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4 votes
Accepted

System identification of a simple motor with only position measurements

The process of system identification consists of the following steps: Choose an appropriate input for the system. The input should definitely satisfy the Persistence of Excitation condition and ...
Teo Protoulis's user avatar
4 votes
Accepted

What is the best graph type to show a comparison value between two cases?

Based on the discussion in comments, you probably want to use a bar chart combined with a line for the error. Have a look at Create a combination chart for more details. In your case, and using dummy ...
am304's user avatar
  • 1,841
4 votes

accurate measurements with less accurate tools

If you know that the errors in your measurements are truly random and have a normal distribution then you can improve the resolution of a measurement by taking several measurements and averaging them. ...
Elliot Alderson's user avatar
3 votes
Accepted

Talking in terms of 6 sigma, why 4 ppm would be very costlier than 1 ppm (part per milion)?

If we talk about quality and 6-sigma (which roughly means 1 ppm defects), the 1 ppm refers to test escapes, not test rejects. Even if a part only costs \$1, if testing fails to catch a bad part and ...
The Photon's user avatar
3 votes
Accepted

Double interpolation for a large set of data in Excel

It appears that your dataset has integer row and column header values starting at 0. You can try the following code. Turn on Excel's Developer ribbon if it's not already on. Click the Visual Basic ...
Transistor's user avatar
  • 10.9k
3 votes

What does (a) the input of the activation function mean?

Just a quick summary of my concluding thoughts on this step in your research. I understand that you have been advised to use the Sigmoidal Function, so this discussion will try to explain it's ...
AsymLabs's user avatar
  • 652
3 votes
Accepted

How do I include statistical significant index in bar chart in excel?

Quite seriously: Friend Don't Let Friends Use Excel. Learn to use Matlab/Octave, or python, or R, or just plain Gnuplot. No matter what tool you use, since "significance" is a separate variable, ...
Carl Witthoft's user avatar
2 votes

Moments of inertia, rods mechanism

The point where center of mass lies so the center of gravity. So, for center of mass For rod AC. B is the mid point of AC.So,let us take A as origin So coordinates of B($\frac{l}{2}$,0).Similarly for ...
Rishi Kakkar's user avatar
2 votes

How to find raw data sets for engineering?

Search for daily maximum and minimum temperatures for your local region. If there is a river nearby, search for river level or river gauge height. If it rains, search for annual rainfall in your ...
niels nielsen's user avatar
2 votes
Accepted

Usage of the three-sigma limits in calculating minimum force

Data is data. This is the capability of the design and manufacturing process. Trust the data. If there is a need to improve the quality of the data one could take for example 3 measurements for each ...
Mahendra Gunawardena's user avatar
1 vote

How to add a Gaussian noise signal with zero-mean in a given data set?

You can use the following formula to produce the white noise for one cell. = 0.5*NORM.S.INV(RAND()) Where: 0.5 : can change to ...
NMech's user avatar
  • 24.4k
1 vote

Usage of the three-sigma limits in calculating minimum force

The problem with your proposed solution of using 3 times the standard deviation, is that it doesn't take into account how accurately the standard deviation has been determined. As you only have 10 ...
ingenørd's user avatar
  • 1,288
1 vote

How to determine the effect of manufacturing variability on assembly of items

A professional statistician can tell you what sample size is required to achieve 95/95, but note that a yearly production volume of 500 units means about 2 units/day. This means statistical quality ...
niels nielsen's user avatar
1 vote

How to Determine a Valid Relationship Equation Between Two Finite Datasets -- Python, Matlab or Other

This is a common question which usually reveals some misunderstandings on the part of the person asking. First point: in most cases you should have some reasonable premise as to the type of equation ...
Carl Witthoft's user avatar
1 vote

How to Determine a Valid Relationship Equation Between Two Finite Datasets -- Python, Matlab or Other

The first step is regression fitting an analytical model to the empirical data. This step is made easier when you can start from a theoretical model. For example, you may have a first principled ...
Jeffrey J Weimer's user avatar
1 vote

Trendline estimation

The value $R^2$ is a regression metric that is best used to compare how well different data sets fit to (or scatter about) a fixed (linear) regression model. You are better to obtain the uncertainty ...
Jeffrey J Weimer's user avatar
1 vote

System identification of a simple motor with only position measurements

Another approach that has not been mentioned here, but which is applicable also to nonlinear systems, is to use a gradient-based optimization scheme over a simulation. Say that you simulate the (...
Fredrik Bagge's user avatar
1 vote

Usage of the three-sigma limits in calculating minimum force

Keep in mind that the failure doesn't have to follow a normal distribution. Weibull distribution is a much better fit for real life situations. And to be more specific, a weibull with a shape like the ...
NMech's user avatar
  • 24.4k
1 vote
Accepted

Compare Genetic Algorithms and Markov Chain Monte Carlo in their statistical properties in parameter estimation task

Question 1: What is the benefit of using MCMC over GA? Which one is better than other in what aspects? As you state, if you are using the Markov Chain Monte Carlo (MCMC) properly, it will give you ...
useless-machine's user avatar
1 vote

Talking in terms of 6 sigma, why 4 ppm would be very costlier than 1 ppm (part per milion)?

1ppm is 4 times better than 4ppm. If 4ppm of parts are indicated it means that 0.0004% of these parts have to be discarded. It is always better to have a lower number of discarded parts which means ...
André Rodriguez's user avatar
1 vote
Accepted

What measurement accuracy/precision is required to detect a 10% relative change in the measured quantity

Direct Measurement of Volumetric Flow Let's handle the (easy) statement of accuracy first. Validating the accuracy of the measurement of volume flow requires that you calibrate your chosen measuring ...
Jeffrey J Weimer's user avatar
1 vote

Double interpolation for a large set of data in Excel

I have a spreadsheet that I wrote years and years ago for interpolating. It generates points that follow the same sort of profile as the 'smoothed line' function when you add a line to an X/Y Scatter ...
Jonathan R Swift's user avatar
1 vote

Find spring constant of frame structure

Yes it would change. For example same load if applied at quarter span would cause less deflection and a different curve. Hence bigger K. basically for the type of loading you display applying the ...
kamran's user avatar
  • 22.5k
1 vote

DOE to optimize a chemical reaction with impurity forming in series

I know this is a while back, but my answer is generally applicable. From experience, these sort of experiments can make use of reaction time as a "free" variable. Before the DOE is even planned, take ...
Beerhunter's user avatar
1 vote

Moments of inertia, rods mechanism

To compute the c.g location, assume that is is at a distance Y below point B. Use the fact that the mass moment about that point should be zero to determine Y. $$ \int_{Y-L}^Y \frac{m}{l}y \, dy = 0$$...
Suba Thomas's user avatar
  • 1,971
1 vote

Choosing significant figures when dealing with a wide range of values

The fundamental problem here is that you've got a bunch of numeric values which are not in engineering/scientific notation, so you have to make up some arbitrary guesses as to how many sig figs really ...
Carl Witthoft's user avatar
1 vote
Accepted

How do I update an individual control chart?

Out of desperation, I got in contact with some very nice statisticians at NIST. They walked me through the answer to my question, which boils down to: control charts are an empirically derived chart ...
Broklynite's user avatar
1 vote

Guidelines to develop quality engineering training content and select a trainer

Apart from current answers, I think a quality engineer must also be aware of the FMEA processes (DFMEA as well as PFMEA in general)... In fact , for a Mfcg company, (if it is not designing the ...
shishir's user avatar
  • 11

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