• Journal of Korean Society of Disaster and Security
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• v.16 no.4
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• pp.75-84
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• 2023

Many developing countries face challenges in estimating long-term discharge due to the lack of hydrological data for water supply planning, making it difficult to establish a rational water supply plan for decision-making on water distribution. The study area, the Bandung region in Indonesia, is experiencing rapid urbanization and population concentration, leading to a severe shortage of freshwater. The absence of water reservoir prediction methods has resulted in a water supply rate of approximately 20%. In this study, we aimed to propose an approach for predicting water reservoirs in developing countries by analyzing water safety and potential water supply using the MODSIM (Modified SIMYLD) network model. To assess the suitability of the MODSIM model, we applied the unit hydrograph method to calculate long-term discharge based on 19 years of discharge data (2002-2020) from the Pataruman observation station. The analysis confirmed alignment with the existing monthly optimal operation curve. The analysis of power plant capacity revealed a difference of approximately 0.30% to 0.50%, and the water intake safety at the Pataruman point showed 1.64% for Q95% flow and 0.47% for Q355 flow higher. Operational efficiency, compared to the existing reservoir optimal operation curve, was measured at around 1%, confirming the potential of using the MODSIM network model for water supply evaluation and the need for water supply facilities.

• Resources Recycling
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• v.33 no.3
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• pp.3-11
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• 2024

This study addressed the cost structure of metallurgical plants for vanadium recovery or production, which were previously planned or implemented. Vanadium metallurgy consists of several sub-processes such as such as pretreatment, roasting, leaching, precipitation, and filtration, in order to finally produce vanadium pentoxide. Here, lots of costs should be spent for such plants, in which these costs are largely divided into CAPEX (Capital Expenditure) and OPEX (Operational Expenditure). As a result, the capacities (feed input rates) and vanadium contents are various along the target projects for this study. However, final production rates and grades of vanadium pentoxide showed relatively small differences. In addition, a noticeable correlation is found between capacities and specific operating costs, in that a steadily decreasing trend is described with a non-linear curve with around -0.3 power. Therefore, for the plant capacity below 100,000 tons per year, the specific operating cost rapidly decreases as the capacity increases, whereas the cost remains relatively stable in the range of 0.6 to 1.2 million tons per year of the capacity. From a technical perspective, effective optimization of the metallurgical process plant can be achieved by improving vanadium recovery rate in the pre-treatment and/or roasting-leaching processes. Finally, the results of this study should be updated through future research with on-going field verification and further detailed cost analysis.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.5
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• pp.53-73
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• 2023

Although it is mandatory to wear a seat belt that can minimize human injury when traffic accident occurs, the number of traffic accident casualties not wearing seat belts still accounts for a significant proportion.The seat belt wearing detection system for all seats is a system that identifies whether all seat passengers wear a seat belt and encourages their usage, also it can be a useful technical countermeasure. Firstly, this study established the viability of system implementation by assessing the factors influencing the severity of injuries in traffic accidents through the development of an ordered probit model. Analysis results showed that the use of seat belts has statistically significant effects on the severity of traffic accidents, reducing the probability of death or serious injury by 0.054 times in the event of a traffic accident. Secondly, a meta-analysis was conducted based on prior research related to seat belts and injuries in traffic accidents to estimate the expected reduction in accident severity upon the implementation of the system.The analysis of the effect of accident severity reduction revealed that wearing seat belts would lead to a 63.3% decrease in fatal accidents, with the front seats showing a reduction of 75.7% and the rear seats showing a reduction of 58.1% in fatal accidents. Lastly, Using the results of the meta-analysis and traffic accident statistics, the expected decrease in the number of traffic accident casualties with the implementation of the system was derived to analyze the traffic safety effects of the proposed detection system. The analysis demonstrated that with an increase in the adoption rate of the system, the number of casualties in accidents where seat belts were not worn decreased. Specifically, at a system adoption rate of 60%, it is anticipated that the number of fatalities would decrease by more than three times compared to the current scenario. Based on the analysis results, operational strategies for the system were proposed to increase seat belt usage rates and reduce accident severity.

• Restorative Dentistry and Endodontics
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• v.36 no.6
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• pp.498-505
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• 2011

Objectives: The purpose of this in vivo study was to investigate the microbial diversity in symptomatic and asymptomatic canals with primary endodontic infections by using GS FLX Titanium pyrosequencing. Materials and Methods: Sequencing was performed on 6 teeth (symptomatic, n = 3; asymptomatic, n = 3) with primary endodontic infections. Amplicons from hypervariable region of the small-subunit ribosomal RNA gene were generated by polymerized chain reaction (PCR), and sequenced by means of the GS FLX Titanium pyrosequencing. Results: On average, 10,639 and 45,455 16S rRNA sequences for asymptomatic and symptomatic teeth were obtained, respectively. Based on Ribosomal Database Project Classifier analysis, pyrosequencing identified the 141 bacterial genera in 13 phyla. The vast majority of sequences belonged to one of the seven phyla: Actinobacteria, Bacteroidetes, Firmicutes, Fusobacteria, Proteobacteria, Spirochetes, and Synergistetes. In genus level, Pyramidobacter, Streptococcus, and Leptotrichia constituted about 50% of microbial profile in asymptomatic teeth, whereas Neisseria, Propionibacterium, and Tessaracoccus were frequently found in symptomatic teeth (69%). Grouping the sequences in operational taxonomic units (3%) yielded 450 and 1,997 species level phylotypes in asymptomatic and symptomatic teeth, respectively. The total bacteria counts were significantly higher in symptomatic teeth than that of asymptomatic teeth (p < 0.05). Conclusions: GS FLX Titanium pyrosequencing could reveal a previously unidentified high bacterial diversity in primary endodontic infections.

• Journal of The Korean Association For Science Education
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• v.18 no.3
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• pp.399-413
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• 1998

This study is based upon the survey for the GALT(Group Assessment of Logical Thinking) full version and short version used in the science education researches for investigating the cognitive levels of students in secondary schools. The main discussions include the annual trends of two GALT versions appeared in the research papers, the distributions of the students' cognitive levels obtained by two GALT versions, the purposes of the GALT used in the researches, and the results of two GALT versions applied to the same group of high school students. The summarized results are as follows. The frequency of the GALT short version used in the research papers has been increased recently relative to that of the full version. For the same grade students, the fraction of students in the formal operational cognitive level obtained from the GALT short version was always bigger than those obtained from the full version. The purposes of the GALT employed in the researches are classified into two groups. One group includes the papers in which the subjects were subgrouped into three cognitive levels from GALT results and it was used as an independent variable to analyze the dependent variable. In this case, the analyzed results might be altered depending on the version of GALT used. The other one includes the papers in which the GALT results were used as a covariable or the GALT scores were used directly without subgrouping the subjects by cognitive levels. For this group, the research results would not depend on the GALT version. When both of the GALT versions were tested on the same group of students with two months interval, the fraction of formal operational level obtained from the short version was bigger than that obtained from the full version.

• Korean Journal of Remote Sensing
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• v.33 no.5_1
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• pp.587-598
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• 2017

Volcanic ash is a fine particle smaller than 2 mm in diameters. It falls after the volcanic eruption and causes various damages to transportation, manufacturing industry and respiration of living things. Therefore diffusion information of volcanic ash is highly significant for preventing the damages from it. It is advantageous to utilize satellites for observing the widely diffusing volcanic ash. In this study volcanic ash diffusion information about two eruptions of Mt. Sakurajima were calculated using the geostationary satellite, Communication, Ocean and Meteorological Satellite (COMS) Meteorological Imager (MI) and polar-orbiting satellite, Landsat-8 Operational Land Imager (OLI) and the Thermal InfraRed Sensor (TIRS). The direction and velocity of volcanic ash diffusion were analyzed by extracting the volcanic ash pixels from COMS-MI images and the height was retrieved by adjusting the shadow method to Landsat-8 images. In comparison between the results of this study and those of Volcanic Ash Advisories center (VAAC), the volcanic ash tend to diffuse the same direction in both case. However, the diffusion velocity was about four times slower than VAAC information. Moreover, VAAC only provide an ash height while our study produced a variety of height information with respect to ash diffusion. The reason for different results is measured location. In case of VAAC, they produced approximate ash information around volcano crater to rapid response, while we conducted an analysis of the ash diffusion whole area using ash observed images. It is important to measure ash diffusion when large-scale eruption occurs around the Korean peninsula. In this study, it can be used to produce various ash information about the ash diffusion area using different characteristics satellite images.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.6
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• pp.24-36
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• 2019

This study shows that the role of residents in landscape management is becoming increasingly important. The purpose of this study is to suggest elements that can continue the operation of landscape agreements and directions for promoting them. Therefore, 1)the operational elements considering the sustainability of the landscape agreements were proposed by way of literature research, expert interviews, and surveys. 2)The sustainable operation of elements of the landscape agreement were applied and best practices were developed through interviews with participants and literature analysis. 3)The final plan operational elements considering the sustainability of the landscape agreements and the directions for implementation were presented. As for the results, it was first presented that the elements of continuous operation of the landscape agreement, consisted of 3 major categories, 10 subcategories, and 25 details. These include resident awareness, practical applicability, effectiveness of administrative means, securing the budget, maintenance, public relations, expert support, dedicated support organization, sustainability of participation, and resident participation and communication methods. It is a detailed list of items that should be considered in the preparation phase, maintenance phase, and conclusion phase. Second, it suggested the direction for the sustainable operation of the landscape agreements be highly backed by the residents, and after reaching consensus on a landscape agreement, it is necessary that the agreement is based on contents that the residents can execute themselves. In addition, it was found that there is a need for a system to prepare the basis for securing the budget for the continuity of work, preparation of the landscape agreements, and consultation and activity costs during the maintenance phase. In addition, continuous exchanges and capacity building among residents have signed landscape agreements, and step-by-step support from experts in accordance with the level of involvement of residents is necessary. Third, even if a landscape agreement is concluded in connection with public projects, it is understood that the residents have the capacity to participate and can continue to support the administration and experts to enable the continued operation of the landscape agreement.

• Korean Journal of Construction Engineering and Management
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• v.12 no.6
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• pp.65-78
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• 2011

Construction business, which is complex and long-term business, requires accurate estimation and verification in construction costs and payment procedure from project planning to the completion of construction phase. And more importantly, it is necessary to investigate and determine the risk factors related to construction costs during the entire process including design planning, construction drawings, and quantity calculating. But, currently, it is not seem to be adequate to cope with the risk and increased construction costs against the operational budget in terms of actual costs when screening and estimating the bidding cost of public apartment. Therefore, this study selected and analyzed 40 sites' report of construction completion account from 2004 to 2010 focused on the adequacy on the modification of contract and design planning and on the complication of the budget in the beginning of the project. This study deducted various risk causes and results by analyzing actual costs according to year, architectural area, region, construction cost and sale/lease classification. We could find out construction risk according to annual variation of government policy and economy, and also deducted risk items by construction characteristic according to region and architectural area. Study result, we first found out the problems of lowest price award system according to the construction costs. The weight of the cost increase risk was analyzed that subcontract and material costs are very high. Roof and tile work were analyzed highly in subcontract cost risk and reinforcing bar and cement were analyzed highly in material cost risk, among direct construction cost. Finally, this study results could be used in comparing the categories of the construction costs made by specific construction process, belonging to the construction costs, with the operational budget made in the beginning of the project that can enable to grasp unpredictable risks over the construction costs and making quantitative analysis for it through analyzing the range of fluctuation and variations led by the fluctuations in the actual construction costs.

• Journal of Wetlands Research
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• v.16 no.3
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• pp.431-440
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• 2014

To propose the improvement and management plans to strengthen the pollutant removal efficiency of dam reservoir's constructed wetlands(CWs), the operation status and configuration of CWs (including water depth, operational flow, water flow distribution, residence time, and pollutant removal efficiency, aspect ratio, open water/vegetation ratio etc.) were analyzed in 10 major wetlands constructed in dam reservoirs. The pollutant concentrations in the inflows of the studied CWs were lower than those of American and European constructed wetlands. Especially, organic matter concentrations in all of inflows were below 3 mg/L(as BOD) due to advanced treatment of sewage disposal plant and an intake of low concentration water during dry and normal seasons. The average removal efficiency of total nitrogen(TN) and total phosphorus(TP) for 10 CWs ranged from 7.6~67.6%(mean 24.9%) and -4.9~74.5%(mean 23.7%), respectively, showing high in wetlands treating municipal wastewater. On the other hand, the removal efficiency of BOD was generally low or negative with ranging from -133.3 to 41.7%. From the analysis of the operation status and configuration of CWs, it is suggested that the low removal efficiency of dam reservoir's CWs were caused by both structural (inappropriate aspect ratio, excessive open water area) and operational (neglecting water-level management, lack of facilities and operation for first flush treatment, lake of monitoring during rainy events) problems. Therefore, to enable to play a role as a reduction facility of non-point source(NPS) pollutants, an appropriate design and operation manuals for dam reservoir's CW is urgently needed. In addition, the monitoring during rainy events, when NPS runoff occur, must be included in operation manual of CW, and then the data obtained from the monitoring is considered in estimation of the pollutant removal efficiency by dam reservoir's CW.

• Korean Journal of Remote Sensing
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• v.34 no.6_2
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• pp.1165-1178
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• 2018

Collapse of an Antarctic ice shelf and its flow velocity changes has the potential to reduce the restraining stress to the seaward flow of the Antarctic Ice Sheet, which can cause sea level rising. In this study, variations in ice velocity from 2000 to 2017 for the Nansen Ice Shelf in East Antarctica that experienced a large-scale collapse in April 2016 were analyzed using Landsat-7 Enhanced Thematic Mapper Plus (ETM+) and Landsat-8 Operational Land Imager (OLI) images. To extract ice velocity, image matching based on orientation correlation was applied to the image pairs of blue, green, red, near-infrared, panchromatic, and the first principal component image of the Landsat multispectral data, from which the results were combined. The Landsat multispectral image matching produced reliable ice velocities for at least 14% wider area on the Nansen Ice Shelf than for the case of using single band (i.e., panchromatic) image matching. The ice velocities derived from the Landsat multispectral image matching have the error of $2.1m\;a^{-1}$ compared to the in situ Global Positioning System (GPS) observation data. The region adjacent to the Drygalski Ice Tongue showed the fastest increase in ice velocity between 2000 and 2017. The ice velocity along the central flow line of the Nansen Ice Shelf was stable before 2010 (${\sim}228m\;a^{-1}$). In 2011-2012, when a rift began to develop near the ice front, the ice flow was accelerated (${\sim}255m\;a^{-1}$) but the velocity was only about 11% faster than 2010. Since 2014, the massive rift had been fully developed, and the ice velocity of the upper region of the rift slightly decreased (${\sim}225m\;a^{-1}$) and stabilized. This means that the development of the rift and the resulting collapse of the ice front had little effect on the ice velocity of the Nansen Ice Shelf.