• Journal of applied mathematics & informatics
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• 제10권1_2호
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• pp.217-226
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• 2002

A circular plate kept zero initial temperature is heated for a certain interval of time over a concentric circular region of the upper face. Deflection is obtained by using Laplace transform technique. Taking the plate material to be aluminium, central deflection is obtained for several values of time and the results shown graphically.

• 한국태양광발전학회지
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• 제6권1호
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• pp.69-75
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• 2020

Mongolia is located between Russia and China in Central Asia. In coal-rich corners, both the energy and energy sectors of our country prevail. Mongolia has vast resources of renewable energy and limited hydropower plants, such as wind and solar. In their first iNDC (intended Nationally Determined Contributions) submitted in 2015, Mongolia has pledged to increase the share of renewables capacity to 20% by 2020, and 30% by 2030 while reducing their energy related GHG emissions.

• 기술사
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• 제42권5호
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• pp.32-36
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• 2009

This project located in IFEZ(Incheon Free Economic Zone) is the first central heating and cooling type for high-rise residential building in korea. The design was performed as the joint venture between Cosentini from U.S.A and wooowon, and our design concept was to save energy. LEED application from USGBC is going on in progress for the first residential building in korea. Careful attention was paid from schematic design for not a durability of structural and architectural, but also durability and safety of M.E.P.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 하계학술발표대회 논문집
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• pp.138-138
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• 2007

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2004년도 하계학술발표 논문집
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• pp.143-143
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• 2004

• 천문학회보
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• 제36권2호
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• pp.142.2-142.2
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• 2011

Hydrodynamic simulations of gas clouds in the central hundred parsecs region of the Milky Way that is modeled with a three-dimensional bar potential are presented. Our simulations consider realistic gas cooling and heating, star formation, and supernova feedback. A ring of dense gas clouds forms as a result of $X_1-X_2$ orbit transfer, and our potential model results in a ring radius of ~200 pc, which coincides with the extraordinary reservoir of dense molecular clouds in the inner bulge, the Central Molecular Zone (CMZ). The gas clouds accumulated in the CMZ can reach high enough densities to form stars, and with an appropriate choice of simulation parameters, we successfully reproduce the observed gas mass and the star formation rate (SFR) in the CMZ, ${\sim}2{\times}10^7\;M_{\odot}$ and ${\sim}0.1\;M_{\odot}/yr$. Star formation in our simulations takes place mostly in the outermost $X_2$ orbits, and the SFR per unit surface area outside the CMZ is much lower. These facts suggest that the inner Galactic bulge may harbor a mild version of the nuclear star-forming rings seen in some external disk galaxies. We also find that the stellar population resulting from sustained star formation in the CMZ would be enlogated perpendicularly to the main bar, and this "inner bar" can migrate the gas in the CMZ further down to the central parsecs region.

• 한국세라믹학회지
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• 제52권3호
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• pp.192-196
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• 2015

Low soda alumina powder was fabricated using silica (${\alpha}$-quartz) as an agent for removing soda components in the alumina. Quartz powder 2 mm in size was added to aluminum hydroxide obtained through the Bayer process, and then the mixture was heated at various temperatures. Finally, the heat-treated powders were sieved for classification. In this study, the effects of the quartz amount and heating temperature on the mechanism of removing soda were examined. A minimum soda content of 0.005 wt% was observed at the conditions of 15 wt% quartz (based on $Al(OH)_3$ amount) heat-treated at $1600^{\circ}C$ for 8 h. The soda components, such as $Na_2O$, NaOH, and $Na_2CO_3$, in alumina were ionized and activated at high temperature, and this facilitated the reaction with quartz silica and alumina producing nepheline. The advantages of using quartz include low iron content and low cost in comparison with the conventional de-soda process using chamotte, another silicate mineral.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.244-251
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• 2003

A two-dimensional BEM code, $FRACOD^{2D}$, was applied to simulate fracture initiation and propagation processes in a rock pillar during an in situ heater test of a rock pillar planned at the $\"{A}sp\"{o}$ Underground Rock laboratory of SKB, in Southern Sweden. To take the advantage of conventional BEM for simulating fracturing processes, but without efforts for domain integral transformation, a hybrid approach is developed to simulate the fracturing processes in rock pillar under coupled thermo-mechanical loading. The code FRACOD was used for simulating the fracture initiation and propagation processes with its boundary tractions reflecting the effects of the initial and redistributed thermomechanical stresses in the domain of interest at multiple excavation and heating steps were produced by a special algorithm of stress inversion, based on resultant thermo-mechanical stress fields at each excavation and heat loading step by a FEM code without considering fracturing processes. This hybrid approach can take the advantages of both types of numerical methods and avoids their shortcomings for fracturing process simulation and domain effects, respectively. In this paper, we present the hybrid approach for the stress, displacements, and fracturing processes at sequential excavation and heating steps of the in situ heater test as a predictive modelling, the formulation of the fracturing models and the predictive results. Two sections of borehole depth, 0.5 m and 1.5 m below the tunnel floor are considered. The pillar area is modelled with the FRACOD and the stress field produced by excavation and heating is transferred with corresponding boundary stresses. From the modelling results, the degree of fracturing and damage are evaluated for 120 days of heating. Dominated shear fracturing in the vicinity of the central pillar was observed from the models at both sections, but spalled area appears to be limited. Based on the modelling results, a sensitivity study for the effect of pre-existing fractures in the vicinity of the holes is also conducted, and the initiation and evolution of EDZ around the deposition holes are investigated using this particular numerical technique.

• 한국지역사회생활과학회지
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• 제27권spc호
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• pp.703-714
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• 2016

Dwelling environments that can help elderly farmers to live more safely, independently, and conveniently are becoming more and more important. Many rural houses are built without any particular architectural or energy-related criteria, so most of them have poor insulation. The construction technology used is also not precise, which increases the loads for heating and cooling. Therefore, rural houses need to be improved. Also, there is more and more need for plans to realize eco-friendly dwellings, so the principle of nature-oriented plans related to the direction, insulation, or landscaping of a house is being emphasized. Insulation is one of the most effective ways to save energy for heating and cooling. This preliminary study to improve the insulation of rural houses examined three regions in South Korea: the central region, the southern region, and the Jeju Island. A field investigation was conducted on a total of 18 houses, including six from each town in the selected regions. The information was used to figure out the current status of rural houses and the characteristics of the buildings. The main living spaces are the living room for the central region and the main room in the southern region and Jeju Island. The southern regions are plane shapes surrounded by rooms, and all ventilation is accomplished by windows. The studied houses were mostly masonry structures with slate rooftops. Additions and improvements included room expansions and bathroom interior installations.

• 건축역사연구
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• 제13권4호
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• pp.19-34
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• 2004

This study examines the dwellings of the Korean diaspora in Maritime Provinces of Russia, and Kazakhstan and Uzbekistan of Central Asia to find the gist of the residence transformed as Korean traditional residence culture to accept Russian foreign culture. Through the examination, transformation process of the dwellings of the Korean diaspora was found as follows: - 1st Period(1864-1937): The Korean diaspora who Immigrated to Maritime Provinces of Russia built traditional houses of Korean style and few of them lived in Russian style houses. - 2nd Period(1937-1955): The Koreans who immigrated to Central Asia from Maritime Provinces under compulsion built 'ground house' by digging the earth and installed gudeul which is a traditional Korean heating system and roofed with reed. - 3rd period(1955-1991): The Koreans built straight lined '-' shape houses with two or three rooms wherein most of them were installed with gudeul to heat the room. Around the 1940s as they economically got well, the Koreans started to build houses with Russian style with one or two rooms with gudeul or a separate building with gudeul. - 4th period(1991-present): Houses of the 3rd period are still used by being enlarged or remodeled with less use of gudeul which is well reflected on Ujeong-maul village in Russia Maritime Provinces. As can be found above, the dwellings of the Korean diaspora in Russia Maritime Provinces and Central Asia are on the process of being transformed into Russian style to adapt to Russian culture.