• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.393-397
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• 2004

In these days, a scale of system is more and more complex and large. The centralized system has the operation management method to be limited in the large scale system. In this paper, we proposed ACOS(Autonomous decentralized Container terminal Operating System). It is applied to container terminal using by autonomous decentralized system which can solve the problem of the centralized operation system. Also, we can defined a function of the ACOS's sub-system and showed a flowchart on operation method for the ACOS.

• Journal of the Korean Operations Research and Management Science Society
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• v.14 no.1
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• pp.16-26
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• 1989

The terminal layout problem is fundamental in may centralized computer networks, which is generated formulated as the capaciated minimum spanning tree problem (CMSTP). We present an implementation of the dual-based procedure to solve the CMSTP. Dual ascent procedure generates a good feasible solutions to the dual of the linear programming relaxation of CMSTP. A feasible primal solution to CMSTP can then be constructed based on this dual solution. This procedure can be used either as a stand-alone heuristic or, else, it can be incorporated into a branch and bound algorithm. A numerical result is given with quite favorable results.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.12
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• pp.58-66
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• 2001

Input queueing is useful for high bandwidth switches and routers because of lower complexity and fewer circuits than output queueing. The input queueing switch, however, suffers HOL-Blocking, which limits the throughput to 58%. To get around this low throughput, many input queueing switches have centralized scheduler, which centralized scheduler restrict the design of the switch architecture. To overcome this problem, we propose a simple scheduler called PRR(Pipelined Round Robin), which is intrinsically distributed and presents to show the effectiveness of the proposed scheduling.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.928-931
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• 2007

In answer to the increase of demand for the safety in railroad, the safety activities are tried out. According to 'KORAIL Instruction number 2001-49', the project for developing Integrated Centralized Traffic Control Center has been carried out and the safety activities are guaranteed by documents named 'Safety Plan' and 'Safety Requirements' from this project. However the development system is not enough for the full safety activities. Therefore this paper we describes the relationship of safety activities and development systems and proposes the efficient direction of safety activities.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.959-963
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• 2007

After the year of 2000, the need of safety increases in field of railroad. The project for developing Integrated Centralized Traffic Control(CTC) center started at 2002 to control the full domestic railroad network. A traffic control software was required the safety activity and assessment, according to 'KORAIL Instruction number 2001-49'. There were many trials and errors to perform safety activity because the technology and recognition of safety activity is in primary stage. However the safety activities are gradually stabilized. This paper describes the safety life-cycle and development life-cycle of Integrated CTC S/W and a suitable life-cycle of safety to develop S/W of Integrated CTC.

• Journal of the military operations research society of Korea
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• v.22 no.2
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• pp.73-89
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• 1996

This paper suggests the new IP, SIMIP(Simple Mobile IP), which supports a continuous mobility between a static host and a mobile host in the static TCP/IP LAN environment where mobile hosts are overlayed with cells. For designing a mobile protocol, routing optimization is very important, and it is directly related to the management mechanism of a mobile host's location information. When the mobile hosts' location information are centralized, the network has high risk when a centralized device fails. On the other hand, when they are distributed, the above problems are solved. But it requires complicated techniques in order to search the encapsulated addresses. SIMP centralizes mobile hosts' location information, minimizes the risk by automatically substituting the failed default mobile router with one of the multiple general mobile routers, and supports the optimal routing path through "default mobile router path alternation" Then since SIMIP isn't reasonable the operations informations to the chief in military operations room.ions room.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.31-34
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• 2002

There are two kinds of network architectures in the IEEE 802.11:[1] distributed (ad-hoc) or centralized (infrastructure) wireless network. Centralized networks have an access point (base station) that can control the wireless medium access of stations in these networks. The 802.11 MAC protocol of an access point is the same as those of other stations in the contention period. This paper propose a novel MAC protocol of an access point to solve these problems. This MAC protocol adds a new contention-free period called EPCF (Extended PCF) to resolve accumulated data in the queue of an access point. Simulation results show that the new protocol performs better throughput than the 802.11 standard MAC with the less queue memory site requirement.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.118-118
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• 2000

This paper suggests the methodology to guarantee the rea1-time service over Ethernet and TCP/IP and to solve the problems such as re-transmission due to collision and platform-transparency and independence. This paper proposes a new mechanism called Real-time Ethernet protocol combined the centralized medium control mechanism with the token passing mechanism. The centralized medium control mechanism is used to get the token, the right to transmit the data, and the token passing mechanism is used to return the token to the token controller and to transmit data within the specified time interval. The proposed Real-Time Ethernet Protocol is based on Java and Java RMI(Remote Method Invocation). The presented protocol is believed to work enough in real-time applications considering latency occurred due to the Java RMI, which is less small than data transmission time.

• Journal of the military operations research society of Korea
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• v.22 no.1
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• pp.1-17
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• 1996

In this paper, a client/server architecture and design concerns deduced from a real system design are described. The MIS system carried on IDIS is the one to be described. The experience from the system design is listed up and analized also. It is common to see that a distributed computing environment has much more complex structure than a conventional centralized one. As a consequence, a distributed system design is a complex task. It is worth to note that there should be sufficient considerations which had not been though ever for a centralized system. The objectives of this paper is to list up these problems and the solutions from experiences on a real system construction.

• Journal of the Institute of Convergence Signal Processing
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• v.13 no.3
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• pp.156-161
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• 2012

Random access protocol takes advantage of constructing a decentralized wireless network due to its intrinsic spectrum sensing capability. Such technical feature goes well with cognitive radio networks consisting of heterogeneous wireless systems, in which a centralized control between heterogeneous wireless systems is hard to be implemented. Motivated by the decentralized feature of the random access, we adopt the random access protocol in cognitive radio networks, and evaluate the performance of a CSMA-based cognitive radio network.