Eung Hyuk Lee

A Study in the Implementation of Environment of Behavior Monitoring System Based on Image Processing

According as society looks graying trend gradually, more shaped system that can achieve measuring health-state of old people more harmoniously construction required in field of old people’s welfare and medical treatment. This study suggests the system that can monitor the user, especially old people’s outward aging and health-state using CCD camera loaded fish-eye lens. Measurement of outward aging is achieved by two steps. The first is based on structure of human musculoskeletal system. This process is achieved by image processing, for example edge detecting, thresholding, skeletonization, etc. Through this process, we get the angles of arm and shoulder and curve of vertebra. The second is image acquisition about behavior pattern. For the second step, CCD camera loaded fish-eye lens is installed from the ceiling. The data-base that is acquired by the methods that this study suggests will be applied to Ubiquitous Home Automation System. So it will be in effective use for the welfare and the monitoring system for old people.

A new parity space approach to fault detection for general systems

This paper proposes a new parity space approach to a fault detection for general systems with noises, actuator faults and sensor faults. The proposed parity space approach could be more systematic than existing approaches since an efficient numerical algorithm is utilized. In addition, since the system and measurement noises are accounted in the proposed approach, the parity space residual will be noise-suppressed. When there are no noises and faults are constant on the interval of parity space’s order, the residual for each fault is shown to be exactly equal to the corresponding fault. The proposed approach is specified to the digital filter structure for the amenability to hardware implementation.

A new seamless handoff mechanism for wired and wireless coexistence networks

This paper deals with design and implementation of seamless handoff mechanism between wired and wireless network adapters for a system with both network adapters. A unique virtual adapter is developed between different adapters and then an IP address is assigned to the virtual adapter. As a general rule, when both network adapters are available, the wired adapter is preferred due to its faster transmission speed than the wireless adapter. When wired communication via the wired adapter gets disconnected while in service, the disconnection of wired adapter is automatically detected and then wireless handoff occurs by mapping information on the wireless adapter to the virtual adapter. According to the proposed handoff mechanism, the session can be continued seamlessly even when handoff between wired and wireless network adapters occurs at lower level in a network application where both IP address and port number are used to maintain session. To evaluate the proposed handoff mechanism, actual experiments are performed for various internet applications such as FTP, HTTP, Telnet, and then their results are discussed.

A finite memory structure filtering for indoor positioning in wireless sensor networks with measurement delay

In this article, an alternative indoor positioning mechanism is proposed considering finite memory structure filter as well as measurement delay. First, a finite memory structure filter with a measurement delay is designed for the indoor positioning mechanism under a weighted least-squares criterion, which utilizes only finite measurements on the most recent window. The proposed finite memory structure filtering–based mechanism gives the filtered estimates for position, velocity, and acceleration of moving target in real time, while removing undesired noisy effects and preserving desired moving positions. Second, the proposed mechanism is shown to have good inherent properties such as unbiasedness, efficiency, time-invariance, deadbeat, and robustness due to the finite memory structure. Third, through discussions about the choice of window length, it is shown that this can be considered as a useful design parameter to make the performance of the proposed mechanism as good as possible. Finally, computer simulations show that the performance of the proposed finite memory structure filtering–based mechanism can outperform the existing infinite memory structure filtering–based mechanism for the abruptly varying acceleration of moving target.

EMG Pattern Classification by Split and Merge Deep Belief Network

In this paper; we introduce an enhanced electromyography (EMG) pattern recognition algorithm based on a split-and-merge deep belief network (SM-DBN). Generally, it is difficult to classify the EMG features because the EMG signal has nonlinear and time-varying characteristics. Therefore, various machine-learning methods have been applied in several previously published studies. A DBN is a fast greedy learning algorithm that can identify a fairly good set of weights rapidly—even in deep networks with a large number of parameters and many hidden layers. To reduce overfitting and to enhance performance, the adopted optimization method was based on genetic algorithms (GA). As a result, the performance of the SM-DBN was 12.06% higher than conventional DBN. Additionally, SM-DBN results in a short convergence time, thereby reducing the training epoch. It is thus efficient in reducing the risk of overfitting. It is verified that the optimization was improved using GA.

An IEEE 802.21 MIH Functionality Assisted Proxy Mobile IPv6 for Reducing Handover Latency and Signaling Cost

This paper proposes an IEEE 802.21 Media Independent Handover (MIH) functionality assisted Proxy Mobile IPv6 (PMIPv6) mechanism for reducing handover latency and signaling cost in heterogeneous wireless networks. The proposed mechanism comes to support fast vertical handover for the mobile node (MN) irrespective of the presence or absence of MIH functionality as well as IP mobility functionality. That is, the MN does not need to be participated in any MIH related signaling for handover procedure, which can be consistent with the essential objective of the PMIPv6. The base station with MIH functionality performs handover on behalf of the MN. Therefore, the proposed mechanism can reduce burden and power consumption of MNs with limited resource and battery power. In addition, the analytical evaluation shows that the proposed mechanism can outperform the existing mechanism in terms of handover latency and total number of over-the-air signaling messages. Thus, the proposed mechanism can be expected to reduce the packet loss and the bandwidth consumption of wireless links during handover procedure comparing with the existing mechanism.

An Estimation Filtering for Packet Loss Probability Using Finite Memory Structure Strategy

A finite memory structure (FMS) strategy is applied for a packet loss probability (PLP) estimation filtering to estimate the packet rate mean and variance of the input traffic process in real-time, which is called the FMS-PLP estimation filter. The proposed FMS-PLP estimation filter uses only the finite traffic measurements on the most recent window and thus has several inherent properties such as unbiasedness and deadbeat. The proposed FMS-PLP estimation filter can be represented in either a matrix form or a simple summation form. Using computer simulations, the proposed FMS-PLP estimation filter is shown to outperform the Kalman filter with the infinite memory structure for the temporarily uncertain system.

Development of the Walking Assistant Robot for the Elderly

In this paper, we propose an architecture of walking assistant robot for the elderly which is usable at outdoor environment. It equips PXA255 embedded board, motors, laser range finder and GPS receiver. User operates it using smart handle bar. It is useful to the elderly for more comfortable walking and path guidance.

Study of ZMP Measurement for Bipedrobot Using FSR Sensor

This paper discuss a method measuring ZMP for biped robot. We obtained feet-bottom pressure distribution using FSR sensors attaching feet-bottom. We calculate value of ZMP coordinates that is the center of gravity for biped robot using their pressure distribution. Value of Biped Robot ZMP coordinates always exists in feet-bottom. When walking limbs of biped robot are controlled, inverse kinematics use method supposed by author. We introduce it in this paper.

A Study on Path Guidance System of Guide Robot for Visually Impaired

In this paper, earth coordinate of the guidance robot for the visually impaired is detected by using GPS (Global Position System), and the system which leads the visually impaired to position information (TM coordinate) in Korea is achieved through map-matching with electronic map. The visually impaired need more information about the walking path than ordinary people when walking outdoor. Therefore, we studied implementation which can guide the visually impaired more safely through map-matching with GPS signal by making electronic map for the visually impaired.