The study involves the following stages: First, coupled-inductor and integrated magnetic structure used in Cuk converter circuit topologies are analyzed and the necessary information about these elements in circuit design is gathered. Also, benefits of using these magnetic elements are presented. Secondly / steady-state model, dynamic model and transfer functions of coupled-inductor Cuk converter topology are obtained via state-space averaging method. Third stage deals with determining the design criteria to be fulfilled by the implemented circuit. The selection of the circuit components and the design of the coupled-inductor providing ripple-free input current waveform are performed at this stage. Fourth stage introduces the experimental results of the implemented circuit operating in open loop mode. Besides, the controller design is carried out and the closed loop performance of the implemented circuit is presented in this stage.

Distributed-memory multiprocessors offer very high levels of performance that are required to solve scientific applications. A traditional programming language cannot be expected to yield good performance when used to program such machines. Data-parallel languages provide programmers with a global memory and relieve them from the burden of inserting time-consuming, error-prone inter-processor communication. The compilers of these languages perform this task. Data-parallel languages also enable the programmers to establish alignment and distribution directives which specify the type of data parallelism and data mapping to the underlying parallel architecture. Parallelizing compilers distribute data and generate code according to the owner-computes rule when compiling an array statement. The array elements in a processor it owns are only a fraction of all the array elements. Not all of the array elements in the processor are active elements, so determining local memory access sequence is important. However, generating local memory access sequences becomes rather complicated when the array references involve complex subscripts. This study considers two types of complex subscript ― coupled subscripts and multiple induction variables. A processor may refer to the rhs (right-hand side) array elements owned by other processors, and the movement of data is inevitable. The overhead to access non-local data by inter-processor communication may be around 10 to 100 times more than the cost of accessing local data. Efficiently generating communication sets is important. This thesis introduces the concept of block compression/decompression, using smaller iteration tables, course distance and local block distance to solve problems of local memory access sequences, coupled scripts, MIV subscripts and communication set generation. Related work on these problems is reviewed and experimental results to demonstrate the benefit of the proposed methods.

A computer program, WINPOST-MULT, is developed for the dynamic analysis of a multiple-body floating system coupled with mooring lines and risers in the presence of waves, winds and currents. The coupled dynamics program for a single platform is extended for analyzing multiple-body systems by including all the platforms, mooring lines and risers in a combined matrix equation in the time domain. Compared to the iteration method between multiple bodies, the combined matrix method can include the full hydrodynamic interactions among bodies. The floating platform is modeled as a rigid body with six degrees of freedom. The first- and second-order wave forces, added mass coefficients, and radiation damping coefficients are calculated from the hydrodynamics program WAMIT for multiple bodies. Then, the time series of wave forces are generated in the time domain based on the two-term Volterra model. The wind forces are separately generated from the input wind spectrum and wind force formula. The current is included in Morison's drag force formula. In case of FPSO, the wind and current forces are generated using the respective coefficients given in the OCIMF data sheet. A finite element method is derived for the long elastic element of an arbitrary shape and material. This newly developed computer program is first applied to the system of a turret-moored FPSO and a shuttle tanker in tandem mooring. The dynamics of the turret-moored FPSO in waves, winds and currents are verified against independent computation and OTRC experiment. Then, the simulations for the FPSO-shuttle system with a hawser connection are carried out and the results are compared with the simplified methods without considering or partially including hydrodynamic interactions.

A new optical imaging modality has been developed for small animal in vivo imaging of near-infrared fluorescence resulting from fluorescent contrast agents specifically targeted to molecular markers of cancer. The imaging system is comprised of an intensified charge-coupled device (ICCD) for the detection of ultra-low levels of re-emitted fluorescence following the delivery of an expanded beam of excitation light. The design of the ICCD detection system allows for both continuous wave (CW) and frequency-domain modes of operation. Since the accurate acquisition of frequency-domain photon migration (FDPM) data is important for tomographic imaging, the imaging system was also validated using experimentally obtained FDPM measurements of homogenous turbid media and diffusion theory to obtain estimates of the optical properties characteristic of the media. The experiments demonstrated that the absorption and reduced scattering coefficients are determined least accurately when relative rel measurements of average light intensity IDC are employed either alone or in a rel combination with relative modulation amplitude data IAC and/or relative phase shift data rel . However, when FDPM measurements of are employed either alone or in rel combination with IAC data, the absorption and reduced scattering coefficients may be found accurate to within 15% and 11%, respectively, of the values obtained from standard single-pixel measurements; a result that suggests that FDPM data obtained from an ICCD detection system may in fact be useful in tomographic imaging. Furthermore, intensified-detection allows for sub-second exposure times, permitting the acquisition of dynamic fluorescence images immediately following administration of the contrast agent. Experimental results demonstrate that when coupled with a suitable pharmacokinetic model describing targeted dye distribution throughout the body, dynamic fluorescence imaging may be used to discriminate spontaneous canine adenocarcinoma from normal mammary tissue. A separate experiment demonstrates that pharmacokinetic analysis of dynamic fluorescence images enables one to estimate the rate constant governing Kaposi's sarcoma tumor uptake of an integrin-targeted dye and integrin receptor turnover rate. The rate constant for uptake was calculated to be 0.16-sec-1 while the turnover rate of the integrin receptor was estimated to occur within 24-hours.

The frequent use of two or more closely positioned vessels during offshore operations makes the study of multi-body hydrodynamics an important topic, especially for the design of deepwater offshore systems. This research investigation studies the response behavior of a coupled mini-TLP / barge system in both head and beam sea conditions. The design sea conditions were selected to represent the combined wind, wave and current conditions for a target location off the coast of West Africa. Both the mini-TLP and the barge were designed to have independent mooring systems. Coupling between the two vessels is introduced through a connection consisting of two breast lines and a fender system. This connection is designed to restrain the horizontal movements of the two vessels while keeping a constant distance between them and avoiding collisions. The main focus of this study is to analyze the experimental data obtained during the model testing, especially the motions of the two bodies and the values related to the fender system, in order to characterize the behavior of the uncoupled and coupled system configurations. A statistical approach is used for the data analysis and interpretation. Statistical parameters are used to provide an overall characterization of system behavior, and Gaussian and Weibull distribution functions are utilized to detect the importance of non-linearity in the data with particular attention to extreme values. Correlations between the two vessels in time domain and frequency domain are investigated. In addition, auto and cross spectrum analyses of the data are used to contrast the motion behavior of the uncoupled and coupled configurations. It is shown that the connection system reduces the horizontal vessel motions; however the forces exerted on the fender system show significant variation depending on sea heading conditions.

The study in this thesis focuses on the DTV antennas for mobile applications. By using the novel techniques in the proposed antenna, the narrow-band problem and the radiation pattern of the conventional DTV antenna can be improved. In the first design, the antenna comprises two radiating arms. By adjusting the open gap between the ends of the two radiating arms, large impedance bandwidth can be obtained for DTV signal reception. In the second design, by integrating a coupling portion into the dipole antenna, the full-wavelength resonant mode can be excited successfully and combined with the half-wavelength mode to form a wide operating band. Finally, in the third design, a U-shaped feeding gap is embedded within the V-shaped antenna to excite the full-wavelength resonant mode. Additionally, the dipole antenna can radiate comparable E£X and E£c components, resulting in no nulls in the total-power radiation patterns in the horizontal and vertical planes.

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The strong electromagnetic field that is induced at the surface of a plasmonic nanoparticle can be utilized for many important applications, including spectroscopic enhancement and electromagnetic waveguides. The focus of this thesis is to study some of the properties of induced plasmonic fields around metal nanoparticles. Current methodologies for fabricating nanoparticles are discussed, including lithography and colloidal synthesis. This dissertation includes studies on plasmonic driven nanoparticle motion of surface supported gold nanoprisms from a substrate into solution via a femtosecond pulse. The mechanism of particle motion is discussed and the stability of the unprotected nanoprisms in solution is studied. Fundamental plasmonic near-field coupling between two plasmonic nanoparticles is also examined. Experimental results using electron beam lithography fabricated samples are used to explicitly describe the plasmonic coupling between dimers as a function of the nanoparticle size, shape, and orientation. These variables are systematically studied and the dependence is compared to mathematically derived functional dependencies in order to model and predict the effects of plasmonic coupling. As an extension, the coupling between plasmonic nanoparticles is shown in a common application, surface enhanced Raman scattering. The final chapter is devoted to an investigation of the nature of nanocatalysis, homogeneous and heterogeneous, for several reactions using metal nanoparticles.

<p>The increasing number of biological databases today requires that users are able to search more efficiently among as well as in individual databases. One of the most widespread problems is redundancy, i.e. the problem of duplicated information in sets of data. This thesis aims at implementing an algorithm that distinguishes from other related attempts by using the genomic positions of sequences, instead of similarity based sequence comparisons, when making a sequence data set non-redundant. In an automatic updating procedure the algorithm drastically increases the possibility to update and to maintain the topicality of a non-redundant database. The procedure creates a biologically sound non-redundant data set with accuracy comparable to other algorithms focusing on making data sets non-redundant</p>

<p>The effects of different shearing processes and sample sizes on the fluid flow anisotropy and its impact on particle transport process in rough rock fractures are significant factors that need to be considered in the performance and safety assessments of underground nuclear waste repositories. The subjects, however, have not been adequately investigated previously in either laboratory experiments or numerical modeling. This thesis addresses these problems using numerical modeling approaches.</p><p>The modeling consists of two parts: 1) fluid flow simulations considering more complex but realistic flow boundary conditions during shear processes that cannot be realized readily in laboratory experiments, using digitalized fracture surfaces scanned in the laboratory, so that anisotropic fluid flow induced by shearing with channeling phenomenon can be directly simulated and quantified; 2) particle tracking simulations to demonstrate the impacts of such channeling effects on characteristic properties of particle transport. The numerical method chosen for the simulations is the Finite Element Method (FEM). Scale effects were considered in the simulations by using fracture surface samples of different sizes.</p><p>The distributions of fracture aperture during shear were obtained by numerically generating relative translational and rotary movements between two digitalized surfaces of a rock fracture replica without considering normal loading. From the evolutions of the aperture distributions during the shearing processes, the evolutions of the transmissivity fields were determined by assuming the validity of the cubic law locally. A geostatistical approach was used to quantify the scale effects of the aperture and transmissivity fields. The fluid flow was simulated using different flow boundary conditions, corresponding to translational and rotary shear processes. Corresponding to translational shear (with a 1 mm shear displacement interval up to a maximum shear displacement of 20 mm), three different flow patterns, i.e., unidirectional (flow parallel with and perpendicular to the shear direction), bi-directional and radial, were taken into account. Corresponding to rotary shear (with a 0.5o shear angle interval up to 90o), only the radial flow pattern was considered. The particle transport was simulated using the Particle Tracking Method, with the particles motion following the fluid velocity fields during shear, as calculated by FEM. For the unidirectional particle transport, the breakthrough curves were analyzed by fitting to an analytical solution of 1-D advection-dispersion equation. The dispersivity, Péclet number and tracer velocity, as well as their evolutions during shear, were determined numerically.</p><p>The results show that the fracture aperture increases anisotropically during translational shear, with a more pronounced increase in the direction perpendicular to the shear displacement, causing significant fluid flow channelling. A more significant increase of flow rate and decrease in travel time of the particles in the direction perpendicular to the shear direction is predicted. The particle travel time and characteristics are, correspondingly, much different when such effects caused by shear are included. This finding may have an important impact on the interpretation of the results of coupled hydro-mechanical and tracer experiments for measurements of hydraulic properties of rock fractures, because hydraulic properties are usually calculated from flow test results along the shear directions, with the effects of the significant anisotropic flow perpendicular to the shear direction ignored. The results also show that safety assessment of a nuclear repository, without considering the effects of stress/deformation of rocks on fluid flow and transport processes, may have significant risk potential. The results obtained from numerical simulations show that fluid flow through a single rough fracture changes with increasing sample size, indicating that representativehydro-mechanical properties of the fractures in the field can only be accurately determined using samples of representative sizes beyond their stationarity thresholds.</p>