ppxscal/embedding_network huggingface dataset:
A compiler optimization to reduce execution time of loop nest
Authors: Oh-Young Kwon, Gi-Ho Park, Tack-Don Han
Venue: ACM SIGARCH Computer Architecture News (1996)

In this paper, a compiler optimization to reduce the execution time of loop nest is proposed. Loop tiling is used to optimize loop nest. Loop tiling is the well-known optimization for improving locality. However, it has a count result that increases the number of instructions to loop control. These increased instructions disturb the effect of locality optimization. Therefore, the tiling of innermost loop is not perform in order to reduce the instructions for loop control in this paper. This optimization consists of two steps. In the first step, loop permutation is used to maximize the spatial reuse of innermost loop. Because innermost loop tiling is not performed, spatial reuse of innermost loop is exploited to reduce execution time of loop nest. In the second step, the tile size of outer loops is decided using the basic cache parameters. When this optimization is applied to the matrix multiplication, execution time is improved 3 to 4 fold. Also, this optimization technique is easily applied to make a parallelizing and/or optimizing compilers.
Time-domain solutions of Oja's equations
Authors: J. L. Wyatt,  Jr., I. M. Elfadel
Venue: Neural Computation (1995)

Oja's equations describe a well-studied system for unsupervised Hebbian learning of principal components. This paper derives the explicit time-domain solution of Oja's equations for the single-neuron case. It also shows that, under a linear change of coordinates, these equations are a gradient system in the general multi-neuron case. This latter result leads to a new Lyapunov-like function for Oja's equations.
Off-Line Recognition of Totally Unconstrained Handwritten Numerals Using Multilayer Cluster Neural Network
Authors: Seong-Whan Lee
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1996)

In this paper, we propose a new scheme for off-line recognition of totally unconstrained handwritten numerals using a simple multilayer cluster neural network trained with the back propagation algorithm and show that the use of genetic algorithms avoids the problem of finding local minima in training the multilayer cluster neural network with gradient descent technique, and improves the recognition rates. In the proposed scheme, Kirsch masks are adopted for extracting feature vectors and a three-layer cluster neural network with five independent subnetworks is developed for classifying similar numerals efficiently. In order to verify the performance of the proposed multilayer cluster neural network, experiments with handwritten numeral database of Concordia University of Canada, that of Electro-Technical Laboratory of Japan, and that of Electronics and Telecommunications Research Institute of Korea were performed. For the case of determining the initial weights using a genetic algorithm, 97.10%, 99.12%, and 99.40% correct recognition rates were obtained, respectively.
Diffusion of innovation theory: borrowings, extensions, and modifications from IT researchers
Authors: Mary B. Prescott
Venue: ACM SIGMIS Database (1995)

Innovation diffusion theory has been widely applied to the study of information technology (IT) innovations for more than the last decade and has provided insight into the adoption, implementation, infusion, and diffusion of IT innovations. This stream of research has strong potential for contributing both to the development of innovation diffusion theory and to providing pragmatic guidance to practitioners faced with the often difficult task of successfully introducing a new information technology or method to the workplace. Brief summaries are included of the five articles in this special issue of the DATA BASE for Advances in Information Systems, which is devoted to information technology adoption, implementation, and diffusion.
Using dataflow analysis techniques to reduce ownership overhead in cache coherence protocols
Authors: Jonas Skeppstedt, Per Stenström
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1996)

In this article, we explore the potential of classical dataflow analysis techniques in removing overhead in write-invalidate cache coherence protocols for shared-memory multiprocessors. We construct the compiler algorithms with varying degree of sophistication that detect loads followed by stores to the same address. Such loads are marked and constitute a hint to the cache to obtain an exclusive copy of the block so that the subsequent store does not introduce access penalties. The simplest of the three compiler algorithms analyzes the existence of load-store sequences within each basic blocks of code whereas the other two analyze load-store sequences across basic blocks at the intraprocedural level. The algorithms have been incorporated into an optimizing C compiler, and we have evaluated their efficiencies by compiling and executing seven parallel programs on a simulated multiprocessor. Our results show that the detection efficiency of the most aggressive algorithm is 96% or higher for four of the seven programs studied. We also compare the efficiency of these static algorithms with that of dynamic hardware-based algorithms that reduce ownership overhead. We find that the static analysis using classical dataflow analysis results in similar performance improvements as dynamic hardware-based approaches.
Intelligent congestion control for ABR service in ATM networks
Authors: Kai-Yeung Siu, Hong-Yi Tzeng
Venue: ACM SIGCOMM Computer Communication Review (1994)

The emergence of asynchronous transfer mode (ATM) technology has generated new challenging problems for computer network designers. One of these challenges lies in the efficient management of ATM traffic so that the communication bandwidth of the network can be optimally utilized. Considerable standardization efforts in recent ATM Forum activities have been centered on the traffic management of available bit rate (ABR) service. In this paper, we examine congestion control schemes for ABR service in ATM networks. We describe a rate-based scheme that is now referred to by the ATM Forum as 'intelligent congestion control' and is currently considered as one of the most promising approaches. Moreover, we present analytical and simulation results illustrating the characteristics of the proposed scheme.
Data-parallel numerical weather forecasting
Authors: Lex Wolters, Gerard Cats, Nils Gustafsson
Venue: Scientific Programming (1995)

In this article we describe the implementation of a numerical weather forecast model on a massively parallel computer system. This model is a production code used for routine weather forecasting at the meteorological institutes of several European countries. The modifications needed to achieve a data-parallel version of this model without explicit message passing are outlined. The achieved performance of different numerical solution methods within this model is presented and compared.
Algebraic Analysis of the Hierarchical Basis Preconditioner
Authors: Howard C. Elman, Xuejun Zhang
Venue: SIAM Journal on Matrix Analysis and Applications (1995)

The use of the hierarchical basis in finite element discretizations of two-dimensional elliptic partial differential equations produces matrices with condition numbers of order $O((\log h^{-1})^2)$. Standard proofs of this result are functional analytic in style. In this paper, it is shown that for uniform grids the result can be obtained using a purely linear algebraic argument.
Feasible Offset and Optimal Offset for General Single-LayerChannel Routing
Authors: Ronald I. Greenberg, Jau-Der Shih
Venue: SIAM Journal on Discrete Mathematics (1995)

This paper provides an efficient method to find all feasible offsets for a given separation in a very large-scale integration (VLSI) channel-routing problem in one layer. The previous literature considers this task only for problems with no single-sided nets. When single-sided nets are included, the worst-case solution time increases from $\Theta(n)$ to $\Omega(n^2)$, where $n$ is the number of nets. But if the number of columns $c$ is $O(n)$, the problem can be solved in time $O(n^{1.5}\lgn)$, which improves upon a "naive" $O(cn)$ approach. As a corollary of this result, the same time bound suffices to find the optimal offset (the one that minimizes separation). Better running times result when there are no two-sided nets or all single-sided nets are on one side of the channel. This paper also gives improvements upon the naive approach for $c\neq O(n)$, including an algorithm with running time independent of $c$. An interesting algorithmic aspect of the paper is a connection to discrete convolution.
Testability of Convergent Tree Circuits
Authors: R. D. Blaton, John P. Hayes
Venue: IEEE Transactions on Computers (1996)

The testing properties of a class of regular circuits called convergent trees are investigated. Convergent trees include such practical circuits as comparators, multiplexers, and carry-lookahead adders. The conditions for the testability of these tree circuits are derived for a functional fault model. The notion of L-testability is introduced, where the number of tests for a p-level tree is directly proportional to p, rather than exponential in p. Convergent trees that are C-testable (testable with a fixed number of tests, regardless of the tree's size) are also characterized. Two design techniques are also introduced that modify arbitrary tree modules in order to achieve L- and C-testability. Finally, we apply these techniques to the design of a large carry-lookahead adder.
Software support for outboard buffering and checksumming
Authors: Karl Kleinpaste, Peter Steenkiste, Brian Zill
Venue: Proceedings of the conference on Applications, technologies, architectures, and protocols for computer communication (1995)

Data copying and checksumming are the most expensive operations when doing high-bandwidth network IO over a high-speed network. Under some conditions, outboard buffering and checksumming can eliminate accesses to the data, thus making communication less expensive and faster. One of the scenarios in which outboard buffering pays off is the common case of applications accessing the network using the Berkeley sockets interface and the Internet protocol stack. In this paper we describe the changes that were made to a BSD protocol stack to make use of a network adaptor that supports outboard buffering and checksumming. Our goal is not only to achieve "single copy" communication for application that use sockets, but to also have efficient communication for in-kernel applications and for applications using other networks. Performance measurements show that for large reads and writes the single-copy path through the stack is significantly more efficient than the original implementation.
Distributed snapshots: determining global states of distributed systems
Authors: K. Mani Chandy, Leslie Lamport
Venue: ACM Transactions on Computer Systems (TOCS) (1985)

This paper presents an algorithm by which a process in a distributed system determines a global state of the system during a computation. Many problems in distributed systems can be cast in terms of the problem of detecting global states. For instance, the global state detection algorithm helps to solve an important class of problems: stable property detection. A stable property is one that persists: once a stable property becomes true it remains true thereafter. Examples of stable properties are &ldquo;computation has terminated,&rdquo; &ldquo; the system is deadlocked&rdquo; and &ldquo;all tokens in a token ring have disappeared.&rdquo; The stable property detection problem is that of devising algorithms to detect a given stable property. Global state detection can also be used for checkpointing.
Parallel and distributed algorithms: laboratory assignments in Joyce/Linda
Authors: Bruce S. Elenborgen
Venue: ACM SIGCSE Bulletin (1996)

A NSF ILI grant funded development of parallel and distributed laboratories for an undergraduate course in parallel algorithms. The laboratory assignments explored various parallel and distributed architectures, and paradigms. These assignments were implemented using the Joyce/Linda[McDonald92] language. The Joyce/Linda software was also utilized to develop parallel and distributed laboratory assignments for courses in data structures, operating systems and computer networks. The parallel and distributed algorithms course examined both theoretical and practical areas of study.
Boosting the performance of hybrid snooping cache protocols
Authors: Fredrik Dahlgren
Venue: ACM SIGARCH Computer Architecture News (1995)

Previous studies of bus-based shared-memory multiprocessors have shown hybrid write-invalidate/write-update snooping protocols to be incapable of providing consistent performance improvements over write-invalidate protocols. In this paper, we analyze the deficiencies of hybrid snooping protocols under release consistency, and show how these deficiencies can be dramatically reduced by using write caches and read snarfing.Our performance evaluation is based on program-driven simulation and a set of five scientific applications with different sharing behaviors including migratory sharing as well us producer-consumer sharing. We show that a hybrid protocol, extended with write caches as well as read snarfing, manages to reduce the number of coherence misses by between 83% and 95% as compared to a write-invalidate protocol for all five applications in this study. In addition, the number of bus transactions is reduced by between 36% and 60% for four of the applications and by 9% for the fifth application. Because of the small implementation cost of the hybrid protocol and the two extensions, we believe that this combination is an effective approach to boost the performance of bus-based multiprocessors.
Dynamic structure discrete event system specification: a new formalism for dynamic structure modeling and simulation
Authors: Fernando J. Barros
Venue: Proceedings of the 27th conference on Winter simulation (1995)

Traditional simulation methodologies do not support changes in model structure during a simulation run. Current methodologies support only changes in model descriptive variables. Changes in structure are thus forced to be represented at the simple behavioral level. Many models are better represented at both behavioral and structural level. We present a new simulation formalism that fully supports changes in model structure and its closure under coupling. The Dynamic Structure Discrete Event System Specification formalism (DSDEVS) supports a new simulation paradigm, structural simulation, as opposed to conventional trajectory simulation. This new formalism supports changes in structure to the full extent, ranging from simple model/connection add/deletion to the exchange of models between network of models. The DELTA simulation environment, an implementation of the DSDEVS formalism, is briefly described.
A Mechanism of Automatic 3D Object Modeling
Authors: Xiaobu Yuan
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1995)

The symbolic representation of 3D objects is the fundamental knowledge for computer systems to understand the environment. This knowledge is usually assumed to exist in a computer but can also be acquired by accumulating spatial features extracted from sensory inputs at different viewing directions. This paper first investigates surface visibility and, then, after introducing mass vector chains (MVC), discusses the relationship between MVC and the spatial closure of object models. An automatic modeling mechanism is established with the observation that the boundary of an object is closed only if the MVC of its model is closed or, alternatively, the tail-to-head vector of an unclosed MVC estimates the visible direction of the missing surfaces. Experimental results and an algorithm are also given at the end.
An evaluation of an automatically generated compiler
Authors: Anthony M. Sloane
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1995)

Compilers or language translators can be generated using a variety of formal specification techniques. Whether generation is worthwhile depends on the effort required to specify the translation task and the quality of the generated compiler. A systematic comparison was conducted between a hand-coded translator for the Icon programming language and one generated by the Eli compiler construction system. A direct comparison could be made since the generated program performs the same translation as the hand-coded program. The results of the comparison show that efficient compilers can be generated from specifications that are much smaller and more problem oriented than the equivalent source code. We also found that further work must be done to reduce the dynamic memory usage of the generated compilers.
Experiments with digital video playback
Authors: Richard Gerber, Ladan Gharai
Venue: Proceedings of the 1996 ACM SIGMETRICS international conference on Measurement and modeling of computer systems (1996)

In this paper we describe our experiments on digital video applications, concentrating on the static and dynamic tradeoffs involved in video playback. Our results were extracted from a controlled series of 272 tests, which we ran in three stages.In the first stage of 120 tests, we used a simple player-monitor tool to evaluate the effects of various static parameters: compression type, frame size, digitized rate, spatial quality and keyframe distribution. The tests were carried out on two Apple Macintosh platforms: at the lower end a Quadra 950, and at the higher end, a Power PC 7100/80. Our quantitative metrics included average playback rate, as well as the rate's variance over one-second intervals.The first set of experiments unveiled several anomalous latencies. To track them down we ran an additional 120 tests, from which we concluded that the video and IO operations were insufficiently tuned to each other.In the next step we attempted to correct this problem, by implementing our own video playback software and accompanying device-level handlers. Our emphasis was on achieving a controlled, deterministic coordination between the various system components. An additional set of 32 experiments were carried out on our platforms, which showed frame-rate increases of up to 325%, with associated reductions in rate variance.
On the distribution of cumulated interference power in Rayleigh fading channels
Authors: Rudolf Mathar, Jürgen Mattfeldt
Venue: Wireless Networks (1995)

This paper deals with the distribution of cumulated instantaneous interference power in a Rayleigh fading channel for an infinite number of interfering stations, where each station transmits with a certain probability, independently of all others. If all distances are known, a necessary and sufficient condition is given for the corresponding distribution to be nondefective. Explicit formulae of density and distribution functions are obtained in the interesting special case that interfering stations are located on a linear grid. Moreover, the Laplace transform of cumulated power is investigated when the positions of stations follow a one- or two-dimensional Poisson process. It turns out that the corresponding distribution is defective for the two-dimensional models.
An APL implementation of the Club of Rome's world model
Authors: Clare Townsend
Venue: Proceedings of the international conference on Applied programming languages (1995)

This paper discusses an application which models world population dynamics using initial value differential equations. The program provides the user with a simple interface that anyone with any level of experience with APL can use to generate different scenarios. In addition, the discoveries and difficulties encountered by a student using APL for the first time are explored.
Resurrecting Core Spreading Vortex Methods: A New Scheme That Is Both Deterministic and Convergent
Authors: Louis F. Rossi
Venue: SIAM Journal on Scientific Computing (1996)

A basic core spreading vortex scheme is inconsistent but can be corrected with a splitting algorithm, yielding a deterministic and efficient grid-free method for viscous flows. The splitting algorithm controls the consistency error by maintaining small vortex core sizes. Routine analysis will show that the core spreading method coupled to this splitting process is convergent in $L^p$ spaces. Analysis of the linearized residual operator establishes the uniform convergence of this method when the exact flow field is known. A sequence of examples demonstrates the sensitivity of the method to numerical parameters as the computed solution converges to the exact solution. These experimental results agree with the linear convergence theory. Finally, direct comparisons between the traditional random walk vortex method and the new method indicate that the new method has several advantages while requiring the same computational effort.
Improving abstract interpretations by combining domains
Authors: Michael Codish, Anne Mulkers, Maurice Bruynooghe, Maria García de la Banda, Manuel Hermenegildo
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1995)

This article considers static analysis based on abstract interpretation of logic programs over combined domains. It is known that analyses over combined domains provide more information potentially than obtained by the independent analyses. However, the construction of a combined analysis often requires redefining the basic operations for the combined domain. A practical approach to maintain precision in combined analyses of logic programs which reuses the individual analyses and does not redefine the basic operations is illustrated. The advantages of the approach are that (1) proofs of correctness for the new domains are not required and (2) implementations can be reused. The approach is demonstrated by showing that a combined sharing analysis&mdash;constructed from &ldquo;old&rdquo; proposals&mdash;compares well with other &ldquo;new&rdquo; proposals suggested in recent literature both from the point of view of efficiency and accuracy.
Multigranularity locking in multiple job classes transaction processing system
Authors: Shan-hoi Ng
Venue: ACM SIGMOD Record (1995)

The conditions of when to apply fine and coarse granularity to different kinds of transaction are well understood. However, it is not very clear how multiple job classes using different lock granularities affect each other. This study aims at exploring the impact of multigranularity locking on the performance of multiple job classes transaction processing system which is common in multiuser database system. There are two key findings in the study. Firstly, lock granularity adopted by identical job classes should not differ from each other by a factor of more than 20; otherwise, serious data contention may result. Secondly, short job class transactions are generally benefited when its level of granularity is similar to that of the long job class since this will reduce the additional lock overhead and data contention which are induced by multigranularity locking.
Modeling a bulk manufacturing system using Extend
Authors: Andrew J. Siprelle, David J. Parsons
Venue: Proceedings of the 27th conference on Winter simulation (1995)

While simulation is readily used for traditional "pieces/parts" manufacturing problems, it is also highly effective in solving problems in the world of bulk (dry) product or fluid manufacture. The nature of bulk or fluid manufacturing problems calls for a unique simulation architecture which is adaptable to many different applications. This paper shows how the simulation package Extend by Imagine That, Inc. of San Jose CA can be used to address such problems. A model of a soap manufacturing operation illustrates the use of this approach for determining the operational impact of expansion projects requiring significant capital while also allowing the user to determine optimum schedules for plant operation. In the long term, the model will likely be used on an ongoing basis to analyze production sequences.