focusing on the case of Korea's abnormal precipitation in the summer of 2020

Thesis(Master) -- KDI School: Master of Public Management, 2022Climate change and urbanization are accelerating the seriousness of urban flooding. Urban flooding is caused by a combination of urban characteristics, drainage systems, and land-use status. Preventive measures are important in terms of the fact that disasters in urban areas cause enormous human and property damages, and that the cost of restoration exceeds the amount of damage. This paper aims to contribute to improving city’s responsiveness to urban floods by investigating major causes of and suggesting improvement measures to urban flooding. It discusses a framework that highlights the three stages of disaster management (i.e., pre-, during, and post-disaster), including each stage’s main activities required and the importance of feedback systems across the stages. Using this framework, a case of urban flooding that took place in the summer of 2020 in Korea, which was recorded the longest rainy season in the country, was analyzed. Through the analysis, two main problems were identified: First, the capacity of urban flood defense facilities may be fundamentally insufficient due to abnormal precipitation exceeding expectations. Each time a rainfall record is updated, a flexible design standard should be prepared that comprehensively considers the climate, topography, and land-use status rather than unconditionally raising the design standard. Second, the response system to urban floods that occur repeatedly every year is unsatisfactory. Starting with the linkage of information distributed among each institution, the information system should be used as a means, not a purpose.1. Introduction 2. Current status and the causes of urban flooding 3. Research design 4. The case of urban flooding in the summer of 2020 in Korea 5. Proposals for improvement 6. ConclusionmasterpublishedHyo-Sung KI

Development of Nanocomposite Powders for the SLS Process to Enhance Mechanical Properties

In an effort to fabricate prototypes with improved mechanical properties in the dual laser sintering process, functionalized graphite nanoplatelets were added to the PA-12 powder to produce a nanocomposite powder. The PA-12 powder was chosen as the matrix polymer because it has features conducive to laser sintering such as relatively low melting temperature and high mechanical properties. The GNPs were oxidized through a nitric acid treatment to improve the interfacial bonding. The resulting nanocomposite powder was layered and sintered by laser without any sign of agglomeration. Although the result is preliminary, it nevertheless shows the suitability of the nanocomposite powder for the laser sintering process.Mechanical Engineerin

A Comparative Study of Traditional Activity-based Costing and Time-driven Activity-based Costing at a University Hospital in South Korea

Due to serious problems associated with activity-based costing (ABC), time-driven activity-based costing (TDABC) was recently suggested as a better alternative. TDABC is designed to enhance the objectivity of data collection and decrease time and cost as well. However, the accuracy of the allocated costs using TDABC has not been widely tested yet, particularly in the healthcare industry. The objective of this study is to review the differences between ABC and TDABC and apply both techniques to a university hospital in South Korea to evaluate the results of cost allocation of outpatient nursing activities in Pediatrics Department. It is shown that the allocated costs are not very different between the two techniques, which implies that TDABC can be effectively used to compute the cost of each patient accurately. The result of this study also demonstrates that, using TDABC, the visibility of unused resources will be improved at all levels of management in the hospital, and non-value added activities can be managed effectively using the information regarding the activity ratios of traditional ABC and TDABC. In addition, it is shown that the accurate cost report to each doctor can provide a motivation for doctors to improve their profitability. Keywords: Activity-based costing; Time-driven activity-based costing, health care industry DOI: 10.7176/RJFA/10-10-01 Publication date:May 31st 201

Electrochemical Investigation of High-Performance Dye-Sensitized Solar Cells Based on Molybdenum for Preparation of Counter Electrode

In order to improve the photocurrent conversion efficiency of dye-sensitized solar cells (DSSCs), we studied an alternative conductor for the counter electrode and focused on molybdenum (Mo) instead of conventional fluorine-doped tin oxide (FTO). Because Mo has a similar work function to FTO for band alignment, better formability of platinum (Pt), and a low electric resistance, using a counter electrode made of Mo instead of FTO lead to the enhancement of the catalytic reaction of the redox couple, reduce the interior resistance of the DSSCs, and prevent energy-barrier formation. Using electrical measurements under a 1-sun condition (100 mW/cm(2), AM 1.5), we determined that the fill factor (FF) and photocurrent conversion efficiency (eta) of DSSCs with a Mo electrode were respectively improved by 7.75% and 5.59% with respect to those of DSSCs with an FTO electrode. Moreover, we have investigated the origin of the improved performance through surface morphology analyses such as scanning electron microscopy and electrochemical analyses including cyclic voltammetry and impedance spectroscopy