Feedforward is known to be one of the best methods for power amplifier linearization due to its superior linearization performance and broadband stable operation. However feedforward systems have relatively poor power efficiency and are complicated due to the presence of two nonlinear amplifiers and the requirements of amplitude, phase and delay matching within two different loops. In this thesis stochastic characterization of a simple feedforward system with autocorrelation analysis has been presented for Code Division Multiple Access (CDMA) applications taking the amplitude and delay mismatches into consideration. It has been assumed that, the input signal can be represented as Gaussian noise, main and error amplifiers can be modeled with third order AM/AM nonlinearities and there exists no phase mismatch within the loops. Hence closed form expressions, which relate the main channel and distorted adjacent channel power at any point in the feedforward circuitry to the system parameters, have been obtained. Consequently, a mathematical handy tool is achieved towards specifying the circuit parameters rapidly for optimum linearity performance and efficiency. The developed analytical model has been verified by Radio Frequency (RF) and system simulations. An alternative approach towards modeling feedforward systems for arbitrary signals has also been brought into consideration and has been verified with system simulations.

O objetivo deste estudo é explorar uma metodologia para análises de autocorrelação em redes utilizando um atributo de fenômenos cuja ocorrência esteja de alguma forma vinculada ou que seja dependente de uma rede. Para isso foram utilizados dados de acidentes de trânsito em um estudo de caso para a cidade de São Carlos, referentes aos anos de 2001, 2002 e 2003. Foram considerados inicialmente os dados totais dos acidentes e, em seguida, separados por tipos (atropelamentos, acidentes com danos materiais e acidentes com vítimas). A próxima etapa considerou os valores dos acidentes totais majorados pela UPS (Unidade Padrão de Severidade). A última etapa do estudo levou ainda em consideração a localização dos acidentes nos arcos ou interseções, que permitiu concluir que esta forma de caracterização espacial dos acidentes pode interferir significativamente nos resultados da análise. Outra conclusão relevante foi a identificação de autocorrelação espacial elevada e positiva no caso estudado. Finalmente a comparação com análise semelhante realizada por áreas demonstra vantagens para a análise por redes. / The objective of this study is to explore a methodology for network spatial autocorrelation analysis by applying it to an attribute of phenomena that are somehow connected to or dependent of a network. In other to do so, traffic accident data recorded in the years 2001, 2002, and 2003 in the city of São Carlos were selected for a case study. A first analysis considered all data, followed by analyses per accident type. In another phase of the study, the total accidents were weighted according to their severity. The last part of the study included in the analysis information about the location of each accident, either at a link or at an intersection. A conclusion drawn from the later analysis indicated that the consideration of the accidents locations can produce significant changes in the results. Another relevant conclusion was the identification of high and positive spatial autocorrelation in the case studied. Finally, the comparison with a similar analysis carried out with areas shows advantages for the network analysis.

O objetivo deste estudo é explorar uma metodologia para análises de autocorrelação em redes utilizando um atributo de fenômenos cuja ocorrência esteja de alguma forma vinculada ou que seja dependente de uma rede. Para isso foram utilizados dados de acidentes de trânsito em um estudo de caso para a cidade de São Carlos, referentes aos anos de 2001, 2002 e 2003. Foram considerados inicialmente os dados totais dos acidentes e, em seguida, separados por tipos (atropelamentos, acidentes com danos materiais e acidentes com vítimas). A próxima etapa considerou os valores dos acidentes totais majorados pela UPS (Unidade Padrão de Severidade). A última etapa do estudo levou ainda em consideração a localização dos acidentes nos arcos ou interseções, que permitiu concluir que esta forma de caracterização espacial dos acidentes pode interferir significativamente nos resultados da análise. Outra conclusão relevante foi a identificação de autocorrelação espacial elevada e positiva no caso estudado. Finalmente a comparação com análise semelhante realizada por áreas demonstra vantagens para a análise por redes. / The objective of this study is to explore a methodology for network spatial autocorrelation analysis by applying it to an attribute of phenomena that are somehow connected to or dependent of a network. In other to do so, traffic accident data recorded in the years 2001, 2002, and 2003 in the city of São Carlos were selected for a case study. A first analysis considered all data, followed by analyses per accident type. In another phase of the study, the total accidents were weighted according to their severity. The last part of the study included in the analysis information about the location of each accident, either at a link or at an intersection. A conclusion drawn from the later analysis indicated that the consideration of the accidents locations can produce significant changes in the results. Another relevant conclusion was the identification of high and positive spatial autocorrelation in the case studied. Finally, the comparison with a similar analysis carried out with areas shows advantages for the network analysis.

The methods that fueled the microscale revolution (top-down design/fabrication, combined with application of forces large enough to overpower stochasticity) constitute an approach that will not scale down to nanoscale systems. In contrast, in nanotechnology, we strive to embrace nature’s quite different paradigms to create functional systems, such as self-assembly to create structures, exploiting stochasticity, rather than overwhelming it, in order to create deterministic, yet highly adaptable, behavior. Nature’s approach, through billions of years of evolutionary development, has achieved self-assembling, self-duplicating, self-healing, adaptive systems. Compared to microprocessors, nature’s approach has achieved eight orders of magnitude higher memory density and three orders of magnitude higher computing capacity while utilizing eight orders of magnitude less power. Perhaps the most complex of functions, homeostatis by a biological cell – i.e., the regulation of its internal environment to maintain stability and function – in a fluctuating and unpredictable environment, emerges from the interactions between perhaps 50M molecules of a few thousand different types. Many of these molecules (e.g. proteins, RNA) are produced in the stochastic processes of gene expression, and the resulting populations of these molecules are distributed across a range of values. So although homeostasis is maintained at the system (i.e. cell) level, there are considerable and unavoidable fluctuations at the component (protein, RNA) level. While on at least some level, we understand the variability in individual components, we have no understanding of how to integrate these fluctuating components together to achieve complex function at the system level. This thesis will explore the regulation and control of stochasticity in cells. In particular, the focus will be on (1) how genetic circuits use noise to generate more function in less space; (2) how stochastic and deterministic responses are co-regulated to enhance function at a system level; and (3) the development of high-throughput analytical techniques that enable a comprehensive view of the structure and distribution of noise on a whole organism level.

Print quality demands for coated papers are steadily growing, and achieving coating uniformity is crucial for high image sharpness, colour fidelity, and print uniformity. Coating uniformity may be divided into two scales: coating thickness uniformity and coating microstructure uniformity, the latter of which includes pigment, pore and binder distributions within the coating layer. This thesis concerns the investigation of both types of coating uniformity by using an approach of quantitative microscopy.First, coating thickness uniformity was analysed by using scanning electron microscope (SEM) images of paper cross sections, and the relationships between local coating thickness variations and the variations of underlying base sheet structures were determined. Special attention was given to the effect of length scales on the coating thickness vs. base sheet structure relationships.The experimental results showed that coating thickness had a strong correlation with surface height (profile) of base sheet at a small length scale. However, at a large length scale, it was mass density of base sheet (formation) that had the strongest correlation with coating thickness. This result explains well the discrepancies found in the literature for the relationship between coating thickness variation and base sheet structure variations. The total variance of coating thickness, however, was dominated by the surface height variation in the small scale, which explained around 50% of the variation. Autocorrelation analyses were further performed for the same data set. The autocorrelation functions showed a close resemblance of the one for a random shot process with a correlation length in the order of fibre width. All these results suggest that coating thickness variations are the result of random deposition of particles with the correlation length determined by the base sheet surface textures, such as fibre width.In order to obtain fundamental understandings of the random deposition processes on a rough surface, such as in paper, a generic particle deposition model was developed, and systematic analyses were performed for the effects of particle size, coat weight (average number of particles), levelling, and system size on coating thickness variation. The results showed that coating thickness variation3grows with coat weight, but beyond a certain coat weight, it reaches a plateau value. A scaling analysis yielded a universal relationship between coating thickness variation and the above mentioned variables. The correlation length of coating thickness was found to be determined by average coat weight and the state of underlying surfaces. For a rough surface at relatively low coat weight, the correlation length was typically in the range of fibre width, as was also observed experimentally.Non-uniformities within the coating layer, such as porosity variations and binder distributions, are investigated by using a newly developed method: field emission scanning electron microscopy (FESEM) in combination with argon ion beam milling technique. The combination of these two techniques produced extremely high quality images with very few artefacts, which are particularly suited for quantitative analyses of coating structures. A new evaluation method was also developed by using marker-controlled watershed segmentation (MCWS) of the secondary electron images (SEI).The high resolution imaging revealed that binder enrichment, a long disputed subject in the area, is present in a thin layer of a 500 nm thickness both at the coating surface and at the base sheet/coating interface. It was also found that the binders almost exclusively fill up the small pores, whereas the larger pores are mainly empty or depleted of binder.

高速公路系統建設可提升區域與區域之間的可及性與易行性，同時達到節省旅行時間和成本、高速公路交流道沿線地區土地價值上升等效果。此外，高速公路系統建設對於周圍地區人口、產業可產生相當程度之影響，例如大量的人口遷移、區域交通影響衝擊、社會和經濟層面產生重大變化等，進而改變國家及區域發展方向。於此情況下，合宜地評估及分析高速公路系統建設開發對國家及區域發展之影響，將有助於其推展並降低對地區之不利影響。 本研究希望以我國從1976至2010年來，共九條高速公路系統 建設為研究主軸，利用台灣城際運輸系統需求模式(TMD2008)之旅行時間資料、內政部戶口普查及工商普查資料為基礎，並運用事前事後比較(before and after analysis)與空間自相關分析(Spatial Autocorrelation analysis)等分析方法對高速公路系統建設所造成區域人口、產業之空間變動進行評估，分析高速公路系統建設對於區域人口、產業及交通可及性之空間分布變化影響。最後則建構高速公路可及性對區域人口及產業空間影響模型，並針對歷年來高速公路系統建設對國家及區域發展的影響進行實證分析。 / The benefits of highway infrastructure investments include promoted inter-regional accessibility and mobility, saved travel time and cost and increased land value in freeway interchange areas. In sum, highway infrastructure investments play an important role in national and regional development. It contributes to the population re-distribution, the growth of economic activities, and more importantly, the land use change. Therefore, how to effectively evaluate the impact of highway investments on national and regional development is an important research topic. The analytical results in this study can be applied to increase the accuracy of population and economic projection, and to manage transportation policy decisions. Between 1976 and 2010, there were nine highway systems had been built in Taiwan. This study emphasizes on the impact of highway investments on the spatial distribution of population and industry, and regional accessibility change. In this paper, we utilize before and after analysis and Spatial Autocorrelation analysis with Geographic Information System to analyze demographic data, economic data and TDM2008 database in order to perform the spatial analysis of population and industry re-distribution along highway constructions. Finally, a spatial gravity model is built to verify and describe the related spatial impacts so that several influential factors can be identified by this empirical study.