ppxscal/embedding_network huggingface dataset:
Principles and techniques of simulation validation, verification, and testing
Authors: Osman Balci
Venue: Proceedings of the 27th conference on Winter simulation (1995)

Sufficient experience has been gained over the last decade in simulation validation, verification, and testing (VV&T) to establish basic principles about its characteristics. This paper presents 15 principles of simulation VV&T. These principles help the researchers, practitioners and managers better understand what model VV&T is all about. They serve to provide the underpinnings for the VV&T techniques that can be used throughout the life cycle of a simulation study. This paper also surveys current software VV&T techniques and current simulation VV&T techniques. Understanding and applying these principles and employing proper testing techniques throughout the life cycle of a simulation study are key factors in increasing the probability of success in a simulation study.
Extremal Cayley Digraphs of Finite Cyclic Groups
Authors: Xing-De Jia
Venue: SIAM Journal on Discrete Mathematics (1995)

Let $\cay(m,A)$ denote the Cayley digraph on ${\bf Z}_m$ generated by $A$, where ${\bf Z}_m$ is the cyclic group of residues modulo $m$. Let $r(m,A)$ denote the average distance of $\cay(m,A)$. For any $r\ge1$ and $k\ge1$ define $m^*(r,k)$ as the largest positive integer $m$ such that the average distance of the Cayley digraph $\hbox{Cay}(m,A)$ is at most $r$ for some set $A$ with $k$ elements. In this paper, an asymptotic formula for $m^*(r,2)$ is proved and a lower bound for $m^*(r,k)$ is also obtained for $k\ge3$. Applications to the construction of optimal distributed loop networks is discussed in this paper. A lower bound of the average order of subsets for asymptotic bases in number theory is proved using the main theorem of this paper.
Database theory in practice: learning from cooperative group projects
Authors: Suzanne W. Dietrich, Susan D. Urban
Venue: Proceedings of the twenty-seventh SIGCSE technical symposium on Computer science education (1996)

This paper describes the use of cooperative group learning concepts in support of an undergraduate database management course that emphasizes the theoretical and practical aspects of database application development. The course project is divided into three main phases, involving requirements analysis and conceptual design, relational database mapping and prototyping, and database system implementation using Microsoft Access. The project deliverables are designed so that students not only develop a database implementation, but also evaluate their design in terms of functional dependencies, normal forms, the lossless join property, and the dependency preservation property, thus establishing the need for sound database design principles. Students are required to actively participate in each phase, with students assuming different roles in each phase to allow them to experience different leadership responsibilities. As part of the grading process, students evaluate their own performance as well as the performance of others in the group. This paper describes our experience with the structure and administration of cooperative groups and provides a discussion of the lessons we have learned, including initial observations of the effectiveness of the approach.
Automating Image Processing for Scientific Data Analysis of a Large Image Database
Authors: Steve A. Chien, Helen B. Mortensen
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1996)

This article describes the Multimission VICAR Planner (MVP): an AI planning system which uses knowledge about image processing steps and their requirements to construct executable image processing scripts to support high-level science requests made to the Jet Propulsion Laboratory (JPL) Multimission Image Processing Subsystem (MIPS). This article describes a general AI planning approach to automation and application of the approach to a specific area of image processing for planetary science applications involving radiometric correction, color triplet reconstruction, and mosaicing in which the MVP system significantly reduces the amount of effort required by image processing experts to fill a typical request.
Activities to attract high school girls to computer science
Authors: Susan H. Rodger, Ellen L. Walker
Venue: ACM SIGCSE Bulletin (1996)

We present several activities used in the two-week PipeLINK summer program for high school girls. These hands-on activities and interactive talks, presented mostly by female faculty, undergraduates, and graduate students, showed the girls the wide range of opportunities in the field of computer science
Synthesis of Delay-Verifiable Combinational Circuits
Authors: Wuudiann Ke, Premachandran R. Menon
Venue: IEEE Transactions on Computers (1995)

We address the problem of testing circuits for temporal correctness. A circuit is considered delay-verifiable if its timing correctness can be established by applying delay tests. It is shown that verifying the timing of a circuit may require tests which can detect the simultaneous presence of more than one path delay fault. We provide a general framework for examining delay-verifiability by introducing a special class of faults called primitive path delay faults. It is necessary and sufficient to test every fault in this class to ensure the temporal correctness of combinational circuits. Based on this result, we develop a synthesis procedure for combinational circuits that can be tested for correct timing. Experimental data show that such implementations usually require less area than completely delay testable implementations.Index Terms¿Testing for timing correctness, path-delay faults, delay-verification tests, primitive path-delay faults, synthesis for delay-verifiability.
Architectural issues in software reuse: it's not just the functionality, it's the packaging
Authors: Mary Shaw
Venue: ACM SIGSOFT Software Engineering Notes (1995)

Effective reuse depends not only on finding and reusing components, but also on the ways those components are combined. The informal folklore of software engineering provides a number of diverse styles for organizing software systems. These styles, or architectures, show how to compose systems from components; different styles expect different kinds of component packaging and different kinds of interactions between the components. Unfortunately, these styles and packaging distinctions are often implicit; as a consequence, components with appropriate functionality may fail to work together. This talk surveys common architectural styles, including important packaging and interaction distinctions, and proposes an approach to the problem of reconciling architectural mismatches.
Computing the Degree of Determinants via Combinatorial Relaxation
Authors: Kazuo Murota
Venue: SIAM Journal on Computing (1995)

Let $A(x)=(A_{ij}(x))$ be a square matrix with $A_{ij}$ being a polynomial in $x$. This paper proposes "combinatorial relaxation" type algorithms for computing the degree of the determinant, $\delta(A) = \deg_x \det A(x)$, based on its combinatorial upper bound $\widehat \delta(A)$, which is defined in terms of the maximum weight of a perfect matching in an associated graph. The graph is bipartite for a general square matrix $A$ and nonbipartite for a skew-symmetric $A$. The algorithm transforms $A$ to another matrix $A'$ for which $\delta(A) = \delta(A') = \widehat \delta(A')$ with successive elementary operations. The algorithm is efficient, making full use of the fast algorithms for weighted matchings; it is combinatorial in almost all cases (or generically) and invokes algebraic elimination routines only when accidental numerical cancellations occur. It is shown in passing that for a (skew-)symmetric polynomial matrix $A(x)$ there exists a unimodular matrix $U(x)$ such that $A'(x)=U(x) A(x) U(x)^\tp$ satisfies $\delta(A) = \delta(A') = \widehat \delta(A')$.
Using Ada and C++ in computer science education
Authors: Raymond J. Toal
Venue: ACM SIGAda Ada Letters (1996)

Undergraduate students of Computer Science or Software Engineering must become familiar with imperative programming languages, due to the extensive use of these languages in industry. Perhaps the two most interesting imperative languages, from a technical standpoint, are Ada and C++, as these two languages include a number of modern features and enjoy widespread popularity. We argue that a four-year undergraduate curriculum in Computer Science which emphasizes imperative programming languages benefits from a thorough coverage of Ada in the first two years, while deferring the direct use of C++ until the junior year. The argument is supported by an overview of the technical features of Ada and C++ which both aid and hinder the learning of software development skills.
Death from above
Authors: John Perry Barlow
Venue: Communications of the ACM (1995)

Over the last 30 years, the American CEO corps has included an astonishingly large percentage of men who piloted bombers during World War II. For some reason not so difficult to guess, dropping explosives on people from commanding heights served as a great place to develop a worldview compatible with the management of a large post-war corporation.
OFL: a functional execution model for object query languages
Authors: Georges Gardarin, Fernando Machuca, Philippe Pucheral
Venue: Proceedings of the 1995 ACM SIGMOD international conference on Management of data (1995)

We present a functional paradigm for querying efficiently abstract collections of complex objects. Abstract collections are used to model class extents, multivalued attributes as well as indexes or hashing tables. Our paradigm includes a functional language called OFL (Object Functional Language) and a supporting execution model based on graph traversals. OFL is able to support any complex object algebra with recursion as macros. It is an appropriate target language for OQL-like query compilers. The execution model provides various strategies including set-oriented and pipelined traversals. OFL has been implemented on top of an object manager. Measures of a typical query extracted from a geographical benchmark show the value of hybrid strategies integrating pipelined and set-oriented evaluations. They also show the potential of function result memorization, a typical optimization approach known as "Memoization" 2 in functional languages.
Algorithm 761: Scattered-data surface fitting that has the accuracy of a cubic polynomial
Authors: Hiroshi Akima
Venue: ACM Transactions on Mathematical Software (TOMS) (1996)

An algorithm for smooth surface fitting for scattered data has been presented. It has the accuracy of a cubic polynomial in most cases and is a local, triangle-based algorithm.
Fuzzy array dataflow analysis
Authors: Jean-François Collard, Denis Barthou, Paul Feautrier
Venue: ACM SIGPLAN Notices (1995)

Exact array dataflow analysis can be achieved in the general case if the only control structures are do-loops and structural ifs, and if loop counter bounds and array subscripts are affine expressions of englobing loop counters and possibly some integer constants. In this paper, we begin the study of dataflow analysis of dynamic control programs, where arbitrary ifs and whiles are allowed. In the general case, this dataflow analysis can only be fuzzy.
I/O limitations in parallel molecular dynamics
Authors: Terry W. Clark, L. Ridgway Scott, Stanislaw Wlodek, J. Andrew McCammon
Venue: Proceedings of the 1995 ACM/IEEE conference on Supercomputing (CDROM) (1995)

We discuss data production rates and their impact on the performance of scientific applications using parallel computers. On one hand, too high rates of data production can be overwhelming, exceeding logistical capacities for transfer, storage and analysis. On the other hand, the rate limiting step in a computationally-based study should be the human-guided analysis, not the calculation. We present performance data for a biomolecular simulation of the enzyme, acetylcholinesterase, which uses the parallel molecular dynamics program EulerGROMOS. The actual production rates are compared against a typical time frame for results analysis where we show that the rate limiting step is the simulation, and that to overcome this will require improved output rates.
Location-independent naming for virtual distributed software repositories
Authors: Shirley Browne, Jack Dongarra, Stan Green, Keith Moore, Theresa Pepin, Tom Rowan, Reed Wade
Venue: ACM SIGSOFT Software Engineering Notes (1995)

A location-independent naming system for network resources has been designed to facilitate organization and description of software components accessible through a virtual distributed repository. This naming system enables easy and efficient searching and retrieval, and it addresses many of the consistency, authenticity, and integrity issues involved with distributed software repositories by providing mechanisms for grouping resources and for authenticity and integrity checking. This paper details the design of the naming system, describes how the system fits into the development of the National HPCC Software Exchange, an virtual software repository that has the goal of providing access to reusable software components for high-performance computing.
Rate-based congestion control for ATM networks
Authors: Hiroyuki Ohsaki, Masayuki Murata, Hiroshi Suzuki, Chinatsu Ikeda, Hideo Miyahara
Venue: ACM SIGCOMM Computer Communication Review (1995)

Congestion control plays an important role in the effective and stable operation of ATM networks. This paper first gives a historical overview of rate-based congestion control algorithms developed in the ATM Forum, showing how the current ATM Forum standard regarding the traffic management control methods is exploited, by these algorithm. Then, analytical approach is used to quantitatively evaluate their performance and show the effectiveness of the rate-based approach. In presenting the numerical examples, we emphasize that appropriate control parameter settings are essential for proper traffic management in an ATM network environment.
Polynomial Filtering for Linear Discrete Time Non-Gaussian Systems
Authors: Francesco Carravetta, Alfredo Germani, Massimo Raimondi
Venue: SIAM Journal on Control and Optimization (1996)

In this work we propose a new filtering approach for linear discrete time non-Gaussian systems that generalizes a previous result concerning quadratic filtering [A. De Santis, A. Germani, and M. Raimondi, IEEE Trans. Automat. Control, 40 (1995) pp. 1274--1278]. A recursive $\nu$th-order polynomial estimate of finite memory $\Delta$ is achieved by defining a suitable extended state which allows one to solve the filtering problem via the classical Kalman linear scheme. The resulting estimate will be the mean square optimal one among those estimators that take into account $\nu$-polynomials of the last $\Delta$ observations. Numerical simulations show the effectiveness of the proposed method.
A simple graph-based intermediate representation
Authors: Cliff Click, Michael Paleczny
Venue: ACM SIGPLAN Notices (1995)

We present a graph-based intermediate representation (IR) with simple semantics and a low-memory-cost C++ implementation. The IR uses a directed graph with labeled vertices and ordered inputs but unordered outputs. Vertices are labeled with opcodes, edges are unlabeled. We represent the CFG and basic blocks with the same vertex and edge structures. Each opcode is defined by a C++ class that encapsulates opcode-specific data and behavior. We use inheritance to abstract common opcode behavior, allowing new opcodes to be easily defined from old ones. The resulting IR is simple, fast and easy to use.
Algorithm 659: Implementing Sobol's quasirandom sequence generator
Authors: Paul Bratley, Bennett L. Fox
Venue: ACM Transactions on Mathematical Software (TOMS) (1988)

We compare empirically accuracy and speed of low-discrepancy sequence generators of Sobol' and Faure. These generators are useful for multidimensional integration and global optimization. We discuss our implementation of the Sobol' generator.
Exact solution of large-scale, asymmetric traveling salesman problems
Authors: G. Carpaneto, M. Dell'Amico, P. Toth
Venue: ACM Transactions on Mathematical Software (TOMS) (1995)

A lowest-first, branch-and-bound algorithm for the Asymmetric Traveling Salesman Problem is presented. The method is based on the Assignment Problem relaxation and on a subtour elimination branching scheme. The effectiveness of the algorithm derives from reduction procedures and parametric solution of the relaxed problems associated with the nodes of the branch-decision tree. Large-size, uniformly, randomly generated instances of complete digraphs with up to 2000 vertices are solved on a DECstation 5000/240 computer in less than 3 minutes of CPU time. In addition, we solved on a PC 486/33 no wait flow shop problems with up to 1000 jobs in less than 11 minutes and real-world stacker crane problems with up to 443 movements in less than 6 seconds.
Exploiting process lifetime distributions for dynamic load balancing
Authors: Mor Harchol-Balter, Allen B. Downey
Venue: Proceedings of the 1996 ACM SIGMETRICS international conference on Measurement and modeling of computer systems (1996)

We measure the distribution of lifetimes for UNIX processes and propose a functional form that fits this distribution well. We use this functional form to derive a policy for preemptive migration, and then use a trace-driven simulator to compare our proposed policy with other preemptive migration policies, and with a non-preemptive load balancing strategy. We find that, contrary to previous reports, the performance benefits of preemptive migration are significantly greater than those of non-preemptive migration, even when the memory-transfer cost is high. Using a model of migration costs representative of current systems, we find that preemptive migration reduces the mean delay (queueing and migration) by 35 - 50%, compared to non-preemptive migration.
Approximation schemes for covering and packing problems in image processing and VLSI
Authors: Dorit S. Hochbaum, Wolfgang Maass
Venue: Journal of the ACM (JACM) (1985)

A unified and powerful approach is presented for devising polynomial approximation schemes for many strongly NP-complete problems. Such schemes consist of families of approximation algorithms for each desired performance bound on the relative error &egr; > &Ogr;, with running time that is polynomial when &egr; is fixed. Though the polynomiality of these algorithms depends on the degree of approximation &egr; being fixed, they cannot be improved, owing to a negative result stating that there are no fully polynomial approximation schemes for strongly NP-complete problems unless NP = P. The unified technique that is introduced here, referred to as the shifting strategy, is applicable to numerous geometric covering and packing problems. The method of using the technique and how it varies with problem parameters are illustrated. A similar technique, independently devised by B. S. Baker, was shown to be applicable for covering and packing problems on planar graphs.
Streamlining data cache access with fast address calculation
Authors: Todd M. Austin, Dionisios N. Pnevmatikatos, Gurindar S. Sohi
Venue: Proceedings of the 22nd annual international symposium on Computer architecture (1995)

For many programs, especially integer codes, untolerated load instruction latencies account for a significant portion of total execution time. In this paper, we present the design and evaluation of a fast address generation mechanism capable of eliminating the delays caused by effective address calculation for many loads and stores.Our approach works by predicting early in the pipeline (part of) the effective address of a memory access and using this predicted address to speculatively access the data cache. If the prediction is correct, the cache access is overlapped with non-speculative effective address calculation. Otherwise, the cache is accessed again in the following cycle, this time using the correct effective address. The impact on the cache access critical path is minimal; the prediction circuitry adds only a single OR operation before cache access can commence. In addition, verification of the predicted effective address is completely decoupled from the cache access critical path.Analyses of program reference behavior and subsequent performance analysis of this approach shows that this design is a good one, servicing enough accesses early enough to result in speedups for all the programs we tested. Our approach also responds well to software support, which can significantly reduce the number of mispredicted effective addresses, in many cases providing better program speedups and reducing cache bandwidth requirements.
Monitor classification
Authors: Peter A. Buhr, Michel Fortier, Michael H. Coffin
Venue: ACM Computing Surveys (CSUR) (1995)

One of the most natural, elegant, and efficient mechanisms for synchronization and communication, especially for systems with shared memory, is the monitor. Over the past twenty years many kinds of monitors have been proposed and implemented, and many modern programming languages provide some form of monitor for concurrency control. This paper presents a taxonomy of monitors that encompasses all the extant monitors and suggests others not found in the literature or in existing programming languages. It discusses the semantics and performance of the various kinds of monitors suggested by the taxonomy, and it discusses programming techniques suitable to each.
Floating Point Fault Tolerance with Backward Error Assertions
Authors: Daniel Boley, Gene H. Golub, Samy Makar, Nirmal Saxena, Edward J. McCluskey
Venue: IEEE Transactions on Computers (1995)

This paper introduces an assertion scheme based on the backward error analysis for error detection in algorithms that solve dense systems of linear equations, $A\mbi{x} = \mbi{b}$. Unlike previous methods, this Backward Error Assertion Model is specifically designed to operate in an environment of floating point arithmetic subject to round-off errors, and it can be easily instrumented in a Watchdog processor environment. The complexity of verifying assertions is $O(n^2)$, compared to the $O(n^3)$ complexity of algorithms solving $A\mbi{x} = \mbi{b}$. Unlike other proposed error detection methods, this assertion model does not require any encoding of the matrix $A$. Experimental results under various error models are presented to validate the effectiveness of this assertion scheme.