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Science topics: Mathematics

Science topic

# Mathematics - Science topic

Mathematics, Pure and Applied Math

Questions related to Mathematics

Question

7 answers

- Aug 26, 2020

why we plot absorbance vs wavelength although there is no direct formula between them and I also want to know that their is any direct or indirect relation between molar extinction coefficient and wavelength. I am trying to generate a theoretical plot between absorbance vs wavelength of single layer MoS2 by using python program,so I need mathematical formula for calculation .

Relevant answer

- Aug 27, 2020

Answer

Very interesting discussion and proposals to solve for calculating the absorbance of a single layer of MoS2 .

The absorbance is important to optically characterize the materials. The absorbance is the absorbed fraction of the incident light with a specific wavelength on a material with a given thickness. It is required for optical filters and for photodetectors and solar cells.

The dependence on the incident light wave length stems from the energy band structure of the material such that it is dependent on the probability of transferring of an electron from the valence band to the conduction band by the incident photons. Specifically it depends on the absorption coefficient as a function of the wavelength.

The key point for the solution is to calculate the energy band structure of the two dimensional material and from it you can get the absorption coefficient as a function of lambda. Then you can calculate the absorbance. As you have here a single layer the absorption coefficient will be equal to the absorbance.

You might benefit from the thesis given in the link: https://digitalcommons.mtu.edu/cgi/viewcontent.cgi?article=1049&context=etds

Question

1 answer

- Jun 29, 2020

the types of board game for mathematical literacy to make the learning and teaching fun

Relevant answer

- Aug 27, 2020

Answer

Draughts , Chess , small-board Go . There will be many others , more modern but similarly challenging , but they all improve 'reading' ability , attention span , appraisal of actions and consequences , problem-solving and stepped solutions rather than reinforce purely the literacy .

What aspect/s of literacy are you thinking of ?

They are also competitive which does little to motivate the 'losers' . Cooperative games might be better , competing against time or with a specific goal perhaps?

I teach maths/numeracy and have a strong interest in the literacy aspect of the process - I will be looking for what you find - good luck !

Question

1 answer

- Aug 26, 2020

please elaborate with good example with mathematical form also

Relevant answer

- Aug 26, 2020

Answer

Please see my latest publication on reaction kinetics and mechanism as well as the references within:

Kinetics and Degradation Mechanism of Adrenaline Derivative CpQ in a Diluted Aqueous Solution

Blasko, Andrei; Tam, James; Gunasekera, Sajeevi; Eboreime, Ale, Biochemistry (2018),

*57*(30), 4536-4546, DOI: 10.1021/acs.biochem.8b00462Question

3 answers

- Aug 25, 2020

FTIR technology is considered the most advance for the detection of adulterants in milk. Is there any mathematical relation that can describe the relationship between the amount of adulterants in milk using the absorbance from the FTIR? Please suggest any research articles that describe this or related areas.

Relevant answer

- Aug 26, 2020

Answer

Hi,

The FTIR is estimated the active groups of milk proteins like NH

_{2}and C=O at 3100-3300cm^{-1}and 1700-1800 cm^{-1}.Question

15 answers

- May 24, 2020

The literature on public (and some school students') understanding of science and mathematics shows many have problems decoding relatively simple information, concepts and data such as from graphs. In the UK, and many other countries, the public have been exposed to unprecedented amounts of information, ideas, scientific findings, formulae, graphs and so on that purport to provide understanding of the global COVID-19 pandemic, so as to presumably advise on risk and guide personal decisions and influence behaviour. But what are the implications of this massive shift in communication for public understanding in general and for future science and mathematics education in schools?

Relevant answer

- Aug 26, 2020

Answer

Thank you for sharing your paper Martin. I found it insightful - particularly your interpretation of graphs and your case for building 'critical STEM literacy'. From recent exploration, I notice that these graphs with data from the pandemic, present interesting outliers and multiple trend-lines which are ignored or cherry-picked in the final interpretation. Inferential stats while allowing decisive conclusions lead us to overlook these interesting data points.

*Critical graphicacy*practices if nurtured from school will create this informed public, who will then find it difficult to simply accept the text interpretation, isn't it?Question

1 answer

- Aug 25, 2020

how I do obtain in the mathematical expression "limiting current density used to reduce Fe+3(A/m2)"? actually how i find the i (Fe)?

i (c)= i (cu)+i (Fe)

Relevant answer

- Aug 26, 2020

Answer

In my publication "design of copper electrowinning ciruit using conventional cells" there is a mathematical equation giving iron limiting current

Question

14 answers

- Aug 25, 2020

In the preprint

W.-H. Li and F. Qi,

*A further generalization of the Catalan numbers and its explicit formula and integral representation*, Authorea Preprints (2020), available online at https://doi.org/10.22541/au.159844115.58373405I concluded two integral formulas indicated in the picture.

(1) Do you know the existence of these two integral formulas? Please give concrete and explicit references containing these two integral formulas.

(2) Can you find direct and elementary proofs for these two integral formulas?

- 633.98 KB新建 Microsoft Office Word 文档.jpg

Relevant answer

- Aug 26, 2020

Answer

Finding the Integral of a Product of Two Functions

Declare a variable as follows and substitute it into the integral: Let u = sin x. ...

Differentiate the function u = sin x. This gives you the differential du = cos x dx.

Substitute du for cos x dx in the integral:

Now you have an expression that you can integrate:

Substitute sin x for u:..

Question

10 answers

- Aug 21, 2020

Hello fellow scientists,

I wish to determine the Dissociation Constant (K

_{D}) of a DNA polymerase binding dsDNA. I won't disclose what the DNA polymerase is because it is unpublished work. I have done some binding assays in Agarose gels, but due to the poor sensitivity of the available dyes I had to visualize the relative binding stoichiometrically, and I could not simply just set the protein or DNA concentration around the expected K_{D}.Previous work in our lab has determined a K

_{D}= 20 nm for our DNA polymerase binding a 33mer locked double stranded DNA hairpin.The purpose of using something so complicated was for kinetics assays. However, I am using a 13-mer dsDNA construct because my goal is to crystallize the DNA complex and a 33-mer is just way too large! My supervisor has advised that I don't believe that my K

_{D}is actually 20 nM for my small dsDNA construct.I am interested in using Isothermal Titration Calorimetry mainly to calculate the K

_{D}of my protein to binding this 13mer dsDNA construct. I would titrate my dsDNA into a fixed concentration of protein. I could guess that the K_{D}is 20 nM, but I actually don't know for sure.I have heard that when you determine the K

_{D}you have to have some estimate of the K_{D}and then scan ligand concentrations above and below the K_{D,}measure the response to get a curve of response vs ligand concentration and the K_{D}is mathematically fit or basically it is just the inflection point of the binding curve.However that advice doesn't tell me if the K

_{D}is say 20 nM, what should fixed concentration of my protein be? (I have appreciable amounts of 100 μM protein because I am a crystallographer so excessive protein isn't an issue.). What is the max and min range that I should scan the ligand concentrations? What if the K_{D}is way worse than we predicted and it is actually 1 μM? What fixed concentration of protein should I use and what min and max concentrations of ligand should I use?Is there a way that I can measure the K

_{D}with a certain fixed concentration of protein, and a huge range of ligand concentrations regardless of if the K_{D }is 20 nM or 1 μM? Is that possible?Relevant answer

- Aug 22, 2020

Answer

Please read the section on the c factor, and other useful information about ITC here:

Question

12 answers

- Aug 20, 2020

The acceptable practice is to validate a model used under any study. What validation methods are available and would we confirm one superior over others?

Relevant answer

- Aug 20, 2020

Answer

Welcome.

You can validate your analytical model by the following methods:

- running experiments under the same assumptions of the analytical mode

- By using numerical simulation where the the system is solved by the numerical methods. There are now powerful simulator for many disciplines of science such as electronic circuits , electronic devices, semicondcutor fabrication processing.

- In some statistical systems they can be validated by Monte Carlo simulations.

This is list may not be exhaustive

Best wishes

Question

16 answers

- Mar 5, 2020

NO. No one on Earth can claim to "own the truth" -- not even the natural sciences. And mathematics has no anchor on Nature.

With physics, the elusive truth becomes the object itself, which physics trusts using the scientific method, as fairly as humanly possible and as objectively (friend and foe) as possible.

With mathematics, on the other hand, one must trust using only logic, and the most amazing thing has been how much the Nature as seen by physics (the Wirklichkeit) follows the logic as seen by mathematics (without necessarily using Wirklichkeit) -- and vice-versa. This implies that something is true in Wirklichkeit iff (if and only if) it is logical.

Also, any true rebuffing of a "fake controversy" (i.e., fake because it was created by the reader willingly or not, and not in the data itself) risks coming across as sharply negative. Thus, rebuffing of truth-deniers leads to ...affirming truth-deniers. The semantic principle is: before facing the night, one should not counter the darkness but create light. When faced with a "stone thrown by an enemy" one should see it as a construction stone offered by a colleague.

But everyone helps. The noise defines the signal. The signal is what the noise is not. To further put the question in perspective, in terms of fault-tolerant design and CS, consensus (aka,"Byzantine agreement") is a design protocol to bring processors to agreement on a bit despite a fraction of bad processors behaving to disrupt the outcome. The disruption is modeled as noise and can come from any source --- attackers or faults, even hardware faults.

Arguing, in turn, would risk creating a fat target for bad-faith or for just misleading references, exaggerations, and pseudo-works. As we see rampant on RG, even on porous publications cited as if they were valid.

Finally, arguing may bring in the ego, which is not rational and may tend to strengthen the position of a truth-denier. Following Pascal, people tend to be convinced better by their own-found arguments, from the angle that they see (and there are many angles to every question). Pascal thought that the best way to defeat the erroneous views of others was not by facing it but by slipping in through the backdoor of their beliefs. And trust is higher as self-trust -- everyone tends to trust themselves better and faster, than to trust someone else.

What is your qualified opinion? This question considered various options and offers a NO as the best answer. Here, to be clear, "truth-denial" is to be understood as one's own "truth" -- which can be another's "falsity", or not. An impasse is created, how to best solve it?

Relevant answer

- Aug 19, 2020

Answer

JN: This may not act s fast.

Question

3 answers

- Aug 7, 2020

My question is: Is there any mathematical or empirical way to prove that given a dataset containing noisy signals y(t) [Y = X +N] and another dataset containing noise N and we want generator to generate clean signals X ? . How to prove other than experiments that generator will be able to generate clean signals from random noise vector z.

- 99.37 KBQuestion.PNG

Relevant answer

- Aug 18, 2020

Answer

Thank you so much for your answers.

Janez Podobnik I have been workikng since your answer and found the optimality condition and also found the proofs of optimal estimator. I have minimized the summary as you can see here in the attached picture.

But I am stuck in linking the attached theory with my case. Since this is the general cndition for an optimal estimator (attached picture) and yes generator would be minimizing a cost function but how can I say that my generator would be able to generate clean signals?

I have changed the notations in main question for simplicity purpose.

Question

9 answers

- Aug 14, 2020

I have a query regarding data transformation if anyone can provide any guidance please?

I was wondering if, generally, it is possible to transform a variable's raw data twice, using 2 different methods, for the purpose of 2 different tests? I will provide you with a little background to my study first.?I have a variable for 'Adverse Childhood Experiences' containing 1 score per participant. N = 113; however, 65 of these are 0 values and 3 are missing data - which I believe is disrupting my data considerably. I understand that it is not advised to simply remove the cases that read 0 just because there are many (however, if you recommend otherwise please let me know if so and why).

Useful to note here is that this variable has a skewness of 1.943, and because of this, I have made the decision to transform it.??

I am carrying out a path analysis with 1 IV, one DV and 2 mediators. In the first instance I am carrying out a t-test (IV - gender, DV - ACE score) and then in the second instance I am carrying out a linear regression (IV age, DV - ACE score), to understand whether age and gender need to be included in my path analysis as covariates. In order to meet the assumptions of the t-test (namely, normal distribution across both levels of the IV: male and female) I have transformed the raw ACE data this using Tukey's formula, which brought the skewness to < 1 for each IV level - great. But then when I go to carry out the linear regression, and aim to meet the assumption of approx. normal distribution of residuals, the assumption is not met on the Tukey transformed ACE data. I have carried out a number of other transformations on the raw ACE data and the only one where the residuals are normally distributed for the regression is through a Log10 transformation.?

My question is this: am I able to carry out the t-test with the Tukey transformed variable data, and then the linear regression with the Log10 transformed data? Or is it the case that I need to use the same transformed data for each stage of the analysis (ie. both Tukey or both Log10 for t-test and linear regression and then the same onward path analyses?)?

If it is the case that I will need to use the Log10 ACE data to go back and carry out the gender t-test, it is useful to note here that I have done this already and when inspecting the Log10 transformed ACE data across the gender variable descriptives table the results come out very strange - for example, N for males goes down from 15 to 6, and N for females goes down from 115 to 59, and there are outliers, where there were none in the Tukey transformed data descriptives, so it is confusing me a little.?

Any guidance welcome!

Thank you

Relevant answer

- Aug 14, 2020

Answer

I assume your data are count values (i.e., the

*number*of adverse childhood experiences). If so, then use a count model (negative binomial is usually a good choice). Transfroming your data is not required at all. If excess zeros are a problem, consider a zero-inflated negative binomial model.Question

2 answers

- Aug 10, 2020

In mathematical ecology, the recent trend is predator induced fear to prey which is an indirect effect of predator to prey. My question is how the prey populace are afraid of infected predator? Are they capable in inducing same level of fear as of healthy predator? Any efforts regarding this will be appreciated.

Relevant answer

- Aug 13, 2020

Answer

I'm sorry, the answer was not for you. I posted by mistake !.

Question

6 answers

- Aug 10, 2020

Hi all,

I am dealing with data with sevaral features and many of them are highly correlated with each other as well as with dependent variable.

In my research on this topics, I found that multicolinearity is harmful for regression problem and may not end up with good model. I got some suggestion that if the features are highly correlated then we have to remove them using VIF criterion.

But, logically when I think of removing correlated features from my analysis how can expect better model as I am not considering all the available information.

Is there any logical explaination or mathematical explaination is available for the above question?

Also, I am thinking that each features are somehow related to any of the other (May be nonlinearly) in that case, do we have problem of multicolinearity ?

Relevant answer

- Aug 10, 2020

Answer

The "mathematicaL" explanation is to examine the formula for the partial regression coefficient. It contains the covariance between the two independent variables, and if this is quite high, it will dominate the estimation of the coefficient. At the most extreme case, the two independent variables are identical, so neither one can make a separate contribution.

In my opinion, the best approach is to choose the most theoretically relevant variable from each set of highly correlated variables and use that one. This may well not cost you as much as you might think, because once you enter one of the variables, adding any of the other variables will amount to putting "the same thing" into the equation, so you R-sq is unlikely to increase.

Question

20 answers

- May 28, 2020

The new Education Act (LOMLOE) that is now being prepared in Spain intends to make Mathematics an optional subject. The Mathematics Institute has issued a manifest that argues about the importance of Mathematics in society, and in favour of keeping Mathematics as a compulsory subject in high school. If you agree with this, please sign the manifest at the link below (the manifest is in Spanish; I don't remember if there is an English version):

There is also a petition at change.org:

Thank you very much in advance.

Hebert

Relevant answer

- Aug 9, 2020

Answer

This link talk about:

What arguments can I give a high school student why mathematics is important?

Question

4 answers

- Aug 6, 2020

In the midst of or post Covid-19, any suggestion(s) or (articles) on how best to implement blended teaching to optimize teaching and learning of mathematics

Relevant answer

- Aug 7, 2020

Answer

Please follow the link below to know in detail

Question

3 answers

- Aug 3, 2020

I need a documented answer with a mathematical derivation, please.

Relevant answer

- Aug 6, 2020

Answer

Check out Brian Hall's book, "Quantum Theory for Mathematicians" in the Springer Graduate Text in Mathematics series vol 267 In it he goes through the history and derivation of DeBroglie's theory.

Question

2 answers

- Jul 24, 2020

Hello

For typical dose-response assays, our lab usually uses steady state intervals for defining the difference between control and tested compound. For those assays, we typically use the angular coefficient or end-point value of given curve (within steady state) to estimate percentage of inhibition, or even kinetic constants

Now we have being working with an enzyme with strong 'sigmoidal' time curse reaction (hill n=3). How can I mathematically compare curves between control and inhibited reactions, or calculate constants?

If anyone could please point me to a good theorical reference or literature examples, I will be very thankful

Stay all safe

Relevant answer

- Aug 5, 2020

Answer

The simplest way is to pick a specific time point as the point at which to calculate % inhibition. This is purely phenomenological. No theory.

If you have an enzyme reaction that shows a time lag before reaching maximal rate, you should investigate the reason for it. Maybe the enzyme autoactivates in the presence of its substrate, like an autophosphorylating kinase, or the substrate may slowly displace a competitive inhibitor. You may be able to preactivate the enzyme so as to get Michaelis-Menten behavior.

Time lags can also occur in coupled enzyme reactions if the concentration of the 2nd enzyme in the sequence is not high enough.

Question

9 answers

- Jul 24, 2020

Many informal settlements have insufficient capacity to forecast, check, handle and reduce disaster risk. These communities face a growing range of challenges including economic hardship, technological and social impediments, urbanisation, under-development, wildfire, climate change, flooding, drought, geological hazards and the impact of epidemics such as HIV/AIDS and COVID-19, sometimes termed ‘the burden of disease’. The inability of these communities to withstand adversities affects the sustainability of initiatives to develop them.

This is a question I would have asked during my masters degree research on Resilience in Disasters. I would like to know the opinions of other researchers as I would like to properly answer this question in a different research-related topic.

Relevant answer

- Jul 31, 2020

Answer

i think the attitude and positivism of the community and their leaders is one big factor to add.

Question

6 answers

- Oct 28, 2017

I want Journals names or list

Relevant answer

- Jul 30, 2020

Answer

Dear search for journal of Mathematics in Web of Science Journal Master list and you will see many journals for Mathematics.

Question

4 answers

- Jul 25, 2020

I am studying mass-spring-damper systems with coulombs friction. There are multiple discussions on simulating such systems using numerical methods and the problems that arise due the discontinuous excitation but I wanted to know if an analytical solution exists. To be mathematically clear about the problem, I am trying to analytically solve the following.

m*(d2x/dt2) + c*(dx/dt) + k*x = F*sign(dx/dt)

where the sign function is defined as:

sign(var) = 0 if var = 0

sign(var) = 1 if var > 0

sign(var) = -1 if var < 0

Note: I am aware of treating such systems as piece-wise linear nonlinear systems but I want to know whether a general solution exists that is capable of solving the problem without breaking it to a number of mini-problems.

Relevant answer

- Jul 28, 2020

Answer

Dear Amir, this equation has the following ananlitics. It can be glue for v more than zero exact solution and for v less than zero. In both cases they are spirals and exactly solvable, but tends to different stationary points. You can even draw its phase space picture: you draw two spirals(exact solutions)each on proper halfspace and jump from one to another, when v=0.

Question

4 answers

- Jun 30, 2020

Much has been said about the differences between physics and mathematics, but less attention has been paid to the differences between physics and chemistry.

The question is, where does physics and chemistry work?

Relevant answer

- Jul 26, 2020

Answer

*After reviewing the answers so far:*

*The question was interesting but ignored.*

*I still like this question.*

*It would be interesting to explore the differences between physics and chemistry*.

Question

27 answers

- Jul 14, 2020

I am interested to solve a mathematical problem (MILP) using evolutionary algorithms but confuse about which one to choose as a beginner in the programming languages. Suggest an algorithm easy to implements with better results.

Thanks

Relevant answer

- Jul 21, 2020

Answer

It feels like you didn't try to use an exact method. Thus, I have to write here that all the beginers are suppose to listen to prof. Patriksson. So, at first try to find an optimal solution. Use CPLEX, learn to model. This will be one of your first sentences in the research paper: "We tried to solve this NP-hard problem... (provide some proof that you really tried)... Because we are not able to generate an optimal solution in reasonable amount of time we decided for a heuristic approach..." I hope this is clear. Otherwise, it is like working with machine learning without knowing about statistical tests. It is slightly embarrassing.

Question

5 answers

- Jul 18, 2020

What are the mathematical equations used to assess the environmental impact using some biological criteria in green algae?

Relevant answer

- Jul 19, 2020

Answer

Dear professor,

The following article may provide inspiration to you about the subject.

Best wishes,

Tahir

Question

5 answers

- Jul 14, 2020

Quadratic equations with complex root were considered unsolvable in secondary schools. this limitation is due to the lack of topic to address the idea of complex number in Nigerian secondary school Mathematics curriculum.

is it Okay to introduce the idea of the complex number so as to enable the student to solve a wide range of questions?

This question was raised by a student I coach when I told him that some quadratic equations do not have solutions in the realm of real numbers!

Relevant answer

- Jul 18, 2020

Answer

As long as the students are comfortable with algebra of real numbers and the quadratic equation, complex numbers should not be particularly challenging to them. These numbers follow rather naturally from a straightforward application of simple algebraic concepts, though novel at the same time. Humans crave novelty, and the younger they are the more so, I think.

Question

9 answers

- Jun 19, 2020

I understand that we can produce that number in MATLAB by evaluating exp(1), or possibly using exp(sym(1)) for the exact representation. But e is a very common constant in mathematics and it is as important as pi to some scholars, so after all these many versions of MATLAB, why haven't they recognize this valuable constant yet and show some appreciation by defining it as an individual constant rather than having to use the exp function for that?

Relevant answer

- Jul 16, 2020

Answer

Dear brother and one of my best friends Mahmoud,

"you are really great researcher" This is how I see you.

Warmest regards,

Kareem

Question

61 answers

- Jul 12, 2020

UPDATE: The values of the variables that I am currently concerned with are:

a~65

V~3.887

While trying to solve a circuit equation, I stumbled onto a type of Lienard Equation. But, I am unable to solve this analytically.

x'' + a(x-1)x' + x = V-------------------------(1)

where dash(') represent differentiation w.r.t time(t).

The following substitution y =x-V and w(y) = y', it gets converted into first order equation

w*w' + a(y+V-1)w + y = 0; ---------------------- (2)

here dash(') represent differentiation w.r.t y.

if I substitute z = (int)(-a*(y+V-1), (int) represent integration. The equation gets converted into Abel equation of second kind.

w*w' - w = f(z). -------------------- (3) differentiation w.r.t z.

it get complicated and complicated.

I would like to solve the equation (1) with some other method or with the method that I had started. Kindly help in solving this,

Thank you for your time.

Relevant answer

- Jul 15, 2020

Answer

I don't know about analytic solutions but this is the equation for a harmonic oscillator in a constant force field with nonlinear damping. It is a like a mass suspended by a nonlinear spring in a gravitational field. There is a single equilibrium point at x=V and x'=0 whose stability depends on the value of a. Solutions will either be unbounded (go to infinity), which is probably unphysical for your electrical circuit, or they will decay to the equilibrium point, following the usual exponential law for a linearly damped oscillator as they approach it. Only the case a=0 has (neutrally) stable oscillations whose amplitude depend on the initial conditions just as you would expect for a harmonic oscillator without damping. There are no limit cycles and no chaos.

Question

3 answers

- Jul 2, 2020

I am interested in including the inverse piezoelectric effect into my GaN HEMT simulation. Sentaurus Device provides a special feature that allows me to update the stress field by invoking the mechanic solver (Sentaurus Interconnect). But I don't have confidence in the results I got. Because from the mathematical point of view, solving the inverse piezoelectric effect is just a simple matrix multiplication (AB = C). However, the final matrix C I got was very weird - some components in C matrix should be zero but they are not. So I was wondering if there is anyone has the same situation about this?

Relevant answer

- Jul 14, 2020

Answer

Dear Han-Wei,

welcome,

You want to validate your results.

you can make this validation by solving a known simple example where it can be solved analytically or its numerical solution is known with high confidence.

You can simplify the geometry of the device such that it can be solved analytically.

Than you can compare your numerical solution with the analytical solution.

You must not solve specifically for the HEMT.

Best wishes

Question

4 answers

- Jun 29, 2020

Heat transfer problem: what mathematical calculations apply to estimate the net current yield in a (TEG HV3-based) thermoelectric panel system where the source emits 5 Mjoule/h at 100°C, and cooling is aimed at by blowing air at 28°C as depicted in the attached drawing. How would you mathematically define a function to maximize net electricity yield by controlling blower speed? What heat exchange design tips are advisable? Thank you.

Relevant answer

- Jul 14, 2020

Answer

Good discussion

Question

14 answers

- Apr 3, 2019

I don't find mathematical problem-solving skills which i can call them my dependent variable. can you please suggest me the mathematical problem-solving skills that work as dependent variable. My research topic is "comparison of students' mathematical problem solving skills taught by guided practice and problem-solving approach"

Relevant answer

- Jul 11, 2020

Answer

I agree with

**Gilbert Lacroix**Question

8 answers

- Jul 8, 2020

Many of the tools I saw and used were designed for measuring performance in a particular topic of mathematics. I am looking for a tool that can capture one's general mathematical thinking skills.

Relevant answer

- Jul 8, 2020

Answer

In fact mathematics is the major tools in applied sciences the best way of measuring academic performance in mathematics is what Prof. Muhammad Ali have mentioned.

Question

6 answers

- Jun 8, 2011

Hallo,

there is a new proof of the 3n+1-Problem !

The paper ist available

?

Perhaps there is a flaw in the proof

?

What is your opinon?

The Collatz-conjecture (the famous 3n+1-problem):

?we construct a sequence of integers starting with integer n = a_0

If a_j is even, the next number ist a_(j+1) = a_j/2.

If a_j is odd, the next number ist a_(j+1) = 3*a_j+1.

Example n = 6:

6, 3, 10, 5, 16, 8, 4, 2, 1

?The Collatz-conjecture: the sequence with a every positive starting-integer ends always in the sequence 4,2 1

Relevant answer

- Jul 6, 2020

Answer

Hello, I observed just this fact, don't know whether or not it can be interesting.

Just analysing the variations: in "even" case the iteration converges (0.5n) and in the odd case the iteration diverges (3n). So calling the f(n)=n/2 the "C" phase and f(n)=3n+1 the "D" phase we have initially the same probability that algorithm start with C or D phase (because even and odds are equally distributed).

The C1 phase will equally (probabilistically) call another C2 phase or a D2 phase (even numbers are equally distributed among multipliers of 4 and not) and so does the D1 phase: numbers that are not multipliers of 3 are equally distributed among even and odds.

The answer seems to be strongly initial conditions dependant, so the algorithm for me is unstable, hence the conjecture is false.

Question

5 answers

- Dec 16, 2019

Matlab based ANN toolbox provides to platform to simulate the following relationship using different algorithms (LM, SCG and so on)

**Y**predicted = function(

**X**i) (1)

Then, a plot of

**Y**predicted to**Y**observed to validate the ANN work.However, is there a way to obtain the mathematical function behind on the above relationship (1)? I know, it has to be highly complex and non-linear function. But is there any specific way to get that function?

Relevant answer

- Jul 2, 2020

Answer

Dear Upaka Rathnayake

This article might help you

Question

4 answers

- Jun 24, 2020

I want to correlate real time application to I newly defined Topology that named Tiny Topology.

Relevant answer

- Jul 1, 2020

Answer

I am not in this area. Please remove me from your list.

Question

53 answers

- May 6, 2019

Dear Sirs,

I think many knows the ideas due to Jules Henri Poincaré that the physics laws can be formally rewriten as a space-time curvature or as new geometry solely without forces. It is because the physics laws and geometry laws only together are verified in the experiment. So we can arbitrary choose the one of them.

Do you know any works, researchers who realized this idea. I understand that it is just fantasy as it is not proved in the experiment for all forces excepting gravitation.

Do you know works where three Newtons laws are rewritten as just space-time curvature or 5D space curvature or the like without FORCES. Kaluzi-Klein theory is only about electricity.

Relevant answer

- Jun 29, 2020

Answer

??

**Preston Guynn****.**added a reply on June 19, 2019:Force, mass, and energy are a parallel set of descriptions of the effects of special relativistic Thomas Precession. All matter and space, and their interactions are described with distance in three dimensions, time, and their derivatives.

Newton's first law of motion is , "Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it."

Yet the concept of motion requires at least two objects, and if there are two objects, then there is

*always*an external force, which is gravitation.So the idea of rewriting Newton's laws without force (or mass or energy) is good, but it should be extended to incorporate the most basic non-linear effects of motion in space time, which are special relativity and Thomas Precession.

See my article describing the recent discovery of the effects of Thomas Precession the particle and galactic scales.

Article Thomas Precession is the Basis for the Structure of Matter and Space

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You could use MathCityMap@顺心彩票 (www.mathcitymap.eu). You can create a learning path with hints and immediate solution check and chat synchronously with the students in the Digital Classroom!

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Dear all :

I

**need to solve the following integral**(attached as an image file)The context is on the calculation of View Factors in Radiation Heat Transfer

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But I'm not sure if I ended with a well defined Integral, since I used two different coordinated systems on a same problem.

I used Cylindrical Coordinates for one of the dA and Spherical Coordinates for the other dA, however both dA are part of the same integral.

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Regards and Thank you !

- 7.84 KBIntegral.png

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When is an integral well defined? First, if the integrating function is integrable (in this case it is); second, if the domain of integration makes sense and is non-contradictory, then the final answer is that it depends on domains A1 and A2. What I do not understand is what the two additional integration variables mean, therefore I suppose that in the domains A1 and A2 the limits for z and η are included. If not, it is a meaningless integral.

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Hi. I'm currently working on my masters' thesis. I will analyse Grade 2 and 3rd (elementary level) maths textbooks and teachers' guides to discover how teaching and learning materials promote students conceptual understanding in mathematics especially the area of number and place value concepts. This will be completely desk-based research.

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Distribution dominates policy. Resources are injected at a point and distribute across communities. Can the distribution be almost instantaneous as in the heat equation? Do the resources morph and distribute, drawing in the wave equation? Where is stability (cf. Laplace equation)? These seem basic questions of public policy. Yet, the big three rarely feature in scholarship on public policy. Why?

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- Jun 20, 2020

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Good Answer

**Muhammad Ali**Question

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- Sep 5, 2019

is there any criteria for evaluation or content analysis in early childhood's mathematics textbook?

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What kind of criteria you want to analysis the book according to it?? You mean Quality Criteria or What?? You should determine which criteria.

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To be clearer, let me ask this:

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Just a saying: maybe a proper deep neural network can suggest best combination of drugs according to the available history.

-----------------------

P.S.

My question is about the direct fight. I don’t mean helping in e.g. producing masks, cloths and …

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Answer

There are two fronts:

1) Short-time efforts that can ease the crisis management, e.g., alternative ways to use/adapt equipment to healthcare needs, taking notes of new empirical knowledge, check the mathematical models, etc.

2) Medium and long term efforts: remediate the healthcare, political and economic by-products the pandemic. I particularly think production engineering can be of great help because several practices could be reorganized to ease all economic sectors.

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I have been receiving complaints from different universities in Germany that master students from countries like India, Nepal, Pakistan can't cope up with the standard of mathematics and the majority of students struggling to pass such courses. Since the Indian Engineering colleges/ universities are divided into IITs, NITs, Government colleges, Private Engineering colleges and so on..the differences in the quality of education are so high that it is difficult for foreign universities to define the qualification criteria in an admission process. Eg. The grades of such students look pretty good on a marks sheet but students' performance in maths exam at German University/FH is poor. Are there any criteria to decide the potential of students during the admission process? Any recommendations to tackle this problem? How other universities in Germany addressing this issue?

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In Nigeria many universities admit students into Preparatory classes called Basic Studies. During this programme the students are properly drilled preparatory to their admissions into the matriculation year

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related literature in my chosen topic

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Are you asking for a list of references related to technology-based pedagogies in mathematics education? If so, get started with ...

Svela, A., Nouri, J., Viberg, O., & Lechen, Z. (2019). A Systematic Review of Tablet Technology in Mathematics Education. International Journal of Interactive Mobile Technologies, 13(8), 139-158. doi:10.3991/ijim.v13i08.10795

Donnelly-Hermosillo, D. F., Gerard, L. F., & Linn, M. C. (2020). Impact of graph technologies in K-12 science and mathematics education. Computers & Education, 146. doi:10.1016/j.compedu.2019.103748

Cullen, C. J., Hertel, J. T., & Nickels, M. (2020). The Roles of Technology in Mathematics Education. Educational Forum, 84(2), 166-1

Akkan, Y. (2012). VIRTUAL OR PHYSICAL: In-service and Pre-顺心彩票 Teacher's Beliefs and Preferences on Manipulatives. Turkish Online Journal of Distance Education (TOJDE), 13(4), 167-192.

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"Random Seed: Definition" From

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I know quantum computers have solved problems that would take an

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If this hasn't happened, is there a proof that it can't happen?

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- Jun 7, 2020

Answer

The whole field was triggered by Shor's invention of his fameous factoring algorithm for quantum computers. 25 years and billions of $ later, it is still not possible to factor the number 15 by using this algorithm, and there are no visible reasons to believe that this wonderful breakthrough might happen within the next 25 years. This simple FACT gives us an idea of the perspectives for QC

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Please see this paper:

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Do we loose information when we project a manifold.

For example, do we loose information about the manifold i.e. Earth (Globe) when we project it to a chart in the book (using maybe stereographic, mercator or any other method)

Similarly, we should be loosing information while we create a Bloch sphere for a 2 state system in Quantum Mechanics which is also a Projected space from a higher dimension i.e. 4 dim.

Also, is there a way to quantify this information loss, if there is any?

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- Jun 5, 2020

Answer

You lose the global information. Examples of global information are the

*characteristic classes*of the manifold "M". A concrete one is the*Euler characteristics "e(M)"*. This number captures different important information of the manifold. Just to exemplify:- it describe (approximately) the behavior of any vector field around its singularities. This means that if the Euler characteristics is not zero, then every vector field must be a singularity (this is a result known as Poincaré-Hopft theorem). For the Earth, we have e(M)=2, so that vector fields must have a singularity. But if we take the vector field describing the wing, this means that it must be zero in some point. Thus,
*at each instant of time there is a point in the Earth in which the wind does not blow!*And since this is a**global**information, you could not conclude it using a chart.

Best,

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They can describe surface roughness of materials Mandelbrot

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I am writing a paper assessing unidimensionality of multiple-choice mathematics test items. The scoring of the test was based on right or wrong answers which imply that the set of data are in nominal scale. Some earlier research studies that have consulted used exploratory factor analysis, but with the little experience in data management, I think factor analysis may not work. This unidimensionality is one of the assumptions of dichotomously scored items in IRT. Please sirs/mas, I need professional guidance, if possible the software and the manual.

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Jimoh Mohammed Idris - See examples below.

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As applied to physics, the source is a mathematically described process and the target is one without a mathematically described process or without a mathematically described process known to the student. Analogy can suggest a mathematical model to a researcher. Analogy assists the student by demonstrating that knowledge already acquired can help in understanding a new subject. Thus analogy can be an investigative tool and a pedagogical tool. John Holland in his book on Emergence from Chaos to Order attributes the source-target characterization to Maxwell (p. 210) but I have not been able thus far to locate Maxwell’s employment of that characterization. Maxwell spoke about analogy as a useful pedagogical tool in an 1870 address to the Mathematical and Physical Sections of the British Association included in his collective works, volume 2, page 215. At page 219: Analogy `is not only convenient for teaching science in a pleasant and easy manner, but the recognition of the formal analogy between the two systems of ideas leads to a knowledge of both, more profound than could be obtained by studying each system separately.’

Do you know the origin of the source-target analogy?

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Dear researchers,

Regarding assumptions of linear regression, can I replace scatter plots with mathematical equations in my article and claim that there is a linear relationship between two variables on the basis of equations. I want to conserve space in my article without presenting scatter plots. Please advise. Thank you.

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- May 29, 2020

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I'm not sure why there's any discussion here. The equation of a straight line is y = mx + c. This is an inviolate mathematical formula. The equation itself justifies nothing - it's perfect. Data sets are fitted with an appropriate model which in the case of a linear fit is usually a least squares procedure. The equation itself tells you nothing about the data going into that best fitting procedure. The 'goodness' of the model is assessed by deviations from that model. Here correlation coefficients (e.g. R

^{2}) can be employed. So, the equation on its own tells you nothing about whether that model is appropriate or not. How close theory and practice are, however, tells you something about the appropriateness of the model. Be careful with 2 things:- Inappropriate correlations. This is where an understanding of the basis of the model is so important. I've shown a couple above
- Over-complicating the situation. n points on a p;lot can be fitted perfectly by an equation of (n - 1)
^{th}degree. This definitely does not mean that the more complicated model explains more. On the contrary, it's basically an empirical fitting...

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I want to construct a model for the world COVID-19 data

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I think, systems dynamics and regression models.

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Review Article in spoecific, Research area Potential Theory

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- May 27, 2020

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I don’t think Scopus advertises the magazines in its database. I have another question Is the list of journals covering the math direction to the scopus database for 2020 approved?

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- Jul 28, 2019

As a founder of making dialectical logic mathematically, author has constructed a mathematical expression for dialectical logic, and proofed the formal logic is only a special case in dialectical logic, see preprint titiled "mathematical foundation for dialectical logic" in my profile, then do you admit author's viewpoints in this field?

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- May 25, 2020

Answer

To Salah Mehdi Salih,

Thanks for reply!

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PhotoMath is a new application for solving math problems by capturing their images. Do you think it will be also useful for solving math proofs? What do you think?

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Victor Christianto , Nice Topic.

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Generally QSR is considered as the parameter for location based service. End-to-end delay, number of hops etc. are the parameters for routing. Why combination of routing and location service enhances the performances of the parameters?

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Answer

Following.

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- Mar 15, 2020

There is a contradiction between the natural width of the energy transition, which is determined by the lifetime at the corresponding energy level and the spectral line width of the radiation line, which is determined by the duration of the wave train.

For example: For the M?ssbauer transition, whose lifetime is of the order of 2 years, while the interaction time at the receiving end is about 10^(-10) sec.

Mathematically, this interaction is expressed by the Feynman diagram of the electron - electron interaction, which integrates over the internal photon line, which, together with the delta functions of the vertex parts, limits the photon spectrum.

By the way, the same paradox applies to any other type of collision.

So, is exist (really) the electromagnetic field?

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- May 22, 2020

Answer

Paradox is in the contradiction between narrow energetic widths of transmitter and receiver, because of long decay times, and wide spectral width of wave packet, because of short interaction time.

As a possible explanation it can be the consideration the process as a virtual, which expressed the Feynman diagram.

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4 answers

- Feb 7, 2020

Hi everyone! Greetings from Munich!

It appears in my mediation analysis, that X is negatively related to M, and M is positively related to Y. Also, i find a significant negative effect of X on Y through M. But since M is determined as a perceived benefit, i am currently struggling with the interpretation of this indirect effect.

Mathematically, of course, this indirect effect result makes sense since "- x + = -", but can i interpret this by saying the benefit is overridden or is it rather that the benefit "backfires" on Y and thus a negative indirect is found?

Many thanks in advance!

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- May 21, 2020

Answer

Nice Dear

**Nik Smidt**Question

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- May 20, 2020

a transport model (e.g logit model or ...) is based on statistical data and field works or merely based on mathematical theories or both of them?

If I want to define a model ( e.g. a new model in freight transportation ), what actions should I do? what kinds of data should I gather?

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- May 21, 2020

Answer

Obviously you need to define in detail

*which*parts of the enormous system, that we may call "the logistics network." What do you want to capture with your model?Also: before you start something new, do you know what parts of this enormous system you would like to provide a model for? You will definitely need to scale down from the global chains of transport and logistics - so what parts are you interested in? What is the purpose of this exercise? Could you, for example, start by reading the recent years of logistics networks papers, so that you can see what the models need, in terms of data, for example? Do you want to collaborate with a logistics partner, in order to obtain real data?

There are lots of questions to be answered, as

*what*model you end up with will determine what questions will be possible to answer. This is not a five-minute exercise, but a PhD project, perhaps with actual partners from logistics.Question

5 answers

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I am trying to justify the use of AT instead of UTAUT for my paper on teacher challenges faced when using technology to teach mathematics...

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Nice Topic , Following

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25 answers

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While many modern causal models do not seem to adhere to Laplace's demon (strict determinism) which treated error factors as merely unknown causes, they do not also always address the issue of freedom and responsibility sufficiently. While it is acknowledged that the human element (as far as intervention) is concerned might involve an exogenous factor (perhaps, "transcendent cause" in neoplatonic terms), posing problem to the equilibrium of an otherwise deterministic system, the models themselves might seem relevant for systems that are independent of human intervention, e.g. artificial intelligence. But, that evokes ethical questions, especially regarding whether formalism of such models can totally ignore the question of responsibility or should they really be resolving them. In more practical terms, can such a machine be constructed based on a causal model that can correctly predict and make right moral decisions for humans?

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- May 18, 2020

Answer

Mathematical models will never simulate human behavior precisely.

Different models show different results. So, if some model provides some precise conclusions about some community, it is not necessarily the same for the others.

People's insights, morals, freedom, and responsibility are very complicated to be captured and recorded in exact equations or tables. Some approximated partial results are accepted for making decisions about some phenomenon.

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12 answers

- Mar 28, 2020

To me it is mostly a story.

There is, at the outset, a puzzle about some natural phenomena, perhaps encountered by inadvertence.

Then some other process exhibits a similar pattern. The question becomes is there some reason, perhaps based on the thermodynamics of the two systems, that connects them?

This takes the curious inquirer into a conceptual forest, or overgrown garden, path obscured, looking for a common principle. When a principle is discerned, there are more questions.

Does the pattern appear elsewhere?

Is there a more fundamental principle underlying the first principle discerned?

Does a principle, even more fundamental, connect all the different phenomena sharing a kind of pattern? Does the same pattern appear but in subtle ways in other phenomena?

Can the phenomena be modeled? What assumptions are extraneous to arriving a model in common? What is the set of minimal assumptions?

Many more paths and tangles appear.

Can the winding path so obscure at the outset be reduced to a set of logical statements that resemble in their appearance mathematical deduction? Never finally, but at least provisionally?

But first, there is a story.

How do you regard physics?

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- May 18, 2020

Answer

Robert Shour,

No truer words were ever spoken. I am somewhat reminded me of the "Two Cultures of Mathematics" discussions that went on in the wee hours between mathematics graduate students. That is the "problem solvers" vs. the "theory builders." Some subjects lend themselves to problem solvers, say analytic number theory which requires everything including the kitchen sink to be thrown at it and on the other hand algebraic number theory which has volumes theory laid as foundations. Paul Endros was maybe the King of the Problem Solvers and Michael Atiyah the King of the Theory Builders.

Of course most mathematicians are somewhere between and broad theories all start out addressing a problem - often with long historical roots. Which category a mathematician falls in is more a matter of temperament and personality than a choice and most mathematicians most likely move between the two. There are those that focus on a problem and during that focus understand what assumptions can be loosen so that the solution is not just of a specific problem but a theory for a much larger category of problems.

Often times one sets out to develop a theory - hoping to apply it to a larger category of problems just to find the assumptions required in the theory are not satisfied by the candidate problems one is trying to address. This happened in the 1960's in what was termed global analysis where problems in the calculus of variations were to be viewed as critical points of functions on infinite dimensional manifolds - with a broad robust calculus developed to apply to this critical point theory similar to Morse theory for function on finite dimensional space to variational prolems. Smale's condition C, now know as the Palais- Smale compactness condition was required for the functional calculus. After this beautiful theory was developed, it turns out that most of the classic problems in calculus of variations do not satisfy condition C. The utility envisioned for this theory - did not fully materialize.

While those that focus on expanding the tools of theoretical physics often find that they make progress by starting with examples (specific problems) and exploring the commonality. For me the solution of the problem (or a category of similar problems) is the key and I lose interest in working to expand the conditions under which the results still hold. As Gauss says once a problem has been wrestled to the ground and tamed, time to move on the the next challenge. But as you say that is a matter of temperament.

As far the theoretical physicists it is often - their vision needs quite a bit of help wrapping mathematical rigor around it. For example without Maurice Grossman, Einstein would not have able to present his theory of general relativity in a coherent and simple mathematical way. Without Roger Penrose, Steven Hawkins would have suffered in his understanding and explaining of black holes, singularities, big bang, etc., in a robust way. In fact on Hawkins' thesis defense, Penrose noted Hawkins' sloppy mathematics. After that the two started working together. It took Stone and von Neumann and later Segal and Bargmann to put quantum mechanics and quantum field theory as envisioned by Dirac, Pauli, Feynman, etc. on a firm robust mathematical footing that it enjoys today. So in reality I think theoretical physicists are more of the story tellers who often depend on others to fill in the details to make the story meaningful and to be able to stand up to experimental validation/falsification.

Question

2 answers

- Jan 15, 2020

In the litterature about quantization schemes, people tend to use Weyl ordering a lot.

Altough it enjoys some desirable properties like sending real functions into self-adjoint operators or sending Schwarz functions into trace class operators, we know that these features are not unique of Weyl ordering.

Is there any deep reason (being mathematical of physical) to prefer Weyl ordered quantizers?

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- May 18, 2020

Answer

From a physical point of view, Weyl ordering provides a consistent procedure for quantizing polynomial Hamiltonians, but of course this is not enough to be preferred as a quantization method. From a mathematical point of view, its importance lies in the subsequent developments of Weyl's idea by Wigner and Moyal which, ultimately, led to the idea of star products and deformation quantization. It was proved by Kontsevich in the late 90s (in a work that gave him the Fields medal) that any Poisson manifold can be quantized following these ideas. You can see a somewhat cursory description of this line of reasoning in the introduction to a paper of mine: https://arxiv.org/pdf/1110.5700.pdf

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5 answers

- Dec 19, 2017

Hi,

I'm attempting to create nonlinear metamaterial structures in comsol and I don't know how to measure second harmonic generation.

How do I measure that frequency x goes into structure and generates frequency 2x ?

Thanks for any help.

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- May 16, 2020

Answer

Does this work?

One fundamental problem I am facing how to see the frequency components (in ewfd physics, frequency-domain study) in COMSOL other than the excited one( mean by the mode at other frequencies).

A very simple experiment if I take one 500nm width by 30 nm height Si waveguide (2d simulation), and excite it with 193.42 THz at port 1 end, now if I want to see the frequency components at 300 or 200 THz it should appear null or no field components. But how to observe it in COMSOL (the modes or the field components can be seen at 193.42 THz since it's the excited one).

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6 answers

- Mar 30, 2017

Why many scientists use the term mathematical model ?

If you have a certain phenomenon and you want to model it, you will describe its, more or less, approximate behaviour by applying to it laws which can be physical, chemical, economical, geometrical and so on, depending on the phenomenon.

Mathematics is only a tool to describe these laws, so you should speak of physical, chemical, economical, geometrical ?... models and not of mathematical ones.

Most of the models I encounter in my research are physical models because, to build them up, the laws of physics are used.

Each time I hear the term mathematical model, my nose?gets wrinkled.

What is your opinion ?

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- May 14, 2020

Answer

I agree with

**Abdulrahman Dahash**Question

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- Mar 1, 2020

What is the mathematics behind r.viewshed module in GRASS GIS

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Answer

Dear Mr.

**Thaisa Jawhly**I sent you a guide that can help you, also this software is open as Mr Som Pal Singh said.

Good luck.

- 5.72 MBGRASS_intro.pdf

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8 answers

- May 11, 2020

I want to conduct a qualitative research about math teaching and learning at pandemic Covid-19 in several specific area in my country. But i don't have any idea to start because i'm not good in qualitative research. It's kindly opened for join research.

Saya ingin melakukan penelitian kualitatif ttg KBM Matematika selama wabah Covid-19 di beberapa daerah di Indonesia. Tapi saya bingung dalam merancangnya krn minim pengalaman dalam penelitian kualitatif. Sangat terbuka untuk penelitian bersama.

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- May 11, 2020

Answer

Hi

Please check the following work. It describes the process in details. I believe it will help you.

Regards

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11 answers

- May 11, 2020

Dear sir/madam!

I'm a final semester student in BS Mathematics and my research interest is in Mathematical Biology. Would you like to provide me the best SEIQR ODEs model for stability and optimal control? I want to do stability and optimal control for our province's real data. So, please recommend the paper.

Thank you so much.

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- May 11, 2020

Answer

Hi, I think this material is for you:

Question

7 answers

- Apr 6, 2020

Is there any alternative topic/theory/mathematical foundation to compressed sensing (CS) theory?

successive to Nyquist Criterion is CS theory, is there any theory that surpasses the CS theory ?

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- May 10, 2020

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Dear Vishwaraj B Manur,

First of all, we should separate the concept of Sampling against the concept of Sensing. These two are not interchangeable!

1. Compressed Sensing theory states that it could recover a set of coefficients (which represents in a specific transform domain the useful information from the analyzed signal) from less samples than Nyquist sampling criteria in order to be able to reconstruct a signal (of course as it could be reconstructed from uniform samples by classical Shannon theory).

2. Compressive Sampling theory states that a signal can be sampled by a protocol (non-uniform sampling, random sampling, modulation and sampling, etc.) which will allow later to be reconstructed by means of a Compressed Sensing algorithm which knows about the used sampling protocol.

3. There are at least 4 sampling ways (according to Figure 2 from https://core.ac.uk/download/pdf/34645298.pdf ) to acquire the information from a signal. Take into account that practical CS is a lossy compression, and this is due to the non-ideal process which happens when the sampling process take place.

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7 answers

- Dec 31, 2013

I want to create an animation to insert it in my math presentation (e.g. a ball hitting the wall, deforming and bouncing back: just an example). Is there any free and easy to use software (preferably, for Mac OS X) to do that?

Which one is the best? I know how to create some animations in Matlab and Mathematica, but this is different: I don't want to code the whole scene as functions.

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- May 9, 2020

Answer

Manim by Grant Sanderson is the best one out there at the moment.

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3 answers

- Mar 24, 2020

Mathematical about the work-related with graphene or any other type of films/coatings.

Lubrication equations in solid films.

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- May 8, 2020

Answer

Have a look at

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10 answers

- Jan 16, 2019

STEM fue el tema principal de la conferencia internacional ASTE 2019, con al menos 8 pósteres, 27 presentaciones orales y 3 talleres que promovieron las

*aulas STEM, la instrucción/ense?anza STEM, las lecciones STEM, los campamentos de verano STEM, los clubes STEM y las escuelas STEM***sin proporcionar una conceptualización o definición operativa de lo que es STEM.**Algunas presentaciones defendían la integración de las disciplinas, pero el ejemplo proporcionado fue principalmente prácticas "indagatorias" y de "dise?o de ingeniería" que de hecho no diferían del tipo de actividades en el aula**hands-on/minds-off**mal conceptualizadas y epistemológicamente incongruentes.Por lo tanto, vale la pena considerar:

(1) ?Por qué lo llamamos STEM si no difiere de las prácticas aplicadas durante décadas (por ejemplo, indagación, actividades hands-on)?

(2) ?Qué beneficios (si los hubiere) puede aportar esta mentalidad/tendencia de

**STEMinificación**a la educación científica y su investigación?Relevant answer

- May 7, 2020

Answer

Radu Bogdan Toma, posiblemente lo decimos/dicen porque se ha convertido en un término "mainstream" que permite "vender el producto" con mucha mayor facilidad.

Sospecho (y es más que una sospecha, de hecho) que este tipo de situaciones se dan con otros muchos otros constructos que se vuelven populares y son utilizados de una forma más o menos gratuíta para justificar algunos trabajos a pesar de que, realmente, no se haga uso esencial de ello.

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3 answers

- Nov 26, 2019

I wish to shift multiple lines or curves (up to 25 lines/curves) so that they are superimposed on one another. This is to enable me see clearly the points or regions where any one of the curves deviate from the others. In this procedure I also want to be able to vary or determine the region or range of superimposition or overlay of the curves. What mathematical function or formulae can enable me do that?

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- May 5, 2020

Answer

The answer to this question can be given in different ways. Suppose the function is a linear function or a quadratic function?

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8 answers

- Sep 7, 2018

I couldn't see any options to show complete axes of 3D plot in MATLAB software ?

There is option to tick Box. But it doesn't covers top axes in

- 16.14 KBBox.JPG

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- Apr 29, 2020

Answer

the best answer is set(gca,'box','on') but in this situation the you add axis. if you want to change the thickness of axis, therefore

set(gca,'linewidth', 2) 2 can be change to an arbitrary thickness

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3 answers

- Apr 28, 2020

Its a book related to biostatistics.

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- Apr 29, 2020

Answer

You can find it in Google Books. D. Booth

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18 answers

- Dec 26, 2019

**Call for Papers & Submissions**

The 9th International Eurasian Conference on Mathematical Sciences and Applications (IECMSA-2020) will be held on

**August 25-28, 2020 in Skopje, North Macedonia**. IECMSA-2020 will be organized in cooperation with International Balkan University.The annual International Eurasian Conference on Mathematical Sciences and Applications (IECMSA) series aim to promote, encourage, and bring together researchers in the different fields of Mathematics by providing a forum for the academic exchange of ideas and recent research works, The previous conferences were held as follows: IECMSA-2012, Prishtine, Kosovo, IECMSA-2013, Sarajevo, Bosnia and Herzegovina, IECMSA-2014, Vienna, Austria, IECMSA-2015, Athens, Greece, IECMSA-2016, Belgrade, Serbia, IECMSA-2017, Budapest, Hungary, IECMSA-2018, Kyiv, Ukraine, and IECMSA-2019, Baku, Azerbaijan.

Website: www.iecmsa.org

**IMPORTANT DATES**

Deadline for Early Registration: May 22, 2020

Deadline for Hotel Reservation: May 22, 2020

Deadline for Registration: July 17, 2020

Deadline for Abstract Submission: July 17, 2020

- 14.98 MBafis_2020.jpg

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- Apr 26, 2020

Answer

Thank you and good luck

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8 answers

- Apr 10, 2020

Have any mathematical relation for all kind of materials?

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- Apr 25, 2020

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Have any mathematical relation for all kind of materials? ?yes

see the following link.

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14 answers

- Apr 21, 2020

The Riemann zeta function or Euler–Riemann zeta hypothesis is the more challenging and unsolved problem in mathematics. What's the applications in physics and science engineering ? Some research advances to solve it ?

- 2.79 KBzeta function.png
- 59.70 KBZeta function.gif

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- Apr 25, 2020

Answer

The

**Zeta function**is a very**important function**in mathematics. While it was not created by**Riemann**, it is named after him because he was able to prove an**important**relationship between its zeros and the distribution of the prime numbers. His result is critical to the proof of the prime number theorem.For more details see

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51 answers

- Apr 24, 2020

I am interested in collaborating with any researcher working on modelling corona virus using fractional derivatives. If you are a researcher or you have a related project, please feel free to let me know if you need someone to collaborate with you on this research study. If you know someone else working on this research project, please share my collaboration interest with him.her. I would be very happy to collaborate on this research project with other researchers worldwide.

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- Apr 24, 2020

Answer

Yes, I am working on such modelling for the COVID-19, and I am ready to cooperate with you in this hot topic.

Regards,

Emad

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10 answers

- Oct 11, 2018

Hi everyone,

I currently use MCS method to analyze effect of some uncertain parameters on electrical power system and run 10,000 simulations to calculate the output which approximately takes around 1 hour.

I recently read some methods which can reduce the MCS scenarios thus, resulting in low computational time.

So, can our fellow researchers elaborate more on this topic or suggest me any other techniques which has the potential to significantly reduce the computational time of MCS (say around 5 minutes for my work) with reasonable accuracy?

Cheers

Sam

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- Apr 22, 2020

Answer

It depends on what is your application of Monte Carlo simulation. You could have different computational time reduction strategy. But generally speaking, to have a good sampling technique will make your Monte Carlo simulation much easier and more efficient. I would suggest the Latin hypercube sampling (LHS) sampling technique, which I used quite often. It will make the distribution of your samples very close to the expected distribution with small number of sample generation.

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6 answers

- Feb 24, 2020

Can someone explain and give me a precise mathematical definition of what "variance" means in terms of principal component analysis (PCA)?

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- Apr 21, 2020

Answer

I suggest you check the following link. Hope it may be helpful. https://stats.stackexchange.com/questions/22569/pca-and-proportion-of-variance-explained

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9 answers

- Oct 5, 2018

I have been looking at different types of inductive teaching for mathematics. These include inquiry-based, discovery, problem-based, project-based, case-based, just-in-time, and a hybrid of project and problem-based.

Is there an inductive teaching approach or curriculum that uses everyday topics and students learn the mathematics needed to understand different pieces of it? For example, a class is discussing gardening. So the students learn how to calculate area of their garden. Then they look at mixture problems (fertilizer and soil). Then they see how Fibonacci plays into petals and seed patterns.

It doesn't quite fit one of the inductive teachings exactly. I think it is a combination of several.

Who has done research on this? Who/what should I be looking for?

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- Apr 20, 2020

Answer

Views differed on induction, so there are those who place it within the direct approach, and there are those who place it within the types of discovery, according to the role of both the teacher and the learner. For you, you can look for a discovery-based induction or a combination of several types of discovery.

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8 answers

- Apr 14, 2020

I need a book, chapter or something like that which discusses PV inverters.

It explains

**Mathematical relationships**and finally**Simulates**it.Relevant answer

- Apr 15, 2020

Answer

Dear Soroush,

Refer the following link and files that helpful for you about PV systems using PSCAD.

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5 answers

- Sep 9, 2013

When we derive the formula for length contraction, we use the direct Lorentz transformation. But for solving the formula for time dilation, we use the inverse transformation. Why is that so?

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- Apr 12, 2020

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SRT is completely erroneous since it is based on the wrong kind of transformations: they have lost the scale factor characterizing the Doppler effect. First,?Lorentz considered a more general form of transformations (with a scale factor), but then he, and also Poincare and Einstein equated it 1 without proper?grounds. Their form was artificially narrowed, the formulas became incorrect. This led to a logical contradiction of the theory, to unsolvable paradoxes.?
Accordingly, GRT is also incorrect.?
For more details, see my brochure "

**Memoir on the Theory of Relativity and Unified Field Theory**" (2000):? http://vixra.org/abs/1802.0136Question

4 answers

- Apr 7, 2020

How can I get an endorsement for my mathematical archive in the arXiv website?

- 43.61 KBaarxiv.jpg

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- Apr 8, 2020

Answer

Have a look at: https://arxiv.org/help/endorsement

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5 answers

- Mar 31, 2020

I am currently for maths project creating a card game that focusses to improve subitizing for students' age between 6-9 years old. I now want to create the 'best' colors for the game but I am looking for research that shows the effect of colors toward children.

**If you could help me or link me to research I'd highly appreciate it.**

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- Apr 7, 2020

Answer

make them happy or sad

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4 answers

- Apr 1, 2020

Hello,

I'm currently working on a Structural Health monitoring approach for the foundations of an offshore wind turbine based on its resonance frequencies. On the basis of a large dataset that recovers measurements of several independent variables , I have already established a linear model in order to predict the target (here, the resonance frequency). I performed a Dominance analysis, Regressions, Features selection etc., in order to evaluate which features influences my target the most. However, I would like to improve the accuracy of my linear model by adding more features to my dataset (and then select the best features to build the most suitable model.), i.e. identify underlying mathematical expression (non-linear) between the independent variables and the target. I already performed Genetic Programming (GP) with symbolic regression (SymbolicRegressor) but didn't get consistent results. Is there a method by which I could get these underlying (non-linear) mathematical relationships ?

Thanks a lot,

Lolo_jr

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- Apr 4, 2020

Answer