• 한국산림과학회지
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• 제112권4호
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• pp.490-501
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• 2023

본 연구에서는 강우의 침투과정 및 수분 재분포 현상을 분석하기 위하여 실내 컬럼실험을 수행하였으며, 토층 내 함수비를 효율적으로 측정하기 위하여 딥러닝 기법 중 하나인 합성곱신경망(Convolutional Neural Network, CNN)을 사용하여 함수비 예측 모델을 구축하였다. 컬럼실험으로부터 획득된 디지털 이미지를 구축된 CNN 모델에 적용한 결과 시간에 따른 토층별 함수비를 효과적으로 측정할 수 있었으며, 토층별로 설치된 함수비 센서에 따른 함수비와도 비교적 잘 일치하는 것으로 나타났다. 결과적으로 CNN을 활용하여 토층 내 연속적인 함수비 분포를 파악하는 것이 가능하였으며, 토성 및 지반 함수비 조건에 따른 침투 과정을 효과적으로 분석할 수 있었다.

• Geomechanics and Engineering
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• 제18권1호
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• pp.97-109
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• 2019

Physical conditions play vital role on the mechanical properties of frozen soil, especially for the temperature and moisture content of frozen soil. Subsequently, they influence the subsidence and stress law of permafrost layer. Taking Jiangcang No. 1 Coal Mine as engineering background, combined with laboratory experiment, field measurements and empirical formula to obtain the mechanical parameters of frozen soil, the thick plate mechanical model of permafrost was established to evaluate the safety of permafrost roof. At the same time, $FLAC^{3D}$ was used to study the influence of temperature and moisture content on the deformation and stress law of frozen soil layer. The results show that the failure tensile stress of frozen soil is larger than the maximum tensile stress of permafrost roof occurring in the process of mining. It indicates that the permafrost roof cannot collapse under the conditions of moisture content in the range from 20% to 27% as well as temperature in the range from $-35^{\circ}C$ to $-15^{\circ}C$. Moreover, the maximum subsidence of the upper and lower boundary of the overlying permafrost layer decreases with the increase of moisture content in the range of 15% to 27% or the decrease of temperature in the range of $-35^{\circ}C$ to $-15^{\circ}C$ if the temperature or moisture content keeps consistent with $-25^{\circ}C$ or 20%, respectively.

• 인간식물환경학회지
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• 제23권3호
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• pp.255-265
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• 2020

Background and objective: The purpose of this study was to provide guidelines for irrigation management by analyzing the effects of soil moisture on the growth characteristics of herbaceous plants in green infrastructure. Methods: In a rain shelter greenhouse, the growth performance of nine species of experimental plants was assessed under different soil moisture contents (20%, 15%, 10%, 5%, and 1%) for about 5 months to analyze plant growth characteristics due to soil humidity. Methods to determine plant growth conditions include surveying growth conditions of the crowns, stems, leaves, flowers and fruits on the aerial part and surveying growth conditions of the roots in the underground part. Results: The results showed that Mukdenia rossii and Astilbe rubra grew well at 15% moisture content with irrigation intervals of 10 and 13 days, respectively. Soil moisture content of 10% with irrigation intervals of 13 and 17 days was appropriate for Sedum kamtschaticum and Pachysandra terminalis. Similarly, Aquilegia japonica and Liriope platyphylla grew well at 15% moisture content with irrigation intervals of 10 and 17 days. However, Ligularia stenocephala grew well-developed stems and roots at 1% soil moisture content and an irrigation interval of 25 days, while the optimum conditions for Lythrum anceps were 5% moisture content and an irrigation interval of 8 days. Conclusion: Although a limited number of experimental plants were used in this study, this study could propose an appropriate irrigation cycle for planting on artificial soil substrates. Based on these results, it is possible to plan suitable planting designs considered irrigation cycles.

• Journal of Ginseng Research
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• 제6권2호
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• pp.168-203
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• 1982

Effects of soil moisture on growth of Panax ginseng, of various factors on soil moisture, and of moisture on nutrition, quality, physiological disorder, diseases and insect damage were reviewed. Optimum soil moisture was 32% of field capacity with sand during seed dehiscence, and 55-65% for plant growth in the fields. Optimum soil moisture content for growth was higher for aerial part than for root and higher for width than for length. Soil factors for high yield in ginseng fields appeared to be organic matter, silt, clay, agreggation, and porosity that contributed more to water holding capacity than rain fall did, and to drainage. Most practices for field preparation aimed to control soil moisture rather than nutrients and pathogens. Light intensity was a primary factor affecting soil moisture content through evaporation. Straw mulching was best for the increase of soil moisture especially in rear side of bed. Translocation to aerial part was inhibited by water stress in order of Mg, p, Ca, N an Mn while accelerated in order of Fe, Zn and K. Most physiological disorders(leaf yellowing, early leaf fall, papery leaf spot, root reddening, root scab, root cracking, root dormancy) and quality factors were mainly related to water stress. Most critical diseases were due to stress, excess and variation of soil water, and heavy rain fall. The role of water should be studied in multidiciplinary, especially in physiology and pathology.

• Geomechanics and Engineering
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• 제29권1호
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• pp.13-23
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• 2022

Peat soil has the characteristics of high moisture content, large void ratio and low shear strength. In this study, unconfined compressive strength and SEM tests are conducted to investigate the effects of ultrahigh moisture content, cement content, organic content and pH value on the strength of solidified peat. As an increase in the cement content and curing period, the failure mode of solidified peat soil changes from ductile failure to brittle failure. The influence of moisture content on the strength of solidified peat is greater than the cement content. As cement content increases from 10% to 30%, strength of solidified peat at a curing age of 28 days increases by 161%~485%. By increasing water content by 100%, decreases of solidified peat at a curing age of 28 days is 42%~79%. Compared with the strength of solidified peat with a pH value of 5.5, the strength of peat with a pH value of 3.5 reduces by 10% ~ 46%, while the strength of peat with a pH value of 7.0 increases by 8% ~ 38%. It is recommended to use filler materials for stabilizing peat soil with moisture content greater than 200%. Because of small size of clay particles, clay added in the cement solidified peat can improve much higher strength that that of sand.

• 한국농공학회지
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• 제26권3호
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• pp.81-89
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• 1984

To examine the moisture adsorption and permeability characteristics, weathered granite soils of different degrees of weathering, cultivated upland soils and sands of Han-river were sampled. The results are as follows: 1. In case that the mother rock was same, the pF values under same moisture content decreased according as the grain size of soil became finer by the weathering process. 2. In case that the mother rock was different, the pF value varied by the behavior of clay minerals, and the cultivated upland soils showed more sensitive reaction than sands and fresh granite soils. 3. The pF value changed by the difference of primary moisture content and also influenced by soil structure, testing method and etc. 4. The pF value and compaction curve had close relation, however under same moisture content, the pF value decreased by the increment of density. 5. The permeability depend on the available void ratio between the soil particles according to the degree of weathering, and the pF value of available void water between the soil particles which related directly to permeability was about 3.3 except the void water holded in the soil particles. 6. As the above, the pF value and permeability were differentiated by degree of weathering, primary moisture content, density and etc. Therefore it is considered unreasonable to define uniformly by soil texture.

• 한국농공학회지
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• 제18권4호
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• pp.4251-4258
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• 1976

In the construction of earth dam, embankment and highway by filling, a compaction contributes to increasing the density of soil by applying pressure. The effect of compaction depends on various factors such as soil type, moisture content, gradation, consistency, and compaction energy. In this study, the correlations amone maximum dry density, moisture content, dry density, and moisture content are analyzed. Some results obtained in this study are summarizep as follows. 1. The maximum dry density sinoreases with increased of optimum moisture content and the correlations of them can be represented by; ${\gamma}$dmx=a-b(W0) 2. Maximum dry density and liquid limit show negative linear correlation and can be represented by; ${\gamma}$dmx=a-b(LL). 3. Optimum moisture content and liquid limit, plastic limit show positive linear correlation and can be represented by the following equation, W0=a+b(LL) W0=a+b(PL). 4. Liquid limit and plastic limit show positive linear correlation, and can be represented by the following equation, LL=a+b(PL).

• 한국농공학회지
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• 제14권4호
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• pp.2761-2769
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• 1972

The following results were obtained by the compression test of 3, 7, 14 and 28 days cured lime soil mixtures. The soil used in this test was clayey soil(sand : 20% silt : 45%, clay : 35%) and the rates of hydrated lime mixture for the dry weight of soil were 4, 8, 12, 19 and 20 percents. 1. The optimum moisture content increases and the maximum dry density decreases with the increase of the lime content. 2. The compacted moisture for the maximum strength in lime soil mixture increases with the increase of the lime content and the increase of curing periods. 3. The compressive strength increase of curing periods and its increasing ratio is largest at the 8 percent lime content. 4. The line content for the maximum strength decreases with increase of curing period and the largest strength shows at the 8 percent lime content when the curing period is over two weeks. 5. It seems to depend on the temperature effect that the compressive strength of lime soil mixtures cured in soil shows the lowest value. Accordingly, the effect of curing moisture does not influence to the strength of lime soil mixtures as much as the variation of curing temperature.

• 한국농공학회지
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• 제20권4호
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• pp.4799-4804
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• 1978

In order to investigate the effect of delayed compaction on the strength of the lime soil mixtures, labroatory test with two kind of soils was performed at four levels of lime content, at five levels of water content, and at six love's of delayed times. The results are summarized as follows; 1. Maximum dry density and optimum moisture content decreased with increase of the delayed times. The decreasing rate of those values at the earlier delayed time were large, and those values showed almost constant after about four hours of delayed time. 2. According to the increase of the delayed time, the decreasing rate of maximum dry density and optimum moisture content was large ia S-2 sampl, but was a little in S-1 sample. 3. Unconfined compressive strength of lime soil mixtures decreased with the increase of the delayed time, and the decreasing rate of its strength increased with the increase of the lime content. 4. Water content corresponding to the maximum strength was a little higher than the optimum moisture content along the increase of lime content and delayed time but its value was large in fine soil.

• Journal of Biosystems Engineering
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• 제21권1호
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• pp.21-33
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• 1996

This study was to obtain basic information needed to develop the effective weed control method for the production of less polluted agricultural products by inducing viability loss of weed seeds in soil with infrared irradiation. Ceramic plates were heated by LPG with the aid of forced air and the infrared produced from plates was used as the heat source for heating soil. The soil heated in this study was sandy loam with four levels of moisture contents (0.5, 5.1, 9.1, 15.0% wb). The temperature distribution was measured at various soil depths when soil was irradiated with infrared for different irradiation time (30, 60, 90 sec). The soil depths with duration time of minimum 3 minutes over $80^circ C$, temperature inducing viability loss of weed seeds, were investigated. When the moisture content of soil was 0.5% and 5.1% wb, the soil depths which can induce viability loss of weed seeds was greatly increased with increasing irradiation time. When 30 seconds of irradiation time was applied on soil with moisture content of 9.1% or 15.0% wb, any depths of soil tested in this study was not reached to the temperature of 8$0^{\circ}C$. Generally, the soil depth being needed for viability loss of weed seeds was decreased with increasing moisture content of soil.