Significance Definition and 279 Threads

I am building a business cycle index, which include 4 variables that drive the index. Each variable I also include autoregessive coefficients that are all significant and negative. I was wondering what is the significance of this? In other words, what is the significance of have autoregessive...

I have had some issues understanding this topic. On two occasions Dale has pointed out to me that they are not really based on physical things, given that their values are completely arbitrarily defined for the purpose of matching certain measurable or defined things, like the ampere and the...

Homework Statement , 2. Homework Equations , 3. The Attempt at a Solution : [/B] If an electron and photon have the same energy, the electron will have a shorter wavelength, and a larger momentum. The shorter wavelength makes it useful for electron microscopes, outperforming optical microscopes...

Homework Statement Hi! So I'm trying to write a lab report about testing BSA solutions for protein concentrations using a Biuret reagent and a spectrophotometer. There is a portion that asks you to give some practical applications for this test and how it applies to biology. The only thing I...

What are the physical significances of the eccentricity and of the semi-latus rectum of the orbital ellipse?

Homework Statement Verify the identity: ## \nabla \times ( A \times B) = (B\bullet \nabla)A - (A\bullet\nabla)B + A(\nabla \bullet B)-B(\nabla\bullet A)## My issue here is I don't understand the significance of why a term has B or A on the left of the dot product, and another has B or A on...

Hi all, Hi all, hope this is not too simple; please feel free to give me a reference if this is so. I want to know how to address having "insignificant" coefficients in my regression: I just did a multilinear regression returning ## y=a_1x_1+...+a_kx_k ## In the resulting analysis, two of...

In a two-tailed test, the value of the test statistic is 2. If we know the test statistic follows a Student’s t- distribution with P (T>2) = 0.03, then we have sufficient evidence to reject the null hypothesis at 0.05 level of significance. I want to say True but I think I'm overthinking the...

In the vector calculus course, I calculated integrals like, ##\int \vec F \times \vec{dr} ## Does this kind of integrals have physical significance or practical application other than Biot-Savart's Law?

So I know that you can't round off numbers in a longer calculation. (in physics) but how is this with adding and subtracting. For example 52,32*13=680,16 -> 680,16/123=5,529...=5,5(because of the 13) but what is correct when adding inbetween 530,014+0,01=530,02 ->...

The volumetric probability density function for the 1s orbital of the hydrogen atom has 1 peak, and it occurs at the Bohr radius. http://img1.mnimgs.com/img/shared/content_ck_images/images/probability%20density.png For the 2s orbital, it has 2 peaks, neither of which coincides with an...

Hi everyone. What you see here is er Fourier spectra. If i want to conclude that there is a statistical significance difference between the peak value around 30 hz, and all the other smaller peaks. Should i do as following. Estimate the mean value as 2. Estimate the mean peak value to around...

Suppose the value of P=0.03. Suppose we assume los is 5%. Then we will accept null hypothesis. If suppose we assume los is 1%,then we reject it. So based on what factors do we assume los and what los do industries follow?

We did a lab on Le Chatlier's principle. A post-lab question asks wether or not Mg(OH)2 fits the pattern of solids being soluble in warm water. NaOH was added to MgCl2 to provide the OH. The phenolphthalein indicator within the solution changed color with NaOH's addition--magenta. When heated...

Hi, I was wondering why dipoles are singled out as a separate section in my physics textbook. For instance, after discussing electric fields the textbook specifies what a dipole is, dipole moment, and the electric field for a dipole. Finding the e-field for a dipole would be the same as finding...

HI guys, a quick question. After the announcement of the discovery of the higgs-like resonance in July 2012 with ~5sigma significance by both ATLAS and CMS, what is the current p-value distribution with the full data set taken into account? And therefore, what is the total significance reached...

If I open a new deck of cards the sequence is known. If I shuffle them, the sequence is unknown. If I then memorize the sequence, it is again known. State 1: New deck State 2: Shuffled deck State 3: Shuffled deck after I have memorized the sequence State 4: Re-shuffled deck I have computed...

What physical interpretation can we draw from the thermophysical property of thermal diffusivity? How might we visualize the true physical meaning of this property and relate it to its definition?

In a simple series RC circuit, when t=RC, the voltage across the resistor and capacitor is the same. Why is this physically significant and why do we choose this as the time constant that dictates the cutoff frequency?

Using the potential energy formula -GMm/R^2 I understand that the maximum potential energy is 0. But what is the significance of the potential energy as it approaches negative infinity? I am not sure how exactly to word this, but I cannot seem to grasp the what negative potential energy tells us...

Hello, I was working on a classical mechanics problem, and I suddenly came up with this question: Let's think about a point in a 2-D plane. This point is represented by (r, θ), where r is the distance between the origin and the point and θ is the angle measured from the x-axis. Now, what is...

I want to know what exactly Eigen value imply. What is its Physical significance ? Physical significance of eigen vector? Does eigen value concept apply in signal processing or evalvating frequency response off a system?

So the textbook I am reading says that a perfect fluid cannot sustain shear stress, or that p_{yx}=2\mu \dot \epsilon_{yx} =0, where \mu is the viscosity, and \dot \epsilon_{yx} is the rate of angular deformation. Then it says when \dot \epsilon_{yx} =0, this means that "two adjacent...

what is Physical significance of Enthalpy for a process where we don't have pressure constant

Happened to pass someone wearing a t-shirt today with the logo: F/C^2(sqrt(-1))PV/nR Could you explain to me what this means? Thank you

I know the definition of the Poisson bracket and how to derive elementary results from it, but I'm struggling to understand intuitively what they are describing physically? For example, the Poisson bracket between position q_{i} and momentum coordinates p_{j} is given by \lbrace...

So from a killing tensor the FRW metric is known to possess, for a massless particle we find the well known result that as the universe expands the frequency of the photons decreases . But , what does this do for gr ? Was this known to happen before gr ? Thanks a lot. (I know it is used to...

Homework Statement What conclusions can be drawn from this data set? What assumptions are you making? Homework Equations http://i.imgur.com/M9YQGAF.png I hope this is legible. The Attempt at a Solution The solution is what I'm having trouble with. I just don't get how that test statistic has...

Homework Statement State the null and alternative hypotheses. The decision to implement changes in the current math program at a junior high will be based on a sample of students' scores on a standardized math exam. If the average is less than the statewide average of 89, all math teachers...

Homework Statement I am just a little bit confused. I have a question that is asking me to explain what the physical significance of volumetric flux is. Homework Equations I am not sure that this problem requires any equations! The Attempt at a Solution I know that the flux corresponds to...

Homework Statement Let X be a random variable with the following probability distribution X 0 1 2 3 4 f(x) 1/16 1/4 3/8 1/4 1/16 If another random variable Y = X^2 + 1 is formed, find the mean E[Y]. 2. Relevant equation...

I am struggling in understanding what the band structure (E vs. k) diagram tells me. Let's say I have the following material: http://www2.warwick.ac.uk/fac/sci/physics/current/postgraduate/regs/mpags/ex5/phonons/indirect_absorption/indirect_absorption.bmp...

We can mathematically derive the equation of wave, \frac{\partial^2 y}{\partial t^2} = v^2 \frac{\partial^2 y}{\partial x^2}, where v is the velocity of wave propagation. Can we prove this equation physically (not just taking derivatives of the equation of wave, but making physical meaning in...

I just finished a course on linear algebra which ended with Jordan Canonical Forms. There were many statements like "Jordan canonical forms are extremely useful," etc. However, we only learned a process to put things into Jordan canonical form, and that was it. What makes Jordan canonical...

Some books say when heat flows into a monatomic gas at constant volume, all of the added energy goes into an increase in random translational molecular kinetic energy. But when the temperature is increased by the same amount in a diatomic or polyatomic gas, additional heat is needed to supply...

Dose anybody knw that why we take cos with dot product and Sin with cross product?

Homework Statement Homework Equations None given The Attempt at a Solution What I tried to do was figure out the force equations and moment equations, but maybe assuming that there is no moment nor net force is incorrect... I know I'm missing something here. I did an equation equating the...

Hello all! I'd like to clarify on the the differences of bipolar and unipolar voltages. I do understand that they both are used to trigger a number of semiconductor devices. Please and thank you!

Does anyone knows the application and Significance of group velocity?

I foolishly skipped most of my analogue electronics classes, and inevitably failed the exam. I'm now trying to revise for the resit but I'm so far behind that I just cannot understand any of the lecture slides, and I'm getting very stressed. The part of the module I am revising at the moment...

In electrical circuits, VIcosθ is actual electrical power while VIsinθ is magnetic power. This expression looks very similar to W=FScosθ, the work done by a force relation. Is there some significance to FSsinθ in a similar way?

After studying the methods of Lagrange and Hamilton for a bit I still find myself uneasy about the action. I don't even know how to define it other than the integral of the Lagrangian with respect to time: $$I=\int_{t_1}^{t_2}\mathrm{d}t\, L(q,\dot{q},t)$$ Does the action have any...

Dear All, I have a question regarding the understanding of anisotropy of cosmic rays and how to understand them better. To determine the anisotropy I have seen a lot of papers where they use maps that have a Relative Intensity map and a Statistical significance map of the sky. I understand...

Can anyone give me a good definition of Euler's number and its significance. I see it everywhere, it's prolific in science and engineering.

Ok so I'm a bit confused as to how to attempt to answer this question? Describing its significance vs explaining its significance? Here is my attempt, please be ruthless when correcting me as I feel like there are some gaps in my knowledge and misconceptions I have: Where I put '/' I...

So if a rubber band is performing small-amplitude oscillations. Does this mean that it is performing quick oscillations or slow ones?

Could someone please help me understand the physical significance of TE and TM waves?

I need help with these statistics problems. Can anyone guide me through them? I would greatly appreciate it. I am completely lost on where to start. 1. Suppose you want to show the significance of an effect size of 0.20 between your sample mean and a hypothesized mean. You intend to conduct...

I understood that the fermi level is a hypothetical energy level given by the Fermi-Dirac distribution where the probability of finding an electron is exactly 50%. My question is: it always takes (Ec-Ev) energy to excite the electrons in the conduction band in an intrinsic semiconductor or...

I need help understanding the significance of curl and divergence. I am nearly at the point where I know how to use Greene's, Stokes and the divergence theorems to convert line, surface, and iterated double and triple integrals. I know how the use the curl and div operators and about...