Windows 7 Write Protection

Start > Run "cmd"
type< diskpart
type< list volume (type< list disk )
type< select volume # (type< select disk #)
type< attributes volume clear readonly

CentOS on Sony Vaio VPCCW21FX: Enabling WLAN

modprobe ath9k
chkconfig NetworkManager on
service NetworkManager start

Unable to open CHM files

Start > Run

regsvr32 itss
regsvr32 jscript

Avoid the conversion of dashed or dotted line patterns to a solid line pattern when you embed a Visio object in another document

Add the MetafileDashLineAsSolid registry entry to the following registry key:
* Visio 2007

HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Visio\Application

* Visio 2003

HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Visio\Application

On the Edit menu, point to New, and then click DWORD Value.
* 0: Do not substitute solid lines for dashed or dotted lines.
* 1: Only substitute solid lines for dashed or dotted lines in extreme situations.
* 2: Substitute solid lines for dashed or dotted lines when reasonable. (Default value)
* 3: Always substitute solid lines for dashed or dotted lines.

Partial Fraction Expansion over Complex Numbers with Mathematica

(*Function Definition*)
FactorC[p_, x_] :=
Times @@ Cases[Roots[p == 0, x, Cubics -> False], u_ == v_ -> x - v]

PartialFractionsC[p_,
x_] := (Apart[Numerator[#1]/FactorC[Denominator[#1], x], x] &)[
Together[p]]

(*Example: Transfer function to be decomposed*)
R := (A s)/(s^2 + \[Omega]^2)

PartialFractionsC[R, s]

A/(2 (s - I \[Omega])) + A/(2 (s + I \[Omega]))

Missing library: libg2c.so.0

If you receive the "libg2c.so.0: cannot open shared object file: No such file or directory" error when ASITIC is invoked, extract the contents of libg2c into /usr/lib

tar xvzf libg2c.tgz
mv libg2c* /usr/lib

DSP style z^-n in Mathematica

To change a polynomial expression in z-domain from z^n to z^-n, modify the global variable $PrePrint:

$PrePrint = # /. {Power[z, n_] -> DisplayForm[SuperscriptBox[z, n]]} &;

Example usage: Linear model of the 2nd order delta-sigma modulator in z^-n form

Calculating the SNR of a bandpass delta-sigma modulator in Matlab

% This calculates the SNR of a bandpass delta-sigma modulator
% Alper Ucar, ucar {at} ieee {dot} org
% -------------------------------------------------------
% [snrv,PxtdB,PxnbdB] = snr(data,tone,fftlen,osr,offset)
% data: output stream in time-domain
% tone: input stream in time-domain
% fftlen: FFT length
% osr: oversampling ratio
% offset: number of samples to be removed from both sides
% of the spectral content for the measurement
% PxtdB: input power
% PxnbdB: noise power
% snrv: SNR
function[snrv,PxtdB,PxnbdB] = snr(data,tone,fftlen,osr,offset)

Coherent Sampling Calculator

% Coherent sampling calculator for ADC testing
% Signal generator resolution in decimal places after MHz is
% considered to be 6 -- i.e. Resolution is 1 Hz
% See http://www.maxim-ic.com/app-notes/index.mvp/id/3190
% for details --Alper Ucar, ucar {at} ieee {dot} org
% Finc: coherent input frequency of the test signal
% Fs: coherent sampling rate
% Fs: sampling rate
% Fin: input frequency of the test signal
% N: number of samples
function[Fsc,Finc] = csr(Fs,Fin,N)

Plotting an Accurate PSD Estimate in MATLAB

% This script plots the power spectral density estimate
% of a signal --Alper Ucar, ucar {at} ieee {dot} org
% data: output stream in time-domain
% fftlen: FFT length
% Fs: sampling rate
% pxf: mean-square power of the signal
function[pxf] = pspec(data,fftlen,Fs)