• International Journal of Highway Engineering
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• v.10 no.1
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• pp.19-29
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• 2008

The main purpose of this study is to introduce Hauer's(2004) approach that overcomes current accident prediction models' limitation and to apply this approach to Korean situation using fatal accident data on motorways. After developing accident prediction models according to this approach, it is found that AADT and vertical grade could improve fitness of the model, whereas a radius of roads is not related to the number of accidents. The advantage of Hauer's approach is to reduce possibility to eliminate critical variables and to keep uncritical variables when we consider many variables to develop accident prediction models.

• Journal of Nutrition and Health
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• v.39 no.7
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• pp.692-698
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• 2006

The voluntary addition of vitamins and minerals to the appropriate foods may help reduce the risks associated with low intakes of these micronutrients, yet the potential of excessive intake, particularly for persons consuming very large amount of foods needs to be addressed. Using the Flynn's model to estimate the level of each vitamins and minerals that can be added safely to foods, maximum levels of fortification to conventional foods per 100 kcal portion were estimated. Critical factors in the Flynn's model included tolerable upper intake level (UL), each micronutrient intake at the $95^{th}$ percentile, the proportion of fortified foods in the diets of individuals, the proportion of foods to which micronutrients could be practically added, and a range of estimates for fractions of foods which might be actually fortified in each nutrient. Food vehicles included all foods except for fresh foods and alcoholic beverages, in general. With fortification of 50% of all potentially fortifiable foods, micrornutrients could be added safely to foods at levels per 100 kcal 1) > 100% Recommended Intake (RI) for vitamin $B_12$, 2) 1,200% RI for vitamin $B_1$ and niacin, 3) 1,000% $B_1$ for vitamins $B_2$ and $B_6$, 4) 400% RI for vitamin E, 5) 30% RI for calcium, 6) 20% RI for folic acid, iron and zinc, 7) 10% RI for manganese, 8) no fortification for magnesium, phosphorous and vitamin A, and 8) further consideration of vitamin D, copper and selenium due to insufficient evidence. Results of this study suggests a wide range of vitamins and minerals that can be added safely to foods in current diets of Koreans.

• Journal of KIBIM
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• v.3 no.2
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• pp.19-27
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• 2013

The application of the BIM for the KEPCO' new headquarters in Naju involved alternative approaches and accompanied many trials-and-errors as the project adopted new targets and purposes that were not used in Korea before. In particular, for a large BIM-based project, clearly defining the BIM-including the objective, scope and the outcome-is critical for a project owner. For a successful implementation, project owners should improve the utilization of the BIM. Against this background, this research examines the case of the BIM application for the KEPCO' new headquarters in Naju, identifies its effects and problems, and proposes how to improve application of the BIM for public projects. The improvement in the BIM application can be divided into several stages: project order, design development, construction, and post-construction maintenance. In the initial stage, it is important to fully discuss the project planning among participants, and clarify the goal, scope, expected outcomes and role of the BIM. In the design stage, the level of detail (LOD) for the 3D model should be defined in consideration of information use in the stages of estimation and construction. In the construction stage, the scope of project that is managed based on the processing and use of the BIM data should be clearly given and understood. After construction is complete, measures should be sought to use the BIM for maintenance, and corresponding requirements and outcomes should be provided. The analysis is expected to provide basic data for successful implementation of BIM-based public projects, by assisting project owners and involved parties in enhancing work in different stages of a project.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.3
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• pp.1-8
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• 2015

In transportation networks, searching speed and result accuracy are becoming more critical on searching minimum path algorithm. Current $A^*$ algorithm has a big advantage of high searching speed. However, it has disadvantage of complicated searching network and low accuracy rate of finding the minimum path algorithm. Therefore, this study developed $A^*$ algorithm's heuristic function and focused on improving it's disadvantages. Newly developed function in this study contains the area concept, not the line concept. During the progress, this study adopts the idea of a heavier node that remains lighter to the target node is better that the lighter node that becomes heavier when it is connected to the other. Lastly, newly developed algorithm has the feedback function, which allows the larger accuracy value of heuristic than before. This developed algorithm tested on real network, and proved that developed algorithm is useful.

• Journal of the Korea Institute of Building Construction
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• v.15 no.4
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• pp.397-404
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• 2015

Construction equipment cost is critical to estimate the total construction costs, particularly in large and complicated projects. Public construction projects are typically estimated using the Poom-Saem which includes hourly rates for workers and equipments. Despite its importance, the construction equipment cost may not properly reflect the current market value because it is being updated every six years at most. To keep the data for construction equipment cost estimation up to date, it is highly recommended to use the standard market price that is reported each year by the Ministry of Security and Public Administration (MOSPA). However, there is still a wide gap to directly adopt the standard market price for updating the construction equipment prices. Therefore, this paper suggests an effective way to develop an ordinary management systems for updating construction equipment prices in the Poom-saem based on the standard market price.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.3
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• pp.133-140
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• 2002

Site-specific minimum temperature forecasts are critical in a short-term decision making procedure for preventive measures as well as a long-term strategy such as site selection in fruits industry. Nocturnal cold air pools frequently termed in mountainous areas under anticyclonic systems are very dangerous to the flowering buds in spring over Korea, but the spatial resolution to detect them exceeds the current weather forecast scale. To supplement the insufficient spatial resolution of official forecasts, we developed a GIS - assisted frost risk assesment scheme for using in mountainous areas. Daily minimum temperature data were obtained from 6 sites located in a 2.1 by 2.1 km area with complex topography near the southern edge of Sobaek mountains during radiative cooling nights in spring 2001. A digital elevation model with a 10 m spatial resolution was prepared for the entire study area and the cold air inflow was simulated for each grid cell by counting the number of surrounding cells coming into the processing cell. Primitive temperature surfaces were prepared for the corresponding dates by interpolating the Korea Meteorological Administration's automated observational data with the lapse rate correction. The cell temperature values corresponding to the 6 observation sites were extracted from the primitive temperature surface, and subtracted from the observed values to obtain the estimation error. The errors were regressed to the flow accumulation at the corresponding cells, delineating a statistically significant relationship. When we applied this relationship to the primitive temperature surfaces of frost nights during April 2002, there was a good agreement with the observations, showing a feasibility of site-specific frost warning system development in mountainous areas.

• Current Research on Agriculture and Life Sciences
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• v.26
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• pp.7-15
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• 2008

This research is significant in terms of estimating the validity by setting evaluation items in view of integrating not only original beauty and visual areas but also natural ecological areas based on questionnaire. The results are as follows. 1) According to literature study, 17 items such as variety, the character of sites in terms of landscape, the beauty of landscape, visibility, and ratio of green visibility are selected. Also, 21 items such as variety of animals and plants species, size of green area, and ecological naturalness are selected in the area of landscape ecological resources. 2) As a result of questionnaire of the group of landscape experts, animals and plants ecological areas show 5.6341, the highest in importance analysis according to assessment areas. Also, as a result of importance analysis on items in each area, for example, in the area of visual resources, the item of skyline analysis is 6.0488, the highest. 3) As a result of corelation of item meaning on landscape effect assesment, for example, meaningness of psychological assessment item and landscape site item indicate 0.710, the highest coefficient correlation. 4) As critical assessment items per unit project, items such as damage minimization of original land features for project in terms of point, ratio of green visibility, variety of animals and plants species marked above 8.0 as high important medium. The project in terms of line, minimization of original land features, preservation of worthy biotope showed high point and the character of sites in terms of landscape, minimization of original land features, the size of green area, and analysis of skyline marked above 8.5 as high importance points. On the contrary, items for climate and soil showed relatively low points.

• Journal of Korea Water Resources Association
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• v.55 no.5
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• pp.383-392
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• 2022

The restoration of the Nakdong River estuary is one of the most important projects of the Ministry of Environment, Republic of Korea. A real-scale experiment of gate operation was executed from 2019 to 2020, and a pilot operation was performed in 2021. The gate of Nakdong River Estuary Barrier (NEB) is supposed to be continuously opened based on the experiment results. Many critical decisions should be made immediately during the experiment based on the real-time measured data and numerical analysis considering the seawater inflows. The decision-making sequence was made systematically with the accurate estimation of seawater inflow. The estimation of seawater inflow is the main research objective and the equations of seawater inflow were developed, reflecting the structural characteristics of NEB. The inflow equations were developed in two forms, overflow and underflow. ADCP (Acoustic Doppler Current Profiler) was used to measure seawater inflow, check the accuracy of the developed equations, and derive the flow coefficient. The comparison error of the developed equations was about 3% compared to the measured data.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.3
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• pp.155-163
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• 2023

Real-time monitoring technology is critical for ensuring the safety and reliability of nuclear power plant structures. However, the current seismic monitoring system has limited system identification capabilities such as modal parameter estimation. To obtain global behavior data and dynamic characteristics, multiple sensors must be optimally placed. Although several studies on optimal sensor placement have been conducted, they have primarily focused on civil and mechanical structures. Nuclear power plant structures require robust signals, even at low signal-to-noise ratios, and the robustness of each mode must be assessed separately. This is because the mode contributions of nuclear power plant containment buildings are concentrated in low-order modes. Therefore, this study proposes an optimal sensor placement methodology that can evaluate robustness against noise and the effects of each mode. Indicators, such as auto modal assurance criterion (MAC), cross MAC, and mode shape distribution by node were analyzed, and the suitability of the methodology was verified through numerical analysis.

• Korean Journal of Construction Engineering and Management
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• v.12 no.6
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• pp.79-92
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• 2011

Quantity take-off is one of the critical tasks that determine the cost of a construction project, and its result should be accurate and reliable. BIM-based quantity take-off is a very attractive process for practitioners since the quantity take-off can be done automatically in a fast and accurate way. However, the result of BIM-based quantity take-off can be varied depending on how BIM was modeled. As a project progresses, more detailed design information is getting available, and it can be expected that the degree of completeness and accuracy for the BIMbased quantity take-off is going to be improved as well. However, when estimation is performed at each stage of a project life-cycle, there is no way to measure or forecast how accurate of the quantity take-off result from the BIM data given at the current stage. Therefore, this research derived factors that affect the BIM-based quantity takeoff and developed a methodology and framework to measure and forecast the completeness of BIM-based quantity take-off. The measurement framework and index that are proposed by this research was verified and validated for their consistency and feasibility through six pilot projects.