ppxscal/embedding_network huggingface dataset:
Tree Reconstruction from Partial Orders
Authors: Sampath K. Kannan, Tandy J. Warnow
Venue: SIAM Journal on Computing (1995)

The problem of constructing trees given a matrix of interleaf distances is motivated by applications in computational evolutionary biology and linguistics. The general problem is to find an edge-weighted tree which most closely approximates (under some norm) the distance matrix. Although the construction problem is easy when the tree exactly fits the distance matrix, optimization problems under all popular criteria are either known or conjectured to be NP-complete. In this paper we consider the related problem where we are given a partial order on the pairwise distances, and wish to construct (if possible) an edge-weighted tree realizing the partial order. In particular we are interested in partial orders which arise from experiments on triples of species. We will show that the consistency problem is NP-hard in general, but that for certain special cases the construction problem can be solved in polynomial time.
Fortran 95
Authors: CORPORATE ANSI Accredited Technical Subcommittee X3J3
Venue: ACM SIGPLAN Fortran Forum (1995)

ISO/IEC 1539 is a multipart International Standard; the parts are published separately. This publication, 1539-1, which is the first part, specifies the form and establishes the interpretation of programs expressed in the Fortran language. The purpose of this part is to promote portability, reliability, maintainability, and efficient execution of Fortran programs for use on a variety of computing systems. The second part, 1539-2, defines additional facilities for the manipulation of character strings of variable length. A processor conforming to 1539-1 need not conform to 1539-2; however, conformance to 1539-2 assumes conformance to this part. Throughout this publication, the term "this standard" refers to 1539-1.
Regenerative randomization: theory and application examples
Authors: Juan A. Carrasco, Angel Calderón
Venue: Proceedings of the 1995 ACM SIGMETRICS joint international conference on Measurement and modeling of computer systems (1995)

Randomization is a popular method for the transient solution of continuous-time Markov models. Its primary advantages over other methods (i.e., ODE solvers) are robustness and ease of implementation. It is however well-known that the performance of the method deteriorates with the "stiffness" of the model: the number of required steps to solve the model up to time t tends to Lambda;t for Lambda;t rarr; infin;. In this paper we present a new method called regenerative randomization and apply it to the computation of two transient measures for rewarded irreducible Markov models. Regarding the number of steps required in regenerative randomization we prove that: 1) it is smaller than the number of steps required in standard randomization when the initial distribution is concentrated in a single state, 2) for Lambda;t rarr; infin;, it is upper bounded by a function O(log( Lambda;t/ epsilon;)), where epsilon; is the desired relative approximation error bound. Using dependability and performability examples we analyze the performance of the method.
Comments on data analysis in software experiments
Authors: Yeh-Ling Chen, Arnold J. Stromberg
Venue: ACM SIGICE Bulletin (1996)

Software development, like other scientific developments, requires formal experiments with a great deal of plan and analysis if they are to provide meaningful results[11]. This paper uses examples to extend the discussion to a certain statistical analysis, the prediction confidence interval, which have been pointed out but never been fully discussed. The purpose of this paper is to provide a better understanding of a statistical analysis for software experimenters when the experimental data is not as nice as expected.
An algorithm for speculative parallel execution of rendezvous-synchronized simulation
Authors: Bruno R. Preiss
Venue: ACM SIGSIM Simulation Digest (1995)

This paper presents an approach for speculative parallel execution of rendezvous-synchronized simulations. Rendezvous-synchronized simulation is based on the notions of processes and gates and on the rendezvous mechanism defined in the basic process algebra of LOTOS&mdash;a standard formal specification language for temporal ordering[2]. Time is introduced via a mechanism similar to the delay behaviour annotation provided by the TOPO toolset[4-6].The algorithm allows speculative gate activations. This increases the available parallelism while ensuring correct execution of the computation.The model is used to describe closed stochastic queueing network simulations. Analysis of their execution results suggests that the model makes available a promising degree of parallelism.
On Effective Execution of Nonuniform DOACROSS Loops
Authors: Ding-Kai Chen, Pen-Chung Yew
Venue: IEEE Transactions on Parallel and Distributed Systems (1996)

It is extremely difficult to parallelize DOACROSS loops with nonuniform loop-carried dependences. In this paper, we present a static scheduling scheme with an accompanying synchronization strategy that can execute such DOACROSS loops effectively and efficiently. Our approach uses one of the parallelization techniques called Dependence Uniformization, which finds a small set of uniform dependence vectors to cover all possible nonuniform dependences in a DOACROSS loop. It differs from the previous schemes in that we demonstrate a better way to select the uniform dependence vectors. When used with the Static Strip Scheduling scheme, the proposed uniform dependence vector set allows us to enforce dependences with more locality, which reduces the requirement of explicit synchronization considerably while retaining most of the parallelism. This paper describes the uniform dependence vectors selection strategy and the static strip scheduling scheme. The performance analysis and examples are also presented.
A combinatorial treatment of balancing networks
Authors: Costas Busch, Marios Mavronicolas
Venue: Journal of the ACM (JACM) (1996)

Balancing networks, originally introduced by Aspnes et al. (Proceedings of the 23rd Annual ACM Symposium on Theory of Computing, pp. 348-358, May 1991), represent a new class of distributed, low-contention data structures suitable for solving many fundamental multi-processor coordination problems that can be expressed as balancing problems. In this work, we present a mathematical study of the combinatorial structure of balancing networks, and a variety of its applications.Our study identifies important combinatorial transfer parameters of balancing networks. In turn, necessary and sufficient combinatorial conditions are established, expressed in terms of transfer parameters, which precisely characterize many important and well studied classes of balancing networks such as counting networks and smoothing networks. We propose these combinatorial conditions to be &ldquo;balancing analogs&rdquo; of the well known Zero-One principle holding for sorting networksWithin the combinatorial framework we develop, our first application is in deriving combinatorial conditions, involving the transfer parameters, which precisely delimit the boundary between counting networks and sorting networks.
Calculating transient distributions of cumulative reward
Authors: Edmundo de Souza e Silva, H. Richard Gail, Reinaldo Vallejos Campos
Venue: ACM SIGMETRICS Performance Evaluation Review (1995)

Markov reward models have been employed to obtain performability measures of computer and communication systems. In these models, a continuous time Markov chain is used to represent changes in the system structure, usually caused by faults and repairs of its components, and reward rates are assigned to states of the model to indicate some measure of accomplishment at each structure. A procedure to calculate numerically the distribution of the reward accumulated over a finite observation period is presented. The development is based solely on probabilistic arguments, and the final recursion is quite simple. The algorithm has a low computational cost in terms of model parameters. In fact, the number of operations is linear in a parameter that is smaller than the number of rewards, while the storage required is independent of the number of rewards. We also consider the calculation of the distribution of cumulative reward for models in which impulse based rewards are associated with transitions.
Modeling the effects of acid leaching on concrete
Authors: Kevin Hartzfeld
Venue: Proceedings of the international conference on Applied programming languages (1995)

This paper describes a partial differential equation model used to determine the service life of buried concrete vaults exposed to acidic ground water. A graphics package helped immeasurably in debugging and testing the algorithm. The collocation program developed in APL can easily be applied to solve other problems.
Memory management techniques for Time Warp on a distributed memory machine
Authors: Bruno R. Preiss, Wayne M. Loucks
Venue: ACM SIGSIM Simulation Digest (1995)

This paper examines memory management issues associated with Time Warp synchronized parallel simulation on distributed memory machines. The paper begins with a summary of the techniques which have been previously proposed for memory management on various parallel processor memory structures. It then concentrates the discussion on parallel simulation executing on a distributed memory computer&mdash;a system comprised of separate computers, interconnected by a communications network. An important characteristic of the software developed for such systems is the fact that the dynamic memory is allocated from a pool of memory that is shared by all of the processes at a given processor.This paper presents a new memory management protocol, pruneback, which recovers space by discarding previous states. This is different from all previous schemes such as artificial rollback and cancelback which recover memory space by causing one or more logical processes to roll back to an earlier simulation time.The paper includes an empirical study of a parallel simulation of a closed stochastic queueing network showing the relationship between simulation execution time and amount of memory available. The results indicate that using pruneback is significantly more effective than artificial rollback (adapted for a distributed memory computer) for this problem. In the study, varying the memory limits over a 2:1 range resulted in a 1:2 change in artificial rollback execution time and almost no change in pruneback execution time.
A case for two-level distributed recovery schemes
Authors: Nitin H. Vaidya
Venue: Proceedings of the 1995 ACM SIGMETRICS joint international conference on Measurement and modeling of computer systems (1995)

Most distributed and multiprocessor recovery schemes proposed in the literature are designed to tolerate arbitrary number of failures. In this paper, we demonstrate that, it is often advantageous to use "two-level" recovery schemes. A two-level recovery scheme tolerates the more probable failures with low performance overhead, while the less probable failures may be tolerated with a higher overhead. By minimizing the overhead for the more frequently occurring failure scenarios, our approach is expected to achieve lower performance overhead (on average) as compared to existing recovery schemes.To demonstrate the advantages of two-level recovery, we evaluate the performance of a recovery scheme that takes two different types of checkpoints, namely, 1-checkpoints and N-checkpoints. A single failure can be tolerated by rolling the system back to a 1-checkpoint, while multiple failure recovery is possible by rolling back to an N-checkpoint. For such a system, we demonstrate that to minimize the average overhead, it is often necessary to take both 1-checkpoints and N-checkpoints.While the conclusions of this paper are intuitive, the work on design of appropriate recovery schemes is lacking. The objective of this paper is to motivate research into recovery schemes that can provide multiple levels of fault tolerance.
Verification of ANDF components
Authors: Frédéric Broustaut, Christian Fabre, François de Ferrière, Éric Ivanov, Mauro Fiorentini
Venue: Papers from the 1995 ACM SIGPLAN workshop on Intermediate representations (1995)

This paper presents validation work done on ANDF at the Open Software Foundation Research Institute. The ultimate ANDF scenario splits a compiler into two separate components (producer/installer). This changes the compiler validation process as the two components have to be validated separately. This paper presents the originality and the difficulties of such an approach and summarizes the status of two pieces of software to which the OSF-RI has contributed: the ANDF Validation Suite and the General ANDF Interpreter.
Fault emulation: a new approach to fault grading
Authors: Kwang-Ting Cheng, Shi-Yu Huang, Wei-Jin Dai
Venue: Proceedings of the 1995 IEEE/ACM international conference on Computer-aided design (1995)

In this paper, we propose a method of using an FPGA-based emulation system for fault grading. The real-time simulation capability of a hardware emulator could significantly improve the run-time of fault grading, which is one of the most resource-intensive tasks in the design process. A serial fault emulation algorithm is employed and enhanced by two speed-up techniques. First, a set of independent faults can be emulated in parallel. Second, simultaneous injection of multiple dependent faults is also possible by adding extra supporting circuitry. Because the reconfiguration time spent on mapping the numerous faulty circuits into the FPGA boards could be the bottleneck of the whole process, using extra logic for injecting a large number of faults per configuration can reduce the number of reconfigurations, and thus, significantly improve the efficiency. Some modeling issues that are unique in the fault emulation environment are also addressed. The performance estimation indicates that this approach could be several orders of magnitude faster than the existing software approaches for large designs.
Viscosity Solutions and Viscosity Subderivatives in Smooth Banach Spaces with Applications to Metric Regularity
Authors: Jonathan M. Borwein, Qiji J. Zhu
Venue: SIAM Journal on Control and Optimization (1996)

In G&acirc;teaux or bornologically differentiable spaces there are two natural generalizations of the concept of a Fr&eacute;chet subderivative. In this paper we study the viscosity subderivative (which is the more robust of the two) and establish refined fuzzy sum rules for it in a smooth Banach space. These rules are applied to obtain comparison results for viscosity solutions of Hamilton--Jacobi equations in smooth spaces. A unified treatment of metric regularity in smooth spaces completes the paper. This illustrates the flexibility of viscosity subderivatives as a tool for analysis.
Nowhere-Zero 4-Flows and Cayley Graphs on Solvable Groups
Authors: Brian Alspach, Yi-Ping Liu, Cun-Quan Zhang
Venue: SIAM Journal on Discrete Mathematics (1996)

We prove that every Cayley graph on a finite solvable group admits a nowhere-zero 4-flow. In particular, every cubic Cayley graph on a solvable group is 3-edge-colorable.
On the performance of bandwidth allocation strategies for interconnecting ATM and connectionless networks
Authors: Edward Chan, Victor C. S. Lee, Jim M. Ng
Venue: ACM SIGCOMM Computer Communication Review (1996)

Using ATM networks as the switching fabric for interconnecting LANs and MANs means that a strategy for bandwidth allocation must be developed to map connectionless traffic in the LAN/MAN to the ATM network which is essentially connection-oriented. This paper presents a bandwidth allocation algorithm based on bandwidth advertising and burst drop when overflow occurs. The performance is evaluated by simulation and shown to reduce Burst Loss Rate significantly.
A short note a small virtually-addressed control blocks
Authors: Jochen Liedtke
Venue: ACM SIGOPS Operating Systems Review (1995)

Being able to access task and thread control blocks in the virtual address space has some structuring and performance advantages, but using one page per control block is too expensive in some cases. This paper describes how to emulate smaller kernel pages though still using the hardware MMU.
Introduction to ARENA
Authors: John E. Hammann, Nancy A. Markovitch
Venue: Proceedings of the 27th conference on Winter simulation (1995)

This paper highlights the features and functions of Systems Modeling Corporation's general purpose simulation system, Arena. Arena represents an advancement in simulation technology by enabling enterprise-wide simulation. It is a comprehensive system that addresses all phases of a simulation project from input data analysis to the analysis of simulation output data. Building on the capabilities of Systems Modeling's earlier products, SIMAN and Cinema, Arena uses a hierarchical approach to provide the user with the power of a simulation language and the flexibility of a simulator. The object-oriented approach that was central to Arena's development, coupled with the hierarchical architecture, enables the professional user to define the personality of the system for the end-user. The professional user can actually build his or her own simulation system by combining SIMAN and Arena constructs into modules for the end-user. Arena is focused on bringing the use of simulation to broad new classes of users. Its application focus addresses the needs of manufacturing as well as decision support for many other areas including, business process reengineering, medical systems, transportation, logistics, and data communications.
YAP3: improved detection of similarities in computer program and other texts
Authors: Michael J. Wise
Venue: ACM SIGCSE Bulletin (1996)

In spite of years of effort, plagiarism in student assignment submissions still causes considerable difficulties for course designers; if students' work is not their own, how can anyone be certain they have learnt anything? YAP is a system for detecting suspected plagiarism in computer programs and other texts submitted by students. The paper reviews YAP3, the third version of YAP, focusing on its novel underlying algorithm - Running-Karp-Rabin Greedy-String-Tiling (or RKS-GST), whose development arose from the observation with YAP and other systems that students shuffle independent code segments. YAP3 is able to detect transposed subsequences, and is less perturbed by spurious additional statements. The paper concludes with a discussion of recent extension of YAP to English texts, further illustrating the flexibility of the YAP approach.
Rethinking the CS-2 course with an object-oriented focus
Authors: Mark Fienup
Venue: ACM SIGCSE Bulletin (1996)

Clearly, switching to the object-oriented paradigm as the first paradigm students learn must be accompanied by curricular changes. After three semesters of experience, this paper addresses the pedagogical problems encountered in switching to the object-oriented programming paradigm in the CS-2 course and our solutions to these problems.
GC: the data-flow graph format of synchronous programming
Authors: Pascal Aubry, Thierry Gautier
Venue: Papers from the 1995 ACM SIGPLAN workshop on Intermediate representations (1995)

Based on an abstraction of the time as a discrete logical time, the synchronous languages, armed with a strong semantics, enable the design of safe real-time applications. Some of them are of imperative style, while others are declarative. Academic and industrial teams involved in synchronous programming defined together three intermediate representations, on the way to standardization:&bull; IC, a parallel format of imperative style,&bull; GC, a parallel format of data-flow style,&bull; OC, a sequential format to describe automata.In this paper, we describe more specifically the format GC, and its links with the synchronous data-flow language SIGNAL. Thanks to the first experimentations, GC reveals itself as a powerful representation for graph transformations, code production, optimization, hardware synthesis, etc.
Books without pages
Authors: Nicholas Negroponte
Venue: ACM SIGDOC Asterisk Journal of Computer Documentation (1996)

Computer Graphics has been a vector oriented high technology for interaction and its images have been those of a silent movie. Current trends toward raster scan in general are bringing together the previously disjoint communities of image processing, broadcast television and computer graphics. Present implementations in video format are making computer graphics ubiquitous. Jointly, these events are leading to broader definitions of man-machine interaction and more generalized applications of computer resources. The user community is growing to include people like: presidents of companies, housewives, six year old children.In this light, this paper is about not throwing away the message with the medium while offering new technological opportunities for communication. In many regards the old fashioned book remains the best random access information resource we have, but new opportunities include: personalization, sound synchronization, spatial data access.
Computation of Shot-Noise Probability Distributions and Densities
Authors: John A. Gubner
Venue: SIAM Journal on Scientific Computing (1996)

The computation of the cumulative distribution (cdf), the complementary cdf (ccdf), and the density of certain shot-noise random variables is discussed. After subtracting off a few terms that can be computed in closed form, what remains can be approximated by a general method for approximating samples of a cdf or ccdf by summing a Fourier series whose coefficients are modulated samples of their characteristic function. To approximate the density, a spline is fit to the cdf samples and then differentiated. When the density has corners, it is important that the spline have coincident knots at these locations. For shot-noise densities, these locations are easily identified.
Software caching and computation migration in Olden
Authors: Martin C. Carlisle, Anne Rogers
Venue: ACM SIGPLAN Notices (1995)

The goal of the Olden project is to build a system that provides parallelism for general purpose C programs with minimal programmer annotations. We focus on programs using dynamic structures such as trees, lists, and DAGs. We demonstrate that providing both software caching and computation migration can improve the performance of these programs, and provide a compile-time heuristic that selects between them for each pointer dereference. We have implemented a prototype system on the Thinking Machines CM-5. We describe our implementation and report on experiments with ten benchmarks.
Modeling and simulation of breakwater construction
Authors: Dulcy M. Abraham, Miao-Hui Joanne Yeh, Daniel W. Halpin
Venue: Proceedings of the 27th conference on Winter simulation (1995)

Discusses the application of computer simulation for the analysis of productivity of breakwater construction. Data collected from the first stage of the South Star Project in Taiwan is used in modeling and analysis. The South Star project involves embanking land from the sea, using industrial waste as deposits and expanding the seashore line as well as increasing land for the industrial city of Kaohsiung. The main benefit of this simulation analysis is a detailed look at the techniques for improving breakwater construction.