• Communications for Statistical Applications and Methods
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• v.18 no.6
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• pp.697-705
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• 2011

This paper proposes an optimal replacement policy following the expiration of a free renewing replacement-non-renewing minimal repair warranty. To do so, the free renewing replacement-non-renewing minimal repair warranty is defined and then the maintenance model following the expiration of free renewing replacement-non-renewing minimal repair warranty from the user's point of view is studied. As the criteria to determine the optimality of the maintenance policy, we consider the expected cost rate per unit time from the user's perspective. We derive the expressions for the expected cycle length and the expected total cost to obtain the expected cost rate per unit time. Finally, the numerical examples are presented for illustrative purposes.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.116-119
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• 2003

본 연구는 전기비저항 탐사법을 이용한 실내실험의 결과를 활용하여 토양의 수리특성별 지층비저항계수를 산출하여 소유역에 대하여 대략적인 수리지질 특성을 규명하는 방안을 제시하는 것이다. 연구결과, 모래로 구성된 토양층의 경우는 본 실내시험에서 얻어진 지층비저항계수에 따른 공극율 및 수리전도도의 관계를 활용할 수 있으며, 점토가 포함된 토양층의 경우는 표면전도도의 영향으로 측정되는 전기비저항이 실제 측정값보다 낮게 나타나므로 향후 전기이중층 효과를 고려하여 개발하는 경험식의 활용이 가능할 것으로 판단된다.

• Geotechnical Engineering
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• v.13 no.1
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• pp.85-100
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• 1997

The heterogeneity of hydraulic conductivity of Metropolitan Waste Landfill is analized by using geostatistical methods and the contaminant transport analysis is performed by using heterogeneous hydraulic conductivity. The hydraulic conductivity data are obtained from laboratory pressurized permeability tests and the insitu, Slug test. Geostatistical methods used in this analysis are Ordinary Kriging and conditional simulation. It is concluded that the heterogeneities of hydraulic conductivity obtained from conditional simulation are greater than those from Ordinary Kriging analysis. The movement of the contaminant on the hydraulic conductivity with greater heterogeneity obtained from conditional simulation is faster than that observed in Ordinary Kriging analysis.

• The Korean Journal of Applied Statistics
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• v.23 no.6
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• pp.1147-1156
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• 2010

This paper proposes a replacement policy following the expiration of a non-renewing free replacement-repair Warranty(NFFRW). The non-renewing free replacement-repair warranty is defined and then the maintenance model following the expiration of the NFRRW is studied from the user's point of view. As the criteria to determine the optimality of the maintenance policy, we consider the expected cost rate per unit time from the user's perspective. All maintenance costs of the system incurred after the expiration of the warranty are paid by the user. Given the cost structures during the life cycle of the system, we determine the optimal maintenance period following the expiration of a NFRRW. Finally, the numerical examples are presented for illustrative purposes.

• Journal of Practical Agriculture & Fisheries Research
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• v.19 no.1
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• pp.99-108
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• 2017

It is Lespedeza cuneata. G. don used as a remedy for cough, asthma, premature ejaculation and so on, though it has been used for a long time. In order to investigate the possibility of using Lespedeza cuneata. G. don as a raw material for functional food, we examined useful substances through analysis. In the study, 124 useful substances were analyzed and 84 of them were found to be functional. In 6 species, 6 of them were found to be functional and 5 of them were functional. In the present study, the other useful substance, D-pinitol, also confirmed its functionality. Potassium isolespedezate and Potassium lespedezate act as antibiotics, Trifolin acts as an antibiotic and hepatoprotectant, and Vitexin acts as a hepatoprotectant. D-pinitol has shown excellent efficacy in patients with prediabetic and insulin-resistant diabetes. As it contains a large amount of useful substances, it can be utilized as a highly functional food.

• Tunnel and Underground Space
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• v.13 no.1
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• pp.44-51
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• 2003

Changes of the hydraulic conductivity resulting from the redistribution of stresses by underground excavation are examined using the strain-dependent hydraulic conductivity modification relation, where the modulus reduction ratio and induced strain are the major parameters. The modulus reduction ratio is defined in terms of RMR(Rock Mass Rating) to represent the full gamut of rock mass condition. Though shear dilation has the effect on the modification of hydraulic conductivity, the extent of it depends on RMR When the extensional strain is applied to a fracture, the hydraulic conductivity increases with the decrease of RMR Loading configuration has the effect on the modification of hydraulic conductivity, where the differential stress mode with a magnitude of the minimum principal stress $($\sigma$_x)$ fixed and a magnitude of the maximum principal stress $($\sigma$_y)$ varied is found to exert the greatest effect on the change of hydraulic conductivity.

• Korean journal of food and cookery science
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• v.17 no.1
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• pp.1-6
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• 2001

The purpose of this study was to investigate sensory and mechanical characteristics of Surichwi-injeulmi by adding Surichwi contents. According to sensory evaluation of Surichwi-injeulmi, the acceptance was the best in the color, flavor and overall quality when adding 20% Surichwi. As the additional ratio of Surichwi was increased, the lightness and yellowness were decreased, however, the redness was negatively increased. As a results of textural analysis of Surichwi-injeulmi by adding Surichwi contents in storing at 20$\^{C}$, the hardness, chewiness, gumminess and cohesiveness were decreased with the increased by adding Surichwi contents. The hardness, chewiness, gumminess and cohesiveness were decreased by increased storage time, whereas the elasticity was increased. Textural characteristics of Surichwi-injeulmi added 30% and 40% Surichwi in storing at 20$\^{C}$ showed less change than those of 0 and 10% group.

• Korean Journal of Plant Resources
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• v.10 no.1
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• pp.39-44
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• 1997

This study was conducted to determine the effects of growth regulators, temperature, and light on the germination of Chwinamul(Aster scaber, Aster tataricus, Synurus deltoides, Solidago virga-aurea var. asiatica, Ligularia fisheri) seeds. Compared to GA, IAA, and kinetin, BA (150ppm) stimulated best seed germination of all five species under the both light and dark condition at $25^{\circ}C$. The effect of growth regulators was not observed significantly under the light condition except of Ligularia fisheri and Synurus deltoides while it was shown markedly under the dark condition. Germination rates of Ligularia fisheri and Synurus deltoides in different concentration of BA were relatively higher under the light at $15^{\circ}C$ while those of other species varied in different concentration and temperature.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1371-1375
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• 2004

하천은 대부분이 단일하천이 아닌 몇 개의 지류가 본류와 만나는 복잡한 하천망으로 구성되어 있다. 이때 지류와 본류가 만나는 합류부는 단일하천내 통상의 단면에 비하여 수위, 유속등의 수리학적 특성이 복잡한 현상을 보이게 되려 상류로부터 유입되는 본류와 지류의 유량비, 합류 각도 등에 따라 합류부에서의 수리학적 특성은 매우 민감하게 변화된다. 이러한 변화는 본류 및 지류에 의한 배수효과도 발생된다. 합류부의 배수효과는 합류점뿐만 아니라 합류점 상류의 본류와 지류의 수위 및 유속변화를 유발하여 홍수피해를 가중시키게 된다. 따라서 본류와 지류가 만나는 합류부의 정확한 수리특성의 파악은 안정적인 하천기능을 유지하기 위한 매우 중요한 요소라 할 수 있다. 이를 위해서 합류후 정체구간의 수리 특성분석과 그에 따른 통수능의 저하가 본류에 미치는 배수효과를 분석하였다.

• Journal of the Korean Data and Information Science Society
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• v.22 no.4
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• pp.775-784
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• 2011

In this paper, we consider the periodic preventive maintenance model for repairable system following the expiration of non-renewing free replacement-repair warranty (NFRRW). Under this preventive maintenance model, we derive the expressions for the expected cycle length, the expected total cost and the expected cost rate per unit time. Also, we determine the optimal preventive maintenance period and the optimal preventive maintenance number by minimizing the expected cost rate per unit time. Finally, the optimal periodic preventive maintenance policy is given for Weibull distribution case.