Typescript (photocopy). / Digitized by Kansas Correctional Industries

Nesta dissertação estudamos uma probabilidade obtida a partir de conceitos da Mecânica Estatística Quântica do ponto de vista da Teoria Ergódica. A probabilidade é obtida a partir de um estado KMS sobre um lattice unidimensional de spins quânticos. Mostramos que esta probabilidade é mixing para o shift. Além disso, mostramos que vale um princípio dos grandes desvios para uma certa classe de funções e exploramos algumas propriedades do Jacobiano. Iremos considerar o estado KMS associado a um certo Hamiltoniano específico agindo sobre o lattice de spins quânticos. Nas seções iniciais vamos apresentar alguns conceitos e prerequisitos básicos (como operadores densidade, produto tensorial, C*-algebras e estados KMS) para o entendimento do resultado principal / In this dissertation we study a probability derived from Quantum Statistical Mechanics through the viewpoint of Ergodic Theory. The probability is obtained from a KMS state acting on a one dimensional lattice of quantum spins. We show that this probability is mixing for the shift map. Moreover, we show that a large deviation principle is true for a certain class of functions and we explore some properties of the Jacobian. We will consider the KMS state associated to a certain specific Hamiltonian acting on the quantum spin lattice. In the initial sections we will present some concepts and prerequisites (such as density operators, tensor product, C*-algebras and KMS states) for the understanding of our main results.

Thesis. 1975. Sc.D.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. / Vita. / Bibliography: leaves 348-359. / Sc.D.

Thesis. 1975. M.S.--Massachusetts Institute of Technology. Dept. of Civil Engineering. / Bibliography: leaves 158-163. / M.S.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by Joseph A. Amram. / M.S.

Learning through examples is a central and widely used instructional device for teaching mathematically-based subjects such as statistical probability. However, the applications of the superficial variability of examples remain controversial. This dissertation investigates how the superficial variability of multiple examples influences students' learning and transfer of probability problem-solving. Moreover, the author discovers whether content difficulty affects the influence of examples' superficial variability. Three conditions were developed and compared: consistent-surface condition (CS), varied-surface-within-rule condition (VSWR), and varied-surface-between-rule condition (VSBR). For the purpose of exploration and methodology improvement for the dissertation study, two pilot studies were conducted. However, conflicting results were shown in those two studies. In the first pilot study, students in CS condition performed the worst. In the second pilot study, students in VSBR condition performed the worst. These conflicting results encouraged the author, even more, to conduct the dissertation study with a larger sample size and improved methodology. In this dissertation study, the author found that students' performance on the posttests in VSBR was significantly worse than in the other two conditions, which was consistent with the second pilot study, and that their performance in CS and VSWR condition was not different. Contrary to expectation, the strength of the pattern of the effect of the superficial variability of examples did not vary between the easy and difficult types of problems. Moreover, the pattern was the same when the difficulty variable was not included. These results suggested that examples' superficial consistency between different problem types promotes more effective learning than superficial variation between different problem types. The consistency can be one single cover story used multiple times for each type of problem or the same battery of varied cover stories used repeatedly for different types of problem. Moreover, the pattern of the influence of superficial variability of examples is robust among types of the problem at varying difficulty levels.

O presente trabalho teve como objetivo a padronização em atividade do radionuclídeo 177Lu, um importante radiofármaco utilizado no tratamento de câncer neuroendócrino. Este radionuclídeo se desintegra por emissão beta acompanhada de várias emissões gama simultâneas, o que tornou possível a aplicação do método de coincidência 4πβ-γ. Para a detecção da radiação beta, foi utilizado um detector proporcional (PC), com geometria 4π e dois cintiladores de NaI(Tl) para a detecção da radiação gama. Os sinais gerados nos detectores passaram por amplificadores, discriminadores e módulos atrasadores, para serem enviados a um analisador multicanal. Para este experimento, foi utilizado um sistema de coincidências que aplica um módulo TAC (Time to Amplitude Converter), o qual converte diferença de tempo em amplitude de pulso. Para obter-se a variação na eficiência beta, foram acrescentados absorvedores de Collodion nas partes superior e inferior da fonte radioativa. Desta forma, foi possível extrapolar o valor para eficiência beta igual a 100%, obtendo assim a atividade da fonte radioativa. A curva de extrapolação experimental foi comparada com a previsão teórica, obtida por meio do método de Monte Carlo. Além da padronização em atividade do 177Lu, também foram determinadas as suas probabilidades de emissão gama por decaimento para cada uma das principais transições gama, por meio de um espectrômetro de HPGe, previamente calibrado. / The present work aimed the activity standardization of radionuclide 177Lu, an important radioisotope used for treatment of neuroendocrine cancer. This radionuclide disintegrates by beta decay followed by several simultaneous gamma-ray emissions, which made possible the application of the 4πβ-γ coincidence method. For the detection of beta radiation in 4π geometry a proportional detector (PC) was used, and for gamma radiation detection a pair of NaI(Tl) scintillators was used. The signals generated by the detectors passed through amplifiers, discriminators and delay modules, and were sent to a multichannel analyzer. For the present experiment, the system includes a TAC (Time to Amplitude Converter) module which converts the time difference in pulse amplitude. To obtain the variation in beta efficiency, Collodion absorbers at the top and bottom of the radioactive source were applied. In this way, it was possible to extrapolate the beta efficiency value to 100%, thereby obtaining the radioactive source activity. The extrapolated experimental curve was compared with the theoretical prediction, obtained by means of the Monte Carlo method. Besides the activity standardization of 177Lu, its gamma-ray emission probabilities per decay for the main gamma transitions were also determined by means of an HPGe spectrometer, previously calibrated.

Lau Siu Ping. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaf 44). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Pari-Mutuel System --- p.1 / Chapter 1.2 --- Different Types of Betting --- p.4 / Chapter 1.3 --- Overview --- p.6 / Chapter 2 --- Testing on Tipsters Prediction --- p.8 / Chapter 2.1 --- Introduction --- p.8 / Chapter 2.2 --- Summary Tables on Tipsters Performance --- p.11 / Chapter 2.3 --- Tipsters Prediction Vs Random Betting --- p.15 / Chapter 3 --- Multinomial Logistic Regression --- p.19 / Chapter 3.1 --- Review --- p.19 / Chapter 3.2 --- Proposed Models for the Horse Racing --- p.23 / Chapter 3.3 --- Simulation and Result --- p.26 / Chapter 3.4 --- Comparison between four Models --- p.35 / Chapter 3.5 --- Concluding Remarks --- p.36 / Appendix I --- p.37 / Reference --- p.44

O presente trabalho teve como objetivo a padronização em atividade do radionuclídeo 177Lu, um importante radiofármaco utilizado no tratamento de câncer neuroendócrino. Este radionuclídeo se desintegra por emissão beta acompanhada de várias emissões gama simultâneas, o que tornou possível a aplicação do método de coincidência 4πβ-γ. Para a detecção da radiação beta, foi utilizado um detector proporcional (PC), com geometria 4π e dois cintiladores de NaI(Tl) para a detecção da radiação gama. Os sinais gerados nos detectores passaram por amplificadores, discriminadores e módulos atrasadores, para serem enviados a um analisador multicanal. Para este experimento, foi utilizado um sistema de coincidências que aplica um módulo TAC (Time to Amplitude Converter), o qual converte diferença de tempo em amplitude de pulso. Para obter-se a variação na eficiência beta, foram acrescentados absorvedores de Collodion nas partes superior e inferior da fonte radioativa. Desta forma, foi possível extrapolar o valor para eficiência beta igual a 100%, obtendo assim a atividade da fonte radioativa. A curva de extrapolação experimental foi comparada com a previsão teórica, obtida por meio do método de Monte Carlo. Além da padronização em atividade do 177Lu, também foram determinadas as suas probabilidades de emissão gama por decaimento para cada uma das principais transições gama, por meio de um espectrômetro de HPGe, previamente calibrado. / The present work aimed the activity standardization of radionuclide 177Lu, an important radioisotope used for treatment of neuroendocrine cancer. This radionuclide disintegrates by beta decay followed by several simultaneous gamma-ray emissions, which made possible the application of the 4πβ-γ coincidence method. For the detection of beta radiation in 4π geometry a proportional detector (PC) was used, and for gamma radiation detection a pair of NaI(Tl) scintillators was used. The signals generated by the detectors passed through amplifiers, discriminators and delay modules, and were sent to a multichannel analyzer. For the present experiment, the system includes a TAC (Time to Amplitude Converter) module which converts the time difference in pulse amplitude. To obtain the variation in beta efficiency, Collodion absorbers at the top and bottom of the radioactive source were applied. In this way, it was possible to extrapolate the beta efficiency value to 100%, thereby obtaining the radioactive source activity. The extrapolated experimental curve was compared with the theoretical prediction, obtained by means of the Monte Carlo method. Besides the activity standardization of 177Lu, its gamma-ray emission probabilities per decay for the main gamma transitions were also determined by means of an HPGe spectrometer, previously calibrated.

Over the recent years, the software industry has faced a steady increase in the number of exposed and exploited software vulnerabilities. With more software and devices being connected to the internet every day, the need for proactive security measures has never been more important. One promising new technology for making software more secure is fuzz testing. This automated testing technique is based around generating a large number of test cases with the intention of revealing dangerous bugs and vulnerabilities. In this thesis work, a new direction within grey-box fuzz testing is evaluated against previous work. The presented approach uses sampled probability data in order to guide the fuzz testing towards program states that are expected to be easy to reach and beneficial for the discovery of software vulnerabilities. Evaluation of the design shows that the suggested approach provides no obvious advantage over existing solutions, but also indicates that the performance advantage could be dependent on the structure of the system under test. However, analysis of the design itself highlights several design decisions that could benefit from more extensive research. While the design proposed in this thesis work is insufficient for replacing current state of the art fuzz testing software, it provides a solid foundation for future research within the field. With the many insights gained from the design and implementation work, this thesis work aims to both inspire others and showcase the challenges of creating a probability-based approach to grey-box fuzz testing.