• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.7
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• pp.2212-2230
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• 2014

Cognitive radio (CR) users, known as secondary users (SUs), should avoid interference with primary users (PUs) who own the licensed band, while trying to access it; when the licensed band is unused by the PUs. To detect PUs, spectrum sensing should be performed over in-band channels that are currently in use by SUs. If PUs return to access the band, SUs need to vacate it, disrupting the SUs' communication unless a non-utilized band is discovered. Obtaining a non-utilized band in a short period facilitate seamless communication for SUs and avoid interference on PUs by vacating from the channel immediately. Searching for a non-utilized band can be done through proactive out-of-band (OB) sensing. In this paper, we suggest a proactive OB sensing scheme that minimizes the time required to discover a non-utilized spectrum in order to continue communication. Although, the duration spent on OB sensing reduces the throughput of the CR networks that can be achieved on band being utilized, the lost throughput can be compensated in the new discovered band. We demonstrate that, the effect of our proposed scheme on the throughput owing to OB sensing is insignificant, while exhibiting a very short channel discovery time.

• Journal of Internet Computing and Services
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• v.9 no.6
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• pp.15-25
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• 2008

Due to the differences between a mobile ad-hoc network and a sensor network, the pre-existing autoconfiguration for a mobile ad-hoc network cannot be simply applied to a sensor network. But. a mechanism is still necessary to assign locally unique addresses to sensor nodes efficiently. This paper proposes a hybrid IDs assignment scheme of local area sensor networks. The IDs assignment scheme of hybrid method combines a proactive IDs assignment with a reactive IDs assignment scheme. The proposed scheme considers efficient communication using reactive IDs assignment, and security for potential attacks using zone-based self-organized clustering with Byzantine Agreement in sensor networks. Thus, this paper has solved the shortage of security due to minimizing network traffic and the problem of repairing the network from the effects of an aberrant node in sensor networks.

• Journal of Information Processing Systems
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• v.8 no.4
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• pp.721-738
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• 2012

The Internet has become an increasingly important source for finding the right employees, so more and more companies post their job openings on the Web. The large amount and dynamic nature of career recruiting information causes information overload problems for job seekers. To assist Internet users in searching for the right job, a range of research and commercial systems were developed over the past 10 years. Surprisingly, the majority of existing job search systems support just one, rarely two ways of information access. In contrast, our work focused on exploring a value of comprehensive access to job information in a single system (i.e., a system which supports multiple ways). We designed Proactive, a recommendation system providing comprehensive and personalized information access. To assist the varied needs of users, Proactive has four information retrieval methods - a navigable list of jobs, keyword-based search, implicit preference-based recommendations, and explicit preference-based recommendations. This paper introduces the Proactive and reports the results of a study focusing on the experimental evaluation of these methods. The goal of the study was to assess whether all of the methods are necessary for users to find relevant jobs and to what extent different methods can meet different users' information requirements.

• Journal of Internet Computing and Services
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• v.11 no.4
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• pp.33-39
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• 2010

In this paper, a data dissemination protocol that transmits data collected for Wireless Sensor Networks (WSNs) is newly proposed, and the proposed proactive protocol takes into account energy consumption minimized and delay time disseminated. The well-known SPMS (Shortest Path Mined SPIN) forms the shortest path-based routing table obtained by Bellman Ford Algorithm (BFA) and disseminates data using a multi-hop path in order to minimize energy consumption. The mentioned properties of SPMS cause memory burden to create and maintain the routing tables. In addition, whenever BFA is executed, it is necessary to suffer from the energy consumption and traffic occurred. In order to overcome this problem, a proactive dissemination protocol using Residual Energy and Signal Strength, called RESS, is proposed in this paper. Simulation results show that RESS outperforms SPMS up to 84% in terms of the number of traffic messages and the transmitted delay time of RESS is similar to that of SPMS using the shortest path.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.12A
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• pp.1226-1237
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• 2007

This paper proposes QoS mesh routing protocol for IEEE 802.16 based wireless mesh networks. QoS mesh routing protocol proposed in this paper is a proactive hop-by-hop QoS routing protocol. The goal of our routing protocol is not only to find a route from a source to a destination, but also optimal route that satisfies QoS requirements, given in terms of bandwidth and delay as default QoS parameters. In this paper, we first analyze possible types of routing protocols that have been studied for MANET and show proactive hop-by-hop routing protocols are the most appropriate for wireless mesh networks. Then, we present a network model for IEEE 802.16 based wireless mesh networks and propose a proactive hop-by-hop QoS routing protocol. Through our simulation, we represent that our routing protocol outperforms QOLSR protocol in terms of end-to-end delay, packet delivery ratio and routing overhead.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.6C
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• pp.457-464
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• 2005

Recently, Portable Internet being standardized provides fast movement with wider service range than wireless LAN does. If Portable Internet service starts, many people will use Portable Internet and thus wireless traffic is going to increase. In Portable Internet, it is important to reduce handover latency to provide user with satisfactory service when handover occurs. In IEEE 802.16e, MSS sends its own security context information to one Base Station which it will move to reduce handover latency. But this is not suitable in the situation that the BS doesn't know the security context. To reduce handover latency of proactive caching method that is to send security context information to adjacency Base Stations in advance has been proposed by[4]. In this paper we propose effective traffic management algorithm to reduce signaling network traffic caused by proactive caching method.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.6
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• pp.721-729
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• 2016

CCN(Content-Centric Network) enables users to retrieve content using the content's name. Researchers face critical challenges in terms of mobility. Since the routing information is part of the content name, when the provider moves, it is necessary to update all the routers routing information. However, this requires significant costs. In this paper, we propose PNPCCN(Proactive Neighbor Pushing CCN), considering the popularity and rarity of mobility support, for providers in CCN environments. Via simulation studies, we demonstrate that our solutions are effective in terms of shorter numbers of retransmitted Interest packets, and average download times and higher delivery ratios during mobility.

• Asia pacific journal of information systems
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• v.11 no.1
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• pp.25-43
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• 2001

The evolution of EDI has opened the flexible and efficient way for business to conduct a greater portion of the routine buyer-seller business activities online. This study focuses on the role of factors that change the innovation characteristics for implementation success of EDI. Three factors promotional efforts, proactive implementation strategy, and provision of technical expertise are proposed to affect EDI implementation success, as these factors directly influence three general and most important attributes of innovation relative advantage, compatibility, and complexity respectively. Hypotheses indicate that promotional efforts, proactive implementation strategy, and provision of technical expertise directly affect EDI implementation success that is represented by three variables volume, depth, and diversity. A structural equation modeling approach(LISREL) is used to analyze data from EDI adopters. The results show that proactive implementation strategy and provision of technical expertise positively affect implementation success of EDI. Given the significant impact of the wide spread use of the EDI system, this study offers quite useful insights on the factors facilitating innovation characteristics under which EDI can be successfully diffused in organizations.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06d
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• pp.151-154
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• 2010

Proactive Display 시스템은 소셜 웹 콘텐츠를 대형 디스플레이 장치에 표시하여 실세계에서의 상호관계 증진을 도울 수 있는 시스템을 말한다. 지금까지의 Proactive Display 시스템은 개인적인 웹 콘텐츠를 표현할 수 있지만 표현하는 콘텐츠에 초점이 맞춰진 상호활동에 적합한 구조를 가지고 있다. 따라서 웹콘텐츠 소유자에게 초점이 맞춰진 상호활동에서 소셜 웹 콘텐츠를 사용하기 위하여 새로운 구조의 Proactive Display 시스템이 필요하게 되었다. 본 논문에서는 개인적인 소셜 웹 콘텐츠를 소유자가 이동함에 따라 주변에 배치된 대형 디스플레이 장치에 표현하도록 하는 Moving Interests 시스템의 설계에 대하여 기술한다. 설계된 시스템을 통하여 사용자는 외모뿐만 아니라 생각과 관심사 등을 드러내어 자신을 소개하는데 사용할 수 있다. 또한 시스템 사용자의 상대방도 내형적인 정보를 직관적으로 확인하여 시스템 사용자와 상호관계를 맺을 수 있으므로 설계된 시스템을 이용하면 보다 폭 넓고 깊은 상호관계활동을 수행할 수 있다.

• Journal of Communications and Networks
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• v.18 no.3
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• pp.288-298
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• 2016

Proactive relay selection in cognitive radio networks has recently received considerable attention. However, its outage probability analysis is limited to partially-identical fading distributions, uncorrelation among received signal-to-noise ratios (SNRs), and no direct channel. This paper completes this literature deficiency by generalizing the existing analysis for non-identical fading distributions, correlation among received SNRs, and with direct channel. Numerous results demonstrate that relay selection with a direct channel achieves a higher diversity order and superior performance than that without a direct channel at virtually no cost of power and bandwidth. Further, proactive relay selection suffers an error floor at either a large maximum transmit power or large maximum interference power; however, the error floor level can be significantly remedied with an increase in the number of relays.