• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.64-66
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• 2007

In this paper, a digital inclinometer to measure the angle and acceleration signals of subject laid on Roll was designed. The designed system consists of a tilt sensor, biaxial accelerometer, microcontroller and BlueTooth module. The designed digital inclinometer was easy to handle and easy to wear. To evaluate the performance of the system, we measured simultaneously the angle and acceleration signals from the 3 subjects on the Roll with two instruments which are ZEBRIS and our system. The measured signals were processed by statistical method and then the correlation coefficient of 0.93 was shown. From the results, the designed digital inclinometer is shown to be useful in assessment of body movement.

• Science of Emotion and Sensibility
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• v.10 no.4
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• pp.631-637
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• 2007

This research focuses on similarity evaluation of images according to tones of images. Color space of images were converted RGB color space into HSI color space. The information entropy criteria has been taken for evaluating similarity of images for digital library. The similarity was then calculated by combining correlation coefficients and information entropy. Those two values are further analyzed with a relation to human sensibility.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.11
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• pp.657-661
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• 2003

In this paper, we designed a portable digital pressure algometer which not only can measure the pain level objectively and quantitatively, but also is able to do RF communication. This system consists of pressure sensor for pain measurement, analog signal analysis, digital hardware based on PIC16C73B, RF communication and display. To evaluate the performance of the developed system, we measured pressure threshold using commercial analog PA(Pressure Algometer) and the proposed system, and then evaluated the correlation and confidence. Using linear regression analysis, standard deviation of 0.1731 and R-square value of 99.3% were obtained. In conclusion, the above results showed good performance and its usability in measuring the pain clinically.

• ETRI Journal
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• v.24 no.3
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• pp.181-189
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• 2002

Digital watermark technology is now drawing attention as a new method of protecting digital content from unauthorized copying. This paper presents a novel audio watermarking algorithm to protect against unauthorized copying of digital audio. The proposed watermarking scheme includes a psychoacoustic model of MPEG audio coding to ensure that the watermarking does not affect the quality of the original sound. After embedding the watermark, our scheme extracts copyright information without access to the original signal by using a whitening procedure for linear prediction filtering before correlation. Experimental results show that our watermarking scheme is robust against common signal processing attacks and it introduces no audible distortion after watermark insertion.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.229-230
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• 2007

카메라 시스템에서 일반적인 Noise Reduction방법은 Noise간에 서로 Correlation이 없고 Independent한 White Noise이며, Zero Mean Noise라는 가정 하에 설계된 것이다. 본 논문에서는, 실제 Non-zero Mean Noise 현상을 규명하고, 이에 의해 발생한 Low Level Signal의 Boost-up 및 High Level Signal의 Drag-down을 Correction하여 화질을 개선하기 위한 방안을 제안한다.

• 한국가시화정보학회:학술대회논문집
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• 2006.12a
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• pp.21-24
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• 2006

Transient and asymmetric density distributions have been investigated by a digital speckle tomography with a novel integration method. Multiple CCD images captured movements of speckles in three angles of view simultaneously because the flows were asymmetric and unsteady. The speckle movements which have been formed by a ground glass between no flow and downward butane flow from an elliptical nozzle have been calculated by a cross-correlation tracking method so that those distances can be transferred to deflection angles of laser rays for density gradients. A novel integration method has been developed to obtain projection data from the deflection angles for the speckle tomography. The unsteady density fields have been reconstructed from the accurate projection values by the digital speckle tomography method using the developed integration method.

• Journal of the Optical Society of Korea
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• v.18 no.3
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• pp.230-235
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• 2014

Two-step quadrature phase-shifting digital holography based on the calculated intensity of a reference wave is proposed. In the Mach-Zehnder interferometer (MZI) architecture, the method only records two quadrature-phase holograms, without reference-wave intensity or object-wave intensity measurement, to perform object recoding and reconstruction. When the reference-wave intensity is calculated from the 2D correlation coefficient (CC) method that we presented, the clear reconstruction image can be obtained by some specific algorithm. Its feasibility and validity were verified by a series of experiments with 2D objects and 3D objects. The presented method will be widely used in real-time or dynamic digital holography applications.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.86.1-86
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• 2002

Polarity correlation is a simplified version of the usual, having a possibility of real-time processing without any reduction of precision. In this paper, its applicability in deterministic signals is first explored generally, by theoretical or numerical analysis of four kinds of the typical signals. Then, based on the results, its two applications are proposed, that are detection and demodulation of FSK signals in digital communication, and time delay estimasion in ultrasonic A-mode measurement. The effectiveness of the proposed applications is confirmed by its superior implementation ability and the results of numerical experiments under practical circumstances.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.2
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• pp.141-147
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• 2011

This study analyzed the issues and its usefulness of drawing small-scale digital map by using the large-scale digital map which was producted with high-resolution digital aerial photograph which are commonly photographed in recent years. To this end, correlation analysis of the feature categories on the digital map was conducted, and this map was processed by inputting data, organizing, deleting, editing, and supervising feature categories according to the generalization process. As a result, 18 unnecessary feature codes were deleted, and the accuracy of 1/5,000 for the digital map was met. Although the size of the data and the number of feature categories increased, this was proven to be shown due to the excellent description of the digital aerial photograph. Accordingly, it was shown that drawing a small-scale digital map with the large-scale digital map by digital aerial photograph provided excellent description and high-quality information for digital map.

• Korean Journal of Optics and Photonics
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• v.31 no.5
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• pp.205-212
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• 2020

In the performance of a wind turbine system, the blades play a vital role. However, they are susceptible to damage arising from complex and irregular loading (which may even cause catastrophic collapse), and they are expensive to maintain. Therefore, it is very important both to find defects after blade manufacturing is completed and to find damage after the blade is used for a certain period of time. This study provides a new perspective for the detection of internal defects in glass-fiber- and carbon-fiber-reinforced panels, which are used as the main materials in wind turbine blades. A gap or fracture between fiber-reinforced materials, which may occur during blade manufacturing or operation, is simulated by drilling a hole 5 mm in diameter in the middle layer of the laminated material. Then, a digital-image-correlation (DIC) method is used to detect internal defects in the blade. Tensile load is applied to the fabricated specimen using a tensile tester, and the generated changes are recorded and analyzed with the DIC system. In the glass-fiber-reinforced laminated specimen, internal defects were detected from a strain value of 5% until the end of the experiment, while in the case of the carbon-fiber-reinforced laminated specimen, internal defects were detected from 1% onward. It was proved using the DIC system that the defect was detected as a certain level of strain difference developed around the internal defects, according to the material properties.