• Title/Summary/Keyword: Visibility Range

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A Study on Assessment of Fire and Evacuation Safety in Environmental Energy Facilities (환경에너지시설의 화재 및 피난 안전성 평가에 관한 연구)

  • Jeon, Yong-Han;Han, Sang-Pil
    • Journal of the Korea Safety Management & Science
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    • v.21 no.4
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    • pp.39-44
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    • 2019
  • In this study, fire and evacuation safety of environmental energy facilities using fire and evacuation simulation was examined as part of performance-oriented design. The worst-case fire scenarios in which fire-fighting facilities such as sprinkler fire extinguishing and smoke control systems are not working, and the FDS analyzes the visibility, temperature distribution, and carbon monoxide concentration distribution through FDS. The safety was examined. As a result, it was proved that evacuation could limit the visibility, temperature, and carbon monoxide concentration in a smooth range, based on the safety standards set by relevant laws. In other words, it was possible to verify the safety of fire and evacuation for environmental energy facilities where a large amount of combustibles and fires coexist.

Establishment of Test & Evaluation Criteria in the Military Electro-Optical / Infrared Devices (군용 EO/IR장비의 시험평가 기준 정립방안)

  • Park, Jong Wan
    • Journal of the Korea Institute of Military Science and Technology
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    • v.19 no.5
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    • pp.613-617
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    • 2016
  • Development-concerned parties, business managers and test evaluators have experienced conflicts among themselves due to the absence of standardized criteria for military electro-optical(EO) and infrared(IR) devices in test evaluation planning and evaluation phases. Therefore, establishment of objectified test and evaluation criteria for EO/IR devices is required. This paper applies South Korea's weather measurement average of minimum 15 km for visibility range, 3 bar from Johnson criteria for EO device and 4 bar from NATO's STANAG-4347 for IR device for target type, and 50 % probability for evaluation criteria, respectively. Based upon these criteria, this paper will establish suitable criteria that are improved for development weapon system in consideration of required capability of demanding forces and field environment.

Improving In-Vehicle Display and Control Design for Older Drivers

  • Ryu, Jae-Heok;Lee, Seong-Il
    • Industrial Engineering and Management Systems
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    • v.10 no.4
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    • pp.288-291
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    • 2011
  • Recommendations for older driver-friendly automobile interior design have been determined by taking into account older people's physical and cognitive characteristics. Twenty three older people (aged from 54 to 78) and five younger people (from 20 to 29) performed several tasks in actual driving conditions, in which their reaction times and performance errors were recorded. Some design factors were found to be related to older drivers' visibility and controllability. Several design recommendations were proposed in terms of cluster color and font, display location, and HVAC control type. Proposed recommendations are expected to satisfy a wider range of older drivers as these will facilitate automobile interior designs which are fitter to older drivers' visual, cognitive, and manual capabilities.

Performance Estimation of Tone Mapping for HDR Images (HDR이미지 톤 매핑 알고리즘의 성능 평가)

  • Lee, Yong-Hwan
    • Journal of the Semiconductor & Display Technology
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    • v.20 no.4
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    • pp.182-186
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    • 2021
  • Tone mapping operator is designed to reproduce visibility of real-world scenes such as HDR images on limited dynamic range display devices. This paper presents and implements compare and to estimate some tone mapping algorithms commonly used. The evaluation is performed by applying tone mapping operators on 7 HDR images, and by presenting the results with subjective estimation. Reinhard tone mapping algorithm is the best in the visual experimental results. The goal of this work is to discuss what is visible of high dynamic range on a normal display device and to determine to which better algorithm is. This work motivates us to make more progress through the new proposal of tone mapping operator on future work.

Intercomparison of Daegwallyeong Cloud Physics Observation System (CPOS) Products and the Visibility Calculation by the FSSP Size Distribution during 2006-2008 (대관령 구름물리관측시스템 산출물 평가 및 FSSP를 이용한 시정환산 시험연구)

  • Yang, Ha-Young;Jeong, Jin-Yim;Chang, Ki-Ho;Cha, Joo-Wan;Jung, Jae-Won;Kim, Yoo-Chul;Lee, Myoung-Joo;Bae, Jin-Young;Kang, Sun-Young;Kim, Kum-Lan;Choi, Young-Jean;Choi, Chee-Young
    • Korean Journal of Remote Sensing
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    • v.26 no.2
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    • pp.65-73
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    • 2010
  • To observe and analyze the characteristics of cloud and precipitation properties, the Cloud physics Observation System (CPOS) has been operated from December 2003 at Daegwallyeong ($37.4^{\circ}N$, $128.4^{\circ}E$, 842 m) in the Taebaek Mountains. The major instruments of CPOS are follows: Forward Scattering Spectrometer Probe (FSSP), Optical Particle Counter (OPC), Visibility Sensor (VS), PARSIVEL disdrometer, Microwave Radiometer (MWR), and Micro Rain Radar (MRR). The former four instruments (FSSP, OPC, visibility sensor, and PARSIVEL) are for the observation and analysis of characteristics of the ground cloud (fog) and precipitation, and the others are for the vertical cloud characteristics (http://weamod.metri.re.kr) in real time. For verification of CPOS products, the comparison between the instrumental products has been conducted: the qualitative size distributions of FSSP and OPC during the hygroscopic seeding experiments, the precipitable water vapors of MWR and radiosonde, and the rainfall rates of the PARSIVEL(or MRR) and rain gauge. Most of comparisons show a good agreement with the correlation coefficient more than 0.7. These reliable CPOS products will be useful for the cloud-related studies such as the cloud-aerosol indirect effect or cloud seeding. The visibility value is derived from the droplet size distribution of FSSP. The derived FSSP visibility shows the constant overestimation by 1.7 to 1.9 times compared with the values of two visibility sensors (SVS (Sentry Visibility Sensor) and PWD22 (Present Weather Detect 22)). We believe this bias is come from the limitation of the droplet size range ($2{\sim}47\;{\mu}m$) measured by FSSP. Further studies are needed after introducing new instruments with other ranges.

Simulation to Evaluate CCTV Positioning in Use of Ray-Tracing Algorithm (Ray-Tracing 알고리즘을 이용한 CCTV배치 평가시뮬레이션)

  • Kim, Suk-Tae;Ahn, Sang-Ook
    • Korean Institute of Interior Design Journal
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    • v.22 no.6
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    • pp.40-48
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    • 2013
  • Utilization of CCTV in crime prevention for public safety is accepted as the most effective measure in terms of crime prevention and control. Also, it is frequently used as a device that shows evidence of an unexpected situation or record on public social relationship. However, it is rare to find a study that qualitatively accessed the monitoring performance of a certain space depending on the choice and positioning of CCTVs. Thus, this study suggested a technology that can quantitatively compare and assess the monitoring performance of CCTVs depending on view angle and effective sight range of cameras as well as the monitoring performance depending on positioning measures. For the analysis, the concept of 3-dimensional surveillance field in the form of a frustum was suggested while deriving 3-dimensional range of sight and quantitative monitoring performance by applying Isovist theory. For the analysis technology, space of analysis subject, point of view (camera), and target point (measurement node) were installed at a 3-dimensional space and in use of ray-tracing algorithm, the line segment that was visually connected between the point of view and target point was extracted and accumulated. For such verification, analysis application was constructed and then applied to four alternative models on view angle and distance as well as four alternatives on positioning in order to verify its efficacy. Through the experiment, it was possible to compare and assess visibility depending on alternatives while quantifying the results by understanding the shadow areas beyond the monitoring range.

Image Fusion using RGB and Near Infrared Image (컬러 영상과 근적외선 영상을 이용한 영상 융합)

  • Kil, Taeho;Cho, Nam Ik
    • Journal of Broadcast Engineering
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    • v.21 no.4
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    • pp.515-524
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    • 2016
  • Infrared (IR) wavelength is out of visible range and thus usually cut by hot filters in general commercial cameras. However, some information from the near-IR (NIR) range is known to improve the overall visibility of scene in many cases. For example when there is fog or haze in the scene, NIR image has clearer visibility than visible image because of its stronger penetration property. In this paper, we propose an algorithm for fusing the RGB and NIR images to obtain the enhanced images of the outdoor scenes. First, we construct a weight map by comparing the contrast of the RGB and NIR images, and then fuse the two images based on the weight map. Experimental results show that the proposed method is effective in enhancing visible image and removing the haze.

Runway visual range prediction using Convolutional Neural Network with Weather information

  • Ku, SungKwan;Kim, Seungsu;Hong, Seokmin
    • International Journal of Advanced Culture Technology
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    • v.6 no.4
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    • pp.190-194
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    • 2018
  • The runway visual range is one of the important factors that decide the possibility of taking offs and landings of the airplane at local airports. The runway visual range is affected by weather conditions like fog, wind, etc. The pilots and aviation related workers check a local weather forecast such as runway visual range for safe flight. However there are several local airfields at which no other forecasting functions are provided due to realistic problems like the deterioration, breakdown, expensive purchasing cost of the measurement equipment. To this end, this study proposes a prediction model of runway visual range for a local airport by applying convolutional neural network that has been most commonly used for image/video recognition, image classification, natural language processing and so on to the prediction of runway visual range. For constituting the prediction model, we use the previous time series data of wind speed, humidity, temperature and runway visibility. This paper shows the usefulness of the proposed prediction model of runway visual range by comparing with the measured data.

SI-traceable Calibration of a Transmissometer for Meteorological Optical Range (MOR) Observation (기상관측용 투과형 시정계의 국제단위계에 소급하는 교정)

  • Park, Seongchong;Lee, Dong-Hoon;Kim, Yong-Gyoo
    • Korean Journal of Optics and Photonics
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    • v.26 no.2
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    • pp.73-82
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    • 2015
  • This work demonstrates the indoor SI-traceable calibration of a transmissometer with a 75-m baseline for the measurement of visibility in MOR (Meteorological Optical Range). The calibration is performed using a set of neutral density (ND) filters (OD 0.1-2.5) and a set of high-transmission quartz glass plates (a bare quartz glass plate and antireflective-coated quartz glass plates), the collection consisting of 20 artifacts in total. The luminous transmittance values of the reference artifacts had been calibrated traceable to the KRISS spectral transmittance scale, which ranges from 0.2 % to 99.5 %. The transmissometer to be calibrated typically consists of a loosely collimated light source based on a white LED (CCT ~5000 K) and a luminous intensity detector with a CIE 1924 V(${\lambda}$) spectral response. As a result of calibration, we obtained the MOR error and its uncertainty for the transmissometer in 20 m - 40 km of MOR. Based on the results, we investigated the applicability of the calibration method and the conformity of the transmissometer to the ICAO's (International Civil Aviation Organization) accuracy requirement for meteorological visibility measurement. We expect that this work will establish the standard procedure for the SI-traceable calibration of a transmissometer.

Safety Identification Lamp Visibility of Micro Cars (초소형전기차의 안전식별등 시인성에 관한 연구)

  • Baek, Seong Chae;Seo, Im Ki;Kim, Jeong Hyun;Park, Je Jin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.42 no.3
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    • pp.417-425
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    • 2022
  • Interest in micro cars is growing around the world, and policy support for micro cars has been increasing in Korea. It is important to meet minimum safety standards for the operation of micro cars on roads due to concerns around micro car safety and the limited driving range of micro cars. In this study, visibility experiments that included safety identification of micro cars were conducted to try and prevent a decrease in driver reaction time. Safety identification lights were installed to the rear of a micro car, and the visibility and discomfort of the vehicle were evaluated to determine whether the micro car was safe to drive on an expressway. As a result, the installation effect of Micro car which install safety identification lamp was found when joining the point at an acceleration lane of the grade separation intersection, and that light on/off could be effective when entering an expressway. If the micro car operation plan proposed in this study is applied, the safety of micro cars on expressways can be increased by improving the visibility of micro car.