• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.4
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• pp.28-46
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• 2021

85-90% of the causes of traffic accidents are human factors, and autonomous vehicles with little free running distance can be an alternative to prevent traffic accidents caused by human factors. However, securing safety of autonomous vehicles should be preceded in order to reduce traffic accident damage through the introduction of autonomous vehicles. Therefore, it is necessary to verify whether the vehicle can respond appropriately to changes in the road and traffic environment through repeated and reproduced test runs in an environment similar to the actual road. In this study, K-City's development strategies for upgrading, differentiating, and systematic development were established by comparing and analyzing the current status of domestic and foreign testbeds and business environment analysis. Furthermore, we derive challenge tasks to achieve each strategy.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.1
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• pp.221-239
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• 2022

Various elements such as geometry, traffic safety facilities, congestion level, weather, etc., need to be appropriately reflected in the assessment scenario evaluating the driving safety of automated vehicles. Therefore, this study first established a scenario structure and defined the layer of elements, to derive the elements to be reflected in the automated driving safety evaluation. After that, all elemental candidates that can be reflected in each layer were derived by reviewing the relevant literature. Finally, as a result of an expert survey, 77 items were selected to be reflected in the automated driving safety evaluation. The selected elements are expected to be actively utilized in developing scenarios for the driving safety evaluation of automated vehicles in simulation, proving ground, and real road assessments.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.1
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• pp.79-85
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• 2011

Bridge Weigh-in-Motion(BWIM) system calculates a travelling vehicle's weight without interruption of traffic flow by analyzing the signals that are acquired from various sensors installed in the bridge. BWIM system or data accumulated from the BWIM system can be utilized to development of updated live load model for highway bridge design, fatigue load model for estimation of remaining life of bridges, etc. Field test with moving trucks including various load cases should be performed to guarantee successful development of precise BWIM system. In this paper, a numerical simulation technique is adopted as an alternative or supplement to the vehicle traveling test that is indispensible but expensive in time and budget. The constructed numerical model is validated by comparison experimentally measured signal with numerically generated signal. Also vehicles with various dynamic characteristics and travelling conditions are considered in numerical simulation to investigate the variation of bridge responses. Considered parameters in the numerical study are vehicle velocity, natural frequency of the vehicle, height of entry bump, and lateral position of the vehicle. By analyzing the results, it is revealed that the lateral position and natural frequency of the vehicle should be considered to increase precision of developing BWIM system. Since generation of vehicle travelling signal by the numerical simulation technique costs much less than field test, a large number of test parameters can effectively be considered to validate the developed BWIM algorithm. Also, when artificial neural network technique is applied, voluminous data set required for training and testing of the neural network can be prepared by numerical generation. Consequently, proposed numerical simulation technique may contribute to improve precision and performance of BWIM systems.

• The Journal of the Korea Contents Association
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• v.19 no.12
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• pp.452-459
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• 2019

In order for an autonomous vehicle to be commercialized, it is necessary to conduct a safety test for every aspect. Considering the implementation of the autonomous vehicles technologies to the highest level, it is necessary to analyze the possible scenarios in the most complex environment as in the urban area. It should be confirmed whether autonomous vehicles can be operated with conventional traffic signal environment. It is also required to confirm the ability of autonomous vehicles in interacting with other vehicles, and coping with possible accidents on the road. In this study, the evaluation factors of autonomous vehicles in the road environment are selected by referring to the other evaluation protocols like ADAS. Study result would be reflected in establishing the autonomous vehicle evaluation method for different test environment along with various technology implementation level.

• Proceedings of the KAIS Fall Conference
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• 2011.05b
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• pp.537-539
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• 2011

최근의 차량 연비는 엔진, 파워트레인 등 차량의 구성품들을 성능 개선하여 많이 향상 되었으나 연비 측정은 현재도 주어진 모드(LA-4, FTP-75 등)에서 컴퓨터 모의시험 및 다이나모에서 수행한다. 본 논문에서는 차량에 미리 장착된 지리정보데이터와 현재 주행하면서 수신되는 GPS 데이터를 이용하여 약 213Km 영동고속도로를 주행하면서 실제 도로의 연비 향상 방안을 도출한다. 지리정보데이터와 주행하면서 수신한 GPS 데이터 중에서 거리와 고도 데이터를 추출하여 각 구간의 경사도, 주행저항을 계산, 연비향상 알고리즘에 따른 속도 프로파일을 영동고속도로 전 구간에 대해서 완성하고 이 속도 프로파일로 컴퓨터를 이용한 AVL사의 CRUISE 프로그램으로 모의 주행하여 연비를 산출하고 연비 향상 방안을 제안한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.5
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• pp.1069-1076
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• 2017

C-ITS(Cooperative-Intelligent Transportation System) provides services that require strict real-time such as forward collision warning, road safety service and emergency stop. WAVE(Wireless Access in Vehicular Environments), a core technology of C-ITS, is a technology designed for high-speed driving. However, in order to provide stable communication service by applying to real road environment, various performance tests of real vehicular environment are required. In the real road environment, WAVE communication performance is influenced by the surrounding environment such as moving vehicle, road shape and topography. Especially, when the vehicle is moving at high speed, the traveling position according to the speed of the vehicle, The surrounding environment changes rapidly. Such changes are factors affecting the communication performance, therefore a system and methods for analyzing them are needed. In this paper, we propose the configuration and test method of an effective performance evaluation system under high-speed driving and describe the results of analyzing the communication performance based on the data measured through the actual vehicle test.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.2
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• pp.41-50
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• 1988

In this paper, main effects of bridge vibration were investigated by arranging static and dynamic test data on 30 highway bridges. The test were conducted using displacement transducers and strain gages attached at midspan of each bridges over which a heavy test vehicle was running. Then, vibrational characteristics of the bridges were obtained in the time domain analysis by distinguishing the forced and free vibration state. The results obtained in this paper will be used properly to simulate the vibrational behaviour of the bridges which is in the state of the beginning in the domestic.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.758-764
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• 2019

The chassis of the Korean light tactical vehicle adopts a frame-on-body structure that uses lightweight design technology in terms of equipment operating characteristics. Military vehicles are operated in much harsher conditions compared to civilian vehicles, including mountainous terrain, especially steep slopes. Due to this characteristic, frame-welded cracks were found on some military vehicles. Therefore, in this paper, road damage analysis was conducted by identifying various roads including the military unit's road. The result confirmed that the operating environment of some military units' tactical road was much harsher than the endurance road test condition. A solution was derived through defect analysis, design review, and actual vehicle driving test. This study can be used as a reference by suggesting the development direction for the durability test of a new vehicle.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.99-107
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• 2014

Abruptly occurred obstacles on highway threaten driving safety. Radar draws the attention to the collision avoidance system because it can be fully operational in all weather, and day and night condition. This paper presents the design, implementation and performance test results of pulsed Doppler radar system for detection and warning of road obstacles. The system is designed to consider highway environment and detection capability about various fixed and moving obstacles. The system consists of 4 subsystems, which include antenna unit, transmitter and receiver unit, radar signal & data processing unit, and controller & display unit. The core technologies include clutter map based change detection for fixed obstacles detection, Doppler estimation for velocity detection of moving targets, and azimuth angle estimation method using monopulse for lane estimation and tracking. The design performance of the developed radar system is verified through experiments using a fixed reference target and moving vehicles in test highway.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.5
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• pp.47-53
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• 2024

This study investigates the noise reduction effects of various road pavement methods to mitigate traffic noise caused by the increasing proximity between roads and residential areas in urban environments. The noise characteristics of four types of road pavement-Dense Asphalt Concrete (DAC), Double Layer Porous Asphalt Concrete (DLPAC), Transverse Tining Concrete (TTC), and Exposed Aggregate Concrete (EAC)-were evaluated using CPX close-proximity noise and pass-by noise measurements. The CPX measurements showed that noise levels increased logarithmically with vehicle speed for all pavements. Specifically, DLPAC demonstrated higher noise levels in the low-frequency range below 800 Hz and lower noise levels in the high-frequency range, which is attributed to resonance effects within the internal pores of the pavement and the reduction of compression and expansion noise. In pass-by noise measurements, DLPAC exhibited higher low-frequency noise compared to DAC, likely due to pavement durability deterioration and the influence of external environmental noise. The results indicate that the CPX measurement method is more effective in evaluating road noise performance as it better reflects the impact of vehicle speed. However, since the study was conducted under limited site conditions, further research across various sites and conditions is necessary to enhance reliability.