High-Brightness Light Emitting Diodes (HB-LEDs) are considered the future trend in lighting not only due to their high efficiency and high reliability, but also due to their other outstanding characteristics: chromatic variety, shock and vibration resistance, etc. Nevertheless, they need the development of new power supplies especially designed for boosting and taking advantage of their aforeme...

a r t i c l e i n f o Keywords: High-power LED lamp Step-stress accelerated test Subsystem isolation method Lifetime Degradation Mechanism 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 source, the driver, and the mechanical fixture. Step-stress accelerated tes...

Sinkhole development occurs in many areas of the world where soluble rocks crop out. Sinkholes are generally the surface expression of the presence of caves and other groundwater flow conduits in carbonate rocks, which are solutionally enlarged secondary permeability features. Their formation may be either natural or caused by man’s activities. In both cases, heavy consequences have to be regis...

The galvactivator is a glove-like wearable device that senses the wearer's skin conductivity and maps its values to a bright LED display, making the skin conductivity level visible. Increases in skin conductivity tend to be good indicators of physiological arousal --causing the galvactivator display to glow brightly. The new form factor of this sensor frees the wearer from the traditional requi...

Smart city is an attractive way of making the city more livable through intelligent solutions that are enabled by information and communication technology. Regarding the lighting system, it achieves the perfect balance between beautiful city ambience and preserving the darkness that makes cities more livable. As a smart city component, a public lighting system offers much more than light itself...

Twelve kinds of luminous environments were set up with white LED light source by changing the color temperature and illumination. Using feel discriminative index and the reaction time as the evaluation index, the effects of different luminous environments on human psychological feelings were researched, based on Signal Detection Theory and open windows. The results showed that lighting environm...

Face Recognition is widely used in security systems, such as surveillance, gate control systems, and guard robots, due to their user friendliness and convenience compared to other biometric approaches. Secure face recognition systems require advanced technology for face liveness detection, which can identify whether a face belongs to a real client or a portrait. However, with the development of...

L IGHTING ACCOUNTS FOR ABOUT 15 PERCENT OF THE WORLD’S TOTAL ELECTRICITY CONSUMPTION, therefore a reduction of energy consumed for lighting will give a significant contribution to better utilization of the natural resources and a reduction of CO2 emissions. Recently, Light Emitting Diodes (LED) have been introduced in street lighting, building lighting, backlighting and automobiles lighting, ow...

Studies of visual effects of road signs have shown that having dynamic imagery, and even better, animation, helps improve road signs as it increases a viewer’s attentiveness. However, currently existing animated imagery signs, which are usually digital billboards, have drawbacks including distraction caused by bright LED lights, large energy consumption, and expensiveness. To overcome the probl...