Which sql database contains the item's display name?

Question: Please help me know which sql database contains the Sitecore's item display name?
Comment: Are you asking for the database or the table where the display name is displayed?
Answer: The item's display name is a property (field) of your item. So it exists in the same database as your item. So I guess the answer is: all of them. You can find display names in master, web, ..
Just in case you are not asking about the database, but the table: you will find these in the UnversionFields (with FieldId B5E02AD9-D56F-4C41-A065-A133DB87BDEB)


Grant access based on classification of documents

Question: My client has Sharepoint 2019 on prem.  They want to classify their files in their EDRMS and grant access based on the type of classification.  For example, all files are located in one library but classified.  One group must be able to see all documents, including confidential documents, but the other group should only be able to see Public documents (no confidential documents).  I know I can manipulate it with views and target audience, but that is not truly a good way to restrict access on files.
How can this be achieved?
Comment: Can't you use Workflow to set document level permission when documents are being uploaded/created? In SPO, using MS Flow I'm doing the same thing, stop inheriting permission from the parent and than grant access to a particular user based on the meta data
Comment: Yes I can do that, but I thought there might be a way that you can configure access rights based on content types.
Answer: You could put different files in different folders and set unique permissions for the folders.
Reference:
https://support.microsoft.com/en-us/office/change-the-permissions-on-a-subfolder-5427bd7c-f20a-4f75-8cf2-5359dd45a1a6


How can I draw this graph by tikz, latex?

Question: I would like to draw the graph in the picture below using LaTeX (tikz). I was trying but I do not know how to make it.
shape
Answer: Here's a fairly quick-and-dirty attempt:
\documentclass{article}
\usepackage{tikz}
\begin{document}
    \begin{tikzpicture}
        \node[draw, circle, fill=black, inner sep=1pt] (x1) at (210:4) {};
        \node[draw, circle, fill=black, inner sep=1pt] (x2) at (210:2) {};
        \node[draw, circle, fill=black, inner sep=1pt] (x3) at (0,0)   {};
        \node[draw, circle, fill=black, inner sep=1pt] (x4) at (330:2) {};
        \node[draw, circle, fill=black, inner sep=1pt] (x5) at (330:4) {};
        \node[draw, circle, fill=black, inner sep=1pt] (x6) at (90:2)  {};
        \node[draw, circle, fill=black, inner sep=1pt] (x7) at (90:4)  {};
        \draw (x3) -- (x1);
        \draw (x3) -- (x5);
        \draw (x3) -- (x7);
        \draw (x2) -- (x4) -- (x6) -- (x2);
        \draw (x3) edge[out=150, in=210] (x7);
        \draw (x3) edge[out= 30, in= 90] (x5);
        \draw (x3) edge[out=270, in=330] (x1);
        \node[anchor=north east]          at (x1) {$x_1$};
        \node[anchor=south east]          at (x2) {$x_2$};
        \node[anchor=east, xshift=-0.1cm] at (x3) {$x_3$};
        \node[anchor=north east]          at (x4) {$x_4$};
        \node[anchor=north west]          at (x5) {$x_5$};
        \node[anchor=south east]          at (x6) {$x_6$};
        \node[anchor=south]               at (x7) {$x_7$};
    \end{tikzpicture}
\end{document}

This places a a number of nodes at named coordinates (x1 to x7) and draws them as circles filled with black. inner sep=1pt is used to shrink these circles; their size is determined by their label text, which is empty here, and inner sep controls how much extra space there is around the label, so you need to set that to something small to get a smaller circle.
Nodes are placed using the <angle>:<distance> syntax for the most part, so x2 for instance, is two cm from the origin, at an angle of 210 degrees. (This is quite a useful TikZ feature, well worth remembering.)
Edges are drawn as usual; the curved ones specify the angles at which the edges leave the source nodes (out=...) and enter the target nodes (in=...). Usually it would preferable to use (x2) -- (x4) -- (x6) -- cycle instead of explicitly repeating the first coordinate, BTW, but for some reason this isn't working here; don't ask me why.
Labels are placed as nodes at the previously set coordinates; anchor= controls which point of the new node will be placed at the specified coordinate. The node labelling x3 is also shifted a bit to keep it from clashing with the previously-drawn lines.
I hope that this'll help --- not just with your immediate problem, but also with learning a bit of TikZ!
Answer: Based on @chsk answer (+1), with some effort to make code a bit more concise:
\documentclass[border=3.141592]{article}
\usepackage{tikz}

\begin{document}
    \begin{tikzpicture}[
dot/.style = {circle, fill, inner sep=1pt},
bend angle = 60
                        ]
    \begin{scope}[nodes=dot]
\node (x1) [label=135:$x_1$] at (210:4) {};
\node (x2) [label=135:$x_2$] at (210:2) {};
\node (x3) [label=180:$x_3$]            {};
%
\node (x4) [label=225:$x_4$] at (330:2)  {};
\node (x5) [label=225:$x_5$] at (330:4)  {};
%
\node (x6) [label=  0:$x_6$] at (90:2)  {};
\node (x7) [label=  0:$x_7$] at (90:4)  {};
    \end{scope}
\draw   (x1) -- (x3) -- (x5)
        (x3) -- (x7)
        (x2) -- (x4) -- (x6) -- (x2)
        %
        (x3) to [bend left] (x1)
        (x3) to [bend left] (x5)
        (x3) to [bend left] (x7);
    \end{tikzpicture}
\end{document}


Where can I see restricted areas for flying?

Question: I am based in Miami and I am aware that some areas do not allow drones such as airports or some public areas. Before I purchase a drone, is there somewhere I can access to see restricted areas? Also, are there permits to still fly these in restricted areas?
Comment: Depending on iOS or Android you have apps dedicated to this bro...like Drone Buddy, Drone Deploy....
Answer: This is a good reference from DJI people...
https://www.dji.com/de/flysafe/geo-map
Miami-Florida looks like this:
Answer: The DJI fly safe map only shows those areas that are block by DJI Go or DJI Go4.  These areas are not the same as FAA airspace designations.  For the definitive answer on where you can legally fly in the USA you should consider viewing a VFR chart.  https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/vfr/
Furthermore,   private (and public) land owners can restrict use of individual on their lands.  For example, it is illegal to operate motorized equipment in a Nation Forest Wilderness Area, National Park, and may city parks.  While an FAA 107 holder could legally fly over these areas it would be illegal to operate the drone from inside the boundary thereof.
FAA 107 holder could apply for an authorization to fly in a controlled airspace.  That authorization would limit the pilot to fly below altitudes listed here:  https://faa.maps.arcgis.com/apps/webappviewer/index.html?id=9c2e4406710048e19806ebf6a06754ad
The above link is also a good reference for what areas are off-limits to drone pilots.  For example, military bases, missile silos, etc...
For specific rules on recreational flying see this link: https://www.faa.gov/uas/recreational_flyers


Is there a way to ping a Minecraft server for basic information?

Question: I am setting up a basic monitoring (with monit) for my children's Minecraft server.
My plan is to check whether port 25565 is open but it would be nice if I could gather some more information to check if the server state, as announced, is healthy.
I tried to nc on its port but there is no feedback to random output. I also saw that the Minecraft wiki has information about the structure of packets but it is not obvious that this can be used to check an initial connection.
Is there something like the equivalent of EHLO for SMTP (or any other text-based protocols) to check for a Minecraft server self-announced status? I am sure there must be something since a server announces e.g. the number of available connections - though it may be part of a more sophisticated exchange between the client and the server.
Answer: I know of no purely text based protocols, but parsers exist to take the binary data from the server and make something readable out of it.
A long while ago, I used this PHP-Minecraft-Query script to push server data into a monitoring system. I don't have the code around anymore (that was a long time ago), but this may give you exactly what you need.
Answer: mcstatus is a tool written in Python that can query a Minecraft (non-Win10 edition) server for basic information about the server state such as the server version, how many player slots it has, and how many players are online. It is written and maintained by one of the Minecraft developers.


Do any sects other than Sri-Vaishnavas worship Viswaksena?

Question: Being generally familiar with major Hindu sects, I never heard of Vishwaksena till recently.  SriVaishnavas like to say that when they worship an elephant-headed God, they are worshiping Vishwaksena or his assistant and not Vinayaka - but is he worshiped by any other Hindus?
Comment: Knowing him and worshiping him are different issues.
Answer: Vishvaksena or Vishwaksena, also known as Senai Mudalvar (Sena Mudaliar) and Senadhipathi (all literally "army-chief"), is the commander-in-chief of the army of the Hindu god Vishnu and the gate-keeper and "chamberlain" of Vishnu's abode Vaikuntha.
Answer: "Yes, Vishvaksena is worshipped"

Vishvaksena is worshipped before any ritual or function in some Vaishnava sects. He occupies an important place in "Vaikhanasa and
  Pancaratra temple traditions", where often temple festivals begin with
  his worship and procession.

source: https://en.wikipedia.org/wiki/Vishvaksena

His worship has been discussed in Kurma Purana ,  Kalika Purana ,  Pancharatra text Lakshmi Tantra

Tirumala Tirupati Devsthanams tradition also worships Vishvaksena, as per Vaikhanasa Agama. In the temple rituals, Sri Vishwaksena is worshipped first.

ref: http://www.tirumala.org/STVishwaksenaTemple.aspx
Comment: @SK This does answer the question. Note the "Vaikhanasas". Ramanujists are Pancharatras.
Comment: @SuryaKantaBoseChowdhury Please use the term SriVaishnavas, it makes the reference clearer.
Comment: This doesn't answer the question - do any other Hindus besides Ramanujiyas worship him?
Comment: Copy paste from Wiki is not considered a good answer here.
Comment: I have added further more information (with other references) on his worship
Answer: Forget what Śri-Vaiṣṇava worship or not, the deity of Viṣvaksena has scriptural basic in the   paurāṇika literature, and as such may be worshipped by anyone. That's another thing, if certain people of certain sects, nowadays might exlusively worship him or not worship him, as per sectarian beliefs.
This is what Agni Purāṇa says -

Chapter 24 - Mode of constructing the sacrificial pit and the oblations unto fire

नारद उवाच:
गुरुः संशिक्षयेच्छिष्यान् तैः पूज्यो नामभिर्हरिः ।
विश्वक्सेनं यजेदीशं शङ्खचक्रगदाधरम् ॥ ५६ ॥

Nārada said:

The preceptor has to instruct the disciples thoroughly. Hari must be worshipped by them by (the recitation of his) names. The Lord
Viṣvaksena (whose powers go everywhere), who bears the conch, disc
and mace has to be worshipped.

तज्जपन्तञ्च तर्जन्या मण्डलस्थं विसर्जयेत् ॥५७॥

(Then that deity) stationed in a circular altar, (and. who is frightening) (is worshipped) with the fore-finger and is requested to
leave.

विष्णुनिर्माल्यमखिलं विष्वक्सेनाय चार्पयेत् ।
प्रणीताभिस्तथात्मानमभिषिच्य च कुण्डगं ॥५८॥
वह्निमात्मनि संयोज्य विष्वक्सेनं विसर्जयेत् ।
बुभुक्षुः सर्वमाप्नोति मुमुक्षुर्लीयते हरौ ॥५९॥

& 59. The entire remnants of offerings to Viṣṇu, must be offered to
Viṣvaksena. Then having bowed down and sprinkled (with waters), (their
own persons), (the disciples) having placed the fire of the pit on
their own person, Viṣvaksena is permitted to leave. One who is
desirous of enjoyment gets all things. One who is desirous of release
from mundane existence. gets merged in Hari.

This seem to suggest that in a Yajña, it is imperative to worship Viṣvaksena, after Viṣṇu, notwithstanding whatever sectarian beliefs exists.

Being generally familiar with major Hindu sects, I never heard of Vishwaksena till recently.
References to Viṣvaksena are also found in Skanda Purāṇa (which is considered predominantly a Śaiva Literature.). Here's one of them -

Chapter 10 - Glorification of the Gift of Umbrellas: The Story of Hemakānta
श्रुतदेव उवाच:
तेन स्मृतो महाविष्णुर्विष्वक्सेन स्वमंत्रिणम् ।
उवाच तूर्णं त्वं गच्छ यमदूतान्निवारय ॥ ६६ ॥

Śrutadeva said:

Recollected by him, Mahāviṣṇu said to his minister Viṣvaksena: "You go
quickly and restrain the messengers of Yama. Protect Hemakānta who was
engaged in the holy rite pertaining to Vaiśākha.


What does it mean that classical operators commute?

Question: I've just read how in quantum mechanics, the commutator $[x, p] = i \hbar$, which is supposedly in contrast to classical physics. But if classical physics doesn't even use wavefunctions and operators (as far as I have learned), then what are the position and momentum operators? Is $x$ the identity operator, $p = m \frac{d}{dx}$, and they operate on the position $x$?
Comment: Read where? Which page?
Comment: Griffiths Intro to Quantum, like the first or second chapter.
Answer: In classical physics, specifically in Hamilton's formulation of classical mechanics, the Poisson bracket plays a crucial role.
Hamilton's equations of motion as defined here, equations 1, can be expressed in terms of the poisson bracket (which is nice because it is a canonical invariant), equations 3. The Poisson bracket appears in the time evolution equation, equation 5, which governs the evolution of a function of generalized coordinates.
As you said, in classical mechanics we don't have a wavefunction, so we don't have to fuss about which representation we wish to express the wavefunction in (position, momentum, spin, etc...). Rather, in classical mechanics the quantities of interest are not operators, they are functions of a set of (well-behaved) generalized coordinates. Since they are not operators there are no "operations."
So, in classical physics, the commutator of the classical observables of position and momentum you mentioned is zero, because multiplication of scalar functions is commutative. However in quantum mechanics, since observables are operators the commutator is not zero, and hence we have an uncertainty relation for position and momentum.


Finding a video using a clip from the video

Question: Is there any solution for finding whole of a video using some of its snapshot or a clip of it?
Comment: Related: http://webmasters.stackexchange.com/questions/43606/googles-image-search-but-for-video
Answer: If you want to search with Google, you can use searching by image in Google Images. It's possible that you will find what you are looking for, but it's not sure. I tested it now by making a screenshot of a "What if Money Was No Object - Alan Watts" video on YT and searching with this image - Google found this video. As you can see on my search results first result is the video I was looking for, but on Vimeo, not on YT. And there are also some other videos that have the same part, so the screenshot matches all of them, and there are also some not connected results, too. I think it highly depends of uniqueness of the screenshot and the video you're looking for.
Comment: Thanks, I tried it. It seems that this method just works for famous scenes of well-known films.
Comment: @PHPst Unfortunately, I don't think there is a better option. Getting each frame of each movie and checking if it's the same or similar to image you're searching with would take long and would consume many resources.


Status of submitted article changes the date but status remain from 'With Editor' to 'With Editor'

Question: I Submitted a paper 2 months ago, the current status is "With Editor" and the status date of the manuscript (from With Editor to With Editor!) has been changed twice. What does it mean?
Answer: I would not deduce anything from this. Most likely the system changes the date whenever the editor accesses the article (or the editor does not use the system in the way it was intended).
Also, it happens that the state is not accurate (e.g., in reality, the paper is already with the reviewers), but there is no way to know that.
Anyway, many journals have a processing time span that is much longer than two months. If after some time the state is still "with editor", you might politely contact the editor to inquire about the process.
Comment: I think it is more likely to be the first. Possibly, the editor is accessing the system to find suitable reviewers fro your article. It's possible that he/she is looking at the references section of your paper and shortlisting a few of those authors as reviewers for your paper.
Comment: Thanks Danny and Kakoli for your answer. Actually the metrics given on the journal website says that on average it takes 14.5 weeks for the first decision and 17 weeks to publish online. What does it mean? Whether 14.5 weeks required by editor to take a decision regarding start of review process or its the expected time to receive the reviewer's comments?
Comment: @Mohaqiq: Although this is an old question, I write my answer for the readers.  The first decision time is computed by the summation of the time of the desk rejected papers and reviewed ones. if a journal rejects 100 papers immediately in one week without any review and review 20 papers in 12 weeks (with the decision to major revision/minor revision/reject/accept), the announced average first decision time would be (100 * 1+ 20* 12)/120. So, if the paper has gone under review, the actual time of review is often much more than the announced averaged time for the first decision.
Answer: This probably means the assigned editor changed. This can happen if, e.g., the first assigned editor declines to handle the paper.


Why do we have to put 'hex' at the end of this function? Buffer.from('key' , 'hex')

Question: I know that this line of code: Buffer.from('key', 'hex') Converts a string into its binary representation. My question is: what does adding the 'hex' at the end do? I am confused, since the key is already in hexa-decimal, why would we want to specify that if the function can work on any string?
Comment: https://nodejs.org/api/buffer.html#buffer_class_method_buffer_from_string_encoding
Comment: `key` is a string which is by default encoded in UTF-8, regardless of whether that string looks like a number represented in hexadecimal.
Answer: A string can consist of an integer in any basis, that's the reason you have to include the basis, so the integer within is interpreted properly. Examples:
'01' Basis 2, or 'binary'
'01234567' Basis 8, or 'octal',
'0123456789' Basis 10, or 'decimal',
'0123456789ABCDEF' Basis 16, or 'hexadecimal'
Example that shows why it is important to specify the representation:
We want to intepret the following number as an octal number: 42
Buffer(42, 5) would create a byte array from the number 2210
Buffer(42, 8) would create a byte array from the number 3410
Buffer(42, 10) would (obviously) create a byte array from the number 4210
note that the string representation for the basis can differ in the Buffer API ('hexadecimal' is only 'hex' in Buffer), checkout the Buffer documentation for more information (https://nodejs.org/api/buffer.html)
btw. please post only Ethereum related questions in this stackexchange, use stackoverflow for language specific questions.


Interleaving in litz wire transformer - to be or not to be?

Question: i am designing a transformer for 2-switch forward converter. For now, primary is wound as 5 wires of 0,5mm diameter (34 turns, 3 layers), the secondary is wound as 3 wires of 1,32mm diameter (17 turns, 2 layers). The frequency of smps is 83khz. The idea is to use litz wire in primary and secondary and increase frequency to 100khz.
So, the primary would be wound as litz wire (0,1mm diameter, 120 strands) in 2 layers. The secondary would be litz too (0,071mm diameter, 1076 strands) in 2 layers too. So, the skin effect must be elliminated completely. But what about a coupling? I have read a lot of books on winding interleaving technique, but all the cases if wire radius is more or less greater than the skin depth.
So, it is easy to do interleaving on this litz wire transformer (1 layer primary, 1 layer secondary, 2 layer primary, 2 layer secondary). So guys, will it worth it? I hope there must be some benefits like increased coupling between windings and reduced proximity losses... But i am not sure about that.
So - is it good idea to use winding interleaving on litz wire windings? Will i get better coupling between windings and decreased leakage inductance?
Thanks for your response. It is easy to do interleaving, but harder than just wound windings as 1P,2P,1S,2S.
I will post results of my experiments most likely.
Comment: Also consider a bobbin that allows a bundle winding gap e.g 6 turns gap 6 turns gap... repeat to raise SRF as required.
Comment: What exactly is your design target here? Do you want to minimize cost or size or temperature or losses? Regardless of these points, interleaving has always the benefit of lower leakage inductance bought at the expense of higher coupling capacitance (main source of common mode EMI) and transformer complexity and hence price.
Answer: This is a bit late, but...
For this frequency range proximity effect losses will be much higher than skin effect losses. Proximity effect loss is reduced by using Litz (also good for reducing skin effect losses) or bunched conductors (less effective at reducing skin effect losses). Loss resistance due to proximity effect is proportional to \$ number\_of\_wire\_strands \times wire\_diameter^4 \$ which is why bunched (or Litz) wire is so effective at reducing AC copper losses. An increase in wire strand diameter will cause proximity effect losses to increase - a seemingly counterintuitive outcome.
Since you're operating at a higher frequency, consider reducing the number of turns by a factor of 0.83 (83kHz/100kHz). You'll maintain the same flux density which allows you to reduce DC & AC copper losses which is proportional to the number of turns.
Reducing the number of turns also reduces leakage inductance \$ (L_l\propto N^2) \$.
To improve coupling (reducing leakage inductance) interleaved windings are your friend. It does increase the complexity of the construction which is costly. The number of interfaces between the primary and secondary winding layers is the important factor and will reduce the leakage inductance by a factor of \$  1/M^2 \$, where \$M\$= number of interfaces. The standard physical arrangement for interleaved windings:

M=1: P : S
M=2: S/2 : P : S/2
M=4: P/4 : S/2 : P/2 : S/2 : P/4
M=6: S/6 : P/3 : S/3 : P/3 : S/3 : P/3 : S/6

Where P & S are primary and secondary number of turns (P & S are interchangeable in the above formulas, e.g., you can do P/2 : S : P/2 for M=2).
For a narrow band transformer there is an optimal wire diameter, in metres, to minimize AC + DC copper losses.
$$ d_{opt} = {\sqrt[6]{128 \left({ \hat I \; \rho_c } \over {\pi \omega s \bar {\hat B} }  \right)^2}}  $$
Where
\$ \;\; \rho_c \$ = resistivity of the wire in \$\Omega \; m\$ (approx \$1.72 \times 10^{-8}\$ for annealed copper wire)
\$ \;\; \omega = 2\pi f\$ = angular frequency
\$ \;\; s = \$ number of wire strands
\$ \;\; \bar {\hat B} = \$ average value of peak flux density [T] over the space occupied by the winding \$ = {{\mu_o N \hat I} \over {l_e}} \$
\$ \;\; \mu_o = \$ magnetic constant \$ = 4 \pi 10^{-7} \$
\$ \;\; \hat I = \$ peak current which cancels out
\$ \;\; l_e = \$ effective magnetic path which is approx equal to the winding breadth for an ungapped core in metres
Good references for transformer design:
"Soft Ferrites", E. C. Snelling
"Ferrites for Inductors and Transformers", Snelling & Giles
These books can be found in uni libraries.
Comment: Thank you! It's never late!
Answer: It is better to do interleave winding method to reduce the number of consecutive layers with rising MMF proximity losses towards centre of core.
Since your turns ratio is 2:1  this is what your interleave pattern should be 2P1S... repeating.
If Eddy current proximity losses can be minimized, the benefit is lower core temp rise at rated current.
There are many variables with core types , geometry and winding methods and skin depth becomes more important as the number of layers increases.
Comment: sounds good, but the transformer has different current ratio: the primary conducts 3A of current while secondary conducts 10A. So, it is impossible to do interleaving as you said.
Comment: Then add insulation between all layers to reduce interwinding proximity flux


Iterm2 disable Command shortcuts

Question: I use Iterm2 on the Mac. Many times, I accidentally press Command+some key, so I'm wondering, is it possible to disable the Command shortcuts? Like Command+D for example, as I use tmux for split panes.
Comment: the most annoying of these accidents is ⌘+Q since Q is just next to Tab. The `ignore` shortcut below also works to disable this
Answer: You'll want to override iTerm's default shortcuts with your own shortcuts to "Ignore".
Go to Preferences > Keys and press the + button at the bottom of the Global Shortcut Keys:

Then add an entry for Cmd+K and choose "Ignore" for the action:

This disables Cmd+K.
Comment: In my case I need to bubble the shortcut action up to the OS. Ignore seems actually stop it. Any solution for this? thanks
Answer: Another useful option - you want to use Ctrl-C, Ctrl-V and Ctrl-Z in iTerm2, but you defined them globally on your Mac as Copy, Paste, Undo shortcuts.
To be able to use those shortcuts in iTerm2 to stop running command (ctrl-c), insert special character (ctrl-v) or put program into background (ctrl-z):

create shortcuts ctrl-c ctrl-v ctrl-z in iTerm2 - Preferences > Keys > + same as in above solution
instead of Ignore chose action "Do Not Remap Modifiers"

And now you can use ctrl-c for copy in rest of mac os and for break inside iTerm2.
Answer: You have the option to remap a key in iTerm2 to send an escape sequence. In your case, to remap ⌘+D to send Esc+D, select the action Send Escape Sequence and provide the sequence of characters
that should follow the Escape character to be sent to the terminal.
Answer: You could just go to Preferences > Keys and manually delete every shortcut with Cmd.
Comment: Those commands are not listed
Comment: The `Preferences > Keys` panel does not contain an entry for Cmd+K so there's nothing to delete that can fix this issue.
Comment: Please delete this answer. It is wrong and misleading.
Comment: @Behrang we don't delete wrong answers for that reason alone. Can you explain he harm here or better, why exactly this is wrong.
Comment: Yes, the harm here is the possibility of a user wasting time trying to use this answer when, in fact, it cannot possibly work.

Iterm2 disable Command shortcuts


How to clean a sleeping bag ?

Question: A sleeping bag will eventually need a cleaning. How do you proceed, in particular according to the different materials?
Comment: Please specify synthetic or down :)
Comment: Are we talking in terms of cleaning gunk from the inside / outside, removing any smells from sweat etc. that may have built up, or just generally (combination of everything?)
Comment: @berry120: technically all, but my question is more about a full, deep cleaning.
Answer: The procedure is roughly the same for both Down and Synthetic, however down requires special precautions:

Never dryclean.
Wash by hand in a bathtub, or use a front-loading washing machine on gentle cycle. Down bags have thin baffles inside that keep the feathers partitioned. Agitators will put enough stress on the bag you risk tearing those baffles resulting in the dreaded clump.
Use non-detergent, no-perfume, non-bleach soap such as Nikwax designed for washing down. (There are common non-detergent laundry soaps as well). Down is a natural organic material, and hard detergents / bleaches can damage it.
When drying, use low heat (or no heat) on gentle cycle, and toss in a couple of tennis balls. The balls add some extra non-destructive ooomph to the process that helps break up clumps of down. Check regularly and pull apart any down clumps by hand you encounter.

Sadly, despite being as careful as possible, washed down almost never seems to be as good as new. So do it only when necessary - if ever. Smelly bags can often improve just by laying out in the sun for a few hours. UV is brutal on funk-bugs.
PROTIP: Using a sleeping bag liner (silk or other) that will intercept your body's dirt and oils (the down-killers) will extend the life or your bag.
Answer: First of all, check the label for directions.
I have a synthetic bag.  I take it to the laundromat and wash it in a sufficiently large front-load machine, using cold water and somewhat less detergent than a normal load.  I put it in a large dryer set to low or no heat until it seems mostly dry.  Then I hang it up indoors for a day or two to finish drying.  This seems to be pretty effective.

How to clean a sleeping bag ?


Installing mass batch of .debs using BASH on a debian system

Question: Background: I'm trying to figure out how to install WINE on an MX 19.3 system offline. I am having great difficulty. I seem to be incapable of building from source code (I never really like having to do this). I don't care about size, I like to keep my own offline repository, If I could I'd download all the dlls I could ever need, so I could install them offline as necessary. The closest method I've found is using the MX package installer, copying the /var/cache/apt/archives/ .debs to the offline system (I add the location of where I copy these debs to /etc/apt/sources.list.d/mysources.list on the offline PC and do sudo apt-get update) and the list of files generated by the MX installer, there are 145 of these this looks like this:
libaom0:i386 (1.0.0-3)
libasound2-plugins:i386 (1.1.8-1)
libasound2:i386 (1.1.8-1)
libasyncns0:i386 (0.8-6)
libatomic1:i386 (8.3.0-6)....

Now, using this list copied from the output of the MX package installer when I install them via the terminal of the offline PC one-by-one (e.g. sudo apt-get install libaom0:i386) they seem to install fine. However, when I try and install the whole lot at once it doesn't work. I think it also tries to go to the online repository for some reason. Pasting them into the terminal one-by-one is not really a practical solution. Three of the examples I've tried are as follows:
sudo apt-get install libaom0:i386 && \
libasound2-plugins:i386 && \
libasound2:i386 && \
libasyncns0:i386 && \
libatomic1:i386 .....

sudo apt-get install libaom0:i386 \
sudo apt-get install libasound2-plugins:i386 \
sudo apt-get install libasound2:i386 \
sudo apt-get install libasyncns0:i386 \
sudo apt-get install libatomic1:i386 .....

sudo apt-get install libaom0:i386 && \
sudo apt-get install libasound2-plugins:i386 && \
sudo apt-get install libasound2:i386 && \
sudo apt-get install libasyncns0:i386 && \
sudo apt-get install libatomic1:i386 .....

However, there are issues in all of the above. I'm not very good at BASH yet, is there a way where I can loop it so that each line is treated as a new paste into the terminal, or even better, a tweak to the above so I can just paste the whole lot into the terminal; because I have a feeling that if they were treated discretely so that each line is processed individually that they would all install. Really I just want to re-create what the MX package installer does.
Thanks in advance!
Comment: Is this what you are looking for? https://askubuntu.com/questions/835655/install-a-program-with-apt-offline
Comment: Thanks for the fast reply nobody. I've tried apt-offline, I appreciate the efforts of the developer, but it's not for me. Thanks anyway
Comment: you mixed the `&&` and backslashes in a wrong way. In your first try, remove the `&&`s and it will work.
Answer: awk '{print $1}' file |
    while read -r package
    do
        sudo apt -y install "$package"
    done

A while loop to read from file and installing the package one by one without asking for confirmation ( apt with -y option).
or:
xargs sudo apt install -y < <(awk '{print $1}' file)

Comment: Thanks! I look forward to trying both of those little codes out.


Listening comprehension - "verstötten"?

Question: While listening to the documentary https://youtu.be/eQsHgNZWxZs?t=102 at around time 1:42, the voice says "... doch das alte Indien verstöttert (?) mit atemberaubender Geschwindigkeit". For the life of me I can't figure out what that word is supposed to be. Thanks for any help.
Comment: "verstädtert" (urbanizes).
Answer:
doch das alte Indien verstädtert mit atemberaubender Geschwindigkeit.

The verb »verstädtern« is derived from the noun »Verstädterung«. »Verstädterung« means »urbanization«, i.e. the trend of people to leave rural regions and to move into fast growing cities.
Comment: And notably, *verstädtern* carries a somewhat negative connotation that is not found in *urbanisieren*.

Listening comprehension - "verstötten"?


When is a complement of verb gerund?

Question: I am confused about when a complement of a verb is a gerund.
For instance
He is going to school.
here "going" is the complement of verb "is" yet not a gerund
He is playing for Australia.
Here "playing" is a complement of verb "is" and not a gerund.
I don't understand what's different in the two cases
Comment: Hi, it's me from your recent one on "is playing"... both the examples in this question are not gerunds.  Perhaps you should include an example that ***is*** a gerund - I think you are overlooking something obvious but I don't know what to say to get you there.
Comment: I'll throw out an idea; if you say *"He likes playing."* it is a gerund... if you say *"He **is** playing"* it is not a gerund.
Comment: Thanks you're right i was confusing finite verb with gerunds
Answer: In your examples these are just the present continuous.  This developed from using participles with forms of the verb "be". Nearly all cases of "be+ ...ing" will be present continuous tense. The example below is artificial and forced.
In fact the classes of "gerund" and "participle" are now so mixed in English that they might as well just be lumped together. There are really just verbs with the -ing suffix.
But let's take something that looks like a gerund:  "my taking the bus".  Now we can't say "the cat is my taking the bus" because cats are animals and the gerund is an action. But we can say:

My first mistake was my taking the bus.

A mistake can be an action. So this makes sense. The word "my" is  repeated. If I drop the subject (remember gerunds often have subjects in the genitive form). We get a sentence that can be parsed in different ways

My first mistake was taking the bus.

Contrast that with

My first child was taking the bus.

Contextually the first only makes sense as a gerund, the second only makes sense as past continuous. The first sentence uses the gerund phrase to identify the "first mistake" was.
Comment: Thanks.This cleared it up

When is a complement of verb gerund?


How to make a required `lightning-input-field` field not required?

Question: Is it possible to make a <lightning-input-field> where field-name is required (such as Contact.LastName) not required on the UI?
I would like the field to not kick in validation rules (client ones) and not to have the required styling once I submit, but it still happens when setting required to false.
Sample code:
    <lightning-record-edit-form
      object-api-name="Contact"
      form-class="slds-grid slds-wrap slds-m-left--xx-large slds-m-bottom--medium"
      onsubmit={handleSearch}
    >
      <template for:each={searchFields} for:item="field">

          <lightning-input-field field-name={field.name} value={field.value} required={isFalse}></lightning-input-field>

      </template>

        <lightning-button class="slds-p-right--large" label="Search" type="submit"></lightning-button>

    </lightning-record-edit-form>

In the JavaScript file:
  get isFalse() {
    return false;
  }

Answer: Since you are using a lightning-record-edit-form, it automatically enforces any validations that salesforce has, in this case the contact.LastName being required.
If you want to make the field 'not required' from the UI, you should not be using the edit-form, hence even the lightning-input-field, the alternative to do this would be, to use the 'lightning-input' element and mark the required=false, but we need to keep in mind that, if it is required from salesforce, it would throw an error. Since you cannot override the salesforce validations from UI. Hope it helps.


Sonic Boom Location

Question: If I'm understanding right#sonic boom it's the first stage rocket that is creating the Sonic boom we hear after a Falcon 9 has been launched from Vandenberg AFB.   I am approximately 100 miles south of the base. I usually am outside observing the launch. I've heard that the sonic boom comes about 8 minutes after the launch. Where in proximity is the first stage rocket from the launch site when it creates the sonic boom? How big of an area should be able to hear the boom? I guess I'm having a hard time understanding why we hear it here 100 miles south of the base when it's approaching the drone ship near Baja?
Comment: After 8 minutes, the booster is back on the ground at the landing zone, about 450m from the launch site.
Comment: I accidentally misread and then voted against the proposed edit but it's a good edit so I hope it's accepted. There's no such thing as " silly or a duhh" questions here :-)
Answer: A sonic boom is a shockwave. This starts at the object that causes it, and travels in a direction that depends on the speed of the object.
At Mach 1 (the speed of sound), the shockwave travels in the same direction as the object. As the speed of the object gets higher, the direction changes: you get an arrow shape, and the angle gets sharper as speed increases. The angle between the long axis of the rocket/airplane and the shockwave is always below 90º.
A shockwave is created continuously, as long as the object is traveling faster than Mach 1.

So when a rocket is launched, its shockwave will travel upwards and you will not hear it. Once the rocket starts to pitch over, the shockwave could reach the ground, but by then the rocket is often too high for the shockwave to be noticeable on the ground.
When the Falcon 9 first stage lands, the shockwave is aimed downwards, and you can hear it on the ground.
Comment: @Diane It's important to realize that a sonic boom is not a single event that happens at a particular moment in flight; it's a wave passing across the land that the vehicle drags behind it as it moves. You hear it as a bang or pop (usually a double-bang because of the way the wave is generated) because the wave just passed by where you're standing.  The metaphor might be a lighthouse sending out a constant beam of light, but it appears to flash as the beam sweeps past you.
Comment: Falcon 9 specifically has a distinctive ba-bang---bang most likely caused by the engines, the landing legs, and the grid fins.
Comment: yep. As you can see in the photo, every major change in the shape causes a shockwave.
Answer: Assuming that by 100 miles south you mean 100 miles southeast down the coast from Vandenberg, that actually puts you less than 60 miles from the ground track of a typical 53 degree inclination Starlink Vandenberg launch. Since you didn't specify an exact location I will use as an example a point along the coast about halfway between Oxnard and Malibu.

Falcon 9 would be about 85 miles downrange when it passes at its closest distance of about 58 miles. 58 miles is definitely close enough to hear a sonic boom, although it probably won't be that loud depending on atmospheric conditions and other factors. Is it something that you notice just because you are listening for it, i.e. is it loud enough that anyone else would notice it?
According to an article on the USAF website:

Ground width of the boom exposure area is approximately one mile for each 1,000 feet of altitude; that is, an aircraft flying supersonic at 30,000 feet will create a lateral boom spread of about 30 miles.

Using this calculation an aircraft (or rocket) flying at 116,000 feet would create a sonic boom that reaches 58 miles. However the distance will vary due to several factors including temperature, air density, and aircraft size and shape. It also depends on what the vehicle is doing at the time. In typical supersonic cruise, for example Concorde, the shockwave trails behind the aircraft.

Shock cone path (author Cmglee, via Wikimedia Commons, CC-BY-SA-4.0)
However if an aircraft is climbing or turning the shockwave can move ahead of the aircraft. This would be the case with Falcon 9 which is climbing quite steeply through the lower parts of the atmosphere.
You are probably aware of the fact that the speed of sound is slower at higher altitudes. Interestingly the USAF article points out that in order for a shockwave to reach the ground the aircraft must be travelling faster than the current speed of sound on the ground.

Depending on the aircraft's altitude, sonic booms reach the ground two to 60 seconds after flyover. However, not all booms are heard at ground level. The speed of sound at any altitude is a function of air temperature. A decrease or increase in temperature results in a corresponding decrease or increase in sound speed.

Under standard atmospheric conditions, air temperature decreases with increased altitude. For example, when sea-level temperature is 58 degrees Fahrenheit, the temperature at 30,000 feet drops to minus 49 degrees Fahrenheit. This temperature gradient helps bend the sound waves upward. Therefore, for a boom to reach the ground, the aircraft speed relative to the ground must be greater than the speed of sound at the ground. For example, the speed of sound at 30,000 feet is about 670 miles per hour, but an aircraft must travel at least 750 miles per hour (Mach 1.12, where Mach 1 equals the speed of sound) for a boom to be heard on the ground.

With all of these complexities, and the fact that SpaceX launch broadcasts don't show the downrange distance, it's difficult to say exactly where Falcon 9 is on its ground track when it generates the sonic boom that you hear eight minutes after launch. And the exact location likely varies from launch to launch even when following the same ground track. Also polar orbit launches head nearly due south and so it's less likely that you would hear sonic booms from those launches.
Answer: Not an answer, but a comment with a diagram:
As an addendum to Steve's excellent answer, the idealized sketch below illustrates the geometric relationship of sonic shock wave to ground "sonic boom" from an aircraft flying a straight, horizontal flight path at Mach3 over a flat Earth with uniform air temperature.
The ground sonic boom forms a hyperbola travelling at the aircraft's velocity.
If the craft is climbing (as in a rocket launch) the ground intersection line will still be a conic section.
The speed of sound in a gas is the average velocity of the gas molecules which varies with the square root of the absolute temperature. Atmospheric temperature falls for the first 10 km of altitude, and begins to increase again above 20 km. Concorde's boom was easily heard at ground level. It cruised at 18km altitude.
Comment: Thanks Woody, although I think I mainly gave a thorough non-answer, explaining why it's difficult to know where the rocket is when it creates the sonic boom that they hear. I have often thought about the sonic boom that is heard after RTLS booster landings, wondering where the booster was during its freefall when it created the sonic boom. Of course that depends on the distance of the hearer. But unlike an airplane passing overhead at high altitude with displaced sound, where you can tell where the plane was when it made the sound you are hearing, I'm not sure you can do that with sonic booms.
Comment: @StevePemberton ... you got me scratching my head and doodling. A craft at constant speed (flying through air at constant temperature) has a conic shock wave. A decelerating craft has a bullet-shaped shock wave. This is the type of thing that keeps me awake at night. Why don't you post a question?

Sonic Boom Location


Alexa won't turn on/off my lamp anymore

Question: I used to be able to say "Alexa, turn on my lamp" to get Alexa to turn on my room's smart lamp. However, sometime last week, this command stopped working. Now, when I try it, Alexa says "My Tile doesn't support that". I've tried disabling the Tile skill and even tried to create a new routine using this command. However, Alexa still won't turn on my lamp through this command. Has anyone else experienced this issue? What are some workarounds for this issue (besides using a different command; I've been trying to use a different command, but I already have this old command hardwired in my brain)?
Comment: So what does Alexa respond with now? What kind of lamp is it? Can you still control the lamp through its app? Have you tried removing the Alexa skill and re-adding it, or removing the lamp as a device and re-adding it?
Comment: `I've been trying to use a different command` ... did that work?
Comment: @romkey As I said in my post, Alexa now responds by saying "My Tile doesn't support that", even after I disabled the Tile skill. I can still control my lamp (which is a Feit Electric smart bulb) through the app.
Comment: @jsotola At first, this workaround didn't work. But yesterday, it started to work.
Answer: When this issue first came up, I created an Alexa routine as a workaround. This routine would use the trigger "Alexa, turn on my lamp", like before. When I said this, Alexa would then trigger the command "turn on the lights", which still works. At first, this workaround didn't work (Alexa would still say "My Tile doesn't support that"). However, starting yesterday, this workaround began to work. I guess it just needed some time to start working.

Alexa won't turn on/off my lamp anymore


Android how to view long string in logcat

Question: I have a HashMap<String, LinkedHashMap<String,String> that is fairly long (not an issue) and I'm trying to make sure things look correct before I use the data inside it. To do this I'm trying to just attempting to do this Log.v("productsFromDB",products.toString()) but in the LogCat It shows about 1/3 of it. Is there a way to output the entire map?
Answer: Logcat can only show about 4000 characters. So you need to call a recursive function to see the entire hashmap. Try this function:
public static void longLog(String str) {
    if (str.length() > 4000) {
        Log.d("", str.substring(0, 4000));
        longLog(str.substring(4000));
    } else
        Log.d("", str);
}

Comment: how to remove  " [ 12-09 12:34:09.886 27901:27901 V/ " all time?i want to see chunk of json but there are v and date .i want to get full chunk with out  v and date.any way?
Comment: @Suman I dont think it can be done though I would like to be proved wrong
Comment: ,thanks for your reply.I want see whole log without time or type or any thing else.mean when i copy from log then some some time and type are added into string,


What are typical naca foils for winglets for ultralights/LSA?

Question: What are typical naca foils for winglets for ultralights?
Comment: There are ultralights with winglets?  They are only really effective on airplanes that cruise at low indicated airspeed where the vortices are strong enough to give an energy recovery benefit that exceeds the weight/drag penalty of the winglet itself.  Which is, mostly, airplanes that cruise above 30000ft   And maybe, gliders.
Comment: Winglets are used on hangliders, trikes, the original ultralight - the lazier, velocity pusher aircraft, and most of all: birds, which is where the idea came from in the first place.  I'm thinking a NACA 009, although I've seen lot's of winglets that don't seem to be foils, just plates.
Comment: The Lazair has a kind of turned up wing tip, no so much a winglet.  The velocity and it's kin are using them as yaw stability surfaces (tip rudders) more than winglets.  Some hang gliders and sailplanes use them, because they fly in a speed range that is able to exploit the energy in the vortice.  Remember that a winglet is a sail. It makes lateral lift, producing an outwash that weakens the circulation around the tip and also generates a forward thrust component. Winglets on a jet point outboard slightly to optimize AOA. Since they are sideways lift makers, you need to use a cambered airfoil.
Comment: They are only worth using when induced drag is the dominant factor.  As soon as you speed up, other types of drag predominate and the induced drag benefit is cancelled out by the form drag of the winglet. Unless you are optimizing your ultralight/LSA for best L/D close to the stall, which is desirable for soaring aircraft, they are a waste of time because you pay for it at the high speed range.
Comment: Winglets are very common on ultralights and trikes, and have been so for more than a decade. http://www.airtrikes.net/wings.shtml  They have been found to improve longitudinal stability in straight and level flight, much as the effect of dihedral http://www.aeros.com.ua/news.php?lang=english&id=144. For winglet airfoils used it's a challenge to find out. You might have to email individual manufacturers.
Answer: The information I have, is that you would want to have the thinnest symmetrical airfoil, that will work in the specified Re range, eg. NACA009


Do iPhones use active scanning to find Wi-Fi networks when Ask to Join Networks is off?

Question: I'm looking into security holes in my daily life, and I ran across an article that says that most devices broadcast their MAC address continuously. I'm wondering if that applies to iPhones (and other iDevices) as well. I would expect them to use active scanning when Ask to Join Networks is on, or if you are actually in the Wi-Fi Settings (though I don't know that that is the case), but what about normally? Is my iPhone broadcasting its identity everywhere it goes as long as the Wi-Fi is on?
Comment: How would one's MAC address be used as a security hole?
Comment: Because it's unique to your device, so that you can be tracked from place to place. As the article I linked says, "basic analysis of this kind of data from a shopping centre can tell me what shops you visit or what areas you like to spend time in. I can tell how long you spend in my building – and where you enter and leave. I can tell how fast you walked from one end to the other. I can tell if you visited the bathroom. I can likely tell if you drove to my building – or took the bus. For me (or any scary three letter organisations), this information is pure gold."
Answer: Since iOS8 the MAC is randomised while scanning for wi-fi networks. I believe that has since been adopted by most devices.
The REAL MAC is only used after connection to a network.
Comment: See the WiFi section of Apple's [iOS Security Guide](https://www.apple.com/business/docs/iOS_Security_Guide.pdf) (PDF). It says iOS 11 "uses randomized Media Access Control (MAC) address when conducting Wi-Fi scans ..."
Comment: Interesting. Do you have a reference for this?


Did people run to Noah's ark when they saw the flood began?

Question: I'm curious if there is any indication in tanakh, whether or not people had tried to get on the ark once they saw the flood?
Comment: In Tanach only?
Answer: Oznayim la-Torah (Rav Sorotzkin) to Gen 7:16 explains that the reason God sealed up the ark – rather than Noah shutting the door himself – was to make sure that any repentant people turning up even at the last minute would be able to make it aboard, but as it happened none arrived.
Answer: Bereshit 7:16:

וַיִּסְגֹּ֥ר ה' בַּֽעֲדֽוֹ׃
Hashem sealed [the Ark] for Him.

This detail needs explanation. Rashi, who makes it his mission to explain the "pshat", the simple meaning of the Torah, says:

ויסגור ה' בעדו. הֵגֵן עָלָיו שֶׁלֹּא יִשְׁבְּרוּהָ, הִקִּיף הַתֵּבָה
דֻּבִּים וַאֲרָיוֹת וְהָיוּ הוֹרְגִים בָּהֶם
AND THE LORD SHUT HIM IN — He protected him so that they could not
smash up the Ark: He surrounded the Ark (thus enclosing it
סגר) with bears and lions which killed some of them (Genesis Rabbah
32:8).

Rashi takes issue with this unnecessary detail. Once Noach entered the Ark, and closed the door, that's all that should be needed to protect against the waters . Rather Hashem sealed the door to fulfil His covenant with Noach (6:18, see Rashi and Bereshit Rabba there) to protected him from the people of the generation who would try to kill him (Siftei Chachamim).
Whatever standard one holds for Torah exegesis, it seems that there is a very strong hint that the people of the generation did show up to the Ark at the last minute, and Hashem had to intervene and close the door Himself. Our rabbinic tradition is that they tried to destroy it, rather than enter it. Follow the sources, marvel at the logic, and see if you feel it is the best explanation.
As Rashi points out, the most simple meaning of all is that Hashem sealed it from the waters, not peoples. It is still an unnecessary detail that needs explanation, and there are other explanations. E.g. Radak that Hashem sealed the Ark to prevent leaks against this huge 40 day rain that was going to take place.
Answer: In addition to the above answer, our sages, brought in Rashi (7-12) say that when G'd started the flood, He at first made it fall gently, in order that if the people would repent, it might prove a rain of blessing; but when they did not repent it became a destructive flood. This shows that they could have entered the Ark, even after the doors were sealed, if only they would have repented.
Comment: "If the people would repent" - would an flood then be necessary?
Comment: That's exactly what the Sages/Rashi say, as quoted above: if they had repented, the waters would have come down as גשמי ברכה, rain of blessing and not as a flood. What % of people would have to repent for that to happen? I can't tell

Did people run to Noah’s ark when they saw the flood began?


Legendary average IVs

Question: In Pokemon X and Y, I checked my Yveltal and it has 3 perfect IVs. A friend of mine told me that having 3 IVs on average in Pokemon X/Y for Yvetal and Xerneas is normal. Can anyone confirm this?
Answer: I'm trying to narrow down the exact generation where this became a mechanic, but at least as of Generation VI, all Pokemon encountered in the wild that are unable to breed (Legendaries, baby Pokemon, etc.) are guaranteed 3 "perfect" (31) IVs.
Comment: None of my legendaries from Gen V (both B/B2) have three 31s, so that seems to narrow it down quite well.

Legendary average IVs


What if my overall ANOVA is significant but my poct hoc independent t-tests aren't?

Question: I have conducted a 2x3 mixed factorial ANOVA, my interaction effect has come out as significant but when I go on to do an independent t-test to determine where the differences are my t-tests all come out as non-significant. My question is how would I interpret this? what does it mean?
Comment: Welcome to CV. It would help to know which post-hoc test you are using. Regardless, it is likely more stringent than an omnibus F-test for at least 1 parameter being significantly different from zero.
Comment: Add the means in your conditions to your question.
Answer: Without further details it is difficult to know your exact issue but you're operating under a mistaken belief that there must be a significant simple effect when you have a significant interaction. As an aside there is no guarantee of any significant simple effect in an ANOVA with more than 2 levels (in which case it's just an alternative to a t-test).
Interactions are about differences among differences. None of the individual differences needs to be significant, or even close to significant, for the differences between the differences to be. Consider that one effect is +5 and the other is -5. The difference between those effects is 10 which is much larger than either simple effect. Therefore, it would be very easy to not have a significant effect of 5 but one of 10.
Further, with something as simple as a 2x3 design you probably should not be conducting any post hoc tests because the important effects are probably obvious. Take your 2 level variable and get the effect for every level of the 3-level variable. Look at the 3 effects. Whatever stands out as differences among those three effects is the important component of your interaction. Don't do a post hoc test unless you want to address something more complex than that.
(You also might want to look at Gelman & Stern (2006) for further exploration into what you are likely doing wrong)


Tomato soup without a blender?

Question: Can you use canned tomato puree to make a simple tomato soup? I want to make my own tomato soup but all the recipes I find call for a blender to puree the soup, and I don't have one! So I was wondering if canned tomato puree and chicken broth will do the trick.
Comment: If you are going to buy cans then why not just buy canned soup?
Answer: Use pureed ingredients, or puree afterward...it makes little difference.  With no blender, in a pinch you can push your product through a sieve.
Comment: Personally I prefer the texture of soup pushed through a sieve and I do this with tomato soup and with pumpkin soup (my favourite).
Answer: A tomato soup made of fresh tomatoes is really the best. What causes trouble here is the skin and the middle part of the tomatoes, the rest of them becomes puree in the course of cooking. Boil water and immerse the whole tomatos for 1 min. Then you can remove their thin skin an effortless way. Cut out their green stalks and throw them including their juice into the soup pot. You can add some cans of chopped ones if you need large quantity, but having at least half from fresh tomatos makes a difference. Otherwise I used to start with frying some finely chopped onions and celery, adding a bit of chili and tandoori masala for last 2 mins of frying, then the tomatos and water as needed. Later add finely chopped garlic and some pepper, and maybe basil. Also sweet potatoes, aubergine and parsley can make the tomato soup better, but then you really need a blender or go for a chunky soup.
Comment: This does not answer the question

Tomato soup without a blender?


Does ISS follow Earth's rotation?

Question: Is ISS orbiting with or against the rotation of Earth? Is it important in any aspect for the space station?
Comment: Because I like to state the obvious: Yes it follow the rotation of the earth around the sun
Comment: Yes on all three accounts. Staying in LEO follows Earth around the Sun. Prograde orbit, moving over the surface in the direction surface travels due to Earth spin. And spinning in the same direction as Earth, at one revolution per orbit, so its orientation to surface below remains fixed (e.g. the Cupola module facing Earth at all times).
Answer: The ISS orbit is prograde - in the direction of the Earth rotation. Prograde orbits are orbits with inclination less than 90 degrees. ISS inclination is 51.6 degrees.
These orbits are slightly easier to reach, because they don't require as much fuel, as you get additional "kick" from the Earth during launch. Retrograde (opposite direction) orbits are rare, because they require more fuel to reach. It would be inefficient to build the ISS in retrograde orbit, because all the craft would have to spend additional fuel to get there. The ISS orbit was chosen to make it accessible from the key launch sites in United States (Florida) and Kazakhstan (Baikonur).
Comment: There's only one space launch site in the world that I know of that regularly launches satellites into retrograde orbits and that's the Israeli launch site of Palmachim. They launch retrograde mostly due to the hostile relations between Israel and it's neighboring countries to the east, and a rocket carrying a satellite can very very difficult to distinguish from a rocket carrying a warhead, especially if you're trying to figure it out after it's launched and is heading (potentially) towards you.
Comment: Agreed, but when you are the neighboring country an actual missile would have a rather short flight time. The reply would have to be fired very quickly - you won't have enough time to watch the burn profile and determine it is actually hostile before it hits you. Launching out to sea sounds sensible.
Comment: Actually, it is very easy to differentiate between them.  They fly VERY different trajectories, with VERY different motor burn profiles.  Orbit identification from a small number of observations used to be a routine undergraduate astrodynamics computer programming homework problem.  (See [Bate, Mueller, White] "Fundamentals of Astrodynamics", Dover Books, for more details.)
Comment: @Nickolai Actually, Vandenberg AFB often launches spacecraft into sun-synchronous orbits, which, at a typical inclination of about 98 degrees, are ever so slightly retrograde.
Comment: @JohnR.Strohm Israel uses the Shavit launch vehicle, which is based on the Jericho missile that they still use as an ICBM, so perhaps those two launch profiles aren't that distinct?
Comment: Low Earth Orbit (LEO) is typically 100 nmi above nominal Mean Sea Level.  A launch vehicle attempting to reach LEO must reach that altitude with zero vertical velocity component at that time, and orbital velocity horizontal component.  ICBM apogees are typically several times that altitude, with almost zero horizontal velocity component at apogee, meaning the payload/warhead starts falling back to Earth (hence the term "ballistic").  You look at the flight path, seeing whether it is pitching over and accelerating to orbital velocity in horizontal.
Comment: @Nickolai Wikipedia says it's so that falling debris doesn't land on countries that could gain from the technology, but doesn't cite any sources for that claim
Answer: It orbits same direction as Earth. You can expect all space stations always to be build to orbit in direction of earth. Saves fuel to reach them since you get extra boost while leaving Earth and less full again when slowing down when reaching the station. If it would rotate against earth the speed would be twice as night relative to you and you would need to spend more power to slow down. Or if you would chase it lose the extra boost leaving earth and waist there no fuel.
Comment: This is not correct. Launching prograde (in direction of Earth's rotation) saves ~ [465 m/s](http://goo.gl/kkWOfC) to orbital velocity, if launched with 0° inclination from equator. That changes a bit if you launch to [ISS inclination of 51.65°](http://space.stackexchange.com/q/5297/49). From Baikonur, where most launches to the ISS happen nowadays, you'd save about [321.5 m/s](http://goo.gl/G5v5SU). Orbital speed of the station is roughly [7,660 m/s](http://goo.gl/DIty60). So Earth's rotation would only have helped ~ 4.2%, if we didn't count atmospheric drag, and ~ 3.3-3.5% since we have to.

Does ISS follow Earth's rotation?


How much pesticide remains on a harvested organic fruit?

Question: Organic fruits can still be treated with pesticides. I would like to limit my intake (or eliminate entirely) of these pesticides. Has there been any investigation into how much pesticides remain on a harvested organic fruit so that I can make a determination on whether or not to eat the rinds?
Comment: Both the benefits (vitamins, etc in peel) and the risks (propensity of peel to absorb pesticides - assuming there is some danger there) would depend on the type of fruit.  Given the number of available fruits, this seems too broad to me.
Comment: @JohnP I would just hope that we can decide from the information, because 'tell me if I should' was deemed too broad and effected this closure? Please feel free to edit my OP directly.
Comment: I would rather see the question deal with whether fruit rinds are a health hazard, regardless of the question of organic or not. (Since the issue of pesticide or other residue on the rind affects both conventional and organic produce.)
Comment: This question needs to specify what type of fruits, pesticides, benefits, and risks we're talking about. Also, plants can naturally produce pesticides, which might not always be dangerous to us.
Answer: Washing and peeling conventional fruits and vegetables only helps to reduce the levels of pesticides that may be on the surface as reflected by USDA test data1999. As we know the pesticides needs to be toxic to kill pests, therefore potential long-term health effects of exposure to pesticides can include: cancer, neurotoxic effects and many morewiki.
Under the FQPA, EPA has the authority to ensure that all pesticides meet the safety standards. They estimates the exposure to a pesticide from different sources such as food, determine the health risks and set the limits of tolerance which is maximum amount of pesticides that is permitted in/on the food. This is systemically tested as part of the Carcinogenic Potency Project.
The recent meta-analysis of 343 studies from 2014 shown that organic food has 4 times less pesticide residues, toxic/heavy metals (e.g. Cd and Pb) and other chemicals than in conventional crops which can bioaccumulate in the body over time 2014.
According to EWG, buying certain organic food can significantly lower residue exposurewiki, because organic crop production standards prohibit the use of synthetic chemical products and certain mineral fertilisers.

How much pesticide residue remains on organic food?

The toxicology of natural and synthetic chemicals is similar, so it's probable that almost every fruit and vegetable contains natural pesticides1992.
One scientific literature notes:

What does not follow from this, however, is that chronic exposure to the trace amounts of pesticides found in food results in demonstrable toxicity. This possibility is practically impossible to study and quantifywiki.

Therefore it's not possible to determine health benefits of eating organic food by measuring how much pesticides remain on food as it really depends on agronomic practices/protocols and soil pollution which can affect crop composition.
Therefore eating organic fruits in general is safe and you shouldn't worry about pesticides too much.
See also: Are organic foods more healthy than conventional foods?
Answer: Organic farming practices generally aim to reduce the use of synthetic pesticides, relying instead on natural pest control methods and approved organic pesticides when necessary. The specific amount of pesticide residue on a harvested organic fruit can vary depending on several factors, including the type of pesticide used, its application method, timing, and adherence to organic regulations.Use plant care app for organic farming because it has various remindes like watering, fertilizing, lux meter etc.


How can I prove property rights to script?

Question: I just programmed a file sharing script but I can't sell it because I don't know how to prove that I'm the programmer.
Answer: Simple. Mail it to yourself. The postmark is your proof. Do not open the package when it arrives. Just put it away. Do this for every major release and you should be okay.
But if you really want to be official, copyright your work and patent any invention including unique processes, calculations, methods, etc.
An easier alternative? Most attorney's will place things on file on your behalf. It is generally accepted that anything on file with an attorney has passed scrutiny. Discuss what you want to do with an attorney so that they understand. I have mailed notices with cc: Attny. Joseph Darby, Bleeker St. Mont Abby (my apologies if this ends up being a real person) and had the attorney file a copy of the letter which most will do for a very small fee or no fee at all. It has come in handy and no court within the U.S. will argue the word of an attorney. Significant weight is given to items filed within an attorney's office as being proper and right.
Even cheaper alternative? Have witnesses. Present your product to some friends and family members and be somewhat official by having them sign a document at the end. As well, be very vocal about what you are developing and what it does so that they can testify to these conversations and how hard and long you worked on your project. Also document the internals in extreme detail. If you can produce a detailed design document and the opposition cannot, then you win.
Best option? All of the above. Or at least several.
Answer: I think you can put your source code on bitbucket so that the date of publishing is recorded. Also, you can let your clients access part of your source code for checking of any plagiarism.


Image preview with Reportlab?

Question: I'm generating some pdf's with Reportlab and Django using a web interface. The pdf's are always going to be a single page. I'd like to generate a png or jpg image of the generated page and return that to the browser for the user to preview before saving the final pdf and delivering it to the end user. Is there anyway to do this?
Answer: This answer explains that you can use ghostscript to convert pdf to png. Depending of the requirements of your app (traffic, response time, nb of pdfs ...) it may or may not be a solution for you.
This is just an idea, but may be you can generate the preview image in parallel using PIL ImageDraw and get rid of the pdf-to-png conversion.
I hope it helps
Comment: Sadly PIL's support of TTF fonts in combination with image creation is very buggy. This comes from spending over 20 hours trying to work around memory leaks and inconsistent handling of identical text and fonts literally from one image generation to the next. Thanks for the ghostscript reference. I'll check it out.

Image preview with Reportlab?


Do countries and institutions have a political interest in allowing researchers to plagiarize scientific research?

Question: Do countries and institutions have a political interest in allowing researchers to plagiarize scientific research? I am wondering if there might be any political interest in allowing plagiarism in research, because as far as I know there's none, but I am thinking I might have overlooked something as some countries have high rates of plagiarism and I would like to know if every country and institutions have an interest in preventing plagiarism or not.
Comment: By "plagiarism" do you mean "industrial or scientific espionage"? I can't really think why passing someone else's work off as your own would be of benefit to a country, but there have been a bunch of stories of countries' nationals (China being the worst offender, at least from the volume of stories I've heard) sending confidential scientific or industrial research back to their home countries. Was that the kind of thing you were thinking of
Comment: I think you may be confusing plagiarism with industrial & military espionage.  Plagiarism only applies to scientific papers &c, and once you publish your research, it's out there for the whole world to use and build upon.  Indeed, that's the point of publication.  About the only thing you can't do with published work is to claim it as your own.
Comment: I think the answer turns on whether you mean internal or external (global) political incentives.  Convincing your own people that they (collectively) are awesome and that their people solved X etc., thereby boosting their morale and their feeling that the country/government is good and right as-is, is much easier than convincing the world, especially global academia itself.
Answer: At least in most mainstream STEM (science, technology, engineering and mathematics) neither countries nor institutions are the primary protection against plagiarism. New knowledge is disseminated via peer-reviewed journals and conferences which are typically run by for-profit commercial academic publishers and plagiarism is detected either via automated checks on submitted text, or via expert reviewers identifying matches with the existing literature.
Since funding and promotions are heavily correlated with the weight of researchers publication history, there are perverse incentives to publish false, plagiarized or self-plagiarized research, and an industry of "predatory journals" (and resort-like conferences) have sprung up to support this. Many of these are based in rapidly developing countries, but this is also an audience with a growing need to publish and (historically) less stringent checks on the quality of publications at the funding/promotion stage. That does seem to be something which is changing, (or at least, changing countries) as the rapid expansion in the higher education area in various high population countries slows down.
Answer: Plagiarism (narrow definition): Pretending that the work of another author is yours.
Plagiarism (expansive definition): Failure to follow current academic practice on citations. This includes citing your own work as required.
By either definition, the policy of allowing plagiarism would turn the academic institution into something of a diploma mill. This provides graduates the "unfair advantage" of having a degree they did not really earn, but only until the rest of the world catches up and starts to discount all the degrees awarded by that institution. I can see no advantage for an entire country to do that, since a country cannot pocket the tuition fees, shut down, and disappear once word gets around.
This is different from having a national policy to shift from vocational to academic tertiary education, with possibly lower academic expectations from those newly invented tracks. In some countries, kindergarten teachers don't need an academic degree. In others they do, and it is probably fair to say that this degree tends to be "easier" than qualification to teach at the college level. But that does not mean those students cheat! They must honestly meet the requirements of their track.


Neural networks: how can convex optimization produce different weights each time?

Question: I am training a multilayer perceptron with a logistic activation function by backpropagation. The weights are not unique - each time I redo the fit, I get a different set of weights. However the optimization function (sum squared error in my case) is convex, which means there is one global minima.  So I suppose this minima has several equivalent sets of weights that map to it.  So how exactly do I describe this minima and what are its properties?  How do I What is the name of this phenomenon and where can I learn more about it?
Comment: So you are saying if the activation function and loss function are both convex then you have unique weights?  Do you know if this is a necessary and/or sufficient condition?
Answer: The loss function is not convex with respect to all of the weights.
It seems that you are getting confused because the loss function is quadratic, so you are suggesting that makes it convex.  But it is not convex with respect to all of the weights in your model.
The loss is $L = (f(w) - y)^2$ where $y$ are your targets, $f$ is your model, and $w$ are its weights.   Without the nonlinear activation functions, $f$ is a linear function, and the loss is convex.  With multiple layers having nonlinear activation functions, the loss is no longer necessarily convex.  The Hessian of $L$ will involve the Hessian of $f$, which need not be positive semidefinite.
You could reduce the loss by both increasing (or decreasing) a weight $w$, which causes a feature to light up more (or less) strongly — if you simultaneously were to change that feature's effect on the outputs (to be more or less like the targets).  This situation of being able to reduce the loss by moving in two opposite directions is like standing on the cusp between two valleys.  Move one way and you fall, move the other and you still fall.  This is not convex.
Another way to see that it's not convex is to notice that for any global minimum, there is another global minimum whose weights are a permutation of the first whereby the hidden nodes have merely been interchanged.
Comment: This is a bit short. There are more aspects to the question. Maybe you can expand your answer and address those too.
Comment: @Andy: Of course it answers the question.  He argued that the loss function is convex so there should be a unique solution.  The mistake is the assumption.  The loss function is not convex with respect to all parameters.
Comment: The previous comment was generated by the system, I changed it. Due to its brevity your post was automatically flagged as low quality.
Comment: @Andy: I have no idea what to add.  I answered the question as directly as possible.  If it still doesn't make sense to osazuwa, I am happy to clarify things.
Comment: Hi @Andy.  Thank you.  Your answer makes intuitive sense.  Tell me if this makes sense.  Suppose Z = wY and Y = aU + bV.  Then Z = waU + wbV. If your optimization function was (Z - waU - wbV)^2 then you could get unique solutions for w * a and w * b, but not for w, a, b separately.  Is that right?  So if I am right and the vector of products  is unique, is there something I can say this vector?
Comment: Cagdas Ozgenc above says the activation function needs to be convex.  Is that related to what @Andy says?
Comment: @osazuwa: That's not your model.  Your model has nonlinear activation functions.  Without those activation functions, the loss function is convex with respect to the parameters.  With the activation functions, it is *not* convex.  I have expanded my answer.


Phone number detected by a web page when browsing from chrome for android

Question: I recently got subscribed to some alerts by the mobile provider automatically and some amount deducted from my phone balance. I called up the customer care centre and they agreed to refund the amount, and said that it was activated from the internet, by some site which captured my number while browsing. Considering the customer care guy was right, isn't this a big security issue, if any website can access the phone number of their visitor?
Comment: On the end of your provider definitively – if "any website can subscribe by specifying some phone number". From the Android end: did the browser ask your confirmation to provide certain data to the visited site? I often receive such popups for e.g. location or account requests.
Comment: As @Izzy says, did it ask for some confirmation? If yes, you most likely became a victim of [WAP billing](https://en.wikipedia.org/wiki/WAP_billing#Critic_of_WAP_billing) ([more  info](http://security.stackexchange.com/questions/99818/dangers-of-wap-billing)).
Comment: @Firelord nope, no confirmation. I use adblocker on untrusted sites and never click on a suspicious popup or such stuff
Answer: It sounds like your customer care centre is telling you a story to get you off the phone. Some mobile phone providers have been caught out in the past passing your phone number in the HTTP request headers when you use their 3G connection from the phone. As you say, it's a huge security problem if they do that, and there's not a lot you can do about it (except change provider and tell them that's why).
You can check if this is happening to you by visiting a website that shows you your HTTP request headers. A quick Google search will find you at least a dozen to choose from. Make sure you use your 3G connection while doing this, because you're trying to see if your 3G provider is adding this data to your request.
It may be that the customer care person was claiming that the website is one you've deliberately told your phone number to, e.g. when shopping online. If they didn't tell you who originated the charge/junk SMS you have no way to verify this claim. Otherwise, most likely they are simply saying the most convenient thing. The entire mechanism of services which bill through your phone provider (via premium SMS, or the like) is horrendously insecure, but the carriers aren't interested in improving it. Any premium SMS company can just say any phone number they like to charge that number, and fraud is mainly detected by auditing afterwards (and when the carrier finds out via complaints like yours).


Construct XML from XSD

Question: I want to generate XML data from a XSD. Particularly, from a given schema a GUI shall be constructed "on the fly", allowing to enter/edit an instance for that schema. Unfortunately, pure XSD is not really suited, to describe, how such GUI must look like.
Q: Is there any generic approch, to construct a GUI from XSD ? Not a final solution, but a way, allowing this by using other tools.
Many Thanks ;-)
Answer: One option would be EMF with its XSD support and Graphiti or GMF for the GUI.

Construct XML from XSD


Is a ball which passes behind the batsman and over the stumps a wide?

Question: If the ball goes behind the batsman, and then goes over the wickets without touching the wickets, then is it a wide ball?
Answer: No, this would not a wide ball. A wide is defined by Law 25:

If the bowler bowls a ball [...] the umpire shall adjudge it a Wide if [...] in his opinion the ball passes wide of the striker where he is and which also would have passed wide of him standing in a normal guard position.

(my emphasis). A striker standing in a normal guard position would be able to play a ball which passes over the stumps, so this is not a wide.
Comment: Additionally any ball in one day cricket that passes over the stumps will not be called wide


Publish a limited GitHub API personal token

Question: According to this link there is a scope for the OAuth tokens that seems to provide access to the GitHub public resources only.

(no scope): Grants read-only access to public information (includes public user profile info, public repository info, and gists)

Is it still insecure to include this personal access token in my JavaScript client side code?
Answer: VonC's answer is correct but the main risk of making the token public is missing:
A malicious person can intentionally overuse your token, which can drain you API quota or may even result in your token or GitHub account blocked.
Find below the response I got from GitHub support:

Publishing such a scopeless token is not insecure in the sense that
  the token can only be used to fetch information that is already
  publicly available -- it can't be used to fetch any private data and
  can't be used to modify any data.
However, you might consider it insecure in the sense that all your
  tokens share the same GitHub API quota
  (https://developer.github.com/v3/#rate-limiting). So, if someone
  takes your token and makes lots of API requests with it -- they will
  drain your quota and all your other tokens and applications you
  authorized will need to wait until the quota refreshes.
Also, if such a person makes lots of API requests in a short period of
  time with your token -- they might trigger our abuse rate limits
  (https://developer.github.com/guides/best-practices-for-integrators/#dealing-with-abuse-rate-limits)
  and if they don't slow down -- it's possible we might need to block
  that token or the whole account to prevent further problems on our end
  (and for other users).
Comment: Interesting feedback, more accurate than my answer. +1
Answer: It is not insecure, you just need to acknowledge the management aspect.
If your account is deleted for any reason, or if you revoke the token, it will become invalid, meaning any user of your Javascript client code will experience a disruption, until you publish an update.
That being said, you can see this approach (include a 'no-scope' PAT) used in this repo for instance.


How do I send a calendar event from the iphone calendar via an email or imessage?

Question: I want to forward a specific calendar event from the iOS Calendar App to an email address or iMessage address or text message using my iPhone. I don't want to use the cloud or sync anything. I am using iOS 8.4 but would also be interested in how to do this in iOS 9.
Answer: The simplest method would be to use a contact in your address-book and add them as an invitee to the calendar event.
You will be prompted to send an invite to them.
EDIT: Previous link sucked.
Here are the steps circa iOS 9:

Launch the Calendar app on your iPhone or iPad
Either create a new event or tap an existing event that you'd like to share
Tap on the Edit button in the upper right hand corner
Tap Invitees. Add all the email addresses of the people you'd like to share the event with

EDIT 2: Added iOS 11 details.
Here are the steps circa iOS 11:

Launch the Calendar app on your iPhone or iPad
Either create a new event or tap and existing event that you'd like to share
Tap "Invitees"
Tap "Add invitees"
Either enter an email address, or tap the (+) at the right to select from your address book
Comment: Your link seems to be about iCloud on OSX, not the iPhone.
Comment: There is no Invitees option when I edit an event
Comment: @jjz The interface has changed since this posting. I will update for clarity.
Answer: Apple failed here, there is no way to actually forward an event from iOS/iPad OS but...
Normally when people create an event, they don't then forward it but rather simply add the new person to the invite list. Therefor I presume you mean forward an event you have received.
To forward the particulars of an event you can:

Tap on the Event
Tap on the Invitees
Tap the small envelope icon in the upper right (creates an email)
Delete the invitee list in the "To" field of the email
Type the email address of the person to whom you wish to forward the info
Tap "Send" in the upper right.

It is not truly forwarding the event but it does contain the event details.
Insane that Apple neglected this very common and needed feature in an otherwise rather decent product. If you think so too, please take the time to tell Apple with "need way to forward an event from iPhone Calendar" here:
https://www.apple.com/feedback/calendar.html
Comment: The worst part is that this feature actually exists on Mac! (right-click > mail event) It creates a link object ".ics" that you can copy/paste and drag/drop anywhere you like, and forwards the notes content. Not sure why they still don't have that on iOS...


Is John Maynard Keynes an economic liberal or an economic nationalist?

Question: I am working on a research project about political economy. However, I stumbled upon differences in the interpretation of the orientation of John Maynard Keynes. Some sources indicate that Keynes is a liberal political economy theorist, since he is advocating for a free economy as a whole, but he thinks that the government has to interfere in order to compensate the fluctuations of economic growth. On the other side, other theorist consider Keynes to be an economic nationalist, because he champions further government interference.
Thus, my question is which interpretation is more correct?
Comment: What source considers Keynes "economic nationalist"? I can't believe someone could make that argument since he was strong proponent of internationalism. He was one of the few voices to argue for welfare of Germans at Versailles conference despite being British
Comment: Maybe Nicolay Bogdanov meant 'statist' , in favor of a heavy role of government.
Answer: May be you can start reading what Keynes thought of himself, regarding that question, in his 1925 essay Am I a Liberal?:

I am ready to sacrifice my local patriotisms to an important general
purpose. What is the real repulsion which keeps me away from Labour? (Keynes, cit.)

This essays was first given as an address to the Liberal Summer School which met at Cambridge in August 1925. It was then published as two articles in the Nation and Athenaeum, 8 and 15 August 1925.


Lycra Printer- Elastic Fabric Printer

Question: I am looking for a printer that prints on Lycra material (This is like swimwear material and also sportswear material).
Does someone maybe know this type of printer? Where I can find it and what is the name of this printer?
Please help :-)
Comment: Hi Ledine, welcome to GDSE and thanks for your question. If you want to know more about the site, please see the [help] or ping one of us in [chat] once your reputation is sufficient (20). Keep contributing and enjoy the site!
Answer: I think the usual way to print that kind of material is screen printing.
The inks used, should be stretchy. I don't have experience in screen printing Lycra, but I believe you can mix an additive to plastisol inks to make them more stretchable.
If you are looking for a machine you could start looking for screen printing equipment
I know there are printers that can print directly on the material using screenprint inks. As far as I know it is quite expensive and usually for prototypes and one-offs.

Lycra Printer- Elastic Fabric Printer


Formula used by Weka for Standardization of data

Question: I am trying to standardize a dataset in Weka. I was able too use to standardize function however the results which I have found using Excel and using Weka were little different.
Following are the screenshots:

Initial Data

Standardized data given by Weka

Manual Excel results

Formula Used for calculating manual results:
z = (x-mean)/SD

z = Std value
x = value to be standardized
mean = mean of dataset
SD = standard deviation

I would like to know the formula which Weka uses to calculate the standardized value.
Any help is appreciated!!
Thanks!!
Answer: To get the formula that weka usage you need to go through the source code that weka provides.
chekc the souece here @  GC: Standardize - weka.filters.unsupervised.attribute.Standardize (.java) - GrepCode Class Source
You may be able to get the formula you are looking for.
Answer: I checked using Python and NumPy to do the standardization procedure. Weka (v3.6.12) uses indeed
z = (x - mean) / std

where std is the standard deviation. Be sure that your SD corresponds indeed the standard deviations (and not the variances, for instance).


How to get a list of latest apps released on Play Store sorted by date?

Question: Is there any way to get a list of recently released apps on Google Play Store sorted according to date added?
Answer: ShivamSoni
As google play store have daily adds New  Updates of Apps of thousand/lakhs/millions  of new versions all of them are new for Play store .
But still I searched and founded links for  new releases sections for you in play store website options.  I am sharing below links of website of new releases  and option to search apps latest releases apps category wise. But i dont think its possible to sort all apps list date wise launch option in app or website.
https://play.google.com/store/apps/new?hl=en
https://play.google.com/store/apps/collection/cluster?clp=Si8KKQojcHJvbW90aW9uXzMwMDA3OTJfbmV3X3JlbGVhc2VzX2FwcHMQBxgDOgIIAQ%3D%3D:S:ANO1ljKj5O4&gsr=CjFKLwopCiNwcm9tb3Rpb25fMzAwMDc5Ml9uZXdfcmVsZWFzZXNfYXBwcxAHGAM6AggB:S:ANO1ljILDUU&hl=en
In Google Play store App version 19.3.36 there are tabs named "for you, Top Charts,  Categories....." tabs of at very last there is a tab in last  "Early Access" which  shows latest to be launched beta developing Apps and  games.

There are  many 3rd party apps that you can utilizes to sort and easy your work  about one of popular one i searched   is called AppBrain App Market, and can be downloaded for free via Google Play (see the link at the below). The best way to find new apps in Google Play.
https://play.google.com/store/apps/details?id=com.appspot.swisscodemonkeys.apps&referrer=utm_source%3Dappbrain%26utm_medium%3Dappbrain_web%26utm_campaign%3Dappbrain_web
According to appbrain website link says product details says
https://www.appbrain.com/app/appbrain-app-market/com.appspot.swisscodemonkeys.apps

Description
The best way to find new apps in Google Play (Android market).
Make the Android market usable, and find your next favorite app, live wallpaper or widget:
  - App recommendations
  - New and hot apps of the day
  - Find top Android apps with a price drop
  - Share your best apps (eg twitter/facebook)
  - Tracks market update: notifies of updates available
  - Fast uninstaller
  - Browse "my apps" on www.appbrain.com and install apps with a sync instead of barcode scanner
  - Keep your list of installed apps as a backup on AppBrain.com
AppBrain is the best way to discover top Android apps in the Android market and to manage your apps. The recommended apps helper provides recommendations based on what you already use. We also have recommended games. It does not work with the Amazon app store.
The manage apps is like a killer file explorer / task manager for your already installed apps:
  - Start app, Quick uninstaller, share to Facebook
  - Fast sync widget to access AppBrain from the desktop and backup your apps to the cloud
  - app2sd functionality to move apps to sd (app 2 sd)
  - Find market update: notifies you of any updates available
Discover cool apps and top games in the Android market:
  - sort by hot apps today, hot apps this week, highest rated apps, price drops etc
  - Filter apps by free apps, paid apps, price reduced apps, app2sd enabled apps, new apps
  - Fast search over the entire Android market
  - Unlike applanet or black market, these are only legal apps.
AppBrain is the best app market and app discovery tool for Android apps from the Android Market. It allows you to easily find the best apps in the Market, the free apps and downloads, the price drops, live wallpaper, widgets and much more.

Hope this app will help you  any further  option i will get  i will update in the answer.

Hope my answer suggestions helped you if any thing helped you out from your search or my or others help do tell me what helped you in comments for my knowledge. if any doubts or further clarification feel free to ask and if worked do not forget  to accept and vote for the answer


Does the frequency of input voltage in induction motors have to be continuously altered?

Question: I understand that for magnetic lines of the rotating magnetic field to cut the windings of the rotor (and induce current), the field has to rotate at a slightly higher rate than the rotor. But if we assume the motor starts from zero RPM, at what speed does the field rotate at this moment in time? Do we have to somehow sense the rotating speed of the rotor and adjust the frequency of the 3-phase input voltage somehow? I think this is not what happens, since such a requirement seems somewhat complicated to achieve, especially given that induction motors have been around for quite a long time. So what am I missing?
Comment: Better on the Electrical Engineering Stack?
Comment: @Solar Mike Sometime ago I saw an electric motor question on EE stack closed as off topic because it wasn't a "question regarding electric circuits"...
Comment: not sure I would agree - usually because it is about repair or somesuch...
Comment: See this for an example : https://electronics.stackexchange.com/q/271333/152903
Comment: @S.Rotos  It depends on the question. Sometimes people do things like "I have a motor in a robot. How do I know how much torque I need to move the robot?" That's kind of question is a mechanical question.
Answer: Induction motors are amazing machines - they utilize several physical principles in a very elegant matter.
Your statement "The field has to rotate at a slightly higher rate than the rotor" is correct, however, there aren't any sensors. The physics is the only thing that makes it happens.
Lets deal with the classical case of a three phase motor, without using any variable-frequency drive. The induced magnetic field angular velocity around the stator axis is the same as the power supply frequency.
Seek for 3 phase electrical machines or rotating magnetic field in google for more information:

Without naming each phenomena specifically (look for Lenz's law and Lorentz force if you are carious about it), lets try to describe what is going on under the motor's hood:
The rotation of the magnetic field exposes the rotor to a time varying magnetic flux, which in turn induces electrical current along the rotor winding. Next, since the winding now conducts electrical current and also subjected to a magnetic field - a force is exerted on the winding, creating a torque around the rotation axis and causing the rotor to accelerate.
This is where the beauty of the motor design really come into play. As the rotor accelerates, its relative angular velocity with respect to the rotating magnetic field is gradually reduced. Is it clear? just to remind you that the magnetic field rotation speed is constant and dependent only on the supplying voltage frequency.
As the relative velocity is getting smaller, the induced current also decreases and so is the accelerating torque.
For each external load (torque) acting on the rotor, a different constant angular speed would be reached. At that speed the relative velocity between the magnetic field and the rotor will result in an internal torque equals to the external one.
This is why an induction motor will never rotate at the exact magnetic field speed (and therefor called asynchronous motor). If it was able to rotate at that speed, the relative velocity would be zero so no torque would be applied on the rotor.
1  1: https://i.stack.imgur.com/bANJf.png
Comment: "As the relative velocity is getting smaller, the induced current also decreases and so is the accelerating torque." That is true if the working point of the motor has already passed the pull-out torque. Otherwise what you say doesn't quite add up.
Comment: Sorry i can't follow the comment,  I don't know what the statement "decrease in the accelerating torque" means. Let's go back to your original statement. Smaller relative velocity means smaller slip so the armature current decrease, finally the main flux, according to the Lenz's law, the rotor current increase to oppose the change. A proper grammar and of course an insight into the subject is necessary to stop wasting peoples time. https://imgur.com/a/ie1lWNV
Comment: I don't see what you try to say. This statement is always true.
A decrease in the accelerating torque still ends up in an accelerating shaft, it just accelerates slower....
Comment: First you gave a very lazy answer to @S. Rotos, who obviously asked to have a little feeling about the mechanics of the motor. Next, you became a "wise guy" by bothering my wording and finally you even try to insult. Shame on you dude, it seems you are the only one wasting peoples time here...
Comment: In my two previous comments, i mentioned and later explained why your statements is wrong. The proper grammar is essential, if you're interested in communicating with people. Your first comment does't make sense at all. Insight into subject is absolute must. Your statement is wrong and i explained why. I kept it totally professional and didn't insult you at all, but you did! And after all I'm not a dude. I'm a lady, yes you get beat up by a girl.