• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.171-174
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• 2005

According as marine leisure industry has developed and the demand of leisure culture has increased rapidly, a desire about service which supply marine safety and connect marine information is enlarging. The performance of personal mobile device has improved and been evolved by composition terminal. So, it became possible that storage and expression of multimedia information as well as simple communication facility. Domestic wireless internet has given development strain to developer and contents Provider(CP) because of different platform. And this has become hindrance factor of wireless internet activation. But, recently, the use of WIPI(Wireless Internet Platform for Interoperability), the wireless internet standard platform, could use different wireless application programs and also guarantee the independency for hardware. We wish to develop contents of download form that supply geographic information of Electronic Navigational Chart(ENC) in the marine that is digitalized to carrying along terminal of WIPI base and various informations for marine leisure. For this, DB that offer ENC and additional information should be constructed. Also, we need server (CPS; Contents provider Server) that offer required contents. In this paper, we design web retrieval agent which store request information to database. When consumer required necessary information through personal mobile device, CPS can inform that by real time. So, we wish to develop agent component that parse informations in various World Wide Webs, and store to database.

• The Transactions of the Korea Information Processing Society
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• v.6 no.9
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• pp.2524-2532
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• 1999

In this paper, we present a new buffer pool management scheme designed for video type news objects to build a cost-effective News On Demand storage server for serving users requests beyond the limitation of disk bandwidth. In a News On Demand Server where many of users request for video type news objects have to be serviced keeping their playback deadline, the maximum numbers of concurrent users are limited by the maximum disk bandwidth the server provides. With our proposed buffer cache management scheme, a requested data is checked to see whether or not it is worthy of caching by checking its average arrival interval and current disk traffic density. Subsequently, only granted news objects are permitted to get into the buffer pool, where buffer allocation is made not on the block basis but on the object basis. We evaluated the performance of our proposed caching algorithm through simulation. As a result of the simulation, we show that by using this caching scheme to support users requests for real time news data, compared with serving those requests only by disks, 30% of extra requests are served without additional cost increase.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.35-40
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• 2019

It is important to constantly provide service in real-time multimedia applications using multicast. Transmission path reconstruction occurs in hybrid multicast using Internet Protocol (IP) multicast and ALM in order to adapt the network status to things like congestion. So, there is a problem in which real-time QoS is reduced, caused by an increase in end-to-end delay. In this paper, we want to solve this problem through multi-layer transmission path construction. In the proposed method, we deploy the control server and application layer overlay host (ALOH) in each multicast domain (MD) for hybrid multicast construction. After the control server receives the control information from an ALOH that joins the MD, it makes a group based on the hop count and sends it to the ALOH in each MD. The ALOH in the MD performs the role of sending the packet to another ALOH and constructs the multi-layered transmission path in order of priority by using control information that is received from the control server and based on the delay between neighboring ALOHs. When congestion occurs in, or is absent from, the ALOH in the upper MD, the ALOH selects the path with the highest priority in order to reduce end-to-end delay. Simulation results show that the proposed method could reduce the end-to-end delay to less than 289 ms, on average, under congestion status.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.3
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• pp.263-272
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• 2017

The concept of Internet of Things (IoT) has been increasingly popular these days, and its areas of application have been broadened. However, if the data stored in an IoT system is damaged and cannot be recovered, our society would suffer considerable damages and chaos. Thus far, most of the studies on fault-tolerance have been focused on computer systems, and there has not been much research on fault-tolerance for IoT systems. In this study, therefore, a fault-tolerance method in IoT environments is proposed. In other words, based on the EVENODD method, one of the traditional fault-tolerance methods, a fault-tolerance storage and recovery method for the data stored in the IoT server is proposed, and the method is implemented on an oneM2M IoT system. The fault-tolerance method proposed in this paper consists of two phases - fault-tolerant data storage and recovery. In the fault-tolerant data storage phase, some F-T gateways are designated and fault-tolerant data are distributed in the F-T gateways' storage using the EVENODD method. In the fault-tolerant recovery phase, the IoT server initiates the recovery procedure after it receives fault-tolerant data from non-faulty F-T gateways. In other words, an EVENODD array is reconstructed and received data are merged to obtain the original data.

• Journal of Digital Convergence
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• v.12 no.8
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• pp.211-217
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• 2014

In this paper, by using geofencing technology to set the area you want to move tourists. Geofence set of tourists in the region enters the smartphone by sending e-mail or SMS alarm to display a detailed map of the area to visit assistance. When you arrive at the destination of the museum exhibits or exhibits to the NFC tag attached to each corresponding to a web server for a detailed description of the exhibits from the get-down. Multimedia content using an existing exhibits described. Media of exhibition space and the interaction between the visitors tour guide system capable was built.

• Journal of The Korean Association of Information Education
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• v.4 no.2
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• pp.202-211
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• 2001

Learner-oriented education and distance education based on Information & Communication technology are educational countermeasure to various demands of Information age. Especially Web has the characteristics of providing proper environments for implementing constructivism study theory. Yet, existing web-based evaluation system is implemented by HTML and Java script so it has low interaction and imperfect educational effects. Therefore, We evaluated students' study understanding ability of real-time distance education system and analyzed evaluation results to offer useful information for level study considering individual variation. In this thesis, with these results, we designed and implemented interworking and multimedia databank system without time and space limitations on Client/Server environment.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2899-2902
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• 2003

Mobile communication is one of the fastest growing industries in the world and especially in Korea, where we have well over 30 million voice subscribers. Mobile communication now offers variety of data communication services such as wireless internet, multimedia messages, and color graphic displays. Handsets also have grown to accommodate such services, thus with functionalities such as programmable virtual machines that users can download and execute their own programs. In this paper, we have demonstrated a PCS handset monitoring system which can monitor biometry signals - in this case ECG over wireless internet and wireless data network (IS95C) based on programmable virtual machine architecture. The remote client handset receives data signals from a centralized server and processes and displays them in human friendly form in real time. Since every single handset on sales in Korea has programmable virtual machine and more than 10 million handsets are in distribution already, proper applications may have substantial impact on the related fields.

• Asia pacific journal of information systems
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• v.7 no.3
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• pp.39-59
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• 1997

This study presents the growth strategy of outsourcing service by finding out the differences of importance between user firms and system integration(SI) firms in Korean outsourcing business, The result of data analysis reveals that there are siginificant differences between user firms and SI firms in some components of information systems(IS) outsourcing services. User firms regarded integation of distributea data centers as the prominent issue of IS environment changes. Meanwhile, SI firms chose management of IS/VAN center, office automation(OA), and management of global network, as the more important issues in the application area of outsourcing. Among the merits of outsourcing, both of them considered cost reduction and IS flexibility as the most important factors, However, they chose the difficulty of management control and the lack of operation knowledge among the demerits of outsourcing, Also, they commonly selected overall IS consulting among the components of outsourcing diffusion. In the question of future outsourcing services, user firms chose the adoption of client/server architecture, while SI firms selected the application of multimedia. These results show that there are some differences of preference between user firms and SI firms. Most of user firms consider the outsourcing to maximize information utilization, while the service suppliers focus on new IT adoption and its application to organization. For the strategic use of outsourcing services, SI firms are required to establish the diffusion strategy to meet the outsourcing needs of user firms.

• Journal of the HCI Society of Korea
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• v.2 no.1
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• pp.1-12
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• 2007

In this paper, we propose a video service system that reflects user interaction in the multimedia contents to increase user satisfaction in the restricted content consumption environment. The proposed system is based on the multiple ROI(Region of Interest) coding in H.264/AVC Scalable Video Coding (SVC). The proposed system provides scalable video quality by adopting SVC. And by bidirectional communication between user and video server, it enables user to select meaningful ROI among multiple ROIs by user interaction. To verify the usefulness of the proposed system, we demonstrate it with a test-bed on which user interactive ROIs are implemented.

• Journal of the Korea Computer Industry Society
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• v.5 no.9
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• pp.911-920
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• 2004

Intensive studies have been made in the area of VOD server. Multimedia files in the VOD sever are characterized with the large volume of data, the requirements of synchronization and real-time playback of streams. The basic goal of the study is to find an efficient mechanism to allow maximum number of users under the limited resources such as Bu11er size and disk bandwidth. we propose a efficient user-grouping policy for multi-casting services with dynamic monitoring and management of VOD sever resources. Simulation results show that the rate of buffer usage and QOS change of proposed scheme are about 23% performance improved than that of traditional methods. This implies that our method can allow much more users for given resources.