• Environmental and Resource Economics Review
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• v.10 no.3
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• pp.413-431
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• 2001

Previous analyses of deposit-refund systems (hereafter DRS) mosty concerned consumer-paid DRS. While there has been a trend to put more emphasis on the producers' responsibility in recycling, especilly in Europe, and the supplier-paid DRS has been enforced in Korea during the past decade, little attempt has been made to analyse rigorously the nature of the supplier-paid DRS. This paper looks into the effects of the supplier-paid DRS on firm behaviors and profits under the oligopolistic market structure. It is shown that, in the cournot model where firms strategically interact each other, when the deposit rate is high enough, firms' profit increase as the deposit rate rises. Furthermore, where the number of firms are sufficiently large, it can happen that, as the deposit rate increases, both social welfare and firms' profit improve.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.264-269
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• 2000

As a part of the ongoing effort towards commercial application of high-temperature fuel cell power generation systems, we have recently built a pilot-scale molten carbonate fuel cell power plant and tested it. The stack test system is composed of diverse peripheral units such as reformer, pre-heater, water purifier, electrical loader, gas supplier, and recycling systems. The stack itself was made of 40cells of $6000cm^2$ area each. The stack showed an output higher than 25kW power and a reliable performance at atmospheric operation. A pressurized performance was also tested, and it turned out the cell performance increased though a few cells have shown a symptom of gas crossover. The pressurized operation characteristics could be analyzed with numerical computation results of a stack model.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.325-328
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• 2009

The 10t/d pyrolysis demonstration plant have been developed for waste tire recycling treatment and value added commercialization. The initial plant model had been started under 2.4t/d capacity with continuous operation, and the commercial plant has been achieved to the 120t/d based on demonstration plant having the tube reactor with chain conveyer attached disk. The next generation pyrolysis plant for waste tire is reviewed and the assignment for plant development is presented briefly.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.4
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• pp.192-202
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• 2009

Disassembly of products at their end-of-life (EOL) is a prerequisite for recycling or remanufacturing, since most products should be disassembled before being recycled or remanufactured as secondary parts or materials. In disassembly sequence planning of EOL products, considered are the uncertainty issues, i.e., defective parts or joints in an incoming product, disassembly damage, and imprecise net profits and costs. The paper deals with the problem of determining the disassembly level and corresponding sequence, with the objective of maximizing the overall profit under uncertainties in disassembly cost and/or revenue. The solution is represented as the longest path on a directed acyclic graph where parameter (arc length) uncertainties are modeled in the form of intervals. And, a heuristic algorithm is developed to find a path with the minimum worst case regret, since the problem is NP-hard. Computational experiments are carried out to show the performance of the proposed algorithm compared with the mixed integer programming model and Conde's heuristic algorithm.

• Land and Housing Review
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• v.14 no.1
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• pp.123-134
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• 2023

The BIM (Building Information Modeling) model created in the design stage can be used for prior review and schedule management for the construction stage. However, in the case of actual BIM application cases, additional work is required, such as creating a new model suitable for the construction stage, rather than using the 3D model in the design stage, due to the difference in the purpose of use between the design stage and the construction stage. Therefore, in this study, a division function of BIM model is proposed as a method of recycling it in the construction stage without a remodeling process. In addition, the application to the actual BIM model and the 4D CAD system linkage of the divided object and the comparison with the existing division method are used to verify the usability.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.7
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• pp.1209-1216
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• 2020

Objective: The present study aimed to evaluate the performance of odor abatement by using two different ventilation-biofilter systems with recycled stablized swine wastewater. Methods: The performance of odor removal efficiency was evaluated using two different ventilation-biofilter-recycled wastewater arrangements. A recirculating air-flow ventilation system connected to a vertical biofilter (M1) and a plug-flow ventilation system connected to a horizontal biofilter (M2) were installed. Water dripping over the surface of the biofilter was recycled at a flow rate of 0.83 L/h in summer and 0.58 L/h in winter to reduce odorous compounds and particulate matter (PM). The experiments were performed for 64 days with M1 and M2 to investigate how these two ventilation-biofilter systems influenced the reduction of odor compounds in the model houses. Odorous compounds, NH₃ and volatile organic compounds (VOCs) were analyzed, and microclimatic variables such as temperature, humidity, and PM were monitored. Results: Ammonia concentration inside M1 was about 41% higher on average than that in M2. PM and total suspended particles (TSPs) inside M1 were about 62.2% and 69.9%, respectively, higher than those in M2. TSPs in the model house were positively correlated with the concentration of NH₃ and VOCs. Conclusion: M2 emitted lower concentration of odorous compounds than M1. Moreover, M2 could maintain the optimum temperature condition for a swine house during the cooler season. The plug-flow ventilation-horizontal biofilter system could be used for pig houses to minimize air pollution produced by swine farming activities and maintain optimum microclimate conditions for pigs.

• Journal of Environmental Health Sciences
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• v.35 no.6
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• pp.526-531
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• 2009

Waste generation was generally expected to steadily rise due to a rapid increase in population and economic growth. However, regulations on disposable goods and a volume-based waste fee system have led to a gradual reduction in the amount of waste. In the case of food waste, separation of food waste from other waste has been put in place since direct landfilling was banned in January 2005. The predicted generation amounts of food waste and wastewater in the model city were 54 ton/d and 127.3 ton/d by year 2020, respectively. However, appropriate treatment technologies for food waste and wastewater discharged from food waste treatment processes are yet to be established. In this study, the food waste and wastewater discharged from food waste treatment process in the model city were characterized by literal and field investigation.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.1
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• pp.3-10
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• 2016

Effects of acid ($HNO_3$ and HCl) modification on the adsorption properties of Pb(II) and Cu(II) onto bamboo-based activated carbon (BAC) were investigated through a series of batch experiments. The carbon content increased and oxygen content decreased with acid treatment. $HNO_3$ induced carboxylic acids and hydroxyl functional groups while HCl added no functional group onto BAC. The pseudo-second order model better described the kinetics of Pb(II) and Cu(II) adsorption onto experimented adsorbents, indicating that the rate-limiting step of the heavy metal sorption is chemical sorption involving valency forces through sharing or exchange of electrons between the adsorbate and the adsorbent. The equilibrium sorption data followed both Langmuir and Freundlich isotherm models. The adsorption capacities of BAC were affected by the surface functional groups added by acid modification. The adsorption capacities were enhanced up to 36.0% and 27.3% for Pb(II) and Cu(II), respectively by the $HNO_3$ modification, however, negligibly affected by HCl.

• Journal of Korean Home Economics Education Association
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• v.35 no.2
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• pp.41-59
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• 2023

This study aimed at analyzing the educational needs of home economics teachers for food literacy cultivation education in secondary school home economics. A total of 192 home economics teachers were surveyed about their perceptions of importance and performance of food literacy education content categories and elements, and their priorities were identified. Among the 38 content elements presented, home economics teachers recognized that the current performance level was significantly lower than that of the importance over 34 content elements. Based on the Borich educational needs assessment and the Locus for Focus Model, we identified five content elements with 'very high' educational needs ('food security/food sovereignty', 'reducing food-related waste', 'food waste management and recycling', 'food-related waste recycling', and 'country of origin information'), and four content elements with 'high' educational needs ('genetically modified food', 'ethical food consumption', 'food additives', and 'eco-friendly agricultural products'). These results indicate that dietary education in secondary school home economics should emphasize both the production and disposal of food. The findings of this study suggest implications for the needs for a new dietary education in secondary school home economics that allows students to learn all stages of food system. These results can also be used as a basis for dietary education for cultivating food literacy in secondary school home economics education.

• Journal of the Korean Society of Safety
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• v.20 no.4 s.72
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• pp.63-70
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• 2005

It has been used so many kinds of architectural materials and interior products in current building construction, and use of composite architectural materials is increasing with the development of chemical technology. As the green architecture has become the center of public interest, much effort is conducted in advanced countries on the LCA point of view, such as restriction of architectural materials that emitting pollution substances, developing of Non-Toxic architectural materials, and recycling of used materials, etc. with the cooperation of related organizations, material manufacture companies, and construction companies. Because the kinds of materials to be used in building constructions are so various, there might be some possibility of personal and subjective choice at the time of materials selection resulting the missing the requirements of building components and the choice of harmful materials to human. One way to resolve the material problem is to present the green architectural materials which coincide with the quality performance at service and not harmful to man and nature. At this point of view, this study aims to develop the material classification model by investigating the major labelling system about green architectural materials in both domestic and abroad and to implement an efficient material selection system by making a powerful database of environmental standard and quality basis of building requirements.