• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.11
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• pp.1-9
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• 1999

As our society turns into the information age from the industrial one, the ministry of information and communication has set up functional software standards for electronic approval systems Several software houses have developed such systems in the client/server environment and subsequently for the intranet. Although electronic approval systems for the intranet have the advantages of less costly implementation and ease of use, they create heavy network traffic, and have a poor document processing functionality resulting from the lack of document processor in web environments. This paper describes a system design that web browsers utilize the resources of clients by adopting the ActiveX technique in order to improve such mallets mentions above. In other words, to use the Hangul word processor as a document processor, the ActiveX control and the Hangul DDE API have been implemented in the form of the DDE server/client, which is capable of mutual communication, and the flow of electronic approve system has been controled by connecting. As a result of running the implemented system lot three months through a real company in multi-server environment, it shows the high usage of electronic approval system as the tate roaches 75%-93% for some departments.

• Journal of the Korea Convergence Society
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• v.9 no.9
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• pp.1-8
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• 2018

It is a key role in leading and activating coding education as a process to solve problems creatively to produce and provide the educational contents on the basis of 3D printing. In this paper, we develop a variety of fusion contents to use 3D printing and 8bit MCU base control board which provides specific functions through Arduino. The developed control program conducts various packet monitoring more than ten times per a second, supporting intrinsically full duplex. In addition, communication protocol optimized in conveying a lot of information enables to control different contents. The contents produced with the control board and 3D printing are useful as a programming education tool to train the principle and the concept of coding.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.6
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• pp.1218-1225
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• 2005

The effort to expand digital contents market and get more users is growing. This is being done by interconnecting the existing broadcasting data services and two-way data services in mobile network with the terrestrial DMB transmitting system. However, the interconnection is not easy because various data service system uses difference protocols to transmit digital contents and the receiving protocol of terrestrial DMB system is the standardized one. In this paper, we designed and implemented the middleware structured system, trying to minimize problems and difficulties in the interconnection of the data service system and terrestrial DMB transmitting system. We considered the readiness of the extension of the various transmitting method in the various data service systems and also implemented Terrestrial DMB Data Inserter system that transmits contents data on the broadcasting schedule.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.5
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• pp.578-587
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• 2003

The DSTM (Dual Stack Transition Mechanism), one of tunneling mechanism, is considered as the best solution in IPv4/IPv6 transition recently. The DSTM provides a method to assure IPv4/v6 connectivity based on 4over6 (IPv4-over-IPv6) tunneling and temporal allocation of a global IPv4 address to a host requiring such communication. A TEP (Tunnel End Point) operates as a border router between IPv6 domain and IPv4 Internet, which performs encapsulation and decapsulation of 4over6 tunneling packets to assure hi-directional forwarding between both networks. In this paper, we analyze basic standards of the IPv6 protocol. And, we design and implement a DSTM TEP daemon block. The TEP daemon analyzes a fevers tunneling packet that is forwarded by the DSTM node, establishes the TEP's 4over6 interface, and supplies communication between a DSTM and a IPv4-only node. Finally, we construct a DSTM testbed and measure performance of the DSTM TEP. Our observation results show that performance of TEP supports the DSTM service.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.5
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• pp.602-609
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• 2016

In a smart society, politicians analyze the big data of voters to build a favorable political positions. In other words, a variety of digital footprints uploaded in SNS or Internet are used to set the election strategies and political directions. In comparison, it is difficult for voters to extract intention information about how politicians are performing a political acts. Therefore, it is important that voters need to analyze what intention of politicians are like for two way interaction between voters and politicians. For this, in this paper, we want to do the identification by analyzing IT technologies to narrative styles of politicians who pursue relative advantages or gains compared to other competitors. The experiments will be carried out to identify about what relative advantages compared to other competitors by narrative styles of next presidential candidates who are expected to run into the next presidential election by analyzing the usual audio interviews.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.5
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• pp.486-496
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• 2013

Time synchronization in underwater environment is challenging due to high propagation delay and mobility of sensor nodes. Previous researches do not consider practical issues affecting on the accuracy of time synchronization such as high-channel access delay and relative position between sensor nodes. Also, those protocols using bidirectional message exchange shorten the network lifetime and decrease the network throughput because numerous transmission, reception and unnecessary overhearing can be occurred. Therefore, in our research, we suggest enhanced time synchronization based on features of underwater environment. It controls the instant of transmission by exploiting the feature of an oceanic movement and node deployment. Moreover, the protocol uses more accurate time information by removing channel access delay from the timestamp. The proposed scheme is also practical on the underwater sensor network requiring low-power consumption because the scheme conducts time-synchronization with smaller transmission and reception compared with previous works. Finally, simulation results show that the proposed protocol deceases time error by 2.5ms and 0.56ms compared with TSHL and MU-Sync respectively, reducing energy consumption by 68.4%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.5
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• pp.409-419
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• 2013

Kinect released by Microsoft in November 2010 is a motion sensing camera in xbox360 and gives depth and color images. However, Kinect camera also generates holes and noise around object boundaries in the obtained images because it uses infrared pattern. Also, boundary flickering phenomenon occurs. Therefore, we propose a real-time virtual-view video synthesis algorithm which results in a high-quality virtual view by solving these problems. In the proposed algorithm, holes around the boundary are filled by using the joint bilateral filter. Color image is converted into intensity image and then flickering pixels are searched by analyzing the variation of intensity and depth images. Finally, boundary flickering phenomenon can be reduced by converting values of flickering pixels into the maximum pixel value of a previous depth image and virtual views are generated by applying 3D warping technique. Holes existing on regions that are not part of occlusion region are also filled with a center pixel value of the highest reliability block after the final block reliability is calculated by using a block based gradient searching algorithm with block reliability. The experimental results show that the proposed algorithm generated the virtual view image in real-time.

• The Korean Journal of Applied Statistics
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• v.26 no.1
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• pp.23-36
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• 2013

In this study, we investigate how churn customers (who play a central connector or broker role) affect other customers' churn in their call networks with ego-network analysis using call data of a mobile telecom company in Korea. As a result of investigating Reciprocal Network, we found a relationship of attrition among churn customers. Churn provokers who influence other customers' attrition exist in customer churn networks. The characteristics of churn provokers is that they play a central connector and broker role in their groups. The proportion of churn provokers increases and the churn provoker's influence increases because the network is a reciprocal one.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.1
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• pp.141-146
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• 2011

The GIS service has to provide latest spatio-temporal data for the effective service. The two-way synchronization scheme collects updated spatio-temporal data in the field and synchronizes with a server by using the wireless network. However, since the two-way synchronization scheme processes sequentially synchronizing work of clients, it has the problem that the synchronization of multiple clients takes long time. In this paper, we propose the concurrent synchronizations scheme based on the multi-queue in order to reduce the waiting time of multiple clients. We also build both schemes and evaulate the performance test. The results show that the proposed scheme reduce the waiting time by 31%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12B
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• pp.1474-1480
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• 2011

Recently the mobile IPTV service has been spread through the wireless LAN(WLAN). In order to provide the commercial mobile IPTV service through the WLAN, re-authentication for the mobile IPTV terminal is required whenever the mobile terminal roams between APs(Access Points). The most popular one of the authentication protocol standards for the wired and/or wireless LAN is IEEE 802.1X. However IEEE 802.1X takes much time to authenticate the terminal and is not adequate for the seamless mobile IPTV service. We introduce the session key and separate the user authentication and the hardware authentication. And we strengthen the device authentication by the initial registration. By these, the proposed authentication protocol reduces the authentication time and can protect the authentication key securely.