Two databases of solar surface irradiance (SSI) derived from satellites are compared to ground measurements for Algeria, Egypt, Libya and Tunisia. It is found that it is possible to accurately derive the SSI from geostationary meteorological satellites, even with a coarse spatial resolution. The two databases HelioClim-1 and SSE exhibit similar and good performances. The bias is lower for SSE t...

We consider the backlight calculation of local dimming as an optimization problem. The luminance produced by many LEDs at each pixel considered is calculated which should cover the gray value of each pixel, while the sum of LED currents is to be minimized. For this purpose a specific approach called as “Sorted Sector Covering” (SSC) was developed and is described in this paper. In our pre-proce...

We present a simple model where photons propagating in extragalactic magnetic fields can oscillate into very light axions. The oscillations may convert some of the photons, departing a distant supernova, into axions, making the supernova appear dimmer and hence more distant than it really is. Averaging over different configurations of the magnetic field we find that the dimming saturates at abo...

Can modern cosmological observations be reconciled with a general-relativistic Universe without an antigravitating energy source? Usually, the answer to this question by cosmologists is in negative, and it commonly believed that observed excess dimming of supernovae relative Milne model evidence for dark energy. In paper, we develop theorems clarify conditions such dimming, based on which argue...

Current energy-saving color design approaches can be classified into two categories, namely, context-aware dimming and color remapping. The former darkens individual regions with respect to the user interactions, and the latter replaces the color set with a new color set that yields lower energy consumption. Both schemes have drawbacks: color dimming tends to cause loss of perceptual quality, a...

Visible light communications (VLC) technology permits the exploitation of light-emitting diode (LED) luminaries for simultaneous illumination and broadband wireless communication. Optical orthogonal frequency-division multiplexing (O-OFDM) is a promising modulation technique for VLC systems, in which the real-valued O-OFDM baseband signal is used to modulate the instantaneous power of the optic...

Polarization sensitivity (PS) was examined in two classes of neurons, sustaining fibers and dimming fibers, in the medulla externa (second optic neuropile) of the crayfish, Pacifasticus leniusculus. Visual responses were recorded intracellularly and extracellularly. The influence of e-vector orientation (theta) was probed in steady-state responses, with brief flashes and with a rotating polariz...

introduction: the purpose of this preliminary study was to evaluate the periodontal condition of intruded molars in various phases of treatments. methods: 30 patients with at least one overerupted upper first molar were selected. upper molar bands with brackets were cemented. two miniscrews were placed in the mesiopalatal and mesiobuccal aspect of the aforementioned teeth. a titanium molybdenum...

This study examines whether or not a controllable task-lighting system that allows people to select high lighting levels will enhance productivity under real working conditions. For a period of 16 months a study was carried out in a luminaire factory in Finland in which such a task-lighting system was installed above 10 individual workstations. The illuminances selected by the users were record...