Long Term Data Storage in 2020
What medium should be used for long term, high volume, data storage (archival)?
The no. of all possible matrices of order $3\times 3$ with each entry $0$ and $1$ and $ -1$. Calculate sum of squares of first $n$ odd numbers Is there an analytical expression for the summation $$1^2+3^2+5^2+\cdots+(2n-1)^2,$$ and how do you derive it? Where does the word "torsion" in algebra come from? Maclaurin Expansion for $e^{e^{z}}$ at $z=0$ How get the :hover css style of an anchor with jQuery? How can i get the :hover in css stylesheet on the fly with jquery?  stupid example:   a.foo {     color: red;     font-size: 11px; }  a.foo:hover {     color: blue;     font-size: 12px;  }   how to retrieve that color and font-size before that mouse will go over the anchor? Is the matrix diagonalizable for all values of t? UPDATE statement to re-assign a column value according to a numeric formula I have a DEM that I would like to smooth or generalize to remove topographic extremes (chop off peaks and fill-in valleys). Ideally, I would also like to have control over the radius or level of "blurriness". In the end, I will need a set of rasters that range from slightly blurry to really blurry. (Theoretically, the blurriest would be a constant raster of the arithmetic mean of all values).  Are there any tools or methods I can use (based on Esri, GDAL, GRASS)?   Do I need to home bake my own  routine?   Could I use a low-pass filter (e.g. ArcGIS's ), and if so, would I need to run it a bunch of times to get the effect of a large radius? Using Fingerprint reader in 16.04 I have a Dell laptop with fingerprint reader inbuilt. I just ran lsusb on terminal and got the following result:   Bus 002 Device 003: ID 138a:0011 Validity Sensors, Inc. VFS5011 Fingerprint Reader Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 003 Device 002: ID 046d:c077 Logitech, Inc. M105 Optical Mouse Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 004: ID 05ca:1820 Ricoh Co., Ltd Integrated Webcam Bus 001 Device 003: ID 0a5c:21bc Broadcom Corp. BCM2070 Bluetooth 2.1 + EDR Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub   Is it possible to use fingerprint scanning instead of traditional login with 16.04 and Unity ? Thanks. Why did Eve die with Maelon's data available? I saved Wrex in ME1, I saved Maelon's data in ME2, the import screen in ME3 confirmed this.    When I get to the missions on Tuchanka, I completed every one of the side missions before starting the mission where they take down the Reaper and distribute the genophage cure.  Then when I finally get to the lab, Mordin tells me that Eve has died.    Yet every site I've been to says that keeping the data allows her to live.  So why did she die? How to format a USB flash drive? In Windows there is a straightforward "Format" option in a flash drive's right-click pop-up menu. Where's that in Ubuntu? Is it possible to unwrap materials made in Vertex Paint? I painted an group of objects in Blender using the Vertex Paint and was wondering if it would be possible to unwrap the mutliple materials(when the objects are joined together using Ctrl+J)? Do I have to paint it all over again? What is the best way to represent show and hide in icons? I have a web page that has a list of columns of information.  All columns have names and then some of the columns have items in them.   I want to have an icon to represent   Hide all empty columns Showing all columns   All of the icons i see for hide look like "delete" so i want to see if there are any representations of "hide" icons that don't look like delete.  And for "show" the only thing i see is an eye graphic which doesn't seem very intuitive to me.  Does anyone have any recommendations for good "hide" and "show" icons? What is the need of acceleration? As we can usually predict the various forces that a body might be undergoing based on its position and its velocity.Hence what is the need of acceleration? How do I install LibreOffice 4? I want to download and install .  How can I do this? How to reinstall kernels after accidental deletion with a separate boot partition and an encrypted LVM volume? My installation is a Ubuntu 12.04 64 bits (Classic "legacy" MBR - No  EFI/UEFI here) with two partition :   A separate boot partition An encrypted LUKS volume that contains the system Logical Volumes   I seems I accidentaly deleted all the current kernel files with:  sudo apt-get purge 'linux-image-3.8*'    I applied the updates with Ubuntu Software Update, rebooted and then: Ubuntu can't boot.  I tried to boot on a live DVD with a 14.04.1 Ubuntu and can still see my partitions (described later):  /dev/sda1 (boot) /dev/sda2 (Encrypted volume) /dev/sda5 (Logical Volume container)  What are the steps to recover/reinstall the kernel files and dependencies in order to cleanly reboot my installed system?  Thanks in advance Assigning row number for sorted table by column in QGIS Field calculator has a great function under &quot;Records&quot; called &quot;$rownum&quot; which returns (assigns) the number of the current row. Is there a way to make it work together with sorting? Let's say I want to sort table by column &quot;length&quot; and get the order (sequence) of lines by length from shortest to longest. I know I can use some office spreadsheet software easily for this to sort by column and populate new column with order (sequence). But I would prefer to do the whole job in QGIS. As workaround there is also  - using mmqgis plugin and function modify/sort and after that use &quot;$rownum&quot; on the new saved file. Disable autostart on boot and restrict background execution Let's have breakfast    Let's have a good breakfast      I've learned that indefinite articles aren't used before uncountable nouns, so why is a used before the adjective "good" here?    Is there an exception to the rules or is it wrong? Mounting Flashdrive - mounted to home directory I wanted to mount my flashdrive, and made the mistake of setting the mount path as /home/my_name. Now all of my documents, downloads, pictures, etc. are unavailable since my flashdrive has replaced my previous home folder.  When I go to terminal and type sudo umount /home/my_name I get the error message:   umount: /home/my_name: device is busy.         (In some cases useful info about processes that use          the device is found by lsof(8) or fuser(1))   Is there a way to fix this, where I can restore my old /home/my_name folder and then mount the flashdrive to a proper location?