• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.5
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• pp.70-81
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• 2020

Point-by-point data, which is abundantly collected by vehicles with embedded GPS (Global Positioning System), generate useful information. These data facilitate decisions by transportation jurisdictions, and private vendors can monitor and investigate micro-scale driver behavior, traffic flow, and roadway movements. The information is applied to develop app-based route guidance and business models. Of these, speed data play a vital role in developing key parameters and applying agent-based information and services. Nevertheless, link speed values require different levels of physical storage and fidelity, depending on both collecting and reporting intervals. Given these circumstances, this study aimed to establish an appropriate collection interval to efficiently utilize Space Mean Speed information by vehicles with embedded GPS. We conducted a comparison of Probe-vehicle data and Image-based vehicle data to understand PE(Percentage Error). According to the study results, the PE of the Probe-vehicle data showed a 95% confidence level within an 8-second interval, which was chosen as the appropriate collection interval for Probe-vehicle data. It is our hope that the developed guidelines facilitate C-ITS, and autonomous driving service providers will use more reliable Space Mean Speed data to develop better related C-ITS and autonomous driving services.

• IEMEK Journal of Embedded Systems and Applications
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• v.18 no.3
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• pp.125-132
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• 2023

Roundabouts have strengths in traffic flow and safety but can present difficulties for inexperienced drivers. Demand to acquire and analyze drone images has increased to enhance a traffic environment allowing drivers to deal with roundabouts easily. In this paper, we propose a roundabout traffic analysis system that detects, tracks, and analyzes vehicles using a deep learning-based object detection model (YOLOv7) in drone images. About 3600 images for object detection model learning and testing were extracted and labeled from 1 hour of drone video. Through training diverse conditions and evaluating the performance of object detection models, we achieved an average precision (AP) of up to 97.2%. In addition, we utilized SORT (Simple Online and Realtime Tracking) and OC-SORT (Observation-Centric SORT), a real-time object tracking algorithm, which resulted in an average MOTA (Multiple Object Tracking Accuracy) of up to 89.2%. By implementing a method for measuring roundabout entry speed, we achieved an accuracy of 94.5%.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.4
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• pp.564-581
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• 1999

This paper introduces a new, small, low cost, robust and quick replaceable pavement-based vehicle detector using CW radar, magnetometer, and UHF small antennal techniques. The detector has been developed for a replacement of loop detectors having wide surface areas, for a more accurate operation under all weather conditions, and for no algorithmic change of the existing traffic information system. The detected vehicle information is sent by a small helical antenna embedded in a plastic material and received by a 5/8 $\lambda$ long GP antenna for signal processing. In a relatively good weather condition, the detector operates at 24 GHz. But in a heavy rain condition, magnetometer is activated by automatic switching.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.1
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• pp.241-249
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• 2017

Recently, as a vehicle black box device has propagated, it has been increasingly used as a legal proof and there are the needs to verify an integrity of the video data. However, since the black box classified as the embedded system has a small capacity and low processing speed, there are limitations to the storage of video files and the integrity verification processing. In this paper, we propose a novel method for video files integrity in the black box environment with limited resources by using lightweight hash function LSH and the security of HMAC. We also present the test results of CPU idle rate at integrity verification in vehicle black box device by implementing this method, and verify the effectiveness and practicality of the proposed method.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1261-1264
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• 2005

In this paper, a new intelligent moving target tracking and surveillance system basing on the pan/tilt-embedded stereo camera system is suggested and implemented. In the proposed system, once the face area of a target is detected from the input stereo image by using a YCbCr color model and then, using this data as well as the geometric information of the tracking system, the distance and 3D information of the target are effectively extracted in real-time.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1891-1892
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• 2006

지능형 자동차에 대한 관심이 높아지면서 AICC(Automatic Intelligent Cruise Control)나 무인 자동차가 개발되고 있다. 이러한 기술을 개발하기 위해서는 자동차의 환경과 운항에 관련된 상황을 실시간 감시하는 것이 중요하기 때문에 본 연구에서는 임베디드 시스템을 구성 후 웹 서버를 구현하여 원격지에 존재하는 자동차의 감시 시스템을 개발하고, 자동차 ECU와 인터페이스 하여 엔진 및 자동차의 내부 상황을 웹으로 확인할 있는 임베디드 시스템을 구현하였다. 또한, ECU의 부담과 자동차 Wireless Hamess(W/H)에 의한 중량을 줄이기 위해 블루투스 방식으로 분산제어 방식을 이용 각 부분별 제어할 수 있도록 하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.505-508
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• 2002

AN EMBEDDED PC-BASED HARDWARE AND SOFTWARE SYSTEM HAS BEEN DEVELOPED TO AUTOMATE THE DATA ACQUISITION AND ANALYSIS OF BRAKE SQUEAL. THE DEVELOPED SYSTEM INTEGRATES ADVANCED SIGNAL CONDITIONING HARDWARE AND SOFTWARE TO ACQUIRE BRAKE NOISE AND VIBRATION DATA RAPIDLY, CONSISTENTLY AND OBJECTIVELY. A SPECIAL PEAK-PICKING ALGORITHM IS USED TO DETERMINE WHEN BRAKE NOISE OCCURS DURING A STOP EVENT AND ACTUALLY DEFINE FROM WHICH CORNER OF THE VEHICLE IT ORIGINATES. A SPECIAL NOISE-RATING TABLE IS FEATURED TO ENABLE THE USER TO DEVELOP CORRELATIONS BETWEEN DRIVER RATINGS AND OBJECTIVE MEASUREMENTS.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.6
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• pp.143-154
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• 2012

The wireless low-floored tram is an innovative transportation system which is environment-friendly and highly energy-efficient. In addition, the system has various advantages such as low construction cost, improvement of urban landscape, revitalization of surrounding commercial area, elevated convenience for passengers, etc. Therefore, more than ten local governments have proposed tram construction projects in Korea. Accordingly, many research and development projects are ongoing funded by government including the developments of tram vehicle, tram trackway, signal system, etc. The embedded rail system are commonly used in order to provide leveled roadway surface in urban area. It is effective to reduce the noise and vibration, caused at the interface between the wheel and track, to minimize the construction period, and to lower the maintenance cost. This paper investigated the design and construction processes for tram trackway and figured out the constructability for the test track with embedded rail system for the first time in Korea. The performance to reduce the noise and vibration were quantitatively measured in the test track with embedded rail system. In addition, the results were compared to the ones for track with conventional rail system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.11
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• pp.1891-1908
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• 2011

Cyber-physical systems (CPSs) are an emerging discipline that involves engineered computing and communicating systems interfacing the physical world. The widespread applications of CPSs still face enormous challenges because of the lack of theoretical foundations. In this technical survey, we review state-of-the-art design techniques from various angles. The aim of this work is to provide a better understanding of this emerging multidisciplinary methodology. The features of CPSs are described, and the research progress is analyzed using the following aspects: energy management, network security, data transmission and management, model-based design, control technique, and system resource allocation. We focus on CPS resource optimization, and propose a system performance optimization model with resource constraints. In addition, some classic applications (e.g., integrating intelligent road with unmanned vehicle) are provided to show that the prospects of CPSs are promising. Furthermore, research challenges and suggestions for future work are outlined in brief.

• Journal of Mechanical Science and Technology
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• v.15 no.8
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• pp.1143-1155
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• 2001

In order to reduce the expensive CPU time for design sensitivity analysis in dynamic response optimization, this study introduces the design sensitivities approximated within estimated confidence radius in dynamic response optimization with ALM method. The confidence radius is estimated by the linear approximation with Hessian of quasi-Newton formula and qualifies the approximate gradient to be validly used during optimization process. In this study, if the design changes between consecutive iterations are within the estimated confidence radius, then the approximate gradients are accepted. Otherwise, the exact gradients are used such as analytical or finite differenced gradients. This hybrid design sensitivity analysis method is embedded in an in-house ALM based dynamic response optimizer, which solves three typical dynamic response optimization problems and one practical design problem for a tracked vehicle suspension system. The optimization results are compared with those of the conventional method that uses only exact gradients throughout optimization process. These comparisons show that the hybrid method is more efficient than the conventional method. Especially, in the tracked vehicle suspension system design, the proposed method yields 14 percent reduction of the total CPU time and the number of analyses than the conventional method, while giving similar optimum values.