Trois essais sur la région MENA et l'économie informelle. / Informality is a social and economical phenomenon that has huge implications on societies. Over $3.1 trillion annually is lost to tax evasion worldwide (see The Tax Justice Network report). Informality means different things to different people. Sometimes this term is used to describe tax evasion and sometimes to refer to noncompliance with labor or regulations. Whatever definition is used, informality can be a serious problem in some countries, stifling investment, undermining the overall competetiveness of the whole economy and impeding growth. It could also be an important remedy in other countries playing a role as a mechanism of economic adjustment and source of livelihood for the poor and unemployed. Hart [1973] was the first anthropologist to observe, study and coin the word "informal economy" in his research in Accra and today’s literature is largely based on his work. Societies started acknowledging the importance of informality and then eventually economists, sociologists and anthropologists started analyzing its characteristics worldwide. […]

Background To be able to push game standards further and further, different graphics techniques have to be implemented by game developers. By utilizing some of those techniques, comes cost in the form of performance issues. Level of detail (LOD) is an optimization technique which uses several different variations of a model and distance from the viewer to determine which model should be rendered. Shadow mapping is, on the contrary from level of detail, a costly technique which aims to create as realistically looking shadows as possible. Objectives The aim of this thesis is to examine whether a novel LOD technique and shadow map technique called LOD-SM can achieve less render time versus using a standard implementation of shadow mapping. This is achieved by using the Unity game engine in which the LOD-SM technique is implemented. With Unity, measurements will be taken to determine if the technique is a viable optimization option in future game development. Methods The methods used to answer the paper’s research question were a pilot user study and a performance study. 20 participants were part of the pilot study, and were asked to rate their perception of shadows shown on a screen in front of them. This yielded results of which shadows the participants noticed differences for. The results were then implemented into Unity and measured with the LOD-SM technique. Results The pilot study showed that user does not notice any differences in 30% decreased polycount-shadows when in a multiple building environment. The gathered results from the performance experiment showed that the LOD-SM technique saved between ∼17% up to ∼70% in render time, compared to a regular implementation of shadow mapping. Conclusions In conclusion, a viable optimization option was found which is to lower a shadow maps appearance based on buildings LODs because as the results has shown, users does not notice the lowering of LODs up to 30% when in a multiple building area. It was discovered that by measuring the LOD-SM technique, clear evidence of optimization was found when using the technique versus using a normal implementation of shadow mapping. Developers would have to consider the size of project and its models before implementing the LOD-SM technique, as it might not be viable for projects with a total polycount of less than 100 000 polygons.

This thesis introduces and reflects on a design proposal, Naturally Artificial, which explores the nature-culture and human-environment relationship through Daoism and the concept of life-world. By embracing the vagueness within the relationship, it is an attempt to focus more on the present, before setting up a future scenario.   It is natural for humans to produce the artificial. Human activities leave traces on the Earth, which becomes deeply implanted in the space that we live in. Daoism suggests to focus on the present which is a complex flow that is producing patterns of humans. With the concept of life-world, human life; activities, emotions, etc, are invited to the center of the discussion. Through a designerly method, is it possible to notice and embrace the complex blend between nature and culture? How could design contribute to understand and feel the reality of the present, instead of guessing and speculating the future?   Pixels of Shadows is one part of the design program Naturally Artificial. It is an experience design installation, which is a wall of light showing constantly moving patterns of shadows. Unlike many interaction design projects or media art projects, East-Asian concepts and formgiving languages are used to test the possibility of a local originality within the Western-based discipline. Instead of LED screens and glossy surfaces, softer materials such as handcrafted paper and wood is used for the front screen. A Korean concept within traditional architectures, to be in harmony and connection with nature and the environment is the core of the design concept and visual language.

A influência orográfica desempenhada pela Serra do Mar é um dos mais característicos fenômenos climáticos do Estado de São Paulo. A configuração do obstáculo e a atuação dos sistemas atmosféricos são responsáveis por totais de precipitação que se encontram entre os mais elevados do território brasileiro. Contudo, a análise isolada dos controles climáticos mostra-se insuficiente para a caracterização do fenômeno da intensificação das precipitações orográficas nesta área, sendo que tal análise só pode ser feita através da relação entre os controles estáticos como o posicionamento das vertentes da escarpa da Serra do Mar, e os dinâmicos, os sistemas atmosféricos frontais. A análise de uma série de eventos de precipitação distribuídos pelas estações do ano e pela intensidade e duração, mostra a influência da orografia ao promover totais de precipitação muito superiores nos postos situados na zona de baixada, nas vertentes oceânicas e no alto da serra do que naqueles situados em direção ao interior, menos expostos aos ventos úmidos do oceano. / The orographic influency performed by Serra do Mar is one of the most characteristics climatics phenomena from São Paulo State.The configuration of the obstacle and the atmospherics systems atuation are responsable for the total rainfall which has been found more elevated in brazilian territory. Although, the isolated analysis of the climatic controls show itself not enough for the characterization of the intensification phenomena by the orographics rainfalls on this area, such analysis only can be done through the relation among the statics controls, or this means, the position of the Serra do Mar, and the dynamics, atmospherics systems which acting differently in the brazilian territory during the seasons of the year. The analysis of the selected events by the criterion of the seasons of the year and the criterion of intensity and duration are showed in a unquestionable way the formation of the elevated rainfall in areas exposed by wet winds from the ocean like in the Baixada Santista and in the higher slopes than in areas situated in direction to São Paulo State contryside which are composed by areas of rain shadow.

Made available in DSpace on 2016-04-28T20:37:32Z (GMT). No. of bitstreams: 1 Gisele Falanga Capela Fabreti.pdf: 1104965 bytes, checksum: accae459b9e90b4d70916198ed6ea52b (MD5) Previous issue date: 2010-11-05 / The aim of this work is to understand the dark experience among female siblings bond, checking also the sister´s relevance in woman´s individuation process. Therefore, the jungian concepts and systemic approach have been used as base to analyze fictitious experiences shown by the movies in three stories: The Wedding Date , In her Shoes and Mystic Pizza . The methodological choice has been made based on theoretical verification that relationship among female siblings brings up several feelings and members of sisterhood tend to guard themselves or attack each other on their speeches, but the authors tend to be more authentic regarding their feelings in their work compared to biographies. In this analysis, it has been verified that this unique bond provides better conditions for the shadow to act out, but it depends on the ego´s structure which allows a better or worse shadow integration, fostering family and sibling´s pattern changes, or keeping up with rooted patterns / Este trabalho tem como objetivo compreender a vivência sombria no vínculo fraterno feminino, observando ainda a importância da irmã no processo de individuação da mulher. Para isso utilizou-se do referencial teórico junguiano e da abordagem sistêmica, buscando aproximações através da análise de vivências ficcionais trazidas pelo cinema em três filmes: Muito Bem Acompanhada , Em seu Lugar e Três Mulheres, Três Amores . A escolha da metodologia deu-se pela constatação teórica de que a relação entre irmãs suscita muitos afetos e que os membros da fratria tendem a resguardar-se ou atacar-se em relatos, mas nas obras culturais, os autores tendem a atribuir a seus personagens grande autenticidade de afetos, mais que em biografias. Verificou-se na análise que o vínculo diferenciado dá sustentação para a atuação da sombra, mas que é a estrutura de ego que permite ou não maior ou menor integração da sombra, promovendo mudanças de papéis familiares e na fratria, ou levando à perpetuação dos padrões arraigados

Made available in DSpace on 2016-04-28T20:38:55Z (GMT). No. of bitstreams: 1 Luciana Guerrieri Barbosa Viana Guimaraes.pdf: 978764 bytes, checksum: fbd979ae8b7167b413c3c89aa21f1734 (MD5) Previous issue date: 2014-08-18 / The research aimed at understanding the motivational factor of registered people participating in the virtual community Zombie walk Rio de Janeiro, placed in the social network website Facebook. Therefore, a survey was applied to men and women with age over 18 (eighteen) years old, registered in the above mentioned community. The survey had 6 (six) identification questions and 6 (six) semi-open questions answered by the internet. To analyze the data, it was used the Thematic Analysis, described by author Douglas Ezzy (2002). From the gathered data, a profile of the zombie character was defined and its context from the Jungian psychology point of view. It was observed that the zombie character represents a metaphor for current constellated complexes associated to feelings of strangeness, bond break, lack of solidarity, existential insecurity, relationship dehumanization, consumerism and fear or denial of death. The conclusion from the analysis of the character is a reflection of the current life panorama in society and relationships, as well as a projection of individual anxieties / A pesquisa realizada visou compreender o fator motivador da participação das pessoas cadastradas na comunidade virtual Zombie walk Rio de Janeiro, presente no website de relacionamento Facebook. Para tanto, foi aplicado um questionário a homens e mulheres acima de 18 (dezoito) anos, cadastrados na comunidade virtual mencionada. O questionário contou com 6 (seis) perguntas de identificação, e 6 (seis) questões semiabertas respondidas via Internet. Para análise dos dados foi utilizado o método de Análise Temática, conforme descrito pelo autor Douglas Ezzy (2002). A partir dos dados levantados, realizou-se uma leitura do personagem zumbi e seu contexto sob a ótica da psicologia junguiana. Foi observado que o personagem zumbi constitui uma metáfora para alguns complexos constelados na atualidade, associados a sentimento de estranheza, ruptura de vínculos, falta de solidariedade, insegurança existencial, desumanização das relações, consumismo e medo, ou negação da morte. Conclui-se que a leitura desse personagem reflete um panorama atual de vida em sociedade e relacionamentos, assim como serve de projeção para angústias individuais

Dado o uso crescente de tecnologias não autorizadas e não suportadas pelo departamento de TI nas organizações, chamadas de Shadow IT, o papel da TI e a forma tradicional de gerenciar tecnologia estão mudando dentro das organizações. Shadow IT refere-se ao uso de tecnologias utilizadas pelos funcionários sem a autorização ou o suporte formal da TI para realizar as tarefas de trabalho. Motivada por este contexto, esta pesquisa tem como objetivo verificar os fatores antecedentes ao comportamento de uso da Shadow IT e a relação deste comportamento com o desempenho individual dos usuários de TI. Para alcançar tal objetivo, foi realizada uma pesquisa survey com 286 usuários de TI da área administrativa. Estes usuários são funcionários de três diferentes empresas: um órgão público, uma empresa de educação profissional e uma cooperativa de crédito, as quais compõe a amostra. Esta pesquisa obteve como resultados que os fatores Experiência do Usuário, Utilidade Percebida e Influência Social têm relação positiva significante com o uso da Shadow IT, bem como o uso da Shadow IT tem relação positiva significante com o desempenho individual do usuário de TI. Este trabalho traz implicações teóricas e práticas. Para a teoria, esta pesquisa ampliou o conhecimento sobre o uso da Shadow IT a nível individual. Ademais, um instrumento para medir o comportamento de uso da Shadow IT foi desenvolvido, o qual pode ser aplicado nas organizações para conhecer o comportamento do usuário de TI com relação ao uso destas tecnologias. A partir do conhecimento dos antecedentes do comportamento de uso da Shadow IT e qual é a sua relação com o desempenho individual do usuário de TI, os gestores podem elaborar políticas de gestão que reduzam os riscos associados a esse fenômeno, bem como potencializar os seus benefícios. / Given the increasing use of unauthorized technologies by employees in organizations, called Shadow IT, the traditional way to manage technology is changing. Shadow IT is the use of an unauthorized technology by employees, changing, thus, the role of IT is changing within organizations. Motivated by this context, this research aims to verify the antecedents factors behind Shadow IT usage behavior and the relationship of this behavior with the individual performance of IT users. To reach this goal, we performed a survey research with 286 IT users of from the administrative area. These users are employees of three different companies: a public agency, a professional education company and a financial cooperative. As results, we found that User Experience, Perceived Usefulness and Social Influence has positive relationship with Shadow IT usage, as well as the use of Shadow IT has a positive relationship with the individual performance of the IT user. This research has theoretical and practical implications. To the academia, this research has extended knowledge about Shadow IT usage at individual level. Furthermore, we also has developed an instrument to measure the Shadow IT usage behavior, which can be applied to the IT users of companies in order to know their Shadow IT usage behavior. To know the antecedents of Shadow IT usage and what is its relationship with individual performance of IT user is also important to companies. Managers must know what drives users to use Shadow IT, as well as what is the outcome of this use in terms of individual performance in order to develop policies and strategies that reduce the risks associated with this phenomenon and maximize its benefits.

<div>Control-flow hijacking attacks allow adversaries to take over seemingly benign software, e.g., a web browser, and cause it to perform malicious actions, i.e., grant attackers a shell on</div><div>a system. Such control-flow hijacking attacks exploit a gap between high level language semantics and the machine language that they are compiled to. In particular, systems</div><div>software such as web browsers and servers are implemented in C/C++ which provide no runtime safety guarantees, leaving memory and type safety exclusively to programmers. Compilers are ideally situated to perform the required analysis and close the semantic gap between C/C++ and machine languages by adding instrumentation to enforce full or partial memory safety.</div><div><br></div><div><div>In unprotected C/C++, adversaries must be assumed to be able to control to the contents of any writeable memory location (arbitrary writes), and to read the contents of any readable memory location (arbitrary reads). Defenses against such attacks range from enforcing full memory safety to protecting only select information, normally code pointers to prevent control-flow hijacking attacks. We advance the state of the art for control-flow hijacking</div><div>defenses by improving the enforcement of full memory safety, as well as partial memory safety schemes for protecting code pointers.</div></div><div><br></div><div><div>We demonstrate a novel mechanism for enforcing full memory safety, which denies attackers both arbitrary reads and arbitrary writes at half the performance overhead of the</div><div>prior state of the art mechanism. Our mechanism relies on a novel metadata scheme for maintaining bounds information about memory objects. Further, we maintain the application</div><div>binary interface (ABI), support all C/C++ language features, and are mature enough to protect all of user space, and in particular libc.</div></div><div><br></div><div><div>Backwards control-flow transfers, i.e., returns, are a common target for attackers. In particular, return-oriented-programming (ROP) is a code-reuse attack technique built around corrupting return addresses. Shadow stacks prevent ROP attacks by providing partial memory safety for programs, namely integrity protecting the return address. We provide a full taxonomy of shadow stack designs, including two previously unexplored designs, and demonstrate that with compiler support shadow stacks can be deployed in practice. Further we examine the state of hardware support for integrity protected memory regions within a process’ address space. Control-Flow Integrity (CFI) is a popular technique for securing forward edges, e.g., indirect function calls, from being used for control-flow hijacking attacks. CFI is a form of partial memory safety that provides weak integrity for function pointers by restricting them to a statically determined set of values based on the program’s control-flow graph. We survey existing techniques, and quantify the protection they provide on a per callsite basis.</div><div>Building off this work, we propose a new security policy, Object Type Integrity, which provides full integrity protection for virtual table pointers on a per object basis for C++</div><div>polymorphic objects.</div></div>

Off-grid hybrid renewable energy systems are known as an attractive and sustainable solution for supplying clean electricity to autonomous consumers. Typically, this applies to the communities that are located in remote or islanded areas where it is not cost-effective to extend the grid facilities to these regions. In addition, the use of diesel generators for electricity supply in these remote locations are proven to be uneconomical due to the difficult terrain which translates into high fuel transportation costs. The use of renewable energy sources, coupling with the diesel generator allows for the diesel fuel to be offset. However, to date, a common design standard for the off-grid system has yet to be found and some challenges still exist while attempting to design a reliable system. These include the sizing of hybrid systems, coordination between the operation of dissimilar power generators and the fluctuating load demands, optimal utilisation of the renewable energy resources and identifying the underlying principles which reduce the reliability of the off-grid systems. In order to address these challenges, this research has first endeavoured into developing a sizing algorithm which particularly seeks the optimal size of the batteries and the diesel generator usage. The batteries and diesel generator function in filling the gap between the power generated from the renewable energy resources and the load demand. Thus, the load requirement is also an important factor in determining the cost-effectiveness of the overall system in the long run. A sensitivity analysis is carried out to provide a better understanding of the relationship between the assessed renewable energy resources, the load demand, the storage capacity and the diesel generator fuel usage. The thesis also presents the modelling, simulation and experimental work on the proposed hybrid wind-diesel-battery system. These are being implemented with a full-scale system and they are based on the off-the-shelf components. A novel algorithm to optimise the operation of a diesel generator is also proposed. The steady-state and dynamic analysis of the proposed system are presented, from both simulation and an experimental perspective. Three single-phase grid-forming inverters and a fixed speed wind turbine are used as a platform for case studies. The grid-forming inverters adopt droop control method which allows parallel operation of several grid-forming sources. Droop control-based inverters are known as independent and autonomous due to the elimination of intercommunication links among distributed converters. Moreover, the adopted fixed speed wind turbine employs a squirrel cage induction generator which is well known for its robustness, high reliability, simple operation and low maintenance. The results show a good correlation between the modelling, the experimental measurements, and the field tested results. The final stage of this research explores the effect of tower shadow on off-grid systems. Common tower designs for small wind turbine applications, which are the tubular and the lattice configurations, are considered in this work. They generate dissimilar tower shadow profiles due to the difference in structure. In this research, they are analytically modelled for a wind turbine which is being constructed as a downwind configuration. It is proven that tower shadow indeed brings negative consequence to the system, particularly its influence on battery lifetime within an off-grid system. This detrimental effect occurs when power generation closely matches the load demand. In this situation, small frequent charging and discharging cycles or the so called microcycles, take place. The battery lifetime reduction due to these microcycles has been quantified and it is proven that they are not negligible and should be taken into consideration while designing an off-grid hybrid system.

Inthisthesiswefocusontheimpactofilluminationchangesinvideoand we discuss how we can minimize the impact of illumination variance in video processing systems. Identifyingandremovingshadowsautomaticallyisaverywellestablished and an important topic in image and video processing. Having shadowless image data would benefit many other systems such as video surveillance, tracking and object recognition algorithms. Anovelapproachtoautomaticallydetectandremoveshadowsispresented in this paper. This new method is based on the observation that, owing to the relative movement of the sun, the length and position of a shadow changes linearly over a relatively long period of time in outdoor environments,wecanconvenientlydistinguishashadowfromotherdark regions in an input video. Then we can identify the Reference Shadow as the one with the highest confidence of the mentioned linear changes. Once one shadow is detected, the rest of the shadow can also be identifiedandremoved. Wehaveprovidedmanyexperimentsandourmethod is fully capable of detecting and removing the shadows of stationary and moving objects. Additionally we have explained how reference shadows can be used to detect textures that reflect the light and shiny materials such as metal, glass and water. ...