• International Journal of Precision Engineering and Manufacturing
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• 제3권3호
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• pp.76-81
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• 2002

In order to study the fatigue crack and retardation mechanism in variable loading, the effects of crack tip branching in crack growth retardation were examined. The characteristics of crack tip branching behavior were considered with respect to microstructure and crack tip branching angle was examined. Crack tip branching was observed along the grain boundary of finite and pearlite structure. It was found that the branching angle ranges from 25 to 53 degrees. Using the finite element method, the variable of crack driving farce to branching angle was examined. The effective crack driving farce (K$\_$eff/) decreased as the branching angle increased. The rate of decrease was 33% for kinked type and 29% for forked one. It was confirmed that the effect of crack tip branching is a very important factor in crack growth retardation. Therefore, crack branching effect should be considered in building the hypothetical model to predict crack growth retardation.

• Journal of Veterinary Science
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• 제25권2호
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• pp.32.1-32.14
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• 2024

Background: Aortic arch (AA) branching patterns vary among different mammalian species. Most previous studies have focused on dogs, whereas those on raccoon dogs remain unexplored. Objectives: The objective of this study was to describe the AA branching pattern in raccoon dogs and compare their morphological features with those of other carnivores. Methods: We prepared silicone cast specimens from a total of 36 raccoon dog carcasses via retrograde injection through the abdominal aorta. The brachiocephalic trunk (BCT) branching patterns were classified based on the relationship between the left and right common carotid arteries. The subclavian artery (SB) branching pattern was examined based on the order of the four major branches: the vertebral artery (VT), costocervical trunk (CCT), superficial cervical artery (SC), and internal thoracic artery (IT). Results: In most cases (88.6%), the BCT branched off from the left common carotid artery and terminated in the right common carotid and right subclavian arteries. In the remaining cases (11.4%), the BCT formed a bicarotid trunk. The SB exhibited various branching patterns, with 26 observed types. Based on the branching order of the four major branches, we identified the main branching pattern, in which the VT branched first (98.6%), the CCT branched second (81.9%), the SC branched third (62.5%), and the IT branched fourth (52.8%). Conclusions: The AA branching pattern in raccoon dogs exhibited various branching patterns with both similarities and differences compared to other carnivores.

• 생물환경조절학회지
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• 제6권2호
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• pp.86-91
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• 1997

분지각을 기준으로 유인방법을 달리한 시설 고추 재배에서 군락내 수광태세와 초고별 기관분포로 살펴본 군락생산 구조 분석과 생육 및 수량을 조사하여 생육 전반적인 군락생산 구조는 흡광계수, 군락 모식도 측면에서 45$^{\circ}$ 처리후 직립구에서 가장 좋았다. 초장은 직립구에서 가장 컸으며 1차분지 이후의 평균 절간장은 45$^{\circ}$ 처리구가 가장 짧았으나 경경, 엽면적, 식물체 무게는 45$^{\circ}$ 처리후 직립구에서 가장 우수하게 나타났다. 수량은 45$^{\circ}$ 처리후 직립구>45$^{\circ}$ 처리구>직립구 순이었으나, 수확 과수는 45$^{\circ}$ 처리후 직립구>직립구>45$^{\circ}$ 처리구 순이었다.

• 한국정밀공학회지
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• 제14권6호
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• pp.83-89
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• 1997

In order to study on fatigue crack retardation and retardation mechanism in variable loading, the effects of crack tip branching in fatigue crack growth retardation were examined. The characteristics of crack tip banching behavior was considered to micro structure. It was examined that the variation of crack tip branching angle. Crack tip branching was observed along the grain boundary of ferrite and pearlite structure. It was found that the abanching angle ranges from 25 to 53 degrees. Using the finite element method, the variable of crack driving force to branching angle was examined. The effective crack driving force ( $K_{\eff}$ ) decreased as the braching angle increases. The rate of decrease was 33% for the kinked type and 29% for the forked one. It was confirmed that the effect of crack tip branching is a very important factor in fatigue crack growth retardation. Therefore, crack branching effect should be considered building the hypoth- etical model to predict crack growth retardation.

• 아시안잔디학회지
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• 제11권2호
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• pp.117-124
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• 1997

This study was carried out to investigate the growth and branching pattern of stolons at Korean lawn(Zoysia japonica Steud.) in the field condition. The results were summarized as follows ; 1.About 80% of observed lawns had one primary stolon. Among the lawns with several primary stolons, 30% of them had two primary stolons, 63% had three, and 7% had four. 2.The angles between the primary stolon and the shoot were increased from 0˚ to 52˚ according to the node order from the terminal shoot apex, and reached maximum angle at the 7th node. 3.The internode length was the longest in the middle position of stolon, and its growing rate which depends on months was increased from May to September. 4.The branching angles between primary and secondary stolon were from 44˚ to 53˚ in each node. The average left branching angle was about 48.20, right branching angle 47.8˚, and the total average branching angle was 48.00. 5.The rate of initial brabch was the highest at the 10th node in May, the 7th node in July and the 5th node in September. But, the initial branching rate at the 7th node in July was higher than any other that at the 10th node in May and the 5th node in September. 6.The distribution rate of secondary stolon in each node of primary stolon was the highest at the 7th node. 7.when the terminal shoot apex of primary stolon was damaged mechanically, the branching rate at the first node after the damaged region was highly increased to 62%. The results of this study may be suggested that the secondary stolon begins to branch with the angle of 480 from the 7th node of the normal primary stolon, and those may be used as a basic data for the branching simulation in lawn.

• Bulletin of the Korean Chemical Society
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• 제11권3호
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• pp.214-220
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• 1990

We have studied the Infrared Multiphoton Dissociation (IRMPD) of 1-bromo-3-chloropropane by using the pulsed $CO_2$ laser. The product yields and the HCl/HBr branching ratios in IRMPD of $BrCH_2CH_2CH_2Cl$ are studied under the focused beam geometry as a function of buffer gas (He) pressure, laser energy, and photolysing wavelength. It is observed that the total dissociation yield has a laser energy dependence of 1.8-2.0 power order and the branching ratio is very slightly dependent on the pulse energy for the laser lines employed. The dependences of total dissociation yield and branching ratio on the buffer gas pressures show that the dissociation yield monotonically decreases and the branching ratio slightly decreases with the increase of the buffer gas pressure. The Energy-Grained Master Equation (EGME) was applied to explain the laser pulse energy and the buffer gas pressure(He) dependence of the dissociation yield and the branching ratio.

• 한국언어정보학회지:언어와정보
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• 제13권1호
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• pp.39-56
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• 2009

This paper investigates ordering alternation phenomena in Korean using the dative construction data from Sejong Corpus of Modern Korean (Kim, 2000). The paper first shows that syntactic weight and information structure are distinct and independent factors that influence word order in Korean. Moreover, it reveals that heaviness and givenness compete each other and exert diverging effects on word order, which contrasts the converging effects of these factors shown in word orders of right-branching languages like English. The typological variation of syntactic weight effect poses interesting theoretical and empirical questions, which are discussed in relation to processing efficiency in ordering.

• Macromolecular Research
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• 제16권3호
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• pp.218-223
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• 2008

In order to obtain crosslinked poly(butylene succinate) (PBS) foams with a closed-cell structure, a commercial-grade PBS was first modified in the melt using two different branching agents to increase the melt viscosity. The rheological properties of the branched and crosslinked PBS were examined by varying the amount of the branching agents. The complex viscosity of the crosslinked PBS increased with increasing amount of the branching agent. However, it decreased with increasing frequency. When 2 phr of the branching agent was added to PBS, the storage modulus (G') was higher than the loss modulus (G") throughout the entire frequency range, showing that the addition of a branching agent increases the melt viscosity and elasticity of PBS effectively. Closed-cell PBS foams were prepared by mixing the chemical blowing agent with the crosslinked PBS. The effect of the foaming conditions such as temperature and time, and the amount of the crosslinking agent on the structure of the expanded PBS foams were also investigated.

• 대한기계학회논문집A
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• 제36권4호
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• pp.361-371
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• 2012

혼합이산비선형계획법(mixed-discrete nonlinear programming) 문제의 최적화를 위한 대표적인 기법 중에 하나인 분지한계법(branch-and-bound method)은 다른 기법에 비해 강건하지만 분지한계법 내부의 각 노드마다 연속최적화를 수행해야 하기 때문에 많은 함수 계산이 요구되는 것으로 알려져 있다. 이러한 분지한계법의 단점을 극복하기 위하여 크게 두 가지 연구를 수행하였다. 먼저, 분지한계법의 각 노드마다 동일한 수렴허용오차를 설정해주던 기존의 방법을 대체할 수 있는 비균일 수렴허용오차 방법을 제안하였다. 또한 분지한계법에 적용할 수 있는 5 가지 분지순서 방법 중에서 분지한계법의 성능을 가장 극대화할 수 있는 분지순서 방법을 제시하였다. 수렴허용오차 방법과 분지순서 방법들을 각각 선택하여 분지한계법에 적용한 후 7 개의 수학예제와 4 개의 공학예제에 대하여 테스트를 수행한 결과, 제안된 비균일 수렴허용오차 방법과 5 가지 분지순서 방법 중 최소간 격차이법을 분지한계법에 함께 적용할 경우 분지한계법의 성능이 가장 극대화 됨을 확인할 수 있었다.

• 한국콘텐츠학회논문지
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• 제11권8호
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• pp.475-487
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• 2011

본 논문에서는 고차원펄스의 스펙트럼을 유도하는 체계적인 방법을 제시하고, 이를 학습내용으로 하는 효율적인 이러닝 시스템을 설계한다. 고차원펄스의 스펙트럼은 연속미분법이나 콘볼루션법 등 기존의 방법에 의하여 유도될 수 있으나, 그 차수가 증가함에 따라 현저하게 높아지는 복잡도 때문에 사용할 수 없다. 우리는 고차원펄스의 차수에 따라 순환적으로 적용되는 알고리듬을 제시하고, 이를 찾아보기표에 의하여 함수적으로 차수에 연관된 스펙트럼의 식을 유도한다. 또한, 이를 이용하여 고차원펄스의 스펙트럼을 분석하는 과정을 학습하는 이러닝 콘텐츠를 설계한다. 여기에는 기존의 순차적 재생을 기본으로 하여 이른바 개념단위 오브젝트별 분기방식을 적용하는 콘텐츠 처리방식이 사용된다. 모델링, 임펄스응답과 전달함수, 파라미터, 찾아보기표 등 전체를 네 개의 개념단위로 분할한 콘텐츠페이지를 설계하고, 이들로부터 하향식으로 분화된 개념단위들을 모듈과 서브모듈로 설정한다. 이들은 개념단위 오브젝트별 분기방식에 의하여 학습자에게 다양한 학습순서와 반복학습 등을 제공하여 상호작용을 증대하고, 저작된 이러닝 콘텐츠에 의한 학습효과를 현저히 향상시킨다. 또한, 콘텐츠 자체의 효율성 측면에서도 현저한 향상을 이룬다.