Kyung-Soo Jang

A novel vertical handoff strategy for integrated IEEE 802.11 WLAN/CDMA networks

The integration of WLANs and CDMA networks has recently evolved into hot issue. We propose a vertical handoff algorithm between WLAN and CDMA network. In this algorithm, a vertical handoff is classified into handoff decision making and MIP (mobile IP) registration process. Then, a handoff initiation is decided by the received signal strength (RSS). To reduce the unnecessary handoff probability, we consider a hand-off initiation model based on the criteria of RSS. As a mechanism of network selection, we also propose a context based network selection and the corresponding algorithms between WLAN to CDMA network, based on wireless channel assignment. We focus on a handoff initiation criteria which uses both the RSS and the network selection method which uses context information such as dropping probability, blocking probability, GOS (grade of service), velocity. As a decision making criterion, velocity threshold is determined to optimize the system performance. The optimal velocity threshold is adjusted to assign available channels to the mobile stations. The proposed scheme is validated by computer simulation.

Multi-agent system based efficient healthcare service

This paper discusses a multi-agent system (MAS) based efficient healthcare system, which is comprised of medical sensor modules in conjunction with wireless communication technology. In particular, the proposed system supports a wide range of services including mobile telemedicine, patient monitoring, emergency management and information sharing between patients and doctors or among the healthcare workers involved. For this purpose, the proposed system provides not only a systematic computing environment between the BAN (body area network) and the subsystem within the hospital, but also participates in an agent network with the BANs PDAs through peers. Information within the hospital is shared under a MAS environment. The tool used to develop the MAS is called JADE, a FIPA-compliant development framework. The ultimate goal of our system is to manage and monitor the patients medical information and to support efficient medical service through the medical staffs cooperation

Agent-Based Discovery Middleware Supporting Interoperability in Ubiquitous Environments

Service discovery in ubiquitous environments faces various issues such as dynamic-topology, devices-capability, resource-sharing, interoperability etc. In this paper, we propose Service Discovery Middleware (SDM) to solve the interoperability issue by using Discovery Middleware (DM), which was introduced by the FIPA (Foundation for Intelligent Physical Agents) [1]. The SDM provides an appropriate choice for providing interoperability in heterogeneous environments. Moreover, it supports a means for autonomic discovery of heterogeneous integration services in ubiquitous computing and transparency between users and services. With these ideas in mind, we design a simple mechanism for building a wide range of distributed services and applications as well as for supporting a softness and adaptable means to control and manage the Service Discovery Protocols (SDP). Furthermore, we implement as an example, a Personal Agent (PA) platform based on the FIPA-OS agent platform, in order to provide SDM component functionality [10] [20].

Delay and Collision Reduction Mechanism for Distributed Fair Scheduling in Wireless LANs

In wireless local area networks, MAC protocol is the main element that determines the efficiency in sharing the bandwidth of the wireless channel. Recently lots of QoS supporting mechanisms which focus on the distributed MAC protocols of IEEE 802.11 were proposed. However, due to the distributed nature of ad hoc networks, nodes may not be able to schedule packets to guarantee QoS metrics. In this paper, we propose a simple mechanism, which reduces collision and delay between packets based on distributed fair scheduling (DFS). Simulation results show that the proposed algorithm outperforms the DFS from delay and throughput viewpoints.

A new paradigm vertical handoff algorithm in CDMA-WLAN integrated networks

The integration of WLANs and CDMA networks has recently evolved into hot issue. We propose a vertical handoff algorithm between WLAN and CDMA network. A handoff initiation is decided by the received signal strength (RSS). To reduce the unnecessary handoff probability, we also consider a distance. As a mechanism of network selection, we propose a context based network selection algorithms between WLAN to CDMA network, based on wireless channel assignment such as dropping probability, blocking probability, GoS (Grade of Service), the number of handoff attempts. As a decision making criterion, velocity threshold is determined to optimize the system performance. The optimal velocity threshold is adjusted to assign available channels to the mobile stations. The proposed scheme is validated by computer simulation.

IU_AMDroid : An Integrated User Authority Manager Model for the Android Platform

Currently, as the Android platform only supports single-user protection, it needs security solution for multi-users. Specially, it has to protect specific applications which have personal and financial information, and be available to support authority management for contents access. Thus, this paper proposes an integrated user authority manger model for the Android platform. It helps application authority which is capable to divide into three statuses: installation, execution, deletion with the help of information technology.

An Efficient Private Registry Management System Using DHT Based on FIPA Agent Platform

In this paper, we have redesigned the conception of SOA (Service oriented Architecture) by extension to existing service registry, and based on this definition; proposed a FIPA agent platform capable of capturing SOA components. According to the FIPA specification and reference model, we adopt several new Web service components called AgWebs in the FIPA agent system. They are designed the service management mechanism in private registry which agents are possible to lookup/register/de-register services using DHT algorithm with the DM module. Also, we can create a overlay network in the service registries on top of the existing physical network infrastructure, as using DHT based FIPA Agent platform. As it will be demonstrated, we develop an efficient private registry management system in FIPA agent platform.

Content Self-Protection for Digital Products Using RFID-Enable Agent Platform

There are lots of protection technologies which protect digital products such as audio, video, and software. We believe that the protection systems using software/hardware based cryptograph have no fault themselves. Nevertheless, these technologies were circumvented shortly after their release. We argue that the reasons are because there are three inevitable factors in current protection system. The first is that people casually share the key, and this shared key is always valid for the same products. The second is that current system cannot distinguish the ordinal and the replica because both can provide the same functionalities and thus it allows people to extract the contents from physical media. The last is that all digital products can be reproduced using their devices. Therefore, this paper proposes a novel approach for the protection of digital products using RFID and agent technologies to resolve these problems.

Design of the Directory Facilitator Supporting Fault-Tolerance in Multi-OSGi Agent System

Multi-agent system and OSGi technologies are essential elements in realizing the upcoming ubiquitous environments. Up until now, different approaches are proposed to support the reliability of multi-agent system level by many researchers. Also, there are mainly focus on fault-tolerance of detection/recovery in the inside system fault or each agent level. We have view on them; will be provide an effective solution of service level for supporting the service reliability of an extended Directory Facilitator (DF) in multi-OSGi agent system. We propose a new, more reliable and extendable DF architecture, and present a detection/recovery algorithm of service fault for safety in railroad system. Through the proposed fault-tolerance architecture, the extended DF of multi-OSGi agent system can improve reliability and interoperability of the service level.