Performance of concurrency control and data allocation in distributed database systems

Chen, David De-Hui University of Michigan 1983 해외박사

A CRITIQUE ON SCIENTIFIC RATIONALITY IN THE PRODUCTION OF ARCHITECTURE (LE CORBUSIER, ALEXANDER CHRISTOPHER, PATTERN LANGUAGE)

CHEN, HUI-MIN Georgia Institute of Technology 1993 국내박사

리얼리즘과 준사회적 상호작용이 리얼리티 프로그램에 대한 태도에 미치는 영향 : - 매개효과를 중심으로 -

CHEN HUI 세종대학교 대학원 2020 국내석사

본 연구에서는 문화계발이론(cultivation theory), 리얼리즘 인식(perceived-realism), 준사회적 상호작용(para-social interaction) 등을 토대로 중국 리얼리티 프로그램 시청정도(시청량, 시청집중도)에 따라 리얼리즘 인식과 준사회적 상호작용 인식에 차이가 있음을 살펴보았으며 리얼리즘 인식과 준사회적 상호작용 인식이 리얼리티 프로그램에 대한 시청자 태도(신뢰도, 선호도, 시청의도, 충성도)에 미치는 정적인 영향을 밝혔다. 또한 그 관계에서 리얼리즘 인식과 준사회적 상호작용 인식의 매개효과가 나타났음을 확인하였다. 이와 같은 연구문제를 검증하기 위해 총 618명의 응답자에게 설문조사를 실시하였고 분석결과는 다음과 같다. 첫째, 육아, 연애, 오디션 리얼리티 프로그램에서 중 시청량층이 경 시청량층과 보통 시청량층에 비해 리얼리즘 인식과 준사회적 상호작용 인식을 더 많이 느끼는 것으로 나타났다. 반면에 중 시청집중도층이 경 시청집중도층과 보통 시청집중도층에 비해 리얼리즘 인식과 준사회적 상호작용 인식을 덜 많이 느끼고 있었다. 둘째, 리얼리즘 인식과 준사회적 상호작용 인식은 시청자 태도에 긍정적인 영향을 미치는 것으로 나타났다. 즉, 리얼리즘과 준사회적 상호작용 인식이 높을수록 리얼리티 프로그램에 대한 신뢰도, 선호도, 시청의도, 충성도가 모두 높아지는 것이다. 셋째, 육아, 연애, 오디션 리얼리티 프로그램의 시청정도와 시청태도 간에 리얼리즘 인식과 준사회적 상호작용 인식이 매개효과가 나타났다. 이와 반대로 시청집중도와 시청태도 간에는 리얼리즘 인식과 준사회적 상호작용 인식이 매개효과가 나타났다. 본 연구는 시청자 태도에 대한 연구 분야의 확장에 기여하고 문화계발 효과를 활용 점에서 이론적 의미가 있으며 리얼리티 프로그램 제작 실무자에게 리얼리즘 인식과 준사회적 상호작용 인식을 고려의 필요성을 보여 주었다는 점에서 실무적 의의가 있다.

Probability modeling and estimation for hourly vanation of air pollation concentrations

Foo, Chen Hui Lisa University Microfilms International 1984 국내박사

Probability modeling and estimation for hourly variation of air pollution concentrations

Foo, Chen-Hui Lisa Stanford University 1980 해외박사

Probability modelling and estimation for hourly variation of air pollation concentrations

Foo, Chen-Hui Lisa University microfilms international 1978 해외박사

Probability modeling and estimation for hourly variation of air pollution concentrations

Foo, Chen-Hui UMI 1979 해외석사

An analytical approach to deriving usage patterns in a Web-based information system

Chen, Hui-Min University of California, Berkeley 2000 해외박사(DDOD)

With the growing popularity of the World Wide Web, Web-based information systems have become one of the primary means for people to access information. Though usage patterns in traditional information systems such as public access library catalogs (OPACs) have been studied for more than three decades, investigations of similar information systems in a hypertext environment remain scarce. This study presents an analytical approach to deriving usage patterns in a Web-based information system. First, system users are divided into groups with similar use of the system by employing multivariate statistical analysis techniques. Second, a continuous-time stochastic model (a semi-Markov chain model) is developed for each user group. The transition rates as well as transition probabilities of the Markov model (called intrasession usage patterns) are used to characterize user behavior probabilistically. Third, a generic algorithm (called GREEDY) is developed to discover both time-invariant and time-dependent sequential usage patterns (called intersession usage patterns) that are common to the members of a group. The intersession usage patterns provide a causal interpretation (cause and effect) of user behavior from a logical/timing perspective. The proposed methodology was demonstrated and tested for validity using two independent samples of user sessions drawn from the transaction logs of the University of California's MELVYL<super>®</super> online library catalog system (<italic>www.melvyl.ucop.edu</italic>). The results indicate that there are five nonsearcher groups and six searcher groups in the MELVYL system. The majority of user groups have 3<super>rd</super>-order sequential dependency in transitions, and the remaining user groups follow 4<super>th</super>-order sequential dependency in transitions. User session length (duration of stay) can be approximated by a lognormal distribution. The differences in derived usage patterns between user groups were tested statistically. The test results show that users of different groups have distinct patterns of use of the system, which justifies the methodology employed in this study. The acquired knowledge of usage patterns can aid the design of an advanced online help system that provides situational learning and customized help, depending on the context the user is in. This study provides a background for further analysis of user behavior on the Web, which has been recognized as the key to the success of electronic commerce.

Signal integrity issues in deep submicron technology

Chen, Hui (Lauren) University of California, Santa Barbara 2001 해외박사(DDOD)

Signal integrity issues, including crosstalk noise and delay due to interconnect capacitive coupling as well as signal timing variations induced by power and ground noise, have begun to play a pivotal role in the circuits designed in 0.18 micron technology and below. It has become increasingly clear that signal integrity analysis must be an integral part of the design flow to ensure quality. The earlier we begin the analysis, correction and prevention in the design cycle, the fewer the iterations, and the less effort needed in redesign. Investing time and effort in this field has paid off handsomely, resulting in higher-quality and lower-cost designs due to fewer design cycles. However, the skyrocketing complexity of high-density ASICs requires innovative analysis methodologies, whereas current modeling techniques have are insufficient for signal integrity analysis in different design stages. In this dissertation, we present a set of new modeling techniques to tackle a variety of signal integrity issues in deep submicron technology. This dissertation consists of eight parts. The first four deal with noise estimation, and the other four focus on signal delay computation for optimization purposes. The following results related to the capacitive coupling noise have been obtained: We developed a new driver modeling technique for the crosstalk noise estimation. We derived new closed form formulas for crosstalk noise computation. We modeled the crosstalk noise propagation through a gate and proposed an algorithm for the aggressor alignment in order to find the worst-case crosstalk noise. To make optimization for signal integrity possible, we have developed efficient closed form formulas to compute interconnect delay and incremental interconnect delay change due to crosstalk noise. Finally, we studied incremental buffer delay changes in the presence of power and ground noise and applied the derived expressions of buffer delay change in the optimal tapered buffer design.

High-Speed Hybrid Silicon Mach-Zehnder Modulator and Tunable Microwave Filter

Chen, Hui-Wen University of California, Santa Barbara 2011 해외박사(DDOD)

The routing of data electronically within microprocessors is becoming increasingly challenging due to the large volumes of data being transferred. Optical interconnects on silicon are an attractive alternative to traditional electronic interconnects because they provide higher bandwidth and have the potential to be compatible with low cost, high volume, mature CMOS processing. Recent efforts in silicon photonics have focused on developing a wide range of optical components, such as lasers, amplifiers, photodetectors, that can be integrated on a single platform. Among all, a lot of work has focused on modulators as they are crucial for the generation and transmission of high-speed signals such that increasing demands on data capacity can be satisfied. In this work, a hybrid silicon modulator based on a Mach-Zehnder interferometer architecture is developed to efficiently send large amount of information with large optical bandwidth, high-speed operation and good modulation efficiency. The tradeoff between modulation efficiency and speed in pure silicon can be overcome by utilizing the hybrid silicon platform, where the carrier depletion effect inside the III-V materials is introduced to create index shift. The demonstrated device has a voltage-length product of 2.5 Vmm and 20 dB extinction ratio. Moreover, the modulation bandwidth can be promoted to a higher regime by employing a capacitively loaded traveling-wave electrode design. With the developed techniques, we successfully demonstrate a high-speed modulator with 25 GHz bandwidth and 10 dB extinction ratio at 40 Gb/s. In addition, a 2x2 hybrid silicon switch, which is a candidate for large-scale optical network, is also reported based on the developed architecture with 0.5 dB power penalty at 40 Gb/s. The application can be further extended to an integrated level by establishing a microwave tunable filter using thermal modulators and amplifiers on the hybrid silicon platform. The details of the design, fabrication, and characterizations of the aforementioned devices will be presented.