Showing papers by "University of Michigan published in 1983"
TL;DR: This paper showed that if two prior analogs were given, subjects often derived a problem schema as an incidental product of describing the similarities of the analogs, and the quality of the induced schema was highly predictive of subsequent transfer performance.
2,740 citations
TL;DR: The theory of 3-manifolds has been revolutionised in the last few years by work of Thurston as mentioned in this paper, who has shown that geometry has an important role to play in the theory in addition to the use of purely topological methods.
Abstract: The theory of 3-manifolds has been revolutionised in the last few years by work of Thurston [66-70]. He has shown that geometry has an important role to play in the theory in addition to the use of purely topological methods. The basic aim of this article is to discuss the various geometries which arise and explain their significance for the theory of 3-manifolds. The idea is that many 3-manifolds admit 'nice' metrics which give one new insight into properties of the manifolds. For the purposes of this article, the nicest metrics are those of constant curvature. An observer in a manifold with a constant curvature metric will see the same picture wherever he stands and in whichever direction he looks. Such manifolds have special topological properties. However, we will also need to consider nice metrics which are not of constant curvature. In this article, I will explain what is meant by a 'nice' metric and describe their classification in dimension three which is due to Thurston. Then I will discuss some of the 3-manifolds which admit these nice metrics and the relationship between their geometric and topological properties. In this introduction all manifolds and metrics will be assumed to be smooth so that the objects of interest are all Riemannian manifolds. It has been known since the nineteenth century that in dimension two there is a very close relationship between geometry and topology. I will start by describing some basic facts about closed surfaces. I will discuss these in more detail in §1. Each
1,677 citations
TL;DR: In this article, the authors show that diffusion-limited aggregation has no upper critical dimension and apply scale invariance to study growth, gelation, and the structure factor of aggregates.
Abstract: Diffusion-limited aggregation (DLA) is an idealization of the process by which matter irreversibly combines to form dust, soot, dendrites, and other random objects in the case where the rate-limiting step is diffusion of matter to the aggregate. We study the process from several points of view stressing the fact that it apparently gives rise to scale-invariant objects whose Hausdorff dimension is independent of short-range details. We show that DLA has no upper critical dimension. We apply scale invariance to study growth, gelation, and the structure factor of aggregates.
1,391 citations
TL;DR: In this article, the authors examine aspects of knowledge and motivation that are critical to becoming a strategic reader, emphasizing that agents are strategic, not actions removed from contexts, and that self-guided learning depends on the intentions, perceptions and attributions of learners.
1,344 citations
TL;DR: In this paper, the role of neutrophils in acute myocardial infarction in dogs was assessed by using rabbit antiserum to reduce the circulating neutrophil levels in dogs.
Abstract: Accumulation of polymorphonuclear neutrophils during the acute inflammatory response may exacerbate tissue injury through the release of activated oxygen products or proteolytic enzymes or both. To assess the role of neutrophils in acute myocardial infarction, circulating neutrophil levels in dogs were reduced by 77 +/- 2% (mean +/- SEM) by administering rabbit antiserum to dog neutrophils. Acute myocardial infarction was induced in open-chest anesthetized dogs by 90 minutes of left circumflex coronary artery occlusion followed by 6 hours of reperfusion. Dogs treated with neutrophil antiserum (n = 8) developed myocardial infarcts that were an average of 43% smaller than infarcts in dogs treated with nonimmune rabbit serum (n = 7) (27.0 +/- 4.5% vs 47.1% +/- 7.5% of the area at risk, p less than 0.05). In a saline-treated control group (n = 8), infarct size was 48.0 +/- 4.7% of the area at risk, a value not significantly different from that of the nonimmune serum group but significantly greater than that in the neutrophil antiserum dogs (p less than 0.05). There were no major hemodynamic differences between groups. Histopathologic examination revealed that infarcted myocardium from dogs given saline or treated with nonimmune serum had a substantial neutrophilic infiltrate, which was virtually absent in infarcted tissue from dogs treated with neutrophil antiserum. These observations suggest that neutrophil accumulation in response to myocardial ischemia may be responsible for a substantial portion of the irreversible myocardial injury resulting from temporary coronary artery occlusion.
1,208 citations
Book•
01 Jan 1983TL;DR: In this paper, the authors present sheet metal properties including stress and strain, tension, and strain hardening, and anisotropic anisotropy for sheet metal forming, as well as other sheet forming operations.
Abstract: 1. Stress and strain 2. Plasticity 3. Strain hardening 4. Plastic instability 5. Temperature and strain-rate dependence 6. Work balance 7. Slab analysis and friction 8. Friction and lubrication 9. Upper-bound analysis 10. Slip-line field analysis 11. Deformation zone geometry 12. Formability 13. Bending 14. Plastic anisotropy 15. Cupping, redrawing and ironing 16. Forming limit diagrams 17. Stamping 18. Hydroforming 19. Other sheet forming operations 20. Formability tests 21. Sheet metal properties.
1,126 citations
TL;DR: Most of the morphological and functional differences between vertebrates and other chordates occur in the head and are derived embryologically from muscularized hypomere, neural crest, and epidermal (neurogenic) placodes.
Abstract: Most of the morphological and functional differences between vertebrates and other chordates occur in the head and are derived embryologically from muscularized hypomere, neural crest, and epidermal (neurogenic) placodes. In the head, the neural crest functions as mesoderm and forms connective, skeletal, and muscular tissue. Both the neural crest and the epidermal placodes form special sense organs and other neural structures. These structures may be homologous to portions of the epidermal nerve plexus of protochordates. The transition to vertebrates apparently was associated with a shift from a passive to an active mode of predation, so that many of the features occurring only in vertebrates became concentrated in the head.
941 citations
TL;DR: The authors argue that realistic group conflict motives do help explain whites' opposition to busing, not self-interest or realistic-gro up conflict motives, and that the tests of symbolic racism versus group conflict explanations have not been fair because of a narrow definition of group interests that ignores the role of subjectively appreciated threat and challenges to group status.
Abstract: The theory of symbolic racism contends that whites' opposition to busing springs from a basic underlying prejudiced or intolerant attitudinal predisposition toward blacks, not self-interest or realistic-gro up conflict motives. The present research argues that realistic group conflict motives do help explain whites' opposition to busing. Two major criticisms of the symbolic racism approach are made: (a) that the tests of symbolic racism versus group conflict explanations of opposition to busing have not been fair because of a narrow definition of group interests that ignores the role of subjectively appreciated threat and challenges to group status; and (b) that by forcing racial attitudes onto a single continuum running from prejudice to tolerance, the symbolic racism researchers overlook the importance of the perception that the civil rights movement is a threatening force. By reanalyzing the Michigan National Election Study data used by Sears, Hensler, and Speer (1979) and Sears, Lau, Tyler, and Allen (1980), the present research broadens the notion of self-interest and operates with a multidimensional conceptualization of racial attitudes and in so doing demonstrates that whites' opposition to busing reflects group conflict motives, not simply a new manifestation of prejudice.
837 citations
TL;DR: In reasoning about everyday problems, people use statistical heuristics, that is, judgmental tools that are rough intuitive equivalents of statistical principles as discussed by the authors, that are more likely when the sample space and the sampling process are clear, the role of chance in producing events is clear, or the culture specifies statistical reasoning as normative for the events.
Abstract: In reasoning about everyday problems, people use statistical heuristics, that is, judgmental tools that are rough intuitive equivalents of statistical principles. Statistical heuristics have improved historically and they improve ontogenetically. Use of statistical heuristics is more likely when (a) the sample space and the sampling process are clear, (b) the role of chance in producing events is clear, or (c) the culture specifies statistical reasoning as normative for the events. Perhaps because statistical procedures are part of people's intuitive equipment to begin with, training in statistics has a marked impact on reasoning. Training increases both the likelihood that people will take a statistical approach to a given problem and the quality of the statistical solutions. These empirical findings have important normative implications.
781 citations
TL;DR: In this paper, a model of job stress that focuses on organizational and job-related stress is presented, where job stress is conceived of as a first-level outcome of the organization and job; it is a feeling of discomfort that is separate and distinct from second-level outcomes or consequences.
741 citations
Journal Article•
TL;DR: It is postulate that a single serum enzyme, with both paraox onase and arylesterase activity, exists in two different isozymic forms with qualitatively different properties, and that paraoxon is a "discriminating" substrate (having a polymorphic distribution of activity) and phenylacetate is a 'nondiscriminating' substrate for the two isozymes.
Abstract: The heterozygous human serum paraoxonase phenotype can be clearly distinguished from both homozygous phenotypes on the basis of its distinctive ratio of paraoxonase to arylesterase activities. A trimodal distribution of the ratio values was found with 348 individual serum samples, measuring the ratio of paraoxonase activity (with 1 M NaCl in the assay) to arylesterase activity, using phenylacetate. The three modes corresponded to the three paraoxonase phenotypes, A, AB, and B (individual genotypes), and the expected Mendelian segregation of the trait was observed within families. The paraoxonase/arylesterase activity ratio showed codominant inheritance. We have defined the genetic locus determining the aromatic esterase (arylesterase) responsible for the polymorphic paraoxonase activity as esterase-A (ESA) and have designated the two common alleles at this locus by the symbols ESA*A and ESA*B. The frequency of the ESA*A allele was estimated to be .685, and that of the ESA*B allele, 0.315, in a sample population of unrelated Caucasians from the United States. We postulate that a single serum enzyme, with both paraoxonase and arylesterase activity, exists in two different isozymic forms with qualitatively different properties, and that paraoxon is a "discriminating" substrate (having a polymorphic distribution of activity) and phenylacetate is a "nondiscriminating" substrate for the two isozymes. Biochemical evidence for this interpretation includes the cosegregation of the degree of stimulation of paraoxonase activity by salt and paraoxonase/arylesterase activity ratio characteristics; the very high correlation between both the basal (non-salt stimulated) and salt-stimulated paraoxonase activities with arylesterase activity; and the finding that phenylacetate is an inhibitor for paraoxonase activities in both A and B types of enzyme.
TL;DR: The results of using a method of convergent analyses of naturally occurring speech to assess the young child’s ability to contemplate and communicate about mental state suggest that still younger children lack awareness of such states, or at the very least, an understanding of their appropriateness as topics of conversation.
TL;DR: In this article, the cosmological implications of N = 1 supergravity with the Polonyi potential were studied, and it was shown that for typical values of the gravitino mass (102-103 GeV) the universe goes through a late period of reheating (i.e., from a temperature of about 10 -7 MeV to 10 -2 MeV).
TL;DR: This paper defines a set of five production planning problems that must be solved for efficient use of an FMS, and addresses specifically the grouping and loading problems.
Abstract: A flexible manufacturing system FMS is an integrated, computer-controlled complex of automated material handling devices and numerically controlled machine tools that can simultaneously process medium-sized volumes of a variety of part types. FMSs are becoming an attractive substitute for the conventional means of batch manufacturing, especially in the metal-cutting industry. This new production technology has been designed to attain the efficiency of well-balanced, machine-paced transfer lines, while utilizing the flexibility that job shops have to simultaneously machine multiple part types. Some properties and constraints of these systems are similar to those of flow and job shops, while others are different. This technology creates the need to develop new and appropriate planning and control procedures that take advantage of the system's capabilities for higher production rates.
This paper defines a set of five production planning problems that must be solved for efficient use of an FMS, and addresses specifically the grouping and loading problems. These two problems are first formulated in detail as nonlinear 0-1 mixed integer programs. In an effort to develop solution methodologies for these two planning problems, several linearization methods are examined and applied to data from an existing FMS. To decrease computational time, the constraint size of the linearized integer problems is reduced according to various methods. Several real world problems are solved in very reasonable time using the linearization that results in the fewest additional constraints and/or variables. The problem characteristics that determine which linearization to use, and the application of the linearized models in the solution of actual planning problems, are also discussed.
01 Jan 1983
TL;DR: The use of sample survey weights in a least square regression analysis is examined with respect to four increasingly general specifications of the population regression model as mentioned in this paper, and the appropriateness of the weighted regression estimate depends on which model is chosen.
Abstract: The rationale for the use of sample survey weights in a least squares regression analysis is examined with respect to four increasingly general specifications of the population regression model. The appropriateness of the weighted regression estimate depends on which model is chosen. A proposal is made to use the difference between the weighted and unweighted estimates as an aid in choosing the appropriate model and hence the appropriate estimator. When applied to an analysis of the familial and environmental determinants of the educational level attained by a sample of young adults, the methods lead to a revision of the initial additive model in which interaction terms between county unemployment and race, as well as between sex and mother's education, are included.
TL;DR: In this paper, a lead model was constructed using the trunk data to obtain the radii of gyration in both the sagittal and frontal planes of a single male cadaver was dissected to compare the trunk measurements with the lead model results.
Abstract: Anatomical data necessary for the analysis of human motion are presented on the total living body segmented into sixteen parts. Cadaver data from Dempster (1955) are applied to water displacement data obtained on 135 living subjects (35 men and 100 women) to obtain the weight, center of gravity, and radius of gyration for the segmented extremities. Thirty-three of these subjects (15 men and 18 women) were used to obtain the weight of the segments of the trunk, using the water displacement method, and sixteen of these subjects (7 men and 9 women) were used to locate the center of gravity of each trunk segment. A lead model was constructed using the trunk data to obtain the radii of gyration in both the sagittal and frontal planes. A single male cadaver was dissected to compare the trunk measurements with the lead model results.
TL;DR: A review of the literature on assignment of responsibility for an accident, small claims, complex disputes and small claims literature from 1947 to 1975.
Abstract: Tonnies, Ferdinand 1957 Community and Society. New York: Harper Torchbooks. Vidmar, Neil and Linda Crinklaw 1974 "Assignment of responsibility for an accident: a methodological and conceptual critique." Canadian Journal of Behavioral Science 6:112-30. Weber, Max 1947 The Theory of Social and Economic Organization. Talcott Parsons (ed.) New York: Free Press. Yngvesson, Barbara and Patricia Hennessey 1975 "Small claims, complex disputes: a review of the small claims literature." Law and Society Review 9:219-74.
TL;DR: In this article, the optimal strategy of the principal is examined in an environment where there are (ex post ) limitations on the maximum penalty that can be imposed on a risk-neutral agent.
TL;DR: Experimental data indicate that although both protein and fat enhance high-protein, low-energy diets, carbohydrate is a more effective supplement than fat.
TL;DR: In this article, the authors investigated the rationale behind interlirm tender offers by examining the returns realized by the stockholders of firms that were the targets of unsuccessful tender offers and lirms that have made unsuccessful offers and concluded that acquisitions via tender offers are attempts by bidding firms to exploit potential synergies, not simply superior information regarding the true value of the target resources.
TL;DR: In this article, the authors present two quite distinct approaches to derive necessary and sufficient conditions involving the derivatives of the demand functions of a consumer's choice behavior subject to a budget constraint.
Abstract: The neoclassical model of consumer behaviour postulates that a consumer's choice behaviour can be described as deriving from utility maximization subject to a budget constraint. One is then naturally led to ask what this model implies about observed behaviour. This question has been addressed from two quite distinct approaches. The first approach, originating in the work of Slutsky (1915) and Antonelli (1886), derives necessary and sufficient conditions involving the derivatives of the demand functions. The second approach, originating in the work of Samuelson (1938), (1947), (1948), derives algebraic conditions on the demand functions implied by maximizing behaviour.
TL;DR: In this paper, the origin of quark and lepton masses is discussed in a low-energy theory of strong and electroweak interactions when the weak scale is induced via supergravity.
TL;DR: In this article, a survey by mail was conducted during 1980-1981 of all voluntary associations that are open to membership and concerned with some aspects of public policy at the national level.
Abstract: Rather than striving to measure the influence of groups in the policy-making process this article concentrates instead on the ways in which interest groups are created and the means by which they remain in existence. A survey by mail was conducted during 1980-1981 of all voluntary associations that are open to membership and concerned with some aspects of public policy at the national level. The sample of groups was chosen from the Congressional Quarterly's Washington Information Directory. Questionnaires were delivered to 913 interest groups, and usable responses were received from 564, yielding a response rate of 64.8%. Most studies of groups have concerned the tactics employed by group leaders in attracting and holding their members. This study demonstrates that the origins and maintenance of groups depends even more upon the success of group leaders in securing funds from outside their membership which are needed to keep their groups in operation. Estimates of patronage from different sources are provided as well as data on the congruence between the policy goals of groups and their patrons,
Journal Article•
TL;DR: The reliability and stability of self-reports of licit and illicit drug use are estimated using longitudinal data, and found to be rather high, although there appears to be a tendency for discrepant reporting of marijuana and alcohol use to be correlated within time.
Abstract: The reliability and stability of self-reports of licit and illicit drug use are estimated using longitudinal data, and found to be rather high. An apparent inconsistency in reporting (less use over a 12-month period than would be expected based on use reported over a 30-day period) is examined (1) for association with personal characteristics and (2) for individual consistency over time. Neither individual consistency nor significant associations are found, although there appears to be a tendency for discrepant reporting of marijuana and alcohol use to be correlated within time. The data used are from the Monitoring the Future project, an ongoing nationwide study of high school seniors, with follow-up surveys after graduation.
TL;DR: The regeneration of skeletal muscle is compared structurally and functionally with its embryonic development and the free muscle graft is used as a model to illustrate the integration of regenerating muscle with the rest of the body.
Abstract: Regeneration is a unique adaptation of skeletal muscle that occurs in response to injury. Following direct trauma or disease, regeneration results in restoration, to some degree, of the original structure and function of the muscle. Our purpose is to summarize the main features of the regeneration of skeletal muscle fibers and entire muscles with an emphasis on aspects of regeneration that may be important to the understanding and treatment of sports injuries. The regeneration of skeletal muscle is compared structurally and functionally with its embryonic development. The free muscle graft is used as a model to illustrate the integration of regenerating muscle with the rest of the body. Finally, the breakdown and regeneration of skeletal muscle fibers are discussed in relation to local anesthetics, sports injuries, and disease.
01 Jan 1983
TL;DR: What does it mean to go out to the wilderness, to leave society behind and to live for a while on what one carries in a pack, devoting one’s time to an exploration of the natural world?
Abstract: What does it mean to go out to the wilderness—to leave society behind and to live for a while on what one carries in a pack, devoting one’s time to an exploration of the natural world?