Bonam Kim

Design and Implementation of a Ubiquitous ECG Monitoring System Using SIP and the Zigbee Network

The use of a Zigbee network in various health monitoring systems has become well accepted. This network promises to develop health care by allowing prompt, secure, low power, and low-cost health monitoring with real-time medical data transmission and update via the session initiation protocol (SIP). In this paper, we present a description and system architecture for a ubiquitous ECG monitoring system based on SIP and the Zigbee Network. Our proposed ubiquitous ECG monitoring system includes a wireless ECG sensor, ECG console, a Zigbee module, a SIP registrar and proxy server, a database server, and wireless devices for users. This system specifically targets patients, senior citizens, and others who may benefit from continuous, Remote health monitoring systems. We performed an evaluation of the results of this research through an ECG monitoring system design and experimentation with a pervasive computing test bed.

A survey of NETLMM in all-IP-based wireless networks

The recent advances in network-based localized mobility management (NETLMM) have facilitated the realization of All-IP based Wireless Networks. In this paper, the Proxy Mobile IPv6 (PMIPv6) actively standardized by the IETF NETLMM working group has been investigated. To explore the availability of network-based localized mobility management, the technological progress of PMIPv6 is discussed. Besides, the comparison of PMIPv6 with existing mobility management schemes is also explained. In addition, the procedure of signaling process and the simplified analysis of PMIPv6 in terms of the handoff latency are presented. Furthermore, practical applications and related open research challenges are illustrated in this paper. In addition, NETLMM in wireless mesh networks (WMNs) is discussed. Although NETLMM is not a totally new paradigm in IP study, it has been re-focused with the trend of convergence in All-IP based Wireless Networks to enhance the network performance in terms of the geographically specialized networks.

caTBUA: Context-aware ticket-based binding update authentication protocol for trust-enabled mobile networks

SUMMARY Existing binding update (BU) authentication protocols do not consider context information, such as trust, location, and current time, when verifying a mobile node’s care-of address (CoA). Instead, the correspondent node executes its own CoA validation in spite of facing a highly trusted situation or simply bypasses the CoA validation, making it difficult to maintain a reasonable trade-off between security and efficiency. This paper applies the context-aware concept to the BU process and proposes a new contextaware ticket-based binding update authentication (caTBUA) protocol. The proposed protocol dynamically performs an appropriate CoA validation based on the context information to achieve a good balance between security and efficiency. Utilizing numerical analysis to compare the performance of the proposed protocol to that of existing authentication protocols in terms of authentication cost and authentication message transmission latency confirmed that the proposed caTBUA protocol yields a better performance than the existing BU authentication protocols. Copyright q 2010 John Wiley & Sons, Ltd.

Distributive Key Management for Mobile Ad Hoc Networks

Security of mobile ad hoc networks is built upon a reliable key management system to generate and distribute symmetric encryption/decryption keys for communicating parties. While central servers generate and distribute the keys in traditional wired networks, distributive key management systems are used in mobile ad hoc networks where central approaches will fail in such dynamic, high mobility networks. Threshold cryptography1 has been proposed to provide a reliable, distributive key management for networks. In an (n, t + 1) threshold system, there are n servers to provide key generation and distribution when needed for the whole network. From these n servers, any x servers (t < x les n) can co-operate and generate a key for any node. Until now, threshold cryptography has remained only a theory. No practical key management system has been proposed to use threshold cryptography that mentioned what kind of shares servers will have in common and the practical way of creating the key from these shares . In this paper, we will construct a practical (n, t + 1)-threshold key management system using maximum distance separable codes (MDS).

DWLT compression method based on MSVQ for a real-time ECG monitoring system in WSNs

The use of a Zigbee network in various health monitoring systems has become well accepted. However, such a system has limited storage, power supply, bandwidth for communication, and processing speed when massive volumes of bio signals, especially ECG signals are involved. Various effective methods, including using low power hardware, have been proposed to maximize the limited resources. Data compression is one of the most efficient methods. In this paper, we propose an ECG compression algorithm based on a Discrete Wavelet lifting Transform (DWLT) and Multistage Vector Quantization (MSVQ) methods for a ubiquitous ECG monitoring system over the Zigbee Network. We performed an evaluation of the results of the proposed compression method through an ECG monitoring system and experimentation with a pervasive computing test bed.

Photograph Indexing and Retrieval using Combined Geo-information and Visual Features

This paper proposes a new method to automatically index searches for relevant images using geo-coded information. Photographic images are labeled with their GPS (Global Positioning System) coordinates and date/time at the moment of capture and this date is then utilized to create two layer spatial and temporal indexes for image searches. A simulation performed to estimate the effectiveness of the proposed method found that the combination of those indexes and visual features improving average recall by up to 59% and average precision by up to 49% compared to the use of visual content alone.

Bandwidth Scalable Wideband Codec Using Hybrid Matching Pursuit Harmonic/CELP Scheme

A novel hybrid harmonic/CELP scheme for bandwidth scalable wideband codec is proposed that utilizes a band-split technique, where the low-band (0-4 kHz) is critically subsampled and coded using 11.8 kbps G.729E. The high-band signal is divided into stationary mode (SM) and non-stationary mode (NSM) components based on its unique characteristics. In the SM portion, the high-band signal is compressed using a multi-stage coding combined sinusoidal model based on the matching pursuit (MP) algorithm and CELP with the circular codebook. In the NSM portion, the high-band signals are coded by CELP with both pulse and circular codebooks. For efficient bit allocation and enhanced performance, the pitch of the high-band codec is estimated using the quantized pitch parameter in low-band codec. In an informal listening test, the subjective speech quality was rated as comparable to that obtainable with 48 kbps G.722 and 12.85 kbps G.722.2.

Importance of Phase Information in Speech Enhancement

At present, the performance of multimedia technology used for processing speech and images and for mobile telecommunications is often degraded due to equipment limitations. For example, noise reduces both signal strength and quality, while channel noise leads to significant signal distortion. Hence, new techniques to deal with noise processing are an inherent part of efforts to develop multimedia technology. This study utilized speech phase information to boost the performance of speech enhancement algorithms and proved experimentally that significant improvement could be achieved by applying a modified spectral subtraction method.

TWO DISTRIBUTIVE KEY MANAGEMENT SCHEMES IN MOBILE AD HOC NETWORKS

Abstract Today’s ever smaller computing systems are increasingly spreading in our ubiquitous environrnent. Being available ubiquitously in the devices and appliances that we use everyday and everywhere, these embedded computing systems are accessible to mobile users via hand-held devices connected over wireless networks. A mobile ad hoc network (MANET) is one of the important wireless networks. In a MANET a reliable key management system is required to generate and distribute symmetric encryption/ decryption keys. The key management schemes proposed in MANETs so far have used trusted third parties (TTP) which have limitations because of the mobility of nodes. A Distributed Key Pre-distribution Scheme was proposed based on a probabilistic method without relying on any TTP but with results identical to TTP-based schemes. The scheme utilized cover-free family (CFF) properties. However, the precondition of the probabilistic method was claimed to be falsely deduced. In this paper, we propose two distributive k...

Link Quality-Based CDS (LQ-CDS) Construction in Smart Home Wireless Mesh Networks

Smart home wireless mesh networks (SH-WMNs) have emerged to become one of the promising applications of Wireless Sensor Networks (WSNs). In SH-WMNs, connected dominating set (CDS) is one of candidates for clustering formation or virtual backbone construction. During the CDS construction, however, the link that has enough bandwidth to support more end-devices should be selected in order to enhance overall network throughput and reliability. Our LQ-CDS construction scheme can improve the network performance via two metrics: interference metric and bandwidth metric. The simulation results show that LQ-CDS constructs the virtual backbone with the small subset ofDS and the link that has better bandwidth.