[카테고리:] 미분류

Useful Expressions

The Elements of Presentation

▣ Title : Energy-Bounding Approaches for Robustly Stable Haptic Interaction,
               Bilateral Teleoperation, & Robot Contact Control
▣ Speaker : Prof.  Jeha Ryu (GIST)
▣ Date & Time : Friday, October 5 (14:00pm ~ 15:30pm)
▣ Place : LG Research Building, Room #101
▣ Host : Prof. Sangchul Won (Tel. 2221)
              BK21 Educational Institute of Future Information Technology
▣ Abstract : Haptic or force feedback can provide useful information to the operator when interacting with virtual, augmented, and real environments through haptic sensations. In these systems, stability is a key issue in haptic interaction control since haptic interaction has a bidirectional energy flow, unlike visual or auditory displays. Instability in haptic systems can significantly deteriorate haptic sensations and may even harm human users or cause damage to the haptic interfaces. Besides stability, high quality force feedback must be provided while guaranteeing interaction stability in order to deliver a transparent haptic sensation to the user.  This seminar presents the EBA (Energy Bounding Approaches) for the robustly stable and transparent haptic interaction, haptic teleoperation, and general robot contact controls.  The proposed approaches are almost the same for the above three systems.  Moreover, the controller is very simple and so robust against the time delays and uncertainties in the system.  Real experimental results including intercontinental haptic teleoperation will be presented. Finally, real haptic teleoperation from POSTECH to GIST will be demonstrated at site.

▣ Title : Coordination in Mobile-manipulators
▣ Speaker : 이장명 교수 (부산대학교) / Prof. Jang Myung Lee (Pusan University)
▣ Time : 4. 20(금) 오후 2:00~3:30 / pm14:00~15:30, April 20 (Fri)
▣ Place : LG동 강당 (101호) / Room #101, LG Research Bldg.
▣ Hosted by : 원상철 교수 (T. 279-2221) / Prof. Sang Chul won (T. 279-2221)   
    BK21 미래정보기술사업단 / BK21 Educational Institute of Future Information Technology
▣ Abstract : 
 The coordination between the mobile robot and manipulators have been discussed in detail.
Through the visual feedback, the end-effector of the manipulator can be controlled to the desired position with a desired configuration.
 While it is moving there are several factors to be considered: energy, torque, time, and efficiency. All those factors are combined to select an optimal posture for the manipulators for a given task.
 The control of the mobile robot needs to be concerned with the configuration of the manipulators to keep the balance.
 The coordination between the mobile robot and the manipulators is required to cope with these requirements.
 Some preliminary experimental results will be demonstrated.

 
▣ Title : Trends of Radar technologies and development process
▣ Speaker : Soo Hong Kim, Director (LIG Nex1 ISR Research Center)
▣ Time : Friday, May 25, 2012 (2:00pm-3:30pm)
▣ Place : Room #101, LG Research Bldg.
▣ Hosted by : Prof. Kyung-Tae Kim (Tel. 279-2381)
▣ Abstract : In this presentation, I will introduce two topics about radar system development. In the first topic, the basic concept of radar system and required technologies are presented. The radar transmits high power microwave signal to space, receives echo signal from target, and extract information of targets. The technology characteristics of radar system include big antenna, high power of amplifier, high dynamic range of a receiver, and high speed signal processing. He talks also new trends and technology about radar. The second is how we can develop radar systems. Radar is very complex system and radar development is not simple. Technologies are very important, but there are more things for radar development, such as time schedule, budget, performance, trade-off issue, and/or people management problem. I will introduce system engineering (SE) and the radar development process with some examples based on the experience of radar development program in LIG Nex1.

▣ Title : On the Design of Secure Codes at Finite Lengths for Wiretap Channel
▣ Speaker : Prof. Jeongseok Ha (KAIST)
▣ Time : Friday, September 14, 2012 (2:00pm-3:30pm)
▣ Place : Room #101, LG Research Bldg.
▣ Hosted by : Prof. Bumman Kim (Tel. 279-2231)
▣ Abstract : Ozarow and Wyner proposed a secrecy code design scheme using a linear code and its cosets. It was shown that when a wiretap channel has a noiseless main channel and an eavesdropper taps a subset of coded bits through a wiretapper’s channel, the eavesdropper’s equivocation is readily obtained by analyzing a parity-check matrix of the linear code. However, for wiretap codes at finite lengths, the complexity to find the equivocation grows rapidly and becomes prohibitive with the increasing length of codewords. In this talk, we introduce a tight lower bound on the equivocation that can be available by simple manipulations when a secrecy code is transmitted over a perfect-BEC wiretap channel of type-I. The lower bound provides a guaranteed secrecy performance for various linear codes at any lengths over perfect-BEC wiretap channels of type-I. It will be demonstrated that the lower bound can be applied to design of secrecy codes for wiretap channels of type-I with Gaussian main and wiretapper’s channels.
 In this talk, we also discuss a binary erasure wiretap channel of type II in which the number of eavesdropped bits becomes available a posteriori. We aim at achieving perfect secrecy over such a channel model. The most appropriate application is a secret key agreement scheme. We present a secret key agreement scheme that adopts the formulation S = HX of Wyner-Ozarows’s linear coset coding. The scheme is based on the following simple observation: even if some information on a secret message S leaked out, it is still possible to have perfect secrecy for some subsequence of S. Our secret key agreement scheme achieves perfect secrecy by taking only those subsequences that are independent of the eavesdropped bits. Our secret key agreement scheme naturally leads to defining a security measure D for parity-check matrices such that the eavesdropper gets zero information on the subsequence as long as the length of the subsequence is less than the security measure D. Possible applications of the key agreement scheme will also be introduce.

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