ppxscal/embedding_network huggingface dataset:
Properties of Z specifications
Authors: J. C. P. Woodcock
Venue: ACM SIGSOFT Software Engineering Notes (1989)

In this paper we show how to calculate properties of specifications written in the Z notation. In particular, we show how the precondition of an operation may be derived using rewrite rules and an application-oriented theory. As an example, we take part of the specification of an industrial-sized problem. If proofs are conducted at the level of the schema, then the structure of the proof follows the structure of the specification, and the technique scales up for verification in the large.
Timestamp-Based Orphan Elimination
Authors: M. Herlihy, M. S. McKendry
Venue: IEEE Transactions on Software Engineering (1989)

An orphan in a distributed transaction system is an activity executing on behalf of an aborted transaction. A method is proposed for managing orphans created by crashes and by aborts that ensures that orphans are detected and eliminated in a timely manner, and also prevents them from observing inconsistent states. The method uses timestamps generated at each site. Transactions are assigned timeouts at different sites. These timeouts are related by a global invariant, and they may be adjusted by simple two-phase protocols. The principal advantage of this method is simplicity: it is easy to understand, and to implement, and it can be proved correct. An 'eager' version of this method uses approximately synchronized real-time clocks to ensure that orphans are eliminated within a fixed duration, and a 'lazy' version uses logical clocks to ensure that orphans are eventually eliminated as information propagates through the system. The method is fail-safe: unsynchronized clocks and lost messages may affect performance, but they cannot produce inconsistencies or protect orphans from eventual elimination. Although the method is informally described in terms of two-phase locking, the formal argument shows it is applicable to any concurrency control method that preserved atomicity.
An algorithm for generating interpolatory quadrature rules of the highest degree of precision with preassigned nodes for general weight functions
Authors: T. N. L. Patterson
Venue: ACM Transactions on Mathematical Software (TOMS) (1989)

The construction of an algorithm is described for generating interpolatory quadrature rules of the highest degree of precision with arbitrarily preassigned nodes for general constant signed weight functions. It is of very wide application in that to operate, only the definition of the 3-term recurrence relation for the orthogonal polynomials associated with the weight function need be supplied. The algorithm can be used to produce specific individual quadrature rules or sequences of rules by iterative application.
Guided tours and tabletops: tools for communicating in a hypertext environment
Authors: Randall H. Trigg
Venue: ACM Transactions on Information Systems (TOIS) (1988)

The author of a complex hypertext document is often faced with the problem of conveying the document's meaning to future readers through a shared computer environment. Two tools implemented in the NoteCards hypertext environment, guided tours and tabletops, allow authors to employ annotation, graphic layout, and ordered presentation when communicating to readers. This paper describes these tools and gives examples of their use. Issues of remote pointing arising from an application in legal argumentation are discussed as well as early work on the use of these tools to support sharing of hypertext strategies among NoteCards users.
Proceedings of the 17th conference on ACM Annual Computer Science Conference
Venue: ACM Annual Computer Science Conference (1989)

The 1989 ACM Seventeenth Annual Computer Science Conference provides an excellent environment for interactions between academic, corporate, and government computer and information science researchers, educators, administrators, and students to broaden the scope of their professional interest. The conference emphasizes current research issues through its keynote and invited speakers, tutorials, panels, refereed papers and abstracts. This proceedings serves as a record of the refereed papers and research abstracts. It can in no way capture the important interactions in panel sessions, the reports of funding agencies, the tutorials, and the other special events. Activities such as the Turing Lecture, ACM Scholastic Programming Contest, and the Department Chair's program all add to the exciting professional environment. A special event this year is the computing history exhibit which blends the old and the new by presenting a UNIVAC I and advanced graphics stations in the same exhibit. The focus of the conference is "Preparing for Computing in the 1990's", with specific theme days on Knowledge Based Systems, Parallel Computing, and Looking to the Fifth Generation. Papers on these and related topics were intensely refereed and approximately thirty-three percent were accepted and are presented in this volume. Abstracts of current research are also presented in this proceedings.
Natural language understanding and speech recognition
Authors: George M. White
Venue: Communications of the ACM (1990)

Natural language understanding must be an integral part of any automatic speech recognition system that attempts to deal with interactive problem solving. The methods for representing and integrating knowledge from different sources may be valuable for the understanding process as well as speech recognition.
Logo as a prelude to LISP: some surprising results
Authors: K. Louden
Venue: ACM SIGCSE Bulletin (1989)

Recently San Jose State University introduced a LOGO-based, rather than a Pascal-based, first course in computer science. This paper reports on an attempt to trace statistically the effect of that curricular change on student performance in a subsequent Lisp course. Student final grades, however, showed no improvement in performance as a result of their prior exposure to functional programming with LOGO.
Computations of soil temperature rise due to HVDC ground return
Authors: H. Greiss, D. Mukhedkar, P. J. Lagace
Venue: Proceedings of the 1989 ACM/IEEE conference on Supercomputing (1989)

The purpose of this paper is to present an application which historically, did not make use of computing methodology in the solution of design problems. The design of High Voltage Direct Current (HVDC) ground electrodes involves the careful selection of several parameters in order to meet strict operating constraints. In particular, the operation of HVDC ground electrodes, results in a rise of the surrounding soil temperature which must be reasonably computed so as to permit safe operation of the grounding network. The classical approach to this design issue was to make several simplifying assumptions and thereby obtain a closed form solution which approximated the situation. Unfortunately, this technique is extremely limited in its scope and the accuracy of solution is dependent on the simplifications made in order to obtain a solution. The technique presented in this paper uses a numerical model to represent the system to be studied. This approach provides extreme flexibility, thus a minimal of assumptions are needed in order to accurately obtain realistic solutions to the problem. The complexity of the numerical model however, requires substantial computing capabilities. Symbols g = heat generated, W/m3 p = soil electrical resistivity, &OHgr; - m J = current density, A/m2 T = temperature of the medium, &deg;C k = thermal conductivity, W/&deg;Cm &agr; = thermal diffusitivity, m2/s Cp = specific heat, J/kg&deg;C d = mass density, kg/m3 V = electrical potential, V &lgr; = over relaxation factor
Computing as a discipline
Authors: D. E. Comer, David Gries, Michael C. Mulder, Allen Tucker, A. Joe Turner, Paul R. Young
Venue: Communications of the ACM (1989)

The final report of the Task Force on the Core of Computer Science presents a new intellectual framework for the discipline of computing and a new basis for computing curricula. This report has been endorsed and approved for release by the ACM Education Board.
A fast, reliable algorithm for calculating Pade&acute;-Hermite forms
Authors: S. Cabay, G. Labahn
Venue: Proceedings of the ACM-SIGSAM 1989 international symposium on Symbolic and algebraic computation (1989)

We present a new fast algorithm for the calculation of a Pad&eacute;-Hermite form for a vector of power series. When the vector of power series is normal, the algorithm is shown to calculate a Pad&eacute;-Hermite form of type (n0, &middot;&middot;&middot; , nk) in O(k&middot;(n02 + &middot;&middot;&middot; + nk2)) operations. This complexity is the same as that of other fast algorithms for computing Pad&eacute;-Hermite approximants. However, unlike other algorithms, the new algorithm also succeeds in the non-normal case, usually with only a moderate increase in cost.
Reasoning in time and space: issues in interfacing a graphic computer simulation with an expert system for an intelligent simulation training system
Authors: L. D. Interrante, J. E. Biegel
Venue: Proceedings of the 21st conference on Winter simulation (1989)

Computer simulation and expert systems technologies have the same goal: the study of intractable, complex systems for which standard algorithmic methods of study are inadequate. An expert system can be interfaced with a graphic computer simulation to reason about physical systems. Such an expert system needs the ability to reason qualitatively about simulation objects. This reasoning includes temporal, spatial, and causal (cause and effect) reasoning. This paper describes an expert-system/graphic-computer-simulation interface for an Intelligent Simulation Training System (ISTS) which is currently under development. Important design considerations include the reasoning tasks involved, mechanisms for reasoning about physical systems, and machine perception of simulation data for use by the expert system. It is necessary to carefully design the interface between a graphic computer simulation and an expert system in order to realize automated, intelligent training related to physical systems.
A Reconfigurable Tree Architecture with Multistage Interconnection Network
Authors: Nripendra N. Biswas, S. Srinivas
Venue: IEEE Transactions on Computers (1990)

A novel approach to the design of a reconfigurable tree architecture is presented. The architecture is implemented with an augmented shuffle-exchange multistage interconnection network and is capable of assuming N distinct binary tree configurations, where N is the number of processing elements (PEs) in the system. The novel features of the architecture include fast switching from one configuration to another, simplified hardware in the PEs and the switching network, and simple routing control.
Performance of REAL/IXTM-fully preemptive real time UNIX
Authors: Borko Furht, J. Parker, D. Grostick
Venue: ACM SIGOPS Operating Systems Review (1989)

The UNIX reg; operating system, developed by AT amp;T Bell Laboratories, has become a standard operating system gaining rapid acceptance because of its superior flexibility, portability, and a number of support tools to increase programmer productivity. However, UNIX was originally designed for multitasking and time-sharing, and therefore conventional UNIX does not have an adequate response time and data throughput needed to support real-time applications.Many attempts have been made to adapt the UNIX kernel to provide a real-time environment. MODCOMP has developed REAL/IX operating system, which is a fully preemptive, low latency UNIX kernel. This paper discusses real-time performance of REAL/IX and compares it to MASSCOMP RTU operating system.
Radial Projection: An Efficient Update Rule for Relaxation Labeling
Authors: P. Parent, S. W. Zucker
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1989)

Relaxation labeling uses contextual information for finding consistent labelings of graphs. Although relaxation labeling is parallel and iterative, the complexity of updating with standard rules is too costly for practical implementation. A description is given of a computationally more efficient updating rule that utilizes radial projection instead of normal projection to avoid the complexities incurred by previous update rules when boundaries to the labeling space are encountered. This reduction in complexity is achieved by first restricting support vectors to the positive quadrant, and then using radial projection onto the constraint instead of normal projection. Crucial order information is conserved through smooth convergence towards the optimum and a rate of convergence proportional to the magnitudes of the support functions.
A Preemptive Scheduling Mechanism for Accurate Behavioral Simulation of Digital Designs
Authors: S. Ghosh, M.-L. Yu
Venue: IEEE Transactions on Computers (1989)

The authors examine the limitations of the timing semantics in the conventional behavioral simulators and present a preemptive scheduling mechanism for accurate behavioral simulation results. They consider two signal transitions at the input ports of a component, where the second input transition arrives later than the first transition. The first and second input transitions cause first output signal transitions O/sub 1/ and O/sub 2/, respectively, to be generated at the output port of the component. When the logical values of O/sub 1/ and O/sub 2/ conflict with each other and O/sub 1/ arrives later than O/sub 2/, O/sub 1/ is preempted by O/sub 2/. In addition, an input signal to a component whose pulse duration is smaller than the inertial delay of the component, T/sub mip/, is discarded during simulation. Empirical measures for T/sub mip/ relative to the high-to-low and low-to-high propagation delays of the component for TL (transistor-transistor logic), NMOS, and CMOS technologies are presented. This approach has been implemented in the ADLIB-SABLE simulator at Stanford University.
Ada implementation of an X Window System server
Authors: S. Lewin
Venue: Proceedings of the conference on Tri-Ada '89: Ada technology in context: application, development, and deployment (1989)

Sanders is in the second year of a two year project to implement an X Window System server using the Ada programming language. X is a highly portable, network transparent display management system which was developed at MIT's Project Athena and has emerged as the industry standard for windowing systems. Our objectives are to implement a production-quality base windowing system suitable for use in Ada-based real-time systems, and to examine Ada's applicability as an implementation language for graphics software. We are currently running a partially implemented server which dispatches incoming protocol requests, performs basic windowing operations and executes basic graphics functions. This paper explains why we chose to do an Ada implementation, describes our implementation approach and server design and relates several lessons learned about using Ada in such an application.
Inline function expansion for compiling C programs
Authors: P. P. Chang, W.-W. Hwu
Venue: Proceedings of the ACM SIGPLAN 1989 Conference on Programming language design and implementation (1989)

Inline function expansion replaces a function call with the function body. With automatic inline function expansion, programs can be constructed with many small functions to handle complexity and then rely on the compilation to eliminate most of the function calls. Therefore, inline expansion serves a tool for satisfying two conflicting goals: minizing the complexity of the program development and minimizing the function call overhead of program execution. A simple inline expansion procedure is presented which uses profile information to address three critical issues: code expansion, stack expansion, and unavailable function bodies. Experiments show that a large percentage of function calls/returns (about 59%) can be eliminated with a modest code expansion cost (about 17%) for twelve UNIX* programs.
A Framework for the Automated Drawing of Data Structure Diagrams
Authors: Chen Ding, Prabhaker Mateti
Venue: IEEE Transactions on Software Engineering (1990)

Data structure diagrams are two-dimensional figures made up of lines that aim to pictorially indicate the interrelationships of the elements of a data structure. The various rules and factors of aesthetics that go into the way data structure diagrams are drawn are collected together. The various subjective factors are formulated into computable objectives and numeric parameters. These are distilled from a large number of data structure drawings found in various textbooks. The rules used have not reached a level of acceptance comparable to that of the relevant rules in engineering graphics. The internal architecture of a (sub)system that helps draw data structure diagrams is outlined.
Failure Dependent Performance Analysis of a Fault-Tolerant Multistage Interconnection Network
Authors: V. P. Kumar, A. L. Reibman
Venue: IEEE Transactions on Computers (1989)

To provide fault tolerance and improve system reliability and performance, a class of fault-tolerant multistage interconnection networks, called augmented shuffle-exchange networks (ASENs) has been proposed. ASENs are gracefully degradable; although an individual component failure reduces ASEN performance, it does not cause a total network failure. The purpose of this work is to analyze how these component failures affect ASEN performance. A key step in performance and reliability modeling is the choice of an appropriate metric for analysis. Because network bandwidth can be an inadequate performance measure when fault are present. The authors consider other network performance measures, including the interreference time distribution for individual outputs (memories).
A generalization of reduction rings
Authors: Sabine Stifter
Venue: Journal of Symbolic Computation (1987)

In 1983 B. Buchberger introduced the notion of a reduction ring. Roughly, reduction rings are rings in which the Grobner bases approach is possible. Reduction rings are characterized by axioms that relate the arithmetical operations in the ring with an ordering. In this paper we generalize this notion of a reduction ring by giving weaker axioms that characterize a wider class of rings. We also prove that the ring of integers modulo z, z an arbitrary not necessarily prime integer, is a reduction ring in this generalized sense.
Automated Test Case Generation for Programs Specified by Relational Algebra Queries
Authors: W. T. Tsai, Dmitry Volovik, Thomas F. Keefe
Venue: IEEE Transactions on Software Engineering (1990)

Black-box software testing requires test cases to be generated from specifications alone. However, it is impossible to automate the process completely for arbitrary specifications. Specifications are thus restricted to being written entirely in terms of relational algebra expressions. An automated test case generation method is developed for such specifications.
Articulating the experience of transparency: an example of field research techniques
Authors: Karen A. Holtzblatt, Sandy Jones, Michael Good
Venue: ACM SIGCHI Bulletin (1988)

Over the past two years, our field research with users has indicated that elements of an application design can disrupt users' work. Understanding how applications disrupt users' work has helped us to articulate the meaning of interface transparency. Interface transparency and related concepts have previously been explored from theoretical perspectives, but have not been grounded in user data.
Range Image Acquisition with a Single Binary-Encoded Light Pattern
Authors: P. Vuylsteke, A. Oosterlinck
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1990)

The problem of strike identification in range image acquisition systems based on triangulation with periodically structured illumination is discussed. A coding scheme is presented based on a single fixed binary encoded illumination pattern, which contains all the information required to identify the individual strikes visible in the camera image. Every sample point indicated by the light pattern is made identifiable by means of a binary signature, which is locally shared among its closest neighbors. The applied code is derived from pseudonoise sequences, and it is optimized so that it can make the identification fault-tolerant to the largest extent. A prototype measurement system based on this coding principle is presented. Experimental results obtained with the measurement system are also presented.
A Dynamic Voting Scheme in Distributed Systems
Authors: Danco Davcev
Venue: IEEE Transactions on Software Engineering (1989)

A dynamic weighted voting scheme for consistency and recovery control of replicated files in distributed systems is presented. The purpose of a replicated file is to improve the availability of a logical file in the presence of site failures and network partitions. The accessible physical copies of a replicated file will be mutually consistent and behave as a single copy. The recovery scheme requires no manual intervention. The control scheme tolerates any number of site failures and network partitions as well as repairs. Correctness results are given.
Gentest: An Automatic Test-Generation System for Sequential Circuits
Authors: Wu-Tung Cheng, Tapan J. Chakraborty
Venue: Computer (1989)

A description is given of Gentest, with emphasis on STG2, a sequential test generator that uses the Back test-generation algorithm and the Split value model. The performance of STG2 on a Convex C-1 computer is compared with that of its predecessor, STG1 and STG1.5. Results are also presented for another set of experiments for Gentest on a Sun 3/60 workstation.
Determination of the Attitude of 3D Objects from a Single Perspective View
Authors: M. Dhome, M. Richetin, J.-T. Lapreste
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1989)

A method for finding analytical solutions to the problem of determining the attitude of a 3D object in space from a single perspective image is presented. Its principle is based on the interpretation of a triplet of any image lines as the perspective projection of a triplet of linear ridges of the object model, and on the search for the model attitude consistent with these projections. The geometrical transformations to be applied to the model to bring it into the corresponding location are obtained by the resolution of an eight-degree equation in the general case. Using simple logical rules, it is shown on examples related to polyhedra that this approach leads to results useful for both location and recognition of 3D objects because few admissible hypotheses are retained from the interpolation of the three line segments. Line matching by the prediction-verification procedure is thus less complex.
Exploiting concurrency in a DBMS implementation for production systems
Authors: L. Raschid, T. Sellis, C. C. Lin
Venue: Proceedings of the first international symposium on Databases in parallel and distributed systems (2000)

An important aspect of integration of AI and DBMS technology is identifying functional similarities in database processing and reasoning with rules. In this paper, we focus on applying concurrency techniques to rule-based production systems. We tailor DBMS concurrent execution to a production system environment and investigate the resulting concurrent execution strategies for productions. This research is in conjunction with a novel DBMS mechanism for testing if the left hand side conditions of productions are satisfied. This set-oriented mechanism uses a special data structure implemented using relational tables. To demonstrate the equivalence of a serial and a concurrent (interleaved) execution strategy, for a set of productions, we assume a locking scheme to enforce serializability and specify what locks must be obtained. We define a logical commit point for a production. After this point the execution of a production is independent of all other (executing) productions. We compare the number of possible serial and parallel execution schedules.