• The Journal of the Korea Contents Association
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• v.9 no.5
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• pp.91-98
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• 2009

Recent digital camera development tendency shows the higher ISO extension which enables a user to take a picture in deemed lighting condition without using a flash or another equipment. Also noise reduction function has been developed to adjust the higher ISO extension. But using the high ISO causes a lot of noises so that proper noise reduction function should be adjusted. So the manufacturers introduce the advanced noise reduction function with higher ISOs as the digital camera performance development. On the other hands, the defect of noise reduction is not widely open such as remaining noise in high ISOs and decreasing resolution. Therefore, in this research we verify and experiment the decrease of resolution by using noise reduction function on a digital camera. Moreover we analyze the results how much the noise reduction function effects to the image resolution. And we present the results as practical numerical values.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.4
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• pp.261-267
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• 2009

Due to the measurement noise or system noise, the performance of photovoltaic power generation system can be degraded. If this noise is contained in the solar array voltage measurement signal, the correct operation of the maximum power point tracker can not be guaranteed. The application of the extended Kalman filter to the photovoltaic system can obtain enhanced states estimation result. The Kalman filter provides a recursive solution to optimally estimate from random noise signals. Additionally, as a consequence of Kalman filter, the unmeasurable state such as inductor current can be estimated without current sensor. The methods for system modeling and extended Kalman filter design are presented and the experimental results verify the validity of the proposed system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.113-122
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• 2016

In this paper, we suggest a approach which comprises fast Fourier transform inversion by wavelet noise attenuation. It represents an inverse filtering by adopting a factor into the Wiener filtering, and the optimal factor is chosen to minimize the overall mean squared error. in order to apply the Wiener filter, we have to compute the power spectrum of original image from the corrupted figure. Since the Wiener filtering contains the inverse filtering process, it expands the noise when the blurring filter is not invertible. To remove the large noises, the best is to remove the noise using wavelet threshold. Wavelet noise attenuation steps are consisted of inverse filtering and noise reduction by Wavelet functions. experimental results have not outperformed the other methods over the overall restoration performance.

• Korean Journal of Digital Imaging in Medicine
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• v.9 no.1
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• pp.21-30
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• 2007

Our objective was to evaluate the CT attenuation coefficient and noise of spatial domain filtering as an alternative to additional image reconstruction using different kernels in abdominal CT. Derived from thin collimated source images was generated using abdomen B10 (very smooth), B20 (smooth), B30 (medium smooth), B40 (medium), B50 (medium sharp), B60 (sharp), B70 (very sharp) and B80 (ultra sharp) kernels. Quantitative CT coefficient and noise measurements provided comparable HU (hounsfield) units in this respect. CT attenuation coefficient (mean HU) values in the abdominal were 60.4$\sim$62.2 HU and noise (7.6$\sim$63.8 HU) in the liver parenchyma. In the stomach a mean (CT attenuation coefficient) of -2.2$\sim$0.8 HU and noise (10.1$\sim$82.4 HU) was measured. Image reconstructed with a convolution kernel led to an increase in noise, whereas the results for CT attenuation coefficient were comparable. Image medications of image sharpness and noise eliminate the need for reconstruction using different kernels in the future. CT images increase the diagnostic accuracy may be controlled by adjusting CT various kernels, which should be adjusted to take into account the kernels of the CT undergoing the examination.

• Journal of the Korea Convergence Society
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• v.9 no.8
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• pp.33-39
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• 2018

In the Internet of Things (IoT) era, objects are connected to each other by wired and wireless networks, and information is exchanged whenever necessary. Channel and network environments change over time; thus, a carrier sensing function that identifies whether signals containing information are present in the channel is essential. The carrier sensing circuit of a wireless communication system determines the receiver sensitivity, and the receiver sensitivity is closely related to the service coverage and service quality of the system. As the receiver sensitivity decreases, the service coverage increases but it becomes sensitive to noise. However, as the receiver sensitivity increases, the service coverage decreases but it becomes insensitive to the noise. Therefore, carrier sensing design and optimization are very important from the viewpoint of the receiver sensitivity and noise sensitivity. This paper proposes an effective carrier sensing technique from the viewpoint of the receiver sensitivity for the long range IoT.

• Journal of radiological science and technology
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• v.31 no.1
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• pp.71-81
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• 2008

Our objective was to evaluate the image of spatial domain filtering as an alternative to additional image reconstruction using different kernels in MDCT. Derived from thin collimated source images were generated using water phantom and abdomen B10(very smooth), B20(smooth), B30(medium smooth), B40 (medium), B50(medium sharp), B60(sharp), B70(very sharp) and B80(ultra sharp) kernels. MTF and spatial resolution measured with various convolution kernels. Quantitative CT attenuation coefficient and noise measurements provided comparable HU(Hounsfield) units in this respect. CT attenuation coefficient(mean HU) values in the water were values in the water were $1.1{\sim}1.8\;HU$, air($-998{\sim}-1000\;HU$) and noise in the water($5.4{\sim}44.8\;HU$), air($3.6{\sim}31.4\;HU$). In the abdominal fat a CT attenuation coefficient($-2.2{\sim}0.8\;HU$) and noise($10.1{\sim}82.4\;HU$) was measured. In the abdominal was CT attenuation coefficient($53.3{\sim}54.3\;HU$) and noise($10.4{\sim}70.7\;HU$) in the muscle and in the liver parenchyma of CT attenuation coefficient($60.4{\sim}62.2\;HU$) and noise ($7.6{\sim}63.8\;HU$) in the liver parenchyma. Image reconstructed with a convolution kernel led to an increase in noise, whereas the results for CT attenuation coefficient were comparable. Image scanned with a high convolution kernel(B80) led to an increase in noise, whereas the results for CT attenuation coefficient were comparable. Image medications of image sharpness and noise eliminate the need for reconstruction using different kernels in the future. Adjusting CT various kernels, which should be adjusted to take into account the kernels of the CT undergoing the examination, may control CT images increase the diagnostic accuracy.

• Journal of the Korea Computer Industry Society
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• v.8 no.2
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• pp.81-88
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• 2007

The dissertation which it sees in communication the noise . it will be able to occur confirms the effect which it gives to this videotex and it the Nagao filter it will be able to reduce a noise in one original videotex which is possible and nearly it analyzes the Nagao filter of existing compared to compared to a different divided territory and for the efficiency which restores it sets the filter which is the possibility of reducing the MSE (Mean Square Error) it proposes simulation and the result it leads and the superiority of this method it confirms.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.3
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• pp.8-8
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• 2004

본 논문에서는 새로운 interpolation-2 방식의 비교기 구조를 제안하여 칩 면적과 전력 소모를 줄이며 오류정정 회로를 내장하는 6-비트 70㎒ ADC를 설계하였다. Interpolation 비교기를 적용하지 않은 flash ADC의 경우 2n개의 저항과 2n -1개의 비교기가 사용되며 이는 저항의 수와 비교기의 수에 비례하여 많은 전력과 큰 면적을 필요로 하고 있다. 또한, interpolation-4 비교기를 적용한 flash ADC는 면적은 작으나 단조도, SNR, INL, DNL 특성이 떨어진다는 단점이 있었다. 본 논문에서 설계한 interpolation-2 방식의 ADC는 저항, 비교기, 앰프, 래치, 오류정정 회로, 온도계코드 디텍터와 인코더로 구성되며, 32개의 저항과 31개의 비교기를 사용하였다. 제안된 회로는 0.18㎛ CMOS 공정으로 제작되어 3.3V에서 40mW의 전력소모로 interpolation 비교기를 적용하지 않은 flash ADC에 비해 50% 개선되었으며, 칩 면적도 20% 감소되었다. 또한 노이즈에 강한 오류정정 회로가 사용되어 interpolation-4 비교기를 적용한 flash ADC 에 비해 SNR이 75% 개선된 결과를 얻었다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.31-32
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• 2019

본 논문에서는 최근 빅데이터 활용 분야의 큰 이슈인 트위터 메시지의 효율적인 감정 분석을 위한 POS 기반의 단어 군집화 기법을 제안하였다. 기존에 군집화를 통한 다양한 텍스트 감정 분석 기법이 제시되어 왔으나, 군집화 된 기능과 분류 결과 간의 관련성에 대한 연구는 미흡하였다. 또한 모든 단어에 대한 감정 분석은 노이즈로 작용될 수 있는 단어로 인해 정확도가 감소할 수 있다. 본 논문에서는 이를 해결하기 위하여 Chi Square 기법을 통하여 분석 결과에 영향을 미치는 단어에 가중치를 부여함으로써 정확도를 향상시킨다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.21-31
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• 2017

In this paper, the Zynq system-on-chip (SoC) platform is used to design an adaptive noise reduction and edge-detection system using partial reconfiguration. Filters are implemented in a partially reconfigurable (PR) region to provide high computational complexity in real-time, 1080p video processing. In addition, partial reconfiguration enables better utilization of hardware resources in the embedded system from autonomous replacement of filters in the same PR region. The proposed edge-detection system performs adaptive noise reduction if the noise density level in the incoming video sequences exceeds a given threshold value. Results of implementation show that the proposed system improves the accuracy of edge-detection results (14~20 times in Pratt's Figure of Merit) through self-reconfiguration of filter bitstreams triggered by noise density level in the video sequences. In addition, the ZyCAP controller implemented in this paper enables about 2.1 times faster reconfiguration when compared to a PCAP controller.