Notre thèse veut démontrer les limites des définitions de nouveaux concepts et de nouvelles générations de tours qui sont développées par les professionnels et les chercheurs. Notre approche consiste à mettre l’accent sur la performance énergétique et environnementale, une notion qui n’est pas suffisamment abordée jusqu’à présent dans les tours et que nous cherchons à définir. Nous montrerons les limites et les barrières de l’introduction des mesures de performance dans l’évolution historiques des différentes générations de tours. Nous prenons position des systèmes d’évaluation environnementale et de la réglementation en vigueur dans différents contextes culturels et climatiques. Nous aborderons la question de la performance à plusieurs échelles afin de démontrer que l’équilibre de l’équation de la performance doit être pris dans une perspective de développement durable, et ce en prenant en considération les différentes dimensions du projet. Notre approche analytique et comparative cherche à combler le décalage entre le discours et la réalité, les intentions de départ et les finalités achevées. Enfin nous montrerons comment le processus de conception linéaire actuel des tours doit évoluer afin de viser une conception intégrée où la question de la performance doit être mise au cœur d’une nouvelle approche innovante et collaborative tout au long du cycle de vie du projet. Notre approche critique et analytique vise à démontrer en quoi la tour est-elle performante ? Dans quel contexte ? Avec quelles mesures ? Et comment faire pour améliorer sa performance afin qu’elle puisse mieux intégrer l’environnement urbain de nos villes contemporaines. / Our thesis aims to demonstrate the limitations of new concepts definitions and new generations of towers that are developed by professionals and researchers. Our approach is to focus on the energy and environmental performance, a notion that has not been addressed enough and we are trying to define. We show the limitations and barriers for the introduction of performance measures in the historical evolution of different generations of towers. We take a position of environmental assessment systems and regulations in different cultural and climatic contexts. We address the performance concept at multiple scales to demonstrate that the balance of the performance equation must be understood in a context of sustainable development. Our analytical and comparative approach seeks to bridge the gap between rhetoric and reality, the original intentions and purposes completed. Finally we show how the linear process of current projects must evolve to foster an integrated design where the issue of performance should be placed in the heart of a new innovative and collaborative approach throughout the life cycle of project development. It is important to note that our research work doesn’t aim to defend or refute the potential for energy efficiency and environmental quality of the architectural object of the tower, nor lead to a unique successful model which could be proposed to designers and professionals in the real estate market. Our critical and analytical approach is to demonstrate how the performance is it round? What is its context and measures? How improve it to better integrate the urban environment of our contemporary cities.

Field programmable gate arrays are a class of integrated circuit that enable logic functions and interconnects to be programmed in almost real time. They can implement fine grained parallel computing architectures and algorithms in hardware that were previously the domain of custom VLSI. Field programmable gate arrays have shown themselves useful at exploiting concurrency in a range of applications such as text searching, image processing and encryption. When coupled with a microprocessor, which is more suited to computation involving complex control flow and non time critical requirements, they form a potentially versatile platform commonly known as a Reconfigurable Computer. Reconfigurable computing applications have traditionally had the exclusive use of the field programmable gate array, primarily because the logic densities of the available devices have been relatively similar in size compared to the application. But with the modern FPGA expanding beyond 10 million system gates, and through the use of dynamic reconfiguration, it has become feasible for several applications to share a single high density device. However, developing applications that share a device is difficult as the current design flow assumes the exclusive use of the FPGA resources. As a consequence, the designer must ensure that resources have been allocated for all possible combinations of loaded applications at design time. If the sequence of application loading and unloading is not known in advance, all resource allocation cannot be performed at design time because the availability of resources changes dynamically. The use of a runtime resource allocation environment modelled on a classical software operating system would allow the full benefits of dynamic reconfiguration on high density FPGAs to be realised. In addition to runtime resource allocation, other services provided by an operating system such as abstraction of I/O and inter-application communication would provide additional benefits to the users of a reconfigurable computer. This could possibly reduce the difficulty of application development and deployment. In this thesis, an operating system for reconfigurable computing that supports dynamically arriving applications is presented. This is achieved by firstly developing the abstractions with which designers implement their applications and a set of algorithm requirements that specify the resource allocation and logic partitioning services. By combining these, an architecture of an operating system for reconfigurable computing can be specified. A prototype implementation on one platform with multiple applications is then presented which enables an exploration of how the resource allocation algorithms interact amongst themselves and with typical applications. Results obtained from the prototype include the measurement of the performance loss in applications, and the time overheads introduced due to the use of the operating system. Comparisons are made with programmable logic applications run with and without the operating system. The results show that the overheads are reasonable given the current state of the technology of FPGAs. Formulas for predicting the user response time and application throughput based on the fragmentation of an FPGA are then derived. Weaknesses are highlighted in the current design flows and the architecture of current FPGAs must be rectified if an operating system is to become main-stream. For the tool flows this includes the ability to pre-place and pre-route cores and perform high speed runtime routing. For the FPGAs these include an optimised network, a memory management core, and a separate layer to handle dynamic routing of the network. / thesis (PhD)--University of South Australia, 2005.

This work presents mechanical nano-grinding as an alternative technique for the fabrication of optical fibers endface microlenses. It also presents a novel surface-roughness improvement technique called Loose Abrasive Blasting (LAB). Traditionally, the majority of such microlenses are made using either chemical etching or heating and pulling methods. Despite the success of these methods, they suffer some common drawbacks such as the lack of controllability on the produced lens profile. Consequently the possible variations of the lens profiles that can be made by these methods are also limited. The difficulty to center the lens on the fiber core is another problem associated with heating and pulling method. The exposure to hazardous chemical such as hydrofluoric acid is yet another problem associated with chemical etching. Nano-grinding technique described in this thesis should provide a much better alternative to the traditional optical fabrication techniques. Nano-grinding experiments were conducted on a nano-grinding machine (NGM) specially built for this purpose. The machine incorporates state-of-the-art air-bearing spindles, piezo electric actuators, and capacitive displacement sensors with accuracy down to 2 nm. Such precise motion provided by this system is the key for the success of this technique. With such system, it was possible to produce a multitude variety of lens profiles with high profile accuracy and with surfaces of optical quality without the need for exposure to any kind of hazardous chemicals. In achieving this objective, the research was conducted on many frontiers. First, the possibility of grinding optical fibers without inducing surface and subsurface damages was investigated. Micro-indentation, nano-indentation, and nano-scratch tests were conducted to determine the critical depth of cut that can be achieved before the occurrence of surface and subsurface cracks. Nano-scratch test in particular provided a clear insight to the cracking and the chipping mechanisms that might unfold if the critical depth of cut was exceeded in an actual grinding situation. The knowledge gained from this exercise laid the ground base for the design of the NGM. Using the NGM, further experiments were carried out to determine the optimal grinding parameters for an efficient and successful grinding process. Parameters investigated include the grit size, the cutting speed, and the in-feed rates. The optimum parameters have to ensure the best endface surface quality and the same time maintain a high throughput. This study shows that based on these optimal parameters, it should be possible to produce endface microlenses of optical surface quality free surface and/or subsurface damages in less than 30 seconds with surface roughness (Ra) less than 3 nm. A novel post-grinding surface improvement techniques was also developed. The technique called loose abrasive blasting (LAB) can be used for polishing at and non-flat surfaces. Experiments were conducted on a loose abrasive blasting machine built specially for this purpose. The performance of this technique was compared with other techniques such as slurry polishing and chemical etching used for polishing of brittle materials. The results showed that while chemical etching was found unsuitable for polishing of at optical fiber endfaces, LAB outperformed slurry polishing by significant margin. After the optimal grinding conditions were established, the NGM was used for grinding of different kinds of optical fiber microlens profiles. Among the endface profiles produced were conical lenses, tapered lenses, D-shaped lenses and others. It has also been shown, in case of conical lenses for instance, that there is almost unlimited number of profiles that can be produced by simply changing the contact angle between the fiber endface and the grinding film. The effect of surface roughness on light coupling efficiency between a fiber endface and a laser diode was also investigated. Cleaved fiber endfaces as well as ground endfaces with variant degrees of surface roughness were used in this experiment. The results showed that surface roughness has significant effect on light coupling efficiency. The effect of lens eccentricity on light coupling was also investigated.

Various methods of estimating the fault probabilities based on defect data of random defects seen in integrated circuit manufacturing are examined. Estimates of fault probabilities based on defect data are less costly than those based on critical area analysis and are potentially more reliable because they are based on actual manufacturing data. Due to limited sample size, means of estimating the confidence interval associated with these estimates are also examined. Because the mathematical expressions associated with defect data-based estimates of the fault probabilities are not amenable to analytical means of obtaining confidence intervals, bootstrapping was employed. The results show that one method of estimating the fault probabilities based on defect data proposed previously is not applicable when using typical in-line data. Furthermore, the results indicate that under typical fab conditions, the assumption of a Poisson random defect distribution gives accurate fault probabilities. The yields as predicted by the fault probabilities estimated from the limited yield concept and kill ratio and those estimated from critical area simulation are shown to be comparable to actual yields observed in the fab. It is also shown that with in-line data, the FP estimated for a given inspection step is a weighted average of the fault probabilities of the defect mechanisms operating at that inspection step. Four bootstrapped based methods of confidence interval estimation for fault probabilities of random defects are examined. The study is based on computer simulation of randomly distributed defects with pre-assigned fault probabilities on dice and the resulting count of different categories of die. The results show that all four methods perform well when the number of fatal defects is reasonably high but deteriorate in performance as the number of fatal defects decrease. The results also show that the BCA (bias-corrected and accelerated) method is more likely to succeed with a smaller number of fatal defects. This success is attributed to its ability to account for change of the standard deviation of the sampling distribution of the FP estimates with the PP of the population, and to account for median bias in the sampling distribution. / Graduation date: 2004

Plastic packaging is a cost-effective solution for housing RF and microwave integrated circuits in low cost communication devices. While enabling low cost packaging of integrated circuits, plastic packages including the circuit ground patch (paddle) inside the package can have a significant parasitic effect on circuit performance. The purpose of this thesis is to develop accurate broadband models and associated extraction procedures for the paddle in plastic surface-mount RF-IC packages. Availability of package models will help the RF design engineer to include the packaging effects directly during the circuit design phase. In this thesis a new lumped element equivalent circuit model for the ground paddle inside a plastic package is presented. The ground paddle is characterized by planar full-wave electromagnetic simulation as well as by measurement of an equivalent paddle test structure. To de-embed the effects of the measurement probes, several test structures are designed. The equivalent circuit parameters for the paddle in a general symmetric 2n-pin plastic package are extracted from a set of measured or simulated two-port scattering parameters. To illustrate the modeling approach, the response of the paddle model for a four-pin and eight-pin plastic package is shown and found to be in good agreement with the measured and simulated data over a broad frequency range extending beyond 5 GHz. Finally, the extraction of the equivalent circuit model of the paddle through the package lead-frame is demonstrated. / Graduation date: 2000

Thesis (M.S.)--Oregon Graduate Center, 1983.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

The purpose of this study is to develop experimental techniques to characterize typical interconnect discontinuities, including bends, steps, T junctions, vias and pads, which are the most commonly encountered interconnections in high speed digital integrated circuits, hybrid and monolithic microwave circuits and electronic packages. The time domain reflection response of these elements is used to classify the interconnect discontinuities as distributed discontinuity elements or as lumped elements depending upon the reflected waveform. For the cases of general distributed discontinuities including bends, steps and T junctions, the distributed equivalent circuit model is characterized by the time dependent impedance profile which is extracted from the time domain reflection measurements. By using known inverse scattering techniques implemented in terms of a new algorithm based on the transfer scattering matrix method of incremental uniform sections, this nonuniform impedance profile is extracted and is used to construct distributed element circuit models to represent the interconnect discontinuities. A circuit model consisting of lumped/distributed elements, is also developed for the interconnect discontinuities which is intended to combine the accuracy of the distributed model with the simulation efficiency of the lumped models. This hybrid mode reduces computer simulation time when used as a net list for general purpose circuit simulators, such as SPICE. For the case of discontinuities modelled as lumped elements, such as vias and wiring pads, closed form equations based on the transfer scattering matrix solution are derived and used to extract the lumped electrical parameters of these elements from the time domain reflection waveform. All of these lumped, distributed and hybrid models are validated by comparing the time domain simulation results with Time Domain Reflectrometer ( TDR ) measurements. A procedure for extracting the excess inductances and capacitances associated with the general discontinuities from the synthesized nonuniform impedance profile or the distributed model is also presented in this report. These results for excess lumped inductances and capacitances show close agreement with the published results for these structures which are based on the electromagnetic computation of excess currents and charges and frequency domain measurements. Finally, some typical cases demonstrating the effects of interconnect discontinuities in high speed clocking systems are presented and the procedure for reducing the reflections and transmission noise voltage by chamfering the bends and junctions is described. / Graduation date: 1992

Youth crime has been increasing rapidly since the Economy Reform and Open-door Policy in 1979 and become a serious social problem in China. Researches on explanations of juvenile delinquency, however, are relatively limited, while a number of scholars in western countries have developed delicate theoretical models to explore this problem. General strain, differential association, and social bond theory are employed in the current study to test if western theories can be applied to a different social context and to empirically explain the causes of youth crime in China. An integrated model is addressed through a self-reported survey with 385 respondents. The respondents are high school students in the city of Shenyang, aged from 16 to 18. Data from the questionnaire survey suggests that these three theories could explain Chinese youth crime. Two separate Ordinary Least Squares (OLS) models are built for analyzing delinquency of males and females. Predictors related to strain and differential association theory are directly associated with youth crime, while weak social bonds have indirect impacts on juvenile delinquency. Males and females are influenced by different factors when they are involved in delinquency. The thesis concludes with a discussion of establishing a theoretical integrated model for Chinese adolescence and provides policy implications for protection programs.

Youth crime has been increasing rapidly since the Economy Reform and Open-door Policy in 1979 and become a serious social problem in China. Researches on explanations of juvenile delinquency, however, are relatively limited, while a number of scholars in western countries have developed delicate theoretical models to explore this problem. General strain, differential association, and social bond theory are employed in the current study to test if western theories can be applied to a different social context and to empirically explain the causes of youth crime in China. An integrated model is addressed through a self-reported survey with 385 respondents. The respondents are high school students in the city of Shenyang, aged from 16 to 18. Data from the questionnaire survey suggests that these three theories could explain Chinese youth crime. Two separate Ordinary Least Squares (OLS) models are built for analyzing delinquency of males and females. Predictors related to strain and differential association theory are directly associated with youth crime, while weak social bonds have indirect impacts on juvenile delinquency. Males and females are influenced by different factors when they are involved in delinquency. The thesis concludes with a discussion of establishing a theoretical integrated model for Chinese adolescence and provides policy implications for protection programs.