• The Journal of the Korea Contents Association
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• v.7 no.1
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• pp.116-123
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• 2007

This paper proposed a new amplitude width modulation for OLED data driver IC. The data driver controls brightness of OLED by adjusting amplitude and width of the data drive current pulse. There were two conventional methods; pulse amplitude modulation(PAM) and pulse width modulation(PWM). The PWM method suffered from lower light emitting time efficiency at low luminance signal. The PAM method suffered from large chip area using DACs for each column. The proposed method was aiming at accurately controlling of the current level by MSB data and light emitting efficiency by LSB data to improve the inefficiencies of the PAM and a PWM. The proposed AWM driver circuit implemented using $0.35-{\mu}m$ 3-poly 4-metal CMOS high voltage process. The simulation result shows the improvement in the accuracy of the gray level control even though the driver circuit is smaller than the PAM.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.3
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• pp.467-472
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• 2022

The 3D ultrasonic anemometer transmits measured data by connecting PC and RS232C interface. Depending on the observation location, it is often necessary to extend the cable connecting the PC and the sensor. When installing on the test bed of the Air Meteorological Agency, the original AWM2919 cable was required to be extended because the distance between the PC container and the equipment installation site was more than 30 m. The cable was extended through a process such as extending the AWM2919 cable, converting the interface with the PC from RS232C to RS485, and testing the RS485 communication. After the equipment was installed with an extended cable, data were remotely collected and analyzed to confirm successful cable extension.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.10
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• pp.468-476
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• 2002

Digital images are easily corrupted by noise during the data transmission, data capture and data processing. A technical method of noise analyzing and adaptive filtering for reducing of quantum noise in medical radio-fluoroscopy images is presented. By adjusting the characteristics of the filter according to local statistics around each pixel of the image as moving windowing, it is possible to suppress noise sufficiently while preserve edge and other significant information required in diagnosis. We proposed adaptive weighed median(AWM) filters based on local statistics. We showed two ways of realizing the AWM filters. One is a simple type of AWM filter, which is constructed by Homogeneous factor(HF). Homogeneous factor(HF) from the noise models that enables the filter to recognize the local structures of the image is introduced, and an algorithm for determining the HF fitted to the diagnostic systems with various inner statistical properties is proposed. We show by the experimented that the performances of proposed method is superior to these of other filters and models in preserving small details and suppressing the noise at homogeneous region. The proposed algorithms were implemented by Visual C++ language on a IBM-PC Pentium 550 for testing purposes and the effects and results of the filter in the various levels of noise and images were proposed by comparing the values of NMSE(normalized mean square error) with the value of the other existing filtering methods.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.5
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• pp.465-473
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• 2002

Images are easily corrupted by noise during the data transmission, data capture and data processing. A technical method of noise analyzing and adaptive filtering for reducing of quantum noise in radiography is presented. By adjusting the characteristics of the filter according to local statistics around each pixel of the image as moving windowing, it is possible to suppress noise sufficiently while preserve edge and other significant information required in reading. We have proposed adaptive weighted median(AWM) filters based on local statistics. We show two ways of realizing the AWM filters. One is a simple type of AWM filter, whose weights are given by a simple non-linear function of three local characteristics. The other is the AWM filter which is constructed by homogeneous factor(HF). Homogeneous factor(HF) from the quantum noise models that enables the filter to recognize the local structures of the image is introduced, and an algorithm for determining the HF fitted to the detection systems with various inner statistical properties is proposed. We show by the experimented that the performances of proposed method is superior to these of other filters and models in preserving small details and suppressing the noise at homogeneous region. The proposed algorithms were implemented by visual C++ language on a IBM-PC Pentium 550 for testing purposes, the effects and results of the noise filtering were proposed by comparing with images of the other existing filtering methods.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.20 no.1
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• pp.37-50
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• 2016

A large eddy simulation (LES) of a turbulent channel flow is performed by using the third order low-storage Runge-Kutta method in time and second order finite difference formulation in space with staggered grid at a Reynolds number, $Re_{\tau}=590$ based on the channel half width, ${\delta}$ and wall shear velocity, $u_{\tau}$. To reduce the calculation cost of LES, algebraic wall model (AWM) is applied to approximate the near-wall region. The computation is performed in a domain of $2{\pi}{\delta}{\times}2{\delta}{\times}{\pi}{\delta}$ with $32{\times}20{\times}32$ grid points. Standard Smagorinsky model is used for subgrid-scale (SGS) modeling. Essential turbulence statistics of the flow field are computed and compared with Direct Numerical Simulation (DNS) data and LES data using no wall model. Agreements as well as discrepancies are discussed. The flow structures in the computed flow field have also been discussed and compared with LES data using no wall model.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.558-561
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• 2016

선로전환기는 분기기에서 철도의 궤도를 변경하는 핵심장치 중 하나로서, 해당 부품의 고장은 열차사고에 직접적인 영향을 미친다. 현재 철도 현장에서는 관리자가 모니터링 시스템을 통해 선로전환기의 장애 및 이상상황을 감시하고 지침서에 따라 관리를 수행한다. 본 논문에서는 실제 현장에서 발생하는 대규모의 선로전환기 이상상황 데이터를 대상으로 빅 데이터 해석학적 입장에서 심층 분석이 가능한 새로운 철도 유지보수 분석 시스템의 프로토타입을 제안한다. 제안하는 시스템은 첫째, 유지관리시스템에 저장된 선로전환기 데이터와 이상상황 데이터를 정규화하고 추출하여 베이스 테이블을 생성한다. 둘째, 베이스 테이블 상의 속성들을 스타 스키마로 설계하여 철도 유지보수 큐브로 구축한다. 마지막으로, 매핑된 철도 유지보수 큐브와 오라클에서 제공하는 AWM을 활용해 다차원적이고 심층적인 OLAP(On-Line Analytical Processing) 분석이 가능하다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.5C
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• pp.542-549
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• 2007

Recently, many research activities in the image processing area are concentrated on developing new algorithms by finding the solution of the 'diffusion equation'. The diffusion algorithms are expected to be utilized in numerous applications including noise removal and image restoration, edge detection, segmentation, etc. In this paper, at first, it will be shown that the anisotropic diffusion algorithms have the similar structure with the adaptive FIR filters with cross-shaped 5-tap kernel, and this relatively small-sized kernel causes many iterating procedure for satisfactory filtering effects. Moreover, it will also be shown that lots of modifications which are adopted to the conventional Gaussian diffusion method in order to weaken the edge blurring nature of the linear filtering process increases another computational burden. We propose a new Median diffusion scheme by replacing the adaptive linear filters in the diffusion process with the AWM (Adaptive Weighted Median) filters. A diffusion-equation-based adaptation scheme is also proposed. With the proposed scheme, the size of the diffusion kernel can be increased, and thus diffusion speed greatly increases. Simulation results shows that the proposed Median diffusion scheme outperforms in noise removal (especially impulsive noise), and edge preservation.