ppxscal/embedding_network huggingface dataset:
Parallel language constructs for tensor product computations on loosely coupled architectures
Authors: P. Mehrotra, J. van Rosendale
Venue: Proceedings of the 1989 ACM/IEEE conference on Supercomputing (1989)

Distributed memory architectures offer high levels of performance and flexibility, but have proven awkward to program. Current languages for nonshared memory architectures provide a relatively low-level programming environment, and are poorly suited to modular programming, and to the construction of libraries. This paper describes a set of language primitives designed to allow the specification of parallel numerical algorithms at a higher level. We focus here on tensor product array computations, a simple but important class of numerical algorithms. We consider first the problem of programming one dimensional &ldquo;kernel&rdquo; routines, such as parallel tridiagonal solvers, and after that look at how such parallel kernels can be combined to form parallel tensor product algorithms.
Unification in permutative equational theories is undecidable
Authors: Manfred Schmidt-Schauss
Venue: Journal of Symbolic Computation (1989)

An equational theory @? is permutative if for all terms s, t: s = "@?t implies that the terms s and t contain the same symbols with the same number of occurrences. The class of permutative equational theories includes the theory of AC (associativity and commutativity). It is shown in this research note that there is no algorithm that decides @?-unifiability of terms for all permutative theories. The proof technique is to provide, for every Turing machine M, a permutative theory with a confluent term-rewriting system such that narrowing on certain terms simulates the Turing machine M.
Indefinite and maybe information in relational databases
Authors: Ken-Chih Liu, Rajshekhar Sunderraman
Venue: ACM Transactions on Database Systems (TODS) (1990)

This paper extends the relational model to represent indefinite and maybe kinds of incomplete information. A data structure, called an I-table, which is capable of representing indefinite and maybe facts, is introduced. The information content of I-tables is precisely defined, and an operator to remove redundant facts is presented. The relational algebra is then extended in a semantically correct way to operate on I-tables. Queries are posed in the same way as in conventional relational algebra; however, the user may now expect indefinite as well as maybe answers.
Experimental Evaluation of a Reusability-Oriented Parallel Programming Environment
Authors: James C. Browne, John Werth, Taejae Lee
Venue: IEEE Transactions on Software Engineering (1990)

Reports on the initial experimental evaluation of ROPE (reusability-oriented parallel programming environment), a software component reuse system. ROPE helps the designer find and understand components by using a new classification method called structured relational classification. ROPE is part of a development environment for parallel programs which uses a declarative/hierarchical graphical programming interface. This interface allows use of components with different levels of abstraction, ranging from design units to actual code modules. ROPE supports reuse of all the component types defined in the development environment. Programs developed with the aid of ROPE were found to have error rates far less than those developed without ROPE.
The Strength of Weak Learnability
Authors: Robert E. Schapire
Venue: Machine Learning (1990)

This paper addresses the problem of improving the accuracy of an hypothesis output by a learning algorithm in the distribution-free (PAC) learning model. A concept class is learnable (or strongly learnable) if, given access to a source of examples of the unknown concept, the learner with high probability is able to output an hypothesis that is correct on all but an arbitrarily small fraction of the instances. The concept class is weakly learnable if the learner can produce an hypothesis that performs only slightly better than random guessing. In this paper, it is shown that these two notions of learnability are equivalent.A method is described for converting a weak learning algorithm into one that achieves arbitrarily high accuracy. This construction may have practical applications as a tool for efficiently converting a mediocre learning algorithm into one that performs extremely well. In addition, the construction has some interesting theoretical consequences, including a set of general upper bounds on the complexity of any strong learning algorithm as a function of the allowed error &epsi;.
State trees as structured finite state machines for user interfaces
Authors: James Rumbaugh
Venue: Proceedings of the 1st annual ACM SIGGRAPH symposium on User Interface Software (1988)

State trees are a technique for specifying the control of an interactive system by organizing states into trees to define shared structure and behavior. The tree structure permits inheritance of state information, event traps, and entry and exit actions from states to substates, thereby sharing information and reducing the amount of code to be written. An interface can be restructured by moving entire subtrees as modules. State trees separate the recognition of commands from their implementation, allowing either to be modified independently. State trees structure flow of control within an implementation without imposing an identical structure on the interface itself, which need not be hierarchical. State trees have been implemented in an object-oriented language and used to write interactive applications.
A MACSYMA program for the multiple bifurcation analysis of double-diffusive convection
Authors: Jerry F. Magnan
Venue: Journal of Symbolic Computation (1989)

We employ a MACSYMA program for the formal, perturbation, multiple bifurcation analysis of a system of nonlinear PDEs arising in double-diffusive convection. The program requires, as input, the system of PDEs to be solved, the form of the asymptotic expansion of the solution and of the bifurcation parameter, the solution of the adjoint linearized system and the desired order of the approximation. The program is automatic and requires no user intervention once started. It outputs the asymptotic solution and its amplitude equation, which describes the bifurcation of the solution branches. A significant amount of hand calculation time is saved by the computer analysis of the problem. The program and its extensions opens up a number of interesting problems which were heretofore intractable due to unwieldy algebra.
Automated support for the enactment of rigorously described software processes
Authors: L. Osterweil
Venue: Proceedings of the 4th international software process workshop on Representing and enacting the software process (1988)

There are many advantages to developing rigorously described software processes. Certainly, they provide the basis for improved project visibility, communication, and coordination. If they are sufficiently rigorous they also provide the basis for effective analysis and error detection which can be used to improve processes. Of the many advantages, however, none strikes me as being more important than the opportunity which rigorous process specifications present for directing the coordination of human and computer resources in support of the effective enactment of software processes. A number of researchers, both at this Workshop and elsewhere, have recognized this opportunity and have begun to study ways of taking advantage of it. Most of this work has focussed on the development of software environments in which explicit software process representations are used to coordinate the application of software tools. As such, this work is forming an important bridge between our software process research community and the software environments research community. Most current research seems to be focussing on 1) what language should be used to express the process description, 2) what should the architecture of a process enaction support environment be like, and 3) what object management facilities should the environment have? In each of these three areas, there are important subissues which I believe are not receiving sufficient attention. In addition, it seems to me that the issues of 1) providing adequate user interfaces to such environments and 2) evaluating process descriptions and environments to support their enaction are both not receiving sufficient attention.
An Analytic Model of Printed Circuit Wiring Distributions
Authors: D. C. Schmidt
Venue: IEEE Transactions on Computers (1989)

A description is given of a mathematical model of wire segment distribution on printed wiring boards. In this model segment, distributions are broken down into two components: net distributions and segment ratios. The net distribution is closely related to the CAD component placement process, whereas the segment ratio is closely related to the CAD net segmentation process. In most cases net distribution is by far the largest part of wiring. Peak segment congestion estimates and segment length estimates are obtained. Both of these estimates are expressed in terms of readily determined circuit properties. The model predicts segment congestion and length reliably.
The Via Minimization Problem is NP-Complete
Authors: N. J. Naclerio, S. Masuda, K. Nakajima
Venue: IEEE Transactions on Computers (1989)

The authors analyze the computational complexity of the constrained via minimization problem. Given an already routed circuit, the problem is to find a minimum cardinality set of vias for which a valid layer assignment exists using only two layers. The authors first prove that the corresponding decision problem is NP-complete. They then show that it remains NP-complete even if one or more of the following restrictions are imposed: (1) the input layout must conform to a rectangular grid; (2) vias are restricted to lie at junctions which existed in the input layout; and (3) the maximum junction degree is limited to six or more.
Indexing and merging in APL
Authors: J. A. Gerth, D. L. Orth
Venue: ACM SIGAPL APL Quote Quad (1987)

Mathematically, an array may be usefully viewed as a function, in this particular case, as a function of its indices. A proposal is made for an operator which derives such a function for its array operand. The proposal is discussed in the context of a review of indexing constructs in various APL systems.
Efficient CSMA/CD-Based Protocols for Multiple Priority Classes
Authors: Suzanne M. Sharrock, David H.C. Du
Venue: IEEE Transactions on Computers (1989)

No abstract availavle.
Parallel algorithm and VLSI architecture for a robot's inverse kinematics
Authors: J. Z. C. Lai, M. Chao
Venue: Proceedings of the 1989 ACM/IEEE conference on Supercomputing (1989)

The inverse solutions of a robotic systems are generally produced by a serial process. Due to the computing time of processing geometry data and generating an inverse solution corresponding to a specified point in Cartesian trajectory is larger than the sampling period, the missing points in the joint space are generated by some interpolation schemes (linear or cubic spline interpolations) between two inverse solutions. The dynamic errors are therefore introduced. Obviously this kind of dynamic errors can be eliminated, if the computational time of generating the inverse solutions and processing geometric information can be less than the sampling period. The dynamic errors are increased when a robot's speed is increased by using the available schemes. For a high speed and high performance robot, the dynamic errors can be significant. In this paper, a parallel algorithm for a robot's inverse kinematics is derived and corresponding VLSI architectures are presented. This algorithm can also be implemented by using multiprocessors. By using the proposed parallel algorithm, it is believed that the dynamic errors can be reduced significantly or even eliminated if the computing time of processing geometric data can be reduced significantly by using the technique of parallel processing.
Hierarchical Chamfer Matching: A Parametric Edge Matching Algorithm
Authors: Gunilla Borgefors
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1988)

The algorithm matches edges by minimizing a generalized distance between them. The matching is performed in a series of images depicting the same scene with different resolutions, i.e. in a resolution pyramid. Using this hierarchical structure reduces the computational load significantly. The algorithm is reasonably simple to implement and is insensitive to noise and other disturbances. The algorithm has been tested in several applications. Two of them are briefly presented. In the first application the outlines of common tools are matched to gray-level images of the same tools, with overlapping. In the second application lake edges from aerial photographs are matched to lake edges from a map, with translation, rotation, scale, and perspective changes. The hierarchical chamfer matching algorithm gives correct results using a reasonable amount of computational resources in all tested applications.
Fault Detection and Design Complexity in C-Testable VLSI Arrays
Authors: F. Lombardi, W.-K. Huang
Venue: IEEE Transactions on Computers (1990)

An extension of a previous approach to fault detection and C-testability of orthogonal iterative arrays is presented. The state transition table of a basic cell is analyzed. Five new states are added to it. It is proved that even though the number of additional states in the proposed approach is greater than previous approaches, (five states compared to four), the required number of test vectors is considerably reduced (by a factor of approximately 4/9). An approach to implement the proposed C-testability approach into logic design is also presented. Complexity of this implementation is analyzed.
Controllable delegation: an exercise in law-governed systems
Authors: N. H. Minsky, E. Rozenshtein
Venue: Conference proceedings on Object-oriented programming systems, languages and applications (1989)

We believe that the regime governing the patterns of sharing between objects, and of exchange of messages between them, should not be &ldquo;hard-wired&rdquo; into a programming language, but should be specifiable by the builders of a system to fit its particular requirements. This thesis has been the primary motivation behind our general concept of law-governed system, which serves as the foundation for this paper. We show how the law can be used to impose a variety of useful constraints over the structure and behavior of delegation-based systems. Such a law may contain some very specific rules that apply only to small parts of a system; it may also impose some very general regimes, such as class inheritance, on the entire system. We also argue that the constraints established by the law can be easily adapted to the changing requirements of an evolving system. This should be very useful in managing the process of software development from its design stage, through prototyping, construction, and beyond.
A General Aperture Problem for Direct Estimation of 3-D Motion Parameters
Authors: M. Yamamoto
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1989)

The necessary and sufficient conditions that an object should satisfy so that motion can be uniquely determined by a direct method are discussed. This direct method, based on the temporal-spatial gradient scheme, can estimate the three-dimensional (3-) motion parameters of a rigid moving object from an image sequence, by utilizing depth information of the object. It is shown that the 3-D motion cannot be uniquely determined for only eight kinds of objects with special geometric structure and surface pattern.
Memory Access Dependencies in Shared-Memory Multiprocessors
Authors: Michel Dubois, Christoph Scheurich
Venue: IEEE Transactions on Software Engineering (1990)

The presence of high-performance mechanisms in shared-memory multiprocessors such as private caches, the extensive pipelining of memory access, and combining networks may render a logical concurrency model complex to implement or inefficient. The problem of implementing a given logical concurrency model in such a multiprocessor is addressed. Two concurrency models are considered, and simple rules are introduced to verify that a multiprocessor architecture adheres to the models. The rules are applied to several examples of multiprocessor architectures.
How Do We Read Algorithms? A Case Study
Authors: Martha E. Crosby
Venue: Computer (1990)

The authors report on an experiment that explored the way subjects view an algorithm, written in Pascal, and the graphical representation of its behavior. They designed the experiment to examine the influence of programming experience on how subjects view a short but complex algorithm, and they analyzed the scan patterns of eye movement for subjects at two experience levels. They describe the experimental procedure in detail, and discuss the results. An important finding was that all subjects needed numerous fixations in most areas of the algorithm and spent more time viewing relevant slide areas than did subjects in studies using simple text. This supports the hypothesis that viewing strategies for algorithms differ from those for prose.
A functional approach to integrating database and expert systems
Authors: Tore Risch, René Reboh, Peter E. Hart, Richard O. Duda
Venue: Communications of the ACM (1988)

A new system architecture shares certain characteristics with database systems, expert systems, functional programming languages, and spreadsheet systems, but is very different from any of these.
A dynamic scheduling strategy for the Chare-Kernel system
Authors: W. Shu, L. V. Kale
Venue: Proceedings of the 1989 ACM/IEEE conference on Supercomputing (1989)

One of the challenges in programming distributed memory parallel machines is deciding how to allocate work to processors. This problem is particularly acute for computations with unpredictable dynamic behavior or irregular structure. We present a scheme for dynamic scheduling of medium-grained processes that is useful in this context. The Adaptive Contracting Within Neighborhood (ACWN), is a dynamic, distributed, self-adaptive, and scalable scheme. The basic scheme and its adaptive extensions are described, and contrasted with other schemes that have been proposed in this context. The performance of all the three schemes on an iPSC/2 hypercube is presented and analyzed. The experimental results show that ACWN algorithm achieves better performance in most cases than randomized allocation. Its agility in spreading the work helps it outperform the gradient model in performance and scalability.
Macrotasking and microtasking a Navier-Stokes algorithm on the Cray-2
Authors: R. A. Fatoohi
Venue: Proceedings of the 17th conference on ACM Annual Computer Science Conference (1989)

This paper presents the results of macrotasking and microtasking a Navier-Stokes algorithm on the Cray-2. The algorithm is a compact difference scheme for the solution of the incompressible, two-dimensional, time dependent Navier-Stokes equations. Two implementations of multitasking on the Cray-2 are considered. These are: macrotasking (parallelism at the subroutine level) and microtasking (parallelism at the do-loop level). These two techniques are briefly described. The implementation of the algorithm is discussed in relation to these techniques and the results for three problem sizes are presented. The timing results for both techniques are in general comparable with differences ranging between 2% to 14% depending on the problem size. The best achieved speedup in a dedicated environment is 3.62 for macrotasking and 3.32 for microtasking. Finally, comparisons are made and conclusions are drawn.
Infinite detail and emulation in an ontologically minimized HCI
Authors: John M. Carroll
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: Empowering people (1990)

By default, we attempt to define practical areas of technological endeavor as &ldquo;applications.&rdquo; For example, the applied psychology of human-computer interaction has characteristically been defined in terms of the methods and concepts basic psychology can provide. This has not worked well. An alternative approach is to begin from a characterization of current practice, to take seriously the requirements of the domain of endeavor, and to define areas of &ldquo;science&rdquo; and &ldquo;application&rdquo; as possible and appropriate in that context.
User interface support for the integration of software tools: an iconic model of interaction
Authors: Michel Beaudouin-Lafon
Venue: Proceedings of the third ACM SIGSOFT/SIGPLAN software engineering symposium on Practical software development environments (1989)

This paper presents a model of interaction based on an iconic representation of objects. An application of the model to an iconic shell for Unix&trade; is described. Finally a client server architecture for the implementation of the model is introduced. We show that a software development environment can take advantage of such a model and architecture in order to provide a consistent, adaptable and extensible user interface.
On the Detection of the Axes of Symmetry of Symmetric and Almost Symmetric Planar Images
Authors: G. Marola
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1989)

A simple algorithm is presented for finding all the axes of symmetry of symmetric and almost symmetric planar images having nonuniform gray-level (intensity images). The technique, which can also be used in conjunction with planar curves, is based on the identification of the centroids of the given image and other related sets of points, followed by a maximization of a specially defined coefficient of symmetry. Owing to the nature of the required procedures, which are strictly based on the computation of mean values, the method is not particularly affected by the presence of noise and is especially suited for application in conjunction with digitized figures.
The use of student workers in computer lab management at the University of Scranton
Authors: T. J. Hughes
Venue: Proceedings of the 17th annual ACM SIGUCCS conference on User Services (1989)

The Computing Systems Department of the University of Scranton has been very successful in implementing a program utilizing student workers to staff its extensive lab facilities. This program was initiated in the early 1980's with a hand full of students staffing one lab, and has grown to the point where we now employ over 60 students to staff eleven labs with more coming on line every year. The fact of the matter is that student employees have become the backbone of our lab support systems. In the early days the department was small and the student workers were under the supervision of the director. As the department grew, and more students were employed, they were eventually assigned to the assistant director and later to other professional support staff. By 1985, running the labs had become involved enough to require establishment of the position of Computer Lab Coordinator (the current title for this position is Information Support Analyst - Labs) to oversee lab management and the growing number of student employees.
A definition optimization technique used in a code translation algorithm
Authors: David M. DeJean, George W. Zobrist
Venue: Communications of the ACM (1989)

Data flow analysis is used to optimize variable definitions in a program that translates microprocessor object code to a higher order language.
The politics of standards and the EC
Authors: Karen A. Frenkel
Venue: Communications of the ACM (1990)

European legislation and power struggles in the standards arena are sparking fear of technical barriers to trade and prompting the American standards community to reevaluate its infrastructure. The National Institute of Standards and Technology may step up its role in order to negotiate at a governmental level with the EC.