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        검색결과 437

        61.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Climate change may result in increases in air temperature and shifts in precipitation patterns as the result of increases in atmospheric CO2. Outdoor, naturally sunlit, plant growth chambers referred to as SPAR (Soil Plant Atmosphere Research) chambers are one of the important research facilities under controlled conditions. SPAR provide precise control of the major environmental variables influencing crop growth including temperature, humidity and atmospheric CO2 concentration. Especially the SPAR system is considered as the most realistic approach for studying crop canopy gas exchange including photosynthesis, respiration, transpiration. Indeed, many reports have confirmed that gas exchange values in SPAR is highly associated with dry matter and yield. So SPAR data can be used to develop quantitative relationships and functions, which are then tested against field data. In ARS, the SPAR system is widely used for research on: (1)Response and adaptation of crops and weeds to elevated CO2 and global warming, (2)Developing analytical and management strategies to improve crop utilization and to reduce losses due to the environment, (3)Mechanistic process-level crop simulation models for assessment of agricultural systems.
        4,000원
        62.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Solar energy has been known as a successful alternative energy source, however it requires a large area to build power generation facilities compared to other energy sources such as nuclear power. Weather factors such as rainy weather or night time impact on solar power generation because of lack of insolation and sunshine. In addition, solar power generation is vulnerable to external elements such as changes in temperature and fine dust. There are four seasons in the Republic of Korea hereby variations of temperature, insolation and sunshine are broad. Currently factors that cause find dust are continuously flowing in to Korea from abroad. In order to build a solar power plant, a large area is required for a limited domestic land hereby selecting the optimal location for the plant that maximizes the efficiency of power generation is necessary. Therefore, this research analyze the optimal site for solar power generation plant by implementing analytic hierarchy process based on weather factors such as fine dust. In order to extract weather factors that impact on solar power generation, this work conducts a case study which includes a correlation analysis between weather information and power generation.
        4,200원
        63.
        2017.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        원자력발전소내 습식저장중인 사용후핵연료의 건식저장을 위해서는 캐니스터 내부에 사용후핵연료를 옮겨 담은 이후, 건 식저장 캐니스터 내장품이나 사용후핵연료 다발의 부식방지 및 피복관의 열화방지를 위해 모든 수분은 제거해야 한다. 캐 니스터 내부의 수분을 제거하는데 사용할 수 있는 기체강제순환 건조시스템 개발을 위한 연구개발이 진행중이다. 본 연구 에서는 기체강제순환 건조시스템 설계, 제작을 위한 예비설계를 수행하였다. 예비설계에는 캐니스터 내부 잔존수분 제거를 위한 건조사례조사, 건조관련 규격이나 표준, 건조합격기준, 건조장치구성, 현장요구분석, 습식저장중인 사용후핵연료 특성 을 포함하였다. 예비설계를 통하여 기체강제순환 건조시스템의 설계 개념도와 P&ID를 도출하였고, 이를 활용하여 건조시 스템 제작을 위한 상세설계를 수행할 것이다.
        3,000원
        64.
        2017.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, numerical modeling is conducted to analyze the tension of an anchor line by varying the size and drag coefficient of a buoy when the trapnet is influenced by the wave and the current simultaneously. A mass-spring model was used to analyze the behavior of trapnet underwater under the influence of waves and current. In the simulation of numerical model, wave height of 3, 4, 5 and 6 m, a period of 4.4 s, and the flow speed of 0.7 m/s were used for the wave and current condition. The drag coefficients of buoy were 0.8, 0.4 and 0.2, respectively. The size of buoy was 100, 50 and 25% based on the cylindrical buoy (0.0311 ㎥) used for swimming crab trap. The drag coefficient of the trapnet, the main model for numerical analysis, was obtained by a circular water channel experiment using a 6-component load cell. As a result of the simulation, the tension of the anchor line decreased proportional to buoy’s drag coefficient and size; the higher the wave height, the greater the decrease rate of the tension. When the buoy drag coefficient and size decreased to one fourth, the tension of the anchor line decreased to a half and the tension of the anchor line was lower than the holding power of the anchor even at 6 m of wave height. Therefore, reducing the buoy drag coefficient and size appropriately reduces the trapnet load from the wave, which also reduces the possibility of trapnet loss.
        4,000원
        65.
        2017.10 구독 인증기관·개인회원 무료
        안산시는 피레스로이드계 살충제들과 Bti 그리고 이산화탄소 유인 트랩 등을 활용하여 주로 모기 발생을 관리하고있다. 안산시에서 발생하는 모기 종들은 약 16종으로 얼룩날개모기류 7.2%, 흰줄숲모기 0.4%, 작은빨간집모기 1.2%등 질병매개와 관련된 매개체 발생율은 약 9% 미만이었다. 가장 흔한 모기 종은 빨간집모기(82.4%)이었고 다음으로금빛어깨숲모기(3.9%)였다. 모기 유충 발생지에서 관찰된 식물은 26과 47속 56분류군이었고 동물은 8속 8종이었다.거주지 인근 하천에서 발생하는 성충 모기를 관리하는 수단으로서 검정색과 노란색 점착트랩의 활용성이 높아보였고, 고인 웅덩이나 논 등에서 발생하는 모기 유충은 개구리밥의 활용도 검토할 만 하였다. 또한 잔효력에기반한 살충제 침지한 네트의 효율성 평가로 향후 안산시의 환경적 특성을 고려한 모기 관리 수단으로서 이들방법들의 유기적인 조합을 도출할 예정이다.
        66.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to clarify the effect of high temperature during winter period(autumn sowing) and spring sowing on yield, quality and growth and development in barley. The varieties used for the experiments were heenchalssalbori and keunalbori 1 having a strong spring habit characteristics. In spring sowing treatment, spikelet differentiation was proceeded rapidly and tillering was proceeded slowly compared to the development stage, because the barley sowed at spring is cultivated in high temperature and long day conditions from sowing to spikelet differentiation stage compared with autumn sowing(control). And in high temperature treatment during winter period, like spring sowing, tillering was inhibited compared to the development stage. The number of grain per panicle and the period required to heading stage from spikelet differentiation were reduced largely at spring sowing, because spring sowing treatment was conducted in high temperature and long day condition compared with autumn sowing and high temperature treatment during the period from spikelet differentiation to heading stage. Meanwhile in spring sowing treatment, average temperature during ripening stage was higher than the autumn sowing and high temperature during winter, because heading stage was so late. After all, starch, amylose content and grain weight were reduced while protein content was relatively increased in spring sowing treatment due to difference of average temperature of ripening stage. These changes affected the decrease of viscosity of peak, trough, breakdown and the increase of setback viscosity
        4,000원
        67.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pig has been known to be one of the most feasible animals as a bioreactor to produce pharmaceuticals in milk and as a mediator in xenotransplantation research. Previously, we generated transgenic pigs for both purposes, which were expressing Factor 8, vWF, hTPA, and hEPO in milk, along with expression of MCP at GalT gene locus (GalT-MCP/-MCP) as well as expressing MCP at GalT gene loci with CD73 expression (GalT-MCP/+/CD73). In this study, we performed comparative analyses of sperm parameters between wild type male (WT) pig and those transgenic males to examine the effects of transgenes integrated into the pigs on motility, morphology, viability, and acrosome integrity of the spermatozoa. Our results showed that the rates of actively motile spermatozoa of WT, Factor 8, vWF, hTPA, hEPO, GalT-MCP/+/CD73, and GalT-MCP/-MCP pigs were 85.0%, 83.3%, 82.5%, 83.3%, 82.5%, 77.5%, and 78.7%, respectively. Whereas, the rates of morphologically normal spermatozoa of WT, Factor 8, vWF, hTPA, hEPO, GalT-MCP/+/CD73, and GalT-MCP/-MCP pigs were 90.0%, 80.0%, 80.0%, 83.3%, 85.0%, 91.8%, and 80.8%, respectively. In addition, the viability in spermatozoa of WT, Factor 8, vWF, hTPA, hEPO, GalT-MCP/+/CD73, and GalT-MCP/-MCP pigs were 93.9%, 82.4%, 89.9%, 83.9%, 87.4%, 92.8%, and 83.6%, respectively. The rates of spermatozoa with normal acrosome integrity in WT, Factor 8, vWF, hTPA, hEPO, GalT-MCP/+/CD73, and GalT-MCP/-MCP pigs were 98.1%, 98.6%, 98.6%, 98.7%, 98.1%, 99.5%, and 95.1%, respectively. There were no significant differences in motility, morphology, viability, and acrosome integrity of the spermatozoa among WT, Factor 8, vWF, hTPA, and hEPO, GalT-MCP/+/CD73, and GalT-MCP/-MCP pigs. These mean that neither random integration nor targeted integration of the transgene into chromosome of pig effect on characteristics of spermatozoa. Ultimately, the transgenic male pigs subjected in this study could apply to propagate their progenies for production of human therapeutic proteins and advancing the xenotransplantation research.
        4,000원
        68.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pigs have been extensively used as mediators of xenotransplantation research. Specifically, the Massachusetts General Hospital (MGH) miniature pig was developed to fix major histocompatibility antigens for use in xenotransplantation studies. We generated transgenic pigs for xenotransplantation using MGH pigs. However, it has not been studied yet whether these pigs show similarity of reproductive physiological characteristics to wild types of MGH miniature pig. In this study we analyzed the estrous cycles and pregnancy characteristics of wild type (WT) and transgenic MGH miniature pigs, which were α1,3-galactosyltransferase (GalT) heterozygous and homozygous knock-out, and membrane cofactor protein (MCP) inserted in its locus, GalT-MCP/+ and GalT-MCP/-MCP pigs. Estrous cycles of WT, GalT-MCP/+ and GalT-MCP/-MCP pigs were 20.9±0.74, 20.1±1.26, and 17.3±0.87 days, respectively, and periods of estrous were 3.2±0.10, 3.1±0.12, and 3.1±0.11 days. The periods of gestation of WT, GalT-MCP/+ and GalT-MCP/-MCP pigs were 114.2±0.37, 113.3±0.67, and 115.4±0.51 days, respectively. Litter sizes of WT, GalT-MCP/+ and GalT-MCP/-MCP pigs were 4.8±0.35, 4.8±1.11 and 3.0±0.32 respectively. There were no significant differences on estrous cycle, periods of estrous and gestation, and litter size among WT, GalT-MCP/+ and GalT-MCP/-MCP pigs, meaning that GalT knock-out and additional expression MCP of the MGH miniature pig did not effect on reproduction traits. These results provide relevant information to establish breeding system for MGH transgenic pig, and for propagation of GalT-MCP/-MCP pig to supply for xenotransplantation research.
        4,000원
        69.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Transplantation is considered to be a very useful approach to improve human welfare and to prolong life-span. Heterologous organ transplantation using pig organs which are similar to human beings and easy to make mass-production has known as one of the alternatives. To ensure potential usage of the pig organ for transplantation application, it is essentially required to generate transgenic pig modifying immuno-related genes. Previously, we reported production of heterozygous α 1,3-galactosyltransferase (GalT) knock-out and human membrane cofactor protein (MCP) expressing pig (GalT-MCP/+), which is enforced for suppression of hyperacute and acute immunological rejection. In this study, we reported generation of homozygous pig (GalT-MCP/-MCP) by crossbreeding GalT-MCP/+ pigs. Two female founders gave birth to six of GalT-MCP/-MCP, and seven GalT-MCP/+ pigs. We performed quantitative real-time PCR, western blot, and flow cytometry analyses to confirm GalT and MCP expression. We showed that fibroblasts of the GalT-MCP/-MCP pig do not express GalT and its product Gal antigen, while efficiently express MCP. We also showed no expression of GalT, otherwise expression of MCP at heart, kidney, liver and pancreas of transgenic pig. Taken together, we suggest that the GalT-MCP/-MCP pig is a useful candidate to apply xenotransplantation study.
        4,000원
        70.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 도시 내 급격한 기상 변화로 인한 자연재해가 심각한 사회적 문제로 대두되고 있다. 도시의 자연 환경 변화에 대한 효과적인 예측과 대처를 위해서는 신뢰성 있는 기상 자료의 확보가 매우 중요하다. 이러한 맥락에서 본 연구는 도시의 기상 환경 중 기온에 초점을 맞춰, 보다 정확한 기온 추정을 위한 대안적 방법을 제시하였다. 특히, 시공간 해상도와 정확성을 높이기 위해 원격탐사 자료와 지형 기반 공간 보간법을 결합한 기온 추정 방법을 제시하였으며, 기존의 여러 추정 방법들과 비교·평가함으로써 제시된 추정법의 적용가능성을 검토하였다. 분석 결과, 각 추정 기법을 통한 기온 결과는 기온 추정값의 범위에 있어서는 유사한 결과를 보였지만 기온의 공간적 분포 특성은 매우 상이하게 나타났다. 특히, 원격탐사 자료를 활용하여 추정된 기온 분포는 토지피복 유형에 따른 차이를 잘 보여주며, 본 연구에서 제시한 추정 기법의 결과는 고도에 따른 기온차를 보다 뚜렷하게 보여줬다. 추정의 정확도에 있어서는 원격탐사 자료와 지형 기반 공간 보간법을 결합한 기온 추정 기법이 높은 정확도를 보여줬다. 종합적으로 본 연구에서 제시한 기온 추정 기법은 토지피복 유형과 고도에 따른 기온 변화를 잘 나타내는 동시에 원격탐사 자료를 활용한 기존의 기온 추정 기법들에 비해 정확도가 높아 기온 분포도와 같이 연속적 공간의 기온값을 정확하게 표현하는 데 유용하게 활용될 수 있을 것으로 기대된다.
        4,600원
        74.
        2017.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        플로우 데이터는 지역간 공간적 상호작용이나 상호작용에 따른 공간 조직의 형성과 변화 등을 분석하고 이해하는데 중요한 자료로 활용되고 있다. 플로우 데이터에 대한 전통적인 지도학적 시각화 방법으로 널리 사용되고 있는 유선도는 복잡하고 많은 유선의 표현에 따른 낮은 가독성이나 중첩성 등이 한계로 지적되고 있다. 이에 본 연구는 최근 비공간적 데이터 뿐 아니라 공간 데이터의 새로운 재현 방법으로 각광받고 있는 정보 시각화 도구에 주목하여, 플로우 데이터의 지리적 시각화 기법으로서 정보 시각화 도구의 적용가능성을 탐색하고 각 기법에 대한 유용성을 체계적으로 평가하고자 한다. 이를 위해 자바스크립트 기반의 데이터 시각화 라이브러리인 D3.js의 강제 유향 그래프, 코드 다이어그램, 위계적 엣지 번들링, 생키 다이어그램, 시간 거리 그래프를 활용하였으며, 실제 고속 철도 운행 플로우에 대한 다양한 시각화 사례를 실제로 개발하여 보여주고 있다. 사례 분석 결과, 각 정보 시각화 기법은 전통적인 유선도가 갖는 한계들을 효과적으로 극복할 수 있으며, 플로우 데이터에 대한 대안적인 시각화 기법으로 유용하다는 것을 확인할 수 있었다. 또한 이를 통해 본 연구는 플로우 데이터의 지리적 시각화 분야에 유용한 가이드라인을 제공할 수 있고, 지리학, 지도학 및 공간 정보 분야에서 공간 정보의 매핑과 시각화 방법에 대한 인식적 변화를 가져올 것으로 기대한다.
        4,800원
        75.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to investigate effects of the length of the buoy and sand bag line on the loss of webfoot octopus pot. A numerical modeling and simulation was carried out to analyze the process that the pot gear affected by wave using the mass spring model. Through the simulation, tensions of sand bag line under various condition were investigated by length of buoy and sand bag line. The drag force and coefficient k of an artificial shell used in the webfoot octopus pot was obtained from an experiment in a circular water channel, and the coefficient k was applied to the simulation. To verify the accuracy of the simulation model, a simple test was conducted into measuring a rope tension of a hanging shell under flow. Then, the test result was compared with the simulation. The lengths of the buoy line in the simulation were 1.12, 1.41, 1.80, 2.23, 2.69, and 3.17 times of water depth. The lengths of sand bag line were 10, 20, 30, and 40 meters, and conditions of water depth were 8, 15, 22 meters. 4 meter height and 8 second period of wave were applied to all simulations. As a results, the tension of the sand bag line was decreased as the buoy and sand bag line were increased. The minimum tension of the sand bag line was appeared in conditions that the length of the buoy line is twice of water depth and the sand bag line length is over 40 meters (except in case of depth 8 meters.).
        4,000원
        76.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to reduce the force exerted to the buoy of the gillnet by wave and current. Five buoy models were selected for experiments and their rope tensions under wave and current action were compared. Five models were EL (ellipsoid), EL-H (ellipsoid-hole), SL (streamlined body), SP (sphere) and CL (cylinder, traditional type). In the first experiment, the Five models were tested without any attachment. In the second experiment, a flagpole was attached to each model. As a result, in the condition without flagpole, the tensions of four models with the exception of the CL were about a half of that of the CL. In the condition with flagpole, the tension of all models was twice larger than that without flagpole. Thus, a new model was suggested to improve the problem, which has a combined body that of a flagpole and a buoy Three new models of CL-L (long and thin cylinder), LF (leaf shape) and LF-F (leaf shape with fin) were designed. Also a cylinder type (CLD) with a flagpole as a control was included in the experiment. As a result, the LF-F had the smallest tension and a half tension of the CLD. Therefore, it is supposed that the flagpole and buoy combined model could reduce the tension on buoy rope and contribute to improve the gillnet loss problem.
        4,000원
        77.
        2016.12 구독 인증기관 무료, 개인회원 유료
        Geological and geomorphological studies were conducted on 50 uninhabited islands around Daeheuksando and Hongdo. The geomorphological investigation showed the geographical features along coast line for each uninhabited island. Geological relation between two great island - Daeheuksando and Hongdo - was analyzed using geological features such as fault, bedding, fracture and unconformity examined throughout the study area.
        4,000원
        78.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        온라인 상거래가 일상의 한 행위로 자리 잡은 요즈음 오프라인 채널과 온라인 채널 간의 간극이 점점 좁혀지고 있다. 즉, 종전에는 오프라인 상에서의 소비자 구매행위와 온라인상에서의 소비자 구매행위가 판이하게 달랐으나 온라인상에 서의 다양한 상거래가 보편화되면서 이제는 온라인상에서의 구매행위에 대한 연구가 활발하게 이뤄지고 있다. 그러나, 아직도 오프라인상에서의 신뢰가 온라인 구매행위에 미치는 영향에 관한 연구가 피상적인 수준에 머물러왔다. 이에 본 연구에서는 기존 연구의 한계를 극복하기 위하여 개인이 느끼는 뉴로티시즘 성향이 온라인상에서 사용자가 느끼는 불확실성, 거래비용, 그리고 만족 및 지속구매의도에 미치는 조절효과를 체계적으로 분석하고자 한다. 406부의 유효한 설문지를 토대로 분석한 결과, 사용자가 느끼는 거래비용은 온라인쇼핑 지속구매의도에 부의 효과를 미치고 있지만, 만족에는 통계적으로 유의한 영향을 미치지 않는 것으로 나타났다. 또한, 사용자가 가지고 있는 뉴로티시즘 성향은 온라인쇼핑 지속구매의도와 그 영향 요인들 간의 모든 관계에서 유의한 조절효과를 보이고 있는 것으로 나타났다.
        4,600원
        79.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To determine the effect of soil salinity and crop response according to drainage methods, a field experiment was conducted in reclaimed tidal flat land adjacent to Yeongsangang located at Sanyimyon Haenamgun Jeonnam province for three years from 2012 to 2014. Three drainage methods, subsurface drainage (SD), 30 cm open ditch drainage (OD30) and 60cm open ditch drainage (OD60) tested on silt loam soil. In SD and ND, soil salinity were lower than OD30 and OD60 but there was no significant soil EC to the depth of open ditch. SD had a little effect in lowering ground water table. Waterlogging intensity in SEW30 values during the growing season was the lowest in SD 297 compared with the OD30 855, ND 1,420 and OD60 1,553 cm-day. From the above results, subsurface drainage system control soil salinity and waterlogging. Also, the open ditch drainage had an effect on drainage improvement but there was no significant effect on desalinization. So drainage and soil reclamation were essentially needed to stable upland crop cultivation at the reclaimed tidal flat land.
        4,000원
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