• Title/Summary/Keyword: 새들

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Erection Sequence Analysis of Suspension Bridge Considering to Sliding of Main Cable (주케이블의 슬라이딩을 고려한 현수교의 시공단계 해석)

  • Yhim, Sung-Soon;Kong, Min-Sik;Kim, Byeong-Cheol
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.13 no.3 s.55
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    • pp.164-172
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    • 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.

Development of the optimal Jig & fixture applied to ultra-precision saddle machining (복합가공기용 초정밀급 새들 가공을 위한 최적의 고정구 개발)

  • Kim, Byoung Chang
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.13 no.3
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    • pp.89-95
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    • 2014
  • The increasing level of demand for multi-tasking machines requires a saddle with an ultra-precise machining accuracy level of $15{\mu}m$, as such a saddle is one of the main components of these machines. The manner of achieving ultra-precise machining accuracy mainly depends on the fixed forces. In this paper, we optimized the number of contact points and the contact positions to reduce the deformation of the saddle while it is machined. The performance levels of the proposed optimal jig and fixture are determined by measuring the flatness, parallelism and perpendicularity of a machined saddle. The machining accuracy is found to be lower than $15{\mu}m$ at all measured points.

해외뉴스

  • Korean Federation of Science and Technology Societies
    • The Science & Technology
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    • v.19 no.1 s.200
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    • pp.33-35
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    • 1986
  • - 되살아나는 프로펠러 비행기 - 전산화된 치과의 - 새들의 음성인식 - 말을 받아쓰는 소프트웨어 - 벽면 보행 로보트 - 정교한 프랑스 톨머신 - 유전공학으로 비타민C의 공법단축

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과학에세이-조류의 성생활 수수께끼

  • Won, Byeong-O
    • The Science & Technology
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    • v.28 no.7 s.314
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    • pp.26-27
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    • 1995
  • 지구상에 있는 9천여종의 새들은 90%이상이 일부일처의 정상적인 혼인생활을 하고 있으며 일부다처나 일처다부 또는 난혼의 형태는 10%미만이다. 바람둥이가 있는가 하면 이혼하는 커플도 있는데 이처럼 다양한 새들의 성생활 현장을 가본다.

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Flexural Strengthening with Wire Rope Using the Tightening Force of Bolts (볼트 조임력에 의한 와이어로프의 휨 보강)

  • Kim, Sun-Young;Song, Jin-Gyu;Lee, Yeong-Wook;Byeon, Hang-Yong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.2
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    • pp.165-176
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    • 2006
  • This paper deals with the experiment and construction case of concrete beams strengthened with wire rope using the tightening force of bolts. The mechanical bolting of wire rope for prestressing force is adopted, which is very easy for construction. For the flexural strengthening effect of the proposed method, the experiment was proceeded as follows. The main parameters of specimens, concrete strength is 24MPa, are initial prestressing forces of wire rope and the number of saddle. The flexural strengths of strengthened specimens compared with non-strengthened test piece were increased about 160%. Also, as the initial prestressing forces were increased, the crack and ultimate moments were increased. The number of saddle did not play an important role for the moment capacity. This proposed method as a construction example showed a more competitive method than any others.

Comparison on Antioxidant Potential of Several Peanut Varieties (땅콩 품종간 항산화 활성 비교)

  • 이승은;박장환;방진기;성낙술;정태영
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.6
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    • pp.941-945
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    • 2004
  • To increase utilities as functional materials, nine peanut varieties were evaluated on antioxidant activity and total phenol content. Peanut varieties were individually divided into three parts such as part without seed coat, seed coat, and seed. Each of the 80% ethanol-extracted solutions from the parts was used for the assay. Inhibitory activities on low density lipoprotein (LDL) oxidation by the part without seed coat, seed coat, and seeds from 9 varieties were respectively 85.3∼91.0%, 77.4∼85.8%, -1.7∼46.1%, and those on linoleic acid oxidation were 94.0∼94.9%, 94.2∼95.0%, 69.4∼80.2%, respectively. Seed coats, parts without seed coat, and seeds from 9 peanut varieties showed scavenging activities as 88.3∼98.7%, 16.7∼56.3%, -28.0∼20.0% on superoxide anion radical and as 89.9∼90.8%, 6.0∼12.0%, 0.6∼2.1% on 1,1-diphenylpicrylhydrazyl (DPPH) radical, respectively. Total phenol contents of seed coat, seed, and part without seed coat were 12.7∼21.0 mg%, 2.46∼4.24 mg%, 0.94∼1.16 mg% as tannic acid equivalent and those of Daekwang, Daesin, Bowon, Saedl, Kipung among the peanut varieties were comparatively high. In conclusion, Daekwang, Daesin, Kipung, and Saedl among the peanut varieties showed comparatively effective antioxidant activities.

봄을 노래하는 새들

  • Yun, Mu-Bu
    • The Science & Technology
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    • v.26 no.4 s.287
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    • pp.31-34
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    • 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.

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마음이 들려주는 이야기 - 파릇 파릇 생기 가~득 초목이 주는 힐링타임

  • Seon, An-Nam
    • 건강소식
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    • v.37 no.4
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    • pp.22-23
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    • 2013
  • 봄이 왔다. 그 길을 걸으면 풀냄새가 난다. 곳곳에 촉촉한 수분감과 흙내음이 가득하다. 초록빛 새순이 어느덧 자라 나무들은 새 옷을 입었다. 나무 곁에서는 이름 모를 곤충이 먹이를 나르고 새들이 저저귄다. 많은 사람들이 초목이 우거진 길을 걷는데 빠져드는 이유는 자연에 몸을 맡기고 몸과 마음에 휴식을 줄 수 있다는 점 아닐까.

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