• Solar Energy
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• v.13 no.2_3
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• pp.53-64
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• 1993

This study investigated heat transfer phenomena during the freezing of an initially superheated or non-superheated liquid in a cooled cylinder tube. Numerical and experimental method were performed to obtatin the temperature and velocity distribution, the shape of interface. Natural convection effects in the superheated liquid were confined and moderated a short freezing time. After natural convection ceases, heat conduction dominated in the whole paraffin, so Crystal and much-zone were found out in PCM. Initial superheating of liquid tended to morderatly diminish the frozen layer thickness at short freezing times but little effect on the these quantities at longer times. On the amount of frozen mass, Iintial liquid superheating is less affected than tube wall subcooling.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.7
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• pp.227-234
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• 2015

USN-based real-time monitoring systems, which receive raw data from sensor nodes and store the processed information in traditional servers, recently get to be replaced by IoT(Internet of Things)/WoT(Web of Things)-based ones. Especially, Social Web of Things(SWoT) paradigm can make use of cloud storage over Social Network Service(SNS) and enable the possibility of integrated access, management and sharing. This paper proposes an improved SWoT-based real-time monitoring system which makes up for weak points of existing systems, and implements monitoring service integrating a legacy sensor network and commercial SNS without requiring additional servers. Especially, the proposed system can reduce emergency propagation time by employing PUSH messages.

• Journal of Chest Surgery
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• v.32 no.8
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• pp.709-714
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• 1999

Background: When internal thoracic artery (ITA) and saphenous vein graft are anastomosed to the same coronary artery, the patency rate of the internal thoracic artery graft with relatively narrow diameter may be decreased owing to competition of pressure and flow rate. We evaluate the clinical outcome and the patency of the ITA graft in patients undergoing dual grafting to the same coronary artery. Material and Method: In 14 patients with the ITA graft having relatively low flow, the ITA and saphenous vein graft were anastomosed to the same coronary artery. During the mean follow-up period of 33.5 months, coronary angiography was performed in 6 patients who complained of recurrent angina, needed confirmation of graft flow, or showed postoperative Q wave. Result: In all 6 patients, the ITA and saphenous vein grafts were patent without stenosis or obstruction. Two patients showed good flow in both grafts, 2 showed competitive flow in the ITA graft, and the remaining 2 showed poor flow in the ITA graft. Conclusion: Early operative closure When saphenous vein grafting was added to the same coronary artery that the internal thoracic artery was anastomosed to, the perfusion to the coronary artery was satisfied and the dual grafting did not affect the short-term and mid-term patency rate of the ITA.

• The Korean Journal of Pain
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• v.21 no.2
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• pp.119-125
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• 2008

Background: Cerebral blood vessels are innervated by sympathetic nerves from the superior cervical ganglia (SCG), and these nerves may influence the cerebral blood flow. The purpose of the present study was to evaluate the neuroprotective effect of superior cervical sympathetic ganglion block in rats that were subjected to focal cerebral ischemia/reperfusion injury. Methods: Eighty male Sprague-Dawley rats (270-320 g) were randomly assigned to one of two groups (the ropivacaine group and a control group). In all the animals, brain injury was induced by middle cerebral artery (MCA) reperfusion that followed MCA occlusion for 2 hours. The animals of the ropivacaine group received $30{\mu}l$ of 0.75% ropivacaine, and their SCG. Neurologic score was assessed at 1, 3, 7 and 14 days after brain injury. Brain tissue samples were then collected. The infarct ratio was measured by 2.3.5-triphenyltetrazolium chloride staining. The terminal deoxynucleotidyl transferase mediated dUTP-biotin nick-end labeled (TUNEL) reactive cells and the cells showing caspase-3 activity were counted as markers of apoptosis at the caudoputamen and frontoparietal cortex. Results: The death rate, the neurologic score and the infarction ratio were significantly less in the ropivacaine group 24 hr after ischemia/reperfusion injury. The number of TUNEL positive cells in the ropivacaine group was significantly lower than those values of the control group in the frontoparietal cortex at 3 days after injury, but the caspase-3 activity was higher in the ropivacaine group than that in the control group at 1 day after injury. Conclusions: The study data indicated that a superior cervical sympathetic ganglion block may reduce the neuronal injury caused by focal cerebral ischemia/reperfusion, but it may not prevent the delayed damage.

• Journal of Service Research and Studies
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• v.8 no.3
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• pp.63-80
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• 2018

This study empirically analyzed impacts of interaction quality and physical environmental quality on university recommendation intention of Chinese international students in Korea. In addition this study analyzed a direct impact of familiarity toward Korea on university recommendation intention, and a moderating impact of familiarity toward Korea on the relationship among interaction quality, physical environmental quality, and university recommendation intentions of Chinese international students in Korea. For empirical analysis, this study collected 204 questionnaires in final from Chinese international students currently living in the KyungBuk province. The analysis result was that all three antecedents interaction quality, physical environmental quality, and familiarity toward Korea positively affect university recommendation intention. And the familiarity to Korea positively moderated the relationship between physical environmental quality and university recommendation intentions. Finally, this study suggested academic and practical implications.

• Management & Information Systems Review
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• v.38 no.3
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• pp.113-125
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• 2019

This study empirically analyzes the effect of SNS informativeness, playfulness and reliability on purchase intention and the effect of consumer's purchase intention on business performance through structural equation model, In doing so, this study aims to suggest ways to enhance consumers' purchase intention and consequently increase the business performance through various SNS marketing strategies that can efficiently manage consumers. The questionnaires were distributed to adult men and women who are in their 20s through 60s, actively use SNS, and primarily reside in Daegu and Gyeongbukdo. The 400 copies of questionnaire were distributed from September 15 to October 1, 2018, of which 364 (91%) were used for the empirical analysis, except for 36 of the questionnaires that were unfaithful or unresponsive. Basic statistical analysis including frequency analysis was performed using SPSS 22.0 and AMOS 24.0, reliability and validity analysis were also performed, and finally hypotheses were tested by performing confirmatory factor analysis and path analysis of structural equation model. All of the SNS informativeness, playfulness and reliability were shown to have positive effects on the purchase intention. In addition, the effect of purchase intention on business performance was found to be significant. Companies should come up with a strategic SNS marketing plan to encourage consumers to enhance the willingness to purchase their products and services through SNS, and to make actual purchases, thereby improving business performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.366-376
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• 2019

Youth unemployment reached a record high in 2017, and business revitalization is emerging as a means of overcoming this situation. The number of venture companies and amounts of new venture investments are increasing year on year, and the government has upgraded Small and Medium Business Administration to the Ministry of SMEs and Startups. However, the success rate of startups is relatively poor. Over the past three years only 39.1% of Korean startups survived and 90% of companies failed in the Valley of Death phase. Survival this phase is critical for early startups, and thus, the amount and timing of investments are critical. Current models for establishing business startups do not effectively attract investments because they lack practical, corporate evaluation variables. In this paper, we develop a mixed process that incorporates the factors and business models focused on by venture capital investors. In addition, we compared our Death Valley Venture (DVV) process with current methods and provide an example of its application.

• The Journal of the Korea Contents Association
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• v.22 no.8
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• pp.542-556
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• 2022

The purpose of this study is to investigate the effect and difference of hotel chef's peer pressure on self-efficacy and collective efficacy, and to examine the relationship between job satisfaction and job performance. For the study, questionnaires were distributed to 6 hotels in Seoul and Busan, and 285 valid copies were analyzed using SPSS 25.0 and AMOS 25.0. In the relationship between variables, collective efficacy was found to have a greater effect on peer pressure among collective efficacy and self-efficacy. And it was found that among self-efficacy, self-efficacy had a greater effect on job satisfaction, and this was collective efficacy due to peer pressure. It is judged that this is due to the professional characteristics and characteristics of the chef, where individual work and skills are important. Also, job satisfaction was found to have a positive effect on job performance. In conclusion, we suggested that these two dimensions of efficacy should be studied together and used in human care programs.

• Korea Trade Review
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• v.41 no.2
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• pp.1-28
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• 2016

The purpose of this study is to identity the relationship between CAGE distance and Korean foreign subsidiaries' social responsibility, which is divided into responsive and strategic activities. The hypothesis is that CAGE distance has positive relationships with subsidiaries' social responsibility to overcome local liabilities of foreignness and acquire social legitimacy. The key findings are as follows. Firstly, culture distance has positive significant impacts on subsidiaries' social responsibility activities. It especially has positive influences on strategic CSR. Secondly, administration distance has no impacts on subsidiaries' social responsibility. Thirdly, geographic distance also has positive impacts on subsidiaries' social responsibility activities, especially on responsive CSR. Lastly, economic distance has significantly negative effects on social responsibility. This empirical study identifies the relationships between cross national distance and subsidiaries' social responsibility. Culture and geographic distance has positive influences on subsidiaries' social responsibility. Market seeking subsidiaries group shows more positive relationship between culture distance and social responsibility activities, which means that foreign subsidiaries would engage in social responsibility activities for strategic purpose.

• The Journal of the Korea Contents Association
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• v.20 no.4
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• pp.427-440
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• 2020

This study is a study on the cooking department where chefs who belong to the desired job of elementary and middle school students work together with the recognition increase through the media. The cooking department, which has a vertical structure at work, can be said to have an absolute influence of the chef. However, the cooking department needs to change according to the times. The purpose of this study was to examine how chef's shared leadership affects the chef's emotional commitment, continuous commitment, job satisfaction, and job performance. Therefore, a questionnaire was distributed to the employees currently working in the cooking department of a five-star hotel in Seoul, and a sample of 319 copies was prepared. In statistical analysis, the items were refined through exploratory factor analysis, confirmatory factor analysis, reliability analysis, and correlation analysis, and the hypotheses were verified through structural model analysis.As a result, Chef's shared leadership influences the emotional commitment of cooks, job satisfaction and job performance. In particular, emotional commitment and continuous commitment did not affect cooks' job satisfaction and job performance. In conclusion, to improve the performance of the organization, the hotel culinary department must establish a culture of sharing and communication. This suggests that establishing goals and visions will lead to job satisfaction and performance not only for individual cooks but also for the entire department. Therefore, it is expected to contribute to the efficient human resource management for the cooks in the hotel cooking department.