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)
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)
This paper describes our effort to improve the performance of the connection management subsystem of the OpenLDAP directory server. Two proposed architec-tures, the multi-listener and the lightweight listener architectures will be described and compared to each other in this paper. This paper will also describe our effort to improve the synchronization of(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)