ppxscal/embedding_network huggingface dataset:
The syntax definition formalism SDF&mdash;reference manual&mdash;
Authors: J. Heering, P. R. H. Hendriks, P. Klint, J. Rekers
Venue: ACM SIGPLAN Notices (1989)

SDF is a formalism for the definition of syntax which is comparable to BNF in some respects, but has a wider scope in that it also covers the definition of lexical and abstract syntax. Its design and implementation are tailored towards the language designer who wants to develop new languages as well as implement existing ones in a highly interactive manner. It emphasizes compactness of syntax definitions by offering (a) a standard interface between lexical and context-free syntax; (b) a standard correspondence between context-free and abstract syntax; (c) powerful disambiguation and list constructs; and (d) an efficient incremental implementation which accepts arbitrary context-free syntax definitions. SDF can be combined with a variety of programming and specification languages. In this way these obtain fully general user-definable syntax.
Exploiting bit level concurrency in real-time geometric feature extractions
Authors: W. Liu, T.-F. Yeh, W. E. Batchelor, R. Cavin
Venue: ACM SIGARCH Computer Architecture News (1988)

Geometric feature extraction can be characterized as a computationally intensive task in the environment of real-time automated vision systems requiring algorithms with a high degree of parallelism and pipelining under the raster-scan I/O constraint. Using divide-and-conquer techniques, many feature extraction algorithms have been formulated as a pyramid and then as a binary tree structure. An efficient mapping from a tree structure into a pipelined array of 2logN, stages is presented for processing a NxN image. In the proposed mapping structure, the identification of the information growing property inherit in feature extraction algorithms allows us to exploit bit-level concurrency in the architectural design. Accordingly, the design of each staged pipelined processor is simplified. A single VLSI chip which can generate (p+1)(q+1) moments concurrently in real-time applications is reported. This chip posses a hardware complexity of &Ogr;(pq(p+q)log2N) where p, q stand for the orthogonal orders of the moment. This hardware complexity is an improvement over other reported methods &Ogr;(pq(p+q)2log2N).
Scaling up output capacity and performance results from information systems prototypes
Authors: J. C. Westland
Venue: ACM Transactions on Database Systems (TODS) (1990)

The advantage of information system prototyping arises from its predict problems and end-user satisfaction with a system early in the development process, before significant commitments of time and effort have been made. Predictions of problems and end-user satisfaction have risen in importance with the increasing complexity of business information systems and the exponential growth of database size. This research investigates the reporting of information to an end user, and the process of inferring from a prototype to a full-scale information system. This inference is called scaling up, and is an important part of the systems development planning process. The research investigates information systems reporting from a linguistic perspective, where a database is used as a central receptacle for information storage. It then investigates the manner in which reporting statistics from the prototype information system may be used to infer the behavior and performance of the full-scale system. An example is presented for the application of the algorithm, and the final section discusses the usefulness, application, and implications of the algorithm developed in this research.
An AI-based approach to machine translation in Indian languages
Authors: Subramanian Raman, Narayanan Alwar
Venue: Communications of the ACM (1990)

Primarily illustrated as an approach to translate the Indian languages, a focus on AI techniques for building semantic representational structures of sentences is presented.
A Mandarin Dictation Machine Based Upon a Hierarchical Recognition Approach and Chinese Natural Language Analysis
Authors: L.-S. Lee, C.-Y. Tseng, K. J. Chen, J. Huang, C.-H. Hwang, P.-Y. Ting, L.-J. Lin, C. C. Chen
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1990)

An experimental Mandarin dictation machine for inputting Mandarin speech (spoken Chinese language) into computers is described. Because of the special characteristics of the Chinese language, syllables are chosen as the basic units for dictation. The machine is designed based on a hierarchical language recognition approach in which acoustic signals are first recognized as a sequence of syllables, possible word hypotheses are then formed from the syllables, and the complete sentences are finally obtained. This approach is implemented by two subsystems. The first recognizes the syllables using speech signal processing techniques, the second subsystem then identifies the exact characters from the syllable and corrects the errors in syllable recognition. The detailed syllable recognition algorithms, word formation rules, parser, grammar, and the syntactic checking algorithms are described. With newspaper text in the form of isolated syllables as input, the preliminary test results indicate that such a dictation machine is not only practically attractive, but technically feasible.
A look back and a look forward
Authors: K. Sparck Jones
Venue: Proceedings of the 11th annual international ACM SIGIR conference on Research and development in information retrieval (1988)

This paper is in two parts, following the suggestion that I first comment on my own past experience in information retrieval, and then present my views on the present and future.
Fast Rounding in Multiprecision Floating-Slash Arithmetic
Authors: M. Scott
Venue: IEEE Transactions on Computers (1989)

A computational algorithm is described which quickly rounds large fractions into a fixed-length multiprecision floating-slash representation, using single-precision operations where possible. An easily calculated criterion for terminating the rounding process is given.
Boundary integral domain decomposition of hierarchical memory multiprocessors
Authors: E. Gallopoulos, D. Lee
Venue: Proceedings of the 2nd international conference on Supercomputing (1988)

A method, called Boundary Integral-based Domain Decomposition was recently proposed for the solution of Laplace's equation. The method is characterized by the complete decoupling of the problem domain into subdomains which is possible after integral equation based techniques are used for the calculation of the solution on the subdomain boundaries. We describe some theoretical and practical issues involved in the use of such methods on shared memory multiprocessors.
Astrophysical APL - diamonds in the sky
Authors: G. Schneider, P. Paluzzi, J. Webb
Venue: ACM SIGAPL APL Quote Quad (1989)

Computational astrophysics seeks to develop numerical models which help elucidate the nature of astronomical systems. Such models must not only adequately describe the underlying physics which give rise to phenomena that have been observed, but must also be predictive in asserting what future observations might unfold. Any model which is in conflict with physical observations, clearly, must be discarded or amended to reflect reality. As a computational modelling tool we find APL useful for testing astrophysical hypotheses, and extending the domain of our observationally based knowledge. Using APL to build, test, and expand astrophysical models frees the investigator from the mechanical drudgery of computer programming, thereby allowing the researcher to concentrate on understanding the physical universe.As a quantitative example of how relatively complex astrophysical phenomena can be explored with ease using APL, we have developed a structure model for white dwarf stars. The model presented here considers such effects as Coulomb interactions between electrons and nucleons, inverse beta decays, and the effects of the general theory of relativity on the condition of hydrostatic equilibrium. This structure model is valid for zero-temperature stars of varying chemical compositions, ionic partitions, and central densities; and is applicable over a wide range of partial and total degeneracy regimes.
The accumulation buffer: hardware support for high-quality rendering
Authors: Paul Haeberli, Kurt Akeley
Venue: Proceedings of the 17th annual conference on Computer graphics and interactive techniques (1990)

This paper describes a system architecture that supports realtime generation of complex images, efficient generation of extremely high-quality images, and a smooth trade-off between the two.Based on the paradigm of integration, the architecture extends a state-of-the-art rendering system with an additional high-precision image buffer. This additional buffer, called the Accumulation Buffer, is used to integrate images that are rendered into the framebuffer. While originally conceived as a solution to the problem of aliasing, the Accumulation Buffer provides a general solution to the problems of motion blur and depth-of-field as well.Because the architecture is a direct extension of current workstation rendering technology, we begin by discussing the performance and quality characteristics of that technology. The problem of spatial aliasing is then discussed, and the Accumulation Buffer is shown to be a desirable solution. Finally the generality of the Accumulation Buffer is explored, concentrating on its application to the problems of motion blur, depth-of-field, and soft shadows.
Improved user service - a 24 hour helpdesk
Authors: John Biddle, John Tyler
Venue: ACM SIGUCCS Newsletter (1988)

How do I do....? Where do I get....? What do I do....? These are some of the kinds of general questions that have flooded the Computer Center ever since it was first formed. While the nature of the questions has switched from cards to terminals and from batch to on-line, they still keep pouring in. These same questions are still being asked over and over again by both administrative and academic customers. In the past, the answer, right or wrong, depended as much upon the person providing the answer and how much they knew as it did on anything else. Also, customers may have been routed to several different individuals before their question was answered.
Designing a Process Migration Facility: The Charlotte Experience
Authors: Yeshayahu Artsy, Raphael Finkel
Venue: Computer (1989)

Experience with process migration in the Charlotte distributed operating system is discussed. Charlotte's migration facility is a fairly elaborate addition to the underlying kernel and utility-process base. It separates policy from mechanism. An overview is given of Charlotte, its process migration facility, and issues encountered that have a general application for any such facility. In the discussion of each issue, alternative design approaches adopted by other process migration facilities are presented. This account is intended to help researchers contemplating the addition of a process migration facility as well as those designing other operating system facilities that might need to interact later with added process migration facilities.
Neural network model of serial learning
Authors: H. A. Broadbent, J. Lucas
Venue: Conference proceedings on APL as a tool of thought (1989)

A brief introduction to neural networks is given, and correspondences between the elements of such networks and the primitive objects of APL are indicated. A neural network model is presented for simulating serial learning, the ability of an animal to respond in a prescribed sequence to an array of stimuli presented simultaneously. The particular network presented is intended to model stimulus-response (s-r) chaining, a behaviorist theory of serial learning. Some results obtained from running the network are discussed.
Hypertext and higher education: a reality check
Authors: S. C. Erhmann, S. Erde, K. Morrell, R. F. E. Weissman
Venue: Proceedings of the second annual ACM conference on Hypertext (1989)

This panel discussion will examine the extent to which today's hypermedia systems are actually used and usable in higher education instruction and research. The panel will seek to foster dialog between hypermedia systems developers, corpus authors, and faculty users. A series of questions will be addressed by the panel and audience, including: How are hypermedia corpuses actually used in classes? How well do today's systems meet the exploratory learning goals so often described as being at the heart of the hypermedia movement? What kinds of assignments make sense pedagogically? Are there system features which tend to discourage or prevent such uses? What are the difficulties involved in administering a course using hypertext? Are there unusual logistical problems? How does one monitor or manage the annotation and expansion of the corpus during the semester? Are today's hypermedia environments, tools, and practices proving to be useful for the faculty researcher? the student researcher? For faculty considering a hypertext to organize data, is periodic porting to new hardware and software a safe bet? or does the faculty member risk marooning two years of work inside an obsolete system? What are the prospects for published hypertext corpuses? What system features are likely to affect the economics of publication and distribution? What are the special problems in creating hypertext materials that can be used on other campuses and in other courses?
Efficient ray tracing of volume data
Authors: Marc Levoy
Venue: ACM Transactions on Graphics (TOG) (1990)

Volume rendering is a technique for visualizing sampled scalar or vector fields of three spatial dimensions without fitting geometric primitives to the data. A subset of these techniques generates images by computing 2-D projections of a colored semitransparent volume, where the color and opacity at each point are derived from the data using local operators. Since all voxels participate in the generation of each image, rendering time grows linearly with the size of the dataset. This paper presents a front-to-back image-order volume-rendering algorithm and discusses two techniques for improving its performance. The first technique employs a pyramid of binary volumes to encode spatial coherence present in the data, and the second technique uses an opacity threshold to adaptively terminate ray tracing. Although the actual time saved depends on the data, speedups of an order of magnitude have been observed for datasets of useful size and complexity. Examples from two applications are given: medical imaging and molecular graphics.
Metaclass compatibility
Authors: N. Graube
Venue: ACM SIGPLAN Notices (1989)

Metaclasses provide control of object description, method compilation and more generally class behaviour. Consequently, they have been widely used in languages such as Smalltalk-80 or more recently CLOS by both users and implementers. Due to their powerful control of instances, careless inheritance of classes with different metaclasses can lead to unsound or inefficient implementations of instance methods. Using examples, we will pin-point these problems. Then we will introduce compatibility rules which need to be fulfilled by metaclasses of inherited classes in order to allow reasonable instance method description.
On the application of syntactic methodologies in automatic text analysis
Authors: G. Salton, M. Smith
Venue: Proceedings of the 12th annual international ACM SIGIR conference on Research and development in information retrieval (1989)

This study summarizes various linguistic approaches proposed for document analysis in information retrieval environments. Included are standard syntactic methods to generate complex content identifiers, and the use of semantic know-how obtained from machine-readable dictionaries and from specially constructed knowledge bases. A particular syntactic analysis methodology is also outlined and its usefulness for the automatic construction of book indexes is examined.
CANDIDE: a learning system for process control
Authors: B. Burg, D. Luzeaux, B. Zavidovique
Venue: Proceedings of the 2nd international conference on Industrial and engineering applications of artificial intelligence and expert systems - Volume 1 (1989)

The aim of this paper is to present an application of artificial intelligence techniques to control. Their use at a high level, as supervisor tools is shortly described and we focuse the attention onto their use at low level, inside the control loops. We describe our approach using artificial intelligence machine learning to acquire knowledge concerning the controlled system, to modelise it and finally to control it. As an example, CANDIDE learns to drive a car. We explain all the learning steps and shows the obtained results.
Rule-based delegation for prototypes
Authors: J. Almarode
Venue: ACM SIGPLAN Notices (1989)

Arguments have been given recently for providing the functionality of prototypes in object-oriented languages. Prototypes allow more flexible sharing of code and data by delegating messages to parent objects without the rigid structure of a class hierarchy. Prototypes can implement classes, and delegation can be used to model both single and multiple inheritance. However, one drawback with delegation is the difficulty in enforcing the semantics that delegation is used to model. This paper proposes a novel mechanism to control the delegation of messages with rules. In this system, the delegation of messages is governed by a set of rules possessed by each object. Rules can be used to implement classical single inheritance and can implement various solutions to multiple inheritance. In addition, rules can be created dynamically to model application-specific semantics. This paper describes how rule-based delegation works and illustrates various rules for rule-based delegation that have been implemented.
The effects of bargaining orientation and communication medium on negotiations in the bilateral monopoly task: a comparison of decision room and computer conferencing communication media
Authors: J. Sheffield
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: Wings for the mind (1989)

Pairs of subjects with either a competitive or an integrative bargaining orientation completed the Bilateral Monopoly Task in one of four communication media (text- only, text-plus-visual-access, audio-only, and audio-plus-visual-access). As hypothesized, an integrative bargaining orientation and/or an audio mode of communication led to a higher joint outcome. In addition, visual access resulted in higher joint outcomes for subjects with integrative bargaining orientations, but lower joint outcomes for those with competitive orientations. The support for negotiation offered by decision room and computer conferencing technologies is compared based on the efficiency and richness of the communication media available in each.
Decentralizing university computer facilities: some UK experience
Authors: P. Brady, R. Startup
Venue: ACM SIGUCCS Newsletter (1989)

At this time there is a need for cost effective ways of extending access to computer facilities in higher education. This paper reports on an experiment whereby clusters of terminals were provided in differing kinds of student residences and is concerned with the educational and social implications of computer use in higher educational settings. This British study was funded by the "Computers in Teaching" initiative of the United Kingdom Computer Board and University Grants Committee. It was apparent that students were allowed greater flexibility in organizing their study schedules. There is evidence of more economical and more widespread use of computer facilities and a better working relationship between users and staff of the Computer Center. There was a rapid growth of electronic mail both to seek help and for administrative purposes. A majority of those coming to the university now have prior experience of computing and attitudes towards it are predominantly favorable. Against this background there is a tendency towards dispersed facilities, associated with changes in students' academic lives. The University of Wales project has attracted considerable interest within the UK higher education community and provides a model being adopted elsewhere.
APL in a development environment
Authors: L. O. Clayton
Venue: ACM SIGAPL APL Quote Quad (1987)

One environment in which APL has been strikingly successful is the APL system development group within I. P. Sharp Associates. The development of system programs requires a range of supporting applications for which APL is well suited. The usefulness of these APL applications can be directly related to certain properties derived from their APL implementation. These properties are discussed, and an application is explored to demonstrate how they make vital contributions to the development environment.
Object-oriented programming in scheme
Authors: Norman Adams, Jonathan Rees
Venue: Proceedings of the 1988 ACM conference on LISP and functional programming (1988)

We describe a small set of additions to Scheme to support object-oriented programming, including a form of multiple inheritance. The extensions proposed are in keeping with the spirit of the Scheme language and consequently differ from Lisp-based object systems such as Flavors and the Common Lisp Object System. Our extensions mesh neatly with the underlying Scheme system. We motivate our design with examples, and then describe implementation techniques that yields efficiency comparable to dynamic object-oriented language implementations considered to be high performance. The complete design has an almost-portable implementation, and the core of this design comprises the object system used in T, a dialect of Scheme. The applicative bias of our approach is unusual in object-oriented programming systems.
Process and workload migration for a parallel branch-and-bound algorithm on a hypercube multicomputer
Authors: K. Schwan, J. Gawkowski, B. Blake
Venue: Proceedings of the third conference on Hypercube concurrent computers and applications - Volume 2 (1989)

This paper describes the design and experimental evaluation of a novel parallel implementation of a branch-and-bound algorithm for solving the Traveling Salesperson Problem on a 32 node Intel hypercube. Issues studied experimentally are trade-offs in speed, memory, and communication costs as well as the effects of workload balancing and node utilization on speedup. Since the actual distribution of work among the parallel tasks of the TSP application cannot be predicted in advance, strategies and tradeoffs regarding the migration of processes from heavily loaded processors or the migration of work from heavily loaded processes can be studied. Toward this end, we have implemented operating system constructs for work and for process migration as extensions to the Intel iPSC hypercube's operating system. Furthermore, operating system support for the rapid sharing of intermediate values of the global objective function being optimized (i.e. 'tour' values in TSP) are provided.
Counting is easy
Authors: Joel I. Seiferas, Paul M. B. Vitányi
Venue: Journal of the ACM (JACM) (1988)

For any fixed k, a remarkably simple single-tape Turing machine can simulate k independent counters in real time.
FUTURES: a mechanism for concurrency among objects
Authors: A. Chatterjee
Venue: Proceedings of the 1989 ACM/IEEE conference on Supercomputing (1989)

A future provides the basic primitive through which a user in an object-oriented distributed system can achieve concurrency. It is based on the notion of being able to translate what appears to be a remote procedure call into a request for computation to be scheduled by the system. The mechanism required to make this translation is discussed. Refinements to the future mechanism allow futures to be passed as arguments to other procedure calls. This provides the user with the added flexibility of implementing synchronization schemes suited to specific needs. Further, it simplifies the process of migrating an object which has outstanding futures at the time of migration.