Understanding Attention Mechanism with example

2022-02-23

Understanding 1D, 2D, and 3D convolutional layers in deep neural networks

2022-02-24

Useful shortcut keys in Linux terminal

Ubuntu Desktop Shortcuts

You can use the following shortcuts to get the maximum benefit from the Ubuntu desktop environment:

Shortcut	Utility
Ctrl+Alt+Delete	Use this shortcut to logout of Ubuntu.
Alt+Tab	Use this shortcut to switch between open programs.
Ctrl+Alt+Tab	Use this shortcut to switch between system controls such as Windows, Top Bar, and Desktop.
Ctrl+Alt +Esc	Use this shortcut to directly switch between system controls.
Super+L	Use this shortcut to lock the screen.
Super+A	Use this shortcut to view all applications.
Super+V	Use this shortcut to view notifications, if any.
Super+S	Use this shortcut to get an overview of open activities.
Alt+F1	Use this shortcut to get an overview of open windows.
Alt+F2	Use this shortcut to open the Run command dialog.
Alt+F4	Use this shortcut to close the current window.
Alt +F5	Use this shortcut to unmaximize the current window.
Alt+F7	Use this shortcut to select the current window for moving.
Alt+F8	Use this shortcut to resize the current window.
Alt+F10	Use this shortcut to minimize or maximize the current window.
Alt+Space	Use this shortcut to view the window menu used to maximize, minimize, move, close, etc. the current window.
Ctrl+Super+D	Use this shortcut to view the desktop.
Super+Pageup	Use this shortcut to move to the above workspace.
super+Pagedown	Use this shortcut to move to the below workspace.
Super+Home	Use this shortcut to move to the first workspace.
Super+End	Use this shortcut to move to the last workspace.
Shift+Super+Home	Use this shortcut to move the window to the first workspace.
Shift+Super+End	Use this shortcut to move the window to the last workspace.
Shift+Super+Up/Shift+Super+Down	Use this shortcut to move the window up/down.
Shift+Super+Left/Shift+ Super+Right	Use this shortcut to move the window left/right.

Ubuntu Application Shortcuts

You can use the following shortcuts to get the most out of Ubuntu applications:

Shortcut	Utility
Ctrl+0	Use this shortcut to open a new file.
Ctrl+S	Use this shortcut to save the current file.
Ctrl+P	Use this shortcut to print the current document.
Ctrl+W	Use this shortcut to close the current file.
Ctrl+Q	Use this shortcut to close the open application.
Ctrl+A	Use this shortcut to select all items/text.
Ctrl+C	Use this shortcut to copy the selected items/text to the clipboard.
Ctrl+V	Use this shortcut to paste the copied items/text.
Ctrl+N	Use this shortcut to create a new file in the currently open application.

Ubuntu Screen Printing Shortcuts

You can use the following shortcuts to quickly use the screen printing feature of Ubuntu:

Shortcut	Utility
PrintScreen	Use this shortcut to take a screenshot of your screen and save it to the Pictures folder.
Alt+PrintScreen	Use this shortcut to take a screenshot of the current window and save it to the Pictures folder.
Shift+PrintScreen	Use this shortcut to select an area which will be saved as a screenshot in the Pictures folder.
Ctrl+Alt+PrintScreen	Use this shortcut to copy a screenshot of a window to the clipboard.
Shift+Ctrl+PrintScreen	Use this shortcut to copy a screenshot of a selected area to the clipboard.
Ctrl+PrintScreen	Use this shortcut to copy a screenshot of your entire screen to the clipboard.

Ubuntu Terminal Shortcuts

You can use the following shortcuts to run terminal commands quickly in the most optimal manner:

Shortcut	Utility
Ctrl+A	Use this shortcut to move the cursor to the beginning of the line.
Ctrl+E	Use this shortcut to move the cursor to the end of the line.
Ctrl+C	Use this shortcut to kill the current process.
Ctrl+R	Use this shortcut to search the history based on the entered keywords.
Ctrl+U	Use this shortcut to delete the current line.
Ctrl+K	Use this shortcut to delete the text at the right side of the cursor.
Ctrl+W	Use this shortcut to delete the text before the cursor.
Ctrl+L	Use this shortcut to clear the output of a terminal command(s).
Alt+F	Use this shortcut to move the cursor forward by one word.
Alt+B	Use this shortcut to move the cursor back by one word.
[letter]<tab><tab>	Enter a letter and then tab twice to list all the commands beginning with that letter.

For those shortcut key lovers out there, here is a long list of keyboard shortcuts for Ubuntu. Most of them should work in most Gnome-based distros. Enjoy the list.

General Keyboard Shortcuts
`Ctrl` + `A`	Select all
`Ctrl` + `C`	Copy the highlighted content to clipboard
`Ctrl` + `V`	Paste the clipboard content
`Ctrl` + `N`	New (Create a new document or new application, not in terminal)
`Ctrl` + `O`	Open file
`Ctrl` + `S`	Save file
`Ctrl` + `P`	Print file
`Ctrl` + `W`	Close file
`Ctrl` + `Q`	Quit current application
`F1`	Show help/documentation about app/function (if available)

Keyboard Shortcuts for GNOME Desktop
`Ctrl` + `Alt` + `Delete`	Log out
`Ctrl` + `Alt` + `Backspace`	Restart GNOME
`Ctrl` + `Alt` + `F1`	Switch to the first virtual terminal
`Ctrl` + `Alt` + `F2(F3)(F4)(F5)(F6)`	Select the different virtual terminals
`Ctrl` + `Alt` + `F7`	Restore back to the current terminal session with X
`Ctrl` + `Alt` + `Tab`	Switch between system controls
`Ctrl` + `Alt` + `Escape`	Switch system controls directly
`Ctrl` + `Alt` + `T`	Launch terminal
`Ctrl` + `Super` + `D`	Hide all windows/Show desktop
`Alt` + `Tab`	Switch between open programs
`Alt` + `Space`	Open the window menu
`Alt` + `F1`	Open the Activities overview
`Alt` + `F2`	Open the “Run a Command” dialog box.
`Alt` + `F4`	Close the current window
`Alt` + `F5`	Unmaximizes the current window
`Alt` + `F6`	Switch windows of an app directly
`Alt` + `F7`	Move the current window
`Alt` + `F8`	Resize the current window
`Alt` + `F10`	Toggle maximization for the current window
`Super` + `A`	Show all applications
`Super` + `H`	Hide window
`Super` + `L`	Lock the screen
`Super` + `N`	Focus the active notification
`Super` + `S`	Show the overview
`Super` + `V`	Show the notification list
`Super` + `F10`	Open the application menu
`Super` + `Tab`	Switch applications
`Super` + `	Switch windows of an application
`Super` + `Escape`	Restore the keyboard shortcuts
`Super` + `Up`	Maximize window
`Super` + `Down`	Restore window
`Super` + `Left`	View split on left
`Super` + `Right`	View split on right
`Super` + `PageUp`/`PageDown`	Move to the workspace above/below
`Super` + `Home`/`End`	Move to the first/last workspace
`Super` + `Space`	Switch to the next input source
`Super` + `Shift` + `Space`	Switch to the previous input source
`Super` + `Shift` + `Up`/`Down`/`Left`/`Right`	Move window one monitor up/down/left/right
`Super` + `Shift` + `PageUp`/`PageDown`	Move window one workspace up/down
`Super` + `Shift` + `Home`/`End`	Move window to first/last workspace
`Super` + `Alt` + `S`	Turn screen reader on or off
`Super` + `Alt` + `8`	Turn zoom on or off
`Super` + `Alt` + `=`	Zoom in
`Super` + `Alt` + `-`	Zoom out

Keyboard Shortcuts for Terminal
`Arrow Up`/`Down`	Browse command history
`F11`	Full screen
`Alt` + `F`/`Right`	Move forward one word
`Alt` + `B`/`Left`	Move backward one word
`Alt` + (any number from 1 to 0)	Switch to respective tab (out of the first ten)
`Shift` + `PageUp` / `PageDown`	Scroll terminal output
`Ctrl` + `A`	Move cursor to beginning of line
`Ctrl` + `E`	Move cursor to end of line
`Ctrl` + `C`	Kill the current process
`Ctrl` + `Z`	Suspend the current process by sending the signal SIGSTOP
`Ctrl` + `R`	Find the last command matching the entered letters
Enter a letter, followed by `Tab` + `Tab`	List the available commands beginning with those letters
`Ctrl` + `U`	Delete the current line
`Ctrl` + `K`	Delete everything to the right of the cursor’s position
`Ctrl` + `W`	Delete the word before the cursor
`Ctrl` + `L`	Clears the terminal output
`Ctrl` + `PageUp`	Switch to previous tab
`Ctrl` + `PageDown`	Switch to next tab
`Ctrl` + `+`	Zoom In
`Ctrl` + `-`	Zoom out
`Ctrl` + `0`	Normal size (Reset zoom)
`Ctrl` + `Shift` + `PageUp`	Move tab to the left
`Ctrl` + `Shift` + `PageDown`	Move tab to the right
`Ctrl` + `Shift` + `C`	Copy the highlighted command to the clipboard
`Ctrl` + `Shift` + `V` (or `Shift` + `Insert`)	Paste the contents of the clipboard
`Ctrl` + `Shift` + `F`	Find
`Ctrl` + `Shift` + `G`	Find next
`Ctrl` + `Shift` + `H`	Find previous
`Ctrl` + `Shift` + `J`	Clear highlight
`Ctrl` + `Shift` + `T`	New hab
`Ctrl` + `Shift` + `N`	New window
`Ctrl` + `Shift` + `W`	Close tab
`Ctrl` + `Shift` + `Q`	Close window

Keyboard Shortcuts for Taking Screenshots
`Print`	Save a screenshot to Pictures folder
`Alt` + `Print`	Save a screenshot of a window to Pictures folder
`Shift` + `Print`	Save a screenshot of an area to Pictures folder
`Ctrl` + `Alt` + `Print`	Copy a screenshot of a window to clipboard
`Ctrl` + `Shift` + `Print`	Copy a screenshot of an area to clipboard
`Ctrl` + `Print`	Copy a screenshot to clipboard
`Ctrl` + `Shift` + `Alt` + `R`	Start screencast recording

Keyboard Shortcut for Files/Nautilus
`Delete`	Move selected files/folders to Trash
`Shift` + `Delete`	Delete selected files/folders permanently
`Ctrl` + `?`/`F1`	Open the Keyboard Shortcut window
`Ctrl` + `T`	Open a new tab
`Ctrl` + `PageUp`	Go to previous tab
`Ctrl` + `PageDown`	Go to next tab
`Ctrl` + `Shift` + `PageUp`	Move tab left
`Ctrl` + `Shift` + `PageDown`	Move tab right
`Ctrl` + `Shift` + `T`	Restore closed tab
`Alt` + 0 … . 8	Go to the specified tab
`Ctrl` + `Shift` + `N`	Create new folder
`Ctrl` + `Shift` + `I`	Invert selection
`Ctrl` + `ENTER`	Open the selected folder in a new tab
`Shift` + `ENTER`	Open the selected folder in a new window
`Ctrl` + `I` or `Alt` + `ENTER`	Show file/folder properties
`Ctrl` + `1`	Toggle view as list
`Ctrl` + `2`	Toggle view as grid
`Ctrl` + `S`	Select pattern
`Ctrl` + `A`	Select all files and folders
`Ctrl` + `F`	Search
`Ctrl` + `D`	Bookmark current location
`Ctrl` + `Z`	Undo
`Ctrl` + `Shift` + `Z`	Redo
`Ctrl` + `W`	Close window
`Ctrl` + `O` or `Enter`	Open selected file/folder (with default application)
`Ctrl` + `Shift` + `Down`	Open file and close window
`Ctrl` + `R`	Reload window
`Alt` + `Up`	Go up
`Alt` + `Left`	Go back
`Alt` + `Right`	Go forward
`Alt` + `Down`	Go down
`Alt` + `Home`	Go to Home folder
`Ctrl` + `L`	Show/go to location bar
`Ctrl` + `Alt` + `O`	Open item location (search and recent only)
`/`	Show/go to location bar with root location
`~`	Show/go to location bar with Home location
`Ctrl` + `H`	Show/hide hidden files
`Ctrl` + `+`	Zoom in
`Ctrl` + `-`	Zoom out
`Ctrl` + `0`	Reset zoom
`Alt` + `Down`	Open selected file with default application
`F2`	Rename selected file/folder
`F5` or `Ctrl` + `R`	Refresh view
`F9`	Show/hide sidepane
`F10`	Show/hide action menu

1. Ctrl + Shift + N => New terminal window
This shortcut can be used to open a new terminal window. For this to work, you should already be on the terminal window.

2. Ctrl + Shift + T => New terminal tab
If you use the above combination, you can open the terminal tab in the same window.

3. Ctrl + C or Ctrl + Z => Kill the current process
If you are running any application through the terminal, you can kill it by using the above combination.

4. Ctrl + R => Reverse search
If you are working in the IT industry or you are a college student, many times the same command repeats. To search previously entered commands, we can use the above combination.

5. Ctrl + U => Delete line
This shortcut will delete the whole line before the cursor.

6. Ctrl + W => Delete the word
This shortcut will delete the whole word before the cursor.

7. Ctrl + K => Delete the word
This shortcut will delete the whole line after the cursor.

8. Ctrl + Y => Undo erased content
If you have mistakenly deleted some content using Ctrl + U, Ctrl + W or Ctrl + K and now you want to undo the change. You can do so by using the above combination.

9. Ctrl + L => Clear console
This is similar to the clear command used to clear the console.

10. Ctrl + Shift + C => Copy
This shortcut is used to copy the selected content.

11. Ctrl + Shift + V => Paste the content from the clipboard
This shortcut is used to paste the content copied on the clipboard.

12. Alt + F => Move forward
This combination is used to move one word forward. Alternatively, we can use the Ctrl + right arrow to do so.

13. Alt + B => Move one word backward
This combination is used to move one word backward. Alternatively, we can use the Ctrl + left arrow to do so.

14. Arrow Up / Down => Browse commands
To go through the previously executed commands, we can use up or down arrow keys.

15. Alt + D => Delete line
This is similar to the Ctrl + U, except it removes the line after the cursor.

16. Shift + PgUp/PgDn => Scroll through console
We can use the above combination to scroll up or scroll down through the console.

17. Ctrl + PgUp => Switch to left tab
We have seen we can use the Ctrl + Shift + T to open a new terminal tab. To move to the left tab, we can use the above shortcut.

18. Ctrl + PgDn => Switch to right tab
Similarly, we can use the above shortcut to move to the right tab.

19. Ctrl + Shift + PgUp => Move current tab to left
We can use the above shortcut to move the current tab to left.

20. Ctrl + Shift + PgDn => Move current tab to right
We can use the above shortcut to move the current tab to right.

21. Ctrl + D => Close terminal
This combination is used to close the current tab. If there is only one tab, it’ll close the terminal window.

22. Ctrl + P => Previous executed command
We can go through the previously executed sequence of commands using the above shortcut.

23. Ctrl + N => Next executed command
We can go through the next executed sequence of commands using the above shortcut.

24. Ctrl + J => Enter

25. Ctrl + Alt + T => Open terminal

26. Ctrl + Shift + Q => Close all
This will close all tabs on the current terminal window. This will not close the other open terminal windows.

27. Super + RowUp => Maximize
This is used to maximize the terminal window.

28. Super + RowDown => Minimize
This is used to minimize the terminal window.

29. Ctrl + Shift + F => Find
Similar to Ctrl + F on any text editor, we can use the above shortcut to find through the terminal console.

30. Alt + C => Capitalizes the word next to the cursor and move to end of the word
For Example: Suppose a word hangout and cursor is before hangout, the above shortcut will capitalize ‘h’ of hangout and go to the end of the word.

31. Use of Tab => To get suggestions
We can enter a partial initial command such as MySQL, and we’ll get a list of the commands that start with MySQL.

How to Create a Custom Shortcut on Ubuntu 18.04

If you find yourself in a situation where you have to perform a task, again and again, Ubuntu enables you to create a custom shortcut for it. Lets us present an example of how to create a custom shortcut in order to launch the graphical text editor gedit on Ubuntu.

Open the Settings from Ubuntu dash or the down-arrow button located at the top right corner of your screen.
Click the Devices tab from the left menu of the Settings window.
Click the KeyBoard tab from the Devices menu. The following Keyboard view will be displayed in the right panel:

Scroll down the right panel and click the + button. The Add Custom Shortcut dialog will appear.

Add the following information in the Add Custom Dialog menu:

Name: Launch gedit
Command: gedit
Shortcut: Set a shortcut by pressing the “Set Shortcut” button and then setting a shortcut by pressing both keys simultaneously. This shortcut should not be already in use.