ppxscal/embedding_network huggingface dataset:
GURPR - a method for Global Software pipelining
Authors: Boronr Su, Shiyuan Dink, Jian Vank, Jinshi Xia
Venue: ACM SIGMICRO Newsletter (1988)

The software pipelining technique is an effective approach to the optimization of loops in array processor programs and microprograms. In this paper we present a global URPR algorithm--GURPR to optimize loops of different structures based on the LURPR method we presented in 1986. We start with a brief introduction to LURPR, then discuss the pipelining of loops with abnormal entries, conditional exits, more than one path, nested loops and subroutine calls respectively. Finally we present the complete GURPR algorithms.
Evaluating the impact of camera placement on teleoperator efficiency
Authors: Gregory M. Pisanich, Michael P. Prevost, Steven B. Hall
Venue: Proceedings of the 1st international conference on Industrial and engineering applications of artificial intelligence and expert systems - Volume 1 (1988)

An increasing body of evidence supports the claim that the placement (position and orientation) of a teleoperator's remote sensors (cameras) has a significant impact on the teleoperator's effectiveness. A clear understanding of what constitutes an optimal placement has however yet to be clearly formalized. Similarly, a cost effectiveness analysis of the alternative methods of achieving this optimal placement has yet to be undertaken. Trades addressing the increased efficiency of autonomous methods must, for instance, be evaluated in the light of increased system weight and reduced system reliability. This project has two goals: The first is to systematically study the impact of sensor/camera placement on teleoperator performance under a variety of circumstances and task requirements. The second goal is to evaluate the feasibility and utility of autonomously controlling the camera positioning and orientation. Initial results of the work to date support the conclusion that autonomous repositioning of the camera can significantly increase teleoperator effectiveness.
Path planning in 0/1/ weighted regions with applications
Authors: L. Gewali, A. Meng, J. S. Mitchell, S. Ntafos
Venue: Proceedings of the fourth annual symposium on Computational geometry (1988)

We consider the terrain navigation problem in a two-dimensional polygonal subdivision consisting of obstacles, &ldquo;free&rdquo; regions (in which one can travel at no cost), and regions in which cost is proportional to distance traveled. This problem is a special case of the weighted region problem and is a generalization of the well-known planar shortest path problem in the presence of obstacles. We present an &Ogr;(n2) exact algorithm for this problem and faster algorithms for the cases of convex free regions and/or obstacles. We generalize our algorithm to allow arbitrary weights on the edges of the subdivision. In addition, we present algorithms to solve a variety of important applications: (1) an &Ogr;(n2W) algorithm for finding lexicographically shortest paths in weighted regions (with W different weights); (2) an &Ogr;(k2n2) algorithm for planning least-risk paths in a simple polygon that contains k line-of-sight threats (this becomes &Ogr;(k4n4) in polygons with holes); and (3) an &Ogr;(k2n3) algorithm for finding least-risk watchman routes in simple rectilinear polygons (a watchman route is such that each point in the polygon is visible from at least one point along the route).
The design of auditory interfaces for visually disabled users
Authors: A. D. N. Edwards
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (1988)

Recent developments in the design of human-machine interfaces have resulted in interfaces which make access to computer-based equipment more difficult for visually disabled people. The aim of this project was to explore whether it is possible to adapt such interfaces so as to make them usable by people who cannot see a screen. The approach adopted was based upon two principles: the replacement of visual interface entities by auditory analogues and appropriately constraining the resultant interface. Two forms of sound were used to embody the auditory interface: musical tones and synthetic speech. In order to test the principles a word processing program was implemented which demonstrated that a visual program might be adapted to be accessed through such an interface.
O2, an object-oriented data model
Authors: C. Lecluse, P. Richard, F. Velez
Venue: Proceedings of the 1988 ACM SIGMOD international conference on Management of data (1988)

The Altair group is currently designing an object-oriented data base system called O2. This paper presents a formal description of the object-oriented data model of this system. It proposes a type system defined in the framework of a set-and-tuple data model. It models the well known inheritance mechanism and enforces strong typing.
Low-synchronization translation lookaside buffer consistency in large-scale shared-memory multiprocessors
Authors: B. Rosenburg
Venue: Proceedings of the twelfth ACM symposium on Operating systems principles (1989)

Operating systems for most current shared-memory multiprocessors must maintain translation lookaside buffer (TLB) consistency across processors. A processor that changes a shared page table must flush outdated mapping information from its own TLB, and it must force the other processors using the page table to do so as well. Published algorithms for maintaining TLB consistency on some popular commercial multiprocessors incur excessively high synchronization costs. We present an efficient TLB consistency algorithm that can be implemented on multiprocessors that include a small set of reasonable architectural features. This algorithm has been incorporated in a version of the MACH operating system developed for the IBM Research Parallel Processor Prototype (RP3).
Hypersim: a hypercube simulator for parallel systems performance modeling
Authors: W. L. Bain, S. Arshi
Venue: Proceedings of the third conference on Hypercube concurrent computers and applications: Architecture, software, computer systems, and general issues - Volume 1 (1988)

This paper describes a software tool for parallel systems performance modeling, called Hypersim. Hypersim was developed by Intel Scientific Computers in order to evaluate the performance of various architectural alternatives for its future parallel machines. Hypersim runs on the Sun* 3 workstation and on the Intel iPSC concurrent super computer. The use of the iPSC system allows us to simulate large models, which do not fit within the Sun's physical memory and cause excessive paging delays. Hypersim currently simulates hypercube architectures with various arities and dimensions. It implements the full user interface of the iPSC Node Operating System, which includes facilities for dynamic process creation and message passing between processes. The simulator is highly parametrized to represent timings for memory access, message and interrupt propagation, process switches, and instruction execution. Key software and hardware functions are implemented in a modular manner, so that detail can be added as the architecture is elaborated. This object oriented approach results in a relatively simple and extensible design, and the iPSC version differs minimally from the Sun version. Global object management and synchronization are provided by the Interwork II concurrent programming environment.
Plan-based representations of pascal and fortran code
Authors: C.-C. Yu, S. P. Robertson
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (1988)

The first step in program modification is comprehension. Several researchers argue that programmers utilize plan-based representations when composing or comprehending code. In this study we tested the psychological validity of this proposal and examined the nature of plan-based program representations. Experienced programmers were asked to segment code and sort programs. The segmenting data showed that programmers agree on the major components of a program and that these components are defined by goals in a plan representation. Pascal and FORTRAN programs that employ the same plan structure were segmented into similar components. Program sorting data also showed clustering into plan groups. However task related dimensions are also important parts of program representations.
Stretching a Knock-Knee Layout for Multilayer Wiring
Authors: M. L. Brady, M. Sarrafzadeh
Venue: IEEE Transactions on Computers (1990)

The problem of stretching a knock-knee layout in the knock-knee mode to ensure its wirability is considered. An optimal algorithm for the problem in two layers is presented. A 4/3 approximation algorithm for the corresponding problem in three layers, shown to be NP-complete, is devised.
Analysis of bus hierarchies for multiprocessors
Authors: D. C. Winsor, T. N. Mudge
Venue: ACM SIGARCH Computer Architecture News (1988)

In order to build large shared-memory multiprocessor systems that take advantage of current hardware-enforced cache coherence protocols, an interconnection network is needed that acts logically as a single bus while avoiding the electrical loading problems of a large bus. This paper develops models of bus delay and bus throughput to aid in optimizing the design of such a network. These models are used to derive a method for determining the maximum number of processors that can be supported by each of several bus organizations including conventional single-level buses, two-level bus hierarchies, and binary tree interconnections. An example based on a TTL bus is presented to illustrate the methods and to show that shared-memory multiprocessors with several dozen processors are feasible using a simple two-level bus hierarchy.
Virtual memory for a hypercube multiprocessor
Authors: J. M. Francioni, D. A. Poplawski, S. Pahwa
Venue: Proceedings of the third conference on Hypercube concurrent computers and applications: Architecture, software, computer systems, and general issues - Volume 1 (1988)

Most hypercube programs are structured so that all nodes contain an identical copy of the node program, as well as a complete copy of the node operating system program. This is a tremendous waste of memory, which ends up limiting the size and complexity of hypercube application programs. One way around this problem is to implement a virtual memory on the hypercube, whereby one copy of the node and operating system program is distributed among all the nodes of the hypercube and each node performs demand paging for the pages not resident in that node. Since almost none of the existing hypercubes have the hardware to support a virtual memory, this must be done in software. In this paper, we discuss a feasibility study of a hypercube virtual memory for executable code based on an implementation which requires no hardware support. We also explain the general principles involved in this type of virtual memory, and discuss how the features and restrictions of a hypercube architecture affect the implementation. In particular we show, via simulation results from real hypercube applications, ways to reduce the paging traffic in the hypercube.
Hypertext as a means for knowledge acquisition
Authors: T. L. Wells
Venue: Issue 108 (April 1989) (1989)

The most time consuming portion of constructing an expert system is the knowledge acquisition phase. A general knowledge acquisition tool designed around a hypertext concept could allow a knowledge engineer to list important concepts, create nodes attached to these concepts which explain their relevance, connect related concepts by linking their nodes, use graphics to explain difficult concepts, and even critique information entered into the system previously. In such a system, knowledge acquisition would not be confined to linear input of information. The knowledge engineer could use the hypertext system to compile knowledge gathered from an expert after interviewing, or s/he could enter the knowledge into the system as the expert sits there telling her/him what information to encode. The advantage of a hypertext knowledge acquisition tool is that all knowledge relevant to the expert system would be centralized into a hypertext knowledge base which the expert, or experts, can peruse and verify before the knowledge is encoded into a representation scheme. Then when the knowledge engineer does transfer the knowledge into a scheme suitable for use by an expert system, s/he can be sure that the knowledge is complete, sufficient, necessary, and correct.
A process oriented approach to an intelligent design aid
Authors: K. D. Baker
Venue: Proceedings of the 2nd international conference on Industrial and engineering applications of artificial intelligence and expert systems - Volume 1 (1989)

The model has strongly influenced the construction of the design aid both in its functionality and in the specification of the user interface. A designer is able to interact with the tool via a direct manipulation interface which offers a drawing board metaphor. Any part of the evolving hierarchical design representation can be accessed and it supports a range of funtionality from user specified mathematical function to individual electronic components. Multiple versions of all or part of the design are maintained by the system and a history of the design steps and decisions establishes a model of the designers' use of the tool. The initial system has been implemented using some of the facilities provided by the Automatic Reasoning Tool (ART) from Inference Corporation within an object-oriented framework. The limitations of these tools are addressed and the future direction of the work discussed.
Plowing: modifying cells and routing 45:9D - layouts
Authors: K. M. Just, W. L. Schiele, T. Krüger
Venue: Proceedings of the 26th ACM/IEEE Design Automation Conference (1989)

This paper describes a plowing procedure which moves and modifies cells and routing. The plow pushes aside all obstacles one by one, thus penetrating into the layout. The process leads to a compaction at the front side of the plow. The compaction is performed in accordance with the minimum spacing rules and with automatic jog insertion. Objects of the layout representation are cells, contacts, and wires. A wire is represented by a path of segments which lie in one of two layers, at angles of multiples of 45&deg;. The generated blank space is used for adding new objects or resizing geometries.
The implications of program dependencies for software testing, debugging, and maintenance
Authors: A. Podgurski, L. Clarke
Venue: ACM SIGSOFT Software Engineering Notes (1989)

This paper presents a formal, general model of program dependencies. Two generalizations of control and data dependence, called weak and strong syntactic dependence, are presented. Some of the practical implications of program dependencies are determined by relating weak and strong syntactic dependence to a relation called semantic dependence. Informally, one program statement is semantically dependent on another if the latter statement can affect the execution behavior of the former. It is shown that weak syntactic dependence is a necessary condition for semantic dependence, but that neither weak nor strong syntactic dependence are sufficient conditions. The implications of these results for software testing, debugging, and maintenance are then explored.
Specification and verification of collusion-free broadcast networks
Authors: P. Jain, S. S. Lam
Venue: Symposium proceedings on Communications architectures and protocols (1988)

For high-speed local area networks that offer integrated services for data, voice, and image traffic, a class of demand-assigned multiple-access protocols have been presented in the literature. These protocols exploit the directionality of signal propagation and enforce time constraints to achieve collision-freedom. A correct implementation of such a protocol requires a careful analysis of time-dependent interactions of event occurrences using a formal method. To date, most protocol verification methods are intended for the analysis of asynchronous communication over point-to-point channels. We present a model for broadcast bus networks. The novel features of our model include the ability to specify broadcast channels and the specification of real-time behavior. The broadcast characteristics of cables or buses are captured by some simple axioms. Real time is modeled as a discrete quantity using clocks and time variables. Real-time properties are specified by safety assertions. To illustrate our model and analysis method, we present a specification of the Expressnet protocol. We found that to achieve collision-freedom, a small modification to the original Expressnet protocol is needed.
Performance comparison of the Cray-2 and Cray X-MP/416 supercomputers
Authors: M. L. Simmons, H. J. Wasserman
Venue: Proceedings of the 1988 ACM/IEEE conference on Supercomputing (1988)

The serial and parallel performance of one of the world's fastest general purpose computers, the CRAY-2, is analyzed using the standard Los Alamos Benchmark Set plus codes adopted for parallel processing. For comparison, architectural and performance data are also given for the CRAY X-MP/416. Factors affecting performance, such as memory bandwidth, size and access speed of memory, and software exploitation of hardware, are examined. The parallel processing environments of both machines are evaluated, and speed-up measurements for the parallel codes are given.
Fast Multiplication Without Carry-Propagate Addition
Authors: M. D. Ercegovac, Tomas Lang
Venue: IEEE Transactions on Computers (1990)

Conventional schemes for fast multiplication accumulate the partial products in redundant form (carry-save or signed-digit) and convert the result to conventional representation in the last step. This step requires a carry-propagate adder which is comparatively slow and occupies a significant area of the chip in a VLSI implementation. A report is presented on a multiplication scheme (left-to-right, carry-free, LRCF) that does not require this carry-propagate step. The LRCF scheme performs the multiplication most-significant bit first and produces a conventional sign-and-magnitude product (most significant n bits) by means of an on-the-fly conversion. The resulting implementation is fast and regular and is very well suited for VLSI. The LRCF scheme for general radix r and a radix-4 signed-digit implementation are presented.
The role of opaque types to build abstractions
Authors: A. Corradi, L. Leonardi
Venue: ACM SIGPLAN Notices (1988)

This note examines the MODULA-2 approach to build data abstractions and abstract data types. MODULA-2 provides a byreference semantics by providing opaque types via pointers. The paper compares this mechanism with the one furnished by ADA (*). A comparison with object-oriented systems brings out the issue of assignment, copy and compare operations. That leads to a constructive methodology for abstract data types in MODULA-2. Any abstraction must furnish copy operations with two different semantics, respectively shallow and deep, and related equality and inequality operations.
Unreachable States in Model-Oriented Specifications
Authors: Robin A. Nicholl
Venue: IEEE Transactions on Software Engineering (1990)

Formal specification methods are being used to improve the quality of written specifications and to eliminate errors at an early stage of software development. The detection of errors in a specification generally requires that the specification be compared against some loosely defined real-world concepts. A criterion for evaluating the quality of a model-oriented specifications is introduced and the problems associated with specifications which do not meet this criterion are explained. These problems are particularly troublesome when reusable software components are being specified or when a bottom-up implementation strategy is being used.
Polynomial Methods for Structure from Motion
Authors: C. Jerian, R. Jain
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1990)

The authors analyze the limitations of structure from motion (SFM) methods presented in the literature and propose the use of a polynomial system of equations, with the unit quaternions representing rotation, to recover SFM under perspective projection. The authors combine the equations by the method of resultants with the MAXIMA symbolic algebra system, reducing the system to a single polynomial. Its real roots are then found with Sturm sequences. Since this system has multiple solutions, a hypothesize-and-verify scheme is used to eliminate incorrect ones. The scheme diminishes the sensitivity of using polynomial equations. The authors examine the effect of different rotation axes and angles on SFM accuracy and compare the performance of the algorithm to a few earlier approaches. Generally, it is found that a large amount of motion is the most important factor in getting good SFM accuracy.
Dimension-based analysis of hypotheticals from supreme court oral argument
Authors: E. L. Rissland
Venue: Proceedings of the 2nd international conference on Artificial intelligence and law (1989)

In this paper we examine a sequence of hypotheticals taken from a Supreme Court oral argument. We use the idea of a &ldquo;dimension,&rdquo; developed previously in our case-based reasoning system HYPO, to analyze the hypotheticals and to speculate on how the Justices might have arrived at them. The case we consider is taken from the area of Fourth Amendment law concerning warrantless search and seizure.
Buying a computer: a guided tour
Authors: S. H. Gammill
Venue: Proceedings of the 17th annual ACM SIGUCCS conference on User Services (1989)

One of the more time consuming tasks for user services personnel is the coordinating of individual computer discount purchase programs, especially in smaller schools where the program is not managed by a separate bookstore or computer store. Frequently the potential student buyer does not have a very clear idea of what they want or need in a computer system, and the same basic questions are asked again and again. In an effort to alleviate this problem, the Concordia College academic computing office is developing a computer purchase information center, consisting of a bulletin board display in the main micro lab with a document rack for price lists and handouts of general instructions. The heart of the system is a PC-PILOT program called &ldquo;Buying a Computer&rdquo;, which takes the user through a series of question/answer frames to determine both the primary use for their computer and individual budget considerations. Based on the user choices, a list of possible options is shown which may be printed out. After this, it is hoped the student will have a clearer idea of what their needs might be, so that when they visit the user services office to discuss a purchase the time will be spend more productively. This paper will discuss the setup of the information center, present a description of the PILOT program, and evaluate its effectiveness over several months.
APL for economic and management control in KTAS
Authors: Torben Iversen
Venue: ACM SIGAPL APL Quote Quad (1990)

In this paper I want to describe the use of APL for economic and management control in the Copenhagen Telephone Company, KTAS.
A language-based design for portable data files
Authors: C. Burch
Venue: ACM SIGPLAN Notices (1989)

Currently data files to be accessed remotely from dissimilar systems must be transformed to the local language processors' file format and data representation; a process that has changed little since punch cards were the main form of portable data files. A standard is proposed for languages to use the data type information available to the runtime library to make these data transformations before the data is transferred to the file or the user's variables. By specifying one binary format for each basic data type (integer, real, logical, etc) and a file organization that is portable between record-oriented and stream-oriented file systems, we can standardize file formats that will be usable on practically all current systems.