The lifetimes of high-power light-emitting diode (LED) lamps are investigated by step-stress
accelerated test. The entire lamp is divided into three subsystems, namely, the LED light …

The lumen degradation of LED lamps undergoing an accelerated aging test is investigated.
The entire LED lamp is divided into three subsystems, namely, driver, lampshade, and LED …

Light-emitting diode (LED) based lights used in safety critical applications need continuous
monitoring of their light output since lumen degradation is one of many failure modes. Airport …

An accelerated aging test is the main method in evaluation of the reliability of light-emitting
diodes (LEDs), and the first goal of this study is to investigate how the junction temperature …

LED products have started to displace traditional light sources in many lighting applications.
One of the commonly claimed benefits for LED lighting products is their long useful lifetime …

Present industry practice allows reporting of LED system life as the time for the light output to
reach the 70% value, estimated according to LM-80 and TM-21. In these procedures, only …

LED luminaire system has lots of failure modes. And the interaction among various failure
mechanisms is extremely complex. There is a great obstacle existed in assessing the system …

This dissertation proposes two main methods as a modification of the semi-parametric
Proportional Hazard Model (PHM) with innovative application for reliability testing. The first …

In recent times, as LEDs are fast becoming the preferred light source to the conventional
halogen and fluorescent-based light sources, the question about their useful life also …

LED lighting products don't always meet their rated lifetime and may fail prematurely,
reducing the expected energy savings in installations. The project aimed at obtaining new …