• Journal of the Korea Society of Computer and Information
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• v.3 no.4
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• pp.97-102
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• 1998

In this paper, 1 proposed methods of fractal image compression to get better orginal images in a high compression raitos with encoding image effectively. For given signal-to-noise raitos tolerances, show the proposed compression method are higher than Fisher's method for compression raitos at all thresholds. This is due to improve compression time in the local IFS structure that reduce PIFS information storage requirements from 48bits range blocks to the 40bits.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.207-210
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• 2003

In this paper, we have implemented the DVR system which is controlled far away, and added a function of TCP/IP Network for image data and control signal transmission, the DVR system has the advantage of easy to search and of no loss in stored quality. The continuously declining price of the hard drive presents the opportunity for the DVR system to displace the analog system. Also, with spread of the internet the needs of PC based the DVR system increase. Therefore, we have implemented DVR system within a function of network. When obtained image through the PTZ camera is transmitted to digital form, very large space of storage is required, hence image compression is essential. We use JPEG2000 for compression of image. JPEG2000 adopt DWT by means of transform. DWT concentrates important information of image on subband and has feature of multi-resolution. It is effective in order to express image. Thus JPEG2000 is suitable for image compression in DVR system. The significance of this paper is to design the DVR system which is controlled through TCP/IP network and to implement transmission of image compression using JPEG2000.

• Journal of the Institute of Convergence Signal Processing
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• v.3 no.1
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• pp.41-47
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• 2002

Fractal image compression can reduce the size of image data by the contractive mapping that is affine transformation to find the block(called as range block) which is the most similar to the original image. Even though fractal image compression is regarded as an efficient way to reduce the data size, it has high distortion rate and requires long encoding time. In this paper, we presented a hybrid fractal image compression system with the modified SOFM Vector Quantizer which uses improved competitive learning method. The simulation results showed that the VQ hybrid fractal using improved competitive loaming SOFM has better distortion rate than the VQ hybrid fractal using normal SOFM.

• The Journal of the Acoustical Society of Korea
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• v.19 no.8
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• pp.12-21
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• 2000

In this paper, we propose a novel hearing aid algorithm for sensorinural hearing loss restoration with multi-channel(band) dynamic range compression and psychoacoustics. In this way, we can present a normal perception condition to the impaired listener. The proposed algorithm make loudness scaling function achieve proper loudness level, and analysis masking property for the signal will be perceived to impaired listener, and then, restore normal spectral contrast using SMR(signal-to-masking ratio) defined by distance between the level of each frequency and masking threshold.

• International Journal of Control, Automation, and Systems
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• v.4 no.3
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• pp.344-350
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• 2006

The software GPS receivers based on the SDR technology provide the ability to easily adapt the other signal processing algorithms without changing or modifying the hardware of the GPS receiver. However, it is difficult to implement the software GPS receivers using a commercial processor because of the heavy computational burden for processing the GPS signals in real-time. This paper proposes an efficient GPS signal processing scheme to reduce the computational burden for processing the GPS signals in the software GPS receiver, which uses a fundamental notion compressing the replica signals and the encoded look-up table method to generate correlation values between GPS signals and replica signals. In this paper, it is explained that the computational burden of the proposed scheme is much smaller than that of the typical GPS signal processing scheme. Finally, the processing time of the proposed scheme is compared with that of the typical scheme, and the improvement in the aspect of the computational burden is also shown.

• Journal of the Institute of Convergence Signal Processing
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• v.22 no.3
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• pp.99-103
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• 2021

Recently, convolutional neural networks (CNNs) have been widely utilized due to their outstanding performance in various computer vision fields. However, due to their computational-intensive and high memory requirements, it is difficult to deploy CNNs on hardware platforms that have limited resources, such as mobile devices and IoT devices. To address these limitations, a neural network compression research is underway to reduce the size of neural networks while maintaining their performance. This paper proposes a CNN compression technique that dynamically adjusts the thresholds of pruning, one of the neural network compression techniques. Unlike the conventional pruning that experimentally or heuristically sets the thresholds that determine the weights to be pruned, the proposed technique can dynamically find the optimal thresholds that prevent accuracy degradation and output the light-weight neural network in less time. To validate the performance of the proposed technique, the LeNet was trained using the MNIST dataset and the light-weight LeNet could be automatically obtained 1.3 to 3 times faster without loss of accuracy.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.1
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• pp.56-63
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• 2009

Nowdays, Most of Internet Contents delivered as a compressed file. It gives many advantages like deduction of communication bandwidth and transmission time etc. In case of JPEG Compression, Quantization is the most important procedure which accomplish the compression. In general signal processing, Quantization is the process which converts continuous analog signal to discrete digital signal. As you known already, Quantization over JPEG compression is to reduce magnitude of pixel value in spatial domain or coefficient in frequency domain. A lot of Data Hiding algorithms also developed to applicable for those compressed files. In this paper, we are going to unveil the influence of quantization table which used in the process of JPEG compression. Even thought most of algorithm modify frequency coefficients with considering image quality, they are ignoring the influence of quantization factor corresponding with the modified frequency coefficient. If existing algorithm adapt this result, they can easily evaluate their performances.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.6
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• pp.661-670
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• 2013

In this paper, we propose the measurement techniques of mixed waveform. Mixed waveform has phase-continuous periodic waveform with fixed frequency signal and Linear Frequency Modulation(LFM) signal. This waveform is generated from a compact radar transmitter with frequency synthesizer and high power amplifier. Frequency synthesizer generates various signal waveform with continuos phase and high power amplifier amplify transmitting signal. First, we describe a compact radar transmitter with the phase-continuos signal and then verify the distortion characteristic of pulse compression by the mismatch of LFM waveform. Second, we describe three kinds of measurement techniques for measuring LFM waveform. These techniques include methods using signal analyzer, signal source analyzer and new methods using RF mixer and phase shifter. Finally, we verify the accuracy of the measurement technique from the pulse compression result of receiving signal.

• Journal of Information Technology Applications and Management
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• v.10 no.4
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• pp.159-168
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• 2003

This paper is concerned with the compression of EEG signals using wavelet-packet based techniques. EEG data compression is desirable for a number of reasons. Primarily it decreases for transmission time, archival storage space, and in portable systems, it decreases memory requirements or increases channels and bandwidth. Upon wavelet decomposition, inherent redundancies in the signal can be removed through thresholding to achieve data compression. We proposed the energy cumulative function for deciding of the threshold value and it works very innovative of EEG data.

• Journal of Information Display
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• v.12 no.2
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• pp.77-83
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• 2011

The memory compression algorithm CCC-LCP (color-count-controlled local color palette) reduces flicker in the liquid crystal display (LCD) overdrive. Its compression ratio is 1:5.4 for 10-bit images, with a 33 dB PSNR peak signal-to-noise ratio and with five times flicker reduction compared with the block truncation coding. The authors' two-alternative forced choice subjective tests proposed two new soundness properties, the 'CMP harmlessness' and 'OD non-lost (or OD liveliness)', to clarify the functional interaction between the overdrive functionality OD and the compression functionality CMP. The tests verified that CCC-LCP is practically applicable (at a 1.2H viewing distance threshold) for 42" 37-ppi WXGA TVs.