simplicial volume – Calculus: Application of Integrals

Q1] Find the volume of the solid that is generated by revolving the region bounded by the lines
y = x, y = 1, and x = 0 about the x-axis.

Q2] Find the volume of the solid that is generated by revolving the region bounded by the curve
y = x^2 +1 and the line y = -x + 3 about the x-axis.

Also draw graphs for both.

Thank you so much for your help!

mql4 – Volume Real e preço do mini-índice do candle [0] MQL5


Estou tentando aprender do zero MQL5 e não estou conseguindo pegar o volume real e o valor/numero do mini-índice do candle (0) e comparar os dois cada um com uma variável do tipo double em uma condição if, mas não consigo captar os dados do candle, mesmo usando MqlRates e CopyRates(parameters); se alguém puder me ajudar por gentileza.
`bool volumeReal() {

  bool vReal= false;
  if ( tick.last >= candle(0).open + varDouble && candle(0).real_volume >= varDouble ) vReal = true;
  return vReal;


bool volumeTick() {

  bool vTick = false;
  if ( tick.last <= candle(0).open - varDouble && candle(0).real_volume >= varDouble ) vTick = true;
  return vTick;


fastboot – Turn phone on with damaged power & volume button?

if Power and volume button is busted, is it possible to turn phone on by using adb or fastboot or any other method?

Or may be, How a powered off phone communicate with the power button and other things(i.e charging animation,volume button etc)? perhaps is it possible to tweak this communication to gain access externally?

Curious, solving this issue by software means, possible?

Extend volume of Ubuntu 20.04

I use Ubuntu 20.04 for nextcloud server, the server physical hd is around 2TB but the volume group size just is 200GB, how can we extend to increase volume group size? Thanks.

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bootcamp – Restore a NTFS volume back up by Disk Utility

I have a Windows installation which I created with Bootcamp. Then I need to expand the volume to add more Software. So I use Disk Utility to create a DMG image for the Bootcamp volume. But after I have deleted the old Bootcamp volume and create a new larger volume, I cannot restore it with Disk Utility:

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Nor asr:

 asr restore --source /Users/phuongnd08/Downloads/BOOTCAMP.dmg  --target /dev/disk0s3 --erase --noverify
    Validating target...done
    Validating source...done
    Erase contents of /dev/disk0s3 ()? (ny): y
    Repartitioning target device...
Could not change the partition type for /dev/disk0s3 - Operation not permitted

I guess due to NTFS? But this sounds very illogical because: you can create image out of it, you should be able to restore it from an image? What should I do now to restore that image?

video – Why does every website seem to use max volume level for sound?

Good question, it has bugged me in the past.

From W3C – Audio Control:Understanding SC 1.4.2, it seems that pages that do not offer sound control, or mute, functionality are not adhering to the criterion. Summarising the link:

1.4.2 Audio Control: If any audio on a Web page plays automatically for more than 3 seconds, either a mechanism is available to pause or
stop the audio, or a mechanism is available to control audio volume
independently from the overall system volume level.

Individuals who use screen reading software can find it hard to hear
the speech output if there is other audio playing at the same time.
This difficulty is exacerbated when the screen reader’s speech output
is software based (as most are today) and is controlled via the same
volume control as the sound. Therefore, it is important that the user
be able to turn off the background sound. Note: Having control of the
volume includes being able to reduce its volume to zero.

Note the the player in offers this control, and remembers previous settings.

Note this page on HTML 5 shows that the controls will be present for volume control.

All of the browsers have start/pause controls, progress bars,
scrubbers, seconds of play, a volume/mute control and, with the
exception of Chrome, also display the total number of seconds in the
sound file.

The issue was with earlier HTML 4 (and 3?) embedded (<embed>) audio players, as this code (from 2006) shows

<embed src="" 

Source: How do I play embedded sounds at a specific volume?

If DOM is used then unfortunately the default is set to 100%, although this can be overriden by the web page designer (should they choose to do so):

Example values:

1.0 is highest volume (100%. This is default)

0.5 is half volume (50%)

0.0 is silent (same as mute)

So, it appears to come down to which mechanism the web page designer has employed to get sound on to the page.

With respect to audio blasting out, as soon as the page is loaded, that is down to the autoplay tag, which should be considered a no-no… but it is still offered as an option:


<audio src="" controls autoplay></audio>

The Boolean autoplay attribute is one that I don’t recommend using
because it specifies that the audio begin playing as soon as the page
loads. This is a usability no-no for most scenarios, so exercise
restraint in using this attribute. If you do decide to utilize
autoplay, please be sure to include the controls attribute (or roll
your own custom controls) so that your users can stop the audio or
reduce volume.

What is wrong with this Windows volume thing, and how do I fix it?

(really hope I used the right stack exchange site for this)

I appear to have accidentally disabled something to do with changing volume in Windows, whenever I use a keyboard or mouse with any option to change volume (etc volume keys/volume wheel on the logitech g815) nothing happens. The inbuilt windows volume popup on the taskbar works fine, it’s just any hotkey or button that is meant to change the volume doesn’t do so. This could be some option or something to disable the player window that appeared before this issue started happening.

This example of the window I mean that I haven’t seen since the issue, just found the image on google as an example:

enter image description here

machine learning – How is the dimensionality of the volume in ConvNets determined for a general case?

In ConvNets, I understand how the dimensionality of a flat image changes after convolving it with a single filter. For example, if you convolve a P x P x 1 image (assume no padding) with a filter with dimensionality FxF, with stride S, the output dimensionality D can be computed from a simple formula $frac{P – F}{S} + 1 $. For example, for a 28 x 28 x 1 image convolved with a 4×4 filter with stride 1, the output we get has dimensionality 12 x 12 because:

$D = frac{P – F}{S} + 1 = frac{28-4}{2} + 1 = 12$

Typically, however, input images have dimensionality P x P x 3 (3 because of the three RGB color channels). More generally, within the ConvNet, we are taking a convolutional layer with dimensionality P x P x Q, where Q is arbitrary, and convolving it with a filter F x F x G and stride S. I understand how the P, F and S can be used to compute the output dimensionality D (by the formula above); but I don’t understand how the Q and G interact to produce an output depth. In particular, can Q and G be entirely arbitrary, or does one have to be a multiple of the other?

macos – disable volume control sound effects when holding shift

Most likely the following issue will result in me buying BetterTouchTool, but before doing so, I’m asking if there’s a solution that doesn’t require third-party software.

The issue: I’ve switched the touch bar on my Mac to show the “extended controls”, because that way the volume and brightness controls are always in the same place and don’t require a long-press in order to use them. I also have all user interface sound effects turned off.

However, the volume control ‘pop’ sound effects still happen if I hold down shift while changing the volume. This is really annoying, because I keep touching the volume controls when holding shift to typing symbols on the number key row.

So I’m wondering if there’s a way to turn this feature off. Ideally, I’d like to disable the volume controls entirely when I’m holding shift, but otherwise, just changing the volume silently wouldn’t be too bad.

tar in pipe with gpg in remote mounted volume occupies space on root / partition

I wrote a code which scope is creating a tar encrypted with a password using gpg and sending it on a mounted remote volume.

tar --hard-dereference -cvzf - -C $filedir $basename | gpg -c --batch --passphrase-file $PASSPHRASEFILE > $encrypted_file;

IN the script the variable $encrypted_file is like:


At the end of process I see that the file has been created in the remote volume, but I see also that the root partition increased its size.

Before tar:

Filesystem                                                        Size  Used Avail Use% 
Mounted on
udev                                                              3,9G     0  3,9G   0% /dev
tmpfs                                                             799M   84M  716M  11% /run
/dev/vda1                                                          79G   71G  5,4G  93% /

After tar:

Filesystem      Size  Used Avail Use% Mounted on
udev            3,9G     0  3,9G   0% /dev
tmpfs           799M   84M  716M  11% /run
/dev/vda1        79G   72G  3,8G  96% /