ppxscal/embedding_network huggingface dataset:
Effect of doping profiles on Si/CoSi2 permeable base transistors
Authors: A. Schüppen, L. Vescan, R. Jebasinski, A. v.d.Hart, H. Lüth
Venue: Microelectronic Engineering (1992)

Permeable base transistors (PBT) with buried epitaxial CoSi"2 Gates have been fabricated by local high-dose cobalt ion-implantation, with subsequent rapid thermal annealing and homoepitaxial overgrowth by low-pressure vapor phase epitaxy. Transistors obtained by Co ion-implantations into low-doped n-type Si (100) as well as Si(111) show typical output characteristics with triode-like and pentode-like regions, depending on doping concentration and applied gate voltage. Pinch-off was observed at zero and at low negative gate voltages, respectively. Breakdown drain-source voltage exceeds 20 V for devices with 0.7 @mm gate spacings and finger widths. A transconductance of 80 mS/mm has been obtained with PBTs on a low resistivity substrate, wherein the CoSi"2 gate was implanted into an epitaxial Si layer.
Schema evolution in database systems: an annotated bibliography
Authors: John F. Roddick
Venue: ACM SIGMOD Record (1992)

Schema Evolution is the ability of a database system to respond to changes in the real world by allowing the schema to evolve. In many systems this property also implies a retaining of past states of the schema. This latter property is necessary if data recorded during the lifetime of one version of the schema is not to be made obsolete as the schema changes. This annotated bibliography investigates current published research with respect to the handling of changing schemas in database systems.
Ray shooting in convex polytopes
Authors: Otfried Schwarzkopf
Venue: Proceedings of the eighth annual symposium on Computational geometry (1992)

Let H be a set of n halfspaces in Ed (where the dimension d &ge; 4 is fixed), and P(H) the convex polytope defined as their intersection. We show that P(H) can be preprocessed in time and space O(n[d/2]/(log n)[d/2]-&egr;) (for any fixed &egr; > 0) so that ray shooting queries with rays starting in P(H) can be answered in time O(log n). This improves previous bounds by obtaining optimal query time and by improving the product Q(n)S(n)1/[d/2] (Q(n) and S(n) denoting query time and storage of a data structure for this problem) to O(n(log n)&egr;) for an arbitrarily small &egr; > 0. By a well known lifting transformation, the results imply the same bounds for nearest (or furthest) neighbor queries in space of one dimension lower, which is an improvement in itself. We furthermore show that a structure for the ray shooting problem can be dynamically maintained under a sequence of random insertions, using the history of the maintenance process for the polytope as a point location data structure. The expected update time is O(m[d/2]-1(log m)O(1)), the query time for ray shooting queries is O(log2 m) with high probability, where m is the current number of points.
CHI'90 workshop on visual interfaces to geometry
Authors: Werner Kuhn, Max J. Egenhofer
Venue: ACM SIGCHI Bulletin (1991)

The purpose of this interdisciplinary workshop was to explore and integrate advanced approaches to the visual representation and interactive manipulation of geometric information. The approach taken was to establish desirable properties of interfaces, identify problems in achieving them, and suggest new approaches to solve these problems, in order to improve the communication between users and systems when dealing with geometric information.
An interface for interactive spatial reasoning and visualization
Authors: James R. Osborn, Alice M. Agogino
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (1992)

An interface for software that creates a natural environment for engineering graphics students to improve their spatial reasoning and 3D visualization skills is described. The skills of interest involve spatial transformations and rotations, specifically those skills that engineers use to reason about 3D objects based on 2D representations. The software uses an intuitive and interactive interface allowing direct manipulation of objects. Animation capability is provided to demonstrate the relationship between arbitrary positions of an object and standard orthographic views. A second skill of interest requires visualization of a cutting-plane intersection of an object. An interface is developed which allows intuitive positioning of the cutting-plane utilizing the metaphor of a &ldquo;pool of water&rdquo; in which the object is partially submerged. The surface of the water represents the cutting plane. Adjustment of the pool depth combined with direct manipulation of the object provides for arbitrary positioning of the cutting-plane. Subjective evaluation of the software thus far indicates that students enjoy using it and find it helpful. A formal testing plan to objectively evaluate the software and interface design is underway.
Functional decomposition of polynomials: The wild case
Authors: Joachim von zur Gathen
Venue: Journal of Symbolic Computation (1990)

If g and h are polynomials of degrees r and s over a field, their functional composition f = g(h) has degree n = rs. The functional decomposition problem is: given f of degree n = rs, determine whether such g and h exist, and, in the affirmative case, compute them. An apparently difficult case is when the characteristic p of the ground field divides r. This paper presents a polynomial-time partial solution for this ''wild'' case; it works, e.g., when p^2 @? r.
Training set issues in SRI's DECIPHER speech recognition system
Authors: Hy Murveit, Mitch Weintraub, Mike Cohen
Venue: Proceedings of the workshop on Speech and Natural Language (1990)

SRI has developed the DECIPHER system, a hidden Markov model (HMM) based continuous speech recognition system typically used in a speaker-independent manner. Initially we review the DECIPHER system, then we show that DECIPHER's speaker-independent performance improved by 20% when the standard 3990-sentence speaker-independent test set was augmented with training data from the 7200-sentence resource management speaker-dependent training sentences. We show a further improvement of over 20% when a version of corrective training was implemented. Finally we show improvement using parallel male- and female-trained models in DECIPHER. The word-error rate when all three improvements were combined was 3.7% on DARPA's February 1989 speaker-independent test set using the standard perplexity 60 wordpair grammar.
Singularities of Principal Direction Fields from 3-D Images
Authors: Peter T. Sander, Steven W. Zucker
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1992)

Generic singularities can provide position-independent information about the qualitative shape of surfaces. The authors determine the singularities of the principal direction fields of a surface (its umbilic points) from a computation of the index of the fields. The authors present examples both for 3-D synthetic images to which noise has been added and for clinical magnetic resonance images.
A perspective on ubiquitous computing
Authors: Vint Cerf
Venue: Proceedings of the 1992 ACM annual conference on Communications (1992)

This panel explores the networking impact of placing hundreds to thousands of computers into the office or home environment using wireless (e.g. infrared) techniques to interlink them.
An adaptive concurrency control algorithm (abstract)
Authors: James Canning, P. Muthuvelraj, John Sieg
Venue: Proceedings of the 1990 ACM annual conference on Cooperation (1990)

Correctness of concurrent executions of multiple database transactions is assured by concurrency control techniques. Performance analyses, e.g., [Agr85], show that optimistic concurrency control techniques perform more efficiently than pessimistic techniques when there is low contention for the data and low resource utilization. Otherwise pessimistic techniques perform better. Because the designer of a database system can rarely predict data contention and resource utilization, it is desirable that a database system adaptively select a concurrency control technique at runtime. We present an algorithm for partitioning the collection of active database transactions into a set of clusters. The partitioning algorithm guarantees that there are no data conflicts between transactions to distinct clusters. Different concurrency control techniques can be applied in distinct clusters. Our algorithm uses the number of transactions in a cluster as a measure of data contention. Transactions in newly formed clusters are handled by an optimistic scheduler. When the number of transactions in a cluster exceeds a certain threshold, the cluster becomes pessimistic. Such a cluster's current transactions complete, and then newly entering transactions can begin, managed by a pessimistic scheduler. We have designed data structures to support the efficient maintenance of clusters. We have also begun to develop a theory of correct cluster configurations. We are undertaking a simulation study to compare the performances of pessimistic techniques, optimistic techniques, and our adaptive approach.
ESPRIT, the European strategic programme for research and development in information technology
Venue: Proceedings of the workshop on Speech and Natural Language (1991)

The communications from several of the panelists concerned the ESPRIT program, which could not fairly be represented in the short time allotted to the panel discussion. Included here are some comments from Patrick van Hove, the head of the ESPRIT program, an outline of the program, the motivation for the program, and a brief description of each of the many projects funded by the program.
The use of Knuth-Bendix methods to solve the wordproblem in automatic groups
Authors: D. B. A. Epstein, D. F. Holt, S. E. Rees
Venue: Journal of Symbolic Computation (1991)

Certain classes of infinite groups arising from geometry and topology are known to have solvable word problem. We describe the development of practical methods for the solution of the word problem based on the reduction of words in the generators to a normal form. The Knuth-Bendix completion procedure is the principal tool used but, in the case that this process does not halt, we use alternative methods involving the construction of finite-state automata. A computer implementation of these procedures together with some performance statistics on some simple examples are also described.
Realizing a temporal complex-object data model
Authors: Wolfgang Käfer, Harald Schöning
Venue: Proceedings of the 1992 ACM SIGMOD international conference on Management of data (1992)

Support for temporal data continues to be a requirement posed by many applications such as VLSI design and CAD, but also in conventional applications like banking and sales. Furthermore, the strong demand for complex-object support is known as an inherent fact in design applications, and also emerges for advance &ldquo;conventional&rdquo; applications. Thus, new advanced database management systems should include both features, i.e. should support temporal complex-objects. In this paper, we present such a temporal complex-object data model. The central notion of our temporal complex-object data model is a time slice, representing one state of a complex object. We explain the mapping of time slices onto the complex objects supported by the MAD model (which we use for an example of a non-temporal complex-object data model) as well as the transformation process of operations on temporal complex-objects into MAD model operations. Thereby, the basic properties of the MAD model are a prerequisite for our approach. For example, time slices can only be directly stored, if non-disjunct (i.e. over-lapping) complex objects are easily handled in the underlying complex-object data model.
Automating the Generation of Coordinated Multimedia Explanations
Authors: Steven K. Feiner, Kathleen R. McKeown
Venue: Computer (1991)

An explanation system developed to overcome the disadvantages of conventional authoring in multimedia applications is presented. This experimental test bed for the automated generation of multimedia explanations is called COMET (coordinated multimedia explanation testbed), and has as its goal the coordinated, interactive generation of explanations that combine text and three-dimensional graphics, all of which is generated on the fly. In response to a user request for an explanation, COMET dynamically determines the explanation's content using constraints based on the type of request, the information available in a set of underlying knowledge bases, and information about the user's background and goals. Having determined what to say, COMET also determines how to express it at the time of generation. A brief overview of COMET's domain and architecture is followed by a description of the specific ways in which COMET can coordinate its text and graphics. The current status and limitations of COMET are discussed.
Combining matching algorithms: The regular case
Authors: Tobias Nipkow
Venue: Journal of Symbolic Computation (1991)

The problem of combining matching algorithms for equational theories with disjoint signatures is studied. It is shown that the combined matching problem is in general undecidable but that it becomes decidable if all theories are regular. For the case of regular theories an efficient combination algorithm is developed. As part of that development we present a simple algorithm for solving the word problem in the combination of arbitrary equational theories with disjoint signatures.
Embedded Processes in Stochastic Petri Nets
Authors: William Henderson, Peter G. Taylor
Venue: IEEE Transactions on Software Engineering (1991)

Embedded discrete time processes are used to study a class of SPNs (stochastic Petri nets) which have a closed-form equilibrium distribution. These SPNs have probabilistic output bags, colored tokens, and alternating periods of arbitrarily distributing enabling and firing times (periods of time between transitions becoming enabled and absorption of tokens and between transitions absorbing tokens and depositing them in output places, respectively). In addition, an aggregation procedure is proposed which, in certain nets, not only reduces a complex SPN to a much simpler skeleton SPN but also obtains results for the skeleton SPN with are exact marginal distributions for the original SPN.
Automating inductionless induction using test sets
Authors: Deepak Kapur, Paliath Narendran, Hantao Zhang
Venue: Journal of Symbolic Computation (1991)

The inductionless induction (also called proof by consistency) approach for proving equations by induction from an equational theory, requires a consistency check for equational theories. A new method using test sets for checking consistency of an equational theory is proposed. Using this method, a variation of the Knuth-Bendix completion procedure can be used for automatically proving equations by induction. The method does not suffer from limitations imposed by the methods proposed by Musser as well as by Huet and Hullot, and is as powerful as Jouannaud and Kounalis' method based on ground-reducibility. A theoretical comparison of the test set method with Jouannaud and Kounalis' method is given showing that the test set method is generally much better. Both the methods have been implemented in RRL, Rewrite Rule Laboratory, a theorem proving environment based on rewriting techniques and completion. In practice also, the test set method is faster than Jouannaud and Kounalis' method. The test set construction can also be used to check for the sufficient-completeness property of equational axiomatizations including algebraic specifications of abstract data types as well as for identifying constructors in an algebraic specification.
Rationale for the proposed standard for a generic package of elementary functions for Ada
Authors: Kenneth W. Dritz
Venue: ACM SIGAda Ada Letters (1991)

This paper supplements the "Proposed Standard for a Generic Package of Elementary Functions for Ada," written by the ISO-IEC/JTC1/SC22/WG9 (Ada) Numerics Rapporteur Group. Based on recommendations made jointly by the ACM SIGAda Numerics Working Group and the Ada-Europe Numerics Working Group, the proposed elementary functions standard is the first of several anticipated collateral standards to address the interrelated issues of portability, efficiency, and robustness of numerical software written in Ada. Organized as a series of questions and answers, this supplement outlines the reasoning by which the proposed standard came to acquire certain features and exclude others.
On the vectorization of graph algorithms (abstract)
Authors: Larry Basenspiler, Thomas Hain, Ben King
Venue: Proceedings of the 1990 ACM annual conference on Cooperation (1990)

We investigate the vectorization, on a Cray X-MP, of three graph algorithms, and introduce a data structure for representing graphs particularly amenable to this technique. The use of bit-wise instructions on the Cray, in conjunction with this data structure, leads to the efficient implementation of graph operations. In addition, this data structure makes the space requirement for the considered graph algorithms virtually optimal. The first investigated algorithm is the Breadth First Traversal, which is linear in execution time relative to the size of input. While this was found to be intrinsically non-vectorizable, execution times of its implementation using the introduced data structure did not increase. The second and third algorithms are both for calculating the chromatic polynomial of a graph, and whose execution time grows exponentially with the size of input. The second, by Read, is the fastest previously existing algorithm. However, since it uses levels of indirection in referencing edges, vectorization is usually inhibited. Only minor loops were vectorizable, and the speedup due to vectorization was less than two. The third algorithm uses the introduced data structure, and achieved a speedup of over three. Furthermore, this algorithm, when compared to the second one, was able to handle sparse graph (with average vertex degree of 4) approximately twice as large, while using similar time and space limits. This work was supported by NSF grant No. ASC-8900690.
The impact of memory organization on the performance of matrix multiplication
Authors: J.-Fr. Hake, W. Homberg
Venue: Proceedings of the 1990 ACM/IEEE conference on Supercomputing (1990)

Matrix multiplication may be considered as a model problem for analyzing the performance of more complex algorithms. On CRAY and IBM computer systems, there are library routines which for this task operate at high megaflop rates. Other programs from numerical linear algebra do not always achieve this level of sophistication; e.g. they suffer from performance degradation caused by memory access conflicts. This effect has been studied considering the performance of subroutines for matrix multiplication on CRAY X-MP, CRAY Y-MP, and IBM 3090. Results are analyzed by means of simulation.
A vectorized 3-D finite element model for transient simulation of two-phase heat transport with phase transformation and a moving interface
Authors: Mark Christon
Venue: Proceedings of the 1990 ACM/IEEE conference on Supercomputing (1990)

The implementation of a fully vectorized 3-D finite element model on the CRAY X-MP/Y-MP architecture is presented. Issues involved in vectorizing the computationally intensive modules of the finite element model are discussed. Fully vectorized numerical integration coupled with a preconditioned conjugate gradient linear system solver results in an application performance of 140 MFLOPS with the linear system solver achieving 162 MFLOPS (Y-MP single processor). The vector/scalar speedup for the finite element code is approximately 14.
EASY/VI&mdash;a new instructional computer
Authors: Luisa Koneva, Jordan Denev
Venue: ACM SIGCSE Bulletin (1990)

In this paper it is suggested a simple hypothetical computer which has been designed to assist teaching of the basic concepts in introductory course in computer organization and assembly language programming. The hypothetical computer and the instructional assembly language presented here have some new features which facilitate learning significantly. They have been designed to be a vehicle in almost all the lectures of the course.
Simulating procurement in the classroom
Authors: Michael W. Berry
Venue: ACM SIGCSE Bulletin (1992)

The process known as procurement is commonly used by academia, industry, and government to acquire the most suitable computer system for their particular working environments. The challenge is to purchase machines yielding the desired performance given certain constraints in funding. The guidelines used in the acquisition of equipment can vary from customer to customer. Similarly, the demonstration of machine performance by computer vendors may differ according to the market type and share they control. In this paper, we describe a project from a recent graduate course on Performance Evaluation within the Department of Computer Science at the University of Tennessee, Knoxville, concerning a simulation of the procurement process by studying the interactions between computer vendors and the scientific community (academia, industry, and government). The goals of this project were: (i) to define and interpret the scientific methods used by customers to acquire their equipment, (ii) to equate computational work with machine performance and make cost-effective purchases, (iii) to select appropriate hardware/software for customer's needs, (iv) to determine effective methods of performance presentation, and (v) to investigate the psychology of vendor-customer relations within a scientific computing environment.
Babbage's Expectations for his Engines
Authors: Maurice V. Wilkes
Venue: IEEE Annals of the History of Computing (1991)

Babbage's expectations for his Difference Engine were those of a young enthusiast. Although he failed to complete his version of the engine, an independent implementation of his ideas was carried through by Georg and Edvard Scheutz. Two Scheutz engines were built and put to work, one at the Registrar-General's Office in London and one at the Dudley Observatory in Albany, N. Y. They performed as intended, but failed to revolutionize the making of mathematical tables as Babbage had hoped they would. When Babbage was 45years old. he wrote, but did not publish, a description of the Analytical Engine. Here he showed vision verging on genius. His judgment on the design and utility of the Analytical Engine was as sound as his judgment on matters concerned with the Difference Engine was weak. Studies by A. G. Bromley, based on an examination of his notebooks, have brought out his remarkable achievements at what we would now call the microprogram level and also the insights that eluded him at the user level. His failure to publish may have been because he never arrived at what he regarded as a satisfactory system for programming at the user level.
Detection of linear errors via domain testing
Authors: Steven J. Zeil, Faten H. Afifi, Lee J. White
Venue: ACM Transactions on Software Engineering and Methodology (TOSEM) (1992)

Domain testing attempts to find errors in the numeric expressions affecting the flow of control through a program. Intuitively, domain testing provides a systematic form of boundary value testing for the conditional statements within a program. Several forms of domain testing have been proposed, all dealing with the detection of linear errors in linear functions. Perturbation analysis has been previously developed as a measure of the volume of faults, from within a selected space of possible faults, left undetected by a test set. It is adapted here to errors and error spaces. The adapted form is used to show that the different forms of domain testing are closer in error detection ability than had been supposed. They may all be considered effective for finding linear errors in linear predicate functions. A simple extension is proposed, which allows them to detect linear errors in nonlinear predicate functions using only a single additional test point.