• Journal of Electrical Engineering and Technology
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• v.8 no.4
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• pp.694-703
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• 2013

In electric power system, the line stability indices adopted in most of the instances laid stress on variation of reactive power than real power variation of the transmission line. In this paper, a proposal is made with the formulation of a New Voltage Stability Index (NVSI) which originates from the equation of a two bus network, neglecting the resistance of transmission line, resulting in appreciable variations in both real and reactive loading. The efficacy of the index and fuzzy based load flow are validated with IEEE 30 bus and Tamil Nadu Electricity Board (TNEB) 69 bus system, a practical system in India. The results could prove that the identification of weak bus and critical line in both systems is effectively done. The weak area of the practical system and the contingency ranking with overloading either line or generator outages are found by conducting contingency analysis using NVSI.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.3
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• pp.27-33
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• 2007

Recently, a new hard problem on a two dimensional vector space called vector decomposition problem (VDP) was proposed by M. Yoshida et al. and proved that it is at least as hard as the computational Diffe-Hellman problem (CDHP) on a one dimensional subspace under certain conditions. However, in this paper we present the VDP relative to a specific basis can be solved in polynomial time although the conditions proposed by M. Yoshida on the vector space are satisfied. We also suggest strong instances based on a certain type basis which make the VDP difficult for any random vector relative to the basis. Therefore, we need to choose the basis carefully so that the VDP can serve as the underlying intractable problem in the cryptographic protocols.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.3
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• pp.500-506
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• 2007

The Type Object Design Pattern is proposed to provide a solution on the situation in the case that one class has too many subclasses or the number of subclasses are undefined. Although this pattern has many advantages in terms of applicability and dynamic object behavior, it has a weak point in runtime pattern operation that it has to build and maintain a class reference mechanism in runtime to reference the class (de facto 'object') of instances. To solve that problem, this paper addresses the solution of the runtime class reference problem of Type Object Pattern. it defines a new class of Type Object Class (TOC) from Type Class and Object Class in Type Object pattern and presents the methods of creating, compiling, and memory-loading the TOC. It depends on built-in class reference mechanism of object-oriented programming language, and is not necessary to fit with the additional mechanism. Consequently, we need not to set up the additional class reference mechanism and system performance is enhanced due to it.

• Journal of the Korea Safety Management & Science
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• v.15 no.2
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• pp.135-141
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• 2013

As the country's elderly people who are 65 years or older recently exceeded 10% of the total population with development of medical technology and improvement of living standards, Korea has turned into an aging society. Especially in Gyeonggi-do, as of late December 2012, elderly people who were 65 years or older were 1,135,242 persons, taking up 18.98% of the region's population and registering the largest number of elderly people in the nation's cities or provinces. Due to such a sharp rise in elderly population, support for the elderly is increasing the burden on families and communities. The study aims to take as its subjects elderly people staying at authorized elderly welfare facilities, who are weak in mind and body and have difficulty in daily life with disabilities, or adult day care facilities that take care of elderly people during the day or at night, examine the concept of adult day care facilities and instances in foreign countries, and study the status of the adult day care facilities located in Gyeonggi-do, their services, and safety by figuring out space arrangement based on program implementation. Spacial arrangement in program operation should satisfy fuction and purpose from the manager and user's perspective, and a desirable program operation should provide separate spaces for the elderly with Alzheimer's and those without Alzheimer's. Compared to residential care facilities, adult day care facilities incur less financial burden and, compared to other authorized services, have many right functions that can upgrade the quality of users and satisfy their desires. Major countries like Japan, the UK, and Sweden recognize the right functions of day and night care services and aggressively support and utilize adult day care facilities. For adult day care facilities, quality services should be developed and use and choices should be enhanced as regards services. Development of special programs for the elderly with dementia and stroke, instead of simple protective functions of a program, must be actively promoted, while manpower training is required for program operation, conveniences, and safety. By developing and providing space arrangement models that focus on efficiency, convenience, and safety of program operation, adult day care operation can be revitalized, while quality of elderly care may be enhanced and welfare budget can be saved.

• Journal of The Korean Association For Science Education
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• v.38 no.2
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• pp.259-271
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• 2018

This study examined the effect of the SSI argumentation program based on social and emotional learning(SEL). The program consisted of 3 stages: (1) express their own feelings about SSI, identify the issues of SSI, and define a goal; (2) think of many possible solutions and envision results through argumentation; (3) select the best solution and make a decision based on warrants, data, and rebuttals. In each stage, the social-emotional strategies of self-awareness, self-management, social-awareness, relationship-management, and responsible decision making were used. Seventeen preservice biology teachers participated in this study during one semester dealing with four socioscientific issues. The results indicated that the preservice teachers, as time went on, became accustomed to expressing identifiable rebuttals, dispute talk, and asking questions. At the first SSI argumentation, argumentation mainly consisted of cumulative talk with no rebuttals, representing level 2 argumentation. Level 3 argumentation represented rebuttals that were implicit and weak, with cumulative talk. In level 2 and 3 argumentation, the preservice teachers represented understanding of others and compassion for self and others. Level 4 argumentation had rebuttals that were explicit, asking critical questions of the opposite sides. In addition, level 5 argumentation represented more than two controversial points with several instances of dispute talk. In levels 4 and 5, the preservice teachers became actively engaged in communication, inquiry self with others, managing vulnerability and negotiation.