ppxscal/embedding_network huggingface dataset:
An object language versus an expert system shell: the school time-table example
Authors: Davor Bonačic, Bruno Stiglic, Tomaž Kolmanič
Venue: ACM SIGPLAN OOPS Messenger (1992)

Often there comes up a problem that is laborious or awkward to solve by means of the third generation languages. Sometimes it is difficult for the programmers to see or know the better way, or even to decide which is the most suitable language or programming tool for solving their problem. Lately, many easily available and not expensive expert shells as well as various kinds of object-oriented languages also for smaller and personal computers have appeared on the market. Various problems can usually be more or less effectively solved by means of either: an object-oriented language or an expert system. In this paper, we describe the example of solving the school time-table problem by first applying one, and then the other way.
General natural language for operating systems
Authors: Xie Li, Du Xing
Venue: ACM SIGART Bulletin (1992)

This paper proposes a general natural language interface for operating systems. It adopts an Application-Independent Hierarchic approach (AIH) to developing general natural language interfaces. AIH separates the application-specific part of natural language processing from the nonspecific one, and represents the former declaratively. In addition to the traditional phases of natural language process, a new phase called domain compiling is introduced. Using AIH, an experimental interface THJ has been developed which is general natural language interface for the Unix, VMS, and MS-DOS operating systems.
Clustering in object-oriented databases
Authors: Everton G. de Paula, Michael L. Nelson
Venue: ACM SIGPLAN OOPS Messenger (1992)

Object-oriented database management systems are still a relatively new area, with many unanswered questions as to their performance. Objects can be clustered on disk (i.e., stored in contiguous storage areas) so that when accessing one object in a cluster, all of the objects in that cluster are brought into main memory. Thus when accessing additional objects in the cluster, it is then a main memory operation rather than a disk operation. Unfortunately, determing which objects to cluster together is often left entirely up to the user, and an improper clustering scheme can severly degrade system performance. This paper presents a set of guidelines for developing a clustering scheme, using an actual application as an example.
Real-time Systems Performance in the Presence of Failures
Authors: Jogesh K. Muppala, Kishor S. Trivedi, Steven P. Woolet
Venue: Computer (1991)

A unified methodology for modeling both soft and hard real-time systems is presented. Techniques that combine the effects of performance, reliability/availability, and deadline violation into a single model are used. An online transaction processing system is used as an example to illustrate the modeling techniques. Dynamic failures due to a transaction violating a hard deadline are taken into account by incorporating additional transitions in the Markov chain model of the failure-repair behavior. System performance in the various configurations is considered by using throughput and response-time distribution as reward rates. Since the Markov chains used in computing the distribution of response time are often very large and complex, a higher level interface based on a variation of stochastic Petri nets called stochastic reward nets is used.
Amortized communication complexity (Preliminary version)
Authors: Tomàs Feder, Eyal Kushilevitz, Moni Naor
Venue: Proceedings of the 32nd annual symposium on Foundations of computer science (1991)

The authors study the direct sum problem with respect to communication complexity: Consider a function f: D to (0, 1), where D contained in (0, 1)/sup n/*(0, 1)/sup n/. The amortized communication complexity of f, i.e. the communication complexity of simultaneously computing f on l instances, divided by l is studied. The authors present, both in the deterministic and the randomized model, functions with communication complexity Theta (log n) and amortized communication complexity O(1). They also give a general lower bound on the amortized communication complexity of any function f in terms of its communication complexity C(f).
Database research at IPSI
Authors: Erich Neuhold, Volker Turau
Venue: ACM SIGMOD Record (1992)

At the Integrated Publication and Information Systems Institute (IPSI) of the GMD (Gesellschaft f&uuml;r Mathematik und Datenverarbeitung) database research is focused towards distributed database management systems to support the integration of heterogeneous multi-media information bases needed in an integrated publishing environment. The objective is to investigate advanced object-oriented and active data modelling concepts together with the principles of distributed data stores and data management. The unifying basis for the database research is the object-oriented data model VML developed in the project VODAK over the last four years. The data model is based on recursively defined meta classes, classes and instance hierarchies paired with a strict separation of structural and operational definitions in a polymorphic type system. This report describes the highlights of the work on the VODAK database system, the research efforts in heterogeneous database integration and the research plans of the multimedia database project as well as applications of our system in different environments such as hypertext and office automation.
Implementation of extended indexes in POSTGRES
Authors: Paul M. Aoki
Venue: ACM SIGIR Forum (1991)

The vaunted "Spartan simplicity" of the relational model can limit the usefulness of the relational database management system (RDBMS) for non-traditional applications. For example, there is no natural way to model a keyword index for bibliographic informational retrieval (IR), or any other index whose key values are computed from column values, in a standard RDBMS. The extended indexing proposed in [LYNC88a] is intended to support applications that require indexes on computed values. This paper reports on an implementation of this type of indexing using the POSTGRES extensible database management system [STON86a], focusing on two issues: general problems, and the features in POSTGRES that proved helpful in the solution of these problems.
Characterizing Three-Dimensional Surface Structures from Visual Images
Authors: Y. F. Wang
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1991)

A new technique for computing intrinsic surface properties is presented. Intrinsic surface properties are those properties of a surface that are not affected by the choice of the coordinate system, the position of the viewer relative to the surface, and the particular parametric representation used to describe the imaged surface. Since intrinsic properties are characteristics of a surface, they are ideal for the purposes of representation and recognition. The intrinsic properties of interest are the principal curvatures, the Gaussian curvatures, and the lines of curvature. It is proposed that a structured-light sensing configuration where a grid pattern is projected to encode the imaged surfaces for analysis be adopted. At each stripe junction, the curvatures of the projected stripes on the imaged surface are computed and related to those of the normal sections that share the same tangential directional as the projected curves. The principal curvatures and their directions at the stripe junction under consideration are then recovered using Euler's theorem. Results obtained using both synthetic and real images are presented.
Boolean resubstitution with permissible functions and binary decision diagrams
Authors: Hitomi Sato, Yoshihiro Yasue, Yusuke Matsunaga, Masahiro Fujita
Venue: Proceedings of the 27th ACM/IEEE Design Automation Conference (1991)

In this paper, we present a new Boolean resubstitution technique with permissible functions and ordered binary decision diagrams, abbreviated as OBDD[8]. Boolean resubstitution is one technique for multi-level logic optimization. Permissible functions are special don't care sets. We represent the data structure of permissible functions and logic functions at each node in Boolean networks in terms of OBDD. Therefore, logic functions can be flexibly manipulated and rapidly executed. We have previously reported a multi-level logic optimization technique called transduction methods[1] using OBDD in ICCAD'89[7]. We have improved the OBDD operation techniques, so that now OBDD operations can be executed faster than we reported before. We also applied Boolean resubstitution to our multi-level logic synthesis. We present results of experiments employing the improved OBDD operation techniques and applying Boolean resubstitution to our multi-level logic synthesis.
The mapping unit approach to subcategorization
Authors: Robert Bobrow, Robert Ingria, David Stallard
Venue: Proceedings of the workshop on Speech and Natural Language (1991)

We present the "mapping unit" approach to representing subcategorization information, a computational framework for encoding subcategorization information which has been developed and implemented for BBN's DELPHI system (the NL component of the HARC spoken language system). The advantage of our approach to subcategorization lies in its flexibility, a flexibility which in turn offers greater robustness of coverage with respect to unanticipated variations of a verbal argument pattern, and easier extension of coverage to new patterns. It handles in a quite natural way argument order variation, optionality of arguments, and metonymy.
Efficient Replicated Remote File Comparison
Authors: John J. Metzner
Venue: IEEE Transactions on Computers (1991)

The author improves on some previous work involving data transfer to find the location of disagreements between two or more large remote data files. Some procedures that permit a significant reduction in the number of back-and-forth interchanges are described, one of which significantly reduces the total amount of data transfer required. The older scheme could locate a disagreeing page with an extremely high degree of confidence more than one interchange. The new procedures require at most one back-and-forth interchange for each disagreeing page, often considerably less.
A simulation based study of TLB performance
Authors: J. Bradley Chen, Anita Borg, Norman P. Jouppi
Venue: ACM SIGARCH Computer Architecture News (1992)

This paper presents the results of a simulation-based study of various translation lookaside buffer (TLB) architectures, in the context of a modern VLSI RISC processor. The simulators used address traces, generated by instrumented versions of the SPEC marks and several other programs running on a DECstation 5000. The performance of two-level TLBs and fully-associative TLBs were investigated. The amount of memory mapped was found to be the dominant factor in TLB performance. Small first-level FIFO instruction TLBs can be effective in two level TLB configurations. For some applications, the cyles-per-instruction (CPI) loss due to TLB misses can be reduced from as much as 5CPI to negligible levels with typical TLB parameters through the use of variable-sized pages.
Computing in a less-developed country
Authors: Seymour E. Goodman
Venue: Communications of the ACM (1991)

Almost all of the nations of Latin America are so-called less-developed countries (LDCs). But unlike many such countries elsewhere, quite a few have recently attempted to install more democratic, or at least less authoritarian, governments that are permitting greater freedom of expression and information and encouraging market-oriented economic developments. The latter include decreasing protectionism and moves toward the privatization of state enterprises such as telecommunications companies. Given the land area, natural resources, and populations involved, these developments are potentially of enormous international importance. The information technologies (IT) could be used to accelerate and reinforce these political and economic changes.
Spatial workspace collaboration: a SharedView video support system for remote collaboration capability
Authors: Hideaki Kuzuoka
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (1992)

Collaboration in three-dimensional space: &ldquo;spatial workspace collaboration&rdquo; is introduced and an approach supporting its use via a video mediated communication system is described. Verbal expression analysis is primarily focused on. Based on experiment results, movability of a focal point, sharing focal points, movability of a shared workspace, and the ability to confirm viewing intentions and movements were determined to be system requirements necessary to support spatial workspace collaboration. A newly developed SharedView system having the capability to support spatial workspace collaboration is also introduced, tested, and some experimental results described.
On algorithms for operative diagnosis of systems (abstract)
Authors: Nageswara S. V. Rao, Jih-sen Lin
Venue: Proceedings of the 1990 ACM annual conference on Cooperation (1990)

As interest in developing expert systems continues to grow, it become more important for us to increase our understanding of how to successfully build these systems. The major problem that currently constricts the development of expert systems is the formidable process of eliciting knowledge from human experts. A possible solution to alleviate this knowledge-acquisition bottlenecks is to equip historical database with some deductive capabilities that will allow us to emulate expert-system reasoning entirely in the database's terms. In this paper we describe a system that tries to extend an existing database containing component test-repair history with several features to support inferencing at the reasoning level of human trouble shooters. That is, the system features automatic knowledge-base derivation. This presentation demonistrate the structure of a system that, when queried with a test step, will provide trouble shooting advice describing the most likely cause for failure.
A Note on 'Generalized Hypercube and Hyperbus Structures for a Computer Network' by L.N. Bhuyan and D.P. Agrawal
Authors: Guan I. Chen, Ten H. Lai, Yao-Nan Lien
Venue: IEEE Transactions on Computers (1991)

The commenters point out that conjectures in the above-named paper concerning the structure of a least-cost generalized hypercube can be proved.
Cellular Automata-Based Signature Analysis for Built-In Self-Test
Authors: P. D. Hortensius, R. D. McLeod, H. C. Card
Venue: IEEE Transactions on Computers (1990)

Relevant signature analysis properties for elementary one-dimensional cellular automata are presented. It is found that cellular automata with cyclic-group rules provide signature analysis properties comparable to the LFSR (linear feedback shift register). A technique of using CALBO (cellular automata-based logic block observation) for both test pattern generation and signature analysis, in a similar manner to a typical BILBO (built-in block observation) implementation, is presented.
Asynchronous Disk Interleaving: Approximating Access Delays
Authors: Michelle Y. Kim, Asser N. Tantawi
Venue: IEEE Transactions on Computers (1991)

The performance implications of asynchronous disk interleaving are examined. In an asynchronous system, adjacent subblocks are placed independently of each other. Since each of the disks in such a system is treated independently while being accessed as a group, the access delay of a request for a data block in an n-disk system is the maximum of n access delays. Using approximate analysis, a simple expression for the expected value of such a maximum delay is obtained. The analysis approximation is verified by simulation using trace data; the relative error is found to be at most 6%.
N factorial computations, timing, etc
Authors: Dexter A. Schnebly
Venue: ACM SIGSMALL/PC Notes (1991)

I recently did a small school project on a DEC MicroVAX II. For the project I rewrote an "N Factorial" calculations program that I had earlier written as a result of discussions in H. K. Hodge's article of SIGSMALL/PC NOTES of May 1989.
Architectural support for reduced register saving/restoring in single-window register files
Authors: Miquel Huguet, Tomás Lang
Venue: ACM Transactions on Computer Systems (TOCS) (1991)

The use of registers in a processor reduces the data and instruction memory traffic. Since this reduction is a significant factor in the improvement of the program execution time, recent VLSI processors have a large number of registers which can be used efficiently because of the advances in compiler technology. However, since registers have to be saved/restored across function calls, the corresponding register saving and restoring (RSR) memory traffic can almost eliminate the overall reduction. This traffic has been reduced by compiler optimizations and by providing multiple-window register files. Although these multiple-window architectures produce a large reduction in the RSR traffic, they have several drawbacks which make the single-window file preferable. We consider a combination of hardware support and compiler optimizations to reduce the RSR traffic for a single-window register file, beyond the reductions achieved by compiler optimizations alone. Basically, this hardware keeps track of the registers that are written during execution, so that the number of registers saved is minimized. Moreover, hardware is added so that a register is saved in the activation record of the function that uses it (instead of in the record of the current function); in this way a register is restored only when it is needed, rather than wholesale on procedure return. We present a register saving and restoring policy that makes use of this hardware, discuss its implementation, and evaluate the traffic reduction when the policy is combined with intraprocedural and interprocedural compiler optimizations. We show that, on the average for the four general-purpose programs measured, the RSR traffic is reduced by about 90 percent for a small register file (i.e., 32 registers), which results in an overall data memory traffic reduction of about 15 percent.
Legally speaking: First Amendment rights for information providers?
Authors: Pamela Samuelson
Venue: Communications of the ACM (1991)

Applying the First Amendment of the U.S. Constitution to computerized communication of information is raising many interesting questions. While the general principle of this amendment can be simply stated&mdash;it forbids the government from interfering with freedom of speech&mdash;the specifies of its application over two centuries of American history have yielded a complex matrix of principles whose application depends on a variety of factors. Where computerized communication of information fits into this schema has yet to be definitely determined. The last &ldquo;Legally Speaking&rdquo; column (Mar. 1991) discussed some First Amendment issues raised by treating computerized information as private property, theft of which might be criminally prosecutable. This column will discuss quite a different First Amendment issue. But these two columns can only begin to introduce a few of the challenging First Amendment issues presented by the &ldquo;Electronic Frontier.&rdquo;
Prototyping Fortran-90 compilers for massively parallel machines
Authors: Marina Chen, James Cowie
Venue: ACM SIGPLAN Notices (1992)

Massively parallel architectures, and the languages used to program them, are among both the most difficult and the most rapidly-changing subjects for compilation. This has created a demand for new compiler prototyping technologies that allow novel style of compilation and optimization to be tested in a reasonable amount of time. Using formal specification techniques, we have produced a data-parallel Fortran-90 subset compiler for Thinking Machines' Connection Machine/2 and Connection Machine/5. The prototype produces code from initial Fortran-90 benchmarks demonstrating sustained performance superior to hand-coded Lisp and competitive with Thinking Machines' CM Fortran compiler. This paper presents some new specification techniques necessary to construct competitive, easily retargetable prototype compilers.
Parallel Programming Using Shared Objects and Broadcasting
Authors: Andrew S. Tanenbaum, M. Frans Kaashoek, Henri E. Bal
Venue: Computer (1992)

The two major design approaches taken to build distributed and parallel computer systems, multiprocessing and multicomputing, are discussed. A model that combines the best properties of both multiprocessor and multicomputer systems, easy-to-build hardware, and a conceptually simple programming model is presented. Using this model, a programmer defines and invokes operations on shared objects, the runtime system handles reads and writes on these objects, and the reliable broadcast layer implements indivisible updates to objects using the sequencing protocol. The resulting system is easy to program, easy to build, and has acceptable performance on problems with a moderate grain size in which reads are much more common than writes. Orca, a procedural language whose sequential constructs are roughly similar to languages like C or Modula 2 but which also supports parallel processes and shared objects and has been used to develop applications for the prototype system, is described.
On the Design of Cost-Tables for Realizing Multiple-Valued Circuits
Authors: Kriss A. Schueller, Jon T. Butler
Venue: IEEE Transactions on Computers (1992)

A heuristic is proposed for finding minimal cost-tables, for use in the design of multiple-valued logic circuits. It is an iterative approach, in which a good table of size t is composed of a good table of size t-1, etc. The authors analyze its performance, comparing it with three other heuristics. The importance of finding good cost-tables is demonstrated by an analysis that shows there is a wide variation in both cost-table performance and in the performance of heuristics for generating cost-tables. A study is made of linear cost, a general cost function of which two previously studied cost functions are special cases. It is shown that the minimal cost-table using one of the (infinitely many) linear cost functions is identical to a minimal cost-table using any other linear cost function. Two additional results on cost-table design are given.
HIS: an information system about hypertext on hypertext
Authors: Hermann Kaindl, Holger G. Ziegeler
Venue: ACM SIGWEB Newsletter (1992)

This paper addresses the issue whether hypertext of paper is more appropriate for certain tasks. We chose the task of getting a quick overview of a new topic. We describe the design of a hypertext system with specific emphasis on hierarchical structuring for semi-formal knowledge representation. The domain of our application is hypertext itself. For the evaluation of our design, and more generally hypertext versus paper, we descirbe the experiment and results on the effectiveness of our system compared to a printout version. In particular, we classify the difficulty of the questions posed to the subjects in our experiment accoring to various methods. It is interesting that the achieved classifications have small correlation. There are no statistically significant differences between the performance of subjects using HIS or the paper version. We interpret this as a compensation of the adverse effects of the usually slower reading from a computer screen and unfamiliarity with the medium of hypertext.
Parametric type classes
Authors: Kung Chen, Paul Hudak, Martin Odersky
Venue: Proceedings of the 1992 ACM conference on LISP and functional programming (1992)

We propose a generalization to Haskell's type classes where a class can have type parameters besides the placeholder variable. We show that this generalization is essential to represent container classes with overloaded data constructor and selector operations. We also show that the resulting type system has principal types and present unification and type reconstruction algorithms.