• Korean Journal of Agricultural Science
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• v.9 no.1
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• pp.357-370
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• 1982

Recent concern regarding price and availability of fossil fuels has spurred the interest in alternative sources for farm crop drying. Among the available options such as biomass energy, wind power, nuclear energy and solar energy etc., the increasing attention is being directed to the utilization of heat from solar energy especially for farm crop drying. Even though solar energy is dispersed over a large land area and only a relatively small amount of energy can be simply collected, the advantages of solar energy is that the energy is free, non-polluting. The study reported here was designed to help supply the informations for the development of simple and relatively inexpensive solar warehouse for farm crop drying and storage. Specifically, the objectives of this study were to determine the performance of the solar collector fabricated, to compare solar supplemented heat drying with natural air drying and to develop a simulation model of temperature in stored grain, which can be used to study the effects due to changes in ambient air temperature. For those above objectives, solar collector was fabricated from available materials. Corrugated steel galvanized sheet, painted flat black, was used as absorbers and clear 0.2mm polyethylene sheet was the cover material. The warehouse for rough rice drying and storage was constructed with concrete block, and the solar collector was used as the roof of warehouse instead of original roofing system of it. The results obtained in this study were as follows: 1. The thermal efficiency of the solar collector was average 26 percent and the overall heat transfer coefficient of the collector was approximately $25kJ/hr.m^2\;^{\circ}K$. 2. Solar heated air was sufficient to dry one cubic meter of rough rice from 23.5 to 15.0 percent in 7 days and natural air was able to dry the same amount of rough rice from 20.0 to 5 percent in l2 days. 3. Drying with solar heat reduced the required drying time to dry the same amount of rough rice into a half compared to natural air drying, but overdrying problems of the bottom layer were so severe that these problems should be thoroughly analyzed. 4. Simulation model of temperature in stored grain was developed and the results of predicted temperature agreed well with test results. 5. Based on those simulated temperature, changes in the grain-temperature were a large at the points of the wallside and the damage of the grain would be severe at the contact area of wall.

• Economic and Environmental Geology
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• v.37 no.5
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• pp.569-583
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• 2004

The rock properties of the West pagoda in the Gameunsaji temple site are composed mainly of dark grey porphyritic granodiorite with medium grained equigranular texture and developed with small numerous dioritic xenoliths. These xenoliths occurred with small holes due to different weathering processes. As a weathering results, the rock properties of this pagoda occur wholly softened to physical hardness because of a complex result of petrological, meteorological and biological causes. Southeastern part of the pagoda deteriorated seriously that the surface of rock blocks showed partially exfoliations, fractures, open cavities in course of granular decomposition of minerals, sea water spray and crystallization of salt from the eastern coast. The Joint between blocks has small or large fracture cross each other, contaminated and corrupted for inserting with concrete, cement mortar, rock fragments and iron plates, and partially accelerated coloration and fractures. There are serious contamination materials of algae, fungus, lichen and bryophytes on the margin and the surface on the roof stone of the pagoda, so it'll require conservation treatment biochemically for releasing vegetation inhabiting on the surface and the discontinuous plane of the blocks because of adding the weathering activity of stones and growing weeds naturally by soil processing on the fissure zone. Consisting rock for the conservation and restoration of the pagoda would be careful choice of new rock properties and epoxy to reinforce for the deterioration surfaces. For the attenuation of secondary contamination and surface humidity, the possible conservation treatments are needed.

• Korean Journal of Heritage: History & Science
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• v.48 no.1
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• pp.4-23
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• 2015

In the Buddhist paintings of the four devas, there is a change in the paper material of V aisravana(多聞天) in the early Joseon Dynasty. Until Goryeo Dynasty, Damuncheonwang, who holds a tower(塔) on the right side of Buddha was changed to the form which holds a mandolin(琵琶) in the early Joseon Dynasty. This change was first checked in Byeonsangdo in the Yuan period "The Avatamska Sutra(大方廣佛華嚴經, 1330~1336)", however the actual paper material change in the Buddhist painting is found first as a mural at the Tibetan temples, Cheolbangsa(哲蚌寺), Odunsa(吳屯寺), Baekgeosa(白居寺), which showed the change of tower which Vaisravaṇa held into mongoose. In Joseon Dynasty, also, new distribution of the four devas appeared first, which showed the change of paper material in the first floor roof-stones of Wongaksaji sipcheung seoktap, . However, the position of the four devas which held a tower and a mandolin consistently appear in the Buddhist paintings in the early Joseon Dynasty by mixing on the left and the right. This means the possibility that the paper material and the position of the four devas might be flexible in the early Joseon Dynasty. Just like reflecting this, painting image of the four devas in illustration of "saddharma-pundari-ka-$s{\bar{u}}tra$(Ming 1432, National Museum of Korea)" and illustration of "Jebulsejonyeorae-bosaljonjamyeongching-gagok(제불세존여래 보살존자명칭가곡, 1417)" has opposite position from each other. Therefore, the phenomenon in the Buddhist paintings of the early Joseon had a transitional characteristic which did not secure the fixed form of painting image by illustration of two copies where paper materials of the four devas were different, which characteristic can be said to be the characteristic of art in the transitional period.

• Korean Journal of Heritage: History & Science
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• v.53 no.4
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• pp.250-273
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• 2020

The three-story stone pagodas in Hyeon-ri and Hwacheon-ri,Yeongyang Gyeongsangbuk-do are stone pagodas that exhibit the typical style of Unified Silla. The two pagodas are believed to have been built in the mid- and late 9th centuries at the latest, considering the style of the three-story roof stone on top of the double-tier base. This is also confirmed by the reliefs carved at the base and the first-story of the pagoda. The Four Heavenly Kings and the Twelve Zodiacal Animal Deities were first combined in the late 8th century in the stone pagoda at the Wonwonsa Temple Site, and the Eight Classes of Divine Beings was also the most popular carved pagoda reliefs in the 9th century. However, the two Yeongyang stone pagodas are characterized by a combination of the Four Heavenly Kings (1st story), the Eight Classes (top base), and the Twelve Zodiacal Animals (lower base), and the stone used for the pagoda consists of sedimentary rocks of the sandstone family, which comprise most of the geological strata in the Yeongyang area, rather than ordinary granite. The new combinations of the three types of guardian deities and the Eight Classes changed from seated to standing poses is interpreted as an attempt to enhance the Buddhist faith and cultural status of the Yeongyang area, along with the fact that the stone pagoda was built using local natural materials. The Eight Classes of the Yeongyang stone pagoda does not follow the two types of arrangement of the pagodas with the Eight Classes, but some of the deities have been relocated to a new location. Composed of AsuraGandharva on the east side, Naga-Mahoraga on the south, Deva-Garuda on the west, and Kimnara-Yaksa on the north, this form can be classified as a unique 'third layout of the Eight Classes' in the Yeongyang area. Such changes in the shape and posture of the reliefs reflect a new perception of the pagodas. The reason why the Gandharva and Yaksa statues were carved on the east and north sides, respectively, was because they were deemed subordinate to the Four Heavenly Kings, and the fact that the Naga and the Mahoraga were carved on the south side was presumed to have influenced the geographical location of the two pagodas on the northern side of Banbyeoncheon Stream. The Hyeon-ri and Hwacheon-ri three-story stone pagodas inherited the tradition of typical Unified Silla-period pagodas, while also bearing their own new regional characteristics.

• Journal of Korean Society of Forest Science
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• v.76 no.2
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• pp.109-118
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• 1987

The purpose of this study was to investigate the inhabiting ecology of wild birds using artificial nests in Gyeongnam province. The sort of birds, the utilization of artificial nests by the materials, by the sites and by the forest type, and other inhabiting ecology of birds were investigated from 1984 to 1986. The results obtained were as follows; 1. Wild birds in surveyed areas were classified into 20 families and 35 species. Among them the birds inhabiting the artificial nests were 6 species and those using them most frequently were Parus ater (17.2%), P. major (16.7%) and P. palustris (12.2%). 2. The artificial nests installed on the top and at the toot of the mountain were chiefly utilized by P. ater and P. major, but the artificial nests in park area were mostly used by Passer montanus and Sturnus cineraceus. 3. Sixty-one percent of the artificial nests were utilized by the birds; 45.5% were used for breeding and 15.6% were inhabitation only. 4. When different nest materials and shapes were tested, mixed nests (sawdust and cement) were used most frequently, and C type. (Diamond shape) of wood nests was used more frequently compared with the A (Roof shape) and B (Box shape) types of wood nests. Meanwhile, the birds prefered the 3cm hole size (81.1% of utilization) to 4cm of hole (57.8%) and 5cm of hole (24.4%). 5. The artificial nests constructed in mixed forest were more frequently inhabited (73.3%) by the birds than coniferous forest (68.3%) and broad-leaved forest (63.3%). 6. The period of egg-laying in Parus species was from late April to early May, while Eophona migratoria, Lanius bucephalus, Motacilla alba and Passer montanus laid eggs generally in the middle of May. 7. Parus species, Passer montanus and Motacilla alba laid one egg every day for 5-10days, but Eopphona migratoria laied 4 eggs in 7 days and Lanius bucephalus laid 5 eggs in 4 days. The incubation period of Parus species was 16-18 days, while the others were about 11 to 14 days. 8. Thirteen days after the hatch of Parus major, chicks reached 13.9g of body weight, 72.0mm of wing-length and 20.9mm of tarsus length. P. montanus chicks reached 20.3g of weight, 66.2mm of wing-length and 20.2mm of tarsus length during the same period. 9. Food item of feeding chicks almost consisted of creatures (98.2%) with following composition; 55.2% of insect larvae, 37.2% adult insects, 2.8% of pupae and 2.8% of spiders. Vegetable items were 2% only. Among those creature food items, 95.2% were insect pests to forest.

• Journal of Bio-Environment Control
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• v.5 no.2
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• pp.215-235
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• 1996

The thermal analysis by mathematical model simulation makes it possible to reasonably predict heating and/or cooling requirements of certain greenhouses located under various geographical and climatic environment. It is another advantages of model simulation technique to be able to make it possible to select appropriate heating system, to set up energy utilization strategy, to schedule seasonal crop pattern, as well as to determine new greenhouse ranges. In this study, the control pattern for greenhouse microclimate is categorized as cooling and heating. Dynamic model was adopted to simulate heating requirements and/or energy conservation effectiveness such as energy saving by night-time thermal curtain, estimation of Heating Degree-Hours(HDH), long time prediction of greenhouse thermal behavior, etc. On the other hand, the cooling effects of ventilation, shading, and pad ||||&|||| fan system were partly analyzed by static model. By the experimental work with small size model greenhouse of 1.2m$\times$2.4m, it was found that cooling the greenhouse by spraying cold water directly on greenhouse cover surface or by recirculating cold water through heat exchangers would be effective in greenhouse summer cooling. The mathematical model developed for greenhouse model simulation is highly applicable because it can reflects various climatic factors like temperature, humidity, beam and diffuse solar radiation, wind velocity, etc. This model was closely verified by various weather data obtained through long period greenhouse experiment. Most of the materials relating with greenhouse heating or cooling components were obtained from model greenhouse simulated mathematically by using typical year(1987) data of Jinju Gyeongnam. But some of the materials relating with greenhouse cooling was obtained by performing model experiments which include analyzing cooling effect of water sprayed directly on greenhouse roof surface. The results are summarized as follows : 1. The heating requirements of model greenhouse were highly related with the minimum temperature set for given greenhouse. The setting temperature at night-time is much more influential on heating energy requirement than that at day-time. Therefore It is highly recommended that night- time setting temperature should be carefully determined and controlled. 2. The HDH data obtained by conventional method were estimated on the basis of considerably long term average weather temperature together with the standard base temperature(usually 18.3$^{\circ}C$). This kind of data can merely be used as a relative comparison criteria about heating load, but is not applicable in the calculation of greenhouse heating requirements because of the limited consideration of climatic factors and inappropriate base temperature. By comparing the HDM data with the results of simulation, it is found that the heating system design by HDH data will probably overshoot the actual heating requirement. 3. The energy saving effect of night-time thermal curtain as well as estimated heating requirement is found to be sensitively related with weather condition: Thermal curtain adopted for simulation showed high effectiveness in energy saving which amounts to more than 50% of annual heating requirement. 4. The ventilation performances doting warm seasons are mainly influenced by air exchange rate even though there are some variations depending on greenhouse structural difference, weather and cropping conditions. For air exchanges above 1 volume per minute, the reduction rate of temperature rise on both types of considered greenhouse becomes modest with the additional increase of ventilation capacity. Therefore the desirable ventilation capacity is assumed to be 1 air change per minute, which is the recommended ventilation rate in common greenhouse. 5. In glass covered greenhouse with full production, under clear weather of 50% RH, and continuous 1 air change per minute, the temperature drop in 50% shaded greenhouse and pad ＆ fan systemed greenhouse is 2.6$^{\circ}C$ and.6.1$^{\circ}C$ respectively. The temperature in control greenhouse under continuous air change at this time was 36.6$^{\circ}C$ which was 5.3$^{\circ}C$ above ambient temperature. As a result the greenhouse temperature can be maintained 3$^{\circ}C$ below ambient temperature. But when RH is 80%, it was impossible to drop greenhouse temperature below ambient temperature because possible temperature reduction by pad ||||&|||| fan system at this time is not more than 2.4$^{\circ}C$. 6. During 3 months of hot summer season if the greenhouse is assumed to be cooled only when greenhouse temperature rise above 27$^{\circ}C$, the relationship between RH of ambient air and greenhouse temperature drop($\Delta$T) was formulated as follows : $\Delta$T= -0.077RH＋7.7 7. Time dependent cooling effects performed by operation of each or combination of ventilation, 50% shading, pad ＆ fan of 80% efficiency, were continuously predicted for one typical summer day long. When the greenhouse was cooled only by 1 air change per minute, greenhouse air temperature was 5$^{\circ}C$ above outdoor temperature. Either method alone can not drop greenhouse air temperature below outdoor temperature even under the fully cropped situations. But when both systems were operated together, greenhouse air temperature can be controlled to about 2.0-2.3$^{\circ}C$ below ambient temperature. 8. When the cool water of 6.5-8.5$^{\circ}C$ was sprayed on greenhouse roof surface with the water flow rate of 1.3 liter/min per unit greenhouse floor area, greenhouse air temperature could be dropped down to 16.5-18.$0^{\circ}C$, whlch is about 1$0^{\circ}C$ below the ambient temperature of 26.5-28.$0^{\circ}C$ at that time. The most important thing in cooling greenhouse air effectively with water spray may be obtaining plenty of cool water source like ground water itself or cold water produced by heat-pump. Future work is focused on not only analyzing the feasibility of heat pump operation but also finding the relationships between greenhouse air temperature(T$_{g}$ ), spraying water temperature(T$_{w}$ ), water flow rate(Q), and ambient temperature(T$_{o}$).