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Encryption Scheme for MPEG-4 Media Transmission Exploiting Frame Dropping
( Dongkyoo Shin ),( Dongil Shin ),( Jaewan Shin ),( Soohan Kim ),( Seungdong Kim ) 한국인터넷정보학회 2010 KSII Transactions on Internet and Information Syst Vol.4 No.5
Depending on network conditions, a communication network could be overloaded when media are transmitted. Research has been carried out to lessen network overloading, such as by filtering, load distribution, frame dropping, and other methods. Among these methods, one of the most effective is frame dropping, which reduces specified video frames for bandwidth diminution. In frame dropping, B-frames are dropped and then I- and P-frames are dropped, based on the dependency among the frames. This paper proposes a scheme for protecting copyrights by encryption, when frame dropping is applied to reduce the bandwidth of media based on the MPEG-4 file format. We designed two kinds of frame dropping: the first stores and then sends the dropped files and the other drops frames in real time when transmitting. We designed three kinds of encryption methods using the DES algorithm to encrypt MPEG-4 data: macro block encryption in I-VOP, macro block and motion vector encryption in P-VOP, and macro block and motion vector encryption in I-, P-VOP. Based on these three methods, we implemented a digital rights management solution for MPEG-4 data streaming. We compared the results of dropping, encryption, decryption, and the quality of the video sequences to select an optimal method, and found that there was no noticeable difference between the video sequences recovered after frame dropping and the ones recovered without frame dropping. The best performance in the encryption and decryption of frames was obtained when we applied the macro block and motion vector encryption in I-, P-VOP.
Real-Time Tracking of Human Location and Motion using Cameras in a Ubiquitous Smart Home
( Dongkyoo Shin ),( Dongil Shin ),( Quoc Cuong Nguyen ),( Seyoung Park ) 한국인터넷정보학회 2009 KSII Transactions on Internet and Information Syst Vol.3 No.1
The ubiquitous smart home is the home of the future, which exploits context information from both the human and the home environment, providing an automatic home service for the human. Human location and motion are the most important contexts in the ubiquitous smart home. In this paper, we present a real-time human tracker that predicts human location and motion for the ubiquitous smart home. The system uses four network cameras for real-time human tracking. This paper explains the architecture of the real-time human tracker, and proposes an algorithm for predicting human location and motion. To detect human location, three kinds of images are used: IMAGE1 - empty room image, IMAGE2 - image of furniture and home appliances, IMAGE3 - image of IMAGE2 and the human. The real-time human tracker decides which specific furniture or home appliance the human is associated with, via analysis of three images, and predicts human motion using a support vector machine (SVM). The performance experiment of the human`s location, which uses three images, lasted an average of 0.037 seconds. The SVM feature of human motion recognition is decided from the pixel number by the array line of the moving object. We evaluated each motion 1,000 times. The average accuracy of all types of motion was 86.5%.
신동규(Dongkyoo Shin),신동일(Dongil Shin),최종화(Jonghwa Choi),권기달(Kidal Kwon) 한국정보과학회 2003 한국정보과학회 학술발표논문집 Vol.30 No.2Ⅱ
일반적인 게임 콘텐츠에 있어서 수행되는 현실세계에 대한 표현은 물리적으로 연속적이지 않다. 이는 실제 콘텐츠의 이용적인 측면에서 사용자에게 거부감을 유발시키기도 하여 게임의 재미를 반감시키기도 한다. 이 논문에서는 물리엔진을 활용한 실감형 게임콘텐츠의 설계 및 제작을 통해서 실시간적인 오브젝트에 대한 물리현상을 물리엔진을 이용하여 처리하는 기법을 보여준다. 또한, 오브젝트의 물리적인 동작을 제어하기 위해 물리엔진의 설계에 대해서 보여주며 물리엔진과 연동되는 렌더링 엔진 및 그것을 이용한 콘텐츠의 제작에 대해서도 서술한다.