• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.03a
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• pp.15-18
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• 1997

The plane strain stretch test (PSST) developed by POSCO as an activity of customer service was applied to the establishment of the formability criteria and the prediction of failure during the stamping processes. The PSST was applied to the actual parts such as oil pan and shock mount and the criteria of PSST value for each forming parts were established. These value can provide the possibility of prediction of failure before the stamping process. These results show that the PSST can precisely predict the stamping formability of steel sheets.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.5
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• pp.1132-1137
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• 1993

A simple simulative test was developed to evaluate stamping formability in plane strain stretching mode. The stamping formability was evaluated by limit punch height(LPH) in plane strain punch stretching test(PSST) compared to limit dome height(LDH) in hemispherical punch stretching test. PSST shows stable plane strain condition and good reproducibility with minimum scatter. Moreover LPH-value in PSST well ranks the stamping formability of various material and correlates with press performance.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.12
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• pp.2073-2080
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• 1997

Recently, the plane strain puch stretching test(called PSST) has been developed and used successfully in the evaluation of the press formability of automotive steel sheets. In this paper, the optimum punch geometry of the original PSST tool was investigated by the FEM analysis. The puch length, crown and corner radius are chosen to be optimized according to the Taguchi's experiment technique with the $L_4$ orthogonal array.

• Journal of Sasang Constitutional Medicine
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• v.30 no.3
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• pp.48-61
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• 2018

Objectives The purpose of this study was to investigate the ordinary symptoms, special symptoms and Body Mass Index (BMI) according to Sasang constitution in female college students. Also, we aimed to analyze the factors affecting BMI. Methods Forty-four female college students participated in this study. Sasang Constitution was determined by Questionnaire for Sasang Constitution Classification (QSCC) II. BMI was measured and ordinary symptoms were acqired through the questionnaire. Special symptoms was determined by Fatigue Severity Index (FSS), Premenstrual Symptom Screening Tool (PSST), ROME III, Ocular Surface Disease Index (OSDI), respectively. For statistical analysis, t-test, analysis of variance and correlation test has been used. Results There existed significant differences in ordinary symptoms and special symptoms between sasang constitutions. Taeumin had higher urine frequency than soyangin, soeumin had higher gap of feces than taeumin. Taeumin had higher BMI and ROME III score than soyangin and soeumin. They showed significant differences in ordinary symptoms and special symptoms according to BMI. Overweight and obese group is higher in water intake than low and normal group. Low weight and normal group is higher in gap of feces than overweight and obese group. High score group in PSST and ROME III showed high BMI than low score group. We analyzed the factors that affect BMI. BMI are highly correlated with systolic and diastolic blood pressure. Also, FSS, PSST, ROME III and OSDI showed high correlation with each other. Conclusion Urine frequency and gap of feces are different among sasang constitutional types. The obese group and normal group showed significant differences in water intake, gap of feces, PSST and ROME III score. It is found that factors that affecting BMI are systolic and diastolic blood pressure. These results may lead to identifying the causes and factors of obesity in female college students related to Sasang constitution.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.11
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• pp.2676-2683
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• 1993

Plane strain punch stretching test(PSST) was performed for various automotive steel sheets. To clarify the effect of tensile properties on plane strain stretchability, the limiting punch height(LPH) values were obtained in plane strain punch stretching test and related to the tensile properties of the materials. The results show that the total elongation El and work hardening exponent n compared to other parameters obtained from tensile test well correlate with the LPH value. In comparision with the Erichsen test and LDH test the PSST can be statistically used as an alternative in assessing the stamping formability of automotive steel sheets with the advantages of good reproducibility and easy testing method.

• Journal of the korean Society of Automotive Engineers
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• v.15 no.2
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• pp.121-129
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• 1993

Plane strain punch stretching test (PSST) was developed to evaluate stamping formability of sheet materials. In this test, the rectangular specimen of sheet material is uniformly stretched up to fracture by raising a specially designed punch to certainly assure plane strain stretching deformation along the longitudinal direction of the specimen. The stamping formability was evaluated by limit punch height(LPH) in plane strain punch stretching test compared to limit dome height(LDH) in hemispherical punch stretching test. LPH-value in PSST well ranks the stamping formability of various material and correlates with press performance. Moreover by using ultrasonic thickness gauge the plane strain intercept-limit plane strain(FLCo)-in forming limit curve can be accurately determined from thickness measurement around the fracture area. The FLCo derived from thickness measurement well correlates with the results from circle grid analysis for the deformed circle grid marked on the surface of the specimen.

• Korean Journal of Psychosomatic Medicine
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• v.20 no.1
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• pp.22-31
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• 2012

Objectives : We investigated the prevalence and functional impairment of premenstrual dysphoric disorder (PMDD) and premenstrual syndrome(PMS) in young women. Methods : A total of 1063 female college students were recruited from two urban areas(Seoul and Suwon) of Korea. Questionnaires for sociodemographic data and risk factors of PMDD, attitude about menstruation, and the Premenstrual Symptoms Screening Tool(PSST) were applied. Results : The prevalence of severe moderate to severe PMS and PMDD were 16.9% and 11.7%, respectively. There were differences in the alcohol and coffee consumption, severity of menstrual cramp, and family history of PMS among the moderate to severe PMS, PMDD, and no/mild PMS groups. Although some participants did not fulfill diagnostic criteria for PMDD, they showed significant functional impairment. Participants with negative attitude about menstruation reported premenstrual symptoms more frequently than those with positive or ambivalent attitude about menstruation. Conclusion : These results suggest that PMS and PMDD were prevalent and associated with functional impairment in young females. Some participants reported significant functional impairments although they did not meet the full DSM-IV diagnostic criteria for PMDD. Negative attitude about menstruation was associated with more premenstrual symptoms experiences.

• Journal of Sasang Constitutional Medicine
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• v.29 no.2
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• pp.104-115
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• 2017

Objectives The purpose of this study was to investigate the premenstrual symptoms according to Sasang constitution and to utilize for understanding the characteristics of Sasang constitution. Methods Thirty one female university students participated in this study and Sasang Constitution and patterns of premenstrual symptoms was determined by Questionnaire for Sasang Constitution Classification (QSCC) II and premenstrual symptoms screening tool, respectively. For statistical analysis, chi-square test, analysis of variance and correlation test has been used. Results There existed significant differences in menstrual symptoms between Sasang constitutions. Taeumin had higher body mass index in severe PMS(Premenstrual Symptoms) group than normal/mild PMS group, and Soyang in and Soeumin are vice versa. Taeumin showed depressed mood and hopelessness, decreased interest in school activities, Soyangin showed decreased interest in home activities, and Soeumin showed decreased interest in social activities. In terms of interfered functional activities, Soyangin had increased feeling overwhelmed or out of control and Taeumin and Soeumin had increased hypersomnia. Conclusion Menstrual symptoms are different among Sasang constitutional types based on PSST(Premenstrual Symptoms Screening Tool). These results may serve as the basis in identifying and treating premenstrual syndromes related to Sasang constitution.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.06a
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• pp.87-87
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• 2006

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.4
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• pp.145-151
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• 2022

Purpose : Stroke patients exhibit abnormal walking patterns such as slow walking speed and asymmetrical walking values. The recovery of symmetrical walking in the stance phase using a treadmill means improvements in walking speed and asymmetrical walking. The purpose of this research was to investigate the effect of unilateral step treadmill training (USTT) on gait speed and the recovery of symmetrical walking in chronic stroke patients. Methods : Fifteen patients (11 men and 4 women) with chronic stroke participated in this study. The 10-meter walk test (10MWT) and GAITRite system were used to determine the intervention-related changes in gait speed and symmetrical walking values such as non-paretic step length (NSL), non-paretic step time (NST), paretic single-support time (PSST), step length asymmetry (SLA), and step time asymmetry (STA) after USTT. All participants completed USTT and underwent measurements at 3 different times: at pretest, posttest, and the follow-up test. Repeated-measures analysis of variance was used to compare walking speed and asymmetrical walking values. The statistical significance level was set at p<.05. Results : Walking speed by 10MWT (p<.05) showed significant improvements after USTT as follows: at pretest and posttest (p<.05), posttest and follow-up test (p<.05), and pretest and follow-up test (p<.05). Recovery of symmetrical walking patterns such as NSL (p<.05), NST (p<.05), and SLA (p<.05) were observed after USTT. However, no significant improvements were found in PSST (p>.05) and STA (p>.05) in symmetrical gait. Conclusion : This study suggests that USTT may have a positive effect on walking speed and symmetrical walking patterns in chronic stroke patients. Thus, this study contributes to the existing knowledge about the usefulness of USTT for the effective management of patients with chronic stroke. Further studies are needed to generalize these findings.