• Journal of the Korea institute for structural maintenance and inspection
• /
• v.13 no.3 s.55
• /
• pp.164-172
• /
• 2009

Anchors and saddles are used to have sufficient geometrical rigidity and make target configuration of main cable of suspension bridge. Neglecting the sliding effect at saddles, points at them have been idealized as fixed nodes in lots of former studies. In general, sliding effects are reported to show significant structural behaviors of main cable and cause to the different responses of bridges. During early erection steps of the suspension bridge, especially, the sliding effect occurs easily because there is large difference of cable tension between main and side span in removing set-back ropes or not applying set-back. This study presents the finite element analysis considering to cable sliding effect and shows the comparison of differences between sliding and non-sliding at election sequence. The analysis of sliding between main cables and saddles needs to obtain more realistic responses because the analysis result can represent unfavorably different responses of bridges. Moreover, the sliding analysis method and results in this study can be used to basic criteria in engineering design and construction steps.

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

• The Science & Technology
• /
• v.26 no.4 s.287
• /
• pp.31-34
• /
• 1993

매년 4월 초가 되면 강남갔던 제비가 마을이나 들판에서 날아다니는 것을 볼 수 있다. 그리고 제비는 앞마당의 빨래줄에 앉아서 봄을 알리는 듯이 「지지 배배」노래를 부른다. 이 새는 비록 몸체는 작지만 입을 크게 힘껏 노래를 한 후 따뜻한 봄의 햇살을 만끽이라도 하듯이 창공으로 날아가는 동작을 반복한다.

• The Korean Journal of Ecology
• /
• v.28 no.4
• /
• pp.199-206
• /
• 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
• /
• v.37 no.4
• /
• pp.347-354
• /
• 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.

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

• Fire Science and Engineering
• /
• v.22 no.3
• /
• pp.239-245
• /
• 2008

In this study, we researched about characteristics of many kinds of tank cars for carrying hazard materials and performed structural strength evaluation using finite element analysis for tank of asphalt tank car to suggest the efficient analysis method that can develop accuracy regarding to characteristics of tank cars. For this, we analyzed the asphalt tank refer to JIS E 7102 (Design Method for Tanks of Tank Cars). As results, we could show that the maximum stress is applied at the area supported by saddle and the maximum stress is under a criterion suggested from JIS E 7102. Therefore we verified that this asphalt tank car had enough structural strength.

• Journal of the Korean Institute of Gas
• /
• v.10 no.2 s.31
• /
• pp.61-67
• /
• 2006

We developed the ultrasonic phased array technique for obtaining ultrasonic images of electrofusion joints of polyethylene piping. And we inspected 4 cases at fields with this technique. First case is for the 300 mm diameter polyethylene electrofusion joint by using 3.5 MHz phased array sensor, second is for the 350 mm diameter saddle electrofusion joint, third is for the 400 mm diameter electrofusion joints and the last one is for the 400 mm diameter piping joints which will be used at 300 kPa suppling pressure.

• Water for future
• /
• v.27 no.2
• /
• pp.63-72
• /
• 1994

In this study, hydraulic characteristics for upstream migration of fish in a pool-and-weir fishway were analyzed through experiment. The results showed that streaming flow was preferable to plunging flow for upstream migration of fish and it was not good to make an orifice beneath the septum since it generates turbulent jet and eddies. Protrusions on the side wall of fishway were preferable to grooves since they decelerate flow velocity and make upstream migration easy. A vertically movable septum was necessary for a flushing of deposited bed material, and net installing over fishway was also needed for birds not to approach the fishway and eat fish.

• Korean Journal of Breeding Science
• /
• v.41 no.4
• /
• pp.635-639
• /
• 2009

A new peanut variety "Pungan"(Arachis hypogaea ssp. hypogaea L.) was developed at the Department of Functional Crop, NICS(National Institute of Crop Science), in Milyang in 2008. It was developed from the cross between the high-yielding cultivar "Saedl" and the very short stem cultivar "Satonoka". "Pungan", a Virginia palnt type, has 20 branches with long ellipseshaped large grains. The 100 grain weight was 88 g, 7 g heavier than the check variety Daekwang. This variety is more resistant to late leaf spot and web blotch compared to Daekwang, a check variety. Moreover, it is lodging resistant owing to its short stem. "Pungsan" outyielded the check variety by 16% with 4.67 MT/ha in regional yield trials.