• 한국발생생물학회지:발생과생식
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• 제14권3호
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• pp.179-184
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• 2010

Water temperature influences on various key biological events in fish, but the internal pathway of the temperature effects are not well understood. Heat shock proteins (HSPs), known to respond in the level of cells to many environmental factors including temperature, could improve our understanding on the pathway. Some biological processes such as gonadal development and sex differentiation in the Nile tilapia Oreochromis niloticus is particularly sensitive to water temperature. In this study, we have investigated the expressions of HSP70 and HSP90 genes in young tilapia at an ordinary temperature ($28^{\circ}C$) and elevated water temperature ($36^{\circ}C$). The distribution of the expressions of HSP70 and HSP90 mRNA in this species were found to be almost ubiquitous, being detected in all tissues studied here (brain, gonad, liver and muscle), suggesting the house keeping functions of these genes. Heat shock by elevating temperature from $28^{\circ}C$ to $36^{\circ}C$ significantly increased the expression of HSP70 mRNA in the gonad, liver and muscle for several hours (P<0.05) (brain tissue was not examined for this). The increased level of HSP70 gene expression recovered to the level at control temperature ($28^{\circ}C$) when fish were kept continuously at high temperature ($36^{\circ}C$) for 24 hours. Contrary to this, expression of HSP90 mRNA did not show significant increase in the gonad and muscle by the same heat shock (P>0.05), except in the liver where the expression of HSP90 mRNA increased continuously for 24 hours at $36^{\circ}C$. The results obtained in this study suggest that response to temperature change in different tissue or organ may utilize different heat shock proteins, and that HSP70 may have some importance in temperature-sensitive gonadal event in the Nile tilapia.

• 전기학회논문지
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• 제66권12호
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• pp.1905-1912
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• 2017

In recent years, Ulaanbaatar, a capital of Mongolia has witnessed major problem that air quality reaches hazardous level during the winter season. Coal combustion for heating of every house in "Ger" district is main reason. One way to reduce the air pollution is mass usage of electric heater. However, there are several difficulties such as overload and degradation of transformers and other equipment used in distribution and transmission systems as well as power shortage occurrence in evening peak period due to residential consumption. This study aims to contribute for solving the air pollution and power shortage problem in Mongolia. One possible solution could be distributed generation (DG) with photovoltaic (PV) penetration. In this study, PV with energy storage (ES) hybrid system to reduce peak load is analyzed. We proposed the suitable structure of PV-ES hybrid for Mongolian household, and suggested several operation scenarios. Optimal operation algorithm is carried out based on a comparison aspect from economical, grid impact and PV penetration possibility. The economic analyse shows annual income of 520USD, and has a payback period of 8 years for selected scenario. The proposed PV-ES system structure is verified by experimentation set on the building rooftop in city center. The suggested scenario is planned to apply for system in further research.

• 한국토양비료학회지
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• 제47권4호
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• pp.225-234
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• 2014

This study was carried out to investigate the sustainable agriculture of no-tillage technique including recycling of the ridge and the furrow of a field for following crops in Korea. No-tillage systems affect soil physical properties such as three phase (solid, liquid, and air phase) and distribution of soil granular. Solid ratio of subsoil in 3-year of no-tillage (NT) treatment was remarkably lower than that in conventional (CT, 2-year of no-tillage + 1-year of tillage) treatment, while air ratio of subsoil in NT remarkably increased. Bulk density of subsoil in NT remarkably decreased. Porosity of subsoil in NT remarkably increased. Deviation of air phase, bulk density, and porosity of top soil and subsoil in NT remarkably decreased in NT compared with CT. Solid phase ratio and liquid phase ratio in NT and CT had positive (+) correlation. Solid phase ratio and air phase ratio in NT and CT had negative (-) correlation, also liquid phase ratio and air ratio had negative (-) correlation. Bulk density and liquid ratio in soil had positive (+) correlation at top soil and subsoil in NT. Bulk density and air ratio in soil had negative (-) correlation in NT and CT. Porosity and liquid phase ratio had negative (-) correlation, r =1), the significant value was lower in NT than in CT. Porosity and air phase ratio had positive (+) correlation (r =1).

• 공업화학
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• 제23권6호
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• pp.561-566
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• 2012

PtRuW/C 촉매를 Pt : Ru : W 비를 5 : 4 : 1, 2 : 1 : 1, 1 : 1 : 1, 1 : 2 : 2로 각각 합성하였다. 촉매의 조성은 EDX분석을 통해 이론값과 비슷하다는 것을 확인하였다. TEM분석과 XRD분석으로부터 3.5~5.5 nm의 균일한 입자 크기 및 결정질 분포를 가지고 있음을 확인하였다. 유효표면적, 전류밀도, 고유 활성 및 피독률과 같은 전기화학적 특성은 CO 스트리핑, 선형쓸음 전기량 측정법, 대시간 전류법 등과 같은 방법으로 분석하였다. 이러한 분석으로부터, $PtRu_2W_2/C$를 제외한 촉매는 상업촉매보다 우수한 반응성과 안정성을 가지고 있음을 확인하였다. 이 중 가장 우수한 촉매는 $Pt_5Ru_4W/C$였으며, $121.05mA{\cdot}m^{-2}$의 specific activity와 $0.01%{\cdot}s^{-1}$의 피독률을 보였다.

• 한국식생활문화학회지
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• 제2권1호
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• pp.45-54
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• 1987

This paper is a part of the regional characteristics of Korean chotkal. The kinds and materials of Korean chotkals are studied by interviewing local people living in 142 different regions which are bigger than 'myon' in size. Regions are classified according to the structural style of commoner's house. Regional characteristics of chotkal are analyzed and interpreted with natural environmental factor. The rest of my further interested subject will be followed in later issues ; the ways of preservation, period of fermentation according to the regional characteristics and uses of Korean chotkal. The results of this study can be summerized as follows, 1. There are 145 different kinds. 2. Raw materials of 145 kinds of chotkal are devided roughly into five groups ; (1) fishes in 87 kinds (2) Pelecypoda and Gastropoda in 14 kinds (3) Cephalopoda in 10 Kinds (4) Crustacea in 32 kinds and (5) Holothuroidea and Echinoidea in 2 kinds. They can also be classified according to the parts of individual material ; (1) body or flesh in 118 kinds (2) internal organs in 15 kinds and (3) eggs in 12 kinds. Regions are devided into four provinces ; 'Kwanso', 'Chungbu', 'Nambu', and 'Kwanbuk' in which the number of different kinds of chotkal are 32, 41, 99 and 34, respectively. Raw materials vary because of the distribution of marine life in different regions. Fishes and Cephalopoda are used in all four regions, Pelecypoda and Gastropoda in 'Kwanso', 'Chungbu' and western part of 'Nambu' regions. Different species of Crustacea used in each different regions ; sea crab and sea shrimp in the western coastal area, fresh water crab in the field area, fresh water shrimp in 'Chollado', mantis crab at 'Shihung-gun' in 'Kyonggi-do', Holothuroidea and Echinoidea are used in 'Nambu' regions. Chotkal are not used at all in six local districts which are located in inland areas where the transportation is inconvenient.

• 한국지리정보학회지
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• 제5권1호
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• pp.1-19
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• 2002

디지털 기술의 발전과 사회 경제적인 성숙을 추구함과 더불어 주택과 토지에 대한소유 및 접근은 공간적 분포의 삶의 질과 빈곤을 평가하는데 있어 매우 중요하고 어려운 문제이다. 첨단 IT 기술과 매우 향상된 지리 및 토지정보 시스템이 공간적 인간 정주문제, 토지이용과 개발, 환경악화 등을 분석하는데 이용되고 있지만, 시공간 차원에서 발생하는 가난의 원인과 결과를 이해하는데 있어 초기연구 단계에 있는 듯 싶다. 이 연구는 육하원칙 인자를 이용하여 공간적 위치의 가난을 해석하고자 하였다. 또한 정보격차로 인하여 생기는 가난한 환경을 토지정보의 공간적 개념과 연계하고 빈곤을 해소하는 관점에서 새로운 모델을 제시하였다.

• Wind and Structures
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• 제29권5호
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• pp.339-359
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• 2019

Pre-stressed concrete poles are among the supporting systems used to support transmission lines. It is essential to protect transmission line systems from harsh environmental attacks such as downburst wind events. Typically, these poles are designed to resist synoptic wind loading as current codes do not address high wind events in the form of downbursts. In the current study, the behavior of guyed pre-stressed concrete Transmission lines is studied under downburst loads. To the best of the authors' knowledge, this study is the first investigation to assess the behaviour of guyed pre-stressed concrete poles under downburst events. Due to the localized nature of those events, identifying the critical locations and parameters leading to peak forces on the poles is a challenging task. To overcome this challenge, an in-house built numerical model is developed incorporating the following: (1) a three-dimensional downburst wind field previously developed and validated using computational fluid dynamics simulations; (2) a computationally efficient analytical technique previously developed and validated to predict the non-linear behaviour of the conductors including the effects of the pretension force, sagging, insulator's stiffness and the non-uniform distribution of wind loads, and (3) a non-linear finite element model utilized to simulate the structural behaviour of the guyed pre-stressed concrete pole considering material nonlinearity. A parametric study is conducted by varying the downbursts locations relative to the guyed pole while considering three different span values. The results of this parametric study are utilized to identify critical downburst configurations leading to peak straining actions on the pole and the guys. This is followed by comparing the obtained critical load cases to new load cases proposed to ASCE-74 loading committee. A non-linear failure analysis is then conducted for the three considered guyed pre-stressed concrete transmission line systems to determine the downburst jet velocity at which the pole systems fail.

• 한국항만경제학회:학술대회논문집
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• 한국항만경제학회 2006년도 국제학술대회
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• pp.277-290
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• 2006

해운업은 일반적으로 선박의 획득, 선박운영 그리고 비즈니스 활동으로 구분할 수 있다. 이러한 기능은 모든 선박이 수행하는 것이나, 중요한 것은 이러한 몇몇 또는 모든 활동이 자사 내에서 수행하는 것보다 제 3 자 관리업체에 의해 수행되는 것이 더 나은 선택인지 아닌지 하는 것이다. 그러나 비용절감을 성취하기 위해 선박관리업의 시장 규모는 지속적으로 지난 몇 십년간에 걸쳐 성장하고 있다. 본 논문은 선박관리와 시장의 발전 추세를 분석하고 우리나라 선박관리 회사와 비교분석을 한 후 선박관리회사의 선택기준에 관한 기초 설문조사를 수행하였다. 결론 부분에 이러한 분석이 갖는 시사점과 우리나라 선박관리회사의 발전 방안에 대해 제시하고자 한다.

• 한국토양비료학회지
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• 제36권3호
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• pp.113-118
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• 2003

국내 3대 절화류중 하나인 장미의 시설재배지 토양 화학적 특성을 조사하기 위하여 전국 72개 절화 장미 시설 재배 농가를 대상으로 본 조사을 수행하였다. 조사지역의 평균 토성분포는 양토 43%, 미사질식양토 19%, 식양토 17%를 차지하였으며, 표토의 평균 양분함량은 pH 5.85, 전기 전도도 $3.61dS\;m^{-1}$, 유기물 함량 $37g\;kg^{-1}$, 질산태 질소 $205mg\;kg^{-1}$, 유효인산 $844mg\;kg^{-1}$, 그리고 교환성 칼륨 $1.41cmol_c\;kg^{-1}$이었다. 유효인산과 교환성 칼륨은 조사지역의 70% 이상이 적정 수준 이상이었으며, 토양양분함량 중 유기물 함량은 레드 산드라 품종의 절화장과 정의 상관관계를 보였으나 전기 전도도와는 부의 상관관계를 보였다.

• 분석과 대안
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• 제4권2호
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• pp.103-132
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• 2020

The purpose of this study is to observe whether intergenerational differences exist in support among major Korean political parties and, if so, how they exist, based on the results of the survey conducted nationwide. To achieve the purpose of the study, a questionnaire was prepared based on conjoint analysis, and the collected data was analyzed by applying a random parameter logit model. The main results of model analysis are summarized as follows. First, among the policy variables, statistically significant results were observed in the generation of 20s and 30s for the education variable. It was found that both 20s and 30s aimed for equal education at a higher level than other generations. Especially, the highest intensity aim for equal education culture was observed in the 20s. Second, the coefficients of major political parties were observed with a high level of statistical significance. This appears to be a result suggesting that voters decide on their voting behavior through thorough policy comparisons in addition to comprehensive consideration on various current issues. Third, a clear support for conservative parties was observed in the generation of 20s. A clear and intense distribution of preference for political parties classified as conservatives was observed in the 20s generation, which can be said to be mainly college students. This seems to be a profound founding related to the issue of "conservatization of the 20s," which has recently become a hot topic in Korean society. Fourth, a high level of support for progressive parties was observed in the 30s and 40s. The Justice Party can be classified as a minority party in the National Assembly House as of January 2019. Nevertheless, it was maintained at a relatively high level in national recognition, and it is presumed that the background was high level of support from the 30s and 40s. Fifth, a large level of standard deviation was observed in the preference for conservative parties in the 50s. This means that some respondents who are in their 50s or older strongly support the Liberty Korea Party, and some respondents in the same generation strongly disapprove it. Due to this countervailing power, it seems that the average support level for the Liberal Korean Party is low in the generations of 50s and older.?