• Journal of the Society of Naval Architects of Korea
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• v.52 no.6
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• pp.460-470
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• 2015

In general ships and FPSOs, roll damping is very small and consequently roll motion is very large at the roll resonance frequency. Proper evaluation of the roll damping coefficient at the resonance frequency is an important task in the study of roll motion and usually it is done by the analysis of free roll decay tests. The relative decrement method based on energy relation has been used mainly for the evaluation of roll damping coefficient from the roll decay test so far. As another method, the logarithmic decrement method based on equivalent linear decay assumption can be used for the same purpose and it is relatively simple. In this paper, both of the relative decrement method and the logarithmic decrement method are used for the evaluation of roll damping coefficient including quadratic damping from the free roll decay tests, and their results are cross-checked for verifying the obtained damping coefficients. Through applications to a box-type floating body equiped with bilge keels, it is shown that the two methods give almost the same damping coefficients in a practical view point and the cross-check of their results is to be a good tool to prevent a possible error. And also the quantitative effects of the bilge keels on the roll damping of box-type floating body are shown and discussed.

• Journal of the Korean Society of Physical Medicine
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• v.19 no.1
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• pp.95-105
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• 2024

PURPOSE: This study aimed to utilize the International Classification of Functioning, Disability, and Health (ICF) tool to identify a problem list and explore intervention effects using proprioceptive neuromuscular facilitation (PNF) for improving the crosswalk performance of patients who have undergone a bilateral hip arthroplasty. METHODS: The subject of this study was a 43-year-old male who had undergone a bilateral hip arthroplasty. To address the subject's functional status, a clinical decision-making process was carried out in the order of examination, evaluation, diagnosis, prognosis, intervention, and outcome. Patient information during the examination was collected using the ICF core set. The evaluation involved listing the items of each problem using the ICF assessment sheet and identifying the interaction between activity limitations and the impairment level. The diagnosis explicitly described the causal relationships derived from the evaluation using ICF terminology. The prognosis presented activity goals, body function, and structured goals in terms of the activity and participation levels that needed to be achieved for an individual's functional status. The intervention approached problems through the four components of the PNF philosophy, namely basic principles and procedures, techniques, and patterns, in an indirect-direct-task sequence. Results were compared before and after the intervention using the ICF evaluation display. RESULTS: The results of the study showed that the primary activity limitation, which was the walking time across the crosswalk, showed improvement, and the trunk's counter rotation and the weight-bearing capacity of both the lower limbs, which were impairment level indicators, were enhanced. CONCLUSION: This study suggests that PNF intervention strategies will serve as a positive approach for improving crosswalk walking in patients with bilateral hip arthroplasty.

• The Research Journal of the Costume Culture
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• v.29 no.5
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• pp.719-734
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• 2021

The aim of this study was to determine the therapeutic effects of beauty care on negative mental health, including stress and depression. Nail care, massage care, and makeup were used as programs for beauty therapy. Qualitative research was conducted with six female participants over five-month period. After interviewing the subjects in advance, beauty care treatments were performed every week 4 weeks in the following order: nail care, massage, and makeup. The results are as follows, First, the participants perceived beauty care in the form of 4 concepts: "courtesy in social life," "investment in oneself," "self-satisfaction," and "self-care." Second, the effects of beauty therapy were categorized as "psychological effects," "confidence," "behavioral changes," "evaluation of others," and "positive social effects." Third, each subject showed different psychological effects during the process when the function of the therapy took effect through the beauty care treatment. It was confirmed that confidence levels increased as a result of treatment through the process of becoming re-aware of oneself. Positive statements from the participants included: "I want to go out," "I have become kind and positive to others," "I have become more active in a given task," and "It seems that my work ability is improving." Finally, t-test results for self-esteem, depression, and stress showed there were significant differences in self-esteem and depression. This confirmed that self-esteem increased, and depression decreased after the beauty care treatment.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.8 no.2
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• pp.273-286
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• 1997

Objective：This study was designed to evaluate effects of methylphenidate(MPH) on event-related potentials(ERP) and continuous performance test(CPT) in attention-deficit hyperactivity disorder (ADHD) and to see the correlation between changes in ERP and changes in performance. Method：ERP and CPT were used to examine the acute effects of MPH(0.5mg/kg) in eleven ADHD boys(89-103 months old). Results：1) After MPH administration, P3 latency to nontarget stimuli at Fz was significantly decreased (p<0.01) and P2 amplitudes to target stimuli at Pz and at Oz and P3 amplitude to target stimuli at Cz were significantly increased(p<0.05). 2) Commission error and omission error in the CPT-X and commission error in the CPT-AX were decreased(p<0.01), and hits and perceptual sensitivity(d') in the CPT-X and d′ in the CPT-AX were increased(p<0.01). 3) The change of P3 latency to nontarget stimuli at Fz and the change of d′ in the CPT-X were negatively correlated(p<0.05), and the change of P2 amplitude to target stimuli at Pz and d′ in the CPT-AX were positively correlated(p<0.05). Conclusion：MPH improves change orienting reaction, the delivery of task relevant information, accuracy and perceptual sensitivity in ADHD. And the increase of ability to discriminate targets from non-targets reflects reduced evaluation time in large memory component task and enhanced change orienting reaction in simple task.

• The Mathematical Education
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• v.58 no.1
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• pp.41-54
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• 2019

The purpose of this study was to examine the effects of career identity on learning persistence and academic achievement, and mediating effect of utility value. To examine the effect of mediating role of utility value, we divided utility value into two types, utility value of daily matters and utility value of career. This study was conducted on 228 senior students in high school, to investigate relations among career identity, utility value, learning persistence and academic achievement in mathematics, by using the structural equation model. The results are as follows. First, career identity positively predicted learning persistence in mathematics. Second, career identity positively predicted the utility value of daily matters and career. Third, both type of utility value in mathematics positively predicted learning persistence in mathematics. Fourth, the utility value of daily matters and career, in mathematics subjects, showed differential predictability toward learning persistence and academic achievement. Both type of utility value in mathematics positively predicted learning persistence, but showed differential predictability toward learning academic achievement. Specifically, the utility value of daily matters in the near future did not predict the academic achievement, but the utility value of career in the distant future positively predicted the academic achievement. Fifth, the utility value was found to play a mediating role in the relationship between career identity and learning persistence. Based on the results of this study, implications for mathematics education were discussed.

• The Journal of Korean Academy of Sensory Integration
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• v.15 no.2
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• pp.46-65
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• 2017

Objective : The purpose of this research is to find clinical effects of application of weighted vest during task-oriented training focused on gross motor performance and balance abilities of children with spastic diplegia. Methods : 34 subjects were divided by simple random sampling into two groups; experimental group (male : 9, female : 8, average age : 8.12) and placebo group (male : 9, female : 9, average age : 7.53). Both two groups underwent to 40 minute intervention, twice a week for 12 weeks. The intervention was task-oriented training focused on facilitating closed kinematic chain and multi-joint functional movement pattern. During the training, the experimental group received loaded-resistance weighted vest and placebo group also received weighted vest but without loaded-resistance. Participants in both groups underwent 8 to 10 reps of the task-oriented training and there were 3 minutes break time between tasks. There were pre-test of gross motor performance and balance abilities, and two times of post-tests were performed upon 6 weeks and 12 weeks after the intervention completed. And in final, an additional follow-up test was performed 12 weeks after the evaluation was finished in order to find any difference between the two groups over time. Results : There was significant difference in Gross Motor Performance Measure (GMPM) between two groups. It is found that average score of the experimental group increased more than the placebo group after 6 weeks and 12 weeks intervention (p<.05). There was significant difference in Pediatric Berg's Balance Scale (PBS) between two groups. It is found that average score of the experimental group increased more than the placebo group after 6 weeks and 12 weeks intervention (p<.05). Conclusion : Based on the results in this study, it is proposed that application of weighted vest into task-oriented training to facilitating closed kinematic chain and multi-joint movement can improve gross motor performance and balance abilities of children with cerebral palsy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3046-3050
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• 2014

The purpose of the present study was to evaluate the effect of 7-point interval scale(EAI) and visual analogue scale(VAS) on perceptual judgement and the reliability of severity on voice problems by dysphonic speakers. 30 undergraduate students studying communication disorder were enrolled in the perceptual evaluation. Those listeners judged overall voice severity within the anchored(condition 1) and non-anchored scales(condition 2) for vowel prolongation and reading tasks by 25 speakers with voice disorder. The results of this study showed that the scores by VAS was significantly higher than EAI in both condition 1 and condition 2 for vowel prolongation and reading task. However, the scores by EAI method was higher than by VAS method on voice severity of vowel prolongation (condition 1) and reading task(condition 2). These results suggest auditory-perceptual scaling procedures must be more studied in the aspects of clinical application of voice disorder.

• Journal of Educational Research in Mathematics
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• v.20 no.3
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• pp.413-444
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• 2010

The purpose of the present study is to develop an instrument of mathematical learning motivation and causal attribution for students and to analyze the results of the instrument. Based on the literature review, mathematical learning motivation is the cumulative effects of self-assessment and self-regulation in mathematical learning and achievement experience. Three factors of mathematical learning motivation is identified as self-regulatory efficacy, task difficulty and mathematical anxiety with 17 self-regulatory efficacy items, 9 task difficulty items and 9 mathematical anxiety items. Three factors of causal attribution for success is identified as ability/effort, luck, and other person with 6 ability/effort items, 4 luck items and 3 other person items. Also, four factors of causal attribution for failure is identified as ability, effort, luck, and other person with 3 ability items, 7 effort items, 3 luck items and 4 other person items. The instrument of mathematical learning motivation and causal attribution for success and failure was administered to 919 middle school students from eight different middle middle schools in Seoul, Gyeonggi-Do, Busan, jeolla-Do area. The correlation of three factors of mathematical learning motivation was calculated. As a result, a positive correlation between self-regulatory efficacy and task difficulty was appeared but mathematical anxiety has a negative correlation with self-regulatory efficacy and task difficulty. This study also examined the differences about mathematical learning motivation's sub-factors shown by three groups of mathematics achievement level. Students of higher achievement level showed that the degree of self-regulatory efficacy and task difficulty was higher than that of lower level group. Students of lowest achievement level showed significantly higher mathematical anxiety degree than that of middle and high group. Students that have higher degree of self-regulatory efficacy and task difficulty preference were attributed into ability/effort cause toward success of mathematics achievement. Also, Male students preferred more difficult task and higher degree of self-regulatory efficacy in mathematics learning than female students. On the contrary, Female students showed higher mathematical anxiety level than male students.

• Journal of The Korean Association For Science Education
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• v.30 no.1
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• pp.68-79
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• 2010

This study utilized the What Is Happening In this Class (WIHIC) questionnaire to examine students' perceptions of their science learning environment. Data was collected from 587 middle school students in seven coeducation schools in Seoul. Higher mean scores occurred on the scales of Student cohesiveness, Task orientation, Cooperation and Equity in the WIHIC, whereas lower mean scores occurred on Teacher support, Involvement and Investigation. The effects of gender on students' perceptions of their science learning environment were not statistically significant overall, but girls perceived Student cohesiveness and Cooperation more positively than boys. Correlations between the WIHIC scales of the low-level group that perceived their learning environments negatively (10 percentiles) and the high-level group that perceived their learning environments positively (90 percentiles) were computed. Teacher support, Involvement, Task Orientation and Investigation were highly correlated with each other in the low-level group, whereas only Teacher support and Equity were correlated in the high group. Educational implications were discussed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.11
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• pp.1000-1009
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• 2013

This study investigated changes in behavioral performance before and after watching a multi-view 3D content by using auditory stimuli based on the selective attention theory in order to quantitatively evaluate 3D visual fatigue. Twenty-one undergraduates were asked to report on their current visual and physical condition both in the pre- and post-experiment. A selective attention task was conducted before and after mobile 3D viewing to compare the changes in performance. After performing a Wilcoxon's matched-pairs signed-ranks test on the subjective ratings of 3D visual fatigue, participants were categorized into two groups, unfatigued and fatigued group with a definite criterion. For the unfatigued group, no significant fatigue effects were found in behavioral response times and accuracies to specific auditory targets. In sharply contrast to the unfatigued group, the fatigued group showed significantly delayed response times and less response accuracies. However, no significant changes in accuracies for a working memory task were observed in both groups.