• Korean Journal of Child Studies
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• v.30 no.6
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• pp.111-124
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• 2009

The importance of information media in personal lives has increased rapidly, indicating the average ages of users are becoming younger. School-age children, despite the inconsequential differences, are reported to have used the internet for their free time, information search, communications, and education. Recent researches are focused on various variables affecting internet-addictions since these problems have become a major issue in education due to prolonged use of the internet or mobile. The regulations as a preventative measure and the setting of standard are also considered as major issues of research. In terms of policy, there should be revisions on laws and regulations about the internet and mobile in order to protect school-age children from vicious environments. For the education's part, there should be appropriate amount of education, for children and their parents, on how to use computers and the internet properly and how to prevent internet-addiction.

• Journal of the Korean Institute of Educational Facilities
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• v.22 no.1
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• pp.13-23
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• 2015

Currently, the group study becomes the most popular method and common custom for learning in public that is distinctly different from the preferred way of self-study in the last decades. As a result, the college and public facilities have been significantly changed to provide more and more new spaces for discussion, learning and sharing information with others as one of the remarkable improvements and advantages. On the other hands, library is one of the all-important public sites to obtain information and knowledge for students. Moreover, we can split out an individual space from the reading rooms to take part in the group activities such as group meetings and academic exchanges. Recently, several universities begin to recognize the value of group study and try to meet the research needs. Also, needs for students, and the group study rooms are applied into the new buildings and rebuilt ones under this background. In this study, It focuses on analyzing of the 134 group study rooms to investigate the variations in universities and classify the types of buildings with site researches through 14 indicators of indoor environments. To investigate different types of group study rooms, we use the SD method to analyze the findings. So far there is no research focusing on the study rooms, especially for the analysis of their types and indoor environments features. Therefore, this article can provide a theoretical basis and evidence to related researches; also can help us to improve indoor environments to offer a better learning environments for the students in the future.

• Journal of Information Technology Applications and Management
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• v.16 no.1
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• pp.51-75
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• 2009

This paper develops an integrative model for IT continuance in the internet shopping environments by integrating the expectation-confirmation and the switching cost factors. Using this model, in addition, this study investigates their differential effects on the mediating variables, such as user satisfaction, commitment, and trust which have been identified as antecedents of users' IT continuance intention. Results show that the product and service-related expectation confirmation factors and the relational switching cost factor can have greater impacts on users continuance intention than the web site design factors, and the financial and procedural switching cost factors. In particular, it is interesting to note that relational switching cost can lead users to more commitment, which is revealed as the strongest antecedent of their continuance intention to use a certain shopping site.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.12C
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• pp.1021-1028
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• 2008

In a network environment, when a user requests a server's service, a remote user authentication system using smart cards is a very practical solution to validate the eligibility of a user and provide secure communication. In these authentication schemes, due to fast progress of networks and information technology, most of provided services are in multi-server environments. However, there are no studies in multi-server authentication schemes using smart cards providing mutual anonymity so far. In this paper, we propose a novel user authentication scheme using smart cards providing mutual authentication and mutual anonymity for multi-server environments. Our proposed scheme achieves the low-computation requirement for smart cards and a user can use permitted various services in eligible servers by only one registration. Also, this scheme guarantees perfect mutual anonymity of participants.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10A
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• pp.1532-1538
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• 1999

In general, because error rate of wireless link is higher than that of wired link, DLC layer protocol for wired network with low error rate is not proper for wireless environments. In addition, the conventional DLC layer protocol for wireless network is optimized for the low-speed data service, so it is difficult to use conventional DLC protocol in the current mobile communication environments handing high-speed and multimedia services. Therefore, a DLC layer protocol that is suitable to current wireless communication environments is required. In this paper, we propose a novel error control scheme that supports a variety of traffic attribute and is applicable to high-speed and multimedia data service in WATM. The proposed scheme provides enhanced throughput performance for real-time traffic by using modified ASR ARQ without ACK and reduces loss rate by using FEC in the case of high error condition. Also, for non real-time traffic, the use of ASR ARQ without ACK enhances throughput performance and delay time is decreased by using FEC in the case of high error rate channel. As a result of simulation, the proposed scheme has better performance than conventional ASR ARQ protocol in view of delay and throughput.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.11
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• pp.1592-1598
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• 2022

This paper proposes an improvement system for the marginalized digital underprivileged of these services due to the lack of intuition and usability for the recently increasing number of unmanned ordering devices' interfaces and device environments. The problem with kiosk service is that it lacks intuition among design principles and cannot be used by wheelchair passengers in environments that meet general standing standards. To solve this problem, we propose a service that can use kiosk-like environments on mobile devices by photographing QR codes with mobile devices. As a result of the experiment, people in their 20s did not experience difficulties in using the existing kiosk model, but in the case of the elderly, it was difficult to use the kiosk, so they asked for help. The improved kiosk model was carried out in their 20s without difficulty, and the results showed that it was carried out without difficulty even in the case of the elderly.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.725-728
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• 2009

This paper describes remote monitoring system for the various environments of a vinyl house, which was located in rural or outer of urban by use internet web connection system in a long distance office. We have constructed remote monitoring system by use a simple experimental model for the monitoring of various factors which need to operate common vinyl house. The experimental model includes temperature, humidity, smoke and infrared sensors for the measuring and AC 220V light bulb for the controlling in the USN system. Also, we have developed monitoring software by use NI Labview and communicate between PC and sensors through the DAQ-board, USN control board. We use CCD camera and grab board for the real time remote monitoring of wanted image in the house area. The computer server for remote connection is constructed in the local PC with Apache web server, PHP and MySQL ODBC. We construct internet communication system for the monitoring remotely the local environments of a vinyl house system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.12
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• pp.822-830
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• 2014

Recently, A Security service in Internet environments has been more important and the use of SSL & TLS is increasing for the personel homepage as well as administrative institutions. Also, IETF suggests using DTLS, which can provide a security service to constrained devices with lower CPU power and limited memory space under IoT environments. In this paper, we implement LEA(Lightweight Encryption Algorithm) algorithm and apply it to OpenSSL. The implemented algorithm is compared with other symmetric encryption algorithms such as AES etc, and it shows the superior performance in calculation speed.

• Journal of Communications and Networks
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• v.15 no.2
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• pp.122-131
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• 2013

We address the problem of effective vehicular routing in hostile scenarios where malicious nodes intend to jeopardize the delivery of messages. Compromised vehicles can severely affect the performance of the network by a number of attacks, such as selectively dropping messages, manipulating them on the fly, and the likes. One of the best performing solutions that has been used in static wireless sensor networks to deal with these attacks is based on the concept of watchdog nodes (also known as guard nodes) that collaborate to continue the forwarding of data packets in case a malicious behavior in a neighbor node is detected. In this work, we consider the beacon-less routing algorithm for vehicular environments routing protocol, which has been previously shown to perform very well in vehicular networks, and analyze whether a similar solution would be feasible for vehicular environments. Our simulation results in an urban scenario show that watchdog nodes are able to avoid up to a 50% of packet drops across different network densities and for different number of attackers, without introducing a significant increase in terms of control overhead. However, the overall performance of the routing protocol is still far from optimal. Thus, in the case of vehicular networks, watchdog nodes alone are not able to completely alleviate these security threats.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.473-476
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• 2008

Mobile network environments are the environments where mobile devices are distributed invisible in our daily lives so that we can conventionally use mobile services at any time and any place. But, Mobile devices has a many security vulnerabilities caused by lower computing of devices and security problem of wireless network. So in this paper, PKI structure is proposed to minimize encrypting and decrypting operation by compounding session key and public key on WIPI environment. Proposed secure authentication system based on korean standard cryptography algorithm will give a more firmness in mobile network and support a more secure service for mobile academic information service that KISTI future plan.