• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.12
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• pp.4372-4388
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• 2014

Robotic sensor network (RSN) contains mobile sensors and robots providing feasible solution for many multi-agent applications. One of the most critical issues in RSN and its application is how to effectively assign tasks. This paper presents a novel connectivity preserving hybrid task allocation strategy to answer the question particularly for RSN. Firstly, we model the task allocation in RSN to distinguish the discovering and allocating processes. Secondly, a fully distributed simple Task-oriented Unoccupied Neighbor Algorithm, named TUNA, is developed to allocate tasks with only partial view of the network topology. A connectivity controller is finally developed and integrated into the strategy to guarantee the global connectivity of entire RSN, which is critical to most RSN applications. The correctness, efficiency and scalability of TUNA are proved with both theoretical analysis and experimental simulations. The evaluation results show that TUNA can effectively assign tasks to mobile robots with the requirements of only a few messages and small movements of mobile agents.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.9
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• pp.4446-4462
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• 2019

In this paper, we focus on interference cancellation for three-hop cognitive radio networks (CRNs) over Rayleigh fading channels. In CRNs, secondary users (SUs) are allowed to opportunistically utilize the licensed spectrum during the idle time of primary users (PUs) to achieve spectrum sharing. However, the SUs maybe power constrained to avoid interference and cover a very short transmission range. We here propose an interference cancellation scheme (ICS) for three-hop CRNs to prolong the transmission range of SUs and improve their transmission efficiency. In the proposed scheme, a flexible transmission protocol is adopted to cancel the interference at both secondary relays and destinations at the same time. And a closed-form expression for the secondary outage probability over Rayleigh fading channels is derived to measure the system performance. Simulation results show that the proposed scheme can significantly reduce the secondary outage probability and increase the secondary diversity in comparison with the traditional cases.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06a
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• pp.36-37
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• 2010

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.5
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• pp.659-665
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• 2013

IPCS(Inter Process Communication Service) is a real-time communication middleware designed for warship combat battle systems based on publisher-subscriber communication model. Because IPCS was originally designed to operated under 100 Mbps network environment, increasing network speed into Gigabit environment does not linearly increase the throughput of IPCS. To solve this problem, we anaylized IPCS structure and optimized IPCS into Gigabit-Ethernet environment. We found parameters to improve IPCS based on UDP and Token-ring structure. By improving, IPCS has reliability and higher throughput than TCP although IPCS is based on UDP.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.2
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• pp.582-596
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• 2019

Considering that the existing Long Term Evolution is not suitable for the fast and frequent handovers of high-speed trains, this paper proposes a relay-assisted handover mechanism to solve the problems of long handover authentication time and vulnerable to security attacks. It can achieve mutual authentication for train-ground wireless communication, and data transmission is consistent with one-time pad at the same time. The security analysis, efficiency analysis and simulation results show that the proposed mechanism not only realizes the forward security and resists many common attacks, but also effectively reduces the computational overhead of train antenna during the secure handover process. When the running speed of a train is lower than 500km/h, the handover delay is generally lower than 50ms and the handover outage probability is less than 1.8%. When the running speed of a train is 350km/h, the throughput is higher than 16.4mbps in the process of handover. Therefore, the secure handover mechanism can improve the handover performance of high-speed trains.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.8
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• pp.681-687
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• 2014

Internet traffic is rapidly increasing due to the spread of personal smart devices. It causes serious burden on base stations and access points which are installed in buildings, buses, trains, and ships. We consider a communication scenario aboard a cruise ship and propose efficient contents distribution schemes to alleviate the burden of access points with multi-device-to-multi-device(MD2MD) communication. The proposed transmission method is based on the hybrid STBC-SM scheme. We compare the error performance of MD2MD communication system on the cruise ship using space-time block coding (STBC) scheme, spatial multiplexing (SM) scheme. The proposed MD2MD communication system is expected to adopt in the ship-area-network (SAN) with efficient contents distribution and reliable communication.

• Journal of Science and Technology Studies
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• v.7 no.1
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• pp.151-175
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• 2007

What are the differences between science communication and science culture? This paper discusses the relationship between 'science communication' and 'science culture', with a consideration of recent activities and endeavours aiming public's understanding of science. For this, it starts with the outcomes and significance of the 9th International Conference on Public Communication of Science and Technology(PCST-9), with a theme of "Scientific Culture for Global Citizenship", held in Seoul May, 2006. Then, it discusses 'Public Understanding of Science(PUS)' to which the PCST network movement is linked, in comparison with 'Popularization of Science(PS)' and 'Science and Society(S&S)'. While PS was one directional movement conveying scientific knowledge to the public, PUS appeared from 1980s was an intentional effort for activating science communication through mass media. Whereas, a recent S&S movement emphasizes dialogue between science and society. And it then introduces theoretical as well as functional definitions of 'science culture' particulary in Korean and explains how the concept of science communication has considerably expanded since 2002. From this, it is finally argued that science communication needs be redefined as a practice of science culture.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06a
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• pp.17-18
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• 2010

• Proceedings of the Korean Information Science Society Conference
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• 2010.06a
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• pp.15-16
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• 2010

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.8
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• pp.2923-2943
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• 2021

The double helix structure of DNA makes it diverse, stable and can store information with high density, and these characteristics are consistent with the requirements of molecular communication for transport carriers. In this paper, a specific structure of molecular communication system based on DNA length coding is proposed. Transmitter (Tx) adopts the multi-layer golden foil design to control the release of DNA molecules of different lengths accurately, and receiver (Rx) adopts an effective and sensitive design of nanopore, and the biological information can be converted to the electric signal at Rx. The effect of some key factors, e.g., the length of time slot, transmission distance, the number of releasing molecules, the priori probability, on channel capacity is demonstrated exhaustively. Moreover, we also compare the transmission capacity of DNA-based molecular communication (DNA-MC) system and concentration-based molecular communication (MC) system under the same parameter setting, and the peak value of capacity of DNA-MC system can achieve 0.08 bps, while the capacity of MC system remains 0.025 bps. The simulation results show that DNA-MC system has obvious advantages over MC system in saving molecular resources and improving transmission stability.