• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.2
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• pp.1-13
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• 2022

Agrivoltaic facility is the composite system that the solar panel is installed above the farmland, and it enables crop and electricity production simultaneously. Solar panels of the agrivoltaic facilities can block and reduce the amount of solar irradiance arriving at the farmland, but it can help the crop growth by preventing excessive solar irradiance. Therefore, to clarify how the agrivoltaic facilities affect the crop growth, precise solar irradiance distribution under the solar panel should be modeled. In this study, PAR (photosynthetically active radiation), radiation from 400 to 700 nm, which crops usually use to grow, was extracted from the total irradiance and its distribution model under various conditions was developed. Monthly irradiance distributions varied because the elevation of the sun was changed over time, which made the position changed that the local maximum and minimum irradiance appear. The higher panel height did not cause any significant difference in the amount of irradiance reaching below the solar panel, but its distribution became more uniform. Furthermore, the panel angles with the most irradiance arriving below the solar panel were different by month, but its difference was up to 2%p between the irradiance with 30° angle which is usually recommended in Korea. Finally, the interval between panels was adjusted; when the ratio of the length of the panel to the empty space was 1:2, the irradiance of 0.719 times was reached compared to when there was no panel, 0.579 times for 1:1 and 0.442 times for 2:1.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.1
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• pp.109-114
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• 2017

In this study, we have developed the active leakage current detection module based on a MSP430 processor, 16bit signal processor. This module can be operated in a desired trip threshold within 0.03 seconds as specified in KS C 4613. This developed module is expected to be applicable as a module for prevention of electric shock in smart distribution panel of smart grid.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.6
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• pp.36-42
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• 2020

Nowadays, the touch screen panel (TSP) cover glass for mobile smart devices is being developed with a curved glass shape due to different design requirements. Because the sizes of mobile smart devices continue to increase, there has also been a great increase in the demand for large-area curved glass greater than 20 inches. In this study, heat and fluid flow analysis using CFD was performed to optimize the heating surface temperature distribution of the large curved glass formation system. Five cooling water flow paths in the cooling block were designed and analyzed for each case. A function that can quantitatively calculate the temperature uniformity of the heating surface was proposed and these values were obtained for the five models. The temperature distributions of the heating surface and the energy consumption of the heating system were also compared and comprehensively analyzed. Based on the analysis results of the five different cooling channel path models, the optimal path design could be presented.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.615-620
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• 2017

In this study, we have developed the resistive leakage current detecting and tripping circuit breaker based on a 32bit ARM processor. The developed leakage circuit breaker can be operated in a desired trip threshold within 0.03 seconds as specified in KS C 4613. This resistive leakage current breaker is expected to be applicable as a circuit breake for prevention of electric fires and electric shock in smart distribution panel.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.8
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• pp.90-97
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• 2013

In recent years, the many electric saving methods are studied because of difficulty of meeting the demand. The electric energy management such as monitoring of branch power consumption, demand control, metering, power quality monitoring, electric safety monitoring can make energy saving. The purpose of this paper is to develop a system which can provide the integrated management of various functions required for energy management by consumers. In this system all functions which were embodied into each devices are integrated into intelligent meter. The developed systems are tested and implemented by installing at consumer electric distribution panel.

• Journal of Aerospace System Engineering
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• v.16 no.5
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• pp.86-93
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• 2022

Generally, a deployable solar panel is used primarily to achieve sufficient power output to perform the mission. However, temperature distribution on the antenna reflector may increase due to the shading effect induced by the presence of the deployable solar panels. Appropriate thermal design is critical to minimize the thermal deformation of the mesh antenna reflector in harsh on-orbit thermal environments to ensure remote frequency (RF) performance. In this paper, we proposed a dual-surface primary reflector consisting of a mesh antenna and a flexible fabric membrane sheet. This design strategy can contribute to thermal stabilization by using a flexible solar panel on the rear side of membrane sheet to reduce the temperature distribution caused by the deployable solar panel. The effectiveness of the mesh antenna design strategy investigates through on-orbit thermal analysis.

• Advances in concrete construction
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• v.9 no.5
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• pp.459-467
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• 2020

Mechanical and thermal properties of composite sandwich wall panels are affected by changes in their external environment. Humidity and temperature changes induce stress on wall panels and their core connectors. Under the action of ambient temperature, temperature on the outer layer of the wall panel changes greatly, while that on the inner layer only changes slightly. As a result, stress concentration exists at the intersection of the connector and the wall blade. In this paper, temperature field and stress field distribution of UHPC-RW-RC (Ultra-High Performance Concrete - Rock Wool - Reinforced Concrete) wall panel under high temperature-sprinkling and heating-freezing conditions were investigated by using the general finite element software ABAQUS. Additionally, design of the connection between the wall panel and the main structure is proposed. Findings may serve as a scientific reference for design of high performance composite sandwich wall panels.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.6
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• pp.511-521
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• 2014

This study proposes an electric vehicle (EV) smart panel board and its control method on the basis of charging scheduling. The proposed system consists of batteries, a three-phase battery charger, three single-phase inverters, transfer switches for electric power distribution, and a controller. The three-phase battery charger usually charges the batteries at midnight when electric rates are cheap and in light load. When the electric power consumption of the EV standard chargers connected to one phase of the power line is relatively large or when a blackout occurs, the electric power stored in the battery is supplied by discharging through the inverters to the EV standard chargers. As a result, the value of peak load and the charging electric power quantity supplied from a utility grid are reduced, and the current unbalance is improved. The usefulness of the proposed system is confirmed through simulations, experiments, and case studies.

• Journal of Convergence for Information Technology
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• v.9 no.1
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• pp.68-73
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• 2019

This study is the central axis of the MG (Micro-Grid) configuration and it has the link through the modular hybrid power source and the DC bus, and it provides the function to detect and block the illegal connection by using the standard socket, And to achieve stabilization. Development of power conversion device, smart distribution panel, integrated control system and efficient demand management are required, and compatibility with MG whole system is urgent. This is a hybrid power generation system that is safe with a common power connection protocol and can be easily connected to anyone. This makes it easy to manage data and prepare for expansion of various manufacturers' systems.

• Design & Manufacturing
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• v.11 no.1
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• pp.1-6
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• 2017

In these days, due to generalization of using smart mobile phone and wearable device such as smart watch, demand of Cover-glass and touch screen panel for protecting display increases. With increasing the demand of Cover-glass, slimming technique is promising for weight lightening, zero bezel. Cover-glass produced by this technique is required to decreasing thickness with increase strength. In the Cover-glass manufacturing process, mechanical processing and chemical processing has improve in the strength. Generally, Diamond electrodeposition wheel is used in mechanical process. Reinforced glass with the characteristics of the brittle and high hardness was manufactured by using a diamond electrodeposition wheel. At this time, Because of surface of the tool present non-uniform distribution of diamond particle, it has generate Loading of wheel and it has been decrease life of grinding tool, efficiency of grinding, quality and shape accuracy of workpiece. Thus Research is needed to controling particle distribution of diamond electrodeposition wheel uniformly. And it is necessary to study micro hole machining such as proximity senser hole, speaker hole positioned Cover-glass. Reinforced glass with the characteristics of the brittle and high hardness is difficult to machining. Processing of reinforced glass have generated wear of tool, micro cracks. Also, it is decreasing shape accuracy. In this paper, We conducted a study on how to control particle distribution uniformly about the diamond tool manufactured using elecetodeposition processing. It analyzed the factors that affect the arrangement of the particles in the electrodeposition process by design of experiment. And There is produced the grinding tool, which derives an optimum deposition conditions, for processing Cover-glass edge and the machinability was evaluated.