• Journal of Communications and Networks
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• v.7 no.3
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• pp.325-336
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• 2005

Mobile ad hoc networks (MANET) are composed of moving wireless hosts which, within range of each other, form wireless networks. For communication to occur between hosts that are not within each other's range, routes involving intermediate nodes must be established; however, since the hosts may be in motion, a host that was part of a route may move away from its upstream and downstream partners, thus breaking the route. In this paper, we propose anticipated route maintenance (ARM) protocol with two extensions to route discovery based routing scheme: Extend the route when nodes on a link move apart from each other and they have common neighbor that can be 'inserted' in the path, and shrink route when a node discovers that one of its neighbor which is not the next hop is also on the same route several hops later on. By utilizing only local geographic information (now a part of some route finding algorithms), a host can anticipate its neighbor's departure and, if other hosts are available, choose a host to bridge the gap, keeping the path connected. We present a distributed algorithm that anticipates route failure and performs preventative route maintenance using location information to increase a route lifespan. The benefits are that this reduces the need to find new routes (which is very expensive) and prevents interruptions in service. As the density of nodes increases, the chance to successfully utilize our route maintenance approach increases, and so does the savings. We have compared the performance of two protocols, pure dynamic source routing (DSR) protocol and DSR with ARM. The simulation results show how ARM improves the functionality of DSR by preventing the links in the route from breaking. Packets delivery ratio could be increased using ARM and achieved approximately $\100%$ improvement. The simulations clarify also how ARM shows a noticeable improvement in dropped packets and links stability over DSR, even though there is more traffic and channel overhead in ARM.

• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.234-236
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• 2007

Even though the existing train route controlling method, using track circuits, ensures the sufficient number of operation, it still has problems such as discordance between train numbers which was planned for operating and train numbers being operated on the track, and allowing only one train entering for one route. To solve those problems, we study and develop the Smart train route controlling system which uses the real-time informations of train positions. This system enables improve the coefficient of utilization in a certain train route controlling section, and the safety level of train route controlling, but we should ensure satisfying reliability of data about tracks operated by trains. In addition, there is a need to protect accidents caused by erroneous information of train position, by reflecting changes of tracks, for example maintenance, improvement, expansion of tracks. In this paper, we describes data structure of a developed program which required to change CAD files to wiring diagrams and to generate them to data of tracks. And we show the result that the simulator, using the data structure, controls speed and route of trains without problems.

• Journal of Navigation and Port Research
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• v.41 no.6
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• pp.445-450
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• 2017

It is necessary to set a route to reflect the traffic flow for the safety of the traffic vessels. This ongoing analysis is needed to ensure that the vessels comply with a route. The purpose of this study is to discover the problems of the recommended route vicinity for Wando Harbor and suggest an improvement plan. We used a support vector machine based on the ship's trajectory to establish an efficient route center line. Since the vessels should navigate to the starboard side, with reference to the center line of the recommended route, the trajectories of the vessels were divided into two clusters. The support vector machine is being used in many fields such as pattern recognition, and it is effective for this binary classification. As a result of this study, about 79.5 % of the merchant eastbound ships in a 2.4 NM distance to Jangjuk Sudo did not observe the recommended route, so the risk of collision always existed. The contraflow traffic rate of the route of the eastbound ships decreased from 79.5 % to 30.9 % when the recommended route was reset about 300 meters to the north, from its present position. The support vector machine applied in this study is expected to be applicable, to effectively set the route center line because the ship trajectories can be classified into two clusters.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1741-1745
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• 2007

Even though the existing train route controlling method, using track circuits, ensures the sufficient number of operation, it still has problems such as discordance between train numbers which was planned for operating and train numbers being operated on the track, and allowing only one train entering for one route. To solve those problems, we study and develop the Smart train route controlling system which uses the real-time informations of train positions. This system enables improve the coefficient of utilization in a certain train route controlling section, and the safety level of train route controlling, but we should ensure satisfying reliability of data about tracks operated by trains. In addition, there is a need to protect accidents caused by erroneous information of train position, by reflecting changes of tracks, for example maintenance, improvement, expansion of tracks. In this paper, we proposes and describes a developed program which required to change AutoCAD files to wiring diagrams, to generate them to data of tracks, to identify errors of those data, to construct the structure of necessary resource(s) for sub-systems of a train control system, and to provide simulations of data structure.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.4B
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• pp.559-565
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• 2010

In Mobile IPv6 handover should be followed by RO(Route Optimization) to support direct communication between a MN(Mobile Node) and CN(Correspondent Node). For this RR MIPv6 must perform RR(Return Routability) procedure before BU(Binding Update) to CN. The Fast Handover for MIPv6(FMIPv6) also performs the RR test for MN to communicate with CN directly. However, Return Routability test has long latency resulting in handover delay in MIPv6. This paper proposes the method to reduce the handover deay by reducing RO latency in FastMobile IPv6.

• International Journal of Computer Science & Network Security
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• v.21 no.4
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• pp.33-40
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• 2021

The traveling salesman problem (TSP) is one of the well-known and extensively studied NPC problems in combinatorial optimization. To solve it effectively and efficiently, various optimization algorithms have been developed by scientists and researchers. However, most optimization algorithms are designed based on the concept of improving route in the iterative improvement process so that the optimal solution can be finally found. In contrast, there have been relatively few algorithms to find the optimal solution using route construction mechanism. In this paper, we propose a route construction optimization algorithm to solve the symmetric TSP with the help of ratio value. The proposed algorithm starts with a set of sub-routes consisting of three cities, and then each good sub-route is enhanced step by step on both ends until feasible routes are formed. Before each subsequent expansion, a ratio value is adopted such that the good routes are retained. The experiments are conducted on a collection of benchmark symmetric TSP datasets to evaluate the algorithm. The experimental results demonstrate that the proposed algorithm produces the best-known optimal results in some cases, and performs better than some other route construction optimization algorithms in many symmetric TSP datasets.

• Journal of the Korean Society of Marine Environment & Safety
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• v.5 no.2
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• pp.79-86
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• 1999

This study aims at improving the channel of Pudo-sudo in Chinhae-Man according to the development project of the port of Masan, by investigating the design criteria of harbour facilities for the maximum sized ship. The new deep-water route was proposed and according to it the present separation scheme was adjusted appropriately. The width of the deep-water route is suggested to be 350m and would be wide enough for the 30,000 DWT container ship to go through However, the proposed channel will be tested and validated by the shiphandling simulator.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.25-30
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• 2006

Marine traffics near Ulsan approaching waters are crossing and converged at the diverging point of No.1 route- No.2 route and No.1 route -No.3 route and are also concentrated at near No1. route approaching area and the headland of cape Gawnjeol. Because the number of berth will increase to 78 from 49 until 2011 due to additional developments, minor modification is expected for the water utilities. This study examined environmental conditions, marine accidental data, marine traffic capacity, traffic flow survery and fisheries zone status near Ulsan approaching water area. Finally, a questionaire survey was carried ou for experts and users to propose new plan.

• Proceedings of KOSOMES biannual meeting
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• 2004.11a
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• pp.95-100
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• 2004

This study is about current operating system and development process of remote island route. 14 companies are providing safe transportation service for remote island residents with total 30 boots on 27 routes. Each route transit analysis shows that the number of passenger tends to increase every year. In order to enhance customer satisfaction, more constructive improvement is demanded, such as implementing operation evaluation on each charter service provider.1he result obtained from this study is to be utilized as basic document for remote island route development process in semi-long run basis.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.153-157
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• 2002

The improvement of the situation on the Korean Peninsula, following the June 2000 Summit, has opened up the possibility of reconstructing the railway between the North and the South. The interconnection of the railway systems would allow cargo transportation from the south of the Korean Peninsula to Russia, China and Europe. This could open up a faster and more economical cargo transportation route than the all-water route.(omitted)