ppxscal/embedding_network huggingface dataset:
System-level power optimization: techniques and tools
Authors: Luca Benini, Giovanni de Micheli
Venue: ACM Transactions on Design Automation of Electronic Systems (TODAES) (2000)

This tutorial surveys design methods for energy-efficient system-level design. We consider electronic sytems consisting of a hardware platform and software layers. We consider the three major constituents of hardware that consume energy, namely computation, communication, and storage units, and we review methods of reducing their energy consumption. We also study models for analyzing the energy cost of software, and methods for energy-efficient software design and compilation. This survery is organized around three main phases of a system design: conceptualization and modeling design and implementation, and runtime management. For each phase, we review recent techniques for energy-efficient design of both hardware and software.
Least fixpoint approximations for reachability analysis
Authors: In-Ho Moon, James Kukula, Tom Shiple, Fabio Somenzi
Venue: Proceedings of the 1999 IEEE/ACM international conference on Computer-aided design (1999)

The knowledge of the reachable states of a sequential circuit can dramatically speed up optimization and model checking. However, since exact reachability analysis may be intractable, approximate techniques are often preferable. Cho et al. presented the Machine-By-Machine (MBM) and Frame-By-Frame (FBF) methods to perform approximate FSM traversal. FBF produces tighter upper bounds than MBM; however, it usually takes much more time and it may have convergence problems. In this paper, we show that there exists a class of methods&mdash;Least Fixpoint Approximations&mdash;that compute the same results as RFBF (Reached FBF, one of the FBF methods). We show that one member of this class, which we call Least fixpoint MBM (LMBM), is as efficient as MBM, but provably more accurate. Therefore, the trade-off that existed between MBM and RFBF has been eliminated. LMBM can compute RFBF-quality approximations for all the large ISCAS-89 benchmark circuits in a total of less than 9000 seconds.
Periodic Folding of Thin Sheets
Authors: L. Mahadevan, Joseph B. Keller
Venue: SIAM Review (1999)

When a thin sheet of a flexible material such as paper is fed from a horizontal spool towards a rough horizontal plane below it, the sheet folds on itself in a regular manner. We model this phenomenon as a free boundary problem for a nonlinearly elastic sheet, taking into account the stiffness and weight of the sheet and the height of the spool above the plane. By using a continuation scheme we solve the problem numerically and follow the evolution of one period of the fold for various values of the parameters. The results are found to agree well with observations of the folding of paper sheets.
Efficient Generation of Minimal Length Addition Chains
Authors: Edward G. Thurber
Venue: SIAM Journal on Computing (1999)

An addition chain for a positive integer n is a set 1 = a0 < a1 < . . . < ar=n of integers such that for each $i\ge 1$, $a_i=a_j+a_k$ for some $k\le j <i$. This paper is concerned with some of the computational aspects of generating minimal length addition chains for an integer n. Particular attention is paid to various pruning techniques that cut down the search time for such chains. Certain of these techniques are influenced by the multiplicative structure of n. Later sections of the paper present some results that have been uncovered by searching for minimal length addition chains.
Partially Observed Analytic Systems with Fully Unbounded Actuators and Sensors-FEM Algorithms
Authors: Guangcao Ji, I. Lasiecka
Venue: Computational Optimization and Applications (1998)

Partially observed control systems described by analytic semigroup are considered. Finite-dimensional feedback control based on FEM approximations and accounting for incomplete observations is constructed. It is shown that this feedback control provides uniform stability (in time) of the originally unstable system. The main novel feature of the problem is that both&mdash;control and observation operators&mdash;are modeled by fully unbounded operators as they frequently arise in modeling of &ldquo;smart&rdquo; sensors and actuators. This contributes to technical difficulties at the level of perturbation theory for analytic semigroups. It is shown that a careful and rather special approximation in the area of support of the unbounded control/observation operators allows to obtain the &ldquo;right&rdquo; stability estimates. Theoretical results are illustrated with several examples of control problems governed by heat and plate equations.
MorphoSys: An Integrated Reconfigurable System for Data-Parallel and Computation-Intensive Applications
Authors: Hartej Singh, Ming-Hau Lee, Guangming Lu, Nader Bagherzadeh, Fadi J. Kurdahi, Eliseu M. Chaves Filho
Venue: IEEE Transactions on Computers (2000)

This paper introduces MorphoSys, a reconfigurable computing system developed to investigate the effectiveness of combining reconfigurable hardware with general-purpose processors for word-level, computation-intensive applications. MorphoSys is a coarse-grain, integrated, and reconfigurable system-on-chip, targeted at high-throughput and data-parallel applications. It is comprised of a reconfigurable array of processing cells, a modified RISC processor core, and an efficient memory interface unit. This paper describes the MorphoSys architecture, including the reconfigurable processor array, the control processor, and data and configuration memories. The suitability of MorphoSys for the target application domain is then illustrated with examples such as video compression, data encryption and target recognition. Performance evaluation of these applications indicates improvements of up to an order of magnitude (or more) on MorphoSys, in comparison with other systems.
Progress in computational molecular biology
Authors: Lawrence Hunter
Venue: ACM SIGBIO Newsletter (1999)

The nature of biological research is changing rapidly, due in large part to the advent of technologies for rapid generation of significant molecular data and the introduction of sophisticated computational methods. In this progress report, I discuss recent work in computational biology, focusing on gene expression analysis, high throughput screening of pharmaceutical leads, and information extraction from the biomedical literature.
A note on the recursive calculation of incomplete gamma functions
Authors: Walter Gautschi
Venue: ACM Transactions on Mathematical Software (TOMS) (1999)

It is known that the recurrence relation for incomplete gamma functions {&ggr;(a + n, x)}, 0 &le; a < 1, n = 0, 1, 2 ..., when x is positive, is unstable&mdash;more so the larger x. Nevertheless, the recursion can be used in the range 0 &le; n &le; x practically without error growth, and in larger ranges 0 &le; n &le; N with a loss of accuracy that can be controlled by suitably limiting N.
The elements of computer credibility
Authors: B. J. Fogg, Hsiang Tseng
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: the CHI is the limit (1999)

Given the importance of credibility in computing products, the research on computer credibility is relatively small. To enhance knowledge about computers and credibility, we define key terms relating to computer credibility, synthesize the literature in this domain, and propose three new conceptual frameworks for better understanding the elements of computer credibility. To promote further research, we then offer two perspectives on what computer users evaluate when assessing credibility. We conclude by presenting a set of credibility-related terms that can serve in future research and evaluation endeavors.
Parallel Hierarchical Solvers and Preconditioners for Boundary Element Methods
Authors: Ananth Grama, Vipin Kumar, Ahmed Sameh
Venue: SIAM Journal on Scientific Computing (1998)

The method of moments is an important tool for solving boundary integral equations arising in a variety of applications. It transforms the physical problem into a dense linear system. Due to the large number of variables and the associated computational requirements, these systems are solved iteratively using methods such as GMRES and CG and its variants. The core operation of these iterative solvers is the application of the system matrix to a vector. This requires $\theta(n^2)$ operations and memory using accurate dense methods. The computational complexity can be reduced to $O(n \log n)$ and the memory requirement to $\Theta(n)$ using hierarchical approximation techniques. The algorithmic speedup from approximation can be combined with parallelism to yield very fast dense solvers. In this paper, we present efficient parallel formulations of dense iterative solvers based on hierarchical approximations for solving potential integral equations of the first kind. We study the impact of various parameters on the accuracy and performance of the parallel solver. We demonstrate that our parallel formulation incurs minimal parallel processing overhead and scales up to a large number of processors. We present two preconditioning techniques for accelerating the convergence of the iterative solver. These techniques are based on an inner-outer scheme and a block-diagonal scheme based on a truncated Green's function. We present detailed experimental results on up to 256 processors of a Cray T3D. Our code achieves raw computational speeds of over 5 GFLOPS. When compared to the accurate solver, this corresponds to a speed of approximately 776 GFLOPS.
Lipschitz-Type Stability in Nonsmooth Convex Programs
Authors: Robert Janin, Jacques Gauvin
Venue: SIAM Journal on Control and Optimization (1999)

This paper deals with upper Lipschitzian continuity of the optimal solution to parametrized convex programs with linear equality and inequality constraints and with a convex nondifferentiable objective function. Under quadratic growth conditions for the objective function, some accurate bound for the rate of the upper Lipschitzian continuity is provided.
Dense Sphere Packings from New Codes
Authors: Jürgen Bierbrauer, Yves Edel
Venue: Journal of Algebraic Combinatorics: An International Journal (2000)

The idea behind the coset code construction (see [G.D. Forney, Coset Codes, IEEE Transactions on Information Theory, Part I: Introduction and Geometrical Classification, pp. 1123&ndash;1151&semi; Part II: Binary lattices and related codes, pp. 1152&ndash;1187&semi; F.R. Kschischang and S. Pasupathy, IEEE Transactions on Information Theory 38 (1992), 227&ndash;246.]) is to reduce the construction of sphere packings to error-correcting codes in a unified way. We give here a short self-contained description of this method. In recent papers [J. Bierbrauer and Y. Edel, IEEE Transactions on Information Theory 43 (1997), 953&ndash;968&semi; J. Bierbrauer and Y. Edel, Finite Fields and Their Applications 3 (1997), 314&ndash;333&semi; J. Bierbrauer and Y. Edel, IEEE Transactions on Information Theory 44 (1998), 1993&semi; J. Bierbrauer, Y. Edel, and L. Tolhuizen, Finite Fields and Their Applications, submitted for publication.] we constructed a large number of new binary, ternary and quaternary linear error-correcting codes. In a number of dimensions our new codes yield improvements. Recently Vardy [A. Vardy, Inventiones Mathematicae 121, 119&ndash;134&semi; A. Vardy, Density doubling, double-circulants, and new sphere packings, Trans. Amer. Math. Soc. 351 (1999), 271&ndash;283.] has found a construction, which yields record densities in dimensions 20, 27, 28, 29 and 30. We give a short description of his method using the language of coset codes. Moreover we are able to apply this method in dimension 18 as well, producing a sphere packing with a record center density of (3/4)^9.
Versions and workspaces in Microsoft repository
Authors: Thomas Bergstraesser, Philip A. Bernstein, Shankar Pal, David Shutt
Venue: Proceedings of the 1999 ACM SIGMOD international conference on Management of data (1999)

This paper describes the version and workspace features of Microsoft Repository, a layer that implements fine-grained objects and relationships on top of Microsoft SQL Server. It supports branching and merging of versions, delta storage, checkout-checkin, and single-version views for version-unaware applications.
Tagged handles: merging discrete and continuous manual control
Authors: Karon E. MacLean, Scott S. Snibbe, Golan Levin
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (2000)

Discrete and continuous modes of manual control are fundamentally different: buttons select or change state, while handles persistently modulate an analog parameter. User interfaces for many electronically aided tasks afford only one of these modes when both are needed. We describe an integration of two kinds of physical interfaces (tagged objects and force feedback) that enables seamless execution of such multimodal tasks while applying the benefits of physicality; and demonstrate application scenarios with conceptual and engineering prototypes. Our emphasis is on sharing insights gained in a design case study, including expert user reactions.
Better operating system features for faster network servers
Authors: Gaurav Bangs, Peter Druschel, Jeffrey C. Mogul
Venue: ACM SIGMETRICS Performance Evaluation Review (1998)

Widely-used operating systems provide inadequate support for large-scale Internet server applications. Their algorithms and interfaces fail to efficiently support either event-driven or multi-threaded servers. They provide poor control over the scheduling and management of machine resources, making it difficult to provide robust and controlled service. We propose new UNIX interfaces to improve scalability, and to provide fine-grained scheduling and resource management.
Relaxation of Energy and Approximate Riemann Solvers for General Pressure Laws in Fluid Dynamics
Authors: Frédéric Coquel, Benoît Perthame
Venue: SIAM Journal on Numerical Analysis (1998)

We consider the Euler equations for a compressible inviscid fluid with a general pressure law $p(\rho,\varepsilon)$, where $\rho$ represents the density of the fluid and $\varepsilon$ its specific internal energy. We show that it is possible to introduce a relaxation of the nonlinear pressure law introducing an energy decomposition under the form $\varepsilon= \varepsilon _1 + \varepsilon _2.$ The internal energy $\varepsilon _1$ is associated with a (simpler) pressure law $p_1(\rho,\varepsilon_1)$; the energy $\varepsilon _2$ is advected by the flow. These two energies are also subject to a relaxation process and in the limit of an infinite relaxation rate, we recover the initial pressure law p. We show that, under some conditions of subcharacteristic type, for any convex entropy associated with the pressure p, we can find a global convex and uniform entropy for the relaxation system.From our construction, we also deduce the extension to general pressure laws of classical approximate Riemann solvers for polytropic gases, which only use a single call to the pressure law (per mesh point and time step). For the Godunov scheme, we show that this extension satisfies stability, entropy, and accuracy conditions.
Finite Element Approximation of the Cahn--Hilliard Equation with Degenerate Mobility
Authors: John W. Barrett, James F. Blowey, Harald Garcke
Venue: SIAM Journal on Numerical Analysis (1999)

We consider a fully practical finite element approximation of the Cahn--Hilliard equation with degenerate mobility $$ \textstyle \frac{\partial u}{\partial t}= \del .(\,b(u)\, \del (-\gamma\lap u+\Psi'(u))) , $$ where $b(\cdot)\geq 0$ is a diffusional mobility and $\Psi(\cdot)$ is a homogeneous free energy. In addition to showing well posedness and stability bounds for our approximation, we prove convergence in one space dimension. Furthermore, an iterative scheme for solving the resulting nonlinear discrete system is analyzed. We also discuss how our approximation has to be modified in order to be applicable to a logarithmic homogeneous free energy. Finally, some numerical experiments are presented.
Achieving industrial relevance with academic excellence: lessons from the Oregon Master of Software engineering
Authors: Stuart R. Faulk
Venue: Proceedings of the 22nd international conference on Software engineering (2000)

Many educational institutions are developing graduate programs in software engineering targeted to working professionals. These educators face the dilemma of providing programs with both industrial relevance and academic excellence. This paper describes our experience and lessons learned in developing such a program, the Oregon Master of Software Engineering (OMSE). It describes a structured approach to curriculum design, curriculum design principles and methods that can be applied to develop a quality professional program.
Cross-Cultural Differences in Risk Perception, But Cross-Cultural Similarities in Attitudes Towards Perceived Risk
Authors: Elke U. Weber, Christopher Hsee
Venue: Management Science (1998)

In this study, respondents from the P.R.C., U.S.A., Germany, and Poland were found to differ in risk preference, as measured by buying prices for risky financial options. Chinese respondents were significantly less risk-averse in their pricing than Americans when risk preference was assessed in the traditional expected-utility framework. However, these apparent differences in risk preference were associated primarily with cultural differences in the perception of the risk of the financial options rather than with cultural differences in attitude towards perceived risk. In all cultures, an equal proportion (the majority) of respondents was willing to pay more for options perceived as less risky, i.e., were perceived-risk averse. These results are most naturally explained within a risk-return conceptualization of risky choice. They have practical implications for cross-cultural negotiation and commerce by suggesting the locus of cultural differences in risky choice that may allow for the creation of joint gains.
First-Order System Least-Squares for Elliptic Problems with Robin Boundary Conditions
Authors: B. Lee
Venue: SIAM Journal on Numerical Analysis (1999)

This paper studies a least-squares approach to scalar second-order elliptic partial differential equations with Robin boundary conditions. As in several earlier papers by Bramble, Lazarov, and Pasciak [ Math. Comp., 66 (1997), pp. 935--955]; 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, 1727--1741]; Chang [ SIAM J. Numer Anal., 29 (1992), pp. 452--461]; and Jiang and Povinelli [ Comput. Methods Appl. Mech. Engrg., 102 (1993), pp. 199--212], the scalar equation is first recast into a first-order system by introducing velocity or flux variables, where some norm is then applied to the residual of this system to create a least-squares functional. We show here that a least-squares principle based on an L2 norm produces optimal discretization error estimates in the H1 norm for all variables in the system. We further show that a least-squares principle based on a combination of L2 and H -1 norms yields optimal discretization error in a corresponding combination of H1 and L2 norms for the variables. Finally, a regularity result for the L2 least-squares formulation and numerical examples for both formulations are given.
What's up with downward collapse: using the easy-hard technique to link Boolean and polynomial hierarchy collapses
Authors: Edith Hemaspaandra, Lane A. Hemaspaandra, Harald Hempel
Venue: ACM SIGACT News (1998)

During the past decade, nine papers have obtained increasingly strong consequences from the assumption that boolean or bounded-query hierarchies collapse. The final four papers of this nine-paper progression actually achieve downward collapse---that is, they show that high-level collapses induce collapses at (what before-the-fact seemed to be) lower complexity levels. For example, for each k ge; 2 it. is now known that if one query to sigma;pk is as powerful as two queries to sigma;pk (i.e., P Sigma;[1] = P Sigma;[2]), then PH = sigma;pk. This article surveys the history, the results, and the method---the so-called easy-hard technique---of the just-mentioned nine-paper progression:1. J. Kadin. The polynomial time hierarchy collapses if the boolean hierarchy collapses. SIAM Journal on Computing, 17(6):1263--1282, 1988. Erratum appears in the same journal. 20(2):404.2. K. Wagner. Number-of-query hierarchies. Technical Report 158, Institut f uuml;r Mathematik. Universit auml;t Augsburg, Augsburg, Germany, October 1987.3. K. Wagner. Number-of-query hierarchies. Technical Report 4. Institut f uuml;r Informatik. Universit auml;t W uuml;rzburg, W uuml;rzburg, Germany, February 1989.4. R. Chang and J. Kadin. The boolean hierarchy and the polynomial hierarchy: A closer connection. SIAM Journal on Computing. 25(2):340--354. 1996.5. R. Beigel. R. Chang. and M. Ogiwara. A relationship between difference hierarchies and relativized polynomial hierarchies. Mathematical Systems Theory. 26(3):293--310, 1993.6. E. Hemaspaandra, L. Hemaspaandra. and H. Hempel. An upward separation in the polynomial hierarchy. Technical Report Math/Inf/96/15, Institut f uuml;r Informatik, Friedrich-Schiller-Universit auml;t Jena, Jena, Germany, June 1996.7. E. Hemaspaandra, L. Hemaspaandra, and H. Hempel. A downward collapse within the polynomial hierarchy. SIAM Journal on Computing, 28(2):383--393, 1999.8. H. Buhrman and L. Fortnow. Two queries. In Proceedings of the 13th Annual IEEE Conference on Computational Complexity. 13--19. IEEE Computer Society Press, June 1998.9. E. Hemaspaandra, L. Hemaspaandra, and H. Hempel. Translating equality downwards. Technical Report TR-657. Department of Computer Science, University of Rochester, Rochester, NY. April 1997.
Optimal Mailing of Catalogs: a New Methodology Using Estimable Structural Dynamic Programming Models
Authors: Fusun Gonul, Meng Ze Shi
Venue: Management Science (1998)

We investigate the key determinants of the optimal direct mail policy in a dynamic environment where customers maximize utility and the direct mailer maximizes profits. We measure the sensitivity of the customers to receiving a catalog in the mail, while controlling for customer characteristics such as elapsed time in responses and number of purchases. We apply our model to a database from a national cataloger that markets nonseasonal products. We summarize the results of our model that are valid for these types of products. We find that the dynamic model significantly outperforms its single-period counterpart. We find that it is not optimal to mail to individuals at low recency levels because they are likely to buy anyway. It is better to save the mailing dollars for customers at higher recency levels. We find that it is optimal to mail to customers who have purchased only a small or a medium number of times to induce them to continue to buy from this catalog and not switch to others. It is not necessary to mail often to customers who have purchased many times before from the company unless they have high recency values. We find that under the optimal mailing policy the cataloguer enjoys higher profits than under the current mailing policy.