• Journal of the Speleological Society of Korea
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• v.31 no.32
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• pp.82-89
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• 1992

지구상에 인류가 있은 후로부터 인류는 생존을 위하여 끊임없이 자연을 개조하고 이용하였으며 자연계에서 자원을 찾아 내여 자기의 새로운 생존조건을 창조하였다. 생산력이 발전됨에 따라 인류가 자연을 이용 개조하는 능력이 계속 높아짐으로써 자연환경의 원래의 면모도 개변되고 있다. 중국 현대 자연환경관에 대한 인류활동의 영향을 고찰하기 위해 우선 중국 현대경관의 형성부터 보기로 하자.(중략)

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.451-451
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• 2018

박층류 자연정화공법은 수로의 폭을 넓히고 수심을 낮추어 박층류를 조성하고, 이를 이용하여 하천을 정화하는 공법이다. 박층류가 조성되면 낮은 수심에서 상대적으로 느린 유속 조건이 형성되며 이 때 박층부에 침전된 오염물질은 자갈층 표면에 형성된 생물막에 의해 산화 분해되어 제거된다. 박층류에 의한 오염물질 제거는 생물막의 형성, 생물 산화를 위한 용존산소량 등이 중요한 인자로 작용하며, 박층부를 조성하기 위해서는 수심 10 cm, 유속 30~50 cm/s 의 조건이 적절하다. 본 연구에서는 박층류에 의한 자연정화 성능을 평가하기 위하여 용인시 오산천 일부 구간 고수부지에 사석자갈을 이용한 박층류 자연정화공법이 적용된 차집수로를 설치하고, 오산천으로 유입되는 농수로의 물을 공급하여 오염물질의 농도 변화를 측정하였다. 측정된 항목은 T-N, T-P, COD, DO 등이며, 측정 결과 박층류 자연정화 수로를 유출부에서의 오염물질의 농도가 유입부에서보다 저감되는 것을 확인 할 수 있었다.

• Electric Engineers Magazine
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• s.334
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• pp.30-35
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• 2010

본 고에서는 현장에 설치된 태양광발전시스템의 출력 측정 방법을 제시 하였다. 태양광발전시스템은 햇빛이라는 자연조건에 따라서 출력이 수시로 변동하기 때문에 태양전지 제조자가 제시하는 규격은 제작시에 태양전지를 표준 시험조건(즉, STC, Air Mass 1.5, 일사량 1000[$W/m^2$], 온도 $25^{\circ}C$기준)에서 시험한 성능 규격을 제시하고 있다. 그러나 적용현장에 설치된 태양전지는 인위적으로 표준 시험조건을 만들어 줄 수 없기 때문에 출력을 측정하면 제조자가 제시한 성능 규격이 제대로 나오는지 여부가 관심사다. 그렇기 때문에 설치현장에서 자연 조건에서 측정된 출력에다 태양전지 제작사에서 제시한 온도 및 일사량 특성곡선에서 추출된 보정계수를 적용하여 보정 출력을 산정해서 보정 출력을 토대로 제조사에서 제시한 규격에 부합하는 지 여부를 판단할 수 있는 방법을 제안하였다.

• Journal of Wetlands Research
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• v.11 no.1
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• pp.39-48
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• 2009

Wetland plants are an important component for wetland design and construction because they determine functions of wetlands through interactions with the abiotic environment such as wetland soil and hydrology as well as with other wetland organisms. In this study, germination experiments with soils from a natural wetland that contain seeds of wetland plants were conducted in wetland mesocosms to investigate the applicability of natural wetland soils for introducing and establishing wetland plants into constructed wetlands. Seven species were germinated in the experiment, with two new species that were not found in the field survey of wetland plants in the West Nakdong River area, Korea. The number of plant individuals germinated in submerged conditions (15 individuals) was much greater than that in waterlogged conditions (2 individuals). In experiments in which soils from a natural wetland and a wetland construction site were mixed at different ratios, the largest number of plant individuals was observed in the condition with 100% natural wetland soil. The highest growth was observed at 50% natural wetland soil for Hydrilla verticillata and 100% for Ceratophyllum demersum. These results suggest that 1:1 mixture of soils from natural wetland wetlands and wetland construction sites would provide an appropriate condition for secure establishment of submerged plants in constructed wetlands.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.6
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• pp.1330-1338
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• 1989

본 연구에서는 직각밀폐용기의 수평경계면이 단열인 경우뿐만 아니라 등온 조건을 갖는 경우에 대해 실험적으로 연구하여 경계조건의 변화가 직각밀폐용기내 흐름 및 열전달에 미치는 영향, 특히 등온조건을 갖는 경우 수직 온도차에 따르는 안정온도 구배효과로 예상되는 흐름의 억제, 지연효과를 작종 물리적 변수들의 영향과 함께 세밀히 조사하였다.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.2
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• pp.54-60
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• 2006

The purpose of this study was to examine the reaction in variable light environments on shade tolerant species, Chloranthus glaber. We raised Chloranthus glaber seedlings under four light conditions: PPFD 400, 250, $100\;{\mu}mol\;m^{-2}s^{-1}$ and full sunlight (PPFD $1600\;{\mu}mol\;m^{-2}s^{-1}$). Using 2 years old seedlings, chlorophyll content, photosynthetic rate, stomata conductance and intercellular $CO_2$ concentration were investigated. Shaded seedlings had higher chlorophyll content, photosynthetic rates, and stomatal conductance, but not higher intercellular $CO_2$ concentration than those in the full sun treatment. This result suggested that growth and physiology of Chloranthus glaber adapted to low light intensity.

• The Journal of Engineering Geology
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• v.17 no.3
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• pp.471-481
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• 2007

The Landslide in natural slope is occurred mostly by a heavy rain of the summer. This landslide is influenced in soil property of the surface than the rock mass. Soils in natural slope are created by weathering phenomena of the bedrock. These soils differed to the geological conditions such as sedimentary rock, metamorphic rock and volcanic rock. Therefore, estimation of landslide in natural slope is the most important analysis of the bedrock distributions and soil characteristics. This study analyzed the soil property to the natural slopes of Busan area where is distributed to volcanic rock, granite and sedimentary rock. Soil sample conducted various soil tests for estimate the soil physical property and soil engineering characteristics, and analysis of the correlation of geological conditions. In the experiment result, soils were mainly classified by a clayey sand. It is also established that $1.07{\sim}1.99kg/cm^3$ for wet density, $28.2{\sim}39.6^{\circ}$ for angle of shearing resistance, and $8.10{\times}10^{-5}{\sim}8.38{\times}10^{-2}cm/sec$ for coefficient of permeability. From the physical parameter, the soils are estimated to the permeable ground with good shear strength, and soil properties are showed a differential tendency for each geological condition.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.11a
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• pp.115-115
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• 2000

제지 공정의 효율적인 운영을 위해 공정변수를 확인하는 작업은 매우 중요하다. 탈수 특성 평가를 위하여 SR(Shopper- RegIer)과 CSF(Canadian Standard Freeness tester) 그리고 원형 수초지기 동의 비난류 상태의 자연탈수 특성 평가 장치와 동적 조건의 감압식 탈수성 분석기 퉁이 도입되어 있으나 제지 공정에 보다 더 근접한 탈수, 보류 특성을 평가 하기 위하여 특히 wet-end 첨가제들의 효능을 보다 정확히 분석할 수 있도록 난휴 발생과 감압 탈수 둥을 유도한 탈수 특성 평가 장치 개발의 필요성이 커지고 있다Il, 2) 이미 소개된 RDA-HSF

• Journal of the Korean association of regional geographers
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• v.9 no.2
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• pp.119-134
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• 2003

This paper analyzes Wu Ha-Youngs Cheonilrok in order to reconstruct the regional characteristics of farming in the late 18th-century Korean countryside. The projected objective is approached through the examination of various indices drawn from the volume such as environment, distribution of arable lands, major crops, agricultural techniques, and productivity. The main finding of this research is that unlike todays homogenous picture of agriculture, quite significant differences of agrarian practices existed across the country in the past. The regional differentiation was attributable foremost to natural environment. To elaborate, landform, climate and soil influenced the distribution and use of land plots, the kinds of main crops produced, and the agricultural productivity. The region-specific agricultural techniques result from the cumulative processes of trial and error against the given environment. Other social and economic conditions which include population, skill of the peasants, size of landownership, and irrigation facilities sustained the regional differentiation of agriculture.

• Explosives and Blasting
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• v.22 no.3
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• pp.1-12
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• 2004

In bench blasting, rock fragmentation is one of the most important factors determining productivity. Rock fragmentation could be affected by various conditions and these were hewn that rock joint conditions and in-situ block sizes were the biggest effect on it. This research is focused on what or how to influence on rock fragmentation according to relation between blasting conditions and the in-situ rock conditions such as rock joint conditions and in-situ block size. Field measurements were carried out in 3 open pit limestone mines, where in-situ rock conditions and blasting conditions were fully investigated. The results show that the parameters interact with blasting conditions complicatedly and especially in-situ block size has bigger effects. Dip direction of major joint set also can affect on fragmentation. Mean fragment size become smallest when dip direction of major joint set is about $30^{\circ}$ with the bench direction. The reason is considered to be come from difference of propagation paths of elastic wave.