• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.9
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• pp.1700-1709
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• 2006

In this raper we researched on the development methods and design of the B-ISDN protocol embedded IP-PBX System with the computers interconnected by the Internet for the previous telephone exchange and communication. We designed the structure of the user terminal and exchange sewer of the IP-PBX System, defined message and data structure for call control, and designed call control state transition and call control message flows for user's communication. And we researched on the message flows for supplementary services and the call control for multiple calls.

• Journal of Communications and Networks
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• v.14 no.6
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• pp.710-718
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• 2012

The implementation of a common control channel is one of the most challenging issues in cognitive radio networks, since a fully reliable control channel cannot be created without reserving bandwidth specifically for this purpose. In this paper, we investigate a promising solution that exploits the ultra wide band (UWB) technology to let cognitive radio nodes discover each other and exchange control information for establishing a communication link. The contribution of this paper is threefold: (i) We define the communication protocol needed to let cognitive radio nodes discover each other and exchange control information for link set up, (ii) we overcome the gap in coverage, which typically exists between UWB and long-medium range technologies, by using multi-hop communication, (iii) we evaluate the performance of our approach by adopting an accurate channel model and show its benefits with respect to an in-band signaling solution.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.3
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• pp.59-63
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• 2019

VoIP technology is a technology for exchanging voice or video data through IP network. Various protocols are used for this technique, in particular, RTP(Real-time Transport Protocol) protocol is used to exchange voice data. In recent years, with the development of communication technology, there has been an increasing tendency of services such as "Kakao Voice Talk" to exchange voice and video data through IP network. Most of these services provide a service with security guarantee by a user authentication process and an encryption process. However, RTP protocol does not require encryption when transmitting data. Therefore, there is an exposition risk in the voice data using RTP protocol. We will present the risk of the situation where packets are sniffed in VoIP(Voice over IP) communication using RTP protocol. To this end, we configured a VoIP telephone network, applied our own sniffing tool, and analyzed the sniffed packets to show the risk that users' data could be exposed unprotected.

• Journal of KIISE:Information Networking
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• v.35 no.4
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• pp.311-317
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• 2008

This paper proposes a session key exchange scheme for providing secure communication between Vehicles and Infrastructure in VANET. In the current VANET environment, IEEE 802.11i or PKI based mechanism is used to provide secure communication between V2I. However, since the vehicles and the frequent changes of network topology, VANET nodes have some difficulties to exchange the session key using IEEE 802.11i or PKI method. In the proposed scheme, Local Router is newly defined for exchanging the session key between moving vehicles and infrastructure. A session key is generated by XOR operation based on the random values between Local Router and OBU. As a result, the proposed scheme has a noticeable advantage on the fastness of key exchange by exchanging session keys between LR and OBU.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.3
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• pp.125-132
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• 2005

Wireless access always has to include the authentication of communication partners and the encryption of communication data in order to use secure M-Commerce services. However, wireless systems have limitations compared with the wired systems, so we need an efficient authentication and key exchange protocol considering these limitations. In this paper, we propose an efficient authentication and key exchange protocol for M-Commerce users using elliptic curve crypto systems. The proposed protocol reduces the computational load of mobile users because the wireless service provider accomplishes some parts of computations instead of the mobile user, and it uses the password-based authentication in wireless links. Also, it guarantees the anonymity of the mobile user not to reveal directly the real identity of the user to the M-Commerce host, and preserves the confidentiality of communication data between the M-Commerce host and the user not to know the contents of communication between them to others including the wireless service provider.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.545_546
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• 2009

전력거래 계량시스템은 회원사의 계량기가 생성한 계량데이터를 주기적으로 취득하고 이로부터 계량값을 산출한 후, 산출된 시간대별 계량값을 타 시장시스템에 전송하는 기능을 수행한다. 이는 전자상거래 시스템과 연계하여 회원사 계량값을 공개하는 전력거래 핵심 시스템이다. 현재 계량데이터 취득 방식은 전용선 및 공중선에 기반한 유선방식 위주로, 복수 개의 전용선 모뎀을 취합하여 계량서버에 연계하기 위하여 FEP를 도입 운영하고 있으며, 현재 운영 중인 FEP보다 향상된 FEP용 펌웨어를 신규 개발하고 있다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.12
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• pp.5135-5149
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• 2015

Communications among multi-party must be fast, cost effective and secure. Today's computing environments such as internet conference, multi-user games and many more applications involve multi-party. All participants together establish a common session key to enable multi-party and secure exchange of messages. Multi-party password-based authenticated key exchange scheme allows users to communicate securely over an insecure network by using easy-to-remember password. Kwon et al. proposed a practical three-party password-based authenticated key exchange (3-PAKE) scheme to allow two users to establish a session key through a server without pre-sharing a password between users. However, Kwon et al.'s scheme cannot meet the security requirements of key authentication, key confirmation and anonymity. In this paper, we present a novel, simple and efficient multi-party password-based authenticated key exchange (M-PAKE) scheme based on the elliptic curve cryptography for mobile environment. Our proposed scheme only requires two round-messages. Furthermore, the proposed scheme not only satisfies security requirements for PAKE scheme but also achieves efficient computation and communication.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.9
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• pp.2147-2154
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• 2014

JXTA does not need to be managed by the central server, and has the property that can communicate with any device that is connected to the network. Thus, JXTA can be applied to the communication between heterogeneous P2P systems. This paper deals with the design of a data exchange system utilizing the JXTA's foregoing property, which is able to connect P2P systems with different protocols and APIs.

• Journal of Electrical Engineering and Technology
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• v.5 no.1
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• pp.1-7
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• 2010

Recently, smart grid has been considered a very important new energy delivery technology, and one that can help ensure a cleaner environment by making use of information and communication technology (ICT) in countries around the world. The many technological benefits smart grid offers is expected to bring about a huge change in the electric energy supply chain. In particular, smart grid with advanced ICT is likely to allow market agents to participate in the decision-making process in the restructured electricity industry, easily facilitating Homeostatic Utility Control. In this paper, we examine smart grid as a market externality, and then illustrate issues from the commercial market perspective as it relates to electricity market design. Finally, our paper identifies some of the impacts of smart grid on electricity market design, which may possibly be incorporated into the evolution of the electricity market, thus ensuring market efficiency.

• Journal of the Korean Dietetic Association
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• v.9 no.2
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• pp.159-171
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• 2003

The food composition tables are frequently used to health and nutrition practices. But it is difficult to find out food exchange lists with food exchange groups in the food composition table. Over 2500 items and many kinds of nutrients are in the food composition table. But now food exchange lists are used a few foods. The internet demands the users needs for obtaining more food exchange lists and nutrient information from food composition. This basic study is to solve the users need and the supply more efficient and effective manipulation system for e-food exchange database construction and search system:ENECC/e-food exchnage(E-Nutrition Education and Couseling Center/e-food exchange). This paper introduces the food exchange database construction and search system(ENECC/e-food exchange) using the formula which calculates the food exchange quantity of 6 food exchange groups and added one extra groups(alcohol) based on the internet. The ENECC/e-food exchange database is basically based on the 6th food composition table(2001) of the National Rural Living Science Institution in Rural Development Administration, Korea. The e-food exchange database are consisted of 2,261 foods in 6 basic food groups and one extra groups by using ENECC calculating formula. Also, the e-food exchange database has the proximate composition, mineral and vitamin content such as energy, moisture, protein, fat, carbohydrate, ash, calcium, phosphorus, iron, sodium, potassium, retinol equivalent, retinol, â-carotene, thiamin, riboflavin, niacin, ascorbic acid, refuse per 100g of each food.