• 한국응급구조학회지
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• 제10권3호
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• pp.71-85
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• 2006

Purpose: The purpose of this study is to investigate the relationship among the variables, personality type, stress, and job satisfaction in firefighters. Methods: The questionnaire research was conducted for field service firefighters who work in two cities for the period of June 20, 2005 through July 20, 2005. A total number of 308 data were used for this analysis. For analysis of the data, the SPSSWIN 10.0 program was used to analyze descriptive statistics, correlation analysis, t-test and one-way ANOVA. Results: The mean score of subjects' stress was 3.30 and the mean score of job satisfaction was 2.86. There were significant differences on stress and job satisfaction by general characteristics. Stress was significantly differed by field of working. Job satisfaction was significantly differed by marital status and field of working. Also, there were significant differences on stress and job satisfaction by characteristics related to working. Stress was significantly differed by sleeping time at night shift, witness their superior's or companion's death or injury, and a threat to death or injury. Job satisfaction was significantly differed by an aptitude for field of working and wish to change the field of working. But there was no significant differences on stress and job satisfaction by personality type. There was statistically significant negative correlation between stress and job satisfaction. Conclusion: Strategies that can decrease their stress need to be developed to increase job satisfaction.

• 한국생산제조학회지
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• 제21권5호
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• pp.733-740
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• 2012

This paper studies with structural and vibration analysis to evaluate the structural safety according to the types of steering wheels. This study models are two, three and four spoke types. As the number of spokes increases, the maximum equivalent stress becomes smaller but the maximum total deformation becomes a little higher. The natural frequency at three models are shown from 180 to 230Hz as the maximum deformation. The frequency responses as maximum amplitude displacement are happened at 200Hz, 500Hz and 500Hz respectively. In this study, the steering wheel with three spoke type is shown to become suitable at durability and production.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1995년도 추계학술대회논문집
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• pp.76-85
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• 1995

The general equation of homogeneous strin for tube drawing has been derived. This can be applied to the general tube drawing method for non-zero plug angle. Also, the derived equation can represent Blazynski's equations for the sinking and tube drawing with a constant plug diameter. The general tube drawing was divided into two steps, sinking and contact drawing zones. The derived equation can calculate the homogeneous strains of the two steps. The various tube drawing methods such as fixed tapered plug, fixed mandrel, fixed back tapered plug, and floating plug have been analysed by the equation and finite element analysis. From the FEM calculations, the total strains and drawing stresses are obtained and consequently the redundancy factor of various drawing methods was analysed. The fixed back tapered plug method showed the largest redundancy factor and the floating plug method had the largest drawing stress.

• 한국콘텐츠학회논문지
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• 제14권2호
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• pp.319-329
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• 2014

본 연구는 청소년의 가족기능, 충동성, 스트레스가 집단따돌림 유형에 미치는 영향을 파악하기 위한 서술적 조사연구이다. 연구대상은 중 고등학생 627명으로, 수집된 자료는 SPSS 18.0 program을 사용하여 평균과 표준편차, t-test, Pearson's Correlation Coefficient 및 stepwise multiple regression analysis으로 분석하였다. 연구결과는 다음과 같다. 집단따돌림 유형(가해 및 피해)은 가족기능, 충동성, 스트레스와 상관관계가 있는 것으로 나타났다. 집단따돌림 가해에 영향을 미치는 요인은 가족기능의 하부요인에서 정서적 반응성, 충동성의 하부영역에서 무계획 충동성, 스트레스의 하부요인에서 친구관련 스트레스, 일반적 특성에서 음주경험(있음), 부모 우울문제 경험(있음)로 확인되었으며, 34.1%의 설명력을 나타내었다. 집단따돌림 피해에 영향을 미치는 요인은 가족기능의 하부요인에서 의사소통, 충동성의 하부영역에서 운동 충동성, 스트레스의 하부요인에서 친구관련 스트레스, 일반적 특성에서 성별(남학생), 학년(중학생)으로 확인되었으며, 30.9%의 설명력을 나타내었다. 결론적으로 본 연구는 청소년의 집단따돌림 유형(가해 및 피해)에 가족기능, 충동성, 스트레스의 역할을 실증적으로 확인하였다는 점과 청소년의 집단따돌림 유형에 따른 중재방안의 기초 자료를 제공하였다는 점에서 의의를 찾을 수 있다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.121-121
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• 2017

The productivity of rice has been influenced by various abiotic factors including temperature which cause to limitations to rice yield and quality. Rice yield and quality are adversely affected by high temperature globally. In the present study, four Korean four cultivars such as Dongan, Ilpum, Samkwang, Chucheong were investigated in order to explore molecular mechanisms of high temperature at seedling stage. Rice seedlings grown at $28/20^{\circ}C$ (day/night) were subjected to 7-day exposure to $38/28^{\circ}C$ for high-temperature stress, followed by 2-D based proteomic analysis on biological triplicates of each treatment. The growth characteristics demonstrated that Dongan is tolerant while Ilpum is sensitive to high-temperature stress. High temperature has an adverse effect in the seedling stage both in high temperature sensitive and tolerant cultivar. Two-dimensional gels stained with silver staining, a total of 722 differential expressed protein spots (${\geq}1.5-fold$) were identified using Progenesis SameSpot software. However, a total of 38 differentially expressed protein spots were analyzed by LTQ-FT-ICR MS. Of these, 9 proteins were significantly increased while 10 decreased under high-temperature treatment. Significant changes were associated with the proteins involved in the carbohydrate metabolism, photosynthesis, and stress responses. Proteome results revealed that high-temperature stress had an inhibitory effect on carbon fixation, ATP production, and photosynthetic machinery pathway. The expression level of mRNA is significantly correlated with the results obtained in the proteome investigation. Taken together, these findings provide a better understanding of the high-temperature resistance by proteomic approaches, providing valuable insight into improving the high-temperature stress tolerance in the global warming epoch.

• 한국생산제조학회지
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• 제22권1호
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• pp.70-76
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• 2013

This study investigates structural durability through the analyses of stress, fatigue life and vibration damage at bike carrier basket. As model 2 has less stress and deformation than model 1 on static structural analysis, model 2 becomes more durable than model 1. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. The amplitude deformations become highest at maximum response frequency of 2400Hz in cases of models 1 and 2. As the values of maximum equivalent stresses become within the allowable material stresses at two holes at the upper parts on models 1 and 2, these models become safe. The structural result of this study can be effectively utilized with the design of bike carrier basket by investigating prevention and durability against fatigue or vibration damage.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.434-438
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• 2006

The purpose of this paper is that investigates the Natural Frequency behavior characteristic of Wind Turbine Jacket Type Tower model, and calculated that the stress values of Thrust Load, Wave Load, Wind Load, Current Loda, Gravity Load, etc., environment evaluation analysis during static Operating Wind Turbine Jacket Type Tower model, carried out of Natural Frequency analysis of total load case to stress matrix, Frequency calculated that calculated Add Natural Frequency to stiffness matrix for determinant to stress results. The finite element analysis is performed with commercial F.E.M program (ANSYS) on the basis of the natural frequency and mode shape.

• 한국소음진동공학회논문집
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• 제17권2호
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• pp.130-135
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• 2007

The purpose of this paper is that investigates the Natural Frequency behavior characteristic of wind turbine jacket type tower model, and calculated that the stress values of thrust load, wave load, wind load, current loda, gravity load, etc., environment evaluation analysis during static operating wind turbine jacket type tower model, carried out of natural frequency analysis of total load case to stress matrix, frequency calculated that calculated add natural frequency to stiffness matrix for determinant to stress results. The finite element analysis is performed with commercial F.E.M program (ANSYS) on the basis of the natural frequency and mode shape.

• 한국생산제조학회지
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• 제23권5호
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• pp.471-477
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• 2014

The purpose of this study was to predict the load effect on a damper installed at a nuclear power plant building after a tsunami using a volume of fluid (VOF) numerical analysis method. The wave height was determined by a sine wave function and the tsunami condition was estimated by the wave length. Also, using computational fluid dynamics (CFD), the maximum damper load was set as a boundary condition for the structural analysis that verified how stress and deformation affect the damper. As a result, such simulations estimated the highest stress distribution for a wave length of 350 m with a maximum stress present at the cross point of stiffness installed at the rear end of the damper. The total deformation was approximately 32 mm at the center of damper.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 춘계학술대회 논문집
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• pp.620-625
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• 1995

Finite element analysis tool was developed to analyze the casting process. Generally, casting processes consists of mold filling and solifification. In order to investigate the effects of process variables and to predict the defects, both filling and solidiffication process were simulated simultaneously. At filling process, especiallywe consider thermal coupling to investigate thermal history of material during the filling stage. And thermal condition at the final stage of filling is used as the initial conditions in a solidification process for the exact simulation of the actual casting processes. At mold filling process, Lagrangian-type finite element method with automatic remashing scheme was used to find the material flow. To avoid numerical instability in low viscous fluid, a perturbation method with artificial viscosity is adopted. At solififfication process, enthalpy-based finite element method was used to solve the heat transfer problem with phase change. And elastic stress analysis has been performed to predict the thermal residual stress. Through the FE analysis, solidiffication time, position of solidus line, liquidus line and thermal residual stress are studied. Finite element tools developed in this study will be used process design of casting process and maybe basic structure for total CAE system of castigs which will be constructed afterward.