The eventual deployment of wave energy converters (WECs) on a commercial scale will necessitate the grouping of devices into arrays or "wave farms," in order to minimize overhead costs of mooring, maintenance, installation, and electrical cabling for shoreward power delivery. Closely spaced WECs will interact hydrodynamically through diffracted and radiated waves. Recent research has focused on the WEC wave field and used its structures to design constructive WEC arrays as well as to describe the means of WEC energy absorption. In this study, the WEC wave field is investigated for a single WEC and a five WEC array with linear wave theory and experimental results. Both regular waves and spectral seas are considered. Computational results are produced with the linear boundary-element-method (BEM) hydrodynamic software WAMIT for a simple WEC geometry. Experimental data comes from WEC array tests that took place at Oregon State University over the winter of 2010-11 [1]. The experimental measurements help validate the computational modeling, and the computational models serve as an aid to interpreting the experimental data. Results reveal two universal WEC wave field features - partially standing waves and a wave shadow, both of which are the result of the coherent interaction of the planar incident wave with the circular generated wave, composed of the diffracted and radiated waves. The partial standing waves in the offshore are seen qualitatively in experimental data but could not be exactly reproduced computationally, because the computational model is only a simple representation of the physical model. In the lee of the WEC, the measured longshore structure of the wave shadow is in good agreement with theoretical expectations as well as computational results. It is believed that the agreement is because the formation of the wave shadow is dominated by energy extraction, which was approximately the same for both the computational and physical models. A study of the linear WEC wave field in regular waves and spectral seas reveals patterns such as the wave shadow that have also been found in experimental data. The positions and magnitudes of the offshore partially standing waves are very sensitive to wavelength, and WEC geometry, motions and location, and in spectral seas, they are smoothed when considering significant wave height. All of which suggest that it may be difficult to use them advantageously in the design of WEC arrays. The wave shadow is a dominant feature of the WEC wave field for both regular waves and spectral seas. It appears to be fairly generic and to be based on power absorption. In the design of WEC arrays, rather than attempting constructive interference by using standing wave crests, perhaps the best one can do is to avoid destructive interference of the wave shadow. / Graduation date: 2013

Fragile states are characterized by institutions which do not have the political will or ability to reduce poverty in the interests of their citizen, to establish basic social security, to promote a successful development process, and to guarantee security and human rights. The regional disintegration processes after the period of imperialism and the fall of the iron curtain have created many new states, which still are politically unstable and unable for a sustainable development. In the literature such states are describes as "weak", "failing or failed", "collapsed", "conflict or post-conflict" - dependant on the extent of the particular state failure. Several indicators try to describe such states and partly allow for projections of the future development. Then the role of taxation is discussed in detail before recommendations for the development cooperation are presented. Obviously taxation plays a key role for the democratization process in fragile states.

3D GIS is the key point of the development in the area in geospatial information domain. 3D visualization techniques, including 3D terrain data processing, the 3D objects modelling , satellite or air photo image texture, model material, level-of-detail terrain, is already gradually mature and had the outstanding performance in the existing 3D GIS software. But 3D spatial analysis function was still lacking in the field of the 3D spatial data processing. The goal of this research is to develop a 3D spatial analysis function for sun shadow in horizontal and vertical direction and to construct a system for 3D geographic objects visualization by using MFC and OpenGL as the development kit. It has some fundamental functions including: camera control, selecting a single face of a object, linking to a database, level-of-detail terrain. The shadow volume algorithm was used for 3D shadow visualization, and light tracing algorithm was used to compute a single face¡¦s culling area, finally sunshine formula of four seasons was utilitized to realize the shadow analysis function.

A self-aligning nanostencil mask is used to fabricate circular features of tin, indium and silver on an atomically clean Si(001) substrate. The shadow mask limits deposited material to areas under openings in the mask, leaving adjacent clean areas for material to diffuse. STM, SEM and AFM have been used to study the surface diffusion of these metals in UHV. The diffusion of tin is relatively limited in comparison to the other metals. Indium forms metal islands that dissolve over time and contribute to the spreading of a surrounding single layer film. Lastly, silver forms a film that spreads even in the absence of metal islands.

A self-aligning nanostencil mask is used to fabricate circular features of tin, indium and silver on an atomically clean Si(001) substrate. The shadow mask limits deposited material to areas under openings in the mask, leaving adjacent clean areas for material to diffuse. STM, SEM and AFM have been used to study the surface diffusion of these metals in UHV. The diffusion of tin is relatively limited in comparison to the other metals. Indium forms metal islands that dissolve over time and contribute to the spreading of a surrounding single layer film. Lastly, silver forms a film that spreads even in the absence of metal islands.

Shadows contribute significantly to the perceived realism of an image, and provide an important depth cue. Rendering high quality, antialiased shadows efficiently is a difficult problem. To antialias shadows, it is necessary to compute partial visibilities, but computing these visibilities using existing approaches is often too slow for interactive applications. Shadow maps are a widely used technique for real-time shadow rendering. One major drawback of shadow maps is aliasing, because the shadow map data cannot be filtered in the same way as colour textures. In this thesis, I present variance shadow maps (VSMs). Variance shadow maps use a linear representation of the depth distributions in the shadow map, which enables the use of standard linear texture filtering algorithms. Thus VSMs can address the problem of shadow aliasing using the same highly-tuned mechanisms that are available for colour images. Given the mean and variance of the depth distribution, Chebyshev's inequality provides an upper bound on the fraction of a shaded fragment that is occluded, and I show that this bound often provides a good approximation to the true partial occlusion. For more difficult cases, I show that warping the depth distribution can produce multiple bounds, some tighter than others. Based on this insight, I present layered variance shadow maps, a scalable generalization of variance shadow maps that partitions the depth distribution into multiple segments. This reduces or eliminates an artifact - "light bleeding" - that can appear when using the simpler version of variance shadow maps. Additionally, I demonstrate exponential variance shadow maps, which combine moments computed from two exponentially-warped depth distributions. Using this approach, high quality results are produced at a fraction of the storage cost of layered variance shadow maps. These algorithms are easy to implement on current graphics hardware and provide efficient, scalable solutions to the problem of shadow map aliasing.

The Evening Shadow, a six-minute work for symphony orchestra, is a short symphonic poem composed with the intent of evoking a sensation of lament and eventual deliverance. Drawing from the “Neapolitan Complex” found in Beethoven’s string quartet in C-sharp minor, op. 131 (exploitation of the semitone between C#-D), I attempted to create a dramatic “storyline” utilizing the semitone relation between E and F. From a programmatic standpoint, upward motion from E to F is meant to represent yearning (mm. 5-6, violins, mm. 14-15, violin/vibraphone, m. 18, cello, embedded in m. 20, flute 2) while downward motion from F to E (mm. 110-113, brass) symbolizes rescue and redemption. Motivic transformation was paramount to the construction of The Evening Shadow. Five primary motives are stated and developed. The first appears in the solo violin from mm. 3-4 and is transformed at m. 44 in the oboe and 2nd violins. The second motive is stated in mm. 9-12 in the 1st violins, and returns in canon from mm. 96-106. The third motive appears in the oboe in mm. 29-30 and is developed extensively (mm. 41-42, 47-48, 110-113). The fourth motive is stated in the 1st violins at m. 33 and returns in m. 52 in the 2nd violins. The final motive is first heard in the horns in mm. 39-40 and ends the piece from mm. 127-129. The motivic transformations make use of transposition, modal “adjustment,” and built in rubato effects, as well a large degree of fragmentation and recombination. Traditional contrapuntal technique was utilized throughout the work. Global harmonic motion of the piece, which makes use of skeletal tonic/dominant relations, can be heard as a progression through the following “tonicizations” and respective modalities: E/F (pitch-centric, no modality, mm. 1-33), D (Dorian, mm. 34-55), A (Dorian, mm. 52-54), E (pseudo-Phrygian, mm. 65-87), C (Mixolydian, mm. 108-121), G (Mixolydian, mm. 127-132), and E/F (pitch-centric, no modality, mm. 133-137). Atonal pitch-class set sonorities were used as structural rhetoric throughout. The aggregate collection, drawing from dodecaphonic theory, is used sparingly both melodically (mm. 16-17, violins and violas), and harmonically (mm. 2-3, 64, 66, 69, 137). Conceptual difficulties arise from orchestrational considerations in a contemporary work due to the broad array of possibilities demonstrated in the scores that span the history of orchestral music. I sought to create a hybrid of advanced traditional orchestration (Mahler, Strauss) and texturalist practices (Lutoslawski, Ligeti).

Shadows contribute significantly to the perceived realism of an image, and provide an important depth cue. Rendering high quality, antialiased shadows efficiently is a difficult problem. To antialias shadows, it is necessary to compute partial visibilities, but computing these visibilities using existing approaches is often too slow for interactive applications. Shadow maps are a widely used technique for real-time shadow rendering. One major drawback of shadow maps is aliasing, because the shadow map data cannot be filtered in the same way as colour textures. In this thesis, I present variance shadow maps (VSMs). Variance shadow maps use a linear representation of the depth distributions in the shadow map, which enables the use of standard linear texture filtering algorithms. Thus VSMs can address the problem of shadow aliasing using the same highly-tuned mechanisms that are available for colour images. Given the mean and variance of the depth distribution, Chebyshev's inequality provides an upper bound on the fraction of a shaded fragment that is occluded, and I show that this bound often provides a good approximation to the true partial occlusion. For more difficult cases, I show that warping the depth distribution can produce multiple bounds, some tighter than others. Based on this insight, I present layered variance shadow maps, a scalable generalization of variance shadow maps that partitions the depth distribution into multiple segments. This reduces or eliminates an artifact - "light bleeding" - that can appear when using the simpler version of variance shadow maps. Additionally, I demonstrate exponential variance shadow maps, which combine moments computed from two exponentially-warped depth distributions. Using this approach, high quality results are produced at a fraction of the storage cost of layered variance shadow maps. These algorithms are easy to implement on current graphics hardware and provide efficient, scalable solutions to the problem of shadow map aliasing.

Micro-Electro-Mechanical Systems (MEMS) micromirrors have been developed for more than two decades along with the development of MEMS technology. They have been used into many application fields: optical switches, digital light projector (DLP), adoptive optics (AO), high definition (HD) display, barcode reader, endoscopic optical coherence tomography (OCT) and confocal microscope, and so on. Especially, MEMS mirrors applied into endoscopic OCT and confocal microscope are the intensive research field. Various actuation mechanisms, such as electrostatic, electromagnetic, electro bimorph thermal, electrowetting, piezoelectric (PZT) and hybrid actuators, are adopted by different types of micromirrors. Among these actuators, the electrostatic is easily understood and simple to realize, therefore, it is broadly adopted by a large number of micromirrors. This thesis reports the design, fabrication, and characterization of a 2-D Silicon-on-insulation (SOI) MEMS micromirror with sidewall (SW) electrodes for endoscopic OCT or confocal microscope imaging. The biaxial MEMS mirror with SW electrodes is actuated by electrostatic actuators. The dimension of mirror plate is 1000micron×1000micron, with a thickness of a 35micron. The analytical modeling of SW electrodes, fabrication process, and performance characteristics are described. In comparison to traditional electrostatic actuators, parallel-plate and comb-drive, SW electrodes combined with bottom electrodes achieve a large tilt angle under a low drive voltage that the comb-drive does and possess fairly simple fabrication process same as that of the parallel-plate. A new fabrication process based on SOI wafer, hybrid bulk/surface micromachined technology, and a high-aspect-ratio shadow mask is presented. Moreover, the fabrication process is successfully extended to fabricate 2×2 and 4×4 micromirror arrays. Finally, a biaxial MEMS mirror with SW electrodes was used into Confocal MACROscope for imaging. Studied optical requirements in terms of two optical configurations and frequency optimization of the micromirror, the biaxial MEMS mirror replaces the galvo-scanner and improves the MACROscope. Meanwhile, a new Micromirror-based Laser Scanning Microscope system is presented and allows 2D images to be acquired and displayed.

Sunshine, air and water are the vital elements to the human. This study investigated the insolation and solar radiation in Kaohsiung city. Solar radiation on the horizontal and declined plane was calculated. Sun shadow model for urban buildings was constructed for computing accumulated sunshining hours. Horizontal and vertical building shadows were displayed in ArcGIS ¡V the GIS software. Raster-based data model was used to analyze the effect of sun shadow shading by neighbour buildings. And the effect of shadow shading for solar water heater was also investigated. According to the results, minor installation error of orientation and decline angles of solar panel will not cause major energy loss. And the distance between the buildings¡Bthe height difference and the orientation between buildings are most important factors which affect optimal installation location of the solar water heater. If there are buildings located to the south, southeast and southwest, and the stories difference between buildings is over three, the installing location should be moved toward north. If buildings are next to each others and the variation of height is large, the efficient of receiving solar radiation will be deteriorated. The larger is the distance between buildings, the better the energy received.