• 한국작물학회:학술대회논문집
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• 한국작물학회 2005년도 국제학술회의
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• pp.75-87
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• 2005

Remote sensing(RS)- and geographic information system(GIS)-based information management to measure and assess agri-environment schemes, and to quantify and map environment indicators for nature and land use, climate change, air, water and energy balance, waste and material flow is in high demand because it is very helpful in assisting decision making activities of farmers, government, researchers, and consumers. The versatility and ability of RS and GIS containing huge soil database to assess agricultural environment spatially and temporally at various spatial scales were investigated. Spectral and microwave observations were carried out to characterize crop variables and soil properties. Multiple sources RS data from ground sensors, airborne sensors, and also satellite sensors were collected and analyzed to extract features and land cover/use for soils, crops, and vegetation for support precision agriculture, soil/land suitability, soil property estimation, crop growth estimation, runoff potential estimation, irrigated and the estimation of flooded areas in paddy rice fields. RS and GIS play essential roles in a management and monitoring information system. Biosphere-atmosphere interection should also be further studied to improve synergistic modeling for environment and sustainability in agri-environment schemes.

• 한국지열·수열에너지학회논문집
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• 제7권2호
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• pp.51-59
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• 2011

Storage and transfer heat in soils are governed by the soil thermal properties and these properties are therefore needed in many engineering applications, including horizontal ground heat exchanger for ground-coupled heat pumps. This paper presents the measured results of the thermal diffusivity of soils(silica, quartzite, limestone, sandstone, and masonry soils) used for the trench backfilling materials of the horizontal ground heat exchanger. To assess this thermal property, we (i) measure the soil thermal conductivities and volumetric heat capacities using dual-probe method and (ii) compare the estimates from the de Vries method of summing the heat capacities of the soil constituents. The results show that the thermal diffusivity tends to increase as dry soil begins to wet, but it approaches a constant value or even decreases as the soil continues to wet. Measurements made by using the dual-probe method agreed well with independent estimates obtained using the single-probe method.

• 한국지반신소재학회논문집
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• 제22권4호
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• pp.83-92
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• 2023

In this study, we conducted verification of key influencing factors during cone penetration testing using the developed Mini Cone Penetration Tester (Mini-CPT), and compared the experimental results with empirical formulas to validate the equipment. The Mini-CPT was designed to measure cone penetration resistance through a Strain Gauge, and the resistance values were calibrated using a Load Cell. Moreover, the influencing factors were verified using a model ground constituted in a soil box. The primary influencing factors examined were the boundary effect of the soil box, the distance between cone penetration points, and the cone penetration speed. For the verification of these factors, the experiment was conducted with the model ground having a relative density of 63.76% in the soil box. It was observed that the sidewall effect was considerably significant, and the cone penetration resistance measured at subsequent penetration points was higher due to the influence between penetration points. However, within the speed range considered, the effect of penetration speed was almost negligible. The measured cone penetration resistance was compared with predicted values obtained from literature research, and the results were found to be similar. It is anticipated that using the developed Mini-CPT for constructing model grounds in the laboratory will lead to more accurate geotechnical property data.

• Geomechanics and Engineering
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• 제36권4호
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• pp.381-390
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• 2024

The introduction of bio-based materials has been recommended in the geotechnical engineering field to reduce environmental pollutants such as heavy metals and greenhouse gases. However, bio-treated soil methods face limitations in field application due to short research periods and insufficient verification of engineering performance, especially when compared to conventional materials like cement. Therefore, this study aimed to develop a machine learning model for predicting the unconfined compressive strength, a representative soil property, of biopolymer-based soil treatment (BPST). Four machine learning algorithms were compared to determine a suitable model, including linear regression (LR), support vector regression (SVR), random forest (RF), and neural network (NN). Except for LR, the SVR, RF, and NN algorithms exhibited high predictive performance with an R² value of 0.98 or higher. The permutation feature importance technique was used to identify the main factors affecting the strength enhancement of BPST. The results indicated that the unconfined compressive strength of BPST is affected by mean particle size, followed by biopolymer content and water content. With a reliable prediction model, the proposed model can present guidelines prior to laboratory testing and field application, thereby saving a significant amount of time and money.

• 한국토양비료학회지
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• 제8권3호
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• pp.113-119
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• 1975

Volcanic Ash Soils are widely distributed in Jeju island, and constitute the important upland soils which are either presently being cultivated or are suitable for reclaiming. The characteristics of Volcanic Ash Soils according to data made available by previous studies in Jeju and the outside of the country are as following: The most conspicuous mineralogical property is the presence of amorphous mineral colloids. The colloids have large and highly reactive surface to which the common physical and chemical properties are related. Soils are low in bulk density and higher both in porosity and permeability. Accumulation of humus in the upper part of soil is found in great quantity. Cation exchange capacity is high mainly due to high humus content, but the absorbing intensity of ammonium and potassium is weaker than that of crystalline clays. The phosphate absorption coefficient is extremely high and deficiency of minor element may occur both crops and animals. Soils are densely populated with actinomycetes and anaerobic bacteria. Nitrification and activity of urease are distinctly stronger than that of non-Volcanic Ash Soils.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
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• pp.32-37
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• 1998

In this paper, the role of intermediate cover soils with respect to the leachate and gas flow is investigated from various field investigations and the hydraulic conductivity of the disposed waste is obtained using pumping and slug tests. From the results of field investigations, it was found that the flow of leachate and gas is prevented by the buried cover soils. The hydraulic conductivities of field pumping test and slug tests are well matched and stayed in the range of hydraulic conductivities of well compacted wastes in the literature.

• 농촌계획
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• 제16권4호
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• pp.139-145
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• 2010

Agricultural information was discussed for suggesting tasks and solutions of knowledge based information system. States of agricultural information systems in rural development administration were described and problems and tasks were summarized in knowledge needs survey of farmers who have to decide many alternatives for farming. Hard to access information are soil state, disease and insect pest. Important information in agriculture are water, soil fertility, soil physical property, and accessibility from main road. In conclusion, knowledge based agricultural information system can be developed based on surveyed needs.

• 한국구조물진단유지관리공학회 논문집
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• 제20권5호
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• pp.85-92
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• 2016

본 연구에서는 경량기포 콘크리트를 이용한 육성용 토양골재의 적용성을 평가하기 위해서 고로슬래그 기반 기포콘크리트의 총 8배합과 인공토양골재를 제조하였다. 고로슬래그 기반 기포콘크리트 배합의 주요변수는 단위결합재량으로서 100에서 $800kg/m^3$으로 변화하였다. 경량기포콘크리트는 플로우, 슬러리 및 절건 밀도와 재령별 압축강도를 측정하였으며, 파쇄된 인공토양골재는 pH, 입도분포, 투수계수, 양이온치환용량(CEC), 유기물함유량(C/N비)을 측정하였다. 측정결과 경량기포콘크리트의 플로우, 슬러리 및 절건밀도와 재령별 압축강도는 단위결합재량이 증가함에 따라 증가하였다. 경량기포콘크리트의 단위결합재량이 $500kg/m^3$ 이상인 배합의 28일 압축강도는 4 MPa 이상이었다. 인공토양골재에 3일 이상의 15% 희석된 제1인산암모늄의 수용액침지는 pH를 저감시키는데 효과적이었다. 또한 제조된 인공토양골재는 양이온 치환용량(CEC) 측면에서 상급으로 평가되었지만 C/N비 측면에서는 조경시방서를 만족시키지 못하였다.

• 한국지반환경공학회 논문집
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• 제16권12호
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• pp.45-52
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• 2015

최근 산림 훼손지를 원래 상태로 되돌리기 위한 생태복원에 대한 관심이 높아지면서 인공 비탈면을 보강하면서 친환경적인 녹화가 될 수 있는 연구가 진행되고 있으며, 이러한 생태복원을 목표로 식생생육의 기반이 되는 인공토양의 조성과 관련된 많은 기술들이 개발되고 있는 추세이다. 본 연구에서는 하수오니, 톱밥, 제지슬러지, 화강풍화토가 포함되어 사용되고 있는 녹생토와 친환경적인 토양안정재를 활용하여 연구수행을 하였다. 토양안정재와 혼합된 녹생토를 이용해 기본물성실험을 통해 녹생토의 기본적인 특성을 분석하였으며, 친환경적인 토양안정재를 일정비율로 녹생토와 혼합하여 각각의 비율에 따른 전단강도실험을 수행하여 최대전단강도를 분석하고 이에 따른 점착력과 내부마찰각을 산정하였다. 그리고 녹생토와 토양안정재의 혼합비율을 전단강도실험과 동일한 조건으로 비탈면의 기울기를 적용하여 토양안정재의 혼합비율에 대한 침식률과 발아율을 분석하여 주변 환경적 요인에 대처 가능한 토양안정재의 경제적인 혼합비율을 고찰하고자 한다. 실험결과 양생기간과 안정재의 혼합률에 따라 최대 51%까지 전단강도가 증가하였으며, 실험결과를 바탕으로 내부마찰각과 점착력이 모두 상승한 점을 확인하여 안정재가 녹생토의 전단성능 과침식저항 향상에 기여하고 있음을 확인하였다.

• Parasites, Hosts and Diseases
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• 제51권4호
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• pp.489-492
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• 2013

A paleoparasitological survey to detect helminth eggs was performed in archaeological sites of Jeolla-do and Jeju-do, the Republic of Korea. Total 593 soil samples were collected in 12 sites of Jeolla-do and 5 sites of Jeju-do from April to November 2011, and examined by the methods of Pike and coworkers. A total of 4 helminth eggs, 2 eggs each for Trichuris trichiura and Ascaris sp., were found in soil samples from 1 site, in Hyangyang-ri, Jangheung-eup, Jangheung-gun, Jeollanam-do. The egg-recovery layer was presumed to represent a 19th century farm, which fact suggested the use of human manures. This is the third archaeological discovery of parasite eggs in Jeolla-do. Additionally, no helminth eggs in archaeological sites of Jeju-do is an interesting problem to be solved in the further investigations.