Ji-Hwan Park

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Digital watermarking has been considered as an important technique to protect the copyright of digital content. For a digital wa-termarking method to be effective, it is essential that a watermark embedded in a still or moving image resists against various attacks ranging from compression, filtering to cropping. As JPEG is a dominant still image compression(More)
1. I will not assign the programming project previously mentioned in " Assignments, Exams, and Grading, " as all of the homework counts as only 40% of the total grade. I have modified the course description appropriately. 2. Information about my office move included. 2 Blackboard From now on, all course documents, including the most recent version of this(More)
A variety of devices are used for robot control such as personal computers or other human interface devices, haptic devices, and so on. However, sometimes it is not easy to select a device which fits the specific character of varied kinds of robots while at the same time increasing the user's convenience. Under these circumstances, in this study, we have(More)
—This paper offers a study on Rayleigh channel capacity of opportunistic cooperative networks in conjunction with adaptive transmission where the source adapts its rate and/or power level according to the changing channel conditions while the best relay simply amplifies and forwards the signals. To this end, the upper and lower bound of the end-to-end(More)
Our study is concerned with avoiding the local minimum that occurs when the mobile robot is trapped at a concave-shaped obstacle. Mobile robots use VFF (Virtual Force Field) as their autonomous navigation method. This algorithm generates the attractive force from the target and the repulsive force from the obstacle. So using the sum of these forces, the(More)