Dooyong Cho

Prof. Dooyong Cho

orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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19 September 2023 in Applied Sciences
Verified
Journal Article
Open access
PDF file
Sangwan LeeSangwan Lee
Sangwan Lee
KCKuk Cho
Kuk Cho
HPHyunbae Park
Hyunbae Park
DCDooyong Cho
Dooyong Cho
This study explored the economic influence of introducing fully autonomous trucks (ATs) on the total cost of operation (TCO) from the viewpoint of freight transport operators. We utilized the cost–benefit analysis and scenario planning frameworks using a case study of a middle-mile route between a port and a large logistics distribution center in South Korea, where an autonomous truck pilot project has been running for several years. We employed a data source obtained from Hanjin Transportation Co., LTD., which enables us to reflect the actual expenses of operating freight transportation in the context of the study route. The findings of this study indicate that ATs would attain substantial operation cost savings for freight transport operators across all five scenarios, ranging from the most pessimistic to the most optimistic. Specifically, results of the base scenario reveal that monthly TCO decreases by 56.25, 47.04, 42.97, and 41.73 percent for 1-, 5-, 12-, and 25-ton trucks, respectively. The cost reduction per month was USD 2399 for a 1-ton truck, USD 2891 for a 5-ton truck, and USD 3438 for a 12-ton truck. Even in the most pessimistic scenario, the operation cost savings for operating with ATs in the route are USD 1415, USD 1642, USD 1985, and USD 2222 per month for 1-, 5-, 12-, and 25-ton trucks, respectively. When factoring in changes in cost, the wage reduction for vehicle drivers was substantial (USD 2430, USD 2835, USD 3240, and USD 3645 for 1-, 5-, 12-, and 25-ton trucks, respectively). However, remote operation was a new cost factor that increased TCO, which increased by USD 243,384,357 in the base case. This study’s findings have multiple implications, including (1) informing economic efficiency and productivity of operating autonomous vehicles (AVs), (2) providing insights on indicative cost estimates for AV operations, (3) providing valuable information for making informed investment decisions, and (4) supporting the notion that freight transport is an especially attractive market for AVs.

20 June 2022 in Applied Sciences
Verified
Journal Article
Open access
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KCKuk Cho
Kuk Cho
DCDooyong Cho
Dooyong Cho
This paper describes a method that precisely estimates the position of images of traffic surveillance camera objects. We suggest a projection method with multiple traffic surveillance cameras through a local coordinate system into a global coordinate system. The transformation of coordinates uses detected objects, parameters of the camera and the geometric information of high- definition (HD) maps. Traffic surveillance cameras that pursue traffic safety and convenience use various sensors to generate traffic information. We suggest a transformation method with images of the camera and HD maps and an evaluation method. Therefore, it is necessary to improve the sensor-related technology to increase the efficiency and reliability of the traffic information. Recently, the role of the camera in collecting video information has become more important due to advances in artificial intelligence (AI) technology. The objects projected from the traffic surveillance camera domain to the HD domain are helpful to identify imperceptible zones, such as blind spots, on roads for autonomous driving assistance. In this study, we proposed to identify and track dynamic objects (vehicles, pedestrian, etc.) with traffic surveillance cameras, and to analyze and provide information about them in various environments. To this end, we conducted the identification of dynamic objects using the Yolov4 and DeepSort algorithms, established real-time multi-user support servers based on Kafka, defined transformation matrices between images and spatial coordinate systems, and implemented map-based dynamic object visualization. In addition, a positional consistency evaluation was performed to confirm its usefulness. Through the proposed scheme, we confirmed that multiple traffic surveillance cameras can serve as important sensors to provide relevant information by analyzing road conditions in real-time in terms of road infrastructure beyond a simple monitoring role.

18 October 2021 in Applied Sciences
Verified
Journal Article
Open access
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HJHoseong Jeong
Hoseong Jeong
BJBaekeun Jeong
Baekeun Jeong
MHMyounghee Han
Myounghee Han
DCDooyong Cho
Dooyong Cho
Visual inspections are performed to investigate cracks in concrete infrastructure. These activities require manpower or equipment such as articulated ladders. Additionally, there are health and safety issues because some structures have low accessibility. To deal with these problems, crack measurement with digital images and digital image processing (DIP) techniques have been adopted in various studies. The objective of this experimental study is to evaluate the optical limit of digital camera lenses as working distance increases. Three different lenses and two digital cameras were used to capture images of lines ranging from 0.1 to 0.5 mm in thickness. As a result of the experiments, it was found that many elements affect width measurement. However, crack width measurement is dependent on the measured pixel values. To accurately measure width, the measured pixel values must be in decimal units, but that is theoretically impossible. According to the results, in the case of 0.3 mm wide or wider cracks, a working distance of 1 m was secured when the focal length was 50 mm, and working distances of 3 m and 4 m were secured when the focal length was 100 mm and 135 mm, respectively. However, for cracks not wider than 0.1 mm, focal lengths of 100 mm and 135 mm showed measurability within 1 m, but a focal length of 50 mm was judged to hardly enable measurement except for certain working positions. Field measurement tests were conducted to verify measurement parameters identified by the results of the indoor experiment. The widths of actual cracks were measured through visual inspection and used for the analysis. From the evaluation, it was confirmed that the number of pixels corresponding to the working distance had a great influence on crack width measurement accuracy when using image processing. Therefore, the optimal distance and measurement guidelines required for the measurement of the size of certain objects was presented for the imaging equipment and optical equipment applied in this study.

21 October 2021 in IEEE Access
Verified
Journal Article
Open access
SKSeungkyung Kye
Seungkyung Kye
HJHoseong Jeong
Hoseong Jeong
DCDooyong Cho
Dooyong Cho
YHYongmoon Hwang
Yongmoon Hwang
HJHyung-Jo Jung
Hyung-Jo Jung
Crack width estimation through remote imaging and digital image processing are the leading diagnostic technologies used for infrastructure. However, owing to limitations in the accuracy of these techniques, alternative methods to detect target crack widths larger than the diagnostic standard are being developed. In this study, the coordinates of fiducial markers were extracted using the Harris corner detector, and fine crack widths of approximately 0.3 mm or less were estimated using the ground sample distance, varied numbers of adjusted pixels, and varied focal lengths. The results of these examinations were compared with the measured values. As a result, it was confirmed that the number of pixels rather than the ground sample distance was the dominant factor affecting the accuracy of the estimated value, and the accuracy could be improved by adjusting the number of pixels, increasing the focal length, and ensuring an effective object distance. The results showed the feasibility of estimating fine crack widths with a high accuracy through the fiducial-marker-based method under the aforementioned conditions. In the future, if the number of crack samples is increased and more detailed focal length and object distance data are supported, this method may provide estimations with a higher accuracy.

25 August 2023 in Urban Science
Verified
Journal Article
Open access
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Sangwan LeeSangwan Lee
Sangwan Lee
JYJicheol Yang
Jicheol Yang
KCKuk Cho
Kuk Cho
DCDooyong Cho
Dooyong Cho
This study explored how transportation accessibility and traffic volumes for automobiles, buses, and trucks are related. This study employed machine learning techniques, specifically the extreme gradient boosting decision tree model (XGB) and Shapley Values (SHAP), with national data sources in South Korea collected from the Korea Transport Institute, Statistics Korea, and National Spatial Data Infrastructure Portal. Several key findings of feature importance and plots in non-linear relationships are as follows: First, accessibility indicators exhibited around 5 to 10% of feature importance except for Mart (around 50%). Second, better accessibility to public transportation infrastructures, such as bus stops and transit stations, was associated with higher annual average daily traffic (AADT), particularly in metropolitan areas including Seoul and Busan. Third, access to large-scale markets may have unintended effects on traffic volumes for both vehicles and automobiles. Fourth, it was shown that lower rates of AADT were associated with higher accessibility to elementary schools for all three modes of transportation. This study contributes to (1) understanding complex relationships between the variables, (2) emphasizing the role of transportation accessibility in transportation plans and policies, and (3) offering relevant policy implications.

28 January 2020 in Applied Sciences
Verified
Journal Article
Open access
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JGJunho Gong
Junho Gong
EHEui-Seok Han
Eui-Seok Han
SPSun-Kyu Park
Sun-Kyu Park
DCDooyong Cho
Dooyong Cho
Natural stone-paved roads have been generally used to preserve historical regions due to its architectural aesthetic aspect and environmental impact. However, there are limitations of travelling speed and traffic volume owing to the defects caused by the increased traffic loading and volume. To deal with these hindrances, ultra-rapid-hardening cement for both jointing and laying course materials in rigid small element pavement was considered. The objective of the present study was to continuously evaluate and compare the long-term performance of the suggested bound stone pavement throughout the various test criteria such as skid resistance and Falling Weight Deflectometer tests. The skid resistance outcome was met to the requirement and the response of deflection was measured following by related test method. To compare rut depth, the Finite Element Method (FEM) analysis was performed by modelling with material properties and by creating the loading cycle for imitating the Accelerated Pavement Testing (APT). The maximum deflections of asphalt, concrete block, stone A and stone B were calculated to 17.7, 6.1, 6.3, and 3.6 mm, respectively. Compared to the final outcomes of APT and FEM analysis, there was a difference ranging from 2.1 to 2.3 mm in bound stone pavement B and A, respectively.