• Journal of electromagnetic engineering and science
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• 제18권3호
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• pp.206-211
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• 2018

In this paper, we proposed a two-level feature vector fusion technique to improve the performance of target classification. The proposed method combines feature vectors of the early-time region and late-time region in the first-level fusion. In the second-level fusion, we combine the monostatic and bistatic features obtained in the first level. The radar cross section (RCS) of the 3D full-scale model is obtained using the electromagnetic analysis tool FEKO, and then, the feature vector of the target is extracted from it. The feature vector based on the waveform structure is used as the feature vector of the early-time region, while the resonance frequency extracted using the evolutionary programming-based CLEAN algorithm is used as the feature vector of the late-time region. The study results show that the two-level fusion method is better than the one-level fusion method.

• Journal of Advanced Marine Engineering and Technology
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• 제27권6호
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• pp.696-703
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• 2003

A photovoltaic power generation system is an infinite and clean energy system. Recently. because of the realization of high efficiency and low cost PV modules, the studies on the PV system have extensively increased. In this paper. we present an online scheme for parameter estimation of solar cell, based on the model adjustment technique and a real-coded genetic algorithm(RCGA). The ideal diode model and the diode model with series and shunt resistors are used to estimate their parameters, Simulation works using field data in the form of a V-I characteristic curve are carried out to demonstrate the effectiveness of the proposed method.

• Journal of information and communication convergence engineering
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• 제18권2호
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• pp.115-122
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• 2020

Audiovisual (AV) facilities such as TVs and signage are installed in various public places. However, audio cannot be used to prevent noise and interference from individuals, which results in a loss of concentration and understanding of AV content. To address this problem, a total technique for remotely listening to audio from audiovisual facilities with clean sound quality while maintaining video and lip-syncing through personal smart mobile devices is proposed in this paper. Through the experimental results, the proposed scheme has been verified to reduce system power consumption by 8% to 16% and provide real-time processing with a low latency of 120 ms. The system described in this paper will contribute to the activation of audio telehearing services as it is possible to provide audio remote services in various places, such as express buses, trains, wide-area and intercity buses, public waiting rooms, and various application services.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.1303-1305
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• 2001

Photovoltaic(PV) and hydrogen are the high quality, clean-burning fuel which could replace oil and natural gas for transportation, heating and power generation. If hydrogen is made via PV-powered water electrolysis, it would be possible, in principle, to provide energy on global scale, with essentially no greenhouse gas emission and very low level of local pollution. In this paper, the operation control of PV-SPE system is briefly discussed and the simulation scheme of the system is also proposed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.1482-1485
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• 2004

Electrostatic Precipitators have been used widely in industry, and play an important role in environmental protection. Electrostatic Precipitators (ESP) can be operated with a high collection efficiency and low pressure drop. Pulse energization is a technique to cope with high resistivity dust, and this results in lower power consumption. In this paper, Pulse energization ESP to use subway station air clean in subway station, design and test a pulse power supply for ESP.

• 전기전자학회논문지
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• 제18권1호
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• pp.8-18
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• 2014

Electrical resistance tomography (ERT) has high temporal resolution characteristics therefore it is used as an alternative technique to visualize two-phase flows. The image reconstruction in ERT is highly non-linear and ill-posed hence it suffers from poor spatial resolution. In this paper, the inverse problem is solved with homogeneous data used as a prior information to reduce the condition number of the inverse algorithm and improve the spatial resolution. Numerical experiments have been carried out to illustrate the performance of the proposed method.

• 한국유체기계학회 논문집
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• 제4권3호
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• pp.62-77
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• 2001

The modern wind turbines are widely used as important natural energy sources for the electric generation in western countries and some Asian nations. They are commercially matured and progressive and clear policy for the more development with higher technical purposes is maintained throughout the world. Modern wind turbines produce nearly 2000 kW output in their largest sizes and this trend increases up to more powerful power and ultimate utilization of wind energy favoured by clean natural energy. This article has the points of reviewing the states of the art of modern wind turbines with their present technical directions toward next generation version. Some descriptionsare given for easy understanding of the turbine components and related fluid mechanics concerned. The general outlines of policy taken over some countries are also introduced.

• 한국분무공학회지
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• 제18권2호
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• pp.81-86
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• 2013

To comply with the regulation of the reinforcing Clean Air Conservation Act, it is necessary for the semiconductor manufacturers to develop effective low-concentration acid gas abatement system to treat the flue gas. The low-concentration acid gas was found to be harder to deal with than the high-concentration one. In this study, the effect of various potential treatments such as air-assist nozzle spraying, magnetizing the scrubbing water, and adding surfactants to spraying and scrubbing water were investigate through the application of the statistical ANCOVA method, which was proved to be very useful tool when the inlet concentration of acid gas could not be controlled precisely and it affected the removal efficiency of the abatement system.

• 대한기계학회논문집A
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• 제25권11호
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• pp.1844-1853
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• 2001

In the present investigation, it was attempted to design the rolling pass schedule fur a clean steel of 0.1C-1.5Mn-0.25Si with the objective of the austenite grain refinement. As the method of approach, a coupled mathematical modeling technique was proposed which consists of a recrystallization model and a flow stress modes. The validity of the coupled model was examined through comparison with results of continuous and discontinuous compression tests at various temperatures, strains and strain rates. The coupled model was incorporated with the finite element method to set up a systematic design methodology far the rolling path schedule for austenite grain refinement. Two path schedules were obtained and discussed in the paper with regard to rolling path time, average grain size, grain size deviation in thickness, etc.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.78-81
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• 2003

Polishing Processes are widely used in the glass, optical, die and semiconductor industry and are conventionally carried out using abrasive slurry and a polishing pad. But abrasive slurry process has a weak point that is high cost of handling of used slurry and hard controllability of slurry. Recently, some researches have attempted to solve these problems and one method is the development of a fixed abrasive pad. FAP has a couple of advantages including clean environment, lower CoC, easy controllability and higher form accuracy. But FAP also has a weak point that is need of dressing because of glazing and loading. The paper introduces the basic concept and fabrication technique of FAP using hydrophilic polymers with swelling characteristics in water and explains the self-conditioning phenomenon. Experimental results demonstrate to achieve nano surface roughness of soda lime glass for optical application