• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.368-370
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• 2001

There are various shapes such as square, rectangular, L, and T type in the grounding systems of substations. IEEE St-d suggests the formula considering the characteristics of the various grounding systems but the final value can not be taken, and them the analysis of complicated computer program for obtaining the more accurate value is needed. In his paper, by using CDEGS(Current, Distribution, Electromagnetic and Soil Structure Analysis) the estimated functions derives form the modification coefficient for each of various types above mentioned. The mesh voltage expected can be obtained without the conventional expensive program using compensating methods that multiply IEEE formula by the estimated function.

• The KSFM Journal of Fluid Machinery
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• v.7 no.1 s.22
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• pp.24-29
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• 2004

The inter-comparison of standards is required to be recognized the calibration results. The sonic nozzle package is developed to do inter-comparison of the bell preyer used to calibrate many gas flow meters for industries. Four national metrology institutes (KRISS, CMS, CENAM, NEL) were participated in this inter-comparison. The deviation of calibration data from the average value was small at the low flow rate and large at the high flow rate, respectively At the high flow rate, the deviation was larger than the expected value from uncertainties asserted by NMIs. This means there are some problems in the uncertainty evaluation and experiment procedures in some of the participated NMIs.

• STI Policy Review
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• v.2 no.3
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• pp.35-44
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• 2011

Korea has rapidly increased R&D investment over the last few decades and the intensity of R&D investment is among the highest in the world; however, there are serious concerns about R&D performance and R&D efficiency. This study is to improve the economic assessment methodology regarding a feasibility study for national R&D programs that are thought to be one of the most prominent ways to enhance R&D efficiency. In order to improve the methodology of economic assessment, a few of important factors such as technical or market uncertainty, spillover effect, and R&D contribution ratio should be covered in the model. The focus of this article is technological and market uncertainty that has a close relation with strategic flexibility and utilization potential to increase the value of R&D programs. To improve the current linear and definitive R&D process, a new framework with strategic flexibility is suggested, in which the result of economic assessment that considers technological and market uncertainty is reflected in planning. That kind of feedback process is expected to enhance the value of the program/project as well as R&D efficiency.

• Korean Journal of Agricultural Science
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• v.40 no.2
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• pp.169-176
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• 2013

The price and revenue of rice are expected to decrease due to increasing rice imports, decreasing consumption and the discontinuance of the government's rice procurement. This degenerating profitability is leading to a rise in the cultivation of upland-crops such as beans, fodder crops and fruits in paddy fields. However, there is a lack of research on the selection of rice substitute crops which are adaptable to the relevant region through profitability analysis. This research, therefore, analyzed investment profitability of rice substitute crops for Cheorwon-gun area in Kangwon province. The study applied net present value (NPV) and internal rate of return (IRR), which fit for mutually exclusive investments that make one selection to the exclusion of other crops. Target crops are green house plants in Cheorwon-gun area. Financial analysis showed paprika and cucumber have investment feasibility for automated vinyl greenhouses and conventional plastic greenhouses respectively.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.244-250
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• 1997

The mean time to failure (MTTF) expressing the mean value of the system life is a measure of system effectiveness. To estimate the remaining life of component and/or system, the dynamic mean time to failure concept is suggested. It is the time-dependent Property depending on the status of components. The Kalman filter is used to estimate the reliability of components using the on-line information (directly measured sensor output or device-specific diagnostics in the intelligent sensor) in form of the numerical value (state factor). This factor considers the persistency of the fault condition and confidence level in measurement. If there is a complex system with many components, each calculated reliability's or components are combined, which results in the dynamic MTTF or system. The illustrative examples are discussed. The results show that the dynamic MTTF can well express the component and system failure behaviour whether any kinds of failure are occurred or not.

• Journal of Ginseng Research
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• v.15 no.2
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• pp.152-165
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• 1991

It is estimated that world ginseng production has increased from 3,200 tonnes In 1983 to 5,132 tonnes in 1987. China produced approximately hart of world ginseng production and South Korea's production amounts to 31.9% of world ginseng production. Canadian ginseng production of 114 tonnes in 1987 represents only 2.2% of estimated world production. World ginseng production is projected to increase to 6,856 tonnes by 1992. Canadian production as a proportion of total world production is expected to increase to 3.3% however, North American production overall is projected to decrease 12.0% of world production by 1992. Assuming that the value of each country's production is equal to average export price, the value of world ginseng production is estimated to be $ 443 million The estimated values of Korean, North Anerican and Canadian ginseng production represent $ 198.3million, 977.1 million, and $ 12.5 million, redpectively.

• Journal of the Society of Naval Architects of Korea
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• v.41 no.2
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• pp.47-54
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• 2004

Exact solution on the vertical responses of ships having uniform sectional properties in waves is derived. Boundary value problem consisted of Timoshenko beam equation and free-free end condition is solved analytically. The responses are assumed as linear and wave loads are calculated by using strip method. Vertical bending moment, shear force and deflection are calculated. The developed analysis model is used for the benchmark test of the numerical codes in this problem. Also the application on the preliminary design of barge-like ships and VLFS (Very Large Floating Structure) is expected.

• Journal of the Microelectronics and Packaging Society
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• v.8 no.3
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• pp.25-30
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• 2001

The stress intensity factors for edge cracks located at the bonding interface between the semiconductor chip and the adhesive layer subjected to a uniform transverse tensile strain are investigated. Such cracks might be generated due to a stress singularity in the vicinity of the free surface. The boundary element method (BEM) is employed to investigate the behavior of interface stresses. The amplitude of complex stress intensity factor depends on the crack length, but it has a constant value at large crack lengths. The rapid propagation of interface crack is expected if the transverse tensile strain reaches a critical value.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.52
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• pp.21-31
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• 1999

This paper considers how to structure the incentive system between a buy and a single supplier of raw materials when early shipments are forbidden. And this paper is used to take the supplier's behavior into account in the buyer's choice of incentives. Combinations of two types of incentives that the buyer might offer are considered : (1) a fixed value incentive and (2) an incentive that decreases in value as time elapses. Given a desired probability of on time delivery, optimal incentives are found by specifying indifference curves for on time delivery and assessing the expected total cost of incentive schemes along that curve. Difficulties of using incentive to achieve 100% on time delivery are considered and two example flow time distributions are presented.

• Journal of Digital Contents Society
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• v.8 no.4
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• pp.419-424
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• 2007

Recently, additional value of games has been started to increase by revitalization of the game market. Especially, Because of the creation of the new trend that is item trade especially in online game, Item trade is as a easy and essential way as item trade can be created. However, compared to other planning factors, occupied weight of item is not as much as expected in exploiting a game. For this reason, we emphasize the importance of game item by giving the opportunity that increases the additional value with raising satisfaction of game through item-based study, plus suggesting new classification.