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abstract: Redundant Binary (RBR) number representations have been extensively used in the past for high-throughput Digital Signal Processing (DSP) systems. Data-path components based on this number system have smaller critical path delay but larger area compared to conventional two's complement systems. This work explores the use of RBR number representation for implementing high-throughput DSP systems that are also energy-efficient. Data-path components such as adders and multipliers are evaluated with respect to critical path delay, energy and Energy-Delay Product (EDP). A new design for a RBR adder with very good EDP performance has been proposed. The corresponding RBR parallel adder has a much lower critical path delay and EDP compared to two's complement carry select and carry look-ahead adder implementations. Next, several RBR multiplier architectures are investigated and their performance compared to two's complement systems. These include two new multiplier architectures: a purely RBR multiplier where both the operands are in RBR form, and a hybrid multiplier where the multiplicand is in RBR form and the other operand is represented in conventional two's complement form. Both the RBR and hybrid designs are demonstrated to have better EDP performance compared to conventional two's complement multipliers. The hybrid multiplier is also shown to have a superior EDP performance compared to the RBR multiplier, with much lower implementation area. Analysis on the effect of bit-precision is also performed, and it is shown that the performance gain of RBR systems improves for higher bit precision. Next, in order to demonstrate the efficacy of the RBR representation at the system-level, the performance of RBR and hybrid implementations of some common DSP kernels such as Discrete Cosine Transform, edge detection using Sobel operator, complex multiplication, Lifting-based Discrete Wavelet Transform (9, 7) filter, and FIR filter, is compared with two's complement systems. It is shown that for relatively large computation modules, the RBR to two's complement conversion overhead gets amortized. In case of systems with high complexity, for iso-throughput, both the hybrid and RBR implementations are demonstrated to be superior with lower average energy consumption. For low complexity systems, the conversion overhead is significant, and overpowers the EDP performance gain obtained from the RBR computation operation. / Dissertation/Thesis / M.S. Electrical Engineering 2011

A novel paste deposition process was developed to widen the range of possible materials and applications. This experimental process developed an increasingly complex series of additive manufacturing machines, resulting in new combinations of novel materials and deposition paths without sacrificing many of the design freedoms inherit in the craft process. The investigation made use of open-source software together with an approach to programming user originated infill geometries to form structural parts, differing from the somewhat automated processing by 'closed' commercial RP systems. A series of experimental trials were conducted to test a range of candidate materials and machines which might be suitable for the PDM process. The combination of process and materials were trailed and validated using a series of themed case studies including medical, food industry and jewellery. Some of the object created great interest and even, in the case of the jewellery items, won awards. Further evidence of the commercial validity was evidenced through a collaborative partnership resulting in the development of a commercial version of the experimental system called Newton3D. A number of exciting potential future directions having been opened up by this project including silicone fabrics, bio material deposition and inclusive software development for user originated infills and structures.

The aim of this thesis was to identify the characteristics of path segments and routes that are associated with where older residents choose to walk for recreation or for getting to destinations in retirement communities. The goal was to use the findings from this study to help formulate criteria and strategic choices that can be used to design retirement communities that support walking among elderly residents. Case studies were conducted at three Continuing Care Retirement Communities. The study shows that route choice for walking to destinations is shaped by practical considerations of distance and convenience and largely determined by the relative location of destination and origin. On the other hand, route choice for recreational walking is more complex and is determined by local, relational and structural environmental characteristics of the path segments that comprise the routes as well as characteristics of the residents themselves. Residents chose routes of different difficulty level for walking based on their physical abilities and health. This study also found that many residents chose to walk indoors for recreation, especially along corridors between resident apartments. Understanding how the different factors together shape route choice leads to the clarification of design alternatives. This study suggests that designing campuses to support walking involves not only a careful consideration of individual local path segment characteristics but also an understanding how path segments and routes fit within the larger network of path segments on campus. Further, it is important to design routes with a range of characteristics and a range of challenge so that residents have many options to choose from and they have the option to move from a lower level of challenge to a higher one when they feel ready.