• 한국해양공학회지
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• 제3권2호
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• pp.125-137
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• 1989

To check technical improvement in the soundness and strength of 12% Cr steel rotor, a 25 tons of rotor with 65 tons of ingot was made in real size and was cut to pieces to take test samples, and the various mechanical tests such as impact, tensile, creep, and fatigue were carried out. The strengths are compared with those of 1% Cr-Mo-V rotor of same size. Microstructures of the samples are examined and reviewed. The results can be summarized as follows. 1) Fracture appearance transition temperatures are 80.deg. C at the center part and 60.deg. C near surface of 12% Cr rotor, and 8.deg. C near surface of 1% Cr-Mo-V rotor. 2) Comparative rapid softening occurs at higher temperatures above 600.deg. C for 12% Cr steel and 550.deg. C for 1% Cr-Mo-V steel in tension tests. 3) Fatigue crack propagation rate of 12% Cr steel is almost same as that of 1% Cr-Mo-V steel at the same corresponding surface part of the rotors. The crack growth rate of center part of 12% Cr rotor is faster than near surface part of the rotor, and the crack growth rate at the load condition of R=0.04 is slower than that of the load condition of R=0.5 for both 12% Cr steel and 1% Cr-Mo-V steel. 4) Crack growth rate of radial direction near surface of 12% Cr rotor is faster than that of transverse direction at the same part because of the difference in residual stresses. 5) Both creep and fatigue strengths of 12% Cr steel are superior to those of 1% Cr-Mo-V steel and the difference is thought the effect of climb and glide controlled creep by solid solution of alloying elements and dispersion of carbides.

• 한국해양공학회지
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• 제3권2호
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• pp.625-625
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• 1989

To check technical improvement in the soundness and strength of 12% Cr steel rotor, a 25 tons of rotor with 65 tons of ingot was made in real size and was cut to pieces to take test samples, and the various mechanical tests such as impact, tensile, creep, and fatigue were carried out. The strengths are compared with those of 1% Cr-Mo-V rotor of same size. Microstructures of the samples are examined and reviewed. The results can be summarized as follows. 1) Fracture appearance transition temperatures are 80.deg. C at the center part and 60.deg. C near surface of 12% Cr rotor, and 8.deg. C near surface of 1% Cr-Mo-V rotor. 2) Comparative rapid softening occurs at higher temperatures above 600.deg. C for 12% Cr steel and 550.deg. C for 1% Cr-Mo-V steel in tension tests. 3) Fatigue crack propagation rate of 12% Cr steel is almost same as that of 1% Cr-Mo-V steel at the same corresponding surface part of the rotors. The crack growth rate of center part of 12% Cr rotor is faster than near surface part of the rotor, and the crack growth rate at the load condition of R=0.04 is slower than that of the load condition of R=0.5 for both 12% Cr steel and 1% Cr-Mo-V steel. 4) Crack growth rate of radial direction near surface of 12% Cr rotor is faster than that of transverse direction at the same part because of the difference in residual stresses. 5) Both creep and fatigue strengths of 12% Cr steel are superior to those of 1% Cr-Mo-V steel and the difference is thought the effect of climb and glide controlled creep by solid solution of alloying elements and dispersion of carbides.

• 대한간호학회지
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• 제24권3호
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• pp.448-460
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• 1994

This study was conducted to investigate risk factors for senile dementia as well as care givers' stresses and thier needs for nursing care. It was done using a retrospective survey. A convenience sample or In senile dementia patients and l20 nor-mal elders in a rural area was used. The tools used in the study were the MMSE-K(Mini-Mental State Examination-Korea) for dementia screening test and a questionaire developed by the research team. Data were collected through home visits by Com-munity Health Practitioners. Data were analyzed using descriptive statistics, T-test, and Chi-square test. The findings are as follows : 1. There were significant differences in age, marital status, and religions between the two groups. 2. There was a significant difference in smoling behavior between the two groups. 3. There was a significant difference in past his-tory of cancer between groups. 4. There was a significant difference in past and present elderftmily relationship between the two groups. 5. There were significant differences in intellectual activities, assuming major role in family and seeking other's help in daily life troubles between the two groups. 6. There were significant differences in stress factors such as child problem, family conflict, health problem and illegal behavior between the two groups. 7. The major problems out by families in caring for dementia patient were catastrophic reactions, dirtiness, mood change, devouring and tremor. The most serious problems faced by families was dirtiness. with catastrophic reactions, sleep distrubance, changeableness, and a suspcio-usness following. The care givers expressed chronic fatigue, anxiety, tension, depression, disorder in daily life, shamefulness, blame from neighbours and guiltiness. 8. There is need for geriatric hospitals, nursing homes, burden sharing, and counselling or education for family care givers. A replicate study in the urban area is recommended to validate the findings of this study. To explore the impact of stress in life and ‘han’ on senile dementia, a qualitative study is recommended.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.153-153
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• 2017

Potato (Solanum tubersosum L.) is susceptible to various environmental stresses such as frost, high temperature, and drought. Enhancement of potato drought tolerance can reduce yield loss under drought that has negative effect on potato tuber growth. Genetic engineering can be utilized to achieve this goal, but such approaches using endogenous potato genes have rarely been applied. Since unpredictable global weather changes cause more severe and frequent water limiting conditions, improvement of potato drought tolerance can minimize such adverse effects under drought and can impact on sustainable potato production. Genetic engineering can be utilized to improve potato drought tolerance, but such approaches using endogenous potato genes have rarely been applied. We were obtained AtbZIP28 gene transgenic potato plants. It is identified transcript levels at various stress conditions, polyethylene glycol (PEG), NaCl, abscisic ${\underline{acid}}$ (ABA). Also, For identification to regulate ER stress response genes in AtbZIP28 gene transgenic potato plant, we screened seven potato genes from RNA-seq analysis under TM treatment. Five and two genes were up- and down-regulated by TM, respectively. Their expression patterns were re-examined at stress agents known to elicit TM, DTT, DMSO and salt stress.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.341-341
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• 2017

Abiotic stress adversely affects crop growth worldwide. Drought of the major abiotic stresses have the most significant impact on all of the crop. The main objective of this study was to assess the effects of drought stress on photochemical performance and vitality of maize (Zea mays L.). The photochemical characteristics were analyzed in the context of period of drought stress during the maize growth. Drought experiment was carried out for four weeks, thereafter, the drought treated maize was re-watered. The polyphasic OJIP fluorescence transient was used to evaluate the behavior of photosystem II (PSII) and photosystem I (PSI) during the entire experiment period. In drought stress, the performance Index (PI) level was reached earlier when compared to the controls. For the screening of drought stress tolerance the drought factor index (DFI) of each variety was calculated as follow DFI= log(A) + 2log(B). All the fourteen cultivars show DFI ranged from -0.69 to 0.30, meaning less useful in selection of drought tolerant cultivars. PI and electron transport flux values of fourteen cultivars were to indicate reduction of photosynthetic performance during the early vegetative stage under drought stress. In conclusion, DFI and energy flux parameters can be used as photochemical and physiological index.

• International Journal of Contents
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• 제5권4호
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• pp.81-87
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• 2009

In the midst of a continued discourse and development concerning design education and its impact on innovation and creativity, I believe that design education still holds the key to enhancing design methodology while increasing creativity by having students take on several creative roles in an interactive and enjoyable studio course. Clearly, there exist impediments that block the creative process in our standard track in design education; however, a course entitled "The Creative Workshop" can overcome such obstacles. Through this course, a student can learn the essential skills of a designer: inventive thinking, a sense of aesthetics, and a spirit of collaboration. In addressing each of the three essential elements, this course has devised role-plays in the way of projects. Simply put, students will be required to demonstrate and, therefore, express their unique creativity that may have otherwise gone muted. Such creative expression can take form in a low stakes, open forum that heralds the invaluable attribute in design such as creative freedom. As a result, the true spirit of creativity is fostered rather than mere aesthetics and styling. Moreover, through role plays, the focus shifts its center from design, allowing each student to explore the uncharted areas of one's own creativity which may come naturally to some extend while disconcerting to others. It may prove particularly uncomfortable for Korean students whose ideas about education have been directly connected to the strict and regimented school system that stresses adherence to standardization such as the national college entrance exam. This course, therefore, is aimed stretch the scope and scale of students' creativity as they learn to collaborate on role plays, utilizing diverse skills from various disciplines.

• Journal of Preventive Medicine and Public Health
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• 제40권5호
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• pp.351-362
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• 2007

Objectives: The present study was intended to assess the mental health of nurses working for university hospitals and to establish which factors determine their mental health. Methods: Self-administered questionnaires were given to 1,486 nurses employed in six participating hospitals located in Daejeon City and Chungnam Province between July 1 st and August 31st, 2006. The questionnaire items included sociodemographic, job-related, and psychosocial factors, with job stress factors (JCQ) as independent variables and indices of mental health status (PWI, SDS and MFS) as dependent variables. For statistical analysis, the Chi-square test was used for categorical variables, with hierarchical multiple regression used for determining the factors effecting mental health. The influence of psychosocial and job-related factors on mental health status was assessed by covariance structure analysis. The statistical significance was set at p<0.05. Results: The factors influencing mental health status among subject nurses included sociodemographic characteristics such as age, number of hours of sleep, number of hours of leisure, and subjective health status; job-related characteristics such as status, job satisfaction, job suitability, stresses such as demands of the job, autonomy, and coworker support; and psychosocial factors such as self-esteem, locus of control and type A behavior patterns. Psychosocial factors had the greatest impact on mental health. Covariance structure analysis determined that psychosocial factors affected job stress levels and mental health status, and that the lower job stress levels were associated with better mental health. Conclusions: Based on the study results, improvement of mental health status among nurses requires the development and application of programs to manage job stress factors and/or psychosocial factors as well as sociodemographic and job-related characteristics.

• 한국구조물진단유지관리공학회 논문집
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• 제13권4호통권56호
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• pp.170-179
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• 2009

복공판은 규격화된 강재를 조합하여 용접에 의해 일체화 시킨 것으로 주로 지하작업공간의 확보, 가설 차도 및 보도의 용도로 사용되며, 지하철, 지하상가 등의 건설을 위한 복개부와 가설교량의 상부구조 등에 적용된다. 이러한 복공판이 부식 손상된 경우에는 정량적인 잔존내하력 평가 없이 육안조사에 의한 판별 후 교체 또는 일정기간 사용 후 교체 등으로 그 기능을 유지하고 있다. 이에 본 연구에서는 부식된 복공판의 지속적 사용한계를 확인하고 경제적이고 효율적인 복공판 교체시기를 결정하기 위하여, 실제 지하철 현장에서 사용되고 있는 부식 손상된 복공판을 대상으로 각 구성 강재의 잔존두께를 측정하고, 휨 재하실험을 실시하였다. 그리고 수치해석을 수행하여 그 결과를 실험결과와 비교, 분석하였다. 그 결과 복공판 측, 하판의 두께 감소량과 잔존내하력과의 관계를 분석하여, 부식두께 감소량에 의한 복공판의 적절한 교체주기를 결정할 수 있는 지표를 제시하였다.

• 한국콘텐츠학회논문지
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• 제13권4호
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• pp.497-507
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• 2013

최근 스마트폰 사용자가 증가함에 따라 교육을 비롯한 전 분야에 걸쳐 모바일 서비스가 확대되고 있다. 학생의 학교생활정보를 제공하는 나이스 학생 학부모서비스도 늘어나는 스마트폰 수요에 맞는 서비스 제공이 절실한 형편이다. 본 연구에서는 이를 위해 학생과 학부모를 대상으로 온라인 설문조사를 실시하여 기존 서비스 제공요소에 대한 학생과 학부모의 인식 및 차이점을 콘텐츠 유용성, 서비스 활용성, 사용자 친화성의 변인들로 분석하였다. 설문자료의 신뢰성 분석, 상관분석 및 다중회귀분석 결과 통계적으로 유의하며 사용자 친화성 요인이 사용자의 만족도 및 스마트폰 서비스 이용의사에 가장 큰 영향을 주는 것으로 나타났다. 이를 통해 스마트폰 기반 나이스 학생 학부모서비스 및 교육정보서비스 제공방향을 제시하였다.

• 대한불안의학회지
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• 제13권1호
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• pp.39-45
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• 2017

Objective : Korean employees tend to release their stress by alcohol drinking. This study aimed to investigate the association between job stress and problematic drinking in Korean employees. Methods : The study participants were 72,119 employees who attended health screenings and responded to the Alcohol Use Disorder Identification Test-Korea (AUDIT-K), Korean Occupational Stress Scale-Short Form (KOSS-SF), Center for Epidemiologic Study-Depression (CES-D), Beck Anxiety Inventory (BAI) and questionnaire on suicidal ideation and sociodemographic characteristics. We investigated the sociodemographic and clinical characteristics of the problematic drinking group ($AUIDT-K{\geq}12$) and used binary logistic regression to determine the impact of job stress on problematic drinking. Results : Age, gender, marital status, education year, sleep duration, obesity, smoking, suicidal ideation, and depression and anxiety showed significant differences between the problematic drinking group and normal group. Among the various kinds of job stresses, job insecurity and lack of reward were associated with problematic drinking. Conclusion : The result of this study suggested that certain kinds of job stress might be associated with problematic drinking in Korean employees.