• 한국지구물리탐사학회:학술대회논문집
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• 2009.10a
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• pp.136-138
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• 2009

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.12
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• pp.1218-1226
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• 2004

This paper presents thermal behaviors and performances of a fresh air load reduction system by using earth tube system combined with air-heated solar collector. The earth tube system reduces a fresh air load by heat exchange with soil throughout the year. In the previous experimental research, it was clarified that the earth tube system was very useful as a fresh air load reduction system. However, since outlet temperature of the fresh air which was heated by earth tube system was below 15$^{\circ}C$ in winter, it is not suitable to introduce the fresh air into the place of residence directly. Therefore, a simulation model using the simple heat diffusion equation was used to examine a rising effect of outlet air temperature in winter by combining with air-heated solar collector. An improvement of annual performance by control of operation is also quantitatively examined. In conclusion, it is confirmed that its performance is improved by control of operation throughout the year and outlet air temperature rose by combining with air-heated solar collector.

• Magazine of the Korean Society of Agricultural Engineers
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• v.6 no.2
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• pp.803-808
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• 1964

In this experiment, it was attempted to determine the thermal conductivities of earth block materials which are recently much available for farm building constructions in Korea as lower cost building materials. For this experiment, two kinds of earth block materials were sampled. One of them was pure earth and the other was cementstabilized earth with a ratio of earth to cement by volume, 20 to 1. Cylindrical sections of specimen surrounding a steel pipe(I.D. =1 inch) were used. A resistance neater in the pipe and thermometers for the measurement of radial temperature distribution were installed as shown in Fig. 1 and photograph 1. The heat which flows through the pipe and the sample was produced by passing a current through a resistance wire stretched along the pipe axis. The complete apparatus used in this experiment is schematically shown in Fig. 1.

• Korean Journal of Remote Sensing
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• v.34 no.2_1
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• pp.301-306
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• 2018

Urbanization causes urban floods and urban heat island in the summer, so it is necessary to understanding the changes of the thermal environment through urban climate and energy balance. This can be explained by the energy balance, but in urban areas, unlike the typical energy balance, the storage heat flux saved in the building or artificial land cover should be considered. Since the environment of each city is different, there is a difficulty in applying the method of retrieving the storage heat flux of the previous research. Especially, most of the previous studies are focused on the overseas cities, so it is necessary to study the storage heat retrieval suitable for various land cover and building characteristics of the urban areas in Korea. Therefore, the object of this study, it is to derive the regression formula which can quantitatively retrieve the storage heat using the data of the area where various surface types exist. To this end, nonlinear regression analysis was performed using net radiation and surface temperature data as independent variables and flux tower based storage heat estimates as dependent variables. The retrieved regression coefficients were applied to each independent variable to derive the storage heat retrieval regression formula. As a result of time series analysis with flux tower based storage heat estimates, it was well simulated high peak at day time and the value at night. Moreover storage heat retrieved in this study was possible continuous retrieval than flux tower based storage heat estimates. As a result of scatter plot analysis, accuracy of retrieved storage heat was found to be significant at $50.14Wm^{-2}$ and bias $-0.94Wm^{-2}$.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.6
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• pp.911-920
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• 2010

The basic principles in the "Spleen-stomach theory(脾胃論)" sets up the phases and roles of spleen-stomach (脾胃) by establishing Earth(地 坤 土) and exposing the reality of spleen-stomach(脾胃) of human body which has its own shape and form with Heaven's reality exhibited. The meaning of Earth is based on the constant meaning of Earth in 'Earth Original-Earth as extended and stable ground(坤元一正之土)' giving form and shape, and Earth's movement with circulation, then exposes itself as 'Earth as plowing land(耕種之土)' concerning both the application of Five Phases and the physical characteristics of Earth. The Yin-Yang recognition on Earth is revealed as Yin Earth(陰土)-Yang Earth(陽土). Spleen(脾) was established as Yin Earth(陰土) and Stomach(胃) as Yang Earth(陽土). The seasonal assignment of Earth is Indian Summer(長夏), which is divided from Summer, and becomes Heat(熱), and the Yin-Yang recognition of Earth comes to be the meaning of the center and border. According to the Five Phasic recognition, it becomes Earth(土) and gets to be Dampness(濕) in accordance with Six Qi(六氣). 'Extreme Yin(至陰)' indicates Qi's status exposing the fundamental meaning regarding the role of creating, changing, and propelling Spleen-Stomach(脾胃) as a characteristic Yin Earth. Earth comprehends 'Four Courses(四維)' meaning, recognizes them as four parts of the 12 Earth's Branches(辰戌丑未) and the terminals of four seasons(四季之末), and has the meaning of the president of the change in four seasons. The theory of principle in the "Spleen-stomach theory(脾胃論)" stands on the basis of the 'Form Qi theory(形氣論)' and that of 'Upbearing, Downbearing, Floating, and Sinking theory(升降浮沈論)'. It manifests the theory of movement in the interaction between Form(形) and Qi(氣), and 'Qi Interior Form Exterior(氣裏形表)' indicates that Qi(氣) moves interiorly and Form(形) exteriorly.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1997.12a
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• pp.227-232
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• 1997

• Journal of the Korean earth science society
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• v.25 no.2
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• pp.94-108
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• 2004

In order to clarify the efficiency of ground level change in Ice-valley on atmospheric circulation, numerical experiment was carried out. The circulations over the slope in North and South are different due to the topography and short wave radiation in Ice-valley. Therefore the circulations in both side are asymmetric and the asymmetric circulations are kept on at 1800 LST. A small difference of the atmospheric circulations formation is made due to the road construction at night. The reason may be the weakness of sensible heat flux from the road and other factors except that the sensible heat is not a principal factor in road construction. The construction of road is associated with growing of sensible heat from the road surface. For this reason, in case of daytime, ascending wind in north slope is more stronger with the road than that without road. The maximum wind speed becomes 4.67 m/s after road construction. And the position of the road is also an important factor in estimation of mesoscale circulation in mountainous area.

• Journal of the Korean Solar Energy Society
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• v.24 no.2
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• pp.63-71
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• 2004

Energy and environmental concerns accelerate the interest in passive solar heating in buildings, which utilizes solar energy through natural heat transfer. Moreover concerns about environmentally friendly materials were also increased. This study aims to evaluate the thermal performance of a Trombe wall built with earth. The thermal performance of the Trombe walls was analysed with results from computer simulations with TRNSYS 15. The thermal performance of the three types of Trombe wall was compared.: concrete. rammed earth. adobe. It was found that Trombe wall with the thermal storage wall of earth performed better than that of concrete. Rammed earth and adobe Trombe walls gained 4.7% and 12.8% more solar energy. respectively. than the concrete Trombe wall. In earth-applied Trombe walls. the energy gain by natural convection released from the airspace was about 75% of the total solar gains. that took 15% more than concrete Trombe wall. Rammed earth and adobe Trombe walls seem to be more suitable for buildings that use mostly in daytime. such as school, office and so on.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.356-361
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• 2005

Earth brush for electrical multiple units(EMUs) is a device through which the current of the EMU load's consumed power fed from the DC 1,500V overhead line (or from the AC 25.000V catenary) flows via axle to the rail(ground) and which prevents the electric corrosion of the axle bearings by preventing the current flow to the axle bearings caused by electric potential from the magnetic field when the bearings rotate together with the earthing function when a thunderbolt falls or a surge comes. The earth brush wear rates among cars, however, shows quite differences when the earth brushes after being separated from the holders are measured with vernier callipers every 6 months of maintenance period. Main causes of the earth brush wear are divided as mechanical, electric arc and electrical one, and the factors can be running speed, current, harmonics, connection state. spring tension, earth brush material, lubricant and so on. but only the earth brushes of the motor(M1) car show the highest wear rate and moreover maintenance difficulty occurs because of the wear rate differences among e earth brushes in one holder. The reason for these preponderant wear comes from the design concept of making preponderant current flow to some particular earth brushes and moreover the heat generated by the harmonics when the inverter starts to operate accelerate the wear. By defining these causes through experiments. I hope that the found results would be helpful for the future EMU design, safety, economy and maintenance.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.2
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• pp.85-90
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• 2018

For the recovering rare earths in the spent nickel-metal hydride batteries, 10 M NaOH is added to the solution leached with sulfuric acid. The rare earth powders were precipitated at rate of 98 % at the condition of pH 2.0 or less. The recovered rare earth complex precipitate increased the leaching rate to nitric acid by heat treatment at $800^{\circ}C$ for 4 hours. Subsequently secondary precipitation was performed by adding oxalic acid to the solution in which the rare earth complex precipitate was dissolved. The re-precipitated rare earth powders were converted into oxide form through heat treatment at $800^{\circ}C$ for 4 hours with purity of 99.5 %.