• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.195-201
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• 1989

Voltage collapse is a serious concern to the electirc utility industry. It is common to associate steady-state stability with the ability of the transmission system to transport real power and to associate voltage collapse with the inability to provide reactive power at the necessary locations within the system. An algorithm to directly calculate the critical point of system voltage collapse was presented by the authors. The method (based on the ordinary power flow equations and explicit requirement of singularity of the Jacobian matrix) is basically one degree of freedom with proper load distribution factors. This paper suggests a modified algorithm to increase the degree of freedom, introducing the nonlinear programming technique. The objective function is a distance measure between the present operating point and the closest voltage collapse point. Knowledge of the distance and the most vulnarable bus from the voltage collapse point of view may be used as a useful index for the secure system operation.

• Journal of the Korean Home Economics Association
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• v.33 no.4
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• pp.11-23
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• 1995

The purpose of this study is to investigate some influencing factors related to the urban housewives' homemanagement and management behavior on the problems of the environment. Questionaire Survey method was used and the sample was taken from 490 housewives who lives in Seoul and has husband and more than one child. The Research for this study was operated by frequency, mean, percentage, Factor Analysis, t-test, ANOVA, Duncan's multiple range test, and multiple regression analysis through the SAS program package. Based on the findings of this study, housewives' value, degree of exposure to mass communications, housewives' level of education were most influencial variables on Housewives' home management behavior pattern. And Housewives' home management behavior pattern, degree of exposure to mass communications, housewives' age, knowledge of the problems of the environment were most influencial variables on Housewives' management behavior onthe problesm of the environment.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.3
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• pp.260-269
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• 2000

The fuzzy and state-feedback control systems have been applied in various areas from non-linear to linear systems. A Fuzzy controller is endowed with control rules and membership function that are constructed on the knowledge of expert, as like intuition and experience. but It is very difficult to obtain the exact values which are the membership function and consequent parameters. though apply back-propagation algorithm to the system, the convergence time a much. Besides, the state-feedback system is most widely used in industry due to its simple control structure and easily able to design the controller. but it is weak in complex system of higher degree and non-linear. In this paper presents the design of a fuzzy switching mode, it these two controllers work at different operation conditions, the advantages of both controller can be retained and the disadvantages can be removed. Between the Fuzzy and the State-feedback controlles, the good outputs are selected by the switching mode. Moreover it is powerful in complex system of higher degree and non-linear. In these sense compared with the state-feedback controller, the performance of the proposed controller was improvedin the section of linearization.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.2
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• pp.293-298
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• 2016

Recently, interests for maintenance of transmission tower are increasing to extend life of structures and reduce maintenance cost. However, existing classical diagnosis method of corrosion deteriorated degree on the transmission tower steel members, visual inspection, has a problem that error often due to difference of inspector's individual knowledge and experience. In order to solve the problem, this study carried out to develop the corrosion deterioration inspection tool for transmission tower steel members. This tool is composed of camera equipment and computer-aided diagnosis system. We standardized the photographing method by camera equipment to obtain suitable pictures for image processing. Diagnosis system was designed to evaluate automatically degree of corrosion deterioration for member of transmission tower on the basis of the RGB color image processing techniques. It is anticipated that developed the corrosion deterioration inspection tool will be very helpful in decision of optimal maintenance time for transmission tower corrosion.

• International journal of advanced smart convergence
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• v.8 no.1
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• pp.133-140
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• 2019

In this paper, we present an algorithm for adjusting degree of belief for consistency on the evidence dependency network where various sets of evidence support different sets of hypotheses. It is common for experts to assign higher degree of belief to a hypothesis when there is more evidence over the hypothesis. Human expert without knowledge of uncertainty handling may not be able to cope with how evidence is combined to produce the anticipated belief value. Belief in a hypothesis changes as a series of evidence is known to be true. In non-monotonic reasoning environments, the belief retraction method is needed to clearly deal with uncertain situations. We create evidence dependency network from rules and apply the evidence retraction algorithm to refine belief values on the hypothesis set. We also introduce negative belief values to reflect the reverse effect of evidence combination.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.505-509
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• 2020

Twitter is a useful medium to grasp various damage situations that have occurred in society. However, it is a laborious task to spot damage-related topics according to time in the environment where information is constantly produced. This paper proposes a methodology of constructing a knowledge structure by combining the BERT-based classifier and the community detection techniques to discover the topics underlain in the damage information. The methodology consists of two steps. In the first step, the tweets are classified into the classes that are related to human damage, infrastructure damage, and industrial activity damage by a BERT-based transfer learning approach. In the second step, networks of the words that appear in the damage-related tweets are constructed based on the co-occurrence matrix. The derived networks are partitioned by maximizing the modularity to reveal the hidden topics. Five keywords with high values of degree centrality are selected to interpret the topics. The proposed methodology is validated with the Hurricane Harvey test data.

• Journal of Home Health Care Nursing
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• v.27 no.1
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• pp.102-113
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• 2020

Purpose: To demonstrate the importance of comprehensive skin observation as an effective intervention for pressure injury prevention in elderly long-term care hospital patients. Methods: The survey was conducted with 70 nursing staff members working at two long-term care hospitals with 200 beds or less in D city. Data were collected from October 16 to October 23, 2019 and analyzed using descriptive statistics, the chi-square test, and the independent t-test with the SPSS 25.0 program. Results: Nursing care knowledge for pressure injury was similar between the two groups. Conversely, nursing care performance for pressure injury degree of the nursing staff in the hospital using skin observation records performed better than those who did not (t=6.11, p<.001). Furthermore, comprehensive skin assessments in long-term care hospitals using skin observation records showed a lower incidence rate of pressure injury than that showed using general skin assessments (t=-5.28, p=.006). Conclusions: Comprehensive skin assessment is important for pressure injury prevention in elderly long-term care hospital patients. To implement this effectively, it is necessary to devise institutional regulations, guidelines, and systematic education programs.

• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1626-1635
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• 2016

This study examines whether online game motivation, with social and expedition needs, are associated with the degree of loneliness among young adolescents. Using data from a survey of 2014 elementary-, middle- and high-school students in South Korea, a three-wave online survey was conducted to collect data from online players. Two latent growth cause-and-effect models were developed to test whether online game motivation influences degree of loneliness. Results showed that both social and expedition needs are positively associated with loneliness. This study contributes to the knowledge of the underlying needs for a player with loneliness and also highlights the social and expedition needs as potential therapeutic factors.

• The Journal of Korean Academic Society of Nursing Education
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• v.10 no.1
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• pp.94-104
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• 2004

Purpose: This descriptive survey was undertaken to find out the offering types of Physical Examination and Health Assessment course, student's ability to utilize web-based multimedia, and the basic knowledge on physical examination and health assessment in students attending baccalaureate(BSN) and associate degree(AD) programs in nursing, RN-BSN completion programs, and medical school. Method: 77 nursing programs in Korea were surveyed for the information on Physical Examination and Health Assessment courses, and the basic knowledge were tested on 169 nursing and medical students. Results: Majority of BSN(90.69%) and AD(85.29%) programs were offering Physical Examination and Health Assessment courses in students's sophomore years. Majority(95.58%) of programs were using face to face teaching method where as only 4.41% were using web-based multimedia programs. Basic knowledge on Physical Examination and Health Assessment were highest among students in medial school(14.04%) and RN-BSN(13.15%) compared to BSN(8.96%) or AD(8.06%) program. Conclusion: Web-based multimedia contents on Physical Examination and Health Assessment should be developed and should be integrated into the nursing curriculum.

• Knowledge Management Research
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• v.20 no.1
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• pp.101-132
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• 2019

In order to enhance the competitiveness of tourism destinations, it is important to manage tourist products considering the characteristics of tourist destinations and the characteristics of tourists. In this study, we divided Seoul's tourism products into four parts (shopping, food, culture, and natural landscape) to explore if there are some direct connections between tourism product involvement, self-congruity, and functional congruity. The other research question is if the degree of tourism product involvement reaches a certain intensity, will the place attachment be generated and the destination satisfaction be fulfilled. The survey was the focus on the international visitors in smart city, Seoul by using the random sampling and convenience sampling and collected 250 data. Finally, we found that destination personality significantly affects both self-congruity and functional congruity. If self-congruity and functional congruity are formed, tourism product involvement will be stimulated which will finally satisfy tourists and arouse their place attachment. The implications of these findings contribute to destination marketers to develop more effective destination management.