• Proceedings of the KSR Conference
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• 2005.11a
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• pp.119-124
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• 2005

Decision of operation performance mode to minimize the energy consumption of urban rail vehicle. This paper analyses how much acceleration and deceleration of urban rail vehicle should be applied andhow to choose an operation mode to minimize energy consumption when train runs between station within the fixed operation time. The decided operation pattern satisfying the minimum energy consumption becomes a target trajectory and a basis for the controller design criteria. To make this goal it grasps the characteristics of urban rail vehicle, realize operation energy model of urban rail vehicle and verify the accuracy of embodied model the Matlab simulation with the same operation result of real route. It searches for operation pattern to minimize operation energy by changing the acceleration and deceleration on the imaginative route and proposes operation pattern minimizing energy consumption by applying real operation data between Dolgogee-Sukgye section of Seoul Metropolitan Subway Line 6.

• Journal of Korea Multimedia Society
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• v.25 no.8
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• pp.1007-1021
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• 2022

Autonomous driving of unmanned aerial vehicles may have to pay expensive cost to create and switch new routes if unexpected obstacles exist or local map updates occured by the control system due to incorrect route information. Integrating digital twins into the path-following process requires more computing resources to quickly switch the wrong path to an alternative path, but it can quickly update the path during flight. In this study, we design a DEVS-based simulation environment which can modify optimized paths through short-term simulation of multi-virtual UAVs for applying digital twin concepts to path follow. Through simulation, we confirmed the possibility of increasing the mission stability of UAV.

• Journal of KIISE:Software and Applications
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• v.36 no.5
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• pp.396-400
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• 2009

During periods of large data transmission, routing selection methods are used to efficiently manage data traffic and improve the speed of transmission. One approach in routing selection is AntNet that applies the Ant algorithm in transmissions with uniform probability. However, this approach uses random selection, which can cause excessive data transmission rates and fail to optimize data This paper presents the use of the Genetic Algorithm (GA) to efficiently route and disperse data transmissions, during periods with "unnecessary weight increases for random selection". This new algorithm for improved performance provides highly accurate estimates of the transmission time and the transmission error rate.

• Journal of Korean Society of Forest Science
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• v.81 no.4
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• pp.363-371
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• 1992

This study was aimed at developing a computer model to determine rational road networks in mountainous forests. The computer model is composed of two major subroutines for digital terrain analyses and route selection. The digital terrain model(DTM) provides various information on topographic and vegetative characteristics of forest stands. The DTM also evaluates the effectiveness of road construction based on slope gradients. Using the results of digital terrain analyses, the route selection subroutine, heuristically, determines the optimal road layout satisfying the predefined road densities. The route selection subroutine uses the area-partitioning method in order to fully of roads. This method leads to unbiased road layouts in forest areas. The size of the unit partitiones area can be calculated as a function of the predefined road density. In addition, the user-defined road density of the area-partitioning method provides flexibility in applying the model to real situations. The rational road network can be easily achived for varying road densities, which would be an essential element for network design of forest roads. The optimality conditions are evaluated in conjuction with longitudinal gradients, investment efficiency earthwork quantity or the mixed criteria of these three. The performance of the model was measured and, then, compared with those of conventional ones in terns of average skidding distance, accessibility of stands, development index and circulated road network index. The results of the performance analysis indicate that selection of roading routes for network design using the digital terrain analysis and the area-partitioning method improves performance of the network design medel.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.1
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• pp.42-50
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• 2008

Unlike a cellular network, a mobile ad hoc network(MANET) is constructed only by mobile nodes without access point. Mobile nodes in MANET operate with scarce resources and restricted battery. If battery of intermediate node is exhausted, overall network might be diverged. Therefore, power-aware is really important. An on-demand multipath routing protocol which is proposed to compensate for shortcoming of on-demand single path routing protocol can reduce mute discovery overhead because route discovery starts only when all routes are disconnected. AOMDV(Ad hoc On-demand Multipath Distance Vector) which is on-demand multipath routing protocol based on AODV, reduces 40% of route discovery frequency. However, AOMDV have none of power-aware. So AOMDV have problem that route discovery for power exhaustion is not reduced at all. This paper proposes new power-aware path selection algorithm for AOMDV and scheme that broadcast REER packets when mobile node's battery can be gone. Performance comparison of proposed algorithm with AOMDV using ns-2 simulator shows that route discovery of proposed algorithm is reduced maximally 36.57% than AOMDV's.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.3
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• pp.25-35
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• 2011

Traffic volume increases due to diversification of industry. Also, Automobile ownerships also increase steadily. It is estimated that the registered number of vehicle is expected to be 20 milion in the year 2015. These trends may result in increasing the number of woman drivers and elderly drivers. Therefore, this study aims to identify routes that reflect characteristics of each driver's preferences. A survey was conducted on different routes attributes for variances drivers. Driver types were classified by gender, age, and driving career. Accordingly, a weight for road composition attribute such as number of lanes, number of accidents, slope was estimated by using Swing Weighting technique in Multi-Attribute Utility Theory. In addition, a case study was conducted and identified weights were applied to routes. In result, drivers commonly prefer short route when they considered their routes. Also, male drivers prefer speedy and shorter route than that of female drivers. Elderly drivers prefer safe routes that represent low accidents rate. Moreover driving career under a year drivers prefer safe and easy routes. Therefore, we may conclude that the necessity of diversified route information is essential in the future car navigation system.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.3
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• pp.72-86
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• 2018

Schedule-based public transit routing algorithm computes a single route that calculated minimum travel time using the departure and arrival times for each stop according to vehicle operation plan. However, additional factors such as transfer resistance and alternative route choice are not reflected in the path finding process. Therefore, this paper proposes a improved RAPTOR that reflected transfer resistance and multi-path searching. Transfer resistance is applied at the time of transfer and different values can be set according to type of transit mode. In this study, we analyzed the algorithm's before and after results compared with actual route of passengers. It is confirmed that the proposed algorithm reflects the various route selection criteria of passengers.

• Journal of Korean Society for Geospatial Information Science
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• v.4 no.2 s.8
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• pp.195-203
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• 1996

The 3-D analysis of terrain for route design and selection is being used as important basic data for effective judgement of political draft. This study is to decide efficient alignment of the entry route and design bridge by modeling, analyzing and displaying surface with digital terrain data. In this study we analyze slope, aspect, shaded-relief, line of sight and watershed on the base of DTM such as contour, TIN and grid. And we can not only esti mate end-area volume for road construction by calculating cut and fill and displaying mass-curve but also recognize the scene after execution with simulation of road and terrain. The result of this study reveals that visual effects of the 3-D terrain data are very effective for designer and decisionmaker to select and review alternative route with regard to terrain characteristics.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1180-1183
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• 2002

Types of problems and solutions to vehicle routing problems are discussed. A case study on a public transport is conducted to discover the characteristics of problems in route selection. The characteristics of problems solved by certain technique or algorithm are also studied to investigate the capability of current techniques in solving public bus routing.

• Journal of Korean Society of Transportation
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• v.12 no.4
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• pp.21-33
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• 1994

The grade is a very significant factor in designing the bikeways. It affects the cyclist's maneuverability as well as route selection. The objective of this paper is to provide the vertical length by grade for bikeway. Field experiments were conducted by primary school children and university students to collect and analyze bike's climbing capability by grade. Combined data suggests that the desirable vertical length is 360m for 3% grade, 220m for 4%, 160m for 5%, 120m for 6% and 90m for 7% grade.