• The KIPS Transactions:PartA
• /
• v.9A no.1
• /
• pp.45-52
• /
• 2002

This paper proposes the fuzzy closed RCMP queueing network model using fuzzy set theory for the performance evaluation of centralized distributed processing system with ambiguous system factors in the network environments. This model can derive the measures for system performances such as the job spending time, the system throughput, average job number and server utilizations using fuzzy mean value analysis which can process the fuzzy factors. Computer simulation has been performed centralized distributed system with fuzzy service requirement time for verifying the effectiveness of derived equations of performance evaluation according to the numbers of clients, and the results were analyzed. The proposed model provides more and flexible realistic than performance evaluation of conventional method when we evaluated system performance with ambiguous factors.

• Journal of Korea Multimedia Society
• /
• v.5 no.1
• /
• pp.77-93
• /
• 2002

Now we are following component-based software development as a solution to improve the reusability, reliability, and extensibility of the software. To support these, the developed components must be reused through component repository at software development. However, traditional centralized repositories couldn't activate component markets since not only the number of users were restricted but also most of the provided components were those on clients like user interface and so on. Recently, a lot of server-side components, reused in a specific domain, have appeared thanks to the development of both Internet technology and component technology such as EJB, DCOM, etc. Therefore, component repositories, based on domain information, classify and provide components and must offer web-based service for many users to use it stably. This study introduces the implementation of a component repository based on J2EE application model. It provides application developers with the service to search and extract appropriate components, and supplies them reliable services in web environment.

• Journal of Advanced Navigation Technology
• /
• v.14 no.6
• /
• pp.882-889
• /
• 2010

The development of network technology has made rapid growth for online gaming industry on the Internet. Recently, game players have been wanting for a free migration on the game character for game player managed by online game servers of different types. Existing research on the acceptance of the game players demands have suggested migration model of the game character. However, the game Character Migration Process between the game server of different types migration is focused only, and safety issue that is necessary in an online transaction is overlooked. Therefore, ensure the safety of transactions information and when a dispute arises is necessary countermeasures. In this paper, Secure game Character Migration System (SCMP) using dual signature method when migrating game characters between the game servers of different types based on existing research is propose and looks to examine the safety.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.5 no.5
• /
• pp.447-453
• /
• 2004

In this paper, we propose a new system to block harmful Internet information based on IP spoofing. The proposed system is located on a organization's internal network and monitors all outgoing traffic and lets all this traffic go outside. Once the proposed system detects a host's access to a harmful site, it sends the host a pseudo RST packet that pretends to be the response from the harmful site, and prevents the connection between the host and the harmful site. The proposed software system is installed on only a server, and need not be installed on user hosts at all. Thus we can maintain and upgrade the blocking system easily. The performance evaluation of the proposed system shows that it effectively blocks the access to the harmful sites. Since the proposed system is based on IP spoofing, it can be used badly as a hacking tool. Finally we propose some methods to eliminate this possibility.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.5
• /
• pp.849-856
• /
• 2008

As the XML is used as the standard format for information delivery and exchange in various fields, the SVG is frequently used as a user interface or expression tool for the embedded system like an internet based mobile phone. The SVG file must contain additional information specifying the structure of the document and it consumes more transmission time than the actual data sent. The SMETA(Svg transmission MEthod using Semantic meTAdata) system[9] is a study to reduce the size of the SVG file by partitioning the SVG file to a minimal size and assigning meaningful meta data to each portion of the data. In this paper, instead of the meta data exchange method for reducing the size of the file exchanged in the existing SMETA system, we studied an improved version of SMETA system that analyzes the data for each user in the server system and only transmits the data that a user needs. In addition, through our simulation, we verified that it provides better performance than the existing system even if encryption is used.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.1
• /
• pp.14-19
• /
• 2007

As XML is used by standard format for information expression and information exchange in various field, Many Company began to use SVG by user interface or information expression tool of embedded system such as mobile phone based wireless internet. Because SVG has many additional information to keep structure of SVG document exception real data, there is a problem that transfer time of SVG file is so cost for quantity of transmitted data actually. To solve this problem, many researches using compression conception have been conducted for applying to an embedded system. This paper proposes SMETA that can use existing researches using compression concept at once. SMETA divides SVG file to each part that can allocate meaning, and gives semantic metadata to each part without alteration of SVG structure. SMETA can reduce site of transmitted SVG file actually by transmitting specification part of SVG file that metadata does not agree or has unlisted part in an embedded system between an embedded system and server, before transmit whole SVG file. By size of transmitting SVG file is decreasing, transfer time can be shortened accordingly.

• Journal of Advanced Navigation Technology
• /
• v.23 no.5
• /
• pp.333-338
• /
• 2019

Satellite communication is not used by many people like mobile communication, but it is a necessary technology for public service and communication services, such as providing the Internet in military, disaster, remote education and medical services, island areas, and infrastructure vulnerable areas. However, most communication modems have problems with two-way communication with server as IP addresses are assigned to floating IP that change every time they communicate with the network. In this paper, we used the Raspberry Pi as the controller of the terminal device to communicate the network through the satellite modem and the PPP protocol, and to solve the problem of the modem with the floating IP, we used the text message function of the satellite modem. Through this process, two-way data links using the Thuraya geostationary orbit satellite were implemented.

• Journal of the Korea Society of Computer and Information
• /
• v.11 no.3
• /
• pp.203-211
• /
• 2006

Today, Internet covers a world wide range and most appliances of our life are linked to network from enterprise server to household electric appliance. Therefore, the importances of administrable framework that can grasp network state by real-time is increasing day by day. Our objective in this paper is to describe a network weather report framework that monitors network traffic and performance state to report a network situation including traffic status in real-time. We also describe a mobile agent architecture that collects state information in each network segment. The framework could inform a network manager of the network situation. Through the framework. network manager accumulates network data and increases network operating efficiency.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
• /
• v.9 no.1
• /
• pp.179-187
• /
• 2019

With the recent development of small computing devices, IoT sensor network can be widely deployed and is now readily available with sensing, calculation and communi-cation functions at low cost. Sensor data management is a major component of the Internet of Things environment. The huge volume of data produced and transmitted from sensing devices can provide a lot of useful information but is often considered the next big data for businesses. New column-wise compression technology is mounted to the large data server because of its superior space efficiency. Since sensor nodes have narrow bandwidth and fault-prone wireless channels, sensor-based storage systems are subject to incomplete data services. In this study, we will bring forth a short overview through providing an analysis on IoT sensor networks, and will propose a new storage management scheme for IoT data. Our management scheme is based on RAID storage model using column-wise segmentation and compression to improve space efficiency without sacrificing I/O performance. We conclude that proposed storage control scheme outperforms the previous RAID control by computer performance simulation.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.16 no.5
• /
• pp.975-980
• /
• 2021

As technology utilizing low-power short-range wireless communication is applied in conjunction with medical information as a development of the fourth industrial revolution, interest in medical information is increasing. As the age group of smart devices increases and becomes more common, related research such as linking mobile devices with various objects and equipment is continuously being conducted. In addition, interest in untact (non-face-to-face) is increasing due to the prevalence of Coronavirus Disease-19 (COVID-19), including various infectious diseases. As a result, it is a state that requires distance not only in social but also in life. In this study, using a low-power near-field wireless communication technology of beacons to create an IoT device by communicating with the web server of the medical information system was studied to make it easier to receive medical treatment during visits to medical institutions.