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Question: <p>Does anybody know how to derive this phase function for that all-pass filter structure? Many papers re-print them, and corresponding chart as well. </p>
<p><a href="https://i.sstatic.net/xo8bQ.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/xo8bQ.png" alt="enter image description here"></a>... | https://dsp.stackexchange.com/questions/53777/phase-shift-of-all-pass-bi-quadratic-filter |
Question: <p>Given are two cosines according to the following formula
<span class="math-container">$x_i(t) = cos(2\pi f_i t)$</span>
with <span class="math-container">$f_1 = 1Hz$</span> , <span class="math-container">$f_2 = 2Hz$</span> and <span class="math-container">$f_3 = 3Hz$</span> .</p>
<p>The two cosines are del... | https://dsp.stackexchange.com/questions/82329/time-shift-and-phase-examples |
Question: <p>I need to define an encoding to beacon IDs. The codes are going to be periodic but in the receiver side I can have phase shifts so I' wondering the best way to decode:
- 8 bits code groups that represent the same ID: </p>
<pre><code>Group1: 00000001, 00000010, 00000100 ..... 10000000
Group2: 00000011, 00... | https://dsp.stackexchange.com/questions/36228/resilient-codes-to-phase-shift |
Question: <p><strong>Background:</strong></p>
<p>I am using a vibration sensor and arduino to record signals and log them with timestamps, where the signals need to be time accurate so that I can glean information about which frequencies are present.</p>
<p>To eliminate aliasing I am connecting a low-pass Butterworth f... | https://dsp.stackexchange.com/questions/82456/accounting-for-phase-shift-in-time-dependent-signals |
Question: <p>I have a signal sampled at 40MHz, I would like to resample it to 37MHz. The signal is <em>not periodic</em>, I did resampling with Matalb resample function and it doesn't cause phase shift (as far as I understood). Matlab applies an anti-aliasing FIR filter and compensate for the delay introduced by the pr... | https://dsp.stackexchange.com/questions/66961/does-resampling-cause-phase-shifts |
Question: <p>The figure below shows in dashed lines sinusoidal signals of the same frequency at three different phase shifts. The signals are then sampled such that the sinusoidal frequency is exactly a half of the sampling frequency, i.e. the frequency of all the sinusoids is the Nyquist frequency. The samples taken... | https://dsp.stackexchange.com/questions/14125/nyquist-frequency-phase-shift |
Question: <p>In reading Rafael Gonzalez Digital Image Processing, second edition, section 4.10.2,
the author writes:</p>
<blockquote>
<p>Notch filters are the most useful of the selective filters. A notch filter rejects (or passes) frequencies in a predefined neighborhood about the center of the frequency rectangle.... | https://dsp.stackexchange.com/questions/68063/zero-phase-shift-filters-must-be-symmetric-about-the-origin |
Question: <p>I want to sample two signals, S and R and later do IQ demodulation on these.</p>
<p>I am multiplying S with R and I also want to multiply S with a 90 degree phase shifted version of R by shifting the samples in R so I get a 90 degree phase shift.
The problem I encounter with this is that unless I have a s... | https://dsp.stackexchange.com/questions/9377/how-to-correct-for-inperfect-90-degree-phase-shift-before-doing-iq-demodulation |
Question: <p>One way of separating downgoing and upgoing wavefields in offshore seimic processing is to add signals from hydrophone and vertical component of the geophone (they are co-located). Hydrophone only registers a change in the pressure whereas geohphone as well as registering a change in seismic field also rea... | https://dsp.stackexchange.com/questions/49221/adaptive-filter-to-scale-and-phase-shift-two-sensors-output |
Question: <p>I have a signal of the form $s(t)=A(t) \sum \cos(\omega_i(t)t +\phi_0) + n(t)$, where $n$ is gaussian noise.</p>
<p>I can only read the <em>signal+noise</em> and thus can not separate them.</p>
<p>I want to phase shift the signal to $A(t) \sum\cos(\omega_i(t)t)+n'(t)$ and I am at a loss on how to do this... | https://dsp.stackexchange.com/questions/29671/phase-shifting-a-noisy-signal |
Question: <p>I'm working with the wonderful Direwolf sound card TNC software, and am attempting to use the OpenCL clFFT GPGPU acceleration library to do FFT on the signal to replace the bandpass and lowpass filters with a much more efficient GPGPU accelerated FFT filter.</p>
<p>In PSK (phase key shifting) the signal wa... | https://dsp.stackexchange.com/questions/94842/does-fft-filtering-preserve-the-phase-shift-of-a-psk-signal |
Question: <p>I am trying to identify the characteristics of an FIR filter in an ideal case as a sanity check. I observe that there is no strange behaviour, but there is an unexplainable issue in the phase plot of the original and identified filters. To make it simple, I've provided the transfer function coefficients be... | https://dsp.stackexchange.com/questions/96533/360-circ-phase-shift-between-bode-plots-of-two-similar-systems |
Question: <p>I am aware this topic has already been addressed in at least one question here, but despite that I could not find the solution to my problem.
Also bear patience with me since I am not a mathematics guru but a coder, so I am not really able to explain my problem with formulas but I will try to expose it to ... | https://dsp.stackexchange.com/questions/63568/phase-shifting-in-frequency-domain |
Question: <p>I'm a bit of a noob here, looking for a simple formula or just a table which can tell me the absolute <em>minimum</em> phase shift angle possible for different variations of QAM. Particularly QAM 16, 64, 256 and 1024. If the answer is zero (is it?), then what is the minimum phase shift possible in each cas... | https://dsp.stackexchange.com/questions/58258/what-is-the-minimum-phase-shift-for-quadrature-amplitude-modulation-qam |
Question: <p>I am designing a 24ghz doppler radar, with 1TX 2RX. Four adc channel are recording at 25khz, applying 256point FFT on adc of both of RX I and Q, I could identify the target in certain doppler frequency(speed) . The next step is to calculate the phase shift to get the angle of the target, that's where I stu... | https://dsp.stackexchange.com/questions/64555/help-to-calculate-phase-shift-in-certain-frequencyidentified-from-fft |
Question: <p>I just learned following notation for a sine wave:</p>
<p>$A e^{j\phi t}$</p>
<p>A low passfilter and a highpass filter respectively generate a phase shift in the complex plane of the sine wave as follows:</p>
<p>$A e^{-j\phi t}$ and $A e^{+j\phi t}$</p>
<p>I don't understand what phase shifting has to... | https://dsp.stackexchange.com/questions/28750/why-do-low-pass-and-high-pass-filters-generate-a-phase-shift |
Question: <p>I was doing some research on filters, So I designed butterworth filter based on pole locations. I applied to a simple sine signal to check for the outputs. I cannot find the reason for what I noticed.</p>
<p><a href="https://i.sstatic.net/A7t6h.png" rel="nofollow noreferrer"><img src="https://i.sstatic.ne... | https://dsp.stackexchange.com/questions/35055/phase-shift-in-higher-order-filters |
Question: <p>The phase shift method (Hilbert Transformer) can be used for single sideband (SSB) generation. The box marked (−𝝅)/𝟐 is a 𝝅/𝟐 phase shifter, which delays the phase of every spectral component by 𝝅/𝟐. Hence, it is a Hilbert Transformer.
An ideal phase shifter is also unrealizable. It is easy to bui... | https://dsp.stackexchange.com/questions/95548/what-are-the-drawbacks-of-using-the-phase-shift-method-hilbert-transformer-for |
Question: <p>I am comparing two signals in MATLAB Simulink for finding the phase between them. To do this I am inspired by using the code found <a href="https://www.researchgate.net/post/How_can_one_find_the_angle_between_voltage_and_current_sinusoidal_waves_in_MATLAB_SIMULINK_environment" rel="nofollow noreferrer">her... | https://dsp.stackexchange.com/questions/41291/calculating-the-phase-shift-between-two-signals-based-on-samples |
Question: <p>I am modelling radar scenarios in python and am trying to make a model which retains phase information. To do so, I'm envisioning something which works like this:</p>
<ol>
<li>Generate samples of an LFM waveform at RF in a numpy array</li>
<li>Calculate the distance to the target (two way)</li>
<li>Divide ... | https://dsp.stackexchange.com/questions/88933/how-can-i-apply-a-phase-shift-to-an-lfm-pulse |
Question: <p>Is phase-shifting in continuous-time analogous to the rotate-left (ROL) and rotate-right (ROR) operations in discrete-time? </p>
Answer: <p>If you mean phase shift of a sinusoid, then yes, a phase shift is equivalent to a translation. </p>
| https://dsp.stackexchange.com/questions/31074/relating-phase-shift-to-the-rol-ror-operations |
Question: <p>I am removing low frequency noise from a signal using Matlab using the DWT and then reconstruction at a specific level:</p>
<p>I am removing the approximation signal at level 10 which approximates the low frequency noise</p>
<pre><code>signal sampled at 500 hz
[a,b] = wavedec(signal,13,'db8'); % DWT to... | https://dsp.stackexchange.com/questions/88953/does-filtering-by-wavelet-decomposition-and-reconstruction-introduce-a-phase-shi |
Question: <p>I have done some measurements and I got two very noisy signals. I want to extract a certain sinusoid from the signals and I want to compute the phase shift between them.</p>
<p>I made some simulations and I saw that the noise modifies a lot the value of the phase shift.</p>
<p>How can I get a trustful va... | https://dsp.stackexchange.com/questions/24941/how-can-i-extract-a-sinusoid-from-a-very-noisy-signal-for-computing-the-phase-sh |
Question: <p>I am currently working of 24GHz FMCW radar signal processing. The Module I'm using has 2 receiving antennas and each has 2 outputs (I and Q channel). So overall I've 4 channels. I'm using combination of harware and software for the processing in frequency domain. Range and velocity is fine, if I sample any... | https://dsp.stackexchange.com/questions/24161/how-to-find-phase-shift-and-process-i-q-channel |
Question: <p>Let <span class="math-container">$$H(s)=\frac{s^{n}}{s^{m}}$$</span>
For <span class="math-container">$n \ne m$</span> the phase shift between output and input will be
<span class="math-container">$\frac{\pi}{2}(n-m)$</span>.</p>
<p>For situations where the poles and zeros are not at the origin, I could fi... | https://dsp.stackexchange.com/questions/89778/bode-plot-phase-shift-equation-when-poles-and-zeros-are-not-at-the-origin |
Question: <p>I know how to change the phase of a complex number by multiplying by $\cos \theta + i \sin \theta$. And I understand that the phase of a sine wave is reflected in its Fourier transform. So, I am trying to phase-shift a signal by changing the phase of its Fourier transform..</p>
<p>This works for "synthe... | https://dsp.stackexchange.com/questions/47063/why-doesnt-this-complex-multiplication-in-the-frequency-domain-produce-my-expec |
Question: <p>I want to simulate the play-rate change function of a modern digital sampler. For the purpose I have constructed a sinc-resampling based algorithm of my own which changes the play-rate of a digital audio signal.</p>
<p>There is some issue with the algorithm, as the output of the algorithm is far from null... | https://dsp.stackexchange.com/questions/46043/playrate-change-based-on-sinc-interpolation-generating-phase-shift |
Question: <p>This is my first question on this platform. Sorry if I made mistakes.</p>
<p>What happens if we add two or more same frequency signals near to Nyquist Frequency with phase shift and sample them?</p>
<p>For example, assume that we have a signal of 18000Hz. And add another signal with same frequency, but h... | https://dsp.stackexchange.com/questions/53605/nyquist-theorem-adding-two-same-frequency-near-to-nyquist-frequency-with-phase-s |
Question: <p>I've got a source signal <span class="math-container">$s_1(t)$</span> and a system affecting that, yielding a phase-shifted version <span class="math-container">$s_2(t)$</span>;</p>
<p><span class="math-container">\begin{align}
\color{blue}{s_1(t)} &= A\sin(t+\phi_1)\\
\color{red}{s_2(t)} &= A\sin... | https://dsp.stackexchange.com/questions/63904/calculating-phase-shift-between-two-sines-of-equal-unknown-amplitude-and-frequ |
Question: <p>I have been asking around if the way I was extracting phase shift (lag) was correct, and I ran into some trouble.</p>
<p>So in general, given 2 arrays of data of the same length, representing:</p>
<ol>
<li>the input sinusoid and</li>
<li>the response, also a sinusoid. </li>
</ol>
<p>So not knowing the f... | https://dsp.stackexchange.com/questions/8673/best-method-to-extract-phase-shift-between-2-sinosoids-from-data-provided |
Question: <p>Let's consider the following filter <span class="math-container">$$y[n]=\frac{1}{3}(u[n-2]+u[n-1]+u[n])$$</span> and <span class="math-container">$M=3$</span>, <span class="math-container">$k=\overline{0,2}$</span> with <span class="math-container">$$u[n]=\sin\left(\frac{\pi}{10}n\right)+\sin\left(\frac{\p... | https://dsp.stackexchange.com/questions/95436/moving-average-filter-general-form-of-a-filtered-signal-how-to-determine-the-p |
Question: <p>If a time-domain signal has sharp corners, its frequency spectrum will contain high-frequency components. Truncating the spectrum results in Gibbs' phenomenon. So if you're trying to design an FIR, you really want the target frequency response to be nice and smooth so that windowing the impulse response do... | https://dsp.stackexchange.com/questions/2934/phase-shift-filter-design |
Question: <p>Sound waves can cause vibration of the particles/objects that are scattering/reflecting/emitting the light. Since vibration is spatial displacement, it causes a phase shift by affecting the value of "<span class="math-container">$x$</span>" from the light (electromagnetic wave) phase formula: <s... | https://dsp.stackexchange.com/questions/84054/is-the-magnitude-of-the-phase-shift-independent-of-the-volume-of-the-sound |
Question: <p>I'm honestly lost on creating timing diagrams for bit sequences. I understand for QPSK there are symbols 00, 01, 10, 11 with phase shifts of 45,135,225 and 315. </p>
<p><a href="https://i.sstatic.net/ztioA.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/ztioA.png" alt="enter image descripti... | https://dsp.stackexchange.com/questions/60159/phase-shifts-of-qpsk |
Question: <p>This is regarding question 5.1-2 (see picture attached) from <em>Modern digital and analog communications, Lathi & Zhi Ding (2010)</em>.</p>
<p><a href="https://i.sstatic.net/ZG49j.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/ZG49j.png" alt="Question" /></a></p>
<p>I do not understand... | https://dsp.stackexchange.com/questions/73601/i-cant-understand-why-there-is-a-phase-shift-in-phase-modulation-of-a-sawtooth |
Question: <p>I am reading proakis, as shown highlighted in attached snap shot,there is '-'sign along with j,but still it is written (underlined red) implies shift in positive n direction,why and how positive?when we have negative sign with j?</p>
<p><a href="https://i.sstatic.net/kMsb7.jpg" rel="nofollow noreferrer"><i... | https://dsp.stackexchange.com/questions/75059/confusion-understanding-phase-shift-delay |
Question: <p>Say I have two non-periodic signals, $f_1(t)$ and $f_2(t)$, with Fourier transforms $F_1(\omega)$ and $F_2(\omega)$. Basically, I need to line up $f_1(t)$ and $f_2(t)$ as close as possible, and I am allowed to shift the signals in time and multiply their Fourier transforms by a constant phase.</p>
<p>What... | https://dsp.stackexchange.com/questions/44057/how-to-calculate-the-phase-shift-and-time-delay-of-non-periodic-signals |
Question: <p>I've seen some information on this topic around, but I don't quite understand it.</p>
<p>I have a time domain signal. I understand that if I want to time shift this signal, I can do so by multiplying its Fourier transform by <span class="math-container">$\exp(-j\omega\delta t)$</span>, where <span class="... | https://dsp.stackexchange.com/questions/64389/how-do-i-perform-a-time-domain-phase-shift-in-the-frequency-domain |
Question: <p>In Matt L's <a href="https://dsp.stackexchange.com/a/31616/59893">answer</a> he states that an ideal phase shifter with a phase shift <span class="math-container">$\theta$</span> has a frequency response</p>
<p><span class="math-container">$$
H(\omega)=
\begin{cases}
e^{-j\theta},&\omega>0 \\
e^{j\t... | https://dsp.stackexchange.com/questions/84914/behavior-at-dc-and-nyquist-of-an-ideal-phase-shifter |
Question: <p><img src="https://i.sstatic.net/eCpbp.gif" alt="enter image description here">
So I found this answer on one of the questions. I wanted to ask how the complex part can be related with the phase shift. I wanted to ask this on the same question but it didn't allow me. Could anyone please help me understand t... | https://dsp.stackexchange.com/questions/11173/how-do-you-relate-imaginary-numbers-with-phase-shift-how-to-imagine-this |
Question: <p>In PSK phase modulation scheme, the signal phase is shifted, hence it looks something like this:
<a href="https://i.sstatic.net/jU5bj.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/jU5bj.png" alt="enter image description here" /></a></p>
<p>I cannot understand why this doesn't introduce a s... | https://dsp.stackexchange.com/questions/89358/does-phase-shift-introduce-high-frequencies |
Question: <p>I am working with <a href="http://holoeye.com/spatial-light-modulators/slm-pluto-phase-only/" rel="nofollow">Spatial Light Modulators</a> for a project and I was wondering why does the producer think someone would need a maximum phase shift $>2 \pi$ since the device works as a monitor and every phase-el... | https://dsp.stackexchange.com/questions/35092/why-would-someone-need-a-spatial-light-modulator-with-a-maximum-phase-shift-2 |
Question: <p>I am working on an FSK demodulator (1200/2200Hz, 1200 baud) featuring a 90 degree phase shift operation. I don't exactly understand what 360 degrees mean for a digital signal.</p>
<p>My sampling frequency is 8 kHz. Is a 90 degree shift a delay by 8000/4 samples, or is it a delay by 4000/4 samples?</p>
An... | https://dsp.stackexchange.com/questions/51889/what-exactly-is-a-90-degree-phase-shift-of-a-digital-signal-in-fm-demodulation-a |
Question: <p>Is there a downside to doing phase shifting at basedband in the DSP section of phased Array systems?</p>
<p>I suppose you trade off analog components for digital which may be more costly but I suspect modern systems give each antenna it's own ADC and DAC regardless.</p>
Answer: <p>The downside is power co... | https://dsp.stackexchange.com/questions/82231/dsp-based-phase-shifting-in-phased-array-systems |
Question: <p>I am little confused with the Phase Modulation and the phase of a sine wave. I get the phase modulated wave from the google images as below:</p>
<p><a href="https://i.sstatic.net/QE7Uv.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/QE7Uv.jpg" alt="enter image description here" /></a></p>
<p... | https://dsp.stackexchange.com/questions/42803/relation-between-normal-phase-shift-of-a-wave-and-phase-modulation |
Question: <p>For 3 phase shifted sine waves using the projected pattern: I = sin(x + δi) where δ ∈ [-2pi/3, 0, +2pi/3] which is then projected onto a scene. The resulting image is captured with a camera. I am using the method mentioned below as <em>Robust sine patterns</em>:
<a href="https://i.sstatic.net/d7Fdx.png" re... | https://dsp.stackexchange.com/questions/86606/depth-estimation-using-phase-shifted-sine-waves |
Question: <p>I am strugling with how to compute the exact value of delay in time-doamin when knowing phase shift in frequency domain.
I have a analog circuit, I sweeped about 30 single tones frequency ranging from 250 MHz to 8 GHz, and achieved amplitude (A) and phase (<span class="math-container">$\phi$</span>) respon... | https://dsp.stackexchange.com/questions/83225/how-to-estimate-the-delay-in-time-domain-when-knowing-the-phase-shift-in-frequen |
Question: <p>When I was studying dispersion of refraction index in semiconductors and dielectrics, my professor tried to explain that if a filter (like a dielectric absorbing some light frequencies, or an electric RC-filter) removes some frequencies, then the remaining ones must be phase shifted to compensate for those... | https://dsp.stackexchange.com/questions/13970/can-a-causal-filter-without-phase-shifts-exist |
Question: <p>I try to estimates shift estimation directly in phase region, by following the proposed method in this <em>Sub-pixel Shift Estimation of Image based on
the Least Squares Approximation in Phase Region</em> by Fujimoto, Fujisawa and Ikehara (<em>Proceedings of 26th European Signal Processing Conference, EUSI... | https://dsp.stackexchange.com/questions/38312/estimates-sub-pixel-shift-directly-in-phase-region |
Question: <p>I was watching <a href="https://www.youtube.com/watch?v=6xaaeop7gJ8#t=1030" rel="nofollow">this</a> video where the presenter remarks: </p>
<blockquote>
<p>For a discrete signal, time shift corresponds to phase change in a discrete signal but not vice versa.</p>
</blockquote>
<p>I was trying to figure... | https://dsp.stackexchange.com/questions/15807/how-does-time-shift-correspond-to-phase-change-in-a-discrete-signal |
Question: <p>Been experimenting with FFT on a generated sinusoid and found something strange that doesn't seem to be described anywhere (though I may be missing something of course).</p>
<p>A sinusoid that exactly corresponds to a bin gives what we all know: an amplitude and a phase shift of the sinusoid in that bin.<... | https://dsp.stackexchange.com/questions/61922/is-it-possible-to-find-precise-peak-frequency-using-fft-phase-shifts |
Question: <p>I'm trying to implement a sub-pixel estimation approach for my stereo matching project that I'm working on, by using the proposed method in the following paper "<em><a href="https://ieeexplore.ieee.org/document/7760216" rel="nofollow noreferrer">Sub-pixel Shift Estimation of Image based on the Least S... | https://dsp.stackexchange.com/questions/81648/obtaining-the-phase-component-of-an-integer-shift-using-phase-only-correlation |
Question: <p>Given 4 foundational identical square wave with different phases:</p>
<ol>
<li>Yellow: (Ground/Phase Reference)</li>
<li>Cyan: 45 degree relative to Yellow</li>
<li>Purple: 90 degree relative to Yellow (a.k.a. the quadrature version of Yellow)</li>
<li>Green: 135 degree relative to Yellow</li>
</ol>
<p><a ... | https://dsp.stackexchange.com/questions/95591/shifting-phase-with-boolean-logic-gate |
Question: <p>I plotted a sine wave(blue) and a 90 degrees phase shifted cosine wave (red) expecting them to overlap each other. </p>
<pre><code>x = 0:0.001:1;
%ploting sine
y = sin(2*pi*x);
plot(x, y);
hold('on');
%ploting cosine
z = cos(2*pi*x-90);
plot(x, z);
</code></pre>
<p><img src="https://i.sstatic.net/muX... | https://dsp.stackexchange.com/questions/15798/why-dont-sin-and-phase-shifted-cosine-overlap |
Question: <p><a href="https://i.sstatic.net/e1pVG.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/e1pVG.jpg" alt="enter image description here" /></a><a href="https://i.sstatic.net/OWhKc.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/OWhKc.jpg" alt="enter image description here" /></a>I h... | https://dsp.stackexchange.com/questions/89491/ofdm-complex-symbols-have-dynamic-phase-shift-after-the-fft-block-before-the-b |
Question: <p>For one of my music projects, I'm playing back periodic audio signals (by looping single periods). Unfortunately, one of my waveforms sounds too quiet (even at maximum volume).</p>
<p>I'm trying to use FFT to obtain harmonic strengths, then phase-shift each harmonic to minimize the peak-to-peak amplitude,... | https://dsp.stackexchange.com/questions/46706/how-to-minimize-peak-to-peak-amplitude-of-periodic-waveform-through-fft-phase-sh |
Question: <p>I am working with Bluetooth specification 5.1 where the advertisement packets can send a constant tone extension (CTE) over the baseband signal to estimate the angle of arrival with an antenna array.</p>
<p>Due to inaccuracy of transciever and reciever clocks for bluetooth devices, the CTE is not exact.. T... | https://dsp.stackexchange.com/questions/88505/how-to-remove-phase-shift-for-a-baseband-signal-given-an-estimated-cfo-bluetoot |
Question: <p>I'm confused about these terms: frequency shift, frequency offset, phase offset, and phase noise. My understanding that frequency shift and frequency offset are the same and caused by Doppler shift. Phase noise is caused by the instability of the local oscillator, and it changes per symbol. However, some b... | https://dsp.stackexchange.com/questions/86997/whats-the-difference-between-frequency-shift-frequency-offset-phase-offset-a |
Question: <p>I'm an EE undergrad that struggles heavily with the intuition behind the Fourier Transform (most likely due to a shoddy mathematical foundation). Specifically:</p>
<ol>
<li><p>From what I understand, the real part of the Fourier Transform is the Fourier Transform of the even part of the function in time do... | https://dsp.stackexchange.com/questions/91503/what-exactly-is-a-frequency-component-and-what-is-the-phase-shift-from-the-argu |
Question: <p>As you can see in the figure attaches below, for individual trials (which is the first row), the bandpass filtering using complex morlet wavelet convolution is in phase with the result of the real part of the hilbert transform applied after filtering the signal. However, when I take the average across all ... | https://dsp.stackexchange.com/questions/96234/why-is-there-a-phase-shift-when-taking-the-average-of-the-hilbert-transformed-si |
Question: <p>I was told to post this question here, originally posted on Overflow.</p>
<p>I have two signals, I1 and I2, which were acquired from a white light source in a spectrally resolved interferometer with a waveplate and a polarizer in one arm, such that they are the X and Y components of the original wave after... | https://dsp.stackexchange.com/questions/94170/phase-shift-between-x-and-y-components-of-the-same-wave |
Question: <p>I am trying to write a basic program that samples a 4 kHz sinewave at a sampling rate of 8 kHz and takes the FFT of the signal and plots it.</p>
<p>From everything I have read, as long as the signal you are sampling has frequency content that is less than or equal to Fs/2 no aliasing will occur and the re... | https://dsp.stackexchange.com/questions/59804/analyzing-a-signal-that-contains-frequency-content-at-fs-2-doesnt-seem-to-work |
Question: <p>I have a simulation to make where I have an array of transmitters that transmit the same signal. At a random point, which I have to consider as a receiver I have to measure the phase shift of the signals and also measure the total signal strength. The requirement is that the transmitter emits the same sign... | https://dsp.stackexchange.com/questions/67139/how-to-calculate-the-total-signal-strength-and-phase-shift-of-multiple-signals-i |
Question: <p>After an FFT of a signal is done, it is plotted as in the image below, with the original signal is on the first subplot.</p>
<p><a href="https://i.sstatic.net/Wf23i.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/Wf23i.jpg" alt="No Ballast"></a></p>
<p>Using the magnitude and phase data of... | https://dsp.stackexchange.com/questions/29545/why-does-this-reconstruction-produce-a-phase-shift-from-the-original-signal |
Question: <p>I want to phase shift an incoming sine wave with varying frequency but I am unsure how to go about doing so in practical terms.</p>
<p>A little more info regarding the requirements:
I have an encoder producing a sine/cosine pair with a fixed Peak to Peak but as the speed changes so obviously does the freq... | https://dsp.stackexchange.com/questions/7988/how-to-process-generate-a-phase-shifted-frequency-varying-sine-wave |
Question: <p>I have a discrete signal <span class="math-container">$x(n)$</span> having <span class="math-container">$N$</span> samples with DFT <span class="math-container">$X(n)$</span>. Here <span class="math-container">$N$</span> is <em><strong>large</strong></em> say <span class="math-container">$N=600$</span>. Le... | https://dsp.stackexchange.com/questions/72828/approximate-using-dft-phase-shifting-property |
Question: <p>Due to alternative RNA splicing, it isn't uncommon to ultimately find multiple gene products expressed from one gene in eukaryotes. I'm looking for a reference value for <em>the average number of final gene products expressed per gene</em> for:</p>
<ul>
<li>... <strong>a particular eukaryote (preferably h... | https://biology.stackexchange.com/questions/3780/average-number-of-gene-products-in-a-eukaryotes |
Question: <p>In my lab we did a microarray to analyze differential gene expression in S. cerevisiae treated with UV irradiation. We are now analyzing the results and one of the up-regulated genes is labeled "Alien4_60." I believe this is some kind of control, but I am having trouble understanding what it is. </p>
<p>I... | https://biology.stackexchange.com/questions/8210/what-is-meant-by-alien-probe-in-a-microarray |
Question: <p>My husband had light brown eyes. His father had hazel and his mother, light brown as well. His younger brother however, has blue eyes. Both my children have blue eyes. Is this possible? I thought once the recessive gene was used in my first child, his dominant brown gene would take over?</p>
Answer: <p>Th... | https://biology.stackexchange.com/questions/15025/2-blue-eyed-children |
Question: <p>Why polysomes are not able to load properly onto a transcript if a transcript has a double-stranded structure in it?</p>
Answer: | https://biology.stackexchange.com/questions/35500/why-is-polysome-loading-affected-by-double-stranded-structure |
Question: <p>My AP Bio assignment asks that I research the effects of UV radiation on melanin production, but the directions and questions suggest that UV radiation influences gene expression. From what I could find, such as on <a href="http://enhs.umn.edu/current/5103/uv/harmful.html" rel="nofollow">this</a> universit... | https://biology.stackexchange.com/questions/44704/is-the-increased-decreased-enzyme-activity-tyrosinase-caused-by-an-environment |
Question: <p>I know what is the TATA box, but I wish to know whether it has specific roles in transcriptional regulation.</p>
Answer: <p>TATA box serves as a binding site for the <a href="https://en.wikipedia.org/wiki/TATA-binding_protein" rel="nofollow">TATA-binding protein</a> (TBP; and its associated factors, toget... | https://biology.stackexchange.com/questions/45783/what-is-the-role-of-tata-box-in-transcriptional-regulation |
Question: <p>Can anyone explain clearly what is the difference between differentially expressed genes and deregulated genes?</p>
Answer: <p>Any gene whose gene expression differs significantly from some reference is considered to be differentially expressed. I think the most common representation of differential expre... | https://biology.stackexchange.com/questions/59131/what-is-the-difference-between-differentially-expressed-genes-and-deregulated-ge |
Question: <p>Cells that are differentiated express the genes that are necessary for their own usage. I've heard that some cell type expresses about 90% of 30,000 proteins that are encoded in the genome. Can anybody tell me what this cell type is?</p>
Answer: <p>Well, I found this paper:</p>
<p><a href="https://genomeb... | https://biology.stackexchange.com/questions/60568/cell-type-that-expresses-90-of-the-genome |
Question: <p>I am trying to validate my RNAseq data by doing qpcr for which I am looking at the fold change of few genes across various timepoints of treatment conditions. I am getting huge amount of variation (in thousand folds ) in my biological replicates. I thought may be it is due to genomic DNA contamination so t... | https://biology.stackexchange.com/questions/74310/qpcr-huge-variation-in-fold-change-of-genes-between-biological-replicates |
Question: <p>I know that there is a classification of promoters like: strong, medium and weak. This shows how a promoter affects gene expression levels. So my question is: what part of the promoter affects it? </p>
<p>For example I want to raise or lower the expression of some gene, so, what part of promoter I need to... | https://biology.stackexchange.com/questions/80737/element-of-promoter-responsible-for-expression-power-of-gene |
Question: <p>How does amplification of gene expression work?
I often find in various articles expressions like "Using substance X or peptide X, we enhanced the expression of gene Z, which led to a certain therapeutic effect.</p>
<p>How to find out which substance enhances the expression of a particular gene? Is there ... | https://biology.stackexchange.com/questions/90948/how-do-substances-for-gene-expression-work |
Question: <p>I've been doing a lot of research on Alu repeats and how they mediate the gene expression. I read the following article <a href="http://link.springer.com/article/10.1007%2Fs00018-007-7084-0" rel="nofollow">"Useful junk: Alu RNAs in the human transcriptome"</a>.</p>
<p>And it says that alu repeats embedded... | https://biology.stackexchange.com/questions/35385/why-do-alu-repeats-form-secondary-structures |
Question: <p>The field seems extremely divided on the debate. On one hand, artificial experiments have suggested that synonymous mutations don't correlate with gene expression but rather, the mRNA 5' structure is the most important <a href="http://www.ncbi.nlm.nih.gov/pubmed/19359587">1</a>. On the other hand, genome w... | https://biology.stackexchange.com/questions/1152/which-is-more-important-for-protein-expression-mrna-structure-or-codon-optimizat |
Question: <p>My expressed proteins are frequently truncated and I'm trying to figure out which bands are which. The first thing to come to mind is using PeptideCutter from ExPASy but there is just a data deluge of potential sites. I was curious what other strategies exists for determining the potential breaks asides us... | https://biology.stackexchange.com/questions/1176/determining-potential-protease-sites-within-a-recombinant-protein |
Question: <p>My understanding is that gene expression, in response to some stimulus, generally occurs on the order of minutes. I'm curious about the extremes...the quickest and the slowest cases.</p>
<p>What is(are) the fastest time(s) recorded for genes being expressed in response to a stimulus? What are the slowest ... | https://biology.stackexchange.com/questions/291/time-from-stimulus-to-gene-expression |
Question: <p>I'm reading about X-inactivation and I can't reconcile some things with it being truly random. In only a small percentage of female carriers Duchenne's will be expressed. But if this was truly random, wouldn't 50% of female carriers expressing the disease?
As one of the X-chromosomes is silenced at random,... | https://biology.stackexchange.com/questions/111596/random-x-inactivation-and-duchenne |
Question: <p>I have been searching for an answer for this question and have some possible solutions, but I am not sure. GC regions are more stable as there are 3 hydrogen bonds instead of 2 with AT, however I am not sure if this would influence the number of protein-coding genes in GC regions? Protein-coding regions wo... | https://biology.stackexchange.com/questions/88062/why-are-protein-coding-regions-rich-in-gc |
Question: <blockquote>
<p><a href="https://i.sstatic.net/I4WtA.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/I4WtA.png" alt="enter image description here" /></a>
In order for a specific gene to be expressed in the mammal’s cells, all of the gene’s binding sites must be bound by transcriptional activato... | https://biology.stackexchange.com/questions/100244/why-can-a-gene-lack-of-a-binding-site-be-expressed-in-skin-cells |
Question: <p>Excuse my ignorance but I've always been curious about this...</p>
<p>For example, a frog is red, but it starts living in a green forest. Over time the frog becomes green to camouflage. But a gene can't see and I'm sure there's no mechanism for color info to be transmitted to individual genes from the bra... | https://biology.stackexchange.com/questions/66019/how-does-a-gene-know-what-to-change-to |
Question: <p>I have a fasta file containing the amino acid sequence of glycogenin-1: <a href="https://www.rcsb.org/fasta/entry/6EQJ" rel="nofollow noreferrer">https://www.rcsb.org/fasta/entry/6EQJ</a></p>
<p>I want to create a plasmid that produces glycogenin-1.</p>
<p>Is it possible to use the glycogenin-1 amino acid ... | https://biology.stackexchange.com/questions/94967/will-a-nucleic-acid-sequence-deduced-from-a-protein-sequence-be-expressed-from-a |
Question: <p>I am working on an RNA-Seq project, and I am aware that some researchers use housekeeping genes as a method of normalization. My project has several different tissues, and I was wondering if housekeeping gene expression is generally invariant across tissue type?</p>
Answer: <p>My experience is: Yes they ... | https://biology.stackexchange.com/questions/51800/do-housekeeping-genes-vary-between-tissues |
Question: <p>After 8 hours of online-research I was unable to find any info at all..</p>
<p>I was able to get some concrete copy numbers of DNA (e.g. plasmid) per cell after transfection of diverse transfection techniques, but I was unable to get any concrete copy numbers of RNAs that correspond to the transgene (of an... | https://biology.stackexchange.com/questions/96820/how-many-copies-of-rna-per-cell-are-usually-reached-through-overexpression-in-hu |
Question: <p>Looking at some more detailed <a href="http://www.faculty.ucr.edu/~mmaduro/codonusage/codontable.htm">codon usage tables</a>, genes may be further clustered into three gene classes: Metabolic genes, highly expressed genes during exponential growth, and horizontal gene transfer. Looking at the original <a h... | https://biology.stackexchange.com/questions/1758/how-are-the-various-classes-of-e-coli-genes-determined |
Question: <p>CD47 aka the "don't eat me" signal has recently been claimed <a href="http://www.pnas.org/content/early/2012/03/20/1121623109.short">to be expressed on all tumor cells</a>. This doesn't seem to corroborate with other cell-biology experiments. On what other cells is CD47 expressed?</p>
Answer: <p>I don't k... | https://biology.stackexchange.com/questions/1901/how-extensive-is-cd47 |
Question: <p>As far as I've seen, this expression is almost always used in relation to gene expression profiling. Unfortunately, I have no background in this area. Can someone please explain this in layman terms?</p>
Answer: <p>Although each cell of your body essentially contains the same DNA and the same genes, cells... | https://biology.stackexchange.com/questions/2176/what-exactly-is-meant-by-the-expression-differentially-expressed |
Question: <p>Can a gene be expressed under the T7 promoter in an E. coli strain (e.g. DH5 alpha), which does not have the T7 polymerase gene encoded in its genome? In other words, is T7 promoter leaky? </p>
<p>To be more specific, how is it possible that a regular E. coli strain, which does not encode for the T7 polym... | https://biology.stackexchange.com/questions/2758/t7-promoter-leakiness |
Question: <p>I'm a mathematician trying to test some things on gene expression data, and I'm thus skimming over various articles such as <a href="http://www.ncbi.nlm.nih.gov/pubmed?term=Sotiriou%20et.%20al.%2C%20Breast%20cancer%20classification%20and%20prognosis%20based%20on%20gene%20%20expression%20profiles%20from%20a... | https://biology.stackexchange.com/questions/5010/a-mathematicians-confusion-regarding-parametric-t-tests-for-gene-expression-d |
Question: <p>I am trying to use the DAVID tool to do some gene analysis. I have some probe set intensities for some cancer cell lines. I found this link in the DAVID tool <a href="http://david.abcc.ncifcrf.gov/tools.jsp" rel="nofollow">http://david.abcc.ncifcrf.gov/tools.jsp</a>. I am a bit confused with the terminolog... | https://biology.stackexchange.com/questions/7299/confusion-related-to-the-david-tool |
Question: <p>I was doing some gene expression analysis using this tool <a href="http://david.abcc.ncifcrf.gov/summary.jsp" rel="nofollow">http://david.abcc.ncifcrf.gov/summary.jsp</a>. However, I have a confusion about what benjamini is. I fed it some gene list and it gave me some potential pathways the genes belong to... | https://biology.stackexchange.com/questions/7354/what-is-benjamini |
Question: <p>Many papers I have seen describing transgenic rodent models (and presumably applicable to other model organisms) involve the knock-in, or modification to, a single gene, possibly two genes. With respect to recombineering techniques, what prevents targeting multiple genes in a single organism? For instance,... | https://biology.stackexchange.com/questions/7619/complexity-in-creating-transgenic-animals-e-g-mice |
Question: <p>Have there been any experimentally-verified systems of microRNAs targeting a gene set (e.g., in cancer, perhaps)?</p>
Answer: <p>Yes. Below is a link to a review of ncRNA (non-coding RNAs) and their role in disease. There are many examples in this review in all sorts of diseases, one of which is miR-200, ... | https://biology.stackexchange.com/questions/9703/known-microrna-gene-systems |
Question: <p>How are bidirectional promoters expressed ? (Won't RNA Pol have to go in 3'-5' direction?)
Why are they more commonly found in eukaryotes than prokaryotes?</p>
Answer: <p>Genes controlled by bidirectionl promoters are in head-to-head configurations, meaning that their 5' ends are facing one-another. Reme... | https://biology.stackexchange.com/questions/9783/expression-of-bidirectional-promoters |
Question: <p>What's the reason why researchers usually use cell lines from "blast cells" (so, immature, like lymphoblastoid cells) for measuring gene expression data? Is that they are growing up, which would make their expression data higher and more significant?</p>
Answer: <p>Some of the reasons why immature blast c... | https://biology.stackexchange.com/questions/13740/the-reason-why-researchers-usually-use-cell-lines-from-blast-cells |
Question: <p>In fruit flies, red eyes are dominant over white eyes. Show a cross between two white-eye fruit flies. </p>
<p>My question is...</p>
<p>How do I know if the white-eye fruit flies are homozygous or heterozygous?</p>
Answer: <p>Just to add an extended perspective to all of the answers submitted so far. <... | https://biology.stackexchange.com/questions/13825/punnett-square-help |
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