Source Definition and 1000 Threads

Greetings, I want to ask you somthing if i understood well this subject. Lets say we have an order 1 binary source. H(a)=-Paa*log(Paa)-Paa*log(Pab) bit/symbol. From what i understand this is the average information of a symbol generated after an "a", like aa or ab. Is it right?

I'm sending this message to anyone who has knowledge about neutron generator. is there anyone who knows how does penning ion source works. I mean how could ions exit the holes but electrons can't exit. I didn't find any explanation about it on the web

Hello there, I want to solve the heat PDE in a 1D domain for a source moving at constant speed. The problem has been solved already, the solution being stationary in a reference frame moving with the source. This is highly un-intuitive, and I suppose the result originate from the fact the...

Is the answer correct?

Homework Statement Hello guys! Now this is not a homework question, but it may sound like one. If a uniform sized and massed sphere was spinning in space away from any source of forces that could affect it, wouldn't the only forces that act on it are the centripetal and centrifugal? And if...

Hello, everyone, I have to design a constant current source for NTC, to have a more precise measurement. The NTC resistance used range is 1kΩ~13kΩ. I have tried several circuits, but the problem is the the current is not precise enough even in simulation. 1uA difference All the...

I'm still not very confident in analyzing circuits. Here's what I know: 1) v_o=v_IN - v_T 2) id=k/2*(v_IN-v_T)^2 3) v_o=v_S-(k/2)(v_IN-v_T)^2*RS 4) v_o = v_S-id*Rs iDS = v_o/RS The answer I chose in the photo was based off of other online discussions. I'm very confused and don't have the...

Homework Statement Homework Equations Anyone Know why If an ideal voltage source and an ideal current source are connected in parallel, then the combination has exactly the same properties as a voltage source alone? and If an ideal voltage source and an ideal current source are...

Does anyone out there know of a US based source or distributor for high capacity lithium batteries? 100Ah, 200Ah? 3 - 3.2 volts Everything I am finding is China, and the shipping is just outrageous. Thanks, pud

If Neutron stars are what they are... I mean made of literally only neutrons ...how do they generate such immense magnetic field (of the order 10^8 or something) .. I think the name is somewhat misleading and it ought to have a near half ratio of protons ...But still being so compact how...

This circuit is really confusing me. I'm trying to find i using KVL and KCL. What's throwing me off is the short circuit effectively created by the inductor. I know that the whole circuit can't be short circuited because there is a current source that is preventing all of i from going through...

1. What is the difference between non-ideal voltage and non-ideal current source ( not in terms of circuit diagram like ideal voltage source plus series resistance )? 2. And how to decide that which source is used where and when ? ( because output of both is not constant)

Solve i_x when a=2. (See attached picture) This is my attempt (mesh current analysis): I made i1 be the lower left loop current. I made i2 be the lower right loop current. I made i3 be the upper loop current. Mesh1: i1 = 2ix Mesh2: -10 + 3(i2-i3) + 20i2 = 0 Mesh3: -5 + 3(i3 -...

Homework Statement For the circuit shown in Figure, find the equivalent resistance seen by the source. How much power is delivered by the source? http://sphotos-b.xx.fbcdn.net/hphotos-snc7/304377_496325960386924_988412599_n.jpg Homework Equations Req = R1R2 / R1+ R2 P = V^2 / R Thanks you...

I am using An Introduction to numerical linear algebra by Charles Cullen and I'm not very satisfied with it. Kindly suggest me some alternatives. Also suggest good linear algebra book to clear up basics. finally also suggest any online study materials, lecture notes, videos regarding the...

Homework Statement A girl 5 feet tall is running at the rate of 12 feet/second and passes under a street light 20 feet above the ground. Find how rapidly the length of her shadow is increasing when she is 20 feet past the base of the street light. The Attempt at a Solution I let the distance...

Homework Statement This problem has two parts, so I might as well inquire about both. https://www.edx.org/static/content-mit-6002x/images/circuits/H4P3%20Thevenin.2b9528ba9f62.png The figure above shows a circuit with a linear current-controlled-voltage-source and its Thevenin...

I've been given the following problem (attached), not sure how to tackle this one, do I use mesh/node analysis and super node analysis, or can I find the v in the loop with the dependant voltage source then use that as the supply to the second and third loops? Not sure, any help would be...

Turning FETs "off" in presence of AC signal at Drain or Source Hello, I have a very interesting problem that surprised me, and as of yet have not been able to find a solution for. I have two coupled coils. One is being driven by a pulses. The other coil has FET switches to switch the...

Homework Statement Basically, I'm having trouble doing the source transformation and subsequently finding the norton equivalent for this circuit and I don't really know where to start. The circuit is attached where: i=3A V=90V Please help!

Is the local propagation of an entity at invariant speed a sufficient condition for its stress-energy tensor, independently of its explicit mathematical form, to be trace-free, or to have null covariant divergence, or both in curved space-time? In the book “An Introduction To Mechanics”, by...

Homework Statement Determine the voltage across the 2A current source Homework Equations kirchhoff voltage law (kvl) kirchhoff current law (kcl) ohm's law The Attempt at a Solution I'm new to the concept of a current source. I'm not sure how there can be voltage drop across the...

Homework Statement https://www.edx.org/static/content-mit-6002x/images/circuits/H1P2.79e52b492b94.png Homework Equations It's been a while since I've done KCL/KVL, could be that I'm being just being stupid. I'm trying to find v1, i4, and the power in all the circuit elements...

1. Making appropriate use of resistor combination techniques, calculate i3 in the circuit of Fig. 3.84 and the power provided to the circuit by the single current source. 2. Connected in Parallel and Series. Ohm's Law. KCL/KVL 3. I honestly am just guessing how to do this one...

Hi folks...I'm new here, please go easy on me, it's been quite a long time since college physics! :-) I need a feasible and readily available heat source for a Stirling cycle engine. (It's a type of engine that runs off of hot air...google it and you'll see plenty of examples.) Is there a...

Homework Statement http://imgur.com/jsIWS Homework Equations Ʃ V_{n} = 0 Ʃ I_{n} = 0 v = ir The Attempt at a Solution I combined the two 2Ω resistors into a single 4 Ω resistor because they're in series. Then I tried to use KCL but I got 2 unknowns in one equation. 0.2A + \frac{Vi}{4} = I

Homework Statement Calculate Vout if a) I=1mA, R1=2.2kΩ, and R2=1kΩ; b) I=2A, R1=1.1Ω, and R2=8.5Ω. c) For each case, state whether the circuit is wired as a non-inverting or an inverting amplifier. NOTE: I is set to 1mA in the circuit below. Homework Equations Req=(R1*R2)/(R1+R2) V=IR...

Hi folks, the subject line says it. I'm currently using geogebra as a note book in which to write "memory cards" in latex. You know the sort of thing: when you learn a new formula and want to keep it in virtual "card" form. I love Sticky Notes, but I can't get latex on to them. does anyone...

Homework Statement Please view PDF for schematic of circuit and more information on loads. Load 1 is the 5 KVA load and Load 2 is the 10 KVA load. Loads 1 and 2 are operating at their rated voltages of 220 V rms. a) Find Load 1’s real and reactive power b) Find Load 2’s real and reactive...

1. Homework Statement Two different single slits are used in an experiment involving one source of monochromatic light. With slit 1 in place, the first dark fringe is observed at an angle of 45 degrees. With slit 2, the first dark fringe is observed at an angle of 55 degrees. a)Which slit is...

Hello semiconductor technologists! I'm thinking at a source of extreme UV for semiconductor lithography, so what would be your wishes, as compared to the first figures that emerge from my rantings? I take 30nm wavelength. Would less be better? I fear fluorescence hampers lithography...

For a neuroscience book I am writing, I am looking for the person who first said/wrote the following quote: "We discover things about the universe we can no longer even imagine." THIS MAY NOT BE THE EXACT QUOTE, BUT ONLY HOW I RECALL IT FROM ABOUT TEN YEARS AGO. I think it was from a Russian...

Hi! I'm having some difficulty understanding how to go about solving the following problem. I'm a beginner at this and am completely lost. I've seen a few similar problems that could be solved with node/current analysis, but I don't really understand if or how to apply that here. Can someone...

Suppose you have a Markov source of symbols (or more generally, a stationary ergodic source). If you Huffman encode longer and longer extensions (that is, you take blocks of n source symbols at a time, letting n increase) of this source, then the frequencies of 1's and 0's in the encoded...

an independent source with a forcing function modeled by cos(500t) is in series with an 100 ohm resistor. A dependent (current controlled) source is placed across the remaining resistor terminal and ground. A 0.3mH inductor is in parallel with the dependent source. The value of the dependent...

Homework Statement I don't really know where to post this but I chose this section. I need help finding the source of this Feynman Quote "The probability of detecting a photon at any point is the sum of all the probabilities of the photon being detected at that point by any path" Homework...

I need to find a switch that can detect whether it should go from 9v source or 5v Source. I am making a tool that has a battery power of 9v and it can also get powered from a USB device, which is 5V. If the customer need to connect the tool to a computer while its running from the battery...

I'm doing an adult-education course this semester which aims to take the student from pre-calc to calc in 18 weeks. The materials on offer at the course (for which I only have 3 contact hours a week) seem pretty slight to me. Does anyone know of a good online source of exercises and worksheets...

Hi, I'm working through a power electronics book and I'm looking at a half-bridge transformer-isolated buck converter (attached page). I've run into something that I can't fully understand even though the author presents it as something obvious. At 0 < t < D*Ts, the Q1 FET is conducting, and...

I know that the Casimir effect is a purely quantum mechanical phenomenon arising from the suppression of photons in the space between the plates and thus pushed together from the photons outside the plates. But just looking at a single cycle of the plates of the plates coming together, where...

Hi How can I see the source codes used for defining intrinsic functions in Fortran 90/95 ? e.g. what is the actual program for sqrt ? thanks

I am trying to teach myself optics out of the text by Sears, with some looks at Optics and Vision and a few other texts. I'm trying all the problems in Sears, and the answers to the odd problems are in the back. Unfortunately, I am getting a good fraction of the problems wrong. Sometimes it...

Homework Statement Find: a) the equivalent resistor seen by the source; b) value of i0; c) value of v; d) value of v0. http://img823.imageshack.us/img823/4406/dasso.jpg Homework Equations Kirchoff's laws and Ohm's laws The Attempt at a Solution To solve b,c,d I need...

This appears to spin forever. Isn't it possible to build it big enough to generate a reasonable amount of power? [Link to Perpetual Motion Machine Deleted]

I'm asked to get the noise signal from the constant current source I built with a 741 Op-Amp. I know I have to read it from the scope, but how do I go about the connections to the scope, and what other procedures must I follow to read the noise contribution? Pls refer to the figure provided in...

Hi all ! This is a weird problem. A simple program to read a file and display it works differently when compiled with different versions of the same compiler. When I compile it as: garbageij@garbageij:~/NMA$ mpif90 exp4.f90 and run it, it gives the correct output. But when I compile it as...

I tried to googling about this, but not find the answer; and even I'm not sure whether this is possible. Here the condition: I have a Windows laptop and a Linux workstation (workstation + monitor). The monitor is connected to: (1) DVI-D: connected to Linux workstation (default) (2) Display...

I'm an A level student, and one that doesn't usually write much in school other than the odd word between squiggles and numbers. (I'm studying maths, further maths, physics and electronics.) But now I find myself in the position of writing two different essays, which should be good, as it's...

I am a mechanical engineer and I'm working on a project in which I need to generate a large magnetic field in a coil of wire. The current system uses AC power (480V or 230V) and I am exploring the possibility of using a DC battery source. The coil is has an OD of 72mm, an ID of 62mm and a...

Is it possible to power the op amp in this diagram in this manner if it requires +18V and -18V? This doesn't seem valid to me, but I'm not sure why it's not exactly. Thanks