نتایج جستجو برای: optical quality

تعداد نتایج: 1007114  

پایان نامه :دانشگاه تربیت معلم - تهران - دانشکده علوم 1393

in this thesis, structural, electronical, and optical properties of inverse pervskite(ca3pbo) in cubic phase have been investigated.the calculation have been done based on density functional theory and according to generalized gradiant approximate (gga) as correlating potential. in order to calculate the configurations, implementing in the wien2k code have been used from 2013 version. first of ...

Journal: :journal of artificial intelligence in electrical engineering 2013
reza ghavidel barsary alireza andalib hamed alipour-banaei

here, we propose an optical filter and an optical power splitter based on two-dimensionalphotonic crystal all circular ring resonators. these structures are made of a square lattice ofsilicon rods with the refractive index n1=3.464 surrounded by air (with refractive indexn2=1). first, we have designed the filter and by using that, we designed a power splitter. thetransmission efficiency and qua...

In this paper, an optical filter based on a two dimensional photonic crystalring resonator (PCRR) with triangular lattice is designed and presented. For thispurpose, the effects of positioning, arrangement and the number of the inner rods of thedual-curved PCRR on the performance characteristics of our optical filter such as thetransmission coefficient and the quality factor have been fully inv...

In this paper, an enhancement design of communication system using optical radio frequency (RF) waves in free space optical communication (FSO) system is presented. To our knowledge, it is the first time that the effect of Gamma-Gamma turbulent channel model on the performance of the proposed system is analyzed and simulated. To obtain an optical communication system with good performance and h...

حیدریان, سمیرا, صادقی, مسعود, محجوب, منیره, مومنی, سید محمد, هرویان, جواد,

Background and purpose: Age related macular degeneration is the most common cause of sever visual impairment and blindness among adults over the age of 65 years in developed countries. The purpose of this study was to review the literature on using low vision aids in age related macular degeneration and their effects on their quality of life. Materials and methods: A comprehensive search of ...

Journal: :journal of current ophthalmology 0
اعظم عسگری azam asgari علی اصغر پرچ ali asghar parach کیخسرو کشاورزی keykhosro keshavarzi

purpose : the aim of this study was to investigate the effect of misalignment (tilt & decentration) of iols in cataract surgery using liu-brennan optical eye model in a simulation. methods : a phantom with the real eye parameters –liu-brennan model– and tecnis z9000 iol were used for simulation. results : results showed that with 0.4 mm decentration and more the modulation transfer function (mt...

Here, we propose an optical filter and an optical power splitter based on two-dimensionalphotonic crystal all circular ring resonators. These structures are made of a square lattice ofsilicon rods with the refractive index n1=3.464 surrounded by air (with refractive indexn2=1). First, we have designed the filter and by using that, we designed a power splitter. Thetransmission efficiency and Qua...

2017
A. V. Kozhevnikov

This work presents a study of the influence and compensation of aberrations in optical imaging systems by superimposing surfaces described by Zernike polynomials. The aim is to investigate how to compensate for aberrations and their effectiveness when dealing with aberrations of different types. The study is done in the Zemax packet by modeling the optical imaging system and passing test images...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2012
negin manavizadeh ali reza khodayari ebrahim asl soleimani sheyda bagherzadeh

the improvement of the physical properties of indium tin oxide (ito) layers is quite advantageous in photovoltaic applications. in this study the ito film is deposited by rf sputtering onto p-type crystalline silicon (c-si) with (100) orientation, multicrystalline silicon (mc-si), and glass substrates coated with zno and annealed in vacuum furnace at 400°c. electrical, optical, structural and m...

2008
Darrin K. Reed Elisa H. Barney Smith

OCR often performs poorly on degraded documents. One approach to improving performance is to determine a good filter to improve the appearance of the document image before sending it to the OCR engine. Quality metrics have been measured in document images to determine what type of filtering would most likely improve the OCR response for that document image. In this paper those same quality metr...

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