ppxscal/embedding_network huggingface dataset:
Dynamic priorities, priority scheduling and priority inheritance
Authors: Fred Maymir-Ducharme
Venue: ACM SIGAda Ada Letters (1990)

Scheduling requirements are a major portion of the set of requirements that must be addressed by the Ada 9X Project. This is evident by the numerous Revision Requests (RRs) submitted (over 25) to the Ada 9X Project Office and the subsequent Revision Issues (RI-7005 and RI-7007). The related 9X requirements are: R1 - Flexible scheduling R2 - Flexible entry queue ordering IR2 - Rendezvous performance IR3 - Extended priority support WR1 - Flexible select algorithm This report summarizes the workshop's discussions on this important area. The discussions first considered dynamic priorities, and then priority scheduling and priority inheritance.
Boolean Matrix Transforms for the Minimization of Modulo-2 Canonical Expansions
Authors: P. K. Lui, J. C. Muzio
Venue: IEEE Transactions on Computers (1992)

Fast transforms for computing modulo-2 ring-sum canonical expansions of a Boolean function are described using Kronecker products of elementary Boolean matrices. These transforms unify and generalize existing ones in the literature. Previous algorithms which employ such transforms for finding a minimal fixed polarity expansion (FPE) are reviewed, analyzed, and extended to a minimal fixed basis expansion (FBE).
A strong generating test and short presentations for permutation groups
Authors: Gene Cooperman, Larry Finkelstein
Venue: Journal of Symbolic Computation (1991)

The group membership problem for permutation groups is one of the most important problems of computational group theory. Solution of this problem seems to depend intrinsically on constructing a strong generating set. Until now, recognizing if a set of generators is strong has been thought to be as hard as constructing a strong generating set from an arbitrary generating set. This paper shows how to verify a strong generating set in O(n^4) time, where n is the size of the set on which the group acts. This is faster than the best known algorithms in the literature. The work also leads to related algorithms for discovering all orbit information contained in an arbitrary set of generators S in O(n|S| + n log n) time, and, if S is strong, for finding a presentation with no more than |S|(n -1) relations. Refinements in the analysis are given for the case in which a small base exists.
A write update cache coherence protocol for MIN-based multiprocessors with accessibility-based split caches
Authors: M. S. Algudady, C. R. Das, M. J. Thazhuthaveetil
Venue: Proceedings of the 1990 ACM/IEEE conference on Supercomputing (1990)

In this paper, we present a cache coherence protocol for MIN-based multiprocessors with two distinct private caches: private-block caches containing information private to a processor, and shared-block caches containing data accessible by all processors. The protocol utilizes a coherence control bus (snooping) for connecting all shared-block cache controllers. Timing problems due to variable transit delays through the MIN are dealt with by introducing Transient states in this protocol. Assuming homogeneity of all nodes, a single node queueing model is developed to analyze the system performance. This model is solved using the MVA technique with protocol state probabilities, and few communication delays as input parameters. System performance measures are verified through simulation.
On the Approximation of NP-Complete Problems by Using the Boltzmann Machine Method: The Cases of Some Covering and Packing Problems
Authors: V. Zissimopoulos, V. Th. Paschos, F. Pekergin
Venue: IEEE Transactions on Computers (1991)

A Boltzmann machine architecture to solve the problems of maximum independent set, set partitioning, clique, minimum vertex cover, minimum set cover, and maximum set packing is described. The authors evaluate the maximum and the average error of the method where the error is defined as the ratio of the cardinality of the obtained solution for an instance with respect to the optimal one. The results are compared with those obtained from the implementation of the heuristic described by D.S. Johnson (1974). The model treats the general case of all these problems that is the case when costs are associated with the data (vertices or subsets). The unweighted case becomes a particular case in this approach. It is shown that the model finds optimal solutions for a large percentage of the treated instances and provides a good performance ratio for the rest.
A framework for integrating perception, action, and trial-and-error learning
Authors: Steven D. Whitehead
Venue: ACM SIGART Bulletin (1991)

Meliora is a system being developed at the University of Rochester that learns to assemble objects from random piles of blocks. It is a testbed for exploring issues in Integrated Architectures. It is based on a control architecture that is reactive, adaptive, has an active -but limited- sensory system, has a limited internal representation, and does not depend on a priori domain knowledge. In these working notes, we describe Meliora's control architecture, discuss its features and limitations, and describe how it can be integrated with more "intelligent" mechanisms that improve its performance. The notes are organized around the question set laid out by the Program Committee.
Flexible Text Display with Lector
Authors: Darrell R. Raymond
Venue: Computer (1992)

Lector, an X11 application for flexible text interaction, is described. Lector was originally devised as a simple, rapid formatter for the display of online text databases. It was then discovered that Lector exhibited useful capabilities for a wide range of text applications. The ways in which Lector distinguishes between content and tags in descriptively marked-up text and achieves flexible interaction are discussed. Its applications as a text previewer, database browser, code prettyprinter, and menu utility are also discussed.
Notes and references on early automatic classification work
Authors: Karen Sparck Jones
Venue: ACM SIGIR Forum (1991)

This informal note was prompted by discussions and questions at the 1990 AAAI Spring Symposium on Text-Based Intelligent Systems (cf Jacobs 1990). There is a growing interest in access to, and the use of, large scale full-text databases for a variety of purposes, and in the application of classification methods to organise the mass of data involved (see e.g. Church and Hanks 1990). A good deal of work has been done in this field in the past, but it is little known, and some of the early research literature is not very accessible. Classification is an area in which it is easy to make plausible but mistaken assumptions, and as this certainly holds for classification in retrieval, there is a good deal that can be usefully learnt from past experience, most of which was hard won from careful thought and grinding experiment. This paper is intended as an introduction to this initial work on automatic classification, to help those now becoming interested in classification to avoid unnecessarily repeating heavy effort or, more especially, reinventing square wheels. It should also be noted that automatic classification and related (e.g. seriation) methods have been extensively developed for biological applications in particular, but have been more variously applied, and that much of this work may be relevant in the broad area of machine learning.It must be emphasised that as this paper is focussed on early work on automatic classification, particularly for information retrieval, and is designed primarily to lead into this research and its literature, it does not attempt a critical evaluation of the overall results established by now, or of the current state of the art. However it should be pointed out that in the retrieval context in general, as opposed to the wider one of classification as a whole, there has been comparatively little work since the seventies, largely for the reasons indicated in the paper. More recent work in any case refers heavily to earlier research, so this note can be taken as an entry point to the research of the last decade for which some references are given at the end of the note.
On Euclidean spanner graphs with small degree
Authors: Jeffrey S. Salowe
Venue: Proceedings of the eighth annual symposium on Computational geometry (1992)

Given a set of points S, a t-spanner for S is a subgraph G of the complete Euclidean graph determined by S having the property that dG(x,y)/d(x,y) &le; t for all x,y &egr; S, x &ne; y, where dG(x, y) is the distance from point x is the euclidean distance from x to y. Dobkin, Friedman, and Supowit posed the problem of determining whether every planar point set S admits a t-spanner having maximum vertex degree 3 for some constant t. We show that for each k &ge; 2, there is a constant t(k) such that every point set in Rk admits a t(k)-spanner with vertex degree at most 4.
A compiler-assisted approach to SPMD execution
Authors: Ron Cytron, Jim Lipkis, Edith Schonberg
Venue: Proceedings of the 1990 ACM/IEEE conference on Supercomputing (1990)

Today, two styles of scientific parallel programming prevail. In the SPMD style, all processors execute the same program, with sequential code executed redundantly and parallel code executed cooperatively. In the fork-join style, a sequential thread of control spawns multiple threads to execute a portion of the code concurrently. In this paper we describe an automatic method for approaching the efficiency of SPMD-style execution for programs written in the more structured fork-join style.
The Pegasus Heterogeneous Multidatabase System
Authors: Rafi Ahmed, Philippe De Smedt, Weimin Du, William Kent, Mohammad A. Ketabchi, Witold A. Litwin, Abbas Rafii, Ming-Chien Shan
Venue: Computer (1991)

Pegasus, a heterogeneous multidatabase management system that responds to the need for effective access and management of shared data across in a wide range of applications, is described. Pegasus provides facilities for multidatabase applications to access and manipulate multipole autonomous heterogeneous distributed object-oriented relational, and other information systems through a uniform interface. It is a complete data management system that integrates various native and local databases. Pegasus takes advantage of object-oriented data modeling and programming capabilities. It uses both type and function abstractions to deal with mapping and integration problems. Function implementation can be defined in an underlying database language or a programming language. Data abstraction and encapsulation facilities in the Pegasus object model provide an extensible framework for dealing with various kinds of heterogeneities in the traditional database systems and nontraditional data sources.
Heap-Filter Merge Join: A New Algorithm for Joining Medium-Size Inputs
Authors: Goetz Graefe
Venue: IEEE Transactions on Software Engineering (1991)

A novel algorithm for relational equijoin is presented. The algorithm is a modification of merge join, but promises superior performance for medium-size inputs. In many cases it even compares favorably with both merge join and hybrid hash join, which is shown using analytic cost functions.
An anatomy of the information resource semantic abstraction
Authors: Leonid Kalinichenko
Venue: ACM SIGMOD Record (1991)

Semantic abstraction mapping establishing a correspondence between an information resource and an application is considered to be a basic notion providing for the study of semantic interoperability of heterogeneous information resources. The structure and necessary properties of a resource class application abstraction are considered. Intensional model-based properties of the abstraction mapping are introduced as provable conditions of a class assertion abstraction and an operation concretization
Radix-4 Square Rot Without Initial PLA
Authors: M. D. Ercegovac, T. Lang
Venue: IEEE Transactions on Computers (1990)

A systematic derivation of a radix-4 square-root algorithm using redundant residual and result is presented. Unlike other similar schemes it does not use a table lookup or PLA for the initial step, resulting in a simpler implementation without any time penalty. The scheme can be integrated with division and incorporates an on-the-fly conversion and rounding of the result, thus eliminating a carry-propagate step to obtain the final result. The result-digit selection uses 3 bits of the result and 7 bits of the estimate of the residual.
Elimination of composite superpositions may cause abortion
Authors: Andrea Sattler-Klein
Venue: Journal of Symbolic Computation (1991)

We will show by examples that the elimination of composite superpositions during the completion of a term rewriting system may lead to an unnecessary stop with failure that cannot be prevented by postponing critical pairs.
A compendium of key search references
Authors: Jun-ichi Aoe
Venue: ACM SIGIR Forum (1990)

How to store and to search, or retrieve, information efficiently is an important problem in computer science because searching is the most time-consuming part of many programs, and the substitution of a good search method for a bad one often leads to a substantial increase in speed. Particularly, a key search technique of finding which record has a special field as its key has been widely used in database management, compiler construction, natural language processing, and many other applications. The aim of this article is to provide a great deal of references, classified by consideration of their problems.
Paradigm: A Highly Scalable Shared-Memory Multicomputer Architecture
Authors: David R. Cheriton, Hendrik A. Goosen, Patrick D. Boyle
Venue: Computer (1991)

Paradigm (parallel distributed global memory), a shared-memory multicomputer architecture that is being developed to show that one can build a large-scale machine using high-performance microprocessors, is discussed. The Paradigm architecture allows a parallel application program to execute any of its tasks on any processor in the machine, with all the tasks in a single address space. The focus is on novel design techniques that support scalability. The key performance issues are identified, and some results to date from this work and experience with the VMP architecture design on which it is based are summarized.
Temporal Logic-Based Deadlock Analysis for Ada
Authors: Gerald M. Karam, Raymond J. A. Buhr
Venue: IEEE Transactions on Software Engineering (1991)

A temporal logic-based specification language and deadlock analyzer for Ada is described. The deadlock analyzer is intended for use within Timebench, a concurrent system-design environment with support for Ada. The specification language, COL, uses linear-time temporal logic to provide a formal basis for axiomatic reasoning. The deadlock analysis tool uses the reasoning power of COL to demonstrate that Ada designs specified in COL are systemwide deadlock-free: in essence, it uses a specialized theorem prover to deduce the absence of deadlock. The deadlock algorithm is shown to be decidable for finite systems and acceptable otherwise. It is also shown to have a worst-case computational complexity that is exponential with the number of tasks. The analyzer has been implemented in Prolog. Numerous examples are evaluated using the analyzer, including readers and writers, gas station, five dining philosophers, and a layered communications system. The results indicate that analysis time is reasonable for moderate designs in spite of the worst-case complexity of the algorithm .
The MVL theorem proving system
Authors: Matthew L. Ginsberg
Venue: ACM SIGART Bulletin (1991)

The MVL theorem-proving system is an implementation of theoretical work currently under way at Stanford University. Theoretical progress made there is regularly included in MVL in order to ensure that the ideas developed theoretically can be tested experimentally as well.
On the synthetic factorization of projectively invariant polynomials
Authors: Bernd Sturmfels, Walter Whiteley
Venue: Journal of Symbolic Computation (1991)

We prove that, after multiplication with a suitable monomial, every homogeneous bracket polynomial of rank r>=3 can be factored into a meet and join expression in the Cayley algebra. The main tool in our construction is an explicit algorithm for rewriting polynomial functions in terms of synthetic constructions in projective geometry. We also discuss applications of Cayley factorization to automated geometry theorem proving.
A queuing model for multi-user teleprocessing system line speed decisions
Authors: Donald A. Carpenter
Venue: Proceedings of the 1992 ACM annual conference on Communications (1992)

Determining the appropriate line speed is one of many critical success factors in the design of teleprocessing systems. This paper integrates queuing formula into a comprehensive model to support line speed decisions. The model includes response time, message lengths and volumes, and computer processing speeds in a manner not previously described in the literatures.
The Lincoln tied-mixture HMM continuous speech recognizer
Authors: Douglas B. Paul
Venue: Proceedings of the workshop on Speech and Natural Language (1990)

The Lincoln robust HMM recognizer has been converted from a single Gaussian or Gaussian mixture pdf per state to tied mixtures in which a single set of Gaussians is shared between all states. There were some initial difficulties caused by the use of mixture pruning [12] but these were cured by using observation pruning. Fixed weight smoothing of the mixture weights allowed the use of word-boundary-context-dependent triphone models for both speaker-dependent (SD) and speaker-independent (SI) recognition. A second-differential observation stream further improved SI performance but not SD performance. The overall recognition performance for both SI and SD training is equivalent to the best reported according to the October 89 Resource Management test set. A new form of phonetic context model, the <i>semiphone,</i> is also introduced. This new model significantly reduces the number of states required to model a vocabulary.
Analysis of multithreaded microprocessors under multiprogramming
Authors: David E. Culler, Michial Gunter, James C. Lee
Venue: Proceedings of the 19th annual international symposium on Computer architecture (1992)

We examine multithreading to improve uniprocessor cost/performance on multiple processes. Processor utilization and cache behavior are studied analytically and under simulation by interleaving reference traces to model timesharing and multithreading. Multithreading a small number of threads is superior with large on-chip caches and significant memory latency. The switch need not be extremely fast. Surprisingly, miss ratios under multithreading may be lower than under timesharing, because switch-on-miss multithreading favors processes with better cache behavior.
The Processor Working Set and its Use in Scheduling Multiprocessor Systems
Authors: Dipak Ghosal, Giuseppe Serazzi, Satish K. Tripathi
Venue: IEEE Transactions on Software Engineering (1991)

The concept of a processor working set (PWS) as a single value parameter for characterizing the parallel program behavior is introduced. Through detailed experimental studies of different algorithms on a transputer-based multiprocessor machine, it is shown that the PWS is a robust measure for characterizing the workload of a multiprocessor system. It is shown that processor allocation strategies based on the PWS provide significantly better throughput-delay characteristics. The robustness of PWS is further demonstrated by showing that allocation policies that allocate processors more than the PWS are inferior in performance to those that never allocate more than the PWS-even at a moderately low load. Based on the results, a simple static allocation policy that allocates the PWS at low load and adaptively fragments at high load to one processor per job is proposed.
A generalized interconnect model for data path synthesis
Authors: Tai A. Ly, W. Lloyd Elwood, Emil F. Girczyc
Venue: Proceedings of the 27th ACM/IEEE Design Automation Conference (1991)

A generalized interconnect model for data path synthesis is presented. This is a multi-level interconnect model designed for synthesis under interconnect constraints. Two novel algorithms for dynamic interconnect allocation and interconnect synthesis are also described. These algorithms help implement the generalized interconnect model in the Elf hardware compiler.
The Requirements Apprentice: Automated Assistance for Requirements Acquisition
Authors: Howard B. Reubenstein, Richard C. Waters
Venue: IEEE Transactions on Software Engineering (1991)

An automated tool called the Requirements Apprentice (RA) which assists a human analyst in the creation and modification of software requirements is presented. Unlike most other requirements analysis tools, which start from a formal description language, the focus of the RA is on the transition between informal and formal specifications. The RA supports the earliest phases of creating a requirement, in which ambiguity, contradiction, and incompleteness are inevitable. From an artificial intelligence perspective, the central problem the RA faces is one of knowledge acquisition. The RA develops a coherent internal representation of a requirement from an initial set of disorganized imprecise statements. To do so, the RA relies on a variety of techniques, including dependency-directed reasoning, hybrid knowledge representations and the reuse of common forms (cliches). An annotated transcript showing an interaction with a working version of the RA is given.
Cryptographic key management
Authors: Dahl A. Gerberick
Venue: ACM SIGSAC Review (1990)

There are two main issues concerning data security on networks; controlling access and the vulnerability of data communication links. A brief introduction to the various techniques which may be applied to these concerns are given in this paper.
Native code process-originated migration in a heterogeneous environment
Authors: Charles M. Shub
Venue: Proceedings of the 1990 ACM annual conference on Cooperation (1990)

Dynamic migration has been investigated in several research efforts as a vehicle for load sharing, resource sharing, communication overhead reduction, failure robustness, and several other contexts. This paper presents a summary of related work in dynamic migration, and suggests motivations for considering heterogeneous migration. Next a design for heterogeneous migration, along with its restrictions is presented. A prototype implementation is described. Conclusions are drawn and future work is suggested.
A general approach to removing degeneracies
Authors: Ioannis Emiris, John Canny
Venue: Proceedings of the 32nd annual symposium on Foundations of computer science (1991)

Algorithms modeled as algebraic branching programs, with inputs from an infinite ordered field, are studied. Direct perturbations on the input, so that an algorithm designed under the assumption of nondegeneracy can be applied to all inputs, are described. A deterministic method for algorithms with determinant tests and a randomized one for arbitrary test expressions are defined. They both incur extra complexity factors that are constant in several cases. Moreover, polynomial and exponential time algorithms always remain in the same complexity class while being enhanced with the power to execute on arbitrary inputs. Both methods are distinguished by their conceptual elegance and are significantly faster than previous ones.