• Title/Summary/Keyword: Poor visibility

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Bird's-Eye View Service under Ubiquitous Transportation Sensor Network Environments (Ubiquitous Transportation Sensor Network에서 Bird's-Eye View 서비스)

  • Kim, Joohwan;Nam, Doohee;Baek, Sungjoon
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.2
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    • pp.225-231
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    • 2013
  • A bird's-eye view is an elevated view of an object from above, with a perspective as though the observer were a bird, often used in the making of blueprints, floor plans and maps. It can be used under severe weather conditions when visibility is poor. Under low visibility environments, drivers can communicate each other using V2V communication to get each vehicle's status to prevent collision and other accidents. Ubiquitous transportation sensor networks(u-TSN) and its application are emerging rapidly as an exciting new paradigm to provide reliable and comfortable transportatione services. The ever-growing u-TSN and its application will provide an intelligent and ubiquitous communication and network technology for traffic safety area.

Analysis of GPS signal environment at DGNSS stations (DGNSS 기준국 관측환경 분석)

  • Sohn, Dong-Hyo;Park, Kwan-Dong;Won, Ji-Hye;Choi, Yong-Kwon;Kee, Chang-Don
    • Journal of Navigation and Port Research
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    • v.35 no.8
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    • pp.625-629
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    • 2011
  • In this study, we analyzed the signal environment of 17 DGNSS stations operated by DGPS Central Office through TEQC quality checking, visibility analysis and site visits. With TEQC, we produced times series of four indices of TEQC quality checking: observation ratio, L1 pseudorange multipath, L2 pseudorange multipath, and the frequency of cycle slip events. From visibility analysis, the directions where missing observations are happening were identified and the result was verified through onsite investigation. Without considering TEQC indices at the six sites(Palmido, Eochungdo, Geomundo, Pyeongchang, Seongju, and Chungju), the average TEQC indices were: 98% observation ratio, 0.19m of L1 pseudorange multipath, 0.71m of L2 pseudorange multipath, and 1.3 cycle slips per 1000 observations. The observation ratios at Palmido and Eochungdo were low. It was found that receiver settings were incorrect so that they could track the P2 signal of GPS satellites with L2C capability. No signal-blocking obstacles were found around the Geomundo station except the lighthouse. Thus, we guess that the poor TEQC indices at the site are believed to be caused by problems in the GPS hardware or cables. The low observation ratio at Pyeongchang is being caused by the surrounding hills blocking the satellite view from the south to the northwest directions. Even though all of four TEQC indices were bad at Seongju and Chungju stations, we found that the signal reception environment at the two sites is in good condition. We think that the quality indices got poor probably because of malfunctioning equipment. So, further investigation is needed for the Seongju and Chungju sites.

Effects of Traffic Islands on Traffic Accidents Reduction (교통섬 설치로 인한 교통사고 감소 효과)

  • Gang, Dong-Su;Lee, Su-Beom;Kim, Yong-Seok;Hong, Ji-Yeon
    • Journal of Korean Society of Transportation
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    • v.28 no.2
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    • pp.21-32
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    • 2010
  • A traffic island, typical channelization facilities, is widely applied to newly road designs and black spots improvement projects as traffic safety measures. However positive effects of a traffic island for traffic safety have not been reported specifically. Accordingly this study analyzed the accidents reduction effectiveness and economics of installing traffic islands under various roadways and traffic conditions. For this purpose normality test, paired t-test and Wilcoxon signed rank test were applied to this study based on traffic accidents, roadways and traffic environments data for 3 years before and after improvement at 54 intersections. The results showed that most of traffic accidents were reduced significantly after installing traffic islands except when traffic islands were installed in outside of cities and farming regions where use efficiency is low, curve sections with poor visibility, poor alignment sections with acceleration/deceleration lanes, road sections where occurs conflicts frequently due to did not install of acceleration/deceleration lanes, and road sections where cross with single lane road.

Concept Analysis of Self-stigma in Patients with Tuberculosis (결핵 환자의 자기 낙인(self-stigma)에 대한 개념 분석)

  • Yeom, Seonmi;Kang, Jeong Hee;Yang, Youngran
    • Research in Community and Public Health Nursing
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    • v.32 no.3
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    • pp.312-324
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    • 2021
  • Purpose: Tuberculosis is an infectious condition with a high disease burden, and the stigma in patients with tuberculosis causes negative health outcomes. The purpose of this study was to define and clarify the concept of self-stigma among patients with tuberculosis. Methods: The analysis was conducted using Walker and Avant's conceptual approach. Twenty-seven studies met the selection criteria. Results: Self-stigma in patients with tuberculosis can be defined by the following attributes: 1) self-esteem decrement; 2) fear; 3) negative emotions to oneself; 4) social withdrawal; and 5) discrimination. The antecedents identified were 1) inappropriate knowledge of tuberculosis, 2) spread of improper health information through media and social communications, 3) stereotypes and prejudices, 4) visibility due to symptoms appearing, 5) recognizing the risk of infection, and 6) low financial status. The consequences were 1) concealing the disease, 2) treatment delay, 3) poor treatment adherence, 4) poor quality of life, and 5) deterioration in or lack of social activities. Conclusion: The definition and attributes of self-stigma identified by this study can be applied to enhance the understanding of stigma in tuberculosis patients and to improve communications between healthcare providers and researchers. It can also be used to develop theories and measurements related to stigma in patients with tuberculosis.

Improvement of Navigation Lights of Middle and Small Size Ships for Marine Traffic Safety in Coastal Areas of Korea (연안 해상교통안전을 위한 중소형선 항해등 개선방안)

  • Song-Jin Na
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.7
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    • pp.1129-1139
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    • 2022
  • Collision accidents happen frequently. The majority of ships involved in collisions in the coastal areas of Korea are middle and small size ships. The proportion of collision accidents is only 9% of all types of marine accidents; however, the number of casualties resulting from collisions is 34.4% of all human life damages. Generally, as reported by the people involved in these collisions, the navigation lights of the opponent ships were poor and invisible when the accident happened even though the weather and visibility were good. Furthermore, there are many insistences for poor navigation light conditions of the opponent ship in the bay or harbor. Therefore, it is necessary to analyze the present conditions and safety of navigation lights. Therefore, in this study, we examined the rules and books of navigation lights and compared it to that of other transportation systems, such as aircraft, trains, and road vehicles. Furthermore, we analyzed the current marine traf ic circumstances and ship collision accidents that happened in the past 5 years. Additionally, a questionnaire was prepared to gather the opinion of ship experts and secure the objectivity for improvement methods of navigation lights. Finally, methods to improve the navigation lights on ships were devised.

Assessing Multiple Hazard Recognition Abilities of Construction Equipment Operators in Dark Environments Using Virtual Reality

  • Sangkil Song;Juwon Hong;Jinwoo Choi;Minjin Kong;Jongbaek An;Jaewon Jeoung;Taehoon Hong
    • International conference on construction engineering and project management
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    • 2024.07a
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    • pp.925-931
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    • 2024
  • Struck-by accidents on construction sites are one of the major accidents that need to be prevented. Poor visual environments (especially, dark environments) and multiple hazards appearing simultaneously can lead to struck-by accidents due to failure of hazard recognition by construction equipment operators. Therefore, this study aimed to assess multiple hazard recognition abilities of construction equipment operators in dark environments. To this end, virtual reality-based experiments were designed and conducted to collect data on three metrics for multiple hazard recognition abilities: (i) initial recognition time (IRT); (ii) average recognition time per hazard (ART); (iii) the number of false alarms (NoFA). The effect of the number of hazards on multiple hazard recognition abilities in dark environments was analyzed using two statistical methods: (i) Friedman test; (ii) Spearman correlation analysis. The number of hazards has a significant effect on multiple hazard recognition abilities. The data groups for IRT and ART, categorized by the number of hazards, had statistically significant differences. In addition, the number of hazards have negative correlations with IRT and ART. Especially, multiple hazard recognition abilities were lowest when the number of hazards was extremely low (i.e., the number of hazards was 1). Based on these results, construction companies will be able to plan worker allocations that prevent struck-by accidents by increasing multiple hazard recognition abilities in dark environments on construction sites.

Analysis of the Economic Disaster Scale for Fog Case occurred at the Incheon International Airport (인천국제공항 안개사례를 통한 경제적 재해 규모분석)

  • Jung, Woo-Sik;Lee, Joong-Woo;Choi, Hyo-Jin;Kwon, Tae-Sun;Back, Jong-Ho;Park, Jong-Kil
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.15 no.2
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    • pp.40-47
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    • 2007
  • Poor visibility is very important information in aviation meteorology factor, because secure safety, trust and economical efficiency increase for aircraft movements. The Incheon International Airport 4 years recent times was to period aircraft movements delay and cancellation due to meteorology is 52% and 30%. And then fog is 63% and 43% in meteorology factor. Therefore, the analysis against the economic loss size of an airline due to the fog is necessary. This study is indirectly estimated economic disaster scale of flight return and cancellation due to the fog in the Incheon International Airport from 5 to 6 March 2006. This is based on an aviation operational statistics data and meteorology observation data. Result of estimated, total 14 flights return to Gimpo, Jeju and Gimhae in this period are about 208,205,700 won. And estimated total 10 flights cancellation are about 718,657,000 won.

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EMERGING POSSIBILITIES FOR NIRS TO CONTRIBUTO TO ENVIRONMENTAL ANALYSIS

  • Malley, Diane
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1071-1071
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    • 2001
  • Near-infrared spectroscopy (NIRS) is potentially a powerful and revolutionary technology for environmental analysis. It is supported by a large body of scientific and experiential knowledge. The instrumentation is well-developed, with easy-to-use, highly dependable instruments, but at the same time it is still developing, particularly with the production of more portable and rapid instruments, and more powerful software. NIRS is used globally in numerous industries for commodity analysis. Yet NIRS is largely unknown in the field of environmental chemistry and monitoring, and is not even routinely used in soil analysis, where the research literature on NIRS extends over four decades. Part of the explanation for the poor visibility of NIRS is the fact that NIRS is not routinely taught in Chemistry programs in universities, where most environmental chemists and environmental technicians are trained. This presentation examines the unique capabilities of NIRS, such as rapid, real-time analysis; analysis of whole samples; simultaneous analysis of multiple constituents; cost-effectiveness, and portability, as they match needs for analysis in several environmental areas. Examples of NIRS usage and published and unpublished results will be described for such areas as soil and sediment analysis; water quality monitoring; and nutrient loading in application of manures and sewage sludge (biosolids) to land. Present barriers to the use of NIRS in environmental analysis will be discussed. It is argued that emerging environmental problems and increasing attention to some traditional problems will enhance the application of NIRS in the future.

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Analysis of Radar Recognition Characteristics of Bridge Piers and Attachments for Safe Passing (교량 안전통항을 위한 레이더의 교각인식 특성 분석)

  • Kim Tain-In;Park Sang Il;Jeong Deuk Dae;Shin Chul Ho
    • Proceedings of KOSOMES biannual meeting
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    • 2003.11a
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    • pp.59-65
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    • 2003
  • For safe passing the waterway crossing bridge without collision with bridge-piers under poor visibility circumstances, it is very important that the pier should be detected definitely as earlier as possible by radar, In this study, the required length of Projecting part of the bridge pier for definite radar recognition was obtained by theoretical and experimental analyses. By presenting the required values depending on the maximum vessel size and passing condition, it is expected possible to design the bridge pier protecting system appropriately suitable to traffic environment of the waterway.

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MULTI-SENSOR DATA FUSION FOR FUTURE TELEMATICS APPLICATION

  • Kim, Seong-Baek;Lee, Seung-Yong;Choi, Ji-Hoon;Choi, Kyung-Ho;Jang, Byung-Tae
    • Journal of Astronomy and Space Sciences
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    • v.20 no.4
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    • pp.359-364
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    • 2003
  • In this paper, we present multi-sensor data fusion for telematics application. Successful telematics can be realized through the integration of navigation and spatial information. The well-determined acquisition of vehicle's position plays a vital role in application service. The development of GPS is used to provide the navigation data, but the performance is limited in areas where poor satellite visibility environment exists. Hence, multi-sensor fusion including IMU (Inertial Measurement Unit), GPS(Global Positioning System), and DMI (Distance Measurement Indicator) is required to provide the vehicle's position to service provider and driver behind the wheel. The multi-sensor fusion is implemented via algorithm based on Kalman filtering technique. Navigation accuracy can be enhanced using this filtering approach. For the verification of fusion approach, land vehicle test was performed and the results were discussed. Results showed that the horizontal position errors were suppressed around 1 meter level accuracy under simulated non-GPS availability environment. Under normal GPS environment, the horizontal position errors were under 40㎝ in curve trajectory and 27㎝ in linear trajectory, which are definitely depending on vehicular dynamics.