Partial derivate of matrix by vector?

How to find derivate of matrix which is function of vector by it vector?

31 December 2014 7,614 1 View

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I need to determine only the first natural frequency of the elastic beam, in order to continue to take the optimization of certain parameters of the beam. Given that the proposed model matrix...

09 October 2014 8,788 10 View

Is there clear limits to the value of the deflection and slope of which goes to the assumption of small elastic deformations of the cantilever beam?

I work on some approximate method for analysis of elastic Euler-Bernoulli cantilever beam. There is a concentrated mass on beam tip. Method works exelent for m/M5. I assume that the higher values...

04 May 2014 8,125 1 View

Is there a way to form a 3x3 stiffness matrix for bending in the plane of a Timoshenko beam?

I want to introduce the slope of this kind of beam as the sum of the angle due to bending and angle due to the shear. I know that the typical stiffness matrix for this case dimensions 2x2.

03 April 2014 6,126 3 View

Is there a typical example of cantilever beam for which there is an obvious difference between Euler Bernoulli and Timoshenko beam theory?

I work on some eigenfrequencies analysis of that kind of beams, and still search for ''good'' dimension ratio.

03 April 2014 3,422 12 View

What is the best method of solution of the stiff system of nonlinear differential equations?

I'm using numerical methods of nonlinear differential equations of motion of mechanical systems containing flexible segments. The problem arises in solving the so-called stiff systems of strong...

11 December 2013 7,898 6 View

How to compare two groups with only two measurements?

Hiiiii everyone! I have an enquiry on statistical analysis. I was looking for many forum and it's still cannot solve my problem. I want to compare means of two groups of data but only with two...

03 March 2021 8,796 3 View

Enhanced Yellow Fluorescent Protein (Aequorea victoria) DNA sequence?

I am on the lookout for the Enhanced Yellow Fluorescent Protein (Aequorea victoria) DNA sequence. Does anyone know where I can find it? Thank you in advance

03 March 2021 3,568 1 View

What kind of fluid could I use for a pitfall trap that also does not invalidate molecular testing?

Hi, I want to start testing pitfall trap to obtain ants samples, but I need to conduct molecular analysis on those insects. So, what kind of fluid can I use? Ethanol expires too early and I need...

03 March 2021 5,978 5 View

Buffer Exchange using column packed with sephadex G-25 effect on protein concentration?

Hello, If i am doing a buffer exchange for an antibody of 1mg/mL, does the elution lose protein in the process of buffer exchange? For example, if i flow through 500 uL of 1mg/mL sample, and...

03 March 2021 6,299 3 View

What's the best way to measure growth rates in House sparrow chicks from day 2 to day 10?

What's the best way to measure growth rates in House sparrow chicks from day 2 to day 10? Since, the growth curve from day 2 to 10 won't be like the "Logistic curve" it might not follow logistic...

03 March 2021 1,401 3 View

Do we need to write protocol for a second study of a systematic review that has been registered and published?

I have conducted and published a systematic review and meta-analysis research with the topic related to public health and health pomotion (protocol was registed in PROSPERO). Now we want to...

03 March 2021 8,920 3 View

How to increase a model accuracy ?

dear community, my model is based feature extraction from non stationary signals using discrete Wavelet Transform and then using statistical features then machine learning classifiers in order to...

03 March 2021 6,994 5 View

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03 March 2021 5,360 2 View

Do I need to do linear regression before running mediation analysis using PROCESS MACRO by Hayes ?

I just wanted to check if I need to run a linear regression separately if I am using PROCESS MACRO to run mediation analysis. Thank you.

02 March 2021 4,359 3 View

Waters 2707 HPLC autosampler problem?

I am using a 2707 waters HPLC device. When I try to inject a sample, it says missing plate or rack. I changed the needle and calibrated its position but I still get the same problem. I even get...

02 March 2021 1,408 1 View