• Proceedings of the KSR Conference
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• 2005.11a
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• pp.884-888
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• 2005

The interests of the government and civil business owner against the Light rail transit are increasing, it may be caused by the enterprise conception which does not consider a city circumstance that the construction plan is insensitively performed. This article present the forecast method of minimum transportation demand which secures a profitability. If It is in advance investigated the number of passenger using the existing traffic system of the area, it will be possible that the LRT project is planned on a realistic basis.

• Journal of Korean Society of Transportation
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• v.28 no.5
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• pp.107-116
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• 2010

The vehicle travel time between locations in a downtown is greatly influenced by both complex road conditions and traffic situation that changes real time according to various external variables. The customer's demands also stochastically change by time period. Most vehicle routing problems suggest a vehicle route considering travel distance, average vehicle speed, and deterministic demand; however, they do not consider the dynamic external environment, including items such as traffic conditions and stochastic demand. A realistic vehicle routing problem which considers traffic (smooth, delaying, and stagnating) and stochastic demands is suggested in this study. A mathematical programming model and hybrid genetic algorithm are suggested to minimize the total travel time. By comparing the results considering traffic and stochastic demands, the suggested algorithm gives a better solution than existing algorithms.

• Journal of Navigation and Port Research
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• v.44 no.6
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• pp.469-476
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• 2020

Modeling and Simulation (M&S) systems which deal with situational complexity often require human involvement due to the high-level decision-making that is necessary for ship movement, navigation, control center management, shipping company logistics, meteorological system information, and maritime transportation GIS. In order to properly simulate maritime traffic, it is necessary to accurately model the human decision-making process of the ship officer, including aspects of the ship officer's behavioral tendencies, personal navigation experience, and pattern of voyage errors, as this is the most accurate way in which to reproduce and predict realistic maritime traffic conditions. In this paper, which looks at agent-based maritime traffic simulation, we created a basic survey in order to conduct behavior analysis on ship operators' collision avoidance strategies. Using the information gathered throughout the survey, we developed an agent-based navigational behavior model which attempts to capture the behavioral patterns of a ship officer during an instance of ship collision. These results could be used in the future in further developments for more advanced maritime traffic simulation.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.6
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• pp.266-283
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• 2022

With the rapid development of autonomous vehicle technology, unexpected accidents are occurring. Therefore, it is necessary to minimize user accident damage through the development of autonomous traffic safety education. Since edge cases, accident type, and risk factor analysis are important for realistic education, overseas case studies and demonstrations were carried out, and based on this, two curriculum for service providers and general users were developed. The service provider curriculum consisted of OEDR, sudden stop, cut-in, take-over, defensive driving, system malfunction, policy and information security education, and the general user curriculum consisted of attention duty, take-over, operating design domain, accidents type, laws, functions, information security education.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.8
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• pp.1933-1954
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• 2013

Multiple wireless devices are being widely deployed in Intelligent Transportation System (ITS) services on the road to establish end-to-end connection between vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) networks. Vehicular ad hoc networks (VANETs) play an important role in supporting V2V and V2I communications (also called V2X communications) in a variety of urban environments with distinct topological characteristics. In fact, obstacles such as big buildings, moving vehicles, trees, advertisement boards, traffic lights, etc. may block the radio signals in V2X communications. Their impact has been neglected in VANET research. In this paper, we present a realistic and efficient radio propagation model to handle different sizes of static and moving obstacles for V2X communications. In the proposed model, buildings and large moving vehicles are modeled as static and moving obstacles, and taken into account their impact on the packet reception rate, Line-of-sight (LOS) obstruction, and received signal power. We use unsymmetrical city map which has many dead-end roads and open faces. Each dead-end road and open faces are joined to the nearest edge making a polygon to model realistic obstacles. The simulation results of proposed model demonstrates better performance compared to some existing models, that shows proposed model can reflect more realistic simulation environments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.12A
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• pp.1189-1197
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• 2006

Ultra-wideband(UWB) is a killer technology for short-range wireless communications. In the past, most of the UWB research focused on physical layer but the unique characteristics of UWB make it different to design the upper layer protocols than conventional narrow band systems. Cross-layer protocols have received high attention for UWB networks. In this paper, we investigate the performance of two physical layer schemes: Time Hopping Binary Pulse Position Modulation(TH-BPPM) and Time Hopping Binary Pulse Amplitude Modulation (TH-BPAM) with proposed private MAC protocol for UWB ad-hoc networks. From pulse level to packet level simulation is done in network simulator ns-2 with realistic network environments for varying traffic load, mobility and network density. Our simulation result shows TH-BPAM outperforms TH-BPPM in high traffic load, mobility and dense network cases but in a low traffic load case identical performance is achieved.

• Journal of the Korea Computer Graphics Society
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• v.3 no.1
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• pp.37-47
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• 1997

This paper presents the algorithms for generating ambient traffic in driving simulation. Each ambient car is modeled as an autonomous agent that obeys the traffic rules by sensing the traffic lights, road signs, lanes, and other cars around. The algorithm is localized to the area where the car driven by the participant is currently located. Therefore the complexity of the algorithm does not depend on the size of the road network, allowing a huge environment to be simulated with no extra overhead. To avoid monotony, we produce artificial fluctuations in the behavior by employing various forms of probability distribution functions. The resulting behavior of the ambient cars is quite realistic. Experiments indicate that it is hard to tell whether an ambient car is computer-controlled or human-controlled.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10B
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• pp.1104-1110
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• 2009

3D A/V services are expected to be a representative service of next generation because it can give more realistic feeling by providing dimensions to the 2D images. In terms of transmission part of 3D A/V systems, however, it is difficult to provide these services on real-time in the wireless OFDMA networks because it has to send large amount of traffic. To address this, we proposed a novel scheduling algorithm which separates a 3D traffic into base layer and enhancement layer, and provides different priority to them. From simulation results, we can show that the proposed algorithm can improve QoS.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.9
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• pp.2642-2664
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• 2024

In the process of modern traffic management, information technology has become an important part of intelligent traffic governance. Real-time monitoring can accurately and effectively track and record vehicles, which is of great significance to modern urban traffic management. Existing tracking algorithms are affected by the environment, viewpoint, etc., and often have problems such as false detection, imprecise anchor boxes, and ID switch. Based on the YOLOv5 algorithm, we improve the loss function, propose a new feature extraction module to obtain the receptive field at different scales, and do adaptive fusion with the SGE attention mechanism, so that it can effectively suppress the noise information during feature extraction. The trained model improves the mAP value by 5.7% on the public dataset UA-DETRAC without increasing the amount of calculations. Meanwhile, for vehicle feature recognition, we adaptively adjust the network structure of the DeepSort tracking algorithm. Finally, we tested the tracking algorithm on the public dataset and in a realistic scenario. The results show that the improved algorithm has an increase in the values of MOTA and MT etc., which generally improves the reliability of vehicle tracking.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.9
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• pp.40-49
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• 2011

Integrating massive components and low-power policies have been actively investigated for system-on-chip designs. But in recent years, finding the optimal interconnection structure among heterogeneous components has emerged as a critical system design issue. Therefore, various simulation tools to model interconnection designs are being developed and performance evaluation of simulation is reflected in the real design. But most of the simulation environments employ traffic generation based on the mathematical probability functions, and such traffic generation cannot fully cover for various situations that may be occurred in the real system. Therefore, the demand for traffic pattern generation based on real applications is increasing. However, there have been few simulators that adopt application-specific traffic generators. This paper proposes a novel traffic generation method in simulating various interconnection structures for multi-processor system-on-chip design. The proposed traffic generation method can generate traffic patterns that can reflect the actual characteristics of the application and evaluate the performance of an interconnection structure under more realistic circumstance than traffic patterns using mathematical probability functions. By comparing the differences between the proposed method and the one based on mathematical probability functions, this paper shows advantages of the proposed traffic generation method.