# Tag Info

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 ...
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 ...
• 1,841

### 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. ...
Accepted

• 2,943
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 (...
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 ...
• 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 ...
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 ...
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 ...
• 2,943
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 ...
• 7,761
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 ...
• 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 ...
• 168
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. $$\int_{Y-L}^Y \frac{m}{l}y \, dy = 0$$...
• 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 ...
• 4,239
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 ...
• 131
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 ...
• 11

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