• 한국통신학회논문지
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• 제42권1호
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• pp.149-152
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• 2017

본 논문에서는 에너지 하베스팅 (Energy Harvesting) 기술을 적용한 BLE (Bluetooth Low Energy) 비콘에서 전력 관리를 위한 PMIC (Power Management IC)의 출력 전압을 일정하게 유지하기 위한 방안을 연구하였다. 에너지 하베스팅 장치에서 제공되는 에너지를 확보하고 저장하기 위한 축전 장치로 캐패시터를 사용하였고, 주어진 Advertising Interval에서 BLE 모듈에 일정한 전압을 제공하기 위한 최적의 캐패시턴스를 분석하였다.

• 대한안전경영과학회지
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• 제16권2호
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• pp.111-119
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• 2014

This paper describes the design and implementation of a electromagnetic energy harvesting mechanism and electronic circuit for autonomous emergency call system. This analysis results show the power output of the proposed harvesting mechanism and circuit up to max power output 5V and it can hold up to 65 msec of the power generation and 10msec of the RF transmission. Based on the these testing results, the implementation of autonomous emergency call device without battery power or any external power source is feasible.

• 한국가시화정보학회지
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• 제19권3호
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• pp.31-38
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• 2021

The energy harvesting system using an inverted flag is analyzed by using an immersed boundary method to consider the fluid and solid interaction. The inverted flag flutters at a lower critical velocity than a conventional flag. A fluttering motion is classified into straight, symmetric, asymmetric, biased, and over flapping modes. The optimal energy harvesting efficiency is observed at the biased flapping mode. Using the three different machine learning algorithms, i.e., artificial neural network, random forest, support vector regression, the energy harvesting efficiency is predicted by taking bending rigidity, inclination angle, and flapping frequency as input variables. The R² value of the artificial neural network and random forest algorithms is observed to be more than 0.9.

• ETRI Journal
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• 제44권5호
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• pp.759-768
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• 2022

A novel energy harvesting technique that uses conducted electromagnetic interference as an energy source is presented. Conducted EMI generated from fluorescent light using a switched-mode power supply was measured and modeled as an equivalent voltage source. Two types of rectifier circuits-a bridge rectifier and a voltage doubler-were used as the harvesting devices for conducted EMI source. The matching networks were designed based on the equivalent model, and the harvested power was improved. The implemented energy harvester produces a regulated power over 68.9 mW and current over 15.1 mA while a regulated voltage can be selected between 3.3 V and 5 V. The proposed system shows the highest harvesting power indoor environment and can provide enough power for the Internet of Things devices.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제14권3호
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• pp.163-173
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• 2010

In this work, we consider a nonlinear budworm model by a system of three ordinary differential equations originally created by Ludwig et al. in 1978. The nonlinear system describes the dynamics of the interaction between a budworm and a fir forest. We introduce stability techniques to analyze the dynamical behavior of this nonlinear system. Then we use constant effort harvesting techniques to control the budworm population. We also give numerical simulations of the population model with harvest and without harvest.

• Journal of Information Processing Systems
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• 제16권3호
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• pp.629-638
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• 2020

In this paper, an unmanned automation system for harvesting chili peppers through image recognition in the color space is proposed. We developed a cutting-edge technology in terms of convergence between information and communication technology (ICT) and agriculture. Agriculture requires a lot of manpower and entails hard work by the laborers. In this study, we developed an autonomous application that can obtain the head coordinates of a chili pepper using image recognition based on the OpenCV library. As an alternative solution to labor shortages in rural areas, a robot-based chili pepper harvester is proposed as a convergence technology between ICT and agriculture requiring hard labor. Although agriculture is currently a very important industry for human workers, in the future, we expect robots to have the capability of harvesting chili peppers autonomously.

• Journal of Biosystems Engineering
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• 제39권2호
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• pp.134-141
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• 2014

Purposes: This study was to validate the Robotic Smart Work System that can provides better working conditions and high productivity in unstructured environments like bio-industry, based on a tele-operation system for fruit harvesting with low cost 3-D positioning system on the laboratory level. Methods: For the Robotic Smart Work System for fruit harvesting and cultivation management in agriculture, a vision based tele-operating system and 3-D position information are key elements. This study proposed Robotic Smart Farming, an agricultural version of Robotic Smart Work System, and validated a 3-D position information system with a low cost omni camera and a laser marker system in the lab environment in order to get a vision based tele-operating system and 3-D position information. Results: The tasks like harvesting of the fixed target and cultivation management were accomplished even if there was a short time delay (30 ms ~ 100 ms). Although automatic conveyor works requiring accurate timing and positioning yield high productivity, the tele-operation with user's intuition will be more efficient in unstructured environments which require target selection and judgment. Conclusions: This system increased work efficiency and stability by considering ancillary intelligence as well as user's experience and knowhow. In addition, senior and female workers will operate the system easily because it can reduce labor and minimized user fatigue.

• 항공우주시스템공학회지
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• 제16권1호
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• pp.49-55
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• 2022

최근 드론의 역할은 농업∙건설∙물류등의 다양한 영역으로 확대되고 있으며 특히 농업인구가 고령화되는 현 상황에 따라 드론은 노동력 부족 문제를 해결할 효과적인 대안으로 떠오르고 있다. 이에 본 논문에서는 농업 현장에서의 부족한 노동력을 보완하고 높은 위치의 과일도 안전하게 수확할 수 있는 드론 탑재형 과일수확 시스템을 제안한다. 과일수확 시스템은 과일인식 알고리즘과 과일수확 메커니즘으로 구성되어 있다. 과일인식 알고리즘은 딥러닝 기반의 객체탐지 알고리즘인 You Only Look Once를 사용하였고, 가상 시뮬레이션 환경을 구축하여 가능성을 검증하였다. 또한, 하나의 모터로 구동이 가능한 과일수확 메커니즘을 제안하였다. 모터의 회전운동을 기반으로 Scotch yoke을 구동시켜 선형운동으로 변환하여 gripper가 전개된 상태에서 과실에 접근 후 과실을 잡고 돌려 수확하는 메커니즘이다. 제안된 메커니즘에 대한 다물체동역학 해석을 수행하여 구동 가능성을 검증하였다.

• Journal of Biosystems Engineering
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• 제37권1호
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• pp.65-74
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• 2012

Purpose: An autonomous robot was developed for harvesting strawberries cultivated in bench-type systems. Methods: The harvest robot consisted of four main components: an autonomous vehicle, a manipulator with four degrees of freedom (DOF), an end effector with two DOFs, and a color computer vision system. Strawberry detection was performed based on 3D image and distance information obtained from a stereo CCD color camera and a laser device, respectively. Results: In this work, a Cartesian type manipulator system was designed, including an intermediate revolute axis and a double driven arm-based joint axis, so that it could generate collision-free motions during harvesting. A DC servomotor-driven end-effector, consisting of a gripper and a cutter, was designed for gripping and cutting the strawberry stem without damaging the strawberry itself. Real-time position tracking algorithms were developed to detect, recognize, trace, and approach strawberries under natural light conditions. Conclusion: The developed robot system could harvest a strawberry within 7 seconds without damage.

• Environmental Engineering Research
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• 제18권2호
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• pp.109-114
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• 2013

In Cukhe, a village located in the outskirts of Hanoi, Vietnam, people suffer from a shortage of high-quality water due to an arsenic contaminated supply water resource. We installed catchments, filters and settled tanks in the existing rainwater harvesting facility to improve water quality, and ten portable rainwater tanks to provide good-quality drinking water to the poor households and kindergartens in the dry season. The triple bottom line considerations, as well as the environmental, economic, and social impacts of the rainwater harvesting (RWH) systems are examined. RWH is a sustainable method to obtain good-quality drinking water at low cost and with little energy expenditure. Education of the system also encourages that continuation of the system and expansion can lead into economic prosperity, as the safe drinking water can be sold to the community. Hence, RWH is a unique proposal as sustainable drinking supply water for improving the lives and health of residents in Cukhe and other sites where water supply sources are contaminated.