Orientador : Ferdinando de Oliveira Figueiredo / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciencias Humanas, Instituto de Economia / Made available in DSpace on 2018-07-15T05:01:25Z (GMT). No. of bitstreams: 1 Rodrigues_Helio_M.pdf: 6382153 bytes, checksum: d7116b9aa9590f8bde339d29e57aae0e (MD5) Previous issue date: 1982 / Resumo: Não informado / Abstract: Not informed / Mestrado / Mestre em Ciências Econômicas

We present an analysis of the effects of heating, suction, and compressibility on the stability characteristics of boundary-layer flows within the framework of a complete nonparallel, linear, spatial stability theory. Included in the theory are disturbances due to velocity, Pressure, temperature, density, and transport properties as well as 'variations of the fluid properties with temperature. The method of multiple scales is used to account for the nonparallelism of the mean flow and equations are derived for the evolution of the disturbance amplitude and wave number vector. / Ph. D.

This dissertation develops an analytical framework for the examination of choice in settings of costly information. Throughout the dissertation the importance of information processing costs are emphasized and used as a basis for establishing several points at a very general level. The framework developed in this dissertation can be viewed as a synthesis of several heretofore independent lines of analysis: economic development, the theory of entrepreneurship, adaptive expectations, the economies of search, and temporary equilibrium theory. The framework itself is a basic extension of the optimizing paradime to include the costs of collecting data and information processing. The consequences of this extension contrast in many ways with conventional applications of the paradime. In the framework developed, information is distinguished from data. Information is defined to be images within an individual's mind, and data is defined to be external, potential sources of information. Information is assumed to be costly and to be able to affect an individual's perception of his opportunities and their relative value (which are themselves information at the moment of decision). The process of decision-making is characterized as an exercise in information processing which is itself costly. Given this specification of the individual choice problem, it is argued that individuals will choose flexible plans, plans which an individual anticipates modifying, rather than rigid plans. Given the existence of reasonably complex circumstances, it is argued that information will be acquired by individuals that causes them to revise their plans. It is argued that a model which includes such information can not be an equilibrium model in the usual sense in any reasonably complex circumstances. / Ph. D.

The problems associated with urban development and its resultant effects on environmental quality present increasingly complex decisions for elected and technical officials. Current approaches to modeling often result in the development of models which are too complex to be understood and require such long time periods to be modified that by the time the model is operational the problem has changed. A modular modeling framework is proposed which considers land use, runoff, and water quality and connects these factors to a budgetary function. In addition, the modular configuration facilitates the process of modifying components of the model in response to a changing problem environment. In order to test the feasibility of the proposed modeling approach, the model is applied to the Upper South River watershed, Waynesboro, Virginia. The following three alternative development plans are evaluated: 1. To permit no additional population growth and preserve the area for agriculture and recreation. 2. To permit concentrated development in the form of two new communities each with a population of three thousand persons. 3. To increase the population by three thousands persons but to allow development to continue to follow the existing pattern of urban sprawl. The study concludes by stating that if zoning ordinances and comprehensive plans focus on consolidating development within the framework of existing water and sewer networks, the cost of providing the sewer network for Alternative 2 will be ten million dollars less than Alternative 3 for the same increase in population. / Ph. D.

The central purpose of this study was to determine if affective work-related skills expected of workers by their employers could be identified using the critical incident technique. Additionally~ this study sought to determine if there were affective skills common among several selected occupational areas. The following research questions gave direction to this study: 1. Can the Critical Incident Technique be used to identify work related affective skills needed by persons employed in the television service and repair, electronic assembler (manufacturing), and television sales (retail) occupational areas? 2. Can these skills be grouped into meaningful clusters? 3. Are different affective skills required by persons in each of the three occupational areas? The research procedure used in this study was the Critical Incident Technique developed by John Flanagan. Five steps are included: (1) determination of the general aim of the activity, (2) developing plans and specifications for collecting factual incidents, (3) collecting data, (4) analyzing the data, and (5) interpreting and reporting the data. The instrument used to collect critical incidents was adapted from the form developed by W. K. Kirchner and M. D. Dunnette. It was composed of two major sections: (1) the Effective Critical Incident Form and (2) the Ineffective Critical Incident Form. Respondents in this study were divided into three strata according to occupational areas: television retail sales supervisor, television service and repair supervisor, and electronic assembler supervisor. Thirty names of line management personnel were randomly selected from each strata for individual interviews. Critical incident interview reports were reviewed and work-related affective behavioral statements were abstracted from each incident. A panel of experts was used to review the list of behavior statements. The final instrument included 63 behavior statements. A random sample of line management personnel (394) were potential respondents in this study. Each participant provided biographical data and indicated degree of agreement (Very Unimportant to Very Important) with 63 work-related affective behavior statements. The analysis of data consisted of computing means for each of the behavior statements and comparing them to an established criterion (mean score greater than 2.50). Factor analysis was used to reduce the data and to group the behavior statements into meaningful clusters (factors). One way analysis of variance was used to determine whether there were significant differences between the factors and the occupational areas used in this study. / Ed. D.

The feasibility of applying active control theory to control both the transient and steady state response of a two cable-stayed bridge has been investigated. The bridge has been modeled as a two degree freedom system in bending and torsion, excited by both buffeting and self-excited loads. The existing suspension cables have been used as active tendons by which the control forces are applied to the bridge deck at the points of the anchorage. The control force from each suspension cable is actuated through a hydraulic-servomechanism which is regulated by the sensed motion of the bridge deck at the anchorage of the cable. Stability and steady state response analyses have been presented for both controlled and uncontrolled motion. The power requirement for the control devices has been derived. Finally, numerical examples have been worked out to demonstrate the feasibility of the derived theory for two cable-stayed bridges. / Ph. D.

The purpose of the study was to evaluate the organization and administration of the interscholastic athletic programs in the AAA public senior high schools of the Commonwealth of Virginia. The study was based on the following null hypotheses: 1. There is no significant difference of opinion among the various levels of administrators that the organization and administration is inadequate in governing the interscholastic athletic program in the Commonwealth of Virginia. 2. There is no significant difference of opinion among the various levels of administrators that a supplemental Public High School Athletic Association in their region in coordination with the League office in Charlottesville would improve the organization and administration of the interscholastic athletic program. 3. There is no significant difference of opinion among the various levels of administrators that the student should have little input about decisions concerning the organization and administration of high school athletics. An opinionnaire was mailed to 371 administrators representing the school beard members, chief school administrators, principals, athletic directors, and assistant athletic directors, Therefore, opinionnaires were sent to 70 school board members, 35 chief school administrators, 98 high school principals, 98 athletic directors, and 70 assistant athletic directors. The data was kevpunched and the computer was programmed to handle the statistical analysis of the data, Data included: 1. Frequency and percentage of response. 2. Analysis of possible relations between and among items within the opinionnaire. 3. Analysis of possible relations between the opinions of the various levels of administration for descriptive purposes, Statistical significance of the relations examined were determined by the use of Chi-square Analysis. 4. One-way Analysis of Variance was used to examine each hypothesis for statistical significance, The .05 level of confidence was considered significant for the rejection of the null hypothesis. Returns were received from 336 of 371 administrators (90.5 percent) of which 328 were used, Eight of the returns were not used for various reasons. On the basis of these analyses, the following conclusions were drawn: 1. A significant difference of opinion does exist among the various levels of administration that the organization and administration is inadequate in governing the interscholastic athletic program in the Commonwealth of Virginia, This evaluation concludes that the Virginia High School League is doing an adequate job for the AAA Public Senior High Schools in the Commonwealth of Virginia with the organization and administration of interscholastic athletics, The five levels of administration in 1977 support the Virginia High School League goals, objectives, rules, and regulations for the administration of interscholastics. 2. A significant difference of opinion does exist among the various levels of administration that a supplemental Public High School Athletic Association in their region in coordination with the League office in Charlottesville would improve the organization and administration of the interscholastic athletic program, The athletic directors and assistant athletic directors are for such a supplemental association to improve interscholastic athletics and the principals and chief administrators are opposed to such a supplemental association. Board members are indecisive, All groups combined would not be in favor of such a supplemental association at this time to improve the communication, the organization, and the administration of interscholastic athletics in the AAA public senior high schools in the Commonwealth of Virginia. 3. A significant difference of opinion does exist among the various levels of administration that the student should have little input about decisions concerning the organization and administration of high school athletics, This evaluation concludes that the student should have input about the decisions that are made concerning policies, rules, regulations, and scheduling of interscholastic athletics in the ASA public senior high schools in the Commonwealth of Virginia. / Ed. D.

This investigation consisted of a study of the break-in behavior of a tungsten oxide on silica catalyst during propylene disproportionation. A catalyst of 10 percent WO3 on silica gel (223 square meters per gram B.E.T. surface area) was used in a microcatalytic reactor. During the initial contacting of freshly activated samples of this catalyst with propylene, significant increases in disproportionation activity were observed for periods of up to 20 hours. The object of this study was to investigate the phenomena responsible for this break-in. The rate of approach to steady-state activity data were obtained using catalyst samples which were first saturated with each of the three gases involved in this reaction (propylene, ethylene, and 2-butene) by pulsing at .94 and 2.7 atmospheres before.starting the propylene flow. Effects of each gas on the break-in behavior of the catalyst were determined. A material balance around the reactor was made for each gas by pulse reactor techniques. / Ph. D.

This study tests the hypothesis: Bark beetles initially locate their host trees in a non-random manner. The association of the southern pine beetle (<u>Dendroctonus frontalis</u> Zimm.) and associated Coleoptera with stressed trees suggested the direction for this study. Loblolly pine trees, <u>Pinus taeda</u> L., were stressed by severing and girdling. The bark beetle population trapped at stressed trees was then compared to the bark beetles trapped at unstressed control trees. The experiments were conducted in an apparently normal, old-field mixed pine-hardwood forest located in Nottoway County, Virginia, during 1975 through 1977. The girdling technique consisted of three circumferential chain saw cuts 5 cm deep at approximately 1 m above the ground. The severing technique was accomplished by guying the trees with 3.2 mm wire rope to maintain the trees' normal vertical position. The bole was then severed with a chain saw. The control trees were not treated in any manner. The insects associated with the treated and control trees were trapped with a four-way glass baffle placed over an aluminum funnel attached to a 1 liter jar containing 2.5 cm of water. The traps were placed at mid-bole and collected weekly during the growing season. The bark beetle complex studied in this experiment consisted of the following species: <u>Dendroctonus frontalis</u> Zimm, <u>D. terebrans</u> Oliv., <u>Ips avulsus</u> Eichh., <u>I. grandicollis</u> Eichh., <u>I. calligraphus</u> Germ., <u>Hylastes</u> spp., <u>Cossonus</u> spp., and <u>Pityophthorus</u> spp. The bark beetles were not trapped at the treated trees until the trees' foliage had begun to fade. The time period varied from two weeks to two years and also with the month of treatment. The number of bark beetles trapped at trees with faded needles was 40.06/trap-week for the first week the bark beetles were trapped at the tree. Control trees trapped the same number of bark beetles per trap-week as treated trees with green needles, .06 bark beetles per trap-week. The southern pine beetle and associated Coleoptera during endemic population levels exhibit a non-random directed attraction to the treated trees after they died, as evidenced by the fading of the trees' foliage. The conclusion is reached that these insects have the ecological role of scavengers in pine forests. / Ph. D.

An important element in the preparation of students for positions in the field of recreation has been an adequate field work experience. Additionally, the quality of an orientation to field programs was seen as an important variable to be evaluated. The purpose of this study was to investigate attitudes about a preparation for field work training programs. The study involved forty undergraduate recreation majors registered for summer quarter 1978 recreation field work course and their respective forty recreation agency supervisors. The study population was assigned to either the experimental or control condition. The experimental group received a treatment (training program) and the control group received no treatment. Attitudes were analyzed through the use of a Field Work Preparation Questionnaire, using an adapted Likert Method of Summated Ratings Scale (1932). Data were gathered from two posttests and evaluated schematically on a revised Weber Model of Educational Evaluation (1973). Responses were tallied; means and t-test differences were used, as appropriate. Eighteen attitude items about a field work preparation program were measured in terms of their respective effectiveness, approval and usability. Based on the findings and within the limitations of the study, it was concluded that significant differences do occur between student experimental and control groups in their attitudes about the relative effectiveness, approval of, and usability of the respective field work preparation programs. Significant differences were found on seventeen of the eighteen attitude items between the recreation agency supervisor experimental and control groups. It was recognized that a long range evaluation program would be required to consistently assess the relative effectiveness of a field work preparation program. In recognition of the constraints imposed by a short term study, a system had to be developed which would accommodate the highest level of evaluative input within existing limitations. / Ed. D.