Su-Min Jang

Design and Implementation of a Navigation System for Visually Impaired Persons

In order to extend the activity range of visually impaired persons, we design and implement a navigation system that supports road information services and points of interest. The proposed navigation system consists of route creation modules and storage modules for visually impaired persons. In particular, the main interface of the navigation system are implemented using TTS(Text-to-Speech) program for sound and braille module that outputs braille with sense of touch. We also use google map APIs that can provide latest map information for the navigation system.

An Efficient MMORPG Distributed Game Server

An important application domain for online services is an interactive, multi-player game. In recent, many increase of users that use on-line services through networks have caused a heavy load to the server. In this paper, we propose a MMORPG(Massively Multi-player Online Role Playing Game) distributed game server using flayer-Cell. Our method provides efficient solution of a MMORPG distributed game server for large numbers of users. It is shown through the experiments that our method outperforms existing methods in terms of memory utilization rate and processing speed.

Design and Implementation of a Non-Shared Metadata Server Cluster for Large Distributed File Systems

Most of large-scale distributed file systems decouple metadata operation from reading or writing operation for a file. In other words, certain servers named metadata server (MDS) is responsible for maintaining the metadata information of file systems. But, mostly the existing file systems are used are strictive metadata management technique, because those systems mostly designed to focus a distributed management of data and an input/output performance rather than the metadata. In this paper, we present a new non-shared metadata management technique in order to provide flexible metadata throughput and scalability. First, we introduce a new metadata distribution technique called dictionary partitions (DP). Then, we introduce load distribution technique based DP. In addition, we demonstrate the superiority of our technique with shared metadata management technique.

Design of a PPL System using Online Game

With recent development of internet, a lot of people use online games through internet networks. Since people that utilize the online games increase, a special company and an advertisement company adopt the PPL(Product in Placement) on online game instead of the advertisement through TV or radio. This paper persents applications of the PPL on online games and problems which was occurred by them. We propose an advertisement system architecture which processes it efficiently. To prove that our proposed PPL system on online game is efficient, we process various questionnaires on PPL efficacy in online game and analyze them.

An Efficient Application Virtualization Method for a Real Time Broadcasting System of Virtual 3D Contents

In recent, the cloud computing makes it possible to provide the on-demand provision of software, hardware, and data as a service in various IT fields. This paper uses the cloud computing techniques for the real time broadcasting service of virtual 3D contents. However, the existing related solutions have many problems that the load of the server is rapidly increased or the cost of the server is very high when the number of service users is increased. Therefore, we propose a new application virtualization method to solve these problems. It promises their stable operations in multi-user services because the proposed method does not execute the rendering commands of the application at the host server but delivers and executes them to clients via the Internet. Our performance experiments show that our proposed method outperforms the existing methods.

An efficient multi-layer grid method for skyline queries in distributed environments

The skyline query has been received much attention as an important operator in database systems for multi-preference analysis and decision making. Most of the previous works have focused on processing skyline queries on centralized data sets. However, the related data of real applications are practically scattered at several different servers. The skyline query computation in distributed environment is needed to gather a large number of data from the connected servers. The existing methods for a skyline query in distributed environment have two problems: (i) They have slow processing time for a skyline query. (ii) Most of the transferred data among servers in the network are unnecessary. In this paper, we propose a multi-layer grid method for efficiently processing skyline queries in distributed environments (MGDS). The proposed method minimizes the unnecessary transferred data using the grid mechanism. Experiments based on various data sets show that our proposed method outperforms the existing methods.

Efficient Distributed Processing Scheme for Load Balancing of MMORPG Servers

In this paper, we propose a new distributed processing scheme to support MMORPG (Massively Multiplayer Online Role-Playing Games). But existing distributed game servers have some problems such as hotspot, congestion, server failure problems, and so on. To solve such problems, our proposed scheme begins by splitting the large virtual world into smaller regions, each region handled by a different server. We present a scheme that reduces the bandwidth requirements for both game servers and clients. Also our scheme allows seamless interaction among players residing on areas handled by different servers. We show an excellence of the proposed solution through various experiments.

Data Security Technology for the Desktop Virtualization Environment using the Graphic Offloading

This paper proposes the data security technology for the desktop virtualization environment using the separated software execution method. In the virtual environment where allocates separate VMs to the users, there is a benefit that the programs in one guest machine are isolated from the programs running in another guest machine, whereas in the separated execution environment that supports application virtualization, the isolation is not offered and it causes the data security problem because the applications are executed by the one root privilege in the server. To solve this problem, we provides the data security method using the server storage filter, the viewer filter, and the file mapping table in this paper.

An Efficient Architecture for Parallel Skyline Computation over Large Distributed Datasets

The skyline query has been received much attention as an important operator in database systems for multi-preference analysis and decision making. Most of the previous works have focused on processing skyline queries on centralized data sets. However, the related data in real applications are practically scattered at several different servers. The skyline query computation in distributed environments is needed to gather a large number of data from the connected servers. The existing methods for a skyline query in distributed environments have two problems: (i) They have slow processing time for a skyline query. (ii) Most of the transferred data among servers in the network are unnecessary. In this paper, we propose a multi-layer grid method for efficiently processing a skyline query in distributed environments. The proposed method minimizes the unnecessary transferred data by using the grid mechanism. Experiments based on synthetic data sets and real data sets show that our proposed method outperforms the existing methods.

Design and Implementation of a Multiple Client Remote Management System using WMI

Recently, multi client PC technologies that several users can use one set of computer at the same time are being designed to use the surplus computer resource. In general, as the existing PC management system considers only a single client PC that only one user uses a computer, various kinds of complicated problems may be arisen. This paper designs and realizes a remote management system that can monitor and control the information used in the windows based OS multi-client using WMI technology. The proposed system herein uses WMI technology and newly defined client management protocol and provides the monitoring and control functions on individual resource use information of multi-client. As well, it provides a communication function between the server and the client, and locking setting and access control functions.