• 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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• 2010.06a
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• pp.933-941
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• 2010

KORAIL has improved profitability through abolition of nonprofitable route and withdraw rolling stocks, operated at that route. as a part of that process, most sections of commuters' train are gone. presently, gyeongui-line and gyeongwon-line's commuter's trains are operated. Despite the abolition, there are demands for commuters' train. so, nonprofitable route operation policies are needed to meet the demands and connect seamlessly to KTX. In this study, we consider the overall operation policies and problems of commuters' train in the past. and then, we analyze foreign nonprofitable route, connected with high speed train, operation policies and search for the development suggestions for applying to the nonprofitable route between Iksan - jeonju section at Honam and joenra line.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.887-890
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• 2007

For a integrated system to control several parking lots within a commercial district, it is required to guide a route to a nearest neighbor parking lot considering diverse realtime constraints such as realtime status of parking lots and changes of an access route. This paper proposes an optimized route-searching technique of integrated parking control system considering realtime contraints. In concrete, it proposes a method of researching a route in the surrounding area considering various status of parking lots that a customer designates (no parking, closed, under construction, no passing of a road) and deals with a route-searching technique optimized for each situation in detail.

• 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.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.12 no.2
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• pp.219-226
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• 1994

When a route is planned, the distance of route and earthwork volume have an important role as an economic factor. In this paper, an investigation is made on the selection of optimum route with respect to two factors above mentioned. For this investigation, a numerical test is also executed to two different types of terrain, i.e. terrain with constant slope and no undulation and terrain with slope and undulation. The results show that the shortest route is determined by the degree of undulation with no relation to the slope of topographic model, and the earthwork volume is affected by the amount of undulation and interpolation function.

• Journal of Korean Society of Transportation
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• v.27 no.1
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• pp.63-71
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• 2009

The purpose of this paper is to identify unreliable routes in the view of users. After headway error ratio per route and travel time error ratio per route were calculated by using BMS data, reliability which incorporated two indicators each route was calculated through data envelopment analysis. Reliability among routes and among traffic zones was compared through the results, the needs to improve severely unreliable routes and to show passengers adjusted bus schedule information considering current reliability were suggested. As a future study, reliability evaluation framework of each route needs to be developed considering operation environment by analyzing bus card data (passengers and operation speed etc.) and pooly unreliable route should be managed strictly and reformed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.2
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• pp.647-669
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• 2016

Multiple attribute for decision making including user preference will increase the complexity of route selection process. Various approaches have been proposed to solve the optimal route selection problem. In this paper, multi attribute decision making (MADM) algorithms such as Simple Additive Weighting (SAW), Weighted Product Method (WPM), Analytic Hierarchy Process (AHP) method and Total Order Preference by Similarity to the Ideal Solution (TOPSIS) methods have been proposed for acoustic signature based optimal route selection to facilitate user with better quality of service. The traffic density state conditions (very low, low, below medium, medium, above medium, high and very high) on the road segment is the occurrence and mixture weightings of traffic noise signals (Tyre, Engine, Air Turbulence, Exhaust, and Honks etc) is considered as one of the attribute in decision making process. The short-term spectral envelope features of the cumulative acoustic signals are extracted using Mel-Frequency Cepstral Coefficients (MFCC) and Adaptive Neuro-Fuzzy Classifier (ANFC) is used to model seven traffic density states. Simple point method and AHP has been used for calculation of weights of decision parameters. Numerical results show that WPM, AHP and TOPSIS provide similar performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.2
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• pp.78-97
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• 2010

Route discovery in wireless mobile networks requires a considerable amount of resources due to the mobility of the hosts. Therefore, it would be wise to utilize the effort already invested in existing paths. This paper proposes an efficient way to reuse, whenever possible, existing paths when a new path is being established. In our proposed algorithm, called Route Reutilization Routing (RRR), the reusability is accomplished by the notion of the dynamic proactive zones (DPZ), through which nearby existing path information is disseminated. By utilizing the information stored in DPZs, RRR can achieve considerable savings over other on-demand routing algorithms that use flooding. The unique feature of the proposed algorithm is that DPZs are created and destroyed dynamically around the existing paths, whereas proactive zones are formed around the nodes throughout the network in other route finding algorithms. Even though using DPZs may not result in the shortest path between source and destination, simulation results show the considerable reduction in traffic needed to find a path and therefore increases the available bandwidth for data transmission.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.8
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• pp.2042-2060
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• 2013

In wireless sensor networks (WSNs), energy efficiency is one of the most essential design considerations, since sensor nodes are resource constrained. Group communication can reduce WSNs communication overhead by sending a message to multiple nodes in one packet. In this paper, in order to simultaneously resolve the transmission security and scalability in WSNs group communications, we propose a hierarchical cluster-based secure and scalable group key management scheme, called HRKT, based on logic key tree and route key tree structure. The HRKT scheme divides the group key into cluster head key and cluster key. The cluster head generates a route key tree according to the route topology of the cluster. This hierarchical key structure facilitates local secure communications taking advantage of the fact that the nodes at a contiguous place usually communicate with each other more frequently. In HRKT scheme, the key updates are confined in a cluster, so the cost of the key updates is reduced efficiently, especially in the case of massive membership changes. The security analysis shows that the HRKT scheme meets the requirements of group communication. In addition, performance simulation results also demonstrate its efficiency in terms of low storage and flexibility when membership changes massively.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.9
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• pp.4183-4204
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• 2018

The existing en-route filtering schemes only consider some simple false data injection attacks, which results in lower safety performance. In this paper, we propose an efficient geographical information-based en-route filtering scheme (EGEFS), in which each forwarding node verifies not only the message authentication codes (MACs), but also the report identifier and the legitimacy and authenticity of locations carried in a data report. Thus, EGEFS can defend against not only the simple false data injection attacks and the replay attack, but also the collusion attack with forged locations proposed in this paper. In addition, we propose a new method for electing the center-of-stimulus (CoS) node, which can ensure that only one detecting node will be elected as the CoS node to generate one data report for an event. The simulation results show that, compared to the existing en-route filtering schemes, EGEFS has higher safety performance, because it can resist more types of false data injection attacks, and it also has higher filtering efficiency and lower energy expenditure.