# 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. ### Engineering Sinusoidal response to sinusoidal input (Process control)

This a homeawork from my graduate course. I know that a sinusoidal input affects both the amplitude and phase of the response, but I don't know how it does. I'd be really glad if someone could help. Thanks
2. ### Current and Future AI Threats to Humanity and the Human Response

There has been an explosion of discussion among experts about the evolving/growing dangers of AI and what to do about it. This debate has gone public, largely due to the recent success of generative AI, and the rapid pace of improvement. As an example, AI models which can generate images based...
3. ### I Dielectric constant, dispersion and response of the medium

Hello, for my PhD, I've been studying an influence of a gain medium on spectral linewidth of light inside a fiber cavity. I've encountered a formula in one paper to which I don't how to get to (see screenshot), it's the formula (A3). On the left hand side there is electric flux density, the...
4. ### Automotive Amplitude based frequency response simulation in Abaqus

Hi, I have inputs like displacement of a driving mechanism and then the frequency of concern . Displacement: 0.2 mm Concerned Frequency: 100 Hz I would like to evaluate a part with the input displacement applied to a node and not as base excitation. It can be sweep over the frequency range...
5. ### Engineering Half-power cut-off frequency and frequency and phase response.

I have been given the attached following question: FIGURE 2 shows the response of a first-order filter to a step input. Estimate the half-power cut-off frequency of the filter and sketch its frequency and phase response. I believe that I have correctly calculated the half-power cut-off...

7. ### Frequency Response Problem for given system

Hello, I am given an exercise in which I need to answer some questions, for this given system : y(n)=1/3[x(n)+x(n-1)] 1/ find the impulse response h(n), then H(n) 2/ calculate the magnitude ||H(n)|| and tell the nature of the filter 3/ calculate Fc which is cutoff frequency when Fe=8Khz , and...
8. ### Inverting op amp frequency response Bode plot help

Using analog discovery 2 kit and the bode plot produced by the network analyzer is off. The scope looks fine and everything is behaving how it should except for the bode plot. The magnitude of the bode plot will start at the correct dB then right before tapering off it shoots up a few dB and...
9. ### Medical What does the absence of any immune response symptoms mean?

It's my (limited) understanding that your immune systems responds to most (all?) microbial threats initially with aches and fever, i.e., that these initial symptoms are not caused by the microbe but by your immune system's activation. So what does it mean if one is infected and infectious but...
10. ### We haven't changed all that much - epidemic social response

Someone should find these interesting reads, with the backdrop of the last year or so of the epidemic. https://www.marquette.edu/cgi-bin/cuap/db.cgi?uid=default&ID=5982&view=Search&mh=1 ... however Milwaukee had in late 1894 and early 1895 one last epidemic, in some ways the most notable, for...
11. ### Engineering Frequency Response Between 100Hz and 100kHz

So am trying to find the Frequency response of a RC LPF between frequencies 100Hz-100kHz ,but i don't know what formula to use .
12. ### Engineering Finding Impulse Response of Difference Equation

And really that's all I know how to do myself. If someone can explain/lead me through this, that will be very helpful. Thanks
13. ### Delaying a COVID vaccine’s second dose boosts immune response

I was wondering if @Ygggdrasil has more information on this. Is there only documentation on people over 80? What is the likely hood that this would also be the case for those younger? I believe the study is only for the Pfizer vaccine. https://www.nature.com/articles/d41586-021-01299-y Is the...
14. ### B RC Low Pass Circuit Sine Wave Response

Hey Everyone, I am trying to gain a level of fundamental understanding of an RC circuit sine wave response through the mathematics and was wondering if someone could help me work it out. Fundamentally a sine wave is represented by the equation y=-ky'' . When a sine wave is used as the input...
15. ### COVID Boost Response by Delaying Second Dose -- Pfizer vaccine in elderly

This applies to the Pfizer vaccine. Article dated May 13, 2021. https://www.nature.com/articles/d41586-021-01299-y Older people who waited 11–12 weeks for their second jab had higher peak antibody levels than did those who waited only 3 weeks. ...could boost antibody responses after the second...
16. ### And The Actual Human Response To Keanu Reeve's Klaatu Would Be....

A six way, all out release of humanity's entire stockpile of "engineered criticality devices" and slag the planet. The damned aliens were exterminating humanity anyway, why should they get what they want, while we go black? I'd bet money neither the movie's writers nor the extraterrestrials...
17. ### Medical Determination of T-cell response in Covid vaccines

Presently some 4-5 Covid vaccines are popular worldwide. pfizer, moderna, astrazeneca, sputnik to name a few. Some Chinese and Indian vaccines are also in the selected markets. It is said that all these vaccines elicit robust antibody responses against the SARS-cov2 virus. My question is if...
18. ### Engineering Step response of RC circuit with independent voltage and current sources

Dear PF, In the figure down below is Q7.47 which asks to determine the voltage v(t) across the capacitor for t > 0. Since it is given that V(0) = 0 there are two scenario's which is between time interval 0 < t < 1 and t > 1 according to the independent sources. For the scenario 0 < t < 1 the...
19. ### Is targeting just the spike protein in a COVID-19 vaccine enough?

My impression is that the vaccines being administered in the United States - not sure about the vaccines in other countries such as the UK - create an immune reponse to the SARS-COV-2 spike protein. Naively, one might ask why have a vaccine against a single viral protein when a virus has many...
20. ### Engineering Magnitude versus Frequency Response Drawing from Pole-Zero Plot

Hi, EDIT: apologies for any ambiguity, but this is for DISCRETE systems, not analogue like the problem states. I was attempting a problem which is shown below . I am not really sure how to attempt this problem, but here is my attempt. Are there general methods for tackling these types of...
21. ### B Inverse Transformation from Response Surface

Let us say we have data which is for simplicity in N tables. All the tables have the same number of rows and columns. The columns ##A_i## have for all tables the same meaning (say measured quantaties like pressure, temperature) where the first 3 columns is the position in space. Again for...
22. ### Response of a motor rotor to just 1/60th of a second of current

Where can I get actual demonstration that a 1/60 sec current can move the magnet. That is. You just apply 1/60 sec current without other power in the middle of it, will the magnet move that fast in 1/60 sec? Or does motor runs because of inertia of the previous rotation?
23. ### MHB Natural and forced response of a differential equation

Greetings everyone, I am a bit new to differential equations and I am trying to solve for the natural and forced response of this equation: dx/dt+4x=2sin(3t) ; x(0)=0 Now I know that for the natural response I set the right side of the equation equal to 0, so I get dx/dt+4x=0, thus the...
24. ### COVID Flawed interferon response spurs severe COVID-19

from: Science magazine: "...in a significant minority of patients with serious COVID-19, the interferon response has been crippled by genetic flaws or by rogue antibodies that attack interferon itself. And appears to be related to a flawed X chromosome that creates antibodies to type I...
25. ### Is this a solution for congestion impacting emergency response?

Consider this situation: I'm sure every one of us would dread being in that ambulance. So I am looking for input on this idea to assist emergency vehicles. Suppose that the city put out a call for pedestrian volunteers to bide in segments of the city where such congestion creates these...
26. ### Engineering How to draw a block diagram of a discrete element with its impulse response

Hello friends, I have a problem with a exercise sheet. Given is the impulse response of a discret element. The task is to draw the block diagram. But I think that the solution in the sheet is wrong. Because based on the difference equation (Exercise.pdf) there should be 3 delay elements. I have...
27. ### What are Immediate Early response Genes?

So I'm studying the MAPK pathway and Erk (MAPK) activates IEGs (Immediate Early response Genes) such as Myc, Fos and Jun. What are IEGs? I was told: IEGs: - expressed at the mRNA level (what does this mean? what's a "level"? what does "expressed" mean?) - and hence don't require protein...
28. ### Physical/conceptual reason for inductor voltage step response

I'm trying to understand the physical reason why when you drive an ideal inductor (no series resistance) with an ideal voltage step input (no series resistance), e.g. some Vin(t) = V0u(t), the output current will be a linear ramp. I can see how to derive this from the inductor equation, v = L...
29. ### Response of (house) lizards to the sounds of various frequencies

Summary:: Is there any peer-reviewed research that tells how (house) lizards respond to sound of different frequencies? At the very beginning, I must admit that my knowledge in Biology does not run beyond high school books. We are becoming more and more disgusted with these house lizards...
30. ### Control Theory - Nyquist Plot - Speed of Response from Low Frequency Asymptote

[Moderator: moved from a homework forum. This does not sound like homework.]Homework Statement:: Why is it the case that when the low-frequency response is to the right of the M = 1 line that the 'speed of response is slow'? Relevant Equations:: M-cirlces Hi, Hope you are doing well and...
31. ### I Asteroid Response Help: Get Answers to Your Questions Here

(If anyone could provide links to information it would be greatly appreciated.) I'm currently taking a class on threats from outer space and have to write a paper on something that could be done in response to an asteroid/meteor coming towards Earth. One of the quickest responses would be to...
32. ### Calculating the spring displacement response from an acceleration input

I'm working on a project where we have a mass (50 kg) sitting on a spring (350 N/mm) and are subjecting it to a sudden impulse (20g) along the spring axis to simulate a shock. We have the profile of the acceleration defined as: ##a(t) = x''(t) = P\cdot \sin^2 (\pi \cdot t / T)## Where P (peak...
33. ### Help Understanding Response Function $$H(\omega)$$

$$<H(\omega)>=\sum_{j} χ_{HAj}h_j(\omega)$$ Where $$χ_{HA}=\frac{1}{2\hbar} Tr{{\rho}[{H(t)},{A(0)}]}$$. But $$[H(t),A(0)]=[H_o,A(0)]-[A(t)h,A(0)]=-h_0 cos(\omega t)[A(t),A(0)]$$. So $$χ_{HA}=-\frac{1}{2\hbar}Tr(\rho h_0 cos(\omega t)[A(t),A(0)])=-h_0cos(\omega t)χ_{AA}$$. Then...
34. ### Electronics Material with response to moisture and electrical changes?

I want to know what is the material that has a moisture and electrical properties response ? Do I have an idea to create an electrical device that is related to moisture using some materials that are responsive to moisture and electrical properties
35. ### MATLAB Ltiview and negative step response of a linear system

Hi, my professor gave me I code where he used to evaluate the answer of a linear system to a step increase in the input variables like this: MySystem = ss(A, B, C, D); ltiveiw('step', MySystem, 'r-', 300); My problem is that with this code I get the response only for a positive step. I'd...
36. ### Output as the convolution of the Impulse response and input

As the title says, I am studying this topic for my control systems fundamentals course. I think I intuitively understand the meaning of the convolution integral that relates input, output and the impulse response, but I am failing to prove it graphically. For example, the intuitive explanation...
37. ### Frequency response - Hydraulic network

Hello everyone, i have a measured signal of a high pressure oscillation in a hydraulic network. Performing a FFT of said signal shows two dominant frequencies, a and b. After performing a linear analysis of the hydraulic network i found out that the network has two eigenvalues at those...
38. ### Finding the settling time of an oscillatory response

I was reading my book on circuit analysis on chapter about RLC response and became curious about how to get an approximate value for the settling time of the response. Particularly this response My first approach was to use the upper envelope of the response and equate to 1 percent of its...
39. ### Frequency Response of a Damped Car-Suspension System

The quarter car system is represented by the above picture and I currently have all of the equations of motion and constants for each spring, mass, damper, distance, and moment of inertia. How can I find the frequency response with this information and knowing both tires hit a pothole of height...
40. ### Engineering Graphing the response of an underdamped circuit

I'm having difficulty as to how I would produce an approximately graph of the response just by hand. I was able to determine the first maximum by taking the derivative of the response and setting to zero and I'm stuck. How do I know the succeding minimum and maximum of this response? TIA.
41. ### A Magnetic response of a degenerate Fermi gas

I know that in a Fermi gas, the two common responses to a lo field are Pauli par. and Landau dia. and the last becomes the H-VA effect My question is, it is the same treatment in degenerated Fermi Gas?
42. ### Definition of isolation and pulse response time for a 3-way power splitter

I will use 3 way power splitter and power detector. 1. This is power splitter data sheet. In this data sheet, there are different isolation values. What does it mean?? Also in that point, I wonder definition of isolation at power splitter. 2. This is power detector data sheet. In this data...
43. ### Determine a transfer function in the s domain and the response to a ramp input

1. A process can be represented by the first order equation ##4\frac{dy(t)}{dt}+y(t)=3u(t)## Assume the initial steady state is steady (y=0 at t=-0) (a) Determine the transfer function of this process in the s domain (b) If the input is a ramp change in u(t)=4t, determine the value of...
44. ### Average response time in a conversation?

Is there any average time between responses in a simple conversation using speech (not text)? For example Bob : Hello 1sec gap Mike : Hey!
45. ### Solving Differential Equation with Frequency Response

Homework Statement The AC response of an inductor can be modeled by the following differential equation: L \frac{di}{dt} + iR = V Find, using frequency response, the current of the system when the applied voltage V is: V = V_0 \sin(\omega t) Homework EquationsThe Attempt at a Solution In...
46. ### Quarter amplitude response method: PID settings

Homework Statement see attached, question 8a and b are what I'm attempting. I've also attached the VERY brief course notes that I'm required to work with. I know Tc= 8 seconds from the graph (0.13minutes) Gain set to 4. is PB therefore 100/4=25%? I'm struggling to calculate the ratio of...
47. ### Sketch the waveform to represent the transient response

Homework Statement Sketch, on a set of common axes, waveforms to represent the transient response of circuits having transfer functions with the following parameters: a) ζ = 0.5, ω = 1×10^3 rad s^-1 b) ζ = 0.2, ω = 2×10^3 rad s^-1 c) ζ = 2, ω = 1×10^3 rad s^-1 Homework Equations wd=wo√(1-ζ^2)...
48. ### Insights Why the Quantum | A Response to Wheeler's 1986 Paper - Comments

Greg Bernhardt submitted a new PF Insights post Why the Quantum | A Response to Wheeler's 1986 Paper Continue reading the Original PF Insights Post.
49. ### Converting impedence response to electrical conductivity

Hi, I have a curve, impedance magnitude vs frequency. i would like to convert this curve to electrical conductivity vs time. how can i do that?
50. ### Response of a System: Transfer Function

Some time ago I made a modelling project and obtained a plot. Now, I want to remember what the transfer function was, as I want to try changing the parameters. The graph is the following: How can I obtain the transfer function? Thanks a lot