• ETRI Journal
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• v.45 no.6
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• pp.1065-1078
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• 2023

In vehicular networks, diverse safety information can be shared among vehicles through internet connections. In vehicle-to-internet communications, vehicles on the road are wirelessly connected to different cloud networks, thereby accelerating safety information exchange. Onboard sensors acquire traffic-related information, and reliable intermediate nodes and network services, such as navigational facilities, allow to transmit safety information to distant target vehicles and stations. Using vehicle-to-network communications, we minimize delays and achieve high accuracy through consistent connectivity links. Our proposed approach uses intermediate nodes with two-hop separation to forward information. Target vehicle detection and routing of safety information are performed using machine learning algorithms. Compared with existing vehicle-to-internet solutions, our approach provides substantial improvements by reducing latency, packet drop, and overhead.

• ETRI Journal
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• v.37 no.5
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• pp.867-876
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• 2015

This paper proposes an efficient interference control scheme for vehicular moving networks. The features of the proposed scheme are as follows: radio resources are separated into two resource groups to avoid interference between the cellular and vehicle-to-vehicle (V2V) links; V2V links are able to share the same radio resources for an improvement in the resource efficiency; and vehicles can adaptively adjust their transmission power according to the interference among the V2V links (based on the distributed power control (DPC) scheme derived using the network utility maximization method). The DPC scheme, which is the main feature of the proposed scheme, can improve both the reliability and data rate of a V2V link. Simulation results show that the DPC scheme improves the average signal-to-interference-plus-noise ratio of V2V links by more than 4 dB, and the sum data rate of the V2V links by 15% and 137% compared with conventional schemes.

• Journal of the Korea Society of Computer and Information
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• v.21 no.1
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• pp.91-99
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• 2016

A certificate revocation list(CRL) should be distributed quickly to all the vehicles in the network to protect them from malicious users and malfunctioning equipments as well as to increase the overall security and safety of vehicular networks. However, a major challenge is how to distribute CRLs efficiently. In this paper, we propose a novel Regional CRL distribution method based on the vehicle location registration locally to manage vehicle mobility. The method makes Regional CRLs based on the vehicles' location and distributes them, which can reduce CRL size and distribution time efficiently. According to the simulation results, the proposed method's signaling performance of vehicle's registration is enhanced from 22% to 37% compared to the existing Regional CRL distribution method. It's CRL distribution time is also decreased from 37% to 67% compared to the existing Full CRL distribution method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.2
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• pp.165-171
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• 2013

WAVE(Wireless Access in Vehicular Environments) is a representative V2V communication protocol and its standards of MAC and PHY parts except for security were published. In order to control traffic flow and ensure driver's safety using V2V communication, various projects are conducting. In particular, safety application has been researched. Therefore, in this paper, we designed the safety application algorithm, which informs a driver of the dangerous status when driver tries to turn left in an intersection and we also implemented the algorithm. Proposed algorithm configures a model for a host vehicle and a vehicle coming in opposite lane and in case that there is collision hazard it provides warning message to driver by using HMI. In order to evaluate the proposed algorithm's performance, we configured the test bed using test vehicles and we tested the algorithm on proving ground with the composed test scenarios. As test results, our system showed excellent performance. If the infrastructures for V2I communications are constructed, we will optimize our system more precisely and stably.

• Journal of IKEEE
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• v.25 no.4
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• pp.750-755
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• 2021

This paper proposes techniques for detecting the damage status of each part of a vehicle using YOLOv4. The proposed algorithm learns the parts and their damages of the vehicle through YOLOv4, extracts the coordinate information of the detected bounding boxes, and applies the algorithm to determine the relationship between the damage and the vehicle part to derive the damage status for each part. In addition, the technique using VGGNet, the technique using image segmentation and U-Net model, and Weproove.AI deep learning model, etc. are included for objectivity of performance comparison. Through this, the performance of the proposed algorithm is compared and evaluated, and a method to improve the detection model is proposed.

• Journal of the Korea Society of Computer and Information
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• v.22 no.12
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• pp.109-116
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• 2017

Short-lived pseudonym certificates as vehicle identities could satisfy both security and privacy requirements. However, to remove revoked certificates especially in vehicle communications, pseudonym certificate revocation list (CRL) should be distributed resource-efficiently from a practical deployment point of view and in a timely manner. In this paper, we propose a novel CRL distribution scheme capable of CRL multicast to only activated vehicles registered to the CRL multicast group using the group communication system enabler, namely, the GCSE which is being standardized. The scheme is resource efficient by using CRL distribution paths instead of paging processes to find out multicast vehicle(s) within a certain region. The analyzed results show that the proposed scheme outperforms in terms of paging cost, packets transmission cost, and the processing cost at the respective entities compared to the existing four schemes in the literature.

• Journal of Korean Society of Transportation
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• v.23 no.8 s.86
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• pp.67-75
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• 2005

This study analyzed the relationships between expenditures on transportation and those on communications, using consumer expenditure data from the U.S. for the 19 years 1984-2002. We first identified 12 categories of goods for transportation and communications, and then applied the linear approximate Almost Ideal Demand System(LA/AIDS) method for estimating consumer demand functions based on aggregating the categories to five (public transportation, personal vehicle capital, personal vehicle operation, electronic communications media, and print communications media) due to the small sample size. Expenditure and price elasticities were also calculated at mean values of expenditure shares. The results indicate that transportation and communications categories have both substitutive(e.g. public transportation and electronic communications media) and complementary(e.g. private vehicle capital and electronic communications media) relationships. Additionally, expenditures in the transportation categories are generally more income-elastic than those in communications.

• IEIE Transactions on Smart Processing and Computing
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• v.6 no.2
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• pp.133-139
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• 2017

Vehicles have increasingly evolved and become intelligent with convergence of information and communications technologies (ICT). Vehicle communications (VC) has become one of the major necessities for intelligent vehicles. However, VC suffers from serious security problems that hinder its commercialization. Hence, the IEEE 1609 Wireless Access Vehicular Environment (WAVE) protocol defines a security service for VC. This service includes Advanced Encryption Standard-Counter with CBC-MAC (AES-CCM) for data encryption in VC. A high-speed AES-CCM crypto module is necessary, because VC requires a fast communication rate between vehicles. In this study, we propose and implement an efficient AES-CCM hardware architecture for high-speed VC. First, we propose a 32-bit substitution table (S_Box) to reduce the AES module latency. Second, we employ key box register files to save key expansion results. Third, we save the input and processed data to internal register files for secure encryption and to secure data from external attacks. Finally, we design a parallel architecture for both cipher block chaining message authentication code (CBC-MAC) and the counter module in AES-CCM to improve performance. For implementation of the field programmable gate array (FPGA) hardware, we use a Xilinx Virtex-5 FPGA chip. The entire operation of the AES-CCM module is validated by timing simulations in Xilinx ISE at a speed of 166.2 MHz.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.2
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• pp.128-141
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• 2018

In this paper, a methodology to analyze the potential safe benefit of six cooperative driver assistance systems via V2V (vehicle-to-vehicle) communications is proposed. Although it is quite necessary to assess social impact with respect to new safety technologies for cooperative vehicles with V2V communications, there are few studies in Korea to predict the quantitative safety benefit analysis. In this study, traffic accident scenarios are classified based on traffic fatality between passenger cars. The sequential collision type is classified for a multiple pile-up with respect to collision direction such as forward, side, head-on collisions. Then movement of surrounding vehicle is considered for the scenario classification. Next, the cooperative driver assistance systems such as forward collision warning, blind spot detection, and intersection movement assistance are related with the corresponding accident scenarios. Finally, it is summarized how much traffic fatality may be reduced potentially due to the V2V communication based safety services.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.7C
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• pp.544-553
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• 2012

A vehicle localization technology is an essential component to support many smart-vehicle applications, e.g. collision warning, adaptive cruise control, and so on. In this paper, we present a new vehicle localization algorithm based on the fusion of the sensing estimates from the local sensors and the GPS estimates from the inter-vehicle communications. The proposed algorithm consists of the greedy location data mapping algorithm and the position refinement algorithm. The former maps a sensing estimate with a GPS estimate based on the distance between themselves, and then the latter refines the GPS estimate of the subject vehicle based on the law of large numbers. From the numerical results, we demonstrate that the accuracy of the proposed algorithm outperforms that of the existing GPS estimates by at least 30 % in the longitudinal direction and by at least 60% in the lateral direction.