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 am trying to attain the parallel axis theorem from the displaced axes therom.
I have the displaced axes thorem stated in this form:
\hat{I}=\hat{I}com+M\hat{A}
-Where Rc is the position of the centre of mass position-
-Where \hat{}is the inertia tensor of a rigid body wrt to rotations...
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I'm currently working on programming a basic circuit simulator for a game. One of the things i don't have a sure answer on is parallel voltage sources. I understand from what I've read so far that when two sources are in parallel the lower of the two gets overloaded. If they are the same...
Question taken from Griffiths Pg 185, Problem 4.19:
For part (b):
-Why are the electric fields the same whether in dielectric or in air? In part (a), they are clearly different!
-Why is σ_{tot} = ε_{0}E = ε_{0}\frac{V}{d}
-In calculation of capacitance, why is the total charge (\frac...
Homework Statement
This is moreof a conceptual question regarding the parallel axis theorem and area.
Lets say I have a solid rectangle with length L, and Width W.
I cut out a circle of radius R at the center.
When calculating the Total Area moment of inertia of the hollow region where the...
I want to know how to calculate the force , I know the formula and such but its just that I'm not sure about the Length part , I mean if Wire1 is longer than Wire2 ,then should I take the common length between them , or just substitue with the total length ? , should F1on2=B2I(delta)l or B2I1L1
I am new to engineering so i might not understand the concept well , but i want an ac source to provide current only in one way , so i can connect them in parallel.
I have 2 AC sources one with a 100 V output and one with a 120 V output , i need to connect them in parallel so i can get a 220 V...
Homework Statement
Two related questions (from Electromagnetics by Notaros)
The dielectric of a parallel-plate capacitor has two homogeneous parts, referred to
as dielectric 1 and dielectric 2. The boundary surface between the parts is flat and
parallel to the capacitor plates. The dielectric...
Hi all
"A parallel plate capacitor in which plates of area A are separated by a distance d, has a capacitance C = \frac{Aε_{0}ε_{r}}{d}
It is charged to a pd V. Neglecting edge effects, derive an equation for the electric field E in the capacitor, and show that the energy stored per unit volume...
Homework Statement
What does Q-factor and Dynamic resistance of a parallel resonance circuits mean?Homework Equations
The Attempt at a Solution
In general, their performance is measured by a dimensionless parameter named quality factor Q, which characterizes the sharpness of the resonant peak...
Homework Statement
I am doing an assignment where I have this (easy) true/false question.
The parallel axis theorem can be used to find moments of inertia of an object about arbitrary axes, provided the moment of inertia about a perpendicular axis through the centroid of the object is...
Consider a capacitor with 4 parallel plates and 3 dielectric insulators arranged like this...+I-I+I-
The insulator in the center has an equal amount of + and - charge on each side of it so shouldn't the electric field across this insulator be almost zero? If I constructed this capacitor with...
Hi,
I'm rather confused as to how this diagram in my book. I know that in order for a mode to propagate, a standing wave must be formed in the waveguide, and this happens above some cutoff frequency that one designs for. What I don't understand is, below cutoff, what happens? I don't...
Everybody says that the distance ,between the two axis, used in the formula, is perpendicular. But in the proof it was a hypotenuse. It was not perpendicular.
Hi,
The attenuation resulting from puting a signal into a parallel plate waveguide is dependent on the excited mode. Why does the TM mode have greater attenuation than the TE mode? I can see in the maths it 'works out' to be that, but what would be a more conceptual/physical reason?
Is the...
I have an argument with classmates about the trajectory that the block will have (circle, ellipse, something else...).
The configuration is similar to this image.
http://minireference.com/_media/physics/momentum-bullet-speed-block.jpg?w=400
Initially, the block will move horizontally...
Homework Statement
A parallel-plate capacitor C , with plate separation d , is given an initial
charge ±Q_{0}. It is then connected to a resistor R, and discharges, Q(t)=Q_{0} e^{-t/RC}
2
(a) What fraction of its energy Q_{0}^{2}/2C does it radiate away?
Homework Equations
The equations for...
So when we calculate divergence (especially referring to the gauss divergence theorem), why aren't the components of the vector field parallel to the boundary considered?
I mean even of, say fluid, is traveling parallel to the boundary when it comes out, fluid is exiting, or diverging out...
Hi,
I think I'm missing something with how a parallel plate waveguide works. In the picture I've shown below, there intensity of the E-field change depending on how far across the waveguide it is. While I know that this has to happen in order for anything to propagate, I don't quite...
I have this question on the calculation of the geometric phase (Berry phase) of a parallel transporting vector over the surface of a sphere, illustrated by Prof. Berry for example in the attached file starting on page 2.
The vector performing parallel transport is defined as ψ=(e+ie')/√2...
In this image, C1 is 1 microfarad and C2 is 3 microfarads and both capacitors are charged with a potential difference of V = 100V.
S1 and S1 are closed.
The solution says this is in parallel, but I don't see how it is. It looks like it's set up in series to me. But even if it is in...
Homework Statement
Q is the edge length of the cube. The moment of inertia of the cube about an axis passing through its center and the center of two opposing faces is (1/6)mQ^2 (PCM in the diagram). Use the parallel axis theorem to find the moment of inertia if the axis is along one face of...
Hello all,
In Carroll's there is a brief mention of how to get an idea about the curvature tensor using two infinitesimal vectors. Exercise 7 in Chapter 3 asks to compute the components of Riemann tensor by using the series expression for the parallel propagator. Can anyone please provide a...
1. The plates of a parallel plate capacitor are separated by a distance (4cm). A point charge of magnitude (q=2e) (3.2*10^-19 C) is fired horizontally through a small hole in the positive plate of the capacitor. The charge is fired with speed (8.5 *10^5 m/s) and, upon reaching point M (located @...
Hello all,
I have two blocks, and I want to draw multiple parallel lines between them. This is the Latex code I have
\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shapes,arrows,fadings, shadows}
\usepackage{amsmath,bm,times}
\begin{document}
\pagestyle{empty}...
Given a curve c(τ) with tangent vector V, a vector field X is parallel transported along c if
\nabla_V X=0
at each point along c. Let x^\mu(\tau) denote the coordinates of the curve c. In components the parallel transport condition is
\frac{dx^\mu}{d\tau}\left(\partial_\mu X^\alpha +...
Hello Guys !
My Question : in this photo i found That Total Resistance will be = 7 ohm .
and I2 = 12 / 7= 1.71 A and I1 = 0.5 * I2= 0.5 * 1.71= 0.85 A
I can't understand why I1= 0.5 I2 ?? and why it isn't the same of I2 ??
here is the photo
Thank you Guys ! :))
Homework Statement
A parallel plate waveguide has perfectly conducting plates at y = 0 and y = b for 0 ≤ x < ∞ and -∞ < z < ∞. Inside that bound, the waveguide is filled with a dielectric with k as a propagation constant.
The Green's function to be satisfied is
\nabla^2G + k^2G =...
Hello Guys !
My question is : why in these photos the ohmmeter reads the total resistance ??
I mean why in (a) the ohmmeter can't read the 8 ohms resistance ?
and
Why in (b) the ohmmeter can't read the (2||10 ) resistance ?
Thank you Guys ! :))
Hi PF,
I am working on a parallel reduction code to sum up approximately 1 million 32-bit floating point numbers. The serial part running on each processor uses Kahan summation, no problems there. My problem is that this produces several sum/compensation pairs that now need to be added...
Homework Statement
Why is R_E in parallel with 1/g_m1?
I drew the small signal model but it does not make sense to me
Homework Equations
The Attempt at a Solution
Homework Statement
Two square metal plates with sides of length 0.1 m are separated in vacuum by 10-3 m. Find their capacitance.
Homework Equations
C = Q/V
For a parallel plate capacitor:
C = E0A/L
The Attempt at a Solution
If A is supposed to be the length of the metal...
I know how to detect when resistors are arranged in parallel or series arrangement and I can also find their equivalent resistance in simple circuits or when resistances are connected in form of triangle but what happens when the arrangement is complex like this :
Which resistors are...
Homework Statement
Say I have a circuit with only 2 components, a battery and a capacitor. Is this circuit considered series or parallel? What about a charged capacitor and an uncharged one? Does the fact I have an oscilloscope connected to the capacitor to read the voltage across it affect...
Homework Statement
I'm having a bit of a problem identifying series and parallel connections of resistors in some new circuits I've been exposed to, like the ones posted below. I'd be very grateful if anyone could give me some pointers or tips, or perhaps link me to some videos/explanations...
Homework Statement
Three capacitors, with capacitances C1 = 4.0 μF, C2 = 3.0 μF, and C3 = 2.0 μF, are
connected to a 12 -V voltage source, as shown in the figure. What is the charge on
capacitor C2 ?Homework Equations
Q=VC
Q = charge
V = voltage
C = capacitance
Ceq = equivalent...
in most of the books i have seen that while finding an impedance for an parallel RLC circuit first they find the individual admittance of each of the element the after summation of these they take reciprocal to find the impedance
why is it done like that can't we find the impedance in a normal...
Problem:
Consider ## I=\int_S \vec{v} \cdot d \vec{S}=\int_S \vec{v} \cdot \hat{n} dS##, where S is a surface that is intersected once by an line parallel to the x-axis. Show that dS=\frac{|\nabla f|}{\partial f/ \partial x}dy \ dx, and that therefore, I=\int_S \vec{v} \cdot \frac{\nabla...
I was discussing with a friend of mine whether the zero vector is parallel to all other vectors. We came to the conclusion that it probably is but we do not know the formal definition of parallel.
What is the formal definition of parallel? Wolfram says that two vectors are parallel iff their...
Homework Statement
A uniform electric field exists in the region between two oppositely charged plane parallel plates. A proton is released from rest at the surface of the positively charged plate and strikes the surface of the opposite plate, 1.59cm distant from the first, in a time...
Homework Statement
Expanded from Griffith's (3rd ed) #2.47
Infinitely long wires parallel to x-axis carrying ±λ charge densities intersect the y-axis at ±a.
A) Calculate V(x,y,z) if V(0,0,0)=0
B)Show that the equipotential surfaces are circular
cylinders. Locate the axis and calculate...
Homework Statement
1)Give a unit vector
a) in the same direction as v=2i +3j
b)Perpendicular to v
2)
a) Find a vector perpendicular to the plane z=2+3x-y
b)Find a vector parallel to the plane
Homework Equations
The Attempt at a Solution
1) a)
Method 1:
u=v/||v|| so i...
I want to know how we can find out the net voltage of a circuit where two batteries with different voltages are connected in parallel... Let's consider the problem stated below...
If I have a circuit where there are 2 batteries in parallel(5V & 15V)... And it is connected in series with...
Homework Statement
A coil of inductance 0.20 H, resistance 60 ohms is connected in parallel with a 20 μF capacitor across a 20 V, variable frequency supply.
Determine:
1. the resonant frequency
2. the dynamic resistance
3. current resonance
4. Q- factor at resonance
Is anyone there...
For what values of "a" are teh vectors parallel
Homework Statement
v = 5a i -3 j
w = a^2 i -6 j
Homework Equations
The Attempt at a Solution
My first thought was too get the unit vectors of both and set them equal to each other and solve for a, but that got messy.
(5a i-...
I have searched google and got no satisfying answer.Someone said that the overall resistance is less so as the voltage is same,the current increases.I don't think this is correct because the current for a single bulb is reduced.Can you give a satisfying answer?:confused:
okay i have this somekind of a paradox
in the circuit below
voltage around R0 and R2 is supposed to be equal
now if it is equal , wouldn't that mean that the current will not pass through the middle vertical wire ?
and if it doesn't then this means that the resistors are now connected in...
Simple circuit -- parallel resistors
Homework Statement
i am asked to find two or more resistors having the same voltage across their terminals , the answer is R2 and R0 , but i want to know why , note that there are no known values(they might or might not be equal i have no idea ) for R nor...
Homework Statement
Two oppositely-charged parallel plates are separated by a distance of 0.03m.
a. What is the strength of the electric field between the two plates if it takes 2.4x10^-19 J of energy to move an electron from one plate to the other.
b. What is the acceleration of that...
Homework Statement
Resolve the force F into
a) a part perpendicular to AB and
b) a part parallel to BC
Homework Equations
a dot b = ab*cos(θ)
The Attempt at a Solution
I attached my attempt in the .pdf file. For some reason it is wrong. I don't understand how my reasoning is...
When springs in parallel are replaced by a new spring of a new effective spring constant, for the proof of this, i.e
keff=k1+k2
Why do we assume the extension in the springs to be equal?