한재선 교수

With the widespread adoption of cloud computing, the ability to record and account for the usage of cloud resources in a credible and verifiable way has become critical for cloud service providers and users alike. The success of such a billing system depends on several factors: The billing transactions must have integrity and nonrepudiation capabilities; the billing transactions must be nonobstructive and have a minimal computation cost; and the service level agreement (SLA) monitoring should be

The ability to record and keep account of the usage of cloud resources in a credible and verifiable way is a precursor to widespread cloud deployment and availability because usage information is potentially sensitive and must be verifiably accurate. In an attempt to provide a mutually verifiable resource usage and billing mechanism, we found that the frequent asymmetric key operations of a digital signature lead to excessive computations and a bottleneck of billing transactions. As a remedy for

Although grid computing has become popular in scientific research and the enterprise domain, there is no way a personal user who does not belong to any organization can construct or access the grid system for solving her problems. The main goal is to propose a lightweight personal grid that is self-organized without complicated configuration and infrastructural support like central servers and self-managed with the cooperation of participants. The key component of our system is the supernode net

This paper advocates the use of RESTful data services in mobile commerce information spaces. REST is a restriction of web services to a simple protocol centered on a limited set of access operations against data resources. This paper analyzes how REST may be used as a general design principle for mobile commerce spaces. This analysis is threefold. First, it provides an abstract component model that contains a minimal embodiment of the REST functionality needed to support mobile commerce. Second,

A new Viterbi decoder is proposed using a modified register exchange scheme. The trace-back operation is eliminated in the new architecture, and the amount of memory is reduced. The elimination of the trace-back operation also reduces the operation cycles to determine decision bits. The Viterbi decoder has low latency, efficient memory organization, and low hardware complexity compared with other Viterbi decoding methods in block decoding architectures. The proposed decoder can be designed with

A global computing system (GCS) harnesses the idle CPU resources of clients connected to the Internet for solving large problems that require a high volume of computing power. Since GCS scales to millions of clients, many projects usually adopt coarse-grained scheduling in order to reduce server-side contention at the expense of sacrificing the degree of parallelism and wasting CPU resources. In this paper, we propose a new type of client, i.e., a scheduling proxy that enables adaptive-grained s

This paper presents the design and evaluation of FastAd, a fast and highly adaptive peer-to-peer (P2P) lookup system for medium-scale network where the number of nodes is not more than tens of thousands. Using routing tables larger than those of previous schemes, a lookup can be performed at just two hops, while maintenance cost of tables can be minimized by adopting lazy consistency with piggybacking. In addition, assigning dynamic node identifier (nodeId) instead of a fixed nodeId by hashing t