Simulation and Modeling

Simulation and Modeling

  • Ab Ka added an answer:
    Could it be possible implementing the fitness function of GA code in matlab to work with simulation rather than equations?

    I chose the GA for optimization by writing the program using ga code in matlab. This program is ok if I put the terms of fitness function as equations; for example:
    y1=1/(s+10)(s+2)
    y2=1(s+par)(s+2)
    f=sum(y1-y2)^2
    When I run the program the ga graphs and results is fine, and par=10.
    However, when I put these equations as a model in simulation, the ga graphs (best value) is constant (line) which is incorrect.
    My issue is that I need to import y1 from the simulation and y2 from data results to estimate par.
    Really I got stuck in this point which is how can I use ga with simulation.
    Moreover, I can share the knowledge with who is interested in.

    Thanks

    Ab Ka · De Montfort University

    Thanks Monica,
    The program is more better now but it is still struggling to use k1 and k2 in the Objective Fcn while these parameters (k1 and k2) in a simulation model.
    If it is implemented via equation, it is working perfectly. However, with simulation is NOT.
    I do not know if there is any one use GA in simulation. It looks stranger, but physically it can be performed.

  • Jinlong Li added an answer:
    How to make an interface between Matlab/simulink 7.9 and PSCAD X4?
    I am trying to make an interface between matlab/simulink 7.9 and PSCAD X4, but all user’s manuals for PSCAD from Manitoba describes how to make that interface with older versions of matlab and PSCAD. Does anybody made any interface between these versions and had any success in it?
    Jinlong Li · shihezi university

    My answer to the question is presient in the attachment

  • Do Toan added an answer:
    Does anyone use COMSOL Multiphysics for simulation?
    Is anyone working in this area - Electromagnetism, Heat transfer and CFD.
    Do Toan · Yuan Ze University

    Does anyone use COMSOL for the simulation of Plasma Electrolytic Oxidation?

  • Garry Riviere added an answer:
    How can I deal with staggered grid boundary conditions?

    I'm using a semi-implicit code and I don't know how to deal with boundary conditions of staggered grids at the implicit part of the code. There is some book that can help me?

    Garry Riviere · University of La Réunion

    You can find boundary conditions implementation in An introduction to computational fluid dynamics. The finite volume method. H. K. VERSTEEG and W. MALALASEKERA.

  • Using Real Time simulation in the case of off-line simulations has no problem to solve equations, could be an advantage to enrich research or no? Why?

    I have applied a new application on excitation of a generator. The simulation is carried out on Matlab environment. But the question is: regarding to the application is applied within excitation system ( it means the applied controller is local and destination factor is not a concern.) using Real Time simulation could be an advantage to enrich research or no?

    Anislei Santiesteban Velázquez · Universidad Las Tunas

    I agree with Luc-Andre Gregoire because all simulation must be corroborated with actual data, it is most important, then perform simulations and real-time experience with simulation object

  • Adebayo Akanbi Oladapo added an answer:
    Can I modify receiver section of SAC-OCDMA by using MATLAB?

    I need a proposed work research. Kindly suggest the relevant work further.

    Adebayo Akanbi Oladapo · University of Central Lancashire

    Sorry, I have no idea; this is not in my area of expertise

  • Balakrishna S G added an answer:
    What is the best TeX editor for LaTeX?
    Give your opinion especially on your experience whether good or bad on TeX editors like LEd, TeXMaker, TeXStudio, Notepad++, WinEdt (Paid), ....

    Some quick ref.
    http://en.wikipedia.org/wiki/Comparison_of_TeX_editors
    Balakrishna S G · Leibniz-Institute for New Materials

    Lyx makes life easy. I recommend LYX

  • Simon Schröder added an answer:
    Which computer language (C, Fortran, Visual basic) is faster in the CFD using FEM? Do any of them work with VBE?
    I'm working on a CFD project using FEM, the time elapsed for every run is high to get results. Now I'm using MATLAB but I want to change coding language. Which program do you suggest?
    Simon Schröder · Fraunhofer Institute for Industrial Mathematics ITWM

    @Paul: I recently had an advanced Fortran course held by a member of the standardization committee. I also used to say "use modern Fortran". But, what he taught us it that many modern features in Fortran (post Fortran 95) only kill performance. He advised us to never use these unless in performance-uncritical code. Maybe numerics is an afterthought in C and C++, but object oriented programming (OOP) is an afterthought in Fortran. As it turns out OOP does not play well with Fortran, whereas numerics can play well with C++. Although matrices are not built into C++ as in Fortran, there are good libraries which prevent you from writing loops. Some of these libraries even do optimizations that the compiler cannot do, e.g. avoiding temporaries and avoiding additional loops when chaining mathematical operations. This goes far beyond a simple DAXPY. With the same simple syntax that you have in Fortran you can have optimizations which are not possible in Fortran. The approach of C++ is not to cram everything into the language, but instead use libraries wherever there is no performance penalty because of this approach. In C++ language syntax cannot make matrices more efficient than they already are with libraries.

    Finally, it is the algorithms and the data structures that decide over performance the most and not just the language. I agree that C++ is harder to master than Fortran, and you can make many stupid mistakes which screw up performance. Using existing libraries will prevent you from making most of these mistakes. Since the algorithms are most important, you should use the language you know best. This will result in the best performing code that you can write.

    PS: Fortran sometimes prevents you from using good algorithms because you have to reinvent the wheel and implement the algorithm yourself. Often people will then choose algorithms with worse complexity classes because they are easier to implement. To give an example of this see this Youtube video about Python vs. Fortran:

  • Naveen Kumar Boiroju added an answer:
    How to approximate the cdf of t-distribution efficiently?
    Approximation of t distribution is essential for finding the p-value in a computer program (while testing the hypothesis about the means). Is it enough to have three decimal point accuracy of the approximation? How many decimals should be correctly approximated by a function? Finally, how to approximate the cdf of t-distribution efficiently? Please suggest some thoughts on the same. Thank you.
    Naveen Kumar Boiroju · Osmania University

    Thank you Wilson

  • Ivana Oleksakova added an answer:
    I am looking for software for simulation of wind for Mac OS.
    I am looking for software for wind simulation for Mac OS. I use Ansys but I heard that there is no version for Mac. Is there any other software that you are satisfied with using? Is there a free version for students?
    Ivana Oleksakova · Slovak University of Technology in Bratislava

    Thanks..I am already learning to work in OpenFOAM... but I will check Comsol as well :)

  • Boris M. Vulović added an answer:
    Empirical Tight-Binding Method vs. Empirical Pseudopotentials Method: Pros and cons?
    In your experience which one is better in terms of ease of programming and computational efficiency: TBM or EPM?
    Boris M. Vulović · University of California, Los Angeles

    Thank you gentlemen.

  • Rivalino Matias Jr. added an answer:
    Which tools do you recommend for visual presentation (animation) of process scheduling in an operating system course?
    Which tools do you recommend for visual presentation (animation) of process scheduling in an operating system course?
  • Ulrich Welling added an answer:
    Can anyone help me to find out the polarizable forcefiled for single gold atom in water?

    I need to run an atomistic molecular dynamics simulation of a system in which some neutral gold atoms are randomly distributed in water box. I need to see how the gold atoms behave in water with time. But for running the simulation I need correct polarizable forcefield for gold atoms in water. There are some papers in which forcefields of various types of gold surface are present, but not for single gold atoms. Can anybody provide me any clue about the polarizable forcefield of single gold atom in water?

    Ulrich Welling · Georg-August-Universität Göttingen

    Wouldn't singular gold atoms react with the water to form some hydrated Au + or Au 2+ ions?

    I guess if you do gold (nano) particles in water that potential for gold surfaces is already quite good.

  • Alaa Alwaisy Alwaisy added an answer:
    Is there any one who worked or working on LIBSVM??

    In fact, I downloaded it and I face a problem with the output of the ([label_vector, instance_matrix] = libsvmread('../data');)

    It gives me usually as empty matrix, and I usually get the same error. although the input matrix for the libsvmwrite a sparse matrix(double).Please,could you help me as faster as you can.

    Notes:
    I'm working on matlab with windows 7, and I'm working on multi classification problem.
    Thank you in advance.

    Alaa Alwaisy Alwaisy · University of Bradford

    Thank you for  your answers on  my  question,

    Dear Falak Shah, I did what you said but my problem is not with compilation, my problem is that the output arrays from  the ([label_vector, instance_matrix] = libsvmread('../data');) , usually an empty arrays without values

    thanks for all

  • Magnus Eriksson added an answer:
    Can anyone help with simulating WSN routing protocols?
    Does anybody know if the RMASE (Routing Modeling Application Simulation Environment) application for PROWLER simulator is still available anywhere for download? As far as I can tell there seems to be no official site or download links available anywhere.
    Magnus Eriksson · Mid Sweden University

    You can download both Prowler for Matlab, and the Java based Jprowler version, from this link http://www.isis.vanderbilt.edu/projects/nest/prowler .

    See also this 2003 paper:  http://www.isis.vanderbilt.edu/sites/default/files/Simon_G_3_8_2003_Simulation.pdf

    RMASE is in application to PROWLER dedicated for routing protocols. Until recently it has been available for download from this link http://www2.parc.com/isl/groups/era/nest/Rmase/download.htm, but I don’t find it right now. Previously it said that before downloading, you need to ask permission by the developers of this software. (RMASE is described in this 2006 paper: http://www.dcs.uni-pannon.hu/~simon/publications/INSS_2006_paper.pdf )

    Here you find a 2013 Master thesis where a student of mine (Sidra Muneer) used Prowler to analyze an own routing protocol based on our cooperative-diversity algorithms: 

    http://www.diva-portal.org/smash/record.jsf?searchId=1&pid=diva2:645942 .

  • Corey Allen Moffet added an answer:
    Simulation models or submodels combining plant/vegetation growth with herbivore grazing
    I am still looking for simulation models or submodels that combine plant/vegetation growth with herbivore grazing on these plants. I aim at using it for an MSc course on the use of models in ecology.
    Corey Allen Moffet · The Samuel Roberts Noble Foundation

    You might want to look at the SPUR (Simulation of Production and Utilization of Rangelands) model that was developed by the USDA-ARS.

  • Ovidiu Borchin added an answer:
    What may have in common the elementary particles physics with hydrodynamics, differential geometry and our knowledge?
    The answer is simple - a model
    Ovidiu Borchin · Carmit Chan Corporation

    Dear Gerard,
    You're right; the solution is based on the differential geometry.

  • Viktor Vojtko added an answer:
    Churn problem analysis, modelling and simulation for Mobile Telecommunications?
    Any successful case studies or System Dynamics simulation models (or alternative modelling approaches) to support Telecom operators, in order to manage customer behaviour and control attrition rate (churning) in mobile telephony market?
    Viktor Vojtko · University of South Bohemia in České Budějovice

    Dear Habib,

    I am not sure whether it's still relevant but I was involved in several projects focused on these topics in the Czech Republic for main telco operators. It was mainly used for understanding the churn after introduction of phone number transfer availability.

    Best regards,

    Viktor

  • Gawas A added an answer:
    Where can I get hydraulic and mechanical circuit simulation done?
    I have a reasonably complex experimental electro-mechanical hydraulic system (using water medium) design I would like to have simulated (to include pressure and flowrate versus time response, valve operation - steady state and transient) before I spend a lot on hardware to build it. If anyone has any connections/suggestions, please let me know.
    Gawas A · Department of Atomic Energy

    http://www.mathworks.in/videos/hydraulic-simulation-with-simhydraulics-81959.html?s_iid=main_custom_SH_cta1

  • Ibrahim Dauda Muhammad added an answer:
    How do I simulate nanotubes using ANSYS?
    My goal is to predict the mechanical properties of zirconia nanotubes.
    Ibrahim Dauda Muhammad · Universiti Teknologi PETRONAS

    Follow the following steps:

    [1] Generate the model of ZrO2 nanotubes using appropriate software, e.g. Material Studio.

    [2] Export the structure as PDB file.

    [3] Extract the xyz coordinates for each atom and the connectivity for all bonds.

    [4] Use the data in [3] to develop a macro in ANSYS to build the structure.

    [5] Simulate using appropriate material properties and boundary conditions.

    For more details see the attached publication.

  • Shao Weidong added an answer:
    Can I use LBM to simulate the flow field with high resolution?

    I want to simulate the flow field with high resolution especially near the wall region in open channel flow with different Re. Can I use LBM, efficiently? Or VFM solution of Navier-Stokes equations using LES as turbulent model is more efficient from accuracy and computational cost (i.e. time) point of view.
    I should be noted that my problem is a incompressible  multi-phase flow.

    Shao Weidong · Xi'an Jiaotong University

    High resolution is always related to high resolution numerical scheme, such as sixth order compact scheme, spectral element methods. Standard LBM is nearly 1.5 order in precision. For high Reynolds number flow, LBM is more time-cost than the RANS. As far as i'm concerned, LBM is used near the wall region and RANS is used in the region far from the wall. 

  • Sarwan Kumar Dubey added an answer:
    How can I use the TRS model for "water quality index" variable?
    TRS is a cost-effective method for determining waste load allocations.
    Sarwan Kumar Dubey · Central Soil and Water Conservation Research and Training Institute

    Hi Amin Mahdipour Varnousfaderani; Following links may be useful to you Dear

    http://link.springer.com/article/10.1007/s10661-008-0390-7

    http://psrcentre.org/images/extraimages/0112169.pdf

    Thanks

  • Sanat Kumar Tiwari added an answer:
    Radially averaged power spectral density (PSD) in 3D space?
    Most people plot PSD with time series data at some space and MATLAB has a function for it. Is there any inbuilt function or file exchange function which could be used with 2D and 3D data with its grids to get power spectral density?
    Sanat Kumar Tiwari · Institute for Plasma Research

    Dear Eric, 

    Thanks for your suggestion. I too have written code. Will try to match both codes and let you know in few days as presently outside institute. 

  • Dennis Schmitz added an answer:
    How can I create a power law filter in matlab ( 1/f^x )?
    Eventually what I need is a power law noise with adjustable exponent (x) between 2 and 3, so I'm planning to filter the white noise with this filter.
    Dennis Schmitz · Terumo

    I have spent the past several days working on a high quality pink noise generator, and have misgivings about the rigor of any method that tries to scale fft output and then transform it back. (These misgivings are mostly based on the unhappy reaction of Dr. Burrus (of Parks and Burrus) whenever anyone suggested it.)

    I found this reference:

    http://www.firstpr.com.au/dsp/pink-noise/

    which makes a solid case for using a filter over white noise to produce 1/f noise.

    There are links to C code and Matlab code. Also, attached is Python code that implements their algorithm directly (I'm not the author, but is freely distributable).

  • Muhammad Zakarya added an answer:
    How to simulate a trusted cloud computing platform?
    Does anyone know any tools that can be used to simulate Trusted Cloud Computing models. Can we simulate this one in CloudSim? or do we need to create our own API for CloudSim for the support of trusted computing? Your comments would be highly appreciated.
    Muhammad Zakarya · Abdul Wali Khan University Mardan

    still there is an option to implement your own security algorithms in cloudsim. I think its very easy to consider in event driven programming

  • Hoskoti L added an answer:
    I need tutorial materials in modeling and simulation of wave propagation(Lamb,P,S and Ultrasonic) using ANSYS. Thanks in advance
    Modeling and simulation of Acoustics wave propagation

    Find the attachment .

    I hope i will be helpful to you

  • Sankar Padmanabhan added an answer:
    Why most transaction in ieee accept modelling and simulation?
    Computer simulation and modelling on networks
    Sankar Padmanabhan · Jerusalem College of Engineering

    It should contain some novelty in  the research work

About Simulation and Modeling

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