261 research outputs found

    Clock routing for high performance microprocessor designs.

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    Tian, Haitong.Chinese abstract is on unnumbered page.Thesis (M.Phil.)--Chinese University of Hong Kong, 2011.Includes bibliographical references (p. 65-74).Abstracts in English and Chinese.Abstract --- p.iAcknowledgement --- p.iiiChapter 1 --- Introduction --- p.1Chapter 1.1 --- Motivations --- p.1Chapter 1.2 --- Our Contributions --- p.2Chapter 1.3 --- Organization of the Thesis --- p.3Chapter 2 --- Background Study --- p.4Chapter 2.1 --- Traditional Clock Routing Problem --- p.4Chapter 2.2 --- Tree-Based Clock Routing Algorithms --- p.5Chapter 2.2.1 --- Clock Routing Using H-tree --- p.5Chapter 2.2.2 --- Method of Means and Medians(MMM) --- p.6Chapter 2.2.3 --- Geometric Matching Algorithm (GMA) --- p.8Chapter 2.2.4 --- Exact Zero-Skew Algorithm --- p.9Chapter 2.2.5 --- Deferred Merge Embedding (DME) --- p.10Chapter 2.2.6 --- Boundary Merging and Embedding (BME) Algorithm --- p.14Chapter 2.2.7 --- Planar Clock Routing Algorithm --- p.17Chapter 2.2.8 --- Useful-skew Tree Algorithm --- p.18Chapter 2.3 --- Non-Tree Clock Distribution Networks --- p.19Chapter 2.3.1 --- Grid (Mesh) Structure --- p.20Chapter 2.3.2 --- Spine Structure --- p.20Chapter 2.3.3 --- Hybrid Structure --- p.21Chapter 2.4 --- Post-grid Clock Routing Problem --- p.22Chapter 2.5 --- Limitations of the Previous Work --- p.24Chapter 3 --- Post-Grid Clock Routing Problem --- p.26Chapter 3.1 --- Introduction --- p.26Chapter 3.2 --- Problem Definition --- p.27Chapter 3.3 --- Our Approach --- p.30Chapter 3.3.1 --- Delay-driven Path Expansion Algorithm --- p.31Chapter 3.3.2 --- Pre-processing to Connect Critical ports --- p.34Chapter 3.3.3 --- Post-processing to Reduce Capacitance --- p.36Chapter 3.4 --- Experimental Results --- p.39Chapter 3.4.1 --- Experiment Setup --- p.39Chapter 3.4.2 --- Validations of the Delay and Slew Estimation --- p.39Chapter 3.4.3 --- Comparisons with the Tree Grow (TG) Approach --- p.41Chapter 3.4.4 --- Lowest Achievable Delays --- p.42Chapter 3.4.5 --- Simulation Results --- p.42Chapter 4 --- Non-tree Based Post-Grid Clock Routing Problem --- p.44Chapter 4.1 --- Introduction --- p.44Chapter 4.2 --- Handling Ports with Large Load Capacitances --- p.46Chapter 4.2.1 --- Problem Ports Identification --- p.47Chapter 4.2.2 --- Non-Tree Construction --- p.47Chapter 4.2.3 --- Wire Link Selection --- p.48Chapter 4.3 --- Path Expansion in Non-tree Algorithm --- p.51Chapter 4.4 --- Limitations of the Non-tree Algorithm --- p.51Chapter 4.5 --- Experimental Results --- p.51Chapter 4.5.1 --- Experiment Setup --- p.51Chapter 4.5.2 --- Validations of the Delay and Slew Estimation --- p.52Chapter 4.5.3 --- Lowest Achievable Delays --- p.53Chapter 4.5.4 --- Results on New Benchmarks --- p.53Chapter 4.5.5 --- Simulation Results --- p.55Chapter 5 --- Efficient Partitioning-based Extension --- p.57Chapter 5.1 --- Introduction --- p.57Chapter 5.2 --- Partition-based Extension --- p.58Chapter 5.3 --- Experimental Results --- p.61Chapter 5.3.1 --- Experiment Setup --- p.61Chapter 5.3.2 --- Running Time Improvement with Partitioning Technique --- p.61Chapter 6 --- Conclusion --- p.63Bibliography --- p.6

    Tracking and data acquisition system for the 1990's. Volume 7: TDAS space technology assessment

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    The results of the TDAS and user spacecraft technology assessment effort are provided. For each TDAS Satellite enhancement and user spacecraft element previously enumerated, the technology issues are identified and the R&D needed to resolve these issues is delineated. Subsequently, taking into account developments taking place elsewhere, the addition unique TDAS satellite module and user spacecraft element R&D efforts needed are identified, and conclusions are drawn in each case. From these conclusions, it is evident that with additional unique R&D efforts carried out for TDAS and appropriate user spacecraft elements the desired TDAS' capabilities for the 1990's can be realized and user spacecraft can be implemented that adequately interface with the projected TDAS

    NASA 60 GHz intersatellite communication link definition study. Baseline document

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    The overall system and component concepts for a 60 GHz intersatellite communications link system (ICLS) are described. The ICLS was designed to augment the capabilities of the current Tracking and Data Relay Satellite System (TDRSS), providing a data rate capacity large enough to accommodate the expected rates for user satellites (USAT's) in the post-1995 timeframe. The use of 60 GHz for the anticipated successor to TDRSS, the Tracking and Data Acquisition System (TDAS), was selected because of current technology development that will enable multigigibit data rates. Additionally, the attenuation of the earth's atmosphere at 60 GHz means that there is virtually no possibility of terrestrially generated interference (intentional or accidental) or terrestrially based intercept. The ICLS includes the following functional areas: (1) the ICLS payload package on the GEO TDAS satellite that communicates simultaneously with up to five LEO USAT's; (2) the payload package on the USAT that communicates with the TDAS satellite; and (3) the crosslink payload package on the TDAS satellite that communicates with another TDAS satellite. Two methods of data relay on-board the TDAS spacecraft were addressed. One is a complete baseband system (demod and remod) with a bi-directional 2 Gbps data stream; the other is a channelized system wherein some of the channels are baseband and others are merely frequency translated before re-transmission. Descriptions of the TDAS antenna, transmitter, receiver, and mechanical designs are presented

    Space Shuttle/TDRSS communication and tracking systems analysis

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    In order to evaluate the technical and operational problem areas and provide a recommendation, the enhancements to the Tracking and Data Delay Satellite System (TDRSS) and Shuttle must be evaluated through simulation and analysis. These enhancement techniques must first be characterized, then modeled mathematically, and finally updated into LinCsim (analytical simulation package). The LinCsim package can then be used as an evaluation tool. Three areas of potential enhancements were identified: shuttle payload accommodations, TDRSS SSA and KSA services, and shuttle tracking system and navigation sensors. Recommendations for each area were discussed

    Neurospora 2018 - Program and Abstracts

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    Program and abstracts from Neurospora 2018, October 18-2

    Characterization of short vegetative phase (SVP)

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    Ph.DDOCTOR OF PHILOSOPH

    Factors Affecting Human Achilles Sub-tendon Mechanical Behaviour and the Clinical Application Potential

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    The human Achilles tendon is composed of three twisted sub-tendons, arising from soleus and gastrocnemii muscles, but the interaction between these sub-tendons during body movements is largely unknown. The most widely reported phenomenon is the non-uniform intra-tendinous displacements during movements; however, how this non-uniformity contributes to the overall tendon mechanical behaviour has not been thoroughly studied. This thesis aims to investigate the potential factors affecting this intra-tendinous displacement non-uniformity, by conducting mechanical and material characterisation and in silico modelling on Achilles sub-tendons, and to discover possibilities to translate these findings into clinical applications. The study conducted on the equine bifurcated tendon-ligament model demonstrated that differences in the material and mechanical properties at the fascicle and sub-tendon levels may be associated with displacement non-uniformity. Human Achilles sub-tendon material properties were not statistically different but a greater cross-sectional area, failure force and displacement were found in the soleus than gastrocnemii sub-tendons. These results suggest that the material and mechanical properties of sub-tendons may affect the overall tendon level mechanical behaviour. Finite element analysis on three reconstructed Achilles sub-tendon models identified that reduced inter-sub-tendon sliding, as reported previously in aged tendons, reduced displacement non-uniformity. Comparing the results from different models further suggested that the inherent tendon morphology, with different length, twist, and sub-tendon arrangements, could result in different tendon level displacements and stress distributions. The results from Raman spectroscopy on both equine and human tendon tissues demonstrated the ability to differentiate tendon samples with known compositional differences based on spectral features alone, suggesting that Raman spectroscopy has the potential for rapid analysis of tendon compositions in the future. In conclusion, this thesis has identified three factors that could affect the overall Achilles tendon mechanical behaviour and proposed potential approaches for future clinical applications to improve tendon healthcare

    Functional analysis of three Arabidopsis SR proteins (SCL33, SC35, SCL30A) in plant development and splicing

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    2012 Fall.Includes bibliographical references.To view the abstract, please see the full text of the document

    JPL Quarterly Technical Review, Volume 2, No. 3

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    Aerospace engineering including materials, orbits and trajectories, power sources, satellite geodesy, and structural engineerin
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