Operationen im Schädel‐ und Gesichtsbereich stellen nach wie vor eine große Herausforderung für die behandelnden Ärzte dar, weil sich oftmals die Abgrenzung des Knochendefekts und die Wiederherstellung der ursprünglichen Knochenstruktur als schwierig erweisen. Die erste Herausforderung dabei ist die Definition der Implantatgeometrie, da jeder Patient eine individuelle Anatomie und, im Falle eines Knochendefekts durch Traumata oder Tumore, jeder Defekt eine spezifische Form aufweist. Das Implantat sollte somit eine der originalen Knochenstruktur entsprechenden Geometrie besitzen und aus einem für die Implantation geeigneten Material bestehen. Weiterhin muss das für die Herstellung des Implantats gewählte Verfahren derart anpassungsfähig sein, dass auch die Erzeugung eines einzelnen individuellen Produktes möglich ist und keine übermäßigen Kosten im Werkzeug‐ und Formenbau verursacht werden. Im gegenwärtigen Szenario flexibler Herstellungsprozesse, die eine effiziente Blechumformung auch in kleineren Stückzahlen erlauben, liegt ein besonderer Schwerpunkt auf dem Verfahren der inkrementellen Umformung. In dieser Arbeit wird daher die Durchführbarkeit der präoperativen Herstellung individueller Implantate zur Wiederherstellung knöcherner Strukturen verschiedener Regionen im Schädel‐ und Gesichtsbereich mit dem Verfahren der inkrementellen Blechumformung untersucht. Dabei wurden unterschiedliche Methoden zur Modellierung von Implantaten aus patientenspezifischen CT‐Daten angewendet und Prozessparameter für die Herstellung verschiedener Formen von Titanimplantaten entwickelt. Ferner werden alternative Techniken vorgestellt, mit denen es ebenfalls möglich ist, solche Implantate herzustellen. Gleichwohl es Einschränkungen hinsichtlich der Formgenauigkeit und Komplexität der zu formenden Geometrie des Implantates gibt, zeigt diese Arbeit, dass das Verfahren der inkrementellen Blechumformung eine geeignete Alternative für die präoperative Herstellung von individuellen Implantaten für den Schädel‐ und Gesichtsbereich darstellt. / Atualmente, cirurgias de reconstrução craniofacial ainda são um desafio à equipe cirúrgica devido às dificuldades em definir e reparar o defeito ósseo. A definição da geometria do implante é o primeiro desafio, uma vez que cada paciente possui uma anatomia individual e, em caso de defeitos ósseos devido a traumas ou tumores, cada defeito possui uma forma específica. O implante deve, então, possuir geometria tal que o possibilite substituir a estrutura original e ser constituído de material apto para a implantação. Além disso, o processo de fabricação selecionado deve ser flexível a fim de possibilitar a produção de uma peça única, dispensando custos excessivos com ferramental. No cenário atual de processos de manufatura flexível, um destaque especial recebe o processo de estampagem incremental, que permite a conformação de chapas metálicas para a fabricação de pequenos lotes. Neste sentido, este estudo ocorre no âmbito da fabricação pré‐operatória de implantes personalizados para reparo de defeitos em diferentes regiões do complexo craniofacial através do processo de estampagem incremental. Foram utilizados diferentes procedimentos para modelagem dos implantes a partir de dados tomográficos e foram desenvolvidos parâmetros para a conformação de diferentes geometrias em titânio. São apresentadas, ainda, técnicas alternativas capazes de produzir tais implantes. O estudo mostra que, embora possua precisão dimensional limitada e restrições com relação à complexidade geométrica dos implantes que podem ser conformados, o processo de estampagem incremental apresenta‐se como uma alternativa viável à fabricação pré‐operatória de implantes personalizados para a reconstrução de defeitos craniofaciais. / Currently, craniofacial reconstruction surgeries are still a challenge for surgical teams due to the difficulty to define and repair bone defects. Defining the geometry of the implant is the first challenge, since each patient has an individual anatomy and, in case of bone defects due to trauma or tumors, each defect has a specific shape. The implant should then have a geometry that permits the replacement of the original structure and should consist of a material suitable for implantation. Moreover, the selected manufacturing process must be flexible enough to enable the production of a single piece, not requiring excessive cost with dyes and tooling. In the current scenario of flexible manufacturing processes, the process of incremental forming, which permits forming metal sheets to manufacture small batches, receives special emphasis. Thus, this study evaluates the feasibility of preoperative manufacturing of customized implants to repair defects in different regions of the craniofacial complex through the process of incremental forming. Different procedures were used for modeling implants obtained from CT data of patients and the parameters for forming different geometries of titanium implants were developed. Alternative techniques capable of producing such implants are also presented. The study shows that, although it has limited dimensional accuracy and restrictions regarding the geometric complexity of the implants that can be shaped, the single point incremental forming (SPIF) process represents a suitable alternative for the preoperative manufacturing of customized implants for the reconstruction of craniofacial defects.

Operationen im Schädel‐ und Gesichtsbereich stellen nach wie vor eine große Herausforderung für die behandelnden Ärzte dar, weil sich oftmals die Abgrenzung des Knochendefekts und die Wiederherstellung der ursprünglichen Knochenstruktur als schwierig erweisen. Die erste Herausforderung dabei ist die Definition der Implantatgeometrie, da jeder Patient eine individuelle Anatomie und, im Falle eines Knochendefekts durch Traumata oder Tumore, jeder Defekt eine spezifische Form aufweist. Das Implantat sollte somit eine der originalen Knochenstruktur entsprechenden Geometrie besitzen und aus einem für die Implantation geeigneten Material bestehen. Weiterhin muss das für die Herstellung des Implantats gewählte Verfahren derart anpassungsfähig sein, dass auch die Erzeugung eines einzelnen individuellen Produktes möglich ist und keine übermäßigen Kosten im Werkzeug‐ und Formenbau verursacht werden. Im gegenwärtigen Szenario flexibler Herstellungsprozesse, die eine effiziente Blechumformung auch in kleineren Stückzahlen erlauben, liegt ein besonderer Schwerpunkt auf dem Verfahren der inkrementellen Umformung. In dieser Arbeit wird daher die Durchführbarkeit der präoperativen Herstellung individueller Implantate zur Wiederherstellung knöcherner Strukturen verschiedener Regionen im Schädel‐ und Gesichtsbereich mit dem Verfahren der inkrementellen Blechumformung untersucht. Dabei wurden unterschiedliche Methoden zur Modellierung von Implantaten aus patientenspezifischen CT‐Daten angewendet und Prozessparameter für die Herstellung verschiedener Formen von Titanimplantaten entwickelt. Ferner werden alternative Techniken vorgestellt, mit denen es ebenfalls möglich ist, solche Implantate herzustellen. Gleichwohl es Einschränkungen hinsichtlich der Formgenauigkeit und Komplexität der zu formenden Geometrie des Implantates gibt, zeigt diese Arbeit, dass das Verfahren der inkrementellen Blechumformung eine geeignete Alternative für die präoperative Herstellung von individuellen Implantaten für den Schädel‐ und Gesichtsbereich darstellt. / Atualmente, cirurgias de reconstrução craniofacial ainda são um desafio à equipe cirúrgica devido às dificuldades em definir e reparar o defeito ósseo. A definição da geometria do implante é o primeiro desafio, uma vez que cada paciente possui uma anatomia individual e, em caso de defeitos ósseos devido a traumas ou tumores, cada defeito possui uma forma específica. O implante deve, então, possuir geometria tal que o possibilite substituir a estrutura original e ser constituído de material apto para a implantação. Além disso, o processo de fabricação selecionado deve ser flexível a fim de possibilitar a produção de uma peça única, dispensando custos excessivos com ferramental. No cenário atual de processos de manufatura flexível, um destaque especial recebe o processo de estampagem incremental, que permite a conformação de chapas metálicas para a fabricação de pequenos lotes. Neste sentido, este estudo ocorre no âmbito da fabricação pré‐operatória de implantes personalizados para reparo de defeitos em diferentes regiões do complexo craniofacial através do processo de estampagem incremental. Foram utilizados diferentes procedimentos para modelagem dos implantes a partir de dados tomográficos e foram desenvolvidos parâmetros para a conformação de diferentes geometrias em titânio. São apresentadas, ainda, técnicas alternativas capazes de produzir tais implantes. O estudo mostra que, embora possua precisão dimensional limitada e restrições com relação à complexidade geométrica dos implantes que podem ser conformados, o processo de estampagem incremental apresenta‐se como uma alternativa viável à fabricação pré‐operatória de implantes personalizados para a reconstrução de defeitos craniofaciais. / Currently, craniofacial reconstruction surgeries are still a challenge for surgical teams due to the difficulty to define and repair bone defects. Defining the geometry of the implant is the first challenge, since each patient has an individual anatomy and, in case of bone defects due to trauma or tumors, each defect has a specific shape. The implant should then have a geometry that permits the replacement of the original structure and should consist of a material suitable for implantation. Moreover, the selected manufacturing process must be flexible enough to enable the production of a single piece, not requiring excessive cost with dyes and tooling. In the current scenario of flexible manufacturing processes, the process of incremental forming, which permits forming metal sheets to manufacture small batches, receives special emphasis. Thus, this study evaluates the feasibility of preoperative manufacturing of customized implants to repair defects in different regions of the craniofacial complex through the process of incremental forming. Different procedures were used for modeling implants obtained from CT data of patients and the parameters for forming different geometries of titanium implants were developed. Alternative techniques capable of producing such implants are also presented. The study shows that, although it has limited dimensional accuracy and restrictions regarding the geometric complexity of the implants that can be shaped, the single point incremental forming (SPIF) process represents a suitable alternative for the preoperative manufacturing of customized implants for the reconstruction of craniofacial defects.

The goal of this thesis is to explore the CSSBox experimental rendering engine, to explore the possibility of its expansion on incremental rendering of documents and then to propose the necessary modifications. The opening chapters contain an overview of existing possibilities and subsequently, the solution is proposed. The proposed changes are implemented and tested. Experiments were performed and results evaluated. The conclusion is dedicated to the evaluation of results and options for further development are outlined.

The appropriation of open space is a common and organic process that is constantly taking place in the contemporary South African city. The tabula rasa approach of Apartheid and modernist planning had little consideration for these natural spatial patterns. This dissertation argues for a democratic approach to architecture and space-making in the contemporary South African city, one that embraces diversity, multifunctionality, and the eventuality of incremental development. Drawing from theories such as Control of Complexity (Habraken 1987), Space as Ritual (van Rensburg & da Costa 2008), and Safe-to-Fail (Ahern 2011), the research explores the possibilities of designing for emergent and adaptable space as a tool for enablement in the context of Mamelodi. The inherited Apartheid spatial legacy of Mamelodi has led to the prevalence of monofunctional, medium density development that has limited economic opportunity and encouraged pendulum migration in search of employment. This presents the opportunity to introduce new scales of urbanity to the context, whilst still being sensitive and encouraging existing spatial functions and patterns. / Mini Dissertation MArch(Prof)--University of Pretoria, 2018. / Architecture / MArch(Prof) / Unrestricted

Machine learning algorithms have shown their abilities to tackle difficult recognition problems, but they are still rife with challenges. Among these challenges is how to deal with problems where new categories constantly occur, and the datasets can dynamically grow. Most contemporary learning algorithms developed to this point are governed by the assumptions that all testing data classes must be the same as training data classes, often with equal distribution. Under these assumptions, machine-learning algorithms can perform very well, using their ability to handle large feature spaces and classify outliers. The systems under these assumptions are called Closed Set Recognition systems (CSR). However, these assumptions cannot reflect practical applications in which out-of-set data may be encountered. This adversely affects the recognition prediction performances. When samples from a new class occur, they will be classified as one of the known classes. Even if this sample is far from any of the training samples, the algorithm may classify it with a high probability, that is, the algorithm will not only be wrong, but it may also be very confident in its results. A more practical problem is Open Set Recognition (OSR), where samples of classes not seen during training may show up at testing time. Inherently, there is a problem how the system can identify the novel sound classes and how the system can update its models with new classes. This thesis highlights the problems of multi-class recognition for OSR of sounds as well as incremental model adaptation and proposes solutions towards addressing these problems. The proposed solutions are validated through extensive experiments and are shown to provide improved performance over a wide range of openness values for sound classification scenarios.

The spatial legacy in South Africa has resulted in fragmented urban environments and development in peri-urban areas, such as Mamelodi, is often implemented with a top-down approach. The focus of development tends to be on connecting these hinterlands to the cities with affordable transportation and trying to satisfy needs for basic services and amenities as quickly as possible. This has resulted in the implementation of solutions that are not place specific but instead tend to be generic models implemented on a large scale. The danger therein lies that projects implemented might not be appropriate to communities and could become dysfunctional and underutilised. Part of the process of developing a solution should be the acknowledgement of the everyday in a specific community; the way in which space is produced, appropriated and the everyday rituals. The intention of this dissertation is to re-conceptualise what an art centre could be in the context of Mamelodi West, the historic centre of Mamelodi. Through an understanding of the everyday, what is generally considered a mono-functional program is re-imagined as a diverse intervention integrated into everyday life and ritual. The dissertation proposes one possible means of connecting isolated communities using the commonality of the need for both individual and collective expression of identity to cultivate gemeinschaft; address misconceptions of the value of the Arts and propose a way in which the spatial legacy can be redressed. / Dissertation (MArch (Prof))--University of Pretoria, 2020. / Architecture / MArch (Prof) / Unrestricted

The fundamental requirement for a coal preparation plant is to transform low value run-of-mine (ROM) material into high value marketable products. The significant aspect relative to the plant is that any gain in efficiency flows almost entirely to the "bottom line" for the operation. The incremental quality concept has gained wide acceptance as the best method to optimize the overall efficiency of the various cleaning circuits. Simply stated, the concept requires that all the cleaning circuits operate as near as possible to the same incremental quality. To ensure optimal efficiency, a plant that receives ROM feed from multiple sources must develop a strategy to operate at the same incremental quality, which yields wide ranges in product qualities from the individual ROM coals. In order to provide products that meet contract specifications, clean coal stockpiles can be utilized to accept coals with various qualities, such as "premium," "low," and "filler" qualities, with shipments formulated from the stockpiles to meet product specifications. A more favorable alternative is raw coal blending to produce the specified clean coal qualities. This study will review the incremental quality concept and present case studies in applying the concept to meet product specifications. / Master of Science

This thesis presents the results of a study of the effect of variations of systemic parameters on the structural response of single degree of freedom systems subjected to Incremental Dynamic Analysis. The systemic parameters are mass, stiffness, damping, yield strength and geometric stiffness. Each of these parameters was varied one at a time while the other values were kept constant. For each variation of parameters a set of single-record IDA curves was obtained. Five to six ground motions were used for this study to generate the single-record IDA curves. These ground motions were scaled prior to their application on the structure. The scaling factor was based on the spectral acceleration at the fundamental frequency of the structure at 5% of critical damping. The scale factor is affected if the system parameters are changed. An important issue for this study was whether to persist with scaling corresponding to the median value from the range of the values of the parameter or to update the scaling according to the system. Based on some tests using both methods, the median scaling approach was found to be more suitable. The IDA curves for variation of parameters were then investigated to identify any trends that may help in qualitatively predicting the response of a system relative to another system. The response was measured by the peak displacement and the maximum base shear of the system. A clear trend was identified when the damping or the yield strength was varied. However, no definite trend was observed when the material stiffness or the geometric stiffness of the system was varied. / Master of Science

No description available.

The focus of this research was to create a linear motor that could easily be packaged and still perform the same task of the current DC motor linear device. An incremental linear motor design was decided upon, for its flexibility in which the motor can be designed. To replace the current motor it was necessary to develop a high force, high speed incremental linear motor. To accomplish this task, piezoelectric actuators were utilized to drive the motor due their fast response times and high force capabilities. The desired overall objectives of the research is to create an incremental linear motor with the capability of moving loads up to one hundred pounds and produce a velocity well over one inch per second. To aid the design process a lumped parameter model was created to simulate the motor's performance for any design parameter. Discrepancies occurred between the model and the actual motor performance for loads above 9.1 kilograms (20 pounds). The resulting model, however, was able to produce a good approximation of the motor's performance for the unloaded and lightly loaded cases. The phase one design was limited by time constraints so a relatively low risk design was produced. The resulting incremental linear motor produced a velocity of 4.9 mm/sec (0.2 in/sec) at a drive frequency of 50 Hz. The velocity of the motor was limited by the drive frequency that the amplifiers could produce. The motor was found to produce a respectable stall load of 17 kilograms (38 pounds). The stall load of the phase one design was severely limited by clearance losses. An analysis of the motor's performance was conducted, possible improvements and future work recommendations for a phase two design are presented. / Master of Science