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. B

    Response to Deleted Thread that I've Worked on Too Hard to Let Go

    Response to Deleted Thread that I've Worked on Too Hard to Let Go! This is one of my responses to the "Cold Air" thread under the "Earth" category. The thread was deleted, but there was one really excellent response, to which I counter-responded, except that the thread was deleted before I...
  2. kelvin490

    Question about solid's response to stress

    I have a question about how the solid respond to stress at different stages. In textbooks the slope of typical stress-strain curve decreases after a point called yield point. Why is it so? Why less stress is required to further increase the strain compared to that before yielding?
  3. L

    Second order frequency response question

    Homework Statement http://img534.imageshack.us/img534/9687/rlc.png Cannot do this question, the first part confuses me when it asks to find an equivalent Parallel circuit. My first instinct was to try to add the capacitor and inductor and 40k Resistance together to create an RLC series...
  4. B

    Quantum linear response theory?

    Can anyone introduce, what is linear response theory in quantum mechanics? Or suggest, where i could read about it, to get acquaintance with it?
  5. G

    Can Loan Default Probability Be Predicted from Personal Attributes?

    Dataset is given in file "tabl3.txt". I know it has something to do with Binary response and probably we should use GLM to model it. However, I kind of stuck with it. My problem is that I can do identify which variable is the response in this case. If I use \log \frac{p}{1-p}=default =...
  6. F

    [Dynamics] Vibration response problem.

    1. The problem statement I have this vibration question, in which i have approach to solve and I came very close to the actual answer but not accuracy correct solution. My work-out solution is 0< k < 28.7 N/m And the correct answer is 0 < k < 27.4 N/m I have tried everythink...
  7. S

    Frequency Response from a Discrete Transfer Function

    Homework Statement Find the DC Gain and the Frequency Response of the above discrete-time system. The Attempt at a Solution This isn't really a homework problem but something I've been struggling with for my exams. I am given a transfer function in terms of z and am asked to find its...
  8. N

    The CDC Emergency Preparedness and Response for Zombie Apocalypse

    Seriously. Wait--what? http://emergency.cdc.gov/socialmedia/zombies_blog.asp
  9. J

    Help: unit-step response of a first order system

    Homework Statement A first-order system G(s)=\frac{k}{s+a} and its response to a unit step input are shown in the figure below. Determine the system parameters a and K 2. The attempt at a solution I’ve tried to find K & a using MATLAB and read a lot but didn’t find...
  10. M

    Determining K and Sigma for Underdamped Waveforms

    An underdamped waveform has the general form Ke-\sigmatsin(\omegat - \varphi) From the graph, determine K, \sigma, \omega, and \varphi i know f = 1/t t = .004 s f = 250 Hz \omega = 2\pif \omega = 1570 \varphi is clearly 0 How do i determine K and \sigma??
  11. russ_watters

    News US Kills Osama so in Response, the Taliban Attacks

    US Kills Osama so in Response, the Taliban Attacks... ...Pakistan? Really? http://www.usatoday.com/news/world/2011-05-13-pakistan-bomb_n.htm Nothin says "marginalized" like attacking an innocent and unwilling bystander in the raid on Bin Laden instead of attacking those who killed him...
  12. L

    Capacitor transient response, what happens in the dielectric?

    I'm trying to marry the concepts from my EM course with what I've been doing in my lab course. Correct me if I'm wrong, in a plain RC circuit, when closed with a DC source, the capacitor initially acts as a short (voltage is zero across the terminals, while I is max), until after a few...
  13. A

    Multiply freq response by w ?

    multiply freq response by "w" ?? hi all, i am not able to proced to this problem lets say there is a signal x(t), which has freq domain representatiojn of X(w) lets say signal is periodic with T = 1 now in freq domian X(w) is multiplied with "w" for 0<w<2 then what would be...
  14. J

    Resistance Temperature Detector (RTD) response time

    How would u work this problem? Q-If a RTD has a time constant of 10.0secs, approximately how long will the sensor take to get with 5% of the final value? I am thinking two ways to approach this problem. S1- It is known that the RTD takes 5 time constants to reach its final value, hence...
  15. S

    Frequency response function (polar diagram)

    This isn't really a homework question but I felt this is the most relevant section for this. I therefore apologize for not following the standard post template. I was going through my electrical engineering notes on frequency response functions. It was explaining how to plot frequency response...
  16. S

    Switching losses ESR and transient response

    I need someone to tell me if what I am saying is true or BS? Switching Frequency: Is simply defined as the frequency (amount of times) the same operation occurs, in our case the amount of times per second each phase is switched on. Duty Cycle: is thought of as the time the object is on...
  17. L

    Fukushima Fukushima, Japan – Constructing an Effective First Response

    There is much that I do not know specifically about this incident or about TEPCO’s policies and procedures for these events. I am not interested in assigning blame. Japan has authorities to handle that. A great deal of reconstruction, establishing timelines, evaluating communications, etc...
  18. D

    Step response of a RC circuit asking for i(t)

    Homework Statement In attachment Homework Equations i don't understand why it would be asking for the current going through the capcitor, in a dc circuit it should be an open circuit but there will be a voltage over it... after searching through lecture notes and textbook can't find...
  19. J

    I can't understand the discrete time unit impulse response and convolution

    hi, i have trouble in understanding the concepts of the impulse response first of all, let's assume that we have a signal y[n] = x[n] which is time invariant and linear, hence if I understand correctly linear means that if for input a*x1[n] we have an output a*y1[n] b*x2[n] we...
  20. P

    Calculating Unit Impulse Response

    I am trying to teach myself DSP, owing to bad lecture notes. In particular at the moment I'm trying to calculate impulse responses for LTI systems, given the system equation. I would really appreciate it if someone could tell me if my working and assumptions below are correct for the following...
  21. J

    I cant understand the impulse response in convolution

    Homework Statement i have this graph http://img858.imageshack.us/img858/1346/56954457.png and i need to find h-1[k] i don't understand, i know that the impulse response is the response for input -> δ[n], in this case it will be δ[n+1], but i don't understand how to calulate the response...
  22. G

    Find the unit impulse response

    Find h[n], the unit impulse response of the system descrived by the following equation: y[n]+3y[n-1]+2y[n-2]=x[n]+3x[n-1]+3x[n-2] Can this be rewritten as?(n-->n+2) y[n+2]+3y[n+1]+2y[n]=x[n+2]+3x[n+1]+3x[n]
  23. L

    The zero state response does not satisfy the diff equation. Why?

    If we have a linear system(it could be a RLC circuit) with the following differential equation: d2y/dt2+7*dy/dt+12*y=dx/dt+5*x So H(s) = (s+5)/((s+4)*(s+3)) = -1/(s+4)+2/(s+3)--> h(t) = (-e^(-4*t)+2*e^(-3*t))*u(t) (Please calculate the unit impulse response by Laplace transform and verify the...
  24. M

    Step response and peak response of a transfer function

    Homework Statement The open loop transfer function to a unity negative feedback system is given as: G(s)=50/s(s+10) Homework Equations Unity feedback is used in this problem, and the system input is a step function. Y(s)=50/s(s^2+10s+50) The Attempt at a Solution I have...
  25. M

    How Do You Convert Frequency Response Function H(iw) to Time Domain h(t)?

    I am trying to find the frequency response function given the input and output spectra from the picture i got that X(iw) = iU(w)U(2-w) - iU(w+2)U(w) and that Y(iw) = iwU(w)U(1-w) - iwU(w+1)U(w) So H(iw) = Y(iw)/X(iw) and H(iw) = wU(1-w) - wU(w+1) / U(2-w) - U(w+2) i am having...
  26. T

    Cascode C-S Amplifier (Find Poles in Frequency Response)

    Homework Statement Heres the question, I honestly don't know where to even begin :( An AC model of a cascode common-source amplifier is shown below. M1 and M2 are biased in saturation mode. The parasitic capacitors in the transistors are included. Determine the poles in frequency response...
  27. J

    Finding the impulse response of a system without using Z-Transform

    Homework Statement Find the impulse response of the following: Assume the system is initially at rest. y[n] - (1/2) y[n-1] = x[n] + 2 x[n-1] + x[n-2] The Attempt at a Solution To find the impulse response y[n]: we know that y[n] = homogenous solution + particular solution so... lamda -...
  28. B

    Finding the impulse response of a system

    Homework Statement So the problem asks to find the impulse response h(t) provided y(t) = integral from -infinity to t of e^-(t-tau)*x(tau-2)dtau Homework Equations none The Attempt at a Solution I understand that the way to begin this problem is to substitute delta(t) for x(t). Therefore the...
  29. J

    RLC DC Transient over-damped response

    Hello All, I have a bit of a problem with a series RLC circuit with no supply voltage. In the process of actually solving the second order differential equation for the voltage across the capacitor I have lost a handle on what it actually represents in terms of the circuit. I have attached...
  30. P

    EM response function of the Phase Action of a BCS superconductor

    EM response function of the "Phase Action" of a BCS superconductor Hello, I am looking for a paper in which people calculated the EM response of phase action of A BCS SC. In the book "Condensed Matter Field Theory" by Altland and Simons, on page 393 they mention such a thing in the discussion...
  31. S

    Engineering Help with Step Response of an RC circuit

    Homework Statement Derive the Voltage and Current equations for Step Response of an RC circuit. Homework Equations End products will be Vc(t) = i(s)R + (Vo - i(s)R)e^(-t/RC) and i(t) = (Is - (Vo/R))e^(-t/RC) The Attempt at a Solution Using KCL on a hypotetical RC circuit with a...
  32. G

    Detrmine the unit impulse response

    Homework Statement Find the unut impulse response h[n] of this system y[n+1]+2y[n]=x[n] Homework Equations I have no clue on how to slove this problem, som pointers would be nice. Thx
  33. M

    Impulse response function & Laplace transforms

    i am given the Laplace transform of an impulse response function, as well as its input. i am supposed to find its output. H(s) = 1/s2 + s + 1 x(t) = sin2(t-1)U(t-1) what i have done so far is the following: i know that Y(s) = H(s)X(s) and from this i can easily find y(t) so i found X(s)...
  34. A

    Is Using a Matrix to Analyze Multiple Sensor Data in FFT Appropriate?

    Hi all, I have input force data and output acceleration data to calculate frequency response functions. As these data are in time domain I converted it to frequency domain using fft function in MATLAB. This is the procedure I used. As an example Let's think, Force matrix =a Acceleration...
  35. A

    What is the dimension of the impulse response of an electric circuit?

    Hi all The impulse response h(t) of an electric circuit (maybe in some special cases) is the derivative of the step response s(t) of the same circuit. right? So does it mean they have different dimension, namely if the dimension of s(t) is X, then the dimension of h(t)=ds/dt is x over...
  36. A

    Frequency response of rc coupled amp

    greetings, At high frequency (more than 20kHz) the reactance of capacitor is very small and act as short circuit.this increase the loading of next stage.whats the meaning of increse of loading in next stage? RC coupled two stage amplifier circuit is here-...
  37. I

    Given a 2nd order system response, how to get equation ?

    I have a 2nd order system response on a graph. How would I go about this to develop the equation that models this system in s- domain when its graphed in time domain like I have ?
  38. E

    Initial conditions for rlc series natural response

    Homework Statement Find v(t) across a cap. in a series rlc circuit with no driving force (initial v across cap: 24V) Homework Equations from the values of the components, \alpha > \omega_0, the circuit is overdamped, and the following equation can be used: v(t) =A_1 e^{s_1 t} + A_2...
  39. O

    Discrete LTI filter impulse response

    If I have the unit impulse response function for a discrete-time LTI system (Unit sequence response?), h[n], how can I calculate the time taken for the output to fall below 1% of its initial value, after a unit impulse is applied to the input? In particular, I have: h[n]=(\alpha...
  40. T

    Matlab: System response query.

    Homework Statement Hi. I need help on this Matlab problem. I need to find the system response of the function, where the input is a unit step and a zero initial condition. G(s) = 1/(s+5)Homework Equations G(s)=C(s)/R(s) The Attempt at a Solution num=[1]; den=[-5]; t=0:0.1:80...
  41. N

    Cmos imaging sensor response

    Hi all, I have a question about the response of a cmos imaging sensor. The total exposure is defined as the irradiance * pixel area * exposure time and it can be varied by changing either the irradiance or the exposure time. Would the sensor response remain constant if measurements are taken...
  42. S

    Transient response of a system (control)

    Homework Statement Find T,K value such that the system's percent overshoot is .254 and peak time is 3 http://img560.imageshack.us/img560/6139/problemz.png Homework Equations [PLAIN]http://img46.imageshack.us/img46/51/releq.png The Attempt at a Solution...
  43. planethunter

    Jerk physics professor response

    I asked a professor for advice on whether he thought I would do well in his course given my limited coursework. This is his response: ” Dear Mr. ..., As a science student you should know that to establish a trend line you would need to provide many data points. With your expectation of an...
  44. 2

    Natural response and step response

    ok i need some clarification if you have a circuit where a current source is in parallel with an inductor a resistor and a capacitor is this considered a natural response or a step response. I guess i thought a step response is if a switch is switched and a source is added then it is a step...
  45. R

    Question about zero input frequency response

    Zero input means input equals zero the input is to some differential equation D2x = Dx + x + Input the input = sin(2pi * f * t) so say I want to make a program that solves for the zero input frequency response. (Matlab actually) what would I need to set the variable for frequency to...
  46. K

    Identifying Impulse Response Function from State Equations

    Hi, given the state equations of a system, x(dot) = Ax + Bu y = Cx is the impulse response function of this system C(e^(At))B? If not, how can i identify the impulse response from a given state equations? Please advise. Thank you.
  47. M

    Convolution and Impulse Response

    If one has input x(t), then convolving x(t) with impulse response of the system would give the zero-state of the system. For example, we have a system described as : (D^{2} + 4D + 3)y(t) = (D+5)f(t). I computed system impulse response which is : h(t) = 2e^{-t} - e^{-3t} Now if say f(t) =...
  48. M

    Transient Response of Straw Filling with Water

    Okay, since the most fluids I've studied are from the Euler equation in the context of plasma physics I may be asking a trivial question, but here goes anyway. What I am wondering about is why there is a transient response when I cap a straw with my finger, place the straw in water (while still...
  49. U

    AP Electrochemistry Free Response Questions

    Homework Statement (i) The mass of Fe(s) produced when 1 faraday is used to reduce a solution of FeSO4 is 1.5 times the mass of Fe(s) produced when 1 faraday is used to reduce a solution of FeCl3. Zn + Pb²⁺ (1.0M) --> Zn²⁺ (1.0M) + Pb (ii) The cell that utilitzed the reaction above...
  50. P

    Step Response of System with Pole in s = 0 at Infinity

    Homework Statement A contininous time system has when laplace transformed, a pole in s = 0. What is de stepresponse for the system when t goes to infinity Homework Equations H(s) is infinity in 0 (H(s) is unit response laplace transformed) s(t) = h(t) * u(t) (the stepresponse is the...
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