Computer Sciences Commons^™

Porting The Chorus Supervisor And Related Low-Level Functions To The Pa-Risc, Ravi Konuru, Marion Hakanson, Jon Inouye, Jonathan Walpole

Computer Science Faculty Publications and Presentations

This document is part of a series of reports describing the design decisions made in porting the Chorus Operating System to the Hewlett-Packard 9000 Series 800 workstation.

The Supervisor is the name given by Chorus to a collection of low-level functions that are machine dependent and have to be implemented when Chorus is ported from one machine to another. The Supervisor is responsible for interrupt, trap and exception handling, managing low-level thread initialization, context switch, kernel initialization, managing simple devices (timer and console) and offering a low-level debugger. This document describes the port of the Supervisor and related low-level functions. …

Constrained-Latency Storage Access: A Survey Of Application Requirements And Storage System Design Approaches, Richard Staehli, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Applications with Constrained Latency Storage Access (CLSA) are those that have large storage needs and hard constraints on the amount of latency they can tolerate. Such applications present a problem when the storage technology that is cost effective and large enough cannot meet their latency constraints for demand fetching. Examples are found in the developing field of multimedia computing and, to a lesser extent, in real-time database literature. This paper examines the nature of timing constraints at the application-storage interface and defines a classification for both the synchronization constraints of the application and the latency characteristics of the storage system. …

Concurrency Control, Version Management And Transactions In Advanced Database Systems, Jonathan Walpole, Muntuck Yap

Computer Science Faculty Publications and Presentations

This document constitutes the final deliverable for the research project titled “An Investigation of Selected Issues in Transaction Mechanism Design for Object Oriented Databases.” The document describes our ideas for extending the traditional transaction concept for use in object oriented databases, and concentrates specifically on providing an underlying model to support the concurrency control and version management aspects of the problem. The ideas presented here are not however restricted to the domain of object oriented databases. They are more generally applicable to database systems that require flexibility in their versioning and concurrency control policies.

In this document we define a …

Benchmarking Parallel Machines Via A Software Architecture, Srikanth Kambhatla, Jon Inouye, Jonathan Walpole

Computer Science Faculty Publications and Presentations

The diversity in parallel architectures and the programming styles induced thereof, make benchmarking of parallel machines a hard problem. Current benchmarking techniques are limited in applicability due to the issues of portability. We present a different approach to benchmarking parallel machines, which would make the resulting benchmarks portable, easy to use and widely applicable. The approach involves the use of a software architecture to mask the diversities of the underlying architectures. The benchmarks are based on the Linda Tuple Space, and is called BeLinda. In this report, we motivate the use of a software architecture, give a specification of the …

Performance Analysis Of A Distributed File System, Meenakshi Mukhopadhyay

Dissertations and Theses

An important design goal of a distributed file system, a component of many distributed systems, is to provide UNIX file access semantics, e.g., the result of any write system call is visible by all processes as soon as the call completes. In a distributed environment, these semantics are difficult to implement because processes on different machines do not share kernel cache and data structures. Strong data consistency guarantees may be provided only at the expense of performance.

This work investigates the time costs paid by AFS 3.0, which uses a callback mechanism to provide consistency guarantees, and those paid by …

Implementing Ray Tracing Algorithm In Parallel Environment, Tjah Jadi

Dissertations and Theses

Ray tracing is a very popular rendering algorithm in the field of computer graphics because it can generate highly-realistic images from three-dimensional models. Unfortunately, the computational cost is very expensive. To speed up the rendering process we present both static and dynamic scheduling (balancing) strategies for a multiprocessor system. Hence, the load balancing among the processors is the most important problem in parallel processing. The implementation of the algorithm is based on a modified octree structure.

An Investigation Of Resolution And Addressability Requirements For Digital Display Systems Used In Word-Processing And Computer-Aided-Drafting Applications, Stephen T. Knox

Dissertations and Theses

Two hardware factors contributing to the overall image quality of digital CRTs are display resolution and addressability. The relationship between these two factors and human performance was modeled by a metric of display quality, the Resolution Addressability Ratio (RAR), and investigated within the contexts of Word-Processing (WP) and Computer-Aided-Drafting (CAD) tasks. The findings indicate a perceptual limit to MTF bandwidth improvements, and significant differences in display quality requirements between the two applications. The regression of image quality as a function of RAR metric values resulted in an r² = 0.94 for the WP task and an r² = 0.79 for …

Incompleteness, Negation, Hazard: On The Precariousness Of Systems, Martin Zwick

Complex Systems Faculty Publications and Presentations

An account is offered of the dialectical tensions which afflict systems of widely differing type, "contradictions" which cannot be fully or permanently resolved, and from which follow the lawfulness of both hazard and opportunity.

Dialectical Thermodynamics, Martin Zwick

Complex Systems Faculty Publications and Presentations

A lugubrious, though highly abstract, proposition about sociocultural systems is suggested by a union of dialectical and thermodynamic concepts: systems are invariably flawed, not only because of poor --or absence of -design, or ill will, but because the "closedness" of a system necessarily wars on its "openness," and because the actualization of the organizing principle upon which a system is based brings with it the development of its "shadow," its negation. Reconciliation of these contradictions is not assured.

The Cusp Catastrophe And The Laws Of Dialectics, Martin Zwick

Complex Systems Faculty Publications and Presentations

The three classical "laws" of dialectics of Hegel and Engels, ( 1) the transformation of quantity into quality, (2) the interpenetration of opposites, and (3) the negation of the negation, can be given precise meanings in terms of the Catastrophe Theory of Rene Thom and E. C. Zeeman. This suffices to counter the charge that dialectics is scholasticism or empty metaphysics, but does not support claims of universality for the dialectical principles, nor guarantee the validity of any particular application of these principles.

Requisite Variety And The Second Law, Martin Zwick

Complex Systems Faculty Publications and Presentations

Although the Law of Requisite Variety (LRV) speaks directly about entropy (of a set of disturbances to a system, and of the states and effects of a regulator), the relation of Ashby's principle to the Second Law of Thermodynamics does not appear to have been commented on, In this paper, it is shown that, when regulation is viewed as a temporal process, the LRV can be interpreted as a statement of, and, in fact, a consequence of, the Second Law. In essence, the regulator reduces the variety (entropy) of the system being regulated by a compensatory increase of variety (entropy) …

Fuzziness And Catastrophe, Martin Zwick, Daniel Guy Schwartz, George G. Lendaris

Complex Systems Faculty Publications and Presentations

In a recent short note, Flondor has alluded to a possible linkage of fuzzy set theory and catastrophe theory. We consider several features of catastrophe theory, namely the properties of discontinuous jumps, hysteresis, and divergence in the "cusp catastrophe," and the role of the bias factor in the "butterfly catastrophe," which have affinities to and suggest possible extensions of fuzzy set ideas. Certain functions extensively considered in catastrophe theory lend themselves in some cases to interpretation as membership functions. The use of such functions may be of interest for the characterization of linguistic descriptions which are time-varying and encompass both …

A Technique To Calculate Complex Electromagnetic Fields By Using The Finite Element Method, Davood Asgharian

Dissertations and Theses

A computer program based on Maxwell's equations is developed to calculate two-dimensional complex potentials by the Finite Element Method. This study offers a solution to a complex continuum problem by allowing a subdivision into a series of simple interrelated problems. The region of interest is divided into triangular elements. For each node in the grid, the Finite Element Method is used to set up an equation for the potential as a function of those of the surrounding nodes. All these equations are solved by the Gaussian Elimination Method. For increased accuracy this method requires a high degree of division of …

Quantum Measurement And Gödel's Proof, Martin Zwick

Complex Systems Faculty Publications and Presentations

The measurement problem in quantum mechanics has the character of a fundamental incompleteness within that theory similar to the incompleteness of axiomatic systems in mathematics, discovered and elaborated by Gödel and others. The difficulty of describing the measurement process by the time-dependent Schrodinger equation may reflect the limitations of formal language , and quantum theory may thus require a formalism consisting of two levels of description, one for the dynamics and one for measurement, levels whose relationship resembles that of a calculus and meta-calculus.

Dialectics And Catastrophe, Martin Zwick

Complex Systems Faculty Publications and Presentations

The three classical principles of Hegelian and Marxist dialectics, (1) the transformation of quantity into quality, (2) the unity and struggle of opposites, and (3) the negation of negation, can be modeled with the Catastrophe Theory of René Thom and E. C. Zeeman, especially with the ‘elementary catastrophes’ known as the cusp and the butterfly.

Qsim2: A Low-Budget Heuristic Approach To Modeling And Forecasting, Wayne Wakeland

Complex Systems Faculty Publications and Presentations

This paper contains a description of a simple mathematical framework and modeling process which can be used to study a large class of socio-techno-natural systems. Models may be designed using intuitive notions or data to help specify the variables, parameters and interrelationships, which, with the aid of a computer program, can be used to forecast system behavior under various assumptions. Two example models are described.

"Large Systems", Richard Ernest Bellman

Special Collections: Oregon Public Speakers

No abstract provided.

"The Ore Plan: A Practical Application Of The Systems Approach To Solid Waste Management In Oregon", Richard Duncan

Special Collections: Oregon Public Speakers

No abstract provided.

"The Curious Behavior Of Complex Systems: Lessons From Biology", Heinz Von Foerster

Special Collections: Oregon Public Speakers

No abstract provided.

"A Philosophy For Complexity", Charles West Churchman

Special Collections: Oregon Public Speakers

No abstract provided.

"Education For Managing Complexity", Harold A. Linstone

Special Collections: Oregon Public Speakers

No abstract provided.

Digital Computer Solution Of Electromagnetic Transients In Large Power Systems, Bijan Navidbakhsh

Dissertations and Theses

This thesis is an introduction to the solution of electromagnetic transients by a combination of the Bergeran method of characteristics and the application of trapezoidal rule of integration.

Three test examples solved by digital computer illustrate the step by step solution and computer programming.

To compare this method with the Laplace transformation technique, a test problem solved by both methods and also digital computer is illustrated. In conclusion, the advantages and disadvantages of both methods are compared.

Moment-Curvature-Thrust Relationships In Hybrid Members, Douglas Wrenn Fiala

Dissertations and Theses

In order to overcome the difficulties encountered in closed form solutions, moment-curvature-thrust relationships are developed for hybrid and nonhybrid cross sections utilizing an open form method. The use of horizontal sectors permits the inclusion of residual stresses and/or nonbilinear stress-strain relationships, if desired. Theoretical and experimental data are compared. Applications to circular tubes and other cross sections are discussed. Results indicate that open form solutions are feasible for calculating moment-curvature-thrust data. Hybrid cross sections are easily treated by open form solutions.

New Computer Methods For Protein Crystallography, Martin Zwick

Complex Systems Faculty Publications and Presentations

New Computer Methods for Protein Crystallography, by Martin Zwick. Submitted to the Department of Biology on 30 August 1968 in partial fulfillment of the requirements for the degree of Doctor of Philosophy. The section, "MYOGLOBIN REFINEMENT," describes the fitting of an idealized polypeptide chain to a set of approximate backbone coordinates for the protein, sperm whale myoglobin. This procedure refines the structure by imposing upon it known bond distances and angles, and simultaneously derives a representation of the polypeptide conformation in terms of the values of the rotation angles about its single bonds. The overall rms and mean deviation between …

On The Definition Of Self-Organizing Systems, George G. Lendaris

Complex Systems Faculty Publications and Presentations

Published in: Proceedings of the IEEE ( Volume: 52, Issue: 3, March 1964)