• Title/Summary/Keyword: Long-term Behavior

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Experimental study on long-term behavior of prestressed steel I-beam-concrete composite beams

  • Sung, Deokyong;Hong, Seongwon
    • Steel and Composite Structures
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    • v.42 no.5
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    • pp.671-683
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    • 2022
  • To investigate and predict the long-term time-dependent behavior, such as creep, shrinkage, and relaxation of PS strands, and prestress loss in prestressed steel-concrete composite beams, named Precom, full-scale tests were conducted and the collected data were compared with those obtained from the two proposed analytical models. The combined effective modulus method (EMM)-empirical model proposed with a flowchart considered the creep effect to determine the prestress loss. Conversely, the age-adjusted effective modulus method (AEMM) with CEB-FIP equation was developed to account for the concrete aging. The results indicated that the AEMM with CEB-FIP model predicts the long-term behavior of Precom effectively.

A 12-year long-term study on the external deformation behavior of Geosynthetic Reinforced Soil (GRS) walls

  • Won, Myoung-Soo;Lee, O-Hyeon;Kim, You-Seong;Choi, Se-Kyung
    • Geomechanics and Engineering
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    • v.10 no.5
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    • pp.565-575
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    • 2016
  • Geosynthetics reinforced soil (GRS) walls constructed on weak grounds may change in both the horizontal earth pressure and deformation on wall facing. However, only few studies were done in the literature to measure and analyze the horizontal external deformation behavior of GRS walls constructed on soft grounds for a long period of time. The present study describes the external deformation behavior of GRS walls observed for 12-year long-term performance. The horizontal deformation of the geosynthetics-wrapped-facing GRS walls shows a passive behavior along one third of the wall height, from top going downwards, and active behavior for the rest of the wall height. Even if the geogrid and nonwoven geotextiles are exposed directly to sunlight and rainfalls in a span of 12 years, they have functioned well as wall facing. Therefore, the geosynthetic reinforcement material is strong enough to resist ultraviolet rays.

The Long-Term Effect of Pleasantly Designed Interior on Pro-spatial Behavior in Institutional Residence Dining Room-Times Series Analysis of Long Term Field Experiment Data- (시설주거 식당공간의 쾌적성 변화가 아동의 친공간적 행동에 미치는 장기적 영향-장기 현장실험연구 자료의 시계열 분석-)

  • 이연숙;이선미;안지영
    • Korean Institute of Interior Design Journal
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    • no.3
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    • pp.91-99
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    • 1994
  • The purpose of this study was to determine the long term effect of a pleasantly designed interior on pro-saptial behavior. For pleasantly designed interior, the existing interior was remodeled through the change of finishing materials for major architectural elements such as wall, floor and ceiling, and changes of furniture and it's arrangement . Pro-spatial behavior was operationalized as seat arranging behavior and measured through the arranged condition and observable arranging behavior. Time-series design, one of quasi-experimental design was used. The data in this study were extracted from an existing field experimental research. Five hundred survey video tapes record during 2 years period were used. In conclusion, the pleasantly designed environment has a long term effect on the pro-spatial behavior change . While self-centered pro-spatial was improved continuously and even reinforced , altruistic pro-spatial behavior was improved but diminished as time passed. There were no differences in the effect between male and female children. The result of the research provide scientific background of an answer to why Interior Design.

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The Influencing Factors on Infection Management Behavior of Health Worker in Long Term Care Facilities (장기요양시설 요양보호사의 감염관리 수행에 영향을 미치는 요인)

  • Kim, Kyoung Ja;Park, Sung Won
    • Journal of Home Health Care Nursing
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    • v.23 no.2
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    • pp.155-165
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    • 2016
  • Purpose: The purpose of this study was to investigate factors influencing health workers' infection management behavior in long-term care facilities. Methods: A descriptive cross-sectional survey was conducted with 180 health workers who are employed in long-term care facilities. The data were collected from April, 25 until July, in 2016. Results: Infection management behavior positively correlated with the perceived importance of infection management (r=.77, p<.001), but role conflict negatively correlated with infection management behavior (r=.28, p<.001). The hierarchical regression model with general characteristics (first step) and perceived importance of infection management, work environment, and role conflict (second step) against infection management behavior was statistically significant (F=31.93, p<.001). This model could explain 62.8% of infection management behavior ($R^2=.62$, ${\Delta}R^2=.39$). Particularly, perceived importance of infection management was identified as factors influencing infection management behavior(${\beta}=.70$, p<.001). Conclusion: The findings of this study imply that systemic education about infection control and monitoring should be considered, so as to encourage proper infection management behaviors among health workers in long-term care facilities.

Prediction of Long-Term behavior of polyethylene pipe buried underground (지중매설 폴리에틸렌 관의 장기거동 예측)

  • Lee, Jae-Ho;Kim, Bin;Yoon, Soo-Hyun;Kim, Eung-Ho
    • Journal of Korean Society of Water and Wastewater
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    • v.31 no.1
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    • pp.7-12
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    • 2017
  • Most of existing buried pipes are composed of reinforced concrete. Reinforced concrete pipes have many problems such as aging, corrosion, leaking, etc. The polyethylene (PE) pipes have advantages to solve these problems. The plastic pipes buried underground are classified into a flexible pipe. National standard that has limited the long-term vertical deformation of the pipe to 5% for flexible pipes including PE pipe. This study presents a prediction for the long-term behavior of the polyethylene pipe based on ASTM D 5365. This prediction method is presented to estimate by using the statistical method from the initial deflection measurement data. We predict the behavior of long-term performance on the double-wall pipe and multi-wall pipe. As a result, it was found that the PE pipe will be sound enough more than 50 years if the compaction of soil around the pipe is more than 95% of the standard soil compaction density.

Long-term Behavior of IPC Girder Bridge (IPC 거더 교량의 장기거동 해석)

  • 권승희;김진근;이상순;한만엽
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.107-112
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    • 2001
  • The IPC(Incremental Prestressed Concrete) which is gradually introducing the tensile force by tendons has been recently developed for reducing the effective depth of PSC bridges. As well known, concrete experiences long-term deformation such as creep and drying shrinkage, and the prediction of the long-term behavior of concrete bridges is essential for both safety and serviceability aspects. This paper was analysed the long-term behavior of a continuous 2-span IPC girder bridge taking into consideration of creep, drying shrinkage and the time of tensile force introduction. As results, the shrinkage of slab concrete increases the negative moment at interior support, and the The difference of concrete ages between slab and girder increases the camber. The effect of initial tensile force is larger than the effect of secondary tensile force in the tendons.

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Lateral long term behavior for web direction of Driven H-Piles in Embankment (성토지반에 타입된 H 말뚝의 약축방향에 대한 횡방향 장기지지거동)

  • 박영호;정경자;김낙영;황영철
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.06a
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    • pp.43-56
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    • 2002
  • To find a lateral long term behavior of driven H-piles in embankment, inclinometer is installed at pile and measurement is done during a year. When behavior of measured slope angles is in accord with behavior of nonlinear p-y curves(Reese, Murchison and O'Neil, Matlock's p-y analysis), maximum displacement of pile head, maximum stress and maximum bending moment of pile obtained from the numerical analysis are shown. As results, maximum lateral displacement at pile head, maximum stress and maximum bending moment of pile are shown linear behavior, And maximum lateral load, maximum lateral displacement, and maximum bending moment at pile obtained from the numerical analysis are 8∼12.4tonf, 9∼10.1㎜, and 10.39∼12.67tonf-m per pile according to the curves, respectively.

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Factors Influencing Care workers' Intention of Implementing Hand Hygiene in Long-term Care Hospitals (요양병원 간병 인력의 손 위생 이행의도에 영향을 미치는 요인)

  • Han, Mi-Hee;Choi, So-Eun
    • Research in Community and Public Health Nursing
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    • v.31 no.3
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    • pp.375-383
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    • 2020
  • Purpose: The purpose of this study was to investigate factors influencing care workers' intention of hand hygiene implementation in long-term care hospitals. Methods: A total of 180 care workers working at long-term care hospitals were recruited. Data collection was done from July 22 to September 7, 2018. Results: The significant TPB variables influencing the intention of hand hygiene implementation were perceived behavior control (β=.41, p<.001), normative belief (β=.28, p<.001) and attitude toward behavior (β=.15, p=.014). These factors explain 39% of care workers' intension of implementing hand hygiene in long-term care hospitals. Conclusion: In order to strengthen the commitment of hand hygiene, it is necessary to have a positive attitude toward hand hygiene by eliminating the obstacles to hand hygiene.

Experimental Study on Long-term Behavior of RC and SRC Columns (RC 기둥과 SRC 기둥의 장기거동에 관한 실험적 연구)

  • 권승희;김진근;정한욱
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.481-486
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    • 2003
  • This paper presents experimental study on long-term behavior of RC and SRC columns. Shrinkage and creep tests were performed for two types of concrete used in manufacturing RC and SRC column specimens. Also, long-term tests under sustained load were carried out for RC and SRC column specimens. Shrinkage functions and creep coefficients to optimally fit the corresponding data were obtained from regression analysis and the regression results, ACI and CEB- FIP 90 model were applied to analyse long-term behvavior of RC and SRC column specimens. Creep coefficients calculated from test data were lower than those predicted by ACI and CEB-FIP 90 models. Long-term analysis results for RC and SRC column specimens using the regression results were relatively more accurate than those obtained using the existing models.

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Effect of Long-term Care Worker's Person-Centered Care on Service Quality of long term care facility -Focusing on mediating effects of long term care worker's emotional labor and job satisfaction- (요양보호사의 인간중심케어와 서비스 질의 관계 -요양보호사의 감정노동과 직무만족의 매개효과 중심-)

  • Song, Myeong-Seop;Rhee, Young-Sun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.3
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    • pp.476-484
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    • 2021
  • In this study, we analyze the relationships between long-term care workers' person-centeredness and job satisfaction, emotional labor, and service quality. Self-administered questionnaires were used to collect data from 460 long-term care workers in long-term care facilities. In the research model, person-centered care was verified using independent variables, with emotional labor (surface behavior, internal behavior) and job satisfaction applied as parameters, and service quality applied as a dependent variable. The results of this study are as follows. First, the fit of the model is good. Second, the implicit behavior of emotional labor is found to be an important factor affecting service quality. Also, emotional labor is an important mediator, improving the value of person-centered care and service quality. There is a positive correlation between internal behavior and service quality, and a negative correlation between surface behavior and service quality. Third, emotional labor (surface behavior, internal behavior) is the most influential variable in terms of service quality. The results of this study demonstrate the necessity to pay clinical and academic attention to person-centered care in terms of long-term care workers' emotional labor and service quality.