• KIEAE Journal
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• v.17 no.1
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• pp.69-75
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• 2017

Purpose: Heat transfer analysis of recently developed 'slim type double-skin system window' were presented. This window system is designed for curtain wall type façade that main energy loss factor of recent elegant buildings. And the double skin system is the dual window system integrated with inner shading component, enclosed gap space made by two windows when both windows were closed and shading component effectively reflect and terminate solar radiation from outdoor. Usually double-skin system requires much more space than normal window systems but this development has limited by 270mm, facilitated for curtain wall façade buildings. In this study, we estimated thermophysical phenomena of our double-skin curtain wall system window with solar load conditions at the summer season. Method: A fully 3-Dimentional analysis adopted for flow and convective and radiative heat transfer. The commercial CFD package were used to model the surface to surface radiation for opaque solid region of windows' frame, transparent glass, fluid region at inside of double-skin and indoor/outdoor environments. Result: Steep angle of solar incident occur at solar summer conditions. And this steep solar ray cause direct heat absorption from outside of frame surface rather than transmitted through the glass. Moreover, reflection effect of shading unit inside at the double-skin window system was nearly disappeared because of solar incident angle. With this circumstances, double-skin window system effectively cuts the heat transfer from outdoor to indoor due to separation of air space between outdoor and indoor with inner space of double-skin window system.

• Journal of Families and Better Life
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• v.27 no.1
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• pp.73-88
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• 2009

The purpose of this study was to investigate the influence of the factors such as self-esteem, social supports, socio-economic status of parents, degree of disability in child, stress coping, religion, and sports.exercise on the qualities of lives in mothers with disabled children. Data were collect from 45 institutions(schools from kindergarten to senior-high, special education institutes, and social welfare institutions) by self-report questionnaire, and the subjects of the study were 386 mothers in Seoul whose children were attending the schools or institutions. Findings according to socio-demographic variables are as follows: 1. Mothers with disabled children in this study thought their quality of life as average degree. 2. The younger the mothers and children, the higher the quality of life was. 3. The higher the educational level and monthly income, the higher the quality of life was. 4. There was no statistically significant difference between the existence and nonexistence of spouse, and between the existence and nonexistence of religion as well. Findings analyzed by multiple regression are as follows: 1. Among 7 independent variables 'self-esteem'(${\beta}$=.49, p<.001), 'social supports'(${\beta}$=.15, p<.01), and 'socio-economic status'(${\beta}$=.11, p<.05) were found to be statistically significant in quality of life in mothers, while the rests were found not significant. 2. 'Self-esteem' was found to be the most influencing variable, meaning that the psychological factor such as self-esteem is more important than environmental factors in qualities of lives in mothers. 3. The total amount of explanation of the model was Adjusted R square=.301, so that it can be said about 30% can be explained among total variance of the qualities of lives in mothers with disabled children. Conclusions and recommendations based on the results above are: First, it is strongly recommended to conduct programs promoting self-esteem in mothers with disabled children, and to include 'self-esteem' hereafter in the studies related to qualities of lives in mothers with disabled children. Second, comprehensive and practical countermeasures should to be formulated to back up expenses for education and medical care, purchasing relative tools and equipments, plus helping to find jobs.

• Korean Journal of Construction Engineering and Management
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• v.16 no.1
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• pp.24-34
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• 2015

As recent multilateral collaboration design system has been advanced, BIM based data exchange is a key factor for successful next generation building project. Even though many studies have been trying to set up a data compatibility system for collaboration, There are still a lot of problem in data exchange between design and engineering phase. Therefore, In this study, we analysis causes of problem for information exchange and suggest a IFC based Information exchange framework for improving BIM based design collaboration environment. In order to find out problems that hinder establishment of advanced open BIM information exchange, proper analysis about transition of process from current and to-be BIM based design collaboration process is important, at first. From analysis of main obstacles to information exchange, this research suggests solution plan using open API and IFC based BIM collaboration supporting system. The suggested open API solution named Integrity feedback system perform a role making up for weak point derived from IFC based data exchange. And main system suggestion about framework for IFC based information exchange reflect technological system support, requirement of function for collaboration including API/BCF plug-in.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.4
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• pp.29-39
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• 2009

The need for radio spectrum is recently considered as a huge hurdle towards the rapid development of wireless networks. Large parts of the spectrum are allocated to licensed radio services in proprietary way. However, enormous success of the wireless services and technologies in the unlicensed bands has brought new ideas and innovations. In recent years cognitive radio has gained much attention for solving the spectrum scarcity problem. It changes the way spectrum is regulated so that more efficient spectrum utilization is possible. Multi-hop relay technology on the other hand has intensively been studied in the area of ad hoc and peer-to-peer networks. But in cellular network, only recently the integration of multi-hop capability is considered to enhance the performance significantly. Multi-hop relaying can extend the coverage of the cell to provide high data rate service to a greater distance and in the shadowed regions. Very few papers still exist that combine these methods to maximize the spectrum utilization. Thus we propose a network architecture combining these two technologies in a way to maximize the system throughput. We present the throughput capacity equations for the proposed system model considering various system parameters like utilization factor by the primary users and primary users' transmission radius and through extensive numerical simulations we analyze the significance of work.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.6
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• pp.88-96
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• 2011

Underwater acoustic communication is applicable in various areas, such as ocean data collection, undersea exploration and development, tactical surveillance, etc. Thus, robot control system construction used for underwater-robot like AUV or ROV is essential in these areas. In this paper, we propose the Message Merging MAC($M^2$-MAC) protocol, which is suitable for real time robot control system, considering energy efficiency in important parts of underwater acoustic sensor network constitution. In this proposed MAC protocol, gateway node receives the data from robot nodes according to the time slots that were allotted previously. And messages delivered from base-station are generated to one MAC frame by buffering process. Finally, generated MAC frames are broadcasted to all robot nodes in the cluster. Our suggested MAC protocol can also be hybrid MAC protocol, which is successful blend of contention based and contention-free based protocol through relevant procedure with Maintenance&Sleep (M&S) period, when new nodes join and leave as an orphan. We propose mathematical analysis model concerned about End-to-End delay and energy consumption, which is important factor in constructing real-time robot control system. We also verify the excellence of performance according to comparison of existing MAC protocols with our scheme.

• Industry Promotion Research
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• v.5 no.1
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• pp.47-52
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• 2020

In this study, parallel work-learning training, which was started in 2013 as a pre-employment promotion policy, is an important factor that determines the success or failure of training. As a time when various institutional supplementation is needed to encourage company participation, this study is to identify the factors of participation of companies participating in work-learning parallel. To this end, a questionnaire survey was conducted of companies participating in parallel work-learning in Chungnam, and the results were analyzed using the structural equation model. As a result of the study, the reason for the company's participation in parallel work-learning was firstly, 84% of government subsidy received education and training expenses. Second, 66% of workers were able to pay less than regular workers, and thirdly, it was easy to hire new employees in the field. 26%, 17% of them were invited by acquaintances for no particular reason. Therefore, the study suggests that participation in the work-learning parallel training contributes to the management costs, management of employee turnover, and human resource development. In future research, it is necessary to subdivide tests and estimates by conducting studies on regions, occupations, gender, wages, and years of service in Korea.

• Culinary science and hospitality research
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• v.20 no.6
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• pp.275-291
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• 2014

The focus of this study was to investigate the relationships of blog's reliability, perceived benefit, perceived risk and words of mouth by online readers. Data were collected by a total of 228 persons reading actively gourmet blogs. The survey was carried out from August 1 to 15, 2014. Total 228 questionnaires were used for final analysis. Frequency analysis, descriptive statistics, exploratory factor analysis, and reliability analysis were conducted through SPSS 18.0 for final analysis, and regression analysis was conducted through AMOS 18.0 for verification of hypothesis. The hypothesized relationships among the models were tested simultaneously by using a structure equation model(SEM). The study results are like below. First, The reliability of the Gourmet blog could be confirmed again very important variable in the fields of food industry like the previous studies. Second, The reliability of the Gourmet blogs affected on the positive (+)relationship to the perceived benefits, and the negative (-)relationship to the perceived risk. Third, Reliability and perceived benefits in relation to the impact on the online word-of-mouth was positive(+). However, perceived risk was found not to affect on it. Finally, perceived benefits for the reliability of the blog have been identified as the key parameters on the online word-of-mouth. The theoretical contributions of this study and the practical implications are discussed and future research directions are detailed.

• Journal of Korean Medicine Rehabilitation
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• v.30 no.3
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• pp.57-69
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• 2020

Objectives The aim of this study was to investigate the inhibitory effect of ChondroT in indomethacin-induced gastric mucosal injury rat model. Methods Sprague-Dawley rats were randomly assigned to intact, control Joins, Celebrex, ChondroT50 and ChondroT200. Indomethacin (25 mg/kg) was used to induce damage to the gastric mucosal injury. ChondroT was administered by orally to inhibit the indomethacin-induced gastric mucosal injury. At the end of the experiment, pH level in stomach, stomach contents volume, tumor necrosis factor-α (TNF-α) level, interleukin-1β (IL-1β) level, prostaglandin E2 (PGE2) level, myeloperoxidase (MPO) activity, erythrocytes, and thrombocytes were measured. Ophthalmologic and histopathological examination was also analyzed. Results pH level in stomach and Stomach contents volume had no difference between Control, PC-Joins, PC-Cele, ChondroT50 and ChondroT200 group. TNF-α level was decreased in PC-Joins, PC-Cele, ChondroT50 and ChondroT200 group and there were no significant difference. IL-1β level was decreased in PC-Joins group and ChondroT200 group compared to control group. PGE2 level had no significant difference between Control, PC-Joins, PC-Cele, ChondroT50 and ChondroT200 group. MPO level and complete blood count level were decreased in PC-Joins, PC-Cele, ChondroT50 and ChondroT200. Symptom score of ophthalmologic examination was decreased in ChondroT50 and ChondroT200 group compared to control group. Conclusion Based on these results, It could be suggested that ChondroT was effective in reducing damage to the gastric mucosal injury. And further study is needed to conduct a rigorous clinical research.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.1
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• pp.73-78
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• 2012

Excessive intake of trans fats is known to be a risk factor for cardiovascular diseases. Previously, we have shown that green tea extract (GTE) lowers the intestinal absorption of lipids and lipid-soluble compounds in rats. This study was conducted to investigate a possible role of GTE on the lymphatic absorption of elaidic acid, a major trans fat in the diet. Adult male Sprague-Dawley rats with lymph duct cannula were infused via an intraduodenal catheter at 3.0 mL/hr for 8 hr with a lipid emulsion containing $180.0{\mu}mol$ elaidic acid, $400.0{\mu}mol$ triolein, $20.7{\mu}mol$ cholesterol, $3.1{\mu}mol$ ${\alpha}$-tocopherol, and $396.0{\mu}mol$ sodium-taurocholate with or without (control) GTE in a 24 mL PBS buffer (pH, 6.4). Simultaneously, lymph was collected hourly for 8 hr via the lymph duct cannula. There was a significant difference in lymph flow by GTE. Also, the lymphatic absorption of elaidic acid for 8 hr was significantly lower in rats infused with GTE than in those not infused with GTE. Similarly, GTE infusion decreased the lymphatic outputs of cholesterol, oleic acid, and phospholipids, compared with the controls. These findings provide clear evidence that GTE has an inhibitory effect on the intestinal absorption of elaidic acid and other lipids. Our work here provides the foundation for further studies to examine and evaluate dietary strategies to ameliorate dietary trans fats from the diet.

• Korean Journal of Social Welfare
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• v.67 no.3
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• pp.83-105
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• 2015

This study has two objectives. First, it examines the relationship between organizational trust and error management culture. Second, it also examines the effect of social workers' perceived work value on the combined model by considering the unique characteristics of social work profession and social desirability. This study employs the stratified sampling method on social workers with more than two year work experiences in their current social service agencies that are located in Seoul and Kyungki province; finally it analyzes the responses from 564 social workers by using the method of multiple regression modeling. This study has the following results: (1) there is a causal relationship between social desirability and organizational trust perceived by social workers; (2) there is a positive causal relationship between social workers' perceived work value and organizational trust; and (3) there is also a positive causal relationship between factor structure of error management culture and organizational trust. This study discusses the theoretical and practical implications of the results.