Signals Definition and 410 Threads

Hi all, I want to know about the complex signals.They say that it is a complex signal and cannot be plotted but at the same time give analogy with cosine or sine functions.Please clear me about this.

I have been handed a challenge that is beyond my reach. I need a way to detect the change in skin conductance, or some other electrical signal on the surface of your hand when you lightly touch your forefinger and thumb together. In this configuration, the skin sensors have to be located on...

is it possible to change voice signals to matrix form? I was thinking of using the neural network to train for voice recognition. The system I will be building is speaker dependent so I don't think that much training is needed besides my own voice

I'm looking ahead to winter quarter 2008 when I will be starting an independent research project. I wanted to get an early start in thinking about what I might be able to do. I am thinking that I want to do something in signal processing, but don't have enough knowledge to make a choice. Here...

Are there any resources on the web that provide example problems (with solutions) to Signals problems? My textbook (shown below) lacks any clear example problems (shows answers without showing you how to get them). If someone could point me toward examples of Convolution, Fourier series, or...

How will we evaluate the integral for calculation of Amplitude Factor for an LTI system for which the input and output are related by a time shift of 3, i.e., y(t) = x(t - 3) The answer is: H(s) = e^(-3s) I want to understand the Mathematics behind the evaluation of the integral...

Hi everybody, I'm a freshman and i want to study signals and systems. so I'm seeking for a good introductory book. I've heard about the book "Signals and Systems" written by Oppenheim and Wilsky. So is Oppenheim's book suitable for a beginner? If you know a better introductory book...

Could anyone explain to me nerve signals in particular action potential and the Myelin Steath? Also animal electricty with Luigi Galvani? Thankyou if you can :) ps Sorry if this in wrong topic, new user:)

Homework Statement I am reading the book Wiley Signal And Systems-Simon Haykin and at the page 34 i read the followings Consider the complex exponential e^j*theta. Using Euler's identity we may expand this term as e^j*theta=cos(theta)+jsin(theta) This result indicates that we may express the...

Hi i am stuck with something really simple :( I know that we can express a signal with the even and odd signal x(t)=xe(t)+xo(t) (xe(t) means even signal and xo(t) means odd signal) x(-t)=x(t) for even signals and (1) x(-t)=-x(t) for odd signals (2) where even signal is...

Hello. I hope you all could help me somehow. I have a pocketPC with a signal generator software. I was confused with why they only produce AC signals and no DC ones. This sounds like a basic question, but why is this? Does flat DC signals produce no sounds or is it just the software...

A satellite telemetry link operating in S-band uses frequency modulation to transmit the value of an analog voltage on the satellite to a receiving Earth station. The voltage has a range from -1.0 volts to +1.0 volts, and a maximum frequency of 1000Hz.The FM modulator on the satellite has a...

I want to find the Fourier coefficients for the following signal: \cos(2 \pi t)^2 Can I simply use the identity?: \frac{1}{2} + \frac{\cos(2 \pi t)}{2} And then use the complex definition: \frac{1}{2} + \frac{1}{4} (\exp{j2 \pi t} + \exp{-j2 \pi t}) From the synthesis equation I can...

Are busses mostly used to carry digital signals? If yes, then why so? Why aren't buses a popular means of carrying an analog signals?

I've read an article in nature and found technical words "B mode signal" and "E mode signal". I don't understand what they are. In a website, they say it's like the electromagnetic field line but I'm still not clear. I also don't understand what k means in " the linear greyscale shows the...

Homework Statement Detmerine the Power and rms value for each of the following signals: a)5 + 10cos(100t+pi/3) ... more signals The Attempt at a Solution It's hard to right out integral signs or I don't know the way to do so I'll use I(lower bound, upper bound) to denote an...

This is kind of a homework topic, but not. Long story short, my beginning of my college career has been horrible in the academic standpoint. Bad calculus classes, a change of major, and 2 1/2 years later I sit staring at my signals book with no clue how to approach any of the problems...

When you go to the checkout, after collecting all the groceries, the money (and the amount of money) transferred serves as a green light. You are then allowed to leave the store legally with the groceries. If it is not enough money it's the red light. If its "I left my wallet at home" it's a...

hey guys. Just wanted to know if you guys agree with my answers: An analogue signal of 1 s duration is sampled at 512 equally spaced times and its DFT is computed. a) what is the separation in rad/s between the successive frequency components? My ans: 2pi/512 b)what is the highest...

Hi I am looking for the solution manual for Fundamentals of Signals and Systems Using the Web and MATLAB (2nd Edition) by Ed Kamen, Bonnie Heck I need most of the solutions at least. If you could help it would be greatly appreciated. I will do anything to get the solutions. Please HELP.

i usually have such a hard time determining whether a signal is time invariant or not ... for example, why would x[-n] not be time-invariant? please don't just tell me why x[-n] would not be time invariant ... tell me techniques that I can apply to other signals too

Folks, I think I got to the right answer for the wrong reason. Could you please verify my approach? Any help is highly appreciated. Problem: Is x [n] periodic? If so, what is the fundamental period? x [n] = \cos \left( \frac{\pi}{8} n^2 \right) Here is what I've got...

Q1. If j = square root of - 1 what is square root of j ? what I did was : Plug in the value of j in square root of j and came up with -1 to the power of 0.25. Is this right. Looks like this wrong. Q2. Given a complex number w = x + jy, the complex congugate of w is defined in...

hey something is really confusing me... we are given this impulse response h[k] = 2d[k] +((0.8)^k).u[k] + (2(-0.4)^k).u[k] where d is delta... anyway the question then asks: using the convolution, determine the ZERO STATE RESPONSE for an input signal x[k] = 2u[k+2] - 2u[k-4]. Now...

hey guys - attached is a solution to a signals related question. Given the system - we must calculate the impulse reponse. please click on attachment to see what I am talking about. two things confuse me: 1)the system is evidently non-causal, but here they decide to shift the entire...

OK. Going to try to explain the background on this one the best I can. I have two data sets which are mixtures of TWO signals, but are both different (Think of it as two people in a room talking at the same time and there are two different microphones listening to what they are saying). Lets...

hey guys - just a question regarding a systems and signals course: if I've got two disctrete signals: x1[n] and x2[n] if i know both signals are periodic (individually) how do i prove the sum of these signals is periodic? requirement for periodicty (one signal): x[n+N] = x[n] where n...

I am trying to come up with a way to monitor a device that alarms. The signal is open collector: high impedance when not alarm. I would also like to be able to connect this to a computer and monitor and log the alarms when they happen. Any help would be greatly appreciated.

I,m trying to do some bike customization and would like to modify my mirrors to have a set of led sequential turn signals on them. You can buy modulators to do this for you but i imagine all it is just a couple cappacitors and resitors pretty much that's involved. I am not a electrical idiot and...

Hi, I hope this is the right forum. I'm a computer science student and at the moment I'm a little confused with some basic theory regarding signals. I am told that some media (such as fibre optics and other forms of unguided media e.g. microwave) only propagate analogue signals. Yet...

Where in the visual system does one begin to recognize the millions of Colors in teh visual spectrum? Do the retinal cells differentiate between them? Or are generic signals carried to the Color Zones(??V4??/IT) where they are differentiated? How would one convert (256,256,256) pixel colors...

Hi i want to find and read about the return to zeroes and non return to zeroes. What are the differences betwwen them ? Advantages Disadvantages>?

Hi i have noticed that some times we can denote an electromagnetic signal using cos os some timew we can write it in exponential form? Is that true? How can we convert from one type to the other? For example i think that the signal Acos(wt-kr) it can be written to Ae^i(wt-kr) Thx a lot

Hi i am wondering how the diffraction interferes with the signals.. I was reading wikipedia's diffaction artiocle .. bt i can't understand clearly what diffraction causes to an e/m wave.. What i know is that the diffraction is bad some times os some other times is good because we can send waves...

Hi, Can someone help explain why something that has the ability to move faster than c can potentially send a signal backwards in time - thus ruling out superluminal travel. If a 'superluminal' ray starts out at t=0 then even if it does travel faster than light, any information it...

Hi do u have any good articles about signals and modulation... I want to know why we use modulation and how the world would be if no modulation was used at all... Waht arre the types of modulation? What are the differences between them? What are the adgvantages and disadvantages for each...

Ok, admit to absolute naivety in this subject, so please excuse any glaring errors and ignorance in this question :) I have a device which according the specs emits a 0.5 Hz square wave that is bipolar and assymetric. The current ranges from 0 - 1000 mA. Figuring that this was a safe...

Method and Apparatus For Transmitting Signals Faster than Light?? (Based on EPR/QM) Method and Apparatus For Transmitting Signals Faster than Light?? (Based on EPR/QM) Does the following apparatus make sense? Please discuss and let me know where the logic or science is falling short, if...

Hi i am wondering in an electromagnetic signal how times bigger the electonic signal is bigger from the magnetic one... I have also read that becuase the electric signal is bigger the most reveivers ignores the magnetic field and only searchs for the electric signal... Do u know any...

signals...help needed hi, can anyone tell me why a discrete time signal x(n-k) where k>0 is shifted right along the X-axis(the time domain) and x(n+k) is shifted left. should'nt it be the reverse? this is for the graphical notation. but for the notation...

Is there a way to tell PSPICE to graph a signal without having to go to Trace>Add-Trace and selecting the signals each time? If I added a signal and then change a component value slightly and run the simulation, is there a way I can refresh the signal without having to go through the add trace...

Hi let's suppore that an antenna creates two signals... The two signal are received from an other antenna but with a main difference. The one of the two signal is reflected in a surface which means that it will travel bigger distance... The two signals are received with a difference in the...

Hi, the title above is a specific instance of a more general question. I'm basically wondering why the atoms in a wall would prevent visible light from passing through, yet allow both X-rays (which are HIGHER frequency) and radio waves such as 802.11b wireless internet (which are LOWER...

Hi, Here's the question: a) There is a radio telescope that is 1000 feet in diameter. It is claimed that it can detect a signal that lays down on the entire surface of the Earth a power of only one picowatt. What power would be incident on the antenna in this case? It seems to me that...

After I have stripped the filters then one of my filters lost all the signals even the signals of the MW marker. What is wrong? The protocol for stripping is this: Warm the stripping buffer (62,5mM Tris-HCl pH 6.7 and 2% SDS) to 50C and put the filter in it for 30min at Room Temp (RT). Wash...

I have a question about finding the signal energy of a signal? What exactly are you suppose to do when you are given a certain function like x(t)=rect(t) sin(2*pi*t)?

does the brain send out signals or frequencies. I believe i recall hearing about something like beta waves perhaps it was. Someone know of this?

http://xyz.lanl.gov/pdf/gr-qc/0501053 The search for quantum gravity signals jan 2005 an overview of ongoing searches for quantum gravity effects.

Digital and Analogue Signals... When learning about digital and analogue signals, I have been told that a fibre optic cable can be used for digital signals, whilst a copper wire is usual used in the case of anaolgue elctrical signals. My question is could they be used for the other things? Ie -...

Suspending clam eggs in seawater containing 60 mM KCl triggers intracellular changes but if the sea water lacks calcium it prevents the activation by the 60 mM KCl. 1) What does this suggest about the mechanism of KCl activation? I know that the membrane potential is maintained by the K...