• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.6
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• pp.11-22
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• 1996

We address an issue of channel sharing among users by using a random assignment-transmitter-based (RA-T) spread-spectrum transmission scheme which permits the contention mode only in the transmission of a header while avoiding collision during the data packet transmission. Once the header being successfully received, the data packet is ready for reception by switching to one of programmable matched-filters. But the receoption may be blocked due to limited number of matched-filters so that this effect is taken into account in our analysis. For realistic analysis, we integrate detection performance at the physical level with channel activity at the link level through a markov chain model. We also consider an acknowledgement scheme to notify whether the header is correctly detcted and the data packet can be processed continuously, which aims at reducing the interference caused unwanted data transmission. It is shown that receiver complexity can be greatly reduced by choosing a proper number of RA codes at the cost of only a little throughput degradation.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.37
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• pp.117-125
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• 1996

The objective of this study is to select reward measure of improved business results. Ga-in sharing is defined as a compensation system that is designed In provide for variable compensation and to support an employee involvement process by rewarding the members of a group or organization for improvements in organizational performance. Gains, as measured by a predetermined formula, are shared with all eligible employees, typically through the payment of cash bonuses. Generally sales, profit value-added, cost reduction portion and otherthings have been used as gains, otherwise improved business results, without any proof which is correlated to productivity improvement. This paper suggests which business result is fit reward measure for each business types and sizes.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.2
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• pp.23-32
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• 2013

The purpose of this study is to make effective mobile grid considered general environment, which can be summarized as irregular mobility, service exploration, data sharing, variety of machines, limit to the battery duration, etc. The data was extracted from the Dartmouth College. We analysed mobile use pattern of a specific group and applied pattern using hybrid method. As a result, we could adjust infra usage effectively and appropriately and cost cutting and increase satisfaction of user. In this study, by applying weighting method based on access time interval, we analysed use pattern added time variation with association rule during users in mobile grid environment. We proposed more stable way to manage patterns in a mobile grid environment that is being used as a hybrid form to process the data value received from the server in real time. Further studies are needed to get appropriate use pattern by group using use patterns of various groups.

• 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 Technology Innovation
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• v.5 no.1
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• pp.1-14
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• 1997

Firms prefer in some specific conditions cooperative R&D to non-cooperative for developing technology. Previous studies on the conditions show firms want to choose cost-sharing type of cooperative R&D (the CS-RJV) rather than non-cooperative one when target technology is either 'relatively easy' or 'relatively difficult', and to join multiple-research or pararell-research type of cooperation (the PR-PJV) than to compete each other if technology is only 'relatively easy'. However, by introducing technological leakage as well as difficulty of technology. it is shown that this seemingly contrasted phenomenon almost disappears ; the PR-RJV can be also preferred by firms even is case of 'relatively difficult' technology only if there exists some extent of a technological leakage.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.159-161
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• 2006

The peer-to-peer (P2P) systems have Brown significantly over last few years due to their hish potential of sharing various resources. Super-peer based P2P systems have been found very effective by dividing the peers into two layers, SP (Super-Peer) and OP (Ordinary-Peer). In this paper, we present ISP2P (Intelligent Super-peer based P2P system), which allows us to choose the best SP. Through analyzing capacity and similarity between SP and OP, we can help OPs to select the most appropriate SP respectively. Proposed system can improve the performance of the average response time by superior SP, reduce the bandwidth cost by small path length due to content similarity and solve frequent SP replacement problem by considering similarity of user behavior.

• Asia pacific journal of information systems
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• v.12 no.4
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• pp.121-137
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• 2002

Researches on P2P, the information sharing model from person to person, up to date have focused on the technical side and there have been lacking of the business side researches such as customer loyalty. Considering the problem, this study tries to examine empirically in what way the factors of service, market, and customer affect the service loyalty of P2P sites. Results of the study show that the three factors have statistically significant effects on the service loyalty in general. In particular, the results uncover that those factors have different impacts on the reuse intention and the recommendation intention, which are the two measures of service loyalty. For example, the cost of service use affects the reuse intention significantly whereas the same element does not affect the recommendation intention. Interestingly, some of the results are not coincide with the results of previous studies and do not meet general expectation. For example, users' tendency of pursuing variety has positive impacts on the service loyalty, especially, the intention of recommendation.

• Knowledge Management Research
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• v.10 no.4
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• pp.43-60
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• 2009

The current study attempts to provide the field of knowledge management with theoretical grounds from the perspective of social network, resource dependency, and institutional theory. Social network theory considers that knowledge management plays a critical role in organizational innovation through the process of knowledge sharing/creation, communication systems, and a cooperative culture and trust, whereas resource dependency perceives knowledge management as contributing to cost reduction through the process of knowledge capture/storage, database systems, and reward/incentive systems. Plus, from the perspective of institutionalization, this study discusses that organizations can not benefit from knowledge management if it is adopted with the motive of isomorphic change. Finally, this study compares and integrates the three perspectives, and discusses the implications and limitations.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.256-259
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• 2013

Data and network security for e-Healthcare Systems are a primary concern due to the easiest deployment area accessibility of the sensor devices. Furthermore, they are often interacting closely in cooperation with the physical environment and the surrounding people, where such exposure increases security vulnerabilities in cases of improperly managed security of the information sharing among different healthcare organizations. Hence, healthcare-specific security standards such as authentication, data integrity, system security and internet security are used to ensure security and privacy of patients' information. This paper discusses security threats on e-Healthcare Systems where an attacker can access both data and network using masquerade attack. Moreover, an efficient and cost effective approach for countermeasures is discussed for the delivery of secure services.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.351-354
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• 2012

The core of cloud computing is to provide efficient computing resource sharing. In this paper, we have designed and implemented a virtual computer lab system using open source cloud computing infrastructure. The proposed virtual computer lab system can be used to reduce computer upgrade and maintenance cost significantly.