n-Sik Yoo

VoD streaming synchronization mechanism with multiple users for service continuity

In this paper, we propose multiple users-based streaming service synchronization mechanism for streaming delivery and synchronization in wire-wireless service environment and analyze the available network performance. Current structure of streaming service for multiple users is not designed to be suitable for the purpose of service continuity. So, multiple users cannot be provided with seamless media experience in wire-wireless service environment. Extending the concept from one user to multiple users, we identify the possibility of service continuity. We introduce the concept of streaming service synchronization, and implement VoD streaming service using proposed synchronized mechanism, and then analyze the available network performance. Finally we discuss the feasibility and practicality in aspect of service deployment.

Analysis of EDCA MAC throughput for the IEEE 802.11e WLANs

IEEE 802.11e MAC (medium access control) is one of the IEEE 802.11 WLAN (wireless local area network) standards define for QoS (quality of service) support on the wireless communications. The 802.11e MAC is based on both center controlled channel access and contention-based channel access mechanisms. EDCA (enhanced distributed coordination function) is contention-based channel access mechanism which provides differentiated channel access method for frames that have different priorities. In this paper, we analyze and compare both theoretical throughput value of EDCA MAC and throughput value of FPGA (field-programmable gate array) implemented EDCA MAC platform at MAC layer. The QAP (QoS access point) is provided with EDCA function and the station is provided with DCF (distributed coordination function). The results on throughput evaluation of the FPGA implemented EDCA MAC Platform shows 92. 6 ~ 94.3% as much as theoretical throughputs of the EDCA MAC Simulation. The parameters evaluated for the throughput measurement are 802.11a PHY, offered load, access category, frame size and number of stations. The results show various throughput values in accordance to the measurement parameter changes.

The impact of feedback information on energy consumption for building types

The paper presents the analysis of the energy consumption patterns and energy saving effect according to the energy information providing method and the building types. This paper also compares the electric power consumption patterns in energy consumption data gathered from the monitoring system according to Korean-style building types and discuss the potential of impact of energy saving effect.

Integrated Energy Management System Framework for the Distributed Smart Meters in Smart Grid Environment

Far beyond the simple energy metering, these devices enable companies to inform the customers, to control the load and to increase the energy consciousness. The standardization of the smart functionalities is in progress. The households for lack of knowledge and information do not care for the energy retrenchment. New central software applications have been developed that can perform remote energy management functions through communication to the distributed smart meters (specific value calculation, trend monitoring, limit violation alarm, etc.). This paper describes an overview about the integrated Energy Management System Framework and makes recommendations which functions would be useful in the Korea environment.

A Study on Ubiquitous Business Process Management for Real-Time Open USN Mash-Up Services

USN (Ubiquitous Sensor Network) technology is recognized as a next-generation core technology and spreads rapidly through various pilot projects. It is widely used especially in the areas such as BPM (Business Process Management) and home network. Service-oriented architecture based on mobile and web services technology provides a promising platform where the enterprises are allowed to coordinate seamlessly e-Services on the heterogeneous information systems. In this paper, we propose a new ubiquitous BPM system architecture for open USN communication that can guarantee the real-time service and mash-up service in various wireless field networks. We also illustrate the proposed architecture with a case study of a health care based on mash-up methodology.

Heuristic analysis of energy information and preference for smart grid infrastructure

The paper presents the analysis of the power saving effect and the customer satisfaction level for In-Home Display usage. Through the validation between the experimental group and the control group, we analyze the power consumption and consumer preferences. From the results obtained from the questionnaire used, we also confirm the customer satisfaction.

Modeling of refreshing sleep aid service based on ubiquitous computing

This paper describes that we propose context-aware computing based model in ubiquitous computings subset for refreshing of humans sleep and examine technological possibility. Human can do fatigue recovery and growth through sleep and we propose methodology with model form in more effective and most suitable context for refreshing sleep in this paper.

Prioritized energy optimal management for home-to-home in smart grid

This paper proposes a prioritized energy optimal management for home-to-home in smart grid. As this proposed mechanism configures the prioritized optimal energy, if there is a surplus of energy from the energy provider of home, the energy broker in smart grid distributes the optimal energy to the requesting user for the purpose of maximizing the users payoff.

Energy optimal management for prioritized distribution in smart grid

This paper designs an energy optimal management in smart grid infrastructure. As a way of assigning the prioritized optimal energy of the adjacent energy provider from the energy-requesting user, if there is a surplus of energy from the energy provider, the smart grid as being the closest to the user preferentially allocates the optimal energy to the requesting user in order to maximize the user satisfaction.

Experimental performance analysis of DER network communication in IEC 61850 server

The DER network management of IEC 61850 system is required to monitor periodically the safety management information in the emergency generator through CTTS of the VPP infrastructure. For the purpose of enhanced monitoring the DER network, this paper proposes DER network interface for improving the data transfer performance in the IEC 61850 server, and analyzes data acquisition, processing and transfer performance between the legacy and the proposed architecture. The proposed scheme is to reduce the data delivery time using an enhanced DER network interface and improves the data throughput performance based on the reliable transfer.