• International Journal of Computer Science & Network Security
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• 제24권4호
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• pp.197-205
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• 2024

This paper presents a fully automated stand-alone irrigation system with GSM (Global System for Mobile Communication) module. Solar energy is utilized to power the system and it is aimed to conserve water by reducing water losses. The system is based on a DC water pump that draws energy from solar panels along with automated water flow control using a moisture sensor. It is also fitted with alert and protection system that consists of an ultrasonic sensor and GSM messages sender that transmits signals showing the levels of the water in the reservoir and the battery charge. The control system is designed to stop the water pump from pumping water either when the battery level drops to equal or less than 10% of its full charge, or when the water level becomes less than 10 cm high in the reservoir. The experimental results revealed that the system is appropriate to use in remote areas with water scarcity and away from the national grid.

• 한국농공학회지
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• 제40권6호
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• pp.79-88
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• 1998

This study was conducted to measure the moisture content of soil using RF impedance in the range of 1 to 30MHz. Considering the water potential flow in the soils, two types of sensor such as parallel cylinder and perpendicular plate type were fabricated and tested. The capacitance and resistance of sonsors for soil samples having moisture content range of 2 to 27% were measured by Q-meter (HP4342). The higher soil moisture content was and the larger soil bulk density was, the more the capacitance of sensors increased. To eliminate the effect of bulk density on measuring soil moisture content using RF impedance, two kinds of model having the density independent functions such as the ratio of capacitance change to conductance change and weight of water and dry soils respectively were developed and estimated by regression analysis.

• Journal of Information Processing Systems
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• 제20권3호
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• pp.399-408
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• 2024

The moisture content of crude oil notably affects various aspects of oil production, storage, transportation, and exploration. However, accurately measuring this moisture content is challenging because of numerous influencing factors, leading to a lack of precision in existing detection methods. This inadequacy hinders the progress of China's petroleum industry. To overcome these challenges, this paper proposes a conductivity-based method for measuring crude oil moisture content. By employing an embedded system, we designed a sensor comprising five electrodes. Additionally, we developed signal excitation and signal processing circuits. Moreover, a software program was designed to analyze and compute the output signal using fast Fourier transform operations. This facilitated the identification of flow patterns, computation of relevant flow rates, and establishment of correlation rates based on frequency spectral characteristics. Based on experimental results, we established a functional relationship between measurement parameters and crude oil moisture content. This study enhanced the precision of moisture content measurement, thereby addressing existing limitations and fostering the advancement of China's petroleum industry.

• 한국지하수토양환경학회지:지하수토양환경
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• 제29권4호
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• pp.1-11
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• 2024

This study evaluated a method for prompt and periodic monitoring of moisture content in the waste layer of a landfill using a Time Domain Reflectometry (TDR) sensor, aimed at ensuring the stable operation of the bioreactor facility at the 2nd landfill of the SUDOKWON Landfill Site. It was found that the TDR sensor is sensitive to variables such as temperature changes and ion content in both the waste layer and leachate, indicating that a correction equation is necessary. A correction equation derived through regression analysis demonstrated a high correlation (correlation coefficient = 0.9647), and field verification experiments confirmed its reliability with an average deviation of only 1.5%. This verifies that the TDR sensor is effective for measuring and monitoring moisture content in landfills. It is also anticipated to be useful for various applications, including monitoring leachate levels, detecting leachate leakage, and assessing rainwater infiltration.

• 대한토목학회논문집
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• 제33권1호
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• pp.329-336
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• 2013

아스팔트 콘크리트 포장의 하부구조는 보조기층, 동상방지층 및 노상층으로 구성되어 있으며, 노상층의 경우 겨울철을 지나 봄이되면 동상효과에 따른 포장 파손과 여름철 장마 기간 동안의 수분 침투로 인한 지지력 감소와 같은 문제점이 발생할 수 있다. 따라서 도로하부의 함수비를 계측하기 위하여 시간이력 반사방식(Time Domain Reflectometry, TDR)의 함수센서를 통하여 실시간 함수비를 계측하는 기술이 국내에 도입되었다. TDR 방식의 함수센서는 흙과 물의 유전율을 통하여 함수비를 측정하기 때문에 온도의 영향을 받을 수 있다. 특히 국내는 계절 영향을 받아서 겨울철 대기 온도가 지역적으로 영하 $20^{\circ}C$ 보다 낮은 온도를 보여줄 수 있기 때문에 영하의 측정 온도 범위에 대한 함수센서의 정확도를 파악할 필요가 있다. 따라서 본 연구에서는 흙의 온도 범위를 영하 $2^{\circ}C$ 미만까지 확장하여 TDR 방식의 함수비 센서에 대한 온도 민감도 시험을 수행하였다. 체적함수비 20%와 30%에 대한 시험 결과 공시체 표면 온도가 영하로 떨어지면서 센서부근의 수분이 감소하고, 공시체 상부의 함수비가 증가하는 경향을 보여주었다. 그러나 함수센서에 대한 온도의 영향은 함수비가 낮을 경우 미소한 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제29권5호
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• pp.753-758
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• 2016

Moisture content influences physiological characteristics of microbes and physical structure of solid matrices during composting of animal manure. If moisture content is maintained at a proper level, aerobic microorganisms show more active oxygen consumption during composting due to increased microbial activity. In this study, optimum moisture levels for composting of two bedding materials (sawdust, rice hull) and two different mixtures of bedding and beef manure (BS, Beef cattle manure+sawdust; BR, Beef cattle manure+rice hull) were determined based on oxygen uptake rate measured by a pressure sensor method. A broad range of oxygen uptake rates (0.3 to 33.3 mg $O_2/g$ VS d) were monitored as a function of moisture level and composting feedstock type. The maximum oxygen consumption of each material was observed near the saturated condition, which ranged from 75% to 98% of water holding capacity. The optimum moisture content of BS and BR were 70% and 57% on a wet basis, respectively. Although BS's optimum moisture content was near saturated state, its free air space kept a favorable level (above 30%) for aerobic composting due to the sawdust's coarse particle size and bulking effect.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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• pp.178-187
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• 2000

The tillage operation by rotary implements is widely done in Korea. In the case of rotary implements, the tillage depth control system is one of important implement control systems. A contact type-sensor for measurement of the ground height was designed and fabricated to evaluate the possibility of application of the sensor on the tillage depth control system. Indoor experiments were conducted to obtain static and dynamic detection characteristics of the sensor under various conditions; 1) several moisture contents for four soil samples, 2) two soil surfaces with a designed configuration, 3) four heights of the sensor from the soil surface, 4) five traveling speeds of the carrier on which the sensor was attached, and so on. The experimental results showed the detection characteristics of the sensor sufficient as the ground height sensor of the tillage depth control system.

• 산업기술연구
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• 제33권A호
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• pp.67-72
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• 2013

CNT(carbon nanotube) humidity sensors with plasma treated electrodes exhibit a much faster response time and a higher sensitivity to humidity, compared to untreated CNT and porous Cr electrodes. These results may be partially due to their percolated pore structure being more accessible for water molecules and for expending the diffusion of moisture to the polyimide sensing film, and partially due to the oxygenated surface of CNT films. This paper shows a plasma process effect and selectivity characteristics of CNT film humidity sensor.

• 한국자원식물학회지
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• 제35권6호
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• pp.762-769
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• 2022

Growth characters and ingredient contents of two-year-old bellflower (Platycodon grandiflorum) roots were investigated under both control and soil moisture treatment condition using soil moisture control system including soil sensing and automatic water supply chain in this study. Root diameter, fine root number, root length, fresh weight and dry weight of the plant were significantly influenced by the automatic water treatment, 20%, 30%, 40% and 50%, respectively. Ingredient contents of the two-year-old roots in bellflower plants were detected in the 20% and 50% of controlled soil moisture content. Contents of amino acids were decreased by the soil moisture treatment, meanwhile, contents of minerals were not showed significant decrease except for phosphorus content. Showing no difference in proline and tyrosine, fourteen of the amino acid contents were gradually decreased by the increased soil moisture contents, with significant decrease in serine, glycine, alanine, leucine, lysine and histidine at 20% treatment.

• 한국농림기상학회지
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• 제24권1호
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• pp.13-34
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• 2022

기상청은 농작물의 생육 및 관개를 비롯한 여러 농경활동에 미치는 토양수분의 중요성을 인식하고, 전국 11개 농업기상 관측지점에서 관측을 수행하고 있다. 그러나 이 자료가 폭넓게 활용되지 못하고 있어 우선적으로 관측자료의 신뢰도를 확보할 필요가 있다. 이 연구에서는 현업 토양수분 자료의 정확도를 검증하고, 품질 향상을 위해 적용할 보정식을 개발하는데 목표를 두었다. 먼저 관측 노장의 토양을 채취하여 토양수분함량에 영향을 미치는 용적밀도, 용적수분함량, 토성 및 보수력 등의 물리적 성질을 분석하였다. 토성은 대부분의 관측지점에서 모래가 주성분인 사양토 또는 양질사토로 분류되었으며, 1.5 g/cm³ 내외의 용적밀도를 나타냈다. 미사와 점토 함량이 상대적으로 높았던 능주와 익산 지점은 용적밀도와 보수력도 다른 곳보다 더 높게 나타난 것으로 볼 때, 토성과 용적밀도, 보수력 사이에 밀접한 연관성이 있는 것으로 판단된다. 자체 설계·제작한 '레퍼런스 토양수분 관측시스템'에 이러한 관측지 토양의 특성을 반영하여 레퍼런스 센서로 사용할 EnviroSCAN 모델의 실험실 보정이 이루어졌다. 보정 작업은 load cell에서 측정한 무게 변화로부터 계산된 토양수분함량과 보정할 센서의 측정값을 비교하는 방식으로 진행되었으며, 제조사의 default 보정식에 대해 추가 보정의 필요성은 없는 것으로 결정되었다. 보정이 완료된 레퍼런스 센서와 현업 센서의 비교 관측 실험이 11개 각 지점에서 3회 이상 실시되었다. 전반적으로 레퍼런스 센서와 현업 센서의 측정값이 변화하는 패턴은 유사하게 나타났지만, 현업 센서가 레퍼런스 센서에 비해 상대적으로 토양수분을 과소평가하는 지점이 많았다. 두 센서 간의 편차는 장기간 건조 상태가 지속될 경우 일정한 추세를 유지하지만, 강수가 빈번한 시기에는 그 양상이 복잡해지는 특징이 있다. 비교 관측 실험의 결과를 바탕으로 각 기간별로 두 센서에 의해 관측된 자료의 범위와 평균을 이용하여 지점 및 깊이별 선형보정식을 개발하였다. 이 보정식을 수원 지점에 시범적으로 적용하여 뚜렷한 개선효과를 확인하였다. 또한 연속데이터에 보정식을 적용할 수 있도록 보정식이 산출되지 않은 기간의 구체적인 보정값 산정 방법도 제시하였다. 이 연구의 결과를 종합해 보면, 모든 관측지점에 대해 1년에 2회 정도의 주기적인 보정 작업이 토양수분 관측자료의 품질 향상을 위해 필수적인 것으로 판단된다.