• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1289-1294
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• 2008

Electrostatic discharge(ESD) phenomenon is a serious reliability concern. It causes approximately most of all field failures of IC. To quality the ESD immunity of IC product, there are some test methods and standards developed. ESD events have been classified into 3 models, which are HBM, MM and CDM. All the test methods are designed to evaluate the ESD immunity of IC products. This study provides an overview among ESD test methods on ICs and an efficient ESD stress method. We have estimated on all pin combination about the positive and negative ESD stress. We make out the weakest stress mode. This mode called a worst-case mode. We proposed that positive supply voltage pin and I/O pin combination is efficient because it is a worst-case mode.

• Human Ecology Research
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• v.53 no.5
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• pp.475-488
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• 2015

Economic activity and social participation by women has recently increased; however, working mothers raising young children are under new stress due to the simultaneous combination of job and parenting responsibilities. This stress has resulted in social problems of career break and low fertility. This study investigates the effect of clinical art therapy on occupational stress and parenting stress of working mothers. We analyzed 34 working mothers in full-time employment (over 8 hours a day) who have preschool children (0-6 years old). They were divided into 17 subjects in the experimental group and 17 subjects in the control group. For the experimental group, 10 hours and a half sessions of group art therapy were participated in once a week from April to August in 2014. We perform Dan Occupational Stress Index by Ivancevich and Matteson, Parenting Stress Index/Short Form and salivary cortisol test before and after the group art therapy. For qualitative analysis, Kinetic House-Tree-Person (KHTP) drawing test was used. Using SPSS ver. 19.0, paired t -test or Wilcoxon signed rank test compared the pre and post analysis results. The results of this study are as follows. First, scores of 'occupational stress factor' subpart showed significant improvement in the Occupational Stress Index after the clinical art therapy. Second, scores of 'parental distress,' 'parent-child dysfunctional interaction,' and 'difficult child' subpart in Parenting Stress Index also showed a significant improvement. Third, a positive change was observed after the clinical art therapy in the KHTP drawing test. In conclusion, this study suggests that the clinical art therapy can be effective for occupational stress factors and the parenting stress of working mothers.

• Journal of Korean Clinical Nursing Research
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• v.20 no.2
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• pp.211-222
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• 2014

Purpose: This study was done to identify the effects of Laughter therapy on recovery status from facial paralysis, pain, and stress in Bell's palsy patients. Methods: This research was a nonequivalent control group non-synchronized pre-posttest quasi-experimental research design. Data were collected from August 8, to October 15, 2013 at D university Oriental Medical Center in B city. Participants were 60 patients with Bell's palsy who were assigned to one of two groups: an experimental group of 30 patients and a control group of 30 patients. t-test, $x^2-test$, Fisher's exact test and Welth-Aspin test were used to test the homogeneity between the two groups and t-test, Welth-Aspin test and ANCOVA were used to test the research hypotheses. SPSS program was used for statistical analysis. Results: There were significant increases in recovery status from facial paralysis and decreases in stress after Laughter therapy in the experimental group. Conclusion: The results indicate that Laughter therapy is effective in facilitating recovery status from facial paralysis and decreasing stress. Therefore, Laughter therapy can be used as an effective nursing intervention for patients with facial paralysis and to relieve stress in these patients.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.660-665
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• 2003

The true stress - true strain relation of SA508 steel was evaluated with analytical and experimental equation on the base of the indentation load-depth curve obtained from the modeling of ball indentation test. The evaluated relation between true stress and true strain is agreed well with that of SA508 teel defined in the modeling. The distribution of effective stress along the center axis of indentation depth was calculated with Tresca criteria in the modeling. The representative strain, which are defined in this study as the corresponding strains obtained from the maximum effective stress, have a linear relation with the true strain. The true stress - true strain relation of austenitic stainless steel was evaluated by the modeling of ball indentation test to verify the case of A508 steel.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.255-260
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• 2003

Most of the fatigue test were achieved in fully reversed condition that mean stress is zero. But, generally, mean stress can not be zero. This research was achieved the bending fatigue test that changes mean stress to spring steel and was studied relation with the mean stress and the fatigue life. The method to search effect about mean stress was extended S-N graph in two cases. One method was extended S-N graph using modified Miner's rule with considering damage. Another was extended using tendency of S-N graph. The exponential value(${\alpha}$) of mean stress-alternating stress equation is converged between the Goodman's and the Gerber's value even if fatigue life increases.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1994.10a
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• pp.74-79
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• 1994

The log-log presentation of stress versus Larson-Miller parameter is obtained by uniaxial tensile test instead of the long time creep test. The used material for example calculations is SUS304 stainless steel. The temperature of the uniaxial tensile test can be determined by the Larson-Miller parameter of the design stress and the 0.1hr's rupture time of the uniaxial tensile test. The rupture time at the design temperature and stress can be determined by the Larson-Miller parameter of the stress. The average creep rate is the total deformation of the tensile test divided by the rupture time at the design stress and temperature. The liner trend and the order of the data of the average creep rate by this method is almost same as that of experimental results.

• Journal of Applied Reliability
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• v.7 no.2
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• pp.57-72
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• 2007

This paper suggests an approach for using ALTA 7 PRO to design accelerated life test plans. Conducting a accelerated life test requires finding life distributions at different stress levels and determining an appropriate life-stress relationship. Moreover, a test plan needs to be developed. In its optimal test plan, stress levels are determined and the proportions of test units are assigned at each stress level so that asymptotic variance of the maximum likelihood estimate of a (log) percentile of the life distribution at the design stress is minimized. Examples are presented for usage.

• International Journal of Contents
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• v.5 no.4
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• pp.44-50
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• 2009

The purpose of this research was to measure the effect of a gestalt group meditation therapy intervention program on occupational stress and anxiety in working women aged 30 to 49 in Korea. Scientific methods were employed to test a gestalt group meditation therapy intervention program as treatment for working women in 30-40s to reduce their level of occupational stress and anxiety. The study involved 18 volunteer subjects ages of 30 to 49 years, randomly divided into two groups: (1) gestalt group meditation therapy intervention program, and (2) no program. Both groups completed a pre-test and a post-test of occupational stress scale and trait anxiety inventory. The outcome data was analyzed as qual1litative information using the SPSSPC+ computer program. Mann-Whitney U test was used to analyze the result in order to verify the sameness between experienced group and controlled group of pre-test scores within the groups. Also U-test comparisons were used to analyze the treatment effects. The results of this investigation indicated that (1) occupational stress scores decrease after gestalt group meditation therapy intervention program on the treatment group, and (2) trait-anxiety scores decrease after gestalt group meditation therapy intervention program on the treatment group. In summary, the gestalt group meditation therapy intervention program for career women, aged 30 to 49, in Korea could reduce the subjects' occupational stress and anxiety.

• International Journal of Reliability and Applications
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• v.15 no.2
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• pp.125-150
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• 2014

Accelerated life tests (ALTs) are extensively used to determine the reliability of a product in a short period of time. Test units are subject to elevated stresses which yield quick failures. ALT can be carried out using constant-stress, step-stress, progressive-stress, cyclic-stress or random-stress loading and their various combinations. An ALT with linearly increasing stress is ramp-stress test. Much of the previous work on planning ALTs has focused on constant-stress, step-stress, ramp-stress schemes and their various combinations where the stress is generally increased. This paper presents an optimal design of ramp soak-stress ALT model which is based on the principle of Thermal cycling. Thermal cycling involves applying high and low temperatures repeatedly over time. The optimal plan consists in finding out relevant experimental variables, namely, stress rates and stress rate change points, by minimizing variance of reliability function with pre-specified mission time under normal operating conditions. The Burr type XII life distribution and time-censored data have been used for the purpose. Burr type XII life distribution has been found appropriate for accelerated life testing experiments. The method developed has been explained using a numerical example and sensitivity analysis carried out.

• Journal of the Earthquake Engineering Society of Korea
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• v.17 no.5
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• pp.219-225
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• 2013

This work examines the feasibility for estimating existing tensile stress on a stressed wire using the permeability of magnetic flux. A closed magnetic circuit has been constructed to induce magnetic flux inside a steel wire. With different tension stress levels on a wire, the permeability of magnetic flux on the wire has been measured. Two different experimental case studies have been conducted for the examination of sensitivity of permeability of magnetic flux on the stressed wire. One is a varying-length stress test, and the other is a fixed-length stress test. The results show that the permeability of magnetic flux in the varying-length stress test is inversely proportional to the applied stress, while the permeability in the fixed-length stress test is linearly proportional to the applied stress on the stressed wire. It is thus expected that the permeability of magnetic flux on a wire can be a promising indicator for the inspection of its tensile stress.