• Journal of Biosystems Engineering
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• v.22 no.3
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• pp.317-324
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• 1997

This study was conducted to develope a machine vision system for a robotic transplanter for bedding plants. Specific objectives of this study were 1) to get coordinates of the healthy seedlings in high-density plug tray, and 2) to get the angle of the leaves of the healthy seedlings to avoid the damage to seedlings by gripper. Results of this study were summarized as follows. (1) The machine vision system of a robotic transplanter was developed. (2) Success rates of detecting empty cell and bad seedlings for 72-cell and 128-cell plug-trays were 98.8% and 94, 9% respectively. (3) Success rates of calculating the angle of leaves fer 72-cell and 128-cell plug-trays were 93.5% and 91.0% respectively.

• Journal of Biosystems Engineering
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• v.29 no.3
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• pp.251-260
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• 2004

As a basic experiment for robot hand for transplanting plug seedling, the experimental robot hand system which moves up and downward vertically, and allows hand blade to open and close was made. The system was constructed with the robot hand mechanism, the tray, the plug seedling, and the measuring equipments. The penetrating force and holding efficiency were analyzed according to the soil moisture and the variation of hand blade angle. The highest holding efficiency could be obtained at the penetrating angle of approximately from 0 to 0.36 degree and at the moisture content of soil from 71% to 75%. The external force acted on the robot hand should maximum force when the robot hand was penetrated to soil, minimum of approximately 30.4 N when the penetrating angle was 0$^{\circ}$ and moisture content was 66-70%. It was increased with increasing or decreasing the Penetrating angle from 0 degree and also with increasing or decreasing the moisture content of soil from 66-70%. For optimal design of the robot hand and manipulator, the external force acted on robot hand had to be based on the returning force of soil, when the robot hand was penetrated to the soil. In consideration of safety ratio, the appropriate external force seemed to be 39-49 N.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.94-96
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• 2022

Plug & Play techniques have been proposed in various ways to overcome the complexity of sensors/drivers in IoT application development. IEEE1451 standard abstracts sensors/drivers into a data structure called TEDS. As a result, characteristics of the sensor/driver are unnecessary when connecting the sensor/driver to the host device. The method proposed by ETRI is a format in which device drivers of sensors/drivers are dynamically loaded and connected to hosts, and there is no particular abstraction data structure. Both schemes are located at both ends in terms of the abstraction unit of the sensor/driver. We present the problem based on this fact, and what optimized methods can exist in the middle of it. In this paper, we analyze existing Plug&Play techniques. Also, we specify abstraction units of sensors/drivers, and analyze them.

• The Plant Pathology Journal
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• v.39 no.2
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• pp.228-233
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• 2023

Two pear cultivars with different degrees of resistance to Venturia nashicola were evaluated on the basis of a disease severity rating for pear scab resistance under controlled environmental condition. Two inoculation techniques were tested: the procedure for inoculation by dropping conidia suspension of V. nashicola; the procedure by deposition of agar plug on the abaxial surface of pear leaves. All tested cultivars resulted in blight symptoms on the inoculated leaves and became spread to uninoculated region or other leaves. Although both methods provide satisfactory infection of V. nashicola on pear leaves, the mycelial plug method of inoculation was more reliable than the spray inoculation method for the evaluation of pear scab disease resistance. The incubation period of V. nashicola in the resistant pear cultivar, Greensis was longer than that in the susceptible cultivar, Hwasan.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.6
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• pp.620-628
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• 2010

Small satellites can be used for various space research and scientific or educational purposes due to advantages in small size, low-cost, and rapid development. Small Satellites have many advantages of application to Responsive Space. Compared to traditional larger satellites, however, Small satellites have many constraints due to limitations in size. Therefore, it is difficult to expect high performance. To approach maximum capability with minimal size, weight, and cost, standard modular platform of Small satellites is necessary. Modularity supports plug-and-play architecture. The result is Small satellites that can be combined quickly and reliably using plug-and-play mechanisms. For communication between modules, standard bus interface is needed. Controller Area Network(CAN) protocol is considered optimum data bus for modular Small satellite. CAN can be applied to data communication with high reliability. Hence, design optimization and simplification can also be expected. For ease of assembly and integration, modular design can be considered. This paper proposes development method for standardized modular Small satellites, and describes design of data interface based on CAN and a method of testing for modularity.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.6
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• pp.202-209
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• 1998

For development of SDI(Spark-ignited Direct Injection) engine, stratified mixture formation with adequate strength at spark plug was required in wide range of engine operating conditions. So, spray structure under high ambient pressure and spray distribution after impingement on piston bowl in motoring engine was visualized by using laser equipments. Also, incylinder bulk flow structure was measured by using PIV (Paiticle Image Velocimetry) system. Counter-rotating tumble port and bowl piston was found effective to conserve bulk motion directed to spark plug in compression stroke. In addition, mask attached near valve seat in intake port was proposed to attenuate conventional tumble component and enhance counter-rotating tumble component.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.2
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• pp.288-298
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• 1999

In spark ignited engines, the electrical spark not only sets the time for the onset of combustion but also is able to greatly influence the character of the initial flame growth and the subsequent combustion, and thereby can influence engine performance. The relative importance of the ignition energy is particularly high under lean or high residual gas or exhaust gas recirculation (EGR). In this study, a modeling of flame Initiation and its development is proposed. Submodels consist in representing of cylinder pressure and temperature, heat transfer to cylinder wall, and flame kernel heat transfer to ambient air and to spark plug electrodes. The breakdown process and the subsequent electrical power input initially control the kernel growth while intermediate growth is mainly dominated by diffusion or conduction. Then, the flame propagates by the chemical energy, and laminar and turbulent flame velocity.

• Journal of the Korean Ceramic Society
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• v.51 no.5
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• pp.435-441
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• 2014

Silicon carbide-based ceramics and their composites have been studied for application to fusion and advanced fission energy systems. For fission reactors, $SiC_f$/SiC composites can be applied to core structural materials. Multilayered SiC composite fuel cladding, owing to its superior high temperature strength and low hydrogen generation under severe accident conditions, is a candidate for the replacement of zirconium alloy cladding. The SiC composite cladding has to retain its mechanical properties and original structure under the inner pressure caused by fission products; as such it can be applied as a cladding in fission reactor. A hoop strength test using an expandable polyurethane plug was designed in order to evaluate the mechanical properties of the fuel cladding. In this paper, a hoop strength test of the multilayered SiC composite tube for nuclear fuel cladding was simulated using FEA. The stress caused by the plug was distributed nonuniformly because of the friction coefficient difference between the inner surface of the tube and the plug. Hoop stress and shear stress at the tube was evaluated and the relationship between the concentrated stress at the inner layer of the tube and the fracture behavior of the tube was investigated.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.318-319
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• 2011

Many countries are concentrating on the development of electric vehicle technology with increasing concerns about the global environment. Along with these concerns, plug-in hybrid electric vehicles(PHEVs) are being developed as environment-friendly cars which reduce greenhouse gas emissions and also eliminate the problem of range anxiety associated to all-electric vehicles, because the combustion engine works as a backup when the batteries are depleted. In this paper, electric equipments of the PHEV which meet the target specifications were developed, and their performance was proven through confirmatory testing on the PHEV at Korea Automotive Technology Institute(KATECH).

• Journal of Bio-Environment Control
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• v.6 no.1
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• pp.55-65
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• 1997

This study was conducted to develop a robotic transplanter for bedding plants. The robotic transplanter consisted of machine vision system, manipulator attached with the specially designed gripper, and plug tray transfer system. Results of this study were as follows. 1. A machine vision system for a robotic transplanter was developed. The success rates of detecting empty cells and bad seedlings in 72-cell and 128-cell plug-trays for cucumber seedlings were 98.8％ and 94.9％ respectively. The success rates of identifying leaf orientation for 72- cell and 128-cell plug-trays were 93.5% and 91.0%, respectively. 2. A cartesian coordinate manipulator for a robotic transplanter with 3 degrees of freedom was constructed. The accuracy of position control was $\pm$ 1mm. 3. The robotic transplanter was tested with a shovel-type finger. Without considering leaf orientation, the success rates of transplanting healthy cucumber seedlings for 72-cell and 128-cell plug-trays were 95.5% and 94.5%, respectively. Considering leaf orientation, the success rates of transplanting healthy cucumber seedling in 72-cell and 128-cell plug-trays were 96.0% and 95.0%, respectively.