El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Empirical methods play an important role in the field of geomechanics due to the recognized complexity of the nature of rock mass. This study aims to analyze the applicability of empirical design methods in vein-shaped hydrothermal mining deposits (narrow vein) using Bieniawski and Barton classification systems, Mathews stability graphs, Potvin and Mawdesley geomechanics classification systems, and mining pit dilution based on the equivalent linear overbreak/slough (ELOS). In most cases, these methods are applied without understanding the underlying assumptions and limits of the database in relation to the inherent hidden risks. Herein, the dilutions obtained using the empirical methods oscillate between 8% and 11% (according to the frontal dimension), which are inferior to the operative dilution of the mine at 15%. The proposed model can be used as a practical tool to predict and reduce dilution in narrow veins.

Gentrification methodologies rarely intersect. Analysis of the process has been cornered to incorporate either in-depth, neighborhood case studies or large-scale empirical investigations. Understanding the timing and extent of gentrification has been limited by this dichotomy. This research attempts to fuse quantitative and qualitative methods to discern the impact of gentrification between census tracts in East Nashville, Tennessee. By employing archival research, field surveys, and census data analysis this project attempts to comprehend the conditions suitable for gentrification to occur and its subsequent effect on residents and the built environment. A model was generated to determine the relationship between a-priori knowledge and empirical indicators of gentrification. Trends were gleaned between these methods, although gentrification’s chaotic and complex nature makes it difficult to pin down.

Characterization of rock masses and evaluation of their mechanical properties are important and challenging tasks in rock mechanics and rock engineering. Since in many cases rock quality designation (RQD) is the only rock mass classification index available, this paper outlines the key aspects on determination of RQD and evaluates the empirical methods based on RQD for determining the deformation modulus and unconfined compressive strength of rock masses. First, various methods for determining RQD are presented and the effects of different factors on determination of RQD are highlighted. Then, the empirical methods based on RQD for determining the deformation modulus and unconfined compressive strength of rock masses are briefly reviewed. Finally, the empirical methods based on RQD are used to determine the deformation modulus and unconfined compressive strength of rock masses at five different sites including 13 cases, and the results are compared with those obtained by other empirical methods based on rock mass classification indices such as rock mass rating (RMR), Q-system (Q) and geological strength index (GSI). It is shown that the empirical methods based on RQD tend to give deformation modulus values close to the lower bound (conservative) and unconfined compressive strength values in the middle of the corresponding values from different empirical methods based on RMR, Q and GSI. The empirical methods based on RQD provide a convenient way for estimating the mechanical properties of rock masses but, whenever possible, they should be used together with other empirical methods based on RMR, Q and GSI. (C) 2016 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting by Elsevier B.V.

Information security technologists and business scholars are motivated by a desire to understand how and to what extent the application of IT within enterprise systems leads to improved and secured organizational performance. An effective relationship between business and IT professionals is a primary determinant of success in gaining business advantage through the enterprise system. As business innovation has relied increasingly on partnerships between business and IT professional, a different perspective of how IT professionals view their organizational contributions was needed for organizations to remain competitive. Business knowledge is essential if IT professionals are to create linkages with other organizational units and have a wider perspective about business objectives, thus achieving fit between IT and organizational strategies. Organizations have started responding to this challenge by demanding more business acumen in their IT staff. The focus of this study is on the knowledge that is beyond that of independent business and IT only domain knowledge of information security. Therefore, technical areas of knowledge, such as hardware and software, all of which are closely associated with IT skills, are not discussed in this thesis. This is not to declare that such knowledge is not important. Clearly technical knowledge is part of the IT professional's overall information security technology expertise, but this study is about the organization proficiency of business and the IT professional, and is therefore interested in what enables business and IT professionals to apply their business domain and technical knowledge in ways that are beneficial to the organization and to act cooperatively with their customers and business partners. The purpose of this study is to employ the triangulation method to identify the theoretical links and empirically examine the association between business and IT perspective of information security. An important contribution of this study is the identification of business and IT perspectives on information security technology. By establishing the link between business and IT, the study focuses and evaluates Virtual Private Network (VPN) as an information security technology to find out if VPN can secure and gain competitive advantage by partisan business process and organization performance. This study articulates distinctive characteristics of Virtual Private Network and management processes that extend the range of applicability across diverse business segments. It distinguishes between business and IT and explains why the exploitation of a complementary set of related information security entities (such as VPN) across multiple functions create competitive vi advantages even across a diverse set of businesses that have limited opportunity to exploit business process and organization performance. The most important direct predictor of this study is a high level of communication between business and IT. However, one cannot mandate meaningful communication between individuals. IT people have to earn the right to play a meaningful role in management forums. Based on the findings from this study, one important way for an IT person to be heard is for him/her to devote the time necessary to create competitive advantage and develop shared domain knowledge, the most influential construct in the research model. An IT person needs to understand the leverage points of the industry, the history and current issues of the business units, and to learn to apply business oriented objectives in the application of technology to business problems. This change in view would help focus their attention on security technology and ideas that could produce the most benefit and create competitive advantage, rather than those that offer the most technical promise.

Nanometer-scale silicon shows extraordinary electronic and optical properties that are not available for bulk silicon, and many investigations toward applications in optoelectronic devices are being pursued. Silicon nanoparticle films made from solution are a promising candidate for low-cost solar cells. However, controlling the properties of silicon nanoparticles is quite a challenge, in particular shape and size distribution, which effect device performance. At present, none of the solar cells made from silicon nanoparticle films have an efficiency exceeding the efficiency of those based on crystalline silicon. To address the challenge of controlling silicon nanoparticle properties, both theoretical and experimental investigations are needed. In this thesis, we investigate silicon nanoparticle properties via quantum mechanical modeling of silicon nanoparticles and synthesis of silicon nanoparticle films via colloidal grinding. Silicon nanoparticles with shapes including cubic, rectangular, ellipsoidal and flat disk are modeled using semi-empirical methods and configuration interaction. Their electronic properties with different surface passivation were also studied. The results showed that silicon nanoparticles with hydrogen passivation have higher HOMOLUMO gaps, and also the HOMO-LUMO gap depends on the size and the shape of the particle. In contrast, silicon nanoparticles with oxygen passivation have a lower HOMO-LUMO gap. Raman spectroscopy calculation of silicon nanoparticles show peak shift and asymmetric broadening similar to what has been observed in experiment. Silicon nanoparticle synthesis via colloidal grinding was demonstrated as a straightforward and inexpensive approach for thin film solar cells. Data analysis of silicon particles via SEM images demonstrated that colloidal grinding is effective in reducing the Si particle size to sub-micron in a short grinding time. Further increases in grinding time, followed by filtration demonstrated a narrowing of the Si particle size and size-distribution to an average size of 70 nm. Raman spectroscopy and EDS data demonstrated that the Si nanoparticles contain oxygen due to exposure to air during grinding. I-V characterization of the milled Si nanoparticles showed an ohmic behaviour with low current at low biases then Schottky diode behaviour or a symmetric curve at large biases. / Graduate / 0794 / 0544 / zahraalbu@hotmail.com

Nanometer-scale silicon shows extraordinary electronic and optical properties that are not available for bulk silicon, and many investigations toward applications in optoelectronic devices are being pursued. Silicon nanoparticle films made from solution are a promising candidate for low-cost solar cells. However, controlling the properties of silicon nanoparticles is quite a challenge, in particular shape and size distribution, which effect device performance. At present, none of the solar cells made from silicon nanoparticle films have an efficiency exceeding the efficiency of those based on crystalline silicon. To address the challenge of controlling silicon nanoparticle properties, both theoretical and experimental investigations are needed. In this thesis, we investigate silicon nanoparticle properties via quantum mechanical modeling of silicon nanoparticles and synthesis of silicon nanoparticle films via colloidal grinding. Silicon nanoparticles with shapes including cubic, rectangular, ellipsoidal and flat disk are modeled using semi-empirical methods and configuration interaction. Their electronic properties with different surface passivation were also studied. The results showed that silicon nanoparticles with hydrogen passivation have higher HOMOLUMO gaps, and also the HOMO-LUMO gap depends on the size and the shape of the particle. In contrast, silicon nanoparticles with oxygen passivation have a lower HOMO-LUMO gap. Raman spectroscopy calculation of silicon nanoparticles show peak shift and asymmetric broadening similar to what has been observed in experiment. Silicon nanoparticle synthesis via colloidal grinding was demonstrated as a straightforward and inexpensive approach for thin film solar cells. Data analysis of silicon particles via SEM images demonstrated that colloidal grinding is effective in reducing the Si particle size to sub-micron in a short grinding time. Further increases in grinding time, followed by filtration demonstrated a narrowing of the Si particle size and size-distribution to an average size of 70 nm. Raman spectroscopy and EDS data demonstrated that the Si nanoparticles contain oxygen due to exposure to air during grinding. I-V characterization of the milled Si nanoparticles showed an ohmic behaviour with low current at low biases then Schottky diode behaviour or a symmetric curve at large biases. / Graduate / 0794 / 0544 / zahraalbu@hotmail.com

Information security technologists and business scholars are motivated by a desire to understand how and to what extent the application of IT within enterprise systems leads to improved and secured organizational performance. An effective relationship between business and IT professionals is a primary determinant of success in gaining business advantage through the enterprise system. As business innovation has relied increasingly on partnerships between business and IT professional, a different perspective of how IT professionals view their organizational contributions was needed for organizations to remain competitive. Business knowledge is essential if IT professionals are to create linkages with other organizational units and have a wider perspective about business objectives, thus achieving fit between IT and organizational strategies. Organizations have started responding to this challenge by demanding more business acumen in their IT staff. The focus of this study is on the knowledge that is beyond that of independent business and IT only domain knowledge of information security. Therefore, technical areas of knowledge, such as hardware and software, all of which are closely associated with IT skills, are not discussed in this thesis. This is not to declare that such knowledge is not important. Clearly technical knowledge is part of the IT professional's overall information security technology expertise, but this study is about the organization proficiency of business and the IT professional, and is therefore interested in what enables business and IT professionals to apply their business domain and technical knowledge in ways that are beneficial to the organization and to act cooperatively with their customers and business partners. The purpose of this study is to employ the triangulation method to identify the theoretical links and empirically examine the association between business and IT perspective of information security. An important contribution of this study is the identification of business and IT perspectives on information security technology. By establishing the link between business and IT, the study focuses and evaluates Virtual Private Network (VPN) as an information security technology to find out if VPN can secure and gain competitive advantage by partisan business process and organization performance. This study articulates distinctive characteristics of Virtual Private Network and management processes that extend the range of applicability across diverse business segments. It distinguishes between business and IT and explains why the exploitation of a complementary set of related information security entities (such as VPN) across multiple functions create competitive vi advantages even across a diverse set of businesses that have limited opportunity to exploit business process and organization performance. The most important direct predictor of this study is a high level of communication between business and IT. However, one cannot mandate meaningful communication between individuals. IT people have to earn the right to play a meaningful role in management forums. Based on the findings from this study, one important way for an IT person to be heard is for him/her to devote the time necessary to create competitive advantage and develop shared domain knowledge, the most influential construct in the research model. An IT person needs to understand the leverage points of the industry, the history and current issues of the business units, and to learn to apply business oriented objectives in the application of technology to business problems. This change in view would help focus their attention on security technology and ideas that could produce the most benefit and create competitive advantage, rather than those that offer the most technical promise.

Submitted by Nelson Bretanha (physikosmos@gmail.com) on 2016-01-01T12:55:20Z No. of bitstreams: 1 Métodos Semi-Empíricos (Princípios Básicos e Aplicações).pdf: 4755970 bytes, checksum: 0e2d74ff6ffd8de112da824ec714d84e (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-01-05T18:04:11Z (GMT) No. of bitstreams: 1 bretanhaneto_ne_me_rcla.pdf: 4755970 bytes, checksum: 0e2d74ff6ffd8de112da824ec714d84e (MD5) / Made available in DSpace on 2016-01-05T18:04:11Z (GMT). No. of bitstreams: 1 bretanhaneto_ne_me_rcla.pdf: 4755970 bytes, checksum: 0e2d74ff6ffd8de112da824ec714d84e (MD5) Previous issue date: 2015-12-18 / Neste trabalho investigamos os efeitos decorrentes da presença de heteroátomos numa folha de “supercoroneno” (molécula C58H18 utilizada como uma primeira aproximação para o grafeno). Mais especificamente, utilizando método semi-empírico PM6, implementado no pacote computacional MOPAC2012®, estudamos as diferentes curvas de energia (calor de formação). As curvas estudadas foram obtidas pela passagem de um átomo de carbono sobre uma folha de supercoroneno na qual existe um heteroátomo (foram utilizadas três diferentes estruturas: C57H18Si, C57H18Ge e C57H18Sn). Nesse contexto, estudamos também o efeito destes heteroátomos sobre a densidade eletrônica e os orbitais HOMO e LUMO das diferentes estruturas. / In this work we investigate the effects of the presence of heteroatoms on a “supercoronene” sheet (C58H18 molecule used as a molecular model for graphene). Specifically, we used the semiempirical method PM6 as implemented in MOPAC2012® software to study several (formation) energy curves. The energy curves were obtained by positioning a carbon atom over a “supercoronene” sheet in which there is a heteroatom (this was done for three different structures: C57H18Si, C57H18Ge and C57H18Sn). In this context, the effect of these heteroatoms on the electronic density distributions, as well as their effect on HOMO and LUMO orbitals were also investigated.

Esta tesis analiza los métodos estáticos, los cuales comprenden los métodos analíticos y semi empíricos que son utilizados para determinar la capacidad de carga teórica en pilotes, y los compara con las pruebas de carga dinámica, las cuales brindan el resultado real de la capacidad de carga de un pilote. El análisis realizado recopila las teorías de Therzaghi, Hansen, Meyerhof y Bowles, en cuanto a los modelos analíticos, y las teorías de Aoki Velloso, Decourt Quaresma, Pedro Paulo Velloso y Texeira, por parte de las teorías semi empíricas. / This thesis analyzes the static methods, which include the analytical and semi-empirical methods that are used to determine the theoretical load capacity in piles, and compares them with the dynamic load tests, which provide the real result of the load capacity of a pile. The analysis compiles the theories of Therzaghi, Hansen, Meyerhof and Bowles, regarding the analytical models, and the theories of Aoki Velloso, Decourt Quaresma, Pedro Paulo Velloso and Texeira, by the semi-empirical theories. / Tesis

Orientador: Douglas Soares Galvão / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-09-27T13:47:49Z (GMT). No. of bitstreams: 1 Troche_KarlaSouza_M.pdf: 1255427 bytes, checksum: 17251baf9cd0c68ce5c4f8e8adefec0b (MD5) Previous issue date: 2003 / Resumo: Neste trabalho apresentamos estudos de estrutura-atividade realizados para 81 hidrocarbonetos policíclicos aromáticos (PAHs) tentando identificar compostos carcinogênicos. Em particular, empregamos uma nova metodologia desenvolvida para tratar o problema da correlação estrutura geométrica com atividade biológica, denominada Metodologia de Índices Eletrônicos (MIE). Utilizamos três métodos semi-empíricos para estudar a dependência entre a qualidade dos resultados obtidos pela MIE e o Hamiltoniano utilizado. Para validarmos os descritores utilizados pela MIE, investigamos a relação entre a atividade experimental dos PAHs e descritores teóricos através de cinco metodologias de reconhecimento de padrões: a Análise de Componentes Principais (PCA), Análise Hierárquica de Agrupamentos (HCA), K-ésimo vizinho mais próximo (KNN), Soft Independent Modeling of Class Analogies (SIMCA) e as Redes Neurais Artificiais (NN). Para estas investigações distintas pudemos correlacionar a atividade dos PAHs estudados com parâmetros teóricos, em sua maioria eletrônicos, onde os parâmetros utilizados na MIE foram selecionados pelos diferentes métodos. Este estudo valida estatisticamente a MIE como uma nova metodologia capaz de identificar compostos biologicamente ativos, e com um custo computacional menor que técnicas convencionais de Relação estrutura-atividade (SAR) e apresentando um desempenho, em geral superior / Abstract: In this work we present the study structure-activity realized for 81 polycyclic aromatic hydrocarbons (PAHs) trying to identify carcinogenic compounds. Particularly, we used a new methodology developed to deal with the problem of correlation between geometrical structure and biological activity, the Electronic Indices Methodology (EIM). We used three semi-empirical methods to analyze the dependence between the quality of results obtained through EIM and the Hamiltonian used. In order to validate the descriptors used in EIM, we investigated the relationship between the experimental activity of PAHs and the theorical descriptors through five methodologies of pattern recognition: Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), Kth Nearest Neighbor (KNN), Soft Independent Modeling of Class Analogies (SIMCA) and Neural Networks (NN). From these different investigations, we could correlate the activity of PAHs studied with theorical parameters, almost all electronic, where the used parameters on EIM were selected with the different methods. These studies validate the statistical value of electronic parameters derived from EIM analysis and their ability to identify active compounds. The EIM out performed more standard Structure-Activity Relationship (SAR) methodologies / Mestrado / Física da Matéria Condensada / Mestre em Física