• Earthquakes and Structures
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• 제13권4호
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• pp.377-386
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• 2017

Earthquake-induced pounding damages to building structures were repeatedly observed in many previous major earthquakes. Extensive researches have been carried out in this field. Previous studies mainly focused on the regular shaped buildings and each building was normally simplified as a single-degree-of-freedom (SDOF) system or a multi-degree-of-freedom (MDOF) system by assuming the masses of the building lumped at the floor levels. The researches on the pounding responses between irregular asymmetric buildings are rare. For the asymmetric buildings subjected to earthquake loading, torsional vibration modes of the structures are excited, which in turn may significantly change the structural responses. Moreover, contact element was normally used to consider the pounding phenomenon in previous studies, which may result in inaccurate estimations of the structural responses since this method is based on the point-to-point pounding assumption with the predetermined pounding locations. In reality, poundings may take place between any locations. In other words, the pounding locations cannot be predefined. To more realistically consider the arbitrary poundings between asymmetric structures, detailed three-dimensional (3D) finite element models (FEM) and arbitrary pounding algorithm are necessary. This paper carries out numerical simulations on the pounding responses between a symmetric rectangular-shaped building and an asymmetric L-shaped building by using the explicit finite element code LS-DYNA. The detailed 3D FEMs are developed and arbitrary 3D pounding locations between these two buildings under bi-directional earthquake ground motions are investigated. Special attention is paid to the relative locations of two adjacent buildings. The influences of the left-and-right, fore-and-aft relative locations and separation gap between the two buildings on the pounding responses are systematically investigated.

• 한국농림기상학회:학술대회논문집
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• 한국농림기상학회 2015년도 하계 학술발표논문집
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• pp.18-28
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• 2015

Apple is cultivated under various climatic conditions in many parts of the world. Better understanding of how climate, genotype, soil, and management factors interact to determine crop productivity will improve our ability to optimize crop selection, management strategies, and resource use efficiencies. We developed and applied a physiology-based apple canopy model to evaluate how climatic factors and crop phenotypes interact to determine biomass accumulation, radiation use efficiency (RUE), and water use efficiency (WUE) at multiple production sites between western and eastern states of the US including WA, CA, NY, WV, and PA. Our results indicate that solar radiation is a dominant factor limiting biomass production in the eastern states while VPD is the primary factor governing crop water use across eastern and western states during the peak growing season. Crop RUE and WUE were strongly correlated in the western states but not in the eastern states while VPD showed highly negative correlation with both RUE and WUE across all locations. The RUE improved with increasing fraction of diffuse radiation ($f_{df}$) and the $RUE-f_{df}$ relationships revealed distinctive responses between western and eastern states. Overall, the eastern locations exhibited slightly higher RUE and WUE than the western locations. However, overall productivity and total water use were greater in the western states. A clear decline of productivity with increasing temperature and afternoon VPD past an optimum was predicted in the western locations but this pattern was less clear in the eastern locations. We also discuss potential phenotypes with specific physiological and morphological traits that are differentially suitable for western and eastern locations. Our results provide plausible, spatially explicit explanations and insights to disentangle the complex relationships between crop productivity, resource use efficiencies, phenotype, and climate drivers in apple grown in the US.

• 한국경제지리학회지
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• 제15권3호
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• pp.437-455
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• 2012

전 세계적으로 환경문제가 큰 이슈가 됨에 따라, 우리나라에서도 신재생에너지에 대한 관심의 일환으로 전라도를 중심으로 많은 태양광발전소가 건설되었다. 그러나 입지 선정 과정에서 환경 사회적 영향을 충분히 고려하지 않아 각종 문제점들이 야기되었으며, 기존 시설의 입지 타당성 평가와 지속가능한 입지 모색이 요구되었다. 현재까지 환경을 고려한 태양광발전소의 입지 선정 연구는 미미하며, 기존 시설을 평가한 연구도 진행된 바 없다. 따라서 본 연구에서는 전라도에서 환경 사회적 영향을 최소화하는 지속가능한 입지를 제안하고, 현존하는 시설의 입지 타당성을 평가하였다. 이를 위해 연구방법으로 크리깅(Kriging)과 네트워크분석법(Analytic Network Process; ANP)를 이용하였다. 네트워크분석법을 통해 도출된 가중치로 모든 공간데이터를 통합하여 최적의 입지를 도출하고, 환경 사회적으로 영향을 줄 수 있는 구역을 최적지에서 제외하였다. 그 결과, 전반적으로 서해안과 남해안 부근에 적합지가 많은 것으로 나타났다. 또한, 환경 사회적 영향을 고려한 최종 입지 적합도와 기존 시설의 위치를 비교 분석한 결과 총 81곳 중 23곳이 부적합한 태양광발전소로 판단되었다. 본 연구의 결과를 통해 사회적 갈등 및 환경문제를 방지하는 지속가능한 입지 선정이 가능할 것이며, 기존 입지를 객관적으로 파악하는 지표를 제공함으로써 대책 마련에 도움을 줄 것으로 기대된다.

• 한국산림과학회지
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• 제99권1호
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• pp.111-124
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• 2010

본 연구는 자연휴양림 유형별 적정입지선정 평가모형을 개발하고, 그 모형을 자연휴양림 예정지에 적용하여 활용 가능성을 모색하고자 하였다. 이를 위해 델파이 전문가 설문조사와 계층화분석법(AHP)을 이용한 평가준거의 선정, 자연휴양림 유형화 및 유형별 적정입지선정 평가모형 개발, 모형적용 단계의 순으로 연구를 수행하였다. 먼저, 자연휴양림 유형화 및 적정입지선정을 위한 평가준거(Criteria)를 구안하고, 2차에 걸친 델파이조사에 의한 타당화 과정을 거쳐 2개 평가영역(Categories) - 6개 평가항목(Items) - 12개 평가지표(Indicators)의 위계를 가진 평가준거를 선정하였다. 제3차 델파이조사에서는 계층화분석과정(AHP)을 통하여 자연휴양림 유형화를 위한 평가준거의 가중치를 산정하고, 2개의 평가영역(자원성과 이용성)을 중첩하여 자연휴양림을 4개의 유형으로 구분할 것을 제안하였다. 이어 제4차 델파이조사의 계층화분석과정(AHP)을 거쳐 산정한 유형별 평가준거의 가중치를 활용하여 자연휴양림 유형별 적정입지선정 평가모형을 개발하고 자연휴양림 입지예정지에 적용하였다. 적용 결과 휴양림 이용성은 수도권과의 거리에 의해 가장 크게 영향을 받으며, 휴양림의 입지가 수도권에서 가까울수록 유리하다는 것을 확인하였다. 본 연구는 유형별로 자연휴양림을 지정할 때 활용될 수 있을 것이다.

• 한국의학물리학회지:의학물리
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• 제11권1호
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• pp.39-47
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• 2000

신경 외과적 수술의 한분야인 정위적 방사선 수술은 두 개강 내의 병변의 위치 계산 후, 고선량의 방사선을 조사하여 병변을 치료하는 방법이기 때문에, 효과적인 수술을 위해서는 병변의 정확한 위치 정보가 무엇보다도 중요하다. 본 연구에서는 DSA(Digital Subtraction Angiography) 영상이 내재적으로 이미지 왜곡이라는 문제점을 가지고 있기 때문에, 이것의 보정을 통하여 더욱 정확한 target 위치를 계산하였다 이미지 왜곡을 보정하기 위하여 grid 팬텀을 제작하였고, localization 알고리즘의 정확도를 평가하기 위하여, target 팬텀을 제작하였다. Image Intensifier의 앞쪽에 grid 팬텀을 부착하고, target 팬텀을 Leksell Frame에 고정시킨 후, DSA 영상을 얻었다. 본 실험을 위하여 개발된 프로그램을 이용하여, Anterior and Posterior, Left and Right 영상에서 bilinear transform을 적용하여 왜곡을 보정한 후, target 위치를 계산하였다. 그리고, 이와 같은 방법을 통하여 계산된 target 위치 좌표와 target 팬텀의 절대 좌표의 비교를 통하여 localization 오차가 계산되었다. 이번 실험의 결과는 왜곡을 보정하지 않은 경우, localization 오차는 $\pm$0.41mm, 왜곡 보정을 한 경우는 $\pm$0.34mm이었다. 따라서 본 연구에서 개발된 알고리즘 정밀도가 인정되며, 환자의 치료에 적합한 것으로 사료된다.

• 디지털융복합연구
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• 제12권6호
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• pp.277-287
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• 2014

위치 기반 소셜 네트워크 서비스에서 사용자들은 체크인 데이터를 이용해 장소를 공유하고 커뮤니케이션을 한다. 체크인 데이터는 POI명, 카테고리, 장소 좌표/주소, 사용자 닉네임, 장소 평가 점수, 관련 글/사진/동영상 등으로 구성된다. 위치 기반 소셜 네트워크 서비스에서 이러한 체크인 데이터를 상황에 맞게 분석하면 다양한 맞춤형 서비스를 제공할 수 있다. 따라서, 본 논문에서는 사용자 체크인 데이터를 활용할 수 있는 LBSNS(Location-based Social Network Service) 기반 장소 추천 시스템을 개발하였다. LBSNS 기반 장소 추천 시스템은 체크인 데이터 중 장소 카테고리를 분석하여 가중치를 추출하고, 피어슨 상관계수를 이용해 사용자간의 유사도를 구한다. 그리고 협업적 필터링 알고리즘을 이용하여 추천 장소에 대한 선호도 점수를 구하고, 추천 대상 장소의 위치와 사용자의 현재 위치에 대해 유클라디안 알고리즘을 적용하여 거리 점수를 구한다. 마지막으로, 선호도 점수와 거리 점수에 대해 가중치 계수를 적용하여 상황에 맞게 장소를 추천한다. 또한, 본 논문에서는 실제 데이터를 이용한 실험을 통해 본 논문에서 제시한 시스템의 우수성도 입증하였다.

• Journal of Biosystems Engineering
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• 제41권3호
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• pp.263-272
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• 2016

Purpose: Pulse crop damage due to wild birds is a serious problem, to the extent that the rate of damage during the period of time between seeding and the stage of cotyledon reaches 45.4% on average. This study investigated a method of fundamentally blocking birds from eating crops by conducting vinyl mulching after seeding and identifying the growing locations for beans to perform punching. Methods: Infrared (IR) sensors that could measure the temperature without contact were used to recognize the locations of soybean cotyledons below vinyl mulch. To expand the measurable range, 10 IR sensors were arranged in a linear array. A sliding mechanical device was used to reconstruct the two-dimensional spatial variance information of targets. Spatial interpolation was applied to the two-dimensional temperature distribution information measured in real time to improve the resolution of the bean coleoptile locations. The temperature distributions above the vinyl mulch for five species of soybeans over a period of six days from the appearance of the cotyledon stage were analyzed. Results: During the experimental period, cases where bean cotyledons did and did not come into contact with the bottom of the vinyl mulch were both observed, and depended on the degree of growth of the bean cotyledons. Although the locations of bean cotyledons could be estimated through temperature distribution analyses in cases where they came into contact with the bottom of the vinyl mulch, this estimation showed somewhat large errors according to the time that had passed after the cotyledon stage. The detection results were similar for similar types of crops. Thus, this method could be applied to crops with similar growth patterns. According to the results of 360 experiments that were conducted (five species of bean ${\times}$ six days ${\times}$ four speed levels ${\times}$ three repetitions), the location detection performance had an accuracy of 36.9%, and the range of location errors was 0-4.9 cm (RMSE = 3.1 cm). During a period of 3-5 days after the cotyledon stage, the location detection performance had an accuracy of 59% (RMSE = 3.9 cm). Conclusions: In the present study, to fundamentally solve the problem of damage to beans from birds in the early stage after seeding, a working method was proposed in which punching is carried out after seeding, thereby breaking away from the existing method in which seeding is carried out after punching. Methods for the accurate detection of soybean growing locations were studied to allow punching to promote the continuous growth of soybeans that had reached the cotyledon stage. Through experiments using multiple IR sensors and a sliding mechanical device, it was found that the locations of the crop could be partially identified 3-5 days after reaching the cotyledon stage regardless of the kind of pulse crop. It can be concluded that additional studies of robust detection methods considering environmental factors and factors for crop growth are necessary.

• The Plant Pathology Journal
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• 제18권5호
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• pp.293-299
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• 2002

A survey of Fusarium wilt of perilla was conducted in 12 locations in Korea from 1999 to 2001. The disease occurred in 74 out of 187 fields in the 12 locations surveyed, and incidence of the disease reached up to 30% at its maximum in some perilla fields in Seosan and Dangjin. Incidence of the disease in the other locations ranged from 0.2 to 20%. A total of 327 isolates of Fusarium spp. were obtained from stems and roots of the diseased perilla plants. The isolates were identified based on their morphological characteristics. Out of the 327 isolates of Fusarium, 277 isolates from 12 locations were identified as F. oxysporum, 11 isolates from three locations as F. solani,17 isolates from two locations as F. equiseti, 4 isolates from one location as F. avenaceum and 6 isolates from one location as F. subglutinans. The other 12 isolates of Fusarium from four locations were unidentified. Twelve isolates of F. oxysporum and two isolates each of the other Fusarium spp. were tested for their pathogenicity to five cultivars of perilla. Seven isolates of F. oxysporum were strongly pathogenic to some perilla cultivars, but the other five isolates were weakly or not pathogenic. One isolate of F. solani was strongly pathogenic to all the perilla cultivars tested, but another isolate was not pathogenic. All the isolates of F. equiseti, F. avenaceum, and F. Subglutinans tested were not pathogenic to any of the perilla cultivars tested. Symptoms on the perilla plants induced by artificial inoculation with strongly pathogenic isolates of F. oxysporum and F. solani appeared as wilt, stem blight, and root yet, which were similar to those observed in the fields. The isolates which induced symptoms by artificial inoculation were re-isolated from the lesions of the perilla plants inoculated. All the isolates of F. oxysporum tested were not pathogenic to eight other crops inoculated. Results of this study reveal that F. oxysporum is the main pathogen of perilla wilt and that it is host specific to perilla. forma specialis of F. oxysporum causing wilt of perilla is proposed as perillae.

• 원예과학기술지
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• 제28권6호
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• pp.937-941
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• 2010

기온 상승이 '신고' 배나무의 만개일에 미치는 영향을 조사하기 위해 배시험장의 시간별 기온자료로 발육지수를 산정하고, 기상청 관측자료에 있는 67개 지역의 최고 최저 온도에 의한 발육속도로 평년 만개일 분포 및 온도상승에 따른 만개일 변화를 추정하였다. 나주지역에서 '신고' 배나무의 발육지수는 0.9593이었다. 천안지역의 만개일 관측자료와 발육지수에 따른 예측자료와의 차이가 0-7일 범위였고, 일치한 해가 35.3%였다. 67개 지역의 평년 만개일은 4월 4일부터 5월 28일까지 분포하였다. 예측 만개일이 평년기온 보다 $5^{\circ}C$ 상승할 때까지 대부분의 지역에서 빨라졌지만 $3^{\circ}C$ 상승부터 남쪽의 해안가 지역에서 늦어졌으며, $4^{\circ}C$와 $5^{\circ}C$ 상승하면 제주, 고산(제주도 서부), 서귀포 지역에서는 개화되지 않는 것으로 추정되었다. 3월 기온 상승 시 예측 만개일의 변화가 가장 컸고, 4월, 2월, 1월 및 12월 순이었다. 기온상승에 따라 우리나라 배 재배 주산지의 만개일이 빨라질 것으로 전망되었다.

• 한국초지조사료학회지
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• 제17권4호
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• pp.315-322
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• 1997

Sixteen cultivars of corn(Zea mays L.) hybrids have been recommended as the government recommended corn hybrids since 1984, however, their forage performances have been mostly tested at two locations, such as Suweon and Sunghwan in the Middle parts of Korea. Therefore, the objective of this experiment was to retest the agronomic characteristics and yield of eleven of sixteen government recommended corn hybrids at five scattered locations, such as Icheon, Suweon, Sunghwan, Keonpan and Kwangju in 1993 and 1995 with the intention of improving recommendations to dairy farmers. Among the corn hybrids tested, 'Suweon 19' was susceptible to foliar diseases and poor stay green at all locations in 1993 and 1995. Generally, all hybrids have less lodging and infection rate of rice black streaked dwarf virus(RBSDV) varied by location but mostly not exceed 10%. Infection rate at Sunghwan and Kwangju among locations was the highest as 13.5 and 15.3% respectively. Among the corn hybrids tested, 'Suweon 19' was the highest RBSDV infection rate, but that of 'Kwanganok' and '3282' was lower than other hybrids. At all locations, '3352' and '3394' were the earliest in growth stage, but 'Kwanganok', '3282', 'DK729', 'G4624' and 'DK713' were the latest among the corn hybrids. Ear percentage in total DM of '3352', '3394' and 'G4624' was higher than other hybrids, but that of 'DK713' was the lowest among the corn hybrids. '3352' and '3394' showed the most suitable DM content for silage production at harvest. Among the corn hybrids tested, 'Suweon 19' and '3282' were the lowest DM yield at all locations in 1993 and 1995, but the highest DM yield varied by location. At Icheon, '3144W' and 'G4743', at Suweon, '3352' and '3144W, at Sunghwan, 'DK729' and '3144W', at Keongsan, '3352' and 'DK729', and at Kwangju, '3352' and 'DK689' were the highest DM yield in 1993 and 1995, respectively. Then, '3394' was higher than other hybrids at all locations in 1995. The government recommended corn hybrids tested were generally adapted across the country. However, in forage production situations where wrn should be harvested before the rainy season in late summer, earlymedium maturing corn hybrids, '3352' and '3394' might be preferred.