• 한국가시화정보학회지
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• 제8권2호
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• pp.51-55
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• 2010

Flow characteristics of a free-horizontal-axis-turbine (FHAT) current power generation system have been investigated by the use of a volumetric PTV. Three types of FHAT system (S50, SE50, S65) have been tested under the current speed 1.35 knot, 1.5 knot and 2 knot. The width of the blade installed around the body is 50 mm. Based upon the power generation characteristics of the FHAT, the flow features of the blade have been investigated. Among the three models it has been verified that the S65 is the most appropriate for power generations.

• 전기학회논문지P
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• 제58권4호
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• pp.568-573
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• 2009

Because of environmental crisis, researchers are seeking and developing a new, clean, safe and renewable energy. Solar cell energy and fuel cell energy have inestimable development potential. The paper introduces hybrid photovoltaic-fuel cell generation systems supplying a remote power load and hybrid system of solar cell and fuel cell considering the advantages of stable and sustainable energy from the economic point of view. Fuel cell power system has been proven a viable technology to back up severe PV power fluctuations under inclement weather conditions. Fuel cell power generation, containing small land us, is able to alleviate the heavy burden for large surface requirement of PV power plants. In addition, the PV-fuel cell hybrid power system shows a very little potential for lifetime $CO_2$ emissions. In this paper shows the I-V characteristics of the solar module which are dependent on the power of the halogen lamp and the I-V characteristics of fuel cells which are connected in parallel. Also, it shows efficiency of the hybrid system.

• 대한전기학회논문지
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• 제43권4호
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• pp.569-579
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• 1994

A 5.9kW phosphoric acid fuel cell(PAFC) power generation system that consists of a reformer, a stack, heat exchangers, an automatic data acquisition and control system was designed, fabricated and analyzed. This system which was firstly fabricated in Korea has been operated for 140 hours with an electricity generation of 684kWh. The PAFC generate electricity in the range of 38-52V and 50-160A and has a typical I-V characteristics of a fuel cell. Using the reformed fuel, the system performance is decreased in some degree due to CO content, compared to using the simulated fuel. At steady state operation condition, the total efficency of this system was 45.2%.

• 한국정보통신학회논문지
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• 제26권12호
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• pp.1934-1937
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• 2022

The meaning of crosswalks and traffic lights in modern society has changed a lot as the enforcement of traffic signal violations has been strengthened. In this paper, we present a new next-generation traffic light method using radar and Can-bus communication methods suitable for the new traffic signal enforcement system. This method is a system that prevents accidents by transmitting information on the entry of a person and a car to a traffic light in a place where a person and a car passing through a mutually invisible traffic light cannot be seen. Since this system has only been developed for a month, it may be somewhat lacking in experimentation. However, in just one month, there have been no incidents except for a few people where the system has been installed.

• 한국광학회지
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• 제18권6호
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• pp.426-431
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• 2007

초소형 전자칼럼을 위한 마이크로 자기장 디플렉터를 제작하여 저에너지 영역에서 디플렉터의 동작 특성을 확인하였다. 마이크로 디플렉터는 지름이 $500{\mu}m$의 원통형 코어에 감겨진 $100{\mu}m$ 지름의 Cu 코일로 구성되어 있다. 두 쌍의 디플렉터는 $10{\times}10mm$ 크기의 절연 기판에 고정되어 전자빔을 2차원 스캔할 수 있도록 고안되었다. 마이크로 자기장 디플렉터를 부착한 초소형 전자칼럼을 저전력으로 시험 구동한 결과 $100{\mu}m/A$의 편향 결과를 얻어 활용 가능성을 확인하였다.

• 설비공학논문집
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• 제16권1호
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• pp.34-41
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• 2004

The chemical heat pump based on the Dehydration/Hydration process with a MgO/$H_2O$ system has been researched. The reactor bed could be expected to store the heat around 200∼37$0^{\circ}C$ by the dehydration reaction and to release the heat around 100∼16$0^{\circ}C$ by the hydration reaction under the heat amplification mode operation. The heat output rate of the heat pump system was evaluated using the experimentally determined parameters. The results show that 6∼50 W/kg of heat output and 0.5∼0.8 of heat recovery ratio are attainable. The heat pump will be applicable for a load leveling in a co-generation system by chemical storage of surplus heat at low heat demand and by supplying heat in the peak load period.

• 한국멀티미디어학회논문지
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• 제25권11호
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• pp.1557-1563
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• 2022

Currently Spatial Data is collected and processed in various methods, and its usability is very high. However, the existing Spatial Data analysis Software usually requires professional knowledge in the collection, refinement, and application of spatial Date, making it difficult to access and apply it. Therefore, this study established a new WebGIS platform with improved accessibility and usability to solve these problems. This platform supports various services such as master map sharing, spatial data generation, automatic coordinate system conversion, WMS issuance, grid generation, and grid analysis. These services increase operational convenience, such as simplifying repetitive tasks and automatically expressing text files. While it is believed that non-experts can easily and conveniently because of them to simplify and express the results. In addition, it is judged to have high accuracy and reliability compared to the analysis results using the existing Open Source-based GIS software.

• Journal of Welding and Joining
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• 제17권5호
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• pp.61-68
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• 1999

For the last two decades, waveform control techniques have been successively developed and applied for the inverter welding machines resulting in the substantial reduction of spatter generated in CO₂ welding. One of the constituents commonly involved in those techniques is to delay the instant of current increase to some extent after the initiation of short-circuiting. Although this technique has been known to be quite effective in reducing the spatter generation through the suppression of is instantaneous short circuiting, the delay time necessary for minimum spatter has not been clearly understood. In this study, the control system for varying the delay time was constructed so that the spatter generation rates could be measured over a wide range of delay time, 0.29-2.0 msec. As a result of this study, it was demonstrated that spatter generation rate(SGR) sharply decreased at delay time of 0.6 msec and longer accompanied with the change in characteristics of short circuit mode from the instantaneous short-circuiting(ISC) dominant to normal short-circuiting(NSC) dominant. Another feature that have been found in current waveform of over 0.6msec was the creation of current pulse right after the arc reignition stage. Because of this current pulses weld pool oscillated in wave-like fashion and it looks like to play an important role in developing short circuiting between electrode and weld pool.

• 신재생에너지
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• 제2권3호
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• pp.15-22
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• 2006

As the distributed generation becomes more reliable and economically feasible, it is expected that a higher application of the distributed generation units would be interconnected to the existing grids. This new market penetration using the distributed generation technology is linked to a large number of factors like economics and performance, safety and reliability, market regulations, environmental issues, or grid connection standards. KEPCO, a government company in Korea, has performed the project to identify and evaluate the performance of Micro Gas Turbine(MGT) technologies focused on 30, 60kW-class grid-connected optimization and combined Heat & Power performance. This paper describes the results for the mechanical, electrical, and environmental tests of MGT on actual grid-connection under Korean regulations. As one of the achievements, the simulation model of Exhaust-gas Absorption Chiller was developed, so that it will be able to analyze or propose new distributed generation system using MGT. In addition, KEPCO carried out the field testing of the MGT Cogeneration system at the R&D Center Building, KEPCO. The field test was conducted in order to respond to a wide variety of needs for heat recovery and utilization. The suggested method and experience for the evaluation of the distributed generation will be used for the introduction of other distributed generation technologies into the grid in the future.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.743-744
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• 2011

Currently, the major issue in power system is construction of smart grid. Unlike conventional electricity grids, smart grid allows two-way communication between electricity suppliers and consumers, as well as enabling more dispersed generation and storage of power. The AMI(advanced metering infrastructure) system is the core technology of smart grid and this paper deals with the design methodology of AMI System using PLC(power line communication) networks.