• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.507_508
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• 2009

As a result of environmental concerns, renewable energy systems are rapidly increasing and particularly tidal current is a potential source of energy. In accordance with a large-capacity trend, doubly-fed induction generator is applied such as wind farms and tidal systems. In this paper, Optimal hysteresis band amplitude of CRPWM Converter is determined for improving rotor current waveform and electrical quality.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.617-622
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• 2002

This paper presents that the Wavelet Transform can be used to detect the various local defects in a gearbos. Two types of defects which are broken tooth and localized wear, are experimented and the signals are collected by accerometer and analyzed. Because of the complecity of the signals acquired from sensor, it is needed to identify the interesting signal. The natural frequencies of shafts and the gear mesh frequency(GMF) is calculated theretically. DWT, CWT and the aplication are used to extract a gear-localized defect feature from the vibration signal of the gearbox with the defective gear. The results shows the transform is more effective to detect the failures than the Fourier Transform.

• 한국가시화정보학회지
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• 제12권3호
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• pp.21-25
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• 2014

Optical distortion of experimental results can be found in many studies. Thus, a method of the optical correction for visualization of an axisymmetric droplet was developed in this study. The correction method was derived to extract refracted vectors. In order to obtain the refracted vectors, a projection vector and a normal vector should be calculated. Then, a distortion distance can be found by the calculated refracted vector and Snell's law. The developed method was also verified by the simulation and the experimental results to apply for a liquid droplet which was formed at a nozzle tip.

• 대한물리치료과학회지
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• 제8권2호
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• pp.953-960
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• 2001

This study is approached the early intervention of children with disability in the aspect of family. The family of didabled children are identified as special individual with responsibilities and roles beyond those of other family. Physical Therapy need of the disabled child should be sought in the context of the family and socio-cultural environment. The process of early developmental facilitation is defined as a approach of the family. As family is the most influential factor in the child developmental facilitation, treatment and education. The family tend to seek complete information about disabilities, desire accurate, straight foreward about their child.

• 조명전기설비학회논문지
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• 제26권8호
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• pp.42-49
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• 2012

Grid-connected photovoltaic generator system requires high performance PCS(Power Conditioning System) according to the standard of 'Distributed Generation Grid-Connected Technology Standards'. This paper presents the MPPT control method which improves output efficiency through fast tracking to the maximum power point of PV and a reduced self-excited vibration. Secondly, in this paper DVR function was applied to PCS to compensate the voltage sag frequently happening for a power system. The proposed PCS control is analyzed and compared to conventional PCS operating characteristic, the various insolation and loads, and voltage sag condition through PSIM tool. It proves the utility.

• The Korean Journal of Pain
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• 제23권1호
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• pp.51-54
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• 2010

A herniated intervertebral disc is the most common type of soft tissue mass lesion within the lumbar spinal canal. Magnetic resonance imaging (MRI) is a useful tool for the assessment of patients with lower back pain and radiating pain, especially intervertebral disc herniation. MRI findings of intervertebral disc herniation are typical. However, from time to time, despite an apparently classic history and typical MRI findings suggestive of disc herniation, surgical exploration fails to reveal any lesion of an intervertebral disc. Our patient underwent lumbar disc surgery with the preoperative diagnosis of lumbar disc herniation; however, nothing could be found during the surgical procedure, except a swollen nerve root.

• 한국IT서비스학회지
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• 제5권2호
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• pp.1-23
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• 2006

An Empirical study was done for finding the e-service quality of public administration focused on customer relationship management(CRM). The e-service quality of public administration was categorized as system quality, information quality, service quality, and CRM after doing a literature review in e-service quality and public administration. The validity and reliability of a questionnaire were examined through factor analysis and regression analysis was done using the customer satisfaction and efficiency improvement of public administration as dependent variables and the 7 factor scores from the factor analysis as independent variables. The results show for that 6 factors are not only very important in explaining the customer satisfaction but also partially important for efficiency improvement of public administration. In particular, CRM has significant effect on both customer satisfaction and efficiency improvement of public administration.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.111-113
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• 2005

In this paper a computer program has been developed using IT technologies for load flow analysis. The program is written in the Java language for the platform and operating system independence. The software technique, such as Standard Widget Toolkit (SWT), Graphical Editing Framework (GEF), and Java web start, are used for the program. The program also has Graphical User Interface (GUI) to enable users to construct power system displays through simple mouse clicks and map directly into visual power system elements on the screen. The input data of the elements of power system can be entered on the screen. The results of the program cail be checked on the screen.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.300-302
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• 2006

The structured lighting technique is a very accurate depth measurement method. One problem in this technique is that the laser light is invisible very often partly or as a whole caused from occlusion, light absorbtion, and reflection on the surface. If there is no laser light detected on a row of the image frame, the depth could not be computed at the point on the row. In this paper, a Dynamic Programing-based efficient laser line tracking algorithm is proposed to find the most likely line of the laser light utilizing all the possible information of the laser light trace. The performance of the algorithm is shown.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.545-547
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• 2006

This paper propose a localization method using color landmark that is applicable to mobile intelligent robot. The color landmarks are attached in the indoor ceiling. The world coordinate of robot is estimated by color patterns and the coordinates of landmarks. A landmark is composed of 4color and these 4 colors are sorted in a line. All of landmarks have a main color which indicates direction of robot. Other 3 colors are the combination of 5 kind of colors. The CCD camera is installed on the top of robot to observe the landmarks in the ceiling.