Showing papers by "University of Michigan published in 1992"

Adaptation in Natural and Artificial Systems: An Introductory Analysis with Applications to Biology, Control and Artificial Intelligence

Abstract: From the Publisher: Genetic algorithms are playing an increasingly important role in studies of complex adaptive systems, ranging from adaptive agents in economic theory to the use of machine learning techniques in the design of complex devices such as aircraft turbines and integrated circuits. Adaptation in Natural and Artificial Systems is the book that initiated this field of study, presenting the theoretical foundations and exploring applications. In its most familiar form, adaptation is a biological process, whereby organisms evolve by rearranging genetic material to survive in environments confronting them. In this now classic work, Holland presents a mathematical model that allows for the nonlinearity of such complex interactions. He demonstrates the model's universality by applying it to economics, physiological psychology, game theory, and artificial intelligence and then outlines the way in which this approach modifies the traditional views of mathematical genetics. Initially applying his concepts to simply defined artificial systems with limited numbers of parameters, Holland goes on to explore their use in the study of a wide range of complex, naturally occuring processes, concentrating on systems having multiple factors that interact in nonlinear ways. Along the way he accounts for major effects of coadaptation and coevolution: the emergence of building blocks, or schemata, that are recombined and passed on to succeeding generations to provide, innovations and improvements. John H. Holland is Professor of Psychology and Professor of Electrical Engineering and Computer Science at the University of Michigan. He is also Maxwell Professor at the Santa Fe Institute and isDirector of the University of Michigan/Santa Fe Institute Advanced Research Program.

A National Customer Satisfaction Barometer: The Swedish Experience:

Abstract: Many individual companies and some industries monitor customer satisfaction on a continual basis, but Sweden is the first country to do so on a national level. The annual Customer Satisfaction Baro...

Extrinsic and Intrinsic Motivation to Use Computers in the Workplace1

Abstract: Previous research indicates that perceived usefulness is a major determinant and predictor of intentions to use computers in the workplace. In contrast, the impact of enjoyment on usage intentions has not been examined. Two studies are reported concerning the relative effects of usefulness and enjoyment on intentions to use, and usage of, computers in the workplace. Usefulness had a strong effect on usage intentions in both Study 1, regarding word processing software (β=.68), and Study 2, regarding business graphics programs (β=.79). As hypothesized, enjoyment also had a significant effect on intentions in both studies, controlling for perceived usefulness (β=.16 and 0.15 for Studies 1 and 2, respectively). Study 1 found that intentions correlated 0.63 with system usage and that usefulness and enjoyment influenced usage behavior entirely indirectly through their effects on intentions. In both studies, a positive interaction between usefulness and enjoyment was observed. Together, usefulness and enjoyment explained 62% (Study 1) and 75% (Study 2) of the variance in usage intentions. Moreover, usefulness and enjoyment were found to mediate fully the effects on usage intentions of perceived output quality and perceived ease of use. As hypothesized, a measure of task importance moderated the effects of ease of use and output quality on usefulness but not on enjoyment. Several implications are drawn for how to design computer programs to be both more useful and more enjoyable in order to increase their acceptability among potential users.

Performing the exact test of Hardy-Weinberg proportion for multiple alleles.

Abstract: SUMMARY The Hardy-Weinberg law plays an important role in the field of population genetics and often serves as a basis for genetic inference. Because of its importance, much attention has been devoted to tests of Hardy-Weinberg proportions (HWP) over the decades. It has long been recognized that largesample goodness-of-fit tests can sometimes lead to spurious results when the sample size and/or some genotypic frequencies are small. Although a complete enumeration algorithm for the exact test has been proposed, it is not of practical use for loci with more than a few alleles due to the amount of computation required. We propose two algorithms to estimate the significance level for a test of HWP. The algorithms are easily applicable to loci with multiple alleles. Both are remarkably simple and computationally fast. Relative efficiency and merits of the two algorithms are compared. Guidelines regarding their usage are given. Numerical examples are given to illustrate the practicality of the algorithms.

Fundamentals of Vehicle Dynamics

Abstract: This book attempts to find a middle ground by balancing engineering principles and equations of use to every automotive engineer with practical explanations of the mechanics involved, so that those without a formal engineering degree can still comprehend and use most of the principles discussed. Either as an introductory text or a practical professional overview, this book is an ideal reference.

Morphometric tools for landmark data : geometry and biology

Abstract: 1. Introduction 2. Preliminaries 3. Landmarks 4. Distance measures 5. Shape coordinates 6. Principal axes of shape change for triangles 7. Features of shape comparison 8. Retrospect and prospect.

Interleukin-8 as a Macrophage-Derived Mediator of Angiogenesis

Abstract: Angiogenic factors produced by monocytes-macrophages are involved in the pathogenesis of chronic inflammatory disorders characterized by persistent angiogenesis. The possibility was tested that interleukin-8 (IL-8), which is a cytokine that is chemotactic for lymphocytes and neutrophils, is also angiogenic. Human recombinant IL-8 was potently angiogenic when implanted in the rat cornea and induced proliferation and chemotaxis of human umbilical vein endothelial cells. Angiogenic activity present in the conditioned media of inflamed human rheumatoid synovial tissue macrophages or lipopolysaccharide-stimulated blood monocytes was equally blocked by antibodies to either IL-8 or tumor necrosis factor-alpha. An IL-8 antisense oligonucleotide specifically blocked the production of monocyte-induced angiogenic activity. These data suggest a function for macrophage-derived IL-8 in angiogenesis-dependent disorders such as rheumatoid arthritis, tumor growth, and wound repair.

The self-regulation of attitudes, intentions, and behavior

Abstract: We argue that attitudes and subjective norms are not sufficient determinants of intentions and that intentions are not a sufficient impetus for action, as maintained by leading theories of attitude. To deepen attitude theory, we address the role of cognitive and emotional self-regulatory mechanisms. The attitude-intention link is hypothesized to depend on conative processes and on certain coping responses directed at the emotional significance of evaluative appraisals

Amplification of a gene encoding a p53-associated protein in human sarcomas

Abstract: Despite extensive data linking mutations in the p53 gene to human tumorigenesis, little is known about the cellular regulators and mediators of p53 function. MDM2 is a strong candidate for one such cellular protein; the MDM2 gene was originally identified by virtue of its amplification in a spontaneously transformed derivative of mouse BALB/c cells and the MDM2 protein subsequently shown to bind to p53 in rat cells transfected with p53 genes. To determine whether MDM2 plays a role in human cancer, we have cloned the human MDM2 gene. Here we show that recombinant-derived human MDM2 protein binds human p53 in vitro, and we use MDM2 clones to localize the human MDM2 gene to chromosome 12q13-14. Because this chromosomal position appears to be altered in many sarcomas, we looked for changes in human MDM2 in such cancers. The gene was amplified in over a third of 47 sarcomas, including common bone and soft tissue forms. These results are consistent with the hypothesis that MDM2 binds to p53, and that amplification of MDM2 in sarcomas leads to escape from p53-regulated growth control. This mechanism of tumorigenesis parallels that for virally-induced tumours, in which viral oncogene products bind to and functionally inactivate p53.

The New Penology : Notes on the emerging strategy of corrections and its implications

Abstract: The new penology argues that an important new language of penology is emerging. This new language, which has its counterparts in other areas of the law as well, shifts focus away from the traditional concerns of the criminal law and criminology, which have focused on the individual, and redirects it to actuarial consideration of aggregates. This shift has a number of important implications: It facilitates development of a vision or model of a new type of criminal process that embraces increased reliance on imprisonment and that merges concerns for surveillance and custody, that shifts away from a concern with punishing individuals to managing aggregates of dangerous groups, and that affects the training and practice of criminologists.

Changes in the structure of wages in the 1980's: an evaluation of alternative explanations.

Abstract: During the 1980's, a period in which the average level of real wage rates was roughly stagnant, there were large changes in the structure of relative wages, most notably a huge increase in the relative wages of highly educated workers. This paper attempts to assess the power of several alternative explanations of the observed relative wage changes in the context of a theoretical framework that nests all of these explanations. Our conclusion is that their major cause was a shift in the skill structure of labor demand brought about by biased technological change.

An empirical model and an inversion technique for radar scattering from bare soil surfaces

Abstract: Polarimetric radar measurements were conducted for bare soil surfaces under a variety of roughness and moisture conditions at L-, C-, and X-band frequencies at incidence angles ranging from 10 degrees to 70 degrees . Using a laser profiler and dielectric probes, a complete and accurate set of ground truth data was collected for each surface condition, from which accurate measurements were made of the rms height, correlation length, and dielectric constant. Based on knowledge of the scattering behavior in limiting cases and the experimental observations, an empirical model was developed for sigma degrees /sub hh/, sigma degrees /sub vv/, and sigma degrees /sub hv/ in terms of ks (where k=2 pi / lambda is the wave number and s is the rms height) and the relative dielectric constant of the soil surface. The model, which was found to yield very good agreement with the backscattering measurements of the present study as well as with measurements reported in other investigations, was used to develop an inversion technique for predicting the rms height of the surface and its moisture content from multipolarized radar observations. >

A Controlled Trial of Fluconazole to Prevent Fungal Infections in Patients Undergoing Bone Marrow Transplantation

Abstract: Background and Methods. Superficial and systemic fungal infections are a major problem among severely immunocompromised patients who undergo bone marrow transplantation. We performed a doubleblind, randomized, multicenter trial in which patients receiving bone marrow transplants were randomly assigned to receive placebo or fluconazole (400 mg daily). Fluconazole or placebo was administered prophylactically from the start of the conditioning regimen until the neutrophil count returned to 1000 per microliter, toxicity was suspected, or a systemic fungal infection was suspected or proved. Results. By the end of the treatment period, 67.2 percent of the 177 patients assigned to placebo had a positive fungal culture of specimens from any site, as compared with 29.6 percent of the 179 patients assigned to fluconazole. Among these, superficial infections were diagnosed in 33.3 percent of the patients receiving placebo and in 8.4 percent of the patients receiving fluconazole (P<0.001). Systemic fungal in...

Sex Differences in Jealousy: Evolution, Physiology, and Psychology:

Abstract: In species with internal female fertilization, males risk both lowered paternity probability and investment in rival gametes if their mates have sexual contact with other males. Females of such spe...

The weathering hypothesis and the health of African-American women and infants: evidence and speculations.

Abstract: Observed variation between populations in fertility-timing distributions has been thought to contribute to infant mortality differentials This hypothesis is based, in part, on the belief that the 20s through early 30s constitute "prime" childbearing ages that are low-risk relative to younger or older ages However, when stratified by racial identification over the predominant first child-bearing ages, maternal age patterns of neonatal mortality vary between groups Unlike non-Hispanic white infants, African-American infants with teen mothers experience a survival advantage relative to infants whose mothers are older The black-white infant mortality differential is larger at older maternal ages than at younger ages While African Americans and non-Hispanic whites differ on which maternal ages are associated with the lowest risk of neonatal mortality, within each population, first births are most frequent at its lowest-risk maternal ages As a possible explanation for racial variation in maternal age patterns of births and birth outcomes, the "weathering hypothesis" is proposed: namely, that the health of African-American women may begin to deteriorate in early adulthood as a physical consequence of cumulative socioeconomic disadvantage

The clinical course of pulmonary embolism.

Abstract: Background. Pulmonary embolism is a potentially fatal disorder. Information about the outcome of clinically recognized pulmonary embolism is sparse, particularly given that new treatments for more seriously ill patients are now available. Methods. We prospectively followed 399 patients with pulmonary embolism diagnosed by lung scanning and pulmonary angiography, who were enrolled in a multicenter diagnostic trial. We reviewed all hospitalizations, all new investigations of pulmonary embolism, and all deaths among the patients within one year of diagnosis. Results. Of the 399 patients, 375 (94 percent) received treatment for pulmonary embolism, usually conventional anticoagulation. Only 10 patients (2.5 percent) died of pulmonary embolism; 9 of them had clinically suspected recurrent pulmonary embolism. Clinically apparent pulmonary embolism recurred in 33 patients (8.3 percent), of whom 45 percent died during follow-up. Ninety-five patients with pulmonary embolism (23.8 percent) died within one y...

An Integrative Framework for Strategy-Making Processes

Abstract: Most prior literature on strategy making has focused on a limited set of themes (e.g., rationality) or actors (e.g., top managers). Resulting typologies have, therefore, tended to be incomplete or overlapping. None have captured the full range of content associated with the phenomenon. In response, this article offers an integrative framework consisting of five modes: command, symbolic, rational, transactive, and generative. The framework is based on the varying roles top managers and organizational members play in the strategy-making process. It goes beyond existing strategy process models by contrasting these roles and illustrating their interaction. Strategy making is viewed as an organizationwide phenomenon. Research propositions are also developed linking strategy-making processes to firm performance.

Why the Child's Theory of Mind Really Is a Theory

Abstract: How do children (and indeed adults) understand the mind? In this paper we contrast two accounts. One is the view that the child's early understanding of mind is an implicit theory analogous to scientific theories, and changes in that understanding may be understood as theory changes. The second is the view that the child need not really understand the mind, in the sense of having some set of beliefs about it. She bypasses conceptual understanding by operating a working model of the mind and reading its

Control and stabilization of nonholonomic dynamic systems

Abstract: A class of inherently nonlinear control problems has been identified, the nonlinear features arising directly from physical assumptions about constraints on the motion of a mechanical system. Models are presented for mechanical systems with nonholonomic constraints represented both by differential-algebraic equations and by reduced state equations. Control issues for this class of systems are studied and a number of fundamental results are derived. Although a single equilibrium solution cannot be asymptotically stabilized using continuous state feedback, a general procedure for constructing a piecewise analytic state feedback which achieves the desired result is suggested. >

Cystic fibrosis: molecular biology and therapeutic implications.

Abstract: Cystic fibrosis is the most common potentially lethal autosomal recessive disease of Caucasians, affecting 1 in 2500 newborns. Since the recent identification of the gene that is defective in patients with cystic fibrosis, a wealth of information about gene structure, the mutational basis of disease, and the function of the protein product has been derived. The product of the gene is a chloride channel that is regulated by adenosine 3',5'-monophosphate (cyclic AMP)-dependent protein kinase phosphorylation and that requires binding of adenosine triphosphate (ATP) for channel opening. Several new approaches to drug therapy for cystic fibrosis are now emerging, and the possibility of successful gene therapy by transfer of the normal gene to airway epithelial cells is being vigorously pursued.

Development and Test of a Theory of Technological Learning and Usage

Abstract: Beliefs, attitudes, and intentions are important factors in the adoption of computer technologies. While contemporary representations have focused on explaining the act of using computers, the role of learning to use the computer needs to be better understood within the overall adoption process. Inadequate learning can curtail the adoption and use of a potentially productive system. We introduce a new theoretical model, the theory of trying, in which computer learning is conceptualized as a goal determined by three attitude components: attitude toward success, attitude toward failure, and attitude toward the process of goal pursuit. Intentions to try and actual trying are the theoretical mechanisms linking these goal-directed attitudes to goal attainment. An empirical study is conducted to ascertain the construct validity and utility of the new theory within the context of the adoption of a word processing package. Specifically, we examine convergent validity, internal consistency reliability, stability, ...

Cognitive development: Foundational theories of core domains

Abstract: DOMAINS AND THEORIES . .. . ..... . . . ..... 338 Framework Theories 341 NAIVE PHySICS.... . . . . . ... . . . . ... . . . . . . . . . . .. 343 Infants 344 Later Developments . . . . .. . . . .. . . . . . . . . .. .... . . . . ..... . . . .... . ........ ... 345 Conclusions 350 NAIVE PSyCHOLOGy ... . . . .. .... 350 Theory of Mind 351 Earlier Developments 353 Auti sm...... 356 Conclusions 357 NAIVE BIOLOGy. . . . . . .. . . ..... ....... . . . 357 Ontology: Living Things 358 Beliefs about Biological Kinds 360 Biologically Specific Causal Processes ". . . . . . . .. 363 Summary. . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . 365 CONCLUSIONS.. . . . ... . . . . . . . . ... . . .. .. . . . . . . .. ... ...... 365