• Journal of the Korean association of regional geographers
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• v.4 no.2
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• pp.165-182
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• 1998

When tour site is being used by people for the destination of tour, it has a life, or it will lose its life as a tour site. Therefore this paper aims to, based on Butler's theory, has chosen 46 hot spring spots in Korea which are legally assigned and presently running, and tried to analyze the life cycles, the stage of dispositional characteristics, and visitors' favoritism, and to try to find activating method which is not decline. Out of 46 spots, 29 Places were found on the stage of development, which took high percentage, 4 were on the growing stage, 5 were on the mature stage, 5 were on the stagnation or decline stage and the rest 3 were on the stage of rejuvenation. Geographically, Korean hot springs were located on the plain or mountainous areas mostly, and less of them were on hills and coast lines. In water quality, most of places had simple water while the places with salt and sulfur contained water were marked low rate. The temperatures of hot spring water were variable between $25^{\circ}C{\sim}78^{\circ}C$, but the older hot springs were hotter than new ones. After observing the relationship between disposition characteristics and life cycles, the geographical locations and the matter of approach were found as majour influential factors to the life cycles of them. The type of mountainous areas were observed slow progress in life cycle, due to traffic problem, until the road expansion or pavement work were done. Meanwhile, the suburban ones adjacent to big cities were favored by hot spring tourists due to their easy approach and easy traffic. The new born hot springs with such conditions have shown the fast growth. As studied above, since the hot springs were supposed to be for recuperation and vacational, a hot spring with better recreational and accommodational facilities was more favored by tourists than the one with pretty interior decorations. It was because the tour purpose of people has been switched from single purpose to multi one. Thus, the suggestion for activating a declining hot spring and bringing people in them is to develop new and attractive tour resources, expanding the related area, maintaining good quality of water, developing a complex site for long-term tour, developed traffic routs, hot spring festivals, utilizing adjacent tour resources, preparing public water supply system, and assigning as special tour zone.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.454-460
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• 2019

The purpose of this study is to analyze the distribution characteristics of mist spray particle size by devising a rotary mist spraying device to develop the evaporative salt water desalination system. The rotary mist spraying device was consisted of a BLDC sirocco fan, a spinning fan, a fan fixed shaft and a salt water supply device etc. In this study we analyzed the characteristics of spray particle size and distribution according to the variation of sirocco fan surface roughness(Ra, ${\mu}m$), revolutions(rpm) and salt water flow rate(mL/min). When sirocco fan surface roughness(Ra) was in the range of $0.27{\sim}7.65{\mu}m$, the spray particle size was $0.117{\sim}1.360{\mu}m$. And then more than 90% of spray particles were found to be less than $0.50{\mu}m$. When sirocco fan surface roughness(Ra) was in the range of $12.70{\sim}22.84{\mu}m$, the spray particle size was $2.51{\sim}184.79{\mu}m$ and more than 98% of spray particles were found to be less than $13.59{\mu}m$. To analyze the effect of fan rotation speed on the size and distribution of spray particles, when surface roughness Ra was fixed $0.27{\mu}m$ and fan rotation speed and salt water flow rate was respectively changed at 3,800~5,600 rpm and 2.77~8.28 mL/min, spray particle size was $0.314{\sim}0.541{\mu}m$. And when salt water flow rate was 9.74 mL/min and fan rotation speed was 3,800~5,200 rpm, spray particle size was in the range of $29.29{\sim}341.46{\mu}m$ and in case of 5,600 rpm more than 98.23% of spray particles were in the range of $2.51{\sim}13.59{\mu}m$.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.118-118
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• 2017

지구 온난화에 따른 환경변화로 인하여 최근 10년('02~'11)간 여름의 일수는 4일, 겨울 일수는 16일 각각 증가하였다. 현재 육계사 내의 고밀도 밀집사육으로 인하여 고온스트레스로 하절기 육계의 폐사율이 증가하고 있는 실정이다. 2016년 폭염으로 닭 406.1천수, 오리 15.7천수, 메추리 70천수, 돼지 8천수가 폐사하였다. 이에 혹서기 가축이 약430만수가 폐사하였으며 피해 보상금액 128억원 소요되었다. 본 연구에서는 하절기 고온스트레스 경감과 폐사율 저감을 위해 계사 냉난방 공조와 냉온 음용수 급수를 병행할 수 있는 고효율 환경 개선 시스템을 개발하여 고온스트레스 저감 및 생산성 향상에 목적이 있다. 계사 냉난방 공조 및 냉온음용수 급수 병행 시스템 설계요인을 분석하고 냉난방 공조부하, 냉온수 생산 부하를 고려한 시스템 용량 산정하고 히트펌프, 축열조, 냉난방 및 냉온수 분배장치 등 구성요소로서 공조 및 냉온음용수 급수시스템을 설치하였다. 시스템 용량은 공기-물 히트펌프(10kW,1대), 축열조(10톤), 음용수조(2톤), 열교환기(열교환량,5만kcal/h), 물순환펌프(250W,2대) 및 팬코일유닛(1만kcal/h,4대)으로 시스템 모니터링 및 제어 시스템 개발하여 계사 내 환경, 시스템 성능에 대한 실시간 모니터링을 통하여 저장하였다. 조사항목으로 위치별 온습도, 체중, 사료섭취량, 페사율 등을 조사 분석하였다. 연구결과 계사의 내부온도는 시험구에서는 평균 $25.3^{\circ}C$를 나타내었고 대조구에서는 평균 $28.1^{\circ}C$로서 $2.8^{\circ}C$ 높게 나타났으나 상대습도는 시험구 76.2%, 대조구 75.0%로 큰 차이가 없었다. 냉수급여에 따른 계사 높이별 내부온도는 상하의 온도차가 $4.5^{\circ}C$로 크게 차이가 났다. 육계의 음수량은 혹서기 냉수를 급여한 시험구에서 일일 23.2L, 대조구에서는 21.5L를 섭취하였다. 일일 사료섭취량은 냉수를 급여한 시험구에서 937g, 대조구에서는 725g을 섭취하였다. 사료섭취량은 냉수를 급여한 시험구가 212g 많이 섭취하였으며 사료요구율은 시험구는 1.86, 대조구는 1.91로서 시험구가 낮게 나타났다. 체중은 냉수를 급여한 시험구가 359g 많았으며 증체량은 냉수를 급여한 시험구에서 495g, 대조구에서는 392g으로 나타났다. 폐사율은 냉수를 급여한 시험구에서 84%가 폐사율을 줄일 수 있었다.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.135-135
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• 2015

Tubes are of extreme importance in industries as for fluid channels or wave guides. Furthermore, some weapon systems such as cannons use the tubes as gun barrels. To increase the service life of such tubes, a protective coating must be applied to the tubes' inner surface. However, the coating methods applicable to the inner surface of the tubes are very limited due to the geometrical restriction. A small-diameter cylindrical magnetron sputtering gun can be used to deposit coating layers on the inner surface of the large-bore tubes. However, for small-bore tubes with the inner diameter of one inch (~25 mm), the magnetron sputtering method can hardly be accommodated due to the space limitation for permanent magnet assembly. In this study, a new approach to coat the inner surface of small-bore tubes with the inside diameter of one inch was developed. Instead of using permanent magnets for magnetron operation, an external electro-magnet assembly was adopted around the tube to confine the plasma and to sustain the discharge. The electro-magnet was operated in pulse mode to provide the strong axial magnetic field for the magnetron operation, which was synchronized with the negative high-voltage pulse applied to the water-cooled coaxial sputtering target installed inside the tube. By moving the electro-magnet assembly along the tube's axial direction, the inner surface of the tube could be uniformly coated. The inner-surface coating system in this study used the tube itself as the vacuum chamber. The SS-304 tube's inner diameter was 22 mm and the length was ~1 m. A water-cooled Cu tube (sputtering target) of the outer diameter of 12 mm was installed inside of the SS tube (substrate) at the axial position. The 50 mm-long electro-magnet assembly was fed by a current pulse of 250 A at the frequency and pulse width of 100 Hz and 100 usec, respectively. The calculated axial magnetic field strength at the center was ~0.6 Tesla. The central Cu tube was synchronously driven by a HiPIMS power supply at the same frequency of 100 Hz as the electro-magnet and the applied pulse voltage was -1200 V with a pulse width of 500 usec. At 150 mTorr of Ar pressure, the Cu deposition rate of ~10 nm/min could be obtained. In this talk, a new method to sputter coat the inner surface of small-bore tubes would be presented and discussed, which might have broad industrial and military application areas.

• Journal of Bio-Environment Control
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• v.21 no.1
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• pp.57-65
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• 2012

Fertilization is essential to seedling production in nursery culture, but excessive fertilization can contaminate surface and ground water around the nursery. The objective of this study was to find optimal fertilization practice of container seedling production for reducing soil and water contamination around the nursery without compromising seedling quality. This study was conducted to investigate chemical properties of the growth medium, growth performance, chlorophyll fluorescence, and chlorophyll contents of larch ($Larix$ $kaempferi$) growing under three different fertilization treatments (Constant rate, Three stage rate, and Exponential rate fertilization). Root collar diameter and height of larch were not significantly different among treatments even though the nutrient supply of the exponential treatment was half that of the constant and three stage treatments. Chemical properties of the growth medium showed the same trends as root collar diameter and height. The total biomass and seedling quality index (SQI) were higher at Constant than at other treatments, but both SQI of Constant and Exponential were not significantly different. Photochemical efficiency and chlorophyll contents were lower at Exponential than at other treatments, but not significantly different among treatments. Therefore, Exponential fertilization which is 50% fertilizer of other treatments would maximize seedling growth and minimize nutrient loss.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.3
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• pp.295-306
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• 2003

Recently efforts are underway to analyze the impacts of anthropogenic $CO_2$ on the global environments and the amount of oceanic uptake increase. The East Sea is now viewed as a miniature ocean because its circulation pattern is similar to the ocean conveyer belt. The biological pump of the East Sea is a vital component to understand the carbon cycle quantitatively. In this paper, the biological pump is estimated utilizing the stoichiometric ratio between carbon and phosphorus. A simple phosphate budget model is constructed based on the seawater and dissolved oxygen box model that can simulate the recent structural change in deep water circulation of the East Sea. A model run from you 1952 to 2040 shows the steadily intensifying biological pump. Currently it exports about 0.016 Pg C yr$^{-1}$ , which corresponds to 35％ of the carbon introduced into the seawater by the air-sea exchange. An increased oxygen supply to the central water mass as a result of from the transition in the ventilation system might enhance the remineralization of sinking biogenic particles. This should strengthen the upward nutrient flux into the surface layer. Consequently, the biological sequestration of anthropogenic carbon is expected to increase with time. The estimated biological uptake of the anthropogenic carbon in the East Sea since the Industrial Revolution is estimated as 0.025 Pg C.

• Analytical Science and Technology
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• v.23 no.1
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• pp.45-53
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• 2010

For the determination of chlorine in uranium compound, analytical methods by using a steam distillation and a pyrohydrolysis have been developed. The steam distillation apparatus was composed of steam generator, distilling flask and condenser etc. The samples were prepared with an aliquot of LiCl standard solution and a simulated spent nuclear fuel. A sample aliquot was mixed with a solution containing 0.2 M ferrous ammonium sulfate-0.5 M sulfamic acid 3 mL, phosphoric acid 6 mL and sulfuric acid 15 mL. The chloride was then distilled by steam at the temperature of $140^{\circ}C$ until a volume of $90{\pm}5\;mL$ is collected. The pyrohydrolysis equipment was composed of air introduction system, water supply, quartz reaction tube, combustion tube furnace, combustion boat and absorption vessel. The chloride was separated from powdered sample which is added with $U_3O_8$ accelerator, by pyrohydrolysis at the temperature of $950^{\circ}C$ for 1 hour in a quartz tube with a stream of air of 1 mL/min supplied from the water reservoir at $80^{\circ}C$. The chlorides collected in each absorption solution by two methods was diluted to 100 mL and measured with ion chromatography to determine the recovery yield. For the ion chromatographic determination of chlorine in molten salt retained in a metal ingot, the chlorine was separated by means of pyrohydrolysis after air and dry oxidation, and grinding for the sample.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.1
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• pp.56-68
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• 2005

We measured nitrate and other nutrients in sediment pore waters retrieved from three sites at the southern upper-tidal flats of the Ganghwa Island. Denitrification rate is estimated by applying a simple 1-D model to the nitrate profiles. Results from Jangwha and Dongmak sites are $7.8{\sim}9.4{\times}10^{-7}{\mu}mol{\cdot}cm^{-2}{\cdot}sec^{-1}$, and $1.4{\sim}3.6{\times}10^{-7}{\mu}mol{\cdot}cm^{-2}{\cdot}sec^{-1}$, respectively. Rates are comparable to those reported around the world in an order of magnitude. Denitrification was lower in summer. The rates were about 1.5 times higher at site where the surface sediments consist of relatively coarser particles. This implies that particle size would control the reactant supply to the subsurface sediment. One may claim the denitrification as an evidence of the biogeochemical purification function of tidal flat. However, the purification seems not a general attribute of a tidal flat when whole system is scrutinized by a thermodynamic criterion. Currently the term 'tidal flat' is used when describing the diverse coastal wetlands such as salt marshes, sandy tidal flats and muddy tidal flats, which exhibit quite different ecological functions. Thus it is worthy of mentioning that the classification of coastal wetlands on the basis of sedimentological characteristics and biogeochemical functions should facilitate our understanding.

• The Korean Journal of Community Living Science
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• v.25 no.1
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• pp.99-111
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• 2014

To verify welfare needs, rural health and environmental factors were compared between agricultural and nonagricultural groups over the past 10 years. Based on a survey of rural life by the Rural Development Administration, whose sample included agricultural (72.8%) and nonagricultural (27.2%) groups, all factors were analyzed using SAS ( 9.3). For rural home heating, the use of oil boilers (77.2%-78.0%) decreased (53.0%-53.7%) over the same period, whereas that of electric boilers increased (21.9% and 13.5% for agricultural and nonagricultural groups, respectively). The joint water- supply increased, and the use of flush toilets (52.4% to 84.5% in the agricultural group and 64.6% to 81.4% in the nonagricultural group) and hot-water bathing was higher in the agricultural group (79% to 92.6%) than in the nonagricultural group (72.2% to 87.6%) at the p<0.001 level. Incineration accounted for the largest portion of household waste until 2006, when it was replaced by other treatment methods such as the pay-per-treatment option (44.4% and 68.3% in the agricultural and nonagricultural groups, respectively) (p<0.001). Garbage disposal in 2001 was mainly burial or animal feed, but separate collection increased in 2010 (42.2% and 64.3% in the agricultural and nonagricultural groups, respectively) (p<0.001). The self-perception of health was lower in the agricultural group than in the nonagricultural group (2.96 to 2.74 on a five-point scale in the agricultural group and 3.07 to 2.98 in the nonagricultural group). Drinking decreased less in the agricultural group (criteria: one point once a week,; 1.48 to 1.20) than in the nonagricultural group (1.13 to 0.80) at p<0.001, and a similar pattern was found for smoking (p<0.001). Health screening decreased in the last 10 years (scoring based one point/1-2 times per year,: 0.94 to 0.64 in the agricultural group and 1.08 to 0.69 in the nonagricultural group;p<0.01). These results indicate that various health and environmental factors were less favorable to farmers except for bathing in comparison to nonagricultural living in the same area. This suggests that people in agriculture are less likely to live and work in favorable environments than those outside the sector and thus indicates a need for more attention to the national health welfare system for farmers for systematic realization.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.5B
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• pp.437-444
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• 2010

Soil moisture has been recognized as the essential parameter when understanding the complicated relationship between land surface and atmosphere in water and energy recycling system. It has been generally known that it is related with the temperature, wind, evaporation dependent on soil properties, transpiration due to vegetations and other constituents. There is, however, little research concerned about the relationship between soil moisture and these constitutes, thus it is needed to investigate it in detail. We estimated the soil moisture and then compared with field data using the hydrometerological data such as atmospheric temperature, specific humidity, and wind obtained from the Flux tower in Selmacheon, Korea. In the winter season, subterranean temperature showed highly positive correlation with soil moisture while it was negatively correlated from the spring to the fall. Estimation of seasonal soil moisture was compared with field measurements with the correlation of determination, R=0.82, 0.81, 0.82, and 0.96 for spring, summer, fall, and winter, respectively. Comprehensive relationship from this study can supply useful information about the downscaling of soil moisture with relatively large spatial resolutions, and will help to deepen the understanding of the water and energy recycling on the earth's surface.