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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
351

Multi-scale thermal and circuit analysis for nanometre-scale integrated circuits

Allec, NICHOLAS 27 September 2008 (has links)
Chip temperature is increasing with continued technology scaling due to increased power density and decreased device feature sizes. Since temperature has significant impact on performance and reliability, accurate thermal and circuit analysis are of great importance. Due to the shrinking device feature size, effects occurring at the nanometre scale, such as ballistic transport of energy carriers and electron tunneling, have become increasingly important and must be considered. However, many existing thermal and circuit analysis methods are not able to consider these effects efficiently, if at all. This thesis presents methods for accurate and efficient multi-scale thermal and circuit analysis. For circuit analysis, the simulation of single-electron device circuits is specifically studied. To target thermal analysis, in this work, ThermalScope, a multi-scale thermal analysis method for nanometre-scale IC design is developed. It unifies microscopic and macroscopic thermal physics modeling methods, i.e., the Boltzmann transport and Fourier modeling methods. Moreover, it supports adaptive multi-resolution modeling. Together, these ideas enable efficient and accurate characterization of nanometre-scale heat transport as well as chip-package level heat flow. ThermalScope is designed for full chip thermal analysis of billion-transistor nanometre-scale IC designs, with accuracy at the scale of individual devices. ThermalScope has been implemented in software and used for full chip thermal analysis and temperature-dependent leakage analysis of an IC design with more than 150 million transistors. To target circuit analysis, in this work, SEMSIM, a multi-scale single-electron device simulator is developed with an adaptive simulation technique based on the Monte Carlo method. This technique significantly improves the time efficiency while maintaining accuracy for single-electron device and circuit simulation. It is shown that it is possible to reduce simulation time up to nearly 40 times and maintain an average propagation delay error of under 5% compared to a non-adaptive Monte Carlo method. This simulator has been used to handle large circuit benchmarks with more than 6000 junctions, showing efficiency comparable to SPICE, with much better accuracy. In addition, the simulator can characterize important secondary effects including cotunneling and Cooper pair tunneling, which are critical for device research. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2008-09-26 13:33:12.389
352

A MOS delay model for switch-level simulation /

Peckel, Marcos David. January 1985 (has links)
No description available.
353

The development of a swarm intelligent simulation tool for sugarcane transport logistics systems.

McDonald, Brendon Clyde. 14 November 2013 (has links)
Transport logistics systems typically evolve as networks over time, which may result in system rigidity and cause changes to become expensive and time consuming. In this study a logistics model, named TranSwarm, was developed to simulate sugarcane harvesting, transport and mill-yard activities for a mill supply area. The aim was to simulate produce flow, and allow individual working entities to make decisions, driven by rules and protocols, based on their micro-environments. Noodsberg mill was selected as a case study because of low current levels of synchronization. Growers were assumed to operate independent harvesting and transport systems causing inconsistent convergences at the mill. This diverse and fragmented system provided a suitable environment to construct a model that would consider interactions between individual growers and their respective transport systems. Ideally, by assessing the micro-decisions of individuals and how they influence the larger holistic supply chain, TranSwarm quantifies the impacts of different types of transport practices, such as staggering shift changes, transport scheduling, core sampling and consortium-based logistics. TranSwarm is visual, mechanistic and represents key entities, such as roads, farm groupings and the mill. The system uses discrete events to create a dynamic and stochastic environment from which observations and conclusions can be drawn. This approach potentially allows stakeholders to identify key components and interactions that may jeopardize overall efficiency and to use the system to test new working protocols and logistics rules for improving the supply chain. / Thesis (M.Sc.)-University of KwaZulu-Natal, 2008.
354

Extracellular potentials from action potentials of anatomically realistic neurons and neuronal populations.

January 2005 (has links)
Extracellular potentials due to firing of action potentials are computed around cortical neurons and populations of cortical neurons. These extracellular potentials are calculated as a sum of contributions from ionic currents passing through the cell membrane at various locations using Maxwell's equations in the quasi-static limit. These transmembrane currents are found from simulations of anatomically reconstructed cortical neurons implemented as multi-compartmental models in the simulation tool NEURON. Extracellular signatures of action potentials of single neurons are calculated both in the immediate vicinity of the neuron somas and along vertical axes. For the neuronal populations only vertical axis distributions are considered. The vertical-axis calculations were performed to investigate the contributions of action potential firing to laminar-electrode recordings. Results for high-pass (750 - 3000 Hz) filtered potentials are also given to mimic multi-unit activity (MUA) recordings. Extracellular traces from single neurons and populations (both synchronous and asynchronous) of neurons are shown for three different neuron types: layer 3 pyramid, layer 4 stellate and layer 5 pyramid cell. The layer 3 cell shows a 'closed-field' configuration, while the layer 5 pyramid demonstrates an 'open-field' appearance for singe neuron simulations which is less apparent in population simulations. The layer 4 stellate cell seems to fall somewhere in between the open- and closed-field scenarios. Comparing single neuron and synchronous populations, the amplitudes of the extracellular traces increase as population radii increase, though the shapes are generally similar. Asynchronous populations produce small amplitudes due to a time convolution of various neuron contributions. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005
355

Techniques for large scale distributed simulations of computer networks

Riley, George F. 08 1900 (has links)
No description available.
356

On large eddy simulations of reacting two-phase flows

Pannala, Sreekanth 05 1900 (has links)
No description available.
357

The validity of simulation techniques for predicting environmental behavior

Jacoby, Joellen January 1982 (has links)
Simulation allows the portrayal of unique environmental design concepts in order to predict the outcome prior to construction. Three (3) simulations--drawings, model and movie--were tested for their effectiveness in communicating future environmental behavior. Communication effectiveness was measured by the ability of simulation viewers to accurately predict their behavior in a built space. A comparison of, responses of on-site subjects to predicted behavioral responses of simulation viewers, found simulation viewers were accurate in their predictions in excess of sixty percent (60%). This indicated that simulations were fairly effective. An individual analysis of the three (3) groups of viewers found movie viewers having the highest rate of accurate predictions, and those viewing drawings the lowest. This general trend was consistent with other work.Testing was completed with design-oriented and non-design-oriented viewers. A significant difference in response between these two (2) groups occurred in seven (7) of the thirty-eight (38) questions. Design-oriented viewers were generally more accurate in their prediction abilities. / Department of Landscape Architecture
358

Neural theory and model of selective visual attention and 2D shape recognition in visual clutter / by Peter Lozo.

Lozo, Peter January 1996 (has links)
Bibliography: leaves 328-352. / xxxi, 352 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis proposes a neural theory, Selective Attention Adaptive Resonance Theory, and a neuro-engineered solution to selective visual attention, memory guided processing and illumination invariant recognition of complete (unoccluded), but distorted 2D shapes of 3D objects in cluttered visual images. / Thesis (Ph.D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 1997?
359

Energy saving through urban design : a microclimatic approach / Mohamed M. El Nahas.

Nahas, Mohamed M. El January 1996 (has links)
Bibliography: p. 133-144. / x, 170 p. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis investigates the impact on residential energy use for climate control or urban design variables, such as building density, spacing and orientation. Energy use for heating/cooling is predicted in a range of urban configurations that are compatible with the following objectives: wind shelter and solar access in winter and urban ventilation and shading in summer. / Thesis (Ph.D.)--University of Adelaide, Dept. of Architecture, 1997?
360

Predictive models for forces, power and hole oversize in drilling operations

Zhao, Hualin Unknown Date (has links) (PDF)
Drilling is one of the most commonly used material removal processes for producing holes in the manufacturing industry. Despite the long history of design and developments of hole making tools, the modern twist drill, which undertakes most of the hole making tasks, is largely based on Morse’s geometrical design patented in 1863. however, considerable improvements in the technological performance of drilling operations as assessed by the forces, power, drill-life and hole quality have been achieved through the use of stronger and more wear resistant tool materials, better selection of the salient drill point features and improvements in drill manufacturing methods involving increased automation and geometrical control of drill variability. A variety of drill point modifications and designs have also been proposed and made commercially available although the modern conventional general purpose twist drill design still remains the standard product of drill manufacturers commonly available in stock. The improvement of the technological performance of twist drills has traditionally been the domain of the drill manufacturers who provide technical information and advice often in the form of machining feed and speed recommendations for use in practice. Such machining recommendations or data may also be found in special handbooks which sometimes include drilling performance data such as thrust, torque and power requirements or the expected drill-life in the form of tables, monographs or empirical equations which include the obvious process variables such as the feed and speed. (For complete introduction open document)

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