Sang Seok Lim

Learn More
—In this paper, a fast path planning method by optimization of a path graph for both efficiency and accuracy is proposed. A conventional quadtree-based path planning approach is simple, robust, and efficient. However, it has two limitations. The first limitation is that many small cells are required to represent obstacles because the positions and shapes of(More)
— In an attempt to expand Public Key Infrastructure (PKI) usage to a ubiquitous and mobile computing environment , we found that the deployment of the PKI on a resource constrained device such as 8 bit microprocessor leads to user-obstructive latency or an additional circuitry for the operations. To alleviate these limitations, we propose a new PKI-based(More)
Lightweight Directory Access Protocol (LDAP) is the predominant Internet directory access protocol and hence so is its use in the Public Key Infrastructure (PKI). This paper presents the design and implementation of LDAP component matching which enhances flexibility and security of the LDAP directory service when it is used for the PKI certificate(More)
As an integral part of the Web Services Security (WS-Security), directory services are used to store and access X.509 certificates. Lightweight Directory Access Protocol (LDAP) is the predominant directory access protocol for the Internet, and hence for the Web services. Values of LDAP attribute and assertion value syntaxes, though defined using ASN.1, are(More)
In this paper a new-type delay acquisition/tracking appro-/ B ach is proposed which is based on partitioning of the PN-code matrix of the CDMA users into submatrices which are then used to form a 'state-space'-type linear combiner. The proposed / B novel formulation and approach is robust to modelling errors such as over-and underestimation of the number of(More)
— This paper describes the issues and challenges in the design of an interoperable mobile security card for campus-wide ubiquitous services. The card holder becomes able to take pleasure of utilizing the ubiquitous services everywhere on a campus with high security. In order to realize the services, the card has been designed to have 1) a ZigBee module for(More)
A framework for the autonomous management of clustered server systems called LAMA 1 (Large-scale system's Autonomous Management Agent) is proposed in this paper. LAMA is based on agents, which are distributed over the nodes and built on JINI infrastructure. There are two classes of agents: a grand LAMA and ordinary LAMAs. An ordinary LAMA abstracts an(More)