• Fire Science and Engineering
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• v.31 no.2
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• pp.52-60
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• 2017

Numerical simulations were performed to evaluate the habitability of an operator for a cabinet fire in the main control room of a nuclear power plant presented in NUREG-1934. To this end, a Fire Dynamics Simulator (FDS), as a representative fire model, was used. As the criteria for determining the habitability of operator, toxic products, such as CO, were also considered, as well as radiative heat flux, upper layer temperature, smoke layer height, and optical density of smoke. As a result, the probabilities of exceeding the criteria for habitability were evaluated through the sensitivity analysis of the major input parameters and the uncertainty analysis of fire model for various fire scenarios, based on V&V (Verification and Validation). Sensitivity analyses of the maximum heat release rate, CO and soot yields, showed that the habitable time and the limit criterion, which determined the habitability, could be changed. The present methodology will be a realistic alternative to enhancing the reliability for a habitability evaluation in the main control room using uncertain information of cabinet fires.

• The Korean Journal of Applied Statistics
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• v.29 no.1
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• pp.41-59
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• 2016

There have been continuous improvements in human life expectancy. Life expectancy is as a key factor in an aging population and can wreak severe damage on the financial integrity of pension providers. Hence, the projection of the accurate future mortality is a critical point to prevent possible losses to pension providers. However, improvements in future mortality would be overestimated by a typical mortality projection method using the Lee-Carter model since it underestimates the mortality index ${\kappa}_t$. This paper suggests a mortality projection based on the projection of the skewness of the mortality versus the typical mortality projection of the Lee-Carter model based on the projection of the mortality index, ${\kappa}_t$. The paper shows how to indirectly estimate future t trend with the skewness of the mortality and compares the results under each estimation method of the mortality index, ${\kappa}_t$. The analysis of the results shows that mortality projection based on the skewness presents less improved mortality at an elderly ages than the original projection.

• Journal of Wetlands Research
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• v.18 no.3
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• pp.209-217
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• 2016

The rational method is formed area, rainfall intensity and runoff coefficient that is representation of land use or surface type. A runoff coefficient is a range for a each surface conditions. Drainage Sewer Design Guideline revised at 2011 proposes return periods 10~30 year instead of 5~10 year for increasing design flood. Ponce and ASCE refer higher values of runoff coefficient require for higher values of rainfall intensity and return period, therefore runoff coefficient had to be corrected but not. In case of park, land use and surface type are different from Korea and U.S, so impervious area ratio is different. The runoff coefficient for park is estimated considering with impervious area ratio and return period. 1,004's parks in 20 cities are randomly selected for impervious area ratio and runoff coefficient is estimated. And a proportion of 30 year return period runoff coefficient to 10 year return period with rainfall duration is calculated for 69 weather stations. The estimated runoff coefficient is 0.43~0.54 for return period 10~30 year and the difference of region and rainfall duration is not significant.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.296-300
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• 2007

우리나라에 내리는 대부분의 강수량은 6월${\sim}$8월의 장마기간 혹은 태풍의 영향으로 인해 발생한다. 특히 국지적으로 발생하는 집중호우로 인해 많은 인명, 재산 피해 등이 발생한다. 우리나라에서 집중호우로 인한 피해는 거의 매년 발생하고 있으며, 집중호우의 발생 지역은 특정 지역에 국한되어 있지 않다. 따라서 집중호우 발생으로 인한 피해 방지를 위해 사전에 충분한 준비를 해야 한다. 2006년 7월 8일부터 10일까지 3일 동안 진주지역 306.5mm, 합천지역 259.5mm, 산청지역 366.0mm의 집중호우가 발생하였으며, 이 기간 동안 이들 지역 외에도 전국적으로 태풍 에위니아(EWINIAR)의 영향으로 많은 호우가 발생하였다. 본 연구에서는 2006년 7월 진주지역 집중호우 특성 연구를 위해 진주지역 시강우 자료를 이용하여 자료를 분석하였다. 시강우 자료를 이용하여 진주지역 재현기간별 확률강우량을 산정하였고 2006년 7월 8일부터 10일까지의 강우분포형태를 설계강우분포형과 비교하였다. 또한 2006년 7월 발생했던 진주지역 집중호우의 무차원 누가곡선을 작성하여 분석을 실시하였다. 분석 결과 일최대 강우량의 경우 그 크기가 50년 혹은 80년 이내였으며, 강우분포형의 경우 하천정비기본계획의 경우 Mononobe 중앙집중형이였지만, 지난 호우의 경우 후방위의 강우가 연속적으로 발생한 형태였다. 또한 대부분의 강우가 6시간 이내에 내려 첨두홍수 발생에 많은 영향을 미쳤을 것으로 판단된다. 앞으로 이상기후와 같은 자연 현상에 대비하기 위해서는 단시간 호우에 대한 정확한 분석과 강우분포에 대한 연구가 더욱 필요할 것으로 생각된다.적자색의 미려한 결정이 석출되므로 이 결정을 여과하여 ethanol로 세척하고 진공 desiccator중에서 건조시켰다. 수득량 1.2~1.3g.)와의 조환가는 11.9565의 상인연소현상을 보였다. 삭과색(Y) 경색(R) 유전자간에는 어느것이나 연소현상이 보이지 않았다. 4. 단일반응성의 변이는 연소적이며 우성은 거의 인정되지 않았고 인자간의 상호작용도 인정되지 않았으며 상가적 유전을 보였다. 광의와 협의의 유전력은 각각 89.50%로서 실용적으로 대단히 높은 것으로 생각되었으며 단일반응성에 관여하는 유전자수는 2대의 인자로 추정하였고 다시 양친의 유전자형을 aabb AABB라고 측정하여 각인자의 작용가는 11.136일로 산출되었고 분해법에 의한 유전분석결과 유전자형의 관찰빈도분포와 이론빈도분포는 서로 잘 적합되었다. 단일반응성에 있어서 유전력이 대단히 높았으므로 비교적 초기세대에서 본 형질의 선발이 가능할 것 같았다. 5. 단일반응성과 엽형 및 엽병색 유전자와의 사이에 $F_2$, $BC_1$ 및 $BC_2$에서 각각 유의적인 상관관계를 볼 수 있었으므로 이들 형질간에 연소가 있는 것으로 인정되었다. 더욱 엽형과 엽병색과의 연소가 있는 것으로 인정되는 이상단일반응성 유전자와의 사이에 연소군이 인정된다. 6. 섬유중 유전자와 엽병색 및 엽형유전자와의 사이에 $F_2$$BC_1$ 및 $BC_2$에서 각각 유의적 상관관계를 볼 수 있었으므로 이를 형질간에 연소가 있는 것으로 인정되었다. 더욱 엽형과 엽병색과의 연소가 있는 것으로 인정되는 이상 섬유중 유전

• Journal of Soil and Groundwater Environment
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• v.12 no.1
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• pp.97-102
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• 2007

An environmental survey from three abandoned metal mine areas was undertaken on to assess the risk of adverse health effects on human exposure to heavy metals influenced by past mining activities. Tailings contained high concentrations of heavy metals may have a impact on soils and waters around the tailing piles. In order to perform the human risk assessment, chemical analysis data of soils, rice grains and waters for As, Cd, Cu and Pb have been used. The HQ values for heavy metals via the rice consumption were significantly higher compared with other exposure pathways in all metal mine areas. The resulting HI values in three mine areas were higher than 9.0, and their toxic risk due to rice ingestion was strong in these mine areas. The cancer risk of being exposed to As by the rice consumption from the A, B and C mine areas was $5.1\;{\times}\;10^{-3}$, $6.8\;{\times}\;10^{-3}$ and $3.1\;{\times}\;10^{-3}$, respectively. The As cancer risk via the exposure pathway of rice ingestion from these mine areas exceeds the acceptable risk of 1 in 10,000 set for regulatory purposes. Thus, the daily intakes of rice by the local residents from these mine areas can pose a potential health threat if exposed by long-term As exposure.

• Economic and Environmental Geology
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• v.44 no.4
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• pp.289-302
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• 2011

Since the frequency of the earthquake occurrence in Korean peninsular is continuously increasing, the possibility that massive landslides are triggered by earthquake is also growing in Korea. Previously, the landslide is known to be induced by large magnitude earthquake, whose magnitude is larger than 6.0. However, the landslide can be induced by only small magnitude earthquake, especially in the fully saturated soil. Therefore, the susceptibility of landslide caused by small magnitude earthquake in fully saturated soil is analyzed in this study. For that, the topographical and geological characteristics of the site were obtained and managed by GIS software. In the procedure of the study, slope angle, cohesion, friction angle, unit weight of soil were obtained and constructed as a spatial database layer. Combining these data sets in a dynamic model based on Newmark's displacement analysis, the landslide displacements were estimated in each grid cell. In order to check out the possibility of the earthquake induced landslides, the level of the groundwater table is varied from dry to 80% saturated soil. In addition, in order to analyze the effect of the magnitude of earthquake and distance to epicenter, four different earthquakes epicenters were considered in the study area.

• Journal of Elementary Mathematics Education in Korea
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• v.14 no.1
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• pp.153-176
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• 2010

The purpose of this study is to rethink the importance of manipulative materials and to extract of manipulative materials program and its application methods. Activity, construction, and operation is stressed in the elementary mathematics. For this, various technological tools and manipulative materials is emphasized in mathematics teaching-learning methods. Applications of manipulative materials in the elementary mathematics is gradually increased together with curriculum revisions and textbook developments. As a result, tangram, geo-board etc., many tools ate introduces to school mathematics. This study is executed in this contexts. To achieve this, We introduce Australian 'Maths With Attitude' program. This program is composed of the primary level and secondary level. Each level consists of four domains - Number & Computation, Space & Logic, Chance & Measurement, Pattern & Algebra -, and each domains is made up of 20 tasks(i.e. manipulative materials) and programs. This study takes the focus to 5-6 grades programs in the mid of the primary level. First, We introduce 'Monkeys & Bananas'(Number & Computation) and 'Triangles & Colours' (Pattern & Algebra) tasks, and investigate the examples of lessons using these tasks. Second, We think the probability of these tasks' application and draw examples in the elementary mathematic textbooks. Through this works, We respect teaching-learning methods is rich and various in the elementary mathematics lessons.

• Journal of Elementary Mathematics Education in Korea
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• v.14 no.1
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• pp.1-22
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• 2010

The purpose of this study was to examine the relationship between teacher's role and interaction patterns in mathematics classrooms. Teacher's role was divided into usual practices with students, usual practices with content and usual practices with students and contents, and interaction patterns were classified into report, inquiry and discussion. The subjects in this study were teachers and students in three fourth- grade classes in T elementary school located in Seoul. After the classes of every math teacher were observed, three teachers who played distinctively unique roles were selected in accordance with the results of the first-semester autonomous supervision, of open class for parents and of the instructional observation. Thus, there was a close relationship between the teacher roles and interaction patterns. And it's concluded that students are able to have a more discussion on each other's ideas in the student-centered classroom, and that teachers should perform active roles in that process. Given the findings of the study, there are some suggestions: First, the teachers appeared to fulfill consistent roles when their videotaped classes, study aids and performance assessment materials were analyzed, and they should play more active roles in mathematics class. Second, they should try to create the kinds of climate that encourages students to come up with ideas in an active manner. Third, earlier studies had focused on student-teacher interaction patterns, but this study found that the roles of the teachers depended on interaction with not only students but study aids and performance assessment materials, and that the interaction patterns hinged on their roles as well. Therefore more profound research efforts should be directed into this issue.

• Journal of Food Hygiene and Safety
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• v.25 no.1
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• pp.16-23
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• 2010

Although concerns about Arsenic (As) contamination in agricultural foods have currently increased, there in on adequate international risk management standards for As particularly on agricultural commodities and processed agricultural products. This scenario holds true also in Korea. Australia, and New Zealand has determined the As maximum level (ML) but only on cereals grains which is based on total As contents. ln addition, Japan has regulated the ML based on trivalent As contents in agricultural commodities, which do not have legal restrictions. On the other hand, China has developed a systemic risk management to restrict the As contamination above MLs in agricultural commodities and processed agricultural products based on inorganic and total As contents. The establishment of an adequate analytical method for As specification in agricultural foods is essential to determine the acceptable level of As in agricultural food. Probabilistic approach may remove some uncertainties in calculating human risk assessment from As. It should be reviewed in terms of maximum levels to set the best scenario based on a realiability and availability to achieve effective As management on agricultural foods in Korea.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.1
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• pp.64-71
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• 2018

Project Management Institute of America separates the types of risk with external risks and internal risks. The external risk is an uncontrollable risk in projects such as changes of policy and related systems, climate, natural disasters, exchange rates and so on. The internal risk is an existing risk in the project itself that is controllable items in the project. Technical risks in project management are cost, quality, time, safety and environment. Therefore, both the external and internal risks should be managed to perform the construction project successfully. In particular, we can secure the quality and safety of facilities through the technical risk management. The importance of potential risk management has been emerging as a major interest and the lack of risk management delays projects and increases construction costs with negative effects of the building safety since the complex building, which is composed of a great number of facilities, consists of many project units and there are conflicts between various participants and stake-holders. This study presents the ways of establishing risk management processes to ensure the safety of the complex building. To that end, establishing procedure of risk management processes is presented and types of risk and factors in construction projects and counter strategies are presented as available risk information on the stages.