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Hello,

I am a student. I am currently looking into graph neural networks (GNNs). My domain is electrical power systems. In electrical power systems, it is extremely important that we get an accurate desired output numerical value of electrical data from a neural network.

1) I have a basic question. Consider an electrical grid network of nodes. I am trying to learn this electrical grid network data using Graph Neural Network (GNN). Every node of a GNN accumulates data from neighboring nodes, then processes it by a few steps of an algorithm, and passes it to the next layer. Finally, data is passed through a non-linearity and then to the output layer of the GNN.

But, if I feed electrical data to the above process, the original value of data at every node gets manipulated by several processing operations, and especially after passing the manipulated data through a non-linearity at the final stage, the output is obtained only in the form of 1's and 0s. Hence, the original electrical data value at every node is totally lost. On the contrary, I am expecting an output of an "accurate" value of electrical data similar to original value electrical data at every node of the network.

How to address the above problem? Please explain systematically if possible. This is a genuine basic question.

2) Also, does anyone have a clue, why Graph Neural Networks (GNNs) have not been introduced yet as a toolbox or in general in Matlab?

Help and opinion on above questions would be greatly appreciated.

Hi Everyone, I am trying to simulate the third-order model of the synchronous generator (figure below). but I have no idea how to do this. Any help would be great.

Shogo
Shogo
上次活动时间: 2020-8-21

help

Thank you for your helping. I'm trying to import csv files form a folder, however it does not work.

The following code might be wrong.. fname=mtlb_dir('Users/shogo/Left_Leg_Single-Leg_Landing/SLLExport/*.exp')

I appreciate it if you help,

Sincerely, Shogo

Meta threads have a tendency to grow large. This has happened several times before (the wishlist threads #1 #2 #3 #4 #5, and 'What frustrates you about MATLAB?' #1 and #2).
No wonder that a thread from early 2011 has also kept growing. After just under a decade there are (at time of writing) 119 answers, making the page slow to load and navigate (especially on mobile). So after a friendly nudge; here is a new thread for the things that are missing from Matlab.
Same question: are there things you think should be possible in Matlab, but aren't? What things are possible with software packages similar to Matlab that Matlab would benefit from? (note that you can also submit an enhancement request through support, although I suspect they will be monitoring activity on this thread as well)
What should you post where?
Wishlist threads (#1 #2 #3 #4 #5): bugs and feature requests for Matlab Answers
Frustation threads (#1 #2): frustations about usage and capabilities of Matlab itself
Missing feature threads (#1 #2): features that you whish Matlab would have had
Next Gen threads (#1): features that would break compatibility with previous versions, but would be nice to have
@anyone posting a new thread when the last one gets too large (about 50 answers seems a reasonable limit per thread), please update this list in all last threads. (if you don't have editing privileges, just post a comment asking someone to do the edit)

This year, the 3-day MATLAB workshop is going Virtual: October 11-13 2020. (Sunday evening - Tuesday afternoon, CST). If you're teaching science, math, engineering or related disciplines, consider signing up now. The application deadline is July 31st. Apply for the workshop: Workshop Application

Details: Name: Teaching Online Computation Using MATLAB (Virtual) Date: October 11-13 2020 (Sunday afternoon -- Tuesday mid-afternoon, US time zones) Location: Zoom session Audience: Educators teaching undergraduate and graduate-level science, math, engineering and related disciplines

At the 2020 virtual workshop, you’ll have opportunities to • Curriculum: Upgrade your curriculum with a focus on transitioning to online learning • Mentoring: Meet in 1-on-1 coaching sessions with faculty, education professionals, and MATLAB experts • Publish and Cite: Get your teaching activities peer reviewed and citable for inclusion in your CV • Community: Collaborate with and build connections to a network of educator peers all working on impactful computational skill development in their courses • Learn: Learn how to embed new MATLAB tools in courses to improve student learning (Note that the workshop will use online technologies to enable 1-on-1 mentoring, group work, and community building. As in past years, the focus will be curriculum development, less presentation.)

In addition, you’ll have the chance to learn how to incorporate MATLAB Live Scripts, MATLAB Online, MATLAB Grader, and more.

This virtual will include working groups for building your curriculum. Participants will be matched with like educators.

Apply now to save your spot and help the conveners plan effective groups.

The workshop hosts will review applications and send acceptances status by early August.

Looking forward to your participation in the workshop, Cathy Manduca, Executive Director, SERC Lisa Kempler, Sponsor, MathWorks Don Baker, McGill University, workshop convener Dan Burleson, University of Houston, workshop convener and review editor Kelly Roos, Bradley University, workshop convener and reviewer Kristi Closser, California State University, Fresno, workshop convener and reviewer

P.S. For reference, 2019 workshop program

Looking to get Solar Grid Tie Inverter developed including Hardware + Software + Enclosure design (IP 65) for single phase inverters from 1 KW to 6 KW.

Here's an thread on comparing various types of instructional labs (on-campus, virtual, remote, kits). Each type has pros/cons and things that you need to consider.

https://twitter.com/RebeccaEE/status/1237561015350386690

Rik
Rik
上次活动时间: 2024-9-17

Similar to what has happened with the wishlist threads (#1 #2 #3 #4 #5), the "what frustrates you about MATLAB" thread has become very large. This makes navigation difficult and increases page load times.
So here is the follow-up page.
What should you post where?
Wishlist threads (#1 #2 #3 #4 #5): bugs and feature requests for Matlab Answers
Frustation threads (#1 #2): frustations about usage and capabilities of Matlab itself
Missing feature threads (#1 #2): features that you whish Matlab would have had
Next Gen threads (#1): features that would break compatibility with previous versions, but would be nice to have
@anyone posting a new thread when the last one gets too large (about 50 answers seems a reasonable limit per thread), please update this list in all last threads. (if you don't have editing privileges, just post a comment asking someone to do the edit)

As an environment for modeling, simulating, and testing dynamic systems, Simulink is used for:

Simulink is now available in a web browser as Simulink Online.

Simulink Online is available to anyone with access to MATLAB Online (see supported license types here) and a Simulink license.

Just sign into MATLAB Online and either start Simulink or open a Simulink model.

Learn more about Simulink Online at the product page on our website.

Simulink Online currently supports the following toolboxes, with more to be added in the future!

  • Simulink
  • Stateflow
  • Simscape
  • Simscape Electrical
  • Simscape Multibody
  • Simulink Control Design
  • DSP System Toolbox

MathWorks gave a perspective on 'Bridging the Technology Readiness Gap with Simulation and Virtual/Remote Testbenches' at the Opal-RT RT20 Panel Session on The Role of Real-Time Simulation in Education. Listen to a recording of the panel session, and also hear perspectives from Quanser, Hydro-Quebec, and RWTH Aachen, by registering for the RT20 conference at the following link .

The EMEA (Europe, Middle East and Africa) Academic Engineering Team are hosting a series of live online webinars every Tuesday and Wednesday. Get up to speed with online teaching and research with MATLAB and access ready-to-use resources.

Watch the introductory video and register here

Where is very courses and how to catch the courses

Hi Everyone,

Require some guidance and pointers on model ee_pmlsm_drive please.

Its regarding a PMSM linear machine model, with a cascade (position and speed) outer loop and a current controller inner loop (Id and Iq currents).

The current Simulink model uses a low voltage DC supply (48v) and uses a step input to the system. My system uses a HV source (400v) and the input is sinusoidal position, with an operating frequency range of 0 to 20hz.

I have used the original model, re-created my own (to learn Simulink/Simscape) with a HV battery source (400v) and used machine parameters that match the application (peer reviewed publication).

As my power electronics background is limited, my background is mechanical, i am unable to tune the inner and outer loops, and am unsure in what order to tune. My project is to use the linear PMSM to drive (motoring) a linear piston for combustion and also use the linear piston to drive the PMSM (generating).

Using the built in PID tuner for the outer speed and position loops i am encountering an error (plant cannot be linearised). I am using a simple 1 hz sine wave to simulate the reference position set-point. With all PID values set to default i have no dq currents, however i have idq ref from the outer velocity controller loop.

Any help with resources and guidance as to how to tune the loops for my updated parameters on this model would be great.

In this article, we discuss how educators can adopt simulation, alternative hardware, and other teaching resources to transition lab-based classes to distance learning: https://medium.com/mathworks/tips-for-moving-your-lab-based-classes-online-1cb53e90ee00.

Do you teach a lab-based class? Please share your thoughts, questions, experience, and feedback on these ideas here. I also welcome you to invite your colleagues to join the discussion here.

One community within MathWorks that has been helping students continue their learning is MATLAB Student Ambassadors. Despite new challenges with transitioning to distance learning, student ambassadors have done a truly amazing job. In a blog that was published recently, I discuss 3 examples of the great things that our student ambassadors have done to aid distance learning. Click here to read the blog. I hope after reading this blog you share my level of admiration for these students.

Student Ambassador at University of Houston hosting a fun and informative virtual event.

hi how to apply single stream into multiple channels in fft simulink simulation from workspace

Sir how can we use Image processing in the Distance Learning

PB75
PB75
上次活动时间: 2020-5-7

Hi, Currently modelling an reciprocating engine coupled to a linear PMSM motor/generator for my PhD. I have downloaded the "Model File Package for Motor Control Design Public Video" simulink model.

Is it possible to convert to rotational PMSM simscape plant model used for a linear PMSM model? As there are none in the library to just drag into the existing control model.

Any ideas i can represent a linear motor based on this existing control model?

My output from the machine needs to be linear position w.r.t, with a total stroke of approximately 100 mm. Can i convert the rotational constant speed input at port "W" to a sinusoidal velocity profile (such that it replicates the velocity profile of a linear machine)?

Any help would be great.

Thanks

I wanted to briefly share my experience in transitioning from a hands-on lab course to a virtual lab in MATLAB. Here at UMass Amherst, Mechanical & Industrial Engineering, we have a required undergraduate lab sequence, one during junior year and another during senior year. I teach the 2nd course, MIE 402, with a focus on measurements, data acquisition, system dynamics, and control.
The main idea behind our labs, in addition to the all too important hands-on experience, is to provide the students with a platform where they can validate and understand limitations of theoretical models from experimental data.
While the hands-on aspect was lost, we were able to create virtual experiments that consisted on Simulink models saved as protected files. In our protected models, students were able to assign input variables, decide on simulation parameters (e.g., integration parameters), and have certain outputs saved to the workspace. The key for making this a challenging lab was twofold: (1) Students were not told about the level of modelling detail inside the protected file (e.g., were dry friction or electrical inductance included?) and (2) each student was assigned a different set of model parameters based on their student ID (via a predefined table inside the protected file). The 2nd point was especially impactful as students felt as if they are working on their own experiment.
We developed virtual labs for a tuned mass damper and a DC motor experiments. Feedback from the students showed that they missed the hands-on experience but really liked being able to interact, as many times as needed, with the virtual lab at their time frame of choice, and have the ability to interact with us (grad assistant and myself) then re-run the experiment to test new ideas.
Some future developments that could significantly enhance the educational impact of such virtual labs would be the addition of real-time animation and increased level of modelling (e.g., data acquisition effects, electromagnetics, etc.’). At UMass we presently do not have access to the entire suite of MATLAB tools, something that prevented us from including these ideas in our virtual labs.
This would have not been possible without Andy Bartlett (tremendous Simulink help) and Div Tiwari (quickly getting us access to required tools).