• Environmental Engineering Research
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• v.25 no.1
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• pp.1-17
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• 2020

With benefits to the human health, environment, economy, and energy, anaerobic digestion (AD) systems have attracted remarkable attention within the scientific community. Anaerobic digestion system is created from (bio)reactors to perform a series of bi-metabolism steps including hydrolysis/acidogenesis, acetogenesis, and methanogenesis. By considering the physical separation of the digestion steps above, AD systems can be classified into single-stage (all digestion steps in one reactor) and multi-stage (digestion steps in various reactors). Operation of the AD systems does not only depend on the type of digestion system but also relies on the interaction among growth factors (temperature, pH, and nutrients), the type of reactor, and operating parameters (retention time, organic loading rate). However, these interactions were often reviewed inadequately for the single-stage digestion systems. Therefore, this paper aims to provide a comprehensive review of both single-stage and multi-stage systems as well as the influence of the growth factors, operating conditions, and the type of reactor on them. From those points, the advantages, disadvantages, and application range of each system are well understood.

• Journal of Agricultural Extension & Community Development
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• v.18 no.1
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• pp.129-152
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• 2011

The study aims to investigate the meaning of the rurality in traditional three-verse Korean poem written by Sadaebu(사대부). We will discuss integration method for Rural and rurality. Rurality is not physical truth, but personal and subjective thing. The meaning of the rurality produce socially. So, the concept of the Rurality can be interpreted in many ways. Sadaebu in the Joseon period put emphasis on rural as a object of a self-discipline and govern. They compose a poem from rural life. There are various meaning related to rurality in traditional three-verse Korean poem. The rurality meaning of the Sijo written by Yakcheon and Jonjae can define union between the natural order and poetic narrator. poetic narrators accept theirselves to nature and work willingly. The host of the program must make visitors homesick and gives more energy by Sijo experience program. The most import thing is the identification of the visitor and rural. To accomplish these purpose, It needs visitors can sing a sijo by oneself.

• Journal of the Korean housing association
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• v.24 no.6
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• pp.189-197
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• 2013

The purpose of the study was to analyze the improvement elements depended on housing quality measurement tool related to mental health. The data for the analysis was collected through questionnaire survey method from November 1, 2012 to January 17, 2013, and the sample consisted of 720 respondents living in single detached houses, multi-families detached houses, apartments, and town houses in 4 cities, Seoul, Busan, Daejeon, and Kwangju. The data were analyzed using descriptive statistics. The results of improvement elements are as follows: 1) Pedestrian-threaten street from cars in physical safety 2) A secluded or dark spot and fear of walking at night in social security, 3) Indoor noise, outdoor noise, and evidence of abandoned trash heap/bottle in neighborhood in health & sanitation, 4) Illegal parking and heating control system in facility convenience, 5) Extra kitchen, number of bathrooms, and community spaces in space convenience, 6) Openness and spaciousness of indoor room, and satisfaction of house and neighborhood in comfort, 7) Management common/sharing space in maintenance, 8) Energy saving facility and environment friendly materials use in sustainability, 9) Burden on housing cost, asset value on house, and school district in economic value, 10) Reflection of residents style, surrounding building's number of layers, and neighborhood appearance of preference in housing environment image.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.243-246
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• 2010

Recently, global warming problem is a major issue in international community. The carbon dioxide ($CO_2$) emissions in the construction industry is one of the main factors causing a global warming problem. Accordingly, various researches on $CO_2$ emissions caused by the construction industry is needed and construction methods which is low $CO_2$ emissions should be developed. In this study, $CO_2$emission cost is compared with roof waterproofing types in construction phase. As a result, the $CO_2$ emission costs of asphalt waterproofing is the highest. This research is to provide basic information for selecting appropriate construction methods in aspect of low $CO_2$ emission cost.

• Journal of Agricultural Extension & Community Development
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• v.14 no.2
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• pp.417-436
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• 2007

The purpose of this study was to prepare for developing rural house remodeling techniques utilizing the traditional residence factor. The study was carried out through both literature research and on-site research. The traditional residence space factors were identified through literature research and on-site research was carried out through analysis of the rural house remodeling cases. The results of this study was as follows ; 1) Traditional space factors were derived by literature research i. e. space arrangement (topography, direction, plane arrangement), exterior factors; walls, madang, interior factors; roofs, ondol, floors, colours. 2) The traditional residence factor utilizations of remodeling were applied a result through investigation case and analysis. Five rural houses in Namsa village, Danseong-myeon, Sangcheong-gun, Gyeongsangnam-Do were analyzed as remodeling cases including traditional residence factors. There were limitation of budget problems and material selection in the traditional residence factor utilizations of remodeling. The researchers have chosen target rural houses which applied for traditional residence factors to remodel the rural houses, and the most important factor to consider was harmony with rural unique characteristics. The researchers suggested considerations should be placed on development with energy savings and convenience in rural house remodelling.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.301-310
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• 2006

A series of laboratory tests was carried out for analyzing compaction characteristics of hydraulic fill soils(or hydraulically filled soils). Hydraulic fill soils were settled down by the weight of soil particle itself in water and consolidated by the extraction of water from the soil structures. Water content and dry unit weight were observed as the depth of sedimentation and consolidation soil. It was found from the result that the optimum water content $(W_{cpt})$ of the maximum unit weight$(\gamma_{dmax})$ is higher than that of laboratory compaction test(KS F 2312 A method). It was due to difference in compaction energy and compaction effect between two methods. And the maximum dry unit of hydraulic fill soil is smaller than that of laboratory compaction test. Especially in terms of compaction effect, the maximum relative compaction degrees$(R_{cmax})$ of Seamangum dredged sand, river sand and mixed sand, half and half of dredged and river sands, were 85%, 91% and 86%, respectively. It means that the compaction effect can be $85\sim91%$ of the maximum unit weight in laboratory compaction test.

• KIEAE Journal
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• v.4 no.3
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• pp.171-178
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• 2004

In recent years, the objective information for the environmental effect of architecture will be furnished to the designer and inhabitant in order to minimize an excessive energy consumption and environmental loads by buildings. In addition, an environmental friendly architectural certification program for a residence, office, and school facilities have been operated to spread and supply environmental friendly architecture. Most of the environmental friendly architectural certification programs proposed in the country are focused on the aspect of the physical environments of architecture in its certification ranges. In the case of a foreign country, however, the certification ranges of an environmental friendly architectural certification program for the school facilities among the programs will be extended not only to the standards for architectural design, environmental aspect, and maintaining and management basis by considering the characteristics of educational effects for students but also to the curriculum, policy of environment, and roles of local community facilities by reflecting a social aspect. Therefore, this study proposes a design and evaluation method by considering an ecological element that will satisfy the requirement for educational well-being that includes not only the requirement for school facilities according to the development of a new curriculum like a space for teaching and learning but also the improvement of the quality of educational environments and the objective of an ecological school.

• Journal of Electrochemical Science and Technology
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• v.11 no.2
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• pp.99-116
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• 2020

The article provides information on ceramic / nanostructured materials which are suitable for solid oxide fuel cells (SOFCs) working between 500 to 1000℃. However, low temperature solid oxide fuel cells LTSOFCs working at less than 600℃ are being developed now-a-days with suitable new materials and are globally explored as the "future energy conversion devices". The LTSOFCs device has emerged as a novel technology especially for stationary power generation, portable and transportation applications. Operating SOFC at low temperature (i.e. < 600℃) with higher efficiency is a bigger challenge for the scientific community since in low temperature regions, the efficiency might be less and the components might have exhibited lower catalytic activity which may result in poor cell performance. Employing new and novel nanoscale ceramic materials and composites may improve the SOFC performance at low temperature ranges is most focused now-a-days. This review article focuses on the overview of various ceramic and nanostructured materials and components applicable for SOFC devices reported by different researchers across the globe. More importance is given for the nanostructured materials and components developed for LTSOFC technology so far.

• Journal of Agricultural Extension & Community Development
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• v.4 no.1
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• pp.293-304
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• 1997

Studies about nutritional status, dietary behaviors and food preferrence as well as health status were performed to 110 homo-living elderly in rural area, Asan. The results obtained by questionnaires and interviews for 24-hr dietary recall were as follows. They were 68.6 years of average age. The weights were 53.8kg and 51.4kg of male and female, respectively and BMI 22.0 and 23.5. Their prevalence of obesity and high blood pressure were 65.5% and 60.5%, respectively, which seemed to be less than ones in large cities. More than 50% of the elderly thought their health as good or so-so. Physical health conditions by check list were indicated as 2.26 points, which meant the listed physical symptoms observed seldom(3pts) to sometimes(2pts). Evaluations on food frequency and seasoning tendency resulted in superior quality of female elderly's meals to that of male ones. Average daily intake of energy, protein, vitamin A, riboflavin and ascorbic acid of the elderly in rural area were lower than Korean RDA for the aged $60{\sim}69$ and riboflavin was found to be the least sufficient nutrient. Their monthly expenditure, meal-accompany and skipped meals were significantly related to daily nutrient intake.

• Journal of KSNVE
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• v.9 no.1
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• pp.184-188
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• 1999

Noise regulation of heavy construction machinery is getting stricter： 3 dB per every 4 year in European community. To meet this requirement many engineers have adopted the enclosing structures with thick absorbing materials and small opening, This increases internal temperature of the enclosure which have engine systems such as electric equipment that are vulnerable to heat, and engine block and muffler that can be regarded as heat sources. So noise control engineers have to consider a coupling problem: combining heat balance and noise reduction. This paper describes this approach by introducing simple heat transfer theory and SEA. The enclosing system of the loader whose enclosing structure consists of two rooms is investigated to show the validity of this method. The results represent that the simple heat transfer theory can be useful to estimate cooling performance when it is linked together by the back pressure theory in duct system. and the radiated noise can also be estimated by the SEA. Therefore a designer can use these approaches to define the opening ratio of an enclosure and the mass flow rate of air considering radiating noise.