ppxscal/embedding_network huggingface dataset:
Two algorithms for polyhedral pictures
Authors: W Whiteley
Venue: Proceedings of the second annual symposium on Computational geometry (1986)

We present two algorithms for pictures of polyhedral scenes. These algorithms have been conjectured (and used for some time), but only now been verified. The combinatorial algorithm, proposed by Sugihara, uses counts on the incidence structure to characterize pictures which are generically the projection of sharp polyhedral scenes of planes and points. The geometric algorithm, described by Clerk Maxwell and rediscovered in the last decade, uses a reciprocal diagram in the plane to characterize pictures of strict oriented polyhedra in space.
A simple technique for handling multiple polymorphism
Authors: Daniel H. H. Ingalls
Venue: Conference proceedings on Object-oriented programming systems, languages and applications (1986)

Certain situations arise in programming that lead to multiply polymorphic expressions, that is, expressions in which several terms may each be of variable type. In such situations, conventional object-oriented programming practice breaks down, leading to code which is not properly modular. This paper describes a simple approach to such problems which preserves all the benefits of good object-oriented programming style in the face of any degree of polymorphism. An example is given in Smalltalk-80 syntax, but the technique is relevant to all object-oriented languages.
Spreadsheets and databases&mdash;alternatives to programming for non-computer science majors
Authors: M. Gene Bailey
Venue: ACM SIGCSE Bulletin (1987)

Microcomputers have become easier and easier to use an emphasis is placed on software design for users with little or no experience. With a minimal amount of training, students or employees can become productive. Yet, academic programs still teach programming as a fundamental part of computer literacy. This paper proposes that the programming portion of the class be eliminated and replaced with a study of spreadsheets and databases. The paper discusses the manner in which spreadsheet and database design can be approached to maximize learning.An important concept that is learned in any programming class is algorithm development. Students learn how to analyze the problem and to set up the step-by-step solution. This process must be done before any coding can begin. Spreadsheets offer the same type of learning and are much more appropriate for non-computer science majors. Students must formulate the problem, determine the equations and formulas necessary to solve it, and then set up the worksheet. Spreadsheet applications are found in every discipline and their design requires a minimal amount of computer knowledge and mathematics.Learning to set up a database and design the queries necessary to obtain information from the database is a concept important to computer literacy. Once again, students learn to &ldquo;program&rdquo; by learning to construct their questions in a manner that is meaningful to the software package.
Knowledge base organization in expert systems
Authors: S Frediani, L Saitta
Venue: Proceedings of the ACM SIGART international symposium on Methodologies for intelligent systems (1986)

This paper describes a method for performing knowledge base (re)organization in expert systems oriented to classification, interpretation and diagnosis problems. The methodology can be applied either to the input descriptions of a set of samples, giving thus a preliminary characterization of groups of samples, or to a set of intermediate level descriptions, supplied by a human expert or previously automatically learned. An example of application is also given.
A shell for modern personal computers
Authors: Mike Meyer
Venue: ACM SIGSMALL/PC Notes (1987)

Over the last five years, the average personal computer has changed radically in both power and typical peripherals. The command interpreters on these machines have not changed to reflect this. The following paper describes a command interpreter designed for a modern personal computer, with a high speed 16/32 bit processor, a megabyte or more of memory, a medium resolution bitmapped display, and a pointing device.
The EXODUS optimizer generator
Authors: Goetz Graefe, David J. DeWitt
Venue: ACM SIGMOD Record (1987)

This paper presents the design and an initial performance evaluation of the query optimizer generator designed for the EXODUS extensible database system. Algebraic transformation rules are translated into an executable query optimizer, which transforms query trees and selects methods for executing operations according to cost functions associated with the methods. The search strategy avoids exhaustive search and it modifies itself to take advantage of past experience. Computational results show that an optimizer generated for a relational system produces access plans almost as good as those produced by exhaustive search, with the search time cut to a small fraction.
Limitations to algorithm solvability: Galois methods and models of computation
Authors: Chanderjit Bajaj
Venue: Proceedings of the fifth ACM symposium on Symbolic and algebraic computation (1986)

We use simple arguments from Galois theory to prove the impossibility of exact algorithms for problems under various models of computation. In particular we show that there exist applied computational problems for which there are no closed from solutions over models such as Q(+, -, *, /, &radic;), Q(+, -, *, /, k&radic;), and Q(+, -, *, /, k&radic;, q(x)), where Q is the field of rationals and q(x)&egr; Q[x] are polynomials with non-solvable Galois groups.
Disambiguating prepositional phrase attachments by using on-line dictionary definitions
Authors: Karen Jensen, Jean-Louis Binot
Venue: Computational Linguistics (1987)

Standard on-line dictionaries offer a wealth of knowledge expressed in natural language form. We claim that such knowledge can and should be accessed by natural language processing systems to solve difficult ambiguity problems. This paper sustains that claim by describing a set of computational tools and techniques used to disambiguate prepositional phrase attachments in English sentences, by accessing on-line dictionary definitions. Such techniques offer hope for eliminating the time-consuming, and often incomplete, hand coding of semantic information that has been conventional in natural language understanding systems.
Architectural Yield Optimization for WSI
Authors: J. C. Harden, II, N. R. Strader
Venue: IEEE Transactions on Computers (1988)

A novel methodology for investigating wafer-scale integration (WSI) designs is proposed. This methodology combines the results of work on integrated circuit yield modeling with a study of the effects of system architecture in large-area integrated circuit yield. This work provides a hierarchical framework in which computing structures may be analyzed to determine functionality on a wafer scale and develops methods by which this functionality can be optimized.
Blending quadric surfaces with quadric and cubic surfaces
Authors: J. Warren
Venue: Proceedings of the third annual symposium on Computational geometry (1987)

We show that a pair of quadric surfaces, M and N, may be blended (smoothly joined) using a quadric surface if and only if the pencil of M and N contains either a plane or a pair of planes. Under this condition, we derive the equations of quadric and cubic surfaces that blend M and N.
Microcomputer security conference review
Authors: R. Callaghan, Leslie D. Ball
Venue: ACM SIGSAC Review (1987)

On September 17, 1986, SIGSAC cosponsored with SIG Small/PC a day long seminar on security in microcomputer systems. Nearly 100 people attended this program which was held at Bentley College, Waltham, Massachusetts.
A note on undetected typing errors
Authors: James L. Peterson
Venue: Communications of the ACM (1986)

Although human proofreading is still necessary, small, topic-specific word lists in spelling programs will minimize the occurrence of undetected typing errors.
DIB&mdash;a distributed implementation of backtracking
Authors: Raphael Finkel, Udi Manber
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1987)

DIB is a general-purpose package that allows a wide range of applications such as recursive backtrack, branch and bound, and alpha-beta search to be implemented on a multicomputer. It is very easy to use. The application program needs to specify only the root of the recursion tree, the computation to be performed at each node, and how to generate children at each node. In addition, the application program may optionally specify how to synthesize values of tree nodes from their children's values and how to disseminate information (such as bounds) either globally or locally in the tree. DIB uses a distributed algorithm, transparent to the application programmer, that divides the problem into subproblems and dynamically allocates them to any number of (potentially nonhomogeneous) machines. This algorithm requires only minimal support from the distributed operating system. DIB can recover from failures of machines even if they are not detected. DIB currently runs on the Crystal multicomputer at the University of Wisconsin-Madison. Many applications have been implemented quite easily, including exhaustive traversal (N queens, knight's tour, negamax tree evaluation), branch and bound (traveling salesman) and alpha-beta search (the game of NIM). Speedup is excellent for exhaustive traversal and quite good for branch and bound.
Clocking Schemes for High-Speed Digital Systems
Authors: S H Unger, Chung-Jen Tan
Venue: IEEE Transactions on Computers (1986)

A key element (one is tempted to say the heart) of most digital systems is the clock. Its period determines the rate at which data are processed, and so should be made as small as possible, consistent with reliable operation.
Evaluation of Performability for Degradable Computer Systems
Authors: A. Goyal, A. N. Tantawi
Venue: IEEE Transactions on Computers (1987)

The performability of degradable heterogeneous computer systems containing k > 1 types of components is considered. Previous analyses of such systems have been numerical in nature and yielded algorithms with either exponential complexity in the number of system states n, or polynomial in n with approximate truncations of infinite series. In this paper, a closed form expression for the performability of degradable heterogeneous systems is derived. Furthermore, an algorithm with polynomial complexity, O(kn3), is presented and applied to study the performability of a multiprocessor computer system.
Access to inter-organization computer networks
Authors: Deborah Estrin
Venue: ACM SIGOIS Bulletin (1986)

When two or more organizations interconnect their internal computer networks they form an Inter-Organization Network (ION). This paper analyzes how this new medium changes the economics of inter-organization communication and interchange and can thereby support communications of greater intensity and scope. Furthermore, in the spirit of transaction cost theory [15], we analyze how the new communication patterns can in turn support changes in the organization of work and industrial activities; in particular, by allowing participants to carry out greater numbers of activities across their organization boundaries, and to do so with greater numbers of interchange partners. However, at the same time ION communications may be more penetrating and segmented and thereby encourage participants to impose restrictions on cross-boundary flows and interchange partners. To benefit from ION use organizations will have to balance these opportunities and risks. We demonstrate our model with examples of commercial buyer-supplier relationships and an investigation of peer relationships among research and development (R D) laboratories. The model and study demonstrate that technical analysis can inform organizational analysis of new technologies without being technologically deterministic. Moreover, our organizational analysis has implications for the technical design of IONs as described in [4].
A graphical tool for the design and prototyping of distributed systems
Authors: J. Dähler, P. Gerber, H.-P. Gisiger, A. Kündig
Venue: ACM SIGSOFT Software Engineering Notes (1987)

This paper presents an approach of using modem graphical user interface techniques in the design and specification of complex distributed systems. A window-oriented and menu-driven net-editor and an integrated simulator with animation support have been implemented. This toolset is based on high-level Petri Nets, extended with an object-oriented paradigm and a hierarchical structuring facility. The flexibility and high level of abstraction support Rapid Prototyping.
A new theoretical framework for information retrieval
Authors: C J Van Rijsbergen
Venue: ACM SIGIR Forum (1986)

A new framework based on a non-classical logic is proposed for investigating IR. The paper motivates the use of a particular conditional logic as the 'right' logic for IR. A new principle, the logical uncertainty principle, is proposed, to deal with the inherent uncertainty associated with applicable inferences.
Analysis of functional programs to detect run-time garbage cells
Authors: Katsuro Inoue, Hiroyuki Seki, Hikaru Yagi
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1988)

We propose a method for detecting the generation of garbage cells by analyzing a source text written in a functional programming language which uses ordinary linked lists to implement list-type values. For a subexpression such as F(G( . . . )) in a program where the function values of F and G are of list type, if a cell c is created during the computation of G and if c does not appear in a list-type value of F, then c becomes a garbage cell at the end of the computation of F. We discuss this problem on the basis of formal languages derived from the functional program text and show some sufficient conditions that predict the generation of garbage cells. Also, we give an efficient algorithm to detect at compile time the generation of garbage cells which are linearly linked. We have implemented these algorithms in an experimental LISP system. By executing several sample programs on the system, we conclude that our method is effective in detecting the generation of garbage cells.
Semantic database modeling: survey, applications, and research issues
Authors: Richard Hull, Roger King
Venue: ACM Computing Surveys (CSUR) (1987)

Most common database management systems represent information in a simple record-based format. Semantic modeling provides richer data structuring capabilities for database applications. In particular, research in this area has articulated a number of constructs that provide mechanisms for representing structurally complex interrelations among data typically arising in commercial applications. In general terms, semantic modeling complements work on knowledge representation (in artificial intelligence) and on the new generation of database models based on the object-oriented paradigm of programming languages. This paper presents an in-depth discussion of semantic data modeling. It reviews the philosophical motivations of semantic models, including the need for high-level modeling abstractions and the reduction of semantic overloading of data type constructors. It then provides a tutorial introduction to the primary components of semantic models, which are the explicit representation of objects, attributes of and relationships among objects, type constructors for building complex types, ISA relationships, and derived schema components. Next, a survey of the prominent semantic models in the literature is presented. Further, since a broad area of research has developed around semantic modeling, a number of related topics based on these models are discussed, including data languages, graphical interfaces, theoretical investigations, and physical implementation strategies.
Fault Tolerance in a Systolic Residue Arithmetic Processor Array
Authors: Ronald J. Cosentino
Venue: IEEE Transactions on Computers (1988)

The regularity of systolic arrays and the potential for redundancy in residue number systems are used to provide fault tolerance in VLSI systems. The fault tolerance is concurrent with normal circuit operation and allows a continuous flow of correct data when a fault occurs. There is no interruption of valid data flow while the circuits are reconfigured. The technique also obviates the need for ultrahigh-reliability switches and switching control circuits. A fault-tolerant implementation of a finite-impulse-response filter with five residue channels, two of which are redundant, demonstrates the technique. As long as not more than one cell in each processing block is faulty, the filter outputs contain no errors.
An Exercise in Plausibility-Driven Design
Authors: Alan R. Hooton, Ulises Aguero, Subrata Dasgupta
Venue: Computer (1988)

The authors describe an evolutionary model of the computer design process and introduce the concept of plausibility of a design, which depends on the history of the design, where history refers to the recorded sequences of design decisions and the cause-effect relationships between design decisions, and the nature of the evidence used by the designer to justify design decisions and/or establish the fact that a design feature satisfies a particular set of requirements. The approach was used to design a special-purpose multiprocessor intended to serve as a computer architecture simulation engine (CASE). The authors present some of the main features of CASEs design as it evolved and, in the process, illustrate the practical application of the theory of plausible design.
Process Scheduling in a Computer System
Authors: Zvi Rosberg
Venue: IEEE Transactions on Computers (1985)

A computer system is modeled by an exponential queueing network with different classes of customers and a general class of service policies. The mean cost per unit time is taken as the loss function. Three lower bounds of the loss function under the whole class of service policies, as well as an upper bound of the minimal loss, are derived. The loss function is expressed in a convenient form from which we derive a simple heuristic service policy so called "Klimov policy." This policy is applied to several examples of computer systems and is evaluated by the bounds. The examples recommend using "Klimov policy" in any case; so we have a first rule for deciding how to provide service capacity to different customers in a network of queues.
Understanding the effectiveness of computer graphics for decision support: a cumulative experimental approach
Authors: Gary W. Dickson, Gerardine DeSanctis, D. J. McBride
Venue: Communications of the ACM (1986)

A total of 840 junior and senior-level undergraduate business students particpated in three experiments that compared computer-generated graphical forms of data presentation to traditional tabular reports. The first experiment compared tables and bar charts for their effects on readability, interpretation accuracy, and decision making. No differences in interpretation accuracy or decision quality were observed for the two groups, although tabular reports were rated as "easier to read and understand" than graphical reports. The second experiment compared line plots to tables for their effects on interpretation accuracy and decision quality. Subjects with graphical reports outperformed those with tables. There were no meaningful differences in interpretation accuracy across treatment groups. The third experiment compared graphical and tabular reports for their ability to convey a "message" to the reader. Only in situations in which a vast amount of information was presented and relatively simple impressions were to be made, did subjects given graphs outperform those using tables. This program of cumulative experiments indicates that generalized claims of superiority of graphic presentation are unsupported, at least for decision-related activities. In fact, the experiments suggest that the effectiveness of the data display format is largely a function of the characteristics of the task at hand, and that impressions gleaned from "one shot" studies of the effectiveness of the use of graphs may be nothing more than situationally dependent artifacts.
Extended use of null productions in LR(1) parser applications
Authors: Gerard D. Finn
Venue: Communications of the ACM (1985)

Applications programmed using LR(1) parsers should be designed so that as many functions as possible are controlled by the driving parsing machine through conveniently staged reductions and associated primitive actions; in this paper this is achieved by making extensive use of null productions and nullable nonterminal symbols.
Student-oriented features of an interactive programming environment
Authors: Gene Fisher
Venue: Proceedings of the eighteenth SIGCSE technical symposium on Computer science education (1987)

This paper describes features of a program development environment of particular use for student programmers. The environment contains tools for both textual and graphical program development. The textual tools include those now commonly found in interactive programming environments: interactive interpreter, language-based editor, debugger. The tools are provided for four languages in the &ldquo;Pascal family:&rdquo; Pascal, C, Modula-2 and Fortran. An important student-oriented feature of the environment is the capability for rapid switching between languages, allowing features in different languages to be compared side by side. The environment also provides a graphical program interface that students may use to test their programs interactively. The graphical interface is based on the notion of the control panel, through which students may interact with gauges and knobs to view and animate program data structures and output.
Learning modes and subsequent use of computer-mediated communication systems
Authors: S. R. Hiltz
Venue: ACM SIGCHI Bulletin (1986)

New users of four computer-mediated communication systems were asked to indicate which of a variety of learning modes they had used, including reading written manuals, using online automated help facilities, personal or group lessons from a human teacher, and trial-and-error learning. Despite often elaborate documentation and online help, the most frequent mode actually selected by users is trial and error learning. Rather than bemoaning the fact that users do not make proper use of written documentation, the implication for system implementation is that it should be designed to effectively encourage and support trial-and-error learning. An experimental intervention offering a guided learning activity supports this conclusion.
Hurricane: an optimizing compiler for Smalltalk
Authors: Robert G. Atkinson
Venue: ACM SIGPLAN Notices (1986)

We discuss a recent attempt at providing a more efficient compilation system for the Smalltalk-80&trade; language than currently exists. The approach is unique in that it attempts to work within the existing semantics of the language. A type declaration and inference mechanism is developed in order to make the problem tractable. Details concerning the compiler implemented to date are given, as well as preliminary speed tests of compiled object code.