Illuminance distribution in obstructed spaces

Illuminance of neonatal units.

We have measured the illuminance (brightness) of seven neonatal units during both the day and the night. When the units were lit solely by fluorescent tubes the mean illuminance was 348 lux (range 192-690). During the day the mean illuminance was 470 lux (range 236-905). The high dependency regions in four of the seven units were significantly brighter than the corresponding low dependency nurs...

fault location in power distribution networks using matching algorithm

چکیده رساله/پایان نامه : تاکنون روش‏های متعددی در ارتباط با مکان یابی خطا در شبکه انتقال ارائه شده است. استفاده مستقیم از این روش‏ها در شبکه توزیع به دلایلی همچون وجود انشعاب‏های متعدد، غیر یکنواختی فیدرها (خطوط کابلی، خطوط هوایی، سطح مقطع متفاوت انشعاب ها و تنه اصلی فیدر)، نامتعادلی (عدم جابجا شدگی خطوط، بارهای تک‏فاز و سه فاز)، ثابت نبودن بار و اندازه گیری مقادیر ولتاژ و جریان فقط در ابتدای...

Illuminance flow over anisotropic surfaces.

A theory is presented to analyze images of anisotropic fine-scale surfaces. We investigate the estimates of illuminance flow by using structure tensors. For anisotropic surfaces, both the gradient-based and the Hessian-based tensors will yield deviations from the true illumination orientation. Our theory predicts this deviation. To show the use of this theory, an algorithm is derived that uses ...

Illuminance requirements for emergency lighting

An analytical model for the illuminance distribution of a power LED.

Light-emitting diodes (LEDs) will play a major role in future indoor illumination systems. In general, the generalized Lambertian pattern is widely used as the radiation pattern of a single LED. In this letter, we show that the illuminance distribution due to this Lambertian pattern, when projected onto a horizontal surface such as a floor, can be well approximated by a Gaussian function.