| Home | [1–10] << 11 12 13 14 15 16 17 18 19 20 >> [21–30] |
|
| Records | |||||
|---|---|---|---|---|---|
| Author | Marchant, P. | ||||
| Title | Do brighter, whiter street lights improve road safety? | Type | Journal Article | ||
| Year | 2019 | Publication | Significance | Abbreviated Journal  |
Significance |
| Volume | 16 | Issue | 5 | Pages | 8-9 |
| Keywords | Public Safety; Lighting; Statistics | ||||
| Abstract | Would a billion‐dollar investment in improved street lighting make Australian roads safer at night? Paul Marchant finds the evidence wanting | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Summary Language | Original Title | |||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1740-9705 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | GFZ @ kyba @ | Serial | 2686 | ||
| Permanent link to this record | |||||
| Author | Mortazavi, S.A.R.; Faraz, M.; Laalpour, S.; Kaveh Ahangar, A.; Eslami, J.; Zarei, S.; Mortazavi, G.; Gheisari, F.; Mortazavi, S.M.J. | ||||
| Title | Exposure to Blue Light Emitted from Smartphones in an Environment with Dim Light at Night Alters the Reaction Time of University Students | Type | Journal Article | ||
| Year | 2019 | Publication | Shiraz E-Medical Journal | Abbreviated Journal |
Shiraz E-Med J |
| Volume | Issue | Pages | e88230 | ||
| Keywords | Human Health; Blue light; smartphone; Reaction Time; shift work | ||||
| Abstract | Background: Substantial evidence now indicates that exposure to visible light at night can be linked to a wide spectrum of disorders ranging from obesity to cancer. More specifically, it has been shown that exposure to short wavelengths in the blue region at night is associated with adverse health effects, such as sleep problems. Objectives: This study aimed at investigating if exposure to blue light emitted from common smartphones in an environment with dim light at night alters human reaction time. Methods: Visual reaction time (VRT) of 267 male and female university students were recorded using a simple blind computer-assisted VRT test, respectively. Volunteer university students, who provided their informed consent were randomly divided to two groups of control (N = 126 students) and intervention (N = 141 students). All participants were asked to go to bed at 23:00. Participants in the intervention group were asked to use their smartphones from 23:00 to 24:00 (watching a natural life documentary movie for 60 minutes), while the control group only stayed in bed under low lighting condition, i.e. dim light. Before starting the experiment and after 60 minutes of smartphone use, reaction time was recorded in both groups. Results: The mean reaction times in the intervention and the control groups before the experiment (23:00) did not show a statistically difference (P = 0.449). The reaction time in the intervention group significantly increased from 412.64 ± 105.60 msec at 23:00 to 441.66 ± 125.78 msec at 24:00 (P = 0.0368) while in the control group, there was no statistically significant difference between the mean reaction times at 23:00 and 24:00. Conclusions: To the best of the author’s knowledge, this is the first study, which showed that exposure to blue-rich visible light emitted from widely used smartphones increases visual reaction time, which would eventually result in a delay in human responses to different hazards. These findings indicate that people, such as night shift or on call workers, who need to react to stresses rapidly should avoid using their smartphones in a dim light at night. |
||||
| Address | Student Research Committee, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran | ||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Summary Language | Original Title | |||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1735-1391 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | GFZ @ kyba @ | Serial | 2534 | ||
| Permanent link to this record | |||||
| Author | Li, X.; Zhao, L.; Li, D.; Xu, H. | ||||
| Title | Mapping Urban Extent Using Luojia 1-01 Nighttime Light Imagery | Type | Journal Article | ||
| Year | 2018 | Publication | Sensors (Basel, Switzerland) | Abbreviated Journal |
Sensors (Basel) |
| Volume | 18 | Issue | 11 | Pages | |
| Keywords | Instrumentation; Remote Sensing | ||||
| Abstract | Luojia 1-01 satellite, launched on 2 June 2018, provides a new data source of nighttime light at 130 m resolution and shows potential for mapping urban extent. In this paper, using Luojia 1-01 and VIIRS nighttime light imagery, we compared several methods for extracting urban areas, including Human Settlement Index (HSI), Simple Thresholding Segmentation (STS) and SVM supervised classification. According to the accuracy assessment, the HSI method using LJ1-01 data had the best performance in urban extent extraction, which presented the largest Kappa Coefficient value, 0.834, among all the results. For the urban areas extracted by VIIRS based HSI method, the largest Kappa Coefficient value was 0.772. In contrast, the largest Kappa Coefficient values obtained by STS method were 0.79 and 0.7512 respectively when using LJ1-01 and VIIRS data, while for SVM method the values were 0.7829 and 0.7486 when using Landsat-LJ and Landsat-VIIRS composite data respectively. The experimented results demonstrated that the utilization of nighttime light imagery can largely improve the accuracy of urban extent extraction and LJ1-01 data, with a higher resolution and more abundant spatial information, can lead to better identification results than its predecessors. | ||||
| Address | Key Laboratory of the Ministry of Land and Resources for Law Evaluation Engineering, Wuhan 430074, China. xuhuimin1985_2008@163.com | ||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | English | Summary Language | Original Title | ||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1424-8220 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | PMID:30380616 | Approved | no | ||
| Call Number | GFZ @ kyba @ | Serial | 2056 | ||
| Permanent link to this record | |||||
| Author | Zhang, G.; Li, L.; Jiang, Y.; Shen, X.; Li, D. | ||||
| Title | On-Orbit Relative Radiometric Calibration of the Night-Time Sensor of the LuoJia1-01 Satellite | Type | Journal Article | ||
| Year | 2018 | Publication | Sensors (Basel, Switzerland) | Abbreviated Journal |
Sensors (Basel) |
| Volume | 18 | Issue | 12 | Pages | |
| Keywords | Instrumentation; Remote Sensing | ||||
| Abstract | The LuoJia1-01 satellite can acquire high-resolution, high-sensitivity nighttime light data for night remote sensing applications. LuoJia1-01 is equipped with a 4-megapixel CMOS sensor composed of 2048 x 2048 unique detectors that record weak nighttime light on Earth. Owing to minute variations in manufacturing and temporal degradation, each detector's behavior varies when exposed to uniform radiance, resulting in noticeable detector-level errors in the acquired imagery. Radiometric calibration helps to eliminate these detector-level errors. For the nighttime sensor of LuoJia1-01, it is difficult to directly use the nighttime light data to calibrate the detector-level errors, because at night there is no large-area uniform light source. This paper reports an on-orbit radiometric calibration method that uses daytime data to estimate the relative calibration coefficients for each detector in the LuoJia1-01 nighttime sensor, and uses the calibrated data to correct nighttime data. The image sensor has a high dynamic range (HDR) mode, which is optimized for day/night imaging applications. An HDR image can be constructed using low- and high-gain HDR images captured in HDR mode. Hence, a day-to-night radiometric reference transfer model, which uses daytime uniform calibration to calibrate the detector non-uniformity of the nighttime sensor, is herein built for LuoJia1-01. Owing to the lack of calibration equipment on-board LuoJia1-01, the dark current of the nighttime sensor is calibrated by collecting no-light desert images at new moon. The results show that in HDR mode (1) the root mean square of mean for each detector in low-gain (high-gain) images is better than 0.04 (0.07) in digital number (DN) after dark current correction; (2) the DN relationship between low- and high-gain images conforms to the quadratic polynomial mode; (3) streaking metrics are better than 0.2% after relative calibration; and (4) the nighttime sensor has the same relative correction parameters at different exposure times for the same gain parameters. | ||||
| Address | State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan 430079, China. drli@whu.edu.cn | ||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | English | Summary Language | Original Title | ||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1424-8220 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | PMID:30513817 | Approved | no | ||
| Call Number | GFZ @ kyba @ | Serial | 2125 | ||
| Permanent link to this record | |||||
| Author | Zhang, K.; Zhong, X.; Zhang, G.; Li, D.; Su, Z.; Meng, Y.; Jiang, Y. | ||||
| Title | Thermal Stability Optimization of the Luojia 1-01 Nighttime Light Remote-Sensing Camera's Principal Distance | Type | Journal Article | ||
| Year | 2019 | Publication | Sensors (Basel, Switzerland) | Abbreviated Journal |
Sensors (Basel) |
| Volume | 19 | Issue | 5 | Pages | 990 |
| Keywords | Instrumentation; Luojia 1-01; nighttime light remote-sensing camera; principal distance; optical-passive athermal design; thermal stability | ||||
| Abstract | The instability of the principal distance of the nighttime light remote-sensing camera of the Luojia 1-01 satellite directly affects the geometric accuracy of images, consequently affecting the results of analysis of nighttime light remote-sensing data. Based on the theory of optical passive athermal design, a mathematical model of optical-passive athermal design for principal distance stabilization is established. Positive and negative lenses of different materials and the mechanical structures of different materials are matched to optimize the optical system. According to the index requirements of the Luojia 1-01 camera, an image-telecentric optical system was designed under the guidance of the established mathematical model. In the temperature range of -20 degrees C to +60 degrees C, the principal distance of the system changes from -0.01 mum to +0.28 mum. After on-orbit testing, the geometric accuracy of the designed nighttime light remote-sensing camera is better than 0.20 pixels and less than index requirement of 0.3 pixels, which indicating that the principal distance maintains good stability on-orbit and meets the application requirements of nighttime light remote sensing. | ||||
| Address | School of Remote Sensing and Information Engineering, Wuhan University, Wuhan 430079, China. jiangyh@whu.edu.cn | ||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | English | Summary Language | Original Title | ||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1424-8220 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | PMID:30813556 | Approved | no | ||
| Call Number | GFZ @ kyba @ | Serial | 2238 | ||
| Permanent link to this record | |||||