Computing Definition and 732 Threads

  1. B

    Use of ancillary bits in quantum computing

    How is an ancillary bit used in a logic gate? I looked at http://en.wikipedia.org/wiki/Ancilla_(quantum_computing ) as well as Quantum Computation and Quantum Information by Nielsen and Chuang, but neither source really explained how an ancillary bit is used (in a logic gate circuit) or...
  2. N

    Please explain why cloud computing is so important now

    I know cloud computer has been around in some form for a good deal of time but all the sudden it is taking off. People are deeming it the future of computing, why is this? what does cloud computing mean for the future of computers and storage et cetera. Thank you
  3. N

    Engineering Computer Engineerng & Quantum Computing

    Context: I am entering my Junior year in a computer engineering undergraduate program, and have not yet taken any course involving quantum physics. The only course I am required to take involving quantum physics is Semiconductor Device Physics. I am doing well academically, and am considering...
  4. W

    Computing a Generating Set in Cohomology

    Hi, this issue came up in another site: We want to compute ( not just ) the deRham cohomology of ## X=\mathbb R^2 - ##{p,q} , but also an explicit generating set for ## H^1 (X) = \mathbb Z (+) \mathbb Z## in deRham cohomology . Only explicit generating set I can see here is {(0, +/-...
  5. B

    MATLAB Computing question 1st year Engineering-MATLAB

    Hi, the question is as follows. I wish to calculate all of the different possible combinations of two vectors in regards to Pythagoras theorem. Not just an element by element operation My code is as follows; opposite=(0:30) adjacent=(0:30) hypotenuse=sqrt(x1.^2+y1.^2) When I use...
  6. A

    Calculating Rth and τ for a Switched Circuit: A Homework Solution

    Homework Statement Homework Equations The Attempt at a Solution I'm trying to calculate Rth so I can compute τ. The problem is that after the switched is flipped for t>0, here is what is left: So you would expect Rth to be 3 ohms but it is actually 2 ohms. Solution for reference:
  7. T

    How to Compute the Sum in the Stationary Distribution of a Markov Chain?

    Suppose we have a Markov chain with stationary distributions ##p_n=\frac{a}{nb+c}p_{n-1}## for ##n\in\mathbb{N}## where ##a,b## and ##c## are some positive constants. It follows that ##p_n=p_0\prod_{i=1}^n\frac{a}{ib+c}##. Normalisation yields...
  8. S

    Quantum Computing: how information is encoded

    I did some quick searches and couldn't find any discussions on this topic. Anyone with background or ability to describe the basics to a novice. I understand the high level basic concepts, but don't know how information is encoded and how the qubits are operated on. Unlike boolean logic gates...
  9. maajdl

    Cloud vs Laptop for Number-Crunching: Which is Faster and More Efficient?

    Hello, I never tried any cloud solution, and I hardly know what it means. Thanks to the CodeProject newsletter, I read this article comparing the performances of different cloud solutions: http://www.infoworld.com/print/237169 from this reading, I guessed that the cloud might be used...
  10. Q

    Where Can I Find a PhD in Quantum Computing with Active Research Groups?

    I want to do a PhD in Quantum Computing. Which universities in English-speaking countries have prominent research groups in this field? Most universities I checked have a Quantum Information group, and they usually mention the term "Quantum Computing" somewhere on their website, but it's not...
  11. MarkFL

    MHB Calculate Volume of Solid of Revolution for y=sinx to y=cosx around y=2

    Here is the question: I have posted a link there to this thread to the OP can view my work.
  12. MarkFL

    MHB Area of a Cardioid - Littlehime's Question @ Yahoo Answers

    Here is the question: I have posted a link there to this thread so the OP can see my work.
  13. MarkFL

    MHB Compute Pool Volume: Angeezzzz's Question at Yahoo Answers

    Here is the question: I have posted a link there to this thread so the OP can view my work.
  14. W

    Program Computing Wedge of Differential Forms?

    Hi, All: Just curious if anyone knows of any online or otherwise software to help compute the wedge of forms, or maybe some method to help simplify. Not about laziness; I don't have that much experience, and I want to double check; I have around 30 terms ( many of which may cancel out) , and...
  15. A

    Engineering [Circuits] Computing the Thevenin Equivalent #2

    Homework Statement Homework Equations The Attempt at a Solution I am trying to find the equivalent resistance for part b. First, we turn off independent sources. We open circuit the 2A source and we close circuit the 30V source. We're left with two resistors. Are they in series or parallel...
  16. MarkFL

    MHB Domenic's question at Yahoo Answers regarding computing the work to empty a tank

    Here is the question: I have posted a link there to this thread so the OP can view my work.
  17. T

    How Do You Calculate Lateral Strain from Diameter Changes?

    I'm trying to compute lateral strain for a bar (strain that would make it thicker, or have more cross sectional area). All I know are the initial and final diameters. This gives me d1 and Δd. Would the lateral strain be Δd/d or ΔA/A? (A is area)
  18. N

    Computing tangential derivative d2x/ds2 at a point on a circle.

    Let P(x,y) be a point on a unit circle that is centered at (0,0). How to compute exactly the function \frac{\partial^2 x}{\partial s^2} where x is the x-coordinate of the point P(x,y) and s is the tangent at point P(x,y) . Clearly, \frac{\partial x}{\partial s} =...
  19. S

    Theoretical Research Topics in Topological Quantum Computing

    Can anyone suggest any? I have all of the coursework for a PhD, So I'm not afraid of anything but I will have lots of questions.
  20. MarkFL

    MHB Compute Area of 2 Simultaneous Inequalities: Don Leon at Yahoo Answers

    Here is the question: I have posted a link there to this thread so the OP can view my work.
  21. A

    Computing the surface integral of a parabloid

    Homework Statement Homework Equations The Attempt at a Solution I am having difficulty understanding how the author determined the limits of integration of ##R##. The author used ##\theta=\pi/3\quad to\quad \theta=\pi/2## and ##r=1\quad to\quad r=1##. More accurately, I'm...
  22. T

    What is the Expected Value in a Probabilistic Computing Scenario?

    Assume we have a number ##S_0##. For ##i=1..n## define$$S_i=\begin{cases}(1+b)S_{i-1}\text{ with probability }p\\(1+a)S_{i-1}\text{ with probability }1-p\end{cases}$$. What is the expected value of ##S_n##?
  23. S

    How Do Different Notations Affect Spherical Harmonic Computations?

    Homework Statement For the spherical harmonics Umn; Vmn, compute the ones of orders 0,1, 2. Umn=cos(nθ)sinn(\varphi)Pmn(cos(\varphi)) Vmn=sin(nθ)sinn(\varphi)Pmn(cos(\varphi)) (b) How many non-zero spherical harmonics are there of order k? Homework Equations Equations of Umn; Vmn...
  24. A

    From simple scientific computing into beginning development

    Hey guys I need some advice: I am a Math/Physics freshman whos pretty much a noob to programming in general; I have some experience with Fortran (taught as part of laboratory) and Python (self taught) but only in the context of elementary numerical methods / scientific computing. I have...
  25. N

    Computing net Moment of Intertia

    Homework Statement An object is made from 2 solid disks: m1 = 23 kg, m2 = 39kg, and r1 = 17cm, and r2 = 33cm. The disks are connected by a thin rod of M = 11kg, L = 67cm. The object is held in a horizontal position and then let go. The object is free to rotate about a pivot through centre of...
  26. PsychonautQQ

    Computing integral over a sphere

    Homework Statement Computer the integral of f(x,y,z) = x^2+y^2 over the sphere S of radius 4 centered at the origin. The Attempt at a Solution so if the parameters for a sphere are in terms of (p,θ,∅) , triple integral (p^2((psin∅cosθ)^2+(psin∅sinθ)^2))dpdθd∅) where the boundaries...
  27. T

    Computing an optimum portfolio for a CARA utility function

    Homework Statement ##u(x)=1-e^{-ax}##. Random variable ##Y\in\mathbb{R}^d## is a multivariate normal distribution with mean vector ##m## and invertible covariance matrix ##\Sigma##. Task: Find ##\xi^*\in\mathbb{R}^d## that maximises ##\mathbb{E}u(\xi\cdot Y)## over ##\xi##. Homework...
  28. T

    Computing a discrete surface integral of a scalar function

    Consider a triangulated discrete manifold (a polyhedron) with known vertices (i.e. each vertex is given in terms of its $$(x,y,z)$$ coordinates ). Assign scalar values (some kind of potentials) to each vertex (i.e. at each vertex, a $$k_t(\mathbf{v})$$ is known through its value, no...
  29. L

    Computing the Unsolvable: Is it Possible?

    Just curious. Is it possible to compute this? if yes then how?
  30. S

    Computing the work of a turbine.

    I am preparing for a re-exam, this is a problem from the exam I took, but I can't see what I did wrong and why. Homework Statement Case: A turbine that is producing work dW is powered by compressed air (treated as a diatomic ideal gas). Known quantities: P_0, P_f, T_0 Wanted...
  31. epenguin

    Advice how to up my scientific computing with I-pad and otherwise.

    When there are answers this might be suitable for Math Learning Materials My untrusty HP48GX graphic scientific calculator conked out two or three years ago and since then for my limited needs (e.g graphs on this forum) in that time I used odd little programmes I found around for graphics and...
  32. R

    Interested in optimization for scientific computing, where to start?

    I've just started programming with Python this summer, and I'm taking a course in computational physics this semester. I've been really enjoying it and programming in general, but I don't have much knowledge in computer science save for intro stuff (string/list methods, functions/classes...
  33. M

    Quantum entanglement and computing

    LiveScience Quantum Computing Breakthrough QE for short. Please read that article. I need someone to set me straight here... Is QE a real thing, as in it's no longer an idea but is 100% a real thing. If two particles become entangled then whatever happens to one particle instantly...
  34. R

    Computing energy in the electron of Li 2+?

    Homework Statement Using the Bohr model of the atom, compute the energy in eV of the one electron in Li2+. Homework Equations E_n=\frac{m\cdot e^4 \cdot z^2}{2n^2 \cdot \hbar^2} Where m= mass of electron, z= atomic number, e= charge of an electron, n is the energy level. ^ I think...
  35. F

    Computing Natural Frequency of a Torus System: 3D vs. 2D Added Mass

    Hi! I am trying to compute the natural frequency of a system and I also need to add the added mass term to my equation. The object I have is a torus and is basically in heaving motion. I found a good paper, which gives a formula for 3d added mass and 2d added mass. I would figure that I...
  36. B

    Quantum Computing: How Fast Could It Go?

    How fast, exactly, is it hypothesized that quantum computers could feasibly reach? If an operation takes 1 second on an average modern-day computer, how long will it take a quantum computer, using an upper-bound idea for the speed these machines could one day reach?
  37. M

    Computing an Integral with a limiting parameter

    Hi All, I am reading a paper in which the following integral is presented $$\int_{-\infty}^{ct-x} \int_{-\infty}^{ct-x} J (2t - \frac{2x+s_1+s_2}{c}) \frac{\mathrm{d}f (s_1)}{\mathrm{d}s_1} \frac{\mathrm{d}f(s_2)}{\mathrm{d}s_2} \mathrm{d}s_1 \mathrm{d}s_2$$ where J and f are unknwon...
  38. E

    MHB Comparing $e^\pi$ and $\pi ^e$ Without Computing

    Without using any computing devices, show which number is larger: $e^\pi$ or $\pi ^e$.
  39. B

    How Much Computing Power is Required for Full CI Calculation of a Molecule?

    For a molecule of n nuclei and x total electrons, how can I work out how much computing power or processing time is required for an exact Full CI calculation for that molecule?
  40. A

    A basic question about computing this derivative

    Hello, This is my first post and I must emphasise that I do not have a science/maths training background and this might be a very basic question. I apologise if it is too basic to belong here. I have a function defined as follows: E(I,J) = \int CC_{p}(I,J)dp Just a little context, I...
  41. W

    Calculating the Pullback of a 1-Form on S1 by a Differentiable Map

    Hi, All: I'm kind of rusty in my computations. I'm trying to compute the pullback of the form dθ on S1 by a differentiable map f: M→S1, where f is differentiable and M is a 3-manifold; please tell me if this is correct: 0)Say we use the basis vectors {∂/∂x1,∂/∂x2, ∂/∂x3, } for TxM ...
  42. O

    Nested Summation Computation for M_K with MATLAB

    M_{K}=\frac{1}{2^{k+1}-2}\sum_{i=0}^{L-1}\sum_{l=1}^{K}\binom{K}{l}h_{i}i^{l}M_{K-l} M_0=1 and the size of h_i is L. I tried to compute this summation in matlab, my attempt is as following: clear h=[ (1+sqrt(3))/4 (3+sqrt(3))/4 (3-sqrt(3))/4 (1-sqrt(3))/4]'; % for simplicity i take...
  43. A

    Computing Average Age of Mothers in Age-Structured Population

    Hi, I have the following problem. Consider an age-structured population growing according to a Leslie matrix. Suppose the population is in stable exponential growth, i.e. its age-structure is constant in time, while the total population is exponentially growing (or decreasing) with exponent...
  44. V

    How does quantum computing work?

    how is it that we are able to get atoms to work like bits? and what is their counting system? because simply counting in 1's and 0's doesn't seem to make so much sense when electrons can be doing any number of things when they are not being observed. i recently watched this but it didnt...
  45. T

    Camera Specifications computing focal length and f/#

    So I have come across a specification of a narrow field of view camera. The specification states IFOV=30 microrad FOV=2x2 resolution=<.1m at 1 km If I assume a 1K sensor at 9micron pitch and an aperture = 3.7cm I have resolution at .013 m Chip size = 9.2mm Focal length is...
  46. B

    Computing The Gravitational Force At A Point

    Homework Statement (a) Compute the vector gravitational field at a point P on the perpendicular bisector of the line joining two objects of equal mass separated by a distance 2a as shown in Figure P13.26. (b) Explain physically why the field should approach zero as r ---> 0. (c) Prove...
  47. S

    Neuroscience/AI/quantum computing

    I have been reading about physicists that study things like computational neuroscience/AI and quantum computing. It is my understanding that these subjects are very closely linked and form a relatively new and open area of science research. I also have the impression that a physics degree is the...
  48. N

    Computing M Sample DFT by Hand

    Homework Statement Compute the M sample DFT of: f(m) = cos(2*pi*(f*m)) for 0 <= m <= M-1 where M = 128, f = 1/16 This should be done by hand, and the solution will reduce to a very simple form. Homework Equations The Attempt at a Solution I slaved through this problem...
  49. MarkFL

    MHB Compute Derivative Using First Principles - MathLoveR's Question

    Here is the question: Here is a link to the question: Calculus Question ... Please HELP? - Yahoo! Answers I have posted a link there to this topic so the OP can find my response.
  50. S

    Technological Impact of Quantum Computing

    What will the technological impact of Quantum Computing be? What meaningful benefits will Quantum Computing bring humanity? What will be the order of progression of its impact? How will Quantum Computing advance our technological growth curve? Where will the money in Quantum Computing be...
Back
Top