Orientador: Nobuo Oki / Banca: Saulo Finco / Banca: Cláudio Kitano / Resumo: Nesse trabalho, propõe-se o projeto e implementação de um sintetizador de sinais ortogonais utilizando técnicas de circuito integrado e processo CMOS. O circuito do sintetizador baseia-se em um modelo matemático que utiliza multiplicadores e integradores analógicos, para geração de bases de funções ortogonais, tais como os polinômios de Legendre, as funções de base coseno e seno, a smoothed-cosine basis e os polinômios de Hermite. Funções ortogonais são bastante empregadas em processamento de sinais, e a implementação deste método matemático é capaz de gerar vários tipos de funções em um mesmo circuito integrado. O projeto proposto utiliza blocos analógicos funcionais para implementar o sintetizador. Os blocos que compõem o sintetizador foram projetados utilizando circuitos diferenciais, processamento em modo de corrente e técnicas de low-voltage. Algumas topologias utilizadas estão descritas na literatura, sendo que algumas foram adaptadas e mesmo modificadas, como no caso do multiplicador de corrente. Outras tiveram que ser propostas. As simulações e os resultados experimentais mostraram que o sintetizador é capaz de gerar funções ortogonais com amplitude e distorções satisfatórias. O sintetizador pode ser alimentado em 3V, tal qual foi projetado, tem faixa de entrada de ±20 μA e apresenta DHT (distorção harmônica total) inferior a 4% no quinto e último estágio em cascata. / Abstract: In this work, a design and implementation of a synthesizer of orthogonal signals using CMOS technology and design technique for integrated circuits is proposed. The synthesizer circuit used analog multipliers and integrators for produce orthogonal functions such as Legendre polynomials, cosine and sine basis of functions, smoothed-cosine basis and Hermite polynomials. Orthogonal functions can be employed in signal processing and the implementation proposed can generate several kinds of functions in the same integrated circuit. In the synthesizer design building blocks was employed. The synthesizer's blocks were design using differential circuits, low-voltage and current-mode techniques. Some topologies from papers were adapted or modified, as in the case of the current multiplier. Other topologies had to be proposed. The simulation and experimental results have shown that the synthesizer is able to produce orthogonal functions with satisfactory quality in distortions and amplitude. The synthesizer has a 3V supply voltage, a input current range of ±20 μA and it presents less than 4% of THD (Total Harmonic Distortion) in the last output in cascade. / Mestre

This diploma thesis is aimed primarily at the analysis and specification of the management specifics at schools with more grades in one class. Due to the proportionally lower number of those type of schools in the school system, these specifics have a general tendency to be neglected or at least only peripherally mentioned in literature, even though its management undoubtly differs from the one applied at fully organized primary schools. The theoretical part specifies the term school with more grades in one class and pursue to describe its specific features and particularities. A description of the general school management follows, aiming at its most important spheres. In this thesis, school management is being described primarily from the point of view of a headteacher. The research part of this thesis is realized through the method of questionnaire survey aimed at fully-organized schools headteachers and at schools with more grades in one class headteachers in Středočeský region, in order to discover their management specifics. This thesis is not framed as a qualitative comparison of those two school types. The specifies of fully-organized schools management are being elicited only as a default source of inrormation, from which the specifcs of school with more grades in one class management are...

Fluid-structure interaction (FSI) is an interesting and challenging interdisciplinary area comprised of fields such as engineering- fluids/structures/solids, computational science, and mathematics. FSI has several practical engineering applications such as the design of coastal infrastructure (such as bridges, levees) subjected to harsh environments from natural forces such as tsunamis, storm surges, etc. Development of accurate input conditions to more detailed and complex models involving flexible structures in a fluid domain is an important requirement for the solution of such problems. FSI researchers often employ methods that use results from physical wave basin experiments to assess the wave forces on structures. These experiments, while closer to the physical phenomena, often tend to be time-consuming and expensive. Experiments are also not easily accessible for conducting parametric studies. Alternatively, numerical models when developed with similar capabilities will complement the experiments very well because of the lower costs and the ability to study phenomena that are not feasible in the laboratory. This dissertation is aimed at contributing to the solution of a significant component of the FSI problem with respect to engineering applications, covering accurate input to detailed models and a numerical wave basin to complement large-scale laboratory experiments. To this end, this work contains a description of a three-dimensional numerical wave tank (3D-NWT), its enhancements including the piston wavemaker for generation of waves such as solitary, periodic, and focused waves, and validation using large-scale experiments in the 3D wave basin at Oregon State University. Performing simulations involving fluid dynamics is computational-intensive and the complexity is magnified by the presence of the flexible structure(s) in the fluid domain. The models are also required to take care of large-scale domains such as a wave basin in order to be applicable to practical problems. Therefore, undertaking these efforts requires access to high-performance computing (HPC) platforms and development of parallel codes. With these objectives in mind, parallelization of the 3D-NWT is carried out and discussed in this dissertation. / Graduation date: 2011

臺灣菸品市場之租稅負擔是個很奇特之現象，當臺灣政府對香菸產品課稅時，菸商會將租稅完全轉嫁給消費者，即便消費者之需求是有彈性的。本文為探討此原因，以Milgrom and Roberts之利潤目標模型為基礎，建立一個廠商追求利潤目標之模型來解釋，當菸商面臨政府課稅時，是否會將租稅百分之百轉嫁給消費者。由此模型推論出，若菸商欲維持市場之獨占或寡占地位時，便會追求較低之利潤目標，使潛在競爭者相信菸品市場利潤不大，此時潛在競爭者便不會進入菸品市場中與現有之菸商競爭。 本文設定利潤模型後，便以此利潤模型進行比較靜態分析，本文假設當菸商欲維持在市場之獨占或寡占地位時，於政府課徵從量稅後，會如何轉嫁租稅給消費者，並分別由價格及數量為切入點分析。經過比較分析後的結果可得知，只要菸商之目標為持續保有獨占或寡占之地位，而非追求利潤極大化時，租稅的完全轉嫁即會存在，即使消費者需求是有彈性的，消費者將會面對一個稅額百分之百增加的供給價格。 / The tax burden of cigarette products in the Taiwanese market baffles many researchers in public finance. Despite that the demand of cigarette products is elastic, when the tax rate of cigarette products increases, cigarette manufacturers, with no exception, raise the prices accordingly, and therefore, the increased taxes are entirely shifted to consumers. This is very different from the traditional idea of tax incidence based on elasticity. In order to figure out the reason, this paper uses the framework of the limit pricing model of Milgrom and Roberts (1982) with the assumption of target profit to establish an economic reasoning of why the tax hikes in the cigarette products are one hundred percent shifted to consumers. This model infers that when cigarette manufacturers have entry deterrence in mind, they tend to pursue a lower profit target to keep potential competitors away. Given the framework and basic assumption from above, comparative statics of tax increases are done for both quantity and pricing games. The results suggest that when cigarette manufacturers are facing an increase in the unit tax rate of their products, it is typical that the incidence of the increased tax been no less than one hundred percent forward-shifted to consumers. The traditional theory of tax incidence by elasticity under the profit maximization firms does not apply here. The economic intuition is that in order to thwart entry, existing firms use the complete forward shifting of the tax increase as a bad signal of the profitability of the market to potential competitors.

CDMA channel selection requires sharp as well as wide-band Filtering. SAW Filters which have been used for this purpose are only available in IF range. In direct conversion receivers this has to be done at low frequencies. Switched Capacitor technique has been employed to design a low power, highly selective low-pass channel select Filter for CDMA wireless receivers. The topology which has been chosen ensures the low sensitivity of the Filter response. The circuit has been designed in a mixed-mode 0. 18u CMOS technology working with a single supply of 1. 8 V while its current consumption is less than 10 mA.

Prostate segmentation is a required step in determining the volume of a prostate, which is very important in the diagnosis and the treatment of prostate cancer. In the past, radiologists manually segment the two-dimensional cross-sectional ultrasound images. Typically, it is necessary for them to outline at least a hundred of cross-sectional images in order to get an accurate estimate of the prostate's volume. This approach is very time-consuming. To be more efficient in accomplishing this task, an automated procedure has to be developed. However, because of the quality of the ultrasound image, it is very difficult to develop a computerized method for defining boundary of an object in an ultrasound image. The goal of this thesis is to find an automated segmentation algorithm for detecting the boundary of the prostate in ultrasound images. As the first step in this endeavour, a semi-automatic segmentation method is designed. This method is only semi-automatic because it requires the user to enter four initialization points, which are the data required in defining the initial contour. The discrete dynamic contour (DDC) algorithm is then used to automatically update the contour. The DDC model is made up of a set of connected vertices. When provided with an energy field that describes the features of the ultrasound image, the model automatically adjusts the vertices of the contour to attain a maximum energy. In the proposed algorithm, Mallat's dyadic wavelet transform is used to determine the energy field. Using the dyadic wavelet transform, approximate coefficients and detailed coefficients at different scales can be generated. In particular, the two sets of detailed coefficients represent the gradient of the smoothed ultrasound image. Since the gradient modulus is high at the locations where edge features appear, it is assigned to be the energy field used to drive the DDC model. The ultimate goal of this work is to develop a fully-automatic segmentation algorithm. Since only the initialization stage requires human supervision in the proposed semi-automatic initialization algorithm, the task of developing a fully-automatic segmentation algorithm is reduced to designing a fully-automatic initialization process. Such a process is introduced in this thesis. In this work, the contours defined by the semi-automatic and the fully-automatic segmentation algorithm are compared with the boundary outlined by an expert observer. Tested using 8 sample images, the mean absolute difference between the semi-automatically defined and the manually outlined boundary is less than 2. 5 pixels, and that between the fully-automatically defined and the manually outlined boundary is less than 4 pixels. Automated segmentation tools that achieve this level of accuracy would be very useful in assisting radiologists to accomplish the task of segmenting prostate boundary much more efficiently.

CDMA channel selection requires sharp as well as wide-band Filtering. SAW Filters which have been used for this purpose are only available in IF range. In direct conversion receivers this has to be done at low frequencies. Switched Capacitor technique has been employed to design a low power, highly selective low-pass channel select Filter for CDMA wireless receivers. The topology which has been chosen ensures the low sensitivity of the Filter response. The circuit has been designed in a mixed-mode 0. 18u CMOS technology working with a single supply of 1. 8 V while its current consumption is less than 10 mA.

Accelerometer sensors fabricated with micromachining technologies started to take place of yesterday&rsquo / s bulky sensors in many application areas. The application areas include a wide range from consumer electronics and health systems to military and aerospace applications. Therefore, the performance requirements extend form 1 &mu / g&rsquo / s to 100 thousand g&rsquo / s. However, high performance strategic grade MEMS accelerometer sensors still do not exist in the literature. Smart designs utilizing the MEMS technology is necessary in order to acquire high performance specifications. This thesis reports a high performance accelerometer with a new process by making the use of bulk micromachining technology. The new process includes the utilization of Silicon-on-Insulator (SOI) wafer and its buried oxide (BOX) layer. The BOX layer helps to realize interdigitated finger structures, which commonly find place in surface micromachined CMOS-MEMS capacitive accelerometers. The multi-metal layered CMOS-MEMS devices inherently incorporate interdigitated finger structures. Interdigitated finger structures are highly sensitive to acceleration in comparison with comb-finger structures, which generally find usage in bulk-micromachined devices, due to absence of anti-gap. The designed sensors based on this fabrication process is sought to form a fully-differential signal interfaced sensor with incorporation of the advantages of high sensitive interdigitated finger electrodes and high aspect ratio SOI wafer&rsquo / s bulk single crystal silicon device. Under the light of the envisaged process, sensor designs were made, and verified using a computing environment, MATLAB, and a finite element analysis simulator, CoventorWARE. The verified two designs were fabricated, and all the tests, except the centrifuge test, were made at METU-MEMS Research Center. Among the fabricated sensors, the one designed for the high performance achieves a capacitance sensitivity of 178 fF with a rest capacitance of 8.1 pF by employing interdigitated finger electrodes, while its comb-finger implementation can only achieve a capacitance sensitivity of 75 fF with a rest capacitance of 10 pF.

Dauguma išsivysčiusių pasaulio šalių susiduria su senatvės pensijų sistemos mokumo problemomis, todėl senatvės pensijų modelių analizei ir jų tobulinimui pastaraisiais dešimtmečiais skiriama vis daugiau dėmesio. Tyrimo objektu pasirinkti senatvės pensijų draudimo modeliai. Tyrimo problema yra ta, kad nėra vieno ir tobulo senatvės pensijų sistemos modelio, kurį būtų galima efektyviai pritaikyti esant konkrečioms ekonominėms, socialinėms ir demografinėms aplinkybėms. Tyrimo tikslas yra išanalizuoti įvairius senatvės pensijų draudimo modelius, identifikuoti pagrindinius jų parametrus, išskirti pagrindinius finansavimo ir išmokų mokėjimo būdus bei įvertinti priežastis, lemiančias modelių pasirinkimą bei jų tęstinumą užtikrinančius kriterijus, atlikti Lietuvos senatvės pensijų sistemos vertinimą. Darbe atlikta mokslinė užsienio ir lietuvių literatūros bei statistinių duomenų analizė, siekiant atskleisti senatvės pensijų modelius, kitimą, problemas ir svarbiausius teorinius aspektus, taip pat atliktas tyrimas siekiant įvertinti Lietuvos senatvės pensijų sistemą. Darbas susideda iš trijų skyrių. Pirmame skyriuje „Senatvės pensijų draudimo modeliai“ apibrėžiama senatvės pensinio draudimo ir tradicinių pensinių draudimo modelių samprata, susijusios sąvokos, administravimo būdai, analizuojami einamųjų mokėjimų ir kaupimo modeliai, pensijų pakopos. Pateikiami mokslininkų tyrimai ir nuomonės apie skirtingus modelius. Antrame skyriuje „Lietuvos senatvės pensijų draudimo modelis“... [toliau žr. visą tekstą] / Most developed countries faces a pension system solvency problems, that‘s why in recent decades old-age pension models analysis and development has received increasing attention. Object of study is chosen old-age pension models. The research problem is that there is no one perfect model, which can be effectively applied to specific economic, social or demographic circumstances. The aim of study is to analyze variety old-age pension models, identify key parameters, distinguish the main financing and payment methods and assess the reasons which influence the choice of models, evaluate Lithuania old-age pension system. Analysis of scientific foreign and Lithuania literature and statistical data are done in study, on purpose to reveal the problems, dynamics and the most important theoretical aspects, also a research is done to evaluate the Lithuanian old-age pension system. The study consists of three chapters. In the first part “The old-age pension models” are defined the concept of old age pension, related terms, traditional old-age models concepts, pension system administration methods are related, pay-as-you-go and fully funded models and pension pillars are analyzed. Scientific research and opinion are presented about different models. In the second part “Lithuania old-age pension model” Lithuania old age pension model is analyzed: current state, funding, legislative basis, performed a statistical data analysis. In the third part respondent’s systematized survey are... [to full text]

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