• 제목/요약/키워드: tension ratio

검색결과 718건 처리시간 0.026초

ROM(Reducing Opposed Multilobed) 피판을 이용한 중간 크기 피부병변의 치험례 (ROM(Reducing Opposed Multilobed) Flap Repair for the Treatment of Medium Sized Skin Lesion)

  • 조종제;홍윤기;서상원;장충현
    • Archives of Plastic Surgery
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    • 제33권6호
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    • pp.748-752
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    • 2006
  • Purpose:Circular skin lesions between 10 and 35 mm in diameter generate problems often. Direct closure of the lesion risks excessive wound tension or wound dehiscence. Skin grafts heal slowly and often remain unsightly. Traditional skin flaps have a limited role. We treated this circular medium-sized skin lesion(10 - 35 mm sized) by reducing opposed multilobed(ROM) flap. Methods: ROM flap involves a series of semicircular lobes extending both cephalic and caudal from the defect. Direction of the semicircular multilobed flap is set parallel to relaxed skin tension line(RSTL) to minimize scar formation. First semicircle is drawn 60% in diameter of the defect. Second semicircles are drawn at the cephalic and caudal aspects of the original semicircles. These semicircles are 60% in diameter of the first semicircle. Additional semicircles are repeatedly drawn until the tension of skin flaps becomes free. ROM flap has a length-to-base ratio of 0.5 resulting in lower theoretical risk of end flap necrosis than a random pattern flap with a large ratio. The technique involves lobes most distant from the primary defect being transposed in turn closer to the defect. Results: The ROM flap reduces skin tension concerns, lowers the risk of flap necrosis and allows for quicker and more aesthetic healing. Results were generally good and major complications, such as dehiscence, infection, or delayed healing, did not occur. Conclusion: ROM flap repair allows the plastic surgeon an additional option when faced with a circular medium-sized skin lesion.

슈퍼자미를 첨가한 생면 파스타의 품질특성 (Quality Characteristics of Fresh Pasta Containing Various Amounts of Superjami)

  • 노재승;박기홍
    • 한국조리학회지
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    • 제19권5호
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    • pp.184-195
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    • 2013
  • 본 연구는 생면 파스타 제조 시 슈퍼자미를 첨가하여 파스타의 품질과 관능적 특성을 높이려는데 그 목적이 있다. 슈퍼자미 가루를 밀가루 대신 0%, 10%, 20%, 30%, 40%를 대체하여 시료로 준비하였다. 슈퍼자미 첨가량이 증가할수록 수분, 중량 및 부피, adhesiveness 및 인장 길이가 높아졌고, 반면에 L, a, b값, hardness, chewiness 및 인장 강도는 낮아졌다. 특성차이검사 결과 슈퍼자미 첨가량이 증가할수록 색의 강도, 슈퍼자미 향, 구수한 향, 슈퍼자미 맛, 구수한 맛, 입자감 및 삼킨 후의 느낌이 유의적으로 강하다고 평가되었다. 기호도 검사 결과 슈퍼자미 20%를 첨가한 것이 외관, 향, 맛, 조직감 및, 전체적인 기호도에서 가장 좋다고 평가되었다. 따라서 본 연구의 결과 생면 파스타 제조 시 슈퍼자미를 첨가할 때에 20%를 첨가하는 것이 가장 최적이라고 사료되었다.

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Long-term condition monitoring of cables for in-service cable-stayed bridges using matched vehicle-induced cable tension ratios

  • Peng, Zhen;Li, Jun;Hao, Hong
    • Smart Structures and Systems
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    • 제29권1호
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    • pp.167-179
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    • 2022
  • This article develops a long-term condition assessment method for stay cables in cable stayed bridges using the monitored cable tension forces under operational condition. Based on the concept of influence surface, the matched cable tension ratio of two cables located at the same side (either in the upstream side or downstream side) is theoretically proven to be related to the condition of stay cables and independent of the positions of vehicles on the bridge. A sensor grouping scheme is designed to ensure that reliable damage detection result can be obtained even when sensor fault occurs in the neighbor of the damaged cable. Cable forces measured from an in-service cable-stayed bridge in China are used to demonstrate the accuracy and effectiveness of the proposed method. Damage detection results show that the proposed approach is sensitive to the rupture of wire damage in a specific cable and is robust to environmental effects, measurement noise, sensor fault and different traffic patterns. Using the damage sensitive feature in the proposed approach, the metrics such as accuracy, precision, recall and F1 score, which are used to evaluate the performance of damage detection, are 97.97%, 95.08%, 100% and 97.48%, respectively. These results indicate that the proposed approach can reliably detect the damage in stay cables. In addition, the proposed approach is efficient and promising with applications to the field monitoring of cables in cable-stayed bridges.

이축 하중을 받는 콘크리트의 응력-변형률 응답 및 파괴 (Stress-Strain Response and Fracture of a Plain Concrete in Biaxial Loading)

  • 이상근;송영철;권용길;한상훈
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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    • pp.921-926
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    • 2001
  • In this paper the biaxial failure criteria and stress-strain response for plain concrete are studied under uniaxial and biaxial stress(compression-compression, compression-tension, and tension-tension combined stress). The concrete specimens of a square plate type are used for uniaxial and biaxial loading. The experimental data indicate that the strength of concrete under biaxial compression, f2/fl=-l/-1, is 17 percent larger than under uniaxial compression and the poisson's ratio of concrete is 0.1745. On the base of the results, a biaxial failure envelope for plain concrete that the uniaxial strength is 398kgf/$cm^{2}$ are developed. The biaxial failure behaviors for three biaxial loading areas are also plotted respectively. In addition, the characteristics of stress-strain response under biaxial compression are compared and verified with the experimental and analytical results.

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Steel Cord와 PVA 혼합섬유 보강 고인성 시멘트 복합체의 인장강도 특성 (Tensile Strength Characteristics of Steel Cord and PVA Hybrid Fiber Reinforced Cement-Based Composites)

  • 윤현도;양일승;한병찬;복산양;전에스더;문연준
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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    • pp.18-21
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    • 2004
  • This paper discusses how steel cord and PVA hybrid fibers enhance the performance of high performance fiber reinforced cementitious composites (HPRFCC) in terms of elastic limit, strain hardening response and post peak of the composites. The effect of microfiber(PVA) blending ratio is presented. For this purpose flexure, direct tension and split tension tests were conducted. It was found that HFRCC specimen shows multiple cracking in the area subjected to the greatest bending tensile stress. Uniaxial tensile test confirms the range of tensile strain capacity from 0.5 to $1.5\%$ when hybrid fiber is used. The cyclic loading test results identified a unique unloading and reloading response for this ductile composite. Cyclic loading in tension appears not to affect the tensile response of the material if the uniaxial compressive strength during loading is not exceeded.

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인장 굽힘피로를 받는 부재의 피로수명과 균열관통 (Fatigue Life and Peneration Behaviour of Material under Combined Tension and Bending Stress)

  • 남기우
    • 한국해양공학회지
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    • 제8권1호
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    • pp.41-49
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    • 1994
  • The leak-before-break(LBB) design on the large structures such as ship's hull, tank structure, pressure vessels etc. is one of the most inportant subjects for the evaluation and the assurance of safety. In these structures, various loads are acting. In some structural members, therefore, out-of-plane stress due to bending often may become with in-plane stress due to stretching. In the present report, the characteristics of fatigue life and peneration behaviour from a surface cracked plate under combined tension and bending have been studied experimentally and analytically by using eccentricity. Estimation of fatigue crack growth was done with the Newman-Raju formula before penetration, and with the stress intensity factor after penetration proposed by the author. Calculated aspect ratio showed the good agreement with the experimental result. It was also found that particular crack growth behaviour and crack shape after penetration can be satisfactorily evaluated using the K solution proposed.

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Post-cracking behavior of UHPC on the concrete members reinforced by steel rebar

  • Rahdar, H.A.;Ghalehnovi, M.
    • Computers and Concrete
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    • 제18권1호
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    • pp.139-154
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    • 2016
  • Since the concrete strength around the reinforcement rebar affects the tension stiffening, the tension stiffening effect of ultra high performance concrete on the concrete members reinforced by steel rebar is examined by testing the specimens with circular cross section with the length 850 mm reinforced by a steel rebar at the center of a specimen's cross section in this research. Conducting a tensile test on the specimens, the cracking behavior is evaluated and a curve with an exponential descending branch is obtained to explain the post-cracking zone. In addition, this paper proposes an equation for this branch and parameters of equation is obtained based on the ratio of cover thickness to rebar diameter (c/d) and reinforcement percentage (${\rho}$).

Crack Propagation at Boundary Face of Composite Compact Tension Specimen

  • Cho, Jae-Ung;Han, Moon-Sik
    • 한국생산제조학회지
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    • 제22권2호
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    • pp.337-341
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    • 2013
  • In this study, fatigue crack propagation in composite material under fatigue is investigated by simulation result. When another material on the specimen exists vertically to the crack line, the phenomena that crack may go straight or propagate along the boundary face according to the elastic modulus ratio of another material to matrix are investigated with compact tension specimen by compliance method. Crack propagation direction is evaluated by compliance method. By arranging this study result systematically about the crack propagation behavior due to the stiffness of inhomogeneous material, high-tech material (automobile, aircraft and steel industry) can be improved. The estimation of safety design and life (construction & nuclear power station, etc.) will be of great value industrially.

콘크리트 파괴거동특성의 실험적 연구I-이축응력시험 (Experimental Study on Failure Behavior of Plain Concrete - Biaxial Stress Test)

  • 이상근;이상민;박상순;한상훈;송영철
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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    • pp.315-320
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    • 2003
  • Two different strength types of plain concrete plate specimens (200$\times$200$\times$60mm) were tested under different biaxial load combinations. The specimens were subjected to biaxial combinations covering the three regions of compression-compression, compression-tension, and tension-tension. The loading platens with Teflon pads were used to reduce a confining effect in boundary surface between the concrete specimen and the solid platen. The principal deformations in the specimens were recorded, and the failure modes along with each stress ratio were examined. Based on the strength data, the failure envelops were developed for each type of plain concrete. The biaxial stress-strain responses of concrete plate specimens for three biaxial loading regions were also plotted. The test data indicated that the strength of concrete under biaxial compression ($f_2 / f_1$$_1$=-1/-1) is about 17 percent larger than under uniaxial compression.

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Cable Array Robot 시스템 설계 (Design of a Cable Array Robot System)

  • 신동목;이연암
    • 대한조선학회논문집
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    • 제48권4호
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    • pp.375-380
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    • 2011
  • Loading/unloading at sea is necessitated as larger container ships are being used. It is also unavoidable to load/unload at sea during military operations. An experimental cable array robot system, which can be used for loading/unloading at sea, consisting of four cables operated by four motors is designed and built. Even though it has simple structure, it has a large pay-load/robot-weight ratio, flexibility and wide workspace and can be easily built at low cost. In order to plan and control the paths of end-effector, two interpolation methods are introduced and compared. Since the robot is entirely based on cable tension, an analysis of tension is also presented for monitoring and planning purpose.