Writing Definition and 712 Threads

Dare I suggest another sticky? (Apparently so.) Atomic Rockets Forensics DemystifiedCommonly referred-to scales: http://tvtropes.org/pmwiki/pmwiki.php/Main/MohsScaleOfScienceFictionHardness Kardashev Scale of Technological Advancement @ Wikipedia Unsure about whether or not to include more...

Hi guys. I want to write fortran programs in eclipse. All I have done so far is install eclipse with Photran (which according to google should allow me to). What do I need to do now to be able to compile and run a sample code? I am trying to run this: program hello_world implicit none...

Could we have a sticky to collect some of the more helpful general advice on the do's and dont's of plot-construction in speculative fiction? I've been reading some of the older threads which have been moved to this board, and came across two insights so far which I found personally useful and...

Dear PF users What is the rationale for Sze to write the exponential terms in ch. 1, Eq. 38 once as \exp \left[ -\frac{E_C - E_F}{kT} \right] and once as \exp \left[ \frac{E_F - E_D}{kT} \right] ? In both cases E_F is larger than either E_C or E_D. To me, for the sake of not having to worry...

Well, the title really sums it up to be honest. Are we allowed to write our own stories and post it piece-by-piece as we write, here on this forum? If so I would love to do something like that. I may even include some of the members as characters even ;)

hello.I am a B.S in mechanical engineering and I want to apply for M.S in U.S. I hope that some members on this forum could help me to correct my cv. Objective Education and Research in the field of Mechanical Engineering Educational Information ·1 B.Sc. Mechanical...

Hello. I'm attempting to write some data in different files (each thread write in each file), but I'm getting an error saying: 'File already opened in another unit'. I'm using the function OMP_get_thread_num() from OpenMP library in order to open individual files in individual threads. !$OMP...

Homework Statement Let X= \{a,b,c\} and Y= \{d,e\}. Write down and explicit bijection N_{|X×Y|} → X×Y The Attempt at a Solution Well I came up with the easiest method, just giving one value to each member of N_{|X×Y|} so I was just wondering whether there is another way of doing it not by...

Homework Statement An open box of maximum volume is to be made from a square piece of material 24 centimeters on a side (24-2x) by cutting equal squares from the corners and turning up the sides. The table shows the volumes V (in cubic centimeters) of the box for various heights, x (in...

i used to believe that i was getting a second rate physics education because i wasn't attending any classes and the only way i could get answers to problems was to ask them here. so a little while ago i went to my first public lecture on physics since i started studying physics heavily. some...

This is related to another post of mine. How would you go about writing \frac{1}{e^{z}-1} in u+iv form? Usually multiplying through with the complex conjugate gives you the desired form, but here I'm not sure that it works. Any suggestions?

I need some help with FREQ. on the MHz Band and the kHz Band? If I am on a Radio that displays the FREQ 909.5 MHz I know I would write this out as 909,500,000 Hz and this is 9 Hundred and 9 Thousand 5 Million Herts Am I right?

Homework Statement Newton's Law of Cooling states that the temperature of an object changes at a rate proportional to the difference between the temperature of the object itself and the temperature of its environment. Suppose the ambient air temperature is 70*F and that the rate constant...

Here's a quick question concerning writing clearly in proofs. I am revising and refining some of my proofs [this is for a self-study], and I across a problem where I had to prove that f: G->G defined by f(x)=axa-1 is a automorphism. To show it has the homomorphism property, I had to do some...

Hi all, This is both linear algebra and physics problem, and I decided to post in physics because I want a "physics-framed" answer. Suppose you have a system with two objects (subsystems) in it described by the state: |ψ> = ƩiƩjcij|i>|j> where |i> and |j> are orthonormal bases for the two...

Has anybody taken part in online collaborations writing a scientific paper ? experiences ? Just what the title says really. I am collaborating with a programmer and a mathematician (myself biophysics) on a computational neuroscience paper. Ill be lead author as the primary concept is mine...

Hi, I'm trying to write out a set of equations I was using in an excel worksheet and am unsure how to represent a modulo function. For example, is there a proper way to write out the following excel formula in mathematical terms? =MOD(280.4+X*(36000.7 + X*0.0003032),360) *Where X...

Recently I went through a bunch of my old solution sets and realized that I've been quite sloppy with my use of punctuation; in particular, examining the quality of my writing in solution sets over a period time, it appears that the lack of proper punctuation is getting more and more pronounced...

For expressions like: f(z) = (1+z2)/(1+z4) how does one write the modulus of that in terms of lzl?

Homework Statement An oxygen atom has a total of 8 electrons. Write the four quantum numbers for the each of the eight electrons in the ground state? I can't seem to figure this out. I know this... O = 1s^2 2s^2 2p^4 But from that, I don't know how to finish the question...

Structural Analysis-Writing Finite Element Code, Dear all, I have written a code ( in fact it is a software) for 3D finite element structural analysis. While developing the code I found that assembling global stiffness matrix is quite complicated. The complication is even more when we...

Homework Statement Be able to write a system of Linear homogenous differential equations as a matrix differential equations. Homework Equations The Attempt at a Solution I have uploaded the work and original problem. My question is did I properly answer this question?

I hope this is the right forum to put this in. This is a strategy I am trying to fine tune for a book I am writing about the card game Pinochle. Here are the rules: Two player game - First player to 40 points wins. Game starts 0 points to 0 points. Players alternate turns. One...

So for my program I want to input this line of code: addPairs 10 [(2,3),(4,15),(87,92),(23,45)] Where the 10 after addPairs is the minimum distance the pair (x,y) must have in order to be outputted as [x+y] For example : addPairs 10 [(2,3),(4,15),(87,92),(23,45)] would output: [ 19...

For a while I've used an IREX DR800 e-book reader, and in the course of my experimentations, I have observed that I can actually write directly onto the screen with a graphite pencil, and erase with a cotton t-shirt. I've been trying to find a larger piece of glass which yields similar effects...

Ok I need some help on how I can approach a problem like this. Say that A B and C are matircies and I know the values of each of them. And let x and y be constants (ie: 7 or 2 or somthing like that) What I want to know is can you write A = xB + yC How would you check to see if...

Hi I am i need of some advice with regards to completing my dissertation. It was based around the idea that i should develop a humidity based control system and integrate it into a temperature control chamber to fully develop an environment chamber. I am basically quite far behind in writing the...

Write a recursive function to compute the Jacobi symbol J(a, n), is defined for relatively prime integers a and n, a> o, \mbox{ and } n > 0 by the formula J(a, n) = 1 \mbox{ if a = 1, } = J(a/2, n)*(-1)^\frac{n^2-1}{8} \mbox{ if a is even, } =J(n \% a, a)*(-1)^\frac{(a-1)*(n-1)}{4} \mbox{...

Hi! Right now I'm in my 2nd year of Mechanical Engineering. The only three ME classes I'm taking are Fluids/Thermo I, Mechanisms, and ME Lab I. I don't particularly like the first two, but I'm doing fairly well in them and they give me something to do. However, the lab is killing me. Every two...

Homework Statement Write \displaystyle \sum_{k=0}^{\infty} \frac{1}{9^k (\frac{2}{3})_k} \frac{w^{3k}}{k!} in terms of the Gauss hypergeometric series of the form _2 F_1(a,b;c;z). Homework Equations The Gauss hypergeometric series is http://img200.imageshack.us/img200/5992/gauss.png...

Homework Statement When writing chemical formulas in Mastering, indicate the physical states using the abbreviation , , or for solid, liquid, or gas, respectively. Use for aqueous solution. Write the total ionic equation (also known as the complete ionic equation) for the reaction of...

Homework Statement A student takes a 30-question mathematics exam on which she got n questions correct and m questions incorrect and left k questions blank. If correct answers are worth 4 points, incorrect answers are worth -1 points, and blank answers are worth 0 points, write an equation to...

Have any of you people tried writing math and physics demos that can be run in a web browser? The physics demos would have to be simulations, of course. I myself have done so: http://homepage.mac.com/lpetrich/Chatters/GeometryDemo_GMap.html - Spherical Delaunay triangulation, convex hull...

Hi, Last semester, an Australian university from which I've earned my Graduate Certificate degree in astronomy asked me to fill an application form for “key generic skills” (equivalent to an undergraduate degree in physics or astronomy) in order to become eligible (if accepted) for pursuing my...

Forgive me for not writing in latex, but I searched this site for 10 minutes looking for a latex reference and could not find anything on matrices. Also, excuse for the excessive amount of info. Homework Statement Determine whether this list of 3 polynomials in P1: p1 = 1+3x p2 = 1+2x...

what are the different ways to write four quantum numbers that designate an electron in a 3d orbital

Homework Statement This is my assignment: (Sorry, it's a little long) You are required to write a UserID Java class to be used when generating and storing the user id and password for a new user of a system. At a minimum, each UserID object should store a first name, last name, user id, and...

Hi, I have been given this problem and the solution however, neither make sense to me. x_t=\int exp(t-s)E(k_s|F_t)ds (the integral is from t to infinity) where k_u=m^d_u-(m^d_u)^*-α(y_u-y_u^*) for all u>0 suppose (m_t, t>0) is a martingale, what is an equation for x_t using...

Homework Statement Analyze a simple beam writing out the integrals in mathcad. Length: 20ft (L) Distance to Reaction: 12ft (B) Distance to Distributed Load: 0ft Distributed Load: 273.33 lb/ft (w) Homework Equations V=r1-w(L-0)+r2=0 M=r1*L-w/2*(L-0)^2+r2*(L-B)=0...

Homework Statement Sketch the graph of a differentiable function f such that f(2)=0, f' < 0 for -infinity < x < 2, and f' > 0 for 2 < x < infinity. Homework Equations The Attempt at a Solution I have answered this question correctly, but what interested me was that in the...

I'm trying to express the tensor equation F'^{\mu\nu}=\Lambda^{\mu}_{\sigma}\Lambda^{\nu}_{ \rho }F^{\sigma\rho} in matrix form. Here the indices range from 0 to 3, so we need 4 by 4 matrices. Let F', F, and \Lambda be the matrices associated with the tensors appearing in our equation. Which...

Homework Statement I'm writing up a mathematics-based assignment and I want to type some formula into a MS Word document. I'd appreciate if anyone could let me know how to go about this. Thank you. Homework Equations The Attempt at a Solution

Im trying to generate a simple beam program in mathcad and am having trouble with the integrals. Attached is what I have so far:

I am trying to write shear and moment equations in mathcad for a simple beam problem. Any help would be greatly appreciated. Thanks

My apologies if this is in the wring place, but is there any way that I can write a matrix out on this forum? Maybe set up a table in excel or word and copy over? Any suggestions?

Does this sentence make sense and is there a better way to say it? "Digital I/O modules have a variety of operating voltage range. " what I'm trying to say is that there are different digital IO modules and each has a different operating voltage range rating.

?hi, im trying to write a code that should do this- create a random sized zeros vector create a random size ones vector i have to do this several times and combine it all(by that order) into one vector that should lookz like- 0000011111001111001... does anybosy have an idea how to do it...

Homework Statement Consider the following initial value problem for two functions y(x),z(x): 0 = y''+(y'+7y)\text{arctan}(z) 5z' = x^2+y^2+z^2 where 0 \leqslant x \leqslant 2,\; y(0)=1.8,\;y'(0)=-2.6,\;z(0)=0.7. Rewrite the system of ODEs in standard form using a suitable substitution...

(Apologies for the lack of LaTeX formatting - I usually do my typesetting with MathType, but I only have Microsoft Equation Editor on this computer which doesn't have LaTeX export). This isn't a homework question, but is problem I've discovered I'm facing after diving into another problem, but...

After 1-2 years of writing formal math proofs in undergraduate school, I now speak and write much more eloquently than I used to. Now, before uttering or writing a statement, I take a quick pause to ask myself whether it's logically valid; it's unambiguous; it's relevant and sequentially...