Hwang-Bin Ryou

Optimal Sensor Deployment for Wireless Surveillance Sensor Networks by a Hybrid Steady-State Genetic Algorithm

An important objective of surveillance sensor networks is to effectively monitor the environment, and detect, localize, and classify targets of interest. The optimal sensor placement enables us to minimize manpower and time, to acquire accurate information on target situation and movement, and to rapidly change tactics in the dynamic field. Most of previous researches regarding the sensor deployment have been conducted without considering practical input factors. Thus in this paper, we apply more real-world input factors such as sensor capabilities, terrain features, target identification, and direction of target movements to the sensor placement problem. We propose a novel and efficient hybrid steady-state genetic algorithm giving low computational overhead as well as optimal sensor placement for enhancing surveillance capability to monitor and locate target vehicles. The proposed algorithm introduces new two-dimensional geographic crossover and mutation. By using a new simulator adopting the proposed genetic algorithm developed in this paper, we demonstrate successful applications to the wireless real-world surveillance sensor placement problem giving very high detection and classification rates, 97.5% and 87.4%, respectively.

An Efficient Clustering Scheme through Estimate in Centralized Hierarchical Routing Protocol

Nodes in WSN(Wireless Sensor Network) have limited energy. Once they are deployed, it is difficult to supply additional energy. Therefore the routing is most important for using energy efficiently in WSN. The routing protocols of this sensor network have two types: Directed Diffusion and SPIN such as Flat routing protocol, and LEACH (Low-Energy Adaptive Clustering Hierarchy) and LEACH-C (LEACH-Centralized) such as Hierarchical routing protocol. In this paper, we present remaining energy predictable method using computing consumption of nodes and cluster head node from first round to next round for solving LEACH-C problem that all nodes must send current energy level and own location to base station at each round in configuration. When using proposed method through simulation, we can extend the life time of network and lessen total energy of network as reducing a number of communications

A genetic algorithm for sensor deployment based on two-dimensional operators

In this paper, we propose a novel and efficient genetic algorithm to the optimal sensor placement of nodes for a wireless sensor network designed to monitor enemy vehicles in a hostile region. A notable feature of our genetic algorithm is the combination of mutation derived from physics and crossover in which heterogeneity between genes is removed by pairing nearest two-dimensional genes. Making experiments by a new simulator that is developed to improve time performance of the sensor deployment simulator based on the geographic information system, we demonstrated the superiority of the proposed genetic algorithm.

A Genetic Algorithm for the Routing Protocol Design of Wireless Mesh Networks

Wireless Mesh Network technology refers to technology that establishes a wireless network whose transmission speed is similar to that of a wired system. It provides enhanced flexibility in the building of the network, compared to the existing wired network. In addition, it has lower mobility and less restriction from the energy effect. However, there are many considerations, such as system overhead, in the case of the setting or the selection of multi-path. Accordingly, the focus is on the design and optimization of a network that can reflect this network feature and the technology to establish the path. This paper suggests methods for programming the dynamic path in Wireless Mesh Network routing. It does so by applying the evaluation value of node service, making use of the loss rate of data, the hop count of bandwidth and link, and the traffic status of the node. To respond to the programming of multi-path effectively it must consider the performance of the link and load in the fitness evaluation function.

QoS routing mechanism using mobility prediction of node in ad-hoc network

MANET(Mobile Ad hoc NETwork) consists of movable only wireless nodes, except fixed station in the wired network. Not only hosts, but also routers for data packet forwarding in network topology changes. It is hard for routing algorithm using previous wired network to be applied to this ad hoc network. In the beginning, table-driven algorithm such as DSDV was shown in MANET, which resulted researches of On-demand routing protocols such as DSR, supporting mobility for mobile terminals. Recently, a routing protocol was developed, combined advantages of the former and the latter, called AODV(Ad hoc On-demand Distance Vector). However, despite advantages of AODV, it makes overall network performance weak due to nodes that move frequently, resulting considerable routing control traffic. In this paper, we propose efficient routing mechanism with route prediction of nodes for link reliability in MANET. Our work collects routes from source to destination with AOMDV. In this process, each node with GPS (Global Positioning System) predicts to move expected location by calculating nodes location and velocity. With this mechanism, it makes source node can decide the route which has the longest connection time. And due to the reason why the node can choose appropriate route to data property among multiple routes collected to AOMDV, it also can reduce unnecessary control messages in MANET. By NS2 simulation, we analyze the former routing protocols to demonstrate the superiority of our work.

An active node management system for secure active networks

While conventional networks have functions such as queuing and delivering data packets only, active networks have been introduced and researched since 1990s, where they have additional functions such as performing operations on the packets being transmitted in the networks. Because of such versatile functions, active networks are obviously more complex than conventional networks, but raise considerable security issues at the same time. In this paper, we propose an active node management system for secure active networks that is based on a discrete approach which resolves the weak points of active networks. The proposed system provides the functions of node and user management in the active networks, and improves the security of packet transmission by packet cryptography and session management. We implement the proposed system and show numerical results on performance.

Design of anonymity-preserving user authentication and key agreement protocol for ubiquitous computing environments

The spread of mobile devices, PDAs and sensors enabled the construction of ubiquitous computing environments, transforming regular physical spaces into “Smart space” augmented with intelligence and enhanced with services. However, the deployment of this computing paradigm in real-life is disturbed by poor security, particularly, the lack or proper authentication, authorization and key management techniques. Also, it is very important not only to find security measures but also to preserve user privacy in ubiquitous computing environment. In this paper, we propose efficient user authentication and key agreement protocol with anonymity for the privacy-preserving for ubiquitous computing environments. Our scheme is suitable for distributed environments with the computational constrained devices by using MAC-based security association token.

Anomaly detection scheme using data mining in mobile environment

For detecting the intrusion effectively, many researches have developed data mining framework for constructing intrusion detection modules. Traditional anomaly detection techniques focus on detecting anomalies in new data after training on normal data. To detect anomalous behavior, precise normal pattern is necessary. For this, the understanding of the characteristics of data on network is inevitable. In this paper we propose to use clustering and association rules as the basis for guiding anomaly detection in mobile environment. We present dynamic transaction for generating more effectively detection patterns. For applying entropy to filter noisy data, we present a technique for detecting anomalies without training on normal data.

An authorization mechanism for Web services using an attribute certificate

Web services make the distributed computing based on XML technology possible and are being watched with a new technology to replace the existing distributed computing such as CORBA, Java RMI, and DCOM. One of the issues that needs to be solved to deploy Web services is just Web services security. It is necessary to satisfy the security features like user authentication, confidentiality, integrity, nonrepudiation, and user authorization. We design and implement a system that makes the effective authorization for Web service users possible by using an attribute certificate for Web services.

User Access Control and Authentication System for VoIP Service in Mobile Communication Environments

VoIP, which is used to transmit voice data on the Internet, is being welcomed as a replacement for the PSTN. In VoIP, voice data are converted to IP data and transmitted in an ordinary IP network. As a result, it is less expensive than the ordinary telephone network and has excellent scalability. With the increasing demand for VoIP services, problems are also occurring, namely, security vulnerabilities and degraded service quality. To address these issues, in this paper an AA (Attribute Authority) server is added to VoIP to design an authentication system with bolstered security and differentiated user access.