ppxscal/embedding_network huggingface dataset:
A lower bound for integer greatest common divisor computations
Authors: Yishay Mansour, Baruch Schieber, Prasoon Tiwari
Venue: Journal of the ACM (JACM) (1991)

It is proved that no finite computation tree with operations { +, -, *, /, mod, < } can decide whether the greatest common divisor (gcd) of a and b is one, for all pairs of integers a and b. This settles a problem posed by Gro&uml;tschel et al. Moreover, if the constants explicitly involved in any operation performed in the tree are restricted to be &ldquo;0&rdquo; and &ldquo;1&rdquo; (and any other constant must be computed), then we prove an &OHgr;(log log n) lower bound on the depth of any computation tree with operations { +, -, *, /, mod, < } that decides whether the gcd of a and b is one, for all pairs of n-bit integers a and b. A novel technique for handling the truncation operation is implicit in the proof of this lower bound. In a companion paper, other lower bounds for a large class of problems are proved using a similar technique.
SetLog, a tool for experimenting with new semantics
Authors: Marco Pellegrini, Raimondo Sepe
Venue: ACM SIGPLAN Notices (1991)

SetLog is a software system that can be used to experiment on several semantics for extensions of Prolog with sets. A first prototype of SetLog has been implemented including the features of a standard Prolog interpreter and of an interpreter for finite set expressions (SETL). Examples of uses of the system are also presented.
An integrated authoring system for diagnostic testing (abstract)
Authors: Thomas L. Hausmann, William Campbell
Venue: Proceedings of the 1990 ACM annual conference on Cooperation (1990)

The IASDT (Integrated Authoring System for Diagnostic Testing) is a flexible, extensible authoring system designed to support the Mathematics Diagnostic Extension Project (MDE). MDE is a test suite designed to assess students' weaknesses and strengths in precalculus level math skills and provide this information to academic advisors. The MDE is implemented as an instance of a testing &ldquo;shell&rdquo; called IASDT that facilitates the development of diagnostic tests, tutorials, and drill and practice suites. The IASD was initially developed in 1985 to deliver a diagnostic mathematics examination at the University of Minnesota, Morris under the direction of Dr. Campbell director of the UMM Academic Assistance Center (AAC). Before IASDT the examination was administered by a student tutor of the AAC presenting questions one at a time from a stack of index cards to the person taking the test. The IASDT was developed in order to overcome the drawbacks of an examination being delivered on index cards. The IASDT is an integrated environment specifically designed to support delivery of diagnostic examinations. The IASDT differs from other authoring systems in that the examiner may design exams that branch in several directions based upon the students performance on a given set of questions. Sets of questions are bundled into modules that correspond to nodes in a digraph. The MDE has been used successfully at UMM since Fall 1985 to guide students into appropriate developmental courses. This paper describes both the historical development of the MDE (including the supporting IASDT) and how is has been used at UMM for the past four years.
Performance evaluation of programs related to the real gamma function
Authors: W. J. Cody
Venue: ACM Transactions on Mathematical Software (TOMS) (1991)

Methods are presented for evaluating the performance of programs for the functions &Ggr;(x), ln &Ggr;(x), and &psgr;(x). Accuracy estimates are based on comparisons using the manipulation theorem. Ideas for checking robustness are also given, and details on specific implementations of test programs are included.
An interactive data analysis system developed under APL
Authors: Peter I. Day
Venue: Proceedings of the international conference on APL '91 (1991)

Unocal Science amp; Technology Division has used STSC APL*PLUS to build a software package --- PC-LogIC --- for analyzing data from oil-wells. Such data is routinely gathered from a variety of electrical, mechanical, and nuclear sensors lowered into the well-bore and, for our purposes, can be regarded as coincident depth-series vectors. PC-LogIC was designed to allow the data analyst to perform two key tasks: rapid "visualizing" of the data; and selecting algorithms and parameters for interpreting the data.APL has been used to fulfill two different needs. At a fundamental level, there is one set of algorithms that actually performs the data analysis. At a higher level, not necessarily tied to the type of data being analyzed, is a second set of functions that provides an interactive interface between the user, the data and the interpretation algorithms. This interface is provided through menus that operate in both text and graphics mode, through text-entry panels, and through an extensive series of graphical routines. In text mode operation, considerable use has been made of squ;WIN and related functions under keyboard control, whereas in graphics mode squ;G-style graphics have been used, with mouse control provided through squ;INT 51. A demonstration of PC-LogIC, concentrating on the higher-level interface, will be given on a 386/AT-compatible machine.
MTR: a modified token ring protocol and its performance
Authors: M. S. Obaidat, M. A. Al-Rousan
Venue: Proceedings of the 1992 ACM annual conference on Communications (1992)

Devising efficient and high performance communication protocols for Computer networks is a challenging issue. This paper presents a new Modified Token Ring protocol (MTR) for token ring LANs. The idea behind proposing this protocol is to improve the performance of the Standard (Traditional) Token Ring protocol (STR). The advantage of the MTR protocol over the STR protocol is its capability of bypassing idle stations in the ring. This is achieved by utilizing two of the reserved bits in the Frame Status (FS) field. The utilized bits are called Transmission Reservation bits (TR-bits). The TR-bits operate as an implicit token while they are circulating around the ring with their associated packet. Our simulation experiments show that the MTR protocol has higher ring throughput and lower packet delay than that of the STR protocol. For high traffic conditions the MTR protocol has shortened the packet delay down to 45% as compared to the STR protocol. Throughput improvement provided by the MTR can reach about 6% as compared to the STR protocol. The MTR protocol is characterized by its fairness, simplicity and cost-effectiveness.
A Retrospective on the VAX VMM Security Kernel
Authors: Paul A. Karger, Mary Ellen Zurko, Douglas W. Bonin, Andrew H. Mason, Clifford E. Kahn
Venue: IEEE Transactions on Software Engineering (1991)

The development of a virtual-machine monitor (VMM) security kernel for the VAX architecture is described. The focus is on how the system's hardware, microcode, and software are aimed at meeting A1-level security requirements while maintaining the standard interfaces and applications of the VMS and ULTRIX-32 operating systems. The VAX security kernel supports multiple concurrent virtual machines on a single VAX system, providing isolation and controlled sharing of sensitive data. Rigorous engineering standards were applied during development to comply with the assurance requirements for verification and configuration management. The VAX security kernel has been developed with a heavy emphasis on performance and system management tools. The kernel performs sufficiently well that much of its development was carried out in virtual machines running on the kernel itself, rather than in a conventional time-sharing system.
The revised Ga&uml;rdenfors postulates and update semantics (extended abstract)
Authors: Leigh Willard, Li Yan Yuan
Venue: Proceedings of the third international conference on database theory on Database theory (1990)

The G&auml;rdenfors postulates can serve as a foundation for the semantics of updates on knowledge sets. It is shown that knowledge sets and G&auml;rdenfors' postulates are not adequate in the deductive database setting. Therefore, partially closed theories are defined for deductive database updates and the G&auml;rdenfors postulates are revised accordingly. By recognizing epistemic importance among clauses in the database, a new deductive database update semantics in the context of partially closed theories is also proposed. The new semantics satisfy the revised G&auml;rdenfors postulates.
Portability in the Janus Natural Language Interface
Authors: Ralph M. Weischedel, Robert J. Bobrow, Damaris Ayuso, Lance Ramshaw
Venue: Proceedings of the workshop on Speech and Natural Language (1989)

Although natural language technology has achieved a high degree of domain independence through separating domain-independent modules from domain-dependent knowledge bases, portability, as measured by effort to move from one application to another, is still a problem. Here we describe a knowledge acquisition tool (KNACQ) that has sharply decreased our effort in building knowledge bases. The knowledge bases acquired with KNACQ are used by both the understanding components and the generation components of Janus.
A survey of algorithms for volume visualization
Authors: T. Todd Elvins
Venue: ACM SIGGRAPH Computer Graphics (1992)

Many computer graphics programmers are working in the area of scientific visualization. One of the most interesting and fast-growing areas in scientific visualization is volume visualization. Volume visualization systems are used to create high-quality images from scalar and vector datasets defined on multidimensional grids, usually for the purpose of gaining insight into a scientific problem. Most volume visualization techniques are based on one of about five foundation algorithms. These algorithms, and the background necessary to understand them, are described here. Pointers to more detailed descriptions, further reading, and advanced techniques are also given.
Running algorithms efficiently on faulty hypercubes (extended abstract)
Authors: Jehoshua Bruck, Robert Cypher, Danny Soroker
Venue: ACM SIGARCH Computer Architecture News (1991)

We examine the issue of running algorithms with a constant factor slowdown on a faulty hypercube in a worst case scenario. We present two sets of novel results related to this issue. We first consider edge faults and show how to tolerate faults with a constant factor slow-down in communication and no slowdown in computation. The key to our approach is an efficient method for embedding a fault free Cube Connected Cycles (CCC) graph in the faulty hypercube. Using this embedding we can run ascend-descend algorithms (such as bitonic sort) on the faulty hypercube by implementing them on the embedded CCC. We then consider hypercubes with both edge and node faults. We prove that for any constant c there exists a fault-free subgraph of an n-dimensional hypercube with nc faulty components that can implement a large class of hypercube algorithms with only a constant factor slowdown. To the best of our knowledge, this result is the first in which a hypercube can tolerate more than O(n) faults in the worst case sense.
Effect of Fault Tolerance on Response Time-Analysis of the Primary Site Approach
Authors: Yennun Huang, Pankaj Jalote
Venue: IEEE Transactions on Computers (1992)

The effect of the primary site approach for fault tolerance on the response time is studied. In the primary site approach, the service to be made fault tolerant is replicated at many nodes, one of which is designated as primary and the others as backups. All the requests for operations on the data object are sent to the primary site. The primary fails, one of the backups takes over as primary. The primary site periodically checkpoints its state on the backups. An analytical model for studying the average response time of the primary site system and analyzing the effects of the checkpointing frequency and the degree of replication on the response time is presented. This model is used to compare the response time of the system to that of a system without any fault tolerance.
GEdit: a test bed for editing by contiguous gestures
Authors: Gordon Kurtenbach, Bill Buxton
Venue: ACM SIGCHI Bulletin (1991)

GEdit is a prototype graphical editor that permits you to create and manipulate three simple types of objects using shorthand and proof-reader's type gestures. The three types of objects that can be manipulated are: squares, circles and triangles. Using hand-drawn symbols, the user can add, delete, move-and copy these objects. Objects can be manipulated individually or in groups. Groups are specified with hand-drawn circling symbols.
Computing similarity in a reuse library system: an AI-based approach
Authors: Eduardo Ostertag, James Hendler, Rubén Prieto Díaz, Christine Braun
Venue: ACM Transactions on Software Engineering and Methodology (TOSEM) (1992)

This paper presents an AI based library system for software reuse, called AIRS, that allows a developer to browse a software library in search of components that best meet some stated requirement. A component is described by a set of (feature, term) pairs. A feature represents a classification criterion, and is defined by a set of related terms. The system allows to represent packages (logical units that group a set of components) which are also described in terms of features. Candidate reuse components and packages are selected from the library based on the degree of similarity between their descriptions and a given target description. Similarity is quantified by a nonnegative magnitude (distance) proportional to the effort required to obtain the target given a candidate. Distances are computed by comparator functions based on the subsumption, closeness, and package relations. We present a formalization of the concepts on which the AIRS system is based. The functionality of a prototype implementation of the AIRS system is illustrated by application to two different software libraries: a set of Ada packages for data structure manipulation, and a set of C components for use in Command, Control, and Information Systems. Finally, we discuss some of the ideas we are currently exploring to automate the construction of AIRS classification libraries.
Ada, an analyst and a metaphysician
Authors: Betty Alexandra Toole
Venue: ACM SIGAda Ada Letters (1991)

Is Ada a fitting name for the software language named after her?Today, words, symbols and language are so manipulated that what Darell Huff proclaimed for numbers, "Statistics Don't Lie, But Liars use Statistics", certainly applies to words. Mario Pei, in Words in Sheep's Clothing, states that words have come to mean either the opposite of what they originally meant, or something so remote and confusing that one hesitates to use them.This article will give you a glimmer of the fascinating human story of Ada. Hopefully that glimmer, or biopsy, will not distort but enrich the information available about her life. Human beings are inconsistent, that is both their weakness and their strength. To fashion data about a human being into a consistency, in order to prove a point often makes me suspicious. However, the more I know about Ada, the software language, the more appropriate. I believe the name Ada is for the software language. You, as users of Ada, are a better judge of that and I would certainly appreciate your reaction and observations.The information that I have selected for this article are from the thousands of letters in the Lovelace-Byron Collection at Oxford University, the British Library, and Ada's Notes. The emphasis is on how Ada approached information, mathematics, science and technology. Perhaps, this glimpse of Ada's life and the way she thought, might prompt you to see a connection between Ada's story and the history, structure and implementation of Ada, the software language.
Men supporting women computer science students
Authors: J. Paul Myers,  Jr.
Venue: ACM SIGCSE Bulletin (1992)

It has become clear that, for a variety of reasons, women CS enrollments are declining at a disproportionate rate and that the number of women &ldquo;in the pipeline&rdquo; is insufficient to mentor and otherwise support the development of CS interests among current young women in the field. Recommendations have been made for male assistance in this mentoring effort; and some ideas toward this end are presented here. Regrettably, in this context, it is necessary to head off charges of &ldquo;patronizing&rdquo; our women students lest the ideas be disregarded or trivialized.
Software metrics, measurement theory, and viewpoints
Authors: Erhard Konrad
Venue: ACM SIGPLAN Notices (1991)

This paper presents a critical discussion of a new approach to software quality assurance. Zuse and Bollmann, the protagonists of this approach, claim that they can offer a methodology for properly selecting and applying software metrics. Their approach incorporates ideas borrowed from measurement theory and information retrieval. In this paper, it is shown that Zuse and Bollmann go astray even under their own premises.
Analysis of parallel replicated simulations under a completion time constraint
Authors: Peter W. Glynn, Philip Heidelberger
Venue: ACM Transactions on Modeling and Computer Simulation (TOMACS) (1991)

We analyze properties associated with a simple yet effective way to exploit parallel processors in discrete event simulations: averaging the results of multiple, independent replications that are run, in parallel, on multiple processors. We focus on estimating expectations from terminating simulations, or steady state parameters from regenerative simulations. We assume that there is a CPU time constraint, t, on each of P processors. Unless the replication lengths are bounded, one must be willing to simulate beyond any fixed, finite time t on at least some processors in order to always obtain a strongly consistent estimator (as the number of processors increases). We therefore consider simulation experiments in which t is viewed as either being a strict constraint, or a guideline, in which case simulation beyond time t is permitted. The statistical properties, including strong laws, central limit theorems, bias expansions, and completion time distributions of a variety of estimators obtainable from such an experiment are derived. We propose an unbiased estimator for a simple mean value. This estimator requires preselecting a fraction of the processors. Simulation beyond time t may be required on a preselected processor, but only if no replications have yet been completed on that processor. being a strict constraint, or a guideline, in which case simulation beyond time t is permitted. The statistical properties, including strong laws, central limit theorems, bias expansions, and completion time distributions of a variety of estimators obtainable from such an experiment are derived. We propose an unbiased estimator for a simple mean value. This estimator requires preselecting a fraction of the processors. Simulation beyond time t may be required on a preselected processor, but only if no replications have yet been completed on that processor.
Two years of experience with a &mgr;-Kernel based OS
Authors: Jochen Liedtke, Ulrich Bartling, Uwe Beyer, Dietmar Heinrichs, Rudolf Ruland, Gyula Szalay
Venue: ACM SIGOPS Operating Systems Review (1991)

This paper describes the basic components of the L3 operating system and the experiences of the first two years using it. The system results from scientific research, but is addressed to commercial application. It is based on a small kernel handling tasks, threads and dataspaces. User level device drivers and file systems are described as examples of flexible OS services realized outside the kernel.
A linear array of processors with partially shared memory for parallel solution of PDE
Authors: Yoshikuni Okawa, Naoki Haraguchi
Venue: Proceedings of the 1990 ACM/IEEE conference on Supercomputing (1990)

We propose a multiprocessor architecture with partially shared memory blocks, which is, we think, best suited for the successive approximation of scientific computing problems, such as matrix operations, partial differential equations etc. The topology is a ring. But the system configuration is a subset of an orthogonal multiprocessor Scherson and Hwang have already proposed. We actually built an experimental system, on which we solved a heat conduction problem. The computing time is about 600 seconds in the case of 256x256 grid points. We conclude that the proposed system is a medium scale specific computer for simulations of physical systems, which is suitable for the coming era of personal and distributed computing.
Software Requirements Analysis for Real-Time Process-Control Systems
Authors: Matthew S. Jaffe, Nancy G. Leveson, Mats P. E. Heimdahl, Bonnie E. Melhart
Venue: IEEE Transactions on Software Engineering (1991)

A set of criteria is defined to help find errors in, software requirements specifications. Only analysis criteria that examine the behavioral description of the computer are considered. The behavior of the software is described in terms of observable phenomena external to the software. Particular attention is focused on the properties of robustness and lack of ambiguity. The criteria are defined using an abstract state-machine model for generality. Using these criteria, analysis procedures can be defined for particular state-machine modeling languages to provide semantic analysis of real-time process-control software requirements.
Understanding Object Configurations using Range Images
Authors: Prasanna G. Mulgaonkar, Cregg K. Cowan, Jeff DeCurtins
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1992)

The authors describe techniques that generate multiple interpretations from dense range images of piles of unknown objects and methods that use physical law, such as object stability, to rank the interpretations. Each of the interpretations completely accounts for the observed range data, but the interpretations differ in the ways visible portions of objects are extended into the occluded portions of the scene. Experiments with 100 range images indicate that the techniques are fairly robust when the scenes consist of shapes that are approximately prismatic or cylindrical. These techniques are based on novel approaches in several key areas, including explicit use of sensor geometry, generic shape models to synthesize scene descriptions, spatial-reasoning techniques that incorporate knowledge about the laws of physics, direct estimation of the physical properties of the objects in the scene, and detection and refinement of descriptions of approximately planar or cylindrical surfaces.
An Artificial Intelligence theory of computer competency
Authors: Christian Wagner, John Vinsonhaler
Venue: ACM SIGCSE Bulletin (1991)

This article reports the development of an Intelligent Tutorial System (ITS) that represents procedural knowledge using a "mental context" that permits generalization. The system behaves much like an advisor, competent in the use of personal computers, who is helping another person perform a word processing task. The nature of the system is discussed and illustrated. Implications are drawn for the definition and measurement of what the authors term "computer competence."
Operations on sets in an OODB
Authors: Jorn Andersen, Trygve Reenskaug
Venue: ACM SIGPLAN OOPS Messenger (1993)

In this article, we express some ideas on how to select an arbitrary set of objects, or to combine objects and information in the objects, in an arbitrary way. In the following will an object-oriented database be thought of as a collection of sets. The sets are collections of objects which all share a common message protocol. Operations originating from relational algebra are defined on these sets. To make the retrieval of objects efficient, a storage strategy for objects is developed. Combination of objects and changes in the objects' message protocol as a result of retrieval request, are solved by a filtering mechanism.