of masked operations that skips over power-of-2-length blocks of false values. This implementation is simpler than skipping arbitrary-length blocks and provides similar performance.
Graphic Java 2 (3rd ed.): mastering the JFC (Volume II SWING)
Authors: David M. Geary
Venue:  (1999)

Master the Java Foundation Classes with Graphic Java 2, the most complete and comprehensive guide to the AWT, Swing, and the 2D APIVOLUME 2: SWINGSwing gives Java application programmers world-class tools for building professional, customizable cross-platform GUIs. This comprehensive reference by former Sun engineer David Geary shows experienced programmers how to take full advantage of Swing's power. Practical explanations and robust code examples provide the resources you need to build Java applications with sophisticated graphical user interfaces.Graphic Java is the one exhaustive reference that contains everything you need to know about Swing. In depth explanations are coupled with class diagrams and code examples for all of the key components, including: Buttons and labels Progress bars and sliders Frames, windows, and dialogs Internal frames and desktop panes Color and file choosers Menus and toolbars Lists and combo boxes Text components Tables and treesYou'll discover the key design considerations associated with Swing development, including Swing's object-oriented idioms and design patterns, and the pluggable look and feel architecture. You will understand how to use the Swing components, but more importantly you will have an understanding of how the components are designed and how they fit together within the Swing framework.The accompanying CD-ROM includes all of the example code from the book, ready to run on Macintosh, Solaris...ï¾, Windows 95, and Windows NT along with JDK...ï¾.
Multiple block coded modulations and applications to unequal error protection
Authors: Huan-Bang Li, Tetsushi Ikegami
Venue: Wireless Networks (2000)

Multiple block coded modulations &lpar;MBCM&rpar; are studied. One characteristic of the studied MBCM schemes is that they have both a block and a trellis structure. A general rule for deriving branch variables so as to establish a decoding trellis is presented. Examples of MBCM schemes employing 8&dash;PSK and 16&dash;PSK constellations are given. Two different methods using these schemes are proposed for producing unequal error protection. Computer simulations are done to show the UEP ability.
Adaptively Preconditioned GMRES Algorithms
Authors: J. Baglama, D. Calvetti, G. H. Golub, L. Reichel
Venue: SIAM Journal on Scientific Computing (1998)

The restarted GMRES algorithm proposed by Saad and Schultz [SIAM J. Sci. Statist. Comput., 7 (1986), pp. 856--869] is one of the most popular iterative methods for the solution of large linear systems of equations Ax=b with a nonsymmetric and sparse matrix. This algorithm is particularly attractive when a good preconditioner is available. The present paper describes two new methods for determining preconditioners from spectral information gathered by the Arnoldi process during iterations by the restarted GMRES algorithm. These methods seek to determine an invariant subspace of the matrix A associated with eigenvalues close to the origin and to move these eigenvalues so that a higher rate of convergence of the iterative methods is achieved.
Classroom Note: A Model of Dieting
Authors: Ronald E. Mickens, Denise N. Brewley, Matasha L. Russell
Venue: SIAM Review (1998)

We construct a mathematical model of the dieting process and investigate the properties of its solutions. While the general solution cannot be explicitly obtained, we show that all the important features can be determined by use of geometrical techniques and linear stability analysis. The results of this study are consistent with all accepted facts relating to the dieting process.
Similarity Solution to a Heat Exchange Problem
Authors: J. David Logan
Venue: SIAM Review (1998)

A similarity solution is obtained for a two-dimensional heat flow problem with unidirectional diffusion and an evolutionary, oblique boundary condition. The problem also can be interpreted in a hydrogeological setting as diffusion of a chemical contaminant into an adjacent porous medium as it convects through a fracture channel.
The Asymptotic Behavior of the Eigenvalues of a Singularly Perturbed Linear Pencil
Authors: Branko Najman
Venue: SIAM Journal on Matrix Analysis and Applications (1999)

The pencil $\widetilde{T}(\lambda,\varepsilon)=\varepsilon\lambda^{2}I + \lambda C+K,$ a singular perturbation of the linear pencil $\widetilde{T}(\lambda,0)=\lambda C+K,$ is considered, and the asymptotic behavior of its large eigenvalues (i.e.,\ those converging to infinity as $\varepsilon$ goes to zero) is analyzed. The Newton diagram method is employed to determine the leading power of the Puiseux $\varepsilon$-expansion of the large eigenvalues of ${\widetilde T}(\lambda,\varepsilon).$ These leading powers are completely identified either in the case when $C$ is diagonalizable and nonsingular, or when both $C$ and $K$ are hermitian matrices. In the remaining cases, some partial information is still obtained.
Web-based learning and teaching technologies: opportunities and challenges
Authors: Anil Aggarwal
Venue:  (2000)

During the past two decades, telecommunication technologies combined with Web-enabled technologies have created a new technology-based focus, Web-based learning and teaching. This new area has changed the concept of education around the world, creating new challenges and opportunities offered by this new technology-based concept.Web-Based Learning and Teaching Technologies: Opportunities and Challenges addresses many issues, trends, opportunities and problems facing colleges and universities in the effective utilization and management of Web-based learning and teaching technologies.
Optical crossconnects for high-capacity lightwave networks
Authors: L. Y. Lin, E. L. Goldstein, L. M. Lunardi, R. W. Tkach
Venue: Journal of High Speed Networks (1999)

Optical crossconnects are rapidly emerging as critical elements for provisioning and restoration in high-capacity wavelength-division-multiplexed optical networks. High port count appears to be emerging as particularly important in this core-network application, with 500-port optical crossconnects (OXCs) widely expected to be needed within about five years. This requirement severely strains current optical-switching technologies. The emergence of this new application is, however, beginning to stimulate new device technologies. One of these is the free-space micromachined optical switch (FS-MOS). This approach combines the advantages of free-space interconnection and monolithic integrated optics, thus offering the possibility of achieving high port-count in a small, low-cost system with excellent optical quality. In this paper, we review the fundamental principles, fabrication, and performance of the FS-MOS, and discuss both its port-count scalability and its ability to incorporate advanced optical-networking functionality within the switch fabric itself.
Wireless protocols design: challenges and opportunities
Authors: J. L. da Silva,  Jr., M. Sgroi, F. De Bernardinis, S. F. Li, A. Sangiovanni-Vincentelli, J. Rabaey
Venue: Proceedings of the eighth international workshop on Hardware/software codesign (2000)

Modern wireless communication systems require the deployment of increasingly complex protocols that satisfy tight requirements at low implementation cost, especially in terms of size and power consumption. Most protocol design methodologies currently in use are inadequate, either because they do not rely upon formal techniques and therefore do not guarantee correctness, or because they do not provide sufficient support for performance analysis and design exploration and therefore often lead to sub-optimal implementations. Therefore, we use a refinement-based formal methodology that relies upon the orthogonalization of function and architecture design and emphasizes the use of formal models to ensure correctness and reduce design time. In this paper we present a case study, the Intercom, consisting of a network of mobile terminals supporting voice communication among end users. We use this case study to validate the methodology and identify directions of further research.
Availability of CAUTRA, a Subset of the French Air Traffic Control System
Authors: Karama Kanoun, Thierry Morteveille, Alain Peytavin, Marie Borrel
Venue: IEEE Transactions on Computers (1999)

The aim of our work is to provide a quantified means of helping in the definition of a new architecture for CAUTRA, a subset of the French Air Traffic Control system. In this paper, we define a set of alternative architectures, give some elements for constructing their dependability models, and compare their availability. Modeling is carried out following a modular and systematic approach, based on the derivation of block models at a high level of abstraction. In a second step, the blocks are replaced by their equivalent Generalized Stochastic Petri Nets to build up the detailed model of the architecture. The evaluations performed permit identification of a subset of architectures whose availability meets the dependability requirements and also identification of the best architecture among this subset.