• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 추계학술대회 논문집
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• pp.223-224
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• 2006

• 한국통신학회:학술대회논문집
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• 한국통신학회 2004년도 추계종합학술대회 논문 초록집
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• pp.86-86
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• 2004

• 한국정밀공학회지
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• 제22권1호
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• pp.175-182
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• 2005

A laser beam expanding technique is employed to fabricate precise nano-patterns in a nano-replication printing (nRP) process. In the nRP process, some patterns can be fabricated in the range of several microns inside on a polymerizable resin by using a volume-pixel (voxel) matrix that is transformed from a two-tone bitmap figure file. The liquid monomers are polymerized by means of a two-photon-absorption (TPA) phenomenon that is induced by a femtosecond (fs)-pulse laser. The yokels are generated consecutively to merge into adjoining yokels in the process of fabricating a pattern. The resolution of a fabricated pattern can be obtained under the diffraction limit of a laser beam by the two-photon absorbed polymerization (TPP). In this work, a beam-expanding technique has been applied to enlarge a working area and to fabricate precise patterns. Through this work, a working area is expanded by the technique as much as 2.5 times compared with a case of without a beam expanding technique, and precision of outside patterns is improved.

• 농업과학연구
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• 제29권2호
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• pp.135-148
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• 2002

In recent years, domestic market environment of rice production is confronted with the problems of excessive production and decrease in per capita consumption, resulting in steady decline of domestic rice price. Moreover, as new trade negotiations of WTO or FTA are being forwarded, cheap price of imported rice will also make the rice production environment being worse off. One of the possible production strategies to relieve this situation could be expanding farm size, which increases market competitiveness in terms of cost-saving. Since 1990's, one of the main agricultural policies for rice production in Korea has been expanding farm size. This study aims at 1)exploring brief history of Korean government's agricultural policy for expanding farm size, 2)examining economic effect of farming size expansion, and 3)discussing major role of government to promote appropriate programs for rice-farming and producers. Main conclusion suggests that appropriate farming size should be expanded upto at least five hectares per farm, with producers' effort to reduce farming costs and continuous investments on agricultural infrastructures including irrigation systems, etc. Continuous government's investment on operation and maintenance on water facility is also one of the important factors in expanding farm size.

• 대한가정학회지
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• 제27권3호
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• pp.117-132
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• 1989

The purpose of present study was to investigate the overall tendency of family life satisfaction in the period of expanding family and to identify the variables affecting family life satisfaction. Also, to provide some basic directions for the expanding period and to improve its family life satisfaction. The major findings of the study can be summarized as folllows; 1. In the family life areas of relations with spouses, self-evaluating scored highest, reflecting the greatest degree of family life satisfaction of both husbands and wives. 2. There is significant differences between husbands and wives in family life satisfaction scores. Generally, husbands were more satisfied with their family wives. 3. In satisfaction with areas specific to the family life, husbands were highly satisfied with instrumental areas which were related to role performences, as the head of family. And wives higly satisfied with areas refer to relations with spouses and communication with their family members. 4. Family life satisfaction scores were relatively high when the educational level and income of the couple were high. So the variables which related to socio-economics status affected seriousiy on family life satis-faction of that period. 5. Family life satisfaction degree of the expanding family was getting lower by degree. But it showed that the higher both spouses were satisfied with finance situation and communication, the higher the genaral familly life satisfaction degree of both spouses would be.

• 대한기계학회논문집
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• 제8권5호
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• pp.435-441
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• 1984

본 연구에서는 반경 방항으로 균일하게 잡아당기는 문제에 대하여 등방성, 직 교 이방경, 평면 이방성의 해를 비교하고, 성형성에 중요한 의미를 갖는 두께방항 변 형도와 원주방항 응력의 분포에 대하여 해석한다. 또 냉간 압연된 철판을 사용하여 평저 펀치(flat punch)에 의한 스트레칭(stretching) 실험을 하고, 실험과 같은 경계 조건으로 시뮬레이션(simulation)하여 결과를 비교한다.

• 정보처리학회논문지C
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• 제13C권4호
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• pp.447-454
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• 2006

에드 혹 네트워크에 사용되는 라우팅 프로토콜인 AODV(Ad hoc On-demand Distance Vector)는 ERS(Expanding Ring Search) 알고리즘으로 경로설정 과정에서의 라우팅 패킷 재전송을 제어한다. 그러나 기존의 ERS는 라우팅 패킷 재전송의 기준이 되는 NTT(Node Traversal Time) 계산에 이동성이 높은 네트워크 상황을 적절하게 반영하지 못한다. 본 논문은 NTT 계산에 RREP(Route Reply) 패킷을 사용하고 출발지 노드와의 인접도에 따라 각 노드의 NTT에 가중치를 달리 적용함으로써 라우팅 패킷의 재전송률을 낮추는 방법을 제안하고 ns2를 이용하여 기존의 ERS와 성능을 비교한다.

• Geomechanics and Engineering
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• 제32권4호
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• pp.453-462
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• 2023

Designing pile foundations subjected to the uplift forces such as buildings, oil platforms, and anchors is becoming increasingly concerned. In this paper, the conceptual design of a new type of driven piles called expanding pile is presented and assessed. Some grooves have been created in the shaft of the novel pile, and some moveable arms have been designed at the pile tip. At first, static analyses using the finite element method were performed to evaluate the effectiveness of the innovative pile on the axial bearing capacity. Then its effect on seismic behavior of moment frame is considered. Results show that the expanding arms were provided an ideal anchorage system because of the soil's noticeable locking-up effect increasing uplift bearing capacity. For example at the end of the static tensile loading procedure, displacement decrement up to 55 percent is observed. In addition, comparing the uplift bearing capacity of the usual and new pile with different lengths in sand and clay layers shows noticeable effect and sharp increase up to about two times especially in longer piles. Besides, a sensible reduction in the seismic response and the stresses in the beam-column connection between 23-36 percent are achieved that ensures better seismic behavior of the structures.

• Corrosion Science and Technology
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• 제23권2호
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• pp.145-153
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• 2024

In the automotive industry, the hole expanding test is widely used to assess the formability of punched holes in sheets. This test provides a good representation of formability within the framework defined by the ISO 16630 standard. During hole expanding tests on galvanized high strength steels, a negative effect was observed when there was a delay between hole punching and expansion, as compared to performing both operations directly. This effect is believed to be caused by hydrogen aging, which occurs when hydrogen diffuses towards highly-work hardened edges. Therefore, the aim of this study is to demonstrate the migration of hydrogen towards work-hardened edges in high strength Zn-coated steel sheets using a novel Thermal Desorption Analyzer (TDA) designed for small samples. This newly-developed TDA setup allows for the quantification of local diffusible hydrogen near cut edges. With its induction heating and ability to analyze Zn-coated samples while reducing artifacts, this setup offers flexible heat cycles. Through this method, a hydrogen gradient is observed over short distances in shear-cut galvanized steel sheets after a certain period of time following punching.

• 기술혁신연구
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• 제21권2호
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• pp.137-167
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• 2013

본 논문은 정부의 R&D 투자를 위한 재정지출의 확대가 민간기업의 연구개발 투자의 확대에 어떠한 영향을 미치며, R&D 투자 확대를 위한 대학과 기업의 지출 간의 관계에서 어떠한 관계가 확인되는지를 추정하고 있다. 본 논문의 추정결과를 통해 얻을 수 있는 결론은 다음과 같다. 첫째, R&D 투자확대를 위한 정부의 재정지출 확대는 민간기업의 R&D 투자를 확대시킨다. 그러나 대학 등의 고등교육기관의 지출 확대는 오히려 민간기업의 투자를 위축시킨다. 둘째, 대학의 R&D 투자의 확대가 민간기업의 R&D 투자를 구축하는 효과는 강하게 나타나고 있으며, 이러한 구축효과는 각 국가의 경제력, 재정상황, 그리고 경기변동 등 구조적인 변화에 강하게 영향을 받는다. 셋째, R&D 투자를 위한 정부지출이 대학과 기업 중에서 대학에 더 집중될수록 대학과 기업 간의 비대칭적인 관계는 강하게 나타나며, 이러한 관계에는 대학의 투자재원 중 기업부분으로부터의 투자재원이 큰 영향을 미친다. 넷째, 비록, R&D 투자의 확대를 위한 정부의 보조금 규모가 커질수록 기업의 R&D 투자가 확대되고 대학과 기업의 비대칭적인 관계가 개선된다고 하더라도, 정부의 보조금을 통해서 이러한 문제들을 전적으로 해결하기는 사실 상 어렵다.