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Evaluation of Flux and Timing Calibration of the XMM-Newton EPIC-MOS Cameras in Timing ModeLarsson, John-Olov January 2008 (has links)
<p>XMM-Newton is a X-ray telescope launched december 1999, by the European Space Agency, ESA. On board XMM-Newton are two EPIC-MOS X-ray detectors. The detectors are build by Charged Coupled Devices (CCDs), of Metal Oxide Semi-conductor type. The EPIC-MOS cameras have four science operating modes. This project aims to evaluate the calibration for one of these four modes, the timing mode.</p><p>The evaluation is divided into two parts. The first part is the evaluation of the flux calibration, performed by analysing various observation made in timing mode. The second part is the evaluation of timing properties by performing timing analysis of XMM-Newton observations of the Crab nebula compared to observations made in the radio wavelengths.</p>
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Instruction Timing Analysis for Linux/x86-based Embedded and Desktop SystemsJohn, Tobias 19 October 2005 (has links) (PDF)
Real-time aspects are becoming more important in
standard desktop PC environments and x86 based
processors are being utilized in embedded systems
more often.
While these processors were not created for use
in hard real time systems, they are fast and
inexpensive and can be used if it is possible
to determine the worst case execution time.
Information on CPU caches (L1, L2) and
branch prediction architecture is necessary
to simulate best and worst cases in execution
timing, but is often not detailed
enough and sometimes not published at all.
This document describes how the underlying
hardware can be analysed to obtain
this information.
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A METHODOLOGY OF SPICE SIMULATION TO EXTRACT SRAM SETUP AND HOLD TIMING PARAMETERS BASED ON DFF DELAY DEGRADATIONZhang, Xiaowei 01 January 2015 (has links)
SRAM is a significant component in high speed computer design, which serves mainly as high speed storage elements like register files in microprocessors, or the interface like multiple-level caches between high speed processing elements and low speed peripherals. One method to design the SRAM is to use commercial memory compiler. Such compiler can generate different density/speed SRAM designs with single/dual/multiple ports to fulfill design purpose. There are discrepancy of the SRAM timing parameters between extracted layout netlist SPICE simulation vs. equation-based Liberty file (.lib) by a commercial memory compiler. This compiler takes spec values as its input and uses them as the starting points to generate the timing tables/matrices in the .lib. Originally large spec values are given to guarantee design correctness. While such spec values are usually too pessimistic when comparing with the results from extracted layout SPICE simulation, which serves as the “golden” rule. Besides, there is no margin information built-in such .lib generated by this compiler.
A new methodology is proposed to get accurate spec values for the input of this compiler to generate more realistic matrices in .lib, which will benefit during the integration of the SRAM IP and timing analysis.
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Comprehensive on-street bicycle facilities: an approach for incorporating traffic signal operational strategies for bicyclesCurtis, Eddie J. 08 June 2015 (has links)
Less than 1% of work and school trips are completed by bicycle in the United States. Comprehensive bicycle facilities improve bicycle ridership by including a diverse set of strategies that accommodate the bicycle mode and seek to minimize the Level of Traffic Stress experienced by riders. Traffic Signal Operational Strategies for Bicycles (TSOSB) are an integral component of comprehensive bicycle facilities. This research presents a methodology to identify critical zones for implementation of TSOSB. After identifying critical zones a process for assessment of gaps in bicycle safety and comfort and convenience for signalized intersections within the critical zones is conducted. The outcome of the methodology is a prioritized list of signalized intersection that could benefit from the application of Traffic Signal Operational Strategies for Bicycles
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Combustion and emission characteristics of biofuels in diesel enginesLabecki, Lukasz January 2010 (has links)
This study was concerned with the performance of biofuels in diesel engines. Generally, the basic combustion and emission characteristics of Rapeseed Oil (RSO) and Soya Oil (SO) result in a lower in-cylinder pressure peak than diesel. This led to the reduction of Nitrogen Oxides (NOx) emissions and to relatively high soot emissions. Further measurements of RSO were done in order to investigate the influence of injection pressure, injection timing and Exhaust Gas Recirculation (EGR) on combustion and emission characteristics. A high soot emission from RSO was reduced by increased injection pressure. Moreover, injection timing also had to be varied in order to reduce the soot emissions from RSO. The retarded injection timing (3 deg bTDC) and increased injection pressure (1200 bar) for the blend of 30% RSO resulted in a reduction of soot emission to the same level as from diesel fuel. Further investigation regarding the soot emissions was done for Rapeseed Methyl Ester (RME) under turbocharged engine operation. The application of the boost pressure resulted in stable engine operation at a late injection timing of 5 deg aTDC. A simultaneous reduction of soot and NOx emissions has been achieved for RME at an injection timing of TDC and high EGR percentage (40 – 50 %). The soot particles size distribution under different engine operating conditions for RME and diesel has also been investigated. Moreover, the characteristic of Electrostatic Mobility Spectrometer (EMS) and the design of primary dilution system have been provided in order to understand the influence of the dilution process and to obtain more real results. Generally, RME showed less particles concentration in the nucleation mode when compared to diesel. Moreover, high EGR caused a shift of the particles from the nucleation mode by agglomeration into the accumulation mode for both fuels. The effect of injection pressure could only be seen in the accumulation mode, where high injection pressure slightly reduced the concentration number. The soot emission was effectively reduced by the usage of the diesel particulate filter (DPF). For this purpose, the soot particles size distributions before and after the DPF have been measured at different engine speeds and loads. At low engine torque, the soot was effectively filtered while the operation under high engine loads resulted in low soot particle concentration especially in the nucleation mode, after the DPF.
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Contracted spans of temporal integration in adults with attention deficit hyperactivity disorderMarusich, Laura Ranee 06 February 2012 (has links)
ADHD is a highly prevalent disorder in both children and adults that involves significant impairment throughout the lifespan, and yet the core cognitive deficits of the disorder are not well understood. Accumulating evidence of dysfunctioning dopamine systems motivated the theory that delay-of-reinforcement gradients are altered in ADHD in such a way that reinforcers must arrive earlier in time following a response for an association between the two to be learned. The current work is motivated by the conjecture that dopamine dysfunction has consequences for the maximum timescales over which connections can be formed, not just in reinforcement learning, but also in the processes of temporal integration and scene formation that allow humans to understand and navigate their world. There is a maximum window of temporal separation over which discrete events can be integrated into a unified experience, and the current experiments indicate that this maximum window of integration is contracted in ADHD. The experiments included multiple tasks designed so that the participant response required implicit integration over temporal intervals, and the length of those intervals was varied as an independent variable. Adults with and without ADHD completed these tasks, and the strength of temporal integration was measured with respect to interval length and compared between the two groups. This methodology was applied in five types of tasks: rhythmic tapping, spatial cuing, irrelevant feature priming, and two apparent motion tasks. On the whole, this suite of studies was successful in demonstrating a contraction in the maximum interval over which temporal integration can occur in ADHD relative to controls. Two of the tasks, rhythmic tapping and spatial cuing, generated unexpected and interesting results, and several follow-up tasks were designed to further explore these findings. As a result, a somewhat improved tapping task was discovered. This tapping task, as well as the irrelevant feature priming task and one of the apparent motion tasks, demonstrated potential utility for the diagnosis of adults with ADHD. / text
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Synthesis of variation tolerant clock distribution networksRajaram, Anand Kumar 01 October 2012 (has links)
In the sub-65nm VLSI technology, the variation effects like manufacturing variation, power supply noise and temperature variation become very significant. As one of the most vital components in any synchronous VLSI chip, the Clock Distribution Network (CDN) is especially sensitive to these variations. The unwanted clock skews caused by the variation effects consume increasing proportion of the clock cycle, thereby limiting chip performance and yield. Thus, making the clock network variation-tolerant is a key objective in the chip designs of today. In this dissertation, we propose several techniques that can be used to synthesize variation-tolerant clock networks. Our contributions can be broadly classified into following four categories: (i) Efficient algorithms for synthesizing link based non-tree clock networks. (ii) A methodology for synthesizing a balanced, variation tolerant, buffered clock network with cross-links. (iii) A comprehensive framework for planning, synthesis and optimization of clock mesh networks. (iv) A chip-level clock tree synthesis technique to address issues unique to hierarchical System-On-a-Chip (SOC) designs that are becoming more and more frequent today. Depending on the performance requirements and resource constraints of a given chip, the above techniques can be used separately or in combination to synthesize a variation tolerant clock network. / text
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Discrete gate sizing and threshold voltage assignment to optimize power under performance constraintsSingh, Jagmohan 2013 August 1900 (has links)
In today's world, it is becoming increasingly important to be able to design high performance integrated circuits (ICs) and have them run at as low power as possible. Gate sizing and threshold voltage (Vt) assignment optimizations are one of the major contributors to such trade-offs for power and performance of ICs. In fact, the ever increasing design sizes and more aggressive timing requirements make gate sizing and Vt assignment one of the most important CAD problems in physical synthesis. A promising gate sizing optimization algorithm has to satisfy requirements like being scalable to tackle very large design sizes, being able to optimally utilize a large (but finite) number of possible gate configurations available in standard cell library based on different gate sizes and/or threshold voltages (Vt) and/or gate lengths (Lg), and also, being able to handle non-convex cell delays in
modern cell libraries.
The work in this thesis makes use of the research-oriented infrastructure made available as part of the ISPD (International Symposium on Physical Design) 2012 Gate Sizing Contest that addresses the issues encountered in modern gate sizing problems. We present a two-phase optimization approach where Lagrangian Relaxation is used to formulate the optimization problem. In the first phase, the Lagrangian relaxed subproblem is iteratively solved using a greedy algorithm, while in the second phase, a cell downsizing and Vt upscaling heuristic is employed to further recover power from the timing-feasible and power-optimized sizing solution obtained at the end of first phase. We also propose a multi-core implementation of the first-phase optimizations, which constitute majority of the total runtime, to take advantage of multi-core processors available today. A speedup of the order of 4 to 9 times is seen on different benchmarks as compared to serial implementation when run on a 2 socket 6-core machine. Compared to the winner of ISPD 2012 contest, we further reduce leakage power by 17.21% and runtime by 87.92%, on average, while obtaining feasible sizing solutions on all the benchmark designs. / text
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A psychophysical investigation of audio-visual timing in the millisecond rangeHotchkiss, John January 2012 (has links)
The experiments described in this thesis use psychophysical techniques and human observers to investigate temporal processing in the millisecond range. The thesis contains five main sections. Introductory chapters provide a brief overview of the visual and auditory systems, before detailing our current understanding of duration processing. During the course of this review, several important questions are highlighted. The experiments detailed in Chapters 8-11 seek to address these questions using the psychophysical techniques outlined in Chapter 7. The results of these experiments increase our understanding of duration perception in several areas. Firstly, Experiments 1 and 2 (Chapter 8) highlight the role of low level stimulus features: even when equated for visibility stimuli of differing spatial frequency have different perceived durations. Secondly, a psychophysical hypothesis arising from the 'duration channels' or 'labelled lines' model of duration perception is given strong support by the adaptation experiments detailed in Chapter 9 and 10. Specifically, adaptation to durations of a fixed temporal extent induces repulsive duration aftereffects that are sensory specific and bandwidth limited around the adapted duration. Finally Chapter 11 describes the results of experiments designed to probe the processing hierarchy within duration perception by measuring the interdependency of illusions generated via duration adaptation and via multisensory cue combination. The results of these experiments demonstrate that duration adaptation is a relatively early component of temporal processing and is likely to be sub served by duration selective neurons situated in early sections of the visual and auditory systems.
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Emotional Modulation of Time PerceptionLake, Jessica January 2014 (has links)
<p>Our perception of time is not veridical but rather is consistently modulating by changing dynamics in our environment. Anecdotal experiences suggest that emotions can be powerful modulators of time perception; nevertheless, the mechanisms underlying emotion-induced temporal distortions remain unclear. Widely accepted pacemaker-accumulator models of time perception suggest that changes in arousal and attention have unique influences on temporal judgments and contribute to emotional distortions of time perception. However, such models conflict with current views of arousal and attention and their interaction from the perspective of affective and cognitive science. The aim of this dissertation was to more clearly examine the role of arousal and attention in driving emotion-induced temporal distortions by explicitly manipulating and measuring these constructs using well-established timing procedures within the context of affective manipulations induced via classical conditioning and drug administration. Measures of physiological arousal and subjective measures of top-down attention to emotional stimuli were assessed both within and across subjects. The findings reported here suggest that current models of time perception do not adequately explain the variability in emotion-induced temporal distortions. Instead these findings provide support for a new theoretical model of emotion-induced temporal distortions proposed in the current manuscript that emphasizes both the unique and interactive influences of arousal and attention on time perception, dependent on temporal dynamics, event relationships, and individual differences. Collectively, these findings may point to plausible neurobiological mechanisms of emotion-induced temporal distortions and have important implications for our understanding of how emotions may modulate our perceptual experiences in service of adaptively responding to biologically relevant stimuli.</p> / Dissertation
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