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        검색결과 109

        62.
        2003.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 전단변형을 고려한 비대칭 박벽 곡선보의 자유진동해석을 수행할 수 있는 일반이론을 제시하기 위하여, 3차원 연속체에 대한 가상일의 원리로부터 전단변형 효과를 고려하고 비대칭 박벽단면과 ?(Warping)을 포함하는 변위장을 도심 축에 대해 정의한 후 곡선보의 변형도-변위관계로부터 공간 박벽 곡선보의 일반화된 탄성변형에너지와 운동에너지를 새롭게 유도한다. 또한, 전단변형이 고려된 곡선보의 총포텐셜에너지에 대해 변분을 취함으로써 평형방정식과 힘-변위관계를 제시한다. 한편, 제시된 이론에 대해 등매개 보요소를 도입하여 유한요소 정식화를 수행하였으며 곡선보의 동적 거동특성을 조사하기 위하여 전단변형, 곡률효과 그리고 진동모드에 대한 매개변수 연구를 수행한다. 마지막으로, 본 연구의 타당성을 입증하기 위하여, 다양한 해석예제에 대한 3차원 고유진동수를 산정하고 타 연구자들의 결과 및 ABAQUS의 쉘요소를 이용한 해석결과와 비교ㆍ검증한다.
        4,500원
        64.
        2020.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The study examines direct and indirect impacts of organizational commitment on employee motivation through two mediating factors – opportunistic behavior and knowledge sharing – in Vietnamese enterprises. The samples were selected by the non-probability sampling method followed convenient sampling, relatively stratified by localities in Vietnam. The sample size was 636 employees in Vietnamese enterprises. The number of collected online questionnaires was 379, while the number of valid questionnaires was 329. In the direct survey, the number of distributed questionnaires was 750, while the number of collected questionnaires was 421 and the number of valid questionnaires was 307. The total number of valid questionnaires used for analysis was 636. The study used quantitative methods with structural equation modeling analysis. The results indicate that among the components of organizational commitment, normative commitment has both direct and indirect impacts on employee motivation through two mediating factors: opportunistic behavior and knowledge sharing. Meanwhile, affective commitment has only an indirect impact on employee motivation through these mediating factors. Continuance commitment has both direct and indirect impacts; however, it has only an indirect impact on employee motivation through opportunistic behavior. In addition, the results show opportunistic behavior has a negative impact on the knowledge sharing of employees in enterprises.
        65.
        2020.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        This research examines the affect of destination image factors on revisit intention of domestic tourists at Ba Ria Vung-Tau (BRVT), by questioning directly 510 domestic tourists. The convenient sampling method is used in dividing the crowds into four groups; the four main surveyed areas in BRVT are: Vung Tau, Long Hai-Phuoc Hai, Xuyen Moc and Con Dao. A combination of qualitative and quantitative methodologies were utilized. A focus group of 10 domestic tourists was set up to review and explore the various factors as well as the conceptual model. An in-depth interview with 12 participants was developed to fine-tune measurement items. The questionnaire applied a 5-point Likert scale. Checking the reliability by Cronbach’s Alpha, exploratory factor analyzing and linear multiple regression were used with the SPSS program. The results show that there are eight main destination image factors affecting domestic tourists revisit intention to BRVT using linear regression and arranged by decreasing importance: Infrastructure, Variety Seeking, Accessibility, Local food, Atmosphere, Environment, Price Value, Leisure and Entertainment. From that, the research offers some suggestions and policy recommendations for the tourism business and provincial policy-makers to identify the main issues and develop better customer services to increase domestic tourists’ revisit intention.
        66.
        2019.06 KCI 등재 서비스 종료(열람 제한)
        약물용출 스텐트(drug-eluting stents, DES)는 일반 금속 스텐트에 비하여 재협착을 현저하게 줄였지만, 여전히 관상동맥 스텐트 재협착은 비율이 높다. 2012년 11월부터 2016년 12월까지의 일 대학교병원 심혈관센터에서 경피적 관상동맥 스텐트 삽입술 후 관상동맥 조영술에서 스텐트 재협착 환자 187명 그룹 I (약물코 팅 풍선카테터 사용, n=127명), 그룹 II (약물용출 스텐트 사용, n=60명)로 분류하여 치료효과, 주요심장사건, 사망 발생률, 심근경색, 표적병변 재개통술 그리고 스텐트 혈전등을 2년 동안 추적 분석하였다. 임상적 특성는 두 그룹간 차이는 없었고(21.1 ± 5.3 vs. 25.3 ± 9.6 mm, p<0.002), 혈관조영검사에서 약물코팅 풍선 카테터 사용 그룹에서 스텐트 재협착 길이가 짧았다. 주요심장사건은 8.7%vs.10.0%, p=0.789, 사망발생률 0%vs.0%,p=1.000, 심근경색 1.6%vs.6.7%, p=0.085, 표적병변 재개통술 8.7% vs. 10.0%, p=0.789 그리고 스텐트 혈전증 0% vs. 0%, p=1000에서 양군 간에 차이를 보이지 않았다. 약물코팅 풍선카테터가 약물방출 스텐트와 비교하여 2년 추적 검사 결과 주요심장사건에서 차이가 없었고, 약물코팅 풍선카테터는 스텐트 재협착 병변에서 약물방출 스텐트와 함께 선택할 수 있는 좋은 치료방법이라고 사료된다.
        67.
        2018.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The present paper describes the design of a Solid State Telescope (SST) on board the Korea Astronomy and Space Science Institute satellite-1 (KASISat-1) consisting of four [TBD] nanosatellites. The SST will measure these radiation belt electrons from a low-Earth polar orbit satellite to study mechanisms related to the spatial resolution of electron precipitation, such as electron microbursts, and those related to the measurement of energy dispersion with a high temporal resolution in the sub-auroral regions. We performed a simulation to determine the sensor design of the SST using GEometry ANd Tracking 4 (GEANT4) simulations and the Bethe formula. The simulation was performed in the range of 100 ~ 400 keV considering that the electron, which is to be detected in the space environment. The SST is based on a silicon barrier detector and consists of two telescopes mounted on a satellite to observe the electrons moving along the geomagnetic field (pitch angle 0°) and the quasi-trapped electrons (pitch angle 90°) during observations. We determined the telescope design of the SST in view of previous measurements and the geometrical factor in the cylindrical geometry of Sullivan (1971). With a high spectral resolution of 16 channels over the 100 keV ~ 400 keV energy range, together with the pitch angle information, the designed SST will answer questions regarding the occurrence of microbursts and the interaction with energetic particles. The KASISat-1 is expected to be launched in the latter half of 2020.
        68.
        2018.02 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 하폭, 하상수리전도도 등의 하천수리특성을 고려할 수 있는 Baalousha (2012)의 해석해를 이용하여 안성천 상류구간 인근에 위치한 관정 17개에 대해 지하수 양수로 인한 하천수 감소량을 산정하고 그 특성을 고찰하였다. 해석해 적용을 위해서 양수시험과 시피지시험을 통해 측정한 대수층과 하상의 수리특성값을 이용하였다. 양수기간 5년 동안 양수량 대비 하천수 감소량은 약 0.23에서 0.89로 관정 위치별로 차이가 크게 나타났으며, 하천고갈인자(Stream Depletion Factor, SDF) 값이 1,000일보다 큰 경우 0.4 미만으로 양수의 영향이 작은 것으로 분석되었다. Baalousha (2012) 해석해 적용 결과를 미소하폭에 대한 Hunt (1999) 해석해 적용 결과와 비교한 결과 연구대상 지역은 상대적으로 간단한 Hunt (1999) 해석해로 지하수 양수 영향을 파악하는데 충분한 것으로 분석되었다. 또한 투수량계수, 저류계수, 하상수리전도도, 하폭, 하천-관정 이격거리, 하폭 등의 수리특성치 조합에 따른 총 3,000가지 조건에 대해 각각의 해석해로 5년 평균 하천수 감소비를 구하여 비교한 결과 하천-관정 이격거리가 하폭 보다 길어야 두 해석해의 차이가 작아 하폭의 영향이 감소하는 것으로 분석되었다.
        69.
        2018.01 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 다중 기후모델에 의한 미래 기후자료를 기반으로 SWAT-K 유역모형을 적용하여, 제주도 지역의 미래 기후변화에 따른 수자원 영향을 평가하였다. 기후모델에 따른 미래 전망자료의 불확실성을 고려하여 9개의 GCM 모델의 기후자료를 미래기간(2010~2099년)에 대한 SWAT-K 모형의 기상자료로 적용하였다. 과거(1992~2013년) 및 미래기간에 대한 연도별 수문변화를 분석한 결과 강수량, 유출량, 증발산량, 함양량 모두 증가하는 추세로 나타났다. 과거기간에 비해 유출량의 변화가 가장 크게 나타났으며(최대 50% 증가), 증발산량은 상대적으로 작게 나타났다(최대 11% 증가). 월별로는 8월과 9월의 강수량 증가에 따라 유출량과 함양량도 크게 증가하는 반면, 동일기간에 대한 증발산량은 감소하는 것으로 분석되었다. 1월과 12월은 반대의 경향이 나타났다. 미래의 물수지 변화를 분석한 결과 강수량 대비 유출량, 증발산량, 함양량의 비율은 변화가 크지 않으나, 과거와 비교했을 때 RCP 8.5 시나리오에서 유출량 비율은 최대 4.3% 증가하는 반면, 증발산량 비율은 최대 3.5% 감소하는 것으로 나타났다. 기존의 타 연구와 본 연구에서 도출한 결과를 종합해 볼 때, 현재 제시되고 있는 기후변화 시나리오 가정 하에서는 미래로 갈수록 점차 강수량과 유출량이 증가할 것이고 특히 여름철 강수량 및 유출량의 증가가 예상된다. 이로 인해 제주도 지역의 함양량도 함께 증가할 것으로 판단할 수 있다. 다만, 본 연구는 장기적인 측면에서 자연적인 기후변화로 인한 영향을 분석한 것이며, 추가적으로 단기적인 수재해 대응을 위한 홍수와 가뭄관리, 인위적인 용수수급 관리 등에 대한 종합적인 분석을 통해 제주도 수자원의 지속가능한 이용을 위한 대응방안이 필요하다고 판단된다.
        70.
        2017.12 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 무심천 유역을 대상으로 지표수-지하수 통합해석 모형인 SWAT-MODFLOW를 이용하여 수량이 부족한 하천으로 지하수를 이용한 물공급 방안을 모색하였다. 2011년부터 2015년까지 다양한 모의실험을 수행한 결과 극한가뭄이 도래했던 2015년에 지하수 공급에 의한 월 유출량의 변화는 현 양수시 23%, 최대 양수시에는 68.3%의 증가를 나타냈다. 이를 연간 지하수 함양량으로 산정할 경우 현 이용량을 적용하면 연평균 강수량의 6.2%인 75 mm, 최대 이용량 적용시 연평균 강수량의 24%인 290 mm에 해당하여 연간 안정적인 공급이 가능한 것으로 나타 났다. 본 연구는 가뭄에 취약한 지표수자원과 달리 지하수는 하천수 부족시 물공급의 효과적인 대안이 될 수 있을 것으로 판단된다.
        71.
        2017.10 KCI 등재 서비스 종료(열람 제한)
        Light is very important for plant growth and a major limiting factor in indoor plant cultivation, such as in balconies. This study was conducted to investigate the light intensity and lettuce (Latuca sativa L.) growth in an apartment balcony affected by the direction of balcony. Photosynthetic photon flux (PPF), air temperature, and relative humidity in the east-, south-, or west-facing balcony were measured for a year. The lettuce was grown in the east-, south-, or west-facing balcony. The time and amount of light entering into the balcony differed according to the direction of the balcony window. Whereas light entered into the east-facing balcony from sunrise to noon, it entered into the west-facing balcony afternoon before sunset. The temperature and humidity in the balcony also varied according to the direction of the balcony window. Daily Light Integral (DLI) in the south-facing balcony was 20~50% of outdoor and DLI in east- or west-facing balconies was 10~20%. Also, the environmental characteristics of the balconies were affected seasonally. In the spring (from March to May), the DLI was around 10 mol・m-2・day-1 and the average temperature was around 25°C. But the DLI was below 10 mol・m-2・day-1 and the average temperature and relative humidity were around 30°C and over 60%, respectively, in the summer (from June to August). In the balcony, the average temperature was maintained around 10°C even in winter, which is a condition of freezing outdoor. Growth of the lettuce in the south-facing balcony was better than that of the other directions. This is attributed to better environmental conditions of south-facing balcony. Therefore, considering the environmental characteristics of the balcony, selection and management of crops with relatively low light demand like leafy vegetables are required. It is also recommended to cultivate crops from autumn to spring.
        72.
        2015.10 KCI 등재 서비스 종료(열람 제한)
        We constructed marine forest to restore barren grounds which are expanding in the east coast of Korea using 2 methods of (1)seedlings transplantation method and (2)underwater floating ropes method. We transplanted 3 macroalgae species, Ecklonia cava, Undaria pinnatifida, and Saccharina. japonica to construct marine forest. Blade length of Undaria pinnatifida on underwater floating ropes was 56.70±8.69㎜ in April and grew 68.75±22.30㎜ in May and 70.75±14.36㎜ in July. Blade length of S. japonica was shown 97.95-143.00㎜ in April to June. Blade length of Ecklonia cava was 30.50±1.91㎜ in May, 41.55±1.84㎜ in August, 45.30±2.57㎜ in November, 2009 and 45.30±1.99㎜ in February, 2010. The survey on Dangsa area, Ulsan-city in January, 2009 found a total number of 15 algal species(1 brown algae, 14 red algae species) with the highest variety at 5m depth of A station and the lowest at 8m depth of A and B stations. The March survey showed a total of 24 species (1 green algae, 1 brown algae, 22 red algae species) with the highest variety of 11 at depths of 3m and 5m of B station and the lowest of 6 at 10m of B station. In May, total biomass was 3,755.4g (green algae 1.2g, brown algae 199.0g, red algae 3,555.2g). From January, 2009, we found that E. cava was dominant at the depths of 3m and 5m of A and B stations while Peyssonnelia capensis was dominant at the depth of 8m of A station. The 8m depth of B station was dominated by Acrosorium polyneurum. In May, Grateloupia lanceolata was dominant at 8m depth of A station while other depths were dominated by Phycodrys fimbriata. In June, the dominant species were G. lanceolata at the 3m depth, E. cava at the 5m and P. fimbriata at the depths of 8m and 10m of A station. Under B station, G. lanceolata was dominant at the depths of 3m and 5m while P. fimbriata was dominant at the depths of 8m and 10m.
        74.
        2012.07 서비스 종료(열람 제한)
        Amylose content of rice endosperm is one of the determinants of rice eating quality. This study was conducted to elucidate the mode of inheritance of dull gene in Milyang262, tentatively designated as du7(t), and to identify the molecular marker for du7(t) to be employed in marker-assisted breeding and gene pyramiding. Genetic analysis was carried out on F2 population derived from a cross between Junam and Milyang262. The low amylose content of Milyang262 was indicated to be under single recessive control. Allelism tests were as well conducted by crossing Milyang262 with Baegjinju and Baegokchal, which harbor du1 and wx gene, respectively. du7(t) was demonstrated to be inherited independently to du1 and wx. F2 population of Baegokchal/Milyang262 was used for molecular mapping. Linkage analysis was conducted on a population consisted of 120 individuals by several SSR markers. Initial mapping indicated that du7(t) is located on the end of long arm of chromosome 6 between SSR marker RM20590 and RM3509. To fine map the gene, a bigger population and several additional markers were employed. du7(t) was further mapped to a 1.74 Mb region between two SSR markers (RM6926 and RM412). Furthermore, we indentified three SSR markers that co-segregated with du(t) i.e. RM6811, RM3765, and RM176.
        76.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        A new graft cactus (Gymnocalycium marsoneri x mihanovichii x G. mihanovichii) cultivar, 'Hwangjo' was developed from a interspecific cross between an orange colored G. marsoneri x mihanovichii breeding line '9834036', a line with characteristics of vigorous growth and stable color under the strong sun light, and an orange colored graft cactus (G. mihanovichii) breeding line 'IG177' and through line selection at the National Horticultural Research Institute, Rural Development Administration in 2005. It was developed with the aim to breed a bright and vivid orange colored cultivar. Its characteristic evaluation was conducted three times during 2003 to 2005. The color of both body and tubercle was yellow. The shape of globe was flattened round and it had 8 to 10 deep ribs. The spine was semi erect, medium sized and grayish brown color. Growth was faster than the comparison cultivar, 'Hugwang'. Propagation capability was excellent, setting 15 tubercles per globe. Characteristics of the cultivar could be maintained by vegetative propagation. Strong sun light and virus infection should be avoided.
        77.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        A new graft cactus (Gymnocalycium mihanovichii) cultivar, 'Simhong' was developed from a cross between graft cactus breeding line 'Keumhong', a cultivar revealing a red colored globe with yellow colored tubercles, and a dark red line '9502052' and consecutive line selection at the National Horticultural Research Institute, Rural Development Administration in 2005. It was developed with the aim to breed a dark red cultivar. Its characteristic evaluation was conducted three times during 2003 to 2005. The color of both body and tubercle was dark red. The shape of the globe was flattened round and it had 8 to 10 deep ribs. The spine was medium sized, straight and dark brown. Its growth was faster than the comparison cultivar, 'Jinhong'. Propagation capability was excellent, setting 12 tubercles per globe. Characteristics of the cultivar could be maintained by vegetative propagation. Strong sun light and virus infection should be avoided.
        78.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        A new graft cactus (Gymnocalycium mihanovichii x G. marsoneri x mihanovichii) cultivar, 'Yeonsim' was developed from a interspecific cross between two black with pink graft cactus (Gymnocalycium mihanovichii) breeding line '9603026' and G. marsoneri x mihanovichii breeding line 'BP', a line with the characteristics of wide spacing between ribs, and vigorous growth and through line selection at the National Horticultural Research Institute, Rural Development Administration in 2005. It was developed with the aim of breeding cultivars with new colors and globe shapes. Its characteristic evaluation was conducted during 2003 to 2005. The color of both body and tubercle was pink. The shape of the globe was flattened round and it had 7 to 9 deep ribs. The spine was short, straight and brown color. Growth was faster than the comparison cultivar, 'Yeonhwa'. Propagation capability was excellent, setting 12 tubercles per globe. Characteristics of the cultivar could be maintained by vegetative propagation. Strong sun light and virus infection should be avoided.
        79.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        A new standard rose cultivar 'Magic Pink' was bred from the cross between light yellow standard cultivar 'Medeo' and pink standard cultivar 'Veronica' at the National Horticulture Research Institute. The cross was made in 2001 and 'Magic Pink' was finally selected in 2006 after investigating characteristics for three years from 2003 to 2006. 'Magic Pink', a pink standard cultivar grows vigorously and has fashionable flower color. The major characteristics of this cultivar are 184.8 stems/m2/year in yield, 63.0cm in length of cut flower, 7.2 cm in flower diameter, 28.5 in petal number, and 10.4 days in vase life. This cultivar can be propagated by both cutting and grafting. The consumer's preference of this cultivar is relatively higher than that of control cultivar, 'Noblesse'.
        80.
        2007.11 KCI 등재 서비스 종료(열람 제한)
        In Korea, chilli pepper (Capsicum annum L.) is a major vegetable crop. The pepper seed market is about $35 million and the whole sale market including processed products is equivalent to $2 billion, representing the second highest market value among crops, next to rice in Korea. Since the development of elite pepper variety is so competitive, vegetable seed companies usually run two important programs to keep the credibility of seed quality. One program is to deliver F1 hybrid seeds with a high purity test to farmers. The purity control of parents and F1 hybrid to avoid any contamination is conducted by DNA markers because pepper seeds are obtained using MS line. The other program is to identify the F1 variety from other varieties by analyzing the polymorphism so that the company and/or breeder protects the intellectual property from copying by others or from non-intentional contamination. We have developed about 900 EST-SSR sets from pepper and used to both programs. A total of 66 markers were selected to identify 32 F1 varieties and their own parents. Using these markers, the purity control of F1 hybrid rose up to the highest degree. We also found several SSR markers to distinguish F1 variety from other varieties and these markers could be useful to find the uniqueness of F1 cultivar.
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