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# Gaussian Beam Propagation Matlab Code

AUTHOR(S) Timothy M. OPTICAL FIBERS BY JAMES MATHEW MARTIN ABSTRACT. As the propagation of the beam diameter along the axis of propagation is described by a. Figure 31: Radial (x at the left, y at the right) energy distribution in two Gaussian beams, incident parallel to the waveguide axis. However, even the exercises with TUTORIALS can be assigned for homework and classwork for students, as. communists take power in china chapter 33 section 2 guided reading answers, Timed. BELLHOP gaussian beam/finite element beam code (M. This Demonstration simulates Gaussian beam propagation and transformation by two lenses. Coupling efficiency and alignment sensitivity models for the coupling of light from a fundamental mode Gaussian light beam into a single mode optical fiber are given. The transverse (-) intensity distribution of the beam is given byIn the above, is the phase of the beam, which is irrelevant when discussing the intensity and is called the. Thomsen (2016). Also the direct simulation of an ideal optical “black hole” is available. 2: A Bessel beam is formed after an incident plane wave passes through a conical lens. Rodríguez, University of Algarve). Values are in nm. To initiate the beam, create a gaussian beam. 3D Wave Optics Beam Propagation Code including diffraction, gain saturation etc. They are symmetric along the optical axis. Notas de aula. Learn more about numerical integration, gaussian beam, propagation. 38 is applied to the transversal components of the E-field in order to derive the magnetic. In this section, we present an example of simulation of the nanocircuit shown in Figure 2(a) fed by the Gaussian beam depicted in Figure 3. Arbitrary terrain and atmosphere profiles can easily be defined. 2: A Bessel beam is formed after an incident plane wave passes through a conical lens. The MATLAB codes for the collimated Gaussian beam case. Class definition for k-Wave linear array transducer. Algorithms are based on the scalar theory of diffraction. The BPM results agree well with analytical solutions. Gained fundamental knowledge in electromagnetic theory, millimeter-wave and microwave circuits, propagation and focusing of Gaussian beams, ray tracing, microwave network analysis using scattering parameters, antenna/array design Performed computer-aided design, modeling and analysis using MATLAB and HFSS. Sign up Raytracing with Matlab. 1 Introduction We saw in the previous chapter that a Gaussian beam can propagate without beam expansion in an optical medium whose refractive index varies in an appropriate manner in the radial direction. The toolbox includes spectral, FFT-based and finite-difference based propagation models. The propagation property of Laguerre-Gaussian (LG) beams passing through a RL was studied, and it was found that a sharp ring was formed at the focal plane first and then a Bessel-similar beam was formed behind the focal plane but the beam size was enlarged with the increase of propagation distance. Here is a Gaussian beam propagating through space. New observation on Seismic anisotropy in subducting slabs inferred by non-double-couple earthquake radiation patterns, Fall AGU. Fortran Code For The Focused Beam Case. The run time of the simulation can take hours or even days depending on the iteration number, the duty cycle, the R1 or R2 ranges. A new theory, the "equivalent index slab (EIS)" method, is proposed to extend the rigorous coupled-wave analysis (RCWA) to rectangular diffraction grating involving surface waves. Ellerbro ek a and G. GaussianBeam computes the profile propagation of a Gaussian laser beam through a set of lenses. A Thermo-Optic Propagation Modeling Capability Karl N. 2020 Dailymotion - designed with ♥ in Paris, FR. It presents past and current research activities to illustrate. Simulation of Wave front propagation with ZEMAX remain Gaussian when the beam propagates • Comparison with MATLAB code 0 5 10 15 20 25 30 35 0. Source: Greynolds, Alan W. Calhoun: The NPS Institutional Archive Theses and Dissertations Thesis Collection 1999-03-01 Strehl ratio probabilities for phase-only adaptive optic. This mode is called the fundamental mode or axial mode , and it has the highest beam quality with an M 2 factor of 1. Wemodel the propagation of light in free space as a Gaussian beam parameterized by a waist w0 and wavelength O (set at 1550nm). BPM_free_space. • Generate set of Gaussian beams at input aperture Step 2: Propagation • Each Gaussian beam is propagated to target plane. The transmitter and receiver gain expressions are, respectively, given by [14, 15] GT=(πDT⁄λ)2 GR=(πDR⁄λ) 2 where D T and D R are, respectively, the transmitter and receiver aperture diameters. SUBJECT TERMS. Laser theory teaches us that by design, most laser beam should have a Gaussian beam shape. mentioned; since this code is based on the Extended General Scattering Matrices [4] other structures such as the Klopfenstein taper can be easily designed and fabri-cated for further performance comparisons. We found that filament propagation length increased with. matlab光学高斯光束传播仿真代码实现，可以根据自己镜头的特征调整参数进而实现光束传播的数值仿真(Matlab Optical Gaussian beam propagation simulation code implementation, according to the characteristics of their own lens parameters can be adjusted to achieve the numerical simulation of beam propagation). (4) to ray propagation in nonuniform photonic crystals. Gained fundamental knowledge in electromagnetic theory, millimeter-wave and microwave circuits, propagation and focusing of Gaussian beams, ray tracing, microwave network analysis using scattering parameters, antenna/array design Performed computer-aided design, modeling and analysis using MATLAB and HFSS. In the inset and indicate the beam waists of the beam after lens 1 and lens ;;. 05:3; plot(x, gaussian(x)); will plot a normalised Gaussian distribution. The Art of Code - Dylan. Propagation des faisceaux gaussiens. The BPM code is ﬁrst tested by calculating the following: 1) the far-ﬁeld light power density of a Gaussian beam propagating in free space; 2) the LP 01 modes; and 3) the butt-joint splice losses. The studies involving the propagation of Gaussian beams mainly focus on the propagation in isotropic medium, based on scalar theory and paraxial optics. 52) from wavefront propagation --Bibliography --8. 5 Gaussian beam optics 1. Because a Gaussian beam is. Here, I’m choosing the parameters to be beam waist (w0) and distance to waist (z0). I've been tasked with writing a code (in MatLab, but I'm currently using Mathematica because I don't know MatLab %\ ) to simulate the propagation of a Gaussian beam. Introduction Within the frame of the linear approximation, the properties of the rays travelling through an optical system can be treated with an elegant and powerful matrix formalism [1,2]. Download MATLAB code: optics6. The transmitter and receiver gain expressions are, respectively, given by [14, 15] GT=(πDT⁄λ)2 GR=(πDR⁄λ) 2 where D T and D R are, respectively, the transmitter and receiver aperture diameters. Accelerated Weeks Method for Numerical Laplace Transform Inversion Author: Patrick O. 1mrad (y-x Direction) By 0. I am trying to build my own raytracing code in MATLAB (for a 2D medium to solve source-receiver raypath) and need one to check my results. write a simple code in Matlab or other compilers. 0 Added: April 08, 2013 | Visits: 259 Basic GUI for Beam Propagation Method for advancing gaussian beam in a profiled medium. For a Gaussian beam, the Fourier coefficients can be shown to be 2 2 0 2 2 0 1 ( ) e x kx x F k π π = − The whole theory explained above is represented by the following picture (Figure 5). Numerical beam propagation in 2D. matlab fibers octave intensity fiber propagation ellipse gaussian-beam-analysis beam-propagation gaussian-beam optical-fiber Updated Aug 29, 2017 MATLAB. Computer Codes for SHG Efficiency. \documentclass. 0at one place along the beam axis, known as the beam waist. Frozen Gaussian Approximation: Elastic Wave Equation. consistent with the expression above for ordinary Gaussian beam propagation, i. Dunn, Optics Express (2009) The FDTD method was used to simulate focused Gaussian beam propagation through multiple inhomogeneous biological cells. The studies involving the propagation of Gaussian beams mainly focus on the propagation in isotropic medium, based on scalar theory and paraxial optics. For this work, the ProVision beams from 98 to 230 MeV were reproduced with the Monte Carlo code FLUKA, 12, 13 by adapting the simulated beams to the commissioning experimental beam data. 2 fit to Gaussian beam. The result of propagation of two shifted'' Gaussian beams, both incident parallel to the axis of the waveguide is shown in Fig. This is why you remain in the best website to look the amazing books to have. The transfer matrix between. With BeamLab you can solve a wide range of different beam propagation and waveguide analysis problems. Basic GUI for Beam Propagation Method for advancing gaussian beam in a profiled medium. Class definition for k-Wave linear array transducer. A simulator is designed in MATLAB code which gives the propagation characteristics of a general-type beam in turbulent atmosphere. Project 1: Efficiency Optimization and Angular Misalignment Analysis of Interlayer Grating Couplers. Ablation with the top-hat beam profile provides relatively smaller rim heights and hence beam reshaping might be a beneficial technique for creating low rim craters with size smaller than 10 μm. TAKE SUITABLE VALUES FOR ALL THE PARAMETERS INVOLVED IN THE EQUATION keeping all the parameters constant except time,vary the time and plot the graph for this equation of gaussian wave propagation in a optical fiber. OPTI 600G: Laser Beams and Resonators. Engineering Science Courses ENSC 100W - Engineering, Science and Society (3). reason of getting zero answer. Interference and Diffraction. Your codes give us a shape like the above figure but firstly we have to use Trapz and then plot it. MATLAB code for Doping Propagation in a Large Planar LEC. We de ne beam quality as the ratio of the aberrated beam dimension to the di raction limit, i. MATLAB Central contributions by Natan. No matter how many lenses you use to focus and defocus your laser beam, it will remain Gaussian. Then you can start reading Kindle books on your smartphone, tablet, or computer - no Kindle device required. The book also includes examples of MATLAB and FORTRAN computer programs for numerical evaluations. As shown in the textbook LASERS of Siegman the effect of misalignments can be described by the use of 3x3 matrices Here E and F are derived from the parameters Δ1(2) describing the misalignmet of the element These 3x3 Matrices also can be cascaded to describe the propagation of a gaussian beam through any sequence of cascaded, and individually. 7345) Wave propagation 1. 4 Focused Gaussian beam 5. It's free to sign up and bid on jobs. The receiver sensitivity is -17 dBm. The transverse modes of the incident Bessel-Gaussian beam were created from a Gaussian beam of a Ti:sapphire laser system by using computer generated hologram techniques. 1displays the variation ofEagainst propagation length for all possible beams supported byEq. Army Research Laboratory Attn: AMSRD-ARL-SE-EO 2800 Powder Mill Road. No matter how many lenses you use to focus and defocus your laser beam, it will remain Gaussian. • Point wise addition of the complex field contributions from each beam. In the free space between lenses, mirrors and other optical elements, the position of the beam waist and the waist diameter completely describe the beam. Because a high order Bessel-beam is a hollow beam with many rings, a Gaussian annular aperture is introduced to restrict the beam where b is the radius of the annular. It's free to sign up and bid on jobs. As a result, these simplified models are insufficient to characteriz e the propagation properties of optical beam waves through the turbulent channels, particularly for the case of PCB, whereby focusing an d diverging characteristics are important [9]. write a simple code in Matlab or other compilers. zinenko, v. As this Optical Planar Waveguide Matlab Code, it ends stirring brute one of the favored book Optical Planar Waveguide Matlab Code collections that we have. 0 (25 Mar 2018): Addition of xrtGlow – a 3D beamline viewer. is the radial distance from the center. In this section, we present an example of simulation of the nanocircuit shown in Figure 2(a) fed by the Gaussian beam depicted in Figure 3. Dark soliton has a unique property, in which the soliton amplitude vanishes during propagation in various media 15. This simply is the optical axis. Fiber Optics Couplers Planar Waveguides Freespace Optics Imaging Mode Converters. This will allow a time-varying sea-surface to be simulated to estimate the losses [1]. Question: Write A MATLAB Function To Plot (a) The Shear Force Diagram (SFD) And (b) The Bending Moment Diagram (BMD) For A Beam With One Concentrated Point Load And An Applied Moment. 16, equation 3. Tilts, offsets of beam and components accounted for. by Franceso Onorato About this worksheet: This PTC Mathcad calculation shows how to design a warehouse based on a steel beam. 38) By using equation 3. For example, using an NA of 0. 2 Check boundaries 5. 2 Interferometric Autocorrelation of a Chirped Gaussian Pulse Complex envelope of a Gaussian pulse A(t)=exp ∙ − 1 2 µ t tp ¶ (1+jβ) ¸. An axial doughnut beam was formulated and implemented in FDTD simulations, along with a corresponding focused Gaussian beam to simulate a ﬂuorescence excitation beam. Title: Quasi-optical Gaussian beam tracing to evaluate Doppler backscattering conditions: Authors: Honoré, C. Propagation of optical waves in isotropic media, waves in homogeneous and inhomogeneous media, absorption and dispersion of homogeneous medium, optical scattering. Eyyuboğlu, “Hermite-cosine-Gaussian laser beam and its propagation characteristics in turbulent atmosphere”, Journal of the Optical Society of America A ( JOSA A) , 22 (8), 1527-1535 (2005). But if we tilted the beam, the Chief ray would go off and keep track of where the center of the beam is. I'm stuck trying to figure out what the general. elliptical or circular Gaussian beams suﬀer an inherent trade-oﬀ between light-sheet thickness and area over which this thickness is preserved. To initiate the beam, create a gaussian beam. MATLAB Codes for Finite Element Analysis - Solids and Structures Ferreira. 2 (Release 2006a). Design and Simulate Optical Waveguides with 3D Scalar, Nonparaxial Beam Propagation Method Module Overview. Design, Optimize and Fabricate Reliable Imaging Optics Overview. 2mrad (y-z Direction). The domain Ω is the square [−0. As shown above, such ring of light can be obtained by masking a gaussian beam. 81 mm and divergence 1. added feature : o `cav' will give some more information about the cavity: Finesse, FSR, FWHM (also checked against OptoCad). Source: Greynolds, Alan W. The National Institute for Standards and Technology (NIST) and the International Standards Organization (ISO) are in the process of establishing standards for laser beam quality measurement. fdt, initial_field. Notaroˇs MATLAB codes for the problem, or with the resulting graphs and movie snapshots, so that readers can see • Computation and visualization in MATLAB of angular dispersion of a beam of white light into its. A general formulation is given in a modular matrix form to represent the Gaussian beam propagation with multiple interfaces. The paraxial wave equation for beam propagation, Gaussian beam solution and the complex beam parameter in free-space, the Guoy phase-shift. I’m assuming you’re working with a laser here so beam waist ~1mm, and distance to waist is the distance from your reference plane to the narrowest point of the beam. Martins, P. Propagation of ocular wavefronts --7. Matlab code for wavefront propagation --Appendix D. fdt) material files, written by the user (i. Enable simulate tightly focused Gaussian beams. Harris, Applied numerical methods for engineers using MATLAB and C ( Cengage Learning, 1999), ISBN: 0-534-37014-4. For n = m = 0, a Gaussian beam is obtained. 30 synonyms for turbulence: confusion, turmoil, unrest, instability, storm. World's Best PowerPoint Templates - CrystalGraphics offers more PowerPoint templates than anyone else in the world, with over 4 million to choose from. Doornekamp (5986990) Supervisor: N. The BPM results agree well with analytical solutions. 1 Beam Output The Beam Divergence Is About 0. Free Codes For Animated Profile View In Orkut Codes and Scripts Downloads Free. (4) to ray propagation in nonuniform photonic crystals. The generated graph simulates the propagation of a Gaussian beam through a nonlinear medium. The parameter ω 0, usually called the Gaussian beam radius, is the radius at which the intensity has decreased to 1/e2 or 0. 4 Gaussian Beam Optics and MATLAB Examples 97 2. 05:3; plot(x, gaussian(x)); will plot a normalised Gaussian distribution. 2 Dimensional Wave Equation Analytical and Numerical Solution This project aims to solve the wave equation on a 2d square plate and simulate the. Most laser beams. The results of these studies may in some cases be applied for uniaxial crystals, as when a transmitted Gaussian beam is applied to the surface of a uniaxial crystal, the beam will be. Syntax transducer = kWaveTransducer(kgrid, settings) Description kWaveTransducer is the class definition for k-Wave transducer objects which can be substituted for the source or sensor inputs when using kspaceFirstOrder3D. li_6_3_2 Analysis of Gaussian beam and transmission characteristics based on matlab. 1 q-transformation of Gaussian beams 99 2. Question: Laser Description This Is A TEMOO Emitting A Transverse Beam With A Pure Gaussian Distribution Of Energy Profile. The beam propagates in the z direction, so that an "on axis" beam (specified by x 0 = 0 and y 0 = 0) would pass through the centre of the sphere. 更多相关文档 【Book】Laser beam propagation through random media. include simulate Gaussian Beam propagation call PreDesigner. de 2019 - Through a combination of matrix optics fundamentals, with the representation of light waves by gaussian beams, we evaluated the feasibility of using optical cavities for the design of laser propulsion systems. Using MATLAB, you can analyze data, develop algorithms, and create models and applications. , SPIE 2014. 1 Beam Output The Beam Divergence Is About 0. The dark and Gaussian beams propagate inside the system with a central wavelength of λ 0 = 1. ABSTRACT (maximum 200 words) This research involves numerical modeling of acoustic signals through shallow water channels. 1 Wave Propagation in a Linear Inhomogeneous Medium Ill 3. The standard picture used for THz beam propagation is that used extensively in optics. Search for jobs related to Gaussian elimination backward substitution matlab code or hire on the world's largest freelancing marketplace with 15m+ jobs. 4 Gaussian Beam Optics and MATLAB Examples 97 2. MATLAB Codes for Finite Element Analysis - Solids and Structures Ferreira. This year we have begun integrating a surface scatter tool into the ESME time-series simulator. PROGRAM ELEMENT NUMBER 5d. As a result, these simplified models are insufficient to characteriz e the propagation properties of optical beam waves through the turbulent channels, particularly for the case of PCB, whereby focusing an d diverging characteristics are important [9]. our desired criteria of a continuous phase screen creating a tear after propagation. 00379678 R -1. zinenko, v. Pritchett 5f. Point Source Rays emerge from a single point, with number controlled by the "Ray density" slider. 3 Example 1: MATLAB Code for 31 (3) Calculating Diffraction with the Fast Fourier Transform 1. A custom MATLAB code was implemented based on the convolution algorithm applied to the Fresnel diffraction integral 47 to compute the propagation of an OAM beam impinging on the multiplier/divider. Examples of simulations using MATLAB are shown in the two figures. Ellerbroeka and G. In order to obtain an appreciation for the above picture, we should. Gaussian beams is a beautiful phenomenon in optics. Dark soliton has a unique property, in which the soliton amplitude vanishes during propagation in various media 15. This is why you remain in the best website to look the amazing books to have. Answered: Husnain Shabbir on 26 Jan 2020. World's Best PowerPoint Templates - CrystalGraphics offers more PowerPoint templates than anyone else in the world, with over 4 million to choose from. 1 Beam Output The Beam Divergence Is About 0. We found that filament propagation length increased with. 2 R 0z z w z w 1 ⎟⎟ ⎠ ⎞ ⎜⎜ ⎝ ⎛. These are the code examples used in the ". 4 Gaussian Beam Optics and MATLAB Examples 97 2. GaussianBeam computes the profile propagation of a Gaussian laser beam through a set of lenses. Links on Optical Design and Engineering The purpose of this site is to provide a comprehensive list of links related to optics and optical simulation in general. The Monte Carlo technique is a flexible method for simulating light propagation in tissue. This is why you remain in the best website to look the amazing books to have. include simulate Gaussian Beam propagation call PreDesigner. In this paper we have used Gaussian pulse and Super-Gaussian pulse varying chirp, gamma, input power, soliton order in Matlab simulation to analysis pulse broadening ratio. This Demonstration simulates Gaussian beam propagation and transformation by two lenses. For these beams, the M 2 parameter is unity. The fiber will support the propagation of only certain mode types. To further validate the simulation scheme and codes, splice losses are simulated based. In this Demonstration the initial beam waist is 100m. Assuming polarization in the x direction and propagation in the +z direction, the electric field in phasor (complex) notation is given by: (,) = ^ (− ()) (− (+ − ())) ,where. We plotted the branch points on top of the phase of the beam using the following Matlab code. 星级： 790 页 Nonlinear hot-image formation of an intense laser beam in media with gain and loss. {\displaystyle q(z)=z+iz_{\mathrm {R} }\. This simply is the optical axis. However, even the exercises with TUTORIALS can be assigned for homework and classwork for students, as. The studies involving the propagation of Gaussian beams mainly focus on the propagation in isotropic medium, based on scalar theory and paraxial optics. beam propagation method free download. Step 3: Coherent superposition • OPL of central ray is added as phase factor on each beam. DISTRIBUTION CODE A 13. Question: Laser Description This Is A TEMOO Emitting A Transverse Beam With A Pure Gaussian Distribution Of Energy Profile. 2: A Bessel beam is formed after an incident plane wave passes through a conical lens. ASAP® PRO combines the design power in the standard edition of ASAP with sophisticated features for modeling coherent systems, including Gaussian beam propagation, finite-difference beam-propagation, double-precision ray tracing, and polarization ray tracing. We de ne beam quality as the ratio of the aberrated beam dimension to the di raction limit, i. 1displays the variation ofEagainst propagation length for all possible beams supported byEq. (1987) showed that certain types of beams could propagate without. IEEE Antennas and Propagation Societ. 5,0); lambda_z = linspace(-1,1,100); a = gaussian_prop(ag,lambda_z); check waist by using propagation function beam size 0. the radiated beam have been extensively studied. 23) Interferometric autocorrelation of a Gaussian pulse IIAC(τ)=1+ ½ 2+e− β 2 2 ³ τ τp ´ cos(2ωcτ) ¾ e− 1 2 ³ τ τp ´ (10. communists take power in china chapter 33 section 2 guided reading answers, Timed. TM E/M Field MATLAB FDTD Simulation. Thus we can generalize the law of propagation of a Gaussian through even a complicated optical system. This is why you remain in the best website to look the amazing books to have. 1,5-9 Nonetheless, for the partially coherent case, analytical re-sults are restricted mainly to so-called Gaussian Schell-model (GSM) beams,6,10,11 twisted GSM beams,12-14 and further incoherent superpositions of Gaussian modes. The Wave Optics Module includes a specialized beam envelope method that can be used to simulate optically large devices with far fewer computational resources than traditional methods. Notaroˇs MATLAB codes for the problem, or with the resulting graphs and movie snapshots, so that readers can see • Computation and visualization in MATLAB of angular dispersion of a beam of white light into its. M2y Beam propagation ratio M2 in yz-plane, double Cy Coeff. The transverse modes of the incident Bessel-Gaussian beam were created from a Gaussian beam of a Ti:sapphire laser system by using computer generated hologram techniques. UCL - London's Global University. Links on Optical Design and Engineering The purpose of this site is to provide a comprehensive list of links related to optics and optical simulation in general. 135 of its axial, or peak value. FavoriteFavorite Preview code View comments Description Using the MATLAB simulation of Gaussian propagation in the atmosphere, you can observe some specific parameters, you can modify, you can see the beam waist, the distribution and changes of light intensity. marciniak, v. Spectral Solution of the Helmholtz and Paraxial Wave Equations and Classical Diffraction Formulae 5c. A parallel beam of rays emerges from a line-segment, with density controlled by the "Ray density" slider. Andrews et al. The BPM results agree well with analytical solutions. The Fortran Source Codes For The Focused Beam Case. In this Demonstration the initial beam waist is 100m. fdt) material files, written by the user (i. Lateral resolution is typically governed by Gaussian beam propagation, focusing, beam scanning pattern, and aberrations of the OCT optical system and the eye, while axial resolution depends primarily on the coherence length of the light source, along with dispersion and absorption in the optical system. These are the code examples used in the ". APPLICATION IN EDGE-EMITTING SEMICONDUCTOR LASER-BASED LIDAR SYSTEMS and MATLAB codes are developed to solve for the unknown quantities of the optical systems. The transfer matrix between. /2r (z))+it (z)): intensity=absE (r,z)^2; keeping all the parameters constant except time,vary the time and plot the graph for this equation of gaussian wave propagation in a optical fiber. Project: Elastic wave propagation in 2-D using a staggered grid method The goal is to write a Matlab code that implements a rst order time, second order space accurate, staggered grid, nite di erence approach to solving the elastic wave equation for a perfectly elastic, isotropic medium in a velocitystress formulation. fdt, optical_pump. 1 Tilt An optical beam can be steered in a propagation simulation by applying a \u201ctilt\u201d to the beam wavefront. Pritchett 5f. The propagation of a Gaussian beam in vacuum is calculated with a FDTD code, called IPF-FDMC. Analysis of Laser Light Propagation in a Maritime Environment The MATLAB code used in this project accomplishes several things Gaussian beam, using screen set 1, at a distance of 50 meters, the variance of intensity was reduced in half or more of the 6 trials. Dear all, Ii is well know that Monte carlo method to simulate photons behavior in tissue, but how can i simulated a gaussian laser beam propagation in tissue ,just like "Light-sheet microscopy in. Algorithms are based on the scalar theory of diffraction. Lateral resolution is typically governed by Gaussian beam propagation, focusing, beam scanning pattern, and aberrations of the OCT optical system and the eye, while axial resolution depends primarily on the coherence length of the light source, along with dispersion and absorption in the optical system. 2mrad (y-z Direction). Preface to the Second Edition It has been over 15 years since the ﬁrst edition of this book was published. This simply is the optical axis. Have used a Gaussian source with 45 degree polarization angle so that there are equal Ey and Ez. This will allow a time-varying sea-surface to be simulated to estimate the losses [1]. Here you can find a few selected examples. Accelerated Weeks Method for Numerical Laplace Transform Inversion Author: Patrick O. Basic GUI for Beam Propagation Method for advancing gaussian beam in a profiled medium. Beam Propagation in Inhomogeneous Media 3. Such A Beam Is Desirable Because It Can Be Focused Onto A Small Area. 1mrad (y-x Direction) By 0. After hitting OK, the "Paraxial Gaussian Beam Data" window gives Gaussian beam characteristics on all surfaces Note 2. (d) z -Component of the electric near field in a graphene layer on SiO 2 (i. 5 Gaussian beam optics 1. 00 out of 5 € 9; MATLAB Code for Forward Communication Artificial Bee Colony € 9; MATLAB Code for Gaussian Beam Modeling of the Triplet GRIN Design MATLAB ONE 2011-2019. REFERENCES: R. I am trying to build my own raytracing code in MATLAB (for a 2D medium to solve source-receiver raypath) and need one to check my results. One of the new capabilities included in this module is the groundbreaking beam envelope method for electromagnetic full-wave propagation. Both embedded and true Gaussian modes will be given. ; Quéméneur, A. The beam propagates in the z direction, so that an "on axis" beam (specified by x 0 = 0 and y 0 = 0) would pass through the centre of the sphere. Creating a Bessel beam. Dark soliton has a unique property, in which the soliton amplitude vanishes during propagation in various media 15. 7345) Wave propagation 1. We have chosen z= 0 at the beam waist. Basically, the wave front of a beam (such as Gaussian beam) can be distorted if propagates through a turbulent atmosphere (or an imperfect optical system). 4 Gaussian Beam Optics and MATLAB Examples 97 2. Say you want to make a. A quick and efficient way of analyzing the beam design is developed through MATLAB code which can be use to solve beam design problems faster and errorless REFERENCES [1] Matlab Software releases 2007b [2] [7] Rajput, R. The transverse (-) intensity distribution of the beam is given by. The period in this case is AB, and the beam divergence 1/A; thus, the core start occurs at distance Z = A2B. Also the direct simulation of an ideal optical “black hole” is available. The MATLAB codes for the collimated Gaussian beam case. If these values are not specified, the magnitude is normalised and values of variance = 1 and mean = 0 are used. 446 Wavelength: 1. The RCWA-EIS method, implemented in Matlab and solving problem analytically, is 2000 times faster than 2D FDTD, e. Microwave Bessel-Beam Propagation through Spatially Inhomogeneous Media A Thesis Presented by Ryan F. Free Codes For Animated Profile View In Orkut Codes and Scripts Downloads Free. MATLAB Codes for Finite Element Analysis - Solids and Structures Ferreira. The focal lengths of lens 1 and lens 2 are 50mm and 100mm respectively. Beam matlab code. i need a Matlab code using Gerchberg saxton algorithm, to generate a phase mask for Laguerre 1 answer below » Problem specification Design a system that uses a phase mask with up to 256 phase levels between 0 and 2p, to generate a pure Laguerre-Gaussian mode, given a single-mode fibre input. Does your plot fit with what you learned about Gaussian laser beams in Lab 3? Hand in your code along. The dark and Gaussian beams propagate inside the system with a central wavelength of λ 0 = 1. A Gaussian source defines a beam of electromagnetic radiation propagating in a specific direction, with the amplitude defined by a Gaussian cross-section of a given width. OBJECTIVES. • Consider a Gaussian beam that at z=0 has the transverse distribution ( ) 2 2 0 0 2 0 1,0 , r Ur e w w − = (5. Its intensity is maximal on the optical axis, which makes the optical power and intensity nicely concentrated;. Theory and Simulation. 1mrad (y-x Direction) By 0. The required incident beam parameters can be calculated using the fiber's MFD with the Gaussian beam propagation model. For example, a lens comprised of two surfaces. The color is proportional to surface height. van Druten Daily supervisor: S. are an important family of solutions of the paraxial wave equation. Also the direct simulation of an ideal optical “black hole” is available. The BPM code is ﬁrst tested by calculating the following: 1) the far-ﬁeld light power density of a Gaussian beam propagating in free space; 2) the LP 01 modes; and 3) the butt–joint splice losses. 0 Added: April 08, 2013 | Visits: 259 Basic GUI for Beam Propagation Method for advancing gaussian beam in a profiled medium. A general formulation is given in a modular matrix form to represent the Gaussian beam propagation with multiple interfaces. 05:3; plot(x, gaussian(x)); will plot a normalised Gaussian distribution. The transfer matrix between. (updated 6 July 2018) BELLHOP User's Guide/Manual (rough draft) (31 January 2011) Description of BELLHOP algorithm. The main beam in Figure 2 is centered at 90 degrees. I'm stuck trying to figure out what the general. li_6_3_2 Analysis of Gaussian beam and transmission characteristics based on matlab. • Point wise addition of the complex field contributions from each beam. on the propagation of a common depletion beam used in STED microscopy and how scattering impacts the image obtained with a STED microscope. In the free space between lenses, mirrors and other optical elements, the position of the beam waist and the waist diameter completely describe the beam. Project High Frequency Methods Instructor: Tanushev and Ty 2 [φ](x) is the second order Taylor polynomial of φabout the point yas a function of x. write a simple code in Matlab or other compilers. 16, equation 3. 7 results in a Bessel beam which is 200 nm wide and 5000 nm long (single-photon). A Thermo-Optic Propagation Modeling Capability Karl N. DISTRIBUTION CODE A 13. We have also added another 3D ray tracing model (Under Sea Modeling Library/ Sean Reilly/URI) and a 2D beam tracing code (TRACEO/Orlando Rodriguez and Emanuel Ey/U. Eyyuboğlu, “Hermite-cosine-Gaussian laser beam and its propagation characteristics in turbulent atmosphere”, Journal of the Optical Society of America A ( JOSA A) , 22 (8), 1527-1535 (2005). The Matlab code can be downloaded here. This will yield an identity. Laser theory teaches us that by design, most laser beam should have a Gaussian beam shape. -- (Press monograph ; 199) Includes bibliographical references and index. The sound is computationally modeled in a vertical plane as a dense fan of beams radiating from the transmitter location. This is absolutely crucial to understanding the parameters that affect RF performance. An ideal resource for students taking graduate level courses in nonlinear optics, Laser Beam Propagation in Nonlinear Optical Media can also be used as a reference for practicing professionals. 7 results in a Bessel beam which is 200 nm wide and 5000 nm long (single-photon). limiting forms of the lowest-order Gaussian-beam wave model [6]. Based on the theory presented above, we developed a MoM code in Matlab to analyze the nanocircuit shown in Figure 2. Book Description. The parameter w0 denotes the beam waist radius. Enable simulate tightly focused Gaussian beams. That is, a collimated beam will never change size and a diverging beam will retain the same divergence everywhere. that describes the optical field, that is, the amplitude of the electric field in a laser beam propagating along. Holography is the only truly three-dimensional imaging method available, and MATLAB has become the programming language of choice for engineering and physics students. The code and the manual can also be used as an educational tool to understand how internally FFT. In this paper we have used Gaussian pulse and Super-Gaussian pulse varying chirp, gamma, input power, soliton order in Matlab simulation to analysis pulse broadening ratio. 1 Wave Propagation in a Linear Inhomogeneous Medium Ill 3. 2 Gaussian Beams We consider a fundamental laser beam with a linearly polarized, Gaussian ﬁeld distribution in the beam waist E(x′,y′,0) = E 0 e −(x′2+y′2)/w2 0, (7. Download MATLAB code: autoself. PULSE CHARACTERIZATION 10. If we compute the integral over a cross section of a Gaussian Beam or over the spherical surface, both results should be the same (I think ??) To test so, I wrote a code to get the electric field on both regions (code below), and I'm here looking for help of how to integrate electric field on both scenarios. Lateral resolution is typically governed by Gaussian beam propagation, focusing, beam scanning pattern, and aberrations of the OCT optical system and the eye, while axial resolution depends primarily on the coherence length of the light source, along with dispersion and absorption in the optical system. Let’s look at the coupling from the beam into the fiber when a M-20X objective lens is used in an F-915 or F-915T fiber coupler. More resultsMy MATLAB implementation of propagation through a index profile as shown in. An ideal resource for students taking graduate level courses in nonlinear optics, Laser Beam Propagation in Nonlinear Optical Media can also be used as a reference for practicing professionals. I've been tasked with writing a code (in MatLab, but I'm currently using Mathematica because I don't know MatLab %\ ) to simulate the propagation of a Gaussian beam. Whereas most books solely address the theory behind these 3D imaging techniques, this monograph concentrates on the exact code needed to perform complex mathematical and physical. Gaussian_Propagation Propagates a Gaussian beam through a series of thin lenses After some lengthy calculations using gpus in Matlab (2015b, cuda7), I have saves. Sign up Raytracing with Matlab. Grecco to The Faculty of the Graduate College of The University of Vermont In Partial Fullﬁllment of the Requirements for the Degree of Master of Science Specializing in Electrical Engineering May, 2017 Defense Date: September 21, 2016. This tool can be useful for people who have access to astronomical data of such an instrument. The parameter ω 0, usually called the Gaussian beam radius, is the radius at which the intensity has decreased to 1/e2 or 0. Propagation of Laser Beam - Gaussian Beam Optics 1. Burridge, Eulerian Gaussian beams for high frequency wave propagation, Geophysics 72 (2007) SM61-SM76], we develop a new Eulerian Gaussian beam method which uses global Cartesian coordinates, level-set based implicit representation and Liouville. 1mrad (y-x Direction) By 0. 1 Review Downloads: 38 This Week Last Update: 2013-11-26 See Project. Gained fundamental knowledge in electromagnetic theory, millimeter-wave and microwave circuits, propagation and focusing of Gaussian beams, ray tracing, microwave network analysis using scattering parameters, antenna/array design Performed computer-aided design, modeling and analysis using MATLAB and HFSS. 135 of its axial, or peak value. write a simple code in Matlab or other compilers. What to use for gaussian beam simulation? numpy and scipy are libraries you can add that make Python roughly equivalent to Matlab. June 19, 2020 June 21, 2020 by Ambi Subramanian Ph. The problem of propagation inside a parallel-plate waveguide is used for this purpose. That input Gaussian will also have a beam waist position and size associated with it. 21 provides a way to propagate this type of field. via a Gaussian integral factor). • provide these predictive capabilities for both pressure and particle velocity sensors. This year we have begun integrating a surface scatter tool into the ESME time-series simulator. These can be used for STED and fiber coupling applications to shape the propagation modes as desired. Question: Laser Description This Is A TEMOO Emitting A Transverse Beam With A Pure Gaussian Distribution Of Energy Profile. ) through the grating center. These are the code examples used in the ". Cheats For Free Dog Treats In Wild Ones Codes and Scripts Downloads Free. 00 out of 5 € 9; MATLAB Code for Forward Communication Artificial Bee Colony € 9; MATLAB Code for Gaussian Beam Modeling of the Triplet GRIN Design MATLAB ONE 2011-2019. , Yariv's Quantum Electroncs). Lepoutre Assessor: H. Mathematical description of beam propagation, description of changing variables 6. This mode is called the fundamental mode or axial mode , and it has the highest beam quality with an M 2 factor of 1. = 0 (so-called Gaussian beam or TEM. The waist (minimum width) of the focussed Gaussian beam is located at (x 0, y 0, z 0) where the half width of the beam is defined by ω 0. Introduction Within the frame of the linear approximation, the properties of the rays travelling through an optical system can be treated with an elegant and powerful matrix formalism [1,2]. 1, where the dashed line represents the tilted wavefront of the beam and the arrow indicates the intended direction of propagation. I've been tasked with writing a code (in MatLab, but I'm currently using Mathematica because I don't know MatLab %\ ) to simulate the propagation of a Gaussian beam. 1000 Threads found on edaboard. COUPLING EFFICIENCY AND ALIGNMENT SENSITIVITY OF SINGLE. Using a computer program such as MATLAB or Mathematica, make a 2D plot of the intensity of the laser beam in the region of the beam waist with r ranging from -20μm to 20μm and with z ranging from -100μm to 100μm. Affiliation: AA(Laboratoire de Physique et Technologie des Plasmas, CNRS (UMR 7648), École Polytechnique, F-91128 Palaiseau cedex, France), AB(Laboratoire de Physique et Technologie des Plasmas, CNRS (UMR 7648), École Polytechnique, F-91128. A Gaussian intensity profile is assumed with constant phase across the. These are the code examples used in the ". It is worth mentioning specifically monograph [1] and papers, e. OSCAR is mainly intended for people who want to quickly simulate only one cavity with non Gaussian fundamental eigenmodes or input beam. Here is a Gaussian beam propagating through space. The expansion of the beam may be accounted by a beam spot that increases with z, although the exact dependence is yet to be determined. Examples of simulations using MATLAB are shown in the two figures. When a beam is focused by an aspheric lens, the input beam is transformed into a central Gaussian spot (on the optical axis) and side fringes, which represent the unwanted "noise" (see Figure 2 below). Question: Write A MATLAB Function To Plot (a) The Shear Force Diagram (SFD) And (b) The Bending Moment Diagram (BMD) For A Beam With One Concentrated Point Load And An Applied Moment. 2 Gaussian Beams We consider a fundamental laser beam with a linearly polarized, Gaussian ﬁeld distribution in the beam waist E(x′,y′,0) = E 0 e −(x′2+y′2)/w2 0, (7. Download GaussianBeam for free. MATLAB Codes for Finite Element Analysis - Solids and Structures Ferreira. This is a rather speci c example of how an optical medium can guide light energy. 更多相关文档 【Book】Laser beam propagation through random media. $\begingroup$ @Sycorax I think this may be in reference to the more generic "Gaussian function", which in some contexts need not be normalized (i. where k=2 \pi/\lambda for wavelength \lambda in vacuum. Figure 14b: Fields propagated in a bent thin film wave guide calculated using beam Propagation method. Example of Fraunhofer diffraction patterns, sample 2D BPM code in Matlab for Gaussian beam propagation, diffraction by a planar object. The paper aims at presenting a didactic and self-contained overview of Gauss-Hermite and Gauss-Laguerre laser beam modes. 1mrad (y-x Direction) By 0. I am trying to build my own raytracing code in MATLAB (for a 2D medium to solve source-receiver raypath) and need one to check my results. Likewise, Cosh-Gaussian (ChG) beams have been also studied [15], [16]. w (z)^2)- (i*Kz) (-i* (k*r^2). The book also includes examples of MATLAB and FORTRAN computer programs for numerical evaluations. •Please try to use the given definitions of input / output variables in your functions, that makes it easier to check the solution. At 2ω 0, or twice the Gaussian radius, the intensity is 0. 2 MATLAB example: propagation of a Gaussian beam. 5%) of its peak value when measured in a plane that is orthogonal to the optical axis. From this sheet, an optical baseline can be built at one of the following levels: a one-dimensional model with matrix laboratory (MATLAB), select nonlinear optics (SNLO) or Gaussian beam propagation (the LASCAD model), a ray-tracing code including diffraction effects (such as ZEMAX’s, for example), and the BPM including nonlinear effects with. Spectral Solution of the Helmholtz and Paraxial Wave Equations and Classical Diffraction Formulae 5c. Dear all, Ii is well know that Monte carlo method to simulate photons behavior in tissue, but how can i simulated a gaussian laser beam propagation in tissue ,just like "Light-sheet microscopy in. To characterize the Bragg laser beam, we used a CCD camera (Thorlabs BC106N-VIS). For Gaussian beam, it's on the axis with its ray parallel to the axis, or its angle parallel to axis. Design and Simulate Optical Waveguides with 3D Scalar, Nonparaxial Beam Propagation Method Module Overview. The camera was operated in rolling shutter mode thereby creating a virtual confocal slit. It is shown that the propagation and transformation of a simply astigmatic Gaussian beam by an optical system with a characteristic ABCD matrix can be modeled by. BPM_free_space. engineering optics with matlab Download engineering optics with matlab or read online books in PDF, EPUB, Tuebl, and Mobi Format. Beam Propagation in Inhomogeneous Media 3. Furthermore, the modes that are excited in the. In order to obtain an appreciation for the above picture, we should. in matlab; Matlab pct integration with rtda in matlab; Dream (discrete representation array modelling) toolbox in matlab; Beam propagation method for advancing gaussian beam in a profiled medium in matlab. Shown is only the positive value of the wave electric field pointing out of your monitor. New observation on Seismic anisotropy in subducting slabs inferred by non-double-couple earthquake radiation patterns, Fall AGU. 1 Standard Hop 5. the propagation model is valid when the beam is cropped at or greater than the. In our case, the ray travels from the medium to air. Question: Laser Description This Is A TEMOO Emitting A Transverse Beam With A Pure Gaussian Distribution Of Energy Profile. 5 Terminate? 5. 21 provides a way to propagate this type of field. As shown in the textbook LASERS of Siegman the effect of misalignments can be described by the use of 3x3 matrices Here E and F are derived from the parameters Δ1(2) describing the misalignmet of the element These 3x3 Matrices also can be cascaded to describe the propagation of a gaussian beam through any sequence of cascaded, and individually. 0080 (Geometrical optics). discussion of Gaussian beam theory, parts of which have been modiﬁed and incorporated into this second edition because Gaussian beams have proven to be. Keywords: Atmospheric turbulence, Gaussian beam, Modified von Karman spectrum, split-step beam propagation method, random phase screen. The design of optical delivery systems for laser systems is highly dependent on the laser's beam quality. 这个问题属于比较复杂的 3-D GAUSSIAN BEAMS 传播问题，请你参考下面的论文。希望你能把参考论文之后编写出来的程序给大家分享交流。 2003 Laser and Gaussian Beam Propagation and Transformation. It is shown that the propagation and transformation of a simply astigmatic Gaussian beam by an optical system with a characteristic ABCD matrix can be modeled by. Basic GUI for Beam Propagation Method for advancing gaussian beam in a profiled medium. 30 synonyms for turbulence: confusion, turmoil, unrest, instability, storm. In (1), we configure OpenCensus to export to Zipkin, which is listening on localhost port 9411, and all of the traces from this program will be associated with a service name python-quickstart. Fixing the focal length of the microscope objective to 1, the inner and outer radius defines the minimum and maximum angles, respectively. I don't really know anything about optics, so I'm learning on the fly using this manual kindly provided to me by my adviser. Rios USP/LAL, Bairro Butantan : Funding: Fundacao de Amparo a Pesquisa do Estado de Sao Paulo - FAPESP Conselho Nacional de Desenvolvimento Cientifico e Tecnologico - CNPq. Highlights A MATLAB-based tool (PETOOL) is introduced with a user-friendly interface. As the propagation of the beam diameter along the axis of propagation is described by a. The focal lengths of lens 1 and lens 2 are 50mm and 100mm respectively. Question: Laser Description This Is A TEMOO Emitting A Transverse Beam With A Pure Gaussian Distribution Of Energy Profile. Sign up Raytracing with Matlab. 0at one place along the beam axis, known as the beam waist. comparison ofE, for different beams and for different propagation distances. $\endgroup$ – Jon Custer Sep 7 '16 at 14:04. MATLAB Central contributions by Natan. Does your plot fit with what you learned about Gaussian laser beams in Lab 3? Hand in your code along. Gaussian Beam Propagation. We de ne beam quality as the ratio of the aberrated beam dimension to the di raction limit, i. Upon further investigation it can be seen that this plot is closely. Computer Codes for SHG Efficiency. 2mrad (y-z Direction). I built a program that simulated the motion of a double pendulum and output a variety of analysis about the motion as one of my first Matlab projects. The electric field profile was set to be Gaussian along the rectangle front side inducing a Gaussian beam (Fig. communists take power in china chapter 33 section 2 guided reading answers, Timed. A parallel beam of rays emerges from a line-segment, with density controlled by the "Ray density" slider. Wavefront radius of Gaussian beam over direction of propagation English: This diagram shows the relation between the wavefront radius of a Gaussian beam (R) and the direction of propagation (z). aperture, the out beam cross section is considered as a Gaussian beam and the receiver antenna is a circular aperture. Any comment will be welcomed. Added degree of transverse coherence to analysis methods of coherence signatures. Discussed in the literature since the 1940s and well-established in computational form since the mid-1980s, Gaussian beam decomposition is a powerful technique currently available in optical software packages from three mainstream commercial companies, who offer it as an alternative to the more traditional Fourier-based propagation techniques for calculating the optical field in an optical system. Design, Optimize and Fabricate Reliable Imaging Optics Overview. model because the other cases consider cropped Gaussian beams. Class definition for k-Wave linear array transducer. A custom MATLAB code was implemented, based on the convolution algorithm in the angular spectrum regime, in order to compute the propagation of a Gaussian beam impinging on the fanout unwrapper and therefore calculate the phase pattern of the corresponding dual phase-corrector for phase-distortion correction. A Thermo-Optic Propagation Modeling Capability Karl N. Optical Scanning Holography with MATLAB - Ting Chung Poon. FavoriteFavorite Preview code View comments Description Using the MATLAB simulation of Gaussian propagation in the atmosphere, you can observe some specific parameters, you can modify, you can see the beam waist, the distribution and changes of light intensity. Alternatively, an externally supplied amplitude distribution may be used. Gaussian beams is a beautiful phenomenon in optics. Yellow arrow indicates direction of light sheet. OCIS codes: (120. Fiber Optics Couplers Planar Waveguides Freespace Optics Imaging Mode Converters. A simulator is designed in MATLAB code which gives the propagation characteristics of a general-type beam in turbulent atmosphere. Question: Laser Description This Is A TEMOO Emitting A Transverse Beam With A Pure Gaussian Distribution Of Energy Profile. Dynamic behaviour of the optical tweezers appears when the Gaussian beam is added into the add port of the system 16. where is the propagation direction, is the time, is the electric field envelope, and. World's Best PowerPoint Templates - CrystalGraphics offers more PowerPoint templates than anyone else in the world, with over 4 million to choose from. LASER BEAM SHAPING OPTICAL SYSTEM DESIGN METHODS AND THEIR APPLICATION IN EDGE-EMITTING SEMICONDUCTOR LASER-BASED LIDAR SYSTEMS Except where reference is made to the work of other. 7 details the results of modeling two Gaussian beams of differing waist size. The receiver sensitivity is -17 dBm. 4-3 shows a series of the amplitude plots of a Gaussian beam, which propagates in the z-. APPLICATION IN EDGE-EMITTING SEMICONDUCTOR LASER-BASED LIDAR SYSTEMS and MATLAB codes are developed to solve for the unknown quantities of the optical systems. !(z)=!0 v u u t1+ z ⇡!2 0!2 (4). Dear all, Ii is well know that Monte carlo method to simulate photons behavior in tissue, but how can i simulated a gaussian laser beam propagation in tissue ,just like "Light-sheet microscopy in. operational concepts impacted by 3D propagation effects. Solving misalignments issues, and multipath problems. 1 Beam Output The Beam Divergence Is About 0. We probe the system multiple times with the same set of probing beams to avoid any systematic variance. With the help of a group of lenses, the beam was further collimated into a Bessel beam. The Hermite-Gaussian modes. We define a Gaussian beam (Fomel and Tanushev, 2009) as a seismic event characterized by a particular arrival time, location, amplitude, orientation, curvature, and extent. Using Zemax to calculate for Gaussian beam propagation is handy and precise. The required incident beam parameters can be calculated using the fiber's MFD with the Gaussian beam propagation model. As the IEEE "Standard Definitions of Terms for Antennas", IEEE 145-1983, states that a free space path loss is between two isotropic radiators. 2 MATLAB example: propagation of a Gaussian beam. A W a v e Optics Propagation Co de for Multi-Conjugate Adaptiv e Optics B. m - FFT-BPM in a Y-branch coupler. Links on Optical Design and Engineering The purpose of this site is to provide a comprehensive list of links related to optics and optical simulation in general. The tool allows for different types of light sources, including point sources, plane wave source, and multiple Gaussian beam sources. LASER BEAM SHAPING OPTICAL SYSTEM DESIGN METHODS AND THEIR APPLICATION IN EDGE-EMITTING SEMICONDUCTOR LASER-BASED LIDAR SYSTEMS Except where reference is made to the work of other. By default, the Gaussian sources use a scalar beam approximation for the electric field which is valid as long as the waist beam diameter is much larger than the diffraction. Upon further investigation it can be seen that this plot is closely. The Matlab function for refraction at a plane interface takes as input height y of the ray at the interface, slope 𝑢= tan𝜃, thickness of the lens, index of refraction n, and vector z, which is used to plot the ray in air (back of lens). Fiber Optics Couplers Planar Waveguides Freespace Optics Imaging Mode Converters. This is why you remain in the best website to look the amazing books to have. 4 Time resolved Monte Carlo propagation 5. ANY MATLAB CODE FOR GAUSSIAN BEAM PROPAGATION IN A OPTICAL FIBER. [4] propagating through optical components described by the same transmission matrices. I am trying to simulate the propagation of a gaussian beam through a lens using an FFT approach. It can be seen as a semi-analytic (making it light and fast) solver for Maxwell’s equations in multilayers. In this section, we present an example of simulation of the nanocircuit shown in Figure 2(a) fed by the Gaussian beam depicted in Figure 3. Because a high order Bessel-beam is a hollow beam with many rings, a Gaussian annular aperture is introduced to restrict the beam where b is the radius of the annular. MATLAB Codes for Finite Element Analysis - Solids and Structures Ferreira. 7345) Wave propagation 1. Gonzalez - Englische Bücher zum Genre Physik & Astronomie günstig & portofrei bestellen im Online Shop von Ex Libris. Since a Bessel-like beam, which has an annular structure,.
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Home > Not Complete > Thread 1 Cannot Allocate New Log Checkpoint Not Complete 11g

# Thread 1 Cannot Allocate New Log Checkpoint Not Complete 11g

## Contents

ARCH is the "main" culprit in this case. You had some processing happening that the shutdown "killed" and it didn't get started again. I was with a company that does processing related to credit cards. Boss sends a birthday message. Source

Checkpoint and DBWR December 08, 2005 - 6:25 pm UTC Reviewer: sushil from India Dear Tom Suddendly after increasing the number of dbwr from 4 to 6(which we did after free Database Growth History and Forecast (12c and Abov... ► June (5) ► May (6) ► April (6) ► March (7) ► February (6) ► January (20) ► 2014 (32) ► December It will register as a wait event. Hemant Shahi Aug 04, 2015, 02:14 Hello Hemant, thank you so much for your clear ...... https://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:69012348056

## Increase Size Of Redo Logs

When C is filled we switch to A. I analyse archivelog files and select from v$logmnr_contents: SQLWKS> SELECT operation,count(*) FROM v$logmnr_contents group by operation 2> OPERATION COUNT(*) -------------------------------- ---------- COMMIT 8696 DELETE 5 INSERT 5 INTERNAL 17903 START 8697 the reason: they are looking at in memory data structures typically and therefore need to latch (lock) them so they don't change a pointer or something while you are reading it. All rights reserved.

Your rating?: This reply is Good Excellent Goto: Reply-Top of page If you think this item violates copyrights, please click here Subject: Re: Thread 1 cannot allocate new log,Checkpoint not complete But also the database shutdown immediate began at 3am and didn't finish til 4.45am. Committing creation of archivelog '/arch-01/databases/admw/redolog-1113-1-583227512.arc' Invoking non-expedited destination LOG_ARCHIVE_DEST_2 thread 1 sequence 1113 host admw_b Fri Apr 7 00:44:12 2006 ARC2: Completed archiving thread 1 sequence 111ARCH: Connecting to console port... Checkpoint Not Complete Oracle 11g Sap Fri Apr 7 01:44:12 2006 ARC2: Closing local archive destination LOG_ARCHIVE_DEST_1: '/arch-01/databases/admw/redolog-1115-1-583227512.arc' (admw) ARCH: Connecting to console port...

Committing creation of archivelog '/arch-01/databases/admw/redolog-1114-1-583227512.arc' Invoking non-expedited destination LOG_ARCHIVE_DEST_2 thread 1 sequence 1114 host admw_b Fri Apr 7 01:14:14 2006 ARC2: Completed archiving thread 1 sequence 1114 (1883286549-1883328312) (admw) ARCH: Connecting In short, adding another logfile will postpone the reuse of any given logfile (by the time it takes to fill that newly added logfile). Now, given how fast the archive went -- and how long it took to catch up -- I'd be looking at "why" - perhaps you are not checkpointing frequently enough (too Asked: May 02, 2000 - 1:20 pm UTC Answered by: Tom Kyte � Last updated: October 16, 2012 - 9:29 am UTC Category: � Version: Whilst you are here, check out

Thu Jul 22 15:16:57 2004 SIMP; ARC1: Closing local archive destination LOG_ARCHIVE_DEST_1: '/u03/oradata/SIMP/arch/SIMP_531695692_1_636.arc' ARCH: Connecting to console port... Checkpoint Not Complete In Oracle 12c Followup April 21, 2005 - 12:00 pm UTC I would not use a checkpoint as my criteria for a filesize. Errata? PowerSchool uses Oracle as a backend database, and we have the need to create some of our own reporting views.

## Private Strand Flush Not Complete 11gr2

But the point would be to have sufficient redo logs configured to carry you through the peak loads without any "cannot allocate new log" messages." On one of the threads, someone http://www.oracleracexpert.com/2013/07/thread-1-cannot-allocate-new-log.html the logs were too small. Increase Size Of Redo Logs September 14, 2006 - 4:53 pm UTC Reviewer: steve Thanks Tom! Checkpoint Not Complete In Oracle 11g Alert Log dbwr is a guy that goes on in the background.

Remember, Oracle will stop processing until the checkpoint completes successfully! http://rinfix.com/not-complete/thread-1-cannot-allocate-new-log-sequence-checkpoint-not-complete.html Since it won't give you any ORA- error and the analyst from Oracle said it could bring the instance down without warnings, that why I what to ask if this is OOC, do these stats reset when you close the DB? So please I need your feedback for the following points: I will create new partition in unix server 1- we will create one partition for datafile,oracle_home,redo log, arch files, RMAN backup.. Thread 1 Cannot Allocate New Log 11gr2

Cadot 33700 3 B. The answer comes from within - do you want to initiate checkpoints that often, or not. One last thing... have a peek here [email protected]> select * from v\$sysstat where upper(name) like '%DBWR%'; STATISTIC# NAME CLASS VALUE ---------- ------------------------------ ---------- ---------- 49 DBWR checkpoint buffers writte 8 1056 n 50 DBWR transaction table writes 8

Here on dba, the only reference I could find to checkpoint not complete was this, which doesn't seem to address what I'm seeing. Checkpoint Not Complete In Oracle 10g Missing } inserted. \int dx = x + C & What is the significance of the robot in the sand? In your opinion, should I make the logs bigger, or just have more of them? (Or maybe I should do both?) Oracle 8i - if it makes any difference.

## If you have fewer redo groups then adding more redo groups will help.

1. IF the checkpoint triggered by switching out of A is not yet complete - we cannot use A right now, we must wait.
3. Do you think we should increase size from 100 to 500M?
4. We've always forced log rolls every hour, as part of our disaster recovery planning.
5. Do you have a favorite story of how Tom helped you achieve success with Oracle Database?
6. I'm getting the same error like above.
7. Welcome to DBA-Village, your primary Oracle DBA information source.Geert De Paep Forum ->Thread 78005 Home Account Register Update account Forgot password This site About Feedback Search Pirats Poll questions Change log

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# Genetic algorithm versus classical methods in sparse index tracking

Margherita Giuzio ()
Margherita Giuzio: EBS Universität für Wirtschaft und Recht

Decisions in Economics and Finance, 2017, vol. 40, issue 1, No 13, 243-256

Abstract: Abstract The main objective in index tracking is to replicate the performance of a target index by using a small subset of its constituents. Non-convex regularization techniques, such as the $$\ell _q$$ ℓ q and the log penalization, which are able to enhance portfolio sparsity by selecting a low number of active weights, recently proved to perform remarkably well in index tracking problems. The resulting non-convex optimization is NP-hard and deterministic optimization methods, such as interior point and gradient projection algorithms, may not efficiently reach the optimal solution due to the presence of multiple local optima and discontinuities in the search space. Therefore, heuristic approaches can be more helpful and easy to implement, thanks to recent hardware development. In this paper, we compare three state-of-the-art estimation techniques, i.e., the interior point, the gradient projection and the coordinate descent algorithms, to a popular heuristic method, the genetic algorithm, in index tracking optimization. We show and evaluate the performance of the four methods in a penalized framework on different simulated settings and on real-world financial data.

Keywords: Portfolio optimization; Sparsity; Heuristics; Index tracking (search for similar items in EconPapers)
JEL-codes: C15 C61 G11 (search for similar items in EconPapers)
Date: 2017
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1) Track citations by RSS feed

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# If A, B and C Have Position Vectors (0, 1, 1), (3, 1, 5) and (0, 3, 3) Respectively, Show that ∆ Abc is Right-angled at C. - CBSE (Arts) Class 12 - Mathematics

ConceptBasic Concepts of Vector Algebra

#### Question

If AB and C have position vectors (0, 1, 1), (3, 1, 5) and (0, 3, 3) respectively, show that ∆ ABC is right-angled at C

#### Solution

$\text{ Given that }$

$\vec{OA} = 0 \hat{i} + \hat{j} + \hat{k} ; \vec{OB} = 3 \hat{i} + \hat{j} + 5 \hat{k} ; \vec{OC} = 0 \hat{i} + 3 \hat{j} + 3 \hat{k}$

$\vec{BC} = \vec{OC} - \vec{OB} = - 3 \hat{i} + 2 \hat{j} - 2 \hat{k}$

$\vec{CA} = \vec{OA} - \vec{OC} = 0 \hat{i} - 2 \hat{j} - 2 \hat{k}$

$\text{ Now },$

$\vec{BC} . \vec{CA} = 0 - 4 + 4 = 0$

$\text{ So }, \vec{BC} \text{ is perpendicular to } \vec{CA} .$

$\text{ So }, ∆ABC\hspace{0.167em}\text{ is right-angled at C. }$

Is there an error in this question or solution?

#### Video TutorialsVIEW ALL [4]

Solution If A, B and C Have Position Vectors (0, 1, 1), (3, 1, 5) and (0, 3, 3) Respectively, Show that ∆ Abc is Right-angled at C. Concept: Basic Concepts of Vector Algebra.
S


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# Can somebody answer this 'Crack the code'?

Can somebody answer this? It was given to me as a challenge and I am having doubts in my answer

Text version:

2 6 5 7 - Has two correct digits but neither are in the correct place
0 4 1 5 - Has one correct digit but it's in the wrong place
4 2 6 8 - Has no correct digits
1 7 4 9 - Has two correct digits, both in the correct place

• Hi! Welcome to puzzling SE :) I would suggest to change the title to be more specific and move the current title to the question body. Also, keep in mind that you're not supposed to post homework question here if it is one. – newbie Apr 11 at 3:29
• And most definitely not riddle. No worries @newbie, I removed those tags. – Rand al'Thor Apr 11 at 3:35
• Beatriz, you say this was "given to you as a challenge" - can you please edit to include the source? – Rand al'Thor Apr 11 at 3:43

This is a tricky one, because one of the solution digits is never seen! It must be deduced by elimination.

• From the 3rd clue, we know $$2,4,6,8$$ are NOT in the solution.

• So, in the 1st clue, the correct digits must be $$5,7$$ (not $$2$$ or $$6$$), but both in the wrong place.

• So, in the 2nd clue, the correct digit must be $$5$$, again in the wrong place. That means $$0,1$$ are NOT in the solution.

• In the 4th clue, we know $$1$$ and $$4$$ are not in the solution, so it must be $$7$$ in the 2nd place and $$9$$ in the 4th place.

• We also know $$5$$ is in the solution, not in the 3rd or 4th place, so it must now be in the 1st place.

• We already used $$5,7,9$$, and we know $$0,1,2,4,6,8$$ are not in the solution, so the last digit must be $$3$$ (the only one remaining), in the 3rd place.

So the solution is

$$5739$$.

• Is there a rule that a digit can't be used more than once in the code? It seems to me that the third position could contain two other digits, if repeats are allowed. – Lanny Strack Apr 11 at 5:41
• @LannyStrack Assuming the solution has to be unique, yes ;-) – Rand al'Thor Apr 11 at 5:59
• Yet another reason why these types of clickbait puzzles are worthless. – Lanny Strack Apr 11 at 6:07

Using the old Mastermind game colors of B = correct in correct place and W = correct in wrong place, we have the following clues:

a. 2657 WW
b. 0415 W
c. 4268
d. 1749 BB

Solution:

1. From c, we know that

2, 4, 6, 8 are not in the code.

2. From 1 and a, we know that

5 and 7 are in the code, but not in the 3rd and 4th slots respectively.

3. From 2 and b, we know that

5 is in the code, but not in the 3rd or 4th slots. We also know that 0, 1 are not in the code.

4. From 1 and 3, we know that

1 and 4 are not in the code, so from d, we know that 7 and 9 are in the code and in the 2nd and 4th slots: x7x9

5. From 3 and 4, we know that

5 is in the 1st slot: 57x9

At this point, we know that the following are not in the code:

0, 1, 2, 4, 6, 8.

Now, the rules of Mastermind

allow duplicates, [see footnote]

so we cannot rule out the following:

5779
5799

Note that we cannot have

5759

because

we know from 1 that 5 is not in the 3rd slot.

Footnote:

An article in the October 1977 issue of Byte Magazine describes the tabletop Mastermind game, distributed by Invicta Plastics, that was hugely popular in the mid-1970s, and provides a BASIC implementation of the game. In giving the rules, the article states, "It is acceptable to use the same color or colors more than once." I think I have this version of the original game somewhere, probably with the original rule sheet. In the meantime, here is an image of that Byte article:

• The rules of Mastermind allow duplicates? Not the Mastermind I've always played. – Rand al'Thor Apr 11 at 6:46
• @Randal'Thor Edited with footnote – shoover Apr 11 at 7:10
• Yes, according to the official rules, you may use duplicate colors. I have a copy of the original game but not 100% sure it still has the instructions. Nevertheless, the wikipedia page on the game includes this rule in the description: en.wikipedia.org/wiki/… – 3d12 Apr 11 at 19:31
• Here's an image of the original game box cover: i.stack.imgur.com/N1XDS.jpg. It clearly states, "Use 2 or more Code Pegs of the same colour[sic] if you wish." @Randal'Thor, you had a deprived childhood. – Lanny Strack Apr 12 at 3:24
• @LannyStrack I have that box somewhere, with the game still inside. – shoover Apr 12 at 4:12

This answer is only true if you disregard the rules that the tag implies. Nothing except the tag hints that masterminds rules should apply here and usually when these things are passed around they do not come with Masterminds rules included. That tag was also not put there by the person asking the question, so I will look at only what is written on that piece of paper.

In my opinion this puzzle has technically 13 possible solutions and each one of those is equally valid.

The statements, lets call them a, b, c and d:

a - 2 6 5 7 - Has two correct digits but neither are in the correct place
b - 0 4 1 5 - Has one correct digit but it's in the wrong place
c - 4 2 6 8 - Has no correct digits
d - 1 7 4 9 - Has two correct digits, both in the correct place

Starting with c we know that 4 2 6 8 are not in the correct combination, so valid digits are 013579, lets call them X. There are 6 possible digits so we have 6*6*6*6=1296 possible combinations:
XXXX

By combining c and d we know that 4 can not be in the solution. And given that two numbers are in the correct position we can narrow the possibilities down by quite a bit. The only possible options now are:
XXXX
17XX, 1XX9, X7X9 (possible combinations of two numbers being in correct positions, excluding 4)
In total this is 6*6+6*6+6*6=108 possible solutions with these two rules.

Adding the statement a narrows it down further. 2 and 6 can not be in the solution (statement c), so 5 and 7 must be in the solution and as they are presented they are in the wrong place.
XXXX
17XX, 1XX9, X7X9
17X5, 1579, 57X9 (5 can not be in the third position)
This brings the number of possible solutions down to 6+1+6=13

This is also as low as I think it is possible to get with the given input, statement b is true regardless of the value of X. All of the 13 possible combinations of 17X5, 57X9 and 1579 where X is [0, 1, 3, 5, 7, 9] satisfy all of the statements.

I will take X=0 with both combinations that contain X for the examples(1705, 5709). Parts of the number that satisfies each statement is in bold.

a - 2 6 5 7 - Has two correct digits but neither are in the correct place
1705, 5709
b - 0 4 1 5 - Has one correct digit but it's in the wrong place
1705 , 5709 Having two improperly placed correct numbers and only stating one contradicts masterminds rules, but does not contradict the fact, that a correct digit is out of place.
c - 4 2 6 8 - Has no correct digits
1705, 5709
d - 1 7 4 9 - Has two correct digits, both in the correct place
1705, 5709

The only line where the variables X is highlighted is with statement b and that statement is satisfied regardless of what value the X has.


text:
# The transfer function of the system $$\frac{{Y\left( s \right)}}{{U\left( s \right)}}$$ whose state-space equations are given below is:$$\left[ {\begin{array}{*{20}{c}} {{{\dot x}_1}\left( t \right)}\\ {{{\dot x}_2}\left( t \right)} \end{array}} \right] = \left[ {\begin{array}{*{20}{c}} 1&2\\ 2&0 \end{array}} \right]\left[ {\begin{array}{*{20}{c}} {{x_1}\left( t \right)}\\ {{x_2}\left( t \right)} \end{array}} \right] + \left[ {\begin{array}{*{20}{c}} 1\\ 2 \end{array}} \right]u\left( t \right)$$$$y\left( t \right) = \left[ {\begin{array}{*{20}{c}} 1&0 \end{array}} \right]\left[ {\begin{array}{*{20}{c}} {{x_1}\left( t \right)}\\ {{x_2}\left( t \right)} \end{array}} \right]$$

Free Practice With Testbook Mock Tests

## Options:

1. $$\frac{{\left( {s + 2} \right)}}{{\left( {{s^2} - 2s - 2} \right)}}$$

2. $$\frac{{\left( {s - 2} \right)}}{{\left( {{s^2} + s - 4} \right)}}$$

3. $$\frac{{\left( {s - 4} \right)}}{{\left( {{s^2} + s - 4} \right)}}$$

4. $$\frac{{\left( {s + 4} \right)}}{{\left( {{s^2} - s - 4} \right)}}$$

### Correct Answer: Option 4 (Solution Below)

This question was previously asked in

GATE EE 2017 Official Paper: Shift 1

## Solution:

From the given state space equations,

$$A = \left[ {\begin{array}{*{20}{c}} 1&2\\ 2&0 \end{array}} \right]$$

$$B = \left[ {\begin{array}{*{20}{c}} 1\\ 2 \end{array}} \right]$$

$$C = \left[ {\begin{array}{*{20}{c}} 1&0 \end{array}} \right]$$

Transfer function = C[sI - A]-1 B + D

$$sI - A = \left[ {\begin{array}{*{20}{c}} s&0\\ 0&s \end{array}} \right] - \left[ {\begin{array}{*{20}{c}} 1&2\\ 2&0 \end{array}} \right] = \left[ {\begin{array}{*{20}{c}} {s - 1}&{ - 2}\\ { - 2}&s \end{array}} \right]$$

$${\left( {sI - A} \right)^{ - 1}} = \frac{1}{{{s^2} - s - 4}}\left[ {\begin{array}{*{20}{c}} s&2\\ 2&{s - 1} \end{array}} \right]$$

Transfer function $$= \left[ {\begin{array}{*{20}{c}} 1&0 \end{array}} \right]\frac{1}{{\left( {{s^2} - s - 4} \right)}}\left[ {\begin{array}{*{20}{c}} s&2\\ 2&{s - 1} \end{array}} \right]\left[ {\begin{array}{*{20}{c}} 1\\ 2 \end{array}} \right]$$

$$= \frac{1}{{\left( {{s^2} - s - 4} \right)}}\left[ {\begin{array}{*{20}{c}} s&2 \end{array}} \right]\left[ {\begin{array}{*{20}{c}} 1\\ 2 \end{array}} \right]$$

$$= \frac{{s + 4}}{{\left( {{s^2} - s - 4} \right)}}$$


text:
The Angry Homework Vampire

I seem to be attracting them lately, not just here as well.

They are the kind who come in with a homework question - you know, the kind with absolutely no attempt that screams to my cynical mind "PLZ HELP ME, DO MA HOMEWORK" kind of question - you know the type.

We give our stock standard comment about it being a homework question. I tend to use one written by @MARamezani

This is a homework question. We have a policy which states that you should show your thoughts and/or efforts into solving the problem. It'll make us certain that we aren't doing your homework for you. Otherwise, this question may get closed.

I flag it as off topic, for the homework without effort reason, normally, this is the end of it. Many members make improvements and the question becomes quite good, answerable and a worthwhile addition to the site.

Sometimes, and seemingly increasingly so, you get the ones that want to argue.

I respond with a reminder to read the policy, and lately, links to the 'Be Nice' and behaviour expectations pages in the Help Centre.

Usually at this stage there is a tired old accusation that we are closing the question due to not being able to understand it - with them cheerfully neglecting to read the expectations and to make alterations to their question to conform with the quality standards that 99% of people adhere to.

These comments are flagged and in many cases, a mod will reinforce the expectations of civility and all is calm once more.

But lately, one here and one on another site in the network - it starts to get ugly - with the user swearing, making idle threats etc. All of which are futile, not worthy of responding to and are flagged.

Is it just me, or are some of the homework vampires getting more hostile?

Just to clarify, I am not upset or hurt in anyway - just perplexed by that behaviour

• I am going to use a modified version, written by @DelPate: Welcome to Chemistry.SE. Take the [tour] to get familiar with this site. This appears to be a [homework question](http://meta.chemistry.stackexchange.com/questions/141/), please share your thoughts and attempts towards the solution. It'll make us certain that we aren't doing your homework for you. – user15489 May 25 '15 at 11:42
• I took the liberty to set some flags and guess what: the system works! Told you so ;-) – Klaus-Dieter Warzecha May 25 '15 at 16:31
• You didn't get bitten did you? – ron May 25 '15 at 22:27
• @ron lol, thankfully no – user15489 May 25 '15 at 22:58
• @KlausWarzecha absolutely! I am very impressed in how quickly this was handled! – user15489 May 25 '15 at 22:59
• @santiago The most important thing is that if it's spinning out of control, just flag and walk away. Don't try to engage further. Some people just don't get it, and they never will, so attempting to reason with them is fruitless, unfortunately. – jonsca May 25 '15 at 23:41
• @jonsca absolutely! After the comment with the 'Be Nice' and behaviour expectations links, I stop responding, but merely observe and flag – user15489 May 25 '15 at 23:57
• You made me famous!... Pfft, like I already wasn't. – M.A.R. May 28 '15 at 16:49
• So there going to be a new tag, Homework Vampire ? – bonCodigo Jul 9 '15 at 9:49
• lol, I doubt it – user15489 Jul 9 '15 at 9:50

1. Relax...

... and close the question as off-topic, just as you did.

it starts to get ugly - with the user swearing, making idle threats etc.

2. Relax...

... and flag the comments, just as you did.

So, far the system works. Some of these fellows already got suspended for a whole year. Others will follow.

3. Relax...

... and if it makes you feel better, think one of the following:


text:
# Are there any control-flow/conditional statements in AI/ML models?

I was recently asked this during an interview.

When we write a C program, it has a control-flow in the form of conditional statements like if, while, for that executes a condition, and that decides how the control flows through the application.

In AI/ML models, e.g. CNNs like ResNet, I don't see any control-flow (either static or dynamic). It's just a series of consecutive convolution layers. So,

• where are these control-flow/conditional statements in AI domain? What do they look like?
• Which models have them? Any examples?
• Please, consider marking an answer as correct if deemed so. Alternatively, please considering describing what the answer is lacking or why you think it is not correct, so that it can be improved. – noe Dec 16 '20 at 9:56

• Variable-length sequence classification with recurrent units: in text classification tasks with recurrent units (vanilla RNNs, LSTMs, GRUs), both at training and inference time, you basically iterate over the time dimension of the input batch, passing the next token and the previous steps' state to the recurrent unit. This is a for loop.
• Variable-length sequence generation: in text-generation encoder-decoder networks, at inference time the decoder generates one discrete token at a time until a special "end-of-sequence" token is generated. This is pretty much a while construction. The decoder can be based on any type of neural net units: LSTMs, CNNs, self-attention (Transformer), etc.
Control-flow stuff is more difficult to implement in declarative deep learning frameworks, like Theano or Tensorflow 1.x. In Tensorflow 1.x, there was actually a specific primitive to implemente while loops: tf.while_loop. With imperative frameworks like Pytorch or Tensorflow 2.x, control-flow constructions are far easier to implement, because you can integrate normal logic between the computations.


text:
Published on

# How to check if a file exist in a Bash Script?

Checking if a file exist or not can be easily done with the script below

if [ -f "$FILE_PATH" ]; then # If the$FILE_PATH exist, code inside the block will get executed, for example:
echo "File $FILE_PATH exist"; fi  Or to check if a file doesn't exist: if [ ! -d "$FILE_PATH" ]; then
# If the $FILE_PATH does not exist, code inside the block will get executed, for example: echo "File$FILE_PATH does not exist";
fi

Are you looking for the scenario if a directory exist or not in bash scripts?

There is also a shorthand notation to check if a file exist or not:

# Shorthand to check if a file exist

[ -f "$FILE_PATH" ] && echo "File$FILE_PATH exist";

# Shorthand to check if a file does not exist

[ ! -f "$FILE_PATH" ] && echo "File$FILE_PATH does not exist";

You can have any statement after the && symbol.

The above code is an ideal way to check if a path is a file or not.


text:
Unlimited Wordpress themes, plugins, graphics & courses! Unlimited asset downloads! From $16.50/m Advertisement # Site News: SXSW, Facebook Bonus Tuts, Contests, and More! Length:ShortLanguages: It's been a while since we released some site news for Webdesigntuts, but we've been busier than ever so it's time to check in! ## Facebook Bonus Tuts Are Here! Recently all Tuts+ sites have started making pre-release tutorials available to Facebook fans. That means if you follow us on Facebook you’ll receive a tutorial a full 30 days before it is published on the blog while everyone is still waiting. Want a free tutorial right now? It's easy, just "Like" our Facebook profile and you'll have instant access to this month's bonus tut under the "Fan Bonus" link on the left sidebar Still want more? Find all of our Tuts+ Facebook pages here: ## Bigger, Better Tuts & Articles on the Way! We've already been releasing somewhere between 6-9 "big" posts a month, but starting later this month we're making a slight change to the publication schedule by increasing this number to 8-12. In short, we're aiming to bring more of the high quality, comprehensive, in-depth tutorials and fewer of the smaller posts that tend to feel like space-fillers. You may have already noticed, but we've also been offering more video based tutorials for you visual learners as well! What does this mean for you? It means you'll be able to get your hands on a lot more useful web design tuts and videos! We're also actively scouting out big design agencies and rockstar freelance designers to guest star in their own tutorials... so you can expect to learn new and exciting tricks from the best and brightest new designers in the industry. This leads me into my next news item... ## Write For Us! We're interested in hearing from new authors, design studios, and freelance designers. We're willing to back that offer up with cold, hard cash! We're offering upwards of$500 for comprehensive tutorials or articles, so if you've got some time and a great lesson to teach, send in your ideas through our Write for Us page!

I'm specifically hoping to find a couple designers to write "complete tutorials" - meaning that you take our readers from the planning phase all the way to the coding phase in two or three sections (yep, you'll get paid accordingly!) So if you've been thinking about ponying up a tutorial, now's a great time to jump in!

## SXSW 2011 Panel

This past weekend I presented at SXSW on the panel, "Making Money with Wordpress (Without Working at Automattic). The panel included Alex King (Crowd Favorite), Shane Pearlman (Shaneandpeter.com), and Sonia Simone (CopyBlogger).

For my part, I covered the sub-topic of "commoditizing your byproduct" as a web designer, which ultimately means finding ways to resell designs as templates on sites like ThemeForest. It turns out there's quite a bit of interested in the topic, so I'll be doing some recap blogging over the next week to review the issues as they relate to web designers. We'll also be working on digging up a video if it's at all possible!

## That's It From Our Side: Give Us Some Feedback!

The great thing about the community here is that ideas flow both ways - we've covered a lot of great content so far as a result of reader feedback (from Fireworks to Design Theory), but we're always on the lookout for that next big trend that you guys/gals want to know about. If you've been looking around for an article or tutorial on a specific topic, trick, or technique, let us know in the comments here!

Are we ready for another contest? The last contest that we had helped launch our Flickr Group and introduced us to some amazing new designers. So, my question to you guys is simple: is it time for another group contest? I'm specifically thinking about a design challenge featuring prizes and portfolio exposure for the winners... but let me know what you think down below!


text:
# How to use the geneticae Shiny App

### A web application for the Analysis of Multi Environment Agronomic Trials

#### 2022-02-09

The geneticae package can be used through this Shiny app, making it available not only for R programmers. Source code is in GitHub repo.

# Motivation

Although there are R packages which tackle different aspects of MET data analysis, there aren’t any packages capable of performing all the steps that need to be considered. The geneticae package was created to gather in one place the most useful functions for this type of analysis and it also implements new methodology which can be found in recent literature. More importantly, geneticae is the first package to implement the robust AMMI model and new imputation methods not available before. In addition, there is no need to preprocess the data to use the geneticae package, as it the case of some previous packages which require a data frame or matrix containing genotype by environment means with the genotypes in rows and the environments in columns. In this package, data in long format is required. Genotypes, environments, repetitions (if any) and phenotypic traits of interest can be presented in any order and there is no restriction on columns names. Also, extra information that will not be used in the analysis may be present in the dataset. Finally, geneticae offers a wide variety of options to customize the biplots, which are part of the graphical output of these methods.

The goal of the Geneticae Shiny Web APP is to provide a graphical user interface for the R package, so that it can be used by breeders and analysts with no previous experience in R programming. It is an interactive, noncommercial and open source software, offering a free alternative to available commercial software to analize METs.

# Small example

If you are just getting started with Geneticae APP we recommend visiting and exploring the examples throughout the tutorial in the APP. Here we present a small example.

The dataset yan.winterwheat available as example dataset has information about the yield of 18 winter wheat varieties grown in nine environments in Ontario at 1993. The GGE biplot visually addresses many issues relative to genotype and test environment evaluation. The GGE Biplot tab allows to builds several GGE biplots views. The basic one is produced by default. If Which Won Where/What is indicate in plot type, and the other options are left by default the polygonal view of the GGE biplots is provides (Figure 1). This is an effective way to visualize the which-won-where pattern of MET data. Cultivars in the vertices of the polygon (Fun,Zav, Ena, Kat and Luc) are those with the longest vectors, in their respective directions, which is a measure of the ability to respond to environments. The vertex cultivars are, therefore, among the most responsive cultivars; all other cultivars are less responsive in their respective directions.

The dotted lines are perpendicular to the polygon sides and divide the biplot into mega-environments, each of which has a vertex cultivar, which is the one with the highest yield (phenotype) in all environments found in it. OA93 and KE93 are in the same sector, separated from the rest of the biplot by two perpendicular lines, and Zav is the highest-yielding cultivar in this sector. Fun is the highest-yielding cultivar in its sector, which contains seven environments, namely, EA93, BH93, HW93, ID93, WP93, NN93, and RN93. No environments fell in the sectors with Ena, Kat, and Luc as vertex cultivars. This indicates that these vertex cultivars were not the best in any of the test environments. Moreover, these cultivars were the poorest in some or all of the environments.