• Communications for Statistical Applications and Methods
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• v.28 no.5
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• pp.511-520
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• 2021

Over the last decade, Bitcoin has attracted a great deal of public interest and Bitcoin market has grown rapidly. One of the main characteristics of the market is that it often undergoes some events or incidents that cause outlying observations. To obtain reliable results in the statistical analysis of Bitcoin data, these outlying observations need to be carefully treated. In this study, we are interested in change point analysis for Bitcoin return series having such outlying observations. Since these outlying observations can affect change point analysis undesirably, we use a robust test for parameter change to locate change points. We report some significant change points that are not detected by the existing tests and demonstrate that the model allowing for parameter changes is better fitted to the data. Finally, we show that the model with parameter change can improve the forecasting performance of Value-at-Risk.

• Proceedings of the KIPE Conference
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• 2003.07b
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• pp.639-643
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• 2003

We are interested in this paper on the control of an electromechanical system consisting of a doubly-fed induction generator(DFIG), driven by a prime mover that can supply or extract mechanical power, e.g., a flywheel inertia, and an induction motor(IM). The stator of the Induction machine is connected to the stator of the generator whose rotor voltage is regulated by a bidirectional converter. The main interest of this configuration is that it permits a bidirectional power flow between the motor, which may operate in regenerative mode, and the generator We propose a passivity-based controller to regulate the motor mechanical speed. Since this kind of controllers achieve stabilization via energy balancing, regulation of the power flow in the system is naturally incorporated. Simulation results are presented to illustrate the main points of our paper.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.593-594
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• 2006

• The Journal of Industrial Distribution & Business
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• v.9 no.9
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• pp.45-52
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• 2018

Purpose - This case study is dedicated to the study of the presence of KIA Motors in the Kingdom of Saudi Arabia (KSA) and its market and entry strategies for strategic globalization that allowed the company to establish itself within a conservative and clustered marketplace dominated by American and Japanese international brands. Research Design, data, and methodology - The main information for the case was gathered through an interview and questionnaire from the executives of the KIA Al Jabr, which got the exclusive dealership in Saudi Arabia. Moreover, secondary data were obtained from reliable and authoritative sources such as the Saudi government agency publications, newspapers, international business journals. Other related periodicals based on the results from previous and current studies on similar topics were critically reviewed as well. Results - The findings of this paper show the different business environments of the Saudi market and the importance of various points regarding the company's global entry strategy even if the host market culture is quite different in many ways from other international markets. Conclusions - This case can provide Korean companies interested in the Middle East with insight into market penetration and global strategy, and present various perspectives and implications for global market access as well.

• Journal of Digital Convergence
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• v.12 no.7
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• pp.239-245
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• 2014

In this paper, a weighted value wrinkle detection method is suggested based on the analysis on the entire facial features such as face contour, face size, eyes and ears. Firstly, the main facial elements are detected with AAM method entirely from the input screen images. Such elements are mainly composed of shape-based and appearance methods. These are used for learning the facial model and for matching the face from new screen images based on the learned models. Secondly, the face and background are separated in the screen image. Four points with the biggest possibilities for wrinkling are selected from the face and high wrinkle weighted values are assigned to them. Finally, the wrinkles are detected by applying Canny edge algorithm for the interested points of weighted value. The suggested algorithm adopts various screen images for experiment. The experiments display the excellent results of face and wrinkle detection in the most of the screen images.

• The Journal of the Korea Contents Association
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• v.11 no.2
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• pp.353-366
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• 2011

The purpose of this study was to present the fundamental direction in training social work supervisors. First it defined the competency of supervisors and by analyzing the contrasts between the present situation and points for compensation, the study searched for alternative solutions to reinforce the role of supervisors. The research was conducted by interviewing 7 Focus Groups, the 20 Delphi questionnaire panel, and the 213 social workers in the community welfare centers. This study multilaterally evaluated the opinions of all supervision interested parties and as a result, defined the core supervisor competence in the areas of knowledge, skill, and attitude(KSA). The main characteristics to be improved were found to be supervisors' leadership, supervision knowledge, self-recognition. conflicts arbitration skills, the communication skills, the team work skills, and the main attitudes of consistency, patience and openness. This study is significant that it presented specific direction in the developing training courses for supervisor, researching the detailed education demands and analyzing the application of the supervisor's competency model in the organization.

• Journal of the Korean Society for Library and Information Science
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• v.29
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• pp.281-304
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• 1995

The purpose of this study is to identify the degree to which the card catalog in a university library serves its users and to provide useful information for the design of conversion from card catalog to online catalog. From August 19th to September 16th 1995, 278 users of Duksung Women's University Library were randomley selected and surveyed in terms of card catalog use, success rate of card searching, and catalog use training received. Major findings are as follows: 1. Taking into considerations the fact that Library users tended to use more heavily oriental card catalog$(61.8\%)$ than western card catalog$(8.3\%)$ or classification card catalog$(26.3\%)$, oriental card catalog should be designed to improve its search function of the catalog. 2. It was found that the university library card catalog was not easy to use by $49.3\%$ of the users of Duksung University Library. 3. One of main reasons why the card catalog is hard to use is that there is no subject card to which users can access for subject searching. Besides, users have difficulties in locating appropriate classification numbers for subjects which users are interested in. 4. When success rate is defined as finding appropriate cards in catalog boxes, the success rate was reported to be $87.0\%$. 5. The major access points of known items which library users utilized mostly were author$(18.3\%)$ and title$(74.5\%)$. 6. In case of translated versions of foreign materials, original author name cards instead of pronounced original name card written in Korean were given to them as access points. $79.9\%$ of library users of Duksung Women's University insisted that both original and pronounced author name writ':en in Korean should be given as access points to foreign authors for the sake of user's convenience. 7. Formal training programs for card catalog use were found not to be sufficient. Small group informal training courses should be offered to users who need to get information for catalog use by library staffs. 8. Considering the trend that orders of access points have been changed from title, author and subject in card catalog to title, keyword, and author in online catalog, the existing card catalog of Duksung Women's University is expected not to meet future users' needs for subject searching unless the funcions of subject searching of catalog is improved.

• Korean Business Review
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• v.11
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• pp.295-317
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• 1998

Environmental accounting identifies and measures environmental costs and provides them to interested parties of corporation. The purposes of this study are as follows: First, it investigates the method of measurement and the timing of recognition of environmental costs. Second, it suggests the method of disclosure of environmental costs. In order to accomplish these objectives, this study reviewed relevant literature and studies in advanced countries and Korea. The main results of this study can be summarized into four points: (1) environmental costs are classified into environmental pollution cost and environmental pollution prevention cost, by considering the sources of occurrence of, the functions of and the types of environmental costs. (2) the methods of measurement of environmental costs are various but they almost all subjective and arbitrary. So an accurate measurement of environmental cost is actually difficult. (3) According to the accrual basis, environmental costs are recognized respective to prior period adjustments, expenses or losses of the current period and the assets of the next period. (4) There are 3 methods of disclosure of environmental costs: an extension model of financial statements, a compromise model, and an original model. An extension model financial statements is easy to apply in business practice because it discloses environmental costs by adding accounts into the framework of a traditional accounting system or supplementary reports. This research can contribute to the establishment of accounting standards for environmental costs in Korea.

• International Commerce and Information Review
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• v.14 no.4
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• pp.339-360
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• 2012

We have more risks in international trade market than in the domestic business market because economic activities are going on with business transactions in different countries. K-sure's Refund Guarantee System is the most important system for Korean Small and Middle Shipbuilding Industries' business, but Korean exporters of Shipbuilding Industries are more interested in export financing through K-sure rather than its financial supporting services. The export insurance becomes more important service for international trade business and it its count as the only one indirect way of supporting export business because export insurance is accepted internationally under the WTO system. Also, it is the only measure that can cover emergency risk, credit risk, exchange risk which cannot be covered by private insurance. As the major risk manager for Korean exporters, the K-sure needs to provide an integrated risk management service for customers. Korean exporters can take more challenges in ever competitive international trade market and we can witness promotion of export in the future which is essential to Korea's economic growth.

• The Journal of Korean Association of Computer Education
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• v.22 no.3
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• pp.135-146
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• 2019

Big data analysis is actively used for collecting and analyzing direct information on related topics in each field of society. Applying big data analysis technology in education field is increasingly interested in Korea, because applying this technology helps to identify the effectiveness of education methods and policies and applying them for policy formulation. In this paper, we propose our approach of utilizing big data analysis technology in education field. We focus on free semester program, one of the current core education policies, and we analyze the main points of interests and differences in the free semester through analysis and visualization of texts that are written on the operation reports prepared by each school. We compare regional differences in key characteristics and interests based on the free semester operation reports from middle schools particularly at Seoul and Gangwon-do regions. In conclusion, applying and utilizing big data analysis technology according to the needs and requirements of education field is a great significance.