Search found 27 matches

by mptsang
12 Jun 2017 11:25
Forum: openLCA 1.6
Topic: Monte Carlo Analysis
Replies: 8
Views: 1370

Re: Monte Carlo Analysis

Dear Andreas, Correct, I have already exported all the data and made the appropriate estimations of the log-transformed data. For me, I was just curious whether openLCA might include an option to automatically report log-transformed statistics, given that inventory data and thus results may commonly...
by mptsang
11 Jun 2017 09:58
Forum: openLCA 1.6
Topic: Monte Carlo Analysis
Replies: 8
Views: 1370

Re: Monte Carlo Analysis

Dear Andreas, Thanks for the reply. So, the final mean and standard deviation for each impact category are reported as arithmetic means and standard deviations, correct? This is problematic for skewed data, no? For instance, if the histogram of 10,000 MC outputs follows a log-normal best fit, it wou...
by mptsang
10 Jun 2017 12:47
Forum: openLCA 1.6
Topic: Monte Carlo Analysis
Replies: 8
Views: 1370

Re: Monte Carlo Analysis

Dear Andreas, My apologies, I didn't make clear my question. Defining the inventory distributions is clear for me. But I am wondering how openLCA calculates the mean and standard deviation for the resulting impacts (i.e. after the impacts are calculated for each Monte Carlo simulation, is the mean a...
by mptsang
09 Jun 2017 13:31
Forum: openLCA 1.6
Topic: Monte Carlo Analysis
Replies: 8
Views: 1370

Re: Monte Carlo Analysis

Hi Andreas, Thank you for the prompt reply and clarification. This is very good to know about the dependent sampling. Perhaps in the future, we can all look forward to an added feature with isolated sampling (e.g. foreground versus background sampling). One additional question, are the means and sta...
by mptsang
05 Jun 2017 15:17
Forum: openLCA 1.6
Topic: Monte Carlo Analysis
Replies: 8
Views: 1370

Monte Carlo Analysis

Dear Andreas, Michael, GreenDelta, Congratulations on the new version of openLCA 1.6 and also updating the Monte Carlo feature. I can now confirm that the negative results previously encountered with openLCA 1.3/1.4/1.5 are no longer there. I do have twp separate questions and they pertain to the sa...
by mptsang
15 Jun 2016 22:52
Forum: Other
Topic: Uncertainty and MC Results
Replies: 1
Views: 2573

Uncertainty and MC Results

Hello, Regarding the MC-results, I know that the results can be exported to Excel and that the uncertainty is shown per impact category and per elementary flow, however does openLCA allow for an uncertainty analysis per unit process (i.e. a global sensitivity analysis per certain unit processes of m...
by mptsang
05 Apr 2016 10:19
Forum: Impact Assessment
Topic: Monte Carlo analysis stopped
Replies: 5
Views: 1919

Re: Monte Carlo analysis stopped

Hi Andreas, Indeed, I have seen the slow MC-simulations on both 1.4 and 1.5 (as I recently installed and tested my datasets on the newest version just released). Have you and your team successfully ran MC-simulations yet running 1.5? (And, in general, I am noticing the same slower work-speeds in 1.5...
by mptsang
02 Apr 2016 11:46
Forum: Impact Assessment
Topic: Monte Carlo analysis stopped
Replies: 5
Views: 1919

Re: Monte Carlo analysis stopped

Hello, I am curious about the length of time it takes to run MC Simulations in openLCA. I tested a few trial-runs of 100 iterations and it was tremendously slow (1+hour), and now when I see that it took someone 10 days to reach 5000 iterations I am not certain I want to use openLCA for this. Is this...
by mptsang
22 May 2015 17:44
Forum: openLCA 1.4
Topic: Uncertainty (Contributional) Analysis
Replies: 0
Views: 2813

Uncertainty (Contributional) Analysis

Hi There, I was wondering if there is a way in openLCA to further analyse the uncertainty results, for example from Monte Carlo Simulations, such that the user can determine at what percentage a specific processes/flow contributes to the final result (the final impact category distribution). Best, M...
by mptsang
22 May 2015 15:43
Forum: openLCA 1.4
Topic: Economic Allocation in 1.4.1
Replies: 0
Views: 2793

Economic Allocation in 1.4.1

Hi There, I have a question regarding the calculation of the economic allocation factors. Let me first start with an example pulled directly from numbers I put into openLCA: Two outputs (both with flow property as "number of items"): Output A = 1 item, Output B = 5 items Economic Flow Properties: Ou...