• Journal of Korean Society of Environmental Engineers
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• v.35 no.5
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• pp.363-370
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• 2013

Small scale hydropower is one of most attractive and cost-effective energy technologies for installation within sewage treatment plants. This study was conducted to evaluate the potential of a semi-kaplan micro-hydropower (MHP) system for application to sewage treatment plants with high flow fluctuations and a low head. The semi-kaplan MHP is equipped with an adjustable runner blade, and is without a guide vane, so as to reduce the incidence of mechanical problems. A MHP rating 13.4 kWp with a semi-kaplan turbine has been considered for Kiheung Respia sewage treatment plant, and this installation is estimated to generate 86.8 MWh of electricity annually, which is enough to supply electricity to over 25 households, and equivalent to an annual reduction of 49 ton $CO_2$. The semi-kaplan turbine showed a 90.2% energy conversion efficiency at the design flow rate of 0.35 $m^3/s$ and net head of 4.7 m, and was adaptable to a wide range of flow fluctuations. Through the MHP operation, approximately 2.1% of total electricity demand of Kiheung Respia sewage treatment plant will be achievable. Based on financial analysis, an exploiting MHP is considered economically acceptable with an internal rate of return of 6.1%, net present value of 15,539,000 Korean Won, benefit-cost ratio of 1.08, and payback year of 15.5, respectively, if initial investment cost is 200,000,000 Korean Won.

• Journal of The Korean Society of Grassland and Forage Science
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• v.44 no.1
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• pp.40-49
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• 2024

This study divided the area capable of producing domestic forage into grazing pasture, hay production area, and silage crop area, calculated the required area according to the forage production volume, and examined whether self-sufficiency in forage leads to cost savings. When the self-sufficiency rate of forage for dairy cows and Hanwoo is 80%, the improvement in profitability per heaf ranges from 3% to 9%, typically around 5%, which is considered a significant benefit for both corporate and individual businesses. The average profit per ranch is expected to increase about KRW 50 million per year, and the country as a whole is expected to reduce forage costs by KRW 0.9 trillion per year. Recently, efforts are being made by the government and local authorities to cultivate summer forage at the rice fields for improving self-sufficiency in forage feed to stabilize rice supply and demand. Furthermore, it is also necessary to conduct research on reducing the cost of concentrated feed and TMR (Total mixed ration).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6D
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• pp.771-778
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• 2011

Preliminary feasibility study on Busan metro line #1 in Yangsan line (Nopo-Bukjeong) depending on active volume of mass transportation between Yangsan city and Busan city was conducted. As the study concluded that it's valid, the necessity to establish the metro railroad network connecting to Busan, Ulsan and Gyeongnam Province is demanded to improve the transportation issues in Ungsang area vulnerable to metro service and to drive the balanced development between metropolitan cities. In addition, the volume of transportation depending on methods in target areas and road traffic assignment are surveyed to put a stress on the necessity to establish the metro railroad network. As the demand of transportation for alternative lines is predicted, the budget and benefits for construction for each alternative line set for the rough economic analysis depending on traffic volume for each method and traffic assignment results. The total project budget necessary for construction of proposal line #1 set as effective one among target three lines in this project is calculated in 794.32 billion won. Construction accounts for the most expensive in expenses for project and contingency allowances, purchases for vehicles and collateral expense are followed in orders. However, compensation for lands is not counted. In particular, according to economic analysis in proposal #1, ratio of benefit/cost (B/C) is 0.584, net present value (NPV) is -217.47 billion won, the internal rate of return (IRR) is analyzed in 0.604 %. At the current stage, it is not economically feasible, but the B/C is 0.737 in long-term upon construction of Yangsan line between Wolpheong and Yongdang which is proposal line #3. Therefore, when Busan metro basic plan is reorganized to aim the benefit of residents in Ungsang area vulnerable to the metro service, we think it must be necessary to establish the metro railroad network connecting to Busan-Yangsan-Ulsan which is proposal line #2 by extending the existing Sinjeong line and including this task line in high-ranked plan related to metro railroad.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.9
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• pp.1345-1353
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• 2015

This study was conducted to investigate the influence of dietary rapeseed meal (RSM) on growth performance, blood profiles, nutrient digestibility and economic benefit of growing-finishing pigs. A total of 120 growing pigs ($[Yorkshire{\times}Landrace]{\times}Duroc$) with an initial body weight (BW) $29.94{\pm}0.06kg$ were used in this experiment. Pigs were randomly allotted into 1 of 5 treatments in a randomized complete block design and 6 replicates with 4 pigs per pen. Treatments were divided by dietary RSM supplementation levels (0%, 3%, 6%, 9%, or 12%) in growing-finishing diets. A linear decrease (p<0.05) of BW and average daily gain (ADG) were observed at 13th wk of finishing and overall periods of pigs. Additionally, gain-to-feed ratio (G/F) tended to decrease by dietary RSM supplementation in growing-finishing diets (linear, p = 0.07 and quadratic, p = 0.08). Concentrations of serum triiodothyronine and thyroxine were not influenced by dietary RSM treatments whereas thyroid gland and liver weight were increased at 13th wk of finishing period (linear, p<0.05; p<0.01) by increasing dietary RSM supplementation level. In blood profiles, serum total cholesterol and low density lipoprotein cholesterol concentrations were not differed by dietary treatments at 13th wk of finishing period whereas concentration of serum high density lipoprotein cholesterol was affected by the supplementation level of RSM, resulting in a linear RSM level responses (p<0.05). Serum blood urea nitrogen concentration tended to decrease (linear, p = 0.07; p = 0.08) at 6th wk of growing and 13th wk of finishing periods and digestibility of dry matter tended to decrease by dietary RSM (linear, p = 0.09). Crude protein, crude fat and nitrogen retention, whereas, were not affected by dietary RSM supplementation level. In the economic analysis, feed cost per weight gain was numerically decreased when RSM was provided up to 9%. Consequently, RSM could be supplemented to growing-finishing diets up to 9% ($3.07{\mu}mol/g\;Gls$) without detrimental effects on growth performance of growing-finishing pigs.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.5
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• pp.417-421
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• 2005

This study was to analyze the changes of levels of alkaline phosphatase before and after enucleation of jaw cysts combined with bone grafting, and to evaluate biochemically the effectiveness of the early detection of bone healing and infection as a prognostic marker. Eighteen patients (13 males, 5 females) with cystic lesions of the jaws were divided into two groups. The bone graft group underwent enucleation and bone graft. The control group underwent only enucleation. Both groups were measured levels of ALP before surgery, and plus-minus 4 weeks postoperatively. The more discriminating results were obtained in the bone graft group. The results were as follows : 1. Levels of ALP after enucleation of jaw cysts were decreased in all patients with and without bone graft. 2. The bone graft group showed more marked decrease in variation of levels of ALP than the control group.(p=0.008) This should be considered as a result of increased osteoblastic activity and new bone formation. 3. Such variation could be used as a prognostic marker for bone healing after cyst operation. In the cost/benefit ratio, measurement of ALP activity could be useful as a convenient procedure in routine clinical practice.

• Weed & Turfgrass Science
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• v.7 no.2
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• pp.120-129
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• 2018

This experiment was conducted to find the most suitable crop establishment method and weed management practices for transplanted aman rice in Bangladesh. Rice variety Bangladesh Rice Research Institute (BRRI) dhan44 was used as planting materials where three crop establishment methods ($T_1$: direct wet seeding by drum seeder; $T_2$: hand broadcasting; $T_3$: transplanting) and four weeding options ($W_1$: Hand weeding (HW); $W_2$: BRRI weeder+HW; $W_3$: Herbicide+HW; and $W_4$: no weeding) were tested. Among the crop establishment methods, the highest grain yield ($5.12t\;ha^{-1}$) was obtained with the $T_3$, while the highest benefit cost ratio (BCR) of 2.08 was found in $T_2$. In case of the weed management method, $W_1$ showed superior results on the plant $density/m^2$ (139.66) at 60 days after transplanting (DAT), grain yield ($4.97t\;ha^{-1}$), and BCR (2.03). On the other hand, the highest plant dry matter (36.20 g) at 60 DAT and the highest yield ($6.10t\;ha^{-1}$) were obtained in a $T_3W_1$ combination. The results of this study show that the productivity of rice during aman season could be most significantly increased with the use of transplanting ($T_3$) alone, hand weeding ($W_1$) alone, or a combination of the two methods ($T_3W_1$).

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.4
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• pp.292-297
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• 2013

In this paper, unusual waveform detection algorithm based on Refractory Period in arrhythmia ECG signal is proposed. Most of arrhythmia ECG signals consist of unusual waveforms with average 10% rate. Thus tremendous benefit can be obtained in terms of time and cost by providing unusual waveform samples reduced more than 90% to medical staffs who have to monitor and analyze for a long time. The proposed algorithm detects the R-peak using the features of R wave and variable refractory period. For the detected R-peak, unusual waveforms are found using means and standard deviation of electric potential and kurtosis of the R-peaks which are not included in unusual waveform. The proposed algorithm was applied to all records of the MIT-BIH arrhythmia database and showed more than average 90% of compression ratio.

• Journal of Fashion Business
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• v.19 no.4
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• pp.183-199
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• 2015

This study aimed to systematize the apparel vendor work processes and provide useful information to future employees of clothing export units by analyzing the processes of vendors' manufacturing tasks. A survey of 20 apparel vendors servicing mainly U.S. buyers was conducted on employees of overseas business departments working for more than five years. buyers. Based on the results, vendors mainly manufactured cut-and-sew knit products. Regarding the production method, OEM was used more frequently than ODM. Fourteen (70%) companies used the ODM method. This suggests that vendors are expanding their production method from OEM to ODM. In order to summarize the work of each business based on the clothing production process research results, buyers were in charge of planning products and the vendors were in charge of sampling. Production of materials and the approval of material tests were out sourced. Overseas factories of vendors were in charge of bulk (mass) production and garment finishing, as well as packaging and shipping the completed products. Even though the vendors' head offices do not directly produce clothes, they play a pivotal role in ensuring planning and management progress in clothing production. As buyers prefer direct contracts for cost reduction, the vendor additionally performs the role of an agent. Also, with the increase in ODM production ratio, the work area of the vendor is expanding. If Korean clothing exporters improve their global competitiveness by investing in the R&D of materials and design to enhance the ODM method, the development of Korea's clothing and export industry will benefit significantly.

• Journal of Korean Society of Transportation
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• v.32 no.5
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• pp.421-430
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• 2014

The greenhouse gas emission generated by idling vehicles is a critical issue in the greenhouse gas reduction from the transportation sector. Recently, the mandatory application of the Idle Stop and Go (ISG) for buses, trucks and taxis is in the process of legislation. Focusing on the regulation is about to apply to passenger cars, this study analyzed the quantitative economic effects of the ISG installation by passenger car types in Seoul metropolitan area to support proper policy making. The benefit cost ratio of ISG installation on commercial passenger car of Seoul is the most effective, calculated as 8.55. Accordingly, the amount of 660 liters (per year per vehicle) of fuel and 1,606 kg (per year per vehicle) of $CO_2$ could be reduced. The results of this study might be used as an index for judgment of policy such as determining appropriate subsidy for ISG installation on passenger cars.

• Journal of the military operations research society of Korea
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• v.33 no.2
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• pp.75-86
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• 2007

This paper presents the overall valuation framework of the Army Tactical Command Information System(ATCIS) with its empirical data which is developed by the ROK Army in 2005 with its own R&D efforts over the past 10 years. The valuation with the appropriate methods is conducted through the full and relentless support of ROK Army HQs, defense agencies, and related firms. And the results include both qualitative and quantitative values of the ATCIS in perspectives of economic, technical, and defense strength effects. As a result, the development of ATCIS is valued over 1.7291 trillion Won which is over 6.55 times benefit and cost ratio comparing with other country's similar system. The worth of this paper includes the actual framework and methods to apply the valuation of other weapon systems and its preliminary research, defense offset valuation, performance evaluation and others.