Dissertations / Theses on the topic 'Duobinary return to zero'

A 4 bit, Rom-Less Direct Digital Frequency Synthesizer (DDFS) is designed in 65nm CMOS technology. Interleaving with Return-to-Zero (RTZ) technique is used to increase the output bandwidth and synthesized frequencies. The performance of the designed synthesizer is evaluated using Cadence Virtuoso design tool. With 3.2 GHz sampling frequency, the DDFS achieves the spurious-free dynamic range (SFDR) of 60 dB to 58 dB for synthesized frequencies between 200 MHz to 1.6 GHz. With 6.4 GHz sampling frequency, the synthesizer achieves the SFDR of 46 dB to 40 dB for synthesized frequencies between 400 MHz to 3.2 GHz. The power consumption is 80 mW for the designed mixed-signal blocks.

Made available in DSpace on 2016-04-25T16:44:54Z (GMT). No. of bitstreams: 1 Stefan C Lee.pdf: 425129 bytes, checksum: b42eba077dbf34d3a8fc08b95deafb31 (MD5) Previous issue date: 2007-05-09<br>This dissertation analyzes the relationship between the return on equity and the cost of equity, as suggested by the CAPM: Capital Asset Pricing Model, for non financial Brazilian companies. Among the various kinds of returns on equity, the net profit divided by shareholder s accounting equity was adopted as the principal return, having advantages including widespread utilization and simplicity. Sector samples, taken from the paper and pulp, steel, textile and petrochemical sectors, and a non sector sample, composed of 105 companies, were analyzed. The differences between ROE and cost of equity were calculated for the period between 1995 and 2005 and the parametrical t Student and non parametrical Wilcoxon statistic tests were carried out to compare means. The results reveal a pessimistic scenario for investments in Brazil and, from the five samples, only one from the steel sector sample reported a compatible ROE with the cost of equity. Most of non financial Brazilian companies do not have equal or higher returns than the cost of equity and, worse of all, these returns are many times lower than federal interest rates. Complementary analysis with the multi regression technique indicated a paradox due to the coexistence of a high cost of equity, shareholder s value destruction, and continuity, creation, and growth of investments. Future studies are proposed to understand and rationalize the results<br>O trabalho se propõe a analisar a relação entre o retorno sobre o patrimônio líquido e o custo do capital próprio, medido pelo Capital Asset Pricing Model, das empresas não financeiras brasileiras. Dentre os diversos retornos do capital próprio, o lucro líquido sobre o patrimônio líquido contábil foi o principal adotado, tendo como vantagens também a simplicidade e difusão. Foram extraídas amostras setoriais de papel e celulose, de metalurgia e siderurgia, têxtil e de petroquímica, e uma não setorial, que foi composta por 105 empresas. As diferenças entre os retornos sobre o patrimônio líquido e o custo do capital próprio foram coletadas para o período de 1995 a 2005 e foram realizados os testes paramétrico t Student e não paramétrico Wilcoxon de igualdade de médias. Os resultados obtidos apontam um cenário pessimista para investimentos no Brasil, uma vez que das cinco amostras, apenas a do setor de metalurgia e siderurgia teve retornos sobre o patrimônio líquido compatíveis com o custo do capital próprio. A maioria das empresas brasileiras não financeiras não consegue igualar ou superar o custo do capital próprio e, em vários casos, não conseguem sequer superar a taxa base. Análises complementares baseadas em regressões multivariadas indicaram um paradoxo entre as coexistências de um alto custo de capital próprio, destruição de valor aos acionistas, e a continuidade, a criação e a ampliação dos investimentos. Estudos futuros são propostos para a compreensão e racionalização dos resultados

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California<br>Although PCM/TDM framed data is one of the most prevalent formats handled by flight test ranges, it is often required to acquire and process other types. Examples of such non-standard data types are radar position information and meteorological data from both ground based and radiosonde systems. To facilitate the process and management of such non-standard data types, a micro-processor based system was developed to acquire and transform them into a standard PCM/TDM data frame. This obviated the expense of developing additional special software and hardware to handle such non-standard data types.

This master’s thesis is dealing with the plan of reconstruction of the house in an effort to get closer to "near zero building". Total heat loss along with calculation of the cost of the house operation and the energy performance of buildings were computed for the given house. Then we have enclosed suggestions of individual methods of building´s insulation (replacing of windows, doors and gates, insulation of exterior walls, roof and ceiling between floor and attic) and a draft of a new technical building services (forced ventilation with heat recovery, photovoltaic system and heat pump). Furthermore, the suitability of the original heating system was evaluated and the also the energy performance for the renovated building was analyzed during the reconstruction. An economic evaluation was calculated for each method of reconstruction, together with the new green subsidy programme. At the end of the dissertation is drawn up the economic evaluation of the whole proposed reconstruction, together with an assessment, what class of the building we have achieved according to its the energy intensity.

This research project explores a direction in the formation of sound and image. In the creation of a series of 'moving paintings' I bring together pieces of moving image and sound using techniques derived from musique concr??te. I have coined the term 'moving painting' to describe these sound/image objects that have grown out of an attention to the form, activity, rhythm and texture of sound and image. This project develops from an understanding that sound and image can be constructed on their own terms as opposed to being organised by specific plot devices. This text offers a context for the formation of these moving paintings and outlines the systems of construction that bring them forth from noise. Firstly, I identify sound and its emergence from noise. Secondly, I address the formation of sound into music within a community. And lastly, I use these ideas to form systems for organising visual imagery. In doing this, I present a series of audiovisual works in which sound and image are woven together to form moving paintings.

碩士<br>國立交通大學<br>光電工程系所<br>95<br>In this thesis, we use a semiconductor optical amplifier (SOA) backward injected with a dark-optical-comb pulse-train at 10 GHz to demonstrate a 10Gbit/s all-optical non-return-to-zero (NRZ) to return-to-zero (RZ) format conversion of an incoming optical pseudorandom binary sequence (PRBS) data-stream. Without any pre-amplification on the degraded optical NRZ PRBS data, its extinction ratio is greatly improved from 7.13 dB to 13.6 dB after converting into a RZ PRBS data. Low bit-error-rate (BER) of 10-12 at data rate up to 10 Gbit/s is obtained with a received optical power of -18.3 dBm. To date, the converted RZ PRBS data exhibits a negative power penalty of >3.7 dB at a BER of 10-12 in comparison with the NRZ PRBS data. The characteristics in our proposed experiment include simple architecture and both of the polarity and wavelength of converted RZ data as same as the incoming NRZ data during the format conversion process. Furthermore, by spectrally and temporally reshaping the gain-window of a SOA with a backward injected multi- or single-wavelength dark-optical-comb, we also theoretically and experimentally investigate the dynamic frequency chirp of the all-optical 10GBit/s RZ data-stream format-converted from the SOA under strong cross-gain depletion scheme. The multi-wavelength dark-optical-comb injection effectively depletes the SOA gain spectrally and temporally, remaining a narrow gain-window and a reduced spectral linewidth and provide a converted RZ data with a smaller peak-to-peak frequency chirp of 11.1 GHz. Even at high dark-optical-comb injection power and highly biased current for improving the operational bit-rate, the chirp of the multi-wavelength injection converted RZ pulse is still 2.1 GHz smaller than that obtained by using single-wavelength injection at a cost of slight pulsewidth broadening by 1 ps.

碩士<br>國立成功大學<br>電機工程學系碩博士班<br>93<br>Current-Steering Digital-to-Analog Converters (DACs) can directly drive external loads and are commonly used for high-speed application. However, these current-steering DACs suffer from the element mismatch of technologies and this limit both the static and dynamic linearity. In this thesis, a new calibration structure to improve the element mismatch is presented. Besides, the nonlinear transient output also degrades the dynamic performance. Recently, the return-to-zero method is used to attenuate the output when this nonlinear transient occurs, but loses half of output power, too. Here, we also propose a fixed-time return-to-zero scheme to improve the dynamic performance without losing much output power. 　A 14-bit 200-MHz current-steering DAC is implemented in this thesis. It uses the above self-calibration circuit to obtain the static linearity and fixed-time return-to-zero output to obtain the dynamic linearity. The DAC occupies 1.07mm X 1.07 mm in a 0.18-um 1P6M CMOS process. In the simulation, the INL and DNL is expected to be less than 0.5 LSB and the SFDR is 77dB at the lower output frequency and 68dB at the high output frequency when this DAC operates at the design clock of 200MS/s. It consumes 43mW from a 1.8V supply. In the measurement, the INL is 3.66LSB and the SFDR remains above 60 dB up to a signal frequency of 3-MHz at the update rate of 20 MS/s.

Pun Siu Sun.<br>Thesis (M.Phil.)--Chinese University of Hong Kong, 2005.<br>Includes bibliographical references (leaves 55-58).<br>Abstract in English and Chinese.<br>ABSTRACT --- p.ii<br>摘要 --- p.iv<br>Chapter 1 --- BLACKGROUND AND INTRODUCTION --- p.1<br>Chapter 1.1 --- OPTICAL FREQUENCY SHIFT KEYING (FSK) --- p.1<br>Chapter 1.1.1 --- Basic concepts --- p.1<br>Chapter 1.1.2 --- Applications --- p.3<br>Chapter 1.2 --- MODULATION FORMATS --- p.6<br>Chapter 1.3 --- ORTHOGONAL MODULATION --- p.9<br>Chapter 1.4 --- THESIS ORGANIZATION --- p.11<br>Chapter 2 --- A NOVEL OPTICAL FREQUENCY SHIFT KEYING TRANSMITTER BASED ON POLARIZATION MODULATION --- p.12<br>Chapter 2.1 --- EXISTING OPTICAL FSK TRANSMITTER DESIGNS --- p.12<br>Chapter 2.1.1 --- Optical FSK transmitter based on complementary intensity modulation --- p.12<br>Chapter 2.1.2 --- Optical FSK transmitter based on direct modulation in a DFB laser --- p.13<br>Chapter 2.1.3 --- Optical FSK transmitter based on single side-band (SSB) modulation technique --- p.15<br>Chapter 2.1.4 --- Optical Continuous-Phase FSK (CPFSK) transmitter based on asymmetric Mach-Zehnder modulator --- p.17<br>Chapter 2.1.5 --- Optical FSK transmitter based on phase modulation --- p.18<br>Chapter 2.1.6 --- Summary --- p.20<br>Chapter 2.2 --- PROPOSED OPTICAL FSK TRANSMITTER BASED ON POLARIZATION MODULATION --- p.21<br>Chapter 2.3 --- EXPERIMENTAL DEMONSTARTION --- p.23<br>Chapter 2.4 --- SYSTEM PERFORMANCE --- p.25<br>Chapter 2.5 --- SUMMARY --- p.27<br>Chapter 3 --- OPTICAL RETURN-TO-ZERO FREQUENCY SHIFT KEYING (RZ-FSK) (RZ-FSK) --- p.28<br>Chapter 3.1 --- INTRODUCTION AND MOTIVATION --- p.28<br>Chapter 3.2 --- PREVIOUS NRZ vs. RZ COMPARISON --- p.30<br>Chapter 3.3 --- RZ-FSK TRANSMITTER DESIGN --- p.32<br>Chapter 3.4 --- PERFROMANCE COMPARISON --- p.33<br>Chapter 3.4.1 --- Back-to-back performance --- p.34<br>Chapter 3.4.2 --- Chromatic dispersion tolerance --- p.35<br>Chapter 3.4.3 --- Fiber nonlinearity tolerance --- p.38<br>Chapter 3.5 --- SUMMARY --- p.41<br>Chapter 4 --- A NOVEL OPTICAL TRANSMITTER FOR HIGH-SPEED DIFFERENTIAL PHASE SHIFT KEYING/INVERSE RETURN-TO-ZERO (DPSK/INV-RZ) ORTHOGONALLY MODULATED SIGNALS --- p.42<br>Chapter 4.1 --- INTRODUCTION --- p.42<br>Chapter 4.2 --- PREVIOUS SCHEME --- p.43<br>Chapter 4.3 --- PROPOSED TRANSMITTER DESIGN --- p.45<br>Chapter 4.4 --- EXPERIMENT AND RESULTS --- p.47<br>Chapter 4.5 --- CONCLUSION --- p.51<br>Chapter 5 --- SUMMARY --- p.52<br>Chapter 5.1 --- THESIS SUMMARY --- p.52<br>Chapter 5.2 --- FUTURE WORK --- p.53<br>LIST OF PUBLICATIONS --- p.54<br>REFERENCES --- p.55

碩士<br>國立成功大學<br>電機工程學系碩博士班<br>94<br>Current-steering digital-to-analog converters (DACs) can drive the external loading directly in high-speed applications. However, the performance of these current-steering DACs is determined by both the static and dynamic linearity. In this thesis, a DEM-like algorithm called “Random Multiple Data-Weighted Averaging, RMDWA” is accomplished to diminish the harmonic distortions resulted from process mismatches with its simple circuit design. BM rotated walk layout technique is proposed to increase the effect. Besides, the DACs also suffer from the glitches when they are operated at high speed. The return-to-zero (RTZ) switching scheme becomes a best candidate to eliminate the glitches from transients. Nevertheless, conventional RTZ schemes are the ways which are shorted the output to the ground. Abrupt voltage change results in current variations and more distortions. A proposed return-to-zero scheme with constant switching load can keep the same environments when transients and can maintain the high spurious free dynamic range (SFDR) in high-speed operations. Using the antecedent of new techniques, a low-power and small-area 14-bit 100-MHz current-steering DAC is implemented in this thesis. The DAC includes a 5-bit MSBs and ULSBs with thermometer decoders and RMDWA algorithm and 4-bit binary-coded LLSBs. A new return-to-zero switching scheme is placed in output of DAC to maintain the high-performance at high-speed output frequency. It just occupies 0.26mm2 in a TSMC 0.18um 1P6M CMOS process. In the simulation, the SFDR achieves 89dB at the lower output frequency, and 69dB at the Nyquist-rate output frequency with operated frequency of 100MS/s. The power consumptions are 21mW for analog circuits and 2mW for digital circuits from a 1.8V supply.

O nosso estudo têm por objetivo analisar as diferenças que existem entre os níveis de transação em empresas que se encontram cotadas no mercado de capitais e perceber o motivo pelo qual permanecem cotadas, com recurso a uma nova medida que analisa a percentagem de dias em que não existe qualquer retorno, denominada por Zero-Return Metric. Utilizando uma base de dados de 2.502 empresas para o período entre 2004 a 2014 do principal índice acionista do Reino Unido, é apresentado uma mediana de 58,7% de dias em que não existe qualquer retorno. Partimos do pressuposto que as empresas pretendem aceder a esta estrutura de financiamento devido às vantagens que apresenta, contudo nem todas as empresas conseguem captar de igual forma os seus benefícios. Com base nisto, é possível observar diferenças significativas na visibilidade, nas necessidades de capital, no grau de concentração da estrutura acionista e na liquidez entre as empresas, o que pode explicar algumas diferenças no nível de transação. Como consequência, a taxa de sobrevivência deste tipo de empresas é bastante inferior, sendo um importante indicador do seu grau de desempenho. O nosso objetivo passa por apresentar um estudo compreensivo sobre este efeito, lançando as bases para um estudo mais aprofundado nesta área.<br>Our study aims to analyze the differences between the transactions levels in companies that are listed on the capital market, and realize why they remain listed, using a new measure that analyses the proportion of zero-return days (thereafter referred to as the zero-return metric). Using a Database with 2.502 firms for the period 2004-2014 of the main UK stock market index, a median with 58,7% of days without a return is represented. We assume that the companies want to access this financing structure due to the advantages they offer, however not all companies are able to capture the same way its benefits. On this basis, it is possible to observe significant differences in visibility, capital needs and growth, in the degree of shareholders structure and liquidity, which may explain some differences in transaction level. As a result, the survival rates for those companies is much lower, being an important indicator of their level of performance. Our objective is to present a comprehensive descriptive study of this effect, laying the foundations to a more in depth study.

碩士<br>國立中山大學<br>電機工程學系研究所<br>107<br>The Implementation of Signal Processing Chips”. Particularly, these topics applied the photonic gyro system are high-efficiency buck converter with wide load current range using dual-mode of PWM and PSM and 12-bit 100 MS/s current steering DAC using dynamic element matching and return to zero techniques. They are implemented using TSMC 0.35 um Mixed-Signal 2P4M Polycide 3.3/5 V and TSMC 45 nm CMOS LOGIC General Purpose Superb (40G) ELK Cu 1P10M 0.9/2.5 V processes, respectively. The proposed high efficiency buck converter is featured with integration of PWM and PSM modes to increase the efficiency given a wide load current range. The peak efficiency is 96.76 % when the load current is 1000 mA, while the efficiency in the load current range from 10 mA to 1000 mA is over 94.80 %. In addition, the proposed design accurately switches between heavy load current and light load current by a well-designed logic decoder circuit. A dynamic element matching and return to zero techniques are used to realize a 12- bit 100 MS/s current steering DAC with a precision of 1 to 10◦/h for the Heterogeneous Silicon Photonics Gyroscope. A pseudo-random number generator carries out the random selection of current sources to reduce the mismatch among these current sources caused by layout issues and also reduce the delay by using compact return to zero technique. Not only is the circuit area greatly reduced, the SFDR is also enhanced to 61 dB at 100 MS/s.