• Korean Journal of Agricultural Science
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• v.42 no.4
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• pp.397-406
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• 2015

Quantitative traits are mostly controlled by a large number of genes. Some of these genes tend to have a large effect on quantitative traits in cattle and are known as major genes primarily located at quantitative trait loci (QTL). The genetic merit of animals can be estimated by genomic selection, which uses genome-wide SNP panels and statistical methods that capture the effects of large numbers of SNPs simultaneously. In practice, the accuracy of genomic predictions will depend on the size and structure of reference and training population, the effective population size, the density of marker and the genetic architecture of the traits such as number of loci affecting the traits and distribution of their effects. In this review, we focus on the structure of Hanwoo reference and training population in terms of accuracy of genomic prediction and we then discuss of genetic architecture of intramuscular fat(IMF) and marbling score(MS) to estimate genomic breeding value in real small size of reference population.

• Journal of Wetlands Research
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• v.19 no.1
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• pp.112-121
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• 2017

This study proposed the quantitative precipitation estimation method using overlapped area in radar network. For this purpose, the dense rain gauges and radar network are used. As a result, we found a reflectivity bias between two radar located in different area and developed the new quantitative precipitation estimation method using the bias. Estimated radar rainfall from this method showed the apt radar rainfall estimate than the other results from conventional method at overall rainfall field.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.2
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• pp.101-111
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• 2004

Risk analysis process, which identifies vulnerabilities and threat causes of network assets and evaluates expected loss when some of network assets are damaged, is essential for diagnosing ISP network security levels and response planning. However, most existing risk analysis systems provide only methodological analysis procedures, and they can not reflect continually changing vulnerabilities and threats information of individual network system on real time. For this reason, this paper suggests new system design methodology which shows a scheme to collects and analyzes data from network intrusion detection system and vulnerability analysis system and estimate quantitative risk levels. Additionally, experimental performance of proposed system is shown.

• Communications for Statistical Applications and Methods
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• v.27 no.6
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• pp.701-714
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• 2020

Quantitative high throughput screening (qHTS) assays are used to assess toxicity for many chemicals in a short period by collectively analyzing them at several concentrations. Data are routinely analyzed using nonlinear regression models; however, we propose a new method to analyze qHTS data using a nonlinear mixed effects model. qHTS data are generated by repeating the same experiment several times for each chemical; therefor, they can be viewed as if they are repeated measures data and hence analyzed using a nonlinear mixed effects model which accounts for both intra- and inter-individual variabilities. Furthermore, we apply a one-step approach incorporating robust estimation methods to estimate fixed effect parameters and the variance-covariance structure since outliers or influential observations are not uncommon in qHTS data. The toxicity of chemicals from a qHTS assay is classified based on the significance of a parameter related to the efficacy of the chemicals using the proposed method. We evaluate the performance of the proposed method in terms of power and false discovery rate using simulation studies comparing with one existing method. The proposed method is illustrated using a dataset obtained from the National Toxicology Program.

• Journal of the Korean Institute of Gas
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• v.12 no.2
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• pp.25-31
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• 2008

Recently risk management based on a quantitative assessment is considered to improve the level of safety in Korea. This paper focuses on the procedure of the quantitative risk assessment for natural gas pipelines. For that purpose, the methods to estimate failure frequency based on failure causes from European Gas Pipeline Incident Data Group and BG Transco, to analyze consequence caused by fire, and to calculate individual risk and societal risk have been proposed systematically in this paper. Risk criteria of individual risk and societal risk have been proposed by considering the environment of pipeline route in Korea. The proposed procedure of quantitative risk assessment may be useful for risk management during the planning and building stages of a new pipeline, and modification of buried pipeline.

• Journal of Korean Tunnelling and Underground Space Association
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• v.12 no.4
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• pp.307-319
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• 2010

As we learned in Daegu subway fire accident, fire in the railway tunnel is prone to develop to large disaster due to the limitation of smoke control and smoke exhaust. In railway tunnel, in order to ensure fire safety, fire prevention and fighting systems are installed by quantitative risk assessment results. Therefore, in this research, developed the program to establish quantitative risk assessment and suggested quantitative safety assessment method including fire scenarios in railway tunnel, fire and evacuation analysis model, fatality estimate model and societal risk criteria. Moreover, this method applys to plan preventing disaster for Honam high speed railway tunnel. As results, we presented the proper distance of escape route and societal risk criteria.

• Journal of Distribution Science
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• v.13 no.5
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• pp.71-82
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• 2015

Purpose - The purpose of this study is to investigate risk price implied from the pricing kernel of Korean stock distribution market. Recently, it is considered that the quantitative easing programs of major developed countries are contributing to a reduction in global uncertainty caused by the 2007~2009 financial crisis. If true, the risk premium as compensation for global systemic risk or economic uncertainty should show a decrease. We examine whether the risk price in the Korean stock distribution market has declined in recent years, and attempt to provide practical implications for investors to manage their portfolios more efficiently, as well as academic implications. Research design, data and methodology - To estimate the risk price, we adopt a non-parametric method; the minimum norm pricing kernel method under the LOP (Law of One Price) constraint. For the estimation, we use 17 industry sorted portfolios provided by the KRX (Korea Exchange). Additionally, the monthly returns of the 17 industry sorted portfolios, from July 2000 to June 2014, are utilized as data samples. We set 120 months (10 years) as the estimation window, and estimate the risk prices from July 2010 to June 2014 by month. Moreover, we analyze correlation between any of the two industry portfolios within the 17 industry portfolios to suggest further economic implications of the risk price we estimate. Results - According to our results, the risk price in the Korean stock distribution market shows a decline over the period of July 2010 to June 2014 with statistical significance. During the period of the declining risk price, the average correlation level between any of the two industry portfolios also shows a decrease, whereas the standard deviation of the average correlation shows an increase. The results imply that the amount of systematic risk in the Korea stock distribution market has decreased, whereas the amount of industry-specific risk has increased. It is one of the well known empirical results that correlation and uncertainty are positively correlated, therefore, the declining correlation may be the result of decreased global economic uncertainty. Meanwhile, less asset correlation enables investors to build portfolios with less systematic risk, therefore the investors require lower risk premiums for the efficient portfolio, resulting in the declining risk price. Conclusions - Our results may provide evidence of reduction in global systemic risk or economic uncertainty in the Korean stock distribution market. However, to defend the argument, further analysis should be done. For instance, the change of global uncertainty could be measured with funding costs in the global money market; subsequently, the relation between global uncertainty and the price of risk might be directly observable. In addition, as time goes by, observations of the risk price could be extended, enabling us to confirm the relation between the global uncertainty and the effect of quantitative easing. These topics are beyond our scope here, therefore we reserve them for future research.

• Korean System Dynamics Review
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• v.14 no.1
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• pp.55-68
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• 2013

It is necessary to evaluate the greenhouse gases (GHGs) reduction policy by central and regional governments to set up the suitable GHG emissions measures. Quantitative, qualitative and synthetic methods have been adopted by previous researches to estimate GHG reduction policy. However, these methods mostly focused on the results of the reduction policy, rather than understanding and fixing the integrated structures of GHG emissions. In this research, System Dynamics(SD) was applied to 1 million green homes program, self-carfree-day system and carbon point program. The results showed that SD analyses could be appliable for the estimation of GHG reduction policy by developing the feedback loops and dynamic simulation model. SD can be consider as a supplementary tool to estimate the GHG reduction policies through the recognition of the structure in complex real system.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.5
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• pp.159-166
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• 2007

Large scale flood disasters bring human losses and properties, which lead to the decrease of our productive value and change social environment. Human loss and economic damage are considered to be the same system but they are viewed as separated systems. The total amount of human loss can be represented as the total amount of economic damage estimated in the frame of social system while it will be possible to make mutual changing by clearing the relations between social and economic systems. In this regard, an attempt to estimate economic loss considering per capita Gross Domestic Production (GDP) caused by flood-related mortality was carried out to the typhoon Rusa of 2002 in Kangwon-do. The proposed method tried to capture quantitative factors which are affecting the loss of per capita GDP. The approach has great importance not only to set up governmental policy but also methodological progress in the research due to impact of disaster-related mortality on GDP loss.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.371-376
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• 2007

This paper describes a study to determine proper escape way interval for the design phase of single bored double track tunnel. Among many methods which determine escape way interval, we choose a QRA(Quantitative Risk Analysis) method. But a different method must be chosen differ from other country because of special design situation of Korea. So, it is necessary to develop a method which considers a special design condition of Korea. Because fire accidents of railway tunnel are a rare event, simulated situation can be produced by CFD simulation and evacuation analysis simulation. However, it is generally difficult to estimate of fatalities from these methods, so a concept of FED is introduced to estimate of fatalities. Quantification process provides effective results for practical design stage and the result were employed in design.