• 한국식물병리학회지
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• 제14권5호
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• pp.526-530
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• 1998

The effect of field sanitation using ecological characters of the pathogen was investigated for controlling Phomopsis seed decay in soybean. Field sanitation which was eliminated the inoculum by removing host debris, abscised petioles and cotyledones out of field, reduced remarkably infection percentage of pods and seeds by Phomopsis spp. as compared to the inoculated field. Neverthless, seed infection was 28.7% in the sanitized field. The fields sanitized by benlate application around the soybean plants also decreased seed infection with Phomopsis spp. Total seed infection including that with miscellaneous pathogens occurred as much as 75∼79% to the no application and their control values were 34∼42% over the routine application schedule. Even though it was not satisfactory, field sanitation seemed to be effective in controlling Phomopsis seed decay when infection pressure was low level. Diaporthe phseolorum va. sojae, D. phaseolorum var. caulivora and Phomopsis longicolla were mostly identified from soybean seeds and Colletotrichum truncatum, Cercospora kikuchiana were also isolated in sequence. Field sanitation did not significantly increase in soybean yield over the no application, while routine application schedule did in field.

• 천문학회보
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• 제35권1호
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• pp.26.2-26.2
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• 2010

It has been a puzzle in solar physics how a low-lying magnetic structure such as a solar prominence surrounded by a strongly line-tied overlying field sometimes intrudes through the latter and goes into eruption. A numerical simulation study of the solar coronal plasma reveals that a ballooning instability can explain this type of eruptive process. We consider an idealized situation with two flux ropes merging. When magnetic field lines from different flux ropes reconnect, a new field line connecting farther footpoints is generated. Since the field line length abruptly increases, the field line expands outward. If the plasma beta is low, this expansion takes place more or less evenly over the whole field line. If, on the other hand, the plasma beta is high enough somewhere in this field line, the outward expansion is not even, but is localized as in a bulging balloon. This ballooning section of the magnetic field penetrates out of the overlying field, and eventually the originally underlying field and the overlying field come to interchange their apex positions. This process may explain how a field structure that has stably been confined by an overlying field can occasionally show a localized eruptive behavior.

• 한국태양에너지학회 논문집
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• 제34권5호
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• pp.33-41
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• 2014

Heliostat field in a tower type solar thermal power plant is the sun tracking mirror system which affects the overall efficiency of solar thermal power plant most significantly while consumes a large amount of energy to operate it. Thus optimal operation of it is very crucial for maximizing the energy collection and, at the same time, for minimizing the operating cost. Heliostat field operational algorithm is the logics to control the heliostat field efficiently so as to optimize the heliostat field optical efficiency and to protect the system from damage as well as to reduce the energy consumption required to operate the field. This work presents the heliostat field operational algorithm developed for the heliostat field of 200kW solar thermal power plant built in Daegu, Korea. We first review the structure of heliostat field control system proposed in the previous work to provide the conceptual framework of how the algorithm developed in this work could be implemented. Then the methodologies to operate the heliostat field properly and efficiently, by defining and explaining the various operation modes, are discussed. A simulation, showing the heat flux distribution collected by the heliostat field at the receiver, is used to show the usefulness of proposed heliostat field operational algorithm.

• 방송공학회논문지
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• 제20권5호
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• pp.676-686
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• 2015

Light field 카메라를 이용하여 영상을 취득한 후 다양한 응용 프로그램으로 확장이 가능한 4차원 light field 영상은 일반적인 2차원 공간영역(spatial domain)과 추가적인 2차원 각영역(angular domain)으로 구성된다. 그러나 이러한 4차원 light field 영상을 유한한 해상도를 가진 2차원 CMOS 센서로 취득하므로 저해상도의 제약이 존재한다. 본 논문에서는 이러한 4차원 light field 영상이 가지는 해상도 제약 조건을 해결하기 위하여, 4차원 light field 영상에 적합한 딕셔너리 학습 기반(dictionary learning-based) 초해상도(superresolution) 알고리즘을 제안한다. 제안하는 알고리즘은 4차원 light field 영상으로부터 추출한 많은 수의 4차원 패치(patch)들을 바탕으로 딕셔너리를 구성 및 훈련하며, 학습된 딕셔너리를 바탕으로 저해상도 입력 영상의 해상도를 향상시키는 과정을 수행한다. 제안하는 알고리즘은 공간영역과 각영역의 해상도를 동시에 각각 2배 향상시킨다. 실험에 사용된 영상은 상용 light field 카메라인 Lytro에서 취득하였고 기존의 알고리즘과의 비교를 통해 제안하는 알고리즘의 우수성을 검증한다.

• 대한방사선치료학회지
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• 제17권1호
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• pp.9-17
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• 2005

목적 : 방사선치료에 있어 치료부위내의 균등한 선량분포는 환자의 치료성적 및 장해를 좌우하는 매우 중요한 인자이다. 이러한 치료부위내의 균등한 선량분포를 얻기 위해 사용하는 여러 가지 방법 중 간단한 Field-in-Field Technique의 유용성을 평가하고 다양한 크기의 전뇌(whole brain)치료 환자에게 적용가능성을 알아보고자 한다. 대상 및 방법 : 전뇌(whole brain)의 일반적인 치료기법인 대향2문조사와 Field-in-Field Technique을 적용했을 때의 선량분포도를 비교하기 위하여 phantom(acryl 16 cm spheral phantom)을 대상으로 치료계획을 수립하였으며, 선량분포평가를 위하여 저감도필름(X-Omat V-film)과 열형광선량계(TLD)를 사용하여 측정하였다. 또한 다양한 두께의 환자20명(대, 중, 소 및 소아-각각 5명)을 대상으로 Field-in-Field Technique의 적용가능성을 평가 하였다 결과 : 전뇌(whole brain)치료에 대향2문조사와 Field-in-Field Technique을 적용한 경우 각각의 치료부위내의 선량분포 및 DVH를 비교한 결과, Field-in-Field Technique을 사용한 경우 고선량(high dose)영역을 $3{\sim}4\%$이하로 줄일 수 있었고, 저감도필름(X-Omat V-film)과 열형광선량계(TLD)에 의한 측정결과 또한 유사한 수치를 얻을 수 있었다. 이러한 Field-in-Field Technique을 다양한 두께의 환자에게 동일하게 적용해도 선량분포의 변화는 $1{\sim}2\%$로 나타났다. 결론 : 전뇌(whole brain)치료에 Field-in-Field Technique를 이용하여 치료계획을 수립하여 적용하면 치료부위내의 균등한 선량분포를 얻을 수 있으므로 추가적인 치료가 필요한 경우 선량합성이 용이하여 쉽게 치료계획을 수립할 수 있었다. 그리고 균등한 선량분포를 얻기 위해 사용하는 wedge filter 및 3D compensator 의 역할을 대체 할 수 있으며, 방사선 치료 시 고선량 영역으로 인해 발생되는 장해를 최소화할 수 있을 것으로 사료된다.

• Wind and Structures
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• 제18권5호
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• pp.549-566
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• 2014

In spite of progress in the numerical simulation of typhoon wind field in atmospheric boundary layer (ABL), using typhoon wind field model in conjunction with Monte Carlo simulation method can only accurately evaluate typhoon wind field over a general terrain. This method is not enough for a reliable evaluation of typhoon wind field over the actual complex terrain with surface roughness and topography variations. To predict typhoon wind field over the actual complex terrain in ABL, a hybrid numerical simulation method combined typhoon simulation used the typhoon wind field model proposed by Meng et al. (1995) and CFD simulation in which the Reynolds averaged Navier-Stokes (RANS) equations and k-${\varepsilon}$ turbulence model are used. Typhoon wind filed during typhoon Dujuan and Imbudo are simulated using the hybrid numerical simulation method, and compared with the results predicted by the typhoon wind field model and the wind field measurement data collected by Fugro Geotechnical Services (FGS) in Hong Kong at the bridge site from the field monitoring system of wind turbulence parameters (FMS-WTP) to validate the feasibility and accuracy of the hybrid numerical simulation method. The comparison demonstrates that the hybrid numerical simulation method gives more accurate prediction to typhoon wind speed and direction, because the effect of topography is taken into account in the hybrid numerical simulation method.

• 천문학회보
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• 제35권2호
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• pp.48.1-48.1
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• 2010

A numerical simulation study of the solar coronal plasma reveals that a ballooning instability can develop in the course of flux rope merging. When magnetic field lines from different flux ropes reconnect, a new field line connecting farther footpoints is generated. Since the field line length abruptly increases, the field line expands outward. If the plasma beta is low, this expansion takes place more or less evenly over the whole field line. If, on the other hand, the plasma beta is high enough somewhere in this field line, the outward expansion is not even, but is localized as in a bulging balloon. This ballooning section of the magnetic field penetrates out of the overlying field, and eventually the originally underlying field and the overlying field come to interchange their apex positions. This process may explain how a field structure that has stably been confined by an overlying field can occasionally show a localized eruptive behavior.

• Bulletin of the Korean Chemical Society
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• 제18권9호
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• pp.976-981
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• 1997

The magnetic susceptibilities of molybdenum ions with 4d1 electronic configuration in the octahedral crystal field were calculated on the basis of ligand field theory. The experimental magnetic susceptibilities for molybdenum ions, which are stabilized at the octahedral site in the perovskite lattice of Ba2ScMoⅤO6 and Sr2YMoⅤO6, were compared with the theoretical ones. We have tried to fit their temperature dependence of magnetic susceptibility with ligand field parameters, spin-orbit coupling constant ζSO, and orbital reduction parameter κ according to intermediate field coupling and strong field theory. Strong field coupling theory could not explain experimental curves without unrealistically large axial ligand field, since it ignores the mixing up between different state via spin-orbit interaction and ligand field. On the other hand, the intermediate field coupling theory could successfully reproduce experimental data in octahedral and trigonal ligand field. The fitting result demonstrates not only the fact that spin-orbit interaction is primarily responsible for the variation of magnetic behavior but also the fact that effective orbital overlap, enhanced by cubic crystal structure, reduces significantly orbital angular momentum as indicated by κ parameter.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.288-288
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• 2010

In this study radio rotatiing field is used in order to form the stable reversed field configuration. The experimental study removing the flux conserving ring not so as to conserve toroidal flux, it was found that there occurred a rapid formation of a stable reversed field configuration, in which toroidal flux was increased shaping reversed field configuration and F-$\Theta$ locus traced close to BFM because it started below F value.

• 한방비만학회지
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• 제22권1호
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• pp.21-29
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• 2022

Objectives: This study aimed to examine the changes in ingredients according to its cultivation method by examining the content of saponin and non-saponin components of ginseng. Methods: Ginseng saponin component analysis was compared and reviewed using the high-performance liquid chromatography method, and acidic polysaccharide component was measured using the carbazole sulfuric acid method. Results: The comparative analysis of ginseng saponin content of 4 and 6 years old fresh ginseng showed the following results. According to the cultivation method, upland field cultivation fresh ginseng showed higher average content of crude saponin than paddy field cultivation fresh ginseng. Whereas, paddy field cultivation fresh ginseng showed higher average content of total saponin than upland field cultivation fresh ginseng. Ginsenoside Rb1 showed higher content of paddy field cultivation fresh ginseng than upland field cultivation fresh ginseng in 6 years old ginseng. However, it showed higher content of upland field cultivation fresh ginseng than paddy field cultivation fresh ginseng in 4 years old ginseng. Additionally, ginsenoside Rg1 showed higher content of paddy field cultivation fresh ginseng than upland field cultivation fresh ginseng in 6 years old ginseng, whereas upland field cultivation fresh ginseng showed higher content of paddy field cultivation fresh ginseng in 4 years old ginseng. The effect on the content of ginseng saponins and acidic polysaccharides according to paddy field and upland field cultivation methods is considered to be small. Conclusions: The paddy field cultivation method, which is more efficient in production cost due to depletion of farmland and long-distance cultivation, is considered to be an economical cultivation method.