• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.4
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• pp.281-285
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• 2015

Electrical energy supply interruption degrades reliability of power supply as well as social costs and economic loss. It is important to assess the reliability of the power system. Nowadays IEC61850 based substation automation system(SAS) has been developed for an updating of automation and interoperability. In this study, three kinds of reliability block diagram(RBD) were proposed to examine of network availability of the three types SAS. And reliability and unreliability of the SAS was formulated using the RBD. Finally, while varying the value of reliability and unreliability, the reliability and the unreliability of the overall system were evaluated.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.589_590
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• 2009

This paper presents a unique approach to scheme a demand response (DR) program in the electricity market from a customer-oriented perspective, which is based on the analytic hierarchy process (AHP). The proposed program is designed as an incentive-based program (IBP) considering Korea power systems with the cost-based generation pool (CBP). And the proposed DR program has the objective to maximize social welfare corresponding customers‘ participation and the constraints including incentive payments, the specific load curtailment conditions and reserve-margin criterion. A test system for the case study is used to demonstrate the usefulness and applicability of the proposed approach, and the load profiles with the proposed DR program are obtained. The results show not only the revenue attributable to the avoided costs but also enhancement of system reliability.

• Journal of Korean Institute of Industrial Engineers
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• v.12 no.2
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• pp.89-99
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• 1986

The study attempts to estimate and evaluate the rates of return on graduate degree holders who major in science and engineering. The model of this study adopts the rate of return method considering unemployment as well as mortality rate. The data are collected by questionnaires and interviews. The results show that the social rate of return(SROR) of bachelors is lower than the rate of return on investment in physical capital which is assumed as a decision criterion of public investment in Korea, but the SROR of Ph.D. holders is balanced. The results also show that the private rates of return (PROR) of all the levels in postgraduate science and engineering education are higher than the private discount rate which is a decision criterion of private investment in Korea. It also indicates that the PROR on investment in graduate education is not likely higher than the SROR because an individual bears high share of the educational costs.

• Structural Engineering and Mechanics
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• v.32 no.1
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• pp.147-165
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• 2009

This study proposes a certain measure or investment strategy for decision making associated with seismic retrofitting. This strategy reduces the risk of a large-scale malfunction such as water supply loss under seismic risks. The authors developed a stochastic value index that will be used in the overall evaluation of social benefit, income gain, life cycle costs and failure compensation associated with existing lifeline systems damaged by an earthquake during the remaining service period. Optimal seismic disaster prevention investment of deteriorated lifeline systems is discussed. Finally, the present study provides a performance-based design method for seismic retrofitting strategies of existing lifelines which are carried out using the target probabilities of value loss and structural failure.

• Journal of Nutrition and Health
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• v.38 no.9
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• pp.786-792
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• 2005

With dramatic transitions from a traditionally food-insecure to a food-sufficient society, over weight and/or obesity are an increasing health concern in Korea. In 2000, $35.9\%$ of Korean adults were over weight (BMI>25) with increasing trends. It is well known that obesity is highly correlated with chronic diseases, such as diabetes, hypertension, cardiovascular disease, cancer and high cholesterol. In 2003, the social cost of obesity is estimated at $529.5\~799.3$ billion won (direct cost) and at $1,200\~1,817$ billion won (including indirect cost). The share of the direct cost is estimated at $2.6\~3.9\%$ of total medical bill 20,742 billion won. These costs are underestimated and would surely be higher if the expenditures outside of the official medical insurance system of Korea were included. Based on the rapid increase of obesity rate among the Korean youth, it is crucial to develop and implement appropriate policies to curb the obesity epidemic.

• STI Policy Review
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• v.6 no.1
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• pp.54-69
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• 2015

Although there is progress in developing green sectors in North America and East Asia, the key challenge facing the expansion of economy-wide green innovation and structural change in these regions is the absence of relevant policy follow-up to the green stimulus enacted during the Great Recession. The boost to green sectors provided by such measures is waning quickly, given that much of the green stimulus focused on energy efficiency. The biggest obstacles to sustaining green growth in North America and East Asiaare major market disincentives, especially the under-pricing of fossil fuels and market failures that inhibit green innovation. A three-part strategy to overcome these obstacles would involve: first, removing fossil fuel subsidies; second, employing market-based instruments to further reduce the social costs of fossil fuel use; and third, allocating any resulting revenue to public support for green innovation and investments. Such a strategy would ensure that green growth is not about promoting niche green sectors but instigating economy-wide innovation and structural transformation in North America and East Asia.

• Journal of Korean Society of Transportation
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• v.8 no.1
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• pp.17-24
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• 1990

The first-best pricing rule which achieves economic efficiency is to equate price with marginal cost. Since public transport demand is derived from some other demand, the user cost as well as the producer cost are considered in its pricing. The optimal price is derived from a derivative of the total social cost with respect to demand. In case of the bus, if there is enough capacity for demand increase, the optimal price is determined by the marginal producer cost resulting from bus sped decrease and by the marginal user cost resulting from journey time increase. Both are caused by boarding and fare collecting time of an additional passenger. Because of the budget constraints, the marginal cost pricing cannot be applied in practice. Then price discrimination as the second-best pricing is introduced. The Ramsey pricing, to charge different prices for different demand elasticities, and nonuniform prices such as travelcards can be applied. However, there is practical difficulty in implementing these prices because of great informational requirements, the costs of administration and the ease to users.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1065-1072
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• 2010

Case studies published in Korea versus the low ground fault is applied on the bridge based on theory or experience in the design of pile bearing capacity by the value of the expression is designed to conduct field tests Disclosure Load bearing capacity value, the result of applying a reasonable construction cost savings of approximately 10 eokyeowon Has, in the design of site investigation was insufficient to require additional efforts. Apply the appropriate value from the extra support in the design of accurate ground survey and air speed to cut the budget and social technology can ensure the reliability was unknown.

• Journal of the Ergonomics Society of Korea
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• v.9 no.2
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• pp.11-20
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• 1990

Recorded injury identified the role of falls in producing injury througout all segments of the nation. The Economic and social costs arising from falls has been established in numerous sources, both nationally and from the intermational literature. Recorded injury also indicated the potential features of falls, the need for a basic understanding of the energy exchange mechanism involved and the subsequent rehabilitation processes required. It appears unlikely that any other major cause of injury has an etiology so little researched and consequently, so little understood, which in turn has prevented the development of an intervention strategy or a scientically based control technology of falls. This paper will emphasize how the postural changes of foot are related to slip/fall severity in different environmental conditions. Lidewise, we will examine the whole slip/fall cycle through the biomechanical parameters involved in a range of walking speed and floor slipperiness

• Journal of the Korean Home Economics Association
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• v.33 no.4
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• pp.301-313
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• 1995

The purpose of this study was to investigate the differences of child care and it's costs between the full time housewives and employed wives' families with preschool children. the results of this study were as follows ; 1) The child care was performed primarily by herselves in the case of full time housewives' families, whereas the child care of employed wife families was done by babysitter or nursing facilities. 2) Most of unemployed wives' families undertook the burden of time cost, whereas the families of employed wives had to pay heavy expenses of money cost f9or the child care arrangements 3) In the estimation of money cost for the child care arrangements income had the highest effect. In contrast with this, in the case of time cost, occupational status of housewives had the highest effect. It was suggested for enhancing the sense of well - being of housewife it is necessary to perceive the value of household production and the social support for child care arrangements in all families, whether unemployed or employed.