Network Definition and 464 Threads

  1. L

    Network Theory: What Do I Need to Study for Academia?

    What do I need to study in order to become a network theorist in academia? What fields and subfields do I need to major or minor in?
  2. J

    Calculating Head Losses through a Pipe Network

    Hey everyone! I'm trying to determine the losses through a pipe network that consists of 254.5 feet of 0.75 inch diameter copper pipe. The flow rate is 0.37125 gpm, with a corresponding velocity of 0.26962 fps. The fluid is water at 150 degrees F. Based off that information, I have a...
  3. G

    Single layer neural network. What am I doing wrong?

    I'm trying to implement this example http://www.cs.bham.ac.uk/~jxb/INC/l3.pdf (page 15) I'm trying to do Iteration training, but it seems as if the results always converging to a steady error rate that is too large to be acceptable, the values centering around 0 while they should be close to -1...
  4. A

    Why Did My Neural Network Fail with Single Input Parameter?

    Hello, I'm interested in neural network programming but I am a beginner. Recently I wrote an example in C++ that I found in a book. It was a feedforward 3 layers network that learns the examples with the backpropagation algorithm. The aim of the network was to learn to "throw a stone": I taught...
  5. B

    Wireless Network Transmission Through Brick Wall

    Homework Statement A wireless computer network transmits data across the space between nodes as a modulation of a 2.45GHz (microwave) carrier signal. The signal is able to pass through a brick wall that is 100mm thick. Measurements have determined that the dielectric function at microwave...
  6. S

    Is it possible to use multiple network adapters at the same time?

    My current problem: I have a machine sending a file every few seconds over its wired connection. While this is occurring, I want to be able to access a wireless network and download a file from a mapped network drive without interrupting the aforementioned file transfers. Any suggestions as...
  7. DaveC426913

    China Building network in middle of desert

    What are these? http://www.wired.com/dangerroom/2011/11/china-gigantic/?mbid=ob_ppc_dangerroom This must be a driving training ground. What's strange is the way the lines are cut. Some of the curves are highly acute, yet the points are carefully constructed, not all the way a bulldozer...
  8. W

    Network Layer And Data Link Layer

    Homework Statement If the network layer is sending a message from A to D via B, it can be sure that a message sent by the data link layer from A to B will always arrive at B, and from B to D will always get to D. How is it possible for the network layer not to be able to correctly deliver a...
  9. J

    Fax from PCs over LAN with Ricoh MFP9001

    we have a ricoh mfp9001. we can scan and print to it from client pc's. is there a way to fax from each workstation over lan from the mfp 9001. we can send and receive from the mfp itself.
  10. M

    Thevenin equivalent of lattice network

    Homework Statement Find the Thevenin equivalent network of the lattice network (see attached), viewed from points As and Br (terminals Bs and Ar are not connected to anything). Homework Equations The Attempt at a Solution Without the resistance f, the problem is quite simple. I...
  11. L

    Working out the impedance of a network query

    Homework Statement Calculate the J notation impedance of the network We have an inductor in series with a resistor and both in parallel with a capacitor. Homework Equations The Attempt at a Solution i believe it is true that if I was to say: if I have an inductor in parallel...
  12. M

    These are the Y parameters with the dependent source added.

    for the following circuit, i am trying to find the y parameters i have found y11, y12, and y22 to match the answer that my text provides, but i am having trouble with y21 the solution given is y11 = 1.5, y12 = -0.5, y21 = 4, y22 = -0.5 in trying to solve for y21, i get 4.5 this is...
  13. M

    Engineering Circuit network with multiple ports

    Find V2/V1 for the network below: What I did was try to solve by reducing to thevenin equivalents for V1 and V2 separately For V1: I got Vth = V1 Zth1 = 41/15 V1 = I1*(41/15) For V2: I got Vth = V2 ...but I am having trouble trying to find the Zeq2: I know once I find that V2 = I2*Zeq2 and...
  14. M

    Transform impedance of given network

    I'm having trouble finding the impedance of the simple given network below: I know Z(s) of each capacitor is 1/2s, but I'm confused on what's in series/parallel. How can you tell? I know it has to do with the nodes. Any help would be appreciated.
  15. P

    Two port network model and analysis

    Homework Statement Greetings. I am having difficulty with a couple of parts to a homework problem. Mainly coming up with the transfer functions to plot V_o. See the picture for the problem statement: http://img827.imageshack.us/img827/5481/problempa.jpg Homework Equations l \leqq...
  16. V

    Short cut tricks to find resistance of large/messed resistance's network.

    Today our physics teacher teach us how to find resistance of a network of resistance that is messed to heavily(example all sides of a cube are resistance find resistance). Ok those are very good methods, but it seems that they are not result of experiments done by genius persons it seems that...
  17. A

    Network Hardware Ethernet Performance

    Homework Statement I'm looking at an Ethernet direct link network with media access control between two computers. What effect will changing the packet size have on the Ethernet performance? The Attempt at a Solution I think if the packet size is increased then the number of collisions is...
  18. N

    Regarding with two port electrical network

    my problems comes from one of a book how to solve this one this is regarding with two port electrical network
  19. N

    Regarding with two port electrical network

    my problems comes from one of a book how to solve this one this is regarding with two port electrical network
  20. Twinflower

    Determine resultant resistance in network (Thévenin)

    Homework Statement I need to calculate the resultant resistance between points A and B The |-| parts are short curcuited ideal DC power supplies (illustration only) This is the circuit: Homework Equations R_P = \frac{1}{\frac{1}{R1}+\frac{1}{R3}+\frac{1}{Rn}} R_S = R_1 + R_2 +...
  21. N

    Engineering Finding Thevenin's equivalent circuit for AC network

    [b]1. Hi everyone, i was given an AC circuit (capture.png) and am required to find the value of the variable resistor Z so that average maximum power is delivered to it. To solve this i am trying to find the thevenin equivalent circuit but i am stuck and unable to figure it out. Any help would...
  22. S

    Flow Network - Linear Optimization

    Homework Statement I am doing an assignment in my Linear Algebra class. But I don't know how I will go about solving this problem. So the problem is a network of water pipes. I start with a matrix and I get the solution to the system from the RREF matrix. All the flow directions are set, so...
  23. Z

    Pi Matching Network Problem: Find X Reactance for C1, L1, C2, C3

    hi i need help with some pi matching for the following cct shown below, i would usually approach this problem with X=sqrt(1000*50) where X is the reactance of L1,C2,C3 but since C1 is in this cct then i can't use this equation so could someone please help me solve this problem
  24. C

    Cellular network Probability distribution function of frequency

    Hi, I am trying to model a PDF of frequency for the WCDMA handset. I have found some info on ways of graphing a PDF of transmit power but nothing on frequency. I am hoping there is a way to model this, but think it might be something that requires field tests with multiple phones. Any...
  25. E

    Critically damped current in this network

    Homework Statement I'm supposed to find whether the current in the following network is a) under-damped b) critically damped c) undamped c) over-damped Homework Equations According to Kirchoff's laws The Attempt at a Solution The answer given by my professor for this...
  26. L

    Network Theorems: Thvenin, Norton & Superposition Explained

    Homework Statement Can someone explain to me what are these theorems with proper example? (a)thevenins theorem (b)nortons Theorem (c)super position principle Homework Equations The Attempt at a Solution
  27. M

    Please help me in this question on network ?

    Hello friends...in this questions the answer is (b) option...this is from indian engg. services exam. if we apply mesh in loop which i have shown , then we find that I = (10 - 5 )/10 = 0.5 amp V=10 - 6 I = 7 volt (right acc. to answer keys)...
  28. A

    Calculating Charge with known voltage and Capacitance in a network

    Calculate the charge Q1, on the positive plate of capacitor. In a previous step in the problem I found the Ceq to be 7.6E-6 and know this to be the correct answer. Q=VCeq I used the equation above but the number I found was incorrect. I am also asked these question and I have no idea what...
  29. A

    Find equivalent capacitance in a network with parallels and series

    What is the equivalent capacitance of the network. Parallel: C1 + C2 + C3 + Cn = Ceq Series: 1/C1 + 1/C2 + 1/Cn = 1/Ceq I added C2 C3 C4 and C5 as parallel and then added this to C1 as a series.
  30. D

    Router Question: Separating a computer from a network

    I want to separate my computer from the rest of the network in my home. I'm really scared about getting viruses through the home network because of other people in my family. I want a computer to use that I know will be safe for dealing with money online. Any ideas?
  31. L

    Can I adjust R4 and R5 to maintain a 12k input impedance?

    How do I reduce this resistor network. The input current and the return current should be equal. But in this case, some current will also flow to ground. Can't get my head around this.
  32. S

    How to incorporate evidence into parameters of a Bayesian network?

    Greetings, Maybe I'm getting a little bit confused, but I'm looking for resources which explain how to update parameters of a Bayesian network as a result of observations. There are various inference methods, but unless I'm missing something here, these methods produce a posterior...
  33. L

    MATLAB Neural Network Classification Problem

    Homework Statement P = [data(1:65,11:100) data(1:65,411:500)]; % Input, all together 180 data set, 65 dimension T = [ones(1,90) zeros(1,90); zeros(1,90) ones(1,90)]; % Actual output, first 90 data set belong to class I and the next 90 belong to class II net =...
  34. M

    Network with resistors problem

    Please see attachment for the problem. I used the rules for parallel and series resistors to find a total resistance in the network of 4560/59 ohms and then found a current of 59/152 amps through the 20 ohm resistor in the original problem. Am I correct?
  35. S

    Calculating Current for Two-port Resistor Network

    Homework Statement A network of resistors has a pair of input terminals AB connected to a dc supply and a pair of output terminals CD connected to a load resistor of 120 ohm. The resistances of the network are AC=BD =180 ohm, and AD=BC=80 ohm. Find the ratio of the current in the load...
  36. N

    What Is Resonance in a Parallel-Series LCR Network?

    I'm having some problems understanding resonance in an LCR network where the capaitor is in parallel to the inductor and resistor, which are in series. How would you go about deriving the equation for the transient response (to a square wave) and the steady state response to a sinusoidal wave...
  37. M

    Finding Data Sets & Ideas for Neural Network Training

    I'm looking for advice. I have an assignment to train a neural network. I am confident in my abilities to write the code and train the neural network. The problems are: 1. I lack an idea. I'd like to do something interesting and potentially useful, obviously. 2. I need a rather large data...
  38. N

    Spatial statistics - Point process on a network of one-dimensional lines

    Hi everyone, My data consists of road accidents and spatial covariates. Originally i wanted to apply an inhomogenous Poisson process with covariates. Then I realized that the accidents cannot occur everywhere in space, but only on roads. I found an example, that is quite similar to mine. it...
  39. atyy

    What is the connection between spin networks and ABJM's dual conformal symmetry?

    This fascinating question was asked by our favourite blogger at http://physics.stackexchange.com/questions/5517/dual-conformal-symmetry-and-spin-networks-in-abjm .
  40. R

    [beginner] Network coverage inside an elevator?

    So many telecom operators claim that their users will get network coverage even inside an elevator. But according to Gauss' theorem, no charge is supposed to exist inside a closed conductor and an elevator (made of metal) is a closed conductor... So how is one supposed to get network coverage...
  41. R

    Ubuntu not detecting wireless network

    I currently have a duel operating system with windows 7 and Ubuntu. The problem I am having is that my ubuntu (10.10) is not DETECTING my wireless router. How do I fix this? Please explain simply as I am 13. thanks.
  42. A

    Bandwidth vs frequency bandwidth in a network

    I can't translate it 100% correctly, but my course notes describe two different properties of a medium: Literal translation: "The band width." - ? "The band width of frequencies" - as the difference of fmax and fmin What does each exactly refer to, and what's its name in english...
  43. N

    Resonance of a Parallel LCR network

    Why does the resonance peak of a parallel LCR network (capacitor in parallel with in-series inductor and resisitor) get smaller in amplitude with increasing resistance? I have impedance/DC resistance plotted against frequency. I'm really not sure about how to go about showing this...
  44. N

    Resonance of a Parallel LCR network

    Why does the resonance peak of a parallel LCR network (capacitor in parallel with in-series inductor and resisitor) get smaller in amplitude with increasing resistance? I have impedance/DC resistance plotted against frequency. I'm really not sure about how to go about showing this...
  45. A

    Equivalent resistance of a purely resistive network

    Homework Statement Calculate the equivalent resistance between the points X1 and X2. Homework Equations R series = sum of resistances R parallel = reciprocal of resistances The Attempt at a Solution I'm sorry I do not get any idea on solving the question. I have done it in the...
  46. C

    Current in a Network of Resistors

    Homework Statement http://img97.imageshack.us/i/physicsquestion.png/ Homework Equations R= V/I For Series: Req= R1+R2 For Parallel: 1/Req= 1/R1+1/R2The Attempt at a Solution I have two attempts remaining for each question
  47. S

    Equivalent resistance in this network

    http://img571.imageshack.us/img571/3774/circuitb.png Uploaded with ImageShack.us For my a level homework i have to find the equivalent resistance in this circuit, i don't want anyone to do my homework i would just like to be pointed in the right direction. We have been doing a bit about...
  48. L

    Help: Understanding Electric Distribution Network Data Using ACS

    Help -- electric distribution network reconfiguration for loss reduction using ACS Recently, I'm doing research based on electric distribution network reconfiguration for loss reduction using ACS, and my reference paper is the one from the link that i post. There are something about Table 1...
  49. E

    Medical Is the cortex a scale-free network?

    Is it known, or widely believed, that the cortex is a scale-free network? I.E. Do a large percentage of neurons have a small number of connections to other neurons, and do a small percentage of neurons have a large number of connections to other neurons?
  50. L

    Social network for user-generated data

    How about a social network whose vertices are user-generated data objects (e.g. math article, jpeg image) and whose connections are based on request and confirmation between users? I.e. the user who owns vertex A can request a connection between vertex A and vertex B; the connection is...
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