• Journal of the Institute of Convergence Signal Processing
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• v.4 no.2
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• pp.25-30
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• 2003

Recently, development of digital technology is occupying a large part of multimedia information like character, voice, image, video, etc. Research about video indexing and retrieval progresses especially in research relative to video. In this paper, we propose new algorithm(Frame Feature Comparison) for MPEG video segmentation. Shot, Scene Change detection is basic and important works that segment it in MPEG video sequence. Generally, the segmentation algorithm that uses much has defect that occurs an error detection according to a flash of camera, movement of camera and fast movement of an object, because of comparing former frames with present frames. Therefore, we distinguish a scene change one more time using a scene change point detected in the conventional algorithm through comparing its mean value with abutted frames. In the result, we could detect more corrective scene change than the conventional algorithm.

• Journal of Broadcast Engineering
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• v.22 no.6
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• pp.734-743
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• 2017

In this paper, we introduce a technique to detect the video forgery using coding pattern analysis. In the proposed method, the recently developed standard HEVC codec, which is expected to be widely used in the future, is used. First, HEVC coding patterns of the forged and the original videos are analyzed to select the discriminative features, and the selected feature vectors are learned through the machine learning technique to model the classification criteria between two groups. Experimental results show that the proposed method is more effective to detect frame deletions for HEVC-coded videos than existing works.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.205-212
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• 2003

This paper may provide a basic design data for the safer car seat mechanism and the quality of the material used by finding out the passenger's dynamic behavior when protected by seat belt during collision. A computer simulation with finite element method is used to accomplish this objective. At first, a detailed geometric model of the seat is constructed using CAD program. The formation of a finite element from a geometric data of the seat is carried out using Hyper-Mesh that is the commercial software for mesh generation and post processing. In addition to seat modeling, the finite element model of seat belt and dummy is formed using the same software. Rear impact analysis is accomplished using Pam-Crash with crash pulse. The part of the recliner and right frame is under big stress in rear crash analysis because the acceleration force is exerted on the back of the seat by dummy. The stress condition of the part of the bracket is checked as well because it is considered as an important variable on the seat design. Front impact model which including dummy and seal belt is analyzed. A Part of anchor buckle of seat frame has high stress distribution because of retraction force due to forward motion of dummy at the moment of collision. On the basis of the analysis result, remodeling and reanalysis works had been repeatedly done until a satisfactory result is obtained.

• Journal of information and communication convergence engineering
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• v.5 no.4
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• pp.339-345
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• 2007

Video transcoding is a technique used to convert a compressed input video stream with an arbitrary format, size, and bitrate into a different attribute video stream different attributes to provide a efficient video streaming service for the customers is dispersed in the heterogeneous networks. Specifically, frames deletion occur in a transcoding scheme that exploits the adjustment of frame rate, and at this time, the loss in temporal relation among frames due to frame deletion is compensated for the prediction of motion estimation by reusing motion vectors in the would-be deleted frames. But the processing time for transcoding don't have an improvement as much as our expectation because transcoding is done only within the transcoder. So in this paper, we propose a new transcoding algorithm based on prediction period to improve transcoding-related processing time. For this, we also modify the existing encoder so as to adjust dynamically frame rate based on the prediction period and deletion period of frames. To check how the proposed algorithm works nicely, we implement a video streaming system with the new transcoder and encoder to which it is applied. The result of the performance test shows that the streaming system with proposed algorithm improve 60% above in processing time and also PSNR have a good performance while the quality of pictures is preserved.

• ETRI Journal
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• v.35 no.2
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• pp.281-291
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• 2013

A video signature is a set of feature vectors that compactly represents and uniquely characterizes one video clip from another for fast matching. To find a short duplicated region, the video signature must be robust against common video modifications and have a high discriminability. The matching method must be fast and be successful at finding locations. In this paper, a frame-based video signature that uses the spatial information and a two-stage matching method is presented. The proposed method is pair-wise independent and is robust against common video modifications. The proposed two-stage matching method is fast and works very well in finding locations. In addition, the proposed matching structure and strategy can distinguish a case in which a part of the query video matches a part of the target video. The proposed method is verified using video modified by the VCE7 experimental conditions found in MPEG-7. The proposed video signature method achieves a robustness of 88.7% under an independence condition of 5 parts per million with over 1,000 clips being matched per second.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.161-162
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• 2011

Recently, many research works are focusing on DVC (Distributed Video Coding) system for low complexity encoder. However the feedback channel-based parity bit control is a major cause of the high decoding time latency. Spatial and temporal correlation is high in video and, therefore, the statistical property can be applied for the parity bit request of LDPCA frame. By introducing frame adaptive parity bit request estimation method, this paper proposes a new method for reducing the decoding time latency. Through computer simulations, it is shown that the proposed method achieves about 80% of complexity reduction, compared to the conventional no-estimation method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.7
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• pp.799-808
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• 2016

The IEEE 802.15.7r1 Task Group (TG7r1), known as the revision of the IEEE 802.15.7 Visible Light Communication standard targeting the commercial usage of visible light communication systems which mainly use either image sensors or cameras, is of interest in this paper. The vast challenge in Image Sensor Communications (ISC), as it has been addressed in the Technical Consideration Document (TCD) of the TG7r1, is the Image Sensor Compatibility to support the variety of different commercial cameras available on the market. The on-going ISC standard must adhere to compatible image sensors regulations. This paper brings an inside review of the TG7r1 and an inside look of related works on Image Sensor Communications. The paper analyzes the compatibility features by introducing a revised model of receiver to explain how those features are necessary. One of the most challenging but interesting features is the capability in being compatible to camera frame rates. The variation of camera frame rate is modeled from verified experimental results. Noticeably, three singular approaches to support frame rates compatibility, including temporal approach, spatial approach, and frequency-domain approach, are proposed on the paper along with concise definitions. Those schemes have been presented as valuable proposals on the call-for-proposal meeting series of the TG7r1 recently.

• Steel and Composite Structures
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• v.9 no.4
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• pp.381-395
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• 2009

This paper presents the details of an advanced Finite Element (FE) analysis of a plane steel portal frame with semi-rigid beam-to-column connections subjected cyclic loading. In spite of several component models on cyclic behaviour of connections presented in the literature, works on numerical investigations on cyclic behaviour of full scale frames are rather scarce. This paper presents the evolution of an FE model which deals comprehensively with the issues related to cyclic behaviour of full scale steel frames using ABAQUS software. In the material modeling, combined kinematic/isotropic hardening model and isotropic hardening model along with Von Mises criteria are used. Connection non-linearity is also considered in the analysis. The bolt slip which happens in friction grip connection is modeled. The bolt load variation during loading, which is a pivotal issue in reality, has been taken care in the present model. This aspect, according to the knowledge of the authors, has been first time reported in the literature. The numerically predicted results using the methodology evolved in the present study, for the cyclic behaviour of a cantilever beam and a rigid frame, are validated with experimental results available in the literature. The moment-rotation and deflection responses of the evolved model, match well with experimental results. This proves that the methodology for evolving the steel frame and connection model presented in this paper is closer to real frame behaviour as evident from the good comparison and hence paves the way for further parametric studies on cyclic behaviour of flexibly connected frames.

• Journal of the Korea Institute of Building Construction
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• v.5 no.1 s.15
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• pp.89-96
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• 2005

The increase of hish-rise residential-commercial buildings is required to cut down a term of works and the cost of construction. Reinforced concrete structures and steel framed reinforcement concrete that are commonly used have the difficulty in reducing them. Therefore, the purpose of this study is to propose a new precast concrete complex system and to analyze its economical feasibility. The economic analysis is performed through comparing the cost of a high-rise reinforced building that was already constructed with that of the new proposed precast concrete system, which is limited to structural frame work of typical floors. This study shows that the proposed precast concrete complex system is economical. Further research should be directed at including the influence of a term of works.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.187-188
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• 2015

The construction finishing work is emphasized according to high dependence on labor and long term that occupy approximately 40% in construction period, so that it is required for the alternatives such as automation technology. However, it is insufficient to develop the automation technology of construction finishing work compared to other works, for instance, frame work. Also it is not enough about this preliminary research which survey the improvement needs to select the development object. Therefore, this study aimed at derivation of detail works required improvement in ceiling finishing work by the questionnaire survey. These results may provide the basic information to develop the automation technology of construction finishing work.