• Journal of the Korean Society for Railway
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• v.20 no.5
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• pp.612-624
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• 2017

As the existing metropolitan area metropolitan railway operates on a one-to-one basis, which leads to long travel times, its competitiveness with other means of transportation is deteriorating. Since there is a limit to attracting road traffic by rail, there is a continuing societal demand to expand express train service. Especially in the northern and the southwestern parts of the metropolitan area, a public transportation network system with express function, connecting to the city center of Seoul, is needed because of the social cost of the increase of traffic congestion and the increase of the travel time. The most efficient express service in Korea is Seoul Subway Line 9, which runs in 27 minutes from Gimpo Airport to the high speed terminal; this is a 40% shorter time compared to 44 minutes by car; the congestion in this area is up to 240%, so the preference for this train is quite high. The technical results of this study are expected to contribute to the implementation of an express service metropolitan railway.

• Journal of Korean Society of Transportation
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• v.20 no.6
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• pp.99-113
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• 2002

The multi-class traffic assignment problem is the most typical one of the multi-solution traffic assignment problems and, recently formulation of the models and the solution algorithm have been received a great deal of attention. The useful solution algorithm, however, has not been proposed while formulation of the multi-class traffic assignment could be performed by adopting the variational inequality problem or the fixed point problem. In this research, we developed a hybrid solution algorithm which combines GA algorithm, diagonal algorithm and clustering algorithm for the multi-class traffic assignment formulated as a variational inequality Problem. GA algorithm and clustering algorithm are introduced for the wide area and small cost. We also performed an experiment with toy network(2 link) and tested the characteristics of the suggested algorithm.

• Structural Engineering and Mechanics
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• v.60 no.2
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• pp.237-249
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• 2016

There are constraints on truck weight, axle configurations and size imposed by departments of transportation around the globe due to structural capacity limitations of highway pavements and bridges. In spite of that, freight movers demand some vehicles that surpass the maximum size and legal weight limits to use the transportation network. Oversized trucks serve the purpose of spreading the load on the bridge; thus, reducing the load effect on the superstructure. For such vehicles, often a quick structural analysis of the existing bridges along the traveled route is needed to ensure that the structural capacity is not exceeded. For a wide vehicle having wheel gage larger than the standard 1830 mm, the girder distribution factors in the design specifications cannot be directly used to estimate the live load in the supporting girders. In this study, a simple approach that is based on finite element analysis is developed by modifying the AASHTO LRFD's girder distribution factors for slab-on-steel-girder bridges to overcome this problem. The proposed factors allow for determining the oversized vehicle bending moment and shear force effect in the individual girders as a function of the gage width characteristics. Findings of the study showed that the relationship between the girder distribution factor and gage width is more nonlinear in shear than in flexure. The proposed factors yield reasonable results compared with the finite element analysis with adequate level of conservatism.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.5
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• pp.14-28
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• 2018

Thanks to technical improvement on the vehicle to vehicle communication and the intelligent transportation system, gradual introduction of the autonomous vehicles is expected soon in the market. The study analyzes the autonomous vehicles' impacts on the network efficiencies. In order to measure the network efficiencies, the study applies the sequential procedures that combines the microscopic and macroscopic simulations. The microscopic simulation attends to the capacity changes due to the autonomous vehicles' proportions on the roadway while the macroscopic simulation utilizes the simulation results in order to identify the network-wide improvement. As expected, the autonomous vehicles efficiently utilizes the existing capacity of the roadway than the human driving does. Particularly, the maximum capacity improvements are expected by the 190.5% on the expressway. The significant capacity change is observed when the autonomous vehicles' proportions are about 80% or more. These improvements are translated into the macroscopic model, which also yields overall network efficiency improvement by the autonomous vehicles' penetration. However, the study identifies that the market debut of the autonomous vehicles does not promise the free flow condition, which implies the possible needs of the system optimal routing scheme for the era of the autonomous vehicles.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.181-187
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• 2011

Since 2003, state transportation study core technology development is being promoted as part of the bimodal trams operating in accordance with the development of refractive vehicle as research infrastructure for building high-tech road transport system has been the research and development. Bimodal trams of refraction as the vehicle for him to introduce domestic first ever operation management system also developed in Korea according to case-based technology system, but most of the country, and, in this study, mainly those based on technology integration building management system and the bimodal trams of refraction of a vehicle operated was to highlight the features and benefits. Bimodal tram station itself is the way the exclusive properties and to operate the route with large transport capacity has the characteristics of the railway, but the only routes such as railroad lines is not of closed roads under certain circumstances, the flexibility to use has to be integrated operations management system of bimodal trams characteristics of the railroads and public transportation by combining the characteristics of a flexible, convenient and secure services to users with the aim of providing research and will denote the system developed. In this study, bimodal integration system required for the operation of the tram station around the wired and wireless network management center, applying the organic integration into one system so that you have to be centrally managed. In addition, the existing traffic management system operates as a unidirectional rather than monitoring all system-wide management via the interactive network through real-time requests and responses were configured to allow management and control. These findings of the existing traffic operation management system that you can jump step can be based on future unmanned vehicles and related systems through control of the operation management system will be offered as a basis.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1029-1036
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• 2006

South and North Koreas are putting forth efforts to overcome the distrust and animosity of the past 50 years to open an era of harmony and cooperation where the two halves can work together for mutual benefits. As part of those efforts, both parties are working now to reconnect the railways between the North and the South that remained broken for the past 60 years. In addition, the restoration of Trans-Korean railway paves the way for the "Silk Road Railway" which links European continent to Asian regions and Pacific Rim. The restoration project acts as a conduit for cooperation within in the Northeast Asian continent, hence, an important tool for facilitating peace and prosperity within the Northeast Asian region. Notably, the Railway project is regarded as the cardinal future-oriented peace building project for cultivating constructive, cooperative relations (Trans-Korean Railway and Trans-Asian Railway works) by stimulating human resources and commodity flows through railroad transportations. Northeast Asian region takes on a similar instance to the unification of European continent through its astounding development in railroad transportation, i.e., the international re-construction of Railroad lines will act as a catalyst to link Eurasian areas into one regional community for cooperation and peace. At present, the government is creating a momentum to bind trans-Eurasian railroad works and an initiative for "Northeast Asia Railroad networks and consultative organization". The South Korean administration paves the way to develop railroad network within South-North Korean, Russia and Eurasian region. It also fosters railroad cooperation with China for people and goods transports. To achieve such objectives, the project requires wide publicity and cross-border cooperation from concerned countries. The blueprint would have to be drafted up for Northeast Asian railroad train demonstration runs, Northeast Asian transportation agreements, with a bid to promote constitute Northeast Asian Railroad Consultation body. Moreover, the government would also have to prepare both, a draft of the linkage and the mandated standardized proposal.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.4
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• pp.39-44
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• 2012

This paper propose a transmission method for "Transportation system" that can decide precise position under wide area road traffic environment. For precise position detecting, central station collect multiple receiver station's satellite navigation data and generate correction information. In this process, we need efficient real time transmission method for satellite navigation message that has variable data size. We propose real time data transmission method. This real time transmission method offer efficient processing structure for multiple receiver station's satellite navigation message. This paper explains proposed real time transmission method and proofs this transmission method.

• Review of KIISC
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• v.26 no.6
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• pp.42-50
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• 2016

Critical infrastructure (CI) such as the electrical grid, transportation systems and water resource systems are controlled by Industrial Control and SCADA (Supervisory Control and Data Acquisition) networks. During the last few years, cyber attackers have increasingly targeted such CI systems. This is of great concern because successful attacks have wide ranging impact and can cause widespread destruction and loss of life. As a result, there is a critical requirement to develop enhanced algorithms and tools to detect cyber threats for SCADA networks. Such tools have key differences with the tools utilized to detect cyber threats in regular IT networks. This paper discusses key factors which differentiate network security for SCADA networks versus regular IT networks. The paper also presents various approaches used for SCADA security and some of the advancements in the area.

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.98-101
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• 2004

Linear Programming(LP) is the term used for defining a wide range of optimization problems in which the objective function to be minimized or maximized is linear in the unknown variables and the constraints are a combination of linear equalities and inequalities. LP problems occur in many real-life economic situations where profits are to be maximized or costs minimized with constraint limits on resources. While the simplex method introduced in a later reference can be used for hand solution of LP problems, computer use becomes necessary even for a small number of variables. Problems involving diet decisions, transportation, production and manufacturing, product mix, engineering limit analysis in design, airline scheduling, and so on are solved using computers. This technique is called Sequential Linear Programming (SLP). This paper describes LP's problems and solves a LP's problems using the neural networks.

• International Journal of Computer Science & Network Security
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• v.22 no.2
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• pp.167-174
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• 2022

Vehicular Ad hoc Networks are considered as special kind of Mobile Ad Hoc Networks. VANETs are a new emerging recently developed, advanced technology that allows a wide set of applications related to providing more safety on roads, more convenience for passengers, self-driven vehicles, and intelligent transportation systems (ITS). Delay Tolerant Networks (DTN) are networks that allow communication in the event of connection problems, such as delays, intermittent connections, high error rates, and so on. Moreover, these are used in areas that may not have end-to-end connectivity. The expansion from DTN to VANET resulted in Vehicle Delay Tolerant Networks (VDTN). In this approach, a vehicle stores and carries a message in its buffer, and when the opportunity arises, it forwards the message to another node. Carry-store-forward mechanisms, packets in VDTNs can be delivered to the destination without clear connection between the transmitter and the receiver. The primary goals of routing protocols in VDTNs is to maximize the probability of delivery ratio to the destination node, while minimizing the total end-to-end delay. DTNs are used in a variety of operating environments, including those that are subject to failures and interruptions, and those with high delay, such as vehicle ad hoc networks (VANETs). This paper discusses DTN routing protocols belonging to unicast delay tolerant position based. The comparison was implemented using the NS2 simulator. Simulation of the three DTN routing protocols GeOpps, GeoSpray, and MaxProp is recorded, and the results are presented.