• Journal of the Korean Institute of Gas
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• v.13 no.3
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• pp.22-27
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• 2009

Recently Urban Gas Business Companies have been allowed to construct High Pressure Natural Gas pipelines, if they adopt the Risk Reduction Measures(RRMs) recommended by Korea Gas Safety Corporation(KGS) after safety assessment. This paper presents a Cost Benefit Analysis(CBA) method, when KGS performs safety assessment and recommends RRMs to Safety Appraisal Committee, to help the Committee make judgements on whether the proposed RRMs are reasonably practicable. We carried out quantitative risk assessment to high pressure natural gas pipelines as a case study and analysed cost benefit for the suggested RRMs. In conclusion, we found out the presented CBA method using PF was proper in Korea.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1165-1168
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• 2008

RRMS는 RRFS에 의해 모의된 소유역 및 지점에 대한 유출량과 관측유출량 및 강우량에 대한 상호관계를 물관리를 위한 운영자의 의사결정 보조 도구로 활용하고자 한다. RRMS는 강우, 유출, 용수부분으로 구분하여 소유역 및 지점별 면적 강우량과 유출량에 관한 분석으로 구성되어 있다. RRMS 구성의 기본 요소는 강우량과 유출량의 분석을 위해 사용된 지표인 강우비와 유출비로 하였다. 이들 지표는 해당월평년과 해당월에 대한 값의 비로 하였다. 강우비와 유출비의 변화에 의해 소유역 및 지점의 유출상황을 판단할 수 있으며 이에 따른 의사결정에 도움이 될 것으로 판단된다. RRMS의 최종적인 목적은 현재 한국수자원공사 수자원연구원에서 생산중인 유출월보의 콘텐츠인 SMI 지수, 용수이용량, 월별유출량, 지점별 강우-유출 현황을 원활하게 생산 할 수 있도록 지원하는 것이다.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.4
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• pp.425-432
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• 2007

This paper describes a development of ship's refer-container remote monitoring system(RRMS). This system consists of Master, repeater with a switched mode power supply(SMPS) and slave terminal. Slave terminal is composed of wireless MODEM and microprocessor part, checks its conditions like temperature. humidity & etc through the interrogate port(IP) of refer-container. and transmits their data to master. Repeater's role is that connect so that signal which is transmitted from Slave Terminal by Master may not receive electric wave interference by container boxes. We verify the effectiveness of proposed system through the experimental works in container yard and ship.

• Journal of the Korean Institute of Gas
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• v.15 no.2
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• pp.40-46
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• 2011

The purpose of CBA(cost-benefit analysis) in risk assessment is to show whether the benefits of implementing additional risk reduction methods(RRMs) derived through risk assessment outweigh its costs and it is proper to implement the methods. In this paper CBA has been conducted in order to select the most effective and reasonable RRM as implementing the RRM derived after QRA for the high pressure urban gas pipelines. As conducting QRA again by applying the derived RRMs, No. 10 measure which includes pipeline corrosion monitoring, MOV(motor operated valve) installation and the method to protect pipeline damage caused by third-party mechanical interference has showed the highest risk reduction effect. Also it has been considered to be reasonably practicable by conducting CBA and then is selected as the most effective and reasonable RRM on the objects of this paper.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.5
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• pp.607-614
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• 2016

The objectives of the study were to estimate genetic parameters for milk production traits of Holstein cattle using random regression models (RRMs), and to compare the goodness of fit of various RRMs with homogeneous and heterogeneous residual variances. A total of 126,980 test-day milk production records of the first parity Holstein cows between 2007 and 2014 from the Dairy Cattle Improvement Center of National Agricultural Cooperative Federation in South Korea were used. These records included milk yield (MILK), fat yield (FAT), protein yield (PROT), and solids-not-fat yield (SNF). The statistical models included random effects of genetic and permanent environments using Legendre polynomials (LP) of the third to fifth order (L3-L5), fixed effects of herd-test day, year-season at calving, and a fixed regression for the test-day record (third to fifth order). The residual variances in the models were either homogeneous (HOM) or heterogeneous (15 classes, HET15; 60 classes, HET60). A total of nine models (3 orders of $polynomials{\times}3$ types of residual variance) including L3-HOM, L3-HET15, L3-HET60, L4-HOM, L4-HET15, L4-HET60, L5-HOM, L5-HET15, and L5-HET60 were compared using Akaike information criteria (AIC) and/or Schwarz Bayesian information criteria (BIC) statistics to identify the model(s) of best fit for their respective traits. The lowest BIC value was observed for the models L5-HET15 (MILK; PROT; SNF) and L4-HET15 (FAT), which fit the best. In general, the BIC values of HET15 models for a particular polynomial order was lower than that of the HET60 model in most cases. This implies that the orders of LP and types of residual variances affect the goodness of models. Also, the heterogeneity of residual variances should be considered for the test-day analysis. The heritability estimates of from the best fitted models ranged from 0.08 to 0.15 for MILK, 0.06 to 0.14 for FAT, 0.08 to 0.12 for PROT, and 0.07 to 0.13 for SNF according to days in milk of first lactation. Genetic variances for studied traits tended to decrease during the earlier stages of lactation, which were followed by increases in the middle and decreases further at the end of lactation. With regards to the fitness of the models and the differential genetic parameters across the lactation stages, we could estimate genetic parameters more accurately from RRMs than from lactation models. Therefore, we suggest using RRMs in place of lactation models to make national dairy cattle genetic evaluations for milk production traits in Korea.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.5
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• pp.976-985
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• 2002

The purpose of this paper is that the roughness(Rrms = 31$\AA$, Rp-v = 270$\AA$) of ITO thin film deposited by sputtering method for OELD is improved to Rrms $\leq$ 10$\AA$, Rp-v $\leq$ 80$\AA$ by chemical mechanical polishing(CMP). First, ITO thin films are polished with a variety of consumables (Pads, Slurries) to choose proper some for the roughness improvement and the CMP mechanism of ITO thin films is demonstrated on the ground of the experiment results. Henceforth, the CMP characteristics (Removal rate, Non-uniformity) of chosen consumables are evaluated according to processing conditions (Polishing pressures, Table velocities) and suitable conditions for ITO film CMP are selected. Finally, the electrical and optical properties (Sheet resistance, Transmittance) of ITO thin films are investigated to verify whether or not ITO thin film are still suitable for OELD after polished.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.256-259
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• 2007

Multicast and Broadcast Service (MBS) provides flexible and efficient transmission of the same information to multiple users using shared radio resources on WiBro network. The advantage of this service is to achieve the most efficient use of radio and network resources as well as to lessen sender's processing load when sending the same information to multiple users. Though radio resources are saved since a multicast or broadcast transport connection is associated with a service flow, it is hard to change MBS service channel dynamically. In this paper, we propose a Radio Resource Management System (RRMS) for supporting dynamic scheduling of MBS service channels. Results show that our proposed scheme using Radio Resource Allocation Table (RRAT) can efficiently support MBS services by providing dynamic schedule for MBS service channels.

• Journal of the Microelectronics and Packaging Society
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• v.11 no.4 s.33
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• pp.81-86
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• 2004

A new method to improve the wet etching characteristics is described. The anisotropic wet-etching of (100) Si with megasonic wave has been studied in KOH solution. Etching characteristics of p-type (100) 6 inch Si have been explored with and without megasonic irradiation. It has been observed that megasonic irradiation improves the characteristics of wet etching such as an etch uniformity and surface roughness. The etching uniformity on the whole wafer with and without megasonic irradiation were less than ${\pm}1\%$ and more than $20\%$, respectively. The initial root-mean-square roughness($R_{rms}$) of single crystal silicon is 0.23 nm. It has been reported that the roughnesses with magnetic stirring and ultrasonic agitation were 566 nm and 66 nm, respectively. Comparing with the results, etching with megasonic irradiation achieved the Rrms of 1.7 nm on the surface after the $37{\mu}m$ of etching depth. Wet etching of silicon with megasonic irradiation can maintain nearly the original surface roughness after etching process. The results have verified that the megasonic irradiation is an effective way to improve the etching characteristics such as etch uniformity and surface roughness.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.7
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• pp.923-930
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• 2009

This study was conducted to compare three models: two random regression models with and without considering heterogeneity in the residual variances and a lactation model (LM) for evaluating the genetic ability of Holstein cows in Korea. Two datasets were prepared for this study. To apply the test-day random regression model, 94,390 test-day records were prepared from 15,263 cows. The second data set consisted of 14,704 lactation records covering milk production over 305 days. Raw milk yield and composition data were collected from 1998 to 2002 by the National Agricultural Cooperative Federation' dairy cattle improvement center by way of its milk testing program, which is nationally based. The pedigree information for this analysis was collected by the Korean Animal Improvement Association. The random regression models (RRMs) are single-trait animal models that consider each lactation record as an independent trait. Estimates of covariance were assumed to be different ones. In order to consider heterogeneity of residual variance in the analysis, test-days were classified into 29 classes. By considering heterogeneity of residual variance, variation for lactation performance in the early lactation classes was higher than during the middle classes and variance was lower in the late lactation classes than in the other two classes. This may be due to feeding management system and physiological properties of Holstein cows in Korea. Over classes e6 to e26 (covering 61 to 270 DIM), there was little change in residual variance, suggesting that a model with homogeneity of variance be used restricting the data to these days only. Estimates of heritability for milk yield ranged from 0.154 to 0.455, for which the estimates were variable depending on different lactation periods. Most of the heritabilities for milk yield using the RRM were higher than in the lactation model, and the estimate of genetic variance of milk yield was lower in the late lactation period than in the early or middle periods.

• Journal of the Korean Vacuum Society
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• v.17 no.2
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• pp.102-108
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• 2008

We have studied the properties of Ag/undoped ZnO (ZnO) multilayer thin films deposited on glass substrate by the facing targets sputtering method. In an attempt to find out the optimum conditions of the Ag thin film, which would be coated on the ZnO thin film, we investigated the changes of sheet resistance, transmittance and surface morphology as a function of deposition times and the substrate temperature. The electrical and optical characteristics of Ag/ZnO multilayers were evaluated by a four-point probe, a UV/VIS spectrometer with a spectral range of 390-770 nm, a X-ray Diffractometer (XRD), an atomic force microscope (AFM) and a Field Emission Scanning Electron Microscope (SEM), respectively. We were able to prepare the Ag/ZnO multilayer thin film with sheet resistance of 9.25 $\Omega/sq.$ and transmittance of over 80% at 550nm.