• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1262-1269
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• 2003

In structural optimization, static loads are generally utilized although real external forces are dynamic. Dynamic loads have been considered in only small-scale problems. Recently, an algorithm for dynamic response optimization using transformation of dynamic loads into equivalent static loads has been proposed. The transformation is conducted to match the displacement fields from dynamic and static analyses. The algorithm can be applied to large-scale problems. However, the application has been limited to size optimization. The present study applies the algorithm to shape optimization. Because the number of degrees of freedom of finite element models is usually very large in shape optimization, it is difficult to conduct dynamic response optimization with the conventional methods that directly threat dynamic response in the time domain. The optimization process is carried out via interfacing an optimization system and an analysis system for structural dynamics. Various examples are solved to verify the algorithm. The results are compared to the results from static loads. It is found that the algorithm using static loads transformed from dynamic loads based on displacement is valid even for very large-scale problems such as shape optimization.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.7
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• pp.673-678
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• 2013

Driving gear units can be affected by various problems, including those associated with external or internal defects in the bearing, problems with the lubricant oil, high-loading of the railway, and frequent impacts generated by rail joints. Temperature monitoring is a basic method in diagnosing abnormal conditions in the reduction gear and other components. This paper describes a new wireless monitoring system for the temperature diagnosis of abnormal conditions of the reduction gear. Integrated circuit (IC)-type temperature sensors were installed in the reduction gear box of a high-speed railway car. The temperature data from the reduction gear were acquired and analyzed in situ during high-speed rail operation. Analysis of these data was used to alert the driver and/or maintenance personnel when problems occurred.

• Culinary science and hospitality research
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• v.11 no.2
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• pp.48-66
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• 2005

This study focused on the culinary curriculums intorduced at the high school, college and university levels in order to analyze the current status and problems associated with the management of culinary related courses, and an effort was made to introduce measures to facilitate the further development of culinary education programs. This study can be summarized as follows: First, the external and internal factors which have led to the changes in the educational environment of the culinary education programs were analyzed. Second, the current state of the management of culinary education was analyzed by focusing on the vocational characteristics of the human resources presently engaged in the culinary field, the state of the management of the culinary courses offered in vocational high schools, colleges, and universities, as well as the characteristics and problems associated with the culinary curriculums at each school level. Lastly, based on the above-mentioned state of the management and the problems associated with culinary education programs, the researcher introduced four measures which were designed to facilitate the education of highly-skilled human resources in the culinary field.

• Korean Parent-Child Health Journal
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• v.20 no.1
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• pp.1-9
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• 2017

Purpose: This study aimed to investigate problem behavior and its related factors in school-aged children. Methods: A descriptive correlational study was conducted with 221 mothers of children at 1st to 6th grades. Data were collected from March to April, 2015 using self-report structured questionnaires. Questionnaires included characteristics of subjects, Korean Child Behavior Checklist for measuring problem behavior and Children's Sleep Habits Questionnaire for assessing sleeping habits. Collected data were analyzed by independent t-test, $x^2$ test, and multiple logistic regression. Results: In logistic regression analysis, having any maternal job (aOR=2.8, 95% CI=1.1~6.9) and higher daytime sleepiness (aOR=2.9, 95% CI=1.2~7.4) were statistically significant contributors of internal problems. Higher bedtime resistance (aOR=2.2, 95% CI=1.0~4.9) and higher daytime sleepiness (aOR=2.8, 95% CI=1.2~6.3) were statistically significant contributors of external problems. Higher bedtime resistance (aOR=4.3, 95% CI=1.5~12.4) was statistically significant contributors of total problem behavior. Conclusion: School-aged children with sleeping problem are at risk for problem behavior. More attention is need to consider sleeping habits for supporting behavioral improvement in school-aged children.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.8
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• pp.1363-1370
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• 2003

In structural optimization, static loads are generally utilized although real external forces are dynamic. Dynamic loads have been considered in only small-scale problems. Recently, an algorithm for dynamic response optimization using transformation of dynamic loads into equivalent static loads has been proposed. The transformation is conducted to match the displacement fields from dynamic and static analyses. The algorithm can be applied to large-scale problems. However, the application has been limited to size optimization. The present study applies the algorithm to shape optimization. Because the number of degrees of freedom of finite element models is usually very large in shape optimization, it is difficult to conduct dynamic response optimization with the conventional methods that directly threat dynamic response in the time domain. The optimization process is carried out via interfacing an optimization system and an analysis system for structural dynamics. Various examples are solved to verify the algorithm. The results are compared to the results from static loads. It is found that the algorithm using static loads transformed from dynamic loads based on displacement is valid even for very large-scale problems such as shape optimization.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.258-259
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• 2017

As the use of advanced quality materials in constructions has been increasing since 1980 with the improvements in the quality of life and economic scale, there has been drastic increase in constructions using stones for the internal and external construction materials. However, the reality is where many problems rise due to improper construction and management of uncertified stones which shorten the expiry date of the stones and act as the factor causing defects in buildings. Such defects not only bring economic losses but also influence consumer choice and act as risk factors to demand expansion of stone market. Therefore, the object of this study lies on proposing plans to prevent personal and economical losses due to repetitive defects by deriving the types of defects generated by process in stone constructions and identify the causes. Also, proposing construction process management plans as the measure for defect prevention, analyzing problems of stone constructions followed by the whole proves of design, construction and maintenance of stones, and solving such problems through appropriate participation of professional consultants depending on situations.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.3
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• pp.143-155
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• 2011

Recently, in forest areas of Gyeonggi-Do where golf courses are developed indiscriminately due to the rapid increase in demand, two and three golf courses are being concentrated and combined to develop and it's occurring lots of problems. This study therefore, aims to examine their problems and propose environment-friendly improvements of combined development, by analyzing laws related to golf course's location and the current location status. The results of this study are as followings; Firstly, when analyzing related laws, it was found that unified standards should be established in relation to regulation of the external conditions of golf course sites and individual index. Secondly, standards of a proper separated distance are needed, when developing golf courses. Thirdly, we need to preferentially preserve areas where should be protected environmentally, and establish criteria approving golf courses built close to the boundary of a buffer area only, by introducing the concepts of a buffer area based on the UNESCO MAB. Lastly, we have to set up criteria considering Network elements for maintaining the connectivity of the ecosystem.

• Journal of Fisheries and Marine Sciences Education
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• v.23 no.3
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• pp.515-525
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• 2011

Due to changes in internal and external environment of coastal & offshore fishery such as decrease in coastal & offshore fishery resources, rising labor costs, rising gas prices, rising turnover rate of seamen, and intensified avoiding 4D types of business, the domestic seamen's avoidance of going to sea is being intensified. In order to solve the problems of domestic seamen shortage, coastal & offshore fishery businesses prefer to employ foreign seamen whose wages are relatively low, so employment of foreign seamen continues to increase. However, the foreign seamen system has the problems in selecting and managing seamen but these problems have been not adequately dealt with, so damages to fishery business continue to occur due to the seamen's deserting. The cases, in which foreigners who entered the country to take the sea in coastal & offshore fishing boats deserted their workplace, recorded 36.4% as of 2010. So in order to achieve the purpose of the foreign seamen system itself through rational management of foreign seamen, the exclusive organization to manage foreign seamen should be established and the system to rationally select foreign seamen who have experiences of fishery should be established. The utilization of foreign seamen during off season needs to be maximized by establishing the employment connection system for the management of foreign seamen and employment stabilization, and the exclusive organization for education of foreign seamen and the organization for nurturing domestic seamen need to be established and operated.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.12
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• pp.1252-1256
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• 2007

U-learning (ubiquitous learning) systems, which deliver learning materials anytime and anywhere, allow learners to watch live lectures on PDAs, tablet PCs and notebook computers via broadband and wireless Internet. These systems have various problems; first, terminal devices are expensive, and it is difficult to maintain their efficiencies. Secondly, Internet does not guarantee quality of service (QoS), and in general it does not provide real-time services. Finally, the security of these systems is weaker in a local network than in an external network. The USB-based terminal system based on the OSGi service platform was designed as a ubiquitous system, in order to solve those problems. The USB terminals, used in this system, are inexpensive, and it is easy to maintain their performances. Also, this system solves the problems of security in a local network and provides guaranteed QoS. To accomplish this, the number of USB terminals connected to the system has to be limited according to the formula proposed in our paper. This system uses the OSGi specification as a middleware. It supports the discovery mechanism of the USB terminals, maintenance and administration of the system. Finally, this paper shows a driver's license testing system as an example u-learning application1.

• The Journal of Korean Society for School & Community Health Education
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• v.19 no.3
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• pp.95-108
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• 2018

Objectives: The purpose of this study was to investigate the actual conditions and operational problems of Health Promotion Model School' in high school. Methods: We conducted a content analysis of 2014 results report and staffs' responses of five high schools among 85 'Health Promotion Model Schools' led by Ministry of Education from 2012 to 2014. Results: The study examined the operational process of health promoting schools in five stages; system development, needs survey & current status survey, school health policy development, program development & execution, and evaluation. Every step was found to be inadequate. In addition, the study discovered three key factors in operating health promoting schools and examined the status of each factor; connection with the curriculum, connection with the community, and consensus among members. Three factors were also applied poorly. Compared to elementary school, high school showed a lack of all respects. Health promoting school staffs have faced difficulties in linking community resources, organizing and operating a working committee, conducting surveys and assessing health problems, preparing self-assessment or external evaluation, and developing strategies and programs. In order to solve the operational problems, active cooperation of all teachers is urgent. Conclusion: 'Health Promotion Model School' conducted in high school is not considered to have faithfully implemented WHO's concept of health promoting school. In the future, incentive policies for health promoting school teachers should be actively reviewed.