• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 한국추진공학회 2010년도 제34회 춘계학술대회논문집
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• pp.469-471
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• 2010

Supercavitating vehicles which cruise under water undergo high longitudinal force caused by thrust and drag. These combination may cause structural buckling. Static and dynamic buckling analysis method by using FEM can be used to predict this structural failure behavior. In this paper, some principles which include method for solution eigenvalue problem for buckling analysis are introduced. And before buckling analysis, we predicted some mode shape and natural frequency of cylindrical shell by using DIAMOND/IPSAP eigen-solver.

• Journal of Digital Convergence
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• 제13권11호
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• pp.549-559
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• 2015

The purpose of this study was to verify whether there are any differences in the level of exercise self-efficacy and perceived health status according to the stage of change for exercise behaviors in older adults. The subjects consisted of 231 older adults (91 male, 140 female) by convenience sampling residing in city D. The collected dates were analyzed using one-way ANOVA, Tukey HSD, and simple regression analysis by SPSS WIN 21.0 program. Moreover, all statistical significance level was set at a=.05. The study results were as follows: Analysis of variance showed that exercise self-efficacy showed significant differences according to the stage of change for exercise behaviors, and as a result of the posthoc analysis, it was found that as the stage became higher, their exercise self-efficacy became higher as well. Perceived health status showed significant differences according to the stage of change for exercise behaviors, and as a result of the posthoc analysis, it was found that as the stage became higher, their perceived health status became higher as well. Analysis of variance showed that exercise self-efficacy and perceived health status were significantly associated with the stages of exercise behavior change. This study identified that exercise self-efficacy and perceived health status were significant variables to explain a possible relationship with exercise stages of older adults. This study provides new information to influence the development of the better health promotion and exercise intervention for older adults in the community.

• Proceedings of the Korean Information Science Society Conference
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• 한국정보과학회 1998년도 가을 학술발표논문집 Vol.25 No.2 (3)
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• pp.568-570
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• 1998

본 논문은 위성간 링크를 이용하여 저궤도 위성망을 구성할 때 발생하는 링크 할당 문제를 효율적으로 풀기 위한 기법을 제안한다. 제안된 기법은 먼저 위성 궤도 운동의 주기성에 기반하여 저 궤도 위성망을 유한 상태기계로 모델링한 후에, 유한 상태기계의 각 상태에서 최적의 링크 할당을 구하기 위해서 조합형 최적화 문제에 많이 쓰이는 시뮬레이티드 어닐링을 이용한다. 제안된 기법의 잇점은 저궤도 위성망을 유한 상태기계로 모델링함으로써 동적인 움직임을 보이는 저궤도 위성망에서의 링크할당 문제를 고정된 위상을 가지는 망에서의 링크할당 문제로 단순화 시키고 이를 토대로 최적화 기법을 적용할 수 있다는 것이다. 시뮬레이티드 어닐링에 의하여 최적화된 링크할당의 성능은 정규링크 할당과의 비교.분석을 통해서 평가된다. 또한, 각 링크할당에 대하여 정적경로배정과 동적경로배정 기법이 적용된다. 시뮬레이션을 통한 실험결과는 정적경로배정을 적용한 최적링크할당 기법이 음성호의 봉쇄확률 측면에서 최고의 성능을 보임을 알려준다.

• Journal of the Korean Geotechnical Society
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• 제16권5호
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• pp.157-168
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• 2000

토류구조물의 안정문제로는 장단기적으로 정적인 경우와 동적인 경우, 그리고 지반의 동적 거동특성, 흙의 강도저하 등을 미리 파악하여 기술적인 대처를 할 필요가 있을 것이다. 본 연구에서는 실내 모형 실험을 통하여 구조물의 배면에 토성이 다른 일반모래, 표준모래, 점성토를 뒷채움하여 다짐없이 강사만 하고, 룰러다짐, 진동다짐을 하여 토피의 수평 진동거리를 길게, 짧게 그리고 중간으로 하여 강성벽체에 작요？는 수평토압에 대한 정적, 동적 특성을 규명하는 것이다. 모형 실험장치로는 실험대, 토조, 토압측정장치, 진동하중 발생장치, 진동측정장치, 강사기, 롤러 등을 설치하여 거리에 따른 병진운동으로 가속도와 수평토압, 수평토압계수, 전체토압, 토압의 작용점, 지진토압증분 증을 구하여, 실험결과와 기존 이론결과, 그리고 유한요소 해석결과와 비교 고찰하였다.

• Journal of the Korean Applied Science and Technology
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• 제36권4호
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• pp.1312-1326
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• 2019

The purpose of this study is to examine whether the 12-week Nordic walking can improve the physical function and arthritis pain of elderly women with osteoarthritis This study were divided into randomly assigned Nordic Walking Exercise Group (n=9) and Control Group (n=7) for 16 Elderly women diagnosed with Osteoarthritis (age: 73±3.79 year, height: 154.3±4.09 cm). The exercise group used Nordic sticks to carry out 30 minutes of Nordic walking exercise three times a week for 12 weeks, and the kinetic intensity was set at 40-60% of HRR. The control group maintained daily life for the same period. Body composition (weight, percentage body fat, skeletal muscle mass), muscular strength, Flexibility (muscular strength of upper and lower limbs, flexibility of upper and lower limbs), balance ability (static balance, dynamic balance) and pain level were measured as subordinate variables. These indicators were measured twice before and after the exercise program. The study shows that percentage body fat and skeletal muscle mass in the body composition function over 12 weeks of Nordic walking exercise have significant effects after the exercise than before (p=004)(p=.003), and it also shows significant interaction effects between the groups and timings(p=.018)(p=.005). In muscular strength, Flexibility factors, there were significant effects between the groups and timings in the upper limb muscular strength and the lower limb flexibility (p=.009)(p=.036), and a significant difference between the exercise group and the control group(p=.006) in the lower limb muscular strength. In addition, in the upper limb flexibility, there was a more significant difference after the exercise than before(p=.020). There were improvement effects after the exercise than before in the balance ability and the static balance(p=.016), but no difference in the dynamic balance(p>.05). In pain, there was a significant improvement after the exercise than before(p=.022), and a significant difference between the exercise group and the control group(p=.013). In conclusion, the 12-week Nordic walking exercise has positive effects on the body composition functions of the elderly women with Osteoarthritis, and has a positive effect on the improvement of upper limb muscular strength and lower limb flexibility in the health fitness factors. These effects are believed to have contributed effectively to the improvement of the level of pain by contributing to the improvement of physical and motor functions of the elderly women with Osteoarthritis. Therefore, it is considered that Nordic walking exercise, which enhances stability and balance of the patients with Osteoarthritis by using poles, is an effective exercise method for the improvement of the body and motor functions by lowering the pain of the joints and reducing the muscular strength and percentage body fat.

• The Journal of the Convergence on Culture Technology
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• 제8권6호
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• pp.421-427
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• 2022

This study was to examine the effect of lower extremity muscle strengthening exercise on balance and fall efficacy in middle older adults women. This study was conducted with one group pre-test and post-test design. A total of 34 older adults women participated in 7 weeks of intervention. Data were analyzed as SPSS ver. 21.0 using descriptive statistics and paired t-test. Right leg balance(t=6.09, p<.001), left leg balance(t=6.76, p<.001), and fall efficacy(t=6.81, p<.001) were significantly increased. Dynamic balance(t= -4.68, p=.001) was significantly decreased. This study found that lower extremity muscle strengthening exercise program could be a useful health promotion method.

• Industry Promotion Research
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• 제8권2호
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• pp.149-156
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• 2023

The purpose of this study is to investigate and analyze the effects of sports fun factors on the willingness to continue exercising and psychological happiness of table tennis club members. The participants in this study collected data using a questionnaire about sports fun factors, willingness to continue exercising, and psychological happiness of 293 table tennis club members. The factors influencing the willingness to continue exercising were identified as victory/competition, interpersonal relationships, practice/benefit, and family support, and the will to continue exercising was found to have a significant static influence on both self-realization and hedonic pleasure. As a result of the mediating effect analysis of the will to continue exercise, the mediating effects of fun factors such as competence/awareness, victory/competition, interpersonal relationships, practice/benefits, and family support, on psychological happiness, self-realization and hedonic pleasure are confirmed as mediating effect except for competence/perception. In particular, it was confirmed that the interpersonal relationship (team atmosphere) factor had a higher mediating effect on self-realization and hedonic pleasure than other factors.

• Journal of Industrial Convergence
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• 제19권6호
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• pp.81-91
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• 2021

This study was conducted to investigate the effect of ankle muscle strengthening exercise using BOSU ball and taping on static and dynamic plantar pressure in patients with hallux valgus. Subjects were 26 men and women in their twenties with hallux valgus, and they were randomly assigned to a taping group (TG; n=13) and an ankle strengthening group (ASG; n=13). Each group received the appropriate intervention over a total of 4 weeks, and static and dynamic plantar pressure were measured before and after the intervention. Independent T-test was performed to examine the difference in the amount of change between groups, and paired-sample T-test was performed to determine whether the difference between the pre-post values within the group was significant. The statistical significance level was set as α=.05. As for the ratio of the total body weight of the foot (Foot), the amount of change in the ASG of the left foot was significantly decreased compared to the TG within the group (p<.05). Significantly increased (p<.05). As for the degree of pronation of the foot (MP/change ratio), the amount of change in the TG of the right foot was significantly decreased compared to the ASG (p<.05), and in the force of the foot, the TG of the left foot was the amount of change within the group compared to the ASG. was significantly increased (p<.05), and in the group-to-group change, the amount of change in TG was significantly different than that of ASG (p<.05). Therefore, it can be considered that ankle strengthening exercise using bosu ball and taping are insufficient to give effective change to patients with hallux valgus.

• Journal of the Korea Society of Computer and Information
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• 제27권8호
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• pp.195-202
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• 2022

In this study, when cardiopulmonary resuscitation continued for a long time, the rescuer's blood lactic acid concentration, heart rate, and rating of perceived exertion were measured to identify the change in the rescuer's fatigue. Data collection was conducted from July 5 to July 9, 2021, with a total of 24 students, 12 students department of special warfare medical non-commissioned officer, and 12 students department of emergency medical technology at D University, undergoing a two-person alternative chest compression resuscitation for 60 minutes. As a result of the study, the rescuer's blood lactic acid concentration, heart rate, rating of perceived exertion, and chest compression speed were significantly changed according to the duration of CPR (p<.001, p<.001, p<.001, p<.001). blood lactic acid concentrations at every measurement cycle (30 minutes, 40 minutes, 50 minutes, 60 minutes) showed a significant positive correlation with heart rate (r=.696, p<.001, r=.672, p<.001, r=.709, p<.001, r=.782, p<.001), there was also a significant positive correlation with the rating of perceived exertion (r=.476, p<).05, r=.426, p<.05, r=.470, p<.05, r=.470, p<.05). Therefore, monitoring the fatigue of rescuers using heart rate and rating of perceived exertion will be useful for maintaining high-quality chest compression in situations where cardiopulmonary resuscitation is required for a long time.

• Journal of Digital Convergence
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• 제16권12호
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• pp.603-610
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• 2018

This study set out to investigate structural relations among positive thinking, identity, sports happiness perception, and athletic burnout and analyze the mediating effects of identity and sports happiness perception on relations between positive thinking and athletic burnout in order to understand the psychological process of athletic burnout experienced by adolescent players. For these purposes, the study applied the convenience sampling method to male and female players at physical education and general middle and high schools around the nation and used total 306 questionnaires as final valid samples. Collected data was tested for the fitness of an overall model with the SPSS 22.0 and AMOS 22.0 programs. Then the hypotheses were tested. The findings were as follows: first, subjective satisfaction and pursuit of a goal in the category of positive thinking had significant effects on athletic identity; second, subjective satisfaction and pursuit of a goal in the category of positive thinking had no impacts on sports happiness perception; third, the athletic identity of adolescent players had positive impacts on their sports happiness perception and negative ones on their athletic burnout; fourth, the sports happiness perception of adolescent players had negative effects on their athletic burnout; and finally, athletic identity had mediating roles on relations between pursuit of a goal of positive thinking and sports happiness perception and on relations between pursuit of a goal of positive thinking and athletic burnout.