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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

An image quality analysis of ANVIS-6 night vision goggles

Abel, Derek H. 10 November 2009 (has links)
This study was undertaken in an effort to relate ANVIS-6 Night Vision Goggle image quality to user performance. The purpose was to determine which of five image quality metrics best related to performance tasks. The image quality metrics examined Modulation Transfer Function Area (MTFA), Integrated Contrast Sensitivity (leS), Square Root Integral (SQRI), Resolution, and Signal-to-Noise Ratio (SNR). The performance tasks were detection and recognition of targets under various levels of moon illumination. The metric that best related to target detection was SNR. The SNR results are consistent with visual psychophysics and SNR effects. The metric that best related to target recognition was Resolution. The resolution results are consistent with the position that recognition performance improves for suprathreshold targets as resolving power increases. / Master of Science
12

Further Studies on the Dark Adaptation of Elementary School Children

Gary, Lois W. 08 1900 (has links)
The present study is part of a long time cooperative study of the Education and Home Economics Departments of North Texas State Teachers College begun in 1940. The purpose is to compare the dark adaptations of second and third grade children made in 1940 with those made in 1941, and to determine also the dark adaptation of a group of fifth and sixth grade children receiving vitamin A concentrate.
13

Dark Adaptation of Second and Third Grade Children

Rohrer, Lois Young 06 1900 (has links)
The purpose of the study is to determine the dark adaptation of second grade children in Denton, Texas.
14

An investigation of stereopsis with AN/AVS-6 night vision goggles at varying levels of illuminance and contrast /

Armentrout, Jeffrey J., January 1993 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 52-55). Also available via the Internet.
15

An investigation of stereopsis with AN/AVS-6 night vision goggles at varying levels of illuminance and contrast

Armentrout, Jeffrey J. 16 December 2009 (has links)
The increased reliance on night operations by the military over the last few decades has led to the development of various night imaging devices. Night vision goggles (NVGs) are one device which have gained widespread use in nighttime helicopter operations. However, rotorcraft accident data have indicated an increased occurrence of "pilot error" type accidents when NVGs are in use. NVG related accidents often can be linked to extremely poor ambient lighting and contrast conditions during nighttime operations as well as the imaging limitations of the NVGs. Research has shown that NVGs reduce visual acuity and depth perception when compared to unaided daylight viewing conditions. In this study the effects of illumination and contrast on stereoscopic vision with and without AN/AVS-6 goggles were investigated. Stereoacuity was measured using a modified Howard-Dolman apparatus with four levels of illumination and three levels of contrast. Testing was performed with NVGs for nighttime illuminations and unaided for daytime levels of illumination. Image measurements were performed on the NVGs to determine the impact of illumination on resolution and signal-to-noise ratio. Stereoscopic vision with NVGs was found to be significantly worse than under daylight conditions. Low levels of contrast also were found to reduce stereoacuity significantly. It was found that the worst stereoacuity in this study occurred under half moon or higher illumination levels. This research revealed that further NVG development should focus on the limitations of the NVGs under high light levels, and special considerations should be made for using NVGs in low contrast, high luminance situations. / Master of Science
16

A three months' study of the dark adaptation of a Texas family during activity

Wade, Alice Mays 08 1900 (has links)
This study was conducted on a family of nine ranging in age from thirteen to fifty-two, to examine dark adaptation during physical activities.
17

Fusion of images from Dissimilar Sensor systems /

Chow, Khin Choong. January 2004 (has links) (PDF)
Thesis (M.S. in Combat Systems Technology)--Naval Postgraduate School, Dec. 2004. / Thesis Advisor(s): Monique P. Fargues, Alfred W. Cooper. Includes bibliographical references (p. 73-75). Also available online.
18

A Dark Adaptation Study of College Men and Women

Henry, Archie 08 1900 (has links)
This study is the result of tests conducted to determine the adaptability of the human eye to darkness.
19

Effects of target size, luminance contrast, and illumination on visual target detection and recognition with AN/AVS-6 goggles

Pierce, Eric Christopher 04 December 2009 (has links)
The military has invested in the development of low light level and night imaging technologies to gain tactical advantages on the battlefield. Moreover, certain military activities such as night aviation maneuvers demand the most sophisticated night imaging devices. Unfortunately, as the frequency of use of night imaging devices increases, so has the number of accidents (Boyd, 1991). Many of these accidents have been attributed to the novel usage as well as the intrinsic limitations of night imaging devices. The present research examined the effects of target size, luminance contrast, and illumination level on visual target detection and recognition while using AN/AVS-6 night vision goggles. Vehicle silhouette targets were rear-projected on random screen positions under various levels of illumination, contrast, and size. The observer's task was to detect and recognize each target while viewing through night vision goggles. The results indicate that visual detection and recognition performance degrade with decreasing levels of illumination, contrast, and target size. The findings of this work can be used to optimize the usage of AN/AVS-6 devices. / Master of Science
20

A Study of the Effect of Feeding High Vitamin A Foods Upon the Dark Adaptation of College Girls

Lewis, Amber Loreta 08 1900 (has links)
It is the purpose of the study to determine if the addition of Vita Yam as a source of vitamin A to the daily diet improves the dark adaptation of college-age students.

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