Byounghee Son

VoIP encryption module for securing privacy

A VoIP encryption module was designed to prevent eavesdropping on Internet telephones communications and involved encoding/decoding the output data at the transmitter and receiver of the Internet telephone. To reduce the voice delay, a 128 bit AES was used and an RSA algorithm for an asymmetric encoding system was used during the key exchange, which is the first process of the encryption system operation. In order to test the speech quality in the encryption system, a Mean Opinion Score (MOS) value and R-value (E Model) Score were measured and resulted in values of 4.18~4.20 (Good) and 91.77~92.92 (Good), respectively.

High-Speed Transmission and Quality of System for Internet Protocol Broadcasting Services

We introduce both high-speed transmitting and quality of system offering Internet services on the HFC (Hybrid Fiber Coaxial) network with low installation cost. It modulates the phase and the amplitude to the carrier wave signal of the IPBS (Internet Protocol Broadcasting Service) data being acquired from Layer 3 switch. The proposed system is effective to embody the HFC based high speed transmission system. The advantages which are illustrated in this paper are as follows: First, it is capable to transmit the IPBS data with no traffic congestion. Secondly, there is little decreasing the service quality of the existing internet network. Finally, it utilizes the IP-QAM (Internet Protocol-Quadrature Amplitude Modulator) transmitter with more competitive price and the IP-QAM modem.

Design of the XML Document Object Model for the home management server

The XML DOM (Document Object Model) provides a logical view of the in-memory structure. It represents the metadata that has a hierarchical treelike structure consisting of nodes. There are several benefits of implementing the XML DOM as a home management server. First of all, the process time decreases by three times in average sense than using general database. Secondly, it would make to meet with the development circumstance change flexibility. Thirdly, it has the advantage of managing and simplifying data effectively. It means to guarantee compatibility.

Implementation of an Auto Configuration Method for the Management Home Server

The existing home appliances could be used after buying and plug in it. Appliances become intelligent, conveniences, and supply a lot of functions. However, the usages and setting ways are complex. Furthermore, the users need to upgrade version occasionally in the using time. In the paper we embody an auto configuration method in the home server which update configuration automatically when the appliances are connected. The suggested method in the smart home-networking environments overcomes those difficulties of the home gateway and/or home server. It can make access to the home gateway and/or home server to yield a lot of profits of maintenances and repairs. This paper describes how it adapts to conditions where administration is minimized, and where network administrators in large enterprises wish to reduce tedium and workload.

A Time-Redundant Recovery Scheme of TMR failures Using Retry and Rollback Techniques

This paper proposes an integrated recovery approach applying retry and rollback techniques to recover the TMR failure. Combining the time redundancy techniques with W system is apparently effective to recover the TMR failure(or masked error) primarily caused by transient faults. These policies need fewer reconfigurations at the cost of extra time required for the time redundant schemes. The optimal numbers of retry and rollback to minimize the mean execution time of tasks are derived for the proposed method through computing the likelihoods of all possible states of the failed system. The effectiveness of the proposed method is validated through examining certain numerical examples and simulations conducted with a variety of parameters governing environmental characteristics.