• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.20-27
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• 2009

This paper presents an analytic study for replacement of the ballast track in existing subway bridge by the Precast slab panel(B2S) track. To evaluate the dynamic responses on application of B2S track, the time history analysis with the 3D modeling. A total of two models, which were one ballast track bridge and B2S track bridge, were used in the FE analysis. The results of this study show that the dynamic displacement and acceleration of the B2S track bridge were significantly reduced for a higher train speed, compared to the ballast track bridge. Also, the replacement of the ballast track bridge in existing subway bridge by the B2S track increased the structural safety of bridge and ensured sufficient dynamic stability and serviceability. As a result, the servicing subway bridge with B2S track system has need of the reasonable measures which could be reducing the static and dynamic response and improving the performance.

• 동력기계공학회지
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• 제17권5호
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• pp.30-37
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• 2013

For vessels operating in the cold climate regions, the ballast water inside or hopper tanks above the waterline may be frozen, starting at the top of the tank and at the side walls. Therefore, countermeasures against freeze-up of the ballast tank such as air-bubbling system, hot steam injecting system, heating coil system and water circulating system are taken to prevent freeze-up phenomenon; however, there are no rigorous investigations of anti-freezing to examine the effectiveness and validity of systems against freeze-up of the ballast tank, in which the temperatures are about -$25^{\circ}C$ (ambient air temperature) and $0^{\circ}C$ (sea water), respectively. In this paper, to ensure reasonable specifications for cold regions if the measures from the above-mentioned systems against freeze-up are effective, the phenomenon of ballast tank freeze-up is simulated and discussed in low temperature conditions. With the results using the commercial CFD code, CFX 14, the most cost-effective solution is conducted to prevent being frozen along the outer surface.

• 한국지능시스템학회논문지
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• 제6권2호
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• pp.43-51
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• 1996

퍼지제어에서 퍼지규칙은 퍼지제어기의 제어결정을 내리는데 중요한 역할을 한다. 그래서, 제어성능은 주로 퍼지규칙의 질에 의해서 결정된다. 본 논문에서 우리는 교차와 돌연번이의 확률이 적응적으로 변화되는 유전자 알고리즘을 사용하여 퍼지규칙을 최적화 하는 방법을 기술한다. 또한 본 논문에서 우리는 플랜트의 응답을 듀개의 부분으로 나누어 제어 목적을 만족하게 하는 적합도 측정 방식을 제안한다. 좀더 빠른 해답을 얻기 위해 우리는 초기의 퍼지규칙으로 무작위적인 규칙을 사용하지 않고 자동으로 퍼지규칙을 생성하는 방법을 사용하여 초기 퍼지규칙으로 사용했다. 이렇게 얻어진 퍼지규칙이 좋은 것인지를 보여주기 위해 비선형 플랜트를 이용하여 시뮬레이션 해보았다. 시뮬레이션 결과 우리의 방법이 합리적이고 유용한 것임이 밝혀졌다.

• 간호행정학회지
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• 제22권4호
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• pp.362-372
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• 2016

Purpose: The aim of this study was to investigate whether job satisfaction in clinical nurses was dependent on work intensity and whether physical discomfort mediated the relationships between these variables. Methods: Structural equation modeling was used with a sample of 253 clinical nurses from four general hospitals. In the model, absolute work intensity, relative work intensity, and flexibility were considered as exogenous variables and physical discomfort as a mediating variable. Data were collected using self-report measures such as the Labor Intensity Questionnaire, the Rating of Perceived Exertion, and the Index of Job Satisfaction. Results: The results of the structural equation modeling found that the higher scores on absolute and relative work intensity were positively associated with physical discomfort but only relative work intensity was significantly related to job satisfaction. Physical discomfort mediated the relationships between absolute work intensity and job satisfaction and between relative work intensity and job satisfaction. Among three kinds of work intensity, only relative work intensity had direct and indirect effects on job satisfaction. Conclusion: The findings suggest that increase in relative work intensity might play an important role in decreasing job satisfaction in clinical nurses and a reasonable reward system considering relative work intensity could be necessary.

• 가족자원경영과 정책
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• 제8권2호
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• pp.27-42
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• 2004

The objective of this study is to induce the importance of manners through the relation between the implementation of manners and degree of life satisfaction in adolescents and to examine positive variants that can enhance degree of life satisfaction A total of 413 questionnaires were used as the final data for this study. The results of the study are as follows. 1. The implementation of manners in adolescents was just above the median. In particular, the lowest sector was in public manners and communication manners requiring intensive activation measures. The variables influencing the results were the score, internal-external control, perceptiveness to the importance of propriety 2. On the level of satisfaction with life as a general, the study showed reasonable standards. The variables influencing the results were the score, internal-external control, gender-role attitudes, perceptiveness to the importance of propriety. Also, considering that implementation of manners contributed to enhancing the level of satisfaction, the establishment of a healthy manners culture of adolescents in required.

• 재활복지공학회논문지
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• 제4권1호
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• pp.35-41
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• 2010

의료장비의 발달로 인해 병원에서의 영상진단, 고주파 수술기를 통한 위생적 치료, 고주파 온열기를 통한 암 치료 등 우리 생활에 가까운 곳에서 고주파를 이용한 의료기기들이 넓게 활용되고 있는 시점에 고주파를 이용한 응용기기들 간의 RF상호 간섭 문제에 대한 대책이 미흡한 실정이다. "그러므로 향후기술개발과 고주파응용 의료기기의 산업발전에 문제가 될 수 있는 요인을 방지하기 위하여 고주파응용의료기기의 사용 현장에서 발생될 수 있는 상호 간섭 문제를 합리적이고 적합한 시험방법개발이 필요하다." 본 논문에서는 고주파응용 의료기기에 대한 상호 간섭문제를 해결하기위해 전자파 평가를 위한 표준시험방법을 연구하였다.

• 한국태양에너지학회 논문집
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• 제30권6호
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• pp.89-94
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• 2010

A large portion of the energy cost of a building is cooling and heating to maintain a comfortable indoor environment. Air conditioning is now one of the important parts in the building design, as increase in energy consumption and pollutant emission in energy conversion process. In this study, elements that affects the energy consumption of model building are identified and the perfomance analysis of the alternative a Low Energy Cooling Systems considering characteristics of model building and energy saving performance is analyzed. In this study, elements that affect the energy consumption of office building are identified and energy saving performance of the alternative air conditioning system is analyzed. As a result, applied to earn and suggest basic data for energy saving measures. In this study, EnergyPlus simulation program was used to evaluate the energy load when alternative Low Energy Cooling Systems are applied to the model building. The reliability of simulation program is verified by comparing actual energy load from operation data of building management office and predicted energy load using simulation program. For Low Energy Cooling System application which considers the purpose and characteristics of the building, reasonable and energy-saving air conditioning method obtained by analyzing energy consumption elements for each expected air conditioning methods is used to deduct result of this study.

• 대한간호학회지
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• 제48권2호
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• pp.195-207
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• 2018

Purpose: The purpose of the study was to develop and test a model for predicting problem gambling in speculative game users based on Blaszczynski and Nower's pathways model of problem and pathological gambling. Methods: The participants were 262 speculative game users recruited from seven speculative gambling places located in Seoul, Gangwon, and Gyeonggi, Korea. They completed a structured self-report questionnaire comprising measures of problem gambling, negative emotions, attentional impulsivity, motor impulsivity, non-planning impulsivity, gambler's fallacy, and gambling self-efficacy. Structural Equation Modeling was used to test the hypothesized model and to examine the direct and indirect effects on problem gambling in speculative game users using SPSS 22.0 and AMOS 20.0 programs. Results: The hypothetical research model provided a reasonable fit to the data. Negative emotions, motor impulsivity, gambler's fallacy, and gambling self-efficacy had direct effects on problem gambling in speculative game users, while indirect effects were reported for negative emotions, motor impulsivity, and gambler's fallacy. These predictors explained 75.2% problem gambling in speculative game users. Conclusion: The findings suggest that developing intervention programs to reduce negative emotions, motor impulsivity, and gambler's fallacy, and to increase gambling self-efficacy in speculative game users are needed to prevent their problem gambling.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.437-446
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• 2006

The major objective of this study is to investigate the effects and application of improvement for railway steel plate girder bridge by resilient panel track system. It analyzed the mechanical behaviors of steel plate girder bridge with applying resilient panel track system on the finite element analysis and laboratory test for static & dynamic characteristics. As a result, the improvement of steel plate girder bridge with resilient panel track systems are obviously effective for the static & dynamic response which is non-ballast steel plate girder bridge. The analytical and experimental study are carried out to investigate resilient panel track system decrease vertical acceleration and deflection on steel plate girder bridge for serviceability. And the resilient panel track system reduced dynamic maximum displacements(about 59%) and stresses(about 82%), the increase of dynamic safety is predicted by adopting resilient panel track system. From the dynamic test results of steel plate girder bridge, it is investigated that vertical acceleration and deflection is very low with applying resilient panel track system. The servicing steel plate girder bridge with resilient panel track system has need of the reasonable improvement measures which could be reducing the effect of static and dynamic behavior that degradation phenomenon of structure by an unusual response characteristic and a drop durability.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.514-521
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• 2006

In strengthening structure, the external post-tensioning method which secure clearness in the structure analysis process is adopted to bridge as well as architecture structure. Therefore, the major objective of this study is to investigate the effects and application of external post-tensioning method for steel plate girder bridge. It analyzed the mechanical behaviors of steel plate girder bridge with applying external post-tensioning on the finite element analysis and laboratory test for the dynamic characteristics. As a result, the reinforcement of steel plate girder bridge the external post-tensioning method are obviously effective for the response which is non-reinforced. The analytical and experimental study are carried out to investigate the post-tension force decrease stress and deflection on steel plate girder bridge for serviceability. It is investigated that the change degree of natural frequency is very low with applying the external post-tensioning method. The servicing steel plate girder bridge with external post-tensioning is the reasonable reinforcement measures which could be secured the stability of dynamic behavior and increase a dropped durability.