• New & Renewable Energy
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• v.4 no.2
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• pp.21-30
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• 2008

Anaerobic digestion (AD) is the most promising method of treating and recycling of different organic wastes, such as OFMSW, household wastes, animal manure, agro-industrial wastes, industrial organic wastes and sewage sludge. During AD, i.e. degradation in the absence of oxygen, organic material is decomposed by anaerobes forming degestates such as an excellent fertilizer and biogas, a mixture of carbon dioxide and methane. AD has been one of the leading technologies that can make a large contribution to producing renewable energy and to reducing $CO_2$ and other GHG emission, it is becoming a key method for both waste treatment and recovery of a renewable fuel and other valuable co-products. A classification of the basic AD technologies for the production of biogas can be made according to the dry matter of biowaste and digestion temperature, which divide the AD process in wet and dry, mesophilic and thermophilic. The biogas produced from AD plant can be utilized as an alternative energy source, for lighting and cooking in case of small-scale, for CHP and vehicle fuel or fuel in industrials in case of large-scale. This paper provides an overview of the status of biogas production and utilization technologies.

• Journal of Environmental Health Sciences
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• v.39 no.3
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• pp.248-255
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• 2013

Objectives: The purpose of this paper is to define the level of recycling standards and its process in paper scrap. As pollution is increased by improperly treated paper scrap, the government has recently strengthened the management of the paper scrap. Methods: In this study, the current status of paper scrap recycling was investigated through a 2012 field survey, and the classification and recycling standards for paper scrap in developed countries and institutions were also investigated through a literature review in order to introduce optimal recycling standards. Results: As a result, the contents of contaminants were identified as the most important recycling standard, and the contents of contaminants in paper scrap was measured at less than 1.0% at most companies. The recycling standard for paper scrap was determined to be below 3% contaminants in the case of paper and 5% in the case of board. In this study, recycling stage was determined by considering regulations on resources and practices in the field. Conclusions: The recycling standard for paper scrap was determined to be below 3% and 5% contaminants for paper and board, respectively.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.202-205
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• 2008

Anaerobic digestion(AD) is the most promising method of treating and recycling of different organic wastes, such as OFMSW, household wastes, animal manure, agro-industrial wastes, industrial organic wastes and sewage sludge. During AD, i.e. degradation in the absence of oxygen, organic material is decomposed by anaerobes forming degestates such as an excellent fertilizer and biogas, a mixture of carbon dioxide and methane. AD has been one of the leading technologies that can make a large contribution to producing renewable energy and to reducing $CO_2$ and other GHG emission, it is becoming a key method for both waste treatment and recovery of a renewable fuel and other valuable co-products. A classification of the basic AD technologies for the production of biogas can be made according to the dry matter of biowaste and digestion temperature, which divide the AD process in wet and dry, mesophilic and thermophilic. The biogas produced from AD plant can be utilized as an alternative energy source, for lighting and cooking in case of small-scale, for CHP and vehicle fuel or fuel in industrials in case of large-scale. This paper provides an overview of the status of biogas production and utilization technologies.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.4
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• pp.385-391
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• 2006

The estimated decommissioning cost of nuclear research reactor is calculated by applying a unit cost factor-based engineering cost calculation method on which classification of decommissioning works fitted with the features and specifications of decommissioning objects and establishment of composition factors are based. Decommissioning cost of nuclear research reactor is composed of labor cost, equipment and materials cost. Labor cost of decommissioning costs in decommissioning works are calculated on the basis of working time consumed in decommissioning objects. In this paper, the unit cost factors and work difficulty factors which are needed to calculate the labor cost in estimating decommissioning cost of nuclear research reactor are derived and figured out.

• Communications for Statistical Applications and Methods
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• v.30 no.5
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• pp.485-499
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• 2023

This study aimed to predict the number of meals served in a group cafeteria using machine learning methodology. Features of the menu were created through the Word2Vec methodology and clustering, and a stacking ensemble model was constructed using Random Forest, Gradient Boosting, and CatBoost as sub-models. Results showed that CatBoost had the best performance with the ensemble model showing an 8% improvement in performance. The study also found that the date variable had the greatest influence on the number of diners in a cafeteria, followed by menu characteristics and other variables. The implications of the study include the potential for machine learning methodology to improve predictive performance and reduce food waste, as well as the removal of subjective elements in menu classification. Limitations of the research include limited data cases and a weak model structure when new menus or foreign words are not included in the learning data. Future studies should aim to address these limitations.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2002.05a
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• pp.43-48
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• 2002

ISP (Information Strategy Planning), which is the first step of the whole database development has been studied to manage effectively information and data related to the decommissioning activities of the Korea Research Reactor 1＆2(KRR-1＆2). In order to establish the scope of the decommissioning DB, user requirement and the importance of the decommissioning information were analyzed and set up the conceptual design of the decommissioning DB and established the classification system related to decommissioning activities. It has been extracted the principle information such as working information facilities information, radioactive waste treatment information and radiological surveying and analysis during the interviewing with an experts. And also, It has been made the code system. These results will be used as the basic data to design the prototyping for the decommissioning DB.

• Journal of Korean Society of Rural Planning
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• v.11 no.4 s.29
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• pp.99-108
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• 2005

In this study, thirteen villages in Chonnam province were selected as case study sites and the spatial distribution of the facilities in the villages was examined to provide basic information fur the establishment of rural plans. According to the questionnaire survey, various problem such as environmental pollution, position, scene, management etc. was brought owing to cattle shed, and dissension was more or less seen by scale of facilities, management of facilities and waste, regional factor(stock farming management condition, life style and attitude of inhabitants) and topographical factor (height, position physical aspect of a mountain, distance with water resources etc.) etc.. The facilities could be classified into 6 types based on the their spatial locations: 1) Type 1, facilities located at the waterside; 2) Type 2, facilities located at the entrance of village; 3) Type 3 facilities, scattered in the residential area: 4) Type 4 facilities, collectivized in village; 5) Type 5 facilities, adjoining village; and 6) Type 6 facilities, scattered irregularly inside and outside of village. Based on the classification, possible implementations for the reduction of environmental impacts were suggested. The results of this study could be used as an example of study on the distribution, classification, and rearrangement of environment-impacting facilities in rural areas for improvement of their roles in providing amenity resources.

• Korean Journal of Construction Engineering and Management
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• v.8 no.1 s.35
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• pp.107-115
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• 2007

Today's human life is more conveniently advantaged and abundant as industrial society advanced. However, the development has been creating a serious environmental crisis. Environmental pollution and exhaustion of natural resources recently became an important issue in construction industry as well as the concern about construction waste management and recycling the resources has arisen. Because the industrial wastes are not only increased quantitatively but also qualitatively intricate and various, groping for ways of reducing the use of resources primarily and recycling is urged on promotion. Currently, only about 33% of the wood wastes produced in construction site are recycled and the others are incinerated or disposed through irregular circulation process. In this study, I will investigate the present status of generating, processing, and recycling construction wood wastes and compare domestic disposal trend to other countries. In addition, I will analyze the actual condition of processing wood wastes in the construction site, verify the irrational causes, and simplify anomalous factors for the purpose of more efficient and correct activation of wood waste treatment and recycling on construction field and protection of environment in the long run.

• Resources Recycling
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• v.27 no.1
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• pp.22-30
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• 2018

In order to industrially recycle nickel, cobalt and rare earth elements included in waste NiMH batteries, electrode powder scraps were recovered by dismantle, crushing and classification from automobile waste battery module. As a result of leaching recovered electrode powder scrap with sulfuric acid solution, 99% of nickel, cobalt and rare earth elements were leached under reaction conditions of 1.0 M sulfuric acid solution, pulp density 25 g/L and reaction temperature $90^{\circ}C$ for 4 hours. In addition, the rare earth elements were able to separate from nickel / cobalt solution as cerium, lanthanum and neodymium precipitated under pH 2.0 using 10 M NaOH.

• Journal of the Korean GEO-environmental Society
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• v.11 no.6
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• pp.77-83
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• 2010

In this study, we tried to determine any detrimental effects on water quality when bottom ash obtained from a coal-fired power plant intended to be used as a fill material in construction sites. Physical-chemical properties of bottom ash were determined using proximate analysis, elemental analysis, XRD, and XRF. Classification of bottom ash as a waste material and soil contamination due to the use of bottom ash were performed by Korea waste standard leaching test and soil toxicity test, respectively. Results of leaching tests were compared to the regulations for water quality and groundwater quality and no harmful effects on water quality were found. Most of heavy metals in leachate were below detection limits but trace amount of $Cr^{6+}$ was found. However, concentration of $Cr^{6+}$ was below the regulation criteria. Column leaching tests indicated that concentrations of Pb and Zn were slightly higher than regulations but below regulations within 1 PVE, but concentrations of sulfate were 10 times higher than regulation and thus, the required time to reach regulation was almost 8 PVE.