• Title/Summary/Keyword: Poor visibility

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A Framework for Object Detection by Haze Removal (안개 제거에 의한 객체 검출 성능 향상 방법)

  • Kim, Sang-Kyoon;Choi, Kyoung-Ho;Park, Soon-Young
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.5
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    • pp.168-176
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    • 2014
  • Detecting moving objects from a video sequence is a fundamental and critical task in video surveillance, traffic monitoring and analysis, and human detection and tracking. It is very difficult to detect moving objects in a video sequence degraded by the environmental factor such as fog. In particular, the color of an object become similar to the neighbor and it reduces the saturation, thus making it very difficult to distinguish the object from the background. For such a reason, it is shown that the performance and reliability of object detection and tracking are poor in the foggy weather. In this paper, we propose a novel method to improve the performance of object detection, combining a haze removal algorithm and a local histogram-based object tracking method. For the quantitative evaluation of the proposed system, information retrieval measurements, recall and precision, are used to quantify how well the performance is improved before and after the haze removal. As a result, the visibility of the image is enhanced and the performance of objects detection is improved.

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.

A Research on the Applicants for the "Campaign for Libraries for Rural Schools" ('시골학교에 도서관을' 캠페인 신청 초등학교 도서관에 관한 연구)

  • Yoon, Cheong-Ok
    • Journal of Korean Library and Information Science Society
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    • v.41 no.3
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    • pp.25-46
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    • 2010
  • In this research the current situations of libraries of 119 rural elementary schools are examined. These schools are the applicants for the 'Campaign for Libraries for Rural Schools' sponsored by Chosun Ilbo in 2009. Through the content analysis of their applications, the factors of facilities, collection, and environment are described. One the surface, most of these applicants look fine with the current size of collection and annual additions. They, however, commonly document the extremely poor conditions of facilities, unbalanced and low quality of books, lack of financial support, and cultural isolation. Even though they are not the typical rural school libraries, it seems urgent to improve their inferior conditions that any library statistics never shows in numbers. In this research, it is considered significant to make local governments and offices of education change their attitude toward rural school libraries and increase their financial support to them. The suggestions are as follows: First, let them know that school library policies concern the voters in communities; Second, use the visibility of various authoritative library assessments and awards; Third, strengthen the qualitative aspect of library evaluations.

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TIN based Matching using Stereo Airphoto and Airborne LiDAR (입체항공사진과 항공 LiDAR를 이용한 TIN 기반 정합)

  • Kim, Hyung-Tae;Han, Dong-Yeob
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.26 no.4
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    • pp.443-452
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    • 2008
  • To deduce 3D linear information which express shapes of buildings out of airphoto by fusion of airphoto and LiDAR data, this research went through 2 process. First, research made LiDAR data into projected data of 2D based on airphoto. For this, the virtual points were added to solve the visual problem of building boundary area which has poor information because the attribute in LiDAR data. Research construct irregular triangular nets from modified LiDAR data and judge visual triangular nets out of image. Through this, research can make reference to information of triangular nets in each image pixel. Second, 3D information was extracted from stereo images segments by combining extracted information of visible region and 2D irregular triangular nets. Matching way based on TIN for segments from stereo images was used. Matching condition based on TIN can improve about 20% of edge matching accuracy compared to existing quadrilateral condition of epipolar geometry.

A Study on Ship Collision Avoidance Algorithm by COLREG (국제해상충돌예방규칙에 따른 충돌회피 알고리즘에 관한 연구)

  • Kim, Dong-Gyun;Jeong, Jung-Sik;Park, Gyei-Kark
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.3
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    • pp.290-295
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    • 2011
  • On the basis of DCPA(Distance to Closest Point of Approach) and TCPA(Time to CPA), the conventional algorithms for collision avoidances have a drawback that the '72 CORLEGs(International Regulations for Preventing Collisions at Sea, 1972) has not taken into account to prevent collisions between ships. In this paper, the proposed algorithm decides whether the own ship is a give-way vessel or a stand-on vessel by observing the relative bearing of the encountered ship. To determine the ship position and time for collision avoidance, the proposed algorithm utilizes the ellipse model for ship safety domain. The computer simulation is done to represent the process of adversive behavior. Using the proposed method, the past maritime accident is analyzed. The proposed method can be effectively applied to collision avoidance by CORLEGs even when the target ship's navigational lights is invisible in poor weather and/or in the restricted visibility.

Evaluation on th e Wear Fit and Activity of Emergency Escape Breathing Devices for Ship Accidents (선박사고용 호흡구난장비의 착용성 및 활동성 평가 연구)

  • Noh, Jae-Hyeon;Park, Yong-Hwan
    • Fire Science and Engineering
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    • v.33 no.2
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    • pp.79-84
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    • 2019
  • The use of emergency escape breathing devices (EEBD) is strongly required to protect against toxic gas or flooding caused by ship fires or accidents. Recently developed domestic EEBD products only satisfy the basic performance requirements, but no wear fit and activity performance evaluation has been done for real usage. In this study, the global level test requirements for wear comfort and activity of EEBDs were developed and the open and closed type of domestic EEBD products were evaluated. Poor visibility, longer wear time, breathing resistance, and hose obstruction in an open type and canister obstruction, weight unbalance, and an invisible black breathing bag in the closed type EEBD were estimated to be the main problems that need to be improved.

Design and Performance Verification of L1 Adaptive Flight Control Law Considering the Change of Center of Gravity for Unmanned Tailless Aircraft (무인 무미익 항공기의 무게중심 변화를 고려한 L1 적응제어 비행제어 법칙 설계 및 성능 검증)

  • Ko, Dong-hyeon;Kang, Ji-soo;Choi, Keeyoung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.47 no.2
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    • pp.114-121
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    • 2019
  • Tailless aircraft have advantages of low visibility compared to conventional aircraft, but drawback of poor stability as well which makes designing controller difficult. The controller design is more difficult, especially when the center of gravity moves due to store release or fuel consumption during flight. In this paper, an L1 adaptive controller is proposed as a way to overcome these problems. The reliability and performance of the controllers were verified by non-linear simulations. RPV Flying Quality Design criteria were used for design criteria. Using the simulation, it is shown that the adaptive controller maintains stability of the unmanned aircraft for sudden large change in the inertial properties. It is also shown that the calculation burden can be reduced when it is used with the gain scheduling method.

Online Fitting service Study -Focusing on Interface design (온라인 피팅서비스 디자인 연구 -인터페이스 디자인을 중심으로)

  • Kim, Ryu-Hee;Yang, Sung-Ho
    • Journal of the Korea Convergence Society
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    • v.12 no.2
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    • pp.147-154
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    • 2021
  • This study focused on the fitting window structure provided by the virtual fitting service web page. We analyzed the current cases and identified the user's needs for the service through usability assessment, survey, and FGI experiments. As a result of the design, the fitting window of the existing web page was opened at the same time as the site was accessed to improve the hassle of using the icons due to their small size and poor visibility. In the case of fitting windows, the problem of information delivery was supplemented so that even the initial user could understand the fitting map of the existing method, and additional items needed for user propensity were provided so that the service could be used accurately and easily. As a result of this study, it can be used as a basic research material in future virtual fitting service studies and is expected to provide good implications to fashion marketers.

Safety and Pitfalls of Blepharoptosis Surgery in Elderly People

  • Yuji Shirakawa;Kazuhisa Uemura;Shinji Kumegawa;Kazuki Ueno;Hiroki Iwanishi;Shizuya Saika;Shinichi Asamura
    • Archives of Plastic Surgery
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    • v.50 no.5
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    • pp.446-451
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    • 2023
  • Background Elderly patients often have complications of blepharoptosis surgery that can result in the appearance or exacerbation of superficial punctate keratopathy (SPK). However, postoperative changes to SPK status have not been previously reported. We used subjective assessment of symptoms and measurement of SPK scale classification to investigate the safety and efficacy of blepharoptosis surgery in elderly patients. Methods Included in this prospective study were 22 patients (44 eyes) with bilateral blepharoptosis that underwent surgery. Patients comprised 8 males and 14 females with a mean (±standard deviation) age of 75.7 ± 8.2 years (range: 61-89). Blepharoptosis surgery consisted of transcutaneous levator advancement and blepharoplasty including resection of soft tissue (skin, subcutaneous tissue, and the orbicularis oculi muscle). Margin reflex distance-1 (MRD-1) measurement, a questionnaire survey of symptoms and SPK scale classification, was administered preoperatively and 3 months postoperatively for evaluation. Results The median MRD-1 was 1 mm preoperatively and 2.5 mm postoperatively, representing a significant postoperative improvement. SPK area and density scores were found to increase when the MRD-1 increase was more than 2.5 mm with surgery. All 10 items on the questionnaire tended have increased scores after surgery, and significant differences were observed in 7 items (poor visibility, ocular fatigue, heavy eyelid, foreign body sensation, difficulty in focusing, headaches, and stiff shoulders). Conclusion Blepharoptosis surgery was found to be a safe and effective way to maintain the increase in MRD-1 within 2.0 mm. Despite the benefits, surgeons must nonetheless be aware that blepharoptosis surgery is a delicate procedure in elderly people.

Effect of sudden rise in underwater rescue activity on increase in reactive oxygen species (수난 구조 활동에서의 급상승이 활성산소 증가에 미치는영향)

  • Jeon, Jai-In
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.5
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    • pp.541-546
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    • 2022
  • This study is to analyze the effect of rapid rise in the rescue activity of suffering on the increase of reactive oxygen species. There is no study that tested the change rate of reactive oxygen species according to the rapid rise in 119 rescue workers, so we want to check the symptoms that appear in rescue workers' bodies. There were 5 subjects, and B, C, and E showed similar values before and after diving: 0.41µmol/L, 0.11µmol/L, and 0.87µmol/L, respectively. However, in subject D, the level of active oxygen rise before and after diving was significantly higher at 1.41µmol/L, which is believed to be due to increased anxiety caused by poor underwater visibility and increased fatigue during rapid ascent after underwater rescue activities. Subject A showed a significantly low increase in active oxygen before and after diving at 0.07µmol/L. The reason seems to be that A is 54 years old and has the most diving experience among the test subjects, and it seems that it is the result of receiving less stress from the poor watch due to the abundant experience of rescue activities as a 119 rescue worker and the skillful underwater activities. Fatigue and anxiety were both high at 4. It is thought that the psychological tension during underwater activities increased fatigue, and the turbidity of the underwater vision raised anxiet.