• Journal of Microbiology and Biotechnology
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• v.10 no.1
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• pp.63-68
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• 2000

GroEL is well known as a molecular chaperone. In order to determine the dynamic stress response of the Escherichia coli groE promoter, a groE-lacZ operon fusion in the chromosome was constructed. Stress leading to ${\sigma}^{32}$ synthesis induces transcription from E. coli groE promoter, since the promoter is ${\sigma}^{32}-regulated$. When the strain was stressed with ethanol, phenol, and sodium chloride, clear inductions of ${\beta}-galactosidase$ were observed. Two types of simultaneous stresses of sodium chloride and phenol induced the enze much more than either of the two alone, suggesting that stress was an additive. The combined stress resulted in the highest induction of the enzyme in this system. The groE-lacZ fusion strain developed in this study can conveniently be used to detect other harmful pollutants in the environment. Stress treatment of cells containing recombinant proteins, which need GroEl, by ethanol, phenol, or sodium chloride, might have a tendency to increase their biological activities.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.6
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• pp.22-27
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• 1997

In general, the load which acts on the structure is almost independent of time in many locations. In this case. It is difficult to estimate the life with the service load history, because the structure is on the multi- axial and multi-point loading states. In this study, the service load of the excavator which is widely used in industry field was calculated using measured cylinder pressures and displacements. The fatigue life was estimated using the multi-axial and multi-point load counting method. Service load history of 4 pin joint which act independently each other is yielded by mult-axial and multi-point load counting method. The stress spectrum is yielded by superposition of the results of FEM stress analysis applied unit load. Palm- gren-Miner's cumulative Damage is 0.000804 for Von Mises equivalent stress sequence by one side fillet weld S-N curve. This result agress with Bench test results. As a result of this study, the fatigue life esti- mation using the multi-axial and multi-axial and multi-point load counting method is useful.

• Journal of Welding and Joining
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• v.31 no.4
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• pp.73-79
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• 2013

Burr grinding, Tungsten Inert Gas (TIG) dressing, ultrasonic impact treatment, and peening are used to improve fatigue life in steel structures. These methods improve the fatigue life of weld joints by hardening the weld toe, by improving the bead shape, and by creating the compressive residual stress. In this study, a new post-weld treatment method improving the weld bead shape and metal structure at the welding zone using Friction Stir Processing (FSP), a welding process, is proposed to enhance fatigue life. For that, a pin-shaped tool and processing condition employing Friction Stir Processing (FSP) is established through experiments. Experimental results revealed that fatigue life is improved by around 50% compared to as-welded fatigue specimens by reducing the stress concentration at the weld toe and by generating a metal structure finer than that of flux-cored arc welding (FCAW).

• Journal of Families and Better Life
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• v.32 no.4
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• pp.41-56
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• 2014

The purpose of this study is to investigate the relationship between the expenditure on private education and stress from private education, and the role conflicts of the mothers of junior and senior high school students. The subjects were 300 mothers of students who are enrolled in junior and senior high school and receiving private education in Seoul and its suburbs. The results were as follows: First, the level of stress from private education was found to be higher than the scale range of the median, whereas the degree of role conflicts was slightly lower than the scale range of the median. Second, a hierarchical regression analysis was performed by using the expenditure on private education and stress from private education as independent variables and the socio-demographic variables of mothers as the control variables in order to identify their effect on the role conflicts of the mothers of the junior and senior high school students. The results show that the age of the mother, the household monthly income, the monthly expenditure on private education, and stress from private education were significantly related to the role conflicts of the mothers. That is, the older the age of the mother, the lower the level of monthly income, the lower the level of the monthly expenditure on private education, and the higher the level of stress from private education, the greater the degree of the role conflicts of the mother.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.192-202
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• 2019

This study was a descriptive study to investigate the factors influencing on self-esteem, ego resilience, impulsivity and life stress on smartphone addiction among college students. The subjects include college students in some areas. Data was collected in November and December, 2018. Total 231 college students were analyzed in the study. Collected data was analyzed in frequency, percentage, and t-test to examine differences in smartphone addiction according to general characteristics. Pearson's correlation was performed to examine correlations between smartphone addiction and main variables, and the factors influencing smartphone addiction were analyzed in multiple regression. The findings show that genera, satisfaction with college life, hours of using a smartphone, hours of using SNS, ego resilience, impulsivity, and life stress had significant effects on smartphone addiction. The study examined relations between general characters and smartphone addiction and found that the level of smartphone addiction was high in female college students, those who were not satisfied with college life, and used a smartphone and SNS for many hours. Ego resilience had negative correlations with smartphone addiction, and impulsivity and life stress had positive correlations with it. Multi-variate regression analysis results show that gender, ego resilience, and life stress were factors that had important influences on the smartphone addiction of college students, having explanatory power of 35.6%. In short, colleges and universities need to develop a school-level program to improve the college life of students and reduce their stress to the minimum and create an environment of encouraging them to grow power of controlling their lives so that they can prevent smartphone addiction.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.472-482
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• 2010

For the massive screening of the genes related to oxidative stress, a cDNA library was constructed from hot pepper (Capsicum annuum L. cv. Nockkwang) leaves treated with methyl viologen. From this library, 1,589 cDNA clones were sequenced from their 5' ends. The sequences were clustered into 1,252 unigenes comprised of 152 contigs and 1,100 singletons. Similarity search against NCBI protein database identified 1,005 ESTs (80.3%) as Known, 197 ESTs (15.7%) as Unknown, and 50 ESTs (3.99%) as No hit. In the ESTs, oxidative stress-related genes such as ascorbate peroxidase, catalase, and osmotin precursor were highly expressed. The cDNA microarray containing 1,252 unigenes was constructed and used to analyze their expression upon methyl viologen treatment. Analyses of the hybridization revealed that various stress-related genes such as peroxidase, tyrosine aminotransferase, and omega-6 fatty acid desaturase, were induced and some metabolism related genes such as aldolase and ketol-acid reductoisomerase, were repressed by methyl viologen treatment, respectively. The information from this study will be used for further study on the functional roles of oxidative stress-related genes and signaling network of oxidative stress in hot pepper.

• Child Health Nursing Research
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• v.21 no.2
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• pp.83-90
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• 2015

Purpose: The purpose of this study was to describe the subjective happiness and satisfaction with life of children with type 1 diabetes and explore related factors. Methods: A descriptive cross-sectional study design was used and the study was conducted with children at a diabetes camp. Data were collected using a self-report questionnaire to explore positive and negative psychological factors. The questionnaire included Subjective Happiness Scale, Satisfaction with Life Scale, Perceived Stress Scale and the Center for Epidemiological Studies Depression Scale for Children (CES-DC), Multidimensional Scale of Perceived Social Support, and General Self-Efficacy Scale. Results: Data from 15 children were used for data analysis. The correlational analysis results showed that subjective happiness was positively correlated satisfaction with life, social support, and self-efficacy, and was negatively correlated with perceived stress. Satisfaction with life was positively correlated social support, and was negatively correlated with perceived stress. Conclusion: Results indicate that the positive psychology factors were closely related with social support and self-efficacy and may alleviate perceived stress and depressive feelings. Therefore, researchers and clinicians should include positive psychological factors in their health management model for children with chronic illness.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.593-603
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• 2020

This study identified the relationship between academic stress and hopelessness among female high school students. The self-administered questionnaires were given to 334 female high school students located in D-city during the period from August 20, 2018 to September 20, 2018. As a result, the distribution of the level of hopelessness among those surveyed was 61.6% for the normal range group, 23.1% for the mild range group, 12.9% for the moderate range group, and 2.4% for the severe range group. The level of hopelessness, according to the academic stress of the study subjects, was significantly higher in the higher academic stress group than that in the lower academic stress group (p=0.000). Hopelessness also showed significant positive correlation with academic stress (r=0.371, p<0.01). The results of the logistic regression analysis showed that the risk ratio of hopelessness was significantly increased 9.27 times in the higher academic stress group when compared to that in the lower academic stress group. According to the multiple regression analysis, the significant variables affecting hopelessness were satisfaction with school life, conversation with parents, eating regularly, stress due to tests, stress due to studies and stress about career paths. Given the above results, the hopelessness of female high school students is significantly related to academic stress. Therefore, it is necessary to develop and implement programs that can properly control academic stress factors.

• The Journal of Korean Society for School & Community Health Education
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• v.16 no.3
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• pp.65-78
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• 2015

Objectives: The purpose of this study was to investigate self esteem and stress of students at their universities for the development of a program related to school life and guidance. Methods: The survey were carried out in 5 universities located in Gyounggi Do, Gyungbuk Do, Busan city and Daegu city from 2014. October 1. to November 30. Out of a total of 500 Questionnaires answered by 500 students, 489 Questionnaires, were analyzed with SPSS version 12.0. Results: The total mean of the self esteem point of college student's school living was $3.41{\pm}0.44$ points. The total mean of the general stress point of college students was $2.67{\pm}0.52$ points. Affecting factors of the self-esteem of subjects(multiple regression analysis) were important things of school living(p<0.05), human and friendship(p<0.05), protector's job(p<0.001), home economic states(p<0.001), and friendship(p<0.001). Based on multiple regression analysis, affecting factors of the stress of subjects were important things of school living(p<0.05), human and friendship(p<0.05), religion(p<0.001), protector's job(p<0.001), friendship(p<0.001), and arbeit job(p<0.05). Conclusions: The results of this study help to provide a basis for development of a strategy to improve the self-esteem and solve problems of stress for university students. Also relevant programs should be developed and provided by related authorities and universities.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.10a
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• pp.138-144
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• 2003

Rencentely, the request for the light weight is more incresed in the area of industrial environment and machinery and consistent effort is needed to accomplish high strength of material for the direction of light weight. we got the following characteristic from crack growth test carried out in the range of stress ration of 0.1, 0.3 and 0.6 by means of opening mode displacement. At the content stress ratio, the threshold stress intensity factor crack range ${\Delta}K_{th}$in the early stage of fatigue crack growth (Region I) and dtress intensity factor range ${\Delta}K$ in the stable of fatigue crack growth (Region II) with an increase in ${\Delta}K$. Fatigue life shows more improvement in the Shot-peened material than in the Un-peening material. And compressive residual stress of surface on the Shot peening processed operate resistance force of fatigue. So we can obtain fallowings. (1) The fatigue crack growth rate on stage II is conspicuous with the size of compressive residual stress and is depend on Paris equation. (2) Although the maxium compressive residual stress is deeply and widely formed from surface, fatigue life does not improve than when maxium compressive residual stress is formed in surface. (3) The threshold stress intensity factor range is increased with increasing compressive residual stress.