• 한국작물학회지
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• 제47권4호
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• pp.269-272
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• 2002

This study was carried out to investigate varietal differences on growth characteristics under the conditions of PE film-mulching and non-mulching in sesame. At maturing stage from 76 to 95 days after sowing, Yangbaeckkae, non-branching plant type, under non-mulching showed larger leaf area index (LAI) than that of film-mulching, while plant height and the number of capsules per plant were similar to those of film-mulching. LAI of Ahnsankkae, branching plant type, under non-mulching was similar to film-mulching, while plant height and the number of capsules per plant were smaller than those of film-mulching. Net assimilation rate (NAR) of two varieties under non-mulching was lower at seedling stage from 25 to 35 days after sowing but higher at flowering stage from 45 to 55 days after sowing. At maturing stage from 66 to 77 days after sowing, NAR and crop growth rate (CGR) of Yangbaeckkae under non-mulching were greater than those of film-mulching, whereas those of Ahnsankkae under non-mulching were lesser than those of film-mulching. Yield under non-mulching was decreased by 7 % in Yangbaeckkae and 33 % in Ahnsankkae compared with that of film-mulching, therefore Yangbaeckkae was more adaptable for non-mulching than Ahnsankkae. Main factors decreasing yield of Yangbaeckkae under non-mulching were small LAI, NAR, and CGR at the stage of young seedling, and small number of capsules at early maturing stage from first flowering to 20 days after first flowering.

• 대한의용생체공학회:의공학회지
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• 제18권2호
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• pp.187-196
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• 1997

The three-dimensional flow analysis using the finite volume method is presented to compare the steady flow characteristics of blood with those of blood substitutes such as water and aqueous polymer solution in an idealized double branching model. The model is used to simlllate the region of the abdominal aorta near the celiac and superior mesenteric branches. Apparent viscosities of blood and the aqueous Separan solution are represented as a function of shear rate by the Carreau model, Water and aqueoiu Separan AP-273 500wppm solution are frequently used as blood substitutes in vitro experiments. Water is a typical Newtonian fluid and blood and Separan solution are non-Newtonian fluids. Flow phenomena such as velocity distribution, pressure variation and wall shear stress distribution of water, blood and polymer solution are quite different due to differences of the rheological characteristics of fluids. Flow phenomena of polymer solution are qualitatively similar to those of blood but the phenomena of water are quite different from those of blood and polymer solution. It is recommended that a lion-Newtonian fluid which exhibits very similar rheological behavior to blood be used in vitro experiments. A non-Newtonian fluid whose rheological characteristics are very similar to those of blood should be used to obtain the meaninylll hemodynamic data for blood flow in vitro experiment and by numerical analysis

• The Korean Journal of Ecology
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• 제16권4호
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• pp.417-428
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• 1993

백목련의 가지 생장유형은 두 가지의 생장전략에 의해 이루어지는 것으로 보인가. 하나는 환경 극복 전략이고 다른 하나는 생명 유지 전략으로 구분할 수 있는데, 이러한 전략은 한 그루의 나무 안에서도 같이 일어나고 있었다. 가지의 생장율은 조도에 밀접한 관련이 있었고(P<0.001) 물리적인 접촉의 유무와도 상당히 관련(P<0.01)되어 있는 반면에 방위별로는 우의차가 없었다. 상대 조도 1%미만의 경우는 주변 가지들과 거의 물리적인 접촉으로 대부분 생장이 제한되어 있었고, 10% 초과의 경우는 접촉에 의해 생장 제한이 거의 일어나지 않았다. 가지간의 물리적인 접촉의 유무는 분지율에 영향을 미치고 있었으나(P<0.05), 분지율은 조도에 무관하고, 방위별로도 유의차가 없었다. 생장 초기에는 주가지에서 부가지로의 물질 분배비가 크게 나타났으나 나무가 자라면서 환겨의 제한을 받게 됨에 따라 분배비는 다양하고 때로는 아주 적은 값을 보이기도 하였다. 이러한 다양한 생장율, 즉 물질의분배비의 다양(0.16~0.98)은 생장과 더불어 빚어지는 제약을 극복하여 태양 에너지를 최대한 효율적으로 흡수하기 위한 가지의 배치로 해석되며, 주어진 환경하에서 백목련이 택하는 최적의 생장 전략인 것으로 생각되다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.229-229
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• 2017

This research study was conducted to analyze the characteristics of different rice cultivars in abnormal temperature conditions (low temperature) for ripening period abnormalities, and to investigate the physiological causes behind the abnormalities. Four Korean high quality japonica-type rice cultivars, Jinbu (JB), Junamjosaeng (JJ), Geumyoung (GY), Hwawang (HW) were used in the experiment. The following day after flowering, they were then moved into two phytotrons under natural daylight with 65% RH but controlled at different temperatures - one at $19/29^{\circ}C$ (night/day) and the other at $13/23^{\circ}C$ as the low - temperature study on ripening. For the cultivars at $13/23^{\circ}C$ (low temperature study), JB and JJ had a ripening rate of 93% which is similar to the ripening rates of cultivars at $19/29^{\circ}C$ at 45 days after heading (DAH). In contrast, GY and HW recorded lower ripening rates of 86% and 57% respectively. However, when the cultivars at $13/23^{\circ}C$ were harvested at 61 DAH (when the accumulated temperature reached $1100^{\circ}C$), the difference in ripening rates compared to the 4 cultivars of $19/29^{\circ}C$ harvested at 45 DAH was not obvious (JB 94%, JJ 97%, GY 97%, HW 88%). Starch content showed little difference among the 4 cultivars at different temperature conditions while amylose content was higher for cultivars at $13/23^{\circ}C$ compared to those at $19/29^{\circ}C$. In addition, the enzyme activities of starch biosynthesis were about 5~10 days slower in cultivars at $13/23^{\circ}C$ compared to cultivars at $19/29^{\circ}C$. The grain-filling rate showed highly significant correlations with the enzyme activities of Sucrose synthase ($R^2=0.70^{***}$), ADP glucose pyrophosphorylase ($R^2=0.63^{***}$), UDP glucose pyrophosphorylase ($R^2=0.36^{***}$), Starch synthase ($R^2=0.51^{***}$), and Starch branching enzyme ($R^2=0.59^{***}$). Among the enzymes, Sucrose synthase activity had the highest correlation coefficient with grain-filling rate. In conclusion, the activity of enzymes such as Sucrose synthase, UDP glucose pyrophosphorylase, ADP glucose pyrophosphorylase, Starch synthase, Starch branching enzyme in starch biosynthesis is proven to be highly related to the grain filling process. Notably, the decrease in the activity of Sucrose synthase and Starch branching enzyme and the late increase in ADP glucose pyrophosphorylase activity at low temperature in the ripening stage are considered to be disadvantageous as they delay ripening and increased amylose content.

• The Plant Pathology Journal
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• 제21권3호
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• pp.221-228
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• 2005

A total of 179 isolates of Trichoderma spp. were collected from oyster mushroom substrates in Korea. On the basis of morphological and cultural characteristics, Trichoderma isolates were divided into seven groups, namely T. atroviride, T. citrinoviride, T. harzianum, T. longibrachiatum, T. virens, and two unidentified species, referred to as Trichoderma sp. 1 and 2. The predominant species was Trichoderma sp. 2 (n=86) followed by Trichoderma sp. 1 (n=52). Trichoderma sp. 1 and 2 were morphologically distinct not only from the other species of Trichoderma reported but also from each other in the characteristics such as mycelial growth rate, colony appearance, shape of conidia and conidiophores and branching pattern of phialides, although branching pattern of phialides of Trichoderma sp. 1 was similar to that of T. harzianum. In virulence test, the degree for compost colonization of Trichoderma sp. 2 was significantly greater than that of the other Trichoderma species. Trichoderma sp. 2 was found to be the main cause of green mold disease in oyster mushroom production. More work including molecular characterization is needed to confirm the species of Trichoderma sp. 1 and 2.

• 한국게임학회 논문지
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• 제17권3호
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• pp.63-70
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• 2017

인공지능 연구에서 바둑은 위치평가의 어려움과 엄청난 분기수로 인해 가장 도전적인 보드게임으로 여겨지고 있다. 몬테카를로 트리탐색은 이러한 문제점을 극복할 수 있는 고무적인 돌파구이다. 알파고의 숨겨진 아이디어는 주어진 위치에서의 승률을 예상하여 깊은 탐색을 유도한 후 가장 고무적인 착수를 찾아내는 것이었다. 본 논문에서는 무전략 MCTS를 활용하여 9줄바둑에서 프로기사들이 최상의 첫수로 여기는 천원점이 옳다는 것을 확인했으며, 또한 가장 유행하는 첫 수들의 평균승률을 비교했다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.221-221
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• 2000

The heat exchange part in a modern multi-type air-conditioning system employs multiple-pass heat exchangers. The heat-transfer performance of an each pass in such an exchanger depends strongly on the length of the two-phase region and the mass flow of the refrigerant. The total length and diameters of the pipes, the exit conditions, and the arrangement of each pass as well as the geometrical shape of the distributor at the branching sections are considered to be major factors affecting the heat-transfer performance. The refrigerant commonly used in these systems is HCFC-22. The two objectives of this paper are to investigate the characteristics of the refrigerant flow rate and the superheat in the evaporator of a multi-type air-conditioning system for a single or simultaneous operating conditions and to control the superheat and the refrigerant flow rate of the evaporator.

• 한국동물위생학회지
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• 제46권3호
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• pp.203-210
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• 2023

Breeding ducks are susceptible to fungal infections due to being bred in confined spaces for long periods. The objective of this study was to show the real state of the clinical fungal contamination of 22 duck breeding farms in Chungcheongbuk-do, South Korea. Out of the 430 carcasses obtained from the 22 duck breeding farms, 80 were diagnosed with invasive pulmonary aspergillosis (IPA). Aspergillus spp. were detected as the causative agents, including 26 cases of A. fumigatus, 35 cases of A. flavus, and 19 cases of A. terreus. The clinical lesions in the breeding ducks had circumscribed cream-and-yellow-colored plaques and/or white-to-greenish mycelium. Septate hyphae with parallel walls and dichotomous branching were observed in the histopathological lesions. AGMAg ELISA was performed to determine the overall positive rate of Aspergillus spp. in duck breeding farms. These results showed a positive rate of 58.97% for Aspergillus spp. Additionally, the positive rate increased with the age of the host.

• 한국균학회지
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• 제4권1호
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• pp.53-58
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• 1976

This study was undertaken to investigate the direct effect of three different kinds of steroid to Trichophyton(T.) mentagrophytes growth in vitro. A loopful of T. mentagrophytes was inoculated into Sabouraud's media and Sabouraud's media containing various concentrations of dexamethasone (0.04%-0.00004%) prednisolone (0.25%-0.00025%), triamcinolone acetonide (0.2%-0.0002%), Sabouraud's media containing imidazole nitrate (econasole nitrate) 10 micro gm. per cc. of media, and Sabouraud's media containing econazole nitrate $10{\mu}g$ per cc. of media of various dexamethasone concentrations (0.04%-0.00004%). After inoculation they were left for two weeks at room temparature and the colony diameter were compared between Sabouraud's media and Sabouraud's media containing various concentrations, of three different steroids, Sabouraud's media containing econazole nitrate and Sabouraud's media containing econazole nitrate of various dexamethasone concentrations. For complementary study, hanging slide culture were done between Sabouraud's media and Sabouraud's media containing various dexamethasone concentrations to compare the degree of branching of hyphae and sporulation serially. The study results were as follows: 1. There is no significant difference in growth rate of T. mentcgrophytes between Sabouraud's media and Sabouraud's media containing various concentrations of three different steroids. 2. There is no significant difference in growth rate of T. metagrophytes between Sabouraud's media containing econazole nitrate 10 micro gm per cc. of media and Sabouraud's media containing econazole nitrate 10 micro gm per cc. of media of various dexamethasone concentrations. 3. In hanging slide culture, there is no significant difference in branching of hyphae and sporulation between Sabouraud's media and Sabouraud's media containing various dexamethasone concentrations.

• Structural Engineering and Mechanics
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• 제86권5호
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• pp.607-619
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• 2023

This study, it was tried to evaluate the asphalt behavior under tensile loading conditions through indirect Brazilian and direct tensile tests, experimentally and numerically. This paper is important from two points of view. The first one, a new test method was developed for the determination of the direct tensile strength of asphalt and its difference was obtained from the indirect test method. The second one, the effects of particle size and loading rate have been cleared on the tensile fracture mechanism. The experimental direct tensile strength of the asphalt specimens was measured in the laboratory using the compression-to-tensile load converting (CTLC) device. Some special types of asphalt specimens were prepared in the form of slabs with a central hole. The CTLC device is then equipped with this specimen and placed in the universal testing machine. Then, the direct tensile strength of asphalt specimens with different sizes of ingredients can be measured at different loading rates in the laboratory. The particle flow code (PFC) was used to numerically simulate the direct tensile strength test of asphalt samples. This numerical modeling technique is based on the versatile discrete element method (DEM). Three different particle diameters were chosen and were tested under three different loading rates. The results show that when the loading rate was 0.016 mm/sec, two tensile cracks were initiated from the left and right of the hole and propagated perpendicular to the loading axis till coalescence to the model boundary. When the loading rate was 0.032 mm/sec, two tensile cracks were initiated from the left and right of the hole and propagated perpendicular to the loading axis. The branching occurs in these cracks. This shows that the crack propagation is under quasi-static conditions. When the loading rate was 0.064 mm/sec, mixed tensile and shear cracks were initiated below the loading walls and branching occurred in these cracks. This shows that the crack propagation is under dynamic conditions. The loading rate increases and the tensile strength increases. Because all defects mobilized under a low loading rate and this led to decreasing the tensile strength. The experimental results for the direct tensile strengths of asphalt specimens of different ingredients were in good accordance with their corresponding results approximated by DEM software.