• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.275-280
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• 2006

The protection of the environment is one of today's key demanding international activities and interests. All of aspects including industry, economy and society should be changed into environmental friendly industries. The building is not exception in this trend. What is not generally realized is that building, in the lifecycle of construction, use and demolition, account for large construction, not considered with environment impact and conservation in the lifecycle. Expecially, the construction materials and components used in the construction stage has much embodied energy. And much $CO_2$ emit on the production of the construction material and component. The energy use and $CO_2$ emission would continuously diminish the limited natural resources and impact the environment such as ozon layer destruction. In this paper, it studied the estimation of the amount of energy use and $CO_2$ emission in the building construction stage, it would provide the estimation process and applied with the multifamily housing.

• Journal of Forest and Environmental Science
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• v.25 no.2
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• pp.101-109
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• 2009

The Hajong are the ancient tribal forest community among the ethnic minorities of the North-East region of Bangladesh. The study was carried out with respect to three income groups highlighting their indigenous knowledge. A total of forty-five households (fifteen from each income groups) were assessed using different participatory appraisals through semi-structured questionnaires. A special type of indigenous knowledge on food habit was explored in the Hajong community, which correspond to the severe dependence on forest resources. They collect their food resources from homestead forest (45%) followed by forest (40%), market and others. They have indigenous hunting procedure to trap the animal in the forest. Twenty three tree species were tremendously planted in their homestead forests which are the very important source of food. Male are highly responsible to collect the food materials from forest as well as other sources.

• Journal of the Korean Chemical Society
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• v.60 no.5
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• pp.327-341
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• 2016

This study explores the effective visual resources in the “regularity in chemical reactions” unit of ninth grade science textbooks (2009 revised version). The frequency and role of visual resources were initially examined, and the students’ perceptions of visual resources were investigated. The results of the analysis represented the learning material presentation (68%), motivational categories (14%), guide to inquiry procedures (9%), and inquiry results and summaries (8%). According to the investigation of the students’ perceptions of visual resources, the most effective visual resource for motivation is a photograph depicting physical and chemical changes, such as in bread baking and the most effective for learning material presentations in mass conservation, definite proportion, and stoichiometric concept units were a cartoon, graph, and formula representing stoichiometric phenomena, respectively. The most effective resource for guide to inquiry (experimental) procedures were photographs of both instruments and sequential experiment processes; and in the inquiry results and summary category, incomplete tables and graphs for students to work on themselves. The aims of this research are to increase the usefulness of visual resources in the teaching-learning activity and provide informative supplements for the development and improvement of visual resources, according to the students’ perceptions.

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.1
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• pp.87-92
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• 1996

The quality of silages, made from whole crop barley, rye, spring oat, Italian ryeglass, orchardgrass, alfalfa and grass-legume pasture mixtures, were evaluated under two different conservation techniques in baled silage making (BS) and conventional silages(CS). Crops materials were harvested at the stage of the greatest dry matter accumulation(hard dough for barley, soft dough for rye and oat, late bloom for Italian ryegrass and others pasture species), and baled in a self constructed square baling chamber weighted by 25~30kg in dry matter basis. Each bales were wrapped with 0.05mm thick polyethylen plastic film and stored six months long in stack silos. Barley, rye, oat and Italian ryegrass including of pasture crops produced higher quality silages in the baled silage making, due to better organic acid fermentation and lower nutrient losses during the period of storage than those in the conventional silages. TDN contents of barley silages were 65.3% in BS and 63.7% in CS, NEL value of barley silages was improved hum 6.48MJ(CS) to 6.61MJ/kg(BS) in dry matter basis. Silage quality of rye, oat and pasture crops were also improved markedly in the baled silage utilization.

• Geomechanics and Engineering
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• v.15 no.2
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• pp.729-738
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• 2018

Soft clay soils due to their various geotechnical problems, stabilized with different additives. Traditional additives such as cement and lime will not able to increase the soil strength properties significantly. So, it seems necessary to use new additives for increasing strength parameters of soft clay soils significantly. Among the new additives, epoxy resins have excellent physical and mechanical properties, low shrinkage, excellent resistance to chemicals and corrosive materials, etc. So, in this research, epoxy resin used for stabilization of soft clay soils. For comprehensive study, three clay soil samples with different PI and various clay mineral types were studied. A series of uniaxial tests, SEM and XRD analysis conducted on the samples. The results show that using epoxy resin increases the strength parameters such as UCS, elastic modulus and material toughness about 100 to 500 times which the increase was dependent on the type of clay minerals type in the soil. Also, In addition to water conservation, the best efficiency in the weakest and most sensitive soils is the prominent results of stabilization by epoxy resin which can be used in different climatic zones, especially in hot and dry and equatorial climate which will be faced with water scarcity.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.5
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• pp.401-410
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• 2002

Concerns for energy conservation, environmental pollution, and the fact that organic wastes account for a major portion of our waste materials, have created the interest of biogas, which usually contains about 60 to 70 percent methane, 30 to 40 percent carbon dioxide, and other gases, including ammonia, hydrogen sulfide, mercaptans and other noxious gases. Cyclone combustors are used for homing a wide range of fuels such as low calorific value gas, waste water, sludge. coal, etc. The 3-dimensional swirling flow, combustion and emission in a tangential inlet cyclone incinerator under different inlet conditions are simulated using a standard k-s turbulence model and ESCRS (Extended Simple Chemically-Reacting System) model. The commercial code Phoenics Ver.3.4 was used for the present work. The main parameters considered in this work are inlet velocity and air to fuel ratio. The results showed that the change of operating conditions had an influence on the shape and size of recirculation zones, mixture fraction and axial velocity which are important factors for combustion efficiency and emission behavior. The application of this kind of computer program seams to be promising as a potential tool for the optimum design of a cyclone combustor with low emission.

• Korean Journal of Plant Resources
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• v.23 no.6
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• pp.550-553
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• 2010

The representative research institutes in North Korea are the Academy of Science and the laboratories of major universities. The National Academy of Science consists of headquarters, Academy of Medicinal Science, Academy of Forestry Science, and Academy of Agricultural Science. Under the authority of the National Academy of Science, Central Information Agency for Science and Technology (CIAST) has built up a database system integrating all the science technology data to provide scientific and technological information. The major universities of North Korea include Kim Il-sung University, Kim Chaek University of Technology, Pyongyang Agricultural College, and Wonsan Agricultural College, and an agricultural college is situated in each province. Out of 3,860 plant species in North Korea, 158 species which amounts to approximately 4% of the total are rare and endangered, and deforestation is under a critical situation. The Oriental Medicine (Koryo Medicine) has been well developed using medicinal plants, and practical researches on biotic pesticide are largely conducted as an alternative to tackle the shortage of farming materials. Hereafter, a South-North joint research on the amount of plant resources and the methods of its conservation is needed and the North Korean research areas of biotic pesticide are worth adopting to the South Korean eco-friendly organic agriculture.

• Journal of Forest and Environmental Science
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• v.30 no.4
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• pp.362-369
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• 2014

This study investigated physical properties and combustion gas characteristics for 8 types of wood pellets (4 domestic and 4 imported products) distributed in the domestic market. Results showed that most pellet types were first-grade pellets in the wood pellet quality standards in Korea with the exception of 3 pellet types from K company (second-grade in mechanical durability), G company (off-grade in nitrogen content) and P company (second-grade in ash percentage). Mixed pellets which contained more lignin and sap content were higher in mechanical durability (%) than that of white pellets. From the combustion gas analysis results, NOx emitted from all pellets combustion was at acceptable levels for national emission standard of the Clean Air Conservation Act except for pellets from G company. In addition, CO levels from all types of wood pellets were acceptable except for pellets from D company and domestic pellets were higher CO levels than imported pellets. These results indicate the higher CO levels in domestic pellets due to the usage of forest thinning materials including logging debris which usually had the high content of bark.

• Journal of architectural history
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• v.10 no.2 s.26
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• pp.55-71
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• 2001

This study reviewed the preservation status of the Early Western Style Architecture in Korea based on the on-site research of church buildings which are registered as National Cultural Properties. I have investigated 21 church buildings regarding the frequency, content and concept of restoration. The results are summarized as follows First, the churches have been restored extensively in every 17 years on the average. Second, the main restorations are replacement of bricks, painting, waterproofing, repair of roof and timber. And the main changes are extension of plan, removal of Interior posts, and replacement of floor. Third, the main concept of restorations are historical restoration(62%), critical restoration(23%), stylistic restoration(14%). Forth, the category of restoration have been changed, that is extending of incompletion (1st stage), functional improvement and extension of the span of life(2nd stage), improvement of facilities(3rd stage), restoration to the original state and conservation(4th stage). Fifth, the issues of repairing techniques are revival and replacement of weathered bricks, the removal of painting, and structural reinforcement. This study will be able to be used as the fundamental materials to improve the techniques of restoration of Early Western style masonry buildings.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.283-288
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• 2010

The characteristics of a condenser dryer and a vented dryer that are common types of domestic clothes dryers for home use are predicted and compared in an effort to improve the efficiency and to overcome economical and environmental problems due to its inefficient power consumption. In the present study, a drying system is simplified by assuming the mechanism is composed of several elements such as heater and drum and mathematical models using the mass and energy conservation of moisture and air through each element are defined. Based on this mathematical model, the computational tool is developed to predict temperature, humidity and enthalpy of moisture and air in a drum and remained moisture contents (RMC) in drying materials. The computational results are verified by comparing with experimental results from existing studies. In addition, the efficiency of a dryer is calculated using these predicted results for a given condition and the drying characteristics of a condenser dryer and a vented dryer are compared and analyzed.