Least squares method for liquid crystal display characterization

2017 ◽  
Vol 56 (5) ◽  
pp. 1438 ◽  
Author(s):  
Dafne Amaya ◽  
Daniel Actis ◽  
Gonzalo Rumi ◽  
Alberto Lencina
Keyword(s):  
Liquid Crystal ◽  
Least Squares ◽  
Least Squares Method ◽  
Liquid Crystal Display

scholarly journals Engineering Aspheric Liquid Crystal Lenses by Using the Transmission Electrode Technique

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 835
Author(s):  
José Francisco Algorri ◽  
Dimitrios C. Zografopoulos ◽  
Luis Rodríguez-Cobo ◽  
José Manuel Sánchez-Pena ◽  
José Miguel López-Higuera
Keyword(s):  
Liquid Crystal ◽  
Numerical Simulations ◽  
Least Squares ◽  
Least Squares Method ◽  
Electric Circuit ◽  
Equivalent Electric Circuit ◽  
Novel Technique ◽  
Analytical Expressions ◽  
Manufacturing Parameters ◽  
Electrode Technique

The transmission electrode technique has been recently proposed as a versatile method to obtain various types of liquid-crystal (LC) lenses. In this work, an equivalent electric circuit and new analytical expressions based on this technique are developed. In addition, novel electrode shapes are proposed in order to generate different phase profiles. The analytical expressions depend on manufacturing parameters that have been optimized by using the least squares method. Thanks to the proposed design equations and the associated optimization, the feasibility of engineering any kind of aspheric LC lenses is demonstrated, which is key to obtain aberration-free lenses. The results are compared to numerical simulations validating the proposed equations. This novel technique, in combination with the proposed design equations, opens a new path for the design and fabrication of LC lenses and even other types of adaptive-focus lenses based on voltage control.

‘Least squares’ method—theorem or law?

1980 ◽  
Vol 59 (9) ◽  
pp. 8
Author(s):  
D.E. Turnbull
Keyword(s):  
Least Squares ◽  
Least Squares Method

An Augmented Iteratively Re-weighted and Refined Least Squares Method for lp Minimization Problem in Inverse Modeling of Potential Field Magnetic Data

2020 ◽  
Vol 1 (3) ◽  
Author(s):  
Maysam Abedi
Keyword(s):  
Magnetic Field ◽  
Magnetic Susceptibility ◽  
Least Squares ◽  
Minimization Problem ◽  
Potential Field ◽  
Field Data ◽  
Least Squares Method ◽  
Porphyry Copper ◽  
Magnetic Data ◽  
Magnetic Field Data

The presented work examines application of an Augmented Iteratively Re-weighted and Refined Least Squares method (AIRRLS) to construct a 3D magnetic susceptibility property from potential field magnetic anomalies. This algorithm replaces an lp minimization problem by a sequence of weighted linear systems in which the retrieved magnetic susceptibility model is successively converged to an optimum solution, while the regularization parameter is the stopping iteration numbers. To avoid the natural tendency of causative magnetic sources to concentrate at shallow depth, a prior depth weighting function is incorporated in the original formulation of the objective function. The speed of lp minimization problem is increased by inserting a pre-conditioner conjugate gradient method (PCCG) to solve the central system of equation in cases of large scale magnetic field data. It is assumed that there is no remanent magnetization since this study focuses on inversion of a geological structure with low magnetic susceptibility property. The method is applied on a multi-source noise-corrupted synthetic magnetic field data to demonstrate its suitability for 3D inversion, and then is applied to a real data pertaining to a geologically plausible porphyry copper unit.  The real case study located in  Semnan province of  Iran  consists  of  an arc-shaped  porphyry  andesite  covered  by  sedimentary  units  which  may  have  potential  of  mineral  occurrences, especially  porphyry copper. It is demonstrated that such structure extends down at depth, and consequently exploratory drilling is highly recommended for acquiring more pieces of information about its potential for ore-bearing mineralization.

Sistem Kontrol Pengisian Air Otomatis Dengan Dua Sumber Suplai Berbasis Mikrokontroler (ATmega 8535)

2016 ◽  
Vol 1 (2) ◽  
pp. 84 ◽  
Author(s):  
Sumardi Sumardi ◽  
Muhammad Nur Anggoro
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystal Display

Sistem kontrol pengisian air otomatis dengan dua sumber suplai berbasis mikrokontroler merupakan sebuah sistem yang dapat digunakan untuk mengendalikan level air pada sebuah bak penampungan secara otomatis. Bahan dan alat yang digunakan dalam sistem kontrol berupa mikrokontroler ATmega 8535, sensor air, downloader DI-USB AVR ISP V2/DI-USB to Serial TTL, liquid crystal display, transisor, resistor, pompa air, adaptor 12 volt dc, saklar, dan program editor code vision avr. Metode yang digunakan dalam pembuatan sistem kontrol pengisian air otomatis ini adalah melakukan percobaan dan ujicoba peralatan secara langsung. Sistem kontrol ini bekerja dalam dua kondisi yaitu ketika air dalam bak penampungan melewati batas bawah maka bak penampungan akan terisi secara otomatis dan ketika telah mencapai batas atas yang ditentukan maka suplai air ke bak penampungan akan berhenti, selanjutnya ditambah pengaturan dari dua buah sumber air sebagai suplai yang akan bekerja sesuai dengan prioritasnya. Proses tersebut dilakukan oleh sensor bagian input yang berupa sensor air pada masukan sumber air yang kemudian diproses oleh mikrokontroler terprogram. Hasil percobaan menunjukkan sensor air berhasil memberikan logika Low atau High pada keluarannya sebagai fungsinya untuk memberikan sinyal masukan pada port mikrokontrol. Pada kondisi high, sensor air mampu memberikan nilai tegangan 4,89 Volt DC untuk digunakan sebagai masukan mikrokontroler. Dan pada kondisi low, sensor air mampu memberikan nilai tegangan 0,11 Volt dc sebagai masukan mikrokontroler ketika elektroda tehubung dengan common oleh media air. Driver Masukan terbukti dapat digunakan untuk menggendalikan kerja dari motor pompa 220 V AC dan lampu indikator 12 V DC. Hasil yang dari sistem kontrol pengisian air ini adalah terjadinya pengurangan kerugian yang ditimbulkan karena masalah ketersediaan air dan juga mempermudah kegiatan dalam pengendalian ketersediaan air. Kata kunci : Sistem kontrol, pengisan air otomatis, mikrokontroler, sensor air.

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