• Title/Summary/Keyword: 연성재하

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An Empirical Study on the Effect of Service Quality Factor on Customer Satisfaction and Repurchases (서비스 품질요인을 활용한 고객만족 및 재이용 의도에 미치는 영향에 관한 연구)

  • Lim, Bu-Young;Kim, Youn-Sung;Lee, Dong-Won;Park, Woon-Yong
    • Proceedings of the Korean Society for Quality Management Conference
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    • 2006.04a
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    • pp.54-65
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    • 2006
  • Since the ending of the IMF period, the Korean health industry has experienced a number of changes in its environment such as hospital bankruptcy, enforcement of SDF(Separation of Dispensing and Prescription), opening of the medical market by WHO, evaluation of medical institutions with more than 100 sick beds, and limited approval for medical service advertisement. Furthermore, the concept of medical service has changed from a beneficent and vortical one to a hi lateral and righteous one. These changes in medical service have required medical institutions to provide customers with medical service options and adopt market principles actively, while considering customer satisfaction. Thus, this paper aims to investigate the service quality and service value of medical institutions, to understand the mutual relationship between customer satisfaction and repeat visits, and to suggest better solutions for the improvement of service quality. For future studies, It will be necessary to overcome the limitations of this research and develop proper measurement tools on service quality in the Korean medical system.

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평판구조물의 진동 및 음향방사 - 통계적 접근

  • 강준수;김정태;김관주
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1996.10a
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    • pp.113-117
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    • 1996
  • 구조물의 진동에 의해 소음이 방사되는 현상은 기계에서 소음의 발생원으로 볼 수 있기 때문에 기게류의 소음을 예측하거나 저감방안을 제시하기 위해서는 구조물의 동특성과 방사특성을 이해하고 있어야 한다. 특히, 엔진블럭, 펀치프레스, 배의 갑판구조물등과 같은 대다수의 소음 발생기계는 평판의 형상을 가진 구조물로서 기계적인 충격 등에 의해 그 표면에서 소음이 발생되므로 강성을 증가시키고, 소음저감을 목적으로 빔과 같은 보강재를 통해 보강되어 있다. 그런데, 해석적인 방법으로는 평판이나 원판 또는 구와 같은 단순한 형태의 특정구조물에 대해서만 그 결과를 얻을 수 있으므로 이와 같은 불연속 평판구조물의 진동 및 방사특성은 평판에 대한 순수 이론으로는 해석이 곤란하여 따라서 본 연구에서는 수치해석적인 방법을 통해 이를 해결하고자 하였다. 수치해석적인 방법으로는 유한요소법(FEM)과 경계요소법(BEM), 및 통계적 에너지 해석기법(SEA)등이 있으며 구조물의 진동-소음연성문제의 경우에 있어서는, 진동해석을 FEM과 SEA으로, 공기 중에서의 방사현상은 BEM으로 예측하고 있다. 본 연구에서는 재질이 균일한 얇은 2차원 평판구조와 보강평판에 대해서 진동특성은 유한요소해석 프로그램을 사용하여 해석하였으며 이때의 진동특성값을 입력데이터로 사용하여 경계요소해석 프로그램으로 방사효율 등을 예측하였다. 또한 이 과정에서 2차원 평판구조의 모우드 밀도와 가진점 모빌리티의 실수값이 가지는 평균치의 물리적 특성을 분석하였으며, 추후 실험을 통해 이를 검증코자 한다.

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The Comparison of Plantar Pressure on Double Limb Support and Single Limb Support according to Soft Surface (연성면에 따른 양발지지와 한발지지 시 족저압 비교)

  • Lee, Jeon-Hyeong;Chung, Hyeung-Jae;Kim, Shin-Gyun
    • PNF and Movement
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    • v.11 no.2
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    • pp.95-102
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    • 2013
  • Purpose : The purpose of this study was to investigate a plantar pressure distribution and the trajectory of the center of pressure on double limb support and single limb support according to level surface, air cushion, and aero step. Methods : 21 healthy adults participated in this study. The plantar pressure were assessed at three different surface conditions(on the level surface, air cushion, and aero step) on double limb support and single limb support. Testing orders were selected randomly. Results : Plantar pressure distribution show a significant difference contact area 1 and contact area 3 on double limb support and single limb support. The trajectory of the center of pressure show an significant difference anteroposterior(AP), mediolateral(ML), and total displacement on double limb support and single limb support. Conclusion : Through the use of soft surface as air cushion and aero step will be using the ankle strategy. This will be to strengthen the muscles around the ankle. Consequently, should help to improve stability and coordination.

A Study on the Strengthening Effect of Reinforced Conctete BeamsFlexural Strengthening after Pre-loading (선가력 후 휨 보강한 RC보의 보강 효과에 관한 연구)

  • Kim, Jeong-Sup;Sin, Yong-Seok;Jo, Cheol-Hee;Kim, Kyoug-Ok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.6
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    • pp.183-190
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    • 2006
  • From the result of this research above, it may be summed up as follows. As a summary of results from each experiment, as the test body reinforced with the carbon rods was embedded inside the concrete section and made it possible uniform movement, this study has shown that it had excellent characteristics in improving the flexural strength and ductility. Also, it was considered as the carbon-steel sheet composite plate was to exert the strength more if it would complement the adherence with the concrete.

Numerical study for Application of H-Pile Connection Plastic Sheet Pile Retaining Wall (HCS) (H-Pile과 Plastic Sheet Pile을 결합한 토류벽체에 대한 수치해석적 연구)

  • Lee, Kyou-Nam;Lim, Hee-Dae
    • The Journal of Engineering Geology
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    • v.27 no.3
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    • pp.331-343
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    • 2017
  • In this study to improve stability, workability and economics of the H-Pile+Earth plate or H-Pile+Earth plate+Cutoff grouting currently in use, we had developed HCS method belonging to the retaining wall which is consisting of a combination H-Pile, Plastic Sheet Pile and Steel Square Pipe for gap maintenance and reinforcement of flexible plastic Sheet Pile, and the behavior of each member composing HCS method is investigated by three-dimensional finite element analysis. To numerically analyze the behavior of the HCS method, we have performed extensive three-dimentional finite element analysis for three kinds of plastic Sheet Pile size, two kinds of H-Pile size and three kinds of H-Pile installation interval, one kinds of Steel Square Pipe and three kinds of Steel Square Pipe installation interval. After analyzing the numerical results, we found that the combinations of $P.S.P-460{\times}131.5{\times}7t$ (PS7) and H-Pile $250{\times}250{\times}9{\times}14$ (H250), $P.S.P473{\times}133.5{\times}9t$ (PS9) and H-Pile $300{\times}200{\times}9{\times}14$ (H300) is the most economical because these combinations are considered to have a stress ratio (=applied stress/allowable stress) close to that as the stiffness of H-Pile, plastic Sheet Pile and Steel Square Pipe composite increased, the horizontal displacement of the retaining wall and the vertical displacement of the upper ground decreased. Especially, due to the arching effects caused by the difference in stiffness between H-Pile and plastic Sheet Pile, a large part of the earth pressure acting on plastic Sheet Pile caused a stress transfer to H-Pile, and the stress and displacement of plastic Sheet Pile were small. Through this study, we can confirm the behavior of each member constituting the HCS method, and based on the confirmed results of this study, it can be used to apply HCS method in reasonable, stable and economical way in the future.

A Study on the Advantage with Staged Construction Procedures and Full-Height Rigid Facing of Geosynthetic Reinforced Soil Retaining Walls (보강토옹벽에서 단계시공과 일체형 강성벽체의 이점에 관한 연구)

  • Won, Myoung-Soo;Kim, You-Seong;Tatsuoka, Fumio
    • Journal of the Korean Geosynthetics Society
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    • v.6 no.3
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    • pp.17-23
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    • 2007
  • To construct an ideal geosynthetic reinforced soil retaining wall (GRS-RW), the facing of the wall should be flexible enough to accommodate a large deformation of the supporting ground and to develop the large tensile force in reinforcements during wall construction as long as the stability is ensured, but should be rigid enough to be stiff and stable as well as durable and aesthetically acceptable for a long life time when the wall is in service. Facing conditions during the construction and service of the wall are quite different. So it is difficult to be satisfied all these conditions with the current construction method which is mainly used in reinforced wall construction in Korea. Most of this contradiction could be solved by the staged construction procedure. According to the results of cases and references analyses, stage construction procedures make it possible to accommodate large deformation of the supporting ground and backfill without losing the stability of the wall, and to derive the tensile strength of reinforcement causing deformation of the facing. When the facing is a full-height rigid one, it also appeared almost impossible to occur a local shear failure of the active zone, and pull-out failure of reinforcements. Therefore, GRS-RWs having a full-height rigid facing have been constructed by the staged construction procedures that matched well with the theory of reinforced soil, which had outstanding stability and durability, and thus could be used for railways and bridge abutments in Korea in the future.

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Effect of Freeze-Thaw Cycles after Cracking Damage on the Flexural Behavior of Reinforced Concrete Beams (균열손상 후 동결융해를 경험한 철근콘크리트 보의 휨거동)

  • Kim, Sun-Woo;Choi, Ki-Bong;Yun, Hyun-Do
    • Journal of the Korea Concrete Institute
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    • v.22 no.3
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    • pp.399-407
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    • 2010
  • The flexural behaviors of two types of beam members exposed to freeze-thaw cycles were evaluated. This study aims to examine the effect of freeze-thaw cycles on the behavior characteristics of reinforced concrete (RC) beams. For the purpose, a part of the beam specimens were damaged until yielding of tension reinforcement was reached, before they were exposed to 150 and 300 cycles of freeze-thaw. Cyclic tests, as well as monotonic tests, were conducted to evaluate the stiffness degradation characteristics when same cycle is repeated. The material tests showed that relative dynamic modulus of concrete exposed to 300 cycles of freeze-thaw moderately decreased to 86.8% of normal concrete, indicating that concrete used in this study has good durability against freeze and thaw damage. The results of monotonic tests showed reduction of flexural strength, ductility and stiffness of the beam specimens exposed to freeze-thaw cycles compared with those of the control speciments. In particular, BDF13 specimens, which had been subjected to artificial cracking damage, did not showed enough flexural strength to satisfy nominal moment required by current concrete structure design code. In the monotonic tests results, BF75 specimens exposed to freeze-thaw cycles showed 10% or more cyclic stiffness degradation. Therefore, it was thought that deformation of concrete in compression have to be considered in design process of members under cyclic load, such as seismic device.

Characteristics of Early-Age Restrained Shrinkage and Tensile Creep of Ultra-High Performance Cementitious Composites (UHPCC) (초고성능 시멘트 복합체의 초기 재령 구속 수축 및 인장 크리프 특성)

  • Yoo, Doo-Yeol;Park, Jung-Jun;Kim, Sung-Wook;Yoon, Young-Soo
    • Journal of the Korea Concrete Institute
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    • v.23 no.5
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    • pp.581-590
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    • 2011
  • Since ultra-high performance cementitious composites (UHPCC) not only represents high early age shrinkage strain due to its low water-to-binder ratio (W/B) and high fineness admixture usage but also reduces the cross section of structure from the higher mechanical properties, it generally has more shrinkage cracks from the restraints of formwork and reinforcing bars. In this study, free and restrained shrinkage experiments were conducted to evaluate the suitability of incorporating both expansive admixture (EA) and shrinkage reducing agent (SRA). The test results indi-cated that approximately 40~44% of free shrinkage strain was decreased. Also, the results showed that 35% and 47% of residual tensile stresses were relieved by synergetic effect of SRA and EA, respectively. Residual tensile stresses from ringtest were relaxed by approximately 61% and 64% of elastic shrinkage stresses due to SRA and EA, respectively, because of the tensile creep effect. Therefore, the creep effect should be considered to precisely estimate the restrained shrinkage behavior of concrete structures. The degree of restraint of UHPCC was approximately in the range of 0.78~0.85. The addition of combined EA and SRA showed minute influence on the degree of restraint. However, the effect decreased when thicker concrete ring was used. Tensile creep strains were measured and compared to the predicted values from 4-parametric prediction model considering time dependent restrained forces.

Performance Evaluation of Underground Pipe with In-Situ Recycled Controlled Low Strength Materials (현장발생토사 재활용 유동성채움재를 이용한 지하매설관의 거동평가)

  • Lee Kwan-Ho;Song Chang-Seob
    • International Journal of Highway Engineering
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    • v.8 no.2 s.28
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    • pp.1-12
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    • 2006
  • An existing Steel pipe, Cast iron pipe and Concrete pipe is can not escaped from aging, specially Metal tube is causing many problems that the quality of water worse is concerned about many rust and mike efficient use of preservation of water. The use of Glassfiber Reinforced Plastic Pipe(GRP PIPE) should be one of the possible scheme to get over these problems. The GRP PIPE has an excellent resistance power and the life is lasting from 50 to 100 years roughly. It's to be useful as a result of high durability and a good construction work also it is a light weight therefore can be expected to short the time of construction and man power. In this research, to executed the small-scaled model test, in-situ model test using CLSM of in-situ soil and to evaluated the stress - strain of the pipe also try to estimated how useful is. From the model test in laboratory, the vertical and horizontal deformation of the GRP PIPE measured in six instance using 200mm and 300mm in diameters. The value of experimentation, theory, analysis got the same results of the test, but the vertical and horizontal deformation gauged in small and the earth pressure was almost zero using CLSM of in-situ soil..

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Improvement of Consolidation Characteristics around PVD Using the Thermal Method (열적 방법을 이용한 연직배수재 주변의 압밀특성 연구)

  • Bergado, Dennes T.;Shin, Eun-Chul;Park, Jeong-Jun
    • Journal of the Korean Geotechnical Society
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    • v.23 no.10
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    • pp.5-11
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    • 2007
  • This paper is to investigate the removal of the smear at elevated temperatures. This study utilized both small cylinder cell and large consolidometer apparatus to investigate the combination of PVD with heat and without heat. Two types of heaters are used in this study. The heater drain made of copper tube is used for all tests except large consolidometer and flexible wire heater is used for large consolidometer. Specimens demonstrated volume contraction upon heat and without heat. This contraction is dependent on temperature magnitude. When the specimen is heated, the magnitude of settlements is higher and rate of consolidation is faster. After treatment using PVD combined without heat and with heat for undisturbed specimens the $C_h$ values obtained were $3.45m^2/yr$ and $3.83m^2/yr$, respectively, from $3.2m^2/yr$ before treatment. The $K_h/K_s$ ratios were 3 for the specimen without heat and 2 for the specimen with heat. Similarly, in reconstituted specimens without heat and with heat, the $C_h$ values were $2.1m^2/yr$ and $2.5m^2/yr$ with $K_h/K_s$ ratios of 1.75 and 1.5, respectively.