scholarly journals Preliminary Analysis of LED Enhanced Signs at a Passive Rural Level Crossing

2015 ◽  
Author(s):  
Adrian D. Hellman ◽  
Aaron Lamplugh
Keyword(s):  
Motor Vehicle ◽  
Light Emitting Diode ◽  
Warning Signs ◽  
Public Works ◽  
Data Sets ◽  
Vehicle Speed ◽  
Test Results ◽  
Level Crossing ◽  
Light Emitting ◽  
Flashing Light

The purpose of this research was to measure motor vehicle speed profiles at a rural level crossing following the replacement of the existing Crossbuck signs and Advance Warning signs (AWSs) with flashing light-emitting diode (LED) versions. Measurements were recorded at four discrete locations on the approach to the level crossing, during three distinct phases: baseline, or prior to any changes at the crossing, after the installation of LED enhanced Crossbuck signs, and after the installation of LED AWSs. Test results after the installation of the LED enhanced Crossbuck signs showed: 1) a statistically significant decrease of 2.9 mph–3.3 mph in mean vehicle speed at night at the four measurement locations and 2) improvements of 1.5%–2.5% in the rate of mean vehicle speed decrease for both daytime and nighttime data sets. The unplanned addition of a double yellow centerline by the local public works department prevented the evaluation of the LED-enhanced AWS technology.

Active matrix organic light-emitting diode (AMOLED) performance and life test results

2011 ◽  
Author(s):  
David A. Fellowes ◽  
Michael V. Wood ◽  
Arthur R. Hastings, Jr. ◽  
Russell S. Draper ◽  
Amalkumar Ghosh ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Test Results ◽  
Life Test ◽  
Active Matrix ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light

scholarly journals The Effect of Different Filament Arrangements on Thermal and Optical Performances of LED Bulbs

2020 ◽  
Vol 10 (4) ◽  
pp. 1373
Author(s):  
Wei Wang ◽  
Jun Zou ◽  
Qiaoyu Zheng ◽  
Yuefeng Li ◽  
Bobo Yang ◽  
...  
Keyword(s):  
Thermal Cycle ◽  
Gas Flow ◽  
Performance Test ◽  
Light Emitting Diode ◽  
Luminous Flux ◽  
Junction Temperature ◽  
Test Results ◽  
Light Emitting ◽  
Three Samples ◽  
Simulation Results

The influences on thermal and optical performances of light emitting diode (LED) bulbs with three different filament arrangements are investigated in detail. The average junction temperature, temperature of the surface of the bulb, and luminous flux of three samples all increased with increasing power. The thermal performance test results show that between the average junction, temperature and power were linear. The junction temperatures of the three samples at a power of 3.5 W were 102.48, 98.46, and 88.88 °C. The optical performance test results revealed that the luminous flux and efficiency in the two vertical filament arrangements were closely related to each other and higher than that of the horizontal filament arrangement. A numerical model of LED filament bulbs was established by the Floefd 17.2 software for analyzing the temperature distribution of the cross section and the gas flow path inside the bulb. The simulation results illustrated that the average temperatures of three samples were 105.88, 101.83, and 96.12 °C. Additionally, the gas flow inside the bulb of the two vertical filament arrangements was subject to forming a thermal cycle during operation work more than that of the horizontal filament arrangement. As a result, the flexible spiral LED filament bulb is feasible as a new light source.

Active matrix organic light emitting diode (OLED)-XL life test results

2008 ◽  
Author(s):  
David A. Fellowes ◽  
Michael V. Wood ◽  
Arthur R. Hastings, Jr. ◽  
Amalkumar P. Ghosh ◽  
Olivier Prache
Keyword(s):  
Light Emitting Diode ◽  
Test Results ◽  
Life Test ◽  
Active Matrix ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light

scholarly journals Environtmentally healthy sleep light

2019 ◽  
Vol 4 (2) ◽  
pp. 274-280
Author(s):  
Tulus Ikhsan Nasution ◽  
Mahyudin K.M Nasution ◽  
Susilawati ◽  
Dara Azdena
Keyword(s):  
Community Service ◽  
Light Emitting Diode ◽  
Economic Value ◽  
Test Results ◽  
Light Emitting ◽  
Voice Control ◽  
Control Application ◽  
Led Lights ◽  
Creativity And Innovation

Healthy sleep lights that will be proposed for community service are the results of research in which the use of LED lights (Light Emitting Diode) is activated with a maximum power of 3 Watts, so that the power consumed is quite low. This healthy sleep lamp also has some uniqueness such as turning on and off with sound by utilizing applications installed on smartphones. This voice control application can also be used to vary the color of the light. This lamp can be turned on and off by touching the light nest by using a sensor system and also the color and brightness of the lamp can be adjusted using the RGB control application on the smartphone. Intensity test results for LED lights 112 - 996 (Weber / m2). The standard intensity limit for healthy bulbs based on H. Steve, H. Gaube and J. Winterhager is 3,000 (Weber / m2), so that meeting the intensity standard is an LED lamp. Our long-term goal is to develop research results into products that have economic value, facilitate students to develop creativity and innovation and create jobs by partnering with partners.

Active matrix organic light emitting diode (AMOLED) performance and life test results

2010 ◽  
Author(s):  
David A. Fellowes ◽  
Michael V. Wood ◽  
Arthur R. Hastings, Jr. ◽  
Russell S. Draper ◽  
Alden K. Lum ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Test Results ◽  
Life Test ◽  
Active Matrix ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light

Performance Analysis of Various Types of High Power Light Emitting Diodes

2018 ◽  
pp. 91-98 ◽  
Author(s):  
Kamalika Ghosh ◽  
Debashis Raul
Keyword(s):  
High Power ◽  
Light Emitting Diode ◽  
Life Time ◽  
Effect Of Temperature ◽  
Light Sources ◽  
Test Results ◽  
Light Emitting ◽  
Tropical Countries ◽  
Cause Of Failure ◽  
Very High

Solid state, energy efficient light emitting diode (LED) technology is coming up to replace the conventional gas discharge, etc. light sources. Although declared life of LED is very high but in tropical countries their life time appears very short. This phenomenon is becoming the most drawbacks for usage of LED. To search out the reason for the failure lead to undertake thorough study on the performance of LED specifically on the various environmental conditions. Experimentation was carried out with various types of commercially available high power LED. Failure in tropical countries may be due to effect of temperature. Test results have been noted at various major parts of LEDs, e.g. die, and sink area. Detail analysis of test results at various parts of LEDs in different conditions tends to have some idea about the cause of failure of the LEDs in tropical countries with high ambient temperature and less scope of heat generation by the light source.

Visibility aid cycling clothing: flashing light-emitting diode (FLED) configurations

2015 ◽  
Vol 27 (3) ◽  
pp. 460-471 ◽  
Author(s):  
Helen S. Koo ◽  
Xiao Huang
Keyword(s):  
Design Methodology ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Content Type ◽  
Light Emitting ◽  
Flashing Light ◽  
Psychological Perceptions ◽  
Detection And Recognition

Purpose – The purpose of this paper is to investigate drivers’ differing psychological perceptions of cyclists’ conspicuity according to active visibility aid configurations on clothing. Design/methodology/approach – The flashing light-emitting diodes (FLEDs) were positioned on the major joints (shoulders, elbows, wrists, hips, knees, and ankles) in eight configurations and pre- and post-surveys were conducted. Findings – The results indicated that there were significant differences among the eight configurations in observers’ detection and recognition of cyclists, contributions of FLEDs, and visibility of cyclists (p<0.001). Among the eight different configurations on joints, FLEDs on the hips, knees, and ankles were the most detectable, recognizable, and visible. Originality/value – Most of the previous studies have investigated passive visibility aids and there is a lack of research on FLED configurations on major joints for cyclists. Thus, this study is expected to be beneficial to designers when developing active visibility aid clothing for cyclists.

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