• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2005년도 제30회 춘계학술대회
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• pp.35-38
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• 2005

국내의 MR영상 기술에 있어서 피부영상 및 MR Microscopy에 대한 연구는 있었지만 그 성과는 크게 만족스럽지 못했다. 본 연구는 고해상도 피부 영상을 얻기 위한 Surface coil을 구상하여 제작하고 임상용 MRI 시스템에서 영상을 얻었다. 그러나, 이러한 초기 영상으로부터 시작하여 피부영상 및 미세구조 영상을 얻는 데는 상당한 기술적 제한이 따른다. 기존의 volume형 RF coil보다 surface coil이 비록 자기장 균질도는 떨어지나 우수한 SNR을 얻을 수 있어, 개선의 방향을 coil의 형태를 조정함으로써 고해상도의 영상을 얻을 수 있다. 따라서 Surface coil 제작의 그 첫 단계인 surface coil의 구조에 따른 자기장 분포를 시뮬레이션함으로써 surface coil을 제작하는데 있어 주요 참고자료가 될 것이다.

• Ocean and Polar Research
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• 제28권3호
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• pp.339-352
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• 2006

Seasonal and tidal variations of density stratification in the Saemangeum waters are investigated based on synoptic CTD observations between July 2003 and September 2005. CTD data used in this study are those obtained after closing the dike No. 4 and before closing the two final gaps, the Sinsi and the Garyeok, on the Saemangeum tidal harrier. A total of 19 field campaigns comprehend a wide temporal spectrum, that is, few seasons, spring and neap tides, and high and low waters. In addition, ADCPs were anchored and CTDs were cast at three stations for 25 h in July 2005. Water columns are vertically homogeneous in autumn and winter. The vertical homogeneity persists in spring but with an occasional weak stratification in i:he northern part of the Gogunsan Islands. Increased reshwater runoff tends to stabilize the water columns and strong density stratification is established in summer. The mean potential energy anomaly (PEA) in summer used as a stratification parameter is the largest $(27.7\;J\;m^{-3})$ in the northern part of the Gogunsan Islands where the Geum River discharge dominates, the smallest $(16.9\;J\;m^{-3})$ is in the inner area of the barrier, in between the two $(21.6\;J\;m^{-3})$ in the southern part of the Gogunsan Islands. Whereas the stratification is generally strengthened in summer, strong winds or large tidal currents over the shallow depths frequently destratify the water column near the mouth of river runoff inside the tidal barrier. Periodic stratification, the development of stratification on the ebb and its breakdown on the flood, occurs in the mid-area inside the barrier induced by the tidal straining, which can also be found in the results of 25 h observation.

• Progress in Superconductivity
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• 제10권1호
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• pp.23-28
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• 2008

We report refinement of crystalline boron by an attrition ball milling system and the superconducting properties of the $MgB_2$ pellets prepared from the refined boron. In this work, we have conducted the ball milling with only crystalline boron powder, in order to improve homogeneity and control the grain size of the $MgB_2$ that is formed from it. We observed that the crystalline responses in the ball-milled boron became broader and weaker when the ball-milling time was further increased. On the other hand, the $B_{2}O_{3}$ peak became stronger in the powders, resulting in an increase in the amount of MgO within the $MgB_2$ volume. The main reason for this is a greater oxygen uptake. From the perspective of the superconducting properties, however, the sample prepared from boron that was ball milled for 5 hours showed an improvement of critical current density ($J_c$), even with increased MgO phase, under an external magnetic field at 5 and 20 K.

• Radiation Oncology Journal
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• 제30권1호
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• pp.27-35
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• 2012

Purpose: To evaluate the effect of common three photon energies (6-MV, 10-MV, and 15-MV) on intensity-modulated radiation therapy (IMRT) plans to treat prostate cancer patients. Materials and Methods: Twenty patients with prostate cancer treated locally to 81.0 Gy were retrospectively studied. 6-MV, 10-MV, and 15-MV IMRT plans for each patient were generated using suitable planning objectives, dose constraints, and 8-field setting. The plans were analyzed in terms of dose-volume histogram for the target coverage, dose conformity, organs at risk (OAR) sparing, and normal tissue integral dose. Results: Regardless of the energies chosen at the plans, the target coverage, conformity, and homogeneity of the plans were similar. However, there was a significant dose increase in rectal wall and femoral heads for 6-MV compared to those for 10-MV and 15-MV. The $V_{20Gy}$ of rectal wall with 6-MV, 10-MV, and 15-MV were 95.6%, 88.4%, and 89.4% while the mean dose to femoral heads were 31.7, 25.9, and 26.3 Gy, respectively. Integral doses to the normal tissues in higher energy (10-MV and 15-MV) plans were reduced by about 7%. Overall, integral doses in mid and low dose regions in 6-MV plans were increased by up to 13%. Conclusion: In this study, 10-MV prostate IMRT plans showed better OAR sparing and less integral doses than the 6-MV. The biological and clinical significance of this finding remains to be determined afterward, considering neutron dose contribution.

• 한국습지학회지
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• 제12권3호
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• pp.15-20
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• 2010

마산만유역의 창원시 수계에서 발생한 오염부하는 차집관로를 통하여 하수종말처리장으로 운반되거나 창원시 하천을 거쳐 봉암갯벌을 경유한 후 마산만으로 유입된다. 즉 마산만 하구 갯벌인 봉암갯벌은 도심에 위치하여 있고 민관산학의 협력으로 보존되어 생태학습장으로 이용되는 귀중한 갯벌이다. 특히 최근 몇 년 동안 조개류, 어류와 물새 등 다양한 생물이 관찰되고 있으며 우리나라 최초의 마산만특별관리해역 연안오염총량관리의 중심 지역에 해당한다. 1970년에 시작한 창원기계공업단지의 가동으로 마산만의 하구와 내만은 중금속으로 오염되었음이 보고되었다. 봉암갯벌의 저서생물의 서식지인 퇴적물에 존재하는 잔류성이 강한 주요 중금속 오염물질의 변화를 분석하였다. 아연, 구리, 납이 오염퇴적물 기준의 상위 기준 또는 심한 오염 기준을 초과하였고 인근 지점 별로도 95% 신뢰구간에서 차이를 보였다. 2006년과 2009년의 자료를 비교할 때 모든 중금속 농도가 점차 감소하고 있었다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2018년도 춘계학술대회 논문집
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• pp.129-129
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• 2018

Hard coating application is effective way of cutting tool for hard-to-machine materials such as Inconel, Ti and composite materials focused on high-tech industries which are widely employed in aerospace, automobile and the medical device industry also Information Technology. In cutting tool for hard-to-machine materials, high hardness is one of necessary condition along with high temperature stability and wear resistance. In recent years, high-entropy alloys (HEAs) which consist of five or more principal elements having an equi-atomic percentage were reported by Yeh. The main features of novel HEAs reveal thermodynamically stable, high strength, corrosion resistance and wear resistance by four characteristic features called high entropy, sluggish diffusion, several-lattice distortion and cocktail effect. It can be possible to significantly extend the field of application such as cutting tool for difficult-to-machine materials in extreme conditions. Base on this understanding, surface coatings using HEAs more recently have been developed with considerable interest due to their useful properties such as high hardness and phase transformation stability of high temperature. In present study, the nanocomposite coating layers with high hardness on WC substrate are investigated using high entropy alloy target made a powder metallurgy. Among the many surface coating methods, reactive magnetron sputtering is considered to be a proper process because of homogeneity of microstructure, improvement of productivity and simplicity of independent control for several critical deposition parameters. The N2 is applied to reactive gas to make nitride system with transition metals which is much harder than only alloy systems. The acceleration voltage from 100W to 300W is controlled by direct current power with various deposition times. The coating layers are systemically investigated by structural identification (XRD), evaluation of microstructure (FE-SEM, TEM) and mechanical properties (Nano-indenter).

• 복식
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• 제60권1호
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• pp.91-100
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• 2010

In the rapid development of science, technology, information, cultural industry during the 21st century, hybridity is consistently shown in which different techniques, systems, and sorts in society, industry, culture, and art are combined. The purpose of this study is to analyze the formative characteristics of hybrid make-up that is shown in the field of make-up as a practical art reflecting society and culture of a specific period, to understand the tendencies of modern make-up, and to present data for predicting changes in the future. According to the results of this study, the hybrid characteristics of make-up indicate as follows. First, hybrid make-up at a timely aspect in which senses transcending times by mixed expression of traditional classicism and modernism coexist and mingled, Characteristics of hybrid make-up at a local aspect are shown in one make-up by expressing modern tendencies that break from homogeneity, uniformity, and concentration as interests in other cultures and borrowing them in modern images. Also in modern period, characteristics of hybrid make-up at a cultural aspect are shown by mixed expression of conflicting cultural factors such as modern beauty of cutting-edge technology, female & male, and elegance & activeness in one makeup. Within the multiplex, modern social system in this period of cutting-edge technology, "tendency of hybrid design" as a social, cultural phenomenon is shown to be a complex, new designing tendency due to mixture and deconstruction of various genres. Hybrid make-up, seeking diversification and open-mindedness, is predicted to be consistently developed owing to infinite materials of design, being expected to be stronger and newer in the future.

• 한국표면공학회지
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• 제42권4호
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• pp.161-168
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• 2009

Effects of TiN/Ti multilayer coating on the Ti-30Ta-xZr alloy surface were studied by using various experiments. The Ti-30Ta containing Zr (5, 10 and 15 wt%) were melted 10 times to improve chemical homogeneity by using a vacuum furnace. And then samples were homogenized for 24 hrs at $1000^{\circ}C$. The specimens were prepared for TiN/Ti coating by cutting and polishing. The prepared specimens were coated with TiN/Ti multilayers by using DC magnetron sputtering method. The analyses of coated surface and coated layer were carried out by field emission scanning electron microscope(FE-SEM), EDX, and X-ray diffractometer(XRD). From the microstructure and XRD analysis of Ti-30Ta-xZr alloys, The equiaxed structure was changed to needle-like structure with increasing Zr content. And $\alpha$-peak and elastic modulus increased as Zr content increased. The $\alpha$ and $\beta$ phase predominantly were found in the specimen containing high Zr content. According to the analysis of TiN/Ti coating layer, the surface defects and structures of Ti-30Ta-xZr were covered with TiN/Ti coating layer and surface roughness decreased.

• 대한원격탐사학회지
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• 제31권6호
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• pp.583-598
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• 2015

본 연구에서는 천리안위성 기반의 지표면 열적 특성 감시 및 기상현상 탐지에 이용할 수 있는 배경 온도장을 산출하고 지상관측자료 및 지리정보와 비교하여 정확도를 검증하였다. 배경온도장은 밝기온도를 선택하였으며 2012년 자료를 이용하여 월별로 매 시간대에 대해 산출되었다. 밝기온도 자료에서 청천화소와 구름화소를 구별하기 위해 천리안 구름탐지를 사용하였고, 천리안 구름탐지의 입력자료로 사용된 수치모델자료와 공간 균질성 검사 부분에서 구름 오탐지현상을 발견하였다. 과다하게 구름으로 오탐지된 화소는 통계적인 방법에 기반한 구름화소 복원을 통해 해결하였다. 산출된 밝기온도 배경장은 지상관측 기온과 0.95의 상관관계를 보였으며 0.66 K의 편향과 4.88 K의 평균 제곱근 오차를 보였다. 밝기온도 배경장과 고도는 시간대와 계절에 따라 변동성을 보이는 음의 상관관계를 보였다. 녹지와의 상관관계는 기온이 높은 계절 및 주간에 높게 나타났으며, 상관관계의 시간에 따른 변화가 관측되었다. 이러한 이유로 지표면온도 산출 시 시간에 따른 방출률을 별도로 구성해야 할 필요성이 제기되었다.

• 패션비즈니스
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• 제17권1호
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• pp.98-113
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• 2013

This study is an attempt to analyze the daily life of the Western-yearning Seoul citizens and the inflow of the Western culture into certain social classes. The customs of the characters in the film are studied to illustrate the process of deconstruction of Korean traditional clothes due to the Western influence. The combined application of the Western and Korean styles is also observed. All this study leads to the sense of homogeneity of the times and the conformity to the culture the Korean women shared, which boils down to the social identity of the Korean women who sought an escape from the men-centered social structure by displaying their competence in the field of global modern fashion. As Seonyeong Oh, the main character of the film, , was wearing in the movie the Korean traditional dress, socks, rubber shoes, and then a western-style coat, it well shows that in 1950's, the traditional dress and ornaments were mixed with Western styles. In time, men's wear were completely changed from the traditional Korean clothes to suits, while women's could not break off from the traditional clothes and become westernized, which indicates that the men-centered conservative ideas to keep women within the feudal regime of the society remained. The military look of Seonyeong Oh while she was acting in the society was a symbol of anti-bias against women and anti-convention as well as the will of freedom as an independent woman. Besides, the modern girls would wear clothes of military fashion, Dior's trapeze line, and knit styles flattering the figures. All these well show their desires to embrace Western cultures, especially their dress fashions as well as manners as so-called enlightened ladies. All these elements show that the director was trying to represent the progress of the drama, characters, and psychological states by means of the dress and ornaments.