Criteria Definition and 80 Threads

I have looked up the definitions of the past tense and present perfect tense in John Warriner's magisterial textbook Warriner's English Grammar and Composition. To me, it seems as though Warriner's definition of the present perfect tense is inadequate. Warriner's definition of the past tense...

Use a numerical method to solve a PDE f[u(x),u'(x),...]=0, where f is an operator, e.g. u'(x)+u(x)=0, and obtain a numerical solution v(x). Define f[v(x),v'(x),...] as the residual of the original PDE. Is this residual of the PDE widely used as the convergence criteria of the numerical solution...

Greetings all I have a question regarding the convergence criteria ratio, abs(an+1/an) or the n√abs(an) when the limit tend to a value less than 1 does it mean the serie is convergent or absolutely convergent? Thank you!

I was wondering if someone can explain how failure criteria work when dealing with viscoelastic materials. I'm quite new to this, so I only know how they work with brittle and ductile materials. (not in too much detail either). And now that I'm at it anyway, if possible an explanation on...

Hello everyone, I don't know which laserdiode and lens system should I choose for my Project. It is all about AFM Microscopy with a cantilever ( Length= 450 um, width = 50 um and thickness= 2um). So as you see it is not a small cantilever. As far as I Know, the larger the cantilever is, a larger...

My criteria for choosing this project-: ->Should be easy. ->Should be doable in 1.5 months. ->Should not to be too easy and should be just hard enough to be a major project. ->It is a group project but since this is nepal lol mainly 1 person is going to do it. max 2 persons will do this. ->Our...

Matt Leifer gives criteria that any good quantum interpretation should satisfy. http://mattleifer.info/2006/06/28/professional-jealousy/?fbclid=IwAR2wl5kEzcfbn6doA53UMty42JP5dADhA5SDxRjaTMNPkq1i9Ag3WPCwB5Q

I read a study that linked cell phone use to infertility. They monitored 2,110 men from 1993-2007. However, they picked all of their subjects from an infertility clinic, therefore their subjects were already experiencing fertility issues. They tried to correct for this bias by having these...

I have written a solver for my thesis which determines various parameters of a conical horn antenna for astronomy application. It is done with Mode Matching Technique (MMT) and some Rumsey's integrals for the aperture free space transitions. I have made some goal functions with the solver which...

Today I was reading about geometric algebra and a kind of vector product that combines the dot and cross/wedge products together and it got me thinking about the meaning of "product". My math background is from an engineering perspective and I've always just accepted the dot and cross products...

Hi everyone, initially let me introduce a concept widely used in ARIMA in the following. $$AICc = AIC + \frac {2k^2+2k} {n-k-1}$$ where n denotes the sample size and k denotes the number of parameters. Thus, AICc is essentially AIC with an extra penalty term for the number of parameters. Note...

Possibly interesting reading... This article ( https://www.inverse.com/article/52691-gre-scores-are-a-bad-predictor-of-phd-success ) alerted me to the article below. See also: https://phys.org/news/2019-01-gre-students-diversity.html http://advances.sciencemag.org/content/5/1/eaat7550...

Let's say there is a set of n elements, S. P is a subset of S, with m elements, and satisfies some conditions, i.e. c1 < f(P) < c2 and g(P) < c3, where f and g are some functions on the elements of P and c1, c2 and c3 are constants. For practical purposes, S is represented as a sorted array of...

I read this wiki and some of the references https://en.wikipedia.org/wiki/Bound_state But I can't really understand. For example the electron in hydrogen has specific energies and not general relations that the articles seem to claim. Thanks

Homework Statement Homework EquationsThe Attempt at a Solution I don't know how to do part d. For di, i know that separation of arm d should be small in order to have spatial coherence. For dii, what is the meaningful criterion, can I say the primary max of blue light lies on the first zero...

I am only 17 years old and i need to ask you this should i take a job which gives lot of money but i will start to hate the job eventually or a job that i love ? The job that i love will not make me poor or something but the thing is that i will never be able to buy expensive cars and...

I am trying to make a spread sheet that compares different investments (cryptocurrencies). So far each investment has 9 criteria. I have normalized each criteria to be worth 0-5 points. I would like to be able to rank each investment based on their total score depending on different criteria. I...

Hi, I have an operator which does not obey the following condition for boundedness: \begin{equation*} ||H\ x|| \leqslant c||x||\ \ \ \ \ \ \ \ c \in \mathscr{D} \end{equation*} where c is a real number in the Domain D of the operator H. However, this operator is also not really unbounded...

Homework Statement [/B]Homework Equations Number of encirclements = Number of open loop poles - Number of Close loop poles on Right side of S plane. The Attempt at a Solution There is 1 open loop pole on RHS For Close loop poles I used Routh Herwitz method and got 1 pole on RHS. 1 sign change...

Hello I have to conduct factory inspections of Polyethylene pipe / fittings manufacturers on behalf of my company. The PE products are to be used in natural gas pipeline network. In order to check conformance to relevant standards / best practices, I have prepared a set of questions to ask...

i need I need to design this mechanism, but have not found the design criteria or how, someone could show me how or where to look. I need to design the mechanism that puts the lid to the product. but not with pneumatic actuators. in the following videos you can see how it works:

Homework Statement The cart is initially at rest. The overall goal will be to determine the cart’s acceleration. Plot the data in such a way that: The position is the independent variable, and plotted on the horizontal axis. The acceleration is inversely proportional to the slope. The resulting...

Homework Statement Let E denote the set of positive even integers. An element p ∈ E is called an E-prime if p cannot be written as a product of two elements of E. Determine a simple criteria for when elements of E can be uniquely factored into a product of E-primes. Homework Equations Some...

The answer is given as (a). I want to know the reason. It is a boson. Why can't it form a Bose-Einstein condensate?

Hi, is there a way to add a user defined convergence criteria to an ode solver so that the solution is stopped?

What is the most important factors that determine if a candidate can be admitted into top theoretical physics PHD program? Since undergraduate students are most likely not able to produce significant research paper, will universities put more emphasis on GRE and GPA?

I am currently in a gap year, as i wanted to be 100% sure on what UNI course i was going to go for in 2016. I've been looking into mechanical engineering as a possible option, but my main worry was regarding the extent to which 'maths' is used during the course, and during your actual career. I...

Hi guys!, i want to know what are the criteria in choosing a substrate to deposit thin films, like what are the physical and chemical properties of the substrate to be compatible in depositing thin films?

Homework Statement The problem is this one: Consider a monocomponent fluid, isolated and in equilibrium, a) Find the homogeneity criteria that must fulfill the number of microstates Ω(U,V,N). b) If Ω(U,V,N)=exp(a*Vα*Uβ) when a>0 use the result in a to find the condition that have to fulfill...

Homework Statement I have been searching online but I am unable to find a site that explicitly states the Den Hartog criteria for a tuned mass damper. What is the Den Hartog criteria? Homework EquationsThe Attempt at a Solution

I know that the criterion of stability for an explicit solution to the heat equation: \frac{\partial T}{\partial t}=D\frac{\partial^2 T}{\partial x^2} is \Delta t <\frac{1}{2}\frac{\Delta x^2}{D} however, what is the stability criterion for an equation of the form \frac{\partial T}{\partial...

1.What would be the effect of the following factor on the maximum power that can be transmitted. (give reasons for your answers) Increasing the included angle of the pulley groove. 2. What would be the effect on the following if the load torque is increased and the speed maintains constant? The...

I am a mechanical engineer with little/no knowledge of wireless communication protocols.I have the need to transfer serial data from my Arduino(microcontroller) to my PC. Steering wheel sends serial data upon request from Arduino-> Arduino receives this serial data -> (wireless protocol...

Hello guys, I hope you all have happy holiday! This question crops up to my mind often when I read through threads in PF. One of the most common points for books recommendation is because of good and instructive problems in them. For specific example, WannabeNewton in this thread is very...

Possible "criteria" or parameters for planetary collision? Suppose a computer model were created to simulate two proto-type planets on a collision course (for example, the Earth-Moon collision in the Hartman theory of the Moon formation). We know that the Moon is spiraling outwards (tidal...

Hi guys, I've recently started studying relativity and I thought I was on a good path but I got a little confused with some concepts. I've red a lot about the Andromeda paradox, the train and tunnel experiment and so on so I'll present my question in a way related to those topics. In my...

I am reading Dummit and Foote Section 9.4 Irreducibility Criteria. In particular I am struggling to follow the proof of Eisenstein's Criteria (pages 309-310 - see attached). Eisenstein's Criterion is stated in Dummit and Foote as follows: (see attachment) Proposition 13 (Eisenstein's...

I don't know whether this has much general interest. I am interested by communication horizons in cosmology, or causal horizons if you prefer. This paper claims to study several cases including how far apart two quasars would have to be to have been out of contact ever since the end of the...

When working problems using Rayleigh's Criteria: θmin=1.22 [λ/D] Why do the answers come out in radians? I'm sure it has something to do with the aperture being circular but I don't understand why. Thanks!

We used to apply periodic boundary condition to simulate an infinite system. What will happen if the interactions between atoms do not drop to zero even when they are infinitely far away? Is the periodic boundary still valid? How can I prove the periodic boundary condition is valid or not? thanks.

Is it possible to solve this equation in terms of H without knowing any numbers? If so what method would I use? If I had numbers I think I could solve it numerically in excel. It's been a few years since I was in school and am fairly (very) rusty: H^5 -10*L*H^4 +25*L^2*H^3 -25*Q^2/K^2 = 0...

Homework Statement Why a spontaneous process is accompanied by a decrease in internal energy? Homework Equations The Attempt at a Solution I know that ΔH and ΔG will be negative for a spontaneous process

I've used many different power series representations of functions and seem to always take it for granted that functions which are "nice" and continuous have such a representation. But what is the criteria for a function to have a power series representation? I know of some that don't, but...

Hi, All: I have the following problem: My department head wants to accurately estimate class attendance, as a measure of the effectiveness of my teaching. For that, I used to take attendance weekly, i.e., once each week, selecting the day at random, from which I would construct...

\text{Let} ~ W_p ~ \text{be a Wagstaff number of the form :} W_p = \frac{2^p+1}{3}~, \text{where}~p>3 \text {Let's define }~S_0~ \text{as :} S_0 = \begin{cases} 3/2, & \text{if } p \equiv 1 \pmod 4 \\ 11/2, & \text{if } p \equiv 1 \pmod 6 \\ 27/2, & \text{if} ~p \equiv 11 \pmod {12}...

I'm not sure where to post this question. In classical mechanics many problems are simplified in the approximation of "small angles" or "small oscillations". Wikipedia gives the following criteria or approximations: \sin \theta \approx \theta. \cos \theta \approx 1 - \frac{\theta ^2}{2} \tan...

Gentlemen, I have a subform with the following fields: name of the step, the scheduled date, place and date rescheduled date. I'm having trouble making a statement in a query that has the following criteria: need to know what the step is smaller than today's date between the date scheduled...

Hello all Friends, I am taking my undergraduate, majoring in Electrical Engineering, concentration in Control It takes 10 semester to pass, 1 semester=4months. Well it might be rare for you. And I am in 8th semester doing my internship as one of the criteria in the curriculum. In this...

I have calculated a static contact stress of 670 N/mm2 using formula from Mechanical Engineering Design, Shigley, 5th Edition. My problems lies that there is no acceptance criteria. I'm using Grade 5 Structural Steel (yield~355 N/mm2). Previous threads have stated that a 2.5 * yield can...

Homework Statement Homework Equations The Attempt at a Solution