• Title/Summary/Keyword: impact tests

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Impact of Nurse Educators' Competency on Job Satisfaction (교육전담간호사 역량이 업무만족도에 미치는 영향)

  • Si, Eun Young
    • Journal of Korean Clinical Nursing Research
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    • v.30 no.2
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    • pp.84-93
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    • 2024
  • Purpose: The purpose of this study was to investigate the impact of nurse educators' competency on their job satisfaction. Methods: The subjects of this study were nurses in charge of nursing education at the general hospital level or higher organization. Data were collected via an online survey from May 3 to May 20, 2024, from 91 respondents. The survey questionnaires included general characteristics, competency, and job satisfaction. Descriptive statistics, Pearson's correlation coefficients, t-tests, and simple linear regression were performed using SPSS 21. Results: There was a positive correlation between nurse educators' competency and job satisfaction. Specifically, professional knowledge (r=.47, p<.001), research competency (r=.47, p<.001), task standardization competency (r=.46, p<.001), communication skills (r=.42, p<.001), and educational implementation competency (r=.42, p<.001) showed positive correlations with job satisfaction. The differences in competency based on completing the advanced nurse training course was not significant (t=-1.46, p=.149). However, competency level was found to significantly affect job satisfaction (β=.49, p<.001). Conclusion: The study highlights the need for competency-based education programs to strengthen nurse educators' qualifications systematically.

The Inflence of Excavation Damaged Zone around an Underground Research Tunnel in KAERI (한국원자력연구원 내 지하처분연구시설 주변의 암반 손상대 영향 평가)

  • Kwon, S.;Kim, J.S.;Cho, W.J.
    • Explosives and Blasting
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    • v.26 no.2
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    • pp.11-19
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    • 2008
  • The development of an excavation damaged zone, EDZ, due to the blasting impact and stress redistribution after excavation, can influence on the long tenn stability, economy, and safety of the underground excavation. In this study, the size and characteristics of an EDZ around an underground research tunnel, which was excavated by controlled blasting, in KAERI were investigated. The results were implemented into the modelling for evaluating the influence of an EDZ on hydro-mechanical behavior of the tunnel. From in situ tests at KURT, it was possible to determine that the size of EDZ was about l.5rn. Goodman jack tests and laboratory tests showed that the rock properties in the EDZ were changed about 50% compared to the rock properties before blasting. The size and property change in the EDZ were implemented to a hydro-mechanical coupling analysis. In the modeling, rock strengths and elastic modulus were assumed to be decreased 50% and. the hydraulic conductivity was increased 1 order. From the analysis, it was possible to see that the displacement was increased while the stress was decreased because of an EDZ. When an EDZ was considered in the model, the tunnel inflow was increased about 20% compared to the case without an EDZ.

Performance Evaluation for All-In-One Construction Method of Curbstone and Gutter Using Formwork Rail and Jig (거푸집 레일과 지그를 이용한 경계석 및 측구의 일체형 시공법에 대한 성능평가)

  • Choi, Jae-Jin;Ko, Man-Gi;Kim, Kyoung-Ju;Choi, Khyung-Dong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.6A
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    • pp.525-534
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    • 2010
  • A road curbstone is a structure installed at the boundary of the sidewalk and the street with the objectives of road drainage, drawing attention and such. The current general construction method of curbstones places foundation concrete for the curbstones first, waits until the concrete reaches the strength to support the curbstones, places the curbstones on top, and then places the gutter and rear filling concrete. Such method has the issues of poor compaction and weakened bond strength of concrete due to split placing of concrete, and causes the curbstones to easily separate due to vehicle impact or earth pressure, in turn creating maintenance costs and spoiling the aesthetics. To improve such conventional construction methods, an all-in-one method was developed using formwork rail and jig where both the curbstones and gutter can be worked at the same time, and to evaluate the structural performance, static tests of lateral loading test, pullout test, and bending test were executed, and dynamic tests such as pendulum test and actual vehicle impact test were executed. In all tests, the all-in-one construction method using formwork rail and jig was shown to be superior to the conventional construction method by the increase of construction quality and bond strength of concrete.

Investigating the Influence of Rate Dependency and Axial Force on the Seismic Performance Evaluation of Isolation Bearing (면진받침의 내진성능평가를 위한 실험 시 속도의존성과 수직하중의 영향)

  • Minseok Park;Yunbyeong Chae;Chul-Young Kim
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.6
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    • pp.22-29
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    • 2023
  • In the evaluation of seismic performance for structural materials and components, the loading rate and axial force can have a significant impact. Due to time-delay effects between input and output displacements, It is difficult to apply high-rate displacement in cyclic tests and hybrid simulations. Additionally, the difficulty of maintaining a consistent vertical load in the presence of lateral displacement has limited fast and real-time tests performed while maintaining a constant vertical load. In this study, slow, fast cyclic tests and real-time hybrid simulations were conducted to investigate the rate dependency and the influence of vertical loads of Isolation Bearing. In the experiment, the FLB System including an Adaptive Time Series (ATS) compensation and a state estimator was constructed for real-time control of displacement and vertical load. It was found that the vertical load from the superstructure and loading rate can have a significant impact on the strength of the seismic isolation bearing and its behavior during an earthquake. When conducting experiments for seismic performance evaluation, they must be implemented to be similar to reality. This study demonstrates the excellent performance of the system built and used for seismic performance evaluation and enables accurate and efficient seismic performance evaluation.

Experimental Study to Evaluate Thermal and Mechanical Behaviors of Frozen Soils according to Organic Contents (유기물 함유량에 따른 동토 시료의 열적·역학적 거동 평가를 위한 실험적 연구)

  • Sangyeong Park;Hyeontae Park;Hangseok Choi;YoungSeok Kim;Sewon Kim
    • Journal of the Korean Geosynthetics Society
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    • v.23 no.2
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    • pp.53-62
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    • 2024
  • Recently, development of non-traditional energy such as oil sands has been actively conducted in the cold region such as Canada. Frozen soil has different thermal and mechanical characteristics from general soil due to its high organic contents. This study evaluated the impact of organic matter content on the thermal and mechanical behavior of frozen soil samples collected from Alberta, Canada, and Gangwon Province, South Korea. As the organic content increases, the maximum dry unit weight decreases and the optimum moisture content increases in compaction tests. In uniaxial compression tests under frozen conditions, the strength of the frozen specimens increased as the temperature decreased. The strength of Canada soil sample increased with higher organic matter content at low temperatures. However, the strength of frozen soil was not significantly affected by organic matter content due to the complex behavior and unfrozen water content. Thermal conductivity tests showed higher thermal conductivity in frozen conditions compared to unfrozen conditions, due to the higher thermal conductivity of ice compared to water. These findings provide essential data for geotechnical design and construction in large-scale projects such as oil sands development in cold regions. Further research is needed to explore the impact of organic matter content on different types of frozen soils.

A Study of Dynamic Behavior of Segmental U-shaped Prestressed Concrete Girder Applied with Integrated Tensioning Systems (복합긴장방식이 적용된 세그멘탈 U형 거더 동적 거동 특성 연구)

  • Hyunock Jang;Ilyoung Jang
    • Journal of the Society of Disaster Information
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    • v.20 no.2
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    • pp.369-378
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    • 2024
  • Purpose: This study aims to verify structural stability by manufacturing a 40m full-scale specimen composed of a segmental U-shaped PSC girder with integrated tensioning systems and a concrete slab, proceeding dynamic behavior tests, and compare the results of the tests with the results of numerical analysis. Method: Dynamic behavior tests were conducted on a full-scale, undamaged specimen using an impact hammer, and the natural frequency and damping ratio were measured and compared with numerical analysis techniques and the general damping ratio of the facilities. Result: The natural frequency of the numerical analysis model consisting of a girder and slab composite section was calculated to be 2.561Hz, the natural frequency of the full-scale specimen was measured to be 2.670Hz, and the damping ratio was calculated to be 0.42~0.68%. Conclusion: The natural frequency of the full-scale specimen was found to be 4.3% larger than that of the numerical analysis model. Since the masses of the full-scale specimen and the numerical analysis model are the same as 99.97%, it can be derived that the stiffness of the full-scale specimen has secured structural safety and stability. As a result, the dynamic behavior stability of the specimen was verified. The measured damping ratio of 0.42~0.68% was found to be a stable dynamic behavior compared to the PSC structures damping ratio of 0.5~1.0% in the elastic region.

Flexural and Impact Resisting Performance of HPFRCCs Using Hybrid PVA Fibers (하이브리드 PVA 섬유를 이용한 HPFRCCs의 휨 및 충격 성능 평가)

  • Kim, Young-Woo;Min, Kyung-Hwan;Yang, Jun-Mo;Yoon, Young-Soo
    • Journal of the Korea Concrete Institute
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    • v.21 no.6
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    • pp.705-712
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    • 2009
  • HPFRCCs (high-performance fiber reinforced cementitious composites), which is relatively more ductile and has the characteristic of high toughness with high fiber volume fractions, can be used in structures subjected to extreme loads and exposed to durability problems. In the case of PVA (polyvinyl alcohol) fiber, it is noted by former studies that around 2% fiber volume fractions contributes to the most effective performance at HPFRCCs. In this study, flexural tests were carried out to evaluate the flexural behavior of HPFRCCs and to optimize mix proportions. Two sets of hybrid fiber reinforced high performance specimens with total fiber volume fraction of 2 % were tested: the first set prepared by addition of short and long PVA fibers at different combination of fiber volume fractions, and the second set by addition of steel. In addition, in order to assess the performances of the HPFRCCs against to high strain rates, drop weight tests were conducted. Lastly, the sprayed FRP was applied on the bottom surface of specimens to compare their impact responses with non-reinforcing specimens. The experimental results showed that the specimen prepared with 1.6% short fibers (REC 15) and 0.4% long fiber (RF4000) outperformed the other specimens under flexure, and impact loading.

A Study on the Effect of Real Estate Policy on Real Estate Price: Focusing on Tax Policy and Financial Policy (부동산정책이 부동산가격에 미치는 영향에 관한 연구: 조세정책과 금융정책 중심으로)

  • Jin-O Jung;Jae-Ho Chung
    • Land and Housing Review
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    • v.14 no.3
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    • pp.55-75
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    • 2023
  • Based on prior studies on real estate policy, tax policy, and financial policy, this study examined how tax policy and financial policy affected real estate prices using monthly data from January 2014 to December 2021. We performed a VAR model using unit root tests, cointegration tests, as well as conducted impulse response analysis and variance decomposition analysis. The results are as follows. First, the tax regulation index and the financial regulation index had no discernible impact on housing prices. Specifically, a one-sided stabilizing regulatory policy was ineffective and, instead, led to unintended side effects, such as price increases resulting from reduced transaction volume. Secondly, mortgage rates had a negative impact on the housing sale price index. In other words, an increase in interest rates might led to a decrease in housing prices. Thirdly, an increase in the transfer difference, which involves capital gains tax, has a positive effect on housing prices. This led to rising housing prices because the transfer taxes were shifted to buyers, causing them to hesitate to make purchases due to the increased tax burden. Fourthly, both acquisition taxes and mortgage loans had relatively little impact on housing prices.

Pier-Scour Characteristics of the Marine Bridge with Ship Impact Protection - Incheon Bridge Case - (선박충돌방지공이 설치된 해상교량의 교각 세굴 특성 분석 - 인천대교를 대상으로 -)

  • Yeo, Woon-Kwang;Ji, Un;Kim, Chang-Sung;Lim, Jong-Chul
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.20 no.2
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    • pp.203-211
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    • 2008
  • More recently, the massive marine bridges in a ship passage have been constructed on the sea. Therefore, the ship impact protection for the bridge-piers are installed to consider the possibility of vessel collision danger. Due to the ship impact protection, the pier-scour characteristics are changed in comparison with the condition without the ship impact protection (SIP). In this study, the physical modeling for the Incheon Sea-Crossing Bridge was performed to analyze the pier-scour characteristics with respect to the vessel collision protection. The rigid and movable bed tests were conducted to evaluate the flow pattern, scour depth, and scourhole with and without the ship impact protection. The experimental results for the maximum scour depth is increased 0.24 m in W1 pier at the same location and 2.4 m in W2+3+4 piers due to the SIP installation. Especially, the maximum scour depth in W2+3+4 piers was occurred around the SIP.

A Study on Characteristics of Passenger Injury for Effective Impact Speed in Vehicles Frontal Collision and Rear-ender (차량 정면충돌 및 추돌시 유효충돌속도에 따른 탑승자 상해특성에 관한 연구)

  • Cho, Joeng-Kwon;Yoon, Jun-Kyu;Lim, Jong-Han
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.4
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    • pp.239-247
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    • 2015
  • Recently, various research studies on frontal collision and rear-ender which occur more frequently compared to others are underway as the public interest on them is growing. This study analyzes scientifically the relationship between effective impact speed and injury incidence for vehicle crash accident reconstruction and presents a relevant model formula. Because real vehicle experiments have certain limitations such as possible injuries, this study efforts to collect and analyze as many materials as possible to substitute real vehicle experiments, including data from various collision tests and human experiments. As a result, this study present a threshold in which head-on collisions and rear impacts do not cause injuries under 7 km/h of effective impact speed, and suggests a model formula showing that injury extent is linearly proportional to effective impact speed through collision speed and amount of plastic deformation. In conclusion, a model formula for estimating effective impact speed and injury incidence newly proposed in this study is expected to be used as a minimum standard of judgment in disputes on the injury extent of passenger in head-on collisions and rear impacts. Furthermore its availability in terms of technological analysis in legal arguments is expected to be very high if this study will be enhanced by referring to scientific analyses of various real accidents so as to apply it in various types of collision accidents.