• Title/Summary/Keyword: polarization phenomenon

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Polarimetric Scattering of Sea Ice and Snow Using L-band Quad-polarized PALSAR Data in Kongsfjorden, Svalbard (북극 스발바드 콩스피오르덴 해역에서 L 밴드 PALSAR 데이터를 이용한 눈과 부빙에 의한 다중편파 산란특성 해석)

  • Jung, Jung-Soo;Yang, Chan-Su;Ouchi, Kazuo;Nakamura, Kuzaki
    • Ocean and Polar Research
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    • v.33 no.1
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    • pp.1-11
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    • 2011
  • This study describes measurements of fast ice recorded on May 23, 2009, in Kongsfjorden (translated as 'Kongs Fjord'), an inlet on the west coast of Spitsbergen in the Svalbard Archipelago. Seasonal fast ice is an important feature for Svalbard fjords, both in relation to their physical environment and also the local ecosystem, since it grows seaward from the coast and remains in place throughout the winter. Ice thickness, snow, ice properties, and wind speed were measured, while SAR (Synthetic Aperture Radar) data was observed simultaneously observed two times from ALOS-PALSAR (L-band). Measured ice thickness was about 25-35 cm while the thickness of ice floe broken from fast ice was measured as 10-15 cm. Average salinity was 1.9-2.0 ppt during the melting period. Polarimetric data was used to extract H/A/alpha-angle parameters of fast ice, ice floe, snow and glacier, which was classified into 18 classes based on these parameters. It was established that the area of fast ice represents surface scattering which indicates low and medium entropy surface scatters such as Bragg and random surfaces, while fast ice covered with snow belongs to a zone of low entropy surface scattering similar to snow-covered land surfaces. The results of this study will contribute to various interpretations of interrelationships between H/A/alpha parameters and the wave scattering Phenomenon of sea ice.

A Study on the Improvement related with the House Remodeling Support Program for Underprivileged Group in Rural Area (농촌지역 주거약자를 위한 주택 리모델링 지원사업 개선방향 설정에 관한 연구)

  • Kim, Hye-Lan;Lim, Chang-Su;Kim, Sang-Bum;Kim, Eun-Ja;Hong, Kwang-Woo
    • Journal of Korean Society of Rural Planning
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    • v.19 no.2
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    • pp.75-91
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    • 2013
  • In rural areas, in spite of the development projects of town and houses has been performed after the New Community Movement, due to rapid industrialization and urbanization, which lasted until the 2000s from the 1980s, out-migration to the cities, changes in the industrial structure, rapid aging was carried. As a result, the gap of housing environment between urban and rural areas became more serious. The meantime, the housing problem is recognized only to the problems of the big cities, mostly urban public housing policy oriented. However, when you check the indicator of the housing environment, such as the percentage of aging housing, rural environment has become a relatively poor compared to the city. In addition, due to a decrease in income and aging of the population living in rural areas of existing infrastructure to improve the living environment is weakened. And inside of the rural areas, changes in the housing environment and polarization phenomenon is becoming increasingly serious. Therefore, in this study, there is a purpose to be presented the improvement direction for efficient implementation of house remodeling support program for underprivileged group in rural areas and requires immediate attention improvement of housing environment. Previously, House remodeling support project in rural areas was carried out at the initiative of local governments and government mainly. For this reason, it is difficult due to limited institutional, to reflect the necessary parts directly to the real life of the residents. And, the demand for improvement of housing environment need modifications to solve the inconvenience of life of residents directly in many cases. It is considered that community-based house remodeling support project is to be carried out through the participation of local residents.

A Study on the Trend Analysis of Rural Houses in the Architectural Magazines (건축잡지에 나타난 농촌주택 경향분석에 관한 연구)

  • Lim, Chang Su;Hong, Kwang Woo;Kim, Hye Ran;Kim, Eun Ja;Park, Mi-Jeong
    • Journal of Korean Society of Rural Planning
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    • v.22 no.4
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    • pp.183-194
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    • 2016
  • Rural house came into the rapid change through the process of modernization and Saemaul movement in the past. This change continue to the current era, there is a such exotic forms and indiscriminate development of new house and Saemaul housing and existing conventional farmhouse in rural area. Such a phenomenon, ultimately creating disharmony in traditional environment of rural. In this respect, reflecting the location characteristics of the region which is based on the regional characteristics and unique model of rural housing, it is absolutely required for the development of rural housing customized to fit the diversity of modern. With that background, the purpose of the research is to try and find out the changes in rural houses and the transforming characteristics. To achieve this research purpose, this research selected a specialized magazine for architecture. Then, it identified contents which has specific keyword. lastly, it analyze type and contents of house in rural area from selected article. This process make up the rural housing for effective utilization. The result showed that the type of economic activity and residents information directly show the character of the members who located in the new homes after retuning to farming. The polarization of structure was clearly visible by the building time. And, propensity to western-style of major components was very high such as shape and form of housing. However, it was found to prefer to reflect traditional aesthetics in the components of the housing partially. Therefore, more research is needed to reflect of the results of a survey. Also, analyzing the characteristic of rural house's element and suggesting ways to take advantage in order to present suitable element of modern rural house.

Cryptotanshinone Induces Inhibition of Breast Tumor Growth by Cytotoxic CD4+ T Cells through the JAK2/STAT4/ Perforin Pathway

  • Zhou, Jun;Xu, Xiao-Zhen;Hu, Yao-Ren;Hu, Ai-Rong;Zhu, Cheng-Liang;Gao, Guo-Sheng
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.6
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    • pp.2439-2445
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    • 2014
  • Cryptotanshinone (CPT), is a quinoid diterpene isolated from the root of the Asian medicinal plant, Salvia miotiorrhiza bunge. Numerous researchers have found that it could work as a potent antitumor agent to inhibit tumor growth in vitro, buith there has been much less emphasis on its in vivo role against breast tumors. Using a mouse tumor model of MCF7 cells, we showed that CPT strongly inhibited MCF7 cell growth in vivo with polarization of immune reactions toward Th1-type responses, stimulation of naive CD4+ T cell proliferation, and also increased IFN-${\gamma}$ and perforin production of CD4+ T cells in response to tumor-activated splenocytes. Furthermore, data revealed that the cytotoxic activity of CD4+ T cells induced by CPT was markedly abrogated by concanamycin A(CMA), a perforin inhibitor, but not IFN-${\gamma}$ Ab. On the other hand, after depletion of CD4+ T cells or blocked perforin with CMA in a tumor-bearing model, CPT could not effectively suppress tumor growth, but this phenomenon could be reversed by injecting naive CD4+ T cells. Thus, our results suggested that CPT mainly inhibited breast tumor growth through inducing cytotoxic CD4+ T cells to secrete perforin. We further found that CPT enhanced perforin production of CD4+ T cells by up-regulating JAK2 and STAT4 phosphorylation. These findings suggest a novel potential therapeutic role for CPT in tumor therapy, and demonstrate that CPT performs its antitumor functions through cytotoxic CD4+ T cells.

The Analysis on Fashion Image through Change in Trend - Focusing on Domestic Women's Wear between $2000{\sim}2006$ - (트렌드 변화에 따른 패션이미지 분석 -2000년${\sim}$2006년 국내 여성복을 중심으로-)

  • Park, Yun-A
    • Journal of the Korea Fashion and Costume Design Association
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    • v.10 no.1
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    • pp.145-159
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    • 2008
  • This study has examined the shift in fashion styles in Korea by analyzing trends in fashion environment and fashion image by seasons in Korea to understand the domestic fashion flow from 2000 to 2006. Since 2000, with the well-being trend, polarization of consumption, preference in luxury orientation, and digital revolution, consumers became individualized and detail oriented. They also became smart consumers equipped with information and knowledge in making choice and purchasing products suiting their taste. To satisfy the consumer trend, fashion market also saw changes such as expansion of advanced distribution, totalization of brands, growing of on-line shopping mall, expansion of outdoor-wear market, and formation of masstage(mass+prestage) market. Fashion images in domestic women's wear since 2000 are analyzed as classic, elegant, minimalism, romantic, bohemian & vintage, ethnic, glam, girlish, kidult, sportive, femiculine, military, and lingerie image. Classic, romantic, and bohemian & vintage are the images that were popular throughout 2000 to 2006. Fashion images of domestic women's wear showed changes in three periods: Sportive image was popular in FW 2002; military image in SS 2003 to SS 2005; and femiculine, glam, and minimalism images in FW 2005 to FW 2006. Through information and detail-oriented emotion, the wide-ranging acceptance of global trends, the consumer tendency towards purchasing products quickly and conveniently, the speedy supply of trendy products both on-line and in-store, and the evolution of the fashion market towards providing one-stop shopping and a cultural space, different fashion images have all emerged at the same time in Korea. It looks like this phenomenon is set to continue for a while.

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Numerical Study on Comparison of Serpentine and Parallel Flow Channel in High-temperature Proton Exchange Membrane Fuel Cells (고온형 고분자전해질형 연료전지에서의 사형 유로와 평행 유로 성능비교에 대한 수치해석적 연구)

  • AHN, SUNGHA;OH, KYEONGMIN;JU, HYUNCHUL
    • Transactions of the Korean hydrogen and new energy society
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    • v.29 no.1
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    • pp.41-55
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    • 2018
  • General polymer electrolyte fuel cell (PEMFC) operates at less than $80^{\circ}C$. Therefore liquid phase water resulting from electrochemical reaction accumulates and floods the cell which in turn increases the mass transfer loss. To prevent the flooding, it is common to employ serpentine flow channel, which can efficiently export liquid phase water to the outlet. The major drawback of utilizing serpentine flow channel is the large pressure drop that happens between the inlet and outlet. On the other hand, in the high temperature polymer electrolyte fuel cell (HT-PEMFC), since the operating temperature is 130 to $180^{\circ}C$, the generated water is in the state of gas, so the flooding phenomenon is not taken into consideration. In HT-PEMFCs parallel flow channel with lower pressure drop between the inlet and outlet is employed therefore, in order to circulate hydrogen and air in the cell less pumping power is required. In this study we analyzed HT-PEMFC's different flow channels by parallel computation using previously developed 3-D isothermal model. All the flow channels had an active area of $25cm^2$. Also, we numerically compared the performance of HT-PEMFC parallel flow channel with different manifold area and Rib interval against the original serpentine flow channel. Results of the analysis are shown in the form of three-dimensional contour polarization curves, flow characteristics in the channel, current density distribution in the Membrane, overpotential distribution in the catalyst layer, and hydrogen and oxygen concentration distribution. As a result, the performance of a real area fuel cell was predicted.

p-contact resistivity influence on device-reliability characteristics of GaN-based LEDs (p-contact 저항에 따른 GaN기반 LED의 device-reliability 특성)

  • Park, Min-Jung;Kim, Jin-Chul;Kim, Sei-Min;Jang, Sun-Ho;Park, Il-Kyu;Park, Si-Hyun;Cho, Yong;Jang, Ja-Soon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.159-159
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    • 2010
  • We conducted bum-in test by current stress to evaluate acceleration reliability characteristics about p-resistivity influence of GaN-based light-emitting diodes. The LEDs used in this study are the polarization field-induced LED(PF-LED) having low p-resistivity and the highly resistive LED(HR-LED) having high p-resistivity. The result of high stress experiment shows that current crowding phenomenon is occurred from the center of between p-bonding pad and n-bonding pad to either electrodes. In addition, series resistance and optical power decrease dramatically. These results means that the resistance of between p-bonding pad and p-GaN affect reliability. That's why we need to consider the ohmic contact of p-bonding pad when design the high efficiency and high reliability LEDs.

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Abnormal Work Function Modification at the Interface between Organic Molecule and Solid Surfaces

  • Kim, Ji-Hoon;Seo, Jae-Won;Kang, Hye-Seung;Kim, Jeong-Kyu;Kim, Jeong-Won;Lee, Han-Gil;Kwon, Young-Kyung;Park, Yong-Sup
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.63-63
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    • 2010
  • Using both experimental and theoretical approaches, we have investigated the adsorption properties of an organic molecule (HATCN), which is used in OLEDs as an efficient hole injection layer, on metal and inert surfaces. We have also studied the structural and electronic properties of such interfaces and the dependences on deposition thickness. We have observed different trends in work function changes with different surfaces. Our photoelectron spectroscopic measurements have revealed an abnormal phenomenon in HATCN on a metal (Cu) surface: the work function decreases at lower coverage (~monolayer) of HATCN on a metal (Cu) surface, but it increases back and becomes higher than that of a bare Cu surface at higher coverage. It has, on the contrary, been observed that the work function of graphene surface just increases as the HATCN coverage increases. Our first-principles density functional calculations has not only verified our experimental observations, but also disclosed the underlying mechanism of such abnormal and different work function behaviors. We have found that the change in work function results from mutual polarization induced by the geometrical deformation and the bond dipole formed at the interface due to the charge redistribution. At low coverage of HAT-CN on Cu substrate, the former reduces the work function significantly by pulling down the vacuum level, while the latter tends to push up the vacuum level resulting in the work function increase.

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A Study on Effects of the Cure Pressure for the Improvement of the Electrical Performance of the Sandwich Type Radome (샌드위치형 레이돔의 전기적 성능개선 위한 성형압력 영향성 연구)

  • Lee, Sang-Min;Seo, Hyun-Soo;Hong, Jun-Pyo
    • Journal of Korean Society for Quality Management
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    • v.43 no.3
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    • pp.299-312
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    • 2015
  • Purpose: This paper analyzes the phenomenon on the degradation of the electrical performance by the pressure in the manufacturing process of sandwich type radomes. Methods: This paper consists of two steps to analyze the relation between the electrical performance and the pressure. First, the thickness of the core of the flat panels which were fabricated with different pressure was measured with the microscope, and then the electrical performance of the flat panels was analyzed with simulation and experiment. Based on the results of the electrical performance and the measured thickness with respect to the flat panels, the relation between the electrical performance and the applied pressure in the manufacturing process was analyzed. Results: The simulated and measured results with respect to the flat panel shows that the high pressure results in the nonuniform thickness of the core, which is applied to the radome fabrication. As a result, the degradation of the electrical performance occurs because the unintended scattered field is generated as the electromagnetic wave transmits (or impinges upon) the radome. Furthermore, we observed that the electrical performance of both the flat panel and the radome got worse as the high pressure was applied. Conclusion: Through simulation and experiment, therefore, it is demonstrated that for the high pressure in the manufacturing process the nonuniform thickness of the core increases and results in the degradation of the electrical performance of the radome.

Dependence of Poling Field on Pyroelectric Property of $Pb_{0.9}La_{0.1}TiO_3$ Ceramics

  • D. J. You;B. S. Kang;Park, S. K.
    • The Korean Journal of Ceramics
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    • v.6 no.3
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    • pp.291-295
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    • 2000
  • The pyroelectric property of $Pb_{0.9}La$_{0.1}TiO_3$ceramics in a range of 1.3-4.1$\mu\textrm{m}$, fabricated by conventional solid sintering, was investigated as a function of poling field. The pyroelectric of the 4.1$\mu\textrm{m}$ of $Pb_{0.9}La$_{0.1}TiO_3$ceramics is higher than that of the 1.3$\mu\textrm{m}$ and 1.7$\mu\textrm{m}$ of $Pb_{0.9}La$_{0.1}TiO_3$ceramics at a low poling field and the pyroelectric coefficient is 25nC/$\textrm{cm}^2$K at a 4kV/mm poling field in every grain size. In order to explain this phenomenon, the intrinsic and extrinsic effects in view of the definition of the pyroelectric coefficient are introduced. The intrinsic and extrinsic effects on the pyroelectric property were investigated by measuring the tetragonal ratio and the $I_{002}$ with temperature with high temperature X-ray diffractometer. The change of spontaneous polarization and the $90^{\circ}$domain wall motion with temperature in the 1.3$\mu\textrm{m}$ and 4.2$\mu\textrm{m}$ of $Pb_{0.9}La$_{0.1}TiO_3$ceramics have no effects on the pyroelectric coefficient. In our study, it can be seen that the pyroelectric coefficient is related to the quantity of $180^{\circ}$domain switching after poling treatment.

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