What is Response: Definition and 538 Discussions

The dose–response relationship, or exposure–response relationship, describes the magnitude of the response of an organism, as a function of exposure (or doses) to a stimulus or stressor (usually a chemical) after a certain exposure time. Dose–response relationships can be described by dose–response curves. This is explained further in the following sections. A stimulus response function or stimulus response curve is defined more broadly as the response from any type of stimulus, not limited to chemicals.

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  1. N

    Uniform Circular Motion extended response

    This began as homework that our Physics teacher set us. However, for some reason he decided no to collect it. I am curious as to whether or not this display my understanding of the topic well as communication is main area my teacher believes I need improvement in. Homework Statement Write a...
  2. P

    Natural and step response RLC find iL(t)

    Homework Statement The switch in the circuit in the figure has been open a long time before closing at t=0. Find iL(t) t>0 Express your answer in terms of t, where t is in milliseconds. https://www.flickr.com/photos/84781786@N03/8899251427/ The Attempt at a Solution We simplify...
  3. J

    How Do You Calculate the Magnitude of a Filter Response?

    Homework Statement F(w) = a / [1 - be^(-jwT)] where a and b are constants Find the magnitude of this filter response Homework Equations e^(-jX) = cos(X) - isin(X) The Attempt at a Solution the answer is a/ √[1-2bcos(wT) + b^2*cos^2(2wT)] but I can't seem to get rid of...
  4. J

    Digital filter response question

    Homework Statement A digital filter is defined by yn = xn - n-2 - 0.81*yn-2. At what frequency, in terms of fNyquist, is the filter response zero and maximum? Homework Equations H(z) = Y(z)/X(z) The Attempt at a Solution I figured out that H(z) = [z2-1] /[z2 +0.81] and...
  5. S

    Position velocity equation free response

    Homework Statement A partcile starts att he point (1,0) and t=0 and moves along the x-axis so that at time t≥0 its velocity v(t) is given by v(t)= \frac{1+ t}{(1+t^2)} A) Determine the maximum velocity of the particle. B) Find an expression for the position s(t) of the particle at time t...
  6. C

    Dipole excitation response function - physical interpretation

    Hi everyone, I'm a new member but it's not the first time I look at the forum. Well, I don't know if this is the right section to post my question. I think it is related to quantum mechanics interpretation too. Anyway, let's have a look at my problem. I've computed cross section for photon...
  7. A

    Impulse Response Function Problem

    I attempted by inputting u(τ-t)u(t-τ) into the second part of the integral. Since I want to change the second part of the integral to go from [+∞, -∞]. And as for first part of the integral I added a u(t-τ) term after the x(τ) to change the integral from [t,-∞] into [+∞, -∞]. I am not sure if I...
  8. K

    Engineering Voltage response of a resistor in an AC circuit

    Homework Statement For the circuit below, assume the source phase angle is 0° Write the differential equation which would allow you to find the voltage response across resistor R2. Using the General Solution for the solution of such a differential equation write the complete...
  9. J

    Impulse response of FIR filter given the output is known

    Hi all, I am faced with this question, I am stumped as it is presented in a different way to what I am used to: The output from a FIR filter for a unit step input u[n] is y[n] = δ[n] + 3 δ[n - 1] + 6 δ[n - 2] + 10 δ[n - 3] + 15 u[n] What is the impulse response of the FIR filter? A...
  10. K

    Convolution integral and fourier transform in linear response theory

    Hello, Consider I have a linear time-invariant (LTI) system, with ##x(t)##, ##y(t)##, and ##h(t)##, as input, output, and impulse response functions, respectively. I have two choices to write the convolution integral to get ##y(t)##: $$ 1)\ \ \ y(t) = \int_{0}^{t} h(t-t')x(t')dt' $$ and...
  11. D

    LTI systems- frequency response

    I have attached an image of a ''brick-wall'' band pass filter. Can someone please help me find the expression of frequency response for it? Homework Statement Homework Equations The Attempt at a Solution
  12. A

    Measurement of Galvanic Skin Response

    Homework Statement I have attached the photo of the circuit. My doubt in the circuit is that, I could not exactly figure out what the diodes do. The description says it is used to set the input of the op-amp to 1.6V above v-. But how exactly does it achieve that? Can somebody show it...
  13. M

    Determine the unit-step response of the discrete-time LTI systems

    Determine the unit-step response of the discrete-time LTI systems described by the following impulse responses: h[n]=(0.9)^{n}e^{j(\pi/2)n}u[n]So I am completely confused. . . I don't even know how to start. . . I want to say that I need to do a summation but the more examples and text I look...
  14. A

    Engineering Response of RC circuit i/v of capacitor help

    Homework Statement after having been in position 1 for a long time, the switch was moved to position 2 at t=0. determine: a) i-c(0-) and vc(0-) b) i-c(0) and v-c(0) c) i-c(infinity) and v-c(infinity) d) v-c(t) for t>=0 e) i-c(t) for t >=0Homework Equations The Attempt at a Solution not sure...
  15. C

    Synchronous Generator transient response problem

    Hi , Hope someone could offer me a solution to this piece of code, the code below shows a period in time of a synchronous generator transient response, My scaling is the problem as I am not getting 50 Hz 230 volts, your help would be appreciated.. My efforts so far are % Transient...
  16. M

    Engineering Laplace Step Response Circuit Analysis

    Homework Statement Shown in attachment Homework Equations The Attempt at a Solution I'm trying to analyze the circuit in the attached picture. This is a step response with a 3V input or 3u(t). What I've done so far is: 1. convert all of the components to the s-domain. R = R, L = sL, C =...
  17. D

    Base Excitation: Find response and transmitted force

    Homework Statement The diagram simulates a vehicle driving on a rough road. Let v=constant. Find an equation for the response z(t) as well as the force transmitted to the vehicle http://imgur.com/GUQcHx7Homework Equations x'' + 2ζω(x'-x_b') + ω^2(x-x_b) = 0 x_b(t) = X(iω)*e^(iωt) The Attempt...
  18. A

    Forced Response of RC Circuit: Derivation and Solution

    Homework Statement what is the forced response for Rc cct. and how to derive it?? Homework Equations I know that the forced response in RL cct. is : i = cos (ωt - tan^-1 we start from : Vm cos (ωt) = Ri + L and i = I am cos (ωt-θ) Can anyone help please!
  19. perplexabot

    Understanding the Impulse Response: A Key Tool for Identifying Unknown Systems

    Hi all. A problem I was working on required that I find the impulse response where I am given the output function ( y(t) ) of a system in terms of the input ( x(t) ). I read somewhere that to find the impulse response, you need a function that relates the output and the input, then you...
  20. B

    Control Systems Engineering : Response of a system to a Harmonic Input

    Homework Statement In my notes it is stated that an integrator adds a phase lag of -Pi/2 and thus can cause instability. I want to understand what this really means and am deviating from the notes somewhat so do not know if I am barking up the wrong tree. Homework Equations Given a...
  21. A

    Impulse Response of Causal Systems

    I am reading "Linear System Theory and Design" by Chen and he says (in what follows g(t,tau) is the impulse response function): If a system is causal, the output will not appear before an input is applied. Thus we have Causal <==> g(t,tau) = 0 for t < tau. However, this seems incorrect...
  22. inflector

    Smolin's Edge Response - Deterministic Quantum Theory?

    Did anyone read Lee Smolin's response to the Edge.org question: "What are you worried about?" http://edge.org/response-detail/23778 Opening paragraph:
  23. F

    Find Impulse Response of LTI system given transfer function

    Homework Statement Find the impulse response of a system with transfer function H(S) = (s+3)/(s^2+2s+1) or H(S)=(s+3)/[(s+1)^2] Homework Equations Poles are s1=s2=-1 y = Ae^st + Be^st The Attempt at a Solution In my notes I do not have an answer for the case when there is...
  24. jegues

    Signals unit impulse response h(t) ECHO

    Homework Statement a) Find the unit impulse response h(t) of an audio system that causes two echoes, one occurring at 0.5 seconds and the other one at 1.5 seconds. Please sketch H(w). (Magnitude and phase) b) Design a system that can eliminate noise coming from the 60Hz power signal (thus...
  25. L

    Bohr's response to the Einstein box

    During one of the Einstein-Bohr debates, Einstein proposed a thought experiment that would prove that one could measure time and energy simultaneously. It's known as the Einstein box: http://en.wikipedia.org/wiki/Bohr%E2%80%93Einstein_debates#Einstein.27s_second_criticism Then Bohr came up...
  26. H

    Simple Zero State Response Signals Question

    Homework Statement Let's say I've got simple y''(t) + 2y' + 1 = x(t), with maybe y(0) = 3 and y'(0)=1. the input x(t) is 12cos(20t). Using a laplace transform, determine zero state response of the output y(t). I know eventually I end up with the Y(s) and X(s) form, and then I have to...
  27. O

    Theoretical impulse response and its normalization

    greetings, helpful people around the world, we all have heard once in our lives that the signal that is measure from your instrument, be it a spectrometer, optical microscope or an NMR machine, is not the real signal distribution, but the convolution of the real signal with an instrument...
  28. A

    Fourier Transform - Solving for Impulse Response

    Homework Statement I'm trying to Solve for an impulse response h(t) Given the excitation signal x(t) and the output signal y(t) x(t) = 4rect(t/2) y(t) = 10[(1-e-(t+1))u(t+1) - (1-e-(t-1))u(t-1)] h(t) = ? y(t) = h(t)*x(t) --> '*' meaning convolution! I am unsure how to take the Fourier...
  29. C

    Time Response of Overdamped System

    Dear PF Mentor, this is NOT homework assignment! This my own personal research intended to use a theoretical approach to develop a transfer function for an overdamped system with a low settling time. This could be used for creating faster robots. Step 1: Initializing the transfer function G(s)...
  30. O

    Drawing the step response of a second order system

    Homework Statement I have to draw the step response of the following two systems. G1 = (4+3s)/(s^2+4s+4) G2 = 3/(s^2+4s+4) So I started to draw the step response of the second system first. It has to be in the funky standard form: \frac{ω2}{s2 + 2ζωs + ω2} EDIT: Seems like the above doesn't...
  31. Faraz Murtaza

    Stability theory and impulse response

    a system is said to be stable if its impulse response approaches zero for sufficiently large time. why? please give me an satisfying answer..
  32. A

    Impulse Response of a discrete system

    Homework Statement Find the Impulse response of this system 3y[n]+4y[n-1]+y[n-2] = x[n] + x[n-1] Homework Equations Eigenvalues = -1/3 and -1 hc[n] = k1[-1/3]n+k2[-1]n 3h[n] +4h[n-1] +h[n-2] = δ[n] + δ[n+1] The Attempt at a Solution I know that normally we would plug in hc[n] for two...
  33. D

    Transfer Function and Steady State Response (Some S-domain)

    Homework Statement Find Vo in steady state. V1 = 5cos(1400t) V R = 100 Ω L = 25 mH C = 20 μF Homework Equations L = Ls C = 1/Cs The Attempt at a Solution I first solved for the transfer function T(s): T(s) = \frac{LCs^2 + 1}{LCs^2 + RCs +1} From here I can plug in...
  34. E

    Unit step response of RC high pass filter

    what is the unit step response of a high pass RC filter ? I want to calculate using transfer function approach. My solution : Y(s)/X(s) = RCs/(1+sRC) X(s)=1/s Y(s)=RC/(1+sRC) taking inverse laplace transform we should get y(t)=exp(-t/RC) But if we consider Y(s)=RC/(1+sRC) RCsY(s)...
  35. R

    Definition of the dielectric function in the linear response regime

    Sometimes the dielectric function is defined as the connection between the total electric field in a material and the external field, \mathbf{E}(\mathbf{r},\omega) = \int \epsilon^{-1}(\mathbf{r},\mathbf{r'},\omega) \mathbf{E}_{\text{ext}}(\mathbf{r'},\omega) d \mathbf{r'}, and sometimes...
  36. C

    What is causing the loss of tracking in my spring-mass system?

    Hi everyone! This is my first post here at PF after years of on & off lurking! So, I'll get straight to it. At work (yes work, not HW) I have a forcing function signal that acts on a spring-mass system. When the spring-mass system "tracks" the forcing function, the curves overlap...
  37. E

    Step response to an impulse response

    Hi all, I'm having a lot of trouble understanding this step response: Problem statement: Consider an LTIC system with impulse response given by: h(t) = u(t) - u(t-2) Sketch the step response s(t). I've already sketched h(t)...but, I know that the step response is found by...
  38. 4

    Forced response and Laplace transform

    Homework Statement d'^2 (y)/dt + 4 (dy/dt) + 4y = -7(e^(-3t)). Here I need to forced response of this differential equation using laplace transform technique. Homework Equations The Attempt at a Solution I understand the part of converting each term to each laplace, d^2y/dt to...
  39. P

    Convolving a signal with its impulse response in MATLAB

    Homework Statement We're supposed to convolve the signal x[k] = u[k] - u[k-8] with its impulse response h[k] = sin(pi*k/4)*( u[k] - u[k-8] ) with the help of MATLAB. Homework Equations - The Attempt at a Solution The thing is that we don't know how to do this in MATLAB...
  40. C

    Obtaining Impulse Response & Frequency Response of LTI System

    Homework Statement An LTI discrete-time system has frequency response given by (a) Use one of the above forms of the frequency response to obtain an equation for the impulse response h[n] of the system. (b) From the frequency response, determine the difference equation that is...
  41. Z

    Signals: Fourier series and frequency response

    Homework Statement A recursive DT system with input x[n] and output y[n] is given by y[n] = -0.25y[n-2] + x[n] a) Determine and plot the impulse response h[n] such that y[n] = x[n]*h[n] b) how would you classify the system and why? c) What modification, if any, should be made so...
  42. C

    Is Each System LTI Based on Given Input-Output Relations?

    LTI/Impulse URGENT 1. Following single input-output relations are given for 3 systems System A: x[n] = (1/2)^n; y[n] = (1/4)^n System B: x[n] = cos (pi/3 n); y[n] = 3j Sin (pi/3 n) System C: x[n] = (1/5) * (1/5)^n * u[n] ; y[n] = -b * (1/2)^n * u[-n-1] - b * (1/3)^n * u[n] where *...
  43. S

    Engineering First-Order Circuit Transient Response Question that i with

    The switch in the diagram below has been open for a long time prior to t = 0; then it closes at t = 0 and opens again at t = 105 µs. Find: 1. Ix(75 µs), 2. Vx(75 µs), 3. Ix(190 µs), 4. Vx(190 µs). Attached is the diagram of the circuit and its answers. so i understand how to get...
  44. R

    External driving force on blackbox system: frequency response

    External driving force on "blackbox" system: frequency response Easy question: I have a blackbox system (it's actually the Earth, but we can just treat it as a blackbox) driven externally by a periodic sinusoidal force (the Sun). If the driving force has a period of say 10 years, is there...
  45. V

    How to use wolfram alpha to plot frequency response

    Can someone please tell me how I can plot the magnitude and phase response of this transfer function on wolfram alpha as I don't have Matlab: H(s) = -(2.1953*10^12)/(66600*((j*ω)^2)+808823539.4*(j*ω)+2.1626*10^12) A link to the output would be very useful also, thanks heaps.
  46. B

    Impulse response from frequency response

    Hi to everybody, I could really use some help in order to understand how to obtain an impulse response from a frequency response. I am dealing with acoustics, but my knowledge on the particular are basic. I am trying to compare a theory for the scattering of sound from an object with...
  47. E

    Oscillations in transient response

    Why oscillations occur in transient response of a system ? Suppose transfer function of a system is 1/(s+1). Then its impulse response will be c(t)=e^{}-t . So why just we don't show only an exponential curve to graphically represent the impulse response, why we also show the oscillations ?
  48. J

    Observe a filter response to a unit step?

    Hi guys, what does it mean to observe a filter response to a unit step? The book gives a transfer function and I've recreated it in Proteus ISIS. Now it asks me to simulate a square wave as an input (i used a pulse generator), and then observe a filter response to a unit step, describing the...
  49. T

    Relation between open loop and unity feedback close loop response

    hi! can someone please help me with this problem...i have to match the open loop respone to the close loop unity feedback system of a control system. what is the relation between the two? thanx in advance
  50. onomatomanic

    Involuntary urination as a normal response

    Other than the obvious case of the (real or perceived) pressure of a full bladder eventually becoming unbearable, under what conditions do healthy people, i.e. those who do not ordinarily suffer from incontinence, lose bladder control? I know of two - extreme fear and choking/strangling. In the...
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