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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.
11

Defining Clinical Events for Heart Failure Patients

Young, Janay R., Young, Janay R. January 2017 (has links)
Heart failure (HF) is a serious, life limiting chronic illness and is the most common cause of <30-day hospital readmission, which is costly both in its profound negative impact on patient mortality and quality of life, and in economics. Limited access to care in rural communities increases the prevalence of hospitalizations for heart disease in rural areas. The aims of this project using data mined from Arizona Health Sciences Center Clinical Research Data Warehouse, are to define clinical events (fever, pain, changes in respiratory status, change in level of consciousness, changes in output, bleeding, and suicide ideation) for patients with heart failure, and determine what assessment values are for chronically ill patients and compare to "normal" assessment values for non-chronically ill patients. A literature review was completed to determine how to define clinical events for chronically ill patients with HF, and how decision making is used at home to manage chronic illness. Assessment value data was mined from the clinical research data warehouse and compared to “normal” assessment values, with identification of associations between clinical events and action taken in the hospital. The project results support that there are differences in "normal" assessment values for fever, pain, and change in respiratory status between chronically ill patients with HF, and non-chronically ill patients; there was insufficient data to define bleeding, change in output, or suicide ideation. Impacts to care include earlier recognition of worsening HF symptoms that could result in an earlier call or visit to primary care provider forestalling the need for emergent care and hospital readmission. Application of the mined clinical may inform development of evidenced-based algorithm to guide decision-making at home, and it may also provide the foundation for the development of a tool for patient use to prevent <30-day hospital readmission.
12

Approche algébrique pour l'étude et la résolution de problèmes algorithmiques issus de la cryptographie et la théorie des codes / An algebraic approach for the resolution of algorithmic problems raised by cryptography and coding theory

Dragoi, Vlad Florin 06 July 2017 (has links)
Tout d’abord, mon sujet de recherche porte sur le cryptographie à clé publique, plus précisément la cryptographie basée sur la théorie des codes correcteurs d’erreurs. L’objectif principal de cette thèse est d’analyser la sécurité des systèmes de chiffrement. Pour cela j’étudie les propriétés structurelles des différentes familles de codes linéaires utilisées dans la pratique. Mon travail de recherche s’est orienté de maniéré naturelle, vers l’étude des deux dernières propositions de cryptosystèmes, plus exactement le schéma de McEliece à base des codes MDPC [MTSB13](moderate parity check codes) et des codes Polaires [SK14]. Dans le cas des codes MDPC on a mis en évidence une faiblesse importante au niveau des clés utilisées par les utilisateurs du système. En effet, on a proposé un algorithme très efficace qui permet de retrouver une clé privé à partir d’une clé publique. Ensuite on a compté le nombre des clés faibles et on a utilisé le problème d’équivalence de codes pour élargir le nombre de clés faibles. On a publié notre travail de recherche dans une conférence internationale en cryptographie [BDLO16]. Ensuite on a étudié les codes Polaires et leur application à la cryptographie à clé publique. Depuis leur découverte par E. Arikan [Arı09], les codes Polaires font partie des famille de codes les plus étudié du point de vue de le théorie de l’information. Ce sont des codes très efficaces en terme de performance car ils atteignent la capacité des canaux binaires symétriques et ils admettent des algorithmes d’encodage et décodage très rapides. Néanmoins, peu des choses sont connu sur leur propriétés structurelles. Dans ce cadre la, on a introduit un formalisme algébrique qui nous a permit de révéler unegrande partie de la structure de ces codes. En effet, on a réussi à répondre à des questions fondamentales concernant les codes Polaires comme : le dual ou la distance minimale d’un code Polaire, le groupe des permutations ou le nombre des mots de poids faible d’un code Polaire. On a publié nos résultats dans une conférence internationale en théorie de l’information [BDOT16]. Par la suite on a réussi à faire une cryptanalyse complète du schéma de McEliece à base des codes Polaires. Ce résultat a été une application directe des propriétés découvertes sur les codes Polaires et il a été publié dans une conférence internationale en cryptographie post-quantique [BCD+16]. / First of all, during my PhD I focused on the public key cryptography, more exactly on the code-based cryptography. The main motivation is to study the security of the latest encryption schemes. For that, I analyzed in detail the structural properties of the main code families. Thus, my research was naturally directed to the study of the McEliece based encryption schemes, among which the latest MDCP based variant [MTSB13] and Polar codes variant [SK14]. In the case of the MDPC based variant, we manage to reveal an important weakness regarding the key pairs that are used in the protocol. Indeed, we proposed an efficient algorithm that retrieves the private key given the public key of the scheme. Next we counted the proportion of weak keys and we used the code equivalence problem to extend the number of weak keys. We published our results in an international conference in cryptography [BDLO16]. Next we studied the Polar codes and their application to public key cryptography.Since they were discovered by Arikan [Arı09], Polar codes are part of the most studied from an information theory point of view, family of codes. In terms of performance they are really efficient since they are capacity achieving over the Binary Discrete Memoryless Channels and they allow extremely fast encoding and decoding algorithms. Nonetheless, few facts are known about their structure. In this context, we have introduced an algebraic formalism which allowed us to reveal a big part of the structure of Polar codes. Indeed, we have managed to answer fundamental questions regarding Polar codes such as the dual, the minimum distance, the permutation group and the number of minimum weight codewords of a Polar code. Our results were published in an international conference in information theory [BDOT16]. We also managed to completely cryptanalyze the McEliece variant using Polar codes. The attack was a direct application of the aforementioned results on the structural properties of Polar codes and it was published in an international conference in postquantum cryptography [BCD+16].
13

Performance Assessment of The Extended Gower Coefficient on Mixed Data with Varying Types of Functional Data.

Koomson, Obed 01 December 2018 (has links) (PDF)
Clustering is a widely used technique in data mining applications to source, manage, analyze and extract vital information from large amounts of data. Most clustering procedures are limited in their performance when it comes to data with mixed attributes. In recent times, mixed data have evolved to include directional and functional data. In this study, we will give an introduction to clustering with an eye towards the application of the extended Gower coefficient by Hendrickson (2014). We will conduct a simulation study to assess the performance of this coefficient on mixed data whose functional component has strictly-decreasing signal curves and also those whose functional component has a mixture of strictly-decreasing signal curves and periodic tendencies. We will assess how four different hierarchical clustering algorithms perform on mixed data simulated under varying conditions with and without weights. The comparison of the various clustering solutions will be done using the Rand Index.
14

Model-based approach for maize yield gap analysis related to climate variability and nitrogen management / Abordagem baseada em simulações para análise de yield gaps da cultura do milho relacionados à variabilidade climática e manejo de nitrogênio

Andréa, Maria Carolina da Silva 30 August 2016 (has links)
To achieve food security and meet environmental requirements, the average rates of major crop yields in crops such as maize are expected to increase instead of expansion of cultivated areas. Maize crop has as main factors responsible for the low yields in Brazil the water and nitrogen (N) deficits. The concept of yield gaps is the difference between the maximum yield that can be achieved in a given place, limited by water (Yw) or not (Yp), and the average yields, observed under practical conditions (Ya). This concept is of great importance for characterizing the range of maximum yields and definemanagement strategies to its mitigation. Yield potential (Yp) is determined by conditions of temperature, solar radiation, photoperiod and genetic potential; to Water-limited yield (Yw) is added the water limitation imposed by crops on rainfed condition. In this study we aimed to characterize the variability of yield gaps related to environmental and management conditions; and to evaluate the economic and energy returns related to management of these yield gaps through the mechanical application of nitrogen fertilizer in six regions located in the South Central portion of the country in two periods of maize cultivation (1st and 2nd maize growing seasons). Yield gaps related to water restriction (CYg = Yp - Yw) and imposed by management conditions (MYg = Yw - Ya) were determined through aid of integrated models DSSAT system (Decision Suport System for Agrotechnology Transfer). The maize model (CSM CERES-MAIZE) was calibrated with cultivars trial data obtained for the last few years in all evaluated regions. In the 1st growing season, Yp was higher and Yw was higher and more variable than on 2nd growing season due to climate variability. The yield gaps relative to management were more limiting than the gaps relative to water deficit in almost all the evaluated regions. In both crops\' growing seasons, higher and lower MYg were found in two regions of Southern and Midwestern portion of the country, respectively. Although both regions presented high average yields (Ya), different environmental conditions determined the largest absolute differences between their rates of Yp, Yw and MYg. When assessing the profitability (R$ k g-1, MJ kg-1, R $ ha-1; MJ ha-1) of N application as MYg reduction strategy, the behavior of the variation in yields with increasing rate of N was observed. In general, the diminishing returns showed higher use efficiency (per harvested yield and per unit area) at lower N rates (20-80 kg ha-1). Economic and energy profits (regardless of their rate of change related to the increased application of cost) were found at higher N rates (90-400 kg ha-1), and this limit is directly influenced by local climate conditions. Local management of MYg can be more or less viable depending on the combination of environmental conditions and usual management conditions. In general, the cost of N application is higher in 2nd growing season due to most limiting climatic conditions, but regions with efficient management of yield gapswere alsofound in 2nd growing season / Para alcançar a segurança alimentar e atender necessidades ambientais, os índices médios de produtividade de importantes culturas na alimentação como a do milho devem aumentar em detrimento da expansão de áreas cultivadas. A cultura do milho possui como principais fatores responsáveis pelos baixos índices de produtividade no Brasil os deficits hídrico e de nitrogênio (N). O conceito de quebra de produtividade (yield gaps) é a diferença entre a máxima produtividade que pode ser atingida em dado local, seja ela limitada pela água (Yw) ou não (Yp), e a produtividade média observada em condições práticas (Ya). Esse conceito é de grande importância para caracterização de limites de alcance de máximas produtividades e definição de estratégias de manejo para mitigação dos mesmos. A produtividade potencial (Yp) é aquela determinada pelas condições de temperatura, radiação solar, fotoperíodo e potencial genético; à produtividade limitada pela água (Yw) adiciona-se a limitação hídrica imposta por cultivos em sequeiro. Nesse estudo buscou-se caracterizara variabilidade das quebras de produtividade referentes às condições ambientais e de manejo; bem como avaliar o retorno econômico e energético do manejo dessas quebras por meio da aplicação mecanizada de fertilizante nitrogenado em seis municípios localizados na região Centro-Sul do país nas duas épocas de cultivo da cultura do milho (safra e safrinha). Quebras de produtividade referentes à restrição hídrica (CYg = Yp - Yw) e impostos pelas condições de manejo (MYg =Yw - Ya) foram determinadas com auxílio da utilização do sistema de modelos integrados DSSAT (Decision Suport System for Agrotechnology Transfer).O modelo da cultura do milho (CSM CERES-MAIZE) foi calibrado com dados de ensaio de cultivares, obtidos para os últimos anos em todas as regiões avaliadas. Na 1ª safra, os indices de Yp foram mais altos e os indices de Yw foram mais altos e variáveis devido à variabilidade climática.A quebra de produtividade relativa ao manejo foi mais limitante do que a quebra relativa ao deficit hídrico em quase todos os municípios avaliados. Em ambas as safras de cultivo, maiores e menores MYg foram encontrados em dois municípios das regiões Sul e Centro-Oeste do país, respectivamente. Apesar de ambas as regiões apresentarem altas produtividades medias (Ya), diferentes condições ambientais determinaram as maiores diferenças absolutas entre seus indices de Yp, Yw e MYg. Ao avaliar a rentabilidade (R$ kg-1; MJ kg-1; R$ ha-1; MJ ha-1) da aplicação de N como estratégia de redução de MYg, observou-se o comportamento da variação dos rendimentos de produtividade com o aumento das doses de N. Em termos gerais, os rendimentos decrescentes apresentaram maior eficiência de uso do insumo (por massa colhida e por unidade de área) nas menores doses de N (20-80 kg ha-1). Lucros econômicos e energéticos (sem considerar sua taxa de variação com relação ao aumento do custo de aplicação) foram encontrados até doses mais altas de N (90-400 kg ha-1), sendo que esse limite é diretamente influenciado pelas condições climáticas locais. O manejo local dos MYg pode ser mais ou menos viável em função da combinação das condições ambientais e de manejo usual locais. Em termos gerais, o custo de aplicação de N é maior na 2ª safra devido às condições climáticas mais limitantes, porém municípios com manejo eficiente da quebra de produtividade foram encontrados mesmo nas condições de cultivo do milho safrinha.
15

INCREASING AND DECREASING PHASES OF FERRITIN AND HEMOSIDERIN IRON DETERMINED BY SERUM FERRITIN KINETICS

Naoe, Tomoki, Maeda, Hideaki, Ohashi, Haruhiko, Tomita, Akihiro, Hayashi, Hisao, Saito, Hiroshi 08 1900 (has links)
No description available.
16

Model-based approach for maize yield gap analysis related to climate variability and nitrogen management / Abordagem baseada em simulações para análise de yield gaps da cultura do milho relacionados à variabilidade climática e manejo de nitrogênio

Maria Carolina da Silva Andréa 30 August 2016 (has links)
To achieve food security and meet environmental requirements, the average rates of major crop yields in crops such as maize are expected to increase instead of expansion of cultivated areas. Maize crop has as main factors responsible for the low yields in Brazil the water and nitrogen (N) deficits. The concept of yield gaps is the difference between the maximum yield that can be achieved in a given place, limited by water (Yw) or not (Yp), and the average yields, observed under practical conditions (Ya). This concept is of great importance for characterizing the range of maximum yields and definemanagement strategies to its mitigation. Yield potential (Yp) is determined by conditions of temperature, solar radiation, photoperiod and genetic potential; to Water-limited yield (Yw) is added the water limitation imposed by crops on rainfed condition. In this study we aimed to characterize the variability of yield gaps related to environmental and management conditions; and to evaluate the economic and energy returns related to management of these yield gaps through the mechanical application of nitrogen fertilizer in six regions located in the South Central portion of the country in two periods of maize cultivation (1st and 2nd maize growing seasons). Yield gaps related to water restriction (CYg = Yp - Yw) and imposed by management conditions (MYg = Yw - Ya) were determined through aid of integrated models DSSAT system (Decision Suport System for Agrotechnology Transfer). The maize model (CSM CERES-MAIZE) was calibrated with cultivars trial data obtained for the last few years in all evaluated regions. In the 1st growing season, Yp was higher and Yw was higher and more variable than on 2nd growing season due to climate variability. The yield gaps relative to management were more limiting than the gaps relative to water deficit in almost all the evaluated regions. In both crops\' growing seasons, higher and lower MYg were found in two regions of Southern and Midwestern portion of the country, respectively. Although both regions presented high average yields (Ya), different environmental conditions determined the largest absolute differences between their rates of Yp, Yw and MYg. When assessing the profitability (R$ k g-1, MJ kg-1, R $ ha-1; MJ ha-1) of N application as MYg reduction strategy, the behavior of the variation in yields with increasing rate of N was observed. In general, the diminishing returns showed higher use efficiency (per harvested yield and per unit area) at lower N rates (20-80 kg ha-1). Economic and energy profits (regardless of their rate of change related to the increased application of cost) were found at higher N rates (90-400 kg ha-1), and this limit is directly influenced by local climate conditions. Local management of MYg can be more or less viable depending on the combination of environmental conditions and usual management conditions. In general, the cost of N application is higher in 2nd growing season due to most limiting climatic conditions, but regions with efficient management of yield gapswere alsofound in 2nd growing season / Para alcançar a segurança alimentar e atender necessidades ambientais, os índices médios de produtividade de importantes culturas na alimentação como a do milho devem aumentar em detrimento da expansão de áreas cultivadas. A cultura do milho possui como principais fatores responsáveis pelos baixos índices de produtividade no Brasil os deficits hídrico e de nitrogênio (N). O conceito de quebra de produtividade (yield gaps) é a diferença entre a máxima produtividade que pode ser atingida em dado local, seja ela limitada pela água (Yw) ou não (Yp), e a produtividade média observada em condições práticas (Ya). Esse conceito é de grande importância para caracterização de limites de alcance de máximas produtividades e definição de estratégias de manejo para mitigação dos mesmos. A produtividade potencial (Yp) é aquela determinada pelas condições de temperatura, radiação solar, fotoperíodo e potencial genético; à produtividade limitada pela água (Yw) adiciona-se a limitação hídrica imposta por cultivos em sequeiro. Nesse estudo buscou-se caracterizara variabilidade das quebras de produtividade referentes às condições ambientais e de manejo; bem como avaliar o retorno econômico e energético do manejo dessas quebras por meio da aplicação mecanizada de fertilizante nitrogenado em seis municípios localizados na região Centro-Sul do país nas duas épocas de cultivo da cultura do milho (safra e safrinha). Quebras de produtividade referentes à restrição hídrica (CYg = Yp - Yw) e impostos pelas condições de manejo (MYg =Yw - Ya) foram determinadas com auxílio da utilização do sistema de modelos integrados DSSAT (Decision Suport System for Agrotechnology Transfer).O modelo da cultura do milho (CSM CERES-MAIZE) foi calibrado com dados de ensaio de cultivares, obtidos para os últimos anos em todas as regiões avaliadas. Na 1ª safra, os indices de Yp foram mais altos e os indices de Yw foram mais altos e variáveis devido à variabilidade climática.A quebra de produtividade relativa ao manejo foi mais limitante do que a quebra relativa ao deficit hídrico em quase todos os municípios avaliados. Em ambas as safras de cultivo, maiores e menores MYg foram encontrados em dois municípios das regiões Sul e Centro-Oeste do país, respectivamente. Apesar de ambas as regiões apresentarem altas produtividades medias (Ya), diferentes condições ambientais determinaram as maiores diferenças absolutas entre seus indices de Yp, Yw e MYg. Ao avaliar a rentabilidade (R$ kg-1; MJ kg-1; R$ ha-1; MJ ha-1) da aplicação de N como estratégia de redução de MYg, observou-se o comportamento da variação dos rendimentos de produtividade com o aumento das doses de N. Em termos gerais, os rendimentos decrescentes apresentaram maior eficiência de uso do insumo (por massa colhida e por unidade de área) nas menores doses de N (20-80 kg ha-1). Lucros econômicos e energéticos (sem considerar sua taxa de variação com relação ao aumento do custo de aplicação) foram encontrados até doses mais altas de N (90-400 kg ha-1), sendo que esse limite é diretamente influenciado pelas condições climáticas locais. O manejo local dos MYg pode ser mais ou menos viável em função da combinação das condições ambientais e de manejo usual locais. Em termos gerais, o custo de aplicação de N é maior na 2ª safra devido às condições climáticas mais limitantes, porém municípios com manejo eficiente da quebra de produtividade foram encontrados mesmo nas condições de cultivo do milho safrinha.
17

Earnings Management for Swedish Listed Firms : An Empirical Study on Real Earnings Management Prior to Stock Repurchases

Lardner, Simon, Willner, Pierre January 2017 (has links)
In this study, we follow Cooper et al. (2017) and intend to further investigate income-decreasing real earnings management through altering production and discretionary expenditure and focus on such actions taken by management prior to stock repurchase. We take on a European perspective of IFRS on real earnings management and empirically test to what extent Swedish listed firms use real earnings management prior to stock repurchases to lower share prices. We follow Roydchowdhury (2006) and Cooper et al. (2017) and establish the firms normal level of real earnings management to compare with the period when firms anticipate stock repurchases. We present our data and results through descriptive statistics and use variables identified by Zang (2011) to perform correlation and regression tests accordingly with Cooper et al. (2017). Our results suggest that managers of Swedish firms on average engage in income-increasing real earnings management and decrease such management actions prior to stock repurchases. These findings emphasize the influence of real operating decisions by firms’ that must be considered by the market around major corporate events similar to repurchasing stock.
18

Exploring the influence of job crafting on organisational commitment and work engagement in a selected financial services organisation

Brandt, Angelique Adelé January 2020 (has links)
Magister Commercii (Industrial Psychology) - MCom(IPS) / The financial industry revolves around organisations that provide financial services to people in the community. The largest contributor is the banking sector followed by the insurance sector. Financial services organisations face an ever-changing working environment that is constantly increasing in its complexity. New market entrants such as banks provide insurance products, customer preferences change, technology changes quickly, and ever-changing legislation governs the way in which insurance organisations conduct business with customers. Having to continuously contend with the losses, regulatory changes, and risk management, while having to increase the shareholders’ value, all impact on the global financial services industry. They in turn increase the job demands on employees.
19

The Impact of Inflation on Capital Rotation in Inflationary Inflection Points : An Investigation on How Inflation Affects Capital Rotation Between Major Market Sectors as Economies Shift from Disinflation to Reflation

Hansson, Lars Lucas Philip, Berzups, Lukas January 2021 (has links)
There has been a multi-decade disinflationary period that, with the conjunction of recent pandemic-related events, led to extremes in various economic metrics: record lowest interest rates and inflation, increasingly loose monetary and fiscal policies leading to severe debt levels and money supply - all resulting in a multi-front pressure on inflation to start increasing, and after 30 years, for economic environments to reach an inflection point from disinflation to reflation. How would various market sectors perform if suddenly inflation starts to surge? Previous research of similar events, such as in the 1970s, as well as theory, points towards certain market sectors and asset classes, such as commodities, to outperform their peers. Research on this topic is fairly scarce, thus, to better prepare for such an inflationary event and gain insight on which market sectors are best to invest in or avoid, this paper conducts an investigation to explore that scenario. By looking at 11 major market sectors over 10 countries' historic inflationary points that shifted from disinflation to reflation, analysis determined that, while certain sectors are indeed more sensitive to changes in inflation than others, many more are sensitive to changes in interest rates that normally accompany inflation. Sectors such as Energy, Consumer Discretionary and Financials would perform well during this period, while sectors such as Information Technology would historically underperform. Contrary to the theory, not enough relation was discovered by the analysis towards the commodity sector as a whole to overperform, however, that does not mean that none exist. Further research is still required on this topic to increase knowledge and awareness so that the negative impact of inflationary events like the ones of the 1930s and 1970s can be avoided and even taken advantage of.
20

Decreasing Acute Diabetes Complications Through Self-Management Education

Okafor, Eugene O 01 January 2018 (has links)
Diabetes mellitus is a chronic disease that affects millions of people in the United States. The purpose of this project was to develop a guideline to help clinical staff provide clear and concise diabetes self-management instructions to patients in a community setting. Orem's self-care deficit theory (SCD) and health belief model (HBM) provided a platform to assess how patients' self-care deficit contributes to illness and the effect of patients' perception of illness. SCD theory and the HBM provided the framework for the development of the guideline to decrease diabetes acute complications through self-management education. The practice-focused question was whether the diabetes treatment guideline would decrease diabetes complication, improve the quality of care received by the diabetic patients, and if the facility would adopt the developed guideline. AGREE II Tool was used to assess the quality of the guideline and the staffs' desire for the adoption of the guideline. Data were collected from questionnaires given to staff members at the practice site in 2 rounds. Six medical staff were asked to critique the initial guideline, and 5 medical professionals were asked to assess the final guideline. Most of the participants' scores indicated strong agreement that full consideration was met. The score in all 6 AGREE II domains was above 90%, and 100% of the participants recommended the guideline to be adopted in the facility. Data analysis indicated the diabetes practice guideline is valid, will enhance the treatment of diabetes, and the practice site employees were eager to adopt the treatment guideline. Findings may be used to increase population health and reduce acute complications from diabetes mellitus.

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