ppxscal/embedding_network huggingface dataset:
An Exterior Newton Method for Strictly Convex Quadratic Programming
Authors: Thomas F. Coleman, Jianguo Liu
Venue: Computational Optimization and Applications (2000)

We propose an exterior Newton method for strictly convex quadratic programming (QP) problems. This method is based on a dual formulation: a sequence of points is generated which monotonically decreases the dual objective function. We show that the generated sequence converges globally and quadratically to the solution (if the QP is feasible and certain nondegeneracy assumptions are satisfied). Measures for detecting infeasibility are provided. The major computation in each iteration is to solve a KKT-like system. Therefore, given an effective symmetric sparse linear solver, the proposed method is suitable for large sparse problems. Preliminary numerical results are reported.
Computing capabilities of mediators
Authors: Ramana Yerneni, Chen Li, Hector Garcia-Molina, Jeffrey Ullman
Venue: Proceedings of the 1999 ACM SIGMOD international conference on Management of data (1999)

Existing data-integration systems based on the mediation architecture employ a variety of mechanisms to describe the query-processing capabilities of sources. However, these systems do not compute the capabilities of the mediators based on the capabilities of the sources they integrate. In this paper, we proposed a framework to capture a rich variety of query-processing capabilities of data sources and mediators. We present algorithms to compute the set of supported queries of a mediator, based on the capability limitations of its sources. Our algorithms take into consideration a variety of query-processing techniques employed by mediators to enhance the set of supported queries.
An MRF Model-Based Approach to Simultaneous Recovery of Depth and Restoration from Defocused Images
Authors: A. N. Rajagopalan, S. Chaudhuri
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1999)

Depth from defocus (DFD) problem involves calculating the depth of various points in a scene by modeling the effect that the focal parameters of the camera have on images acquired with a small depth of field. In this paper, we propose a MAP-MRF-based scheme for recovering the depth and the focused image of a scene from two defocused images. The space-variant blur parameter and the focused image of the scene are both modeled as MRFs and their MAP estimates are obtained using simulated annealing. The scheme is amenable to the incorporation of smoothness constraints on the spatial variations of the blur parameter as well as the scene intensity. It also allows for inclusion of line fields to preserve discontinuities. The performance of the proposed scheme is tested on synthetic as well as real data and the estimates of the depth are found to be better than that of the existing window-based DFD technique. The quality of the space-variant restored image of the scene is quite good even under severe space-varying blurring conditions.
Test Generation Based on High-Level Assertion Specification for PowerPCTM Microprocessor Embedded Arrays
Authors: Li-C. Wang, Magdy S. Abadir
Venue: Journal of Electronic Testing: Theory and Applications (1998)

Test and validation of embedded array blocks remains a major challenge in today&lsquo;s microprocessor design environment. The difficulty comes from twofold, the sizes of the arrays and the complexity of their timing and control. This paper describes a novel test generation methodology for test and validation of microprocessor embedded arrays. Unlike traditional ATPG methods, our test generation method is based upon the high-level assertion specification which is originally used for the purpose of formal verification. The superiority of these assertion tests over the traditional ATPG tests will be discussed and shown through various experiments on recent PowerPC microprocessor designs.
Establishing a foundation for collaborative scenario elicitation
Authors: Ann M. Hickey, Douglas L. Dean, Jay F. Nunamaker,  Jr.
Venue: ACM SIGMIS Database (1999)

Eliciting and integrating requirements from large groups of diverse users remains a major challenge for the software engineering community. Scenarios are becoming recognized as valuable means of identifying actions taken by users when executing a business process and interacting with an information system, and therefore have great potential for addressing requirements elicitation problems. A review of the scenario literature indicates that, although there is widespread agreement on the usefulness of scenarios, there are many unanswered questions about how to elicit scenario definitions from individual users and user groups efficiently.This research examines how increasing the structure of scenario definitions affects scenario quality and the efficiency of scenario definition by individual users. During a laboratory experiment, subjects defined scenarios using a general-purpose GSS, GroupSystems Group Outliner, with one of three textual scenario formats that ranged from unstructured to very structured. Scenario quality and the efficiency of scenario definition by users were compared across the formats. Results highlighted the efficiency of the unstructured format but revealed that all formats produced incomplete scenario definitions. Recommendations are made for an iterative collaborative scenario process and a special-purpose GSS scenario tool that may overcome some of these problems.
First-Order System Least Squares (FOSLS) for Convection-Diffusion Problems: Numerical Results
Authors: J. M. Fiard, T. A. Manteuffel, S. F. McCormick
Venue: SIAM Journal on Scientific Computing (1998)

The focus of this paper is on planar linear convection-diffusion problems, to which we apply a special form of first-order system least squares (FOSLS [Cai et al., SIAM J. Numer. Anal., 31 (1994), pp. 1785--1799; Cai, Manteuffel, and McCormick, SIAM J. Numer. Anal., 34 (1997), pp. 425--454]). This we do by introducing the gradient of the primary variable, scaled by certain exponential functions. The convection-diffusion equation is then recast as a minimization principle for a functional corresponding to a sum of weighted L2 norms of the resulting first-order system. Discretization is accomplished by a Rayleigh--Ritz method based on standard finite element subspaces, and the resulting linear systems are solved by basic multigrid algorithms. The main goal here is to obtain optimal discretization accuracy and solver speed that is essentially uniform in the size of convection. Our results show that the FOSLS approach achieves this goal in general when the performance is measured either by the functional or by an equivalent weighted H1 norm. Included in our study is a multilevel adaptive refinement method based on locally uniform composite grids and local error estimates based on the functional itself.
Matrices with Low-Rank-Plus-Shift Structure: Partial SVD and Latent Semantic Indexing
Authors: Hongyuan Zha, Zhenyue Zhang
Venue: SIAM Journal on Matrix Analysis and Applications (1999)

We present a detailed analysis of matrices satisfying the so-called low-rank-plus-shift property in connection with the computation of their partial singular value decomposition (SVD). The application we have in mind is latent semantic indexing for information retrieval, where the term-document matrices generated from a text corpus approximately satisfy this property. The analysis is motivated by developing more efficient methods for computing and updating partial SVD of large term-document matrices and gaining deeper understanding of the behavior of the methods in the presence of noise.
EMP &mdash; A Database-Driven Electronic Market Place forBusiness-to-Business Commerce on the Internet
Authors: Susanne Boll, Andreas Grüner, Armin Haaf, Wolfgang Klas
Venue: Distributed and Parallel Databases (1999)

Electronic commerce systems for business-to-business commerce on the Internet are still in their infancy. The realization of Internet electronic markets for business-to-business following a n-suppliers: m-customers scenario is still unattainable with todays solutions. Comprehensive Internet electronic commerce systems should provide for easy access to and handling of the system, help to overcome differences in time of business, location, language between suppliers and customers, and at the same time should support the entire process of trading for business-to-business commerce. In this paper, we present a DBMS-based electronic commerce architecture and its prototypical implementation for business-to-business commerce according to a n-suppliers: m-customers scenario. Business transactions within the electronic market are realized by a set of modular market services. Multiple physically distributed markets can be interconnected transparently to the users and form one virtually central market place. The modeling and management of all market data in a DBMS gives the system a solid basis for reliable, consistent, and secure trading on the market. The generic and modular system architecture can be applied to arbitrary application domains. The system is scalable and can cope with an increasing number of single markets, participants, and market data due to the possibility to replicate and distribute services and data and herewith to distribute data, system, and network load.
Load Balancing in CORBA: A Survey of Concepts, Patterns, and Techniques
Authors: Thomas Schnekenburger
Venue: The Journal of Supercomputing (2000)

CORBA is an industrial standard for distributed object-oriented applications covering aspects such as heterogeneity and interoperability of products of different vendors. However, the CORBA standard does not define any methods for load balancing and there is a considerable confusion of terms describing associated load balancing techniques. Starting from the general platform- and language-independent CORBA object model, this paper presents a new hierarchical classification of possible load distribution methods for CORBA applications. The classification is a valuable starting point to identify the load balancing method that is appropriate for a given application. Furthermore, we show the relations to modern software design patterns and indicate the places in a CORBA application where load balancing components such as monitoring (obtaining load information), strategy (performing load distribution decisions), and control (executing the strategy decisions) may be integrated. Besides the discussion of the general object model as defined in the CORBA standard, we deal with concrete CORBA-compliant Object Request Brokers such as Orbix and VisiBroker. The presented techniques and examples are useful to systematically evaluate whether a given CORBA ORB can be used to implement a load balancing method as required by the application.
Hypergraph-Partitioning-Based Decomposition for Parallel Sparse-Matrix Vector Multiplication
Authors: Umit Catalyurek, Cevdet Aykanat
Venue: IEEE Transactions on Parallel and Distributed Systems (1999)

In this work, we show that the standard graph-partitioning-based decomposition of sparse matrices does not reflect the actual communication volume requirement for parallel matrix-vector multiplication. We propose two computational hypergraph models which avoid this crucial deficiency of the graph model. The proposed models reduce the decomposition problem to the well-known hypergraph partitioning problem. The recently proposed successful multilevel framework is exploited to develop a multilevel hypergraph partitioning tool PaToH for the experimental verification of our proposed hypergraph models. Experimental results on a wide range of realistic sparse test matrices confirm the validity of the proposed hypergraph models. In the decomposition of the test matrices, the hypergraph models using PaToH and hMeTiS result in up to 63 percent less communication volume (30 to 38 percent less on the average) than the graph model using MeTiS, while PaToH is only 1.3¿2.3 times slower than MeTiS on the average.
Interference analysis in fixed service microwave links due to overlay of broadband SSDS-CDMA wireless local loop system
Authors: Mirolav L. Dukic, Marko B. Babovic
Venue: Wireless Networks (2000)

In this paper the results of the interference analysis in FS&dash;ML due to new WLL systems with broadband SSDS&dash;CDMA techniques, sharing the same frequency band, is evaluated. Effects of WLL systems are expressed through the interference noise power at the FDM/FM receiver and BER at the DML receiver output, respectively. The results obtained show that in the typical working conditions with careful cell planning, interference can be neglected, and in most situations WLL overlay would not cause excessive interference in the FS&dash;ML. This conclusion is of great importance for the development of telecommunication systems, specially in rural areas, because it is possible to develop telecommunication systems fast and economically, without any additional frequency demands and under favourable economical conditions.
Evaluating phosphors for use in X-ray image detectors by the effective performance index (EPI) method: application to Eu3+ activated yttrium based materials
Authors: D. Cavouras, I. Kandarakis, P. Prassopoulos, E. Kanellopoulos, C. D. Nomicos, G. S. Panayiotakis
Venue: Technology and Health Care (1999)

Phosphor materials used in X-ray image receptors were evaluated by the effective performance index (EPI). EPI describes the dependence of image quality on X-ray to light energy conversion and light diffusion processes. EPI was experimentally determined by means of X-ray luminescence (XLE) and MTF measurements performed on Y2O2S:Eu, Y2O3:Eu, and YVO4:Eu phosphors. The spectral compatibility of these materials with optical detectors (films, photocathodes, photodiodes) was also determined. Highest EPI values were obtained for Y2O2S:Eu-GaAs combination at mammographic energies. All phosphors could be of use in digital X-ray imaging being adequately compatible to silicon photodiodes employed in digital detectors.
High Performance CMOS Analog Arithmetic Circuits
Authors: Jing Xu, Ray Siferd, Robert L. Ewing
Venue: Analog Integrated Circuits and Signal Processing (1999)

Unique designs for CMOS analog arithmetic circuits are presented which perform addition (V_1 &plus; V_2), subtraction (V_2 &minus; V_1), add/invert &minus;(V_1 &plus; V_2), and multiply (V_1 &times; V_2). The circuit operation is based on the inherent square law of MOS transistor drain current when operating in the saturation region. Key features include: good linearity and accuracy, single ended voltage inputs and output, wide input and output range and no input bias voltages. The circuits can be directly coupled (no buffer) and serve as basic building blocks for analog signal processing implementations such as analog filters and adaptive equalizers. All circuits were implemented in 1.2 &mu;m CMOS technology.
Design of dynamic load-balancing tools for parallel applications
Authors: Karen Devine, Bruce Hendrickson, Erik Boman, Matthew St. John, Courtenay Vaughan
Venue: Proceedings of the 14th international conference on Supercomputing (2000)

The design of general-purpose dynamic load-balancing tools for parallel applications is more challenging than the design of static partitioning tools. Both algorithmic and software engineering issues arise. We have addressed many of these issues in the design of the Zoltan dynamic load-balancing library. Zoltan has an object-oriented interface that makes it easy to use and provides separation between the application and the load-balancing algorithms. It contains a suite of dynamic load-balancing algorithms, including both geometric and graph-based algorithms. Its design makes it valuable both as a partitioning tool for a variety of applications and as a research test-bed for new algorithmic development. In this paper, we describe Zoltan's design and demonstrate its use in an unstructured-mesh finite element application.
The implementation of a data communications laboratory in small to medium sized universities
Authors: Martin H. Levin
Venue: ACM SIGCSE Bulletin (1999)

This poster describes techniques for establishing a Data Communications Laboratory in the small to mid-sized university. The experience for the poster was gained in the building of a lab funded by a NSF-ILI grant.. We provide a tactical approach to the lab and a discussion of the physical environment and basic equipment requirements. Special interest is devoted to sources of assistance for equipment procurement, as well as how to lower both hardware and software costs. Included are the capabilities of the suggested lab for teaching the major network operating systems. The security aspects required by the laboratory are also covered.The type of Data Communications Laboratory described in the poster can be established with a minimum of funds and using excess or donated equipment. It will provide students some hands-on experience with data communications and establish the lab as a reality from which to expand to ever changing technologies. One secret of success in this effort is to make the establishment of a lab, a rallying point between the Faculty, students and university's Instructional Technology Department. Students should be involved in all steps of the planning and installation. The students involved with the project will be happy to be taking part in an effort that will add an effective hands-on approach to their data communications courses.
Transient sensitivity computation for transistor level analysis and tuning
Authors: Tuyen V. Nguyen, Peter O'Brien, David Winston
Venue: Proceedings of the 1999 IEEE/ACM international conference on Computer-aided design (1999)

This paper presents a general method for computing transient sensitivities using both the direct and adjoint methods in event driven controlled explicit simulation algorithms that employ piecewise linear device models. This transient sensitivity capability is intended to be used in a simulation environment for transistor level analysis and tuning. Results demonstrate the efficiency and accuracy of the proposed techniques. Examples are also presented to illustrate how the transient sensitivity capability is used in timing characterization and circuit tuning.
Generalized Gaussian Quadratures and Singular Value Decompositions of Integral Operators
Authors: N. Yarvin, V. Rokhlin
Venue: SIAM Journal on Scientific Computing (1998)

Generalized Gaussian quadratures appear to have been introduced by Markov late in the last century and have been studied in great detail as a part of modern analysis. They have not been widely used as a computational tool, in part due to an absence of effective numerical schemes for their construction. Recently, a numerical scheme for the design of such quadratures was introduced by Ma et al.; numerical results presented in their paper indicate that such quadratures dramatically reduce the computational cost of the evaluation of integrals under certain conditions. In this paper, we modify their approach, improving the stability of the scheme and extending its range of applicability. The performance of the method is illustrated with several numerical examples.
A Framework for Collaborative, Content-Based and Demographic Filtering
Authors: Michael J. Pazzani
Venue: Artificial Intelligence Review (1999)

We discuss learning a profile of user interests for recommending information sources such as Web pages or news articles. We describe the types of information available to determine whether to recommend a particular page to a particular user. This information includes the content of the page, the ratings of the user on other pages and the contents of these pages, the ratings given to that page by other users and the ratings of these other users on other pages and demographic information about users. We describe how each type of information may be used individually and then discuss an approach to combining recommendations from multiple sources. We illustrate each approach and the combined approach in the context of recommending restaurants.
QoS based routing algorithm in integrated services packet networks
Authors: Chotipat Pornavalai, Goutam Chakraborty, Norio Shiratori
Venue: Journal of High Speed Networks (1998)

In this paper we study QoS based routing algorithm for supporting resource reservation in high-speed Integrated Services Packet Network (ISPN). Recently, this problem was proved to be NP-complete. However, when the considered QoS constraints are bandwidth, delay, delay jitter, and loss-free, we have shown that by employing Weighted Fair Queueing (WFQ) service discipline, the complexity of the problem could be reduced to that of shortest path routing without any QoS constraints. Then such a multiple QoS constrained route could be searched in polynomial time. We also present that routing algorithm (called "QoSRBF"), which is a modified version of Bellman-Ford shortest path algorithm. Simulation results show that QoSRBF has better performance compared to the existing QoS routing algorithms.
Minimum Cross-Entropy Approximation for Modeling of Highly Intertwining Data Sets at Subclass Levels
Authors: Qiuming Zhu
Venue: Journal of Intelligent Information Systems (1998)

We study the problem of how to accurately model the data sets that contain a number of highly intertwining sets in terms of their spatial distributions. Applying the Minimum Cross-Entropy minimization technique, the data sets are placed into a minimum number of subclass clusters according to their high intraclass and low interclass similarities. The method leads to a derivation of the probability density functions for the data sets at the subclass levels. These functions then, in combination, serve as an approximation to the underlying functions that describe the statistical features of each data set.
A Numerical Study of a Pathological Example of p-System
Authors: Philippe Hoch, Michel Rascle
Venue: SIAM Journal on Numerical Analysis (1999)

In this paper, we consider several high-order schemes in one space dimension. In particular, we compare the second-order relaxation ($\epsilonComm. Pure Appl. Math., 48 (1995), pp. 235--277] with the second-order Lax--Friedrichs scheme of Nessyahu and Tadmor [ J. Comp. Phys., 87 (1990), pp. 408--463] and with higher-order essentially nonoscillatory (ENO) and weighted essentially nonoscillatory (WENO) schemes. This comparison is made first on a Sod shock tube and then on a very pathological example of a p-system constructed by Greenberg and Rascle [ Arch. Ration. Mech. Anal., 115 (1991), pp. 395--407]. This exotic system admits a family of periodic solutions which are shock-free but present pairs of interacting centered compression waves. Therefore, the exact solution contains big spikes. We show how these different schemes face this numerical challenge.
Energy-efficient code generation for DSP56000 family (poster session)
Authors: Sathishkumar Udayanarayanan, Chaitali Chakrabarti
Venue: Proceedings of the 2000 international symposium on Low power electronics and design (2000)

This paper presents a procedure to generate energy-efficient code for the Motorola DSP56K processor based on increasing the packing efficiency and minimizing the number of address instructions. The key features are a novel scheduling algorithm that reduces the dependencies between instructions, a register allocation algorithm that spills variables based on their packability, and an address code generation algorithm that minimizes the number of additional instructions. The size of the code generated by this procedure is on the average 45% (25%) smaller than that generated by Motorola's g56K (SPAM).