338 research outputs found
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A Prototype Toolkit For Evaluating Indoor Environmental Quality In Commercial Buildings
Measurement of building environmental parameters is often complex, expensive, and not easily proceduralized in a manner that covers all commercial buildings. Evaluating building indoor environmental quality performance is therefore not standard practice. This project developed a prototype toolkit that addressed existing barriers to widespread indoor environmental quality performance evaluation. A toolkit with both hardware and software elements was designed for practitioners around the indoor environmental quality requirements of the American Society of Heating, Refrigeration and Air Conditioning Engineers / Chartered Institution of Building Services / United States Green Building Council Performance Measurement Protocols. This unique toolkit was built on a wireless mesh network with a web-based data collection, analysis, and reporting application. The toolkit provided a fast, robust deployment of sensors, real-time data analysis, Performance Measurement Protocol-based analysis methods and a scorecard and report generation tools. A web-enabled Geographic Information System-based metadata collection system also reduced field-study deployment time. The toolkit was evaluated through three case studies, which were discussed in this report
Aging-In-Place Home Modification: LED Lamp Color Temperature Preference Among Adults
This study evaluated LED color temperature preference and effectiveness in a task light setting for older adults with a comparison to younger adults. Test subjects included visually active adults, male and female, from 19 years to 96 years of age. The researcher tested one hundred participants from several test sites. The researcher ascertained conclusions based on the correlations of age, gender, visual acuity, time of day, and visual medical conditions to LED preference. A tunable lamp with four correlated color temperatures (CCT/K), 2700K, 3500K, 4100K, and 5000K was analyzed using timed and graded, reading and number comparison tasks. Lumen output between the correlated color temperatures was adjusted for consistency to prevent illuminance (lumens) from effecting the outcome. Test subjects choose a preferred correlated color temperature and completed a subjective survey accessing the preferred comfort level. Results indicated the test subjects performed better with the 4100K correlated color temperature. Regarding personal preference of correlated color temperature by test subjects on average: the 4100K correlated color temperature was preferred first (36%), the 3500K correlated color temperature was preferred second (28%), the 5000K was preferred third (24%), and the 2700K was preferred least (12%). A significant difference was discovered between men and women with men, on average, taking longer to complete the reading and number matching tasks than women
Visual Quality, Motility Behavior, and Retinal Changes Associated with Reading Tasks Performed on Electronic Devices
Background: The purpose of this study was to objectively evaluate visual discomfort using an eye tracker and aberrometer after a 21-min reading session on an iPad and an Ebook. Additionally, retinal changes were analyzed using optical coherence tomography (OCT). Methods: A total of 31 young subjects (24 ± 4 years) participated in this study. They read for 21 min on an Ebook and for another 21 min on an iPad under controlled lighting conditions while their eye movements were monitored using an eye tracker. Aberrometry and retinal OCT measurements were taken before and after each reading session. Parameters such as pupil diameter, fixations, saccades, blinks, total aberration, high-order aberration, low-order aberration, and central and peripheral retinal thickness in the nine early treatment diabetic retinopathy study (ETDRS) areas were measured for each reading situation. Statistical analysis was performed on the collected data. Results: No statistically significant differences (p > 0.05) between the two devices were observed in terms of the different types of eye movements or the changes in retinal thickness. However, the aberrometric analysis showed variations in post-reading situations depending on the device used. Conclusion: Reading speed and visual discomfort resulting from electronic device usage can be objectively assessed using an eye tracker and aberrometer. Additionally, changes found in central and peripheral retinal thickness between the two devices and the baseline measurements were not significant and remained relatively stable
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