• Spatial Information Research
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• v.21 no.6
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• pp.91-98
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• 2013

Government introduces a Total Maximum Daily Loads(TMDL) which can be implemented for total pollutant amounts in 2004. Normally, the local governments have been calculated the amounts of pollutant discharge of each watershed using a water quality model. However, among the input data to use the water quality model, creating a schematic diagram of the stream or the modeling usually requires considerable amount of time and efforts due to the manual work. Therefore, this study tried to develop an algorithm which automates the creation of a schematic diagram for water quality modeling using the Korean Reach File capable of river network analysis. Further, this study creates a schematic diagram with the shape of a stream utilizing GIS capabilities. The diagram can be easily analyzed with overlapping various spatial information such as pollution sources and discharge points. This study mainly has automated element segmentation algorithm to divide streamflows into equal distance using line graphic data of Koran Reach File. Also, automated attribute input algorithm has also been developed to enable to insert element order and type into elements using point graphic data of Korean Reach File. For the verification of the developed algorithm, the algorithm was applied to kyungan stream basin to see the acceptable results. To conclude, it was possible to automate generating of schematic diagram of water quality model and it is expected to be able to save time and cost required for the water modeling. In future study, it is necessary to develop an automatic creation system of various types of input data for water quality modeling and this will lead to relatively easier and simple water quality modeling.

• Geophysics and Geophysical Exploration
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• v.27 no.2
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• pp.119-128
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• 2024

Marine magnetic surveys provide a rapid and cost-effective method for pioneer geophysical survey for many purposes. Sea-surface magnetometers offer high accuracy but are limited to measuring the scalar total magnetic field and require dedicated cruise missions. Shipboard three-component magnetometers, on the other hand, can collect vector three components and applicable to any cruise missions. However, correcting for the ship's magnetic field, particularly viscous magnetization, still remains a challenge. This study proposes a new additional correction method for ship's viscous magnetization effect in vector data acquired by shipboard three-component magnetometer. This method utilizes magnetic data collected simultaneously with a sea-surface magnetometer providing total magnetic field measurements. Our method significantly reduces deviations between the two datasets, resulting in corrected vector anomalies with errors as low as 7-25 nT. These tiny errors are possibly caused by the vector magnetic anomaly and its related viscous magnetization. This method is expected to significantly improve the accuracy of shipborne magnetic surveys by providing corrected vector components. This will enhance magnetic interpretations and might be useful for understanding plate tectonics, geological structures, hydrothermal deposits, and more.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4B
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• pp.233-242
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• 2012

In the past, the domestic water supply benefit of dam has been estimated by replacement dam cost approach. But it is logically inappropriate that we use the second priority dam as a replaced facility. Therefore, this study aims to suggest the estimation method of the domestic water supply benefit by using demand function, which is deduced from Willingness-To-Pay (WTP) of consumers. For this purpose, a survey concerning the marginal WTP is carried out according to the change of water use amount used, targeted 1,000 households in metropolitan area. And by using the marginal WPT, we estimated the demand function of a family. Finally, the monthly benefit equation is derived. The approach is demonstrated and discussed for an example, the Song-Li-Won dam project which is now renamed Young-Ju dam. From the example study, the total benefit for the durable years (50 years), was about 90 billion won. The method proposed herein is expected to be practical and useful in the economic analysis of the domestic water supply project including dam construction, as well as in further studies.

• Clean Technology
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• v.21 no.2
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• pp.124-129
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• 2015

The constant-volume method was used to determine the solubility of CO₂ in various physical absorbents such as DMPEG (dimethyl ether of polyethylene glycol), DEC (diethyl carbonate), DMC (dimethyl carbonate), and TAT (triacetin) in the total pressure range from 5 to 30 bar. The Peng-Robinson equation of state has been used to describe the equilibrium behavior of these mixtures. It was found that the solubility of absorbents was in the of DMPEG250 > TAT > DEC > DMC at the same temperature. Futhermore, the solubiity of blended absorbent of DMPEG250 and DEC is higher than that of DMPEG 250 alone. Therefore, blended absorbent of DMPEG250 and DEC is expected to be an effective and low cost absorbent for physical absorption in precombustion CO₂ capture.

• Journal of Korean Society of Transportation
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• v.23 no.7 s.85
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• pp.63-74
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• 2005

When we introduce the BRT systems, it is very important to decide the operating factors, such as bus-stop locations or headway. If the factors are inappropriate, unessential expenses for the operator and users of the bus line may be caused, and it leads increase of social total cost. So, it is necessary that we consider users' origin and destination of each bus line when we set location of bus-stops and the optimal headway. Meanwhile, Smart Card System was introduced of fare collection for the Public Transportation Reform in Seoul last year. This new card system makes it possible to store up the information about bus operating and passenger's trip link. With these substantial information. we can estimate bus-stop-based O-D table. So, in this thesis, it was studied a systematic methodology to find the optimal location and headway for skip-stop bus system (as a type of first step for BRT). The proposed methodology in this thesis is expected to be useful to effect analysis or setting operating factors for skip-stop bus system in each bus line.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.24 no.1
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• pp.47-54
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• 2016

Global aviation is projected to grow in demand by an annual average of 4.1% between 2014 and 2034. It can be said that environmental impact from aviation will therefore be expected to increase on a similar scale. As regards civil aviation emissions, the sector contributes between 2~3% to International aviation GHG emissions. In the European Union(EU), aviation emissions account for about 3% of the EU's total green house gas emissions, of which a majority are said to come from international flights. In terms of traffic volume in 2013, Korea's international aviation industry 11th with regard to passengers and 3rd with regard to cargo, attaining the overall rank of 5th in the world. GHG emissions has been increasing steadily over the last 4 years, averaging 3.9 percent a year, due to the growth of low cost carriers and the increased demand for air transportations. As for aviation in Korea, there are a number of means intended to attain the Government's emission control objective in an efficient manner, such as AVA (Agreement of Voluntary Activity), TMS (Target Management System) and ETS (Emission Trading Scheme). In addition, the Government intends to better adapt to ICAO's Global MBM(Market-based Measures) that will come into performance on Year 2020. In the study, we focused on GHG mitigation measures that is fulfilling the AVA, TMS, ETS in the Government and suggest the effective measures to reduction the aviation GHG emissions.

• The Korean Journal of Applied Statistics
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• v.31 no.5
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• pp.587-597
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• 2018

Procedures, such as sampling technique, survey method, and questionnaire preparation, are required in order to obtain sample data in accordance with the purpose of a survey. An important procedure is the decision of the sample size formula. The sample size formula is determined by setting the target error and total cost according to the sampling method. In this paper, we propose a sample size formula using population changes over time, estimation error of the previous time and response rate of past data when the target error and the expected response rate are given in the simple random sampling. In actual research, we use estimators that apply complex weights in addition to design-based weights. Therefore, we induce a sample size formula for estimators using design-based weights and nonresponse adjustment coefficients, that can be a formula that reflects differences in response rates when survey methods are changed over time. In addition, we use simulations to compare the proposed formula with the existing sample size formula.

• Journal of Convergence for Information Technology
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• v.10 no.10
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• pp.80-87
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• 2020

The purpose of this study was to compare in antiseptic effect between povidone-iodine and chlorhexidine-ethanol for laparoscopic cholecystectomy on the port site. A total of 46 patients admitted to surgery at one university hospital in Seoul were included in the study. A study group was randomly assigned using a random number table. The antiseptic effect was evaluated and compared to povidone-iodine and chlorhexidine-ethanol by using a culture and identification of bacteria, measurement of the number of bacteria (CFU/ml) and incidence of surgical site infection. Our results show that povidone-iodine and chlorhexidine-ethanol have no statistically significant difference in the incidence rate of bacteria after 3 minutes of disinfection and before removal of the trocar and in the number of bacteria and the incidence of surgical site infection. Thus, in order to select an efficient and appropriate skin antiseptics, we suggest that it is necessary to consider not only the disinfectant effect but also cost and convenience. In this research, our results about effect and usage of skin antiseptics can be used as basic data and educational resource, and this is expected to improve comprehension of skin antiseptics.

• Journal of the Korean Wood Science and Technology
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• v.42 no.4
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• pp.439-449
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• 2014

RPS (Renewable Portfolio Standard) has increased wood pellet demand dramatically in recent years in Korea where self-supply rate of wood pellet is not more than 10%. However global production capacity of wood pellet is prospected to be unable to meet the global demand after 2020. Therefore it is urgently needed to develop new sustainable biomass energy resources which can replace wood pellet at lower cost. As a result of this study EFB (empty fruit bunch) and MF (mesocarp fiber), the representative solid palm biomass, are estimated to be generated at the rate of 20 and 28 million tons per year (based on 10% moisture content) in Malaysia and Indonesia, respectively in 2012. Total annual generation rate of EFB and MF is estimated as 48 million tons per year only in Malaysia and Indonesia in 2012. With calorific value of over 90% of wood pellet EFB is expected to be a excellent biomass energy resource which can replace wood pellet. EFB can be utilized as fuel for power generation or industrial purpose. However EFB may not be a proper fuel for domestic and greenhouse heating because of its high ash content.

• Journal of the Korean Dietetic Association
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• v.21 no.2
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• pp.140-153
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• 2015

Considering the importance of institutional foodservice in modern dietary life and its influence on the environment, sustainable development in institutional foodservice industry carries great significance. The current study was conducted to investigate dietitians' perceptions of sustainable business-and-industry foodservice and their intentions to perform sustainable practices by applying a mixed methodology. For the quantitative study, an online survey was conducted on 362 dietitians who had worked at a contact foodservice company for more than 1 year. The survey was performed from December 15th, 2011 to January 30th, 2012, and 202 responses were used for the analysis. For the qualitative a study, a focus group interview was conducted during May, 2012 with representative employees of the company. According to the results, dietitians seemed to be unfamiliar with the terms "sustainability" or "sustainable development," whereas they understood related contents and practices. Dietitians' awareness and perceived need in terms of sustainable business-and-industry foodservice were not significantly different across general characteristics. Dietitians seemed to be highly aware of the impacts of business-and-industry foodservice on economy, whereas they appeared to lack understanding of its impacts on society and environment. Cost increase and levy on work in daily operations were considered as main obstacles hampering dietitians' intentions to perform sustainable practices. A total of 88.1% of responding dietitians expected that the meal price at a sustainable business-and-industry foodservice should be higher than the supposed standard price of 4,000 won, with an average reaching 5,270 won. Findings from this study could be used as baseline information for vitalizing sustainable business-and-industry foodservice in Korea.