• Journal of Korean Tunnelling and Underground Space Association
• /
• v.13 no.1
• /
• pp.19-32
• /
• 2011

The risk assessment is essential for tunnel design in order to minimize risks associated with uncertainty about geological conditions and tunneling method. This paper provides a comparative risk analysis of a large single bore TBM driven tunnel against sequentially excavated NATM tunnel for a mixed-face large-diameter urban tunnel project near or under a river. The focus of this assessment is on the risks associated with the tunnel excavation methods, in particular whether a TBM or NATM presents more or less risk to achieve the planned excavation duration and bring the project within the estimated bid price. First, the impacts and risks to tunnel construction under each method were discussed, and the risks were scored and ranked in the order of perceived severity and likelihood. Finally, the assessment from a risk based perspective was conducted to decide which alternate tunneling method is more likely to deliver the project with the least time and cost. It is very important to note that this study is only applied to this tunnel project with specific geological conditions and other contract requirements.

• Journal of Korean Society on Water Environment
• /
• v.25 no.4
• /
• pp.494-501
• /
• 2009

Probabilistic Ecological risk assessment (PERA) is extensive approach to qualify and quantify risk on the multi species based on species sensitivity distribution (SSD). As a while, deterministic ecological risk assessment (DERA) considers the comparison of predicted no-effect concentration (PNEC) and predicted exposure concentration (PEC). DERA is used to determine if there is potential risk or no risk, and it doesn't consider the nature variability and the species sensitivity. But PERA can be more realistic and reasonable approach to estimate likelihood or risk. In this study, we compared PERA used in developed countries, and proposed PERA applicable for the Korean water environment. Taxonomic groups were classified as "class" level including Actinopterygill, Branchiopoda, Chlorophyceae, Maxillapoda, Insects, Bivalvia, Gastropoda, Secernentea, Polychaeta, Monocotyldoneae, and Chanophyceae in this study. Statistical extrapolation method (SEM), statistical extrapolation method $_{acutechronicratio}$ ($SEM_{ACR}$) and assessment factor method (AFM) were used to calculate the ecological protective concentration based on qualitative and quantitative levels of taxonomic toxicity data. This study would be useful to establish the PERA for the protection of aquatic ecosystem in Korea.

• Fisheries and Aquatic Sciences
• /
• v.18 no.2
• /
• pp.183-193
• /
• 2015

Several transgenic marine medaka Oryzias dancena strains harboring a green fluorescent protein (GFP) reporter construct regulated by an endogenous ${\beta}$-actin promoter were established and their expression characteristics in relation to transgene copy numbers were examined in 21 transgene genotypes. Most of the transgenic strains displayed transgene insertion patterns typical of microinjection-mediated introduction of foreign DNA into fish embryos, characterized by the random integration of multiple transgene copies (ranging from 1 - 282 copies per cell), often accompanied by the formation of concatemer(s), as assessed by genomic Southern blot hybridization analysis and qPCR. Transgenic strains showed ubiquitous and continued temporal and spatial expression patterns of the transgenic GFP during most of their life cycle, from the embryonic stage to adulthood, enabling assessment of the expression pattern of the endogenous ${\beta}$-actin gene. However, a comparative evaluation of transgene copy numbers and expression levels showed that copy number-dependent expression, the stability of the ubiquitous distribution and expression efficiency per transgene copy varied among the transgenic strains. Fluorescence expression levels were positively correlated with absolute transgene copy numbers, whereas the expression efficiency per transgene copy was inversely related to the number of transgene integrant copies. Data from this study will guide the selection of potentially desirable transgenic strains with ubiquitous expression of a fluorescent transgene, not only in this marine medaka species but also in other related model fish species.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.6 no.3
• /
• pp.33-42
• /
• 2003

As airborne laser scanning technique is developed with high vertical accuracy recently, there come many studies on DEM(digital elevation model creation, building extraction, flood risk mapping and 3D virtual city modeling. This study applied point comparative method, contour comparative method and digital map with scale 1/5,000 to calculate RMSE of DEM in according to resolution that was constructed using rawdata being acquired by airborne laser scanning. As a result, point comparative method showed lower DEM standard error than contour comparative method, it is a reason that contour comparative method was not carried out detailed grid calculation for point comparative method. Also, digital map with scale 1/5,000 showed higher DEM standard error than point comparative method and contour comparative method in below 25.4m that is average horizontal distance among contour line, and showed similar result with contour comparative method in over 25.4m.

• Korean Journal of Community Nutrition
• /
• v.13 no.1
• /
• pp.125-133
• /
• 2008

This study was carried out to compare bone density risk factors affecting women's BMD, and to examine the relationship age, lifestyle and dietary habits for bone health by physical measurement and questionnaires. The subjects of this study were 194 women living in the Seoul area. When the subjects were divided into normal and risk groups, BMD, height, weight, BMI, total body water, soft lean mass, fat free mass, protein, mineral, body-fat of normal group were much higher than those of the risk group. The breakfast eating rate of the normal group was much higher than that of the risk group, walking time was significantly longer and exercise was more (p < 0.05). The normal group had more frequent intakes of tunas, squid, radishes, the green parts of radish, cucumbers, carrots and Iucchinis, tomatoes, and grapes than the risk group (p < 0.01 or p < 0.05). In conclusion, breakfast eating, exercise, intakes of some foods such as anchovies, radishes, carrots, zucchinis and tomatoes were significantly important factor to prevent bone density risk.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2022.11a
• /
• pp.99-100
• /
• 2022

As the danger of exposure to the asbestos has been revealed, the importance of demolition asbestos in existing buildings has been raised. Extensive body of study has been conducted to evaluate the risk of demolition asbestos, but there were confined types of variables caused by not reflecting categorical information and limitations in collecting quantitative information. Thus, this study aims to derive a model that predicts the risk in workplace of demolition asbestos by collecting categorical and continuous variables. For this purpose, categorical and continuous variables were collected from asbestos demolition reports, and the risk assessment score was set as the dependent variable. In this study, the influence of each variable was identified using logistic regression, and the risk prediction model methodologies were compared through decision tree regression and artificial neural network. As a result, a conditional risk prediction model was derived to evaluate the risk of demolition asbestos, and this model is expected to be used to ensure the safety of asbestos demolition workers.

• Korea Trade Review
• /
• v.47 no.3
• /
• pp.17-35
• /
• 2022

The Pandemic crisis caused by COVID-19 has raised awareness of the importance of supply chain risk management, such as the control of movement between countries and the simultaneous manufacturing paralysis in the world. Effective risk management within the supply chain of the company is a core competency in the global environment. Therefore, this study quantitatively analyzed the perspective of domestic large corporations and small and medium enterprises (SMEs) by using the hierarchical analysis method (AHP) to identify the factors that should be considered as the priority when establishing supply chain risk management plans for large and small business employees. In order to conduct the study, a survey was conducted on large corporations and small and medium enterprises in Gyeongnam and Busan, and AHP analysis was conducted using Microsoft 365 excel program. In addition, Mann-Whitney U test (independent sample-nonparametric test) was conducted using SPSS/18 version of statistical package program for comparative analysis between groups. As a result, the priority was highly evaluated in the order of financial ability, competitiveness, disaster in the overall priority evaluation. There were statistically significant differences in internal risk and strategic decision making of supply chain between groups. This suggests that fandemics such as COVID-19 can not be predicted, but strategic responses are needed to utilize opportunities expressed in the crisis through supply chain risk management and to increase the competitive advantage of domestic companies even in the crisis.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2004.10a
• /
• pp.1459-1460
• /
• 2004

An AHP-based framework for comprehensive comparison of several power technologies haas been developed. A questionnaire has been designed and is about to surveyed for extracting boty weight vectors and subjective evaluation values. The attitude of evaluator groups will be incorporated into these two types of quantification.

• KDI Journal of Economic Policy
• /
• v.46 no.2
• /
• pp.21-43
• /
• 2024

This paper provides a new theoretical rationale for public procurement for innovation (PPI), a unique policy encouraging public procurers to purchase innovative products. In contrast to existing studies that primarily emphasize the advantages of PPI, this paper takes a comprehensive approach, examining both the costs and risks associated with PPI, alongside its benefits. It finds a general condition under which PPI outperforms traditional public procurement. Under this condition, this paper demonstrates that PPI enhances social welfare by facilitating optimal risk-sharing between public procurers and the general economy. Additionally, it draws policy implications from a comparative analysis between the current PPI policy in Korea and an optimal PPI policy.

• Journal of the Korean Society of School Health
• /
• v.29 no.3
• /
• pp.256-266
• /
• 2016

Purpose: This study was to compare and to examine the factors related to risk behaviors of adolescents living in small and medium-sized cities and in rural areas. Methods: The subjects were 545 adolescents (295 from small and medium-sized cities and 250 from rural areas). The data was analyzed by descriptive statistics, Pearson corelation coefficients, and multiple regression with IBM SPSS 19.0 program. Results: The factors influencing the risk behaviors of adolescents in small- medium cities were school, peer risk factors and community risk factors, self- control among protective factors, positive communication with parents, positive peer associations, these variables explained 42.0%. The most important variable explaining the risk behaviors of adolescents in small- medium cities was positive communication with parents, followed by community risk factors, peer risk factors, positive peer relationships, school and self-control. The factors affecting the risk behaviors of rural adolescents were school, personal risk factor, peer risk factor, self- control factor, which explained 38.5% of the risk behaviors of adolescents in rural areas. Among them, the most important variable explaining risk behaviors was personal risk factors, followed by peer risk factors, school, and self-control. Conclusion: These finding suggest a need to develop a strategy to improve positive communication with parents for adolescents living in small- medium cities and a strategy to reduce personal risk factors and peer risk factors for rural adolescents.