<p>This thesis describes the design of fast JPEG processing accelerators for a DSP processor. </p><p>Certain computation tasks are moved from the DSP processor to hardware accelerators. The accelerators are slave co processing machines and are controlled via a new instruction set. The clock cycle and power consumption is reduced by utilizing the custom built hardware. The hardware can perform the tasks in fewer clock cycles and several tasks can run in parallel. This will reduce the total number of clock cycles needed. </p><p>First a decoder and an encoder were implemented in DSP assembler. The cycle consumption of the parts was measured and from this the hardware/software partitioning was done. Behavioral models of the accelerators were then written in C++ and the assembly code was modified to work with the new hardware. Finally, the accelerators were implemented using Verilog. </p><p>Extension of the accelerator instructions was given following a custom design flow.</p>

<p>H.264/AVC is a new video compression standard designed for future broadband network. Compared with former video coding standards such as MPEG-2 and MPEG-4 part 2, it saves up to 40% in bit rate and provides important characteristics such as error resilience, stream switching etc. However, the improvement in performance also introduces increase in computational complexity, which requires more powerful hardware. At the same time, there are several image and video coding standards currently used such as JPEG and MPEG-4. Although ASIC design meets the performance requirement, it lacks flexibility for heterogeneous standards. Hence reconfigurable DSP processor is more suitable for media processing since it provides both real-time performance and flexibility. </p><p>Currently there are several single scalar DSP processors in the market. Compare to media processor, which is generally SIMD or VLIW, single scalar DSP is cheaper and has smaller area while its performance for video processing is limited. In this paper, a method to promote the performance of single scalar DSP by attaching hardware accelerators is proposed. And the bottleneck for performance promotion is investigated and the upper limit of acceleration of a certain single scalar DSP for H.264/AVC decoding is presented. </p><p>Behavioral model of H.264/AVC decoder is realized in pure software during the first step. Although real-time performance cannot be achieved with pure software implementation, computational complexity of different parts is investigated and the critical path in decoding was exposed by analyzing the first design of this software solution. Then both functional acceleration and addressing acceleration were investigated and designed to achieve the performance for real-time decoding using available clock frequency within 200MHz.</p>

Real time image guided radiotherapy has been proposed by integrating an in-line 6 MV linear accelerator (linac) to a magnetic resonance (MR) imager in either a parallel or transverse configuration. In either configuration, magnetic interference in the linac is caused by its immersion in the magnetic fringe fields of the MR imager. Thus in order to minimize the effect of the magnetic interference, investigations on linac performance in external magnetic fields was completed through various simulations. Finite difference and finite element methods as well as particle simulations were performed in order to design an electron gun and an in-line 6 MV linac waveguide. Monte Carlo simulations provided calculations of dose distributions in a water tank from the derived electron phase space at the linac target. The entire simulation was validated against measurements taken from a commercial medical in-line 6 MV linac, other simulation programs, and theory. The validated linac simulation was used to investigate linac performance in external magnetic fields. The results of this investigation showed that the linac had a much lower tolerance to transverse magnetic fields compared to longitudinal fields. While transverse magnetic fields caused a global deflection of the electron beam away from the central axis of the waveguide, longitudinal fields changed the optics of the electron gun in a suboptimal way. Both transverse and longitudinal magnetic fields caused excessive beam loss if the field strength was large enough. Heating caused by excessive beam loss in external magnetic fields was shown to have little effect on the resonant frequency of the waveguide, and any change in dosimetry, if it existed, was shown to be easily corrected using the jaws or multileaf collimators (MLCs). It was determined that the low-field parallel configuration linac-MR system investigated did not require any magnetic shielding, so the focus was on shielding the transverse configuration. Using beam loss, MLC motor tolerance to magnetic fields, and MR imager homogeneity as constraints, passive and active magnetic shielding was designed and optimized. Thus through the parallel configuration, or using magnetic shielding, magnetic interference has been reduced to within the linac operational tolerance. / Medical Physics

In this thesis, the feasibility to use sodium cooled fast reactors loaded with MOX, metallic and nitride fuels for efficient transmutation of americium is investigated by performing transient analysis for cases with different americium contents in fuels, using safety parameters obtained with the SERPENT Monte Carlo code. It was then demonstrated that there is no solid limit for the Am introduction into oxide, metallic and nitride fuels that were loaded into sodium fast reactors. Instead, higher Am contents could be permitted if specific levels of power penalty were accepted. Transient analysis of a new Accelerator Driven System design with higher neutron source efficiency than the reference EFIT-400 design, was also performed. Based on simulation results, the suggested ADS design was proved to survive the full set of transients, preserving 130 K margin to cladding rupture during the most limiting transient. After comparing Am transmutation performances in SFRs and the suggested ADS, it can be concluded that: 1. Nitride fuel could provide the highest Am transmutation efficiency, when loaded into SFRs; 2. One SFR loaded with nitride fuel is sufficient to transmute Am inventory produced by more than 15 commercial LWRs within the same time period, which is three times higher than the supporting ratio reported for the suggested ADS; 3. The total fraction of ADS power in the power park is half of cases for critical reactors. / QC 20120201

Understanding the link between the Sun and climate is vital in the current incidence of global climate change, and 10Be in natural archives constitutes an excellent tracer for this purpose. As cosmic rays enter the atmosphere, cosmogenic isotopes like 10Be and 14C are formed. Variations in solar activity modulate the amount of incoming cosmic rays, and thereby cosmogenic isotope production. Atmospherically produced 10Be enters natural archives such as sediments and glaciers by wet and dry deposition within about a year of production. 10Be from natural archives therefore provides information on past solar activity, and because these archives also contain climate information, solar activity and climate can be linked. One remaining question is to what degree 10Be in natural archives reflects production, and to what extent the local and regional environment overprints the production signal. To explore this, 10Be was measured at annual resolution over the last 600 years in a Greenland ice core. Measurement potentials for these samples benefited from the development of a new laboratory method of co-precipitating 10Be with niobium. To diversify geographic location and archive media type, a pioneer study of measuring 10Be with annual resolution in varved lake sediments from Finland was conducted, with samples from the entire 20th century. Pathways of 10Be into lake sediments are more complex than into glacial ice, inferring that contemporary atmospheric conditions may not be recorded. Here, it is shown for the first time that tracing the 11-year solar cycle through lake sediment 10Be variations is possible. Results also show that on an annual basis, 10Be deposition in ice and sediment archives is affected by local environmental conditions. On a slightly longer timescale, however, diverse 10Be records exhibit similar trends and a negative correlation with solar activity. Cyclic variability of 10Be deposition persisted throughout past grand solar minima, when little or no sunspot activity was recorded. 10Be levels indicate that although solar activity has been high during the 20th century, levels are not unprecedented in the investigated 600 years. Aerosol 10Be/7Be values indicate possible influence of stratosphere-troposphere exchange on isotope abundance and the production signal.

ASIPs are needed to handle the future demand of flexible yet highperformance embedded computing. The flexibility of ASIPs makes them preferable over fixed function ASICs. Also, a well designed ASIP, has a power consumption comparable to ASICs.  However the cost associated with ASIP design is a limiting factor for a more wide spread adoption. A number of different tools have been proposed, promising to ease this design process. However all of the current state of the art tools limits the designer due to a template based design process. It blocks design freedoms and limits the I/O bandwidth of the template. We have therefore proposed the Novel Generator of Accelerator and Processors (NoGAP). NoGAP is a design automation tool for ASIP andaccelerator design that puts very few limits on what can be designed, yet NoGAP gives support by automating much of the tedious anderror prone tasks associated with ASIP design. This thesis will present NoGAP and much of its key concepts. Such as; the NoGAP-CL) which is a language used to implement processors in NoGAP, This thesis exposes NoGAP's key technologies, which include automatic bus and wire sizing, instruction decoder and pipeline management, how PC-FSMs can be generated, how an assembler can be generated, and how cycle accurate simulators can be generated. We have so far proven NoGAP's strengths in three extensive case studies, in one a floating point pipelined data path was designed, in another a simple RISC processor was designed, and finally one advanced RISC style DSP was designed using NoGAP. All these case studies points to the same conclusion, that NoGAP speeds up development time, clarify complex pipeline architectures, retains design flexibility, and most importantly does not incur much performance penalty, compared to hand optimized RTL code. We belive that the work presented in this thesis shows that NoGAP, using our proposed novel approach to micro architecture design, can have a significant impact on both academic and industrial hardware design. To our best knowledge NoGAP is the first system that has demonstrated that a template free processor construction framework can be developed and generate high performance hardware solutions. / NoGAP

名古屋大学年代測定総合研究センターシンポジウム報告

A modular and area-efficient 3D graphics accelerator for tile based rendering in FPGA systems has been designed and implemented. The accelerator supports a subset of OpenGL, with features such as mipmapping, multitexturing and blending. The accelerator consists of a software component for projection and clipping of triangles, as well as a hardware component for rasterization, coloring and video output. Trade-offs made between area, performance and functionality have been described and justified. In order to evaluate the functionality and performance of the accelerator, it has been tested with two different applications. / En modulär och utrymmeseffektiv 3D-grafikaccelerator för tile-baserad rendering i FPGA-system har designats och implementerats. Acceleratorn stöder en delmängd av OpenGL med funktioner som mipmapping, multitexturering och blending. Acceleratorn är uppdelad i en mjukvarudel för projektion och klippning av trianglar och en hårdvarudel för rastrering, färgsättning och utritning till skärm. Avvägningar som gjorts mellan area, prestanda och funktionalitet har beskrivits och motiverats. För att evaulera funktionalitet och prestanda har acceleratorn testats med två olika applikationer.

Searching for textual information has become an important activity on the web. To satisfy the rising demand and user expectations, search systems should be fast, scalable and deliver relevant results. To decide which objects should be retrieved, search systems should compare holistic meanings of queries and text document objects, as perceived by humans. Existing techniques do not enable correct comparison of composite holistic meanings like: "evidences on role of DR2 gene in development of diabetes in Caucasian population", which is composed of multiple elementary meanings: "evidence", "DR2 gene", etc. Thus these techniques can not discern objects that have a common set of keywords but convey different meanings. Hence we need new methods to compare composite meanings for superior search quality. In distributed search engines, for scalability, speed and efficiency, index entries should be systematically distributed across multiple index-server nodes based on the meaning of the objects. Furthermore, queries should be selectively sent to those index nodes which have relevant entries. This requires an overlay Semantic Routed Network which will route messages, based on meaning. This network will consist of fast response networking appliances called semantic routers. These appliances need to: (a) carry out sophisticated meaning comparison computations at high speed; and (b) have the right kind of behavior to automatically organize an optimal index system. This dissertation presents the following artifacts that enable the above requirements: (1) An algebraic theory, a design of a data structure and related techniques to efficiently compare composite meanings. (2) Algorithms and accelerator architectures for high speed meaning comparisons inside semantic routers and index-server nodes. (3) An overlay network to deliver search queries to the index nodes based on meanings. (4) Algorithms to construct a self-organizing, distributed meaning based index system. The proposed techniques can compare composite meanings ~105 times faster than an equivalent software code and existing hardware designs. Whereas, the proposed index organization approach can lead to 33% savings in number of servers and power consumption in a model search engine having 700,000 servers. Therefore, using all these techniques, it is possible to design a Semantic Routed Network which has a potential to improve search results and response time, while saving resources.

Innerhalb der handschriftlichen Überlieferung, die aus dem Mittelalter auf uns gekommen ist, gehören Palimpseste zu den Zeugnissen, die schon immer in besonderer Weise das Interesse auf sich gezogen und Phantasien beflügelt haben.