the Choenan warship incident

Thesis(Master) --KDI School:Master of Public Policy,2010masterpublishedby Seung-Woo Nam

Depolarized Holography with Polarization-multiplexing Metasurface

The evolution of computer-generated holography (CGH) algorithms has prompted significant improvements in the performances of holographic displays. Nonetheless, they start to encounter a limited degree of freedom in CGH optimization and physical constraints stemming from the coherent nature of holograms. To surpass the physical limitations, we consider polarization as a new degree of freedom by utilizing a novel optical platform called metasurface. Polarization-multiplexing metasurfaces enable incoherent-like behavior in holographic displays due to the mutual incoherence of orthogonal polarization states. We leverage this unique characteristic of a metasurface by integrating it into a holographic display and exploiting polarization diversity to bring an additional degree of freedom for CGH algorithms. To minimize the speckle noise while maximizing the image quality, we devise a fully differentiable optimization pipeline by taking into account the metasurface proxy model, thereby jointly optimizing spatial light modulator phase patterns and geometric parameters of metasurface nanostructures. We evaluate the metasurface-enabled depolarized holography through simulations and experiments, demonstrating its ability to reduce speckle noise and enhance image quality.Comment: 15 pages, 13 figures, to be published in SIGGRAPH Asia 202

Characteristics of the Aragonitic Layer in Adult Oyster Shells, Crassostrea gigas: Structural Study of Myostracum including the Adductor Muscle Scar

Myostracum, which is connected from the umbo to the edge of a scar, is not a single layer composed of prismatic layers, but a hierarchically complex multilayered shape composed of minerals and an organic matrix. Through the analysis of the secondary structure, the results revealed that a β-antiparallel structure was predominant in the mineral phase interface between the myostracum (aragonite) and bottom folia (calcite). After the complete decalcification and deproteinization, the membrane obtained from the interface between the myostracum buried in upper folia, and the bottom folia was identified as chitin. The transitional zone in the interface between the adductor muscle scar and folia are verified. The myostracum disappeared at the edge of the scar of the posterior side. From this study, the entire structure of the myostracum from the adult oyster shell of Crassostrea gigas could be proposed

Unusual thermopower of inhomogeneous graphene grown by chemical vapor deposition

We report on thermopower (TEP) and resistance measurements of inhomogeneous graphene grown by chemical vapor deposition (CVD). Unlike the conventional resistance of pristine graphene, the gate-dependent TEP shows a large electron-hole asymmetry. This can be accounted for by inhomogeneity of the CVD-graphene where individual graphene regions contribute with different TEPs. At the high magnetic field and low temperature, the TEP has large fluctuations near the Dirac point associated with the disorder in the CVD-graphene. TEP measurements reveal additional characteristics of CVD-graphene, which are difficult to obtain from the measurement of resistance alone

Clinical Efficacy of Primary Tumor Volume Measurements: Comparison of Different Primary Sites

ObjectivesThe purpose of study was to determine the clinical efficacy of primary tumor volume measurements of different primary sites in the oropharynx compared to the oral cavity.MethodsA retrospective analysis of 85 patients with oral cavity or oropharynx cancer. The tumor area was manually outlined from axial magnetic resonance (MR) series. The software calculated the tumor volumes, automatically. The values of the primary tumor volumes were then subdivided into separate groups (≤3,500 mm3, >3,500 mm3).ResultsThe prognostic indicators were the cT and cN (oral cavity); age, primary site, cT, cN, and primary tumor volume (oropharynx) on the univariate analysis. There was no significant prognostic factor for oral cavity cancer on the multivariate analysis. Primary site, cN, and primary tumor volume were independent prognostic indicators for oropharynx cancer by multivariate analysis.ConclusionPrimary tumor volume measurement is a reliable way to stratify outcome, and make up for the weak points in the American Joint Committee on Cancer staging system with oropharynx cancer

A Case of Retinal Detachment in Colobomatous Macrophthalmos With Microcornea Syndrome

We report a rare case of retinal detachment in colobomatous macrophthalmos with microcornea syndrome. A 25-year-old female who had suffered from poor vision in her left eye since early childhood and high myopia in her right eye (-11 D) visited our clinic because of a sudden deterioration of vision. Examination of the anterior segment showed microcornea with coloboma of the inferior pupil margin in the left iris. Fundus examination of the left eye revealed an inferior choroidal coloboma extending from the optic disc and macula. The patient also had total bullous retinal detachment. Pars plana vitrectomy with silicone oil tamponade was performed, and the retina was reattached. In the very rare condition of colobomatous macropthalmos with microcornea, retinal detachment may develop. Pars plana vitrectomy with additional silicone oil tamponade may be performed to treat this condition

Quantum Hall effect in graphene decorated with disordered multilayer patches

Quantum Hall effect (QHE) is observed in graphene grown by chemical vapour deposition using platinum catalyst. The QHE is even seen in samples which are irregularly decorated with disordered multilayer graphene patches and have very low mobility (<500 cm2V−1s−1). The effect does not seem to depend on electronic mobility and uniformity of the resulting material, which indicates the robustness of QHE in graphene

Nasal Hemangiopericytoma Causing Oncogenic Osteomalacia

Oncogenic osteomalacia is a rare cause that makes abnormalities of bone metabolism. Our case arose in a 47-year-old woman presenting a nasal mass associated with osteomalacia. We excised the mass carefully. After surgery, it was diagnosed as hemangiopericytoma and her symptoms related with osteomalacia were relieved and biochemical abnormalities were restored to normal range. We report and review a rare case of nasal hemangiopericytoma that caused osteomalacia

Selective laser ablation of metal thin films using ultrashort pulses

Selective thin-film removal is needed in many microfabrication processes such as 3-D patterning of optoelectronic devices and localized repairing of integrated circuits. Various wet or dry etching methods are available, but laser machining is a tool of green manufacturing as it can remove thin films by ablation without use of toxic chemicals. However, laser ablation causes thermal damage on neighboring patterns and underneath substrates, hindering its extensive use with high precision and integrity. Here, using ultrashort laser pulses of sub-picosecond duration, we demonstrate an ultrafast mechanism of laser ablation that leads to selective removal of a thin metal film with minimal damage on the substrate. The ultrafast laser ablation is accomplished with the insertion of a transition metal interlayer that offers high electron-phonon coupling to trigger vaporization in a picosecond timescale. This contained form of heat transfer permits lifting off the metal thin-film layer while blocking heat conduction to the substrate. Our ultrafast scheme of selective thin film removal is analytically validated using a two-temperature model of heat transfer between electrons and phonons in material. Further, experimental verification is made using 0.2 ps laser pulses by micropatterning metal films for various applications.Comment: 19 pages, 4 figures. This manuscript has been submitted to International Journal of Precision Engineering and Manufacturing-Green Technolog