Three high performance circuits for a low power supply DRAM¡¦s are presented in this thesis. First, a modified multi-stage sense amplifier is proposed, that utilizes the auxiliary transmission gate and charge recycling technique. The auxiliary NMOS transistor of the multi-stage sense amplifier is replaced by the transmission gate to improve the sensing speed. In addition, the charge recycling technique is used to reduce the power dissipation of multi-stage sense amplifier. It improves the sensing time by 6.1ns (24.4%) compared to that of the conventional multi-stage sense amplifier and the power saving percentage of 25.6% compared to that of the conventional one. Second, an improved Standby Power Reduction (SPR) Circuit is reported. The capacitor boosting technique is utilized in our proposed Static Current Cut-off Standby Power Reduction (SCCSPR) Circuit, which turns off the always-on MOS transistor of SPR circuit. The power consumption is 30.9% reduced by our design compared to that of the conventional SPR circuit. Third, an improved voltage doubler is developed. The indirect switch is utilized in our proposed circuit, it provides larger gate source bias applied to the PMOS pass transistor. Thus, the current drivability is arisen and the pumping speed is improved as well. In the 2V supply voltage, the pumping speed of our modified voltage doubler is arisen about 18.6% compared to that of the conventional voltage doubler. These high performance circuits in this thesis are applied in a 1-Kbit DRAM circuits. A data access time of 36ns and total power consumption 52.58mW are attained when the supply voltage is 2V. The access time of 10.3ns (22.2%) and power consumption of 6.44mW (11%) are reduced compared to that of the conventional DRAM.

Abstract Cr-containing diamond-like carbon coatings (Cr-DLC) with gradient interlayers were studied to elucidate the effects of Cr content and substrate bias on the mechanical properties and microstructure of the deposited coatings. The coatings were deposited with a closed field unbalanced magnetron sputtering (CFUBMS) system. The Cr content and substrate bias were varied from 5 at.% to 30 at.% and -22 V to -60 V, respectively. Mechanical properties of the coatings were evaluated with nano-indenter, scratch tester, ball-on-disk tribo-tester and ball crater. Microstructures of the films were characterized by SEM, TEM, and Raman spectroscopy. Experimental results show that an increases in Cr content from 5 at.% to 30 at.% for the Cr-DLC coatings deposited at substrate bias of ¡V40V results in the increase of the hardness, Young¡¦s modulus, adhesion and friction coefficient, and the decrease of the deposition rate. A minimum abrasive wear rate was found at about 10 ~ 15 at.% Cr content. An increase in substrate bias from -22 V to -60 V for the Cr-DLC a of 10 at% Cr content results in a maximum hardness, Young¡¦s modulus and adhesion, and a minimum friction coefficient and abrasive wear rate at a substrate bias of -50 V, the although the deposition rate is decreased. TEM analysis revealed layered structure of about 35 nm period and fine CrC crystallite nanometer in size on the top layer of the Cr-DLC coatings.

ABSTRACT This thesis presents the equivalent circuit of basic semicondonductor equations, which are implemented as the device elements of circuit simulator: spice3. We use a simple example of a pn junction diode to study the DC and transient characteristics. Using this technique, it is easy to simulate the semiconductor device composed of the elements and to include the semiconductor device as a part of a circuit.

Video on demand (VoD) services are becoming more and more popular today. As high bandwidth communication infrastructure is being established in many countries around the world, high bandwidth communication lines will reach millions of family in the near future. Due to the increasing improvement of communication technology, more and more families enjoy the VoD services which are provided by telecommunication companies and cable TV provider via the Internet. In such a case, scalability and fault tolerance will be the key issues. We propose an architecture for VoD services which is based on multi-server circumstance. In our proposed architecture, each movie is replicated on a subset of the servers. When a server crashes or disconnects from its clients, it is replaced by another server in a transparent way. Regarding of load balancing problem, clients are also migrated from one server to another when a new server is brought up. The benefit of our service is to use common hardware and general network technologies (e.g. TCP/IP). In addition, we provide a machine-independent environment to let the servers and clients execute on any machine through the network. Furthermore, we can get the media players from a web browser by utilizing the cross-platform characteristics of Java. The client host does not need to install any relevant applications. Since Java Media Framework (JMF) provides a unified architecture and messaging protocol for managing the acquisition, processing, and delivery of time-based media data. It can support many standard media content types, such as AIFF, AVI, MIDI, MPEG, QuickTime, and WAV. Using JMF, we can create applets and applications to present, manipulate, and store time-based media.

ABSTRACT In recent years, there has been increasing demands for high dielectric materials to replace SiO2 for high-density dynamic random access memories with ultra large scale integration (ULSI). As the dimensions of the charge storage node decrease in high-density dynamic random access memories (DRAMs), TiO2 and BaTiO3 are very promising candidates for applications with exhibiting higher dielectric constant, high refractive index and high chemical stability. The physical and chemical properties of LPD thin film by means of several measuring instruments, including Fourier Transform Infrared Spectrometer (FTIR), Auger Electron Spectroscopy (AES), Secondary Ion Spectrometer (SIMS), and X-Ray Diffractometer (XRD). As for the category in the electrical properties, such as C-V curve and I-V curve, of LPD-BTO thin film is comprehended in the most important part of this chapter. Further, we try to improve these electrical properties of LPD-TiO2 and LPD-BTO thin film by post-annealing in oxygen atmosphere at several high temperatures. From leakage current density-electric field intensity voltage (J-E) and capacitance-voltage (C-V) measurements, the leakage current densities are about (LPD-TiO2: 1 ¡Ñ 10-5 A/cm2 and LPD-BTO: 5 ¡Ñ 10-9 A/cm2). And the individual dielectric constants of both films (TiO2 and BTO) are calculated about 40 and 60. This value is larger than thermal oxide, PECVD oxide, and LPD-SiO2. We also can obtain the flat band voltage shifts of LPD-TiO2 and LPD-BTO films which are about ¡V0.5V and 0V; the effective oxide charges which are calculated about ¡V4.52¡Ñ1011 cm-2 and ¡V2.27¡Ñ1012 cm-2 The future goals: (1) Raising the atomic concentration of oxygen within both films and of barium within LPD-BTO film. (2) Shortening the process in preparation of both deposition solutions. (3) Re-checking both models.

In this study, a pilot-scale Regenerative Thermal Oxidizer (RTO) was used to test its performance for volatile organic compound (VOC) destruction and degree of thermal energy conservation. The RTO is electrically heated and contains two 0.5 m ¡Ñ 0.5 m ¡Ñ 2.0 m (L ¡Ñ W ¡Ñ H) columns both packed with gravel particles of 1.0 cm in diameter to a height of 1.4 m. The bed has a void fraction of 0.415. The purpose of this study is to establish the influencing operating conditions and to improve the technique for further applications. Experiments include two phases: (1) energy conservation test with no VOC in the influent air stream , and (2) VOC destruction test with influent air streams containing one of the three VOCs: isopropyl alcohol, acetone, and xylene. Phase 1 experiments were conducted in the maximum gravel temperatures (Tmax) of 402-704 oC, superficial gas velocities (Ug, evaluated at ambient temperatures of 25-30 oC) of 0.15-0.50 m/s, and bed shift times (ts) of 0.5-2.0 min. Results indicate that the temperature raise (

In Taiwan, the fire code is prescriptive in nature and is inappropriate to be utilized in buildings with large spaces and atria, where performance-based fire safety design method is applied. It is the goal of this dissertation to develop a design guide for this application. Through literature survey and theoretical analysis, the important parameters were induced, including: plume transport time lag, ceiling jet transport time lag, smoke entrainment rate, mechanical and natural ventilation rate. To predict smoke behavior and descending rate accurately, algebraic equations and field model were both used to calculate and compare with experimental result so that its applicability can be evaluated. Furthermore, a full-scale experiment has been conducted in the USTC campus to validate that the field model can predict the smoke behavior and descending rate accurately. Finally, the calculation models developed in this study were compiled into a guideline for fire engineering performance-based designs. Design examples were also demonstrated to explain its procedure in engineering application.

Three improved operational amplifiers with low voltage and rail-to-rail constant are proposed. Two of the amplifiers are modified from the amplifier with a level shifting circuit. One improved amplifier has fewer devices, higher speed, and reduced area and the other improved amplifier is added an additional adjustable gain. The third amplifier is a floating voltage controlled voltage source (FVCVS) amplifier, which has reduced area and improved frequency response. The first two level shifting operational amplifiers are designed in a 0.5£gm UMC CMOS process. They use about half number of devices. The supply voltage is 1.3V, and the current consumes just only 22.6¢H of the original circuits. The unity gain frequency increases 56.8%. The slew rate, CMRR and PSRR are higher. The 2nd amplifier still has a rail-to-rail constant gm; however, the gm can be adjusted. The third amplifier uses the 0.35£gm UMC CMOS process with 1.2V operating voltage. The gain-bandwidth product is 53.8¢H larger than the original circuits. No frequency compensation is used and the devices are fewer. The results are obtained in HSPICE simulation.

The objective of this thesis is to develop a theoretical understanding of team-based knowledge sharing and creation in professional cyber-communities. In order to provide contextual richness in environmental, information technology, project, organizational, group, and individual contexts, we apply the grounded theory approach to discover essential factors affecting team-based knowledge sharing and creation across organizational boundaries. Moreover, the thesis summarizes five types of processes of team-based knowledge sharing and creation in professional cyber-communities, defined by the sequence of causal conditions, action/interactional strategies, and consequences, and concludes nine main propositions that can be tested empirically in the future research. The research results will support sustained development of professional cyber-communities and be a basis for further studies of team-based knowledge sharing and creation across organizational boundaries.

In 1996, the promulgation of the amended Telecommunications Act initiated a series of liberalization in telecommunication industry. From 1998 to 2000, Taiwan had become the most rapid growth area around the world with 130% compound annual growth rate and had marked a milestone with more than 80% of penetration by the end of 2000. This study focuses on the pricing plans offered by the main operators, CHT, TCC and FET, to analyze the pricing strategies and the competition scenarios with one another. In this study, we, first, gather the pricing plans of the operators and then review the history of the price adjustment. At last, we compare the pricing plans across the boundary of the operators. From the history of the price adjustment and the market evolution, we realize that the new subscribers encouraged by low prices are mostly low in airtime usages. The operators discriminates these low airtime users more in prices under the consideration of market competition and profit gaining. From reviewing the pricing plans of the operators respectively, we find the existence of ¡§redundant¡¨ pricing plans, which might bring the operators extra income. From comparison of the pricing plans offered by the three main operators, we conclude the three players try to lower the competition strength by charging high in different segments.