• Journal of Broadcast Engineering
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• v.17 no.1
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• pp.179-190
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• 2012

In Distributed Video Coding(DVC), a low complexity encoder can be realized by shifting complex processes of encoder such as motion estimation to decoder. Since not only motion estimation/compensation processes but also channel decoding process needs to be performed at DVC decoder, the complexity of a decoder is significantly increased in consequence. Therefore, various fast channel decoding methods are proposed for the most computationally complex part, which is the channel decoding process in DVC decoding. As the channel decoding process becomes faster using various methods, however, the complexity of the other processes are relatively highlighted. For instance, the complexity of side information generation process in the DVC decoder is relatively increased. In this paper, therefore, a fast method for the DVC decoding is proposed by using adaptive search range method in side information generation process. Experimental results show that the proposed method achieves time saving of about 63% in side information generation process, while its rate distortion performance is degraded only by about 0.17% in BDBR.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5D
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• pp.635-644
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• 2009

Image processing technique in the outdoor environment is very sensitive, and it tends to lose a lot of accuracy when it rapidly changes by outdoor environment. Therefore, in order to calculate accurate traffic information using the traffic monitoring system, we must resolve removing shadow in transition time, Distortion by the vehicle headlights at night, noise of rain, snow, and fog, and occlusion. In the research, we developed a system to calibrate the amount of traffic, speed, and time occupancy by using image processing technique in a variety of outdoor environments change. This system were tested under outdoor environments at the Gonjiam test site, which is managed by Korea Institute of Construction Technology (www.kict.re.kr) for testing performance. We evaluated the performance of traffic information, volume counts, speed, and occupancy time, with 4 lanes (2 lanes are upstream and the rests are downstream) from the 16th to 18th December, 2008. The evaluation method performed as based on the standard data is a radar detection compared to calculated data using image processing technique. The System evaluation results showed that the amount of traffic, speed, and time occupancy in period (day, night, sunrise, sunset) are approximately 92-97% accuracy when these data compared to the standard data.

• Archives of Plastic Surgery
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• v.46 no.6
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• pp.535-543
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• 2019

Background A high incidence of breast animation deformity (BAD) has been reported following immediate breast reconstruction with subpectorally placed implants. The aim of this study was to assess and compare the incidence of BAD in women who underwent either subpectoral or prepectoral immediate breast reconstruction. Therefore, we developed a grading tool and tested its reproducibility in a clinical setting. Methods Video recordings of 37 women who had undergone unilateral or bilateral immediate breast reconstruction were evaluated by two consultant plastic surgeons. The degree of BAD was assessed by our grading tool, named the Nipple, Surrounding Skin, Entire Breast (NSE) grading scale, which evaluates the degree of tissue distortion in three areas of the breast. Blinded assessments were performed twice by each observer. Results Eighteen patients were reconstructed with subpectoral implant placement and 19 with prepectoral implant placement. Using the NSE grading scale, we found a significant difference in the degree of BAD between the groups, in favor of patients who underwent prepectoral immediate breast reconstruction (0.2 vs. 4, P=0.000). Inter- and intraobserver agreement was moderate (74%) to strong (88%). Conclusions The incidence and severity of BAD was significantly lower in women reconstructed with a prepectorally placed implant than in those who underwent subpectoral immediate breast reconstruction. All patients reconstructed using the subpectoral technique had some degree of BAD. The inter- and intraobserver agreements were high when using the NSE grading scale, suggesting it is an easy-to-use, reproducible scale for assessing BAD in women who undergo immediate breast reconstruction.

• Journal of Broadcast Engineering
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• v.22 no.4
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• pp.448-461
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• 2017

This paper proposes a vehicle counting and speed estimation method for traffic situation analysis in road CCTV videos. The proposed method removes a distortion in the images using Inverse perspective Mapping, and obtains specific region for vehicle counting and speed estimation using lane detection algorithm. Then, we can obtain vehicle counting and speed estimation results from using optical flow at specific region. The proposed method achieves stable accuracy of 88.94% from several CCTV images by regional groups and it totally applied at 106,993 frames, about 3 hours video.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.43 no.2 s.308
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• pp.28-32
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• 2006

In this paper, NTSC TV Transmitter Modulo will be designed and produced which make possible playing the motion picture not only on TV but also on portable TV. NTSC TV Transmitter Module modulates signals that received Video and Audio signals from a mobile on NTSC TV CH4 mechanism. so it has an advantage of convenience that watching the motion picture of mobile on TV without any other cable through transmitting signals by wireless. But it has some demerits of long size antenna and noise sensitiveness. In the future, if some problems like a size of antenna distortion of signal and noise can be solved through continuous researching about Radio Frequency part, it is possible to play mobile motion pictures on the more media like a camcorder, DVD player and so on.

• Journal of the Korea Society of Computer and Information
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• v.10 no.6 s.38
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• pp.233-238
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• 2005

In general CELP(Code Excited Linear Prediction) type vocoders provide good speech qualify around 4.8kbps. Among them, G.723.1 developed for Internet Phone and video-conferencing includes two vocoders, 5.3kbps ACELP(Algebraic-CELP) and 6.3kbps MP-MLQ(Multi-Pulse Maximum Likelihood Quantization) In order to improve the speech qualify in CELP vocoder, in this paper. we proposed a new spectrum analysis algorithm with variable window In CELP vocoder, the spectrum of the synthesised speech signal is distorted because the fixed size windows is used for spectrum analysis. So we have measured the spectral leakage and in order to minimize the spectral leakage have adjusted the window size. Applying this method G.723.1 ACELP, we can got SD(Spectral Distortion) reduction 0.084(dB), residual energy reduction 6.3$\%$ and MOS(Mean Opinion Score) improvement 0.1.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.1
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• pp.366-381
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• 2020

Steganography has been successfully employed in various applications, e.g., copyright control of materials, smart identity cards, video error correction during transmission, etc. Deep learning-based steganography models can hide information adaptively through network learning, and they draw much more attention. However, the capacity, security, and robustness of the existing deep learning-based steganography models are still not fully satisfactory. In this paper, three models for different cases, i.e., a basic model, a secure model, a secure and robust model, have been proposed for different cases. In the basic model, the functions of high-capacity secret information hiding and extraction have been realized through an encoding network and a decoding network respectively. The high-capacity steganography is implemented by hiding a secret image into a carrier image having the same resolution with the help of concat operations, InceptionBlock and convolutional layers. Moreover, the secret image is hidden into the channel B of carrier image only to resolve the problem of color distortion. In the secure model, to enhance the security of the basic model, a steganalysis network has been added into the basic model to form an adversarial network. In the secure and robust model, an attack network has been inserted into the secure model to improve its robustness further. The experimental results have demonstrated that the proposed secure model and the secure and robust model have an overall better performance than some existing high-capacity deep learning-based steganography models. The secure model performs best in invisibility and security. The secure and robust model is the most robust against some attacks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.7B
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• pp.1252-1260
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• 1999

The HFC network has a architecture of a star topology in fiber optic trunks, and tree and branch topology is used in the part of coaxial cable. It is well known that the HFC upstream channel is noisy. Ingress, common mode distortion and impulse noise exist in the upstream channel. In order to provide Quality of Service(QoS) to users with real-time data such as voice, video and interactive services, the evolving IEEE 802.14 standard for HFC networks must include an effective priority scheme. The scheme separates and resolves collisions between stations in a priority order. It is important to simulate protocols under a practical environment. The proposed algorithm in this paper is simulated with the assumption that the collision detector made certain mistake due to noises. Simulation results show that the proposed algorithm is more efficient than existing tree-based algorithm under practical environment.

• Journal of Broadcast Engineering
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• v.23 no.5
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• pp.628-635
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• 2018

In this paper, we propose a fast motion estimation algorithm which is important in video encoding. So many fast motion estimation algorithms have been published for improving prediction quality and computational reduction. In the paper, we propose an algorithm that reduces unnecessary computation, while almost keeping prediction quality compared with the full search algorithm. The proposed algorithm calculates the sum of partial block matching error for each candidate, selects the candidates for the next step, compares the stability of optimal candidates with minimum error, and finds optimal motion vectors by determining the progress of the next step. By doing that, we can find the minimum error point as soon as possible and obtain fast computational speed by reducing unnecessary computations. Additionally, the proposed algorithm can be used with conventional fast motion estimation algorithms and prove it in the experimental results.

• Progress in Medical Physics
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• v.9 no.3
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• pp.143-154
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• 1998

The image intensifier is the key component which determines the imaging characteristics in a fluoroscopic imaging system. A system performance program for clinical evaluation of two image intensifiers, that is simple, non-invasive and time effective, was described. Tests were grouped into three headings: x-ray generator, image quality, and collimation. For the x-ray generator, the kVp accuracy and the automatic exposure control operation were compared. Low- and high-contrast resolution measurements, and mesh pattern study belong to the image quality tests and those tests were performed for the video monitor and photospot images. For the collimation, usable field diameter and image distortion of image intensifiers were measured and quantified. The procedures and the results are hoped to be used for the clinical evaluation of system performance and/or acceptance tests for image intensifiers.