ppxscal/embedding_network huggingface dataset:
Multiprocessor memory organization and memory interference
Authors: Alan Jay Smith
Venue: Communications of the ACM (1977)

ture of shared memory in a multiprocessor computer system is examined with particular attention to noninterleaved memory. Alternative memory organizations are compared and it is shown that a home memory organization, in which each processor is associated with one or more memories in which its address space is concentrated, is quite effective in reducing memory interference. Home memory organization is shown to be particularly suited to certain specialized computational problems as well as to possess advantages in terms of interference and reliability for general purpose computation. Results for interleaved memory are drawn from previous work and are used for comparison. Trace-driven simulations are used to verify the conclusions of the analysis.
Binary Space Partitions for Fat Rectangles
Authors: Pankaj K. Agarwal, Edward F. Grove, T. M. Murali, Jeffrey Scott Vitter
Venue: SIAM Journal on Computing (2000)

We consider the practical problem of constructing binary space partitions (BSPs) for a set S of n orthogonal, nonintersecting, two-dimensional rectangles in ${\Bbb R}^3$ such that the aspect ratio of each rectangle in $S$ is at most $\alpha$, for some constant $\alpha \geq 1$. We present an $n2^{O(\sqrt{\log n})}$-time algorithm to build a binary space partition of size $n2^{O(\sqrt{\log n})}$ for $S$. We also show that if $m$ of the $n$ rectangles in $S$ have aspect ratios greater than $\alpha$, we can construct a BSP of size $n\sqrt{m}2^{O(\sqrt{\log n})}$ for $S$ in $n\sqrt{m}2^{O(\sqrt{\log n})}$ time. The constants of proportionality in the big-oh terms are linear in $\log \alpha$. We extend these results to cases in which the input contains nonorthogonal or intersecting objects.
Finding refactorings via change metrics
Authors: Serge Demeyer, Stéphane Ducasse, Oscar Nierstrasz
Venue: Proceedings of the 15th ACM SIGPLAN conference on Object-oriented programming, systems, languages, and applications (2000)

Reverse engineering is the process of uncovering the design and the design rationale from a functioning software system. Reverse engineering is an integral part of any successful software system, because changing requirements lead to implementations that drift from their original design. In contrast to traditional reverse engineering techniques ---which analyse a single snapshot of a system--- we focus the reverse engineering effort by determining where the implementation has changed. Since changes of object-oriented software are often phrased in terms of refactorings, we propose a set of heuristics for detecting refactorings by applying lightweight, object-oriented metrics to successive versions of a software system. We validate our approach with three separate case studies of mature object-oriented software systems for which multiple versions are available. The case studies suggest that the heuristics support the reverse engineering process by focusing attention on the relevant parts of a software system.
Building an object oriented problem solving environment for the parallel numerical solution of PDEs
Authors: Mikel Luján
Venue: Addendum to the 2000 proceedings of the conference on Object-oriented programming, systems, languages, and applications (Addendum) (2000)

Traditionally, the development of parallel implementations of algorithms for the Numerical Solution of Partial Differential Equations (PDE) and Linear Algebra Problems is based on software libraries; typically, Fortran libraries. Due to the lack of abstraction of Fortran-like libraries, two main problems are encountered: the libraries are complex to develop and the library interfaces are difficult to use. This PhD project proposes to investigate (1) the advantages and disadvantages that object oriented design and programming can bring to the Numerical Solution of PDEs and Numerical Linear Algebra (NLA) and (2) the integration of PDE and NLA object oriented libraries with intelligent Agents to form the basis of a Problem Solving Environment (PSE) for Numerical Computation.
Cellular Automata-Based Recursive Pseudoexhaustive Test Pattern Generator
Authors: Prabir Dasgupta, Santanu Chattopadhyay, P. Pal Chaudhuri, Indranil Sengupta
Venue: IEEE Transactions on Computers (2001)

This paper presents a recursive technique for generation of pseudoexhaustive test patterns. The scheme is optimal in the sense that the first $2^k$ vectors cover all adjacent k-bit spaces exhaustively. It requires substantially lesser hardware than the existing methods and utilizes the regular, modular, and cascadable structure of local neighborhood Cellular Automata (CA), which is ideally suited for VLSI implementation. In terms of XOR gates, this approach outperforms earlier methods by 15 to 50 percent. Moreover, test effectiveness and hardware requirements have been established analytically, rather than by simple simulation and logic minimization.
Providing soft real-time QoS guarantees for Java threads
Authors: James C. Pang, Gholamali C. Shoja, Eric G. Manning
Venue: Proceedings of the 2001 joint ACM-ISCOPE conference on Java Grande (2001)

The Java platform has many characteristics that make it very desirable for integrated continuous media processing. Unfortunately, it lacks the necessary CPU resource management facility to support quality of service guarantees for soft real-time multimedia tasks. In this paper, we present our new Java Virtual Machine, Q-JVM, which brings CPU resource management to the Java platform. Q-JVM is based on Sun's JVM version 1.1.5. It implements an enhanced version or the MTR-LS algorithm in its thread scheduler. Combined with admission control that could be implemented in an application-level resource manager, it is able to support QoS parameters such as fairness, bandwidth partitioning and delay bound guarantees, as well as the cumulative service guarantee. Our test results show that Q-JVM is backward compatible with the standard JVM from Sun, has low scheduling overhead, and is able to provide QoS guarantees as specified.
Multimedia content protection by cryptography and watermarking in tamper-resistant hardware
Authors: Feng Bao
Venue: Proceedings of the 2000 ACM workshops on Multimedia (2000)

With the rapid growth of broadband network, distribution of multimedia via Internet is a must way to go. Content protection has become one of the most significant and challenging problems of this field. In this paper, we propose a general scheme that combines public key cryptography and watermarking technology together, to achieve wonderful content protection. The scheme is reliable, flexible and efficient.
Information extraction for Thai documents
Authors: Rattasit Sukhahuta, Dan Smith
Venue: Proceedings of the fifth international workshop on on Information retrieval with Asian languages (2000)

An increasing amount of electronically available information is stored in Asian language documents, which makes Information Retrieval (IR) and Information Extraction (IE) for these languages important for a large number of users. Analysis and extraction of information in these languages presents several interesting problems not seen in Western European languages; these are interesting in their own right and for the insights they can give into more general IR and IE techniques. We describe these problems and our system for Thai language IE One of the main concerns when working with Thai natural language is that the structure of the language itself is highly ambiguous. The analyser therefore requires more sophisticated techniques and large amounts of domain knowledge to cope with these ambiguities. We describe our approach to a natural language analysis system that performs preprocessing for the Thai language and the extraction module to retrieve specific information according to the predefined concept definitions.
Retiring computer pioneer&mdash;
Authors: Anthony G. Oettinger, Howard Aiken
Venue: Communications of the ACM (1962)

In retrospect, it is obvious that Charles Babbage, when writing these words, had Howard Aiken in mind. In July 1961, twenty-four years after conceiving the idea that led to Mark I and after over a quarter century of service to Harvard University and to the advancement of science, Howard Aiken became Professor of Applied Mathematics, Emeritus, and embarked on his present career as a consultant with the same boundless energy and imagination that gave momentum to one of the most revolutionary and important technological advances of this century.
Experiments with the M N tree-searching program
Authors: James R. Slagle, John K. Dixon
Venue: Communications of the ACM (1970)

The M N procedure is an improvement to the mini-max backing-up procedure widely used in computer programs for game-playing and other purposes. It is based on the principle that it is desirable to have many options when making decisions in the face of uncertainty. The mini-max procedure assigns to a MAX (MIN) node the value of the highest (lowest) valued successor to that node. The M N procedure assigns to a MAX (MIN) node some function of the M (N) highest (lowest) valued successors. An M N procedure was written in LISP to play the game of kalah, and it was demonstrated that the M N procedure is significantly superior to the mini-max procedure. The statistical significance of important conclusions is given. Since information on statistical significance has often been lacking in papers on computer experiments in the artificial intelligence field, these experiments can perhaps serve as a model for future work.
Differential--Algebraic Equations of Index 1 May Have an Arbitrarily High Structural Index
Authors: Gunther Reissig, Wade S. Martinson, Paul I. Barton
Venue: SIAM Journal on Scientific Computing (1999)

It is shown that the structural index of a linear {differential--algebraic equation} (DAE) with constant coefficients and with index 1 may be arbitrarily high, contrary to a previous result from the literature. This demonstrates that Pantelides' algorithm applied to DAEs of index 1 may perform an arbitrarily high number of iterations and differentiations.
Scaffolding learning in virtual environments
Authors: Peter Chalk
Venue: ACM SIGCSE Bulletin (2001)

As the use of on-line teaching environments increases, tutors need to identify the tasks, procedures and interventions that enhance the quality of student learning. One theory of instruction in problem solving is scaffolding and this is used as a guide to analysis of actual interventions by the author in a software engineering assignment. Stored models of the students' solutions show various misconceptions and the tutor's comments in each case are shown to belong to one of the six categories listed in the original definition of scaffolding. One possible outcome could be the outline of a possible new instructional design pattern for this method of tutoring.
Algebraic simplification: a guide for the perplexed
Authors: Joel Moses
Venue: Communications of the ACM (1971)

Algebraic simplification is examined first from the point of view of a user who needs to comprehend a large expression, and second from the point of view of a designer who wants to construct a useful and efficient system. First we describe various techniques akin to substitution. These techniques can be used to decrease the size of an expression and make it more intelligible to a user. Then we delineate the spectrum of approaches to the design of automatic simplification capabilities in an algebraic manipulation system. Systems are divided into five types. Each type provides different facilities for the manipulation and simplification of expressions. Finally we discuss some of the theoretical results related to algebraic simplification. We describe several positive results about the existence of powerful simplification algorithms and the number-theoretic conjectures on which they rely. Results about the nonexistence of algorithms for certain classes of expressions are included.
State-space problem-reduction, and theorem proving&mdash;some relationships
Authors: Gordon J. VanderBrug, Jack Minker
Venue: Communications of the ACM (1975)

This paper suggests a bidirectional relationship between state-space and problem-reduction representations. It presents a formalism based on multiple-input and multiple-output operators which provides a basis for viewing the two types of representations in this manner. A representation of the language recognition problem which is based on the Cocke parsing algorithm is used as an illustration. A method for representing problems in first-order logic in such a way that the inference system employed by a resolution-based theorem prover determines whether the set of clauses is interpreted in the state-space mode or in the problem-reduction mode is presented. The analogous concepts in problem-reduction and theorem proving, and the terminology used to refer to them, are noted. The relationship between problem-reduction, input resolution, and linear resolution is is discussed.
Safely creating correct subclasses without seeing superclass code
Authors: Clyde D. Ruby
Venue: Addendum to the 2000 proceedings of the conference on Object-oriented programming, systems, languages, and applications (Addendum) (2000)

A major problem for object-oriented frameworks and class libraries is how to provide enough information about an extensible superclass so that programmers can safely create new subclasses without studying superclass code. The goal of my work is to determine what information is needed so library providers do not have to give away the code of library superclasses. A closely related goal is to provide guidelines that simplify reasoning about classes that inherit from such frameworks and class libraries. The long-term goal of my research is to develop tool support to automatically generate some of the necessary documentation and to assist programmers in reasoning about how to create correct subclasses.
A critique of the foundations of Hoare style programming logics
Authors: Michael J. O'Donnell
Venue: Communications of the ACM (1982)

Much recent discussion in computing journals has been devoted to arguments about the feasibility and usefulness of formal verification methods. Too little attention has been given to precise criticism of specific proposed systems for reasoning about programs. Whether such systems are to be used for formal verification, by hand or automatically, or as a rigorous foundation for informal reasoning, it is essential that they be logically sound. Several popular rules in the Hoare language are, in fact, not sound. These rules have been accepted because they have not been subjected to sufficiently strong standards of correctness. This paper attempts to clarify the different technical definitions of correctness of a logic, to show that only the strongest of these definitions is acceptable for Hoare logic, and to correct some of the unsound rules that have appeared in the literature. The corrected rules are given merely to show that it is possible to do so. Convenient and elegant rules for reasoning about certain programming constructs will probably require a more flexible notation than Hoare's.
Electronic structure of materials using self-interaction corrected density functional theory
Authors: Adolfy Hoisie, Stefan Goedecker, Jurg Hutter
Venue: Proceedings of the 1996 ACM/IEEE conference on Supercomputing (CDROM) (1996)

We have developed an highly efficient electronic structure code, for parallel computers using message passing. The algorithm takes advantage of the natural parallelism in quantum chemistry problems to obtain very high performance even on a large number of processors. Most of the terms which scale cubically with respect to the number of atoms have been eliminated allowing the treatment of very large systems. It uses one of the most precise versions of Density Functional Theory, namely Self-Interaction Corrected Density Functional Theory. On a 6 processor Silicon Graphics Symmetric Multiprocessor based on the MIPS R8000 microprocessor, we obtain a performance of 6.3 Gflops per million dollar.
Java without the coffee breaks: a nonintrusive multiprocessor garbage collector
Authors: David F. Bacon, Clement R. Attanasio, Han B. Lee, V. T. Rajan, Stephen Smith
Venue: ACM SIGPLAN Notices (2001)

The deployment of Java as a concurrent programming language has created a critical need for high-performance, concurrent, and incremental multiprocessor garbage collection. We present the Recycler, a fully concurrent pure reference counting garbage collector that we have implemented in the Jalape&ntilde;o Java virtual machine running on shared memory multiprocessors. While a variety of multiprocessor collectors have been proposed and some have been implemented, experimental data is limited and there is little quantitative basis for comparison between different algorithms. We present measurements of the Recycler and compare it against a non-concurrent but parallel load-balancing mark-and-sweep collector (that we also implemented in Jalape&ntilde;o), and evaluate the classical tradeoff between response time and throughput. When processor or memory resources are limited, the Recycler runs at about 90% of the speed of the mark-and-sweep collector. However, with an extra processor to run collection and with a moderate amount of memory headroom, the Recycler is able to operate without ever blocking the mutators and achieves a maximum measured mutator delay of only 2.6 milliseconds for our benchmarks. End-to-end execution time is usually within 5%.
Three papers from the third international conference on information systems: introduction
Authors: Michael J. Ginzberg
Venue: Communications of the ACM (1983)

The International Conference on Information Systems provides an annual forum for keeping abreast of the latest trends and developments in IS research. The conference is sponsored by the TIMS College on Information Systems and the Society for Information Management in cooperation with ACM SIGBDP. The Third International Conference on Information Systems was held December 13-15, 1982, in Ann Arbor, Michigan, with Alan G. Merten as chairman. Two papers from that conference have been published in recent issues, one by Ahmed S. Zaki in February and one by Margrethe H. Olson in March. They were concerned with the impact of information systems on organizations and society. The following three papers discuss new methodological approaches to the development and use of information systems. Abdel-Hamid and Madnick focus on the problem of estimating resource requirements and schedules for software development projects. They use System Dynamics, a tool for modeling systems consisting of multiple, interacting feedback loops, to explore this problem. Their results show that policies often built into the project management process can assure that projects will fail to meet their scheduled completion, regardless of the accuracy of resource requirement and project size estimates. Hart Will explores the idea of a single, unified interface to provide auditors with the access they need in today's computer-based accounting environment. Instead of the proliferation of audit software seen so far, he suggests that a common language for accessing data, programs, and text can be developed. He describes the design of such a language and speculates about its likely impact. Mason and Carey's paper is concerned with the area of information systems design. They present an Architecture-Based Methodology for prototyping interactive information systems, derived from an analogy to the architectural approach to designing buildings or other physical structures. They discuss both the special role of &ldquo;architect&rdquo; and the tools required to support this approach to system design, including one commercially available program product.
A multi-disciplinary course on augmented reality design
Authors: Blair MacIntyre, Jay Bolter
Venue: Proceedings of DARE 2000 on Designing augmented reality environments (2000)

In this position statement, we summarize a research seminar we are teaching this spring as a vehicle for discussing our common research interest in the design of augmented reality applications.
Stratified operational semantics for safety and correctness of the region calculus
Authors: Cristiano Calcagno
Venue: ACM SIGPLAN Notices (2001)

The region analysis of Tofte and Talpin is an attempt to determine statically the life span of dynamically allocated objects. But the calculus is at once intuitively simple, yet deceptively subtle, and previous theoretical analyses have been frustratingly complex: no analysis has revealed and explained in simple terms the connection between the subleties of the calculus and the imperative features it builds on. We present a novel approach for proving safety and correctness of a simplified version of the region calculus. We give a stratified operational semantics, composed of a highlevel semantics dealing with the conceptual difficulties of effect annotations, and a low-level one with explicit operations on a region-indexed store. The main results of the paper are a proof simpler than previous ones, and a modular approach to type safety and correctness. The flexibility of this approach is demonstrated by the simplicity of the extension to the full calculus with type and region polymorphism.
MPI versus MPI+OpenMP on IBM SP for the NAS benchmarks
Authors: Franck Cappello, Daniel Etiemble
Venue: Proceedings of the 2000 ACM/IEEE conference on Supercomputing (CDROM) (2000)

The hybrid memory model of clusters of multiprocessors raises two issues: programming model and performance. Many parallel programs have been written by using the MPI standard. To evaluate the pertinence of hybrid models for existing MPI codes, we compare a unified model (MPI) and a hybrid one (OpenMP fine grain parallelization after profiling) for the NAS 2.3 benchmarks on two IBM SP systems. The superiority of one model depends on 1) the level of shared memory model parallelization, 2) the communication patterns and 3) the memory access patterns. The relative speeds of the main architecture components (CPU, memory, and network) are of tremendous importance for selecting one model. With the used hybrid model, our results show that a unified MPI approach is better for most of the benchmarks. The hybrid approach becomes better only when fast processors make the communication performance significant and the level of parallelization is sufficient.
An environment for research in microprogramming and emulation
Authors: Robert F. Rosin, Gideon Frieder, Richard H. Eckhouse,  Jr.
Venue: Communications of the ACM (1972)

The development of the research project in microprogramming and emulation at State University of New York at Buffalo consisted of three phases: the evaluation of various possible machines to support this research; the decision to purchase one such machine, which appears to be superior to the others considered; and the organization and definition of goals for each group in the project. Each of these phases is reported, with emphasis placed on the early results achieved in this research.