• Journal of Environmental Health Sciences
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• v.34 no.2
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• pp.175-182
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• 2008

This study investigates the optimal conditions for electrogenerated hydrogen peroxide production and the application of the electro-Fenton process using DSA electrodes. The influences of parameters for the hydrogen peroxide generation such as electrode materials, electrolyte concentration, current, pH, air flow rate and electrode distance were investigated using a laboratory scale batch reactor. The relative performance for hydrogen peroxide generation of each of the six electrodes is : Ru-Sn-Ti > Ru-Sn-Sb > Ru > Ir > Pt > Sn-Sb. Optimum NaCl dosage, current and air flow rate were 2.0 g/l, 12.5 A and 2 l/min, respectively. When the pH is low, hydrogen peroxide concentration was high. Electrode distance dos not effect to a hydrogen peroxide generation. A complete color removal was obtained for RhB (200 mg/l) at the 8 min mark of the electro-Fenton process under optimum operation conditions of $Fe^{2+}$ 0.105 g/l and 5.0 A. The electro-Fenton process increased initial reaction and decreased final reaction time. However the effect was not high.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.311-313
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• 2003

There have been public attraction and studies about distributed generation systems. But protective relay must be installed between utility system and customer owned distributed generation system has not been developed. So this paper describes the development of a digital protective relay for interconnection. The developed protective relay includes protective elements required by KEPCO at the interconnection point.

• Proceedings of the KIPE Conference
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• 2003.07b
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• pp.961-964
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• 2003

Recently, because of the depletion of fossil fuels and the environmental pollution by using fossil fuels and atomic power generation, the interests concerning of new and renewable energy resources are rising rapidly. In this study, the 3kWP photovoltaic power generation system is realized to verify the performance of the PCS developed. The photovoltaic array used in this system is composed of 60 modules of 50Wp capacity. The developed system is tested and the experimental results show the excellent electrical characteristics.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.11
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• pp.192-199
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• 2002

This paper demonstrates that hybrid neural-genetic multimodel parameter estimation algorithm can be applied to structured system Identification of electro-hydraulic servo system. This algorithm are consist of a recurrent incremental credit assignment (ICRA) neural network and a genetic algorithm. The ICRA neural network evaluates each member of a generation of model and genetic algorithm produces new generation of model. We manufactured electro-hydraulic servo system and the hybrid neural-genetic multimodel parameter estimation algorithm is applied to the task to find the parameter values(mass, damping coefficient, bulk modulus, spring coefficient) which minimize total square error.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.6
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• pp.442-447
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• 2003

This paper demonstrates that a modified hybrid neural-genetic multimodel parameter estimation algorithm can be applied to structured system identification of an electro-hydraulic servo system. This algorithm is consists of a recurrent incremental credit assignment(ICRA) neural network and a genetic algorithm. The ICRA neural network evaluates each member of a generation of model and genetic algorithm produces new generation of model. The modified hybrid neural-genetic multimodel parameter estimation algorithm is applied to an electro-hydraulic servo system the task to find the parameter values such as mass, damping coefficient, bulk modulus, spring coefficient and disturbance, which minimizes the total square error.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.5
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• pp.196-203
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• 2003

This paper demonstrates that an improved hybrid neural-genetic multimodel parameter estimation algorithm can be applied to the structured system identification of an electro-hydraulic servo system. This algorithm is consists of a recurrent incremental credit assignment (ICRA) neural network and a genetic algorithm, The ICRA neural network evaluates each member of a generation of model and the genetic algorithm produces new generation of model. We manufactured an electro-hydraulic servo system and the improved hybrid neural-genetic multimodel parameter estimation algorithm is applied to the task to find the parameter values, such as mass, damping coefficient, bulk modulus, spring coefficient and disturbance, which minimize total square error.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.253-253
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• 2008

Recently, high performance microelectronic devices are designed in multi-layer structure in order to make dense wiring of metal conductors in compact size. For making dense wiring of metal conductors, we investigated CTE and peel strength of dielectric materials for next generation PCB. It is an object of this research to develop an epoxy resin composition for an interlayer insulating material exhibiting low CTE and high peel strengnth and making an insulating layer thinner.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.4
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• pp.715-722
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• 1998

A large electric system of a vacuum circuit breaker(VCB) has been studied for the electro-thermal analysis by finite element methods. Since the heat generation in VCB causes not only energy loss but deterioration of the VCB system with oxidization of parts, the overheating of the system must be prevented. For the analysis, a finite element formulation is derived for both electric analysis and thermal analysis that are coupled together. Two sets of formulations are uncoupled after finite dimensional approximation. First, the electric potential is obtained for the entire field and scaled to the given electric current. The electric field obtained is then used to calculate the heat generation in the VCB system including contacts and connections for the calculation of the temperature distribution in the entire domain. The finite element analysis is carried out to study the effect of shapes and locations of contacts and connections. From the results, the existing VCB has been modified to enhance its capacity with reduction of heat generation and temperature elevation.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.5
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• pp.677-684
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• 2006

Electro-flotation(EF), a novel sludge thickening method, could improve the dewaterability of activated sludge. The gas(microbubbles) generated during EF decreased the solid-liquid separation time below 1/5 of the time required for gravity sedimentation. In addition, over 90% of the sludge volume reduction could be achieved by EF although the settling characteristics of the sludge was very poor. The SRF(specific resistance to filtration) of the thickened sludge by EF was much lower than that of the sludge thickened by gravity sedimentation. The SRF of the thickened sludge decreased exponentially with increase of gas generation rate of the EF system. Gas generation rate could be controlled by varying the current density of the electrode. Degasing of the microbubbles by vigorous mixing of the thickened sludge layer deteriorated the dewaterability of the sludge. Therefore, it is obvious that the gas bubbles entrapped in the thickened sludge play a key role in the observed dewaterability improvement.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.11
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• pp.138-145
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• 2009

A suspended membrane micro fluidic heat flux sensor that is able to measure the heat flow rate was designed and fabricated by a complementary-metal-oxide-semiconductor-compatible process. The combination of a thirty-junction gold and nickel thermoelectric sensor with an ultralow noise preamplifier, low pass filter, and lock-in amp has enabled the resolution of 50 nW power and provides the sensitivity of $11.4\;mV/{\mu}W$. The heater modulation method was used to eliminate low frequency noises from sensor output. It is measured with various heat flux fluid of DI-water to test as micro fluidic application. In order to estimate the heat generation of samples from the output measurement of a micro fluidic heat-flux sensor, a methodology for modeling and simulating electro-thermal behavior in the micro fluidic heat-flux sensor with integrated electronic circuit is presented and validated. The electro-thermal model was constructed by using system dynamics, particularly the bond graph. The electro-thermal system model in which the thermal and the electrical domain are coupled expresses the heat generation of samples converts thermal input to electrical output. The proposed electro-thermal system model shows good agreement with measured output voltage response in transient state and steady-state.