• Title/Summary/Keyword: peak strength

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Does Kinesio Taping Improve Vertical Jumping Performance?

  • Lim, Hyoung-Won
    • The Journal of Korean Physical Therapy
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    • v.28 no.5
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    • pp.269-273
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    • 2016
  • Purpose: This study was conducted to examine the effect of kinesio taping (KT) on vertical jumping performance. Methods: Young women (n=24) performed vertical jumping under three conditions: kinesio taping, placebo taping, and no taping. All tapes were applied to both quadriceps and the gastrocnemius of the subjects. Vertical jump height and power were measured using an OptoGait, and the non-parametric Friedman test was used to identify differences between conditions. Results: No significant differences in maximum jump height or peak jump power between were observed between taping conditions. Conclusion: The results showed that KT did not facilitate muscle performance by generating higher jumping power or yielding a better jumping performance. As the functional performance is related to muscle strength, this finding may be explained by the fact that KT has no effects on muscle strength.

A Method on the Control of Hydration Heat of Mass Concrete Considering the Difference of Setting Time (응결시간차를 활용한 매스콘크리트의 수화열 조정공법)

  • 심보길;윤치환;한민철;김기철;오선교;한천구
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.379-384
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    • 2001
  • This Paper Presents field application test results of mass concrete using super retarding agent. The field test was carried out at mat foundation(thickness 1m) of newly constructed information center of Chongju university. Placing lift composed of 2 layers, and each layer is 50cm. Fly ash and flowing method is also applied. Difference of setting time of concrete between with super retarding agent and without super retarding agent is considered. Concrete without super retarding agent is placed at upper layer and with super retarding agent at lower layer According to test results, the reducing method of hydration heat considering difference of setting time with super retarding agent can reduce the highest temperature about 3~4$^{\circ}C$, and delay the peak time about 3~4days. Compressive strength using super retarding agent is somewhat higher than that of normal concrete. Accordingly, super retarding agent does not affect the strength development.

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

  • Yun Hyun Do;Yang Il Seung;Han Byung Chan;Hiroshi Fukuyama;Cheon Esther;Moon Youn Joon
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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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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Corrective TIR Determination with Reflecting Effectiveness and Adjusting Relationship Strength

  • Kim, Yong-pil;Yun, Deok-gyun
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2001.10a
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    • pp.31-34
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    • 2001
  • The customer unsatisfaction in the new products exists, though the most of enterprises using QFD. It is mainly caused by the failure of corrective determination of technical importance rating(TIR). To derive the technical importance rating, the impact of the fulfillment of design requirements on the satisfaction of customer requirements must first be quantified. This has been accomplished through the use of a 1-3-9 or a 1-5-9 scale and ignored the peak of the house of quality(HOQ). In this paper we suggested the methodology reflecting effectiveness among engineering characteristics and adjusting the relationship strength between customer attribute(CA) and engineering characteristic (EC), by using limit probability and PCMR(pairwise comparison and median rank). With using this method, the determination of TIR would be more suitable for the voice of customers objectively. Here negative correlation is ignored.

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Seismic Performance Evaluation of Existing Buildings Using Equivalent Double Diagonal Strut Model for Corrugated Steel Plate Walls (파형강판벽의 등가 양방향 대각 스트럿 모델을 이용한 기존 건물의 내진성능 평가)

  • Lee, Chang-Hwan;Son, Joo-Ki
    • Journal of Korean Association for Spatial Structures
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    • v.20 no.1
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    • pp.87-94
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    • 2020
  • A corrugated steel plate wall (CSPW) system is advantageous to secure the strength and stiffness required for lateral force resistance because of its high out-of-plane stability. It can also stably dissipate large amounts of energy even after peak strength. In this paper, a preliminary study has been carried out to use the CSPW system in the seismic retrofit of existing reinforced concrete (RC) moment frame buildings. The seismic performance for an example building was evaluated, and then a step-by-step retrofit design procedure for the CSPW was proposed. An equivalent analytical model of the CSPW was also introduced for a practical analysis of the retrofitted building, and the strengthening effect was finally evaluated based on the results of nonlinear analysis.

A Study on the strength improvement in weldment by the impact loading (충격하중에 의한 용접구조물의 강도 증가에 관한 연구)

  • 양영수
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.3
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    • pp.76-82
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    • 2000
  • It is well known that during the oxygen cutting process residual thermal stresses are produced in weldment. The local non-uniform heating and subsequent cooling which takes place during any welding process causes complex thermal strains and stresses to finally lead to residual stresses exceed to the yield stress. High tensile stresses combined with applied structural load in the region near the welded joint can given rise to distortion brittle fracture change of the fatigue strength and stress corrosion cracking. The appropriate treatment of the welded component which reduces the peak of he welding residual stresses is believed to lower risk of the fracture during the service of the structure. In this study the impact loading in oxygen cutting frame was applied to reduce the residual stress. After applying the impact loading redistribution of resid-ual stress was measured by cutting method and the effect of fatigue was tested.

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Strength and Ductility of R/C Columns with Welded Reinforcement Grids(II) - Focused on Comparisons with Columns Confined by Conventional Reinforcement (용접 띠철근으로 보강된 철근콘크리트 기둥의 강도와 연성(II) - 보편적인 띠철근 보강 기둥과의 비교를 중심으로)

  • ;Murat Saatcioglu;Mongi Grira
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.10a
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    • pp.561-568
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    • 1997
  • Conventional confinement reinforcement for rectangular columns consist of closely spaced perimeter hoops, overlapping hoops, and crossties. One of the potential alternatives to conventional reinforcement is a welded reinforcement grid, prefabricated to required size and volumetric ratio of transverse reinforcement. An experimental investigation was carried out to investigate the strength and deformability of reinforced concrete columns confined with welded reinforcement grids. The comparisons of the envelopes of experimental force-displacement hysteric relationships for columns confined by welded grids with analytically generated force-displacement curves for columns confined with conventional ties. In general, inelastic deformability beyond the peak, as indicate by the slope of the cuvers, was similar to those indicated by columns with conventional ties. The superior performance of columns with welded grids may be attributed to the improved confinement characteristics of grids associated with increased rigidity of welded ties.

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Effects of Anisotropic Consolidation on Flow Failure Behavior of a Silty Sand (이방압밀이 실트질 모래의 유동파괴거동에 미치는 영향)

  • 강병희;김방식;정혁일
    • Journal of the Korean Geotechnical Society
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    • v.17 no.5
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    • pp.173-180
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    • 2001
  • 이방압밀이 실트질모래의 정적재하에 의한 유동파괴거동에 미치는 영향을 연구하기 위하여 비배수삼축압축시험을 수행하였다. 이를 위하여 상대밀도가 약 17%인 공시체를 습윤다짐방법에 의해서 성형하고 4가지의 압밀응력비, 1.0, 0.7, 0.55, $K_{o}$ 로서 압밀시켰다. 시험결과로서 정상상태선은 p-q 공간상에서 압밀응력비에 관계없이 유일한 직선이며 collapse line의 기울기는 압밀응력비가 증가함에 따라 선형적으로 감소한다는 사실을 보여준다. 또한, 유동파괴거동을 보이는 느슨하게 다져진 실트질모래의 잔류강도($S_{us}$ )와 첨두강도($S^{p}$ )와의 관계는 압밀응력비의 크기에 관계없이 $S_{p}$ /$p_{c}$ = $A_{L}$ +$B_{L}$ ($S_{us}$ /$p_{c}$ )로 표현되는 일반식으로 나타낼 수 있으며 계수 $A_{L}$$B_{L}$은 압밀응력비의 크기에 따라 선형적으로 변하는 경향을 나타낸다.

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The Influence of the BTA on Electrical Properties of Synthetic Fluids (합성절연유의 전기적 특성에 미치는 BTA의 영향)

  • Shin, Jong-Yeol;Shin, Hyun-Teak;Hong, Jin-Woong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.2
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    • pp.162-166
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    • 1998
  • Synthetic fluid, class 7 group 2, as an insulating and cooling material is selected as. specimen, arid it is studied for the physical and electrical properties. Also, Benzotriazole(following as BT A) known as a suppressant of streaming electrification is added to it, and the change of physical and electrical properties by addition of BT A is investigated. From the spectrum of FT-IR, it is confirmed that the absorption peak in wavenumbers $3400{\sim}3450[cm^{-1}]$ is small or disappears when BTA is added. AC breakdown strength and volume resistivity of each specimen are investigated. It is considered that the effective content of BTA is about 10[ppm] for the suppression of electrification in this experiment.

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Effect of Heat Setting on Physical Properties of Dyeable Polypropylene Fabric (Dyeable polypropylene 직물의 열처리에 따른 물성변화)

  • Lee, Shin-Hee
    • Fashion & Textile Research Journal
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    • v.11 no.3
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    • pp.481-487
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    • 2009
  • The purpose of this study is to improve the defects of dyeable polypropylene(DPP) fabric by heat setting and to describe the change of physical properties of DPP fabrics. The thermosetting was carried out in autoclave from 100 to $140^{\circ}C$ temperature range for 2 min. In this study, we investigated the effect of the thermosetting temperatures on the structural, thermal, mechanical properties(e.g., the strength and elongation) and dyeability of DPP fabrics. The melting energy(J/g), the tensile strength was found to increase with increasing temperature of thermosetting. The diffraction peak at Bragg angle($2{\theta}$) about $13.8^{\circ}$ were very strong and diffraction intensity increased with increasing thermosetting temperatures. And d-spacing and half-width decreased with increasing thermosetting temperatures. On the other hand, the dyeability(K/S) and crease recovery decreased with an increasing thermosetting temperatures.