• Resources Recycling
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• v.31 no.3
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• pp.40-52
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• 2022

This study analyzed the amount of carbon dioxide reduction and economic benefits of detailed processes of CO₂ 6,000 tons plant facilities with mineral carbonation technology using carbon dioxide and coal materials emitted from domestic circulating fluidized bed combustion power plants. Coal ash reacted with carbon dioxide through carbon mineralization facilities is produced as a complex carbonate and used as a construction material, accompanied by a greenhouse gas reduction. In addition, it is possible to generate profits from the sales of complex carbonates and carbon credits produced in the process. The actual carbon dioxide reduction per ton of complex carbonate production was calculated as 45.8 kgCO₂eq, and the annual carbon dioxide reduction was calculated as 805.3 tonCO₂, and the benefit-cost ratio (B/C Ratio) is 1.04, the internal rate return (IRR) is 10.65 % and the net present value (NPV) is KRW 24,713,465 won, which is considered economical. Carbon mineralization technology is one of the best solutions to reduce carbon dioxide considering future carbon dioxide reduction and economic potential.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.2
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• pp.113-118
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• 1995

Eighteen Holstein Friesian ${\times}$ Native heifers with an average live weight of $175.4{\pm}27.8kg$ were allotted to 3 dietary groups. All animals were kept individually in a stanchion barn with free access to water and urea-treated rice straw (UTS). The supplemented feeds were as follows: Group (Gr) 1 - concentrate mixture (15% CP) at 1% body weight (BW), Gr 2 - concentrate mixture at 0.7% BW + free licking of multinutrient block (MNB), Gr 3 - as Gr 2 + 0.3% BW ground com. Multinutrient block composed of 20% mineral mixture, 10% urea, 18% molasses, 20% soybean meal, 22% sesame meal, 10% cement, 0.15 million IU and 50 IU/kg MNB of vitamin A and E. The experimental period lasted 12 weeks. The result revealed that MNB enhanced intake of UTS and total dry matter intake. Animals in Gr 3 consumed a higher amount of feed than the other 2 groups, thus resulting in the highest live weight gain and tended to possess the best feed conversion ratio. Heifers in Gr 2 also performed better than Gr 1 although the difference was not significant. Average MNB intake found to be 0.65 kg/day. Feed cost per kg gain was not significantly different amon groups. However if the cost of MNB could be lower, it would benefit the production cost of animals. The advantage of MNB is the safety of using a high level of urea. Although it was supplemented to UTS which also contained non-protein nitrogen (NPN), no toxic sign was shown. The results indicated that MNB could be partially substituted to concentrate mixture and it was even better when used incombination with soluble carbohydrate feed.

• Economic and Environmental Geology
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• v.42 no.2
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• pp.133-141
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• 2009

For economic impact analysis on a R&D project of high-yield groundwater development in Jeju conducted by KIGAM from 2004 to 2007, benefit/cost ratio(BCR), net present value(NPV), and internal rate of return(IRR) were calculated by contingent valuation method(CVM), production function analysis, domestic water market analysis and technology factor analysis. Measurable direct impact parameters among the major outputs of this R&D project consisted the estimation 4 high-yield and high mineral groundwater reserve in Jeju. Annual use of the reserve by piped water and bottled water was estimated as 12.23 million ton and its monetary value was calculated as 293.4 million dollar in 2006 year value applied of 5.5% discount rate. Economic impact of this R&D project in NPV of year 2006, with applying a discount rate of 5.5%, was identified and estimated as 13.66 million dollar in NPV, 4.05 points in BCR, and 22.74% in IRR, respectively. Additional early launch benefit was 5.58 million dollar. Even increased of the 1% discount rate, NPV of this R&D project was also positive as 12.18 million dollar and BCR was 3.71.

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.1
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• pp.75-78
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• 2001

The whitefly, Dialeuropora decempuncta Quaintance and Baker (Homoptera : Aleyrodidae) causing considerable damage to mulberry, Morus alba. Crop loss caused by the whitefly was estimated in mulberry. Quantitative yield loss was estimated on the basis of harvest data from both sprayed and unsprayed plots. Data on pest incidence has been recorded at weekly intervals in both sprayed and unsprayed plots from 30 th day of plant age till harvesting i.e., 60 days after pruning in August October season. An attempt has been made to establish a relationship between whitefly population and percentage of crop loss due to it. Percentage of crop loss due to whitefly has got a linear relationship with the whitefly population. An initial population of 24 adults/top leaf would be able to cause 24% loss (l,630 Kg leaf/ha ) in a period of 30 days. Economic analysis postulates that application of pesticide can stove a net amount of 1,630 Kg leaf/ha which is sufficient to produce 67.65 Kg of additional multivoltine cocoons. This determines the cost/benefit ratio which will enable to workout the economics of management practices.

• Journal of the Korea Concrete Institute
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• v.29 no.3
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• pp.307-314
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• 2017

Concrete is a durable and cost-benefit construction material, however performance degradation occurs due to steel corrosion exposed to chloride attack. Penetration of chloride ion usually decreases due to hydrates formation and reduction of pores, and the reduced chloride behavior is considered through decreasing diffusion coefficient with time. In the work, HPC (High Performance Concrete) samples are prepared with 3 levels of W/B (water to binder) ratios of 0.37, 0.42, and 0.27 and 3 levels of replacement ratios of 0%, 30% and 50%. Several tests containing chloride diffusion coefficient, passed charge, and compressive strength are performed considering age effect of 28 days and 180 days. Chloride diffusion is more reduced in OPC concrete with lower W/B ratio and GGBFS concrete with 50% replacement ratio shows significant reduction of chloride diffusion in higher W/B ratio. At the age of 28 days, GGBFS concrete with 50% replacement ratio shows more rapid reduction of chloride diffusion than strength development, which reveals that abundant GGBFS replacement has effective resistance to chloride penetration even in the early-aged condition.

• 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.

• Journal of Korean Society on Water Environment
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• v.37 no.2
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• pp.128-136
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• 2021

It is generally known that a wastewater treatment plant (WWTP) consumes immense energy even if it can produce energy. With an aim to increase the energy independence rate of WWTP from 3.5% in 2010 to 50% in 2030, the Korean government has invested enormous research funds. In this study, cost-effective operating alternatives were investigated by analyzing the energy efficiency and economic feasibility for biogas and power generation using new and renewable energy. Based on the US EPA Energy Conservation Measures and Korea ESCO projects, energy production and independence rate were also analyzed. The main energy consumption equipment in WWTP is the blower for aeration, discharge pump for effluent, and pump for influent. Considering the processes of WWTP, the specific energy consumption rate of the process using media and MBR was the lowest (0.549 kWh/㎥) and the highest (1.427 kWh/㎥), respectively. Energy-saving by enhancing anaerobic digester efficiency was turned out to be efficient when in conjunction with stable wastewater treatment. The result of economic analysis (B/C ratio) was 2.5 for digestive gas power generation, 0.86 for small hydropower, 0.49 for solar energy, and 0.15 for wind energy, respectively. Furthermore, it was observed that the energy independence rate could be enhanced by installing energy production facilities such as solar and small hydropower and reducing energy consumption via the replacement of high-efficiency operating.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.285-292
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• 2014

BIM (Building Information Modeling) is a new paradigm that includes construction life-cycle, and BIM has become mandatory regulation according to the Public Procurement Service since 2016, which accelerates its application. BIM is now expand from architectural field to infrastructure industry. Through pilot projects, BIM has been challenged with verification process. This trend has affected to maintenance and operation (M&O) phase of construction life-cycle. Advanced country has already published their research and result with feasibility study and guidelines. In this paper, we conduct the feasibility study to adopt BIM-based infrastructure management system. Bridges and tunnels were selected as application target, and benefit/cost ratio were used. The result shows that BIM-based infrastructure management system is feasible when the level of detail is more than "Medium" in bridge, and "High" in tunnel.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.5
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• pp.1-18
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• 2019

A short-turn bus is a bus that is operated within a subsection of an existing bus line. Previous studies regarding short-turn buses decided optimal turn-back points for a single bus line rather than a bus network. Also, in-vehicle crowding which has a significant impact on transit convenience was rarely considered. Therefore, this study aimed to develop a methodology to set priorities for the introduction of short-turn buses of bus lines and sections, considering crowding. To achieve this objective, we calculated occupancies and crowding alleviation benefits of existing bus lines overlapping a new short-turn route based on transit card data, before and after the introduction of short-turn strategy. Also, operator and social costs caused by the introduction of short-turn buses were calculated. Those procedures were iterated over bus lines and sections to operate a short-turn service, and a section whose benefit-to-cost ratio (B/C) is the largest in a line was selected to operate a short-turn service in the line. After, priorities of bus lines to introduce short-turn services could be determined based on B/C values, and the optimum total fleet size could be determined when a short-turn strategy is applied in multiple lines.

• Korean Journal of Agricultural Science
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• v.44 no.3
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• pp.451-461
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• 2017

Korean agriculture has recently focused on the 6th dimension of industrialization, which includes the functions of healing and care. The green care and healing business is one of the most representative models, satisfying modern consumers' needs for care or healing in rural agricultural environments. Many studies have shown physical and social benefits from green care and healing, but studies regarding economic performance are rarely found. The present study aimed to analyze the economic feasibility of different green care and healing farm complexes proposed in recent domestic research, with various possible combinations of business scenarios. The results show that most of the scenarios are economically feasible as B/C (benefit-cost ratio) and IRR (internal rate of return) are 1.19 and 8.53%, respectively, under scenario 1. This study also performed a break-even analysis for providing more flexible decision-making information. Overall, scenario 1 from green care and healing site and scenario 4 from green care and healing cluster are found to be superior to the other scenarios in terms of B/C and IRR. The scenarios in this study reflect the domestic farms or complexes which have similar functions of care or healing. Therefore, the results of this study provide information on practical policies and business implications in making decisions on the specific size and operational patterns when adopting green care and healing complexes by central or local governments and private sectors in the future.