Soon-Seok Kim

Adaptive video-on-demand broadcasting in ubiquitous computing environment

Video-on-demand (VOD) is a service that allows users to view any video program from a server at the time of their choice, such kind of services are expected to be popular in future ubiquitous computing environment. Lots of broadcasting protocols for VOD services have been proposed, but they usually focus only on the tradeoff between bandwidth and delay, thus they are usually not efficient for the local storage. Since the ubiquitous network is heterogeneous and users will have different resource and communication capability, we need to address the storage issue in VOD systems. In this paper, we present several new effective broadcasting schemes, which can intelligently adjust the solution according to available bandwidth and local storage to achieve an ideal waiting time.

Analysis of Medical Data Using the Big Data and R

It is medical and health industry that Big Data is most valued. However, Big Data has not been actively introduced in the domestic medical field. In this respect, the present study was aimed to use R, which is an analyzing tool of Big Data, to promote various business models in health and medical field, and to analyze medical data of diseases and genetic information so Big Data can be utilized in the field. In this study, SGA consortium electrocardiogram data was used, which is database of ECG-ViEW provided in http://egcview.org. R was used to analyze the medical Big Data from various angles. RStudio Version 0.98.1103 was used as R tool to perform association rule analysis, outlier diagnosis and simple regression analysis with ECG-ViEW data.

Speed-Sensitive Handover Scheme over IEEE 802.16 Multi-Relay Networks

Abstract —Multi-Relay Networks should accommodate mobile users of various speeds. The cellular system should meet the minimum residency time requirements for handover calls while considering an efficient use of available channels. In this paper, we design speed-sensitive handover under dynamic hierarchical cellular systems, in which mobile users are classified according to the mean speed of mobile users and each class has its cellular layer. In order to meet the minimum residency time, the cell size of each cellular layer is dynamically determined depending on the distributions of mean speeds of mobile users. Since the speed-dependent non-preferred cell can provide a secondary resource, overflow and take-back schemes are adopted in the system. We develop analytical models to study the performance of the proposed system, and show that the optimal cell size improves the blocking probability. Keywords —Multi-Relay Networks, Handover 1. I NTRODUCTION The existing IEEE 802.16 is a series of Wireless Broadband standards known as WiMAX as an important technology for providing high-speed Internet access to home and business sub-scribers in a wide area cellular network[1]. Handover is a key factor for the quality of wireless communication services. Due to the geographical problem, significant data loss occurrs, the coverage region for high data rates is decreased, and even dead spot areas in the coverage region occurr. IEEE 802.16j adopts multihop or relay technologies in order to eliminate dead spot areas and extend the coverage region. In IEEE 802.16j networks, the Relay Stations (RSs) relay sig-naling and data messages between the Multihop Relay BS (MR-BS) and the Mobile Station (MS)[2, 3]. Therefore, handover issues for the RS on IEEE 802.16j have been carried out[4]. The increasing demands for mobile communications are proceeding with a strong tendency toward increasing need for high traffic capacity and mobility in the access links within the wire-less links[5, 6]. Since the micro-cell of the micro-cellular systems makes an efficient use of available channels by using low-power transmitters to allow channel reuse at much smaller dis-tances, the micro-cellular systems with an extremely small cell radius can meet the traffic de-mand[7, 8]. However, the micro-cell increases the number of cell boundary crossings for high-mobility users, and the increasing handover rates of ongoing calls may cause an excessive proc-essing load in the network. Furthermore, the handover calls of fast-moving users cannot meet

A Study of International Trend Analysis on Web Service Vulnerabilities in OWASP and WASC

All projects conducted in both the OWASP (Open Web Application Security Project) and the WASC (Web Application Security Consortium) are open-projects in which a company and an individual have voluntarily participated with a vision for web application security. Specifically, these open type projects have studied the web application vulnerabilities and thus have provided their results. Therefore, all these projects can be considered as very influential open-projects. This paper will examine overall introduction of the OWASP and the WASC and then, the major features of their different projects which have been currently conducting as analyzing the similarities and differences between the OWASP and the WASC. Based on the results, the study may suggest a type of synergetic effects from their cooperative work. Finally, with related to the web application security area, this research will discuss about the latest trends in industrial as well academic fields and further directions toward its development.

National Standardization Strategy in Health Information Security Environment

Source technology for standard platform and common security infrastructure, ID/UHID management, and EMR-PHR security interlocking, combined with information technology within the hospital, are expected in the near future. In this paper, we propose a new strategy for future national standardization through international standardization trends and linkage in the field of health information security.

Fair Scheduling Strategy for Delay-Sensitive Handover of IEEE 802.16 Real-Time Communications

The existing IEEE 802.16 is a series of Wireless Broadband standards known as WiMAX as an important technology for providing high-speed Internet access to home and business subscribers in a wide area cellular network. It has defined real time and non-real time services. But the standard does not specify transmission scheduling schemes to support the services. In order to support the delay sensitive handover calls with multiple quality of service (QoS) of the services with fairness, this paper divides a waiting queue into a sleep queue and a ready queue. Our simulation results show that the analytical model is good agreement with the simulation model, and the proposed scheme can improves the fairness index at the expense of increasing that of higher delay-sensitive traffics without degrading the new call blocking probability, and the carried traffic.