Could a genuine non-periodic random signal be generated using periodic components ?
397969
Random from pure sines? Only if you can add up an infinite number of them.\nI think, it can be "proved": if you will add only a finite number of sines, the result sum will be continuous for all x and then in sufficient small vicinity of point x it will be bounded by interval of any given length. In other words, values of finctions in points NEAR x will be NEAR value of function in x itself. So it couldn't be called "random".\n\nBut non-periodic is quite simple.\n\nsin(x) + sin(x*sqrt(2)) is non-periodic.\n\n\nPS. I'm just curious: why do you need REALLY genuine white noise? I think it has only theoretical meaning. For all practical tasks it's enough to use "pseudorandom" sequences.\nFor example, x_(n+1) = sin(x_n * 10^9).\nIt isn't uniformly distributed, but also exists a bit more complicated uniform ones.
536183
Hello, you may be able to achieve this with software from  http://www.realtimesoft.com/ultramon/.
763829
I'm not familiar with that particular book, but the differential equations of simple harmonic motion are interesting.  You can make the system as complex as you like.  I've studied SHM in both maths and physics.  I simulated SH oscillators with operational amplifiers; in other words an analogue computer.  First you simulate a frictionless pendulum, then you introduce friction so the oscillations die away, then you introduce forcing terms of various frequencies to see what happens; like pushing a child on a swing.  If you're really clever, you can introduce hysteresis (delay), and extra degrees of freedom (flexible joints in the pendulum), and vary the Q of the system (how sharply you can tune it to the resonant frequency).  It's about the most open-ended project I ever saw.  I did it in second-year physics.  At its simplest, it's just sixth form maths, but you can turn it into an impossibly complex exercise in chaotic systems if you're clever.
535874
www-ccrma.stanford.edu/~jos/mdft/FFT_Zero_Padded_Sinusoid.html\n\nTry the above link\n\nVisit wolframs site they have some material on the interpolation.
810773
The following assumes you want to generate square and\ntriangle waves of relatively low frequencies:\n\nJust use a microcontroller. Use one output pin for the square\nwave and feed it through a D-type flip-flop configured as a \ndivide-by-two to get 50% duty cycle on the output. For the\ntriangle wave you can use PWM (Pulse Width Modulation)\nand hook the output pin to an RC (Resistor Capacitor) filter\nto form a simple D/A (Digital to Analog) converter.\n\nAlternatively, you can either buy a microcontroller with a\nbuilt-in D/A converter or add one externally. This will allow\ngeneration of any arbitrary waveform.\n\nA few of the many manufacturers of suitable microcontrollers\nare: \n\nAtmel, Microchip, Silicon Laboratories, and Texas Instruments.
601386
Through the fourier map generator.
387983
A digital signal is composed only of electrical pulses representing either zero or one. Because digital signals are made up only of binary streams, less information is needed to transmit a message. Digital encoding therefore increases the capacity of a given radio frequency. Furthermore, only digitized information can be transported through a noisy channel without degradation\n\nSignals that are recorded in analogue format are modulated, ie their information is contained in amplitude or amount of signal. Digital, conversely, is either on or off, and amplitude is identified in a different way
972053
look here:\n\nhttp://en.wikipedia.org/wiki/Wavelet
773766
From a software developer point of view. This will be really hard to do and come up with a algorithm for seperating human voices from the regular music. They are sampled in digital files and to find which wave is the vioice is too hard for a computer to tell apart.
9363
No.  You can't definitively "prove" a sequence of numbers is not randomly generated by just looking at the numbers, but you can still draw conclusions with a high degree of confidence.\n\nFor example, it is extremely unlikely that a random number generator will produce the same number twenty times in a row, but technically, it is possible.  So seeing this happen doesn't prove it's not random, but you can still conclude that it's not.
556680
http://en.wikipedia.org/wiki/Modulation_index
348945
Technically, all things are written in a long enough random sequence of numbers.  For example, the number Pi contains an infinite sequence of unpatterned numbers, so if you looked deeply enough, you could find any piece of information you wanted was already encoded in it.  But in practical terms, you can only find what you already know, so it has no predictive value.  So the answer is, no, a random event generator is not a real way to see into the future.
200277
Are you asking for the mathematical representation of a frequency modulated signal (FM)?  If so, it is:\n\nXc(t)=Ac*cos[omegaC*t + fDelta*X(t)]\n\nWhere t is time, Xc is the the modulated carrier, Ac is the amplitude of the carrier, omegaC is the frequency of the carrier (in radians per second), fDelta is the modulation index (amount of frequency change allowed), and X(t) is the message.\n\nSee chapter 5 of reference in "source(s)".
961641
http://hamilton.bell.ac.uk/hncexam/Samplepaper.doc ;-)
616514
Generating static electricity.
1014972
Because one of the main reasons of modulation is to shift a signal from one frequency band to another. Multiplication by a sinusoidal does this shifting directly because multiplication by a sinusoid in time domain is equivalent to a shift in frequency domain, this is one of the properties of fourier transform. Any other periodic signal other than a sinusoid will, in addition to the shift you want, introduce other "waste" or rubbish components at other frequency bands which may harm your system or someone else's. Got the point?
55122
Better way is to creat an instance of Random class.\nIt has methods, nextInteger(), nextdouble(), and others.