• Title/Summary/Keyword: Road visibility

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Development and Evaluation of Children's Smart Photonic Safety Clothing ( 어린이의 스마트 포토닉 안전의복의 개발 및 평가)

  • Soon-Ja Park;Dae-jin, Ko;Sung-eun, Jang
    • Science of Emotion and Sensibility
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    • v.26 no.2
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    • pp.129-140
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    • 2023
  • Following ISO 20471, in this study, first, two sets of safety clothes and safety vests were made by designing and attaching animal and bird patterns preferred by children to retroreflective films and black fabrics on those fluorescent fabrics and retroreflective materials prescribed by international standards. Second, by mounting a smart photonic device on the safety clothing so that the body can be recognized from a distance even without an ambient light source at night, children can emit three types of light depending on the situation with just one-touch of the button. From a result of comparison with visibility a day and night by dressing a mannequin in the made smart safety clothing, the difference in visibility was evident at night, it was confirmed that we can see the figure of a person even at a distance of approximately 70 m. Therefore, it is expected to contribute to the prevention of traffic and other accidents on the road, as the drivers driving at night or in bad weather can recognize a person from a distance. Third, in case of the energy is exhausted and cannot maintain the stability of the light-emitting function of the optical faber, we can use energy harvesting device, and the light-emitting time will be extended. As a result it comes up to emit light stably for a long time. And this prove that smart photonic safety clothing can also be used for night workers. Therefore, optical fiber safety clothing is expected to be highly wearable not only in real life but also in dark industrial sites due to stable charging by applying the energy harvesting provided by solar cells.

Road Image Enhancement Method for Vision-based Intelligent Vehicle (비전기반 지능형 자동차를 위한 도로 주행 영상 개선 방법)

  • Kim, Seunggyu;Park, Daeyong;Choi, Yeongwoo
    • Korean Journal of Cognitive Science
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    • v.25 no.1
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    • pp.51-71
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    • 2014
  • This paper presents an image enhancement method in real road traffic scenes. The images captured by the camera on the car cannot keep the color constancy as illumination or weather changes. In the real environment, these problems are more worse at back light conditions and at night that make more difficult to the applications of the vision-based intelligent vehicles. Using the existing image enhancement methods without considering the position and intensity of the light source and their geometric relations the image quality can even be deteriorated. Thus, this paper presents a fast and effective method for image enhancement resembling human cognitive system which consists of 1) image preprocessing, 2) color-contrast evaluation, 3) alpha blending of over/under estimated image and preprocessed image. An input image is first preprocessed by gamma correction, and then enhanced by an Automatic Color Enhancement(ACE) method. Finally, the preprocessed image and the ACE image are blended to improve image visibility. The proposed method shows drastically enhanced results visually, and improves the performance in traffic sign detection of the vision based intelligent vehicle applications.

An Epidemiological Study for Child Pedestrian Traffic Injuries that Occurred in School-zone (어린이 보호구역 내에서 발생한 6-14세 어린이들의 보행 중 교통사고에 대한 역학적 조사)

  • Shin, Min-Ho;Kweon, Sun-Seog
    • Journal of Preventive Medicine and Public Health
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    • v.38 no.2
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    • pp.163-169
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    • 2005
  • Objectives: Pedestrian traffic injuries have been an important cause of childhood mortality and morbidity for decades. The aim of this study was to describe the epidemiological characteristics of child pedestrian traffic injuries that occurred during 2000 in one metropolitan city and its school-zones, and to determine the factors associated with those accidents. Methods: A cross-sectional study was performed in 2001. Police records were used to identify the cases of pedestrian injury. Children aged between 6 and 15 years, injured during road walking, were included in this study. A direct survey of the environmental factors within the school-zones in study area (n=116) was also performed. Self-administered questionnaires, via mail and telephone surveys, were used to assess the safety education programmes. The schools were divided into two groups according to the occurrence of pedestrian traffic injuries in their school-zone. Results: Pedestrian injuries (n=597) were found to account for 3.2% of all traffic injuries in the subject area. The epidemiological characteristics were not significantly different between genders. There were some significant risk factors within the environmental factors, such as local road (OR: 2.3, 95% CI=1.05-5.35), heavy traffic volume (OR: 2.2, 95% CI=1.00-5.04), poor visibility of speed-limit signs (OR: 2.8, 95% CI=1.25-6.42), no separation of pedestrian routes from cars (OR: 2.6, 95% CI=1.02-6.75) and barriers on the pedestrian routes (OR: 2.2, 95% CI=1.01-5.08). Only one factor, that of education in a safety-park (OR: 0.3, 95% CI=0.09-0.96), was significantly associated in the traffic and pedestrian safety education factors. Conclusion: Significant associations with pedestrian injury risk were identified in some of the modifiable environmental factors than in the educational factors.

Proposed Message Transit Buffer Management Model for Nodes in Vehicular Delay-Tolerant Network

  • Gballou Yao, Theophile;Kimou Kouadio, Prosper;Tiecoura, Yves;Toure Kidjegbo, Augustin
    • International Journal of Computer Science & Network Security
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    • v.23 no.1
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    • pp.153-163
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    • 2023
  • This study is situated in the context of intelligent transport systems, where in-vehicle devices assist drivers to avoid accidents and therefore improve road safety. The vehicles present in a given area form an ad' hoc network of vehicles called vehicular ad' hoc network. In this type of network, the nodes are mobile vehicles and the messages exchanged are messages to warn about obstacles that may hinder the correct driving. Node mobilities make it impossible for inter-node communication to be end-to-end. Recognizing this characteristic has led to delay-tolerant vehicular networks. Embedded devices have small buffers (memory) to hold messages that a node needs to transmit when no other node is within its visibility range for transmission. The performance of a vehicular delay-tolerant network is closely tied to the successful management of the nodes' transit buffer. In this paper, we propose a message transit buffer management model for nodes in vehicular delay tolerant networks. This model consists in setting up, on the one hand, a policy of dropping messages from the buffer when the buffer is full and must receive a new message. This drop policy is based on the concept of intermediate node to destination, queues and priority class of service. It is also based on the properties of the message (size, weight, number of hops, number of replications, remaining time-to-live, etc.). On the other hand, the model defines the policy for selecting the message to be transmitted. The proposed model was evaluated with the ONE opportunistic network simulator based on a 4000m x 4000m area of downtown Bouaké in Côte d'Ivoire. The map data were imported using the Open Street Map tool. The results obtained show that our model improves the delivery ratio of security alert messages, reduces their delivery delay and network overload compared to the existing model. This improvement in communication within a network of vehicles can contribute to the improvement of road safety.

An Analysis on Compliance of Variable Speed Limit under Foggy Conditions using Driving Simulator (차량 시뮬레이터를 이용한 안개 도로 가변제한속도 순응 경향 분석)

  • Kim, Soullam;Lee, Sukki;Kim, Yongseok
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.16 no.2
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    • pp.116-127
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    • 2017
  • A fog on road is known as a weather factor that affects traffic flow. The method in order to solve the problem, recently, Variable Speed Limit(VSL) which provide reasonable speed limit by road and weather conditions in real time is introduced. However, if drivers do not comply with VSL, the road safety more decrease than without VSL because individual vehicle's speed deviation is larger than without VSL. Therefore, this paper aims to analyze to speed limit compliance and traffic characteristics under foggy conditions with and without VSL. A test using driving simulator divides into normal and foggy condition with visibilities are 200m, 150, 50~100m. The test results showed that 70 subjects's average speed mostly obeyed speed limit, but speed deviation generally declined with VSL. Especially, the speed deviation more reduced under foggy conditions. According to this study, compliance of VSL clearly rose in low visibility and VSL helped improve road safety due to reduction of speed deviation. The results of this study are expected to make use of reasonable speed limit for reference.

An appropriateness review on the road tunnel ventilation standards by pollutants site measurement and case study (오염물질 현장측정 및 사례조사를 통한 도로터널 환기기준의 적정성에 관한 연구)

  • Kim, Hyo-Gyu;Baek, Doo-San;Yoo, Ji-Oh
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.22 no.3
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    • pp.323-335
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    • 2020
  • In this study, a series of site measurement of particulate and gases pollutants at five tunnels were carried out along with case studies to review the suitability of the current road tunnel ventilation design standards. Previous studies by other researchers have shown that the ratios of the level of measurement to the standard were 27.9%, 1.6% and 3.4% for TSP, CO and NOx, respectively. Those measured in this site study shows even lower ratios; the ratios were 2.6%, 0.8% and 0.3%, for TSP, CO and NOx, respectively. The particle size analysis of TSP for the five tunnels shows that PM10 including tire wear and re-suspended road dust exceeded 20.4%. This implies that non-exhaust particulate matter must be taken into account, since the current design standards for the particulate matter (visibility) include only the engine emission. Based on the recent research results, for vehicle emission rate and slope-speed correction factors, revision of ventilation design standards for pollutants is required. WRA (PIARC) also emphasizes the necessity of the ventilation design standards for pollutants. In addition, enactment of a new road tunnel ventilation system operation standard or guideline is strongly recommended when considering the low operating rate of the ventilation system with jet-fans.

A Study on the Visibility Distance of Road Traffic Signs (도로표지 시인거리에 관한 연구)

  • 최기주;최병운
    • Journal of Korean Society of Transportation
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    • v.19 no.4
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    • pp.123-137
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    • 2001
  • 도로표지는 도로상에서 도로이용자가 원하는 목적지까지 쉽게 도착할 수 있도록 안내해 주는 기능을 갖는 도로부속물로 꼭 필요한 곳에, 눈에 잘 띄도록, 간단 명료하게 의미가 전달될 수 있도록 설치되어야 한다. MUTCD (Manual On Uniform Traffic Control Devices)의 교통통제설비의 기본요건처럼 무엇보다도 표지판을 보고 필요한 행동을 취하는데 있어서 안전과 시인성이 확보되도록 여유 있게 설치되어야 한다. 그러나, 우리의 표지의 설치 및 운영상황은 그렇지 못하다는 데에서 본 연구는 시작되었다. 시인거리측면을 중심으로 우리나라와 외국 여러 나라의 그것을 비교한 결과, 우리의 규정에서는 판독거리의 중요한 변수인 표지판 정보수가 고려되지 않았음이 드러났다. 따라서, 본고에서는 정보수에 초점을 맞추어 속도와 정보수, 주행 차로 등의 변수를 고려한 표지판 시인거리 측정실험을 하였다. 실험은 현재 국도상에 설치되어 있는 표지판을 대상으로 GPS(Global Positioning System) 수신기를 이용하여 시인거리를 측정하여 진행하였다. 그 결과 실제 시인거리가 현재의 도로표지규정에 의한 시인거리와 다소 차이가 있음을 발견할 수 있었고, 판독거리에서 가장 큰 영향을 미치는 변수는 속도 > 정보수 > 주행차로의 순임을 분석할 수 있었다. 본 연구결과를 통하여 한 개의 물리적 표지내에 정보수가 많은 우리나라의 표지판에 현실적인 시인거리를 고려한 설치가 유도될 수 있을 것으로 기대되고, 향후 도로표지규정을 개정할 때에도 이 연구결과를 반영한 현실적인 규정의 재정립이 기대된다. 또한 표지판의 실제 크기, 글자 및 문안의 크기는 물론 판의 크기 및 여백의 설정도 재산정될 필요가 있으며 이에 대한 추후 연구가 필요하다고 사료된다.

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Analysis of Landscape Information and Web GIS Implementation of Using 3D Topographic Modeling (3차원 지형모델링에 의한 경관정보 분석과 Web GIS 구현)

  • Kim, Yong-Suk;Hong, Soon-Heon;Ok, Chi-Yul
    • The Journal of the Korea Contents Association
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    • v.7 no.9
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    • pp.204-211
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    • 2007
  • In this study 3D topographic modeling was made by using aerial photography and digital terrain map, through this we did visibility analysis and implemented Web GIS of Dong-A university. Studying area was Busan Saha-gu Hadan-dong, we used aerial photography on a scale of 1:20,000 and digital terrain map on a scale of 1:5,000. Ortho correction image was made by aerial photography through selecting GCP, image matching, image resampling and precise differential rectification. And DEM on digital map was created using ArcView program, making 3D topographic modeling by road layer and building layer and implementing Web GIS about Dong-A university.

Impact Variables of Dump Truck Cycle Time for Heavy Excavation Construction Projects

  • Song, Siyuan;Marks, Eric;Pradhananga, Nipesh
    • Journal of Construction Engineering and Project Management
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    • v.7 no.2
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    • pp.11-18
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    • 2017
  • The cycle time of construction equipment for earthwork operations has a significant impact on project productivity. Elements that directly impact a haul vehicle's cycle time must be identified in order to accurately quantify the haul cycle time and implement strategies to decrease it. The objective of this research is to scientifically identify and quantify variables that have a significant impact on the cycle time of a dump truck used for earthwork. Real-time location data collected by GPS devices deployed in an active earthwork moving construction site was analyzed using statistical regression. External data including environmental components and haul road conditions were also collected periodically throughout the study duration. Several statistical analyses including a variance analysis and regression analysis were completed on the dump truck location data. Collected data was categorized by stage of the dump truck cycle. Results indicate that a dump truck's enter idle time, exit idle time, moving speed and driver visibility can significantly impact the dump truck cycle time. The contribution of this research is the identification and analysis of statistically significant correlations of variables within the cycle time.

Lane detection method using the Retinex algorithm in foggy roads (Retinex 알고리즘을 사용한 안개 구간에서의 차선 검출 방법)

  • Kang, ji-hun;Choi, seo-hyuk;Kim, chang-dae;Ryu, sung-pil;Kim, dong-woo;Ahn, jae-hyeong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.05a
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    • pp.376-380
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    • 2015
  • This paper proposes new recognition method of road lanes misty day. The method enables autonomous-driving of cars and the safety of the drivers while driving with bad visibility in foggy roads. The proposed method, firstly, determines whether the foggy or not according to pixel number distributions and starting point of the fog period from input images. If it is foggy then the median filter's size of the Retinex algorithm is set to 1000 or more and it performs histogram equalization and normalization. The computer simulation results show that the proposed method can recognize better long distances and fine detection than earlier methods.

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