p. 1-115 / Submitted by Santiago Fabio (fabio.ssantiago@hotmail.com) on 2013-03-14T21:03:06Z No. of bitstreams: 1 9999.pdf: 810798 bytes, checksum: 1cc093c8ad8b27edcba959af1730c5bb (MD5) / Approved for entry into archive by Tatiana Lima(tatianasl@ufba.br) on 2013-04-08T16:24:17Z (GMT) No. of bitstreams: 1 9999.pdf: 810798 bytes, checksum: 1cc093c8ad8b27edcba959af1730c5bb (MD5) / Made available in DSpace on 2013-04-08T16:24:17Z (GMT). No. of bitstreams: 1 9999.pdf: 810798 bytes, checksum: 1cc093c8ad8b27edcba959af1730c5bb (MD5) Previous issue date: 2005 / Este trabalho analisa a contribuição dos efeitos da estratégia da empresa, do setor em que ela opera, do grupo econômico a que pertence e da conjuntura econômica como um todo para a lucratividade das empresas brasileiras no período de 1996 a 2003. Também é verificada a evolução da contribuição destes fatores ao longo do período. Finalmente o modelo é testado com outra variável dependente, correspondendo às características da estrutura do capital das empresas. Os resultados demonstram que o principal elemento da lucratividade é a estratégia da empresa. A participação da estratégia vem aumentando nos últimos oito anos. Contrariamente ao esperado, o efeito da conjuntura é muito pequeno e semelhante ao encontrado no mercado americano. Também surpreende os resultados para a estrutura de capital. Ao contrário do esperado, o modelo revela uma importância ainda maior da estratégia, com uma pequena participação do mercado de atuação. / Salvador

New technology and new innovations have for long been considered as a spring for growth. Conservation farming (CF) is a new production method introduced in rural Zambia and previous research shows that it increases yields and improves soil fertility. Even though the method is proven more efficient than conventional agriculture, only approximately 10 % of Zambia’s farmers have adopted the method. The purpose of this study is to discuss the implications of the introduction of CF on the capabilities of farmers and on economic growth. Furthermore, the study aims to explore why CF, which is proven to be more economically efficient than the conventional method, is not adopted to a larger extent in Zambia. A qualitative study of 25 farmers, farming with either CF or conventional methods, was performed in the region of Mumbwa, Zambia. The results were divided depending on whether the farmers were using the new method or not. To analyze the selected material theories were chosen that regard economic growth and technological change, the adoption process of new innovations, incentive creation and the expansion of capabilities. The two groups showed differences in age, the size of their land, how many crops they grew and to what extent they were working for others or hiring labor. The conclusion from the small sample of farmers is that the farmers using CF had been able to expand their capabilities in different ways. They had food for all the year, the new method allowed them to plan their time better and it was more environmentally sustainable than the old method. The negative aspect of CF is that it is not compatible with the old method in terms of social norms. CF leads to a more efficient use of capital and labor and therefore it can increase the economic growth. In terms of a new innovation, CF seems to have a relative advantage over the old method but it must be spread to a larger group of farmers to reach a breakthrough. To create a higher adoption rate of the method the farmers’ perception must be taken into account. / Minor Field Study (Sida)

Unternehmen, die den organisierten Kapitalmarkt in Anspruch nehmen, steuern sich zunehmend und mehrheitlich nach den Methoden einer am Wert des Unternehmens ausgerichteten Unternehmensführung. Bei börsennotierten Unternehmen wurden bereits seit Mitte der 1990er Jahre empirische Untersuchungen zum Stand der Anwendung wertorientierter Unternehmensführungsmethoden durchgeführt. Für deutsche, mittelständische Unternehmen existieren diesbezüglich noch keine Untersuchungen. 2.000 mittels einer geschichteten Zufalls-stichprobe ausgewählte Unternehmen wurden mit Hilfe einer strukturierten schriftlichen Befragung danach untersucht, wie weit eine wertorientierte Denkhaltung und die verschiedenen Facetten der wertorientierten Unternehmensführung in mittelständischen Unternehmen verbreitet sind und was wesentliche Einflussfaktoren, die den Einsatz wertorientierter Methoden fördern bzw. hemmen darstellen. Auf der Basis von 307 auswertbaren Fragebögen (Rücklauf-quote 15,4 %) können wertvolle Ergebnisse zur Einstellung des Managements bzw. der Ei-gentümer zur wertorientierten Steuerung, zu eingesetzten Methoden und zur Verzahnung mit anderen Managementsystemen gewonnen werden. / Companies using the organized capital market are increasingly and dominantly controlled by management methods that focus on a company’s value. Already since the mid-1990s empirical studies have been conducted about the dispersion of value-based management methods in listed companies. But, there have been no such studies of German SMEs. In our study, 2,000 German small- and medium-sized companies randomly selected through a stratified sample are investigated by using a standardized written questionnaire to receive information about the dispersion of value-orientated attitudes, application of value-based management methods, and factors of influence supporting or hindering the diffusion of value-based management in German SMEs. Based on 307 usable questionnaires (response rate 15.4 %) valuable insights have been gained into the attitudes of managers and owners about value based management, applied methods, and interconnections with other management systems.

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[pt] A tese investiga as etapas do ciclo de planejamento de vendas e operações (S&OP), ampliando o entendimento sobre as etapas pouco pesquisadas do Global Roll-up e Global Executive Meeting. Apresenta um estudo de caso múltiplo, envolvendo cinco importantes subsidiárias latino-americanas de quatro corporações multinacionais. Dois modelos de S&OP são usados para orientar as observações e análises de campo, auxiliando na caracterização do fenômeno S&OP. Acadêmicos e profissionais podem obter conhecimento em primeira mão sobre como as etapas de Global Roll-up e Global Executive Meeting são conduzidas em corporações multinacionais para melhorar seus processos de planejamento. O papel do setor de finanças nos ciclos de S&OP/ Planejamento Integrado de Negócios (IBP) também é examinado e discutido em detalhe, fornecendo informações e ideias úteis para melhorar esses processos em outras organizações, abordando outra lacuna de pesquisa. Os resultados indicam que há desafios para consolidar e usar informações coletadas de várias subsidiárias em diferentes contextos em todo o mundo, mas benchmarking interno e compartilhamento de melhores práticas são explorados, bem como oportunidades de negócios entre países em relação a excessos de estoque, possibilidades de expansão do portfólio e utilização de capacidade ociosa. Adicionalmente, as observações permitiram concluir que o envolvimento precoce do setor de finanças no ciclo de S&OP é benéfico para o negócio, agregando valor ao processo decisório nas etapas iniciais e assumindo um papel central nas etapas de Premeeting e Executive Meeting do ciclo de S&OP. / [en] The thesis investigates the sales and operations planning (S&OP) cycle steps, expanding the understanding about the under-researched Global Roll-up and Global Executive Meeting steps. It presents a multiple case study embracing five important Latin American subsidiaries of four multinational corporations. Two S&OP frameworks are used to guide the field observations and analysis, aiding to improve the S&OP phenomenon s characterization. Scholars and practitioners can gain first-hand knowledge about how Global Roll-up and Global Executive Meeting steps are conducted in multinational corporations to improve their planning processes. The role of finance in S&OP / Integrated Business Planning (IBP) cycles is also examined and discussed in detail providing useful insights to improve these processes in other organizations, addressing another research gap. Findings indicate that there are challenges to consolidate and use information gathered from multiple subsidiaries in different contexts worldwide but internal benchmarking and sharing of best practices are explored as well as business opportunities among countries regarding inventory excess, portfolio expansion possibilities, and spare capacity utilization. Additionally, observations led to the conclusion that early involvement of finance in the S&OP cycle is beneficial for the business, adding value to the decision making process in the initial steps and taking a central role in the Pre-meeting and Executive Meeting steps.

Mean variance optimization has shortcomings making the strategy far from optimal from an investor’s perspective. The purpose of the study is to conduct an empirical investigation as to how modern methods of portfolio optimization address the shortcomings associated with mean variance optimization. Equal risk contribution, the Most diversified portfolioand a modification of the Minimum variance portfolio are considered as alternatives to the mean variance model. Portfolio optimization models introduced are explained in detail and solved using the optimization algorithms Cyclical coordinate descent and Alternating direction method of multipliers. Through implementation and backtesting using a diverse set of indices representing various asset classes, the study shows that the mean variance model suffers from high turnover and sensitivity to input parameters in comparison to the modern alternatives. The sophisticated asset allocation models equal risk contribution and the most diversified portfolio do not rely on expected return as an input parameter, which is seen as an advantage, and are not affected to the same extent by the shortcomings associated with mean variance optimization. The paper concludes by discussing the findings critically and suggesting ideas for further research. / Maximering av avkastning i samband med minimering av varians, på engelska kallat Mean variance optimization, är inte optimalt ur en investerares synpunkt. Syftet med denna uppsats är att genomföra en empirisk studie av hur moderna metoder för portföljallokering adresserar de problem som är förknippade med Mean variance optimization. Mer specifikt undersöks allokeringsstrategierna Equal risk contribution, Most diversified portfolio samt en variant av Minimum variance som ersättare till Mean variance optimization. Allokeringsmetoderna beskrivs detaljerat och löses med optimeringsalgoritmerna Cyclical coordinate descent och Alternating direction method of multipliers. Genom implementering och historisk simulering med ett antal index som representerar olika tillgångsslag visar studien att Mean variance optimization innebär hög portföljomsättning och har en större känslighet för ingångsparametrar i jämförelse med de moderna alternativen. De sofistikerade allokeringsmodellerna Equal risk contribution och Most diversified portfolio bygger inte på ingångsparametern förväntad avkastning, vilket ses som en fördel, och drabbas inte i samma utsträckning av problemen associerade med Mean variance optimization. Studien avslutas med att diskutera resultatet kritiskt och ge förslag på vidare studier som bygger på den teori och det resultat som har presenterats.

Free and Open-Source Software (FOSS) has become an integral part of the software supply chain in the past decade. Various entities (automated tools and humans) are involved at different stages of the software supply chain. Some actions that occur in the chain may result in vulnerabilities or malicious code injected in a published artifact distributed in a package repository. At the end of the software supply chain, developers or end-users may consume the resulting artifacts altered in transit, including benign and malicious injection. This dissertation starts from the first link in the software supply chain, ‘developers’. Since many developers do not update their vulnerable software libraries, thus exposing the user of their code to security risks. To understand how they choose, manage and update the libraries, packages, and other Open-Source Software (OSS) that become the building blocks of companies’ completed products consumed by end-users, twenty-five semi-structured interviews were conducted with developers of both large and small-medium enterprises in nine countries. All interviews were transcribed, coded, and analyzed according to applied thematic analysis. Although there are many observations about developers’ attitudes on selecting dependencies for their projects, additional quantitative work is needed to validate whether behavior matches or whether there is a gap. Therefore, we provide an extensive empirical analysis of twelve quality and popularity factors that should explain the corresponding popularity (adoption) of PyPI packages was conducted using our tool called py2src. At the end of the software supply chain, software libraries (or packages) are usually downloaded directly from the package registries via package dependency management systems under the comfortable assumption that no discrepancies are introduced in the last mile between the source code and their respective packages. However, such discrepancies might be introduced by manual or automated build tools (e.g., metadata, Python bytecode files) or for evil purposes (malicious code injects). To identify differences between the published Python packages in PyPI and the source code stored on Github, we developed a new approach called LastPyMile . Our approach has been shown to be promising to integrate within the current package dependency management systems or company workflow for vetting packages at a minimal cost. With the ever-increasing numbers of software bugs and security vulnerabilities, the burden of secure software supply chain management on developers and project owners increases. Although automated program repair approaches promise to reduce the burden of bug-fixing tasks by suggesting likely correct patches for software bugs, little is known about the practical aspects of using APR tools, such as how long one should wait for a tool to generate a bug fix. To provide a realistic evaluation of five state-of-the-art APR tools, 221 bugs from 44 open-source Java projects were run within a reasonable developers’ time and effort.

<p dir="ltr">This dissertation investigates the dynamics of co-regulated learning within the context of teamwork in higher education with a focus on software development courses. Co-regulated learning, where team members collaboratively manage, adapt, and synchronize their learning processes, is essential for effective teamwork and improved learning outcomes. The study comprises three interrelated investigations: a systematic literature review of co-regulation in higher education, an empirical evaluation of co-regulated learning strategies in a software development course, and a longitudinal study on the evolution of these strategies over time.</p><p dir="ltr">The systematic literature review synthesizes findings from 25 empirical studies on co-regulation in teamwork, highlighting the theoretical foundations, methodological approaches, and gaps in existing research on co-regulation. The first study examines how co-regulated learning strategies influence team interactions, performance, and learning outcomes in a semester-long software development course, identifying common challenges and effective practices such as adaptive planning, proactive monitoring, and reflective practices. The second study provides a dynamic view of how co-regulation strategies evolve over multiple project milestones, demonstrating how teams transition from initial role exploration to more defined responsibilities and improved collaboration over time and offering deeper insights into the factors influencing team dynamics and effectiveness.</p><p dir="ltr">Key findings highlight the importance of structured planning, continuous monitoring, reflective evaluation in fostering effective teamwork and co-regulation, and the dynamic evolution of teamwork strategies. The research contributes to understanding co-regulated learning in software development education and offers practical insights for fostering effective teamwork skills such as integration of co-regulation strategies into educational curricula and the development of instructional interventions to support collaborative learning. This research contributes to the theoretical understanding of co-regulated learning and offers practical recommendations for educators, policymakers, and researchers to enhance teamwork and co-regulation skills in higher education, ultimately preparing students for the collaborative demands of the software industry.</p>

The rapid growth of Mobile Health (mHealth) applications, particularly those focusedon mental health, has provided accessible and affordable support for users’ well-being.However, this growth has raised substantial privacy concerns, especially regardinghandling sensitive personal health data. This thesis evaluates the extent to whichmental health apps allow users to exercise their Data Subject Rights (DSRs) under theEuropean General Data Protection Regulation (GDPR) and provides recommendationsfor enhancing data protection and user privacy. The primary objectives are to identifythe relevant DSRs for mental health apps, empirically assess the extent to which suchrights are respected on the existing apps, and propose actionable recommendationsfor improvement. The study’s methodology involved a comprehensive review ofprivacy policies, using automated tools for privacy assessment, and submitting DataSubject Access Requests (DSARs) to app providers. Findings indicate that whilesome apps demonstrate high conformity with DSRs, the majority still falls short invarious aspects. Common issues include inadequate transparency in privacy policies,incomplete responses to DSARs, and non-compliance with the right to data portability.Specifically, only 45.5% of apps responded to the DSARs with a partial or completeanswer, and only 40% of the responses contained data in machine-readable formats,meeting the requirements for data portability. The study emphasizes the need formental health app developers to enhance privacy practices, ensuring users are fullyinformed about data collection and usage, can easily access and delete their personaldata, and receive their data in portable formats. Recommendations include improvingthe clarity and accessibility of privacy policies, adopting best practices for datasecurity, and implementing user-friendly mechanisms for data access and deletion. Inconclusion, while progress has been made in GDPR compliance among mental healthapps, significant improvement is still needed. Addressing these challenges will betterprotect user privacy, build trust, and support the responsible development of digitalhealth technologies. / Den snabba tillväxten av mobila hälsoappar, särskilt de som fokuserar på psykisk hälsa,har gjort det möjligt för användare att få tillgång till prisvärt och lättillgängligt stöd förderas välbefinnande. Men denna tillväxt har också väckt betydande integritetsfrågor,särskilt när det gäller hantering av känsliga personuppgifter om hälsa. Dettaexamensarbete utvärderar i vilken utsträckning hälsoappar för psykisk ohälsa tillåteranvändare att utöva sina rättigheter enligt den europeiska dataskyddsförordningenoch bidrar med rekommendationer för att förbättra dataskydd och användarintegritet.De primära målen är att identifiera relevanta rättigheter för hälsoappar för psykiskohälsa, empiriskt bedöma i vilken utsträckning sådana rättigheter respekteras ibefintliga appar och föreslå konkreta rekommendationer för förbättring. Studienhar genomförts med en omfattande granskning av integritetspolicys, användning avautomatiserade verktyg för integritetsbedömning och inlämning av begäranden omregisterutdrag till applikationsleverantörer. Resultaten visar att även om vissa apparuppvisar hög överensstämmelse med rättigheterna från GDPR, faller majoritetenfortfarande kort på flera områden. Vanliga problem inkluderar otillräcklig transparensi integritetspolicys, ofullständiga svar på DSARs och bristande efterlevnad av rätten tilldataportabilitet. Specifikt svarade endast 45,5% av apparna på DSARs med ett delviseller komplett svar, och endast 40% av svaren innehöll data i maskinläsbara format,vilket uppfyller kraven för dataportabilitet. Studien betonar behovet för utvecklare avhälsoappar för psykisk ohälsa att förbättra deras integritet, säkerställa att användareär fullt informerade om datainsamling och användning, lätt kan komma åt och raderasina personuppgifter samt ta emot sin data i portabla format. Rekommendationerinkluderar att förbättra tydligheten och tillgängligheten av integritetspolicys, antabästa praxis för datasäkerhet och implementera användarvänliga mekanismer fördataåtkomst och radering. Sammanfattningsvis, även om framsteg har gjorts i GDPR-efterlevnad bland hälsoappar för psykisk ohälsa, behövs betydande förbättringar. Attta itu med dessa utmaningar kommer att bättre skydda användarnas integritet, byggaförtroende och stödja den ansvarsfulla utvecklingen av digitala hälsoteknologier.

This thesis explores a methodology to quantify trust in wearable medical devices (WMD) by addressing two main challenges: identifying key factors influencing trust and developing a formal framework for precise trust quantification under uncertainty. The work empirically validates trust factors and uses a Bayesian network to quantify trust. The thesis further employs a data-driven approach to estimate Bayesian parameters, facilitating query-based inference and validating the trust model with real and synthetic datasets, culminating in a customizable parameterized trust evaluation prototype for WMD. / Advances in sensor and digital communication technologies have revolutionized the capabilities of wearable medical device (WMD) to monitor patients’ health remotely, raising growing concerns about trust in these devices. There is a need to quantify trust in WMD for their continued acceptance and adoption by different users. Quantifying trust in WMD poses two significant challenges due to their subjective and stochastic nature. The first challenge is identifying the factors that influence trust in WMD, and the second is developing a formal framework for precise quantification of trust while taking into account the uncertainty and variability of trust factors. This thesis proposes a methodology to quantify trust in WMD, addressing these challenges. In this thesis, first, we devise a method to empirically validate dominant factors that influence the trustworthiness of WMD from the perspective of device users. We identified the users’ awareness of trust factors reported in the literature and additional user concerns influencing their trust. These factors are stepping stones for defining the specifications and quantification of trust in WMD. Second, we develop a probabilistic graph using Bayesian network to quantify trust in WMD. Using the Bayesian network, the stochastic nature of trust is viewed in terms of probabilities as subjective degrees of belief by a set of random variables in the domain. We define each random variable in the network by the trust factors that are identified from the literature and validated by our empirical study. We construct the trust structure as an acyclic-directed graph to represent the relationship between the variables compactly and transparently. We set the inter-node relationships, using the goal refinement technique, by refining a high-level goal of trustworthiness to lower-level goals that can be objectively implemented as measurable factors. Third, to learn and estimate the parameters of the Bayesian network, we need access to the probabilities of all nodes, as assuming a uniform Gaussian distribution or using values based on expert opinions may not fully represent the complexities of the factors influencing trust. We propose a data-driven approach to generate priors and estimate Bayesian parameters, in which we use data collected from WMD for all the measurable factors (nodes) to generate priors. We use non-functional requirement engineering techniques to quantify the impacts between the node relationships in the Bayesian network. We design propagation rules to aggregate the quantified relationships within the nodes of the network. This approach facilitates the computation of conditional probability distributions and enables query-based inference on any node, including the high-level trust node, based on the given evidence. The results of this thesis are evaluated through several experimental validations. The factors influencing trust in WMD are empirically validated by an extensive survey of 187 potential users. The learnability, and generalizability of the proposed trust network are validated with a real dataset collected from three users of WMD in two conditions, performing predefined activities and performing regular daily activities. To extend the variability of conditions, we generated an extensive and representative synthetic dataset and validated the trust network accordingly. Finally, to test the practicality of our approach, we implemented a user-configurable, parameterized prototype that allows users of WMD to construct a customizable trust network and effectively compare the trustworthiness of different devices. The prototype enables the healthcare industry to adapt and adopt this method to evaluate the trustworthiness of WMD for their own specific use cases. / Thesis / Doctor of Philosophy (PhD) / In this thesis, two challenges in quantifying trust in wearable medical devices, are addressed. The first challenge is the identification of factors influencing trust which are inherently subjective and vary widely among users. To address this challenge, we conducted an extensive survey to identify and validate the trust factors. These factors are stepping stones for defining the specifications and quantifying trust in wearable medical devices. The second challenge is to develop a precise method for quantification of trust while taking into account the uncertainty and variability of trust factors. We constructed a Bayesian network, that captures the complexities of trust as probabilities of the trust factors (identified from the survey) and developed a data-driven approach to estimate the parameters of the Bayesian network to compute the measure of trust. The findings of this thesis are empirically and experimentally validated across multiple use cases, incorporating real and synthetic data, various testing conditions, and diverse Bayesian network configurations. Additionally, we developed a customizable, parameterized prototype that empowers users and healthcare providers to effectively assess and compare the trustworthiness of different wearable medical devices.