• Journal of Auto-vehicle Safety Association
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• v.16 no.1
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• pp.35-41
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• 2024

In order to verify autonomous driving scenarios and safety, a lot of driving and accident data is needed, so various organizations are conducting classification and analysis of traffic accident types. In this study, it was determined that accident recording devices such as EDR (Event Data Recorder) and DSSAD (Data Storage System for Automated Driving) would become an objective standard for analyzing the causes of autonomous vehicle accidents, and traffic accidents that occurred from 2015 to 2020 were analyzed. Using the database system of IGLAD (Initiative for the Global Harmonization of Accident Data), approximately 360 accident data of EDR-equipped vehicles were classified and their characteristics were analyzed by comparing them with accident types of ADAS (Advanced Driver Assistance System)-equipped vehicles. It will be used to develop autonomous vehicle accident investigation guidelines in the future.

• International Journal of Highway Engineering
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• v.17 no.1
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• pp.91-98
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• 2015

PURPOSES : Although signalized intersections have been considered the best way to control traffic volume in urban areas for several decades, roundabouts are currently being discussed as an alternative way to control traffic volume, especially when traffic is light. Because a roundabout's efficiency depends on the load geometry as well as the traffic volume, design guidelines for roundabouts are recommended only if the incoming traffic volume is very low. It is rare to substitute a roundabout for an existing signalized intersection in urban areas. This study aims to estimate the benefits from the transformation of an existing signalized intersection into a roundabout in an urban area. When there is a more moderate volume of traffic, roundabouts can be effectively used by optimizing signals located at an approaching roadway. METHODS : The methodologies of this paper are as follows: First, a signalized intersection was analyzed to determine the traffic characteristics. Second, the signalized intersection was transformed into a roundabout using VISSIM microscopic traffic simulation. Then, we estimated and analyzed the effects and the performance of the roundabout. In addition, we adjusted a method to improve the benefits of the transformation via the optimization of signals located at an approaching road to control the incoming traffic volume. RESULTS : The results of this research are as follows: The signal-optimized roundabout improved delays compared with the signalized intersection during the morning peak hour, non-peak hour, and evening peak hour by 1.78%, 12.45%, and 12.72%, respectively. CONCLUSIONS : According to the simulation results of each scenarios, the signal-optimized roundabout had less delay time than the signalized intersection. If optimized signal control algorithms are installed in roundabouts in the future, this will lead to more efficient traffic management.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.11
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• pp.4268-4289
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• 2020

Advanced traffic signal timing method plays very important role in reducing road congestion and air pollution. Reinforcement learning is considered as superior approach to build traffic light timing scheme by many recent studies. It fulfills real adaptive control by the means of taking real-time traffic information as state, and adjusting traffic light scheme as action. However, existing works behave inefficient in complex intersections and they are lack of feasibility because most of them adopt traffic light scheme whose phase sequence is flexible. To address these issues, a novel adaptive traffic signal timing scheme is proposed. It's based on actor-critic reinforcement learning algorithm, and advanced techniques proximal policy optimization and generalized advantage estimation are integrated. In particular, a new kind of reward function and a simplified form of state representation are carefully defined, and they facilitate to improve the learning efficiency and reduce the computational complexity, respectively. Meanwhile, a fixed phase sequence signal scheme is derived, and constraint on the variations of successive phase durations is introduced, which enhances its feasibility and robustness in field applications. The proposed scheme is verified through field-data-based experiments in both medium and high traffic density scenarios. Simulation results exhibit remarkable improvement in traffic performance as well as the learning efficiency comparing with the existing reinforcement learning-based methods such as 3DQN and DDQN.

• Journal of Advanced Navigation Technology
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• v.19 no.6
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• pp.492-498
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• 2015

With the rapid growth of technologies and demand of remotely piloted aircraft systems (RPASs), integration of such systems into the existing airspace is becoming an issue in many countries. To assess the impact of integrated operations of manned and remotely piloted aircraft (RPA), it is necessary to perform Human-in-The-Loop (HiTL) simulations of likely situations with an integrated simulation system. This paper defines several operational concepts for the integrated simulation. Several probable scenarios were developed including a traffic pattern at a small airport and an altitude maneuver at a route crossing. HiTL simulations were performed according to the developed scenarios. The simulation results are analyzed focusing on the impacts of different communication, safety, performance, and human machine interface (HMI) characteristics of RPA.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.1
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• pp.16-22
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• 2017

In this paper, we first introduce a mobile data traffic offload method called Local IP Access (LIPA) with femtocell networks. Then, we evaluate the traffic transmission time and probability of mobile data traffic that is transmitted to the core network (CN) when mobile devices transmit the mobile data traffic to indoor devices in three different scenarios, i.e., conventional systems, femtocell based systems, and femtocell and LIPA based systems. Through performance results, it is shown that the next generation mobile network with the femtocell and LIPA not only decrease the density of the mobile data traffic in CNs but also reduce the total transmission time of the mobile data traffic in indoor environments. That is, for the traffic transmission time, the conventional systems and femtocell based systems have 3 and 4 times higher than the femtocell and LIPA based systems, respectively, when the Internet delay is 10ms while 14 and 26 times higher than that, respectively, when the Internet delay is 100ms.

• Journal of Korean Society of Transportation
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• v.35 no.1
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• pp.25-36
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• 2017

The purpose of this study is to analyze traffic accident reduction effect of the introduction of motorcycle safety inspection. To analyze the effect of motorcycle inspection, we first estimate the number of defective motorcycles, and calculate the probability of accident occurrences caused by the defect using four year traffic accident data. Finally, we estimate the number of reduced accidents due to the introduction of the inspection and the total reduced accident cost. In this study, we analyzed three scenarios. It is analyzed that when the safety inspection system is applied to all motorcycles, 642 cases of traffic accidents and 325 million won per year of traffic accident costs are reduced. It is approximately 0.1% of 2014 total traffic accident cost of 26.5725 trillion won per year. It suggests that the cost of traffic accidents and traffic accidents due to vehicle factors are reduced when the safety inspection system is introduced.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.12
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• pp.1602-1608
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• 2019

In this study, we developed a "Zetton Children's Traffic Safety Education" application using mixed reality to help children experience a variety of traffic situations indirectly and to help them defend themselves from accidents. We analyze the types of high mortality child traffic accidents to set learning goal. And we developed the experience-oriented contents that players could acquire signal systems and traffic information naturally and funny in the course of playing scenarios according to designed various traffic situations. In order to verify the educational effectiveness of the developed application, children were given traffic safety education through after-school education activities. The result shows that the frequency of right answers to questions related to traffic safety awareness and learning objectives is increased.

• Journal of Internet Computing and Services
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• v.21 no.1
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• pp.191-199
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• 2020

Cyber warfare training is a key factor for boosting cyber warfare competence. In general, cyber warfare training is conducted by scenarios, and the effects of training can be enhanced by including various elements in the scenarios that can improve the quality of training. In this paper, we introduce the training information, network map, traffic generation policy, threat/defense behavior identified as elements to be included in training scenarios, and propose a method of authoring training scenarios by layering and combining them. We also propose a database design for integrated management of each scenario layer. The layered training scenario authoring method has the advantage of increasing convenience of authoring by reusing existing layers and extending training scenarios based on various combinations between the layers.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.2
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• pp.278-287
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• 2022

With the development of technology, driving simulators have been used in various ways. In driving simulator experiments, scenario creation is essential to increase fidelity, achieve research aims, and provide an immersive experience to the driver. However, challenges remain when creating realistic scenarios, such as developing a database and the execution of scenarios in real-time. Therefore, to create realistic scenarios, it is necessary to acquire real-time data. This study intends to develop a method of acquiring real-time weather and traffic speed information for actual, specific roads. To this end, this study suggests the concatenator for dynamic data obtained from Arduino sensors and public open APIs. Field tests are then performed on actual roads to evaluate the performance of the proposed solution. Such results may give meaningful information for driving simulator studies and for creating realistic scenarios.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.4
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• pp.359-372
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• 2005

The strong protection method of radiation emergency preparedness is the evacuation when a great deal of radionuclide material is released to environment. Required factors for evacuation time estimate of Ulchin nuclear power plant site were investigated. The traffic capacity and the traffic volume by season were investigated for the traffic analysis and simulation within EPZ of Ulchin site. As a result, the background traffic volume by season were established. The NETSIM code was applied to simulate for 12 scenarios in the event of normal traffic/summer peak traffic/winter peak traffic, daytime/night, and normal weather/adverse weather conditions. The results showed that the evacuation time required for total vehicles to move out from EPZ took generally $210\~315$ minutes. The evacuation time took longer about 45 minutes at night than in the daytime, and 45 minutes in adverse weather than normal condition.