• Journal of Forest and Environmental Science
• /
• v.32 no.2
• /
• pp.189-195
• /
• 2016

Logging equipment and method have a major influence on harvesting productivity and cost. This study investigated the productivity and operational costs of tree-length cable yarding system using HAM300, a domestically developed tower yarder. We tested HAM300 for thinning operation in Pinus densiflora stands at Gangreung, Gangwon-do on April, 2014. To assess the productivity we conducted time study for each stage of the operation. When the average time/cycle was examined for each stage of the operation, the longest was for yarding (241 sec), followed by delimbing (237 sec), felling (153 sec), and processing (103 sec). Furthermore, productivity for felling was $8.6m^3/hr$, followed by delimbing ($5.1m^3/hr$), yarding ($3.5m^3/hr$), and processing ($8.1m^3/hr$). The total cost for the tree-length logging system was $58,446won/m^3$, of which the majority was incurred by the yarding cost at $46,217won/m^3$ (79.3%), whereas the lowest cost was for felling at $2,359won/m^3$ (4.1%). We suggest that it is necessary to foster specialized operators and provide training in operating the tower yarder thereby implementing efficient harvesting system resulting from low-cost yarding.

• Journal of Biosystems Engineering
• /
• v.39 no.2
• /
• pp.134-141
• /
• 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.

• Journal of Biosystems Engineering
• /
• v.36 no.6
• /
• pp.397-406
• /
• 2011

In this study, surveys on operation status of the 73 tractors with rated power of over 75 kW from six provinces in Korea were performed to obtain basic data required for development and efficient use of the high-power and high-performance tractors. And types of tractors and implements, operation crops, types of operations, annual operation areas, annual operation days, annual operation hours, operation speeds and widths, and problems and improvements in use were investigated. Most (91.7%) of the tractor surveyed were operated for forage and silage crops such as rice straw, whole barley, rye grass, reed canary grass, sudan grass, and the remains were operated for upland crops such as ginseng, sweet potato, potato, chinese cabbage, radish. Main operations of the tractors were cutting, baling, and wrapping for forage crops, plow tillage, rotary tillage, and manure spreading. About half (47.9%) of the tractors were used exclusively for forage crop harvesting such as forage crop cutting, forage baling, and bale wrapping, 24.5% of the tractors were used exclusively for plow or rotary tillage, and 27.4% of the tractors were used for both forage crop harvesting, and plow or rotary tillage. For the tractors with power ranges of 75~83, 89~94, 98~101, 113, 124 kW, average annual operation areas per tractor for plow tillage, rotary tillage, forage crop harvesting (cutting, baling, wrapping), and manure spreading operations were analyzed as 112.6. 144.8, 158.9. 390.0. 215.6 ha, respectively. and total average annual operation area per tractor was 171.3 ha. Average annual operation days per tractor for those operations were analyzed as 24.1, 28.9, 38.3, 55.4, 33.4, respectively, and total average annual operation days per tractor was 33.6. Average annual operation hours per tractor for them were analyzed as 260.0, 321.6, 408.1, 664.8, 413.8, respectively, and total average annual operation hours per tractor for the all tractors was 377.1. Ranges of operation widths of plow tillage, rotary tillage, forage crop cutting, forage baling, bale wrapping, and manure spreading operations were shown as 1.5~2.6, 2.3~3.0, 1.8~3.2, 1.8~2.0, 1.8~2.3, 3.1~6.6 m, respectively. Ranges of operation speed of plow tillage, rotary tillage, forage crop cutting, forage baling, bale wrapping, and manure spreading were shown as 6~9, 4~11, 9~16, 8~15, 8~17, 12~16 km/h, respectively.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.14 no.6
• /
• pp.488-495
• /
• 2009

This paper proposes a new AC/DC RPPB(Resonant Piezo-Powered Boost) converter for energy harvesting using a piezoelectric device which converts mechanical vibration energy to electrical energy. The AC/DC RPPB converter can operate with only the harvested energy without an additional power conversion circuit for switching circuit and transfer energy to a load of which the voltage is higher than piezoelectric voltage. With the review of published topologies of the converter for energy harvesting, the operation principle of the AC/DC RPPB converter, and the results of PSPICE simulation and experiment are presented to prove the feasibility of the new converter for the energy harvesting.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.35 no.9
• /
• pp.955-960
• /
• 2011

This study was aimed at investigating the applicability of energy harvesting technologies, which are regarded as new and renewable energy sources for real-time/wireless monitoring of intelligent railroad vehicles. The surrounding energy generated in a normal operating environment was monitored using a high-speed railroad vehicle in operation. This monitoring was performed in an attempt to evaluate the effectives of energy harvesting and the applicability of energy-harvesting-monitoring technologies under the conditions in which thermal energy and vibration energy are generated.

• Journal of Advanced Navigation Technology
• /
• v.18 no.1
• /
• pp.56-66
• /
• 2014

In this paper, the solar cell need the characteristic interpreting because the solar cell changes greatly according to the isolation, temperature and load in the photovoltaic development. Moreover, to get many energy in photovoltaic development need the position tracking of the sun according to the environment change and it is necessary to control the output of solar cells up to the time. Simulation and composed microprocessor and sensor chip an power conversion system with boost converter to experiment results are performed to prove the analysis of the converter operation, and to show the possibility of energy harvesting and photovoltaic development need the position tracking small capacitance, the boost rate of boost converter was similar to 167 percent.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.10a
• /
• pp.429-432
• /
• 2017

In this paper, a full - wave rectifying harvesting circuit with a high-performance comparator is designed. Designed circuits are divided into Negative Voltage Converter and Active Diode stages. The comparator included in the active diode stage is implemented as a 3-stage type and divided into pre-amplification, decision circuit, and output buffer stages. The main purpose of this comparator is to reduce the propagation delay and improve the voltage and power efficiency of the harvesting circuit. The proposed circuit is designed with magna $0.35{\mu}m$ CMOS process and its operation is verified by simulation. The chip area of the designed energy harvesting circuit is $900{\mu}m{\times}712{\mu}m$.

• Journal of Advanced Navigation Technology
• /
• v.21 no.1
• /
• pp.99-106
• /
• 2017

In this paper, an energy harvesting and profiling system is designed for smart video devices in internet of things environments without dedicated power source. The energy harvesting module provides the harvested energy from solar panel to the smart video device. The energy profiling module measures the battery outflow current and the battery voltage of the smart video device and the consumed energy of processes, and calculate the harvested energy from the energy harvesting module to the smart video device and the total energy consumption of the smart video device. The accuracy of the harvested energy measured by the device energy profiling module is validated by comparing with the calculated energy using the regional solar radiation provided by Korea Meteorological Administration. Energy harvesting data from the designed energy harvesting and profiling system can be used to design the perpetual operation of smart video devices or Internet of Things sensors.

• Food Science and Preservation
• /
• v.30 no.5
• /
• pp.811-821
• /
• 2023

This study investigated the storability of onions according to manual and mechanical harvesting. Moreover, we simulated the onion-to-onion impact during the mechanical harvesting process and investigated the storability after artificially subjecting the onions to impact treatment. The onion harvesting methods included hand plucking + manual collection, digger + manual, and digger + mechanical collection. The maximum impact height during the mechanical harvesting process was 0.5 m. Immediately after harvesting, no significant difference in the bruise and wound rate among the harvesting methods was observed. Any increased bruise or wound rate because of mechanical harvesting was presumed to be influenced by soil conditions, such as the presence of gravel, and machine operation factors. Furthermore, the storability during the 8.5 months storage showed no significant difference according to the harvesting methods. In treatments by simulating the impacts during the mechanical harvesting process, the impact heights were 0.0 m (0.0 J), 0.25 m (0.86 J), 0.5 m (1.72 J), and 0.75 m (2.57 J), each performed once, and four times at the same position (3.43 J) and four times at different positions (3.43 J) at 0.25 m. Throughout all the treatments, there were no significant differences in the storability during the 8.5 months storage period.

• Journal of Korea Society of Industrial Information Systems
• /
• v.16 no.1
• /
• pp.31-36
• /
• 2011

Ubiquitous network and wireless sensor networks is being applied in various fields. Located at target areas, node of wireless sensor network uses batteries as a power source. Batteries have a limited energy in sensor network applications. Also, before use, the battery must be charged and It is difficult to replace the battery. Therefore, energy harvesting technology is being researched and being developed for long life of sensor node. Especially, sola energy is being extensively researched. because that can have great amounts of energy than other environmental energy in a short time. In this study, we tested battery charging and recharging, operation of sensor node using Solar Cell. Also, monitoring data gathering and voltage Analysis showed energy harvesting time of Sola Cell battery for sensor node and operation of sensor node.