• 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.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.3
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• pp.59-66
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• 2010

Around a toll plaza, vehicles do such maneuvers as slow down, stop, and speed up to pay their tolls when they use ordinary toll gates. They can be expected more fuel consumptions compared to the vehicles which use the Hi-pass, a Korean type of Electronic Toll Collection System(ETCS). To measure the exact amount of difference between the two gas consumptions, we equipped a test vehicle with a measurement system and constructed a model toll gate on our test field. Through the field tests on fuel consumptions, we could confirm a 36.7 % of energy saving when the test car used the Hi-pass. Then we projected the result on the total traffic volumes which had used national expressway network for five months from January 2009. Projected to the whole traffic, potential cost savings reached 5.34 billion won. We expect this result be frequently mentioned of to prove the fuel efficiency of the Hi-pass system.

• Korean Journal of Agricultural Science
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• v.42 no.4
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• pp.389-396
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• 2015

This study was performed to investigate the opinions of various related-industries on ban of antibiotics growth promoters (AGPs) in commercial mixed feed. The answers on a total of 21 questions were summarized by response number and percentage. 93% of those surveyed were in agreement of a ban of dietary AGPs. The agreement reasons were the livestock safety (61.5%), the reduction of antibiotic use (23.1%), and decrease of antibiotic-resistant bacteria (11.5%). The negative effects expected by the ban of AGPs were poor growth performance (44.2%), elevated disease emergence (31.4%), increasing the feed cost (18.6%), and quality degradation of livestock (5.8%). As the efficient plans for decline of AGPs use, the feeding environment improvement was the highest with 43%, and farmer training and the consolidation inspection of residual substance on antibiotics in livestock product was 27.9% and 22.1%, respectively. 46.5% of respondent are considering the modification of feed spec and 39.5% of those surveyed have staged a modified feed spec. In conclusion, livestock related-industries approve a ban of AGPs, and they assert that the policy support, improvement of management and environment in the farm, providing technology from related-industries are multiply essential for a stable settlement of a ban policy of AGPs.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.4 s.22
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• pp.51-60
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• 2002

As the use of GIS becomes more widespread, the quality and source of data is becoming more of a concern among users. But accuracy is a component of quality, and the positional accuracy is a component of total accuracy. If only we consider the positional accuracy, simultaneously collecting technology of location and attribute information, whether it be manually, using conventional surveying method, GPS, or remote sensing, is a practical way of insuring that location and attribute information are correctly correlated. This study analyse the positional accuracy from a view-point of user and supplier, which is the considerations that can ensure quality level and continuously maintain the road and underground utility information. The positional accuracy of road and underground utility information are considered as two categories - expected accuracy of data collection procedure, required accuracy of data usage process. And the project manager must consider the cost/benefit view of data generation in order to determine the surveying method.