The objectives of the proposed research are to model, optimize, and control variable frequency microwave (VFM) curing of polymer dielectrics. With an increasing demand for new materials and improved material properties, there is a corresponding demand for new material processing techniques that lead to comparable or better material properties than conventional methods. Presently, conventional thermal processing steps can take several hours. A new thermal processing technique known as variable frequency microwave curing can perform the same processing steps in minutes without compromising the intrinsic material properties. Current limitations in VFM processing include uncertain process characterization methods, lack of reliable temperature measuring techniques, and the lack of control over the various processes occurring in the VFM chamber. Therefore, the proposed research addressed these challenges by: (1) development of accurate empirical process models using statistical experimental design and neural networks; (2) recipe synthesis using genetic algorithms; (3) implementation of an acoustic temperature sensor for VFM process monitoring; and (4) implementation of neural control strategies for VFM processing. and #8194;

The main purpose of this study is to investigate eighth-grade students¡¦ understanding of the equal sign and analyzed error types of quadratic equation in one variable. To achieve this purpose, the investigator did a survey and development instruments. Participants were 215 eighth-grade students who formed a convenient sample. There are three results. First, participants with a relational definition of the equal sign added to about 80% of the sample. Second, the performance of students with relational definitions is higher than the performance of students with operational definitions. Third, students¡¦ understanding of the equal sign was related to their respective problem-solving performance on quadratic equation in one variable. In this study, participants with an operational definition of the equal sign tended to guess randomly or leave a blank. Problem-solving performance of participants with a relational definition of the equal sign involved multiple strategies. The researcher suggested that teachers should strengthen students¡¦ understanding of equal sign and related students¡¦ prior algebraic knowledge.

The effect of variable inertia flywheel (VIF) on the driving speed fluctuation, and residual vibration of high speed machine systems is investigated in this thesis. Different variable inertia flywheels are proposed to an experimental purpose roller gear cam system and a commercial super high speed paper box folding machine. The effects of time varying inertia and intermittent cam motion on the dynamic responses of different high speed cam droved mechanism systems are simulated numerically. The nonlinear time varied system models are derived by applying the Lagrange¡¦s equation and torque-equilibrium equations. The dynamic responses of these two nonlinear systems under different operating speed are simulated by employing the 4th order Runge-Kutta method. The effects of VIF parameters on the dynamic responses, i.e. the output precision, variation of motor speed, and torque, during the active and dwell periods for these two systems are studied and discussed. The difference between the dynamic responses of constant inertia and variable inertia flywheel systems are also compared. The feasibility and effectiveness of depression of driving speed and torque fluctuations by analying variable inertia flywheel has also been demonstrated.

A study of double-variable-curvature microlenses (DVCM) for promoting coupling efficiency between the high-power 980-nm laser diodes and the single-mode fibers has been proposed. The purpose of the fiber microlens fabrication was to make the mode field match between the laser beam and the fiber as the beam propagating through the fiber microlens. To make the mode match, the shapes of the fiber microlens demanded nothing else but the offset and the curvature radii in minor and major axes. The double-variable-curvature fiber endface (DVCFE) was manufactured through a single-step fully automation grinding process and had less average offset of 0.3£gm, consequently. The radii of curvature in minor and major axis were controlled as an average of 1.2£gm and 33.6£gm, respectively. In the fusing procedure, the slight arc fusion was mainly applied for fine polishing merely instead of reshaping for the reason that the fabricated DVCFE was very close to the ideal shape. Hence, the fabrication time was reduced and the yield was promoted due to the withdrawn step of tip elimination. Furthermore, while the fusion parameters were set to be: fusing distance: 10£gm, arc intensity: 3bits, and fusing time: 200ms in the slight fusion process, the offset was reduced to 0.2£gm due to the shape constraint and surface tension of the DVCFE. And the radii of curvature increased 1.7£gm to 2.9£gm in the minor axis and increased 4.5£gm to 38.1£gm in the major axis, respectively. Owing to the controls of the fully automated grinding procedure and the omission of the tip elimination, the coupling efficiency and yield were improved. As a result, in the experiment, the average and maximum coupling efficiency of 83% and 88% were demonstrated, respectively. And the coupling efficiencies of the 20 samples were higher than 80%. In other words, the proposed DVCM structure of this study was a high coupling efficiency, a high yield output, and reproducible and fully automated single-step grinding process.

¡@¡@The dynamic power flow in a dual-input parallel planetary gear train system is simulated in this study. Different wind powers for the small wind turbines are merged to the synchronous generator in this system to simplify and reduce the cost of the system. Nonlinear equations of motion of these gears in the planetary system are derived. The fourth order Runge-Kutta method has employed to calculate the time varied torque, root stress and Hertz stress between engaged gears. The genetic optimization method has also applied to derive the optimized tooth form factors, e.g. module and the tooth face width. ¡@¡@The dynamic power flow patterns in this dual input system under various input conditions, e.g. two equal and unequal input powers, only single available input power, have been simulated and illustrated. The corresponding dynamic stress and safety factor variations have also been explored. Numerical results reveal that the proposed dual-input planetary gear system is feasible. To improve the efficiency of this wind power generation system. An inertia variable flywheel system has also been added at the output end to store or release the kinetic energies at higher or lower wind speed cases. A magnetic density variable synchronous generator has also been studied in this work to investigate the possible efficiency improvement in the system. Numerical results indicate that these inertia variable flywheel and magnetic density variable generator may have advantages in power generation.

In the past few years, increased penetration of wind energy has made more disturbances into electrical power systems. The proper integration of wind turbine models within power system simulations is of great importance for analysis of wind energy penetration and power system performance. This thesis analyzes the impacts of the connection of wind turbines on the operations of weak electric distribution systems. Using an actual feeder located in a rural area, the effects on the voltage profile caused by variable-speed wind turbines are compared to those caused by fixed-speed wind turbines. Simulations are conducted by using the developed models in Matlab/Simulink Keywords: Wind energy, Variable-speed turbines, Fixed-speed turbines

Nowadays almost all products used in our daily life are made in pursuit of streamline and good look, including mobiles, motorcycles, aerospace and 3C industry; therefore, how to shorten process time and enhance the smoothness of the product¡¦s surface has become one of the important issues. However, the process method of traditional CNC machines only can support line and circular interpolations but cannot accept motion along curve and circular paths. Therefore, the traditional CNC machines have to rely on CAM, a method to generate the NC code called G-code and M-code by approximating many tiny linear or circular segments, to plan the cutter paths. But this approximating method requires higher transmission speed; it also occupies huge memory capacity and makes the velocity of machine tool discontinuous, in order to difficultly meet the requirement of high speed and better precision. In order to solve the above problems, this thesis adopts the NC code created by CAD/CAM¡¦s NURBS curve which called NURBS-code, making CNC machines have the function of processing NURBS curve interpolations to improve the defect of the traditional processing and thus reach the goal of high speed and better precision. Furthermore, due to NURBS interpolators are always implemented by the controller. This always makes CNC machine become very expensive; meanwhile, adjusting parameters is very troublesome. Therefore this thesis also provides the intergrated method of NURBS and DDA real-time interpolator to make the application in the easy way without the consideration of controller design for AC driver.

The first topic of this thesis proposes a digital video decoder for NTSC. The new fully digital design employs a DDFS (digital direct frequency synthesizer) and an adaptive digital PLL to track and lock the demodulation carrier. The complexity of the digital video decoder, hence, is drastically reduced. The overall cost of the proposed design is 6.0 mm2 (39K gates). The maximum power dissipation is 86 mW at the hightest clock rate which is 21.48 MHz. The second topic is to carry out a codec (encoder-decoder) design for interfacing variable-length and fixed-length data compression. The poor memory efficiency caused by the variable-length words converting into a fixed-length packet such that the compression can be hardwaredly and parallelly processing is significantly improved. The proposed codec is to encode more symbols in the redundant bits of the padding bits of the fixed-length packets. This novel encoding scheme relaxes the intrinsic poor bit rate of the traditional fixed-length data compression.

Generally speaking, business cycle could be discussed as a short-term fluctuation of business cycle and long-term economic growth. In this research, we will confer what impact factors might have affected the business cycle of correlations (BCCs) across countries in a period of short time. Many empirical analysis have pointed out the temporary factors to the business cycle mainly come from the transferred factors of economic aspect. This is called ¡§Transmission Mechanisms.¡¨ What is ¡§Transmission Mechanisms?¡¨ Economists often try to substitute it in good markets, financial markets, and the coordination of monetary policies. However, in this duration of the empirical analysis, using only these proxy variables to explain BCCs between two countries seems too limited. According to this situation, we believe if the BCCs can be explained by using proxy factors of non-economic variable, the result can be utilized by making up the defect. We attempt to find new factors in political approach and combine with the ¡§Transmission Mechanisms¡¨ that we have introduced earlier. After that, we expect to comprehend the BCCs among G7 countries from the inputs of the two completed different variables. To analyze further economic implication in our research, five conclusions have been summarized below: Firstly, increasing bilateral trade has significantly provided positive effect to BCCs among G7 countries from 1980 to 2002. Because the empirical result of Single Country is insignificant, we then use a two-stage method. First, we estimate ¡§Trade¡¨ from endogenous variable to exogenous one. Secondly, we use Panel method to expand its matrix. Finally, we improve the empirical estimators of insignificant statistics before. In other words, the important variables of the correlation of bilateral trade are whether or not the two countries speak the same language; the border problem, and the distance between the two are the same, etc. So, when we talk about the relations between BCCs and good and service markets, we must consider these exogenous factors. Eventually, we will receive more detailed results. Secondly, although to trade in financial markets can increase the BCCs between two countries, the statistic report is insignificant -0.0019 (0.0012). About this empirical result, we can obtain reasonable explanations from the researches (for instance: Imbs, 2004 or Kose et al, 2003), they point out that financial markets are bound excessively by globalization. Therefore, this will aggravatingly make each country to focus on its specialization. Finally, this situation will make the BCCs getting collapsed among these countries. This also explains that the specialization among these countries will reduce the positive effect from the BBCs to financial markets. Thirdly, in this empirical research of Single-Country, we use three proxy estimators of economics to substitute common properties of the monetary policy. At this point, there are no identical correlations of corresponding among other countries except some significantly negative trends shown to the member countries of European Union. According to this situation, we believe it may be the consequence to all the member countries under some ERM restrictions, which is Treaty of Maastricht. Also, because of the rules form this treaty, the monetary policies are getting to be accordant, and the BCCs among the countries will soon appear in obviously positive trend. Fourthly, in the model, the difference of the inflation rate between two countries is not significant with BCCs; therefore, an identical correlation is hardly shown. Moreover, the coefficient symbol is not in our expecting direction, so we think maybe some policies are neglected to the influence of this variable. After all these, we believe if we can control some relative policy effect to inflation rate when discussing the relationship between this variable and the BCCs, we should be able to find out the real effect of this substitutive variable to BCCs Lastly, in the research, the statistics effect of the party variables and business cycle of correlations are very significant. This also indicates the political factor will play an important role for many sources of the fluctuation tread of BCCs. In other words, when we discuss the issue of BCCs if miss the contribution of political factors to the BCCs. Then, this might cause the omitted variable biased, and finally cause the whole computation become inefficient. In addition, we can have further discussion by an input of a factor: to conserve the joint benefit of all the member countries in an economic organization, these countries need to be ruled by the same ideal political party. Otherwise, the institute will never reach its essential result. Combining all the conclusions we have shown above, we can find out the BCCs among G7 countries from 1980-2002. Besides the influence of the ¡§Transmission Mechanisms,¡¨ the result will be varied by the political factors. In conclusion, we need to consider the contribution of the political party variables to the BCCs when talking about this issue, therefore; the original theoretical model can be more persuasive. According to a statistics of IMF, the BCCs among those industrial countries are falling little by little in recent years. Therefore, consolidating trade cooperation is essential for what we believe to improve the BCCs among G7. At the same time, pass through a strong integrate monetary policy can move forward all the incumbent parties from all the countries to agree among themselves, and even reach more substantial effect. From the example like this, we might find evidence from BCCs issues by discussing the integration process in European Monetary Union.

Two robust control strategies are proposed in this dissertation for a class of multi-input multi-output dynamic systems with matched and mismatched perturbations. First of all, a novel design methodology of switching variables is proposed for solving the regulation problems. A serial state transformations are needed in order to design pseudo feedback gains and adaptive mechanisms. By utilizing the pseudo control input gain embedded in each of the switching variable, the proposed controller can not only suppress the mismatched perturbations when the controlled systems are in the sliding mode, but also attain locally asymptotic stability. The design of a robust output tracking controller is presented next for solving the tracking problems. Without utilizing the information of state variable, the proposed output feedback tracking controllers are capable of driving the state tracking errors into a small bounded region whose size can be adjusted through the designed parameters, and guarantee the stability of controlled systems. These two robust control schemes are designed by means of the variable structure control technique with sliding mode and Lyapunov stability theorem. Each controller contains three parts. The first part is for eliminating measurable feedback signals. The second part is used for adjusting the convergent rate of state variables (or tracking errors) of the controlled system. The third part is an adaptive control mechanism, which is to adapt some unknown constants of the least upper bounds of perturbations, so that the knowledge of the least upper bounds of matched and mismatched perturbations are not required. Several numerical examples and an application of controlling aircraft's velocity are demonstrated for showing the feasibility of the proposed control methodologies.