For which complex numbers bj , we have b0= \sum_{j=1}^3 bj exp(i vj) for some real vj?

05 June 2015 8,415 0 View

What is a time-space scale version of KdV equation?

09 October 2014 6,025 0 View

If sin(a sk)/a= sin(b sk)/b for the sequence sk\to infty as k \to infty for some a not equal to b, then a/b is rational and sk=2k pi/b? Is it true?

For particular case b=2a we have sin(2b sk)/(2b)= sin(b sk)/b which yields cos(b sk)=1 or sk=2k pi/b. It is true also if the sequence sk that approaches infinity as k approaches infinity is...

31 December 2013 1,229 4 View

Are there unbounded solutions of (1-cos(x pi))/x-(1-cos(y pi))/y+(1-cos((x-y)pi))/(x-y)=0 but with even integers?

The sequence x=2k y=2n where k and n are natural numbers solves this equation. Is there any other unbounded sequence of solutions?

11 December 2013 3,637 7 View

Quadratic equation (complex coefficients) have roots with equal real parts if and only if discriminant is real, non-positive. What about quartic?

z^2-(2+3i)z+3i-1=0 has discriminant=-1, roots (1+i) and (1+2i) have equal real parts. Find a similar statement for the quartic equation: z^4+az^2+bz+c=0.

10 November 2013 2,425 8 View

2 roots of x^3+6a x+2b=0 where a, b are complex have the equal real parts if a, b are real and discriminant is non-positive. Is it true?

For the quadratic equations with complex coefficients 2 roots have the equal real parts if and only if the discriminant is nonpositive.

07 August 2013 2,957 4 View

e^(z_1)+e^(z_2)=0 if and only if Re(z_1)=Re(z_2) and Im(z_2-z_1)=pi(2n+1), where z_1, z_2 are complex numbers. Is there a similar statement for the sum of 4 exponents e^(z_1)+e^(z_2)+e^(z_3)+e^(z_4)=0 ?

This question is connected with the oscillations of differential equations. Since every solution of the linear equation with constant coefficients is the linear combination of exponents this...

04 May 2013 2,279 51 View

Resistor definition in Piezoelectric bimorph with ANSYS workbench

Hello, good day! I am trying to simulate similar bimorph piezoelectric harvester with below commands. However, the output power doesn't change with resistor value. Please help to find the reason. ET,10,CIRCU94,0 !SET UP RESISTOR R,1,100000 !RESISTANCE VALUE TYPE,10 !SET ELEMENT TYPE E,1,2 !CREATE RESISTOR BETWEEN NODES 1 AND 2 Thanks in advance Regards,

02 March 2021 0 0 View

How to perform statistical analysis of coefficients extracted from transform techniques?

I am studying the potential of DCT and FFT coefficients extracted from a signal to classify the different objects that emit the signal. I applied the Shapiro-Wilk to confirm that data was not...

01 March 2021 8,079 2 View

What are the application of Fixed points thoery in Chemistry.?

It is said that fixed point theory has lot of applications not in the field of mathematics only but also in various areas. So I am looking for applications in Chemistry only..

26 February 2021 3,533 1 View

Anyone that can help with Maxquant TMT16plex which is missing?

Hi I am very new to proteomics analysis. I have got raw files from core facility running thermofisher TMT 16plex 4 hours. I cannot find on maxquant the option TMT16Plex there is only up to 11...

25 February 2021 1,675 3 View

Fractional impervious surface (FIS) map ?

Need Help Does anyone Know how to make a Fractional impervious surface (FIS) map from NDVI map, in ArcGIS environment? Thanks in advance

24 February 2021 8,455 2 View

Can I ask did any good platform or journals for learning the calcluation on the reference governors and command governor?

Recently I face some problems with the mathematical ( calculation) on the reference governor and command governor, so I need some help from you all to get which platform or journal can let me...

23 February 2021 7,746 2 View

Can you mention any source which presents an updates forest-fire hazard or vulnerability map of North-East India?

There exists a confusion of generating fire-hazard maps with MODIS data as that way, we cannot distinguish between shifting agriculture and wildfires. I am looking for a source that provides me...

22 February 2021 9,616 2 View

Covid 19 Pandemic ' impact on digital transformation?

Covid 19 Pandemic and digital transformation

22 February 2021 3,351 5 View

Special issue on PLS-SEM in Mathematics. Are you interested?

21 February 2021 5,601 3 View

What is the better software for approximation of 3D surface with equations?

I have a massive of x, y, z coordinates of 2D surface in 3D space, which builded in Ansys HFSS or AutoCAD. How can I get the analitical aproximation of this surface by formulas?

21 February 2021 3,444 7 View