ppxscal/embedding_network huggingface dataset:
An iterative gate sizing approach with accurate delay evaluation
Authors: Guangqiu Chen, Hidetoshi Onodera, Keikichi Tamaru
Venue: Proceedings of the 1995 IEEE/ACM international conference on Computer-aided design (1995)

This paper introduces a new gate sizing approach with accurate delay evaluation. The approach solves gate sizing problems by iterating local sizing results from linear programming within small variable ranges of gate sizes. In each iterative step, variable ranges of gate sizes are updated according to the result from a previous step. Solutions with accurate delay evaluation which consider input signal slopes and separately evaluate rising and falling delays are obtained after several iterative steps. A speedup technique is used to pick out gates actually involved in each local sizing step so as to reduce CPU time. Experiments on sample circuits show that our approach can provide solutions with smaller circuit area than conventional approaches for the same circuit delay or provide solutions under tight delay constraints where conventional approaches can not reach. Moreover, our approach is faster than the conventional approaches for most circuits, especially under loose delay constraints.
Transfer optimization via simultaneous perturbation stochastic approximation
Authors: Stacy D. Hill, Michael C. Fu
Venue: Proceedings of the 27th conference on Winter simulation (1995)

We consider the problem of optimizing a transit network with respect to customer service, when simulation of the network is necessary to accurately characterize performance. In particular, we consider the transfer optimization problem, where the goal is to minimize the total expected waiting time of riders by coordinating transfers in the network. We apply the technique of simultaneous perturbation stochastic approximation to optimize system performance. For a simple test case, we provide simulation results and discuss difficulties in applying the technique to this problem, specifically with regard to the smoothness of the objective function.
Ethics and computer use
Authors: Sue Conger, Karen D. Loch
Venue: Communications of the ACM (1995)

Over the past 50 years, computers have undergone transformation from monolithic number crunchers, to centralized repositories of management information systems, to distributed, networked, cyberspace support systems. During the same period, uses of computers have moved from computational problems to life support, from machine language to GUIs, from abstractions of work to virtual reality on the World-Wide Web. These transformations have brought with them situations that have ethical implications.
Increasing cache port efficiency for dynamic superscalar microprocessors
Authors: Kenneth M. Wilson, Kunle Olukotun, Mendel Rosenblum
Venue: ACM SIGARCH Computer Architecture News (1996)

The memory bandwidth demands of modern microprocessors require the use of a multi-ported cache to achieve peak performance. However, multi-ported caches are costly to implement. In this paper we propose techniques for improving the bandwidth of a single cache port by using additional buffering in the processor, and by taking maximum advantage of a wider cache port. We evaluate these techniques using realistic applications that include the operating system. Our techniques using a single-ported cache achieve 91% of the performance of a dual-ported cache.
Security issues with TCP/IP
Authors: Renqi Li, E. A. Unger
Venue: ACM SIGAPP Applied Computing Review (1995)

An introduction to network security , basic definitions and aa brief discussion of the architecture of TCP/IP as well as the Open System Intercornnection(OSI) Reference Model open the paper. The relationship between TCP/IP and of some OSI layers is described. An indepth look is provided to the major protocols in TCP/IP suite and the security features and problems in this suite of protocols. The secutiy problems are discussed in the context ofthe protocol services.
Distributed, Deadlock-Free Routing in Faulty, Pipelined, Direct Interconnection Networks
Authors: Patrick T. Gaughan, Binh V. Dao, Sudhakar Yalamanchili, David E. Schimmel
Venue: IEEE Transactions on Computers (1996)

This paper focuses on designing high performance pipelined networks that can operate in the presence of dynamic component failures. A general, rigorous framework for deadlock-free communication in faulty, pipelined networks is developed. A mechanism is also proposed for recovering from dynamic link and node failures. The recovery mechanism 1) is fully distributed, 2) does not require timeouts, 3) prevents fault-induced deadlock, and 4) is integrated into the virtual channel flow control mechanisms. This recovery mechanism is used to develop a new pipelined communication mechanism¿acknowledged pipelined circuit-switching (APCS). This mechanism supports existing routing protocols [19] that can tolerate a maximal number of static link failures, i.e., one less than the number of ports on a node. An implementation of a novel router architecture is described and the results of detailed flit level simulations are presented. Finally, the proposed recovery mechanism is shown to be applicable to existing adaptive wormhole routing protocols which are prone to deadlock in the presence of dynamic faults.
Development of reusable expert system components: preliminary experience
Authors: W. Dai
Venue: ACM SIGSOFT Software Engineering Notes (1995)

This paper addresses the metrics of expert system reusability through practical experience obtained in developing and using a previously implemented system called INDEX. It presents a principled approach in defining expert system component granularity, transparency, and a specification methodology in identifying and building reusable expert system skeletons and components to allow them to be used in most conventional software environments. The adoption of such an approach has led to the production of reusable expert system components for different expert system development projects. The preliminary experience in reusing INDEX facilities has been presented. Two applications are chosen to show the effectiveness of such an approach.
Real-time control of a tokamak plasma using neural networks
Authors: Chris M. Bishop, Paul S. Haynes, Mike E. U. Smith, Tom N. Todd, David L. Trotman
Venue: Neural Computation (1995)

In this paper we present results from the first use of neural networks for real-time control of the high-temperature plasma in a tokamak fusion experiment. The tokamak is currently the principal experimental device for research into the magnetic confinement approach to controlled fusion. In an effort to improve the energy confinement properties of the high-temperature plasma inside tokamaks, recent experiments have focused on the use of noncircular cross-sectional plasma shapes. However, the accurate generation of such plasmas represents a demanding problem involving simultaneous control of several parameters on a time scale as short as a few tens of microseconds. Application of neural networks to this problem requires fast hardware, for which we have developed a fully parallel custom implementation of a multilayer perceptron, based on a hybrid of digital and analogue techniques.
&ldquo;Interval rational = algebraic&rdquo; revisited: a more computer realistic result
Authors: Anatoly V. Lakeyev, Vladik Kreinovich
Venue: ACM SIGNUM Newsletter (1996)

In [1], it is shown that if we add "interval computations" operation to the list of arithmetic operations that define rational functions, then the resulting class of "interval-rational" functions practically coincides with the class of all algebraic functions. By "practically coincides", we mean that first, every interval-rational function is algebraic, and that second, for every algebraic function A(x), there exists an interval-rational function that coincides with A(x) for almost all x. In [1], "almost all" was understood in terms of Lebesgue measure; this result is therefore, not very computer realistic, because all the numbers representable in a computer are rational and therefore, form a set of Lebesgue measure 0. In this article, we formulate a more computer-realistic version of the result that interval + rational = algebraic.
Internal representation and rule development in object-oriented design
Authors: Jinwoo Kim, F. Javier Lerch, Herbert A. Simon
Venue: ACM Transactions on Computer-Human Interaction (TOCHI) (1995)

This article proposes a cognitive framework describing the software development process in object-oriented design (OOD) as building internal representations and developing rules. Rule development (method construction) is performed in two problem spaces: a rule space and an instance space. Rules are generated, refined, and evaluated in the rule space by using three main cognitive operations: Infer, Derive, and Evoke. Cognitive activities in the instance space are called mental simulations and are used in conjunction with the Infer operation in the rule space. In an empirical study with college students, we induced different representations to the same problem by using problem isomorphs. Initially, subjects built a representation based on the problem description. As rule development proceeded, the initial internal representation and designed objects were refined, or changed if necessary, to correspond to knowledge gained during rule development. Differences in rule development processes among groups created final designs that are radically different in terms of their level of abstraction and potential reusability. The article concludes by discussing the implications of these results for object-oriented design.
The RISC processor DMN-6: a unified data-control flow architecture
Authors: Gerard Páez-Monzón
Venue: ACM SIGARCH Computer Architecture News (1996)

This work presents an academic RISC processor architecture, named DMN-6 that executes every instruction in the datapath. It concentrates all the movement, branch and alu instructions in the arithmetic-logic unit. The idea is to normalize the control signal generation for an integer functional unit. This is obtained by implementing a number of queue registers of different deepness around the datapath unit. These queues will control an assigned logic corresponding to a stage in the pipeline. The architecture reduces even more the complexity of a pipelined program execution. The main features are : Load/Store architecture, 4-stage pipeline, integer arithmetic, sixteen byte registers, internal separate data and instruction main memories, thirteen 16-bit instruction words.
On a Special Class of Generalized Doubly StochasticMatrices and its Relation to Bezier Polygons
Authors: Miroslav Fiedler
Venue: SIAM Journal on Matrix Analysis and Applications (1995)

We introduce and study a new set $\cal B$ of $m \times n$ nonnegative integral matrices $B_{mn}$, $m \geq n \geq 1$. They have column-rhomboidal form and are closely related to the confluent Vandermonde matrices $V_{mn}$ with $n$-tuple node 1 and to Bezier polygons.
A composition-alias method for generating gamma variates with shape parameter greater than 1
Authors: Tapas K. Sarkar
Venue: ACM Transactions on Mathematical Software (TOMS) (1996)

In this article the author describes a procedure for generating gamma variates with shape parameter >1. Given a supply of &ldquo;good&rdquo; uniform (0,1) variates, the procedure makes use of composition method, squeeze method, and aliasing to generate gamma variates. Comparison with existing methods shows that the author's method is faster in terms of computer time and uses a smaller number of uniform (0,1) variates. The method is also statistically exact.
Parallelism and its price: a case study of nonstop SQL/MP
Authors: Susanne Englert, Ray Glasstone, Waqar Hasan
Venue: ACM SIGMOD Record (1995)

We describe the use of parallel execution techniques and measure the price of parallel execution in NonStop SQL/MP, a commercial parallel database system from Tandem Computers. Non-Stop SQL uses intra-operator parallelism to parallelize joins, groupings and scans. Parallel execution consists of starting up several processes and communicating data between them. Our measurements show (a) Startup costs are negligible when processes are reused rather than created afresh (b) Communication costs are significant &mdash; they may exceed the costs of operators such as scan, grouping or join. We also show two counter-examples to the common intuition that parallel execution reduces response time at the expense of increased work &mdash; parallel execution may reduce work or may increase response time depending on communication costs.
A tight bound for black and white pebbles on the pyramid
Authors: Maria M. Klawe
Venue: Journal of the ACM (JACM) (1985)

Lengauer and Tarjan proved that the number of black and white pebbles needed to pebble the root of a tree is at least half the number of black pebbles needed to pebble the root. This result is extended to a larger class of acyclic directed graphs including pyramid graphs.
Comments on Large Least Squares Problems InvolvingKronecker Products
Authors: Hongyuan Zha
Venue: SIAM Journal on Matrix Analysis and Applications (1995)

In this note we point out that the least squares solution of $(A\otimes B)x=t$ can be obtained numerically without referring to Kronecker products.
An empirical study of precise interprocedural array analysis
Authors: Michael Hind, Michael Burke, Paul Carini, Sam Midkiff
Venue: Scientific Programming (1994)

In this article we examine the role played by the interprocedural analysis of array accesses in the automatic parallelization of Fortran programs. We use the PTRAN system to provide measurements of several benchmarks to compare different methods of representing interprocedurally accessed arrays. We examine issues concerning the effectiveness of automatic parallelization using these methods and the efficiency of a precise summarization method.
A Parallel Algorithm for the Sylvester Observer Equation
Authors: Christian H. Bischof, Biswa Nath Datta, Avijit Purkayastha
Venue: SIAM Journal on Scientific Computing (1996)

We present a new algorithm for solving the Sylvester observer equation arising in the context of the Luenberger observer. The algorithm embodies two main computational phases: the solution of several independent equation systems and a series of matrix--matrix multiplications. The algorithm is, thus, well suited for parallel and high-performance computing. By reducing the coefficient matrix $A$ to lower-Hessenberg form, one can implement the algorithm efficiently, with few floating-point operations and little workspace. The algorithm has been successfully implemented on a CRAY C90. A comparison, both theoretical and experimental, has been made with the well-known Hessenberg--Schur algorithm which solves an arbitrary Sylvester equation. Our theoretical analysis and experimental results confirm the superiority of the proposed algorithm, both in efficiency and speed, over the Hessenberg--Schur algorithm.
Comments on batched searching of sequential and tree-structured files
Authors: Marek Piwowarski
Venue: ACM Transactions on Database Systems (TODS) (1985)

Exact formulas for the expected cost savings from batching requests against two types of j-ary trees are given. Approximate expressions are also presented.
Moving Mesh Methods for Problems with Blow-up
Authors: Chris J. Budd, Weizhang Huang, Robert D. Russell
Venue: SIAM Journal on Scientific Computing (1996)

In this paper we consider the numerical solution of PDEs with blow-up for which scaling invariance plays a natural role in describing the underlying solution structures. It is a challenging numerical problem to capture the qualitative behaviour in the blow-up region, and the use of nonuniform meshes is essential. We consider moving mesh methods for which the mesh is determined using so-called moving mesh partial differential equations (MMPDEs). Specifically, the underlying PDE and the MMPDE are solved for the blow-up solution and the computational mesh simultaneously. Motivated by the desire for the MMPDE to preserve the scaling invariance of the underlying problem, we study the effect of different choices of MMPDEs and monitor functions. It is shown that for suitable ones the MMPDE solution evolves towards a (moving) mesh which close to the blow-up point automatically places the mesh points in such a manner that the ignition kernel, which is well known to be a natural coordinate in describing the behaviour of blow-up, approaches a constant as $t\to T$ (the blow-up time). Several numerical examples are given to verify the theory for these MMPDE methods and to illustrate their efficacy.
MARCO: MAp Retrieval by COntent
Authors: Hanan Samet, Aya Soffer
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1996)

A system named MARCO (denoting MAp Retrieval by COntent) that is used for the acquisition, storage, indexing, and retrieval of map images is presented. The input to MARCO are raster images of separate map layers and raster images of map composites. A legend-driven map interpretation system converts map layer images from their physical representation to their logical representation. This logical representation is then used to automatically index both the composite and the layer images. Methods for incorporating logical and physical layer images as well as composite images into the framework of a relational database management system are described. Indices are constructed on both the contextual and the spatial data thereby enabling efficient retrieval of layer and composite images based on contextual as well as spatial specifications. Example queries and query processing strategies using these indices are described. The user interface is demonstrated via the execution of an example query. Results of an experimental study on a large amount of data are presented. The system is evaluated in terms of accuracy and in terms of query execution time.
Optimal File Sharing in Distributed Networks
Authors: Moni Naor, Ron M. Roth
Venue: SIAM Journal on Computing (1995)

The following file distribution problem is considered: Given a network of processors represented by an undirected graph $G=(V,E)$ and a file size $k$, an arbitrary file w of $k$ bits is to be distributed among all nodes of $G$. To this end, each node is assigned a memory device such that by accessing the memory of its own and of its adjacent nodes, the node can reconstruct the contents of w. The objective is to minimize the total size of memory in the network. This paper presents a file distribution scheme which realizes this objective for $k \gg \log \Delta_G$, where $\Delta_G$ stands for the maximum degree in $G$: For this range of $k$, the total memory size required by the suggested scheme approaches an integer programming lower bound on that size. The scheme is also constructive in the sense that given $G$ and $k$, the memory size at each node in $G$, as well as the mapping of any file w into the node memory devices, can be computed in time complexity which is polynomial in $k$ and $|V|$. Furthermore, each node can reconstruct the contents of such a file w in $O(k^2)$ bit operations. Finally, it is shown that the requirement of $k$ being much larger than $\log \Delta_G$ is necessary in order to have total memory size close to the integer programming lower bound.
Generalized Discrete-Time Riccati Theory
Authors: Vlad Ionescu, Cristian Oara
Venue: SIAM Journal on Control and Optimization (1996)

A Riccati-like equation, termed the generalized (discrete-time) algebraic Riccati equation, which incorporates as special cases both the standard and the constrained discrete-time algebraic Riccati equations, is introduced and investigated under the weakest possible assumptions imposed on the initial data. A complete characterization of the conditions under which such an equation of general form has a stabilizing solution is presented in terms of the so-called proper deflating subspace of the extended Hamiltonian pencil. An evaluation of an associated quadratic index along constrained stable trajectories is given in terms of the stabilizing solution to the generalized Riccati equation. Possible applications of the developed theory range from nonstandard spectral and inner-outer factorizations to $H^2$ and $H^{\infty}$ control in singular cases. The results exposed in the present paper are the discrete-time counterpart of those stated in the authors' previous paper concerning the generalized (singular) continuous-time Riccati theory. The results could be also seen as an extension to singular cases of the usual discrete-time algebraic Riccati equation theory (of indefinite sign).
Industrial strength hypermedia: managing engineering information with hypermedia
Authors: Peter R. Nelson, Steven E. Poltrock
Venue: ACM SIGOIS Bulletin (1996)

In a paper entitled "Industrial Strength Hypermedia: Requirements for a Large Engineering Enterprise" published in the Proceedings of Hypertext '91 [Malc91], K. C. Malcolm and two of the authors (Steve Poltrock and Doug Schuler) presented their vision for the use of hypermedia to manage large-scale engineering information. Since that time, engineers and scientists within the Boeing Company have been working to refine and implement that vision in conjunction with vendors of hypermedia and information management technology. This paper presents some of the results of that work, including a short description of the systems engineering environment within Boeing, a scenario which depicts some of the uses and benefits of hypermedia in this environment, and Boeing's requirements for hypermedia technology to support the creation, management, access, and use of richly interrelated systems engineering information. The purpose of this paper is to present an updated vision of the need of large industrial companies for robust, scaleable, secure and flexible information management based on hypermedia technology and to encourage researchers and developers to address that need.
An evaluation of some new cyclic linear multistep formulas for stiff ODEs
Authors: P. E. Tischer, G. K. Gupta
Venue: ACM Transactions on Mathematical Software (TOMS) (1985)

We evaluate several sets of cyclic linear multistep formulas (CLMFs). One of these sets was derived by Tischer and Sacks-Davis. Three new sets of formulas have been derived and we present their characteristics.The formulas have been evaluated by comparing the performance of four versions of a code which implements CLMFs. The four versions are very similar and each version implements one of the sets of CLMFs being studied. We compare the performance of these codes with that of a widely used code, LSODE. One of the new sets of CLMFs is not only much more efficient in solving stiff problems that have a Jacobian with eigenvalues close to the imaginary axis but is almost as efficient as LSODE in solving other problems. This is a significant improvement over the ony other CLMF code available, STINT from Tendler, Bickart, and Picel.
Creating host compliance in a portable framework: a study in the reuse of design patterns
Authors: Phillip M. Yelland
Venue: Proceedings of the 11th ACM SIGPLAN conference on Object-oriented programming, systems, languages, and applications (1996)

This report describes an experiment carried out at ParcPlace-Digitalk which sought to increase the look-and-feel compliance of portable applications built using the company's Smalltalk-based VisualWorks product. We outline the structure of the current VisualWorks user interface framework, and the precise requirements which the experimental system sought to fulfill. We go on to show how we were able to reuse design patterns from the literature in a generative fashion, to direct the evolution of the new framework. This contrasts with most pattern-related work to date, which has concentrated on discerning design patterns in existing systems. Finally, we draw generalizations from our experience concerning the evolution of software architecture using patterns.