• Journal of the Korean Society of Safety
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• v.11 no.3
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• pp.89-96
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• 1996

This paper presents a study on the analysis and evaluation for ELF( Extremely Low Frequency) electric and magnetic fields under the transmission line according to the power system states. The power system states are classified into two types, normal state resulting from normal operation and alert state from outages. The current in a system is changed continually owing to the load fluctuations even in a normal operation. To calculate the current of the concerned line in a normal state, the system load level is devided into light, base and heavy load level. In case of contingency, an efficient algorithm based on matrix inversion lemma is developed to figure out the current changes. In order to analyze the variations of ELF field caused by the current fluctuations the electrostatic field approach which is far simpler than the electromagnetic field one based on Maxwell equation is introduced in this paper. The suggested method is applied to the IEEE 14 bus system to demonstrate the usefulness.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.12
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• pp.597-602
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• 2005

The introduction of competition in electricity market emphasizes the importance of sufficient transmission capacities to guarantee various electricity transactions. Therefore, when dispatch scheduling, transmission security constraints should be considered for the economic and stable electric power system operation. In this paper, we propose an optimal dispatch scheduling algorithm incorporating transmission security constraints. For solving these constraints, the dispatch scheduling problem is decomposed into a master problem to calculate a general optimal power flow (OPF) without transmission security constraints and several subproblems to inspect the feasibility of OPF solution under various transmission line contingencies. If a dispatch schedule given by the master problem violates transmission security constraints, then an additional constraint is imposed to the master problem. Through these iteration processes between the master problem and subproblems, an optimal dispatch schedule reflecting the post-contingency rescheduling is derived. Moreover, since interruptible loads can positively participate as generators in the competitive electricity market, we consider these interruptible loads active control variables. Numerical example demonstrates efficiency of the proposed algorithm.

• Journal of Korea Technology Innovation Society
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• v.7 no.3
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• pp.479-505
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• 2004

The purpose of this study is to investigate between CEO's Entrepreneurship in Venture Business and Organizational Effectiveness. CEO's Entrepreneurship variable consist of Innovativeness, Risk-taking and Proactiveness. Organizational effectiveness concept composed of system approach and the contingency theory and it's variable consisted of job satisfaction and organizational commitment. Statistical methods are adapted Frequency, Factor Analysis and CFA(Confirmatory Factor Analysis) of LISREL.8 program. Refined Survey data are 412/Major findings are as follows; Only Proactiveness variable of CEO's entrepreneurship have significant relation to Organizational Effectiveness(job satisfaction and organizational involvement). Innovativeness and Risk taking variables are partially supported to influence to Organizational Effectiveness.

• Journal of Technology Innovation
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• v.13 no.3
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• pp.175-196
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• 2005

This Paper examines analytic studies of the evaluation system used for evaluating government-supported R&D Institutes (GSRIs), and designs a new model for analyzing the evaluation system's effectiveness. The analytic models in existing studies use the meta evaluation and balanced scorecard (BSC) models. However, theses studies focused on the structure and elements of the evaluation system for examples, the appropriateness of the elements within the evaluation system and the balance of the evaluation index. Accordingly, the effectiveness of the GSRI evaluation system, that is, the evaluation's influence on GSRI performance improvement was not analyzed. This study uses the institution theory and contingency theory perspectives as related to government organization management to develop an analytical model of GSRI evaluation system effectiveness. The new model proposes an analytical approach for improving the effectiveness of the GSRI evaluation system in an institutionalized environment.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.2
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• pp.256-263
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• 2009

For the power system to keep in a stable operating state, sufficient ancillary services must be available to respond to credible contingency events and return the power system to a satisfactory operating state in the case of contingencies as well as blackout events within specified predefined limits. The logical and reasonable bases of valuing and pricing the ancillary services are required to reach the common ground among market participants. The total amount of black start service transactions is quite small compared to the total ancillary service transactions as well as energy market transactions. Black start services must be provided as one of the ancillary services in the deregulated electricity market. In order to procure and remunerate black start services, it is necessary to quantify the value of the black start sources within the power system. In this paper, an approach to assess the value of the black start service is presented based on the cost-of-service solution. Financial simulation of the influence on market participants for the proposed approach on the service is carried out. The cost of the black start service is allocated in accordance with the principle of "causer pays", and the cost is shared by the producers and consumers equally that created the requirement for the service. Under the present electricity market, the mechanism to recover the cost is not implemented, a new approach to the ancillary services to provide incentive for the service providers has to be studied in the near future.

• Korean Institute of Interior Design Journal
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• v.18 no.6
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• pp.44-51
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• 2009

Various and complex cultural phenomena have led to many changes in the space. The concept of unconsciousness, among others, and experimental expression technique and the concepts from surrealism that rather attaches great importance to contingency than intentional attempt have been employed in the space. The abstract expression as expressional characteristics of surrealism makes the space ambiguous through the concept of automatism using the approach of indeterminism and double image expression, and represents the space providing diversity through the dualism. In contrast, objective expression, which was based on depaysement, generates the tension and expresses the dramatic situation in such a way and manner which are intentional, distorted transformed, together with heterogenous meanings aligned through the reversal appeared in the techniques of collage and paranoiac-critical method. However if such space accommodating the expressional characteristics of surrealism is approached as superficial concept in analyzing the human's inner consciousness and imaginary society, expression of the ultimate concept contained in the expressional characteristics of surrealism can hardly be achieved. Hence, the spatial analysis from the semiotic approach, instead of unilateral method aimed to convey the meaning only, which creates the signification, was adopted. The study, as effective approach to the space accommodating the expressional characteristics of surrealism, was intended systematically evaluate the concreteness of understanding and generation of meaning through the semiotic method. Greimas' semiotic square analysis to the space plays the important role in generating the spatial meaning, as well as is needed for objective analysis of the importance of various characteristics and methodology which the space contains through the expressional characteristics of surrealism.

• Journal of the Korean Institute of Landscape Architecture
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• v.15 no.2
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• pp.57-66
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• 1987

본 연구는 경관선호에 관한 평가방법을 서술적으로 구명하면서 기존의 경관선호에 관한 평가방법이 자연적 요소를 많이 포함한 경관의 평가출 정착히 하는데 따르는 문제점을 제시하고 경관의 우연적 국면에 따라 경관선호의 우연성(Contingency in Landscape Preference)을 개관하면서 경관평가의 우연성(Contingency in Landscape Evaluation)에 의한 우연적 경관평가방법(Contingent Approach in Landscape Evaluation)의 가능성을 시사했다. 최근까지의 경관평가방법을 크게 분류하면 총체적(Universal) 접근방법, 개성적(Idiosyncratic) 접근방법, 조화적(Contrastic) 접근방법 등으로 나눌 수 있다. 그런데 경관성에서의 우연성을 강조함 으로써, 앞의 세방법만을 가지고서는 경관의 실체 파악이 어렵기 때문에 새로운 방법이 강구되어야 한다. 이의 한 대안으로 경관선호에 대한 평가를 우연적 접근방법으로 해결함으로써 평가영역과 평가요소를 확장시킬 수 있다. 따라서 수학적 매트릭스가 가능하다는 시사를 본 연구에서 구시하면서 새로운 평가방법으로 우연적 경관평가방법을 제시했다. 우연적 경관평가방법은 우연적 경관성에 의한 심미성을 고려하여 종합적으로 분석할 수 있으나 우연적 영역을 의도적으로 설정하지 않는 한 현실적으로 재정적 흑은 시간적 제약성을 지니고 있다. 그러나, 경관선호의 정도에 관한 평가보다는 경관의 본질을 구성하는 모든 요소를 고려한 평가가 경관선호평가에 대한 종합성을 반영할 수 있다. 경관평가의 모호성에도 불구하고 경관의 본질은 우연성에 의존한다고 본다면 우연적 경관평가방법은 크게 무리가 없다. 결국 경관은 생명성을 지니고 있기 때문에 현상으로만 볼 것이 아니라 동시적이면서 산재적 이며 상황적 다양성으로 간주해야 하며 고러란 관점을 강조한 것이 우연적 경관선호 및 경관평가에 대한 접근이라 할 수 있다.도 나타났다. 직업간의 유의성은 학생과 타 직업간에 나타났다. 직업간의 유의성은 학생과 타 직업간에 현격하게 나타났으나, 개인차를 나타내는 속성적 변수는 상호보완적인 변수기능을 수행하고 있기 때문에 다양한 행동의 설명력있는 이유로 볼 수 없다.때로는 민담에서도 풍수가 주제가 되는 경우가 있고, 일반적으로는 역사적 사실이나 인물을 통하여 취락민이지녀온 자연요소에 대한 인식관 또는 그러한 생활에서 나타나는 윤리관 등이 암암리에 표현되기도 한다. 민담을 통하여 우리는 주민들 의식 속에 남아있는 취락의 중요한 요소나 장소들을 찾아볼수 있고 더불어 이들을 중심으로 이루어 졌을지도 모를 생활모습들을 생각해볼 수 있다. 이러한 것들은 $\ulcorner$순응$\lrcorner$의 다른 일면 또는 때에 따라서는 극히 의도적인 $\ulcorner$표현$\lrcorner$적인 한 면모 - 그 대표적인 경우로 정원을 구성하는데 개재된 인간의 의미는 무언가를 표현 또는 표출하고자 함에 있다는 점 -라 볼수도 있을, 예로써 성리학적 사고관념으로써 집과 정사 그리고 주변 경관을 자신의 내적본직 또는 윤리적 영역으로 삼아 묘사.표현.구체화 시켜가기도 한다. 최소한 동족부락의 한두 예들에서 그러한 $\ulcorner$표현$\lrcorner$적 의도에 의한 경관구성의 일면을 확인할수 있지만 엄밀히 생각하여 보면 이러한 예의 경우도 최락의 총체적인 외형은 마찬가지로 $\ulcorner$순응$\lrcorner$의 범위를 벗어나지 않는다. 그렇기 때문에도 $\ulcorner$순응$\lrcorner$과 $\ulcorner$표현$\lrcorner$의 성격과 형태를 외형상으로 더욱이 공간상에서는 뚜렷하게

• Journal of the Korean Home Economics Association
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• v.34 no.4
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• pp.327-343
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• 1996

The objective of this study were 1) to determine the stages of concern of HE teachers about the practical problem-based curriculum approach, as illustrated by the Ohio's Work and Family Life Curriculum (W&FLC); 2) to determine the relationships between home economics (HE) teacher's stages of concern about W&FLC and personal and professional characteristics of HE teachers; and 3) to determine aspects of interest about the practical problem-based curriculum approach, such as the Ohio W&FLC. Respondents in this study were 225 HE teachers. The data were collected during the in-service teacher training sessions after presentation about W&FLC. Concerns Based Adoption Model (CBAM) was modified to provide a conceptual framework for this study. Frequencies, SD, mean, mode, range were used to determine the stages of concern of HE teachers. To determine the relationships between stages of concerns and personal and professional characteristics of HE teachers, coefficient of Chi-Square contingency tables was used. Content analysis was used to determine aspects of interest about the practical problem-bsed curriculum approach, such as W&FLC. The median of the stages of HE teachers' concerns about W&FLC was Stage 1, Information Stage. About 60% of HE teachers were interested in learning more details about W&FLC. Chi-square revealed no statistically significant relationships between stages of concerns about W&FLC and characteristics of HE teachers. Content analysis was used to determine aspects of interest about W&FLC of HE teachers. Nine categories were found: content, teaching strategies, implementation of the curriculum, philosophical framework, how to adopt W&FLC, resource materials, students' outcomes, in-service teacher training, and HE teacher organization. The majority of HE teachers were interested in relationships with family and others, resource management, family relationships, personal development, communication skill, family life, creating a self-identity, life planning, roles of family members, homemaking management, child care, and parenting.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.18-29
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• 2015

State Estimation (SE) is the basis of a variety of advanced applications used in most modern power systems. An SE problem formed with enough phasor measurement units (PMUs) data is simply a linear weighted least squares problem requiring no iterations. Thus, designing a minimum-cost placement of PMUs that guarantees observability of a power system becomes a worthy challenge. This paper proposes an equivalent integer linear programming method for substation-oriented optimal PMU placement (SOOPP). The proposed method uses an exhaustive search to determine a globally optimal solution representing the best PMU placement for that particular power system. To obtain a more comprehensive model, contingencies and the limitation of the number of PMU measurement channels are considered and embodied in the model as changes to the original constraints and as additional constraints. The proposed method is examined for applicability using the IEEE 14-bus, 118-bus and 300-bus test systems. The comparison between SOOPP results and results obtained by other methods reveals the excellence of SOOPP. Furthermore, practical large-scale power systems are also successfully analyzed using SOOPP.

• Journal of Electrical Engineering and Technology
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• v.10 no.2
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• pp.474-486
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• 2015

This paper proposes a multi-objective optimal placement method of Phasor Measurement Units (PMUs) in large electric transmission systems. It is proposed for minimizing the number of PMUs for complete system observability and maximizing measurement redundancy of the buses, simultaneously. The measurement redundancy of the bus indicates that number of times a bus is able to monitor more than once by PMUs set. A high level of measurement redundancy can maximize the system observability and it is required for a reliable power system state estimation. Therefore, simultaneous optimizations of the two conflicting objectives are performed using a binary coded firefly algorithm. The complete observability of the power system is first prepared and then, single line loss contingency condition is added to the main model. The practical measurement limitation of PMUs is also considered. The efficiency of the proposed method is validated on IEEE 14, 30, 57 and 118 bus test systems and a real and large- scale Polish 2383 bus system. The valuable approach of firefly algorithm is demonstrated in finding the optimal number of PMUs and their locations by comparing its performance with earlier works.