Gearold R. Johnson

Motivation and framework for using genetic algorithms for microcode compaction

Genetic algorithms are a robust adaptive optimization technique based on a biological paradigm. They perform efficient search on poorly-defined spaces by maintaining an ordered pool of strings that represent regions in the search space. New strings are produced from existing strings using the genetic-based operators of recombination and mutation. Combining these operators with natural selection results in the efficient use of hyperplane information found in the problem to guide the search. The searches are not greatly influenced by local optima or non-continuous functions. Genetic algorithms have been successfully used in problems such as the traveling salesperson and scheduling job shops. Microcode compaction can be modeled as these same types of problems, which motivates the application of genetic algorithms in this domain.

Modern Control Concepts in Hydrology

Two approaches to an identification problem in hydrology are presented, based upon concepts from modern control and estimation theory. The first approach treats the identification of unknown parameters in a hydrologic system subject to noisy inputs as an adaptive linear stochastic control problem; the second approach alters the model equation to account for the random part in the inputs, and then uses a nonlinear estimation scheme to estimate the unknown parameters. Both approaches use state-space concepts. The identification schemes are sequential and adaptive and can handle either time-invariant or time-dependent parameters. They are used to identify parameters in the Prasad model of rainfall-runoff. The results obtained are encouraging and confirm the results from two previous studies; the first using numerical integration of the model equation along with a trial-and-error procedure, and the second using a quasi-linearization technique. The proposed approaches offer a systematic way of analyzing the rainfall-runoff process when the input data are imbedded in noise.

A generator for microprocessor assemblers and simulators

ASM/SIMGEN is a software system comprised of a set of independent Fortran program writer modules designed to generate microprocessor assemblers and simulators. It is simple enough to be used by those with limited architecture and programming backgrounds, but flexible and powerful enough to generate efficient well-structured assemblers and simulators for microcomputers with sophisticated architectures and instruction sets. This paper gives a description of the generating system, the generated simulators and the advantages it offers in both engineering and pedagogical applications.

Automated Generation of Cross-System Software for Microcomputers

GEN is a set of Fortran program writer modules designed to generate microcomputer assemblers and simulators. It is simple enough to be used by those with limited architecture and programming backgrounds yet flexible and powerful enough to generate efficient and well-structured assemblers and simulators for microcomputes sophisticated tectures and instruction sets. This paper describes the generating system, the generated gPoassemblers and simulators, and the advantages they offer in both programming and pedagogical applications.

A random number generator for microprocessors

An algorithm is presented for generating uniformly distributed random deviates on microprocessors or minicomputers utizizing memories with a small word- Zength. other alternative solutions are discussed, and the statistical quality of sample streams of generated numbers is evaluated and compared with the quality of other widely used generators.

An estimate of space-time correlations

Laboratory measurements of the autocorrelation and space-time correlations for probe separations alined with the mean flow are used to test a hypothesis of Pielke and Panofsky (1970) which relates these measures by means of an empirical decay parameter taken from coherence data. The direct laboratory measurements of the space-time correlations are in good agreement with the functions estimated using the method of Pielke and Panofsky (1970). However, the decay parameters implied for the laboratory measurements are much smaller than those reported for atmospheric turbulence.

The automated generation of cross-system software for supporting micro/mini computer systems

ASM/GEN and SIM/GEN are a software system comprised of a set of independent FORTRAN program writer modules designed to generate micro computer and small minicomputer assemblers and simulators. It is simple enough to be used by those with limited architecture and programming backgrounds, but flexible and powerful enough to generate efficient and well-structured assemblers and simulators for small micro/mini computers with sophisticated architectures and instruction sets. This paper presents a brief description of the generating system, the generated assemblers and simulators and the advantages they offer in both programming and pedagogical applications.

SIMSHAC: a simulation program for solar heating and cooling of buildings

A dynamic simulation model for use in analyzing the performance of specific designs of solar-heated-and- cooled buildings has been developed. The name of the program is SIMSHAC, an acronym for SImulation Model for Solar-Heated-And-Cooled buildings. To use the design program, one has merely to specify the components (that is, each subsystem; for example, collectors, storage units, splitting and mixing valves, house heating and cooling loads, auxiliary heating, auxiliary cooling, heat exchanger, etc.), and the manner in which they are connected and all initial conditions. Program SIMSHAC then writes the program for the specific system to be analyzed. Each subsystem is described by a set of time-dependent differential equations or, possibly, algebraic equations. System state variables include tempera ture, mass flow rate, and enthalpy. The model can handle three types of incident solar radiation data models. These are (1) deterministic (e.g., an algebraic-equation sun model), (2) random simulation (e.g., a model based upon cloud-cover statistics), and (3) actual tabulated input information based upon collected solar data for a specific site. The model has been used for the analysis of five different types of buildings in five locations within the United States. The types include single-family residences, small businesses, three-story apartments, schools, and mobile homes. The locations considered are Atlanta, Georgia; Madison, Wisconsin; Wilmington, Delaware; Mobile, Alabama; and Santa Maria, California. The program has also been used to simulate the solar- heated-and-cooled experimental laboratory presently being built by the National Science Foundation on the campus at Colorado State University.

Contrasting translation, verification and synthesis in software and firmware engineering

Translation, verification and synthesis are commonly used terms in the software field, yet these terms seem to be misunderstood by many which may inhibit progress. This paper attempts, through the use of definitions and examples, to clarify these concepts and their significance in both software and firmware engineering.

A microprocessor based solar controller

This paper presents the development, analysis, and simulated experimentation with a discrete control algorithm for optimal control of a solar energy system for heating buildings. The contents include the mathematical formulation of the system and objective function, the solution technique, the microprocessor control system and its components, and the results of tests conducted using a control-driven dynamic simulation computer model to perform comparisons with conventional controls.