• 한국CDE학회논문집
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• 제8권1호
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• pp.41-47
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• 2003

In this paper, a tetrahedral mesh generation algorithm which uses a grid based method for interior region and an advancing front method for outer surface region is proposed. In order to apply an advancing front method for outer region of an object, a new operator so called a hole operator has been developed to handle multiple shells. With this grid based approach in the interior region, more stable and uniform meshes can be constructed especially in the interior region.

• 한국의류학회지
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• 제40권1호
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• pp.171-187
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• 2016

The study performed a comparison analysis of market brand patterns for slim-fit dress shirts and analyzed the body surface development figure of men in their 40s using 3D body scan data and developed slim-fit dress shirt patterns suitable for middle-aged men. The sizes of slim-fit dress shirt patterns showed a slight difference depending on brand. The overlap map of slim-fit dress shirt patterns for brands demonstrates how difference of one-dimensional sizes reflect on two-dimensional patterns. This map provides useful information for pattern design and allows and easy recognition of pattern size differences. A try-on system evaluation through 3D-Simulation allows a grasp of the fitness of neckline and size tolerance of under the arms in front, the silhouette of side lines, and overall fitness in front that also allows analysis of the front/back balance of a shirt in side, the size tolerance proportion in front/back, and the fitness of the arm-hole line. Thus, we obtained try-on results that were equivalent to wearing actual clothing. According to the drafting size suggested in the developed final pattern, the total width was 'C/2+5.5cm', and the front was set at 1cm bigger in the size difference of the front and back. The width of the front neck and the back neck was set identically at 'C/12', while the width of the front neck was set to 'C/12+1.5cm'. For the armhole depth, we added 'C/4+2cm', and '0.5cm and 1.5cm' for the width of the front and back to anthropometry. The results of the try-on evaluation through 3D-Simulation indicated that the fitness of the final slim-fit dress shirt pattern was superior to available slim-fit dress shirt patterns on the market and evaluated as superior to the types for middle-aged men.

• 한국생산제조학회지
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• 제22권2호
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• pp.248-255
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• 2013

The objective of this study is to optimize the Metal Injection Molding(MIM) process with design of experiments(DOE) and numerical analysis. To derive the optimal process condition, experiment or numerical analysis was performed under various process conditions. To analyze the interaction among influential factors contributing to the temperature at flow front and response surface in MIM, both central point and axial point were added to the full factorial design with 2 levels and 5 factors and then their impacts on response variable in 43 experimental conditions were analyzed and the significance was evaluated. As a result, sprue, runner, and gate were completely filled in about 0.247 seconds after injection, the front part of the green body was filled in about 0.3344 seconds, the green body except gate, etc changed to almost solid state in about 3.29 seconds, the Packinging pressure was completed in about 6.29 seconds, and the green body inside and outside and sprue, etc became solid in 13.2 seconds. The impact of individual or reciprocal action of factors on the temperature at flow front was analyzed through regular probability, test statistics, main effect, and interaction effect. As a result, of a total of 31 combinations of factors, 9 unit factors and reciprocal actions were significant, and the screening was also possible. A proper regression equation was drawn with regression analysis and response surface design on the response variable of temperature at flow front, and the applicability could be verified.

• 환경위생공학
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• 제21권4호
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• pp.61-76
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• 2006

A Line Density algorithm was developed to quantify the sea surface temperature distribution using NOAA Sea Surface Temperature(SST) data and Geographic Information Systems(GIS), In addition, a GIS based automation model was designed to extract the Line Density Indices were determined by applying K-means Cluster. SST data in terms of March to May obtained on the coastal area of the Uljin from 2001 to 2004 in spring were used to make two data sets of average sea water temperature map in terms of year as well as month. From the result it was formed that water temperature gradient in April was the strongest among the other months, In particular very strog formation of oceanic front as well as temperature gradients were observed in front of the coastal area around Wonduk and Jukbyeon countries. Because those coastal area is a confront zone of two cold and a warm. It is expected that the development of a Line Density Algorithm would contribute to quantify of the SST for the research of Sea Surface Front(SSF) related to marine life management and the sea environmental conservation.

• 한국의류산업학회지
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• 제22권2호
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• pp.222-232
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• 2020

This study analyzes changes in the knees, hips, and hip joint length according to the different angles of bending knees by 45°, 90°, and 135° respectively for knees, hips, and the hip joint that have high fracture rates when falling down. The research subjects were 10 elderly women in their 60s (or older) that obtain data collected through direct measurement. For analysis, the study drew a diagram of elongation and shrinkage based on changes and change rate from a straight posture (0°) and conducted a statistical analysis on differences of body surface length by zone according to movements. The more the knees were bent, the vertical surface length in front of the knees, the horizontal surface length above the knee line, the horizontal body surface length below the knee lines on the back, and the vertical surface lengths between front side lines and the side lines increased; however, the vertical surface length on the back decreased. For the hip joint, the difference in the vertical surface length was more distinctive when compared to the horizontal. Finally, the horizontal surface length increased below the hips and the vertical surface length increased in most areas except the sidelines and the front. The result of the change in body surface length according to the movements of this study can be utilized in the development of the motion-variable protector.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.493-493
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• 2014

The manufacturing cost of thin-film photovoltics can potentially be lowered by minimizing the amount of a semiconductor material used to fabricate devices. Thin-film solar cells are typically only a few micrometers thick, whereas crystalline silicon (c-Si) wafer solar cells are $180{\sim}300\mu}m$ thick. As such, thin-film layers do not fully absorb incident light and their energy conversion efficiency is lower compared with that of c-Si wafer solar cells. Therefore, effective light trapping is required to realize commercially viable thin-film cells, particularly for indirect-band-gap semiconductors such as c-Si. An emerging method for light trapping in thin film solar cells is the use of metallic nanostructures that support surface plasmons. Plasmon-enhanced light absorption is shown to increase the cell photocurrent in many types of solar cells, specifically, in c-Si thin-film solar cells and in poly-Si thin film solar cell. By proper engineering of these structures, light can be concentrated and coupled into a thin semiconductor layer to increase light absorption. In many cases, silver (Ag) nanoparticles (NP) are formed either on the front surface or on the rear surface on the cells. In case of poly-Si thin film solar cells, Ag NPs are formed on the rear surface of the cells due to longer wavelengths are not perfectly absorbed in the active layer on the first path. In our cells, shorter wavelengths typically 300~500 nm are also not effectively absorbed. For this reason, a new concept of plasmonic nanostructure which is NPs formed both the front - and the rear - surface is worth testing. In this simulation Al NPs were located onto glass because Al has much lower parasitic absorption than other metal NPs. In case of Ag NP, it features parasitic absorption in the optical frequency range. On the other hand, Al NP, which is non-resonant metal NP, is characterized with a higher density of conduction electrons, resulting in highly negative dielectric permittivity. It makes them more suitable for the forward scattering configuration. In addition to this, Ag NP is located on the rear surface of the cell. Ag NPs showed good performance enhancement when they are located on the rear surface of our cells. In this simulation, Al NPs are located on glass and Ag NP is located on the rear Si surface. The structure for the simulation is shown in figure 1. Figure 2 shows FDTD-simulated absorption graphs of the proposed and reference structures. In the simulation, the front of the cell has Al NPs with 70 nm radius and 12.5% coverage; and the rear of the cell has Ag NPs with 157 nm in radius and 41.5% coverage. Such a structure shows better light absorption in 300~550 nm than that of the reference cell without any NPs and the structure with Ag NP on rear only. Therefore, it can be expected that enhanced light absorption of the structure with Al NP on front at 300~550 nm can contribute to the photocurrent enhancement.

• 대한원격탐사학회지
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• 제34권6_2호
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• pp.1179-1192
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• 2018

이 연구는 남빙양(Southern Ocean)에서 나타나는 주된 전선(Front)들 중에 남극 극 전선(Antarctic Polar Front; PF)을 탐지하기 위하여 위성 기반 해수면 온도(sea surface temperature)와 해수면 고도(sea surface height) 자료를 복합적으로 사용하였다. 정확한 PF 탐지를 위하여 일별 SST와 SSH 자료를 각각 기반으로 하여 베이지안 결정 이론(Bayesian decision theory)을 적용하였으며, 이를 근거로 전선/비전선의 신호를 격자 별로 분류하였다. 이후, 시공간적인 합성을 통하여 일차적인 노이즈(noise) 제거 및 지리학적 연결성을 보완하였다. 그러나 이들 과정을 수행하고도 여전히 잔존하는 일부 노이즈를 제거하기 위하여 해빙 및 연안 마스킹(masking)을 수행하였다. 또한 모폴로지 연산(morphology operation)을 통하여 지류 성분을 최대한으로 배제하고 주된 전선 성분만을 추출하였다. 최종적으로 선택된 전선 격자 들에서 PF의 특징을 나타낼 수 있도록 가장 최남단의 전선만을 선택하여 평활 스플라인(smoothing spline) 최적화 방식을 통해 선 형태의 월별 PF를 산출하였다. 산출된 PF는 기존의 연구에서 제시한 PF의 위치와 상당히 유사한 것으로 나타났으며, 특히 바닥 지형에 따라 상당 부분 결정되는 PF의 변화를 잘 모사하는 것으로 보인다. 로스해 주변(${\sim}180^{\circ}W$)과 호주 이남의 해역($120^{\circ}E-140^{\circ}E$)은 PF의 위치에 대한 계절적 변동이 높게 나타나며, 그러한 변동이 기존에 제시된 결과와 상당히 유사한 경향을 지닌다. 그러므로 이 연구에서 산출된 PF의 위치에 대한 탐지 결과가 향후 장기적 관점에서 수행될 연구에 사용될 수 있는 가치를 지닐 것으로 기대한다.

• 한국전기전자재료학회논문지
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• 제24권4호
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• pp.328-332
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• 2011

The formation of front metal contact silicon solar cells is required for low cost, low contact resistance to silicon surface. One of the front metal contacts is Ni/Cu plating that it is available to simply and inexpensive production to apply mass production. Ni is shown to be a suitable barrier to Cu diffusion into the silicon. The process of Ni electroless plating on front silicon surface is performed using a chemical bath. Additives and buffer agents such as ammonium chloride is added to maintain the stability and pH control of the bath. Ni deposition rate is found to vary with temperature, time, utilization of bath. The experimental result shown that Ni layer by SEM (scanning electron microscopy) and EDX analysis. Finally, plated Ni/Cu contact solar cell result in an efficiency of 17.69% on $2{\times}2\;cm^2$, Cz wafer.

• 한국안광학회지
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• 제8권2호
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• pp.57-63
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• 2003

본 연구에서는 안경렌즈의 전면굴절력, 굴절률, 그리고 중심 두께의 변화에 따라 상측정점초점면에 맺는 착락원 직경 변화를 조사하기 위해 Code V와 LOSA 2.0 프로그램을 사용하였으며, 상측정점굴절력이 -4.00D이고 직경이 70 mm인 근시교정용 안경렌즈를 고려하였다. 또한 안경렌즈의 전면 굴절력은 0~10D, 중심 두께는 1.1~2.0mm 그리고 굴절률은 $n_d$ = 1.498, 1.523, 1.586, 1.60인 경우를 각각 고려하였다. 안경렌즈의 전면굴절력이 증가할수록 상측정점초점면에서 맺는 착락원 직경의 크기는 급격하게 증가하였다. 또한 안경렌즈의 굴절률이 증가한 경우에 상측정점초평면에 맺는 착락원 직경의 크기는 감소하였으며, 전면굴절력의 변화에 따른 착락원 직경의 크기 변화는 작았다. 안경렌즈의 중심 두께가 증가할수록 상측정점초평면에 맺는 착락원 직경 크기에는 거의 영향이 없지만 안경렌즈의 가장자리의 두께는 증가하였다. 이러한 결과로부터 구면렌즈의 경우에는 전면굴절력이 작고, 굴절률이 클수록 상측정점초평면에서 더 좋은 결상을 하고 있음을 알 수 있다.

• 한국해양공학회지
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• 제11권2호
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• pp.138-144
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• 1997

This is describes the automatic mesh generation on the ship hull surface. At first ship hull is defined as a cillocation of composite surface patches which satisfy the geometic continuity between adjoining patches by using Gregory surface method. Node points that would be mesh points are ganerated by considering the surface curvature. The triangulation of the node points is by the combination of Ohtsubo's method and Choi's one. After triangulation, shape improvement and quadrilateralization is done with specific criterin. An application to the actual ship and the results are shown.