• The Journal of Information Technology and Database
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• v.7 no.2
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• pp.1-15
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• 2000

The World-Wide-Web have many advantages as a front-end of database systems. Hence in Internet applications, such as E-Commerce systems, the requirements for Web-based database applications have been increasing. In this work we propose a framework for java-based Web database applications-JaWAF(Java-based Web Application Framework). JaWAF has the 3-tier architecture of Client/Server, and consists of database gateway, application server, and communication and message component. When this framework is applied to the database applications developments, it can provide advantages, such as ease understanding and fast implementations of the Web applications. Thus we can build 3-tier Web-based database application systems with high scalability and distributed processing capability. Database gateway in JaWAF works as a daemon process that connects to the database systems and waits for requests from clients, and supports state-oriented service between clients and database servers. Hence the performance of Web applications could be increasing.

• Journal of information and communication convergence engineering
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• v.15 no.1
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• pp.14-20
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• 2017

In this paper, we discuss physical layer security techniques in downlink networks, including eavesdroppers. The main objective of using physical layer security is delivering a perfectly secure message from a transmitter to an intended receiver in the presence of passive or active eavesdroppers who are trying to wiretap the information or disturb the network stability. In downlink networks, based on the random feature of channels to terminals, opportunistic user scheduling can be exploited as an additional tool for enhancing physical layer security. We introduce user scheduling strategies and discuss the corresponding performances according to different levels of channel state information (CSI) at the base station (BS). We show that the availability of CSI of eavesdroppers significantly affects not only the beamforming strategy but also the user scheduling. Eventually, we provide intuitive information on the effect of CSI on the secrecy performance by considering three scenarios: perfect, imperfect, and absence of eavesdropper's CSI at the BS.

• Journal of information and communication convergence engineering
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• v.15 no.1
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• pp.37-42
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• 2017

The constrained application protocol (CoAP) can be used for remotely controlling various sensor devices in Internet of Things (IoT) networks. In CoAP, to support the handover of a mobile sensor device, service discovery and message transmission needs to be repeated, although doing so would increase the handover delay significantly. To address this limitation of CoAP, a centralized CoAP scheme has been proposed. However, it tends to result in performance degradation for an inter-domain handover case. In this letter, we propose a distributed CoAP handover scheme to support the inter-domain handover. In the proposed scheme, a distributed mobility agent (DMA) is used for managing the location of mobile sensors in a domain and performing handover control operations with its neighboring DMAs in a distributed manner. A performance comparison reveals that the proposed scheme offers a performance improvement of up to 29.5% in terms of the handover delay.

• Journal of Communications and Networks
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• v.10 no.2
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• pp.194-203
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• 2008

This paper considers the multi-input multi-output (MIMO) relay channel where multiple antennas are employed by each terminal. Compared to single-input single-output (SISO) relay channels, MIMO relay channels introduce additional degrees of freedom, making the design and analysis of optimal cooperative strategies more complex. In this paper, a partial cooperation strategy that combines transmit-side message splitting and block-Markov encoding is presented. Lower bounds on capacity that improve on a previously proposed non-cooperative lower bound are derived for Gaussian MIMO relay channels.

• Journal of Information Technology Applications and Management
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• v.9 no.3
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• pp.13-30
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• 2002

ebXML (Electronic Business using extensible Markup language), sponsored by UN/CEFACT and OASIS, is a modular suite of specifications that enables enterprises of any size and in any geographical location to conduct business over the Internet. Using ebXML, companies now have a standard method to exchange business messages, conduct trading relationships, communicate data In common terms and define and resistor business processes. It is the mission of ebXML that provides an open XML-based infrastructure enabling the global use of electronic business information in an interoperable, secure and consistent manner by all parties for creating a single e1ectronic electronic market. This paper briefly overviews the concept of core component, context, assembly rule and context rule. Then, It designs by standard specifications of ebXML core component commonly used in an industry and among industries, and assembles business messages by using XML schema. Therefore, it suggests the mechanism which effectively exchanges business messages among the trading partners. This paper designs core component by using only three business messages of retail industry : orders, dispatch report, sales report.

• Journal of Information Technology Applications and Management
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• v.23 no.2
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• pp.239-261
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• 2016

Wide use of smart and high performing mobile device makes consumers use diverse distribution channels, composed of online and offline channel. Smart companies are trying to deploy omni channel. In order to successfully integrate these diverse channels, it is necessary to understand consumers' preference of channel choice. Thus, this study was focused on the influencing factors of channel preference such as price sensitivity, consumer innovativeness, time pressure, and need-for-touch. And this study compared these influencing factors between Korea and China, and drew meaningful message for e-commerce companies and offline distribution companies.

• ETRI Journal
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• v.24 no.5
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• pp.381-390
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• 2002

We analyze the performance of a telecommunications management network (TMN) system using models of networks of queues, Jackson's theorem, and simulation. TMN systems for managing public asynchronous transfer mode (ATM) networks generally have a four-level hierarchical structure consisting of a network management system, a few element management systems (EMSs), and several pairs of agents and ATM switches. We construct a Jackson's queuing network and present formulae to calculate its performance measures: distributions of queue lengths and waiting times, mean message response time, and maximum throughput. We perform a numerical analysis and a simulation analysis and compare the results.

• Journal of Contemporary Eastern Asia
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• v.13 no.2
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• pp.3-14
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• 2014

Online communities are an important source of electronic-word-of-mouth (eWOM), however few studies have examined these types of messages within the Middle Eastern context. This study focuses on Kuwaiti women as members of an online beauty forum; previous work has suggested a mediating effect of gender with women being more likely to trust and follow-up word-of-mouth with a purchase. A conceptual model, based on existing theoretical contributions, provides the basis of a coding framework for the message characteristics that influence members' eWOM adoption. A sub-set of the analysis is presented: 218 threads (1820 messages, coded into 6702 units) illustrating cases where eWOM was adopted and thereby demonstrating continuance intention with members returning to the forum. Content analysis revealed the prevalence of emotional aspects in messages, coded into a new category of 'community bonding'. Findings show that emotion expressed in messages is as influential and important as cognitive aspects of argument quality.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.688-690
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• 1999

오늘날 통신 환경에서 널리 사용되고 있는 TCP는 유선망과 고정된 호스트로 이루어진 전통적인 네트워크에 적합하여 유선망의 특성을 적용한 것이기 때문에, 무선 구간의 제한된 대역폭, 높은 지연, 산발적인 비트 에러, 일시적인 연결 두절 및 핸드오프 등과 같은 특징을 가진 특성상 유선망과는 상이한 무선망에 이를 그대로 적용하게 되면 오히려 불필요한 메커니즘의 호출로 인해 End-to-End Throughput의 성능 저하를 가져온다. 이러한 무선망에서 발생되는 핸드오프로 인해 TCP 성능이 저하되는 것을 방지하기 위한 방안으로 핸드오프 과정 동안 무선 구간에서 발생되는 패킷 손실로 인한 고정 호스트 재전송 타이머의 타임아웃과 불필요한 혼잡제어 절차의 수행에 따른 성능감소를 미연에 방지하기 위한 방안으로 핸드오프가 발생했을 때 핸드오프를 가장 먼저 알게 되는 이동 호스트가 ICMP(Internet Control Message Protocol) 형태의 EHN(Explicit Handoff Notification) 패킷을 고정 호스트에 전송하여 새로운 기지국과 고정 호스트에 핸드오프의 시작을 명시적으로 알림으로써 핸드오프 과정 동안에 발생되는 고정 호스트 재전송 타이머의 타임아웃과 혼잡제어 절차를 강제로 일어나지 않게 하여 기지국에서의 부하를 감소하게 할 수 있는 새로운 방식의 EHN 알고리즘을 제안한다.

• Journal of Life Science
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• v.8 no.4
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• pp.395-399
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• 1998

Neurokinin A(NKA) and its derivatives ([Nle$^{7}$NKA,[Leu$^{7}$NKA] were synthesized by solid phase peptide synthesis method using Fmoc-TFA strategy and their smooth muscle contractile activities were measured to examine the structural effect of alkyl group at the 7th amino acid NKA on the smooth muscle contractile activity. The smooth muscle contractile activity. The smooth muscle contractile activities of [Nle$^{7}$]NKA and [Leu$^{7}$]NKA were only 5.64% and 1.55%, respectively when compared with NKA. This result suggested that the more three dimensional structure of th 7th amino acid as well as the whole message segment of NKA would be necessary to show the biological activity.