• The Transactions of the Korean Institute of Electrical Engineers P
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• v.55 no.4
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• pp.202-206
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• 2006

In this paper, an auto detection method of stator winding fault of small induction motor is suggested. The Park's vector pattern which is obtained from 3-phase current signal by d-q transforming, is very good to detect winding fault. Comparing the Park's vector pattern of testing motor with its of healthy motor, the Park's vector pattern of fault motor is became an ellipse and the asymmetry is increased by the winding fault series. So for detecting the dis-symmetry, id-filtered function, Min-value, and Max-value are suggested for auto detecting. Using LabVIEW programing, 3-phase healthy motor and several kind of winding fault motors are tested and the test results are shown that the suggested method can gives us a possibility of an auto detecting winding fault.

• Journal of the Korea Furniture Society
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• v.20 no.5
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• pp.431-439
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• 2009

When we look at the pattern techniques of wooden furniture in the 19th century Joeson Dynasty, we see that furniture patterns in the main living room were showy and colorful while furniture patterns in the library room, where noble men used to study, were natural and moderate, retaining the actual color of the material without any artificial coloring. Even the serial patterns in the Hwe-Jang technique, Which were used rarely, used moderate techniques. such as weaving in patterns with colorless woods - willow and black persimmon ets. - rather than using excessive techniques. However, considering the marquetry&intarsia technique of ceramic and the silver string intarsia technique of metal then current, wood work must also have been technically advanced. Korean modern wood furniture needs remedies to improve the standard of sound wood work techniques. This study shows that pattern unit production, composition techniques, and color effects etc. Using colored patterns bars, by improving the pattern composition techniques of Marquetry&Intarsia, can be substituted for the production logic of modern manufactured furniture.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.179-181
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• 1998

In this paper, one chip PWM pattern generator which eliminates time delay of computations and improves utilization factor of voltage is proposed. Both amplitude of sinusoidal signal and triangular signal are directly controlled. Thus, time delay of computations can be eliminated, and it is possible to track accurately instantaneous current for a sudden change of load with microprocessor 80C196KC. In addition, setting dead-time is also possible for wide range. From experimental work with inverter system for driving induction motor, the validity of proposed one chip PWM pattern generator is verified.

• KSTLE International Journal
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• v.6 no.2
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• pp.51-57
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• 2005

Surface texturing of tribological applications is an attractive technology of engineered surface. Therefore, reduction of friction is considered to be necessary for improved efficiency of machines. The current study investigated the potential of textured micro-scale grooves on bearing steel flat mated with pin-on-disk. We discuss reducing friction due to the influence of sliding direction at surface pattern. We can indicate lubrication mechanism as a Stribeck curve, which has a relationship between the friction coefficient and a dimensionless parameter for the lubrication condition. It was found that the friction coefficient was changed by the surface pattern and sliding direction, even when surface pattern was the same. It was thus verified that micro-scale grooves could affect the friction reduction considerably under mixed and hydrodynamic lubrication conditions. The lubrication regime influences the friction coefficient induced by the sliding direction of groove pattern. The friction coefficient depends on a combination of resistance force and hydrodynamic.

• Journal of Institute of Convergence Technology
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• v.6 no.1
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• pp.13-16
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• 2016

The purpose of this study is analysing the characteristics of vehicle fuel economy and greenhouse gase emissions according to driving pattern of drivers. Current fuel economy has not established on official test methods. The difference between actual fuel efficiency and specification fuel efficiency bring up consumer complaints and misunderstandings about fuel economy. Against this background, The country is progressing the study on influence of the fuel efficiency according to variety test conditions. This study analyze the driving pattern of the different drivers and influence of the fuel efficiency according to driving pattern of different drivers.

• Current Optics and Photonics
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• v.2 no.2
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• pp.172-178
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• 2018

We propose a precise 3D endoscopic technique for medical and industrial applications. As the 3D measuring principle, the continuously scanning structured illumination microscopy (CSSIM), which enables to obtain 3D sectional images by the synchronous axial scanning of the target with the lateral scanning of the sinusoidal pattern, is adopted. In order to reduce the size of the probe end, the illumination and detection paths of light are designed as coaxial and a coherent imaging fiber bundle is used for transferring the illumination pattern to the target and vice versa. We constructed and experimentally verified the proposed system with a gauge block specimen. As the result, it was confirmed that the 3D surface profile was successfully measured with $16.1{\mu}m$ repeatability for a gauge block specimen. In order to improve the contrast of the sinusoidal illumination pattern reflected off on the target, we used polarizing optical components and confirmed that the visibility of the pattern was suitable in CSSIM.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.321-323
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• 1996

In this paper, it introduces a several circuit type of current-fed Full Bridge high frequence inverter with VVVF function. These inverter circuit presents various output control method according to on/off signal pattern of switches. also, It is certify that the accordance of characteristics is compared theoretical waveform with experimental results according to each signal pattern.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.9-11
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• 2003

This paper deals with the comparison of rotor eddy current losses In two types of permanent magnet high-speed machines. The analytical method and two dimensional finite element analysis have been used to evaluate the rotor eddy current loss with the rotor magnetization Pattern. It is shown that the Halbach array produce rotor loss less than parallel magnetization.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.45-48
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• 1997

The low frequency pulsed MIG welding process of new current waveform control to switch over unit pulse conditions (pulse current, pulse duration) in the fixed cycle was developed and its effect were investigated for aluminium and its alloy. By using this new welding process, the bead appearance having clear ripple pattern, such as TIG welding bead can be obtained and the gap tolerance of lap and butt welding joint can be expanded.

• Journal of Ecology and Environment
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• v.30 no.4
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• pp.331-340
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• 2007

We examined the evolutionary and ecological processes shaping current geographical distributions of a Korean wood-eating cockroach species, Cryptocercus kyebangensis. Our research aims were to understand evolutionary pattern of DNA sequences, to construct genetic network of Cryptocercus kyebangensis local populations and to understand evolutionary and ecological processes shaping their current geographical distribution patterns via DNA sequence information and genetic networks, using sequence data of two genes (ITS-2 and AT region) from local populations of C. kyebangensis. The results suggest that the ITS-2 and AT region are appropriate molecular markers for elucidating C. kyebangensis geographic patterns at the population level. The MSN-A based on the ITS-2 showed two possible routes, the Hwaak-san and Myeongji-san route and the Seorak-san and Gyebang-san route, for migration of ancestral C. kyebangensis into South Korea. The MSNs (MSN-A and -B) elucidate migration routes well within South Korea, especially the route of Group I and Group II.