• Journal of the Korean Society for Precision Engineering
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• v.19 no.12
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• pp.20-26
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• 2002

Deformation phase can be obtained by using Least-Square fitting. In extraction of phase values, Least-Square Fitting is superior to usual method such as 2, 3, 4-Bucket Algorithm. That can extract almost noise-free phase and retain 2 $\pi$ discontinuities. But more fringes in phase map, 2 $\pi$ discontinuities are destroyed when that are filtered and reconstruction of deformation is not reliable. So, we adapted Least-Square fitting using an isotropic window in dense fringe. Using Sine/cosine filter give us perfect 2 $\pi$ discontinuities information. We showed the process and result of extraction of phase map and filtering in this paper.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.6 s.249
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• pp.643-652
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• 2006

This paper is concerned with computer simulations of a biped robot walking in static and dynamic gaits. To this end, a three-dimensional robot is considered possessing a torso and two identical legs of a typical design. For such limbs, a set of inverse kinematic solutions is analytically derived between the torso and the feet. Specific walking patterns are off-line generated meeting stability based on the VPCG or ZMP condition. Subsequently, to verify whether the robot can walk as planned in the presence of mass and ground effects, a multi-body dynamics CAE code has been applied to the resulting joint motions determined by inverse kinematics. As a result, the key parameters to successful gaits could be identified including inherent characteristics as well. Upon comparisons between the two types of gaits, dynamic gaits are concluded more desirable for larger humaniods.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.438-442
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• 1997

The pupose of this study is the development of CAM system which can cut any shape by CNC lathe.. The overall goal of the CAM system is to achieve the CNC lathe machining, form roughing through to final measuring. The hardware of the system comprises PC and CNC lathe. There are three steps in the CNC lathe machining, (1) geometric modeling by the shape patterns, (2) NC commands generation by the tool path compensated for tool nose radius,(3) machining and workpiece measuring on the lathe. It is developed a software package, with which can conduct a micro CAM system in the PC without economical burden.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.911-914
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• 2003

The non-contact laser measurement system what can be used for the vibration analysis of structures is discussed. There are few systems using laser speckle interferometer for vibration analysis. One of these systems is the Electronic Speckle Pattern Interferometer (ESPI). With ESPI system, one can obtain the vibration mode shape qualitatively and the maximum vibration amplitude quantitatively of the structure at each resonance frequency. In this paper, the phase-shifting ESPI system with stroboscopic illumination for measuring vibration mode shapes is constructed and the operating software is programmed. The results are compared with that of commercial ESPI system.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.1
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• pp.37-43
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• 2005

Plant pipe has a fatigue life which is induced by repeated stress come from the variation of temperature and pressure. To avoid the fatigue crack of plant pipe which is produced by long term repeated stress, plant operator has to limit the mont of operating transient. This paper introduced the study result about discrimination methodology of plant transient by using the fuzzy pattern recognition. As result of applying the fuzzy pattern recognition to actual plant operation data, it is confirmed that fuzzy pattern recognition methodology can be useful for the comparison of similarity for the transients of similar output but has different time pattern.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.5
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• pp.81-86
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• 2011

In this paper, fractal microstrip patch antenna in a semicircle, by designing a multi-resonant antenna was improved by bandwidth issues, including the IEEE 802.11 wireless LAN and IEEE802.16e-band mobile WiMax specification both of which can contain non-directional antenna design and measured characteristics of the antenna for multi-resonant resonant frequency, impedance matching, radiation pattern, brilliantly polarity and multiple independent frequencies that can be controlled to meet the three semicircular wireless communications by inserting fractal patch antenna was designed.

• Journal of the Korean Institute of Telematics and Electronics
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• v.17 no.6
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• pp.44-50
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• 1980

A microcomputer based automatic insulin del ivory system was designed to control the speed of the Infusion pump depending upon the required amount of insulin at one minute interval for 24 hours. The desired insulin pattern for a diabetic patient was computed by computer programs based on a mathematical model of the insulin transport where the transport parameters were obtained using a linear regression analysis of the measured changes of insulin concentration in normal subjects.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.299-301
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• 1999

This paper describes the characteristics of PD pattern and acoustic signal for the possible four states of particles in GIS. For each case of defect, the PD patterns and acoustic signals were measured and analyzed. As a result, the characteristics of the discharge patterns and ultrasonic signals depending for each defect state could be distinguished. Using the discharge patterns and ultrasonic signal waves, the defects in the GIS and the states of the particles can be distinguished.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2000.11a
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• pp.183-187
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• 2000

This paper deals with multiresolution analysis of wavelet transform for partial discharge(PD), both corona and surface discharge. Multiresolution analysis was used for performing discrete wavelet transform. PD signals was decomposed into "approximation" and "detail" components until 4 levels by using discrete wavelet analysis. In this paper, daubechies family is adopted for the research of the characteristics of PD signals. The results show that in corona discharge the segment 7, 8, 9, 10, 11 values of defined variable is increased with discharge process, so phase distribution is characterized by 210~330 ranges. In case surface discharge in expoxy insulator inserted, defined variable values is fairly symmetric discharge pattern because coupled both corona and dielectric bounded discharges. We can confirmly discriminate the type PD source. the type PD source.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.443-447
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• 2001

The PLL synthesizer is used often in communication system due to several merits, such as broad bandwidth, high accuracy and stability of frequency. But it is difficult to use in torrent digital communication systems that need frequency hopping at a high speed because of its long frequency hopping time. In this paper, we designed frequency synthesizer that generate the clock frequency randomly at a high speed using the DDS technology and is applied to the pattern generator system for digital image.