• 한국작물학회지
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• 제38권6호
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• pp.495-508
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• 1993

연초 종자생산의 기초자료를 얻기 위하여 임성품종과 웅성불임 품종을 공시하여 격리거리 및 이식시기에 따른 자연교잡율을 조사하였다. 1. 임성품종간의 인접재배시 자연교잡율은 평균 1.6%이었고 0.9～2.5%범위로 나타났다. 2. 임성품종과 웅성불임 게통의 인접재배시 자연교잡율은 29%로 임성품종에 비하여 현저히 높게 나타났다. 3. 이식시기따른 자연교잡율은 4월20일 이식한 처리구가 5월 5일 및 5월20일 이식한 처리구보다 현저히 높았다. 4. 격리거리에 따른 자연교잡율은 격리거리가 멀수록 낮았고 300m 격리구에서도 자연교잡이 0.8%로 나타났다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.613-618
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• 2000

It is well known that the rotating motion of a blade-like structure induces centrifugal inertia force that causes the variation of the natural frequencies of the structure. Even though most of blade-like structures can be successfully Idealized as beams, some behave like plates rather than beams. This paper presents a modeling method for the flapwise bending vibration analysis of rotating cantilever plates. The dependence of natural frequencies and free vibration modes on the angular speed as well as the aspect ratio of a rotating plate is investigated. Particularly. the natural frequency loci crossing is observed and discussed In the present study.

• 한국철도학회논문집
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• 제5권2호
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• pp.125-132
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• 2002

As the public use part of the railway and the road, the railway crossing is important to work properly by two transportation means. Also, It is important to provide the good face of friction on the railway crossing in aspect of protecting the railway crossing accident. Lately, the material of railway crossing panel is the wood, the asphalt, and the steel. As they have a various fault, it was studied to analyze the structural action of the new material, rubber panel. This paper analyzed eigenvalue, stress and displacement by truck passing weight, thermal stress and train moving weight, using the Finite Element Method model

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1553-1556
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• 2003

As the public use part of the railway and the road, the railway crossing is important to work properly by two transportation means. Also, It is important to provide the good face of friction on the railway crossing in aspect of protecting the railway crossing accident. Lately, the material of railway crossing panel is the wood. the asphalt, and the steel. As they have a various fault, it was studied to analyze the structural action of the new material. rubber panel. This paper analyzed eigenvalue, stress and displacement by truck passing weight and thermal stress using the FEM model.

• Kyungpook Mathematical Journal
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• 제57권1호
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• pp.145-161
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• 2017

If a virtual knot diagram can be transformed to another virtual one by a finite sequence of crossing changes, Reidemeister moves and virtual moves then the two virtual knot diagrams are said to be homotopic. There are infinitely many homotopy classes of virtual knot diagrams. We give necessary conditions by using polynomial invariants of virtual knots for two virtual knots to be homotopic. For a sequence S of crossing changes, Reidemeister moves and virtual moves between two homotopic virtual knot diagrams, we give a lower bound for the number of crossing changes in S by using the affine index polynomial introduced in [13]. In [10], the first author gave the q-polynomial of a virtual knot diagram to find Reidemeister moves of virtually isotopic virtual knot diagrams. We find how to apply Reidemeister moves by using the q-polynomial to show homotopy of two virtual knot diagrams.

• 한국가스학회지
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• 제14권6호
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• pp.51-56
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• 2010

해외 하천통과 매설배관 사고사례를 수집하여 분석하였다. 이는 국내 하천통과 도시가스매설배관의 합리적인 매설심도를 결정하기 위한 기본 자료로 활용하기 위함이다. 사고사례 조사결과 하천을 통과하는 천연가스매설배관 사고의 주요원인은 홍수로 분석되었다. 홍수에 의한 배관 노출 및 과도 유량에 의한 하중이 파손 원인인 경우가 많다. 파손발생 위치에서 부식이 발생한 것도 원인이 되었다. 따라서 국내 하천통과 매설배관의 합리적이고 효율적인 매설심도 결정을 위해서는 국내 하천특성에 맞는 하천의 수리학적 특성평가와 배관의 구조해석이 요구된다. 일반 천연가스배관의 사고사례 조사 결과도 주요 원인이 외부간섭과 부식임도 요약하였다. 이들 두 주요원인은 매설환경에 따라 전체사고에서 차지하는 비율이 차이가 있었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1001-1006
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• 2004

Railroad disasters are frequently occurred by man-made causes or natural causes. In general, man-made causes are illegal construction practices, deterioration with the lapse of time and railroad crossing accidents, and natural causes are rainfall. snow, wind, earthquake, etc. Of cause, railroad disasters by man-made causes are prevented from keeping the safety principle, constructing multi-level crossing, securing enough men of ability and financial resources and making a thorough check using equipments with high capacity. And railroad disasters by natural causes are also minimized by construction of disaster prevention facilities, introduction and operation of general disaster prevention system and reasonable train passage control. Therefore, to setup the criterion of train passage control for train safety at railroad bridge under heavy rainfall, risky factors, national and oversea criteria under such circumstances are reviewed and a scheme to setup the criterion is suggested.

• 한국산림과학회지
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• 제96권3호
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• pp.290-294
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• 2007

참나무속(Q. serrata, Q. dentata, Q. mongolica var. crispula, Q. aliena)의 인공교배에 의 한 종간잡종의 묘목을 조취(鳥取)대학농학부 구내의 묘포장에 식재하였다. 또한 조취(鳥取)대학 산산(蒜山)연습림에서 자연교잡종(Q. fabri와 $Q.{\times}mccormickii$) 가계의 묘목을 선발하여 조취(鳥取)대학 산산(蒜山)연습림에 식재하였다. 인공종간잡종 $F_1$은 4년생, 자연교잡종 $F_1$은 3년생 때에 개화하였다. 2001년도에 이 중에서 개화한 개체로부터 화분과 종자를 채취하여 화분의 크기와 임성, 종자의 활력을 조사하였다. 인공종간잡종 화분의 발아율은 1개체를 제외하고 84% 이상이었고, 화분관의 신장도 양호하였다. 인공종간잡종의 건전한 종자의 발아율은 90% 이상으로 양친과 비슷한 높은 발아율을 보였다. 자연잡종 가계의 종자도 건전한 종자의 발아율은 각 가계의 평균이 64% 이상이었고, Q. fabri, $Q.{\times}mccormickii$의 자식종자도 높은 번식 능력을 유지하는 것으로 나타났다.

• 한국전문물리치료학회지
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• 제18권3호
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• pp.16-25
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• 2011

This study aimed to evaluate factors related to the ability of ambulatory patients with cerebral palsy (CP) to walk over vertical and horizontal obstacles. Twenty patients with spastic CP who were able to walk independently for at least 10 m with or without walking devices were recruited for the study. Participants were required to walk over small obstacles (1, 4, and 8 cm in height or width; total of 6 conditions). A 'fail' was recorded when either the lower limbs or the walking device contacted the obstacle. Linear regression analyses were used to determine the effects of age, sex, walking devices, eyeglasses, subtype (hemiplegia or diplegia), ankle foot orthoses, functional level, and score of body mass index on the ability of obstacle crossing. Fifteen participants (75%) failed to adequately clear the foot or walking device over obstacles in at least 1 condition. The chance of failure in crossing vertical obstacle was affected by the use of ankle foot orthoses, eyeglasses, gender, and CP subtype (p<.05). The failure rate crossing horizontal obstacle was affected by CP subtype. These findings suggest that rehabilitation procedures should (1) consider the clinical characteristics of patients in order to prepare them to be more independent while performing daily activities, and (2) incorporate environmental conditions that patients encounter at home and in the community.

• Acta Via Serica
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• 제2권2호
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• pp.133-162
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• 2017

The Bering Strait crossing would link the entirety of Eurasia to the entirety of the Americas, and it can be seen as a natural extension of the historical Silk Road. There are some immense geopolitical benefits to such a project. It would bring about a profound and lasting change to the global economic and political outlook. The most valued function of the Bering Strait crossing and the extension of the associated railroad network would be to release the massive natural resources trapped underneath the tundra and permafrost for the benefit of Russia and the world. Moreover, the railroad project(s) would also build development corridors in those underdeveloped parts of the Russian Federation. The development of the resources and their rapid transportation to the global markets would contribute not only to the overall development of the region but also would be valuable for the resource-poor countries of Northeast Asia such as Japan, Korea, and China (relative to its economic size). This paper will explore the possible impact(s) of the Bering Strait crossing as a formidable infrastructure project for the economic development of the Russian Far East (RFE) from the Russian perspective under the frame of geopolitics. Furthermore, it will equally scrutinize the implications for the adjacent countries in the region.