Since future microprocessors will have higher current in accordance with Moore's law, there are still challenges for voltage regulators (VRs). Firstly, high efficiency is required not only for easy thermal management, but also for saving on electricity costs for data centers, or battery life extension for laptop computers. At the same time, high power density is required due to the increased power of the microprocessors. This is especially true for data centers, since more microprocessors are required within a given space (per rack). High power density is also required for laptop computers to reduce the size and the weight. To improve power density, a high frequency is required to shrink the size of the output inductors and output capacitors of the multi-phase buck VR. It has been demonstrated that the output bulk capacitors can be eliminated by raising the VR control bandwidth to around 350kHz. Assuming the bandwidth is one-third of the switching frequency, a VR should run at 1MHz to ensure a small size. However, the efficiency of a 12V VR is very poor at 1MHz due to high switching losses. As a result, a 12V VR can only run at 300kHz to 600kHz, and the power density is very low. To attain high efficiency and high power density at the same time, two-stage power architecture was proposed. The concept is "Divide and Conquer". A single-stage VR is split into two stages to get better performance. The second stage has about 5V-6V input voltage; thus the duty cycle can be extended and the switching losses are greatly reduced compared with a single-stage VR. Moreover, a sub-20V MOSFET can be used to further improve the efficiency at high frequencies. The first stage of the proposed two-stage architecture is converting 12V to 5-6V. High efficiency is required for the first stage since it is in series with the second stage. Previous first stage which is a buck converter has good efficiency but bulky size due to low frequency operation. Another problem with using a buck converter is that light-load efficiency of the first stage is poor. To solve these problems, switched-capacitor voltage dividers are proposed. Since the first stage does not require voltage regulation, the sweet point for the voltage divider can be determined and high efficiency can be achieved. At the same time, since there are no magnetic components for the switched-capacitor voltage divider, high power density can be achieved. By very careful design, a power density of more than 2000W/in3 with more than 97% efficiency can be achieved for the proposed voltage divider. The light-load efficiency of the voltage divider can be as high as 99% by reducing the switching frequency at light load. As for the second stage, different low-voltage devices are evaluated, and the best device combinations are found for high-frequency operation. It has been demonstrated that 91% efficiency can be achieved with 600kHz frequency, and 89% efficiency can be achieved with a 1MHz frequency for the second stage. Moreover, adaptive on-time control method and a non-linear inductor structure are proposed to improve CCM and DCM efficiency for the second stage respectively. Previously the two-stage VR was only used as a CPU VR. The two-stage concept can also be applied to other systems. In this dissertation, the two-stage power architecture is applied to two different applications: laptop computers and high-end server microprocessors. The common characteristics of the two applications are their thermal design power (TDP) requirement. Thus the first stage can be designed with much lower power than the maximum system power. It has been demonstrated that the two-stage power architecture can achieve either higher efficiency or higher power density and a lower cost when compared with the single-stage VR. To get higher efficiency, a parallel two-stage power architecture, named sigma architecture, is proposed for VR applications. The proposed sigma VR takes advantage of the high-efficiency, fast-transient unregulated converter (DCX) and relies on this converter to deliver most of the output power, while using a low-power buck converter to achieve voltage regulation. Both the DCX converter and the buck converter can achieve around 90% efficiency when used in the sigma VR, which ensures 90% efficiency for the sigma VR. The small-signal model of the sigma VR is studied to achieve adaptive voltage positioning (AVP). The sigma power architecture can also be applied to low-power point of load (POL) applications to reduce the magnetic component size and improve the efficiency. Finally, the two-stage VR and the sigma VR are briefly compared. / Ph. D.

The objective of this study was to determine the association between the student’s general adjustment and his attitudes towards his parents and teachers and his school progress and the degree to which he was accepted by associates in social situations. Seventy high school senior girls and boys living in a small town and the surrounding area furnished the date for this study. The data on these students were secured from five sources. Information on attributes towards parents and teachers, social acceptability, and socio-economic factors was obtained by the questionnaire method. The questionnaires were completed by the students during their homeroom periods. Information on personality adjustments was obtained by the use of the bell adjustment inventory which was completed by the students during their home-room periods and was augmented by the combined ratings of three teachers. Rating of I. Q. was obtained by the Otis Quick-Scoring Gamma test. Information on school progress was obtained from the permanent school records. / Master of Science

The tremendous advancement in VLSI technologies in the past decade has fueled the need for intricate tradeoffs among speed, power dissipation and area. With gigahertz range microprocessors becoming commonplace, it is a typical design requirement to push the speed to its extreme while minimizing power dissipation and die area. Multipliers are critical components of many computational intensive circuits such as real time signal processing and arithmetic systems. The increasing demand in speed for floating-point co-processors, graphic processing units, CDMA systems and DSP chips has shaped the need for high-speed multipliers. The focus of our research for modern digital systems is two fold. The first one is to analyze a relatively unexplored logic style called MOS Current Mode Logic (MCML), which is a promising logic technique for the design of high performance arithmetic circuits with minimal power dissipation. The second one is to design high-speed arithmetic circuits, in particular, gigahertz-range multipliers that exploit the many attractive features of the MCML logic style. A small library of MCML gates that form the core components of the multiplier were designed and optimized for high-speed operation. The three 8-bit MCML multiplier architectures designed and simulated in TSMC 0.18 mm CMOS technology are: 3-2-tree architecture with ripple carry adder (Architecture I), 4-2-tree design with ripple carry adder (Architecture II) and 4-2-tree architecture with carry look-ahead adders (Architecture III). Architecture I operates with a maximum throughput of 4.76 GHz (4.76 Billion multiplications per second) and a latency of 3.78 ns. Architecture II has a maximum throughput of 3.3 GHz and a latency of 3 ns and Architecture III has a maximum throughput of 2 GHz and a latency of 3 ns. Architecture I achieves the highest throughput among the three multipliers, but it incurs the largest area and latency, in terms of clock cycle count as well as absolute delay. Although it is difficult to compare the speed of our multipliers with existing ones, due to the use of different technologies and different optimization goals, we believe our multipliers are among the fastest found in contemporary literature. / Master of Science

The purpose of this study is to analyze and evaluate the library as both a teaching and a service agency in the junior high schools.

The problem in this study is threefold: (1) to discover cases of maladjustment which exist among the students of a certain small high school; (2) to determine as far as possible the causes of these maladjustments, particularly the role of the school as a contributing agent; and (3) to suggest and to apply as far as possible remedial measures.

The problem in this study is twofold. First, there will be an attempt to determine the values that organizations in the secondary school have for the development of its students. Second, a survey will be made of the four-year accredited high schools in District Five of Texas to determine how and to what extent they are realizing their responsibilities in this respect.

The problem of this study is to determine the normal teaching load of teachers teaching in the various fields in certain selected high schools of Texas.

The purpose of this study is to make an evaluation of Gainesville Junior High School to determine the extent to which it meets criteria for this type of school. The different phases of the school evaluated were: plant and equipment, library, course of study, techniques of teaching, and extra-curricular activities.

This is a study to determine a psychologically and democratically sound solution of the distribution of high school offerings in an American city.

The problem is to determine by questionnaire the extent to which a representative sampling of Texas high schools provide activities to meet pupil needs.