• 제목/요약/키워드: poor visibility

검색결과 66건 처리시간 0.022초

저가형 수신기를 이용한 GPS/GLONASS/BDS 통합 측위 정확도 분석 (Analysis of Integrated GPS/GLONASS/BDS Positioning Accuracy using Low Cost Receiver)

  • 태현우;박관동;김미소
    • 대한공간정보학회지
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    • 제23권4호
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    • pp.49-55
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    • 2015
  • 본 연구에서는 GPS/GLONASS/BDS 통합 측위를 수행하기 위해 고려해야 할 사항을 소개하였으며, 저가형 수신기를 통해 개활지 환경과 난수신 환경에서의 통합 측위의 정확도를 분석하였다. 개활지 환경에서는 통합 측위 시 수평 RMSE가 1.2m로 단일 시스템만을 이용한 측위에 비해 수평 정확도가 17-55%만큼 향상되었으며 편향이 개선되어 높은 측위 성능을 나타내는 것을 확인하였다. 난수신 환경에서의 가시 위성 개수를 파악한 결과 단일 시스템을 이용하여 측위를 할 때에는 가시 위성의 개수가 4개 미만이 되어 측위가 되지 않는 경우가 발생했으나, 통합 측위를 할 때에는 가시 위성 개수가 항상 4개 이상이 되어 측위가 되지 않는 경우가 발생하지 않았다. 난수신 환경에서 통합 측위의 수평 RMSE는 6.4m로 단일 시스템만을 이용하여 측위를 수행했을 때보다 8-47%만큼 수평 정확도가 향상되는 것을 확인하였다.

장대해상교량의 방재시스템 구축에 관한 연구 (Study on Disaster Prevention System for Long Span Bridge over the Sea)

  • 공병승
    • 한국해양공학회지
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    • 제23권3호
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    • pp.59-64
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    • 2009
  • Bridge types such as the suspension bridges and the cable stayed bridges maintained by cables present the dangerous possibility of a ship running through the bottom of the bridge. Due to hangers and main cables in the upper structural system, the bridge is also susceptible to disasters. However, these cable bridges are usually used for long span bridges over the sea. This structure is relatively more exposed to disasters, such as wind, hail, and earthquake, than other structures. This structure also has the potential to cause car accidents on account of the poor visibility due to foggy conditions. If a fire breaks out because of a car accident due to wind, a car explosion will likely occur.

수중 로봇을 위한 다중 템플릿 및 가중치 상관 계수 기반의 물체 인식 및 추종 (Multiple Templates and Weighted Correlation Coefficient-based Object Detection and Tracking for Underwater Robots)

  • 김동훈;이동화;명현;최현택
    • 로봇학회논문지
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    • 제7권2호
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    • pp.142-149
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    • 2012
  • The camera has limitations of poor visibility in underwater environment due to the limited light source and medium noise of the environment. However, its usefulness in close range has been proved in many studies, especially for navigation. Thus, in this paper, vision-based object detection and tracking techniques using artificial objects for underwater robots have been studied. We employed template matching and mean shift algorithms for the object detection and tracking methods. Also, we propose the weighted correlation coefficient of adaptive threshold -based and color-region-aided approaches to enhance the object detection performance in various illumination conditions. The color information is incorporated into the template matched area and the features of the template are used to robustly calculate correlation coefficients. And the objects are recognized using multi-template matching approach. Finally, the water basin experiments have been conducted to demonstrate the performance of the proposed techniques using an underwater robot platform yShark made by KORDI.

영상 화질 개선을 위한 레티넥스 기반 영상 보정 기법 (Color Image Compensation Method Based on Retinex For Improving Visual Image Quality)

  • 최호형;김현덕;윤병주
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2008년도 하계종합학술대회
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    • pp.829-830
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    • 2008
  • In modern days, many of the images are captured by using various devices, such as PDA, digital camera, or cell phone camera. Because all these devise have a limited dynamic range, images captured in real world scenes with high dynamic ranges usually exhibit poor visibility and low contrast, which may make important image features lost or hard to tell by human viewers. In this paper, the efficient color image enhancement method is presented. Experimental result show that the proposed method yields better performance of color enhancement over the previous work for test color images.

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차량용 측위 시스템에 RFID 적용 가능성 연구 (A Feasibility Study on Car Positioning system Using RFID)

  • 유영민;이채흔;박준구;박찬국
    • 제어로봇시스템학회논문지
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    • 제12권10호
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    • pp.975-981
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    • 2006
  • This paper shows a feasibility analysis results on RFID for car positioning system. Usually, a car navigation is mainly based on GPS combined with map-matching. However, in the case of poor visibility of satellites, GPS can not supply accurate position information continuously. In recent years, RFID has been considered to be one of key technologies in positioning and localization area. But its application and research results in the area of vehicular positioning are not popular. RFID system consists of tag, reader, antenna and software such as drivers and middleware. The main function of RFID system in a vehicular positioning is to retrieve ID recorded position information from tags which set on the center of road. We propose a positioning method for vehicles using RFID and we present some indoor and outdoor experiment results to show that the proposed method is available in vehicle operational environments.

물류센터 안전교육에 관한 연구 : 지게차 교육을 중심으로 (A Study on the Safety Education of Logistics Center : Forklift Training Approach)

  • 김기홍;정병현
    • 대한안전경영과학회지
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    • 제22권3호
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    • pp.9-14
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    • 2020
  • A forklift accident occurs in the logisitcs center. there are many kinds of accidents such as a casualty accident or a minor accident, etc. there are many other causes of accident, including poor visibility and habitual operational mistakes The result of the accident is the phenomenon of cutting, falling, scratching of the product. In the case of minor accidents, workers do not report accidents, so the occurrence of accidents is unknown. The customer receives the goods and then notifies them that they are defective product. After the product is returned, we can see that the forklift accident caused the problem of the product The result of the late response affects the image of the enterprise. In this study, we recognized the need for safety education to prevent accidents and found out which of the education items could raise awareness of safety. As result of the study, disinfection and forklift maneuverability regarding speed were mentioned as the most important items in education.

형상을 통한 수동형 레이더 리프렉터의 RCS 증대방법 연구 (A Study on the RCS Enhancement Method of Passive RADAR Reflector Through Shaping)

  • 임정빈;김우숙;안영섭;김인현;박성현;김창경;심영호;김봉석
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2002년도 춘계학술대회논문집
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    • pp.161-176
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    • 2002
  • Collision avoidance is the most important part of a small vessel. Small and mediurn sized ships are surprisingly poor targets for radar reflection and are frequently in danger of being overrun by large vessels, even under good condition of visibility. One of the best way to prevent collisions at sea is to use as large and well designed a radar reflector. Thus, RCS(Radar Cross Section) increase is key element in the design of radar reflector. Radar Reflectors are normally classified into active-type and passive-type. In this paper, the RCS increase methods for passive-type reflector through shaping are explained, and analyzed with RCS performance test by computer simulation. As results from analysis, It is shown that the effective diameter of radar reflector is over 10 λ to provide a return above the threshold RCS of 25m$^2$, lower limit of detectability using X-band radar in a moderate sea.

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강교량 재도장 로봇의 모니터링 모듈 시제품 개발 (Development of a Prototype Monitoring Module for Steel Bridge Repainting Robots)

  • 서명국;이호연;박일환;장병하
    • 드라이브 ㆍ 컨트롤
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    • 제17권4호
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    • pp.15-22
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    • 2020
  • With the need for efficient maintenance technology to reduce maintenance costs for steel bridges, repainting robots are being developed to automate the work in narrow and poor bridge spaces. The repainting robot is equipped with a blasting module to remove paint layers and contaminants. This study developed a prototype monitoring module to be mounted on the repainting robot. The monitoring module analyzes the condition of the painting surface through a camera installed in the front, guides the direction of movement of the robot, and provides the operator with a video to check the working status after blasting through a camera installed in the back. Various image visibility enhancement technologies were applied to the monitoring module to overcome worksite challenges where incomplete lighting and dust occurs.

정치, 기업, 테크놀로지: 연극환경에 대한 소셜네트워크 분석 (Politics, Business and Technology: Social Network Analysis of Theater Environment)

  • 최지애;권오병
    • 한국콘텐츠학회논문지
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    • 제20권6호
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    • pp.267-278
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    • 2020
  • 연극공연 산업은 대표적인 문화 콘텐츠 산업임에도 불구하고 그동안 국가 차원의 지원이 빈약하고 연극 관련 종사자들도 연극환경과의 능동적인 상호작용보다는 연기력 향상 등 개인 노력에 치우쳐온 경향이 있다. 그래서 연극 산업에 대한 실효성 있는 활성화 대책의 필요성이 커지고 있으며, 이는 연극과 연극환경과의 상호작용의 질을 증진하는 데서 찾아야 할 것이다. 이에 본 연구의 목적은 연극 배우들의 연극의 주요 환경인 정치, 기업 및 테크놀로지와의 상호작용 정도가 연극의 활성화에 미치는 영향을 분석하는 것이다. 이를 위해 소셜네트워크 분석을 수행하였다. 연구 결과 매개 중심성이 소셜네트워크 상의 연극 관련 액터(연극인, 연극기관)들의 가시성에 유의한 영향을 주는 것으로 나타났다. 이는 연극 관련 액터가 연극환경 요소들 간의 정보나 자원흐름의 중심에 있을수록 더욱 가시성이 높아진다는 의미이며, 연극이 적극적으로 테크놀로지를 습득하며 아방가르드를 창출하고, 정치 및 기업과의 능동적인 상호작용을 통해 영향력과 외연을 넓히는 노력을 부단히 해야함을 보이고 있다.

도로변 작업자와 도로교통 업무 경찰관의 안전의복 착용실태 및 그 소재와 착용 만족도 분석 (Analysis of Current Wearing Status and Satisfaction of Warning Clothing for Road Cleaner and Traffic Workers)

  • 박순자
    • Human Ecology Research
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    • 제56권4호
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    • pp.347-360
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    • 2018
  • We surveyed 223 road workers between 2017 July-August about wearing and satisfaction in order to find basic data to develop safety clothing that enhances visibility of motion and comfort while meeting international standards. It was found that most of the current warning clothing owned by road cleaners and about 2/3 of policemen clothes were provided by public institutions. The purpose of wearing, color, properties, satisfaction and protectiveness differed significantly by occupation. Second, the most popular response for the type and quantity of warning clothing was 2 sets of spring/autumn, summer, and winter type for road cleaners, whereas policemen chose 2 sets of all types plus a safety vest. Therefore, a top-level (3rd class) warning clothing study is required. Third, satisfaction ranked Moderate>Good>Poor; in addition, the main reason for satisfaction was that 'retroreflective tape increases safety at night (54.4%)' for road cleaners and 'the fluorescent color stands out (43.7%)' for policemen. Thus, it was accepted that visibility contributed to safety. Fourth, body-protectiveness was evaluated higher compared to wearing satisfaction, and it was recognized more by road cleaners than policemen. Overall satisfaction was higher for road cleaners versus policemen both in Seoul than Incheon. Fifth, the main dissatisfaction in both groups was 'low sweat absorbency' showing improving the air permeability, moisture regain and permeability was the highest priority. Finally, those working 8 hours a day tended to evaluate more positively the 6 properties of the material.