Muitos materiais termoluminescentes têm sido desenvolvidos e utilizados para a monitoração individual externa de fótons, mas nenhum tem todas as características desejadas sozinho. Estas características incluem robustez, alta sensibilidade, independência de resposta quanto à energia do fóton, larga faixa de detecção de energia, boa reprodutibilidade, evanescência pequena e curva de emissão termoluminescente simples, com picos abaixo de 150oC. O dosímetro de sulfato de cálcio dopado com disprósio CaSO4:Dy) tem sido usado por muitos laboratórios, principalmente no Brasil e na Índia. Outro fósforo interessante é o fluoreto de cálcio (CaF2). As vantagens destes fósforos começam a ser mais requisitadas e suas desvantagens mais aparentes, no mercado globalizado mais e mais competitivo. Estes fósforos são utilizados em monitoração de área e ambiental devido à sua maior sensibilidade do que outros fósforos, como o LiF:Mg. A sua maior desvantagem é a forte dependência energética da resposta, que deve ser corrigida para suas aplicações em campo, onde o fóton é desconhecido a priori. Um modo interessante de fazer esta correção numa incidência ortogonal da radiação no fósforo é a interposição de um filtro plano vazado entre o feixe e o fósforo. Com o objetivo de reduzir a dependência energética sob incidência em qualquer ângulo, reduzindo a incerteza de medição da dose em campo também, este trabalho apresenta um estudo de simulação em geometrias de filtro esféricas. Foram simuladas irradiações de fótons com raios gama do cobalto 60, com raios-X de 33, 48 e 118 keV, em vários ângulos de incidência de zero a noventa graus. Estas simulações computacionais semi-empíricas, utilizando diferenças finitas em três dimensões, foram feitas em coordenadas esféricas. Os resultados indicaram as melhores espessuras e larguras para a otimização da correção da dependência energética. / Many thermoluminescent materials has been developed and used for photon personal dosimetry but no one has all desired characteristics alone. These characteristics include robustness, high sensitivity, energy photon independence, large range of photon energy detection, good reproductibility, small fading and simple glow curve with peaks above 150oC. Calcium Sulfate Dysprosium doped (CaSO4:Dy) phosphor Thermoluminescent Dosimeter (TLD) has been used by many laboratories, mainly in Brazil and India. Another interesting phosphor is Calcium Fluoride (CaF2). These phosphor advantages begin to be more required and its disadvantages have became more apparent, in a global market more and more competitive. These phosphors are used in environmental and area monitoring, once they present more sensibility than other phosphors, like LiF:Mg. Theirs mainly disadvantage is a strong energetic dependence response, which must be corrected for theirs application in the field, where photon radiation is unknown a priori. An interesting way do make this correction in orthogonal incidence of the radiation on the phosphor is to interject a plane leaked filter between the beam and the phosphor. In order to reduce the energetic dependence on any incidence angle, reducing the field dose measurement uncertainty too, this work presents a simulation study on spherical filter geometries. It was simulated photon irradiations with Gamma rays of 60Co and x-rays of 33; 48 and 118 keV, on many incidence angles from zero to ninety degrees. These semi-empirical computational simulations using finite differences in three dimensions were done in spherical coordinates. The results pointed out the best filter thicknesses and widths, in order to optimize the correction on energetic dependence.

The thesis analyzes the relationship of the perceived happiness level and the level of work busyness of full time employees. For this purpose, a questionnaire was built which mapped happiness and busyness with considering both subjective and objective variables. 205 employees participated in the questionnaire survey. The sample showed above-average education, a high level of busyness and above-average salary (or wages). It has been shown that the work happiness level depends on the level of workload: the unbusy employees are the least happy ones. Influence of ambitions or influence of the importance of work area to the relationship of happiness level and workload level has not been confirmed.

Começamos por estudar fronteiras para uma classe especial de medidas de risco quantis, chamadas medidas de risco distorcidas. A hipótese básica é que o conhecimento da estrutura de dependência (ou seja, da distribuição conjunta) da carteira de riscos é incompleta, fazendo com que não seja possível obter um valor exato para tais medidas. Isso é muito comum na prática. Fornecemos duas formas de obter tais limites nessa situação, apresentando seus prós e contras. A modelagem de risco, em um cenário de desconhecimento total ou parcial da distribuição conjunta dos mesmos, geralmente faz uso de cópulas. Entretanto, as cópulas vêm sendo alvo de críticas na literatura recente. Um dos motivos é que as mesmas desprezam o comportamento marginal e comprimem os dados no quadrado unitário. Dentro desse cenário, apresentamos uma função que pode ser vista como uma alternativa e complemento ao uso de cópulas: função de dependência de Sibuya. / We begin our work studying an special class of quantile risk measures, known as distorted risk measures. The basic assumption is that the risk manager does not know the complete dependence structure (that is, the risks\'s joint distribution) embedded in the risk\'s portfolio, what makes the exact computation of the risk measure an impossible task. This is a common scenario in practical problems. We present two approaches to compute bounds for the distorted risk measures in such situation, underlining the pros and cons of each one. In risk modeling, in the absence of complete knowledge regarding their joint distribution, one often relies on the copula function approach. However, copulas have been criticized in recent publications mostly because it ignores the marginal behavior and smash the data into the unity square. In order to overcome such problems we present and alternative and complement to the copula approach: the Sibuya dependence function.

Muitos materiais termoluminescentes têm sido desenvolvidos e utilizados para a monitoração individual externa de fótons, mas nenhum tem todas as características desejadas sozinho. Estas características incluem robustez, alta sensibilidade, independência de resposta quanto à energia do fóton, larga faixa de detecção de energia, boa reprodutibilidade, evanescência pequena e curva de emissão termoluminescente simples, com picos abaixo de 150oC. O dosímetro de sulfato de cálcio dopado com disprósio CaSO4:Dy) tem sido usado por muitos laboratórios, principalmente no Brasil e na Índia. Outro fósforo interessante é o fluoreto de cálcio (CaF2). As vantagens destes fósforos começam a ser mais requisitadas e suas desvantagens mais aparentes, no mercado globalizado mais e mais competitivo. Estes fósforos são utilizados em monitoração de área e ambiental devido à sua maior sensibilidade do que outros fósforos, como o LiF:Mg. A sua maior desvantagem é a forte dependência energética da resposta, que deve ser corrigida para suas aplicações em campo, onde o fóton é desconhecido a priori. Um modo interessante de fazer esta correção numa incidência ortogonal da radiação no fósforo é a interposição de um filtro plano vazado entre o feixe e o fósforo. Com o objetivo de reduzir a dependência energética sob incidência em qualquer ângulo, reduzindo a incerteza de medição da dose em campo também, este trabalho apresenta um estudo de simulação em geometrias de filtro esféricas. Foram simuladas irradiações de fótons com raios gama do cobalto 60, com raios-X de 33, 48 e 118 keV, em vários ângulos de incidência de zero a noventa graus. Estas simulações computacionais semi-empíricas, utilizando diferenças finitas em três dimensões, foram feitas em coordenadas esféricas. Os resultados indicaram as melhores espessuras e larguras para a otimização da correção da dependência energética. / Many thermoluminescent materials has been developed and used for photon personal dosimetry but no one has all desired characteristics alone. These characteristics include robustness, high sensitivity, energy photon independence, large range of photon energy detection, good reproductibility, small fading and simple glow curve with peaks above 150oC. Calcium Sulfate Dysprosium doped (CaSO4:Dy) phosphor Thermoluminescent Dosimeter (TLD) has been used by many laboratories, mainly in Brazil and India. Another interesting phosphor is Calcium Fluoride (CaF2). These phosphor advantages begin to be more required and its disadvantages have became more apparent, in a global market more and more competitive. These phosphors are used in environmental and area monitoring, once they present more sensibility than other phosphors, like LiF:Mg. Theirs mainly disadvantage is a strong energetic dependence response, which must be corrected for theirs application in the field, where photon radiation is unknown a priori. An interesting way do make this correction in orthogonal incidence of the radiation on the phosphor is to interject a plane leaked filter between the beam and the phosphor. In order to reduce the energetic dependence on any incidence angle, reducing the field dose measurement uncertainty too, this work presents a simulation study on spherical filter geometries. It was simulated photon irradiations with Gamma rays of 60Co and x-rays of 33; 48 and 118 keV, on many incidence angles from zero to ninety degrees. These semi-empirical computational simulations using finite differences in three dimensions were done in spherical coordinates. The results pointed out the best filter thicknesses and widths, in order to optimize the correction on energetic dependence.

Problematic painkiller use is a large and increasing problem worldwide, leading to serious physical, psychological and social consequences. Existing research indicates that accessibility of painkillers and psychological factors could have a role in problematic painkiller use. To clarify, accessibility refers to ease of obtaining painkillers, whilst psychological factors refer to individual-level processes and meanings that influence mental states (Upton, 2013). However, there have been few studies conducted, and these studies have focused mainly on either clinical samples or women with childbirth pain. Hence, the role among the general population is less clear. The aim of the present thesis was therefore to focus on the role of accessibility and psychological factors in problematic painkiller use among the general population. Three studies were conducted: one study compared the general population of the UK (N = 295) and Egypt (N = 420) regarding the role of accessibility of painkillers and psychological factors, including attitudes and beliefs towards pain, painkillers, self-medication and alternative methods of pain relief; another study was a multi-national comparison of these variables among the general population of more countries including Germany (N = 217), USA (N = 146), Australia (N = 93) and China (N = 76); another study focused on the role of psychological factors over time among the UK general population (N = 529), specifically attitudes and beliefs towards painkillers, as well as pain catastrophising, pain acceptance, pain self-efficacy and alexithymia. In these studies, the role of accessibility and psychological factors was investigated using online surveys, with participants aged 18 years or over, who experienced pain in the last month, used over-the-counter (OTC) or prescription painkillers in the last month, and were residents of the countries concerned. An additional study was conducted to develop 14-item versions of the Survey of Pain Attitudes-Brief (SOPA-B-14) and the Pain Medication Attitudes Questionnaire (PMAQ-14), which also tested the validity of these scales. Results Accessibility of painkillers and psychological factors predicted problematic painkiller use. However, there were several differences between the countries regarding the particular role of these factors. In the longitudinal study of the UK general population, changes in psychological factors were found over time, but attitudes and beliefs about withdrawal from painkillers was the only psychological factor that predicted problematic painkiller use over time. In addition, testing the validity of the SOPA-B-14 and PMAQ-14 showed that these scales were valid. The present research provided understanding regarding the role of accessibility and psychological factors in problematic painkiller use among the general population, and the role of psychological factors over time. Based on this understanding, interventions focusing on accessibility and psychological factors should be developed to reduce problematic painkiller use, but tailored to the particular factors that were predictors for each country. The present research also developed a valid SOPA-B-14 and PMAQ-14, therefore these scales can be used rather than the full versions to make assessment easier.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Background: The purpose of this study was to determine the association between social media dependence and depressive symptoms and also, to characterize the level of dependence. It was a transversal, analytical research. Subjects and Methods: The stratified sample was 212 students from a private university that used Facebook, Instagram and/or Twitter. To measure depressive symptoms, Beck Depression Inventory was used, and to measure the dependence to social media, the Social Media Addiction Test was used, adapted from the Internet Addiction Test of Echeburúa. The collected data were subjected for analysis by descriptive statistics where STATA12 was used. Results: The results show that there is an association between social media dependence and depressive symptoms (PR [Prevalence Ratio] = 2.87, CI [Confidence Interval] 2.03–4.07). It was also shown that preferring the use of Twitter (PR = 1.84, CI 1.21–2.82) over Instagram (PR = 1.61, CI 1.13–2.28) is associated with depressive symptoms when compared to the use of Facebook. Conclusion: Excessive social media use is associated with depressive symptoms in university students, being more prominent in those who prefer the use of Twitter over Facebook and Instagram. / Revisión por pares

Multi-Output Dependence (MOD) learning is a generalization of standard classification problems that allows for multiple outputs that are dependent on each other. A primary issue that arises in the context of MOD learning is that for any given input pattern there can be multiple correct output patterns. This changes the learning task from function approximation to relation approximation. Previous algorithms do not consider this problem, and thus cannot be readily applied to MOD problems. To perform MOD learning, we introduce the Hierarchical Multi-Output Nearest Neighbor model (HMONN) that employs a basic learning model for each output and a modified nearest neighbor approach to refine the initial results. This paper focuses on tasks with nominal features, although HMONN has the initial capacity for solving MOD problems with real-valued features. Results obtained using UCI repository, synthetic, and business application data sets show improved accuracy over a baseline that treats each output as independent of all the others, with HMONN showing improvement that is statistically significant in the majority of cases.

Negative affect plays a critical role in nicotine dependence. Smokers report feeling that negative affect is a primary motivation to keep smoking. This study examined the relationship between individual differences in emotional experience, in particular emotional clarity and differentiation (individuals' ability to understand, describe, and differentiate between emotions), and smoking motivation. We hypothesized that emotional clarity would be related to affect, craving, and smoking satisfaction. A second goal was to test the ability of an emotional-labeling intervention to reduce negative affect and smoking motivation resulting from a negative emotion induction. We also tested whether emotional clarity moderated the effect of the negative affect manipulation upon smoking-related variables. We hypothesized that emotional clarity would moderate the effect of the emotional-labeling manipulation upon affect, craving, and smoking satisfaction. A correlational and two-group between-subjects design was used. Participants (170 participants; 86 males) first completed baseline measures, then received a mood induction (via video). They then were randomized to one of two conditions (emotion labeling and writing control). Results indicate that emotional clarity was related to affect, craving, and smoking satisfaction ratings, such as those higher on emotional clarity reported more positive affect, less cravings, and having experienced aversive effects after smoking. We found no effect of the emotional labeling task. Although we replicated findings from previous studies showing a relationship between emotional clarity and mood, this study is the first to establish such a relationship with craving for a cigarette and aspects of smoking satisfaction.

The main purpose of this dissertation was to examine the statistical dependence of imputed microRNA (miRNA) data in a colorectal cancer study. The dissertation addressed three related statistical issues that were raised by this study. the first statistical issue was motivated by the fact that miRNA expression was measured in paired tumor-normal samples of hundreds of patients, but data for many normal samples were missing due to lack of tissue availability. We compared the precision and power performance of several imputation methods, and drew attention to the statistical dependence induced by K-Nearest Neighbors (KNN) imputation. The second statistical issue was raised by the necessity to address the bimodality of distributions of miRNA data along with the imputation-induced dependency among subjects. We proposed and compared the performance of three nonparametric methods to identify the dierentially expressed miRNAs in the paired tumor-normal data while accounting for the imputation-induced dependence. The third statistical issue was related to the development of a normalization method for miRNA data that would reduce not only technical variation but also the variation caused by the characteristics of subjects, while maintaining the true biological dierences between arrays.

This study examines the relationship between age of onset of drug use and later drug dependence, and that of age of onset of drug use and current offense type/severity. In addition, it investigates the relationship between mental disorders, drug dependence, and current offense type/severity. Data from years 2007 to 2010 of the Arrestee Drug Abuse Monitoring Program II (ADAM II) were used. The analyses included cross tabulation and chi square. The results indicated that early onset marijuana users (those who began using at age fourteen or younger) were more likely to develop drug dependence than late onset users of marijuana. In addition, early onset users of heroin and of methamphetamine were more likely to develop drug dependence than late onset users of those drugs. No significant relationships were found between early onset of any of the four drugs and offense type; however significant relationships were found between early onset of marijuana and of methamphetamine, and offense severity. Significant relationships were found between offense severity and mental disorders, but not between offense type and mental disorders. Significant relationships were found for both offense type and severity when cross tabulated with mental disorders and drug dependence. These results indicate that more research is needed on these topics. This is because the findings of the current study partially support what has been found in existing literature. A clearer understanding of the topics of the current study is needed in order to draw definite conclusions.