Network planning is an essential phase in successfully operating state-of-the-art telecommunication systems. It helps carriers increase revenues by deploying the right technologies in a cost effective manner. More importantly, through the network planning phase, carriers determine the capital needed to build the network as well as the competitive pricing for the offered services. Through this phase, radio tower locations are selected from a pool of candidate locations so as to maximize the net revenue acquired from servicing a number of subscribers. In the Universal Mobile Telecommunication System (UMTS) which is based on the Wideband Code Division Multiple Access scheme (W-CDMA), the coverage area of each tower, called a cell, is not only affected by the signal's attenuation but is also affected by the assignment of the users to the towers. As the number of users in the system increases, interference levels increase and cell sizes decrease. This complicates the network planning problem since the capacity and coverage problems cannot be solved separately. To identify the optimal base station locations, traffic intensity and potential locations are determined in advance, then locations of base stations are chosen so as to satisfy minimum geographical coverage and minimum quality of service levels imposed by licensing agencies. This is implemented through two types of power control mechanisms. The power based power control mechanism, which is often discussed in literature, controls the power of the transmitted signal so that the power at the receiver exceeds a given threshold. On the other hand, the signal-to-interference ratio (SIR) based power control mechanism controls the power of the transmitted signal so that the ratio of the power of the received signal over the power of the interfering signals exceeds a given threshold. Solving the SIR based UMTS/W-CDMA network planning problem helps network providers in designing efficient and cost effective network infrastructure. In contrast to the power based UMTS/W-CDMA network planning problem, the solution of the SIR based model results in higher profits. In SIR based models, the power of the transmitted signals is decreased which lowers the interference and therefore increases the capacity of the overall network. Even though the SIR based power control mechanism is more efficient than the power based power control mechanism, it has a more complex implementation which has gained less attention in the network planning literature. In this thesis, a non-linear mixed integer problem that models the SIR based power control system is presented. The non-linear constraints are reformulated using linear expressions and the problem is exactly solved using a Benders decomposition approach. To overcome the computational difficulties faced by Benders decomposition, two novel extensions are presented. The first extension uses the analytic center cutting plane method for the Benders master problem, in an attempt to reduce the number of times the integer Benders master problem is solved. Additionally, we describe a heuristic that uses the analytic center properties to find feasible solutions for mixed integer problems. The second extension introduces a combinatorial Benders decomposition algorithm. This algorithm may be used for solving mixed integer problems with binary variables. In contrast to the classical Benders decomposition algorithm where the master problem is a mixed integer problem and the subproblem is a linear problem, this algorithm decomposes the problem into a mixed integer master problem and a mixed integer subproblem. The subproblem is then decomposed using classical Benders decomposition, leading to a nested Benders algorithm. Valid cuts are generated at the classical Benders subproblem and are added to the combinatorial Benders master problem to enhance the performance of the algorithm. It was found that valid cuts generated using the analytic center cutting plane method reduce the number of times the integer Benders master problem is solved and therefore reduce the computational time. It was also found that the combinatorial Benders reduces the complexity of the integer master problem by reducing the number of integer variables in it. The valid cuts generated within the nested Benders algorithm proved to be beneficial in reducing the number of times the combinatorial Benders master problem is solved and in reducing the computational time that the overall algorithm takes. Over 110 instances of the UMTS/W-CDMA network planning problem ranging from 20 demand points and 10 base stations to 140 demand points and 30 base stations are solved to optimality.

The single-row facility layout problem (SRFLP) is concerned with finding the optimal linear placement of n departments with different lengths in a straight line. It is typically achieved by minimizing the cost associated with the interactions between the departments. The semidefinite programming (SDP) relaxation model that incorporates cutting planes proposed recently by Anjos, Kennings, and Vannelli (AKV) was considered a breakthrough in the field. This thesis presents a new SDP model AKV' and compares the two relaxations. The AKV' is largely based on the previous model, but it reduces the number of linear constraints from O(n³) to O(n²). Therefore, it reduces the computing time at the expense of a slightly weaker lower bound. However, AKV' is observed to pay off as the instance size increases. By examining the gap for both the AKV and AKV' relaxations, we notice that both relaxations generate very small gaps at the root node, which demonstrates the effectiveness of the relaxations. Six different strategies are presented to separate the cutting planes for the medium-sized SRFLP. In combination with the two SDP relaxations, we compare the six strategies using three instances of different characteristics. An overall best strategy is deduced from the computational results, but the best choice of relaxations and the best number of cuts added at each iteration changes depending on the characteristics of the instances. Two new cutting plane strategies are proposed for large instances. This allows the solution to optimality of new instances with 36 departments, which is higher than previously published results in literature. We also briefly point out how the computing time can vary greatly between different sets of data of the same size due to the characteristics of the department lengths.

The knowledge of the phase behaviour of heavy oils and bitumen is important in order to understand the phenomenon of coke formation. Computation of their phase behaviour, using an equation of state, faces problems due to their complex composition. Hence n-alkane binaries of polyaromatic hydrocarbons are used to approximate the phase behaviour of heavy oils and bitumen. Appropriate values of binary interaction parameters are required for an equation of state to predict the correct phase behaviour of these model binary fluids. This thesis deals with fitting of the binary interaction parameter for the Peng-Robinson equation of state using landmarks in the binary phase space such as K- and L-points. A K- or an L-point is a point in the phase space where two phases become critical in the presence of another phase in equilibrium. An algorithm to calculate K- and L-points using an equation of state was developed. The variation of calculated K- and L-points with respect to the binary interaction parameter was studied and the results were compared with the experimental data in the literature. The interaction parameter was then fitted using the best match of experimental results with the computed ones. The binary interaction parameter fitted using a K- or an L-point was then used to predict the P-T projection of the binary system in phase space. Also, the qualitative effect of the binary interaction parameter on the P-T projection was studied. A numerical and thermodynamic study of the algorithm was done. Numerical issues like the initial guesses, convergence criterion and numerical techniques were studied and the thermodynamic constraints in the generalization of the algorithm are discussed. It was observed that the binary interaction parameter not only affects the location of K- and L-points in the phase space but also affects the calculation procedure of K- and L-points. Along with the propane binaries of polyaromatic hydrocarbons, K- and L-points were also calculated for systems like methane binaries of higher n-alkanes and the ethane + ethanol binary. In the case of the ethane + ethanol system, K- and L-points, matching the experimental results were calculated with different values of the binary interaction parameter. But the Peng-Robinson equation of state was unable to predict the correct type of phase behaviour using any value of the binary interaction parameter. The Peng-Robinson equation of state was able to predict the correct type of phase behaviour with the binary interaction parameter, fitted using K- and/or L-points for methane + n-alkane systems. The systems studied were the methane binaries of n-pentane, n-hexane and n-heptane. For the propane binaries of polyaromatic hydrocarbons, no value of the binary interaction parameter was able to predict the K-point with a good accuracy. The binary interaction parameter which gave the best possible results for a K-point failed to predict the correct type of phase behaviour. The binary interaction parameter fitted using the P-T projection enabled the Peng-Robinson equation of state to give a qualitative match for the high pressure complex phase behaviour of these systems. Solid phase equilibria were not taken into consideration.

Film flow of a suspension has been investigated both experimentally and theoretically. Gravity-driven free-surface inclined plane flow of a suspension of neutrally buoyant particles has been investigated using a stereoscopic particle imaging velocimetry technique. Particles have been shown to migrate away from the solid surface, and the film thickness has been shown to decrease as the fluid moves down the inclined plane. The free surface has been characterized using a light reflection technique, which shows that surface topography is affected by the inclination angle, and the particle concentration. This flow has been modeled based on a suspension normal stress approach. A boundary condition at the free surface has been examined, and model predictions have been compared with experimental results. The model predicts that the film thickness, relative to its initial value, will decrease with the bulk particle concentration. The thin film flow over the inner cylinder in partially filled Couette flow of a suspension has been experimentally investigated as well as modeled. Concentration bands have been shown to form under a variety of different fill fractions, bulk particle concentrations, inclination angles, ratio of inner to outer cylinder, and rotation rates of the inner cylinder. The banding phenomena ranges from a regime where bands are small, mobile and relatively similar in concentration to the bulk, to a regime where the concentration bands are larger, stationary, and where the space between them is completely devoid of particles. The role of the film thickness in the band formation process has been investigated, and has led to a model for the band formation process based on a difference in the rate that fluid can drain from height fluctuations relative to the particles.

Simulation and experiments quantify the effect of moving a horizontal dipole antenna close to a metal ground plane. Solutions to the radiation problems are offered.

M-plane (101 ¡Â0) ZnO thin films were grown on m-plane sapphire (101 ¡Â0) substrates by RF magnetron sputtering. We varied the RF power, working pressure, and O2/Ar ratio to obtain the best growth conditions. Structural properties were investigated by X-ray diffraction(XRD). XRD measurements showed that the crystal orientation of ZnO films was non-polar m-plane (101 ¡Â0). In addition, photoluminescence (PL) spectrum showed the bandgap energy of ZnO films was about 3.24 eV. PL spectrum showed zinc vacancy signal for films grown in oxygen rich condition. Carrier concentration was measured by hall measurement as well as FTIR spectrometry. The results showed the carrier concentration calculated by optical measurements was higher than hall measurements. One possibility for this could be the band tail at the bottom of conduction band. This band tail can make the effective mass larger and thus influencing the optical carrier concentration.

In rapid wireless communication technology development environment, antennas, the interface among many wireless communications, are an indispensable component for wireless systems. Miniaturization and functionality stability (high tolerance to environmental variations) of the antenna are fast becoming the design trends in research and development of wireless communication systems. They are also the main objectives of this thesis. In the first part of this thesis, we designed two highly stable antennas, which can be used in notebook computers or tablet PCs. The antenna has self-balanced characteristics, where the environmental interference is minimized, in its performance/functionality and patterns. The first antenna design, which can be easily integrated into an RF front-end board, employed capacitive coupling, differential feed printed loop configurations. Comparing to the existing differentially fed antenna design, our designs are much more miniaturized: the antenna size was 13 mm ¡Ñ 27 mm, the ground size was 4.5 mm ¡Ñ 4.5 mm. Implemented on a low-cost FR4 board, the antenna reduced the leakage current formed on coaxial transmission line, due to the advantage of being differentially fed. The second antenna design, fed by coaxial cable (single-ended fed), and without a ground plane, excited only self-balanced modes. The radiation patterns of higher modes in this antenna design are complete and without side lobes. This antenna design also has wide bandwidth characteristics: at 2.4 GHz it had 380 MHz, and at 5.2 GHz it had 1270 MHz bandwidths of high tolerance (stability). The actual measurement validated our simulation results. In the second part, MIMO antennas were designed for 802.11n wireless standards with maximum transfer rates of up to 300 Mbps. First, we designed two small single antennas, which were applied later in MIMO antenna designs. The size of our MIMO antenna designs was only 19 mm ¡Ñ 30.3 mm. In MIMO antenna designs, we employed two methods to increase the isolation between the two MIMO antennas: one manipulated the ground plane size, in which the isolation reached 18.9 dB; the other utilized a decoupling metal, where the overall isolation reached 24.6 dB in all of the operating frequencies, with the best isolation being 31.4 dB. The frequency of the coupling/decoupling for the decoupling metal can be adjusted independently; thus not affecting the original resonant frequency and the return loss of the two MIMO antennas. Actual measurements conducted in the microwave chamber (Reverberation Chamber) have verified the channel capacity were effectively increased, the total radiation efficiencies were about 60%, and the effective diversity gain was about 7dB. The MIMO antenna designs can practically and easily applied in the USB dongles.

In this thesis, the growth of nonpolar m-plane zinc oxide (ZnO) nano-materials on (100) £^¡VLiAlO2 (LAO) substrates by a chemical vapor deposition (CVD) process had been studied. The mixture powders of ZnO and graphite are used as the precursor of reaction sources. Ar/O2 are used as the carrier gas and reaction gas source respectively, and the Au thin-film coated on the LAO substrate is the catalyst for the vapor-liquid-solid (VLS) growth mode. The X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to study the influence of the varied growth conditions, such as deposition time, reaction pressure, growth temperature, and the distance between substrates and reaction powder ¡K etc., on the crystal structure, surface morphology, orientation and microstructure characterizations of the ZnO nanostructure. The pure (10-10) m-plane ZnO nano-materials can be obtained at the growth parameters of 830¢XC, 10 torr, 5 minutes, and 50 sccm of Ar/O2. Furthermore, photoluminescence (PL), cathodoluminescence (CL) and Raman spectroscope (Raman) were used to study optical properties and the inner stress of the materials.

Abstract Whether an Open Area Test Site (OATS) is qualified is based on the Normalized Site Attenuation (NSA). The purpose is to eliminate the influence of Antenna Factor (AF). Usually the AF provided by the manufacturer adopts the Standard Site Method (SSM) and is quoted from measurements at a 10-m range. In practice, the AF varies with the measurement conditions. This uncertainly will translate into error in NSA measurements. Currently radiated electromagnetic interference measurement mostly adopts the broadband antennas, and LPDA is one of the antennas used extensively. However, the AF provided by the manufacturer does not consider shifts in the phase center of LPDA with frequency. In the meantime the radiation pattern of LPDA is different from that of a short dipole. The investigation of this thesis will focus on these two parts. In determining the phase center of LPDA antenna we adopt the average shift of phase center to improve the AF. The numerical simulation results show that such an arrangement can result in improvement. We also use the method of PCPM (Phase Center and Pattern Matching) to modify the AF under different conditions of measurement when a ground plane is present. Our study, by using the numerical simulation and measurement, shows that this indeed improves the variation of AF over that obtained by SSM. In addition, efforts are also made to have a detailed discussion in mutually coupling effects between the LPDA antenna and the ground plane, in order to distinguish the impact on AF due to the coupling of the LPDA antenna and its image. Our numerical simulation results indicate that it does not have a significant effect.

A new type of heterogeneous carbon fiber bunch bipolar plate developed in our lab is applied to portable pure hydrogen proton exchange membrane fuel cell stacks. Several different types of bipolar plate structures have been designed, and the voltages and currents of these fuel cell stacks are measured to compare their performance. The new type of heterogeneous carbon fiber bunch bipolar plate is well in low contact resistance, weight low, small volume and the flexible geometry shape. Due to its flexible structure of carbon fiber bunch, the compressing pressure is small while assembling stack so that the electrode can not be over compressed and out of shape. Therefore the high porosity of diffusion layer can be keep and reaction gas can enter and distribute to all reaction areas easily. For using to portable equipments, a small 6-cell flat type of fuel cell stack are developed firstly. The total weight is about 75g and the total volume is about 68cm . The second stack is cylinder-type(I) fuel cell stack. The total weight is about 60g and the total volume is about 71cm . The third stack is cylinder-type (II). The total weight has been reduced to about 20g and the total volume has been reduced to about 30cm . Above three kinds of the 6-cell stacks the total electrode area is 13.5cm . Using Nafion, the catalyst content anode Pt 0.4mg/cm , cathode Pt 1.0mg/cm , On room temperature and inlet hydrogen gauge pressure 0.15atm air-breathing, total output power of the cylinder (II) can reach 1.85W, and the power density of unit area can reach about 137mW/cm^2.