• Composites Research
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• v.35 no.6
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• pp.371-377
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• 2022

Triboelectric nanogenerator (TENG) devices have generated a lot of interest in recent decades. TENG technology, which is one of the technologies for harvesting mechanical energy among the energy wasted in the environment, is obtained by the dual effect of electrostatic induction and triboelectric charging. Recently, a multilayer thin film stacking method (or layer-by-layer (LbL) self-assembly technique) is being considered as a method to improve the performance of TENG and apply it to new fields. This LbL assembly technology can not only improve the performance of TENG and successfully overcome the thickness problem in applications, but also present an inexpensive, environmentally friendly process and be used for large-scale and mass production. In this review, recent studies in the accomplishment of LbL-based materials for TENG devices are reviewed, and the potential for energy harvesting devices reviewed so far is checked. The advantages of the TENG device fabricated by applying the LbL technology are discussed, and finally, the direction and perspective of this fabrication technology for the implementation of various ultra-thin TENGs are briefly presented.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.4
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• pp.29-36
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• 2022

Existing IoT sensor nodes operate by receiving energy from a battery. But due to the characteristics of sensor nodes that are widely distributed for collecting various information, there is a disadvantage that the battery needs to be periodically replaced. In order to overcome this disadvantage, energy can be harvested from sunlight or high-temperature steam through an energy harvesting system. However, since the harvested power is quite limited, it is difficult to use applications that require instantaneous high power such as communication. We propose the design of the high-power energy harvesting system where a switch control unit compensates for the limited harvested energy with the energy storage device such as a capacitor. To verify the proposed system, an energy harvesting system based on sunlight was implemented, and we confirmed the maximum supply power to the application and the maximum supply time according to capacity of the energy storage device.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.497-498
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• 2017

최근 딸기는 고소득 부가가치 작물로 인식되기 시작하면서 수확작업에 노력이 적게 들고, 재배 및 작업 환경이 개선된 딸기 수경재배에 관심이 높아지고 있다. 현재 우리나라에서도 한국형 배양액 자동공급시스템을 개발하여 보급하기 시작하였지만 딸기 수경재배에서는 배양액의 EC와 pH관리 및 배양액의 급액에 따른 적절한 배액량 구명이 가장 시급하게 필요한 사항이다. 본 논문에서는 생육과 밀접한 관계가 있는 딸기 수경재배 생육 정보를 수집하는 장치를 개발하였고, 이 장치를 통해 딸기 수경재배 생육 데이터들을 수집하고 분석하여 딸기 수경재배 농가에 균일화 된 품질생산 및 수확량 증대에 기여할 수 있을 것으로 기대된다.

• Journal of Biosystems Engineering
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• v.22 no.2
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• pp.177-188
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• 1997

A pepper harvester using a pair of counter rotating helically wound cylinders as a pepper removal mechanism has been developed. Pepper harvesting by machines under the customary cultivation practice was expected to lower land productivity, that most farmers were concerned about. As one way to compensate for loss in land productivity by machine harvest, experts on pepper cultivation suggested change of both varieties and plant density per area. From the view of machine design, their suggestion implied that distance between rows should be narrower and height of the pepper removal mechanism could be shorter. Experiments to improve perfect pepper recovery ratio and to reduce size of the pepper removal mechanism was accomplished. In order to be a economically feasible harvester, minimum pepper recovery ratio was required to be greater or equal to 80%. The research goal was achieved by both reducing the diameter of the wire-helices from 30 cm to 18 cm and increasing rotational speed of the wire-helices up to 425 rpm. The best perfect pepper recovery ratio was 82.3%. Validity of experiment design and interpretation on statistical analysis were discussed. To understand the pepper removal mechanism properly, a pepper removal theory based physics was judged to be necessary.

• Journal of Food Hygiene and Safety
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• v.35 no.1
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• pp.60-67
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• 2020

This study determined the microbial contamination levels of hot pepper at harvest, sorting, and distribution stages to suggest a way of reducing the microbial contamination of hot peppers by changing work gloves used throughout these processes. According to the monitoring results, the contamination levels of total aerobic bacteria (TAB) were found in the following order: soil (5.3±0.9 log CFU/g), hot pepper (4.2±0.9 log CFU/g), gloves (4.2±0.6 log CFU/g), baskets (4.1±0.7 log CFU/ g), clippers (3.9±0.6 log CFU/ g) and water (3.2±1.1 log CFU/g) at harvest stage. The contamination level of coliforms were found in the following order: soil (2.2±0.9 log CFU/g), hot pepper (2.2±0.3 log CFU/g), gloves (2.1±0.6 log CFU/g), clippers (2.0±0.21 log CFU/ g) and baskets (1.9±1.1 log CFU/ g) at harvest stage. TAB on hot pepper at the harvest stage was reduced from 4.2±0.9 log CFU/g to cold storage 3.8±0.2 log CFU/g and room temperature storage 2.6±0.3 log CFU/g, respectively. By the replacement of work gloves and lower distribution temperature, TAB levels of the peppers were significantly reduced compared to those without replacement and distributed at room temperature. In addition, the utilization of plasma was effective on reducing microbial contamination of hot pepper. These results demonstrated that appropriate replacement of gloves at the harvest stages, using plasma in the distribution stage, and refrigerated distribution conditions, which are simple and easy to practice in the field, are effective to reduce microbial contamination on hot peppers.

• The KSFM Journal of Fluid Machinery
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• v.18 no.6
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• pp.27-30
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• 2015

In this study, we attempted to harvest energy using water droplet based on Reverse Electro Wetting On Dielectric (REWOD) phenomenon between water droplet and dielectric surface without external bias. REWOD device can be fabricated via simple coating process, which is highly economic and easy. We believe that our system is well-suited for IoT(Internet of Things) embedded electronics that require low but consistent electricity. Moreover, our device can be integrated with window to generate electricity upon raindrops.

• Smart Media Journal
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• v.6 no.4
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• pp.58-64
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• 2017

Modern society is characterized by rapid increase in world population, aging of the rural population, decrease of cultivation area due to industrialization. The food problem is becoming an important issue with the farmers and becomes rural. Recently, the researches about the field of the smart farm are actively carried out to increase the profit of the rural area. The existing smart farm researches mainly monitor the cultivation environment of the crops in the greenhouse, another way like in the case of poor quality t is being studied that the system to control cultivation environmental factors is automatically activated to keep the cultivation environment of crops in optimum conditions. The researches focus on the crops cultivated indoors, and there are not many studies applied to the cultivation environment of crops grown outside. In this paper, we propose a method to improve the harvestability of poor areas by monitoring the areas with bad harvests by using big data analysis, by precisely predicting the harvest timing of fruit trees growing in orchards. Factors besides for harvesting include fruit color information and fruit weight information We suggest that a harvest correlation factor data collected in real time. It is analyzed using the Apache Spark engine. The Apache Spark engine has excellent performance in real-time data analysis as well as high capacity batch data analysis. User device receiving service supports PC user and smartphone users. A sensing data receiving device purpose Arduino, because it requires only simple processing to receive a sensed data and transmit it to the server. It regulates a harvest time of fruit which produces a good quality fruit, it is needful to determine a poor harvest area or concentrate a bad area. In this paper, we also present an architectural model to determine the bad areas of fruit harvest using strong data analysis.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.02a
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• pp.440-445
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• 2003

식물의 공장적 생산에 있어서 재배적인 측면에서 중요한 요소 중의 하나는 환경조절과 양액제어 그리고 종자발아기술, 녹화기술일 것이다. 그 중에서도 종자를 파종한 후의 발아기간이 일정하지 않거나 조절이 어려우면 엽채류의 공장적 생산에서 중요한 매일 정식, 매일 수확이 어렵게 된다. 일반적으로 상추의 발아적온은 18-$25^{\circ}C$이다. 그러나 작물생육에 중점을 두어 환경을 조절하는 현재의 제어온실내에서는 발아적온을 맞추기가 어렵다. 따라서 별도의 발아장치가 필요하다. (중략)

• Proceedings of the Korean Society of Crop Science Conference
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• 2023.04a
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• pp.24-24
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• 2023

현대화된 재배법은 작물의 생육을 위해 시설내부의 환경을 제어하고 실시간 센싱 정보를 저장하는 시스템을 구축하고 이를 활용하고 있으나, 작물의 생육·생장에 미치는 직접적인 영향에 대한 생육데이터 취득은 아직까지도 전문 재배사·농민이 수작업을 통해 조사되고 있다. 본 연구는 작물의 생육데이터 자동 취득을 위한 장치를 개발하고 이를 실용화하기 위한 정확도 측정 시험을 진행하였다. 실험을 위한 장치구성은 3D Depth 카메라(Intel D415)와 운용 PC이며 딥러닝 모델을 이용하여 작물의 세부기관을 자동으로 인식하는 모델을 포함한다. 장치는 다양한 재배환경의 작물 생육데이터 취득을 위하여 휴대용, 고정형, 로봇형 3가지 유형으로 개발하였고 측정 정확도 검증은 휴대용 생육측정장치를 활용하여 조사하였다. 이러한 연구를 통해 수작업이 아닌 영상에 의한 생육 데이터수집으로 작물의 생육정보(측정값+이미지)를 확보함으로써 환경데이터와 함께 객관적인 정보에 의한 작물의 생산량, 수확시기 등을 예측하는데 활용될 수 있을것으로 예상된다.

• Journal of Digital Convergence
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• v.10 no.7
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• pp.267-272
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• 2012

Overcoming harsh light environment, as well as increased growth of crops even in high-quality production can play an important role when using the LED light system of photosynthetic products will be able to effectively reduce consumption. In this study, low efficiency of farm greenhouses, growing annual reduction in income due to rising operating costs and increase crop growth by inducing the proper planting environment Factory-type raise farmers' income and at the same time will contribute to the increase of Light device using LED Supplemental through photosynthesis, promote and improve product quality, plant growth regulators are considered possible for them to develop more efficient LED devices and LED Optical processing devices of Light leaf lettuce grown using normal fluorescent or incandescent bulbs grown in the results than the growth can see that the speed improvements. Usually shipped from seedling to harvest leaf lettuce from 25 to 30, whereas optical processing device be required red light (wavelength: 645nm) using a leaf of lettuce grown enough to be harvested after seven days increased the rate of growth. In addition, red light (wavelength: 645nm) and blue light (wavelength: 470nm) emitting at the same time, room, and grown for 5 days to harvest the growth rate was fast enough.