This limited facsimile edition has been issued for the purpose of keeping this title available to the scientific community. © 1985 Springer Science+Business Media New York Originally published by Plcnum Press, New York in 1985 Softcover reprint of the hardcover Ist edition 1985 AII rights reservedNo part of this book may bc reproduced, storcd in a retrieval system, or transmittcd in any form or by any means, electronic, mechanical, photocopying, microfilming.recording, or othcrwise, without written permission irom the Publisher · .. II, that r",weth light, and cont",,,,th In C",/, re",vtlh mort bght: and that bght grou,tlh brighter and brighter .. Doctrine and Covenants 50:24 DEDICATIONRecognizing its several limitations, we unpretentiously dedicate this book to our Creator, Who, through holy writ, has inspired us to seek light and understanding where darkness exists, and Who, through these same records, has taught us to place our professional pursuits in perspective with greater obligations of service to family and to society. PREFACE ix 4. Chapters 9, 10, and 14 provide the fundamental equations and background for turbulent combustion systems. 5. Chapters 11-13 and 15 document in some detail the approach and theory for the interactions between chemistry and turbulence in reacting systems encompassing gaseous flames, particle-laden systems, and pollutant formation in these systems.This work has formed the basis for model development at our Combustion Laboratory. These fundamentals were treated generally in the first book. The treatment in this new book for governing equations and for radiation is not greatly changed. However, significant new material is added for chemically reacting, turbulent, heterogeneous systems and for formation of nitrogen oxide pollutants. Included in several of these chapters are comparisons of measurements with predictions from a comprehensive model developed at the Combustion Laboratory. These comparisons demonstrate the state of development of the comprehensive code which, in the view of the authors, is suitable for some practical application to pulverized-coal systems. While this method has been developed principally for pulverized-coal combustion and gasification, this and similar methods have far more general applicability. The code is directly applicable to nonreactive gaseous and particle-laden flows and to reactive gaseous systems. Progress is being made for application to coal slurries and only minor work would be required for use with liquid fuel flames.The authors recognize the several uncertainties in constructing and applying models of this nature. Coal is a very complex heterogeneous substance whose structure and behavior are highly variable and are not well known. Pyrolysis and oxidation of coal are dependent upon coal type, size, size distribution, temperature history, etc., thus making generalization difficult. In addition, the complexities of turbulent recirculating flows, turbulent reacting flows, and turbulent two-phase flows are not fully resolved. Only recently ...

Both optimization techniques and expert systems technologies are popular approaches for developing tools to assist in complex problem-solving tasks. Because of the underlying complexity of many such tasks, however, the models of the world implicitly or explicitly embedded in such tools are often incomplete and the problem-solving methods fallible. The result can be "brittleness" in situations that were not anticipated by the system designers. To deal with this weakness, it has been suggested that "cooperative" rather than "automated" problem-solving systems be designed. Such cooperative systems are proposed to explicitly enhance the collaboration of the person (or a group of people) and the computer system. This study evaluates the impact of alternative design concepts on the performance of 30 airline pilots interacting with such a cooperative system designed to support en-route flight planning. The results clearly demonstrate that different system design concepts can strongly influence the cognitive processes and resultant performances of users. Based on think-aloud protocols, cognitive models are proposed to account for how features of the computer system interacted with specific types of scenarios to influence exploration and decision making by the pilots. The results are then used to develop recommendations for guiding the design of cooperative systems.

No abstract

No abstract

This research focused on the design of a decision-support system to assist blood bankers in identifying alloantibodies in patients' blood. It was hypothesized that critiquing, a technique in which a computer monitors human performance for errors, would be an effective role for such a decision-support system if the error monitoring was unobtrusive and if the critiquing was in response to both intermediate and final conclusions made by the user. A prototype critiquing system monitored medical technologists for (a) errors of commission and errors of omission, b) failure to follow a complete protocol, (c) answers inconsistent with the data collected, and (d) answers inconsistent with prior probability information. Participants using the critiquing system had significantly better performance (completely eliminating misdiagnosis rates for 3 out of 4 test cases) than a comparable control group. Detailed analysis of the behavioral protocols provided insights into how specific design features influenced performance. Practical applications of this research include its use (after refinements) as a tool for routine antibody identification in blood banks.

the STM capacity should also be adversely affected by exposure to mercury. This study was conducted to test this prediction and to provide converging evidence that one locus of the neurotoxic effect of mercury is short term memory.Two alternative measures of STM capacity were evaluated under field study conditions. The first, the Wechsler digit span forward,6 was included because it is the test of STM span that has traditionally been used in behavioural toxicology studies.7A second, more extensive test of STM span was also evaluated because it has been suggested that the Wechsler digit span test taken alone "is not sufficiently discriminating to detect significant differences in intellectual (that is, retention) functioning."8 This second test entails estimating an individual's 50% threshold for serial recall-that is, the number of digits that can be correctly recalled 50% of the time, in serial order.The reliability and precision of these two tests were assessed within the context of evaluating the effects of chronic exposure to elemental mercury on STM. This provided an opportunity to study the performance of a heterogeneous population (mercury cell chlor-alkali workers) and to illustrate the usefulness of precise behavioural measures in assessing the neurotoxic effects of chronic exposure to elemental mercury. 413

Reports from Scandinavia have suggested behavioural impairment among long term workers exposed to solvents below regulatory standards. A cross sectional study of behavioural performance was conducted among printers and spray painters exposed to mixtures of organic solvents to replicate the Scandinavian studies and to examine dose-response relationships. Eligible subjects consisted of 640 hourly workers from four midwestern United States companies. Of these, 269 responded to requests to participate and 240 were selected for study based on restrictions for age, sex, education, and other potentially confounding variables. The subjects tested had been employed on average for six years. Each subject completed an occupational history, underwent a medical examination, and completed a battery of behavioural tests. These included the Fitts law psychomotor task, the Stroop colour-word test, the Sternberg short term memory scanning test, the short term memory span test, and the continuous recognition memory test. Solvent exposure for each subject was defined as an exposed or non-exposed category based on a plant industrial hygiene walk-through and the concentration of solvents based on an analysis of full shift personal air samples by gas chromatography. The first definition was used to maintain consistency with Scandinavian studies, but the second was considered to be more accurate. The average full shift solvent concentration was 302 ppm for the printing plant workers and 6-13 ppm for the workers at other plants. Isopropanol and hexane were the major components, compared with toluene in Scandinavian studies. Performance on behavioural tests was analysed using multiple linear regression with solvent concentration as an independent variable. Other relevant demographic variables were also considered for inclusion. No significant (p greater than 0.05) relation between solvent concentration and impairment on any of the 10 behavioural variables was observed after controlling for confounding variables. Exposed/non-exposed comparisons showed a significantly poorer digit span among those exposed, but this has not been generally reported in the Scandinavian studies. The medical examination showed no abnormalities of clinical significance. The inability to replicate the findings of the Scandinavian studies could have been due to the shortness of the duration of workers' exposure, the type of solvents in the mixtures, use of different behavioural tests, or to selection factors.

Research on the nature of knowledge-based systems for bibliographic information retrieval is summarized. Knowledge-based search tactics are then considered in terms of their role in the functioning of a semantically based search system for bibliographic information retrieval, EP-X. This system uses such tactics to actively assist users in defining or refining their topics of interest. It does so by applying these tactics to a knowledge base describing topics in a particular domain and to a database describing the contents of individual documents in terms of these topics. This paper, then, focuses on the two central concepts behind EP-X: semantically based search and knowledge-based search tactics.