• The Korean Journal of Ecology
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• v.28 no.4
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• pp.199-206
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• 2005

Estuary islets should be managed systematically because they are important places for birds to rest and breed. This paper investigates the environmental properties of islets where the sand banks are located from east to west on the southernmost of Nakdong estuary during a year (September 2003 $\sim$ August 2004). The research showed that 59 species and 19,148 individuals were found in the area A (Jangja Shinja-Do) and 61 species and 28,394 individuals in the area B (Saja-Do; Beakhapdeung Doyodeung). Totally, 74 species and 47,539 individuals were observed in both of this estuary. Shorebirds are the most observed species in both areas. In area, most of individuals were especially observed in the spring when Shorebirds migrate northward for breeding. In B area, various species were also observed in the fall when they migrate southward for wintering. Therefore, many groups of birds are observed around Shinja-Do in the spring. They passed the winter in Doyodueng, associated with feeding in the main stream of Nakdong river mainly. Although the southernmost sand bar is the breeding place to access to outside without interception, invasion by human beings and predators (mice, weasels and etc.) gives a fatal blow for birds to breed or rest. The reed which is a tall herbaceous plant is flourished according to the process of ecological succession. Therefore, the sand bar becomes a land. It results in reduction of habitats and breeding grounds for birds. In conclusion, these areas where birds can use the islets as habits and breeding places must be preserved by restraining luxuriance of reeds and systematic management of human beings and predators is necessary.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.4
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• pp.347-354
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• 1992

Late harvest in peanut has often resulted in reduced yield and dissipation of labor by virtue of increasing over-matured pods causing the pod shattering. Present study was conducted to obtain a basic information for deciding optimum harvest time of the peanut in Chungbuk province by examination of yield components at different harvest time of leading cultivars Saedl and Youngho cultivated with vinyl mulching or non-mulching conditions. Peg number and pod number were significantly increased by vinyl mulching and also significantly different by the harvest time. Pod number increased with the lapse of days after flowering was gradually decreased from 100 days after flowering in saedl and 110 days in Youngho. Number of seed-bearing pods and matured seed percent were significantly increased by vinyl mulching and had tendency to increase with the lapse of days after flowering. There was no significant difference in number of over-matured pods and pod shattering percent between vinyl mulching and non-mulching. They increased drastically in 110 days after flowering in Saedl, but in 120 days after flowering in Youngho, Increase in 100 seed weight by vinyl mulching was statistically nonsignificant in both varieties, however, total seed yield was significantly increased by vinyl mulching, showing maximum yield in 100 days after flowering in the variety Saedl and 110 days in Youngho, respectively, Seed yield was negatively correlated to peg number and positively correlated to pod number, seed-bearing pod number, pod shattering percent, matured seed percent and 100 seed weight, respectively.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.3 s.192
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• pp.55-60
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• 2007

The electro-acoustic guitar pickup converts the vibration of strings to the electric signals, and delivers them to an amplifier. The vibration of the strings is transferred to the piezoelectric material through the saddle. This paper aims to improve sound quality for electro-acoustic guitars through the finite element analysis of the saddle. Firstly, the conventional pickup is modeled and analyzed with a commercial program called ANSYS. It is obvious that there exists interference phenomenon of stress. A structural modification of the pickup is performed, based on the beam theory. The modified structure is modeled and analyzed. Finally, the fabricated structures are subjected to the measurements and compared with the conventional pickup. It can be concluded that the interference with the modified structure is much less than that with the conventional structure, and that the sound quality is improved with the modified structures.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.2
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• pp.160-167
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• 2004

The correlation between the object function and the design parameter is shown on this paper by using the characteristic function for the mixed result of the structural analysis, the buckling analysis and the table of orthogonal array according to the original overhead crane's dimensional change. About the above two functions, the effectiveness of design change according to the change of design parameters could be estimated. Also, the overhead crane's weight is reduced up to 10.55 percent maintaining the structural stability according to the thickness of plate.

• 건강소식
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• v.32 no.6
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• pp.30-31
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• 2008

연둣빛 신록이 온 산과 들판을 뒤덮어 어디론가 떠나고 싶은 화창한 봄날, 새들이 옹기종기 모여 앉아 큰 소리로 지저귀는 미곡 창고 옆에 자리한 전남 강진군 군동면의 군동농업협동조합을 찾았다. 강진군 군동농협은 미곡 영농 조합으로, 총 1,690명의 조합원 중 1,180명이 65세 이상의 고령자이다. 군동면은 여느 농촌처럼 젊은 사람들의 도시 이주로 심각한 고령화를 겪고 있다. 지속되는 고유가 및 물가 상승, 금융 시장의 급변, 농축산물 수입 개방 가속화와 같은 요소들이 지역 경제를 더욱 어렵게 하고 있다. 이러한 힘든 여건 속에서 군동농협은 신용 사업 및 공제 사업 등의 난항을 겪고 있지만, 희망을 잃지 않고 영농 소득 증대 및 사업 확대를 위해서 애쓰고 있다. 그 결과 2007년도에는 농협중앙회의 공제 부문 평가 항목에서 실적이 우수하여 NH보험 연도 대상 본상 부문에서 동상을 수상하기도 했다. 또한 경제 사업 부문에선 각종 영농 자재를 적기에 농가에 공급하거나, 유류 판매 사업에서 큰 실적을 거두는 등 좋은 결과들을 냈다. 사회 환원 사업에도 힘쓰고 있어 영농 자재 환원과 조합원 자녀 장학금 수여 등 활발한 활동을 보이고 있다. 그리고 무엇보다 일본 수출 작물인 착색단고추(파프리카)가 꾸준한 수출 증가 추세 속에 군동면을 대표하는 효자 작물이 되고 있다

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1471-1474
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• 2003

The correlation between the object function and the design parameter is shown on this paper by using the characteristic function for tile mixed result of the structure analysis. tile buckling analysis and the table of orthogonal array according to the original crane's dimensional change. About the above two object functions, the effective of design change according to the change of design parameters could be estimated. Also, the crane's weight is reduced up to 20.58 percent maintaining the structural stability according to the thickness of plate.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.466-471
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• 2011

본 연구에서는 장대 현수교 주케이블의 가설시 선형관리를 위한 기초적 연구를 수행하였다. 우선, 포물선 요소 및 탄성현수선 요소의 정식화 과정을 검토하고, 각 요소의 적용에 따른 현수교 주케이블 완성계 및 가설계의 형상, 장력, 무응력장 등을 비교검토 하였다. 또한, 탄성현수선의 적용시 주케이블 가설계의 setback량 산정 방법을 제시하였으며, 이에 따른 산정 결과를 유한요소해석 결과와 비교검토 하였다. 최종적으로, 주케이블 가설계의 중앙경간 새그량 변화에 따른 탑정 새들부에서의 미끌림 안정성에 대한 민감도 해석을 수행할 예정이다.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.5
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• pp.60-70
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• 2001

In multi-purpose lathe, the design of tilting turret slide system has an important and critical role to enhance accuracy of the machining process. Tilting turret unit is traveled by 3-axis slide systems. There is a need to design this part very carefully. In this research, 3-axis sliding system with tilting turret unit is modeled by considering the element dividing, material proprties, and boundary conditions with PATRAN. Normal mode and frequency analysis of each structures such as saddle, cared, and turret are simulated by NASTRAN, for the purpose of developing the effective design. The results of mode analysis and frequency analysis are visualized with PATRAN, and the design method which can solve the resornance problem by eigenvalues and eigenvectors of each axis is developed as well.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.01a
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• pp.287-288
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• 2016

항공기 버드스트라이크 사고는 공항활주로 주변에서 이 착륙 중이거나 저고도 상공에서 비행중인 항공기와 새의 접촉으로 인해 발생하는 사고다. 이러한 버드스트라이크사고는 항공운항의 역사와 함께 우리를 위협해 왔고 앞으로도 계속해서 위협하게 될 것이다. 이에 본 논문에서는 공항활주로에서 일어났던 버드스트라이크 사고의 다양한 사고예방법 중 새들의 천적인 맹금류 중 매의 울음소리를 활용한 예방법에 관해서 연구하였다.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.3
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• pp.50-57
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• 2003

In this study, the structural optimal design was applied to the girder of over head crane. The optimization was carried out using ANSYS code fur the deadweight of girder, especially focused on the thickness of its upper, lower, reinforced and side plates. The weight could be reduced up to around 15% with constraints of its deformation, stress and buckling strength. The structural safety was also verified by the buckling analysis of its panel structure. It might be thought to be very useful to design the conventional structures fur the weight save through the structural optimization. The objective function and restricted function were estimated by the orthogonal array, and the sensitivity analysis of design variable fur that was operated.