ppxscal/embedding_network huggingface dataset:
Light-water interaction using backward beam tracing
Authors: Mark Watt
Venue: Proceedings of the 17th annual conference on Computer graphics and interactive techniques (1990)

A new two pass approach is presented based on a variation of backward ray tracing backward beam tracing. Advantages include its capability of rendering complex, hitherto unattainable, specular to diffuse phenomenon and its easy insertion into standard renderers. The algorithm is applied to aspects of the interaction of light with water. Within this context a variety of first generation effects, including shadowing and light scattering, are both rendered and animated. Results taken from the treatment of caustics within classical optics are included as they provide valuable insights into the precise nature of specular to diffuse transfer.
Security-control methods for statistical databases: a comparative study
Authors: Nabil R. Adam, John C. Worthmann
Venue: ACM Computing Surveys (CSUR) (1989)

This paper considers the problem of providing security to statistical databases against disclosure of confidential information. Security-control methods suggested in the literature are classified into four general approaches: conceptual, query restriction, data perturbation, and output perturbation. Criteria for evaluating the performance of the various security-control methods are identified. Security-control methods that are based on each of the four approaches are discussed, together with their performance with respect to the identified evaluation criteria. A detailed comparative analysis of the most promising methods for protecting dynamic-online statistical databases is also presented. To date no single security-control method prevents both exact and partial disclosures. There are, however, a few perturbation-based methods that prevent exact disclosure and enable the database administrator to exercise "statistical disclosure control." Some of these methods, however introduce bias into query responses or suffer from the 0/1 query-set-size problem (i.e., partial disclosure is possible in case of null query set or a query set of size 1). We recommend directing future research efforts toward developing new methods that prevent exact disclosure and provide statistical-disclosure control, while at the same time do not suffer from the bias problem and the 0/1 query-set-size problem. Furthermore, efforts directed toward developing a bias-correction mechanism and solving the general problem of small query-set-size would help salvage a few of the current perturbation-based methods.
Recovery of algebraic numbers from their p-adic approximations
Authors: John Abbott
Venue: Proceedings of the ACM-SIGSAM 1989 international symposium on Symbolic and algebraic computation (1989)

We describe three ways to generalize Lenstra's algebraic integer recovery method. One direction adapts the algorithm so that rational numbers are automatically produced given only upper bounds on the sizes of the numerators and denominators. Another direction produces a variant which recovers algebraic numbers as elements of multiple generator algebraic number fields. The third direction explains how the method can work if a reducible minimal polynomial had been given for an algebraic generator. Any two or all three of the generalizations may be employed simultaneously.
Teaching database using a real DBMS: experience with INGRES
Authors: David F. Haas
Venue: ACM SIGCSE Bulletin (1988)

This paper discusses the advantages of using a large, relational database system in a database course and describes in detail a course that has been taught at UW Oshkosh using INGRES as a vehicle for instruction.
The design and implementation of a Karel compiler and interpreter
Authors: Rose Hoskins
Venue: ACM SIGAda Ada Letters (1988)

"The Design and Implementation of a Karel Compiler and Interpreter"This paper details the design and implementation of a system which compiles and interprets programs written in Karel, a simple robotic language with significant possibilities as an educational tool for beginning programmers, which system was coded in the Ada programming language. Moreover, the paper also discusses several of the features of Ada which actually facilitated the system design.
An algebraic model for the parallel interpretation of equationally defined functions (abstract)
Authors: F. Cherief
Venue: Proceedings of the international symposium on Symbolic and algebraic computation (1990)

Algebraic Languages [EM85] are well suited for rapid prototyping. Their operational semantics is given by means of term rewriting systems. Here, we propose a new approach for the parallel interpretation of term rewriting systems by mapping every defined function into parallel processes [CH90]. The target language is HAL, a new process algebra [BH90] where parallel computations are described as a set of interconnected processes which communicate through the explicit sending and receiving of messages. HAL is derived from LOTOS [ISO89], FP2 [SJ89] and CCS [MI89]. In HAL an event is a set of simultaneous communications. Each communication within an event transports one term along one connector. When two connectors are linked, the corresponding communication unifies the two terms. This essential feature makes it possible to perform all computations via communications. (computation = communication). In the case considered here unification reduces to matching. A complete definition of the mapping from equationally defined functions to HAL processes can be found in [CH90]. The process network associated with a function reflects the syntaxic structure of the terms in the equation. A proof of correctness of the mapping is given in [CH90]. It shows that the transitions of the network correspond to innermost rewritings of the represented term and conversely. One application of this process representation is to provide a formal semantics for parallel interpretation of functional programming languages.
GI/S: A graphical user interface for symbolic computation systems
Authors: Douglas A. Young, Paul S. Wang
Venue: Journal of Symbolic Computation (1987)

The design and implementation of GI/S, a Graphical user Interface for Symbolic computation systems, is described. The system provides a multiple window environment for the high-resolution 2-D display of mathematical expressions, the ability to select and manipulate parts of expressions with a mouse, and graphics plotting of mathematical expressions. GI/S also provides command line editing and a history mechanism for editing and re-executing past commands. GI/S is written in Franz Lisp for the Macsyma system and has been implemented on the Tektronix 4404 workstation.
Image Enhancement for Segmentation by Self-Induced Autoregressive Filtering
Authors: C. K. Yang, C.-C. Yang
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1989)

A filter induced by the autoregressive pattern from an image is used to enhance the image itself. The enhanced image usually reveals the wave pattern and nonstationary structures more clearly than the original. Unlike the Fourier analysis, local structures in the image are still retained. The merits have been demonstrated on simulated data and synthetic-aperture radar (SAR) ocean imagery.
On the extended direct sum conjecture
Authors: N. H. Bshouty
Venue: Proceedings of the twenty-first annual ACM symposium on Theory of computing (1989)

We consider the quadratic complexity of certain sets of quadratic forms. We study a classes of direct sums of quadratic forms. For these classes of problems we show that the complexity of one direct sum is the sum of the complexity of the summands and that every minimal quadratic algorithm for computing the direct sums is a direct-sum algorithm.
Towards interactive query expansion
Authors: D. Harman
Venue: Proceedings of the 11th annual international ACM SIGIR conference on Research and development in information retrieval (1988)

In an era of online retrieval, it is appropriate to offer guidance to users wishing to improve their initial queries. One form of such guidance could be short lists of suggested terms gathered from feedback, nearest neighbors, and term variants of original query terms. To verify this approach, a series of experiments were run using the Cranfield test collection to discover techniques to select terms for these lists that would be effective for further retrieval. The results show that significant improvement can be expected from this approach to query expansion.
The automation of syllogistic I. Syllogistic normal forms
Authors: Domenico Cantone, Susanna Ghelfo, Eugenio Omodeo
Venue: Journal of Symbolic Computation (1988)

''Boole first put forth the problem of Logical Science in its complete generality: Given certain logical premisses or conditions, to determine the description of any class of objects under those conditions.''
Inexpensive implementations of set-associativity
Authors: R. E. Kessler, R. Jooss, A. Lebeck, M. D. Hill
Venue: ACM SIGARCH Computer Architecture News (1989)

The traditional approach to implementing wide set-associativity is expensive, requiring a wide tag memory (directory) and many comparators. Here we examine alternative implementations of associativity that use hardware similar to that used to implement a direct-mapped cache. One approach scans tags serially from most-recently used to least-recently used. Another uses a partial compare of a few bits from each tag to reduce the number of tags that must be examined serially. The drawback of both approaches is that they increase cache access time by a factor of two or more over the traditional implementation of set-associativity, making them inappropriate for cache designs in which a fast access time is crucial (e.g. level one caches, caches directly servicing processor requests). These schemes are useful, however, if (1) the low miss ratio of wide set-associative caches is desired, (2) the low cost of a direct-mapped implementation is preferred, and (3) the slower access time of these approaches can be tolerated. We expect these conditions to be true for caches in multiprocessors designed to reduce memory interconnection traffic, caches implemented with large, narrow memory chips, and level two (or higher) caches in a cache hierarchy.
Simulation run length planning
Authors: W. Whitt
Venue: Proceedings of the 21st conference on Winter simulation (1989)

To design a stochastic simulation experiment, it is helpful to have an estimate of the simulation run lengths required to achieve desired statistical precision. Preliminary estimates of required run lengths can be obtained by approximating the stochastic model of interest by a more elementary Markov model that can be analyzed analytically. When steady-state quantities are to be estimated by sample means, we often can estimate required run lengths by calculating the asymptotic variance and the asymptotic bias of the sample mean in the Markov model.
Beyond schema evolution to database reorganization
Authors: Barbara Staudt Lerner, A. Nico Habermann
Venue: Proceedings of the European conference on object-oriented programming on Object-oriented programming systems, languages, and applications (1990)

While the contents of databases can be easily changed, their organization is typically extremely rigid. Some databases relax the rigidity of database organization somewhat by supporting simple changes to individual schemas. As described in this paper, OTGen supports not only more complex schema changes, but also database reorganization. A database administrator uses a declarative notation to describe mappings between objects created with old versions of schemas and their corresponding representations using new versions. OTGen generates a transformer that applies the mappings to update the database to the new definitions, thus facilitating improvements in performance, functionality, and usability of the database.1
Characterising program behaviour with phases and transitions
Authors: J. M. Murphy, R. B. Bunt
Venue: Proceedings of the 1988 ACM SIGMETRICS conference on Measurement and modeling of computer systems (1988)

A detailed quantitative study of program behaviour is described. Reference strings from a representative set of programs were decomposed into phases and transitions. Referencing behaviour is studied at both the macro level (program-wide) and the micro level (within the phases and transitions). Quantitative data, suitable for the parameterization of program behaviour models, is presented.
Protecting user interfaces through copyright: the debate
Authors: P. Samuelson
Venue: ACM SIGCHI Bulletin (1989)

This paper will provide an overview of the legal controversy about the extent of copyright protection that is appropriate for software user interfaces. The controversy reflects different views of how traditional principles of copyright law should be applied to software. After a brief introduction to copyright principles, the paper will set forth an argument for maximal copyright protection for software user interfaces, and then an argument for minimal copyright protection for user interfaces. Both arguments apply copyright principles; they simply draw on different parts of copyright doctrine in doing so. The paper does not aim to resolve the debate, but only to familiarize the user interface design community of the legal context in which the debate is taking place.
An object oriented approach to CAD tool control within a design framework
Authors: J. Daniell, S. W. Director
Venue: Proceedings of the 26th ACM/IEEE Design Automation Conference (1989)

As VLSI design frameworks evolve, a distributed control mechanism for CAD tools has become a central research issue. In this paper, we present an object oriented tool integration methodology that treats the tools as objects. This approach simplifies CAD tool control within a design framework making the framework more general, easier to use, and more capable of supporting a large population of CAD tools.
A Historical Overview of Computer Architecture
Authors: Richard E. Smith
Venue: IEEE Annals of the History of Computing (1988)

Computer architecture concentrates on the logical aspects of computer design as opposed to the physical or electronic aspects. The underlying logical design of most modern computers is still based on that of the earliest electronic computers despite decades of progress in electronic circuitry. the innovations that have occurred in computer architecture have been driven by two different goals: higher performance and lower cost. Performance driven improvements have yielded computer systems with increasingly higher computation speeds and throughput. Cost driven improvements have yielded systems that are easier to use and applicable to a broader range of automatic control problems. Improvements in electronic circuitry have not led directly to architectural innovations; computers that pioneered new circuit technologies usually relied on older architectural concepts.
Never mind the language, what about the paradigm?
Authors: P. A. Luker
Venue: Proceedings of the twentieth SIGCSE technical symposium on Computer science education (1989)

There is increasing discussion about the primary programming language used for undergraduate courses in Computer Science. In particular, the language used for CS1 and CS2 is regarded as a crucial factor in students' subsequent progress in the discipline, not to mention their mental well-being. It is argued here that instead of focussing our attention on whether we should be teaching Ada&trade; or MODULA-2, we should be asking if these languages belong to the right class. There is mounting evidence that &ldquo;small&rdquo; languages are not only beautiful but that they lead to more easily verifiable programs, more predictable implementations, and a better foundation for &ldquo;programming in the large&rdquo;. I do not pretend to answer any more questions than I ask.
Relating models of polymorphism
Authors: J. Meseguer
Venue: Proceedings of the 16th ACM SIGPLAN-SIGACT symposium on Principles of programming languages (1989)

A new general notion of model for the polymorphic lambda calculus based on the simple idea of a universe, is proposed. Although impossible in nonconstructive set theory, the notion is unproblematic for constructive sets, yields completeness and initiality theorems, and can be used to unify and relate many different notions of model that have been proposed in the literature, including those that extend the basic calculus with additional features such as fixpoints or a type of all types. Moreover, the polymorphic lambda calculus and Martin-L&ouml;f type theory are related by a map of logics. A categorical and initial model semantics is given for the basic calculus and for richer calculi that extend the basic one with fixpoints or with a type of all types.
Distributed multi-destination routing in hypercube multiprocessors
Authors: Y. Lan, L. M. Li, A-H. Esfahanian
Venue: Proceedings of the third conference on Hypercube concurrent computers and applications: Architecture, software, computer systems, and general issues - Volume 1 (1988)

An efficient interprocessor communication mechanism is essential to the performance of hypercube multiprocessors. All existing hypercube multiprocessors basically support one-to-one interprocessor communication only. However, multi-destination communication (multicast), which is highly demanded in executing many data parallel algorithms, is not directly supported by existing hypercube multiprocessors. A multicast algorithm should attempt to inform each destination in a minimum number of time steps while generating a least amount of traffic. This problem is formally modeled as a graph theoretical problem, the Optimal Multicast Tree problem. We conjecture that the optimal multicast tree problem remains NP-hard even for hypercube topology. A heuristic greedy multicast algorithm which guarantees a minimized message delivery time is proposed. Simulation results show that the performance of the greedy algorithm is very close to optimal solution. Routing of multicast messages is done in a distributed manner.
The software lifecycle with Ada: A command and control application
Authors: M. Goyden
Venue: Proceedings of the conference on Tri-Ada '89: Ada technology in context: application, development, and deployment (1989)

Ada has been described as the cure-all for future DoD software projects. However, Ada is just a tool. Only if Ada is properly used, will it help aid software engineers produce a better system. The key to developing a system successfully, is a combination of good software engineering with Ada, an incremental software development approach, rapid prototyping, identification of solutions to recurring design problems, and a team of &ldquo;ego-less&rdquo; professionals. This paper provides a specific case study of a system developed using Ada as a tool in the DoD community. An overview of an incremental software development is presented to demonstrate how Air Force Space Command is applying Ada to a command and control (C2) decision-making problem. Specific lessons learned are provided for future Ada projects.
Performance of a QCD code on the NCUBE hypercube
Authors: D. W. Walker
Venue: Proceedings of the third conference on Hypercube concurrent computers and applications: Architecture, software, computer systems, and general issues - Volume 1 (1988)

The performance of a pure gauge QCD code on the NCUBE hypercube is analysed. Both load imbalance and communication contribute to the concurrent overhead, with the load imbalance term becoming dominant for sufficiently large hypercubes. The performance model is compared with timings measured on the NCUBE using both the standard and fast versions of the CrOS III communication systems.
An integrated debugging system based on E-beam test
Authors: Isabelle Guiguet, Meryem Marzouki, Bernard Courtois
Venue: Microelectronic Engineering (1988)

A data processing system, as part of a whole integrated test system for debugging VLSI circuits using a scanning electron microscope is described here. A link between a CALMA description and the S.E.M. images of a circuit is particularly reported. This forms the basis of an expert system for fault diagnosis.
More analysis of double hashing
Authors: George Lueker, Mariko Molodowitch
Venue: Proceedings of the twentieth annual ACM symposium on Theory of computing (1988)

In [GS78] a deep and elegant analysis showed that double hashing was equivalent to the ideal uniform hashing up to a load factor of about 0.319. In this paper we give an analysis which extends this to load factors arbitrarily close to 1. We understand from [Ko86, Gu87] that Ajtai, Guibas, Koml&oacute;s, and Szemer&eacute;di obtained this result in the first part of 1986; the analysis in this paper is of interest nonetheless because we demonstrate how a resampling technique can be used to obtain a remarkably simple proof.
Artificial intelligence methods in process plant layout
Authors: A. McBrien, J. Madden N. R. Shadbolt
Venue: Proceedings of the 2nd international conference on Industrial and engineering applications of artificial intelligence and expert systems - Volume 1 (1989)

A constraint-based system, PLS, capable of deriving a technically acceptable three-dimensional layout for a chemical process plant of typical complexity is described. In the application of PLS to an exemplar plant, over five hundred instances of constraints were identified and manipulated.PLS has been implemented in a frame system created in-house. This features recursively structured frames to represent both the initial plant data and the intermediates derived by the system. Reasoning is conducted by applying rules in which the pattern and action are represented as complex frames.A particular feature of PLS is its powerful problem reduction abstraction. A nested hierarchy of groups is formed by PLS. The groups are formed for sound engineering reasons and reflect the underlying experience of layout engineers.
Accurate rendering technique based on colorimetric conception
Authors: Atsushi Takagi, Hitoshi Takaoka, Tetsuya Oshima, Yoshinori Ogata
Venue: Proceedings of the 17th annual conference on Computer graphics and interactive techniques (1990)

We have developed a rendering technique to generate realistic images meeting designers' requirements by strictly analyzing various physical phenomena relevant to the appearance of actual objects.We have numerically compared the results of the calculations using this technique with colorimetry values. As a result, both values were virtually equal, so we have been able to confirm the effectiveness of the established technique.Application of this technique to car design, which has not been realized to a large extent because of severe requests for realism, will make it possible to evaluate styles and colors on a graphics display before making a clay model.