• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.1
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• pp.82-88
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• 2017

This study proposes a new topology for the performance test of a valve consisting of a modular multilevel converter (MMC)-based static synchronous compensator (STATCOM). The conventional valve performance test equipment requires high-voltage AC source of several kV rating because the number of submodules to be tested in a valve should be at least six or eight. However, the power source of the proposed scheme is DC and not AC source. The DC power source voltage range of the proposed test circuit is from several volts to several tens of volts. Therefore, the size and cost for the performance test equipment can be reduced considerably compared with the conventional method. The proposed scheme satisfies the requirements of the IEC 62927 standard. Simulations are conducted for a valve of 50[MVA] MMC-based STATCOM. Experimental results with a scale-downed setup show the validity of the proposed performance test topology.

• Journal of Information Technology Applications and Management
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• v.17 no.3
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• pp.83-97
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• 2010

The purpose of this study is to examine the impacts of media symbol variety on group performance in virtual teams. Symbol variety is defined as the number of ways in which information can be communicated and includes Daft and Lengel [1986]'s multiplicity of cues and language variety. According to media richness theory and media synchronicity theory, the use of media with high symbol variety is assumed to facilitate and promote communications among virtual team members. Therefore, it is expected that the media symbol variety is positively associated with group performance in virtual teams. Furthermore, online relationship building is expected to mediate the impacts of symbol variety on the performance. To confirm the suppositions, a controlled lab experiment was conducted with 60 undergraduate students as subjects. In the experimental virtual teams, subjects were allowed to communicate with other members using text-based messenger with emoticons. Subjects in the control virtual teams were allowed to communicate using only text-based messenger. The direct impact of symbol variety on group performance in virtual teams was found insignificant. However, the online relationship was found to completely mediate the positive impact of symbol variety on group performance. The implications and limitations of this study are also discussed for future research.

• Management & Information Systems Review
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• v.13
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• pp.27-47
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• 2003

The strategic usages of IT(Information Technology) can convey important competitive advantages with an operational productivity. For this reason, many firms have heavily invested in IT and computing power. However, many companies were getting expected results by IT investment, but some companies had to be satisfied with a poor results. The question of whether or not benefit lead to expected performance is not easy to answer. The purpose of this study was to investigate the relationship among IT strategy, IT investment, and IT performance to resolve this problem. The 147 questionnaire responses completed by IS managers in manufacturing sector was conducted for a test of research hypothesis. ANOVA was used to investigate the relationship among three constructs and six factors. An operational performince of fitted group between IT strategy and IT investment was higher than not fitted group(H1). And also an competitive performance of fitted group between IT strategy and IT investment was higher than not fitted group(H2). The study shows a positive relationship between IT strategic orientation, IT investment direction, and performance of IT. The research results provide empirical evidence that supports the research hypothesis that closer fit between IT strategies and IT investment directions does lead to increase operational and competitive performance of IT.

• Journal of The Korean Society of Integrative Medicine
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• v.7 no.4
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• pp.273-282
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• 2019

Purpose : The purpose of this study was to provide the effective method for exercise therapy in soccer player. Methods : 30 soccer players were recruited for subjects. The subjects were divided to dynamic stretching exercise combined tDCS (Group I), dynamic stretching exercise combined Sham-tDCS (Group II) of which 15 subjects were randomly allocated. The subjects were given 3 hour of soccer skill and performance and additionally given 20 minutes of dynamic stretching exercise combined tDCS and sham-tDCS for each group, five times a week, for 6 weeks. Their muscle activity and jump performance were analyzed before the intervention. After 6 weeks of the intervention, the mentioned parameters were measured once more for between-group analysis. Results : Comparative analysis of the muscle activity and jump performance between the groups I and groups II showed statistically significant difference. Conclusion : Such results revealed that dynamic stretching exercise combined with tDCS is effective in muscle activity and jump performance. Based on the current study, more effective program is to be proposed for neurologic and musculoskelectal disorder as well as soccer player. Based on the current study, studies that incorporates various combine of variable is required for development of effective tDCS program.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.3
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• pp.201-208
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• 2005

This study presents the experimental study on improvement of frost/defrost performance in an heat pump system with newly developed fin and multiple compressors. As multiple compressors system, the variable and single speed compressor combinations has been introduced and compared with single speed 1-compressor system in a view point of improvement of frost/defrost performance. Also, newly developed corrugate shaped fin has been compared with conventional louver shaped fin. The frost/defrost performance is defined and some parameters are compared to discuss the effect of each combination. From this experimental study, it is known that if the variable and single speed compressor combination system equipped with corrugate shaped fin, the system performance has greatly improved not only for heating capacity, but also for frost performance.

• Journal of Korean Academy of Nursing
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• v.45 no.3
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• pp.429-438
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• 2015

Purpose: This study was conducted to develop key performance indicators (KPIs) for home care nursing (HCN) based on a balanced scorecard, and to construct a performance prediction model of strategic objectives using the Bayesian Belief Network (BBN). Methods: This methodological study included four steps: establishment of KPIs, performance prediction modeling, development of a performance prediction model using BBN, and simulation of a suggested nursing management strategy. An HCN expert group and a staff group participated. The content validity index was analyzed using STATA 13.0, and BBN was analyzed using HUGIN 8.0. Results: We generated a list of KPIs composed of 4 perspectives, 10 strategic objectives, and 31 KPIs. In the validity test of the performance prediction model, the factor with the greatest variance for increasing profit was maximum cost reduction of HCN services. The factor with the smallest variance for increasing profit was a minimum image improvement for HCN. During sensitivity analysis, the probability of the expert group did not affect the sensitivity. Furthermore, simulation of a 10% image improvement predicted the most effective way to increase profit. Conclusion: KPIs of HCN can estimate financial and non-financial performance. The performance prediction model for HCN will be useful to improve performance.

• 한국전산유체공학회:학술대회논문집
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• 2006.05a
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• pp.209-210
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• 2006

• Journal of Korean Academy of Nursing
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• v.36 no.3
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• pp.532-541
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• 2006

Purpose: This study was conducted to verify the effects of an education program of restraints use on nurses' knowledge, attitude and nursing performance related to restraints use. Method: A quasi experimental study with a pre and post non-equivalent design was used. The subjects were nurses who met the selection criteria and worked in intensive care units of two university hospitals located at K-city, Gyeongbuk. Twenty nurses in A hospital were designated as the experimental group and 20 nurses in B hospital as the control group. Result: The first hypothesis which assumed that the experimental group would have higher scores of knowledge than the control group was supported(F=62.66, p=0.000). The second hypothesis which assumed that the experimental group would have lower scores of attitude toward using restraints than the control group was supported(F=23.77, p=0.000). The third hypothesis which assumed that the experimental group would have higher scores of nursing performance than the control group was supported(F=3.28, p=0.032). Conclusion: An education program for nurses' on the use of restraints needs to be introduced to decrease inappropriate use of restraints.

• The Journal of Korean Academic Society of Nursing Education
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• v.16 no.2
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• pp.292-300
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• 2010

Purpose: This study examined the effects of Testicular Self-Examination (TSE) small-group education on knowledge, self-efficacy, and performance intention in male college students. Method: A non-equivalent pre-post test of quasi-experimental design was used. Out of 74 male college students selected by convenient sampling, 37 students were assigned to the experimental group and were given TSE small-group education. A 60-minute program consisted of lecture, demonstration, practice, discussion, and Q&A. Result: With an initial homogeneity between the two group, scores of knowledge about testicular cancer (p<.001), self-efficacy for TSE (p<.001), and performance intention of TSE (p<.01) of the experimental group were significantly higher than those of the control group after the intervention. Conclusion: Small group education for TSE was effective in improving knowledge about testicular cancer, self-efficacy for TSE, and intention to perform TSE. Thus, this education program is considered to be useful for testicular cancer prevention and reproductive health promotion in male college students.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.1
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• pp.151-161
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• 2021

Purpose : This study was to investigate the effectiveness of ESWT and plantar fascia-specific stretching exercise vs ESWT and high-load strengthening exercise in patients with chronic plantar fasciitis. Methods : The subjects were randomized to extracorporeal shock wave therapy ( ESWT, for 3 weeks) and daily plantar-specific stretching (Group I: Stretch group) or ESWT and high-load progressive strength (Group II: Strength group) performed every second day. The main outcome measures were ultrasound, visual analogue scale (VAS), and Korean Foot Function Index (KFFI). The ultrasound (plantar fascia thickness), pain intensity I, II (the most painful of the day?, the pain when you first step in the morning?) and KFFI (functional performance) were compared between the groups. Results : No significant difference was observed between the groups in the plantar fascia thickness but pain intensity I, II was significantly lower in Group 2 than in Group 1 at only 12weeks and functional performance was also significantly increased in Group 2 compared to Group 1 at only 12 weeks. Conclusion : The high-load strengthening exercise consisting of the progressive exercise protocol, resulted in superior after 12 weeks compared with plantar-specific stretching. High-load strength exercise may aid in a quicker reduction in pain and improvements in functional performance.