• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1646-1648
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• 2001

This paper described the outputs of acoustic sensors due to the vibration of particles in the mock up GIS. We used the two type of acoustic sensors which had 150kHz resonant frequency and 60kHz resonant frequency respectively. In the experiment of the mock up GIS, we paid attention to the magnitude and attenuation of sensor outputs due to particles. In this results the output of each sensor in frequency characteristic depended on the material of GIS tank and the output of sensor in magnitude characteristics depended on the size of particles and dropping height.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2528-2530
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• 2004

Neural network minimization problems are often conditioned and in this contribution way to handle this will be discussed. It is shown that a better conditioned minimization problem can be obtained if the problem is separated with respect to the linear parameters. This will increase the convergence speed of the minimization. One of the most powerful uses of neural networks is in function approximation(curve fitting)[1]. A main characteristic of this solution is that function (f) to be approximated is given not explicitly but implicitly through a set of input-output pairs, named as training set, that can be easily obtained from calibration data of the measurement system. In this context, the usage of Neural Network(NN) techniques for modeling the systems behavior can provide lower interpolation errors when compared with classical methods like polynomial interpolation. This paper solve of single-variable minimization using neural network.

• Journal of IKEEE
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• v.19 no.1
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• pp.80-86
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• 2015

There are many studies and products using a test paper impregnated with chemical solution can react with ozone. The color of a test paper can indicate the concentration of ozone. The purpose of this research is to design and manufacture a system using ultraviolet light source to measure the ozone density. This new technique is based on the characteristic of decomposition from ozone into oxygen under ultraviolet light. We used two sources of ultraviolet light including UV lamp and UVLED to determine the decomposition of ozone. This system is built with the electronic components, sensors and sealed pump tube to measure the ozone density in units of $g/cm^3$,ppm,ppb. In this paper,, we present some initial results of measuring the ozone density from ozone generator after completing inspection for safety.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.264-266
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• 2006

This traveling wave tube amplifier maintenance system was developed for performance of microwave Surveillance radar traveling wave tube amplification parts, and field operation. The Maintenance system is traveling wave tube amplification part RF output waveform measurement and HVPS Voltage adjustment and a maintenance function are offer. The system was developed as an embedded system base it consisted of Linux os which applied a top-down design and visual technique. Therefore change and easy extension of a system. This paper discussed characteristic of maintenance equipment function, composition, and an employment program.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.3-5
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• 2004

The single phase SRM has some demerits that has a torque ripple, noise and vibration because of being excited by switching pulse power source. Therefore, to make up for these demerits, it is realized many studies for the structure design used by computer and the operating methods by power electronic technique. On this paper, we will measure the accurate torque characteristics of the disk type single phase SRM, which is designed and manufactured for fan drive through the previous studies. With this results, we'll find the control elements to reduce the torque ripple and then design and manufacture the optimal drive circuit.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.269-271
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• 2004

In this study, on-line measuring system were developed to verify performances and characteristics of electric braking system that is used in KTX(Korea Train eXpress) synthetically and efficiently Because KTX is commercial vehicle, effective measurement and evaluation of measuring signals were performed beyond the range of change for equipment components. KRRI(Korea Railroad Research Institute) described about running-braking measuring program, running-braking backup program and running-braking analysis program that were developed using a software called LabVIEW in this paper. Also, we analyzed the characteristics comparing experimental values with design values about braking distance, braking time, negative acceleration and braking effort in rheostatic braking and regenerative braking. In result, main performances and characteristics for electric braking system in KTX were verified.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.388-390
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• 1997

We describe the characteristic of LVI(Low-voltage Impulse) test system and methods to detect the deformation of windings in the power transformers. Any winding deformation will result in a change of capacitance between winding parts and possibly some change in the winding inductance. These changes will then result in a change in the responce to the applied pulse in both the magnitude and period of the resulting oscillations. A results of measured differential method in stead of typical method, the sensitivity is greatly improved by the use of differential methods where the pulse is applied to two identical windings and the response measured with a differential amplifier.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1495-1496
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• 2008

The Ceramic Metal Halide lamp is different from optical characteristic on shapes of arc-tube and driving method of ballast. In this paper, we measured optical characteristics of the Ceramic Metal Halide lamp that uses arc tubes which are spherical and cylindrical shapes, and analyzed the Ceramic Metal Halide lamp connecting ballast that is electronic and magnetic types through the lamp measurement system that is given for stabilization period of fifteen minutes. In result, the arc-tube of spherical shape is more improvement in the optical properties than the arc tube of cylindrical shape, moreover, the electronic ballast is more efficient than the optical properties of the magnetic ballast.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1473-1475
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• 2002

This study presents the dielectric properties of $Ta_2O_5$ MIM capacitor structure processed by thermal oxidation. The AES(auger electron emission) depth profile showed thermal oxidation effect gives rise to the $O_2$ deficiened into the new layer. The leakage current density respectively, at $1{\sim}3{\times}10^{-3}$(kV/cm) were $3{\times}10^{-4}-10^{-8}(A/cm^2)$. Leakage current density behavior is stable irrespective of applied electric field, the frequency va capacitance characteristic enhanced stability. The capacitance vs voltage measurement that, $V_{fb}$(flat-band voltage) was increase dependance on the thin films thickness, it is changed negative to positive.

• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.534-536
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• 2000

In this paper, propagation and damping characteristics of PD Pulse in GIS are analyzed using SNM. These characteristics are very important to make a diagnosis and protection of accident in GIS. SNM is numerical method in time domain and very useful method to analyze 3-Dimensional structure such as GIS. GIS modeling is made simply as the form of coaxial cable and then spacers are inserted in it. The scattering and reflection in the GIS are appeared and damping characteristics of PD pulse are shown. When simulation using SNM compare to measurement, two results are similar.