Thesis (doctoral)--Philipp-Universität zu Marburg.

SANTOS, Luan Falcão Daniel. Network effects, conformism and misbehavior in Brazilian classrooms. -2016. 79f. Dissertação (mestrado). - Universidade Federal do Ceará, Programa de Pós Graduação em Economia, CAEN, Fortaleza, 2016. / Submitted by Mônica Correia Aquino (monicacorreiaaquino@gmail.com) on 2017-07-28T19:24:46Z No. of bitstreams: 1 2016_dis_lfdsantos.pdf: 1161764 bytes, checksum: 657efde122aaf7a32fa71aa91069e159 (MD5) / Approved for entry into archive by Mônica Correia Aquino (monicacorreiaaquino@gmail.com) on 2017-07-28T19:25:15Z (GMT) No. of bitstreams: 1 2016_dis_lfdsantos.pdf: 1161764 bytes, checksum: 657efde122aaf7a32fa71aa91069e159 (MD5) / Made available in DSpace on 2017-07-28T19:25:16Z (GMT). No. of bitstreams: 1 2016_dis_lfdsantos.pdf: 1161764 bytes, checksum: 657efde122aaf7a32fa71aa91069e159 (MD5) Previous issue date: 2016 / For understanding how networks a ect the behavior of individuals, speci - cally the behavior os students in the last year of high school inside the classroom, we estimate a model of Network e ects, the Local-average model for two behavioral variables: doing an exam without being prepared and cheating in an exam, in order to understand how the behavior of individual's friends a ects his or her behavior. It was found a positive and statistically signi cant e ect for the network e ect of the probability of doing an exam without being prepared, and a positive, but not signi cant e ect for the network e ect of the probability of cheating in an exam. This result shows that policies or actions aiming the reduction of the probability of a student do an exam without being prepared have what is called social multiplier e ect, because besides this policy change the behavior of the student regarding this variable, his or her change of behavior a ects positively the behavior of people in his or her network. / Para entender de que forma as networks afetam o comportamento dos indiv duos, em espec co o comportamento de estudantes no ultimo ano do ensino m edio dentro da sala de aula, estimamos um modelo de Network e ects, o Localaverage Model para duas vari aveis comportamentais: fazer uma prova ou teste sem ter se preparado e colar em uma prova, a m de entender como o comportamento dos amigos de um indiv duo afeta o comportamento do mesmo. Encontrou-se uma efeito positivo e estatisticamente signi cante para o network e ect da probabilidade de se fazer uma prova ou teste sem ter se preparado, e um efeito positivo, mas n~ao signi cante para o network e ect da probabilidade de se colar em uma prova. Este resultado mostra que pol ticas ou a c~oes que visam a redu c~ao da probabilidade de um estudante fazer um exame sem se preparar tem o que se chama social multiplier e ect, pois al em dessa pol tica mudar o comportamento do estudante em rela c~ao a essa vari avel, sua mudan ca de comportamento afeta positivamente o comportamento das pessoas em sua network.

This thesis presents experimental studies on the relationship between external surface pressure and the perceived discomfort in seated body areas, in particular those under the ischial tuberosity and the mid-thigh. It consists of three parts. Part one provides a comprehensive review of the existing knowledge concerning seated discomfort. The current assessment methods of seated discomfort are summarised, with the emphasis on the validity and reliability of the rating scale methods. The implications of surface pressure to seated people are outlined from the perspective of clinical, sensory and perceptual, and ergonomics domains. A brief review of current technologies for pressure measurement is also provided. Part two presents the experimental work. It starts with an exploratory assessment model of seated discomfort, based on pressure measures. Two preliminary experiments were conducted to test the feasibility of the model. Three further psychophysical experiments were carried out to test the validity and reliability of the selected six rating scales, and to investigate the effects of surface pressure levels on perceived pressure intensity and discomfort in the seated mid-thigh and ischial tuberosity areas. Surface pressure stimuli were applied to a seated body area of 3,318 mm2• Subjects judged three items of sensations: pressure intensity, local discomfort, and the overall discomfort. The main results are: I) A 50-point category partitioning scale was identified to be most sensitive and reliable for scaling pressure intensity and discomfort; 2) Sensations of pressure intensity and discomfort linearly increase with the logarithm of the pressure stimulus level; 3) Thresholds for pressure intensity and discomfort in the seated ischium and thigh areas were derived; 4) The sensitivity of intensity and discomfort to the stimuli differs between the locations .The mid-thigh is more sensitive to surface pressure than the ischium. It is considered that this is due to differences in load adaptation, body tissue composition and deformation; 5) Local pressure discomfort dominates the overall discomfort, and ratings of the local discomfort are higher than those of overall discomfort. Part three discusses the findings from this research. Four integration models of the overall discomfort from local discomfort components were proposed. The Weighted Average model asserts that the overall discomfort is a linear combination of local discomfort components, and that the weight of each local discomfort is the proportion of this component out of the arithmetic sum of all local discomfort components. The mechanisms of discomfort were analysed. The fundamental research presented herein uniquely contributes to the knowledge on the human perception of seated pressure discomfort. Although this is not application based, the findings contribute to the methods of seating comfort evaluation as well as provide criteria by which seat designers may formulate design requirements.

The purpose of this study was to investigate the relationship among the need to achieve, field independence, and grade-point average.

Our purpose was to examine characteristics of progeny test herds and their effects on the genetic evaluation of young sires. Data for a study of response to pedigree selection by stud were evaluated from 6238 Holstein sires in four USDA animal model evaluations from January 1995 to February 1997. When data were restricted to the nine major semen producing organizations, a common intercept and slope for prediction of daughter yield deviation from pedigree merit were appropriate for milk but R2 was low at 0.14. We detected no important differences in response to pedigree selection among progeny testing methods used by major semen producing organizations. Data for a study of specific progeny test herds were 4154 Holstein progeny test herds from two AI studs and 6361 remaining herds from two states. We grouped herds into four categories, 21st Century Genetics and Genex progeny test herds, other Minnesota herds and other New York herds. Herds were described by DHI profile and average cow evaluation data. Cows with extreme yield deviations (± 3 herd standard deviations) were identified, as were daughters of progeny test bulls with extreme daughter performance relative to pedigree merit of the bull. 21st Century Genetics and Genex appear to have chosen the larger, genetically superior and better managed herds from within their regions in which to conduct their progeny testing. We were not able to predict if a bull was going to exceed or fail to meet pedigree prediction by characteristics of the progeny test herds in which he was sampled. / Master of Science

The purpose of this paper is to examine the interactions between two plant species endemic to Florida and develop a model for the growth of one of the plant species. An equation for the growth of Hypericum cumulicola is developed through analyzing how the distance to and the height of the nearest Ceratiola ericoides (Florida rosemary) affects the growth of Hypericum cumulicola. The hypericums were separated into five separate regions according to the distance to the nearest rosemary plant. The parameters for a basic growth equation were obtained in each of the five regions and compared to each other along with the average deviations in each of the five regions. Analysis of the five separate regions aided in the creation of different growth equations that each encompassed all of the regions together. Four different growth equations are developed and then compared and analyzed for their accuracy.

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<p> This thesis deals with combinatorial properties of hyperplane arrangements. In particular, we address a conjecture of Deza, Terlaky and Zinchenko stating that the largest possible average diameter of a bounded cell of a simple hyperplane arrangement is not greater than the dimension. We prove that this conjecture is asymptotically tight in fixed dimension by constructing a family of hyperplane arrangements containing mostly cubical cells. The relationship with a result of Dedieu, Malajovich and Shub, the conjecture of Hirsch, and a result of Haimovich are presented.</p> <p> We give the exact value of the largest possible average diameter for all simple arrangements in dimension two, for arrangements having at most the dimension plus two hyperplanes, and for arrangements having six hyperplanes in dimension three. In dimension three, we strengthen the lower and upper bounds for the largest possible average diameter of a bounded cell of a simple hyperplane arrangements.</p> <p> Namely, let ΔA(n, d) denote the largest possible average diameter of a bounded cell of a simple arrangement defined by n hyperplanes in dimension d. We show that • ΔA(n, 2) = 2[n/2] / (n-1)(n-2) for n ≥ 3, • ΔA(d + 2, d) = 2d/d+1, • ΔA(6, 3) = 2, • 3 - 6/n-1 + 6([n/2]-2) / (n-1)(n-2)(n-3) ≤ ΔA(n, 3) ≤ 3 + 4(2n^2-16n+21) / 3(n-1)(n-2)(n-3) • ΔA (n, d) ≥ 1 + (d-1)(n-d d)+(n-d)(n-d-1) for n ≥ 2d. We also address another conjecture of Deza, Terlaky and Zinchenko stating that the minimum number Φ0A~(n, d) of facets belonging to exactly one bounded cell of a simple arrangement defined by n hyperplanes in dimension d is at least d (n-2 d-1). We show that • Φ0A(n, 2) = 2(n - 1) for n ≥ 4, • Φ0A~(n, 3) ≥ n(n-2)/3 +2 for n ≥ 5. We present theoretical frameworks, including oriented matroids, and computational tools to check by complete enumeration the open conjectures for small instances. Preliminary computational results are given.</p> / Thesis / Master of Science (MSc)

As is the case for DC-DC converters, multi-phase converters require both high-quality power control and high power-density. Although a higher switching frequency not only improves the quality of the converter output but also decreases the size of the converter, it increases switching losses and electromagnetic interference (EMI) noise. Since the soft-switching topologies reduce the switching losses of the converter main switches, the topologies make converters partially independent from the switching frequency. However, the conventional soft-switching topologies have already proposed most of the possible ways to improve converter performance. In addition, the trends of the newly generated power devices reduce the advantages of soft-switching topologies. This critical situation surrounding soft-switching topologies gives research motivations: What features of soft-switching topologies facilitate their practical applications? Given this motivation, the dissertation discusses two aspects = simplifying auxiliary circuits and accounting for the effects of soft-switching operations on the converter control. Engineers working with medium- and high-power multi-phase converters require simplified soft-switching topologies that have the same level of performance as the conventional soft-switching topologies. This demand is the impetus behind one of the research objectives = simplifying the auxiliary circuits of Zero-Voltage-Transition (ZVT) inverters. Simplifying the auxiliary circuits results in both a smaller number of and lower cost for auxiliary components, without any negative impact on performance. This dissertation proposes two major concepts for the simplification - the Single-Switch Single-Leg (S3L) ZVT cell and the Phase-Lock (PL) concept. Throughout an effort to eliminate circulating currents of inductor-coupled (IC) ZVT converters, the S3L ZVT cell is developed. The proposed cell allows a single auxiliary switch to achieve zero-voltage conditions for both the top and bottom main switches, and it achieves the same level of performance as the conventional ZVT cell, as well. This proposal makes IC ZVT topologies more attractive to multi-phase converter applications. Because all of the top main switches generally have identical sequences for zero-voltage turn-on commutations, one auxiliary switch might handle the commutations of all of the top main switches. This possibility introduces the PL concept, which allows the two auxiliary switches to provide a zero-voltage condition for any main switch commutation. In order to compensate for restrictions of this concept, a modified space-vector modulation (SVM) scheme also is introduced. A soft-switching topology changes the duty ratios of the converter, which affects the controllability of the converter. Therefore, this dissertation selects resolution of this issue as one of the research objectives. This dissertation derives the generalized timing equations of ZVT operations, and the generalized equations formulize the effect of ZVT operation on both duty ratios and DC current. Moreover, the effect of SVM schemes is also investigated. An average model of the ZVT converter is developed using both the timing analysis and the investigation of SVM schemes, and small-signal analysis using the average model predicts the steady-state characteristics of the converter. / Ph. D.