M.A. (Latin) / Please refer to full text to view abstract

This master thesis presents, examines, designs, implements, and evaluates with respect to energy efficiency a secure and robust VoIP system. This system utilizes a Session Initiation Protocol (SIP) infrastructure assisted by a cloud service, specifically focusing on small to medium sized enterprises (SME) and homes. This research focuses on using inexpensive, flexible, commodity embedded hardware (specifically a Linksys WRT54GL wireless router for the local site with a customized operating system, specifically DD-WRT). The idea is to reduce the local site's power consumption to very low levels by examining which functions can be done in a cloud service rather than at the local site. The thesis presents the design of a low-power IP telephony system for the local site and the cloud site. A number of different usage scenarios and desirable features are described. The methodology for conducting a set of experiments is defined to perform stress-testing and to evaluate the low- power IP telephony system's design. The experiments concern the overall power consumption of the local site under various configurations, the VPN link's call capacity, the QoS metrics for the VoIP calls, the session request delay (SRD) and the registration request delay (RRD). The results from these experiments show that there is a potential for significant power savings when using the proposed design for an IP telephony system. / Detta examensarbete presenterar, undersöker, utformar, implementerar, och försöker att utvärdera ett säkert och robust VoIP-system med energieffektivitet. Detta system använder en Session Initiation Protocol (SIP)-infrastruktur med hjälp av en molntjänst med särskild inriktning på, små, och medelstora företag (SME) och hemmanvändare. Denna forskning fokuserar att använda en prisvärt, billig, flexibel, med program inbyggd hårdvara (speciellt en Linksys WRT54GL trådlös router för den lokala platsen med ett anpassat operativsystem DD-WRT). Tanken är att minska energiförbrukningen på, den lokala platsen till mycket låga nivåer genom att undersöka vilka funktioner, som kan köras på, ett molntjnst snarare än på, den lokala platsen. Avhandlingen presenterar utformningen av ett IP-telefonisystem på, den lokala platsen med ett lågt strömbehov och på, molntjänsten. Ett antal olika användningsförhållanden och önskvärda egenskaper är beskrivna. Metodiken för att genomföra en rad experiment definieras för att utföra stresstester och för att utvärdera designen av IP-telefonisystem med ett lågt effektbehov. I försöken experimenteras den totala energiförbrukningen av den lokala platsen under olika konfigurationer, VPN-länkens samtalskapacitet, QoS-mätning för VoIP-samtal, Session Request Delay (SRD) och Registration Request Delay (RRD). Resultaten från dessa experiment visar att det finns en potential för betydande energibesparing när du använder den föreslagna designen för en IP-telefoni system.

Bandlimited optical intensity channels, arising in applications such as indoor infrared communications and visible light communications (VLC), require that all signals satisfy a bandwidth constraint as well as average, peak and non-negative amplitude constraints. However, the signaling designed for conventional radio frequency (RF) electrical channels cannot be applied directly, since they take energy constraints into consideration instead of amplitude constraints. In addition, conventional transmission techniques optimized for broad-band optical channels such as fiber optics, terrestrial/satellite-to-satellite free-space optical (FSO) communications are typically not bandwidth efficient. In this thesis, a two-dimensional signal space for bandlimited optical intensity channels is presented. A novel feature of this model is that the non-negativity and peak amplitude constraints are relaxed. The signal space parameterizes the likelihood of a negative or peak amplitude excursions in the output. Although the intensity channel only supports non-negative amplitudes, the impact of clipping on system performance is shown to be negligible if the likelihood of negative amplitude excursion is small enough. For a given signal space, a tractable approximation approach using a finite series is applied to accurately compute the likelihood of clipping under average and peak optical power constraints. The uncoded asymptotic optical power and spectral efficiencies using two-dimensional lattice constellations are computed. The Monte-Carlo (MC) simulation results show that for a given average or peak optical power, schemes designed in the presented signal space haver higher spectral efficiency than M-ary pulse amplitude modulation (PAM) using previously established techniques. / Thesis / Master of Applied Science (MASc)

This thesis project explores and investigates the potential benefits of implementing AR as an educational support tool for dyslexic students in higher education. This was conducted through three design explorations which investigate if the characteristic of AR holds any potential benefits for the participants while reading academic papers. These design explorations were created in the form of prototypes which explore and investigate how well AR could increase the readability in comparison to already existing technology, applications, and physical tools which is currently being used by dyslexic students. Main findings from the user-testings, indicate that augmented reality could allow the students to maneuver easily through multiple papers, increase readability of different texts, and that AR holds multiple benefits compared to traditional more commonly used educational support tools.

In cluster analysis, a fundamental problem is to determine the best estimate of the number of clusters, which has a deterministic effect on the clustering results. However, a limitation in current applications is that no convincingly acceptable solution to the best-number-of-clusters problem is available due to high complexity of real data sets. In this dissertation, we tackle this problem of estimating the number of clusters, which is particularly oriented at processing very complicated data which may contain multiple types of cluster structure. Two new methods of choosing the number of clusters are proposed which have been shown empirically to be highly effective given clear and distinct cluster structure in a data set. In addition, we propose a sequential type of clustering approach, called multi-layer clustering, by combining these two methods. Multi-layer clustering not only functions as an efficient method of estimating the number of clusters, but also, by superimposing a sequential idea, improves the flexibility and effectiveness of any arbitrary existing one-layer clustering method. Empirical studies have shown that multi-layer clustering has higher efficiency than one layer clustering approaches, especially in detecting clusters in complicated data sets. The multi-layer clustering approach has been successfully implemented in clustering the WTCHP microarray data and the results can be interpreted very well based on known biological knowledge. Choosing an appropriate clustering method is another critical step in clustering. K-means clustering is one of the most popular clustering techniques used in practice. However, the k-means method tends to generate clusters containing a nearly equal number of objects, which is referred to as the ``equal-size'' problem. We propose a clustering method which competes with the k-means method. Our newly defined method is aimed at overcoming the so-called ``equal-size'' problem associated with the k-means method, while maintaining its advantage of computational simplicity. Advantages of the proposed method over k-means clustering have been demonstrated empirically using simulated data with low dimensionality. / Ph. D.

Si l’on conçoit le développement comme un processus d’élimination des rentes, le cadre conceptuel de Douglass North, John Wallis, Barry Weingast (NWW) élaboré en 2009 qui le définit comme processus de transition institutionnelle d’un ordre social d’accès limité (pays en développement) où la violence est permanente et disséminée, vers un ordre social d’accès ouvert (pays développés) où les accès économiques et politiques sont ouverts à tous grâce à la libre compétition, élimine-t-il véritablement les rentes ? Par une critique théorique interne et une critique empirique illustrée par l’histoire du Nigeria et en particulier l’activité des multinationales pétrolières, nous soutenons que le cadre conceptuel de NWW est défaillant i) dans sa conception du rôle des élites et des non-élites dans le processus d’ouverture des accès au sein de l’ordre social d’accès limité ii) et dans sa construction épistémologique du modèle d’ordre social d’accès ouvert basé sur la libre compétition politique et économique. L’ordre d’accès ouvert de NWW entretient des rentes, et légitime la prédation, que nous définissons comme l’exploitation de rentes de domination. Les prédateurs font ainsi peser sur leurs victimes des coûts sociaux que les démarches de développement durable (DD) et de responsabilité sociétale des entreprises (RSE) peinent à éliminer. Le DD et la RSE ne parviendront à éliminer la prédation qu’en développant des institutions et des référentiels qui contraignent les acteurs à la prise en compte de l’asymétrie de pouvoir et du risque de domination dans les négociations entre parties prenantes, en vue du respect de la dignité humaine dans les transactions. / The conceptual framework developed in 2009 by Douglass North, John Wallis, Barry Weingast (NWW) regards development as an institutional transition from a limited access social order (developing countries), where violence is a spread and permanent threat, to an open access social order (developed countries), where economic and political accesses are open to all through free competition. If we consider development as a process of rents elimination, does this framework enable rents elimination? Combining a theoretical analysis, and an empirical analysis illustrated by the history of Nigeria and oil multinationals’ activities, we argue that NWW’s framework fails i) in the design of the role of elites and non-elites in the transition process within the limited access order ii) and in the epistemological shaping of the open access order based on political and economic free competition. The NWW’s open access order maintains rents, and legitimizes predation which we define as the exploitation of domination rents. Predators generate on their victims various social costs which sustainable development (SD) and corporate social responsibility (CSR) initiatives are failing to eradicate. SD and CSR approaches will succeed in eradicating predation only if they consider within transactions the power asymmetry and the risk of domination in negotiations between stakeholders, in order to protect the human dignity.

Die vorliegende Arbeit stellt eine biographische und werkanalytische Untersuchung über Ellen Key dar. Mittels biographisch-historischer, phänomenologischer und hermeneutischer Methoden wurden mehrere voneinander abgrenzbare Facetten des Lebenslaufes und des Werkes der schwedischen Reformpädagogin in ihren Beziehungen untereinander wie auch zu den epochalen und gesellschaftlichen Rahmenbedingungen herausgearbeitet. Im Sinne des Strukturmodells Wilhelm Diltheys sind alle diese Facetten als Strukturelemente aufzufassen, welche in ihrer Anordnung und gegenseitigen Bedingtheit die Individualität Ellen Keys abbilden. Strukturelemente, die im Rahmen dieser Untersuchung detailliert dargelegt wurden, sind: Ellen Keys Verhältnis zur Philosophie, zur Dichtung, zur Frauenfrage, zum libertären Sozialismus, zum Pazifismus, zur Religion, zur Anthropologie und Psychologie sowie zur Pädagogik. Es konnte gezeigt werden, dass Keys Denken weit über pädagogische Einflüsse hinaus sehr stark von europäischen Kulturtraditionen, insbesondere auch von deutschsprachiger Philosophie und Dichtkunst, geprägt war. Ihr pädagogisches Konzept kann daher nur unter Berücksichtigung ihrer kulturanalytischen und kulturkritischen Neigungen und Interessen angemessen verstanden und eingeordnet werden. Ellen Key stand im Schnittpunkt bedeutender Kulturtraditionen Europas wie etwa des Darwinismus, der nietzscheschen Philosophie, des libertären Sozialismus eines Oscar Wilde, der Pädagogik Rousseaus und des Menschen- wie auch Weltbildes Goethes. Daneben unterhielt sie intensive persönliche Kontakte zu bedeutenden Künstlern, Wissenschaftlern und Schriftstellern ihrer Zeit, wie etwa Rainer Maria Rilke, Romain Rolland, Georg Brandes, Stefan Zweig, Lou Andreas-Salomé, Poul Bjerre und Bertha von Suttner. All diese Einflüsse haben es Ellen Key ermöglicht, ein Werk zu schaffen, welches die Pädagogik in ihren vielschichtigen und komplexen Zusammenhängen mit anderen Kulturbereichen definiert - eine Art von Erziehungslehre, die durch ein hohes Maß von Integration vielfältiger wissenschaftlicher und philosophischer Erkenntnisse und Überlegungen besticht und damit auch zukünftig große Aktualität aufweist. / The following essay is intended as a biographical and analytical examination of Ellen Key and her work. Using biographical/historical, phenomenological and hermeneutical methods several disconnected facets of the life and work of the Swedish reformist educationalist were elaborated in their relationship to each other as well as to their contemporary and social setting. In close adherence to Wilhelm Dithey's structural model all of these facets can to perceived as structural elements which in their sequence and mutual conditionality reflect the individuality of Ellen Key. Structural elements presented in detail in the course of this examination are: Ellen Key's relationship to philosophy, poetry, women's rights, libertarian socialism, pacifism, religion, anthropology, psychology and education. It was possible to demonstrate that Key's thinking encompassed far more than just pedagogical influences and was very strongly determined by European cultural traditions and especially by German philosophy and poetry. Her pedagogical concept can therefore only be adequately understood and quantified when one considers her inclinations and interests when analysing and criticising contemporary culture. Ellen Key found herself at the crossing point of significant European cultural traditions like Darwinism, Nietschean philosophy, libertarian socialism as promulgated by Oscar Wilde, Rousseau's theory of education and Goethe's views on mankind and the world picture. She also had close personal contacts to eminent artists, scientists and writers of her time like Rainer Maria Rilke, Romain Rolland, Georg Brandes, Stefan Zweig, Lou Andreas-Salomé, Poul Bjerre and Bertha von Suttner. All these influences allowed Ellen Key to create a work which defines pedagogy in its multifarious and complex connections with other cultural areas - a sort of educational doctrine, which achieves significance through its high level of integration of diverse scientific and philosophical insights and reflections and in doing so demonstrates its continued relevance for the future.

Esta dissertação tem como objetivo descrever e conceituar o habitual sistema de remoção dos resíduos de construção e demolição, ou RCD, através do preenchimento de recipientes metálicos avulsos posicionados nos espaços públicos urbanos fronteiros às obras - mais conhecido como sistema de caçambas estacionárias - particularmente quando praticado em comunidades de médio porte do interior, e das conseqüências ou influencias de sua adoção sobre a malha viária urbana local, mediante uma análise de sua efetivação em seis cidades médias situadas no centro-oeste do Estado de São Paulo, assim como aportar subsídios sobre esse assunto, preconizando o desenvolvimento de metodologia apropriada. / The objective of this work is to describe and to concept the commonly system used to remove away the C&DD (construction and demolition debris), by filling single mettalic open up boxes located in the nearest urban public spaces of the building site - that it\'s so-called stationary skips or dump-cart system - specially when used in medium size communities in the Brazil\'s hinterland, and the consequences or influencies of its adoption concerning the local urban street\'s net, based upon an analysis of its reality in six medium towns in the middle-west of São Paulo State, as well to increase knowledge about this matter, and precognize the development of one proper methodology.

Esta dissertação tem como objetivo descrever e conceituar o habitual sistema de remoção dos resíduos de construção e demolição, ou RCD, através do preenchimento de recipientes metálicos avulsos posicionados nos espaços públicos urbanos fronteiros às obras - mais conhecido como sistema de caçambas estacionárias - particularmente quando praticado em comunidades de médio porte do interior, e das conseqüências ou influencias de sua adoção sobre a malha viária urbana local, mediante uma análise de sua efetivação em seis cidades médias situadas no centro-oeste do Estado de São Paulo, assim como aportar subsídios sobre esse assunto, preconizando o desenvolvimento de metodologia apropriada. / The objective of this work is to describe and to concept the commonly system used to remove away the C&DD (construction and demolition debris), by filling single mettalic open up boxes located in the nearest urban public spaces of the building site - that it\'s so-called stationary skips or dump-cart system - specially when used in medium size communities in the Brazil\'s hinterland, and the consequences or influencies of its adoption concerning the local urban street\'s net, based upon an analysis of its reality in six medium towns in the middle-west of São Paulo State, as well to increase knowledge about this matter, and precognize the development of one proper methodology.

Magister Philosophiae - MPhil / One of the population structures associated with demographic dividend is “demographic transition”, which is a shift from high fertility and mortality to low fertility and mortality. It is understood that low dependency ratio (shows that there are relatively more adults of working age who can support the young and the old of the populace) is one major factor in achieving a successful demographic dividend (DD) (Esther, 2013). DD refers to the fast-economic growth that is achieved by a country when there are dependency ratios. This definition means that the proportion of people of working age group (15-64) is higher, compared to those of ages lower than 15 and above 64 years (Statistics SA, 2017). In addition, having a large proportion of working age people does not necessarily guarantee a successful demographic dividend. There are certain conditions to support a successful DD. According to Dewald Van Rensburg, 2017, South Africa is almost done with the achievement of demographic transition. These does not guarantee a successful demographic dividend. This study will therefore look at socio-economic conditions in support of a demographic dividend, because most of the working age people are still not employed, therefore are not productive enough to contribute to the economic growth. Socio economic conditions include (favorable labor market, economic growth, good governance, education and training, health care, family planning and gender equity) (StatsSA, 2017). These conditions if well-established will lead to a reduction of unemployment and therefore result in more labor resources becoming available to devote to production. Since many people entering working age find it difficult to get employment. Statistics South Africa shows that 38.2% of youth were unemployed in the first quarter of 2018 (Statistic South Africa, 2018), this study will have a close look at South African youth unemployment in relation to the demographic characteristics such as gender, population group, marital status, geography type and province of residence.