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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Sucesso de sistemas de Business Intelligence: uma abordagem multidimensional. / Business intelligence systems sucess: a multidimensional approach.

Aristizabal, Catalina Ramirez 09 May 2016 (has links)
Assim como outros investimentos em tecnologia da informação, os sistemas de Business Intelligence (BI) também têm sido questionados em relação aos benefícios e retornos obtidos depois de sua implantação. Isso porque o produto de BI é inteligência, ou, em outras palavras, algum tipo de informação processada, e o valor da informação é difícil de avaliar. A presente pesquisa pretende contribuir ao estudo desse problema de pesquisa, abordando o tema da avaliação dos sistemas de BI por meio do modelo de sucesso de sistemas de informação proposto por DeLone e McLean. Além das dimensões tradicionais inter-relacionadas do modelo: capacidade de BI, qualidade da informação, satisfação dos usuários e nível de uso, foi incluída a variável a abordagem de decisão, pois um dos principais objetivos dos sistemas de BI é processar dados advindos de diferentes fontes, para produzir informação que sirva como suporte para a tomada de decisão. Uma vez que a capacidade de BI e a qualidade da informação são constructos multidimensionais, uma das contribuições desta pesquisa foi realizar um levantamento na literatura sobre as dimensões que operacionalizam esse constructo e avaliá-las empiricamente. A capacidade de BI foi definida em termos de acessibilidade, capacidades analíticas, flexibilidade e integração, e qualidade da informação em termos de atualidade, completude, oportunidade e precisão. O problema de pesquisa foi abordado por meio da metodologia de survey, em que os respondentes foram convidados a participar da pesquisa via e-mail e o questionário foi disponibilizado em forma eletrônica através da ferramenta SurveyMonkey. No total, foram obtidas 483 repostas, das quais 246 foram válidas. Já que o modelo conceitual proposto inclui múltiplas relações de interdependência, a técnica estatística selecionada para analisar os dados foi a modelagem de equações estruturais. O software utilizado foi o SmartPLS que testa o modelo estrutural por meio do método de mínimos quadrados ordinários. Foi possível comprovar empiricamente todas as relações de causalidade propostas entre as dimensões de sucesso dos sistemas de BI, a exceção da relação de moderação da variável abordagem de decisão na relação de causalidade entre satisfação e nível de uso. Um teste subsequente permitiu observar que essa variável poderia ser preditora do nível de uso. Segundo os resultados, é possível afirmar que o sucesso de BI pode ser definido em termos da capacidade de BI, qualidade da informação, satisfação dos usuários e nível de uso. A operacionalização realizada dos constructos multidimensionais \"capacidade de BI\" e \"qualidade da informação\" poderia dar luzes sobre quais características devem ser priorizadas na implantação e/ou desenvolvimento dos sistemas de BI nas empresas. / As well as other investments in Information Technology (IT), Business Intelligence (BI) systems have also been questioned in relation to the benefits and returns obtained after its implementation. These questions arise because the BI product is intelligence, or, in other words, some kind of processed information and the value of information is difficult to assess. This research aims to contribute to this by addressing the issue of evaluation of BI systems through the information systems success model proposed by DeLone and McLean, beyond the traditional dimensions that are interrelated: BI capabilities, quality of information, user satisfaction, and level of use. The decision approach was included as a variable since a key objective of BI systems is to process data coming from different sources to produce information that serves as a basis for the decision-making process. Once the BI capability and information quality are multidimensional constructs, one of the contributions of this study was to review the literature available about the dimensions that operationalize this construct and evaluate them empirically. BI capability was defined in terms of accessibility, analytical capabilities, flexibility and integration, and the information quality in terms of opportunity, completeness, timeliness and accuracy. The research problem was addressed by the survey methodology: the respondents were invited to participate in the survey via email and the questionnaire was made available in electronic form through the SurveyMonckey tool. A number of 246 responses were usable out of the 483 total responses that were obtained. Since the proposed conceptual model includes multiple interdependencies, the statistical technique selected to analyze the data was the structural equation modeling. The software used was the SmartPLS, which tests the structural model using the ordinary least squares method. It was possible to prove empirically all the causal relationships proposed between success dimensions of BI systems, except for the moderation effect of making-decision approach variable on the relationship between satisfaction and usage level. A subsequent test allowed us to observe that this variable could be a predictor of the level of use. According to these results, we can say that the success of BI can be defined in terms of BI capability, the quality of information, user satisfaction and the level of use. The operationalization of the variables BI capability and information quality as a multidimensional construct could enlighten the decision about which features should be prioritized in implementing the development of BI systems in companies.
92

O papel da ferrovia Santos - Iquique na integração da América Latina e no comércio com a Ásia

Reis, Alfredo Teodoro 09 October 2007 (has links)
Made available in DSpace on 2016-04-26T20:48:49Z (GMT). No. of bitstreams: 1 Alfredo Teodoro Reis.pdf: 4728870 bytes, checksum: 3ed51e2822aca4de31eb11d44d52dcb6 (MD5) Previous issue date: 2007-10-09 / All Brazilian evolution happened, one way or another, in the Atlantic Ocean. Everything began with the slave ships, in a triangle that seemed to be Brazil Portugal Africa and that, with time; eventually became Brazil England Africa. Since then, all development happens on the coast, the inner lands were left behind. The economic concentration on the east coast became even more clear with the growth of the American economy, in the XX century. It came to the point that, one of the planet s biggest wealth the Amazon forest is practically abandoned throughout these five hundred years. Our beautiful coast created in us, Brazilians, an intrinsic cultural difficulty we don t know what happens right there on the Pacific Ocean. Due to its gigantism, due to its natural resources which are considered endless, Brazil, even committing errors, even consenting losses, became a leader. Leader of a poor South America, nevertheless it is also naturally rich, our sister, our people and land, our brothers. Due to their even bigger difficulties, due to their freedom being obtained through sword and blood, full of resentment and differences, our brothers, Colombians, Ecuadorians, Peruvians, Bolivians e Paraguayans could not reach the same Brazilian development. In this way, it was created, throughout these 500 years, a death frontier on the West, that isolates us from the Asian development process. Chile, the Latin tiger , more similar to Hong Kong than to Brazil, that should be the gateway to Asia, due to its fantastic coast, is the clog, the fetter. If not, how to explain the isolation, the forgetfulness of its neighbors and brothers? While in the United States, the Anglo-Saxon entrepreneurship united two oceans with trains in 1880, Brazil was sleeping on a splendid cradle. The bi-oceanic junction Santos Iquique is a current and innovative idea and, considering all alternatives, it is an economically viable option to unite the South American people in order to reach the global markets / Toda a evolução do Brasil se deu, de uma forma ou de outra, no Oceano Atlântico. Tudo começou com os navios negreiros, num eixo que parecia ser Brasil Portugal África e que, com o tempo, percebeu-se ser Brasil Inglaterra África. Desde então, todo o desenvolvimento se dá no litoral, o interior ficou relegado em segundo plano. Com a liderança norte-americana a partir do século XX, a concentração no eixo leste tornou-se ainda mais evidente. A ponto de uma das maiores riquezas do planeta a nossa Amazônia estar praticamente abandonada nesses quinhentos e poucos anos, mal aproveitada. Nossa maravilhosa costa criou-nos uma dificuldade cultural intrínseca não sabemos o que se passa ali, na outra vertente, no Oceano Pacífico. Com seu gigantismo, com as riquezas naturais consideradas infinitas, o Brasil, mesmo com todos os erros que cometeu, mesmo com todas as perdas consideradas e com todas as dificuldades enfrentadas tornou-se líder. Líder de uma América do Sul pobre, embora toda ela também rica por natureza, nossa irmã, povos e terras irmãos. Por suas dificuldades terem sido ainda maiores que as nossas, por terem conseguido sua libertação com espada e sangue, com ressentimentos e diferenças, nossos irmãos colombianos, equatorianos, peruanos, bolivianos e paraguaios não conseguiram acompanhar o desenvolvimento brasileiro. Criou-se assim, ao longo de mais de 500 anos, uma fronteira morta a oeste, que nos isola do processo de crescimento asiático. O Chile, tigre latino, mais parecido com Hong Kong do que com o Brasil, que deveria ser a porta para a Ásia, com seu fantástico litoral, é a trava. Se não, como explicar o isolamento, o esquecimento dos irmãos vizinhos? Enquanto nos Estados Unidos o empreendedorismo anglo-saxão uniu os dois oceanos com trens de ferro no longínquo 1880, o Brasil dormia em berço esplêndido. A ligação bi-oceânica Santos - Iquique está hoje na ordem do dia e, dentre as várias alternativas, é opção economicamente viável de unir os povos da América do Sul para atingirem os mercados globais
93

Bi-directional relationship between obesity and depression among adolescent girls

Hu, Anyu 12 March 2016 (has links)
Major depressive disorder is one of the most common mental health conditions in the world while obesity, a condition tied to numerous chronic conditions throughout the lifespan, is at epidemic levels throughout most of the world. Adolescence is a crucial transition period for physical, cognitive, and social-emotional development. Adolescents, particularly girls, are at high risk of developing depression and obesity. Some studies suggest that obesity is a risk factor for the development of depression while others suggest that depression alters health habits, thereby leading to obesity. The overall goal of this work is to examine both of these questions in adolescent girls and further to explore whether the relationship between obesity (and other related risk factors) and depression is a bi-directional one. The National Heart, Lung, and Blood Institute's Growth and Health Study (NGHS) is an observational study of 2379 adolescent black and white girls. Height and weight was measured annually (and used to estimate body mass index) over 10 years from early to late adolescence. Diet and other risk factors were also measured longitudinally over 10 years. Depression was measured twice using the Centers for Epidemiologic Studies Depression Scale (CES-D): first at exam 8 and then at the final exam (exam 10). Multivariable logistic regression and longitudinal (repeated measures) mixed models were used to control for potential confounding by age, socio-economic status, physical activity, hours of television/video watching per day, and dietary factors. The first objective was to determine whether young adolescent girls who were already overweight or obese had a higher risk for developing depression during the follow-up exams in later adolescence. Overall, the prevalence of moderate (or worse) depression was much higher in girls who were classified as obese (474% with depression) than either overweight (37.8%) or normal-weight (34.3%) girls. After adjusting for baseline age, race, SES, television/video hour per day), physical activity level, diet quality (using Healthy Eating Index scores), and percent of energy from protein, obese girls had a 68% increase risk of subsequent depression (95% CI: 1.17 to 2.39) compared with normal weight girls. There was no increased depression risk for overweight girls. The risk of incident depression associated with obesity was the same for blacks and whites in the study. Finally, after controlling further for a measure of self-worth (using the Harter Scales), the effect of obesity was somewhat attenuated. The second objective of the study was to explore other risk factors for depression in these adolescent girls. In these analyses, several factors from the early adolescent years predicted the development of later depression (moderate or worse). These included hours spent watching television (risk increased by 6% for each additional hour watched per day), white race, SES, obesity, and self-worth score. While the self-worth score ranged only from 1 to 4, there was nearly a 60% reduction in risk for each increase of one point in the score. Thus, self-worth was a particularly important predictor, with higher self-worth scores protecting these girls from incident depression. The final objective of this work was to examine the change in behavioral risk factors associated with prevalent depression at exam 8. Depressed (vs. non-depressed) girls who were not obese at exam 8 were approximately 75% more likely to become obese by exam 10. The results of this study support a finding of a bi-directional relationship between obesity and depression in adolescent girls.
94

Cloud BI : a multi-party authentication framework for securing business intelligence on the Cloud

Al-Aqrabi, Hussain January 2016 (has links)
Business intelligence (BI) has emerged as a key technology to be hosted on Cloud computing. BI offers a method to analyse data thereby enabling informed decision making to improve business performance and profitability. However, within the shared domains of Cloud computing, BI is exposed to increased security and privacy threats because an unauthorised user may be able to gain access to highly sensitive, consolidated business information. The business process contains collaborating services and users from multiple Cloud systems in different security realms which need to be engaged dynamically at runtime. If the heterogamous Cloud systems located in different security realms do not have direct authentication relationships then it is technically difficult to enable a secure collaboration. In order to address these security challenges, a new authentication framework is required to establish certain trust relationships among these BI service instances and users by distributing a common session secret to all participants of a session. The author addresses this challenge by designing and implementing a multiparty authentication framework for dynamic secure interactions when members of different security realms want to access services. The framework takes advantage of the trust relationship between session members in different security realms to enable a user to obtain security credentials to access Cloud resources in a remote realm. This mechanism can help Cloud session users authenticate their session membership to improve the authentication processes within multi-party sessions. The correctness of the proposed framework has been verified by using BAN Logics. The performance and the overhead have been evaluated via simulation in a dynamic environment. A prototype authentication system has been designed, implemented and tested based on the proposed framework. The research concludes that the proposed framework and its supporting protocols are an effective functional basis for practical implementation testing, as it achieves good scalability and imposes only minimal performance overhead which is comparable with other state-of-art methods.
95

Cycloalkane Metathesis using a Bi-metallic System: Understanding the Effect of Second metal in Metathesis Reaction

Alshanqiti, Ahmed M. 12 1900 (has links)
Over the past decades, since the discovery of a single–site silica-supported catalyst for the alkane metathesis reaction by our group, we have been extensively working on the development of supported catalytic systems for the improved alkane metathesis reaction. During these developments, we understand the reaction mechanism and reached a new perspective for the synthesis of various supported bimetallic systems via the surface organometallic chemistry (SOMC) approach. Recently, with this bi-metallic system, we got a very high TON (10000) in propane metathesis reaction. As these catalysts are very efficient for linear alkanes we thought to apply it for cyclo-alkanes specifically, for cyclo-octane metathesis expecting better activity. Besides, the value of the ring alkanes are higher than the linear alkanes. The current work demonstrates a combination of [(ΞSi−O−)W(Me)5] and [(ΞSi− O−)Ti(Np)3 pre-catalyst with several supports (SiO2-700, SBA-15 and MCM-41) for metathesis of cyclooctane. The catalysts have been synthesized and fully characterized by elemental analysis (EA), FT-IR and NMR spectroscopies. After fully characterization the bi-metallic catalyst was tested for metathesis of cyclooctane with highest ever TON 2500 as compared to that of mono-metallic catalyst where we got 430 TON. Which again corroborates our prediction that bimetallic catalysts are better catalysts than monometallic catalysts.
96

Etude de la déconstruction de résidus agricoles lignocellulosiques par extrusion biocatalytique

Gatt, Etienne 24 January 2019 (has links) (PDF)
L’extrusion biocatalytique, ou bioextrusion, est une technique d’extrusion réactive utilisant des enzymes comme catalyseurs. Cette technique est considérée en temps qu’étape intermédiaire, subséquente au prétraitement physico-chimique et précédente à l’hydrolyse enzymatique enréacteur fermé. L’utilisation de l’extrusion permet un procédé continu, facilement modulable et adaptable à des conditions de hautes consistances, de nombreuses biomasses et facilement transférable à l’échelle industrielle. Néanmoins, les données bibliographiques font ressortir la complexité des entrants et leurs interactions lors de la bioextrusion de biomasses lignocellulosiques. Les conclusions des bioextrusions de biomasses amidonnées soulignent l’importance de l’étude de l’influence de la concentration en substrat et en enzymes. Les résultats obtenus à partir de la bioextrusion des biomasses lignocellulosiques valident l’existence d’une activité enzymatique en extrudeuse malgré la contrainte thermomécanique et le temps de séjour limité. Lors de cette étape, l’hydrolyse de la fraction cellulosique est favorisée pour des milieux concentrés en substrat et en enzymes. Des modifications significatives des fractions cellulosiques cristallines et amorphes en surface, des réductions des tailles de particules, une dégradation visuelle des structures de la biomasse et l’augmentation de la sensibilité à la décomposition thermique, sont aussi observées sur la fraction solide. L’hydrolyse enzymatique des bioextrudats est prolongée en réacteur fermé. La bioextrusion permet des améliorations significatives des taux et vitesses de conversion des sucres sur le long terme, jusqu’à 48 h. Les gains observés sont relativement constants pour la paille de blé et augmentent avec le temps pour les écorces de bouleau et les résidus de maïs. Post-extrusion, la concentration en substrat influence négativement la conversion des sucres. Cependant, les plus-values de conversion du glucose lié à la bioextrusion de paille de blé sont principalement observables pour des concentrations en substrat et en enzymes élevées. À partir de 4 h, des baisses significatives de la conversion du xylose sont observées après bioextrusion. Les déstructurations de la fraction solide, déjà observées au cours la bioextrusion, se poursuivent en réacteur fermé. Les meilleurs résultats hydrolytiques aux niveaux des hautes charges en enzymes et en substrat sont associables aux bonnes conditions de mélanges caractéristiques des éléments bilobes. L’ensemble enzymatique est probablement réparti de façon plus homogène (mélange distributif) pour cibler plus de sites disponibles. De plus, le mélangé dispersif limite la proximité entre enzymes de même type et les gênes associées. Le procédé d’extrusion permet une agitation efficace, un bon transfert de masse et probablement un meilleur contact entre enzymes et substrat. Les moins bons résultats de conversion du xylose sont probablement à relier à des phénomènes d’adsorption non-spécifique, ou encore de désactivation des hémicellulases, provoqués par l’intensité des contraintes thermomécaniques et les résidus ligneux. Les bons résultats de déstructuration après bioextrusionsont associables à une action synergétique des contraintes mécanique et biochimique. Les analyses d’autofluorescence montrent l’évolution de la fraction ligneuse dans le processus de déconstruction de la fraction solide. Une production progressive de particules très fines,visiblement associée à la fraction ligneuse, est observée. Des complexes lignine-carbohydratessont aussi détectés dans la fraction liquide. Etant peu, voire pas hydrolysable par voie enzymatique, ces fractions hétéropolymériques sont un frein à la déconstruction. Si la déstructuration des lignines est probablement majoritairement liée au prétraitement alcalin, le procédé de bioextrusion provoque une diminution de la teneur en hétéropolymères de plus hautes masses moléculaires.
97

Rumination and Worry: Factor Structure and Predictive Utility

Kiselica, Andrew Mark 14 May 2018 (has links)
Criticism of discrete classification systems for mental disorders has led to a focus on identification of mechanisms that cut across symptom clusters, known as transdiagnostic factors. One such proposed factor is negative repetitive thought (NRT), or a perseverative, often uncontrollable, focus on negative information, experiences, or expectations. Worry and rumination are two major constructs thought to compose NRT. No confirmatory factor analyses have investigated whether worry and rumination might compose a general NRT factor, discrete factors, or some combination of the two. The first purpose of the current study was to use confirmatory factor analyses to uncover whether worry and rumination are best characterized as separate or common constructs. In addition to this purpose, the study investigated NRT as a transdiagnostic factor for psychopathology. Finally, it examined incremental associations of NRT with mental illness symptoms, after controlling for negative emotionality, the most well established transdiagnostic risk factor. A bi-factor conceptualization of worry and rumination, in which there was a common NRT factor and specific worry and rumination factors, yielded the best fit to the data across three separate samples. The NRT factor was associated with both internalizing and externalizing psychopathology; however, it demonstrated significant overlap with negative emotionality. Further exploration of this overlap using bi-factor modeling demonstrated that NRT and negative emotionality are likely best thought of as a unidimensional general negative affect construct, and this structure was replicated across samples. Importantly, evidence was found that this tendency to experience negative affect was also a common liability for mental illness symptoms.
98

Business Intelligence-system och deras inverkan på rationellt beslutsfattande : En studie på två företag

Lagerström, Robin, Ährlig, Fredrik January 2009 (has links)
<p>I alla typer av organisationer måste beslut fattas och att kunna fatta korrekta beslut är en avgörande faktor för om en organisation ska bli framgångsrik eller ej. En stark tradition bland ekonomer är att beslut bör fattas utifrån den så kallade rationella beslutsmodellen, där beslutsfattare antas ha tillgång till den nödvändiga informationen för att kunna fatta väl underbyggda beslut i enlighet med de övergripande organisatoriska målen. Denna uppfattning har emellertid kritiserats för att vara otillräcklig när verkliga beslut i verkliga organisationer ska fattas, och att rationaliteten är begränsad. Dock finns en uppfattning att datorbaserade beslutsstöd ska kunna minska dessa begränsningar för att mer rationella beslut ska kunna fattas, då dessa exempelvis ska kunna bistå beslutsfattare med adekvat information för snabba och korrekta beslut. Ett sådant beslutsstöd som blivit alltmer populärt under det senaste decenniet är business intelligence-system (BI-system). Vi vill i denna uppsats undersöka vilken inverkan BI-system har på beslutsfattares möjligheter att fatta rationella beslut, men även hur dessa BI-system är uppbyggda. Problemfrågorna blir därför:</p><ul><li>Hur kan företags BI-system vara uppbyggda? </li><li>Vilken inverkan kan BI-system ha på beslutsfattares möjlighet att fatta rationella beslut? </li></ul><p>Syftet med denna magisteruppsats blir således<em> att beskriva företags BI-systems möjliga uppbyggnad, samt analysera deras inverkan på beslutfattares möjlighet att fatta rationella beslut.</em></p><p>De centrala delarna i denna uppsats teorikapitel utgörs av rationellt beslutsfattande samt allmän teori kring BI-system och dess komponenter. Dessa båda delar vigs sedan samman i en modell vilken vi sedan kommer att använda för att genomföra studien som ligger till grund för uppsatsen och sedan vid analysen av nämnda studie. Metoden som använts för insamlingen av empiriskt material är besöksintervjuer hos två företag (<em>SNA Europe</em> och <em>KG Knutsson AB</em>), och de som intervjuats är personer som använder BI-system i sitt dagliga arbete som ett stöd i deras beslutsfattande. Vi har även intervjuat personer från respektive företags IT-avdelningar för att få en inblick i hur BI-systemet är uppbyggt och fungerar rent tekniskt.</p><p>De slutsatser vi kommit fram till gällande BI-systemens uppbyggnad är att de varierar i ganska stor utsträckning, beroende på hur företagets övriga IT-infrastruktur ser ut. Dock medför detta inte några nämnvärda skillnader i hur företagen sedan använder sina respektive BI-system, då besluten som fattas och de data som utgör grunden för dessa är av samma typ oavsett företag. Vidare har vi kunnat se att lättare det är att få fram information relevant för sammanhanget, desto mer används BI-systemen vid beslutsfattande. Ytterligare en slutsats är att det företag som har flera legacy-system på plats tenderar att ha en mer traditionellt uppbyggt BI-system. Gällande BI-systems inverkan på möjligheten att fatta rationella beslut kan vi dra slut­satsen att BI-system framförallt bidrar till att öka rationaliteten när besluten grundas i kvantifierbara data som är enkla att mäta. Dessa enklare beslut kan vi konstatera är i det närmaste rationella. Vi har vidare sett att när besluts­förutsättningarna blir mer komplicerade så bidrar i alla fall BI-systemen till att öka rationaliteten. Detta framförallt då de, i många fall, kan förse beslutsfattare med informa­tionen som behövs för att kunna fatta mer objektiva beslut baserade på adekvat information och på så sätt minska begränsningarna i rationaliteten.</p> / <p>In all kinds of organizations decisions have to be made and if an organization is to succeed, the ability to make the right decisions is of uttermost importance. When it comes to decision-making the so called rational decision model, in which decision-makers are assumed to possess the necessary information in order to make the correct decisions in accordance with the organizations overall objectives, has been one of the most popular among economists. However, this view has been criticized and said to be inadequate when real decisions in real organizations are to be made, and that the rationality is bounded. There are, however, those who are of the opinion that these limitations can be overcome by computer-based decision-support systems in order to make rational decisions, and, in addition, that these systems can provide the information necessary for making quick and accurate decisions. One such decision-support that has gained popularity during the last decade is the business intelligence system (BI system). In this thesis we want to investigate what impact BI systems may have on rational decision-making, and, in addition, how these BI systems may be composed. Hence, our research questions are:</p><ul><li>How may companies' BI systems be composed? </li><li>What impact do BI systems have on decision-makers ability to make rational decisions?</li></ul><p>Hence, the purpose of this master thesis is <em>to describe how companies' BI systems are composed and analyze the impact BI systems have on decision-makers ability to make rational decisions</em>.</p><p>The focus in this thesis's framework of ideas is on rational decision-making and general ideas concerning BI systems and their components. These sections are then merged into a research model which is used in order to analyze the results of the study that constitute the foundation of this thesis. The method used in this study is interviews at two companies (<em>SNA Europe</em> and <em>KG Knutsson AB</em>), and the interviewees are persons that use BI systems in their everyday work as a support in their decision-making. We have also interviewed persons from each of the companies' IT depart­ments in order to understand the structure and technical functionality of each of the companies' BI system.</p><p>When it comes to the composition of the BI systems we have been able to come to the conclusion that they vary quite a bit, depending on the overall IT infrastructure of the company. This does not induce any differences worth mentioning regarding the two companies' use of their BI systems, since the decisions supported and the data used in order to make these decisions are practically the same regardless of company. We have also noted that the easier it is to access information the more the BI system is used. Another conclusion is that company IT infrastructures including several legacy-systems tend to have a more traditionally composed BI system. Regarding the impact on rational decision-making we have been able to come to the conclusion that BI systems improves the rationality concerning decisions based on quantifiable data that are easily measured. These more simple decisions have turned out to be, if not completely rational, at least very close to being rational. We have also seen that when the conditions in which decisions are being made are more complicated, the BI systems at least have some positive effect on the rationality of the decisions. Above all, the BI systems can provide the decision-makers with the information necessary to make more objective, informed decisions and by doing so reduce the limitations of the rationality.</p>
99

Investigating the Relationship between Acculturation and Metabolic Syndrome among a Bi-national Sample of Mexicans and Mexican-Americans

Guerrero, Julio 14 March 2013 (has links)
Mexican-Americans are disproportionately burdened by metabolic syndrome, a medical condition characterized by the concurrence of clinical abnormalities that contributes to diabetes, obesity, and cardiovascular disease (CVD). This is alarming since Mexican-Americans constitute two-thirds of the US Latino population, the largest minority and fastest growing group in the US. Investigating acculturative stressors associated with immigration is crucial for eliminating health disparities, but few studies have examined the acculturative impact of Mexican migration to the United States or the relationship between acculturation and metabolic syndrome among Mexican-Americans. The purpose of this dissertation research was to investigate the associations between acculturation and metabolic syndrome among a bi-national sample of Mexicans and Mexican-Americans. Metabolic syndrome was assessed among a bi-national sample of individuals with diabetes using the definition outlined by the International Diabetes Federation, and acculturation was assessed by proxy measures (years lived in the US and generational status) and responses on the Acculturation Rating Scale for Mexican-Americans, version-II. Chi-square, analysis of variance, and logistic regression were used to determine relationships between country, gender, and acculturation status and metabolic syndrome and its biomarkers. The overall prevalence of metabolic syndrome was 79.7%, with 85.0% prevalence among Mexican-Americans and 75.7% among Mexicans (p=0.069). Mexican-Americans had higher blood pressure and central obesity, while Mexicans had higher triglycerides levels. The majority (81.2%) of Mexican-Americans was first generation and lived in the US for an average of 27.65 +/- 16.05 years. The mean acculturation score was -1.83 +/- 1.56, which indicated participants in this study were Mexican-oriented, or more closely associated to Mexican cultural influences than Anglo cultural influences. Higher acculturation scores were positively associated with fasting blood glucose and systolic blood pressure and lower acculturation was negatively associated with fasting blood glucose. Logistic regression analysis showed first generation Mexicans-Americans were more likely to develop metabolic syndrome than second generation Mexican-Americans (OR 7.399, 95% CI 1.464-37.401, p=0.015). Mexican and Mexican-American individuals with type 2 diabetes have a high prevalence of metabolic syndrome, which increases their risk for heart disease and other cardiovascular complications. Mexican-Americans are especially affected by central obesity and hypertension and Mexican immigrants appear to be impacted by negative lifestyle factors upon entering the United States. Acculturation is a complex process and the unclear relationship between acculturation and metabolic syndrome warrants further investigations.
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Normalización estadística para fusión biométrica multimodal

Ejarque Monserrate, Pascual 17 March 2011 (has links)
Los sistemas de reconocimiento biométrico utilizan ciertas características humanas como la voz, los rasgos faciales, la huella dactilar, el iris o la geometría de la mano para identificar a un individuo o verificar su identidad. Dichos sistemas se han desarrollado de forma individual para cada una de estas modalidades biométricas hasta llegar a obtener unos niveles notables de rendimiento. Los sistemas biométricos multimodales combinan diversas modalidades en un sistema de reconocimiento único. La fusión multimodal permite mejorar los resultados obtenidos por una sola característica biométrica y hacen el sistema más robusto a ruidos e interferencias y más resistente a posibles ataques. La fusión se puede realizar a nivel de las señales adquiridas por los distintos sensores, de los parámetros obtenidos para cada modalidad, de las puntuaciones proporcionadas por expertos unimodales o de la decisión tomada por dichos expertos. En la fusión a nivel de parámetros o puntuaciones es necesario homogeneizar las características provenientes de las diferentes modalidades biométricas de manera previa al proceso de fusión. A este proceso de homogeneización se le denomina normalización y se ha demostrado determinante en la obtención de buenos resultados de reconocimiento en los sistemas multimodales. En esta tesis, se presentan diversos métodos de normalización que modifican la estadística de parámetros o puntuaciones. En primer lugar, se propone la normalización de la media y la varianza de las puntuaciones unimodales por medio de transformaciones afines que tienen en cuenta las estadísticas separadas de las puntuaciones de clientes e impostores. En este ámbito se presenta la normalización conjunta de medias, que iguala las medias de las puntuaciones de clientes e impostores para todas las modalidades biométricas. También se han propuesto técnicas que minimizan la suma de las varianzas de las puntuaciones multimodales de clientes e impostores. Estas técnicas han obtenido buenos resultados en un sistema bimodal de fusión de puntuaciones de espectro de voz e imágenes faciales y se ha demostrado que una reducción de las varianzas multimodales puede comportar un mejor resultado de reconocimiento. Por otro lado, se ha utilizado la ecualización de histograma, un método ampliamente utilizado en el tratamiento de imágenes, como técnica de normalización. Para ello, se han ecualizado los histogramas de las características unimodales sobre diversas funciones de referencia. En primer lugar, se ha utilizado el histograma de las puntuaciones de una de las modalidades biométricas como referencia en el proceso de ecualización. Esta técnica se ha mostrado especialmente efectiva al combinarla con métodos de fusión basados en la ponderación de las puntuaciones unimodales. En una segunda aproximación, se han ecualizado las características biométricas a funciones previamente establecidas, en concreto, a una gaussiana y a una doble gaussiana. La ecualización a gaussiana ha obtenido buenos resultados como normalización en sistemas de fusión de parámetros. La ecualización de doble gaussiana se ha diseñado específicamente para la normalización de puntuaciones. Las dos gaussianas representan los lóbulos de las puntuaciones de clientes e impostores que se pueden observar en los histogramas unimodales. Se han probado diferentes variantes para determinar las varianzas de dichas gaussianas. Las técnicas de normalización estadística presentadas en esta tesis se han probado utilizando diferentes estrategias y técnicas para la fusión, tanto para bases de datos quiméricas como para una base de datos multimodal. Además, la fusión se ha realizado a diferentes niveles, en concreto, a nivel de puntuaciones para diferentes escenarios multimodales incluyendo características de espectro voz, prosodia y caras, y a los niveles de parámetros, puntuaciones y decisión en el entorno del proyecto Agatha.

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