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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.
121

Produktingripanden på finansmarknaden : Leder begränsningar och förbud till ett stärkt investerarskydd för ickeprofessionella kunder? / Product interventions in the financial market : Do limitations and prohibitions lead to stronger investor protection for retail clients?

Blomdahl, Eric January 2018 (has links)
På finansmarknaden finns det flera olika typer finansiella instrument och utbudet ökar stadigt. Utvecklingen har lett till att det har blivit svårare för icke-professionella kunder att utvärdera riskerna med instrumenten. Vissa finansiella instrument som finns på marknaden är så kallade finansiella derivatinstrument, vars värde beror på en underliggande tillgångs värdeutveckling. En ny reglering om produktgodkännande av finansiella instrument introducerades genom Europaparlamentets och rådets direktiv 2014/65/EU. Processen för produktgodkännande är reglerad i 8 kap. 13 § lag (2007:528) om värdepappersmarknaden. Regleringen innebär att, värdepappersinstitut måste ha en välordnad process för godkännande av egenproducerade finansiella instrument innan marknadsföring eller distribution till kund får ske. I och med Europaparlamentets och rådets direktiv 2014/65/EU och Europaparlamentets och rådets förordning (EU) nr 600/2014, har nationella behöriga myndigheter och Esma erhållit befogenhet att utföra produktingripanden. Syftet med produktingripanden är att skydda ickeprofessionella kunder från produkter på finansmarknaden som är riskfyllda och har svårbedömda egenskaper. Esma har nyligen publicerat ett åtgärdsförslag avseende begränsningar av marknadsföring, distribution och försäljning av contracts for difference samt ett förbud av marknadsföring, distribution och försäljning av binära optioner till ickeprofessionella kunder. I uppsatsen visas att produktingripanden är ett verktyg som kan komma att gynna både nationella behöriga myndigheter och Esma i tillsynsarbetet, i syfte att stärka investerarskyddet för icke-professionella kunder. Samarbetet mellan Esma och nationella behöriga myndigheter bör även utvecklas för att genomdriva framtida åtgärdsförslag. Åtgärdsförslag bör främst vara antagna av Esma för att därefter antas av nationella behöriga myndigheter inom EU. Genom ett sådant tillvägagångssätt kan harmoniseringsarbetet, avseende regleringen av kapitalmarknaden i EU, fortsätta på ett ändamålsenligt sätt. I uppsatsen visas även att Esma:s nuvarande åtgärdsförslag, angående begränsningar och förbud av marknadsföring, distribution och försäljning av contracts for difference och binära optioner, är ett välgrundat förslag med beaktande av de risker som icke-professionella kunder utsätts för vid handel av dessa riskfyllda finansiella derivatinstrument.
122

Mortalidade materna no município de São Paulo, 2000 a 2008 / Maternal Mortality in the city of São Paulo, 2000 to 2008

Tatiane Sano Furukawa Zacarias 21 February 2013 (has links)
Introdução: A mortalidade materna é um grande problema de Saúde Pública no Brasil e no mundo. Atinge muitas mulheres e representa um indicador de pobreza e iniquidade social. Objetivo: Analisar as mortes maternas ocorridas no município de São Paulo em uma série histórica de 2000 a 2008. Métodos: Estudo ecológico, que analisou os óbitos maternos ocorridos em residentes do município de São Paulo entre os anos de 2000 a 2008. Foram utilizados dados das Declarações de Óbito e dos relatórios do Comitê de Mortalidade Materna. O mapa de exclusão/inclusão social e as áreas homogêneas dos 96 distritos administrativos foram utilizados como unidades de análise. Foram calculadas as razões de mortalidade materna, o percentual de subnotificação de causas maternas declaradas e fator de correção. Foram analisadas as causas que ocultavam os óbitos maternos. A análise de tendência da mortalidade para o município foi realizada por meio de modelos de regressão polinomial e a para análise de correlação utilizou-se o teste de correlação de Pearson. Foi considerado o nível de significância de 5 por cento (p<0,05). Para análise do preenchimento das variáveis 43 e 44, as Declarações de óbito foram localizadas no arquivo morto da Prefeitura Municipal. Resultados: Ocorreram 877 óbitos. A Razão de Mortalidade Materna (RMM) foi de 53,2 óbitos/100.000 Nascidos Vivos. A série histórica apresentou tendência decrescente estatisticamente significativa, com redução de 1,73 ao ano. As menores RMM foram encontradas nas áreas homogêneas de menor exclusão social, e as maiores, nas áreas de maior exclusão. As áreas mais excluídas apresentaram risco de morte materna aproximadamente três vezes maior que na área menos excluída. A correlação de Pearson revelou moderada correlação negativa entre a RMM e o índice de exclusão/inclusão global (-0,37), o índice de desenvolvimento humano (-0,40) e de autonomia (-0,36). As principais causas de morte materna foram as obstétricas indiretas. O percentual médio de subnotificação das causas maternas foi de 45,38 por cento, e o fator de correção médio foi 1,83. Destacou-se o grande percentual de causas mal definidas declaradas. Entre 2004 a 2006, 43,4 por cento das declarações apresentaram os campos 43 e 44 preenchidos corretamente. A maioria das declarações apresentou três diagnósticos informados. Conclusões: A RMM mostrou relação com as condições socioeconômicas. É necessário maior investimento em treinamentos para o correto preenchimento das Declarações de óbito. É necessário a implementação mais efetiva de ações de saúde voltadas para a mortalidade materna / Background: Maternal mortality is a big problem of public health in Brazil and in the world. Affects many women and is an indicator of poverty and social inequity. Objective: To analyse maternal deaths occurred in the city of São Paulo in a series from 2000 to 2008. Methods: Ecologic study, which analyzed maternal deaths that occurred among residents of city of São Paulo during the years 2000 to 2008. Data were used from deaths certificates and reports of the Committee on Maternal Mortality. The map of social inclusion/exclusion and homogeneous areas of the 96 districts were used as units of analysis. We calculated maternal mortality ratios, the percentage of underreporting of maternal causes and the correction factor. We analyzed the causes that hid maternal deaths. The analysis of trends in mortality for the city was conducted using polynomial regression models and for correlation analysis used the test of correlation of Pearson. It was considered the significance level of 5 per cent (p<0,05). For examination of completing the variables 43 and 44, the deaths certificates were located in the archive of the city. Results: There were 877 deaths. The Maternal Mortality Ratio (MMR) was 53,2/100.000 live births. The series showed trend decreasing statistically significant, with a decrease of 1,73 per year. The lower MMR were found in homogeneous areas with lower social exclusion and higher than areas with higher exclusion. Areas most excluded showed risk of maternal deaths about three times higher than in area less excluded. The correlation of Pearson showed moderate negative correlation between MMR and index inclusion/exclusion overall (-0,37), the index of human development (-0,40) and the index of autonomy (-0,36). The main causes of maternal deaths were obstetric indirect. The mean percentage of underreporting of maternal causes was 45,38 per cent , and the correction factor medium was 1,83. We emphasize the high percentage of illdefined causes declared. During 2004 and 2006, 43,4 per cent of the declarations presented fields 43 and 44 filled in correctly. Most declarations presented three diagnoses listed. Conclusion: The MMR showed relationship with socioeconomic conditions. It is necessary greater investment in training for correct completion of death certificates. It is necessary the implementation more effective heath actions to maternal mortality
123

Avaliação da qualidade dos dados do Sistema de Informações sobre Nascidos Vivos (SINASC) em São Luís-MA e Ribeirão Preto-SP,

D'eça Junior, Aurean 16 December 2015 (has links)
Made available in DSpace on 2016-08-19T17:24:50Z (GMT). No. of bitstreams: 1 Tese-AureanDEcaJunior.pdf: 1288393 bytes, checksum: a2ffa691714b1f559fb869901954f2c8 (MD5) Previous issue date: 2015-12-16 / The present study aimed to evaluate the quality of information (System coverage, completeness of the data fulfillment and reliability of the information) of SINASC in the city of Ribeirão Preto, São Paulo, through the linkage technique, comparing them to the data obtained from the project entitled Etiology factors of pre-term birth and consequences of perinatal factors on children's health , which studies birth cohorts in São Luís-Maranhão and Ribeirão Preto-São Paulo (BRISA cohort); as well as to analyze and compare the temporal trend of completeness of fulfillment of the variables of SINASC in these two Brazilian cities that make up the study of BRISA cohort, in a time series of 1996-2013. Evaluative study that analyzed the following variables: newborn sex, birth weight, Apgar indices, presence of congenital anomaly, race/color, mother's age, education, marital status, number of living children, length of gestation, type of childbirth, type of pregnancy and number of prenatal visits. The degree of concordance (reliability) of the information was evaluated by Kappa and intraclass correlation coefficients (ICC) for categorical variables and by the Bland-Altman method for numerical variables. Completeness referred to the degree of fulfillment of the field analyzed following the scoring system proposed by Romero and Cunha: excellent, when the variable presents less than 5% of incomplete fulfillment; good (5.0 to 9.9%); regular (10.0 to 19.9%); bad (20.0 to 49.9%) and very bad (50.0% or more). The trend analysis was done by estimation of polynomial regression models. In Ribeirão Preto, the estimated coverage of SINASC, in 2010, classified as good, was 88.3% (95% CI; 87.6% to 89.0%), according to the eight hospitals analyzed. In São Paulo city, the variables that showed nearly perfect or excellent agreement were: hospital of birth, newborn sex, type of pregnancy, type of childbirth, birth weight, maternal age and marital status. The variables number of prenatal visits and length of gestation obtained moderate reliability. The following variables had poor/low reliability: presence of congenital anomaly, race/color, Apgar score at 1st and 5th minutes and number of living children. On the completeness, the variables mother's age, marital status, type of pregnancy, type of childbirth, newborn sex, Apgar scores and birth weight had excellent completeness in the both cities studied. The variables congenital anomaly and race/color of the newborn obtained completeness ranging from bad to very in the capital of Maranhão, unlike the city of Ribeirão Preto, where they had a non-fulfillment percentage of less than 5%. The variable length of gestation showed variation in completeness for all time series, achieving excellence in fulfillment between the years 1999-2010. In Ribeirão Preto, this same variable had excellent completeness between 2000-2013. The chosen polynomial regression models pointed upward trend of non-fulfillment for the variable congenital anomaly in the two cities. In São Luís, the variable marital status had a declining trend for incompleteness, which did not occur in Ribeirão Preto. In São Paulo city, the variable maternal education was presented with decreasing trend of non-fulfillment, which was not evidenced in the capital of Maranhão. The other variables had decreasing trend for the incompleteness in the two cities with statistically significant values in the tested models. This research adds to the evidence of the potential of secondary data as an important source for epidemiological research. Although the results can be translated in advance, it is important to continuously invest in training in order to ensure a system capable of subsidizing policies of intervention and organization of maternal and child health. / Este estudo propôs analisar a qualidade das informações do SINASC nas cidades de São Luís- Maranhão e Ribeirão Preto- São Paulo. Em Ribeirão Preto, a técnica linkage foi utilizada para comparar os dados do SINASC com aqueles obtidos do projeto intitulado Fatores etiológicos do nascimento pré-termo e consequências dos fatores perinatais na saúde da criança, que estuda coortes de nascimentos (coorte BRISA) e a tendência temporal da completitude do preenchimento de variáveis do SINASC por modelos de regressão polinomial foi analisada nestas duas cidades brasileiras, numa série cronológica de 1996-2013. As variáveis analisadas foram: sexo do recém-nascido, peso ao nascer, índices Apgar, presença de anomalia congênita, raça/cor, idade da mãe, escolaridade, situação conjugal, número de filhos vivos, duração da gestação, tipo de parto, tipo de gravidez e número de consultas pré-natal. Em Ribeirão Preto, a cobertura estimada do SINASC, em 2010, classificada como boa, foi de 88,3% (IC95%; 87,6% a 89,0%) segundo os oito hospitais analisados. Na cidade paulista, as variáveis que apresentaram concordância quase perfeita ou excelente foram: hospital de nascimento, sexo do recém-nascido, tipo de gravidez, tipo de parto, peso ao nascer, idade da mãe e situação conjugal. As variáveis número de consultas pré-natal e duração da gestação obtiveram confiabilidade moderada. Tiveram confiabilidade sofrível/fraca as variáveis: presença de anomalia congênita, raça/cor, índice de Apgar no 1° e 5° minutos e número de filhos vivos. Sobre a completitude, as variáveis idade da mãe, estado civil, tipo de gravidez, tipo de parto, sexo do recém-nascido, índices de Apgar e peso ao nascer tiveram excelente completitude nas duas cidades estudadas. As variáveis anomalia congênita e raça/cor do RN obtiveram completitude oscilando entre ruim a muito ruim na capital do Maranhão, ao contrário da cidade de Ribeirão Preto, onde as mesmas tiveram percentual de não preenchimento menor que 5%. Em São Luís, a variável duração da gestação apresentou variação na completitude em toda a série temporal, atingindo excelência no preenchimento entre os anos de 1999-2010. Em Ribeirão Preto, esta mesma variável teve excelente completitude entre 2000-2013. A análise temporal do Sistema nas duas cidades por regressão polinomial evidenciou que a variação no preenchimento de todas as variáveis estudadas não seguiu uma ordem linear, ou seja, toda análise indicou modelos erráticos o que representou a escolha da tendência predominante a cada modelo selecionado que melhor explicava a relação entre completitude de cada variável na série de tempo analisada. Os modelos de regressão polinomial escolhidos apontaram tendência ascendente do não preenchimento para a variável anomalia congênita nas duas cidades. Em São Luís, a variável estado civil teve tendência decrescente para a incompletude, o que não ocorreu em Ribeirão Preto. Na cidade paulista, a variável escolaridade da mãe apresentou-se com tendência decrescente do não preenchimento, o que não se evidenciou na capital maranhense. As demais variáveis tiveram tendência decrescente para a incompletude nas duas cidades com valores estatisticamente significantes nos modelos testados. Da pesquisa, concluiu-se no artigo 1: A cobertura do Sistema na cidade de Ribeirão Preto, classificada como boa revela a necessidade da atenção dos gestores em saúde em ampliar estratégias e investimento em treinamento aos profissionais que preenchem a DNV; importantes variáveis da DNV que tiveram confiabilidade e completitude excelente podem ser utilizadas como cálculo de indicadores de saúde; ainda que o acesso aos serviços de saúde pública em Ribeirão Preto sejam de excelência, as informações do SINASC precisam avançar em estruturação e consolidação de dados robustos afim de que se possa garantir completa e adequada avaliação epidemiológica da saúde materno-infantil. Do artigo 2, pôde-se concluir que: Em ambas as cidades estudadas, o SINASC revelou-se em potencial como fonte de informação epidemiológica de nascimentos; a completitude mostrou-se excelente na maioria das variáveis investigadas e a análise da séria temporal sugere predominância em tendência decrescente do não preenchimento de variáveis do SINASC, configurando avanços. Ainda assim, qualificação profissional e supervisão devem ser garantidos, visto que variáveis ainda apresentam-se com limitações no preenchimento e as causas dessas limitações precisam ser mais detalhadas para que se possam efetivar estratégias de melhorias em seu preenchimento.
124

Essays on the Economics of Sustainable Energy Policies

Dressler, Luisa 01 September 2017 (has links)
This dissertation seeks to contribute to the policy discussion on how to design efficient and sustainable energy policies. In three self-contained chapters, it applies microeconomic theory and empirical analysis to identify three market failures in European energy markets and to evaluate specific policy measures that strive to overcome these failures in order to increase market efficiency and to enhance environmental or societal sustainability. Chapter 1 and 2 study European electricity markets, which play an important role in the transition towards a carbon-neutral energy future. Overcoming barriers to efficient electricity markets is a crucial step to keep the costs of this transition as low as possible to society. Both chapters focus on obstacles to electricity market efficiency that have recently been highlighted by the European Commission. On the supply side, subsidies for renewable electricity may distort production incentives and competition in wholesale electricity markets. Chapter 1 applies a theoretical model to study the effect of different subsidies on producer strategies and competition in wholesale electricity markets. On the demand side, the European Commission seeks to overcome the reluctance of residential electricity consumers to switch electricity supplier in order to ensure effective competition in the retail electricity market. Chapter 2 empirically quantifies different reasons for switching inertia using a structural discrete choice model and performs counterfactual analysis to study the effect of different policy measures that seek to overcome switching inertia. Chapter 3 looks at the building sector, which accounts for 40% of final energy consumption in Europe and is a major emitter of carbon emissions. In the residential housing market information asymmetries hamper incentives to invest in energy efficiency improvements of rental property. This chapter empirically analyzes the effect of a European policy that mandates the use of energy performance certificates aiming at establishing an efficient market for energy efficient dwellings. / Doctorat en Sciences économiques et de gestion / info:eu-repo/semantics/nonPublished
125

Intégration de la production éolienne aux réseaux électriques : approches techniques et économiques / Electrical supply networks, systems of economic incentive and distributed production of energy

Ruiz Gomez, Lina Maria 24 October 2012 (has links)
La Directive européenne et les politiques de prévention du changement climatique conduisentà un développement important des Énergies Renouvelables pour la production d'électricité. Cecontexte politique est en train d'induire l'insertion massive de production intermittente d'origineéolien dans les réseaux électriques. Pour répondre à la question des limites de l'intégration de l'éoliendans les réseaux électriques, nous nous appuyons sur l'étude des aspects technique et économiques.Dans ce cadre, cette thèse s'intéresse d'une part à l'étude de l'efficacité des dispositifs d'incitationéconomique du point de vue de leur efficacité à stimuler la croissance de l'énergie éolienne et d'autrepart, aux problématiques techniques de court et long terme liées à l'intermittence de l'éolien. Dans lecourt-terme, les problèmes du réseau électrique ainsi que les ajustements dans le marché del'électricité sont abordés. Dans le long terme, l'impact de l'éolien sur la sûreté de fonctionnement estévalué au moyen d'un algorithme de calcul du crédit de capacité de l'éolien. / The development of Renewable Energy for electricity production has increased due to theEuropean policies and directives to prevent climate change. This political context is promoting amassive insertion of intermittent wind electricity production into electrical networks. There are stilldoubts about the limitations of integrating wind power into the electrical networks. For this reason,we focus on the study technical and economic aspects to approach these limitations. The firstpurpose of this research is to determine the effectiveness of the economical incentives policies inorder to stimulate growth in the wind power production. The second one is to evaluate the technicalproblems in the short and long term caused by the intermittency of wind power. In the short-term,the problems of power systems as well as the adjustments in the electricity market are discussed. Inthe long term, the impact of wind power reliability (in the network) is evaluated by using an algorithmto calculate the capacity credit of wind power.
126

Justification for a credit union to charter a bank

Eazell, Diane Patricia 01 January 2000 (has links)
No description available.
127

Cost-effectiveness assessment of energy efficiency obligation schemes - implications for Swedish industries

Xylia, Maria January 2013 (has links)
This thesis is an investigation of whether an energy efficiency obligation scheme would be cost-effective for the Swedish industrial sector. The basic guidelines of the scheme were constructed based on the characteristics proposed in the Energy Efficiency Directive and the previously implemented schemes in other EU Member States. In order to measure the cost effectiveness of the scheme for the industries, a Cost Benefit Analysis was performed. The results of the study show that the participation of the industries in an energy efficiency obligation scheme seems to be cost effective, and the Benefit to Cost Ratios of the analysis where ranging in numbers higher than one, showing that the benefits outweigh the costs. The scheme is in general more cost effective when scenarios assuming high policy intensity for the whole economy of the country are used as input for the calculation of the BCRs, which are also affected positively when higher fuel prices scenarios are adopted. The obligation should be placed upon the distributors, since the prices of energy distribution are administratively regulated. There is opportunity of financial benefits for the Swedish industries from agreements of energy savings delivery to the distributors in order for them to fulfill their obligation. These benefits will support the cost recovery of the investments for the energy savings measures. The possibility of certificate trading in the context of the scheme is another option that can create opportunities for financial gains and stimulate further the energy market. Basing the costs inputs from other EU Member States offers an insight on how these costs could be formed in the case of Sweden, but they cannot be taken as a complete calculation of the scheme’s financial effects. As a result, this study does not offer a final conclusion on the cost-effectiveness of the scheme; it rather serves as a means of support of the final conclusion regarding the cost-effectiveness of energy efficiency obligation schemes for the Swedish industries.
128

Småskaliga vindkraftverk på byggnader i urban miljö : Möjligheter och hinder för ökad implementering / Small-scale wind turbines mounted on buildings in the urban environment : Possibilities and barriers for increased use

Halvarsson, Patrik, Larsson, Emma January 2013 (has links)
Intresset för småskaliga vindkraftverk på byggnader har ökat under de senaste åren. Allt fler människor blir mer energi- och miljömedvetna samt ser fördelarna med att elektriciteten produceras där den konsumeras; i den bebyggda miljön. Det är dock en större utmaning att installera ett vindkraftverk i urban miljö, jämfört med i öppet landskap, då det finns många faktorer som skall beaktas. Stadens komplexa uppbyggnad gör att vindens hastighet och riktning varierar och ger upphov till turbulenta strukturer i den omgivande luften. Många av dagens vindkraftverk kan ej operera effektivt vid turbulens, därför måste dessa vindkraftverken placeras på höga höjder för att nå den laminärt strömmande vinden över staden, vilket ger orealistiska längder på de master som krävs, även om vindkraftverket monteras på en byggnad. För att kunna utnyttja de vindar som uppkommer i urbana miljöer bör vertikalaxlade vindkraftverk med en helixformad geometri på rotorn användas. Dessa har visat sig vara både de effektivaste och de vindkraftverk som utsätter omgivningen för lägst nivå av störningar. Att placera ett vindkraftverk på en byggnad i urban miljö, där många människor vistas, kräver god kunskap om säkert montage samt vilka störningar som vindkraftverket kan generera. Ett vindkraftverk som monteras felaktigt kan bidra till hälso- och säkerhetsrisker, och om dessa risker blir för stora kan vindkraftverket tvingas att tas ur drift. För att vara säker på att vindkraftsanläggningen är tillförlitligt bör vindkraftverket och montaget vara stadardiserat och certifierat, något som i dagsläget saknas i Sverige. I dag finns inga direkta stöd för småskaliga vindkraftverk i Sverige, vilket är en bidragande faktor till att ekonomin kring dessa vindkraftverk är bristfällig. Elcertifikatsystemet som skall ge stöd åt förnyelsebar energi är inte utformat för småskalig elproduktion. Men i takt med att detta användningsområde för vindkraft utvecklas samt att priset för energi förväntas stiga kommer troligtvis byggnadsmonterade vindkraftverk bli en lönsam investering i framtiden. / The interest for small-scale wind turbines mounted on buildings has increased during the last couple of years. More and more people are giving more consideration to energy and environmental questions and are appreciative of the benefits of producing electricity where it is consumed; in the urban environment. However it is a greater challenge to install a wind turbine in the urban environment, compared to an open landscape, because of the many factors that needs to be taken in consideration. The complex structure of the city has an effect on the speed and direction of the wind and causes turbulent structures in the surrounding air. Many of today’s wind turbines cannot operate effectively in turbulence, this is why these turbines need to be placed on high heights to reach the laminar wind flow over the city, which gives unrealistic lengths of the towers that are required, even if the turbine is mounted on a building. To be able to utilize the existing wind in urban environments a vertical axis wind turbine with a helix shaped rotor should be used. These turbines have shown themselves to not only be the most effective but also the turbines that expose the surroundings to the lowest level of disturbances. To place a wind turbine on a building in an urban environment, where a lot of people reside, requires a good knowledge of how to securely mount the turbine but also what kind of disturbances that a turbine can emit. A turbine that is mounted incorrectly can contribute to health and safety hazards, and if these risks become to great the turbine may be forced to be taken out of operation. To be certain that the wind turbine and its components are trustworthy the turbine and mounting should be standardized and certified, a feature that don’t exist today in Sweden.  Currently there is no direct support scheme for small-scale wind turbines in Sweden, which is a contributing factor to the inadequate economics surrounding these wind turbines. The Swedish system with certificates is meant to give support renewable energy but the system is not suited for small-scale production of electricity.  But the more this field of application for wind turbines develops, together with the assumption of rising cost of energy will most likely make building mounted wind turbines a profitable investment in the future.
129

The Security Layer

O'Neill, Mark Thomas 01 January 2019 (has links)
Transport Layer Security (TLS) is a vital component to the security ecosystem and the most popular security protocol used on the Internet today. Despite the strengths of the protocol, numerous vulnerabilities result from its improper use in practice. Some of these vulnerabilities arise from weaknesses in authentication, from the rigidity of the trusted authority system to the complexities of client certificates. Others result from the misuse of TLS by developers, who misuse complicated TLS libraries, improperly validate server certificates, employ outdated cipher suites, or deploy other features insecurely. To make matters worse, system administrators and users are powerless to fix these issues, and lack the ability to properly control how their own machines communicate securely online. In this dissertation we argue that the problems described are the result of an improper placement of security responsibilities. We show that by placing TLS services in the operating system, both new and existing applications can be automatically secured, developers can easily use TLS without intimate knowledge of security, and security settings can be controlled by administrators. This is demonstrated through three explorations that provide TLS features through the operating system. First, we describe and assess TrustBase, a service that repairs and strengthens certificate-based authentication for TLS connections. TrustBase uses traffic interception and a policy engine to provide administrators fine-tuned control over the trust decisions made by all applications on their systems. Second, we introduce and evaluate the Secure Socket API (SSA), which provides TLS as an operating system service through the native POSIX socket API. The SSA enables developers to use modern TLS securely, with as little as one line of code, and also allows custom tailoring of security settings by administrators. Finally, we further explore a modern approach to TLS client authentication, leveraging the operating system to provide a generic platform for strong authentication that supports easy deployment of client authentication features and protects user privacy. We conclude with a discussion of the reasons for the success of our efforts, and note avenues for future work that leverage the principles exhibited in this work, both in and beyond TLS.
130

Applications of Foundational Proof Certificates in theorem proving / Applications des Certificats de Preuve Fondamentaux à la démonstration automatique de théorèmes

Blanco Martínez, Roberto 21 December 2017 (has links)
La confiance formelle en une propriété abstraite provient de l'existence d'une preuve de sa correction, qu'il s'agisse d'un théorème mathématique ou d'une qualité du comportement d'un logiciel ou processeur. Il existe de nombreuses définitions différentes de ce qu'est une preuve, selon par exemple qu'elle est écrite soit par des humains soit par des machines, mais ces définitions sont toutes concernées par le problème d'établir qu'un document représente en fait une preuve correcte. Le cadre des Certificats de Preuve Fondamentaux (Foundational Proof Certificates, FPC) est une approche proposée récemment pour étudier ce problème, fondée sur des progrès de la théorie de la démonstration pour définir la sémantique des formats de preuve. Les preuves ainsi définies peuvent être vérifiées indépendamment par un noyau vérificateur de confiance codé dans un langage de programmation logique. Cette thèse étend des résultats initiaux sur la certification de preuves du premier ordre en explorant plusieurs dimensions logiques essentielles, organisées en combinaisons correspondant à leur usage en pratique: d'abord, la logique classique sans points fixes, dont les preuves sont générées par des démonstrateurs automatiques de théorème; ensuite, la logique intuitionniste avec points fixes et égalité,dont les preuves sont générées par des assistants de preuve. Les certificats de preuve ne se limitent pas comme précédemment à servir de représentation des preuves complètes pour les vérifier indépendamment. Leur rôle s'étend pour englober des transformations de preuve qui peuvent enrichir ou compacter leur représentation. Ces transformations peuvent rendre des certificats plus simples opérationnellement, ce qui motive la construction d'une suite de vérificateurs de preuve de plus en plus fiables et performants. Une autre nouvelle fonction des certificats de preuve est l'écriture d'aperçus de preuve de haut niveau, qui expriment des schémas de preuve tels qu'ils sont employés dans la pratique des mathématiciens, ou dans des techniques automatiques comme le property-based testing. Ces développements s'appliquent à la certification intégrale de résultats générés par deux familles majeures de démonstrateurs automatiques de théorème, utilisant techniques de résolution et satisfaisabilité, ainsi qu'à la création de langages programmables de description de preuve pour un assistant de preuve. / Formal trust in an abstract property, be it a mathematical result or a quality of the behavior of a computer program or a piece of hardware, is founded on the existence of a proof of its correctness. Many different kinds of proofs are written by mathematicians or generated by theorem provers, with the common problem of ascertaining whether those claimed proofs are themselves correct. The recently proposed Foundational Proof Certificate (FPC) framework harnesses advances in proof theory to define the semantics of proof formats, which can be verified by an independent and trusted proof checking kernel written in a logic programming language. This thesis extends initial results in certification of first-order proofs in several directions. It covers various essential logical axes grouped in meaningful combinations as they occur in practice: first,classical logic without fixed points and proofs generated by automated theorem provers; later, intuitionistic logic with fixed points and equality as logical connectives and proofs generated by proof assistants. The role of proof certificates is no longer limited to representing complete proofs to enable independent checking, but is extended to model proof transformations where details can be added to or subtracted from a certificate. These transformations yield operationally simpler certificates, around which increasingly trustworthy and performant proof checkers are constructed. Another new role of proof certificates is writing high-level proof outlines, which can be used to represent standard proof patterns as written by mathematicians, as well as automated techniques like property-based testing. We apply these developments to fully certify results produced by two families of standard automated theorem provers: resolution- and satisfiability-based. Another application is the design of programmable proof description languages for a proof assistant.

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