• 대한토목학회논문집
• /
• 제30권4D호
• /
• pp.423-432
• /
• 2010

본 연구에서는 공사기획단계와 시공단계에서 공사의 성공적 이행을 보장하기 위해 기존의 리스크관리 프로세스를 살펴보고 이에 적합한 새로운 리스크분석 모델인 CRMS를 제시한다. CRMS는 시공자가 건설공사의 이행중 리스크를 확인하고, 분석하고, 관리해 가기 위한 리스크관리절차이다. 이것은 시공자가 인지한 리스크를 정량화하고 이에 적절한 리스크관리 방안을 수립하는데 큰 도움을 줄 수 있다. 특히 건설공사의 리스크관리 중 가장 중요하고 어려운 부문이 리스크를 인지하는 것으로 볼 수 있다. 따라서 본 연구에서는 건설공사의 리스크인지를 쉽게 할 수 있는 절차의 개발에 좀 더 집중하였다. 리스크의 확인은 프로젝트의 외적 리스크와 내적 리스크로 구분한다. 글로벌 리스크의 경우 확인을 용이하게 하기 위해 분석에 필요한 목록을 제시하고, 아울러 RBS의 구축방법과 WBS와의 연계방안을 제시하였다. 이러한 연구결과는 리스크관리용 전산시스템을 개발하기 위한 기초자료로 활용되게 될 것이다.

• Journal of the Korean Data and Information Science Society
• /
• 제27권5호
• /
• pp.1225-1239
• /
• 2016

We investigate pediatric tumor incidence data collected by the Florida Association for Pediatric Tumor program using various models commonly used in disease mapping analysis. Particularly, we consider Poisson normal models with various conditional autoregressive structure for spatial dependence, a zero-in ated component to capture excess zero counts and a spatio-temporal model to capture spatial and temporal dependence, together. We found that intrinsic conditional autoregressive model provides the smallest Deviance Information Criterion (DIC) among the models when only spatial dependence is considered. On the other hand, adding an autoregressive structure over time decreases DIC over the model without time dependence component. We adopt weighted ranks squared error loss to identify high risk regions which provides similar results with other researchers who have worked on the same data set (e.g. Zhang et al., 2014; Wang and Rodriguez, 2014). Our results, thus, provide additional statistical support on those identied high risk regions discovered by the other researchers.

• 한국터널지하공간학회 논문집
• /
• 제24권6호
• /
• pp.725-744
• /
• 2022

도심지에서의 교통인프라 개발이 활발해 지고, 대심도 지하터널을 이용한 도시의 기반시설 확충으로 인하여 도심지 구간에서 대심도 터널시공이 많이 이루어지고 있다. 이에 따라 대심도 터널시공으로 인한 터널안전 문제와 주변 지반 및 구조물의 안전 확보여부는 중요한 이슈가 되고 있으며, 터널시공에 앞서 대심도 터널공사에 따른 리스크를 분석하고 평가하여 리스크 관리를 반드시 수행하여야 한다. 본 연구에서는 대심도 터널과 도심지 터널이라는 특성을 반영하여 터널구간에 대하여 지반조사 자료, 설계 도서, 각종 사전 검토자료 및 시공계획 등을 바탕으로 수직구, 본선터널 및 대단면 터널 정거장 구간의 지하 안전성에 대한 주요 리스크를 분석하고 평가함으로서 수직구, 본선터널과 대단면 터널정거장 구간에 대한 안전리스크를 정량적으로 관리하고자 하였다. 본 연구는 도심지 대심도 터널공사에서 시공시 리스크와 안전 문제를 사전에 검토하는 경우 기본적인 기초 참고 자료로 활용될 수 있을 것으로 기대된다.

• 산업기술연구
• /
• 제21권A호
• /
• pp.7-14
• /
• 2001

In building structure, the story height can be minimized by providing openings in beams which serves for the utility equipments passing through. The dead space in false ceiling thus put to economical use in the form of a substantial reduction in materials and construction cost. In the case of steel structure, there is no critical risk in the structural strength because of reinforcing methods of stiffness and steel plate but in the case of reinforced concrete structure, proper provision should be made in designing these openings, otherwise there is a risk that these opening will possibly weaken the structural strength of the building frame to a critical degree. In this paper, for the numerical analysis of the reinforced concrete beams with circular opening in the web, expecting stress concentration of the circular opening, reinforcing methods were studied. Twenty test pieces with each different reinforcing methods were tested and their resisting forces were defined. From the numerical analysis and test results, the followings were founded;(1)high shear stress distributed around the openings reduce the shearing strength, (2)from the numerical analysis, the maximum tensile stress occurred at opening nodes 1,7, these phenomena were agreed with the test results, (3)reinforcing method around openings have to carried out for stopping diagonal cracks, and (4)both, by steel plate, and wire mesh, are effective reinforcing methods.

• Nuclear Engineering and Technology
• /
• 제54권1호
• /
• pp.386-400
• /
• 2022

Seismic fragility analysis, a part of seismic probabilistic risk assessment (SPRA), is commonly used to establish the relationship between a representative property of earthquakes and the failure probability of a structure, component, or system. Current guidelines on the SPRA of nuclear power plants (NPPs) used worldwide mainly reflect the earthquake characteristics of the western United States. However, different earthquake characteristics may have a significant impact on the seismic fragility of a structure. Given the concern, this study aimed to investigate the effects of earthquake characteristics on the seismic fragility of concrete containments housing the OPR-1000 reactor. Earthquake time histories were created from 30 ground motions (including those of the 2016 Gyeongju earthquake) by spectral matching to the site-specific response spectrum of Hanbit nuclear power plants in South Korea. Fragility curves of the containment structure were determined under the linear response history analysis using a lumped-mass stick model and 30 ground motions, and were compared in terms of earthquake characteristics. The results showed that the median capacity and high confidence of low probability of failure (HCLPF) tended to highly depend on the sustained maximum acceleration (SMA), and increase when using the time histories which have lower SMA compared with the others.

• Structural Engineering and Mechanics
• /
• 제78권1호
• /
• pp.53-66
• /
• 2021

The determination of the damage index to reveal the performance level of a structure can constitute the seismic risk generalization approach based on the parametric analysis. This study implemented this concept to one kind of civil engineering structure that is the concrete gravity dam. Different cases of the structure exhibit their individual responses, which constitute different considerations. Therefore, this approach allows the parametric study of concrete as well as soil for evaluating the seismic nature in the generalized case. To ensure that the target algorithm applicable to most of the concrete gravity dams, a very simple procedure has been considered. In order to develop a correlated algorithm (by response surface methodology; RSM) between the ground motion and the structural property, randomized sampling was adopted through a stochastic method called half-fractional central composite design. The responses in the case of fluid-foundation-dam interaction (FFDI) make it more reliable by introducing the foundation as being bounded by infinite elements. To evaluate the seismic generalization of FFDI models, incremental dynamic analysis (IDA) was carried out under the impacts of various earthquake records, which have been selected from the Pacific Earthquake Engineering Research Center data. Here, the displacement-based damage indexed fragility curves have been generated to show the variation in the seismic pattern of the dam. The responses to the sensitivity analysis of the various parameters presented here are the most effective controlling factors for the concrete gravity dam. Finally, to establish the accuracy of the proposed approach, reliable verification was adopted in this study.

• 한국농공학회지
• /
• 제28권3호
• /
• pp.69-78
• /
• 1986

This studies were established to find out the characteristics of frequency distributiom for the number of occurrence and magnitude, probable flood flows according to the return periods, design floods, and design frequency factors for the studying basins in relation to the risk levels which can be correlated with design return period and the life of structure in the non-annual exceedance series. Eight watersheds along Han, Geum, Nak Dong and Seom Jin river basin were selected as studying basins. The results were analyzed and summarized as follows. 1. Poisson distribution and Exponential distribution were tested as a good fitted distributions for the number of occurrence and magnitude for exceedance event, respectively,at selected watersheds along Han, Geum, Nak Dong and Seom Jin river basin. 2.Formulas for the probable flood flows and probable flood flows according to the return periods were derivated for the exponential distribution at the selected watersheds along Han, Geum, Nak Dong, and Seom Jin river basin. 3.Analysis for the risk of failure was connected return period with design life of structure in the non-annual exceedance series. 4.Empirical formulas for the design frequency factors were derivated from under the condition of the return periods identify with the life of structure in relation to the different risk levels in the non-annual exceedance series. 5.Design freguency factors were appeared to be increased in proportion to the return periods while those are in inverse proportion to the levels of the risk of failure. Numerical values for the design frequency factors for the non-annual exceedance series ware appeared generally higher than those of annual maximum series already published by the first report. 6. Design floods according to the different risk levels could be derivated by using of formulas of the design frequency factors for all studying watersheds in the nor-annual exceedance series.

• 한국학교ㆍ지역보건교육학회지
• /
• 제20권2호
• /
• pp.13-24
• /
• 2019

Objective: Recently, Korean adolescent has the problems of nutrition unbalance due to bad eating habits. Also, single-parent and step-parent families have consistently increased because of the increase of divorce rates. Adolescent who lives with a single or step family tends to have unhealthy behaviors and habits. The purpose of this study was to analyze relationship between family structure and irregular breakfast among Korean adolescent. Method: We analyzed 60,040 participants from Korean Youth Risk Behavior Web-based Survey 2018. Study variables included family structure and irregular breakfast. Control variables were sex, school, economic status, parent education levels, drinking, smoking and nutrition education. In terms of this study, descriptive, Chi-square and multivariate logistic regression analysis were performed. Results: After adjusting for socio-demographic variables among boys, family structure was associated with irregular breakfast (living with both parents reference group vs living with single-parent : OR 1.250, 95% CI: 1.142, 1.368). Among girls, after adjusting for control variables, family structure was also associated with irregular breakfast (living with both parents reference group vs living with no both parents : OR 1.409, 95% CI: 1.065, 1.865). Conclusion: According to this study, family structure would be a risk factor of adolescent breakfast habit. Nutrition programs for adolescent should consider these factors.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2013년도 춘계 학술논문 발표대회
• /
• pp.192-193
• /
• 2013

In recent years, risks associated with mixed used development in urban regeneration projects which have actively been implemented have been on the rise due to uncertainties and complexities of those projects. Thus, risk management is needed to effectively manage those risks that may occur during the process of a project. Many studies have contributed to deal with risk management of those projects. These studies, however, have focused main on identification stage and deriving the main risk factors and have limitations on presenting the relationship among those risk factors. Since many risks are interdependent and have multiple effects, the purpose of this study is to present a way(ISM method) to provide a hierarchical structural framework of risks in Urban Regeneration. The structural of risks can helps decision makers to trace the actual source of these risks.

• International Journal of Quality Innovation
• /
• 제7권3호
• /
• pp.1-14
• /
• 2006

Economic value added (EVA) is introduced on two levels: as index for evaluation of corporation and as index for evaluation of business unit. In the latter case, application of one and the same cost of capital to all business units of a business corporation may be possible, but it is a fundamental policy for EVA to apply different cost of capital to business units with different risks. Estimate of cost of capital of business units is a problem to be resolved. The author, focusing on the question of the estimate of cost of capital of business units, has conducted a demonstrative study on risk structure of cost of capital estimates by using financial indices of Japanese manufacturers (37 automotive industries, 141 electrical and electronic machinery industries, 63 food processing industries, 98 chemical industries, 125 general machinery industries) for a period of 5 years from 1995 to 1999. The author presumes that $\beta$ is explained by a regression formula ${\beta}=B_0+{\Sigma}B_iY_i+{\alpha}$ ($Y_i$: financial indices) and selects 40 explanatory variables from financial statements as risk components. Using their financial indices, the author concludes through a series of statistical analyses that there is a good likelihood of estimating cost of capital for Japanese industries and is convinced that it will lead to more reliable and practical results by assigning averages and variances to 40 primary financial indices for a period of 3 to 5 years selected in this demonstrative study.