Parallel computing is a type of computation in which many calculations or processes are carried out simultaneously. Large problems can often be divided into smaller ones, which can then be solved at the same time. There are several different forms of parallel computing: bit-level, instruction-level, data, and task parallelism. Parallelism has long been employed in high-performance computing, but has gained broader interest due to the physical constraints preventing frequency scaling. As power consumption (and consequently heat generation) by computers has become a concern in recent years, parallel computing has become the dominant paradigm in computer architecture, mainly in the form of multi-core processors.Parallel computing is closely related to concurrent computing—they are frequently used together, and often conflated, though the two are distinct: it is possible to have parallelism without concurrency (such as bit-level parallelism), and concurrency without parallelism (such as multitasking by time-sharing on a single-core CPU). In parallel computing, a computational task is typically broken down into several, often many, very similar sub-tasks that can be processed independently and whose results are combined afterwards, upon completion. In contrast, in concurrent computing, the various processes often do not address related tasks; when they do, as is typical in distributed computing, the separate tasks may have a varied nature and often require some inter-process communication during execution.
Parallel computers can be roughly classified according to the level at which the hardware supports parallelism, with multi-core and multi-processor computers having multiple processing elements within a single machine, while clusters, MPPs, and grids use multiple computers to work on the same task. Specialized parallel computer architectures are sometimes used alongside traditional processors, for accelerating specific tasks.
In some cases parallelism is transparent to the programmer, such as in bit-level or instruction-level parallelism, but explicitly parallel algorithms, particularly those that use concurrency, are more difficult to write than sequential ones, because concurrency introduces several new classes of potential software bugs, of which race conditions are the most common. Communication and synchronization between the different subtasks are typically some of the greatest obstacles to getting optimal parallel program performance.
A theoretical upper bound on the speed-up of a single program as a result of parallelization is given by Amdahl's law.
I did a little experiment recently where I took a plane mirror and held it underneath a ceiling light. Then, I began to lower my head so that my view was closer and closer to the surface. When I did this, the image of the light began to drift lower and lower in the mirror until it completely...
Hi,
I've a doubt about how to the energy is stored in a 'real' RLC parallel resonant network feeds from a sinusoidal source. Take a 'real' RLC parallel network having a resistor ##R_s## in series with the inductor ##L_s## (modeling its loss) with the capacitor C in parallel and consider it in...
I'm sorry if the wording is a bit clunky, but this is not a common topic for me.
Say you have some 3D object consisting of vertices and facets. There are many tools that can visualize this and they only show its projection on 2D, i.e. on your screen. I presume that you would filter the faces...
I tried to solve this problem on my own, but I'm not sure whether I solved correctly or not.
it is electromagnetics homework from my Uni, and it is pretty tough for me.
I attached the image of the problem and how I tried to solve this one.
I hope somebody will give some feedback.
Hello! I'm having trouble with getting the right result in this litle example. Consider this admittance
$$ C + Cs - w^2_{pr} CCs $$ Now to get the resonance we need to set the imaginary part of the admittance 0.I did that like this
$$0 = C + Cs - w^2_{pr} CCs $$ Now I need to get ## w^2 ##...
Basically, I want to determine how many microchannels I can have in parallel to drive a fluid (for now assume water),without the syringe pump stalling. Let's say a syringe pump have a maximum linear force of 50 lbf. and I want to drive the fluid at 60 ml/hr. So if I have 4 parallel channels...
Suppose you have a tensor quantity called "B" referenced in a certain locally inertial frame (with four Minkowski components for instance). As far as I know, a parallel transportation of this quantity from a certain point "p" to another point "q" consists in expressing it in terms of the...
the impedance of the parallel RLC circuit is shown as attached.
The equation above is the impedeance of RLC circuit in series, how can I convert that in parallel? Thanks.
b) The Points on L1 satisfy the equations of the planes P1 and P2. The Points on L2 satisfy the equations of the planes P2 and P3. The Points on L3 satisfy the equations of the planes P1 and P3. Let v1 be a vector along L1 which lies on both planes P1 and P2. Let v2 be a vector parallel to v1...
I am having too much trouble to solve this exercise, see:
Using (R,phi,z)
ub is the path derivative
U is the path
V is the vector
$$V^{a};_{b}u^{b} = (\partial_{b}V^{a} + \Gamma^{a}_{\mu b} V^{\mu})u^{b}$$
$$U = (0,\theta,Z)$$
I am not sure what line element to use, i mean, a circle around a...
I'm not understanding this question at all and am not sure how to even begin answering this. Any help would be appreciated.
Write the slope-intercept equation of the line that is parallel to -9x-7y=4 and has the same y-intercept as the graph of -5x+11y=-22.
In my book, the potential gradient for a charge placed anywhere in space is defined as: E = -V/r
HOWEVER, for parallel plate (capacitors) the potential gradient is defined as E = V/d (V being the potential difference). How come there's no negative sign for the potential gradient of the parallel...
I use the following equations to understand this question/answer.
First, C = k(ε*Area)/distance = Q/V = Q/ (E*distance)
As a slab of glass is added, k increases and thus E decreases.
F=QE, as E decreases, force decreases as well. How does this relate to the 'force attracts the glass into the...
If we do not consider diffraction,why lasers rays are parallel?Do atoms stimulatedly emission photons in same direction?It seems to me stimulated emission photons have same frequancy but random in direction?
The problem states:
Two parallel plates separated by distance h, the plate at the top moves with velocity V, while the one at the bottom remains stationary.
My initial approach was:
I considered, ##du/dy = V/h## and for the shear stress ##\tau = \mu \frac{\partial u}{\partial y}##
For...
Hey guys,
I've started to read some OpenMP programming and now I'm trying to parallelize small part of a fortran code.
The first thing I would like to do is to parallelize the innermost DO loop. It loops through the number of particles (na) and calculates
the distance between some point in 3D...
Suppose I connect two identical signal generators to a dividing coaxial cable with two input ends and one output end. Is the signal amplitude from the output end the same as from one source, is it twice that or something in between? If this should be seen as analogous to two DC voltage sources...
Hello Forum,
Some of my electrical outlets (3) in the kitchen stopped working (one of them is a GFCI outlet). Reading online, I found out that outlets are generally connect in a daisy-chain fashion and if one goes back they all stop working. See the figure below showing a daisy chain...
$\tiny{311.1.5.19}$
find the parametric equation of the line through a parallel to b.
$a=\left[\begin{array}{rr}
-2\\0
\end{array}\right],
\, b=\left[\begin{array}{rr}
-5\\3
\end{array}\right]$
ok I know this like a line from 0,0 to -5,3 and $m=dfrac{-5}{3}$
so we could get line eq with point...
When parallel transporting a vector along a straight line on flat space, does the connection (when calculating the covariant derivative) always equal zero? Do things change at all when using an arbitrary connection, rather than Christoffel symbols?
Very simply, I can't understand why the charges of capacitors placed in series are all the same, and why even the total one(of the circuit) is equal to those.
How is it possible that the total charge is the same as the individual ones?
There must be some concept/property about capacitors which...
Does anyone have a reference or solution for a parallel plate capacitor in the Rindler metric? I'm particularly interested in the case where the capacitor plates are in the xz or yz planes, z being the direction of the acceleration.
The motivation is to get an idea how a transmission line...
Potentials in points E, F, A, B are equal because there is no resistance. In my opinion, losses of potential energy in the resitors R1 and R2 are not equal (potential C ≠ potential G). Then why do we say that voltage in this circuit is the same?
a) E = s / E0 so s is 4.87E-9
b) The electron will be projected at up angle since its charge is negative ( not sure if there's another reason behind it)
c)
Initial speed:
V0 = 5 * 10^6 * cos(theta) + 5 * 10^6 * sin(theta)The force suffered by the electron is:
Fy = q*Ey
Fy = -1.602*10^19 *...
Given the circuit above, I have to solve for the labelled currents, find V total and R total accordingly. 1A is flowing through the 5Ω resistor as shown. Assuming electron flow (negative terminal to positive) for circuit.
The connector in the middle was somewhat confusing. Without it, this...
Attached is the subsection of the book I am referring to. The previous section states that the electric field magnitude at any point set up by a charged nonconducting infinite sheet (with uniform charge distribution) is ##E = \frac{\sigma}{2\epsilon_0}##.
Then we move onto the attached...
Sorry if the question is not rigorously stated.Statement: Let ##(q,p)## be a set of local coordinates in 2-dimensional symplectic space. Let ##\lambda=(\lambda_{1},\lambda_{2},...,\lambda_{n})## be a set of local coordinates of certain open set of a differentiable manifold ##\mathcal{M}.## For...
Hello, there. A friend asked me a problem last night.
Suppose that a system consists of a rod of length ##l## and mass ##m##, and a disk of radius ##R##. The mass of the disk is negligible. Now the system is rotating around an axis in the center of the disk and perpendicular to the plane where...
These are my attempts at doing this question, and I was wondering if I am correct so far.
At t= 0-, i(L) will be 0A, since the capacitor acts as a open circuit.
However, I'm not sure why V(c) at t=0- will be -20V as given by the answers. Won't it be 0V?
Moving on, since current in inductor and...
I'm reading 'Core Principles of Special and General Relativity' by Luscombe - the part on parallel transport.
I guess ##U^{\beta}## and ##v## are vector fields instead of vectors as claimed in the quote. Till here I can understand, but then it's written:
I want to clarify my understanding of...
Homework Statement:: n/a
Relevant Equations:: n/a
Sorry for the wonky mouse sketching. Teacher said that arrows must touch the plate at the other end. Is there actually such a thing or is this just preference? I thought convention was for arrow to be in the middle of the line.
if the ends P and Q are being pulled down with a uniform speed its acceleration is zero and hence the Tension in the string will also be zero and if this is the case which force will make the block of mass M rise? is this a fatal flaw in the question?
In a parallel connection heat is produced.
R1 = 5 Ohm
R2 = 10 Ohm
What is the relation of W1/W2?
1:4
1:2
2:1
1:8
3:1
I’d tend to say 1:2, but I am not really sure…
Summary:: Griffiths problem 8.5
Problem 8.5 of Griffiths (in attachment)
I already solved part (a), and found the momentum in the fields to be $$\textbf{p}=Ad\mu_0 \sigma^2 v \hat{\textbf{y}}$$
In part (b), I am asked to find the total impulse imparted on the plates if the top plate starts...
https://www.feynmanlectures.caltech.edu/I_19.html
"Suppose we have an object, and we want to find its moment of inertia around some axis. That means we want the inertia needed to carry it by rotation about that axis. Now if we support the object on pivots at the center of mass, so that the...
The problem is symmetric around the z axis, thus the force must be in the z direction only.
I tried dividing both rings into differential elements, then integrating through the upper ring to get the z component of the total force on the upper ring due to a differential element of the lower ring...
Hi,
the approximate (not accounting for plate size and separation distance) formula for heat flux exchanged via radiation between two parallel plates is:
$$q=\frac{\sigma (T_{1}^{4}-T_{2}^{4})}{\frac{1}{\varepsilon_{1}}+\frac{1}{\varepsilon_{2}}-1}$$ where: ##\sigma## - Stefan-Boltzmann...
Hi,
I would like to ask for a clarification about the difference between parallel transport vs Lie dragging in the following scenario.
Take a vector field ##V## defined on spacetime manifold and a curve ##C## on it. The manifold is endowed with the metric connection (I'm aware of it does exist...
This is the problem I'm working on. So far I know:
1. I am assuming the free charge density is +sigma for the top plate and -sigma for the bottom plate.
2. The electric field from the plates goes from top to bottom plate, in the negative z direction.
3. The electric field of the capacitors...
a) I found this part to be quite straight forward. From the Parallel transport equation we obtain the differential equations for the different components of ##X^\mu##:
$$
\begin{align*}
\frac{\partial X^{\theta}}{\partial \varphi} &=X^{\varphi} \sin \theta_{0} \cos \theta_{0}, \\
\frac{\partial...
Hi PF!
I am trying to computer a matrix of integrals. Think of it something like this:
Table[Integrate[x^(i*j), {x, 0, 1}], {i, 0, 5}, {j, 0, 5}]
I have 16 cores, and would like to have each core handle a specified amount of integrals. Anyone know how to do this?
Thanks so much!