Transit visa for Indian citizen flying to Australia via Hong Kong

Question: I am travelling to Australia (Adelaide) on PR (E-Visa) 1st time from India (So do i need any transit visa at Hong Kong & at Perth airport if i stay inside the airport only & my time b/n the connecting flights is less than 8 hrs)
Comment: You never need a transit visa for the country that is your final destination. If Australia is happy for you to visit, they're certainly happy for you to change planes as part of that visit.
Answer: As David Richerby stated in his comment, you don't need a transit visa for Perth if you've already got a visa for Australia.
And according to Timatic, you don't need a visa for Hong Kong either if you stay in the transit area:

TWOV (Transit Without Visa):
Passengers with a confirmed onward (Air-to-Air or Air-to-Sea) ticket to a third country within 48 hours. They must stay in the international transit area and have documents required for the next destination.


View saved wifi password Iphone 4S

Question: Im new to Iphone.  Love it except that I have forgotten the previous saved wifi password for my iphone 4s.  I needed to delete some apps to make room for more and my friend did a reset.  Now I have no password to re-download what I need.  She also did this to my daughters Alcatel Fierce One Touch phone.  So I'm effectively screwed. Im really not phone savvy and have no idea how to find the password I've had saved for a year.  Any help would be greatly appreciated.  Thanks.
Answer: There is no way to view a saved password on your iPhone.
However, if the password is a WPA security key, it should be on the internet router itself. The same goes for most other types of Wi-Fi password. Try finding the router and see if you have a line labeled WPA or Passcode, or something along those lines.
Answer: There is no available applications and any tools to show the password of available Wifi networks that you already connected, if your iPhone is not jailbreak. But we have our own tip. Look at the following tips:
Find Router iP address > Attempt to login to Router with default user and password > view the Wifi password in router setting.

To login to the Router, your need to find it's ip address first. Open the Settings app and tab "Wi-Fi" settings > Look at targeted the wi-fi router / network name that want to reveal the password> tap on the (i) info button.

You then should see Router ip address:

Open safari > type the Router ip address > Enter. You then is directed to the Router login panel page.

The router model is now revealed. You can attempt to login with default user/password (they normally are admin/admin). However, you can go on google to search the exact default user/password quickly with specific Router Model.
Hope it helps!

View saved wifi password Iphone 4S


"netrw" mishandling long filenames

Question: I see an odd problem with netrw for file names that are long enough to run into the next column (which is for the file size).  When I press "Return" or "o" to view the file, it gets confused by the file name.  It believes that the file name is the actual file name with the file size appended to it.  The resulting buffer is blank, as an actual file with such a file name does not exist.  I used Bash to confirm that the actual file name does not have the file size appended to it.

If I use "m" to rename, it normally presents me with source and destination file names, where the destination file name defaults to the source file name and the user has to cursor over and modify the destination file name.  If I try that here, both the source and default destination file names have the file size appended.
The command ":setl tabstop=60" (where 60 is much longer than the file name to avoid the clash) doesn't do anything.  I used "set list" to see that the white space between the file names and the file sizes are spaces rather than tabs, which is abnormal.  On another machine that doesn't exhibit this problem, netrw also shows spaces between columns rather than tabs, so I think it that this must be a recent design decision for netrw (I recall not too long ago seeing tabs).  I am certain that this is not due to ":set[l] expandtab"; I removed this in /etc/vimrc and reran Gvim.  The setting appears in some functions and commands, but none that I use, and none that are invoked in other functions/commands.
Launching a fresh instance of Gvim doesn't seem to avoid the problem.  Upgrading my Cygwin installation seemed to solve the problem temporarily, but it came back.  Reinstalling all packages did not make the problem go away.  Harmonizing /etc/vimrc between the laptops (one exhibiting the problem and the other not) doesn't make the problem go away.  I confirmed that both had tabstop=33.  The one without the problem still has spaces between the filenames and the files sizes even if a filename is greater than 33.
Is there anything further I can do to sleuth down or eliminate the problem?
Here is my Gvim version information:
VIM - Vi IMproved 8.2 (2019 Dec 12, compiled Feb 13 2022 22:00:24)
Included patches: 1-4372
Modified by <firstname.lastname@example.com>
Compiled by <email@example.com>
Huge version with GTK3 GUI.  Features included (+) or not (-):
+acl               +cmdline_hist      +ex_extra          +jumplist          +mouse_dec         +perl/dyn          +sodium            +textobjects       +wildmenu
+arabic            +cmdline_info      +extra_search      +keymap            -mouse_gpm         +persistent_undo   +sound             +textprop          +windows
+autocmd           +comments          -farsi             +lambda            -mouse_jsbterm     +popupwin          +spell             +timers            +writebackup
+autochdir         +conceal           +file_in_path      +langmap           +mouse_netterm     +postscript        +startuptime       +title             +X11
-autoservername    +cryptv            +find_in_path      +libcall           +mouse_sgr         +printer           +statusline        +toolbar           -xfontset
+balloon_eval      +cscope            +float             +linebreak         -mouse_sysmouse    +profile           -sun_workshop      +user_commands     +xim
+balloon_eval_term +cursorbind        +folding           +lispindent        +mouse_urxvt       +python/dyn        +syntax            +vartabs           +xpm
+browse            +cursorshape       -footer            +listcmds          +mouse_xterm       +python3/dyn       +tag_binary        +vertsplit         +xsmp_interact
++builtin_terms    +dialog_con_gui    +fork()            +localmap          +multi_byte        +quickfix          -tag_old_static    +vim9script        +xterm_clipboard
+byte_offset       +diff              +gettext           +lua/dyn           +multi_lang        +reltime           -tag_any_white     +viminfo           -xterm_save
+channel           +digraphs          -hangul_input      +menu              -mzscheme          +rightleft         -tcl               +virtualedit
+cindent           +dnd               +iconv             +mksession         +netbeans_intg     +ruby/dyn          +termguicolors     +visual
+clientserver      -ebcdic            +insert_expand     +modify_fname      +num64             +scrollbind        +terminal          +visualextra
+clipboard         +emacs_tags        +ipv6              +mouse             +packages          +signs             +terminfo          +vreplace
+cmdline_compl     +eval              +job               +mouseshape        +path_extra        +smartindent       +termresponse      +wildignore
   system vimrc file: "/etc/vimrc"
     user vimrc file: "$HOME/.vimrc"
 2nd user vimrc file: "~/.vim/vimrc"
      user exrc file: "$HOME/.exrc"
  system gvimrc file: "$VIM/gvimrc"
    user gvimrc file: "$HOME/.gvimrc"
2nd user gvimrc file: "~/.vim/gvimrc"
       defaults file: "$VIMRUNTIME/defaults.vim"
    system menu file: "$VIMRUNTIME/menu.vim"
  fall-back for $VIM: "/usr/share/vim"
Compilation: gcc -c -I. -Iproto -DHAVE_CONFIG_H -DFEAT_GUI_GTK -I/usr/include/gtk-3.0 -I/usr/include/pango-1.0 -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/include/cairo -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/uuid -I/usr/include/harfbuzz -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/gio-unix-2.0/ -I/usr/include/atk-1.0 -I/usr/include/at-spi2-atk/2.0 -I/usr/include/at-spi-2.0 -I/usr/include/dbus-1.0 -I/usr/lib/dbus-1.0/include -D_REENTRANT -ggdb -O2 -pipe -Wall -Werror=format-security -fstack-protector-strong --param=ssp-buffer-size=4 -fdebug-prefix-map=/pub/devel/vim/vim-8.2.4372-1.x86_64/build=/usr/src/debug/vim-8.2.4372-1 -fdebug-prefix-map=/pub/devel/vim/vim-8.2.4372-1.x86_64/src/vim-8.2.4372=/usr/src/debug/vim-8.2.4372-1 -fstack-protector-strong -DSYS_VIMRC_FILE=/etc/vimrc -D_REENTRANT -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1
Linking: gcc -L. -fstack-protector-strong -L/usr/local/lib -Wl,--as-needed -o vim.exe -lgtk-3 -lgdk-3 -lpangocairo-1.0 -lpango-1.0 -latk-1.0 -lcairo-gobject -lcairo -lgdk_pixbuf-2.0 -lgio-2.0 -lgobject-2.0 -lglib-2.0 -lintl -lSM -lICE -lXpm -lXt -lX11 -lXdmcp -lSM -lICE -lm -lncursesw -lcanberra -lsodium -liconv -lacl -lattr -lintl -Wl,--enable-auto-import -Wl,--export-all-symbols -Wl,--enable-auto-image-base -fstack-protector-strong -L/usr/lib/perl5/5.32/x86_64-cygwin-threads/CORE -lperl -lpthread -ldl -lcrypt

Comment: https://github.com/vim/vim/issues/10055 Try to set `g:netrw_maxfilenamelen` to a larger number
Comment: I gave up on netrw and start creating "my own file manager with files and directories", wip though: https://github.com/habamax/vim-dir
Comment: try to change the view of the netrw with `i`
Comment: Thanks, Christian.  That worked.  One has to close the netrw window and re-open it after (say) `let g:netrw_maxfilenamelen=66`.  In the past, however, there was a tab delimiter between the filename and the file size, which made it unnecessary to change netrw_maxfilenamelen (which one might have to do frequently, depending on the file names displayed).  On a related note, I wonder why this is a problem on one system and not another, despite identical vimrc files.  Did you want to post your comment as the answer?
Answer: It has been almost 2 years since I posed this question and the problem persists.
As per Christian Brabandt's comment, the only solution thus far seems to be (say) let g:netrw_maxfilenamelen=66.  You may have to close and re-open the netrw window.

"netrw" mishandling long filenames


An SEO software tool says 'keywords' meta tag is obsolete

Question: Can anyone tell me where on the Craft dashboard I can correct this and upload new keywords?
Answer: So this isn't a simple answer, because we don't know how the SEO has been implemented on your particular site. It could have been done manually, or they could have used my SEOmatic plugin or it could have been another plugin. You also don't mention what version of Craft CMS you're using.
In any event, what that SEO tool is telling you is that the <meta name="keywords"> tag is largely ignored by Google. I say largely, because if you stuff it with all sorts of keywords that look "spamy" it can be a negative ranking signal for your site.
Other search engines such as Bing, Yandex, etc. do look at the meta keywords tag, though, and as long as you're not "keyword stuffing", there's no harm in leaving that tag in there.


Digicam as recording device

Question: Are there digicams with HDMI out, so that I can connect the digicam to a TV card in my computer and record directly, what the digicam sees? Also the digicam then of course shouldn't go into any kind of standby while recording. Thanks for any hint :-)
Answer: When I plug a Nikon J1 into my TV using an HDMI cable the TV displays the live-preview that is normally shown on the LCD on the back of the camera. I expect I could configure the camera not to sleep and (possibly) not to display settings as an onscreen overlay. If I instead pluggedt the HDMI into a recording device I am sure I could record that (HDCP notwithstanding).
I imagine this may be true for many such cameras.
So yes, such devices exist.

Digicam as recording device


How do I find the canonical questions for certain general topics?

Question: Is there a list somewhere of the "canonical questions" for general topics like the "has this food gone bad" one?  I want to close something as duplicate, but I can't find the question it should link to.
Answer: This doesn't exist as an official feature. Meta sites tend to use a special tag for this called [faq], but it doesn't exist on the main sites.
There is a way to get close to it using SEDE. It is possible to write a query which finds questions that have been most frequently used as duplicate targets. It turns out that Glorfindel had already written one for Stack Overflow, so I copied it for our site: https://data.stackexchange.com/cooking/query/1630878/most-frequent-duplicate-targets.
These are not questions which are "canonical" by community decision. In fact, I don't think these decisions have ever been explicit, except for How long can I store a food in the pantry, refrigerator, or freezer?. Instead, people have gotten tired of similar questions, and written a more general one, and maybe mentioned "I hope we will be able to cover this topic now without the bothersome piecemeal questions", and the community started closing as duplicates afterwards. So they are questions which are used as canonical in practice, and the community has adopted them as useful resources.
Comment: wait, we can run queries directly against the SQL Server database???? Oh golly, I have some uses for that.
Comment: Anyway, it might be worthwhile to create a canonical question/answer for "Is this food bad?"  For all of the questions where it's not a matter of health regulations.
Answer: I just drop a few related terms in the search box and go looking in the results for highest number of votes, usually. That often works, though sometimes the best one is not the one with the most votes, but it's usually on the first page of results.


Which literary movement do Pushkin's Little Tragedies belong to?

Question: Some say Pushkin quit Romanticism in year  1825. To which literary movement do his Little Tragedies (1830) belong to, then?
Comment: Hi and welcome to Literature Stack Exchange. Could you please give an example of a critic claiming that "Pushkin quit Romanticism in 1925." (Or was it 1825? Pushkin died in 1837. In either case, I would appreciate it if you could provide a source.)
Comment: You will have to ask the people who say he quit Romanticism in 1825. Even his later work is widely perceived to have Romantic elements. Although there is probably a tendency towards realism. And what does it mean to belong to a literary movement - if you mean "Did Pushkin deliberately write his *Little Tragedies* as examples of Romantic or Realist literature, according to set principles, or in the way that Wordsworth or Tzara wrote according to manifestos?" the answer is probably no, but they have elements of various literary movements.
Comment: @StuartF This is a tradition of Russian literary critique: to consider everything Pushkin wrote after 1825 as realism. Everybody writes it without a reference. I do not see anything realistic in "Little tragedies".  Why do you say "The answer is probably no" for romanticism? Can you say anything specific about it?
Comment: @StuartF I am asking anybody who has something to say about it, one way or another. Thanks.
Answer: It seems that authors find elements of both realism and romanticism in Little Tragedies.
The Pushkin Handbook (2005) explains that Soviet authors overstated a case for realism for ideological reasons:

Pushkin had to be read as "progressive" and to have "overcome"
romanticism, thus laying the path for critical realism.

It's covered in more detail in the book's chapter on Pushkin and romanticism.
Soviet researchers found realism, for example, in more complex psychology or depiction of historical processes. Yuri Lotman in his article «Пушкин. Очерк творчества» (Pushkin. Outline of the oeuvre) says (auto-translated):

The most complete expression of the realism of the Boldino period were
the so-called "little tragedies". In this respect, they sum up the
entire creative development of the poet since his break with
romanticism. The desire for historical and ethno-cultural concreteness
of images, the idea of the connection of a person's character with the
environment and the epoch allowed him to achieve an unheard-of
psychological fidelity of characters. […] G. A. Gukovsky saw this as a
feature of Pushkin's realism, based, in his opinion, on the
determination of characters by their environment.

That said, The Stone Guest, e.g., has a statue coming to life, and the play borrows some elements from Mozart's opera (according to Wikipedia).
Some romantic elements are desribed in the article «Маленькие трагедии» (Little Tragedies, publ. in Zvezda magazine, 1999, #3) by N. V. Belyak and M. I. Virolaynen (auto-translated):

The poetics of "A Feast in time of Plague" is entirely organized
according to the laws of the romantic era. First of all, this is the
poetics of the fragment; the reason why the text of the tragedy is
woven from someone else's text is probably connected with it. The
fragment was appreciated by romantics for the fact that, devoid of
borders and frames, it remained as if inseparable from the world, or
vice versa — "embedded" directly into the world.
Comment: Soviet critics had to tow a party line: everything acceptable for CPSU is realism.  Lotman followed rules also. Contemporary Russian critics studied literature in Soviet Universities. Besides, in Russia today it is considered uncultured to discard Soviet heritage. The only acceptable deviation is to take Christian views on literature.  So, almost all  the literary analysis today in Russia is either communist or Christian. Which makes it pretty much useless for a not-Comunist and not-Christian.


Why XGboost does not work on small dataset

Question: Here I am using Xgboost for classification for a simple small dataset, when x = 0 then y = 1 elif x = 1 then y = 0. Then I use the xgb.XGBClassifier() but the resulting probability is just 0.5. I wonder why this happens.
Answer: There's too few different samples so XGBoost is unable to split the trees properly (you can check the actual trees using clf.get_booster().get_dump()). Reducing the min_child_weight hyperparameter (e.g. clf = xgb.XGBClassifier(min_child_weight=0.5)) should get you some traction.
Comment: Thanks very much for your answering. It is really an important hyper-parameter


Emulator for Digi-Comp I

Question: I'm looking for an emulator for Digi-Comp I.
I can't find one. All I've found is this Turing train thing. Any Help? I'm trying to see if I can recreate the classic toy.
Comment: For what operating system?
Comment: Probably wrong place to ask. I had a Digicomp1 when I was a kid. It basically is a finite state automaton implemented by mechanical hardware
Answer: Larry Groebe and I developed a Digi-Comp I emulator in HTML and Javascript in 1999.  It's been hosted in various places and disappeared for a while.  I recently resurrected it and moved it to the Google Cloud Platform.
Here's the URL:  http://digicomp-1.appspot.com/

Emulator for Digi-Comp I


linux command to find files and replace with another file

Question: I'm looking for a linux command to search a folder directory and it's subfolders for a file by name and replace all of them with a copy of another file. Any idea?
Answer: Assuming you have the replacement file in your home directory (~), you can use find to do the replacing.  This will find all boom.txt files and replace them with the replace.txt file (keeping the boom.txt name).
find . -name "boom.txt" -exec cp ~/replace.txt {} \;

Comment: Is there a way to not keep the boom.txt name and use the new file name instead?
Answer: Adding to the answer by user1683793, the following command can also be an alternative for the copy and replace. This command is verified on Mintty(Windows 10).
find . -name "boom.txt" -print -exec cp ~/replace.txt {} \;


Forcing Speedbar's Sorting Order of Org File Headers to Mirror File's

Question: I use both org-sidebar (https://github.com/alphapapa/org-sidebar/) and Speedbar to navigate Org files.  Both have minor issues.  However, I find Speedbar works best, but it has a terrible habit of sorting headers in an order different to that of the file.  In particular, headings with no sub-headings (such as when drafting an outline) are always displayed after headings with sub-headings.  Does anybody know how to force the headeings' sort order in Speedbar to match that of the file's?
Comment: Type `C-h v` and have a look at the doc-string for `speedbar-tag-hierarchy-method` ("*List of hooks which speedbar will use to organize tags into groups.*"), which has options such as:  `speedbar-prefix-group-tag-hierarchy`; `speedbar-trim-words-tag-hierarchy`; `speedbar-simple-group-tag-hierarchy`; `speedbar-sort-tag-hierarchy`.  You can even write your own sorting functions ....  Or, you can have no sorting order -- which may be what you want (although I am unsure from the question because there is no before and after example).
Comment: ... continued from comment above:  To see what those functions do, type `C-h f` and read the doc-strings ... perhaps they will mention something you may find useful ....  And, if you are super interested, you can type `M-x find-function` and peek at the source code ....
Comment: @lawlist, you are correct in your assumption.  I don't want Speedbar to sort the headings.  I assume this will force their display in the same order as they appear in the file.  How do I accomplish this?  Do I

    (setq speedbar-tag-hierarchy-method nil)
Comment: Because you have not provided a before/after example, I have no way to test your desired output and I don't even know what version of org-mode you are using.  With that being said, you can see what the default value is for `speedbar-tag-hierarchy-method` and modify it with `(setq speedbar-tag-hierarchy-method '(NAME-OF-FUNCTION-ONE NAME-OF-FUNCTION-TWO))`.  Eliminate the offending sorting function, save, restart Emacs and give it a whirl.
Comment: Let me try your suggestion.  I will post examples following my test
Comment: @lawlist, I want to thank you much.  Your suggestion worked perfectly.  I set the variable to nil. This forces Speedbar to display headers in the same order as they appear in the Org file.
Answer: The variable speedbar-tag-hierarchy-method has a doc-string that states in relevant part:  "List of hooks which speedbar will use to organize tags into groups."  The list can contain values such as:  speedbar-prefix-group-tag-hierarchy; speedbar-trim-words-tag-hierarchy; speedbar-simple-group-tag-hierarchy; speedbar-sort-tag-hierarchy.
The original poster has stated a preference that the tags not be sorted; i.e., that the order in which they appear be the same as the order in the file from which they were gathered.  In a comment underneath the question, the O.P. has indicated that he is happy with setting the above-mentioned variable to nil.  It may be preferable, however, to nevertheless keep a non-offending value such as trimming the words; e.g.
(setq speedbar-tag-hierarchy-method '(speedbar-trim-words-tag-hierarchy))


What guarantees that for every credit there is a debit in an electronic fund transfer?

Question: I'm worried about the difference between seeming honest and actually being honest.  I know banks rely in part on a good reputation to stay in business.  But it seems to me that as long as a bank has a plausible argument that they acted in good faith, they are free (and perhaps indeed it might be greatly in their interest) behind the scenes to be arbitrarily dishonest.
Answer: Double-entry bookkeeping guarantees that for every credit there is a debit.
It's not really different for a bank than for you or I.
I can claim that I've got an account with myself for 10 squillion pounds, but everyone will ignore me. The only balances that matter are the physical currency that I hold, and the accounts I have with other people or institutions; e.g. my bank account.
It's the same for a bank: the balances that matter are the physical currency that it holds, and its accounts with other people and institutions. Predominantly, other banks, including Central Banks.
Clearing Houses are institutions, or groups of institutions, that act as intermediaries to ensure that when one bank has a bunch of transactions with another, the net balance is transferred correctly while minimising counterparty risk. And the Central Bank offers a settlement service: for example, banks with sterling deposits will (typically) have an account with the Bank of England, which carries out settlement between banks.
Comment: What do you mean by cash in hand?
Comment: I still don't really understand.  Say I bank with Wells Fargo and my power company banks with Deutsche Bank.  I arrange for an electronic funds transfer to pay my electrical bill.  Wells Fargo debits my account, and sends money to Deutsche Bank.  How?  Do they both have accounts in some central government bank or other third party?  The central bank then debits one account and credits another?  Who exactly are these third parties?
Comment: I've edited the answer to try to make it easier to understand. But it sounds like your actual question is "how does banking work", which is far too huge a question for this Q&A format. You might want to look at one of the introductory economics courses on Edx or Coursera.
Comment: I guess this kind of answers my question: https://www.occ.gov/news-issuances/bulletins/2006/bulletin-2006-39.html


Do the electrical and magnetic fields around a photon move faster than the speed of light?

Question: I have seen similar questions to this, but I can't seem to get a firm answer. My understanding is that photons move in straight lines at the speed of light. These photons have perpendicular electrical and magnetic fields that move at various wavelengths around the photons. If this is true, then the effects of these waves must move several times faster than the speed of light to keep up with the photon. Is this true?
If not, do the waves just lag way behind the photons? Or do I have it completely wrong and the photons themselves are moving along these waves, thus making the overall speed of the light much slower than $c$.
Comment: No, it's the other way around. Photons don't consist of waves, waves consist of photons. Are there waves of water around molecules of water? No, the waves of water consist of the molecules of water.
Answer: According to Einstein's theory of Special Relativity nothing travels faster than the speed of light (in a vacuum). When light travels through a medium, on the other hand, like water, material etc, a wave of high frequency can become low frequency as it loses energy. In some specific cases such as when Cherenkov radiation is emitted, a charged particle such as an electron passes through a dielectric medium at a speed exceeding the phase velocity of light in that medium (wiki- Cherenkov radiation).
From the position of light being the fastest thing in the universe, relativistic corrections need to be applied to anything with mass travelling "fast enough" or "within a fraction" of the speed of light. An object with mass actually gets heavier the faster it goes. This increase in mass is why it's so difficult for particles to obtain "near light speed".
Final year physics and math student.


Do I use the article "the" before the name of a specific database in a sentence?

Question: When you name a specific database, do you use the before it? I'm helping a friend translate from Japanese into English, and she's referring to a database such as Earthquakes database, the actual name of the database.  Should a sentence say:  Refer to Earthquakes database or should it say refer to the Earthquakes database?  It will be read by those familiar with the particular database.
Answer: In US usage, if the sentence uses the word database or other descriptive noun after the proper name, the definite article would normally be used. However, if just the proper name is used, the article is often omitted.

I looked it up in the Books In Print database.
I saw it on the Bloomberg monitor.

but

I looked it up in Books In Print.
I saw it on Bloomberg.
Answer: Because you have put "database", I suggest that you use "the" before "Earthquakes database". You are specifying which database and therefore need the article.
However, if you do not use "database" and simply say "Earthquakes", you will not need an article, as it becomes a proper noun, its name.  Obviously,you will have defined what Earthquakes is prior to using it in this way.
Compare these two sentences:
The Google Chrome search engine is a great tool.  (You wouldn't say "Google search engine...")
Google Chrome is a great tool.  (You wouldn't say "The Google Chrome is a great tool.")
Comment: Google Chrome is the browser, not the search engine. Interestingly, omitting _the_ before proper nouns doesn't apply when naming cars: we say _The Accord is a dependable car_, not _Accord is a dependable car._


Why someone use this?

Question: I heard some sentences with this form from English speakers: "what I do know is that..." or
" We do share the same..."
The question is: what is the applicant of do in these sentences? Why they use it before main verbs?
Answer: It's one of the many uses of "do-support", which is worth researching generally.
In this case it either adds emphasis, or contrasts with a previous negative:

I don't know if the case you are thinking of contrasted with a previous negative, but I do know this sentence does.

Why someone use this?


Le Chateliers principle and increase in temperature

Question: If you increase the temperature, the endothermic reaction is favored. The Le Chatelier's principle states that the endothermic reaction is favored in order to minimize the effect of an increase in temperature. Endothermic reactions absorb heat so the temperature must, in a way, remain constant in that system. So that way, the equilibrium constant is never changed due to a change in temperature as the temperature doesn't change. I know I went wrong somewhere but can someone explain where. Please don't include equations like the ones with Gibbs free energy and Van't hoff equations and stuff as we didn't learn all of that in school yet. Please make the explanation as intuitive as possible.
Comment: Are you confusing the reaction being [endothermic](https://en.wikipedia.org/wiki/Endothermic_process) or [exothermic](https://en.wikipedia.org/wiki/Exothermic_process) with the system being [isothermal](https://en.wikipedia.org/wiki/Isothermal_process) or [adiabatic](https://en.wikipedia.org/wiki/Adiabatic_process)?
Comment: You may perhaps have an idea endothermic reaction absorbs near all provided thermal energy. It is not like that, it absorbs just a small part.  *...in order to minimize the effect...*  is misleading. "to decrease the effect" is more correct.
Comment: Heat is not a species in the reaction. It does not enter into the equilibrium expression. Therefore, you cannot apply Le Châtelier's Principle.
Answer: The right way to do this is to understand the Van't Hoff equation.
Barring that, I can provide some intuition, but it'll have to be a bit hand wavy.
The way I think about this is that at higher temperatures, the intrinsic preference for reactants or products becomes less. That's because the thermal energy of the system is becoming more relevant than the energy difference between reactants and products.
For an exothermic reaction, when we increase the temperature, we'll reduce some of the preference for the product, thereby pushing the reaction backwards.
For an endothermic reaction, when we increase the temperature, we'll reduce some of the preference for reactant, thereby pushing the reaction forwards.
Of course, it's pretty hard to truly justify these kinds of quantitative relationships without the use of proper mathematical tools. In this case, the relationships are most clearly captured in the Van't Hoff equation.


Building animation in Android app

Question: I have done apps which uses only pictures and sound clips. What I want to do is to build an Android app which involves animation. I have seen many of the "Water effect" apps in play store, which has quite good animation effect. One of my them is "Koi Pond". I would like to do the similar kind of app for sand. The detailing of the animation should look good as we see and touch the real sand.
 I'm new to animation stuff and have no idea about it. Can anyone please help me out with how to use the detailed animation for Android?  I know that it is not possible only with java. Please refer me to any blogs/docs available on this stuff.
Thanx
Answer: For such effects (as used in Koi Pond) you will need several pixel shaders. To use it you will need to us OpenGL ES 2.0. I would recommend using a game engine like AndEngine for the basic setup and the shader usage. If you have no experience with shaders it won't be that easy!
I'm not sure if AndEngine is the best choice for that, but it is possible with it.
Check it out http://www.andengine.org/
There are also a couple of shader tutorials in the forum
Answer: At first for translate or some other simple animation you can use android native animation method , but for great things you can use , this , I think it's all you want ;)
Regards Hayk Nahapetyan

Building animation in Android app


Temperature / heat transfer through multiple layers of insulation materials

Question: how can I determine the resultant temperature on one side of a wall after a specified time when the wall has a series of different insulation layers and when the temperature on the other side is known, and is constant?
Comment: What exactly are the boundary conditions on the two sides of the wall, and what is the initial condition?
Comment: The answer depends on the accuracy you're seeking. Strictly speaking, temperature is discontinuous across an interface, although usually, but not always, this fact is completely neglected.
Comment: http://cecs.wright.edu/~sthomas/htchapter03.pdf
Comment: The standard numerical approach is the [finite difference method](https://en.wikipedia.org/wiki/Finite_difference_method), discussed in a heat transfer context by Incropera and DeWitt. An alternate method appears [here](https://apps.dtic.mil/dtic/tr/fulltext/u2/a594913.pdf) ("1-D Heat Transfer in Multilayer Materials Using a Finite Volume Approach"). Özışık discusses the analytical solution in Chap. 8 of *Heat Conduction* [here](http://sharif.ir/~moosavi/Ozisik%20Heat%20Conduction%20%28ISBN%200471532568%29.pdf). The search for more convenient analytical solutions is an area of active research.
Comment: If this was for example a home it would depend on the furnace setting, no furnace and the house eventually be the same temperature as the outside.  An interesting question to as his what is the rate of heat loss so that you can figure out how often your furnace needs to run.
Comment: The R value issued for home insulation, is delta T divided by heat flux ( per unit area).
Answer: The relevant partial differential equation is the heat equation:
$$\frac{\partial T}{\partial t}=\alpha(\vec{x})\nabla^2 T$$
where $\alpha$ is the thermal diffusivity of whatever material a layer is made of, and so will depend on position for a wall made of different materials. The spatial variation in temperature along the wall is likely negligible, so we can treat this as a 1-dimensional problem:
$$\frac{\partial T}{\partial t}=\alpha(x)\frac{\partial^2T}{\partial x^2}$$
where the $x$-direction points perpendicular to the wall. It is likely that this must be solved numerically at this point, given the variation of $\alpha$ within the wall.
Comment: @Gert Heat capacity is included in the definition of thermal diffusivity, which is equivalent to thermal conductivity divided by density and specific heat capacity.
Comment: *"so will depend on position for a wall made of different materials."* What needs to be calculated is the *overall thermal resistance* of the composite wall.
Comment: Also, because this is *transient* problem, heat capacities must come into play at some point.
Comment: Yep, momentarily forgot that. But I'm sure this problem does not need a numerical solution, not with this simple geometry.
Answer: To show just how tedious this problem is, mathematically, let's take the simpler case of a homogeneous wall (no layers):

Because heat only flows in the $x$ direction, we can treat it as a quasi-one dimensional problem.
As @probably_someone stated, the relevant partial differential equation (PDE) is Fourier's Equation:
$$\frac{\partial T}{\partial t}=\alpha\nabla^2 T$$
Or in partial derivatives shorthand:
$$T_t=\alpha T_{xx}$$
The problem states that for all times, $T(t,0)=T_0$ and for that reason I make a small substitution:
$$U(t,x)=T(t,x)-T_0$$
So that:
$$U(t,0)=T(t,0)-T_0=0$$
This is our first boundary condition.
The PDE becomes:
$$U_t=\alpha U_{xx}$$
For a second boundary condition we'll assume that no heat flows from the $x=L$ boundary because air is a good insulator. This means:
$$\dot{Q}(t,L)=0 \Rightarrow T_t(t,L)=U_t(t,L)=0$$
Finally we need an initial condition ($t=0$) and we'll assume $T(0,x)=T_1$, so that:
$$U(0,x)=T_1-T_0$$
For PDEs of this type we use the Ansatz:
$$U(t,x)=\Theta (t)X(x)$$
where $\Theta (t)$ is a function dependent on $t$ only and $X(x)$ a function  dependent on $x$ only. Now insert $U(t,x)$ into the PDE:
$$X(x)\Theta'(t)=\alpha \Theta(t)X''(x)$$
Now divide by $\Theta X$ (abbreviated):
$$\frac{\Theta'}{\Theta}=\alpha \frac{X''}{X}$$
Introducing a separation constant (a Real number):
$$\frac{1}{\alpha}\frac{\Theta'}{\Theta}= \frac{X''}{X}=-m^2$$
The original PDE can now be separated into two ODEs:
$$\frac{X''}{X}=-m^2$$
Or:
$$X''+m^2X=0$$
and:
$$\frac{\Theta'}{\Theta}=-\alpha m^2$$
Starting with the first, it has a general solution of:
$$X(x)=A\sin mx +B\cos mx$$
Using our first boundary condition:
$$U(t,0)=0 \Rightarrow X(0)=0$$
$$0=A\sin 0 +B\cos 0 \Rightarrow B=0$$
So that $X(x)=A \sin mx$
$$U_t(t,L)=0 \Rightarrow X'(L)=0$$
Or: $A\cos mL=0 \Rightarrow \cos mL=0$
Cosines become zero for $\pi/2, 3\pi/2, 5\pi/2, etc$
So:
$$mL=\frac{n\pi}{2}\:\mathrm{for}\:\ n=1,3,5,7,...$$
So we have: $m=\frac{n\pi}{2L}$
Finally: $X(x)=A\sin \Big(\frac{n\pi x}{2L}\Big)$
The eigenvalues $m$ can now be used in the first ODE:
$$\frac{\Theta'}{\Theta}=-\alpha \Big(\frac{n\pi}{2L}\Big)^2$$
Solved we get:
$$\Theta(t)=Ce^{-\alpha \Big(\frac{n\pi}{2L}\Big)^2 t}$$
with $C$ an integration constant.
Going back to the Ansatz: $U=\Theta X$, then:
$$U_n(t,x)=D_ne^{-\alpha \Big(\frac{n\pi}{2L}\Big)^2 t}\sin \Big(\frac{n\pi x}{2L}\Big)$$
For $n=1,3,5,7,...$
The integration constants $A$ and $C$ have been lumped together.
Each $n$ presents a solution but the Superposition Principle demands we take the sum of all these solution to have the complete solution:
$$U(t,x)=\displaystyle\sum_{n=1}^{+\infty} U_n(t,x)$$
$$U(t,x)=\displaystyle\sum_{n=1}^{+\infty}D_ne^{-\alpha \Big(\frac{n\pi}{2L}\Big)^2 t}\sin \Big(\frac{n\pi x}{2L}\Big)$$
We now need to determine the coefficients $D_n$, using Fourier. The initial condition was set as:
$$U(0,x)=T_1-T_0$$
Inserting this into our solution, the exponential terms all become $1$, so:
$$T_1-T_0=\displaystyle\sum_{n=1}^{+\infty}D_n\sin \Big(\frac{n\pi x}{2L}\Big)$$
$$D_n=\frac{2}{L}\int_0^{L}(T_1-T_0)\sin\Big(\frac{n\pi x}{2L}\Big)dx$$
$$D_n=\frac{2}{L}(T_1-T_0)\Big(\frac{2L}{n\pi }\Big)\Big[1-\cos\Big(\frac{n\pi }{2}\Big)\Big]$$
$$D_n=4(T_1-T_0)\Big(\frac{1}{n\pi }\Big)$$
Finally we need to add $T_0$ to $U(t,x)$ to obtain $T(t,x)$. Then put Humpty Dumpty back together and presto, done!
From $T(t,x)$ can then be determined the time evolution at the boundary $L$:
$$\boxed{T(t,L)=T_0+\frac{4}{\pi}(T_1-T_0)\displaystyle\sum_{n=1}^{+\infty}\Big[\frac{1}{n} e^{-\alpha \Big(\frac{n\pi}{2L}\Big)^2 t}\sin \Big(\frac{n\pi }{2}\Big)\Big]}$$
For $n=1,3,5,7,...$
Although this is a complete solution to the problem for a simple homogeneous wall, its very user unfriendly.
Furthermore, in this 'simple' case $\alpha$ is a constant but in the case of a composite wall, $\alpha=f(x)$, complicating matters enormously.


What is the following houseplant with thin stem and wrinkled leaves?

Question:
What is the name of the above plant?
Comment: I note you've changed the photo, but can you get the foliage into daylight to take the pic - still can't see it clearly enough. Are the leaves soft and easily brushed against without damage, or firmer, waxier?
Answer: This is Castanospermum australe, common names Black Bean or Moreton Bay Chestnut. It is unrelated to true Chestnuts (Castanea spp.) and is in fact in the legume family, Fabaceae.
It is native to coastal rainforests of eastern Australia & also occurs on some Pacific islands. It will grow to a large tree if planted in the ground, but can also apparently be grown as an indoor or patio plant. I believe the small, potted specimens are often sold as 'Lucky Bean Plants'.
Comment: @pnuts, Thanks! I originally joined Stack Exchange for the GIS community then stumbled into this one...I look forward to spending some time here.
Answer: This is not a great photo, it's dark and it doesn't magnify well, so I can't see if there are clear veins in the leaves; it might be Spathiphyllum (Peace Lily) which has developed an unusual growth habit because it's constricted by the small pot and, presumably, you have removed leaves from the stems. It looks like this plant is in a pot with no drainage holes; if that's the case, when you repot into something larger (which it looks as if it needs now) use a pot with holes in. Alternatively, it could be a Ficus variety or Coffea arabica, though the length of the leaves at the top probably rule the latter out.
With the image currently available, I'll go for Spathiphyllum, but a clearer brighter photo might change that.


Multiple .NET Host Running in UnrealEditor

Question: Unreal Editor has 64+ services running under it with .Net host and console window host running multiple times. I am running Unreal Engine 5.3.2 source build. I have tried recompiling and redownloading the source several times with the same effect. How to get rid of those many process of .NET running, which are making my system laggy?
Comment: This might be a support question to direct to Unreal's customer support channels or bug reporting systems.
Answer: I would generally caution you against thinking any specific process is causing your system to be "laggy" without a good reason for assuming so.
Your computer is running tens of thousands of concurrent threads all the time. A handful of (what appear to be) internal processes for Unreal are not likely to be introducing any load into your system. (For example don't ever look at chrome.exe it is frightening)
You do seem to have some memory pressure, increasing the amount of RAM in your system is an option assuming you have the time and resources to do so, but this still may not solve your problem.
There are dozens of factors which could cause your system to feel slow. Those processes could be the reason. I would recommend filing a support ticket with the owners of the tooling directly as recommended in the comments if you want to know more about specifically those processes.
In general if your system is running at 80-90% memory utilization you are potentially going to run into hiccups.
Comment: I asked my friend and he only has 4 process running as a child of unreal in task manger my  Ram is 32Gb and i9, i think that's more then enough to run an empty project i think. i download the binary version and its running perfectly with only 4 process running inside unreal its some kind of bug from MS or Epic Idk.


How to associate an email address with Yammer Groups

Question: Can you find out if we can associate an email address with Yammer Groups? For example, we have an ITRMS Yammer group and when I'm sending an e-mail to consultants via Exchange, it would be nice to be able to just copy an e-mail address that will post to a Yammer group as opposed to copying it over to Yammer (saves a few steps). When I click on the "members" or "info" link for Yammer groups, it just hangs so not sure if this would be available if that function worked.
Answer: Every group has an email address associated with it. The mailto link is contained in the Post to this group by email link.


Why doesn't the Earth release you as soon as you escape it?

Question: I've always wondered, that since the Earth is moving at a very fast velocity around the Sun, why is it that when astronauts leave the Earth, the Earth doesn't immediately move away from them at extremely large speeds?
Comment: The earth is rotating, so by your logic, when you jumped in place, you wouldn't land where you took off, since the earth would have moved below your feet.
Comment: @kba The difference is the proximity.
Answer: Because you were also in orbit around the sun with the Earth and still have that velocity.
You may be imagining this in terms of stepping off of a slow moving vehicle on the Earth: you jump off, you come to a stop relative the ground and watch the trolley car go it's merry way. But that is a feature of friction between you and the ground.
There is no such thing as a absolute reference frame in the universe and when you "leave the Earth" you don't come to stop relative anything so that you can watch the Earth fly away.
Newton's laws apply here: "a body in motion (that's the you or the planet) will continue in motion unless acted on by an external force". You just keep going except for changed induced by your drive.
Answer: Imagine that you're sitting in a car that's sitting on a wide flatbed truck.  The truck is moving down the freeway at, say, 65 miles per hour.  You step out of the car onto the bed of the truck.  You've just left an object that's moving at 65 mph, but it doesn't move away from you -- because you, the car, and the truck are all still moving at 65 mph relative to the ground.
Now step off the truck onto the freeway.  (Don't actually try this!)  Your ground-relative speed will rapidly diminish from 65 mph to 0, and you'll see the truck, with the car on it, continue moving off into the distance.  (You'll also have numerous broken bones.)  This happens because a force was applied to you when you hit the ground.  From the point of view of the truck driver, the ground hit you and rapidly propelled you backwards.
When you "step off" the Earth by launching into space, there is no "ground" to hit you and push you backwards.  Your initial momentum continues to carry you along in Solar orbit.
We can view the situation from any of several points of view, or "frames of reference".
From a Sun-centered frame of reference (where the Sun is treated as stationary), you start out travelling in Solar orbit along with the Earth, then you leave Earth with enough velocity to escape the planet, but not enough to leave Solar orbit.  (Earth's escape velocity is about 11 kilometers per second; Earth's orbital velocity around the sun is about 30 kps.)
From an Earth-centered frame of reference (where the Earth doesn't move but it does rotate), you start out on the Earth's surface, moving at a few hundred kilometers per hour because of the Earth's rotation, then you accelerate and leave the surface.  You have, let's say, barely enough velocity to leave the Earth, but not enough leave it at a very high speed.  Since we're treating the Earth as stationary, its orbital movement around the Sun can be ignored.
Both of these frames of reference are valid, and calculations using either of them will yield the same description of what happens physically.  This is the basis for the theory of relativity, though everything I've described has been known since Newton.
Answer: The title question and the text question are different.  The title question "Why doesn't the Earth leave you as soon as you escape it?" has the answer: the Earth does leave you as soon as you escape it.  The definition of "escape" is greater than escape velocity (around 11 km/s), which means that you no longer orbit the Earth.  You and the Earth will be moving away from each other.
Unless you have also reached escape velocity from the Sun (about 17 km/s from the Earth), then you will still be orbiting the Sun, and so with no other maneuvers you will come close to intersecting Earth's orbit every one of your orbits (depending on the effect of other planets, mainly Jupiter), and you may eventually reencounter the Earth depending on the phases of your orbits.
The text question asks about astronauts leaving the Earth. To date, astronauts have never reached escape velocity, and the vast majority of them (all but 24 of them) have been confined to low-Earth orbit (about 8 km/s).  So the answer to the text question is that astronauts (so far) are bound to the Earth by their orbits.
Comment: The OP asks "Is it known how far one would have to travel to not feel the effects of Earth's gravitational field?"  Technically, the answer is infinity.  The effect of the gravity of any body decreases as one over the distance squared.  Which is never zero.  In practice however it can get pretty close to zero, so one can define boundaries past which the effect is small compared to other effects.  The Earth's "Hill Sphere" goes out to about 1.5 million km, outside of which orbits around the Earth are not stable due to perturbations from the gravity of other objects, e.g. the Sun and Jupiter.
Answer: Because until you're far enough to leave Earth's gravitational field, you will still feel it. That means that if you go into space (say at ISS level) and put on a spacesuit and go for a walk, you'll still be moving with the Earth as it rotates around the Sun.
When you've traveled far enough that the force of Earth's gravitational field is negligible, you will see movement.
Comment: Is it known how far one would have to travel to not feel the effects of Earth's gravitational field?
Comment: Not quite.  Certainly you'll still feel the effects of the Earth's gravity, but even if the Earth had *no* gravity, it wouldn't move rapidly away from you as soon as you leave it.  @mohabitar: The Earth's gravitational pull (or any body's gravitational pull) falls off gradually with distance; the force is inversely proportional to the square of the distance.  It never vanishes completely.
Answer:
... since the Earth is moving at a very fast velocity around the Sun ...

You problems start here. Nothing is orbiting anything, until you select a reference frame. So, what's orbiting something is a matter of individual decision, not a fact of nature. This is a result of the Principle of Relativity.
According to this principle every point in the universe, is as suitable as others to be used as the basis for a reference frame and that must not cause you any problem (thinking that the big bang started everywhere helps also).
Then, let's analyze just 2 choices of frames and see what it "tells" about your problem.
Select the sun as your reference frame:
In this choice of frame earth is orbiting the sun in the usual Copernican (heliocentric) system and sun is fix. Still, in this setup, you are orbiting the sun as well, so you have the same translational velocity as earth and since sun's gravity affect you both the same way you won't be left behind (the same as dmckee's answer).
Select earth as your reference frame:
In this choice of frame, earth is at rest, therefore the sun is the one who's orbiting earth (Ptolemaic or geocentric system). In this frame, everything becomes clear, since earth is not going anywhere.
This is the simplest way of explaining your problem.

PS: Heliocentric way of viewing things is not the right way, is another way of viewing it. It happens to be the one that produces the simplest paths (*solutions** to the laws of motion) when describing the motion of the planets in the solar (earth?) system. But, it is not the ideal to describe the motion of the moon; in this case, earth is a better choice. Reference frames should be chosen as per case basis.
As said before in another comment: "Neither Galileo nor the Catholic Church were right. They were both right and wrong simultaneously. There is not a preferred reference frame." Just choose a reference frame and describe the universe from that point of view
For further comments on this issue see my comments in this and this answers from another question.
Comment: There's nothing fundamentally wrong with answering an old question... and I don't want to dissuade you from providing answers!  But anytime you're answering (especially an already answer-accepted question) I would just recommend considering what new/better you're contributing to the solutions.
Comment: This does not answer the question and definitely does not contribute anything to the existing discussion.  In general, questions from 4 years ago with accepted, popular, and comprehensive answers don't need new answers.
Comment: @DilithiumMatrix But a question/answer based on earth movement is speculative (half true?) since **none** can measure such a movement in first place. Showing this is what is new in this answer. By the way, ptolomaic description was accepted, popular and comprehensive for more than 2000 years. That didn't make it *totally* right. Did it? ;-)
Comment: So, you've included a good description of reference frames in your answer, but not how that *answers the question*.  The ultimate answer is that the reference frame doesn't matter: an astronaut feels the same force as the earth (from the sun), and thus they're motion will be the same.
Comment: @DilithiumMatrix The OP is concern to be released (left behind) by earth because of it's motion. If I tell him that earth is not in motion **at all** (prove me wrong) his problem is solved intrinsically. However showing this is so counter intuitive that makes his question legit, deserving a proper answer.
Comment: So is there a reference frame then where all the planets in our solar system are orbiting the earth?
Comment: @AndyBroda Yep. And that is not *a* point. It's **every** point you choose, it could be the tip of your nose :-) if you choose so. There is no such a thing as *the* movement of a point. All one can say is *the* movement of a point **relatively to** other point. Every experiment trying to detect earth movement failed. Tell me. Do you feel yourself moving right now? For all that matters you are at rest and everything else is moving around you.
Comment: So why is the everything revolves around the sun the mainstream reference point?
Comment: @AndyBroda Because when seen from that point of view, the paths (solutions to the laws of motion) of most of the *interesting* objects in the solar system, like the planets becomes simpler and they are just simple ellipsis. But when seen from the earth they are more complex (not *wrong* but *complex*) and you will need things like [Ptolemy's epicycles] (https://en.wikipedia.org/wiki/Deferent_and_epicycle)


In a master's thesis, should relevant theory be part of the literature survey?

Question: Does literature survey/review include relevant theory (from textbooks/old references) or should it only include recent publications? Should I place the theory as a separate chapter?
Answer: The age of theory really does not matter.  If there is a relevant contribution from the 17th century that still matters today, then it is includable.  It doesn't mean you should include it, but there is no reason at all to exclude it.  Because of the pressure of "publish or perish," many current articles are of poor quality.  Indeed, I just wrote to authors of an article because I felt they missed a very obvious explanation.
Conversely, there were fewer scholars the further you go back in time and they were often the pinnacle of the profession.  While there was less knowledge to work with, there tended to be greater rigor.  There are two important reasons to quote older works.  The first is when the older work implies a broader range of options than the profession has taken or unintentionally foreclosed a path of research.  The second is when an important element of prior theory is wrong.  A quotation from a prior author can illustrate how incorrect thinking developed.  For prior theory to be wrong, it has to make perfect sense as to how it is correct.  The error has to be subtle.
Your literature review should include prior theory.  The scope of that review should be deep enough and broad enough to cover the discussion of your research project.  You should be aware of controversies that could impact you, the timing of that discussion is irrelevant.  There is no virtue to an article written in 2017 and no reason to not quote older works, even including the ancient Greek mathematical writings.  There are good reasons to quote Euclid's Elements.
If it is in print, ever, it can be used.  Relevance is up to you and your advisor.  As to whether it should be in a separate chapter, we can't really help you.  You are writing a book.  It needs to make sense.  How can you best make sense.
Answer: There is a difference between previous empirical findings and theory. In my experience papers that pit these in separate sections tend to be a lot clearer.
However, conventions differ a lot between disciplines. I suspect that at some point in your study program the appropriate structure of a paper was discussed. Look at that again and stick to that format.
Answer: In many disciplines there's a strong tendency to prefer quoting more recent work. This has some legitimate reasons:

New findings/developments even in the fundamental theoretical underpinnings of the field
Modern restatements of fundamental theory which do not dwell on issues which are no longer relevant today (e.g. disputing the existence of the Ether and Phlogiston if you're a physicist)

but there are also motivations/reasons which I believe are inappropriate:

"I quote the book/papers I was taught from" - people who don't bother to read original statements of theories to which they only read mentions elsewhere.
Fashion: In Sociology I know that at some point, neo-Marxism was more popular and lots of people cited that, then post-Colonialism became all the rage etc. So you would see people quoting a bunch of articles and books from 10 years back or so, almost exclusively, as though that was the alpha and the omega of social theory. If I'm mixing up my examples then never mind, it's the principle that matters.
Timidity in quoting non-academic / primary sources: Some people seem to have been inculcated with the notion that they're only supposed to quote from respectable academic work. Not so. Often better to quote a 19th-century rabble-rousing speech than the sedate and sometimes mis-representative article who mentioned it in passing a century later.

So don't shy from quoting any source which is materially relevant.

PS - Always provide detailed references of course, especially to sources which are potentially obscure. If the description of your source doesn't fit typical fields, don't hesitate to add a comment to your bibliography explaining what that source is and how to locate it.


What is the maximum recommended number of items to put in a drop down list?

Question: I am introducing searchable drop down lists to filter grid data. The number of items in a list could range from anything like ten to a ten thousand.
The larger the number of items, the more awkward the feel of the view (let alone the performance hit).
So, what is the maximum recommended number of items to put in a drop down list (searchable or otherwise)?
Comment: Also see related questions: http://ux.stackexchange.com/questions/15550/replacement-for-long-drop-down-list and http://ux.stackexchange.com/questions/20828/drop-down-list-best-practice-usability
Comment: From a maximum limitation point of view, we just ran into a situation where we were populating a Select with 100,000 Options. On a top-of-the-line MacBook Pro, this was crashing Chrome for me. After a little trial and error, I ended up with a maximum of about 10,000 but I would even lower that for a slower machine. So, something to think about that it's not just an experience thing but a crashing of your browser window thing. :)
Comment: To add to what @JoshuaPinter mentioned, this depends on how the field is rendered. A `` field will have better performance (= will be able to show more `` fields), than using `` elements; I did a demo of this here trying to render a list of 1m search results: https://github.com/radekstepan/coding-challenges/tree/master/apps/casumo#list
Answer: There is no recommended maximum number of items to put in a drop down list.
No-one can say the maximum is 7 or 12 or 200 or 10,000 and definitively say that for all scenarios, that is the maximum you should use.
There is a myth for drop down lists and menus that you should not use more than 7 +/- 2 because that's how your memory chunks things, but that's not true because of the way lists are inherently scannable - you don't have to remember all the items in a list.
The next factor is the number of items visible at any one time in the list - let's say 10 to 20 items. That seems reasonable but depends on whether the list is wide and/or covers the content underneath and how that affects the user's ability to be able to choose an item when other content is covered.
After that there's the introduction of a scrollbar and the difficulty of making a choice is increased because you only have a relatively small window view to the whole set of options. So the ratio of number of options to the number visible at any one time is the factor there.
At that point you also really start to care about how the items are sorted, so as to make the list scannable, and aid memory of where you saw an item earlier or later in the list.
So a typical scenario is choosing a country when entering an address. We're all familiar wih 200 or so items in such a list and can deal with that reasonably well most of the time, but imagine if that list wasn't sorted - it would be a horrendous task.
Unfortunately that really happens in the wild - here's a preposterous example from Hyatt Hotels asking you to choose an airline from 180+ options. Note the rediculous position in the list of "Other Airlines (Not Listed)"

Even so - when sorted, all lists are not equal - some numbers are more easily scanned than some words, especially if the numbers are sequential, and the words are unevenly distributed across the alphabetical ordering.
Once you start getting over this 200 or so mark then things get unweildy. The numbers 1 to 1000 could work, but 1000 cities around the world would be undesirable if you can only see 10 at a time and have a tiny scrollbar to manage it with.
At that point you no longer want users to interact by scrolling - the searchable option comes into play much more dominantly. There is a step change in the way the user is expected to interact at that point - the drop down list no longer is a static list, but a dynamic list showing results of a search.
If you treat the drop down as a results list rather than a list of all possible items then the sky is your limits - your entire inventory is at your fingertips. However, you need to present it as a search box (not a static list), firstly because performance issues arise as you point out, and secondly because you will always get some users who decide to scroll up and down this immense list. Such a dynamic list should show as empty when no search term is entered rather than contain all the items.
To summarise - it depends. It depends on the visual relationship between the underlying screen content and the drop down content; it depends on the scanability of the list data; it depends on the sorted state of the items and the distribution within the sort key range; and you should question whether a static list content is even desirable in the first place.
Finally - because every situation is different (and because you just should) you should A/B test a few options with users in order to verify any such assumptions, so that you can make evidence based arguments to yourself and others that yes this was the best way to do it.

I have made the assumption that only a single dropdown can be used. One way to reduce number of items in a list is to use a multi-column option - either by using the first drop down to dynamically filter the content of the second - eg continent & country, or by extending the UI to open up a more sophisticated dialog allowing you to create a way to choose an item which is much more focused on the data in your given situation. Eg using Miller columns or filters, or whatever works for your data.
It can help to think about what you could do in an ideal world, then look back at the drop down list and see how unsuitable or archaic the drop down list feels. If it feels like that, then you have realised that the drop down is not the best way to do it. If you proceed to use the drop down anyway (eg due to time/cost/toolkit constraints), then you just made a decision based on some business rules rather than on providing a good UX, and you have to live with that.
Ultimately, the best UX does not come for free. It costs money - get over it.
Comment: I (as a relatively experienced web user) type the first few letters of the drop down menu that I am looking for which selects the item that starts with those letters - thus I don't really care how long the drop down list is. All the major modern web browsers support this. Of course, this is only useable when I know what I am searching of.
Comment: Also worth noting that while pretty much any list of things can be sorted alphabetically, not all lists are improved by sorting. Lists of proper nouns, such as names of countries, are good when sorted. Lists of product categories of which the user is unfamiliar with are not so useful sorted because the user doesn't know what words you've used for the concepts (eg are Persian cats listed as "cat, Persian", or "Persian cat", or "_felis cattus_ (Persian)")
Comment: It's important to note that the reasoning for the 7 +/- 2 bit is not strictly for data that is to be memorized - it also applies to data that will be scanned. When content has more elements than that, much of it will be missed when it gets scanned. So that general rule still applies.

For example, if you provide users with a list of four, all three will most likely be read. If you provide them with 30, you'll be lucky to have three be read. Often the entire list is skipped. 7 +/- 2 still helps ensure content is absorbed and not ignored.
Answer: I'm currently building a web-based application to replace some hideous behemoth written about 10 years ago and have encountered a similar issue, with some drop downs in the extant version having over 1000 entries.
Whilst not being able to offer any specific UX tips as above, I've managed to reduce the user's problem to some extent by allowing them to filter the contents of the select based on text input - have a look at the jQuery Chosen plugin (although I didn't use this in the end).
Using a multi-line select helps as well (I went for an arbitrary 10 in my case) as it allows the user to visually scan the contents without having to do so much typing - it also has a fixed height and doesn't obscure stuff below.
This may not however solve your problem if your users don't really now what to start looking for, but in my case (an intranet application), the users are already familiar with the data so it works for them very well. To back this up, we've had very positive feedback about how much of an improvement this is from the relevant user working group.
I considered a few other options to get my version to work well, including things like a Miller Column style output, but I didn't have a hierarchy to justify one and wasn't going to impose one for the sake of it. In the end a custom jQuery fn has done the filtering and performs really well in my version with around 1000 rows (my application is tested for IE8 and there is no noticeable lag with lots of data).
Answer: Generally if the dropdown requires the user to do extra work and scan a significant list (such as needing to scroll) hen a dropdown can present usability issues.
However!
The one thing that dropdowns have going for them is that everyone uses them... so users know how to use them. So while it may not provide the best experience users are likely to know what to do when they encounter it.
I generally think dropdowns are over used.
Answer: Most country dropdown lists will have 300+ entries in, selecting your birth year will probably have 100+ entries in it (you don't want to exclude those Centenarians). But those are for well known options. The problem comes when people don't know what they're looking for, e.g. even in country lists it can be a pain searching for the UK in country lists as some people list is as United Kingdom, some as Great Britain, some as Britain, some as England/Scotland/Wales, some put it near the top etc.
So the list has to be either numerically or alphabetically sorted but then certainly lists of 100 should be ok. Beyond that you can start using 'Typeahead' concepts:
Answer: For desktop (Keeping only user's convenience in mind)
If your list is a dynamic, then go with an auto-suggest.
If your list is static and small (upto 10 items), then go for a simple drop-down
If your list is static but large, then based on the size of the text
--- for smaller length (upto 20-25 characters), go with a scrollable dropdown
--- for bigger length (more than 25-30 chars), go with an auto-suggest
For Mobile
Go with something as lightweight as auto-suggest. As per my experience, drop-downs are bit too heavy to use on a mobile device.
If the list is as small as 3-4 items, go for radio buttons


Fail to connect to a XPRA server

Question: Why can't I connect to the remote xpra server?
t@ocean:/u/l/jvm$ xpra shadow ssh:"onion":0

(xpra:24602): dbind-WARNING **: 21:28:35.326: Couldn't register with accessibility bus: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
2020-04-06 21:28:35,442 Xpra GTK3 X11 client version 3.0.7-r25627 64-bit
2020-04-06 21:28:35,721  running on Linux Ubuntu 18.04 bionic
2020-04-06 21:28:35,724  window manager is 'Openbox'
2020-04-06 21:28:35,770 Warning: failed to import opencv:
2020-04-06 21:28:35,770  No module named 'cv2'
2020-04-06 21:28:35,770  webcam forwarding is disabled

(Xpra-Audio-query:24619): dbind-WARNING **: 21:28:36.798: Couldn't register with accessibility bus: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
2020-04-06 21:28:36,926 GStreamer version 1.14.5 for Python 3.6.9 64-bit
2020-04-06 21:28:37,314 No OpenGL_accelerate module loaded: No module named 'OpenGL_accelerate'
2020-04-06 21:28:37,772 Error: cannot handle window transparency
2020-04-06 21:28:37,772  screen is not composited
2020-04-06 21:28:37,848 Warning: vendor 'Intel Open Source Technology Center' is greylisted,
2020-04-06 21:28:37,848  you may want to turn off OpenGL if you encounter bugs
2020-04-06 21:28:38,043 Error: cannot handle window transparency
2020-04-06 21:28:38,043  screen is not composited
2020-04-06 21:28:38,053 Warning: window 4294967295 changed its transparency attribute
2020-04-06 21:28:38,054  from False to True, behaviour is undefined
2020-04-06 21:28:38,133 OpenGL enabled with Mesa DRI Mobile Intel® GM45 Express Chipset
2020-04-06 21:28:38,407 Connected (version 2.0, client OpenSSH_7.6p1)
2020-04-06 21:28:38,961 loaded RSA private key from '/home/t/.ssh/id_rsa'
2020-04-06 21:28:38,981 Authentication (publickey) successful!
2020-04-06 21:28:39,275  keyboard settings: rules=evdev, model=pc105, layout=us
2020-04-06 21:28:39,356  desktop size is 1440x900 with 1 screen:
2020-04-06 21:28:39,356   :0.0 (381x238 mm - DPI: 96x96) workarea: 1440x876
2020-04-06 21:28:39,357     LVDS-1 (303x190 mm - DPI: 120x120)
2020-04-06 21:28:39,432 no ethtool interface speed available for wlx801f02b5c389
^C
2020-04-06 21:28:55,157 got signal SIGINT
2020-04-06 21:28:55,157 exiting

My local xpra client is
t@ocean:/u/l/jvm$ xpra --version
xpra v3.0.7-r25627

A remote xpra (server, or client or both?) is
t@ocean:/u/l/jvm$ ssh t@onion
t@onion:~$ xpra --version
xpra v3.0.8-r25889
t@onion:~$ logout
Connection to onion closed.

Both local and remote are running Lubuntu 18.04.
Thanks.
Answer: After upgrading local xpra version to be the same as the remote xpra version,
sudo apt install xpra

the problem disappeared.

Fail to connect to a XPRA server


Will people who buy my newly created erc20 Token also have to buy ETH as well?

Question: I'm currently deciding which crypto platform to go for (Ethereum or Waves). So I'm asking this question because I just wonder if the people, who will buy my newly created token, will HAVE TO buy Ether as well since they need to pay transaction fee in ETH whenever they transfer the bought token forward to other people. Please Help explaining for me in Clear-but-plain English. Thank you in advance!
Answer: Short answer is: not necessary.
ERC-20 standard requires token owner to personally initiate, or at least approve all transfers of his tokens, so when using ERC-20 functions, token owner has to execute some transaction from his own address in order to move tokens forward.  If token owner uses an Externally Owned Address (EOA) to hold tokens, then executing any transaction from this address requires transaction fee to be paid in ether from this very address, so in such case token owner will have to have some ether.
However, there are at least two options how token owners may avoid touching ether when moving their tokens:

use non-ERC-20 functions, or
use non-EOA to hold tokens.

The first option ought to be supported by token smart contract, while the second option should work with any token contracts.
Here is how the first option works:

Token owner signs transfer order with his private key
Token order sends gives signed transfer order to a third party called "relayer"
The relayer sends signed order to token smart contract (the relayer pays transaction fee in ether here)
Smart contract verifies token owner's signature
Smart contract executes transfer

The second option works like this.

Token owner hold tokens on a wallet smart contract.
Token owner controls the wallet by signing orders and asking a third party to send them to the wallet (third party pays transaction fee in ether)

In this schema wallet smart contract may be deployed for token owner by the third party, so token owner does not need ether even for setting up wallet.
Answer: Mostly: yes. They can receive the tokens but if they want to transfer them onwards they need Ether to pay for the gas fees.
There are various schemes to let someone else pay for the gas, see for example here: How to make someone else pay for Gas? . One option not (directly) mentioned there is meta transactions but that is also something quite new and not widely adopted (yet).
So for most scenarios the user has to pay for the fees with Ethers but this situation may change in the future when the aforementioned projects get more widespread.


Windows Firewall - how to block inbound for all .exe files in a folder

Question: In Windows Firewall with Advanced Settings I can create a rule which blocks all inbound or outbound traffic for particular program by pointing to its .exe file. The problem is that this program has many .exe files in its directory, as well as additional ones in its sub directories.
So my question is: do I need to make separate rules for each .exe file, which in this case would mean about 50 rules? Or is there a way to block the traffic for a group of .exe files based on their location on the local hard drive?
Comment: Might be worth investigating which of the 50 files handles network traffic.
Comment: @MarkC.Wallace, And how would you even do that assertatively?
Comment: Here's a simplier way: https://sites.google.com/site/mytools4000/home/allow-block-multiple-programs-through-windows-7-firewall Although @saber tabatabaee yazdi answer is much more thorough.
Comment: Is the question about both inbound and outbound rules, or only inbound?
Answer: You can use a Simple Batch File.  Open Notepad and copy/paste the script below into a blank document.  Save the file as BLOCKALL.BAT.  Now copy that file to the same directory as the EXEs you want to block and double click it.  It will add outbound rules to advanced Windows Firewall settings blocking all EXEs in that folder and sub-folders as well.
It is tested with Windows 7, but it should work with other versions of Windows that use Windows Firewall.
NOTE: Batch starts itself in system32. Thus you need to prepend it with cd /d "%~dp0" to make it work in current directory.
The resulting script would be as follows:
@ setlocal enableextensions
@ cd /d "%~dp0"

for /R %%a in (*.exe) do (

netsh advfirewall firewall add rule name="Blocked with Batchfile %%a" dir=out program="%%a" action=block

)

Comment: If you need to "Run as Administrator" then you will need to edit the file to look like this: @ setlocal enableextensions @ cd /d "%~dp0" for /R %%a in (\*.exe) do ( netsh advfirewall firewall add rule name="Blocked with Batchfile %%a" dir=out program="%%a" action=block ) If you Run as Administrator, and don't edit the file to look like that. It will just add all your exe files from the system32 folder to the firewall. It happens because the batch files runs from system32 when running as an Administrator.
Comment: Elaborating on `setlocal enableextensions`. This ensures that environment changes made are local to the batch file and restored upon exit. It might be useless for such a simple script, but nonetheless might be a nice touch to it.
Comment: @user109756 - Can you or someone update/ add this comment into the answer for greater clarity. It is hard to read and apply. Thanks.
Comment: Now that was beautiful. Worked like a charm! Thank you very much for your contribution.
Answer: **Configure and Add rules in windows firewall based on dynamic content (exe files) in that folder: **
you should work with PowerShell or command line tools that run everyday.
like this : Article Link
function Add-FirewallRule {
   param(
      $name,
      $tcpPorts,
      $appName = $null,
      $serviceName = $null
   )
    $fw = New-Object -ComObject hnetcfg.fwpolicy2
    $rule = New-Object -ComObject HNetCfg.FWRule

    $rule.Name = $name
    if ($appName -ne $null) { $rule.ApplicationName = $appName }
    if ($serviceName -ne $null) { $rule.serviceName = $serviceName }
    $rule.Protocol = 6 #NET_FW_IP_PROTOCOL_TCP
    $rule.LocalPorts = $tcpPorts
    $rule.Enabled = $true
    $rule.Grouping = "@firewallapi.dll,-23255"
    $rule.Profiles = 7 # all
    $rule.Action = 1 # NET_FW_ACTION_ALLOW
    $rule.EdgeTraversal = $false

    $fw.Rules.Add($rule)
}
# Sample Usage
Add-FirewallRule "Test port 1234" "1234" $null $null
Add-FirewallRule "Test port 5555-6666" "5555-6666" $null $null
Add-FirewallRule "Test port 2222 Calc" 2222 "c:\windows\system32\calc.exe" $null
Add-FirewallRule "Test port 3333 W3SVC" 3333 $null "W3SVC"

There are also some good VBScript samples on MSDN  which I used as a starting point.
BUT recommended that you add firewall or proxy in edge of your network, like ISA or SQUID for all of your inbound traffic in your LAN.
open ISA Server Management, click Start, point to All Programs, point to Microsoft ISA Server, and then click ISA Server Management.
Block responses containing Windows executable content visit this Article here
To block responses containing Windows executable content

 1. In the console tree of ISA Server Management, click Firewall Policy.

 2. In the details pane, click the applicable access rule or Web
        publishing rule.
 3. On the Tasks tab, click Edit Selected Rule.
 4. On the Traffic tab (for Web publishing rules) or on the Protocols
        tab (for access rules), click Filtering, and then click Configure
        HTTP.
 5. On the General tab, click Block responses containing Windows
        executable content.

in our network that based on windows we have cache server named SQUID :
Squid content filtering: Block / download of music MP3, mpg, mpeg, exec files

First open squid.conf file /etc/squid/squid.conf:
vi /etc/squid/squid.conf

Now add following lines to your squid ACL section:
acl blockfiles urlpath_regex "/etc/squid/blocks.files.acl"

You want display custom error message when a file is blocked:
Deny all blocked extension
deny_info ERR_BLOCKED_FILES blockfiles
http_access deny blockfile
Answer: Firewall App Blocker (Fab) added a feature to block all executable files in a folder in version 1.5. You can select between inbound and outbound rules.
Answer: If the .exe's are located in the same folder you can probably add it in the windows firewall list.If they are located in different folders then you have to manually add those.In general,the firewall will ask for user's permission if an .exe tries to access the network i.e one that is not recognized as a trusted application.But it wont track what are the individual exe's that are called inturn by that process.You can either disable all ports or specific ports.
In general the windows firewall is not my recommendation unless you update your windows everyday.Use Comodo's free edition to have better control and it can be easily setup.
Comment: If the .exe's are located in the same folder you can probably add it in the windows firewall list.

How - I  am only able to add one .exe per rule, but I can't find an option to add a whole folder containing .exes to a rule.
Comment: I have just tested the method, and it does not work (Windows 10 Enterprise x64). I have blocked `outbound`, folder `c:\program files\mozilla firefox`, scopes `Default Gateway` and `Internet`. However, Firefox still loads all internet pages.
Comment: @AlexPopov instead of selecting the .exe file, select the folder. Then teh rule will block all the exe's in that folder.


How to install ubuntu on a PC without an OS

Question: I'm trying to install Ubuntu on my dad's old gateway PC.  What does each distro say on their website as to minimum specifications?
Comment: Could you clarify what you are trying to do? You question is very confusing.
Comment: possible duplicate of [How do I install Ubuntu?](http://askubuntu.com/questions/6328/how-do-i-install-ubuntu)
Comment: Just burn the ISO to a DVD or a USB-key / SDcard, and install it.
Comment: Please add more details: The model of the Gateway, memory, hard drive space, CPU and graphics card (if there is one). Sign in, click on this link http://askubuntu.com/posts/438156/edit , and add the info to your original question.
Answer: Get the Ubuntu .iso file you wish to use and from there you can either burn it to a disk, or my preferred method, put it on a flash drive.  Now if you are going to go the second route, you must find a boot downloader such as this one: http://unetbootin.sourceforge.net/
Once you download it to the usb drive (or disk), put it in the computer you wish to turn into an Ubuntu computer.  From an off state, turn the computer on, but before it shows anything more than the make (yours is gateway), press f2 (It can be different on different motherboards, so if it's not f2, you will have to find it for yourself).
Now you should be at the bio's section of your computer.  From here, you go to boot options, and set the boot order so that the USB (or disk) boots first, before it boots from the hard drive.
After that, save the options and continue, and it will boot from the USB, at which point you will be given several options to install the OS.  These are fairly self explanatory, so you should be fine, just know, if you say replace OS with Ubuntu, your old OS will be gone from your computer.
Hope that helped.
Answer: Flying blind here, because you have not specified the model number of the Gateway PC, which CPU (32-bit vs 64-bit) how much RAM and hard drive space it has, which graphic card. Therefore, this is a generic answer.
Some older PCs won't boot from a USB flash drive, so start with burning a CD or DVD from the downloaded image.
There are many versions of Ubuntu Linux so I suggest you try several, and choose the version you like, from those which will run on your old Gateway. There are differences in both the desktop environment as well as the apps and utilities they use; suggest you pick the desktop you like (Unity vs Classic GNOME vs KDE vs Xfce vs LXDE)
From the Lubuntu website:

Lubuntu is a flavor of Ubuntu based on the Lightweight X11 Desktop
  Environment (LXDE), as its default GUI. The goal is to provide a very
  lightweight distribution, with all the advantages of the Ubuntu world
  (repositories, support, etc.). Lubuntu is targeted at "normal" PC and
  laptop users running on low-spec hardware.
System Requirements
A Pentium II or Celeron system with 128 MB of RAM is probably a
  bottom-line configuration that may yield slow yet usable system with a
  reduced lubuntu desktop.
The 13.10 32 bit ISO require your CPU to have Physical Address
  Extensions, or PAE. "PAE is provided by Intel Pentium Pro and above
  CPUs, including all later Pentium-series processors (except most 400
  MHz-bus versions of the Pentium M)."
If you have a pre-Pentium II CPU, start from the Ubuntu 12.04 mini
  .iso and please consider the tips in this link

I suggest you start with the 32-bit version of Lubuntu 12.04, since this is an older PC.
If there's a different app you find in one distro which you want in another (e.g., a different file manager), you can install it later.


Did the modern usage of katakana predate the Americans?

Question: How long has katakana been used as today, to represent non-Japanese words, onomatopoeia et al.? But specifically, has this usage been around since before U.S. Commodore Matthew Perry arrived in Japan in the 19th century? I read in Goto-Jones' A Very Short Introduction to Modern Japan that Japan around this time was very insular and distrusting of foreigners, Perry's arrival being a catalyst that changed this. So I assumed that around that time, the Japanese wouldn't have used katakana to represent foreign words if they didn't associate with other countries anyway.
Comment: As important as the arrival and subsequent activities of Perry and his gunboats were, they were part of a chain of events. You may be giving him a bit too much credit for all the changes that took place in the latter part of the 19C.
Comment: Another thing to keep in mind is that the whole concept that Japan was shutting out foreigners during the so-called "sakoku" period is a very western-centric view. Many historians argue that the real point of that time was to prevent individual warlords and regional powers *within* Japan from making their own deals with foreigners and importing their own weapons, which could potentially destabilize the nation. It's a big topic, but the point is that Japan was importing foreign ideas before Perry showed up, just in a way the ruling powers tried to keep under tight control.
Comment: Japanese orthography has gone through several eras. For a while, katakana was used to write grammatical terms. Early meiji documents had this pattern. It still kind of is in dictionaries. The flip to using katakana for foreign words happened well after Perry.
Answer: A direct answer to this question seems to be yes.
According to this, the person who introduced the usage of katakana for foreign words is Hakuseki Arai (1657-1725), which can be confirmed in his 西洋紀聞(1715) (Digital Library Link; Wikisource)

You can see カステイラ, キリシタン, ロウマ, イタリヤ, ロクソン (I'm not sure what this is).
However, like any change, it didn't happen all at once, and the actual transition coincides with the arrival of Perry. According to Wikipedia,

現在の外国語の日本語表記の慣習は、ほぼこの幕末の開国時から明治初期に確立している。

I guess, as comments suggest, increasing contacts with foreign countries played a large role, but it didn't have particularly anything to do with America.

This has also an early katakana usage (in Meiji).
Answer: My understanding is that until the Meiji era, through the early 1900's, foreign words were most often written in kanji. Perhaps the sudden exposure to foreign cultures and the rise of the merchant class and marketing led to it's emergence as the definitive way to write foreign non-Chinese words. As the script was imported centuries ago, it is possible that it has had always been widely regarded as non-native.

檸檬 (レモン) lemon
仏蘭西 (フランス) France
麦酒 (ビール) beer
Comment: I think "until the meiji era" is the wrong way to describe it. The meiji era had a strong love for 当て字 -- which I think was not constantly true before that.
Comment: I suspect katakana did not become the kana for loan-words until after the war, when the likes of English was no longer prohibited as the enemy language and a large no of words must have been imported, and there were many other reforms, but I have not been able to confirm it (in English at least).
Answer: My informal understanding is that hiragana was originally "woman's alphabet" and katakana was "man's alphabet."  Now, it has evolved to hiragana to represents Japanese native words and grammar parts while katakana represents foreign words.  Of course, sometimes katakana is used instead of hiragana just to be rude or funny or whatever.  For example, ゴメン was used instead of ごめん just to be less polite or whatever.
Just a fun tidbit I learned myself......
Comment: "Early on, katakana was almost exclusively used by men for official text and text imported from China." from Wikipedia with citation:  Taku Sugimoto; James A. Levin (2000). Global Literacies and the World-Wide Web. London: Routledge. p. 137. ISBN 9781134657759.
Comment: No, man actually used 真名 (aka. kanji).


Unity Gameobject turned grayed

Question: I accidently pressed some key combination which turned all the gameobjects in Unity engine gray and now I cannot restore them to the original form. Any suggestions?
Below is the link of what I am talking about: https://ibb.co/izAVRo
Answer:
Remove that f from the search bar.
It's trying to find gameobjects containing f letter, but none of them contains f in their name so all of them became gray.
Comment: Thanks for the anwser I don,t know how I made that mistake but even this small mistake was enough to ask the question on gamedev.stackexchange As I was unable to find answer on internet cheers

Unity Gameobject turned grayed


Does Immunity Stack?

Question: So I've got a guy who's playing an "elemental" character with the Insubstantial 3 (Fire-Energy) power. He already has Fire Immunity 5, so when he "flames on" does the Fire-immunity of the Insubstantial power stack with his previous fire damage immunity, thus granting the elemental the equivalent of a complete immunity to Fire effects?
Answer: No, your Immunity ranks do not stack with Insubstantial ranks for extra degrees of Immunity.
5 ranks of Immunity would make a hero either immune against certain non-damage effects, or immune against damage effects with one chosen descriptor.

5 ranks: alteration effects, sensory Affliction effects, emotion effects, entrapment (grabbing, snares, or bonds), fatigue effects, interaction skills, or a particular Damage effect, descriptor (such as bullets, cold, electricity, falling, fire, magic, radiation, sonic, etc.)

Immunity against all fire effects would require 10 ranks.

10 ranks: a common power descriptor (such as all effects with cold, electricity, fire, radiation, or weather descriptors, for example)

In case the Immunity power's wording is ambiguous, below are examples from the Power Profile documents, demonstrating some expected applications of the Immunity power effect.
From the Fire Powers document:

Immunity to Heat: Immunity 1 (Environmental Heat), Immunity 5 (Heat Damage), or Immunity 10 (Heat Effects) • 1, 5, or 10 points

From the Speed Powers document:

Frictionless: Immunity 5 (grab and entrapment effects)  •  5 points

From the Talent Powers document:

Unfazeable: Immunity 5 (Interaction Skills)  • 5 points

Meanwhile, using Insubstantial 3 (Fire Energy) means that the hero's body is made of fire and becomes immune to both physical damage and fire attacks.

Rank 3  - Energy
You become coherent energy. You have no effective Strength, but have Immunity to Physical Damage. Energy attacks (other than the energy making up your form, to which you have Immunity) damage you normally. You can pass through solid objects permeable to your type of energy, but energy resistant barriers, like heavy shielding or
  force fields, block your movement.

Immunity against Fire attacks would protect the hero against any Attack-type power (either Affliction, Damage, Nullify, Weaken), or anything else that requires an attack roll, with the Fire descriptor. But they may be vulnerable against other fire-based hazards or effects.
By default, Immunity is a permanent effect, and Insubstantial is sustained. When used together, Immunity 5 (Fire Damage) and Insubstantial 3 (Fire Energy) are mostly redundant, and redundant abilities do not usually stack to provide a greater degree of benefit.
Note that Insubstantial 3 (Fire Energy) costs 15 power points, whereas Immunity 5 (Fire Damage) costs only 5 power points; hence the overlap in defenses.
However, if the hero spends 5 Power Points, then they can increase Immunity 5 (Fire Damage) to Immunity 10 (Fire Effects).
Comment: @SeanDuggan I checked some Power Profiles for any non-damage examples of Immunity 5, and it looks like you're right. However it does not change my answer regarding stacking.
Comment: Caveat, I'm pretty certain that the 5 PP immunity covers general Interaction, general Emotional, general Entrapment, etc, without the need for a descriptor. It's damage that needs that descriptor since that's such an extremely common effect.
Answer: I feel obliged to add to Mike Q's excellent answer. I do agree with him that in general Immunity does not stack, but provides a series of discrete categories that may overlap. However, Immunity is a power specifically noted to be very subjective, based on the utility in the game in question, which gives your GM fairly broad purview in how they adjudicate the power. In a situation where it might make sense, they might allow it to be additive, such as the example of someone with a 5 PP Immunity to Fire Damage who has an Alternate Form that uses those 5 PP, plus 5 more, to gain Immunity (Fire). I would, however, caution GMs from allowing this as a matter of course, particularly when it comes to "bundled" powers like the Energy Form's immunity to attacks of its own descriptor, as part of their  discount involves them being tied to other aspects, which makes them less broadly useful (for example, enemies generally assume hitting The Human Torch with flamethrowers is useless, so it comes up less often).
The other area where I disagree is the standard list of 5 PP immunities. Within the latest release, the Basic Heroes Handbook, a comma has been eliminated, bringing Immunities back to the 2E definition:

5 ranks: Alteration effects, dazzle effects, emotion effects,
  entrapment (grabbing, snares, or bonds), fatigue effects,
  interaction skills, or a particular Damage effect descriptor
  (such as bullets, cold, electricity, falling, fire, magic, radiation, sonic, etc.)

That pretty clearly indicates that the only item in the list that require a particular descriptor is the Damage effects (which are some of the most common effects), which matches official builds that simply include Immunity (dazzle effects) or Immunity (entrapment) as 5 PP immunities.

Does Immunity Stack?


Can't clone eclipse project into workspace

Question: I'm using Eclipse Juno to develop a java project cloned from bitbucket but when importing the project from my bitbucket repository using Egit eclipse plugin I get this error : Invalid project description
I deleted the project folder and retried to clone using git clone and after importing the project to workspace I get the same error !!
can anyone help ?!
Comment: have you seen this?: http://stackoverflow.com/questions/6084056/invalid-project-description-importing-from-git-repo-problem
Comment: yes .. but this doesn't help cuz I'm working in an empty workspace
Comment: Can you edit your question to put the detailed error?
Comment: Please confirm the existence of a file named ".project" in the root folder for the project.
Answer: You have to distinguish between a Java project and an Eclipse project. Not every Java project is already a Java project and not every Eclipse project is a Java project. You can recognize an Eclipse project by the files that exist. An Eclipse project contains a file .project and a folder .settings. In this files the Project settings and metadata (e.g. if it's a Java project) are saved.
Make sure if the project you want to check out is an Eclipse project or a plain Java project.
It seems to me as if it is not but you try to import it as such. If it is not an Eclipse project you should import the project using the "New Project Wizard". Choose Java project and you'll be fine.
Eclipse will now create the project configuration files. If you commit your changes, make sure you ignore those files. You don't want them in your repository because they contain system specific settings which might not work with other machines. This is the reason why you most likely won't find Eclipse projects in repositories.
Answer: You can first create a project in Eclipse and clone it from repo


mount point available in desktop Removable Media using shell command line

Question: How mount a mount point available in desktop/file manager under Removable Media category but has not ever been clicked so not been recognized from shell yet, by use of command line?
Then only if this first click was done, it further can be recognized and used on shell by commands
Comment: For full clarity: what file manager are you using? E.g. I see "Removable Devices" in the left panel of Dolphin (KDE's default file manager). Are we referring to the same list of devices? Also, which KDE version are you running?
Answer: On a systemd system you likely have udisksctl, from the udisks2 package. Quoting the udisks(8) manual:

udisks provides interfaces to enumerate and perform operations on disks and storage devices. Any application (including unprivileged ones) can access the udisksd(8) daemon via the name org.freedesktop.UDisks2 on the system message bus[1].

Use
$ udisksctl status

to list the devices you can act upon,
$ udisksctl info --block-device /dev/sdXn

to inspect them (either the block device sdX or one of its partitions, sdXn) and
$ udisksctl mount --block-device /dev/sdXn

to mount a volume. The command will output the full path of its mount point. Finally, to unmount and power-off a device:
$ udisksctl unmount --block-device /dev/sdXn
$ udisksctl power-off --block-device /dev/sdX

See also

How to mount an image file without root permission?
Mounting from dolphin vs commandline
Eject / safely remove vs umount