Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - 2006garg

Pages: [1]
1
Earthquake Engineering (EE-UQ) / Re: Validating the Surrogate Model
« on: June 19, 2023, 11:59:47 AM »
Thank you Kunashi and Sang-ri for your answers and explanations.

So i understand that since PLOM modelling is all about approximating the joint distribution of input parameters and the output responses of the model, it is not possible to validate the results one by one but rather looking at the metrics such as mean, or other statistical quantities for the two data sets, the validating data set and the new realizations data set.

Then Sang ri talked about the importance of the sample distribution of the input parameters between the training and test dataset. However if it is not the same, it has to be constrained. This is also mentioned in your paper(https://onlinelibrary.wiley.com/doi/pdf/10.1002/eqe.3839) and can be best understood by the image attached. I did find the option for constraints under the advanced options button on the UQ Tab. However i guess it needs an python script. Can you help me with what this python script should look like and the what configuration should be used for iteration number and iteration tolerance?

Best regards,
Gaurav

2
Earthquake Engineering (EE-UQ) / Validating the Surrogate Model
« on: June 09, 2023, 10:14:06 AM »
Hello all,

I had a question regarding Surrogate Modelling. As part of my project, i am making a Surrogate Model via EE-UQ to get more number of data points.

As input for the training i am using Ground Motion Intensity Parameters PGA, PSA and SAavg. On the output side i have the peak displacement and peak acceleration. I have roughly 60 data points from experimental studies which can be used for the training. However i am leaving out some of the data sets for the validation of the Model.

> My first question is having obtained the model, how can i validate my model with the left over datasets? I mean lets say i say that i have a scatter plot for SAavg vs Peak acc. The model gives me new realizations. How can i find out, for e.x. what value of peak acc would the model have given for a particular SAavg, so that i can compare it at the end to the exact value for the same SAavg?
I tried understanding the same from this research paper (https://onlinelibrary.wiley.com/doi/10.1002/eqe.3839), wherein they considered uncertainties in both physical properties as well as the GM parameters., but i have not been able to understand it so far.

Most examples on the official forum (EE-UQ and quo-FEM) have uncertainties in the physical properties, as in Young's Modulus or Floor weight for example. Since in those examples the training data is being generated by the SIM (in EE UQ) or FEM (in quo-FEM), and since the physical properties can be changed for validation studies, they are able to plot the Leave-One-Out Cross validation Prediction curves and able to verify their models. Example: (https://github.com/NHERI-SimCenter/EE-UQ/tree/master/Examples/eeuq-0009).

> My second question is not related to the tool but rather understanding the process: Unlike the first part where i was leaving some datasets(derived from experimental studies) for validation purposes, i also want to verify the new realizations given by the surrogate model with the help of a simplified open-sees numerical model. Since the generated realization (in this case as input PGA, PSA and SAavg) represents a time history is it possible to have a time history curve which might have the same parameters? I have read that we can scale earthquakes so that the IMs might match, but it is really difficult matching multiple IMs. If not, how can one validate the generated realizations by the model apart from the scatter plot, as in this example https://github.com/NHERI-SimCenter/EE-UQ/tree/master/Examples/eeuq-0006, wherein one sees whether the generated realizations lie in the same zone or not. Any suggestions for some other techniques which i can read or look into?               

> My third question is, is there a difference between the Surrogate Modelling via EE-UQ and quo-FEM and does there exist a possibility of plotting the LOOCV curve in either of these softwares, when there are uncertainties in the Ground motion?

I hope you can bear with so many questions of mine but this is the only forum where there exists a possibility of discussing such questions.  Thank you in advance!

Regards,
Gaurav



     

3
Earthquake Engineering (EE-UQ) / Re: Not able to Run surrogate Modelling in EE-UQ
« on: March 24, 2023, 10:55:44 AM »
Hi Sang-ri,

Thanks again. It works now with my files. I am sure i would not have been able to find this error without your help.

Best,
Gaurav


4
Earthquake Engineering (EE-UQ) / Re: Not able to Run surrogate Modelling in EE-UQ
« on: March 23, 2023, 03:34:34 AM »
Hallo again,

It works super with the input output files you provided. The files i just attached, do not have column names right now, but earlier i tried with %x1 and %y1, i even tried with simple keywords like, acc(acceleration) for input and disp(displacement) for output. That also did not work.
I would also appreciate  if you could point me in the right direction, where i can read about the file format or column names, to be used in case of PLoM modelling.

Regards,

Gaurav

5
Earthquake Engineering (EE-UQ) / Re: Not able to Run surrogate Modelling in EE-UQ
« on: March 23, 2023, 03:26:28 AM »
Hello Sang-ri,

thank you for replying. Attached you will find the input and output csv files. I tried changing the column names in the input output files as well and removing the column names altogether as well, but still it didn't work. I will try with the input output files you provided. The Error it shows with my input and output is : 'No Tab file - PLoM failed .. possibly no QoI or a permission issue. Check out Jobs Directory'.

Thanks,
Gaurav

6
Earthquake Engineering (EE-UQ) / Not able to Run surrogate Modelling in EE-UQ
« on: March 22, 2023, 04:33:11 PM »
Hallo,

i am trying to make a surrogate model where i am giving the input csv and the output csv. I go under UQ tab, select Engine as SimcenterUQ and give the files. But somehow it does not run. I am attaching the log file under tmp. Simcenter folder. There is a dakota.err file but it is empty and in the templatedir folder, there are a host of json files and other files. I tried going via the troubleshooting page, but in vain. Tried changing the local directories as well, in case it was a permission problem with documents folder under C drive but nothing still works. Could you please help me with this? It would be a great help.

Regards,
Gaurav

Pages: [1]