As the information age comes to fruition, terrorist networks have moved mainstream by promoting their causes via the World Wide Web. In addition to their standard rhetoric, these organizations provide anyone with an Internet connection the ability to access dangerous information involving the creation and implementation of Improvised Explosive Devices (IEDs). Unfortunately for governments combating terrorism, IED education networks can be very difficult to find and even harder to monitor. Regular commercial search engines are not up to this task, as they have been optimized to catalog information quickly and efficiently for user ease of access while promoting retail commerce at the same time. This thesis presents a performance analysis of a new search engine algorithm designed to help find IED education networks using the Nutch open-source search engine architecture. It reveals which web pages are more important via references from other web pages regardless of domain. In addition, this thesis discusses potential evaluation and monitoring techniques to be used in conjunction with the proposed algorithm.

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This dissertation investigates deformable computer input device technologies to facilitate capturing complex physical-world gestures. By capturing the physical gestures and using appropriate haptics, it is possible to create virtual models using pinching and squeezing gestures similar to those used when sculpting clay. To date, most desktop modelling applications employ pointing devices that capture a single cursor location to manipulate a model with tedious sequential steps. One reason for this is developers have focused efforts on adopting applications to work with generic two-dimensional pointing devices, such as a mouse or digitising tablet. This is due to the difficulty of developing three-dimensional input technologies. In particular, deformable sensors capable of capturing natural sculpting techniques are undeveloped. / PhD Doctorate

Nanoclusters have special importance in nanotechnology because of their low dimensionality, which provides electronic, chemical, and magnetic properties that differ from those of the equivalent bulk materials. Suitably controllable self-assembly methods are required in order to incorporate nanoclusters into useful devices. The self-assembly method used in this study employs V-grooves as a template element for nanocluster device fabrication. The V-grooves are fabricated by optical lithography on SiO2/Si wafers and KOH wet etching. Bi clusters deposited on a V-groove form a self-assembled conducting wire. The clusters are produced using an inert gas aggregation source inside an ultra high vacuum compatible system. In order to characterise the assembly process, Bi clusters with different average sizes and velocities are deposited on V-grooves with different widths. The cluster bouncing was found to be the main process in forming the cluster wires. The bouncing angles were smaller than the incident angle, and they are dependent on the cluster size and velocity. For a certain bouncing angle, the wire width reflects the V-groove width because of the fixed bouncing angle. Nanocluster devices were fabricated by depositing the clusters on V-grooves with pre-formed Au/NiCr electrical contacts. The amount of the deposited material required to form an electrically conducting wire was found to be a function of the V-groove width and the wire length. The two point I(V) measurements in the voltage range between -1 and +1V showed linear characteristics for low resistance wires (kΩ), and non-linear characteristics for the high resistance ones (MΩ). The silicon substrate was used as a back gate. Applying a voltage to the gate was found to modify the electrical conduction of the cluster wire. The temperature dependence of the resistance of the nanocluster wires was studied in the temperature range of 4.2-473K, and all of the measured wires showed a negative temperature coefficient of resistance. These measurements allowed a detailed study of the conduction mechanisms through the cluster wires. The study showed that Bi clusters can be used for device fabrication. To size select the clusters prior to using them for the device fabrication, a high transmission mass filter is required. This transmission can be obtained using the von Issendorff and Palmer mass filter if it is operated using the optimum operation conditions. The mass filter consists of two pairs of parallel plates with horizontal openings in Plates 1 and 2, and it operates on the time of flight principle. During this project, the operation conditions of this mass filter were studied using both experiment and simulation. The study showed that the beam deflection angle is a critical factor in optimising the mass filter transmission efficiency. This angle is dependent on the accelerating voltage, ion mass, and the horizontal velocity of the ions. The optimum operation conditions for the mass filter were found and used to study the mass distribution of Pd ions produced by a magnetron sputtering source with variable cluster aggregation length.

Univ., Diss.--Duisburg-Essen, 2005.

Thesis (MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Please refer to full text for abstract.

The aim of the work presented in this thesis is to study the opto-electronic properties of semi-conducting perovskite materials when being used in unconventional solar cell device configurations. Being a young technology, perovskites as solar cell materials have seen an unparalleled rise in the research community which has driven the fastest performance inflation to power conversion efficiencies competing with the ones of long established single crystalline technologies. The ability to process perovskites inexpensively makes them the new hope in the fight against climate change. Herein device architectures were developed with a special focus on potential commercial applications. Initially the work in this thesis has been motivated by the interest in crystal growth and morphology of perovskite thin-films, which has led to the study of confined crystal growth within microstructures. Controlling the crystal domain geometry enabled the fabrication of enhanced semi-transparent devices. More efforts were directed into the improvement of specifically neutral colour semi-transparent devices, which could be improved via a simple treatment of selectively attaching shunt-blocking layers. Furthermore, a back-contacted perovskite device design was introduced, which allows not only for the fabrication of a new type of perovskite solar cell, but also represent a great material testing platform to study perovskite and electrode characteristics. This led to the discovery of charge transport distances, that exceed those of other thin-film devices. Finally, perovskite-on-silicon tandem solar cell designs were analysed through a rigorous optical model to estimate the expected real world energy yield from such systems. Important implications include the fact that two terminal tandem solar cells come close to four-terminal configurations and can overall compete, in relative terms, well with established single junction silicon cells.

Os sistemas de controle solar auxiliam no controle da radiação solar incidente no envoltório, e, de acordo com a NBR 15220-3, é recomendável seu uso para a zona bioclimática 3, na cidade de Porto Alegre. Assim, com a ação de retrofitting, é possível utilizar os sistemas de controle solar como modo de adaptar o envoltório das edificações ao clima local e aos padrões de consumo atuais. Dessa forma, o retrofitting do envoltório pode contribuir com a redução do consumo energético e a dependência de sistemas de refrigeração e aquecimento mecânico. Logo, o objetivo da dissertação é qualificar e quantificar energeticamente os sistemas de controle solar com vistas à redução do consumo energético nos ambientes construídos. Um estudo de caso foi realizado na cidade de Porto Alegre, onde um edifício foi selecionado perante um conjunto de edificações existentes. Com o auxílio de um método expedito de cálculo energético, foi realizada a avaliação energética do envoltório da edificação atual e do seu retrofitting proposto. A edificação passou de nível energético E para nível A, comprovando o êxito do estudo de retrofitting aplicado. A pesquisa concluiu que, alinhado com o encontrado na revisão da literatura, as edificações com grandes aberturas orientadas para oeste são um equívoco de projeto no clima de Porto Alegre e que as ações de retrofitting são uma alternativa de adaptação ao clima local, tornando os edifícios eficientes energeticamente. / Shading systems help to control the incident solar radiation on the envelope, and, according to NBR 15220-3, its use is recommended for the bioclimatic zone 3, in the city of Porto Alegre. Hence, with retrofitting, it is possible to use shading systems as a way of adapting the building envelope to the local climate and current consumption patterns. Thus, the retrofitting of the envelope can contribute to the reduction of the energy consumption and of the dependence on systems of refrigeration and mechanical heating. Therefore, the objective of this dissertation is to qualify and quantify the energy of shading systems in order to reduce energy consumption in built environments. Thus, a case study was conducted in the city of Porto Alegre, where a building was selected from a set of existing buildings. We performed an energetic evaluation of current envelope of buildings and its proposed retrofitting by using a facilitated method for energy calculation. The buildings moved from energy level E to level A, proving the success of the study on the applied retrofitting. We conclude that, as also shown in literature review; buildings with large openings oriented to the west in Porto Alegre are a design misconception due to the city’s climate. Thus, retrofitting actions are alternative ways to adapt to the local climate so that buildings are energy efficient.

Os sistemas de controle solar auxiliam no controle da radiação solar incidente no envoltório, e, de acordo com a NBR 15220-3, é recomendável seu uso para a zona bioclimática 3, na cidade de Porto Alegre. Assim, com a ação de retrofitting, é possível utilizar os sistemas de controle solar como modo de adaptar o envoltório das edificações ao clima local e aos padrões de consumo atuais. Dessa forma, o retrofitting do envoltório pode contribuir com a redução do consumo energético e a dependência de sistemas de refrigeração e aquecimento mecânico. Logo, o objetivo da dissertação é qualificar e quantificar energeticamente os sistemas de controle solar com vistas à redução do consumo energético nos ambientes construídos. Um estudo de caso foi realizado na cidade de Porto Alegre, onde um edifício foi selecionado perante um conjunto de edificações existentes. Com o auxílio de um método expedito de cálculo energético, foi realizada a avaliação energética do envoltório da edificação atual e do seu retrofitting proposto. A edificação passou de nível energético E para nível A, comprovando o êxito do estudo de retrofitting aplicado. A pesquisa concluiu que, alinhado com o encontrado na revisão da literatura, as edificações com grandes aberturas orientadas para oeste são um equívoco de projeto no clima de Porto Alegre e que as ações de retrofitting são uma alternativa de adaptação ao clima local, tornando os edifícios eficientes energeticamente. / Shading systems help to control the incident solar radiation on the envelope, and, according to NBR 15220-3, its use is recommended for the bioclimatic zone 3, in the city of Porto Alegre. Hence, with retrofitting, it is possible to use shading systems as a way of adapting the building envelope to the local climate and current consumption patterns. Thus, the retrofitting of the envelope can contribute to the reduction of the energy consumption and of the dependence on systems of refrigeration and mechanical heating. Therefore, the objective of this dissertation is to qualify and quantify the energy of shading systems in order to reduce energy consumption in built environments. Thus, a case study was conducted in the city of Porto Alegre, where a building was selected from a set of existing buildings. We performed an energetic evaluation of current envelope of buildings and its proposed retrofitting by using a facilitated method for energy calculation. The buildings moved from energy level E to level A, proving the success of the study on the applied retrofitting. We conclude that, as also shown in literature review; buildings with large openings oriented to the west in Porto Alegre are a design misconception due to the city’s climate. Thus, retrofitting actions are alternative ways to adapt to the local climate so that buildings are energy efficient.

Data to understand the inventiveness and technology transfer process for medical devices in India is lacking and majority of medical devices are imported. The presence of a medical school in a university system is expected to enhance healthcare inventiveness. Universities with medical schools have 2.5 times more R&D expenditure and productivity than universities without medical schools. Therefore, the presence or absence of medical schools in universities serves as interesting samples for technology transfer analysis. This thesis focuses on medical device inventiveness and technology transfer office efficiencies of American universities. Three sample sets are used. The first is data from 1242 US universities, of which 734 had medical schools, and their Technology Transfer Office (TTO) productivity from years 1999-2008. The second consisted of 5693 medical device patents filed at USPTO by universities worldwide during years 1999-2008, including US universities. The third consisted of 32 cochlear implant university based patents from 7 primary patent classes in USPTO. Universities involved in medical device research (MDU) and universities not involved in medical device research (NMDU) are compared in our study to understand differences in their technology transfer activities. Initially, Social network analysis is used to understand the interrelatedness of technologies in university based research using patent classes. Degree, betweenness and closeness centrality of 32 cochlear implant patents (out of 345 overall filed patents in USPTO including corporate filings), showed the importance of universities’ R&D contribution to the overall evolution of cochlear implant technology. Dynamics in terms of emergence and disappearance of technologies (represented by US patent classes in years 1977 to 2012), are identified. Our study highlights that universities' research focus within medical device research is confined to few technology classes like surgery, drugs and body treating compositions for therapeutic purposes and image analysis. In these technology areas, universities share of patent holding is found to be more compared to other medical device technologies. Multivariate OLS and binary logistic regressions are used to understand university characteristics that influences amount of patenting by universities. Our study attempts to delineate and highlight university characteristics that may influence amount of patenting in general, i.e., across all technologies and specifically those university characteristics that may influence more patenting in medical device technologies. Our study establishes that university characteristic variables like age, public/private ownership and research productivity influences amount of patenting by universities in general, across all technologies. However, additional university characteristics like presence of medical school and expenditure on legal fees are found influencing amount of patenting in medical device technologies by universities. Data Envelopment Analysis (DEA) is used in our attempt to understand the efficiency of universities in transferring their technologies to industries. Interesting insights are obtained on observing slack obtained during DEA. Our study highlights that some universities may have to reduce their research expenditure in large scales and number of employees working in their technology transfer offices in large scales compared to other universities in order to improve their efficiency in technology transfer process. Our study establishes that in order to improve technology transfer efficiencies, MDUs with higher research expenditure may have to reduce their research expenditure in large volumes compared to universities with lesser research expenditures. However, these MDUs may not be required to greatly reduce their technology transfer employees as compared to universities with lesser research expenditures, in order to improve their technology transfer efficiencies. Moreover, MDUs generating more number of invention disclosures and receiving more faculty awards annually can increase their patenting, licensing and startups in smaller volumes, in order to improve their technology transfer efficiencies, as compared to universities generating lesser invention disclosures and receiving lesser faculty awards, which can increase their patenting and licensing in larger volumes.