Magnetic Word Games On Shabbos

Question: Is a magnetic version of scrabble permitted to be played on shabbos? Generally, Scrabble is not considered writing (although there may be other problems if you usually write while playing) but Shemiras Shabbas Kehilchasa (beginning of perek 15 as well as other modern day sefarim) mentions that the deluxe versions that are framed are a problem of Koseiv, so I'm wondering if the magnetic version is a problem? The comparison would be that both of these editions makes it morre permanent. If so, please specify if mi'dioraysa, mi'drabanan, or just as a chumra.
Also if there is a problem of tofeir please adress that as well, although generally these type of games aren't permanent at all.
Comment: The magnet itself is not problematic, [see here](https://www.zomet.org.il/?CategoryID=208&ArticleID=78)
Comment: '(although there may be other problems if you usually write while playing)' - refer to the Chaye Adam 38:11 and also the Sefer Tiltulei Shabbos p.24 adds for this reason it is a Kli Shemelachto l'issur - something whose primary use (in this case writing) is forbidden on Shabbos.
Comment: @Dov does that depend on the indivual person if he usually writes while playing or not?
Comment: @Asher I am not certain but I think it would seem not. כלי שמאלכתו לאיסור implies that since the usual usage requires writing as a way of scoring and that is the norm, regardless of whether one does or doesn't normally write, it would be not allowed. However, as you pointed out there are poskim that still allow the use of the regular scrabble  (i.e. flat board as opposed to deluxe version with grooves) so that would seem to circumvent this point?
Answer: Playing scrabble on Shabbos is a point of contention, and when magnetic, it makes it additionally troublesome. The full breakdown is as follows:
It is worth noting, building on your point mentioned in parentheses, based off the Chayei Odom klal 38, se'if 11) that it would be forbidden to play Scrabble as it normally entails writing down the score, even if one is definitive that they won't do any writing. The Sefer Tiltulei Shabbos p.24 adds for this reason it is a Kli Shemelachto l'issur - something whose primary use (in this case writing) is forbidden on Shabbos.
However, if we ignore this first point, we still need to know whether or not putting tiles of letters to form words is deemed a derivative of writing? The Levush 340:4 speaks about a book that has writing along the pages so that when one opens and closes the book he both erases and reconstitutes the letters (i.e. the melachos of mechika and koseiv). This is transferable to Scrabble in that one is both bringing letters together and disassembling to create words.
However, according to the Taz this can be disregarded as the whole purpose of a book is to be opened and closed much like a door - (See Taz). Rav Tzvi Pesach Frank in his responsa Har Tzvi notes that even the Levush would agree that bringing together two complete letters is not a case of Koseiv, as his whole argument is predicated on joining and separating letter fragments. The letters on the side of a book are destroyed when opened each time and then reformed when closed. As such, separating two letters is not considered erasing, nor is returning letters adjacent to each other viewed as writing.
Perhaps this is why the OU writes - "Accordingly, those who play such games as Scrabble on Shabbos should be careful to maintain a small space between the letters...."
However, it then adds...
Games that hold the letters locked in place (such as Deluxe Scrabble and Boggle) are not permitted because of koseiv." - (This is also highlighted in Sefer Tiltulei Shabbos p.24)
It would seem that the regular flat boards of Scrabble are okay as the tiles are largely disparate and aren't fixed in place. Indeed, Rav Moshe (Igros Moshe OC 135) writes "אבל הכא שלא מחובר כלל אינו ענין כתיבה כלל" - "But here where there's no connection/attachment at all it is not considered writing at all." The Deluxe version has grooves which keeps the tiles fixed in place much like the magnetic version. As such, the magnetic version ensures that the tiles adhere to the board much more strongly and there is a sense of 'chibur' - connection which is thus regarded as a stronger form of Koseiv and not allowed on Shabbos.
Comment: thanks. can you please specify if mi'dioraysa or mi'drabanan
Answer: "Shulchan Shlomo" (Shabbos, Vol. III, Siman 340, note 35) records an oral ruling by Rabbi Shlomo Zalman Auerbach, that one may take plain letters and put them together to form words. This is not considered "writing", as they have no "basis", and they maintain their status of "individual" letters. However, taking plain letters and putting them in a "basis" would be prohibited, as this would be the equivalent of attaching letters to a sheet of parchment, which is the melacha of "writing".
Rav Shlomo Zalman added; that for this reason, it is prohibited to attach magnetic letters to a metallic tray on Shabbos. While intrinsically magnets may be used on Shabbos (for example, a magnetic chess game, see ibid. 314:1), and the temporary connection "chibur arai" need not concern us vis a vis the prohibitions of "boneh" and "soser", nevertheless, affixing magnetic letters is prohibited as a form of "writing".
He rules there, that this applies to "chelkei tzurah" (magnetic puzzles of pictures), and "kal vachomer" (all the more so) in the case of "osiyos" (letters) "chelkei osiyos" (partial letters).
["Shulchan Shlomo" does not elaborate if this action would be included in the "di'oraysa" Torah based prohibition, or prohibited by rabbinical ordinance, "mi'derabbanan". However, see the extensive discussion in Shu"t Maaseh Choshev (vol. 2:11) by Rabbi Levi Yitzchak Halpern regarding the issue of combining letters into words].
Answer: This article by Rabbi Yoav Sternberg concludes it's allowed.
The main part of the article says:

כשלוקחים אותיות בעלמא וקובעים אותן בבסיס, הרי זה כמחבר אותיות לקלף…
  ...ומהאי טעמא הוסיף מרן זללה"ה, דאסור לקבוע אותיות מגנטיות במגש מגנטי
  בשבת…
אלא שיש לומר, שכל האמור בדברי הגרש"ז הוא רק כאשר לוקח אות שאין לה רקע,
  ומחבר אותה לרקע. במקרה כזה יש לומר...[שאסור] אבל כשיש אות שלמה, שאינה
  יכולה להתקלקל, כגון שהיא כבר כתובה על גבי רקע....
  [נראה שמותר]

When you take letters by themselves and set them in a frame, it's like attaching letters to a parchment... and that is why our Rabbi ZT"L [Hagrasha"Z] you can't set magnetic letters on Shabbat.
But we should say that the Hagrasha"Z said when the letter has no background and the latter is attached to a background, that is when we say [it's forbidden].... but when the letter is whole, so the letter cannot be broken, like when there is background [it's allowed].
Comment: The source quoted in the link, misquotes the שולחן שלמה, and selectively left out the line, where RSZA clearly stated, that both complete letters or partial letters, are both prohibited אותיות או חלקי אותיות אסור.
Comment: @IsraelReader It's clearly says so, but the RSZA does not talk about letters with background, right?

Magnetic Word Games On Shabbos


How can I can clone or ghost my system drive to restore it to a bigger HD?

Question: How can I can clone or ghost my Ubuntu System drive to restore it to a bigger HD?
Something like Norton Ghost does with NTFS or FAT on Windows.
Answer: Clonezilla is the closest free option to Ghost.
The underlying tools it uses, partimage and ntfsclone, understand the underlying filesystem.  So unlike a simple low-level copy (dd) which copies all bytes, they only copy the used space on the filesystem and its metadata.  This results in a much smaller disk image.
Comment: Do you mean like. If i have 40GB disk, and my system is using 10GB and 30GB is free. while using dd it will write 40GB to given usb/dvd/cd? Or it will only write 10GB?
Answer: If you want to move your data to a new harddrive, the Simple Backup Suite can make it very easy for you. Just backup your data, then install Ubuntu onto the new hard-drive and restore from your backup.
If what you really want is a perfect transfer of data from your old harddrive to your new one, you can use the "dd" command-line tool to easily transfer the data. There's a great discussion of this technique on Server Fault.
Comment: *`The stability and reliability of this package is questionable. As of 6/14/2011 there were 48 open bugs and little sign of development. A second bug reporting site shows signs of development.`* (signs are dead in the second site as well)
Answer: I was half way through a response when I found this page mirror.
The classical unix way is a tool called "dd". The page explains how to use it.
Comment: I just took a look at the SimpleBackupSuite that Ryan mentioned, it looks pretty awesome actually.


Efficiently compute the sum of edge weights product of all possible path in a DAG

Question: I thought of using Depth First Search (DFS) to find all possible paths in O(|V|+|E|). However, computing the product of all the edge weights for a path is O(2^N). Is there any way to compute this more efficiently?
Comment: To clarify: in your problem, each edge $e$ is assigned a weight $w(e)$, and you're meant to compute $\sum_{p} \prod_{e \in p} w(e)$, where the sum is over all paths in a given DAG?
Comment: Can someone point out some online problem where this needs to be implemented, I would like to write it out and test it.
Comment: @RobertAndrews This reply may be late but what you said is correct.
Answer: You can actually solve this in $O(|V|+|E|)$ time. Since it is a DAG, we can apply dynamic programming.
Let $p = u_1u_2\dots u_k$ be a path and $cost(p) = w(u_1,u_2)\times w(u_2,u_3)\times\dots \times w(u_{k-1}, u_k)$ be the edge weight product of the path. One important observation is that $cost(u_0p_1) = w(u_0,u_1)\times cost(p_1)$.
Now, for each node $u$, let $dp(u)$ be the sum of edge weight products of all paths originating from $u$.
Let the children of $u$ be $v_1,v_2,\dots,v_m$. We can compute $dp(u)$ using the relation
$$dp(u)=\sum_{i=0}^m w(u,v_i) \times dp(v_i)$$
A Topological sorting can find the order of nodes to compute. Then, the final answer is the sum of all $dp$
$$\sum_{u\in V} dp(u)$$


Can I use mystic disciplines while wild-shaped?

Question: Since the mystic disciplines do not need to use gestures, vocals, or components, could a druid/mystic multiclass use disciplines while in wildshape?
Answer: The argument for "No"
Wildshape specifically bans spells (PHB 67):

You can't cast spells, and your ability to speak or take any action that requires hands is limited to the capabilities of your beast form.

Thus, even if a spell theoretically doesn't have any verbal or somatic components, you can't cast it in your wild shape.
Are mystic disciplines spells? The UA says "kind of" (UA:Mystic 9):

Psionic disciplines are magical and function similarly to spells.

Based on that argument, one could say that you can't use psionic disciplines, because they are like spells and you can't cast spells while wildshaped.
The argument for "Yes"
Wildshape states (PHB 67),

Your game statistics are replaced by the statistics of the beast, but you retain your alignment, personality, and Intelligence, Wisdom, and Charisma scores.
  ...
You retain the benefit of any features from your class, race, or other source and can use them if the new form is physically capable of doing so.

Because psionic disciplines depend only on your mental abilities, and you retain your mental abilities while whileshaped, you should retain the benefit of your class feature.
We can compare this situation to a Warlock's eldritch invocations. While most of them are spells, some of them, like Gaze of Two Minds or One With Shadows, give you magical abilities that are not spells. Because you retain your non-spellcasting class features, you should be able to use those abilities while wildshaped.
Conclusion: Unclear, probably yes
I'd probably rule "yes" at my table, because I find the argument for yes more compelling. However, the evidence can arguably go both ways. It's important to remember that the mystic class is still playtest material. Jeremy Crawford, who makes official statements on rules, has stated that UA material isn't tuned for multiclassing at all. I expect that if/when the class is officially published, interactions like this will have been taken into account.
Comment: "like spells" does not mean "are spells". Psionic powers are not "cast".  They can't be dispelled, they can't be counterspelled. They can't be put in Rings of Spell Storing. See entry: Components on page 9
Comment: Thank you for giving me such a detailed answer!  I am largely just looking through the material and probably wouldn't do this.  But I like to power-game in my head even if I don't like to do so at the table.  E.g. It is fun to think about trying out new combinations that might be OP and ruin the game at the table--or just be silly.
Answer: UA classes are not balanced for multi-classing
Wizards of the Coast has, via Jeremy Crawford on Sage Advice, stated repeatedly that

Unearthed Arcana material isn't tuned for multiclassing.

Rule as you and your DM seem fit and fair - but be prepared to scale it back if it seems overpowered. However, the intent does seem to suggest that you shouldn't.
And you probably shouldn't
Wildshape states (PHB, 67)

You can't cast spells, and your ability to speak or take any action that requires hands is limited to the capabilities of your beast form.

Not all spellcasting require all three components (verbal, somatic, material), but all spellcasting has been removed during wildshape. The intent with this suggests that while class abilities are permitted, the control of the weave is not. You can concentrate on something you started, but you can't start something new.
It seems like the intent of Wild Shape is to give you a boost of HP and physical attack options in exchange for your magical abilities. If you read it as such, then the Mystic Class would also not likely be able to utilize those abilities while Wild Shaped to maintain the balance.
Comment: +1: If it applies to spells and ki, it should apply to mystic disciplines just as a rule of thumb. Even if RAW allows it when/if mystic is published, I wouldn't allow it at my table.
Comment: @jeanquilt Wild Shape doesn't prevent using ki. Class features that use ki aren't even magical by default, unless the particular feature says otherwise.
Answer: tl;dr Yes, you can, but you (or the DM) shouldn't allow multiclassing with UA classes.

A druid cannot cast spells in wild shape:

You can't cast spells, and your ability to speak or take any action that requires hands is limited to the capabilities of your beast form.

but...  Disciplines are not spells.
Disciplines follow some of the rules found in PHB ch.10 spellcasting, because they have effects and the rules to define effects' areas and other mechanics are there.
But nonetheless, they are magical effects, not spells.

Disciplines do not have levels. Spells have levels. Were disciplines spells, they would need a level to interact with Dispel Magic and/or Counterspell.
Disciplines do not use spell slots. They use psi an entire new mechanic.
Mystic do not have the spellcasting trait. How could they use spells if they do not have spellcasting or any other trait (like pact magic) that allows spellcasting? Their effects cannot be spells, or they wouldn't be able to use them. They have the psionics trait. Their powers are psionics.

So, by all the evidence presented above, Mystic/Druid can use their psionic powers while in wild shape.
But the DM should not allow such multiclass into the game, before evaluating the possible ramifications.

Unearthed Arcana material isn't tuned for multiclassing. #DnD - JeremyECrawford on Twitter.


How to Calculate Pre-flop Odds of Making a Hand By The River?

Question: How do you calculate the pre-flop odds of making a hand after the river card? For example, what are the odds of making a set if you hold a pocket pair after the river card? What are the odds of making a straight if you hold A3 after the river card?
Answer: Each scenario is different. Some are straightforward (or at least feasible) to calculate mathematically. For those that are not, it is simplest to iterate all hand combinations (using a computer) since the total number of combinations is not that large.
For your first example, if you hold a pocket pair then there are two cards (out of the remaining 50) that will make you a set. To not make a set, you'd need to avoid these two cards five times in a row, for which the odds are:
(48/50) * (47/49) * (46/48) * (45/47) * (44/46)
which is 80.82%. So the odds that you do make a set by the river are the remaining 19.18%.
Note that this 19.18% includes the possibility of making four-of-a-kind using your pocket pair or a full house which include your pocket pair as part of a 'set'. Both the 80.82% and the 19.18% also include (for example) straights and flushes. So if you mean 'a set or better', or 'a set but nothing more', then those are different questions and much more complicated to calculate.
The question of making a straight with A3 is also harder. You need to consider 5-high, 6-high and 7-high straights, as well as Ace-high straights. What about straights which don't include either of your hole cards - do they count? And again, do you mean 'a straight or better' or 'a straight but nothing more'? If the latter, what about a straight flush?
The problem with many of these "What are the chances of that?" questions is that they are not strictly defined, so it's hard to give a proper answer. But usually, if you can define the question sufficiently clearly, the approach is either to use probability (as with the 'set' example above) or brute force with the help of a computer.
Comment: To be specific, If you have A3 what is the probablity of a 2, 4, and 5 running out?
Comment: Also why do you not take into account the cards that are dealt out when you calculcate the probability? 48/50 when the cards left in the deck are going to be less than 50.
Comment: Re your second question: the cards dealt to other players don't affect the calculation because they are unknown. There are 50 unknown cards, of which two are your "set-makers". Any of the 50 cards is equally likely to be one of those two set-makers. Put another way, the first community (board) card to be dealt is equally likely to be any of the 50 remaining (unseen) cards. Of course, if any of your opponents show their cards, or muck face up, then that would change the probability of hitting a set for that specific situation, because you can then remove the visible cards from the calculation.
Comment: Regarding the A3 question: this is a lot more complicated. If you would like a mathematical answer I think you should ask a new (precisely worded) question - adding the working to my answer above would make it too long, and diverge too much from the original question. If you just want the answer, I make it 2.69% that A3 will make a "wheel" straight by the river (including e.g. hands which also contain a flush or straight flush as well as "straights on the board").


Move an object on on a Bézier curve path

Question: I want to move my image on a Bézier curve path from top to bottom but I can't get how can I calculate x/y points and slope from this path. The path looks like the following image:

I have start points, end points and two control points.
Path path = new Path();
Point s = new Point(150, 5);
Point cp1 = new Point(140, 125);
Point cp2 = new Point(145, 150);
Point e = new Point(200, 250);
path.moveTo(s.x, s.y);
path.cubicTo(cp1.x, cp1.y, cp2.x, cp2.y, e.x, e.y);

Answer: Android gives you an API to accomplish what you want. Use the class called android.graphics.PathMeasure. There are two methods you will find useful: getLength(), to retrieve the total length in pixels of the path, and getPosTan(), to retrieve the X,Y position of a point on the curve at a specified distance (as well as the tangent at this location.)
For instance, if getLength() returns 200 and you want to know the X,Y position of the point in the middle of the curve, call getPosTan() with distance=100.
More info: http://developer.android.com/reference/android/graphics/PathMeasure.html
Comment: http://stackoverflow.com/questions/18651025/how-to-move-image-on-curve-on-touch-event-in-android please help me on this question
Answer: This is a cubic Bézier curve for which the formula is simply [x,y]=(1–t)^3*P0+3(1–t)^2*t*P1+3(1–t)t^2*P2+t^3*P3. With this you can solve for each point by evaluating the equation. In Java this you could do it like this:
/* t is time(value of 0.0f-1.0f; 0 is the start 1 is the end) */
Point CalculateBezierPoint(float t, Point s, Point c1, Point c2, Point e)
{
  float u = 1 – t;
  float tt = t*t;
  float uu = u*u;
  float uuu = uu * u;
  float ttt = tt * t;

  Point p = new Point(s.x * uuu, s.y * uuu);
  p.x += 3 * uu * t * c1.x;
  p.y += 3 * uu * t * c1.y;
  p.x += 3 * u * tt * c2.x;
  p.y += 3 * u * tt * c2.y;
  p.x += ttt * e.x;
  p.y += ttt * e.y;

  return p;
}

So if you wanted to move a sprite along the path, then you would simply set the t value from a  value of 0 - 1 depending on how far down the path you want to be. Example:
int percentMovedPerFrame = 1;// Will complete path in 100 frames
int currentPercent = 0;
update() {
   if (currentPercent < 100) {
      this.pos = CalculateBezierPoint(currentPercent / 100.0f, this.path.s, this.path.c1, this.path.c2, this.path.e);
      currentPercent += percentMovedPerFrame
   }
}

Comment: hello... i want to move the image on path manually. I mean I want to move image on touch event.. how can i modify your code for that??
Comment: My code is as manual as you could possibly get unless you want to write rasterizing routines for that image...
Answer: To find a point on a Bezier curve, you can use the De Casteljau algorithm.
See for example http://www.cs.mtu.edu/~shene/COURSES/cs3621/NOTES/spline/Bezier/de-casteljau.html or use Google to find some implementations.
Answer: If you only have 2 control points, a bezier curve is a linear line.
If you have 3, you have a quadratic curve. 4 control points define a cubic curve.
Bezier curves are functions which depend on "time". It goes from 0.0 - 1.0. If you enter 0 into the equation, you get the value at the beginning of the curve. If you enter 1.0, the value at the end.
Bezier curves interpolate the first and last control points, so those would be your starting and ending points. Look carefully at what package or library you are using to generate the curve.
To orient your image with the tangent vector of the curve, you have to differentiate the curve equation (you can look up the cubic bezier curve equation on wiki). That will give you the tangent vector to orient your image.
Comment: can you give me some hint on how to find the quadratic equation of a bezier curve with 2 and 3 control points.
Comment: Look at: http://en.wikipedia.org/wiki/B%C3%A9zier_curve

It shows equations for linear, quadratic and cubic
Comment: also note that in your example you have 4 control-points. the start- and end-point are also considered to be controlpoints. To evaluate the curve just use the last formula in the 'Cubic Bézier curves' section of the wiki. e.g.
P0 = s, P1=cp1, P2=cp2, P3=e
B(0) = s and B(1) = e in your example.
Answer: Note that changing the parameter in the parametric form of a cubic bezier does not produce linear results. In other words, setting t=0.5 does not give you a point that is halfway along the curve. Depending on the curvature (which is defined by control points) there will be non-linearities along the path.
Answer: For anyone who needs to calculate static value points of Bezier curve Bezier curve calculator is a good source. Especially if you use the fourth quadrant (i.e. between X line and -Y line). Then you can completely map it to the Android coordinate system doing mod on negative value.


On the maximal ideal m of the formal power series ring

Question: Let $A \colon= K[[X_1,X_2,\ldots,X_{\infty}]]$ be the formal power series ring with infinitely many variables over a field $K$. We can represent it also by the following manner$\colon$
\begin{equation*}
A = \underset{n \geq 1}{\varprojlim}\, K[[X_1,\ldots,X_n]].
\end{equation*}
$A$ is complete with the unique maximal ideal ${\frak m}_A$ which is closed and denoted by ${\frak m}_A = \overline{(X_1,X_2,\ldots,X_{\infty})}$. For example, we have the following inclusion$\colon$
\begin{equation*}
\Sigma_{n=0}^{n=\infty}\,X_n = X_1 + X_2 + \ldots \in A.
\end{equation*}
Define the $K$-vector space $V$ by the following$\colon$
\begin{equation}
V \colon= {\frak m}_A/{\frak m}^2_A = \underset{{\lambda} \in \Lambda}{\bigoplus} K\omega_{\lambda}.
\end{equation}
Q. How can one prove that $\omega_{\lambda}$'s generate ${\frak m}_A$?
That is, the following equality holds$\colon$
\begin{equation*}
(\omega_{\lambda}\,|\,\lambda \in \Lambda) = {\frak m}_A.
\end{equation*}
Comment: Please fix your post before people possibly try to give you some answer: 1/ The ring of power series in infinitely many variables is *not* the projective limit you believe it is; 2/ What do you mean when you write $X_\infty$ ? 3/ What is $\Lambda$? What is $\omega_\lambda$? 4/ No need to shout; we can read math, even without boldface characters.
Comment: $X_1^2$ is in both $\mathfrak{m}_A$ and $\mathfrak{m}_A^2$
Comment: To anyone who is down-voting: though the question may look weird and/or  meaningless, there is actually a genuine question lurking in there with a real theory behind it (though it seems the OP is not aware of that, explaining some of the mild confusion in the formulation), so please refrain from down-voting.  The "flaws" in this question are no different from questions about higher categories that have imprecision in the formulation, except that the topic of pseudo-compact rings is not as trendy as higher categories (and so imprecision about it is not as widely accepted for informal purposes).
Comment: @ACL: Ironically, the one thing that is "right" in the question is that the formal power series he wants to use likely is the same as his definition of $A$; see my answer below. But I agree that it is full of other confusion, so not completely clear what is being sought (though I have a guess).
Comment: OK, in view of the OP's comments to my answer, I retract my suggestion not to down-vote. There is in fact a well-posed question with genuine answer fitting into a useful framework, as developed in the SGA3 reference in my answer, but the OP is insisting (mistakenly, I believe) that this is not in the direction he wants, so nothing productive is going to emerge from further discussion until the OP thinks more carefully about the precise meaning of what he is asking about and looks closely at that SGA3 reference.
Answer: Setting aside the meaningless "$X_{\infty}$", your notion of formal power series is an instance of that notion in an arbitrary (in your case countably infinite) set of variables as in the theory of pseudo-compact rings in SGA3, Exp. VII$_{\rm{B}}$. More specifically, the completion of $K[X_1,X_2,\dots]$ for the system of ideals
$$I_{J,N}=(X_j:j\in J)^N + (X_i:i\not\in J)$$
 for $N>0$ and finite subsets $J \subset \{1, 2, \dots\}$ is topologically the same as $A$ with inverse limit of max-adic topologies as in the question.
It seems that you are looking for a criterion to make a "topological change of variables".  But the version of Nakayama's Lemma appropriate for local pseudo-compact rings (adapting the version for formal power series in a finite set of variables) is not the one that you seem to have in mind (and have not stated).
One issue is that the square of the maximal ideal is never closed when the number of variables is infinite, so the right quotient to consider for a notion of "cotangent space at the origin" is really $V_0 := \mathfrak{m}_A/\overline{\mathfrak{m}_A^2}$.  A second issue is that the notion of "basis" of $V_0$ appropriate to consider here is not a raw  algebraic basis in the sense of a direct sum but rather should be a topological $K$-basis for $V_0$ viewed as a profinite $K$-module (in the sense of SGA3, Exp. VII$_{\rm{B}}$: inverse limit of finite-dimensional $K$-vector spaces, equipped with topology as such).  It is a general fact that if $W$ is any profinite $K$-vector space then it is topologically free in the sense that $K^S \simeq W$ for some set $S$, where $K^S = \varprojlim_{S_0 \subset S} K^{S_0}$ for $S_0$ varying through the finite subsets of $S$; the elements $\{w_s\}_{s \in S}$ in $W$ corresponding to the evident "factors" $K$ of $K^S$ constitute a "topological $K$-basis" of such a $W$. This $K^S$ is the same as $\prod_{s \in S} K$ with the product topology for the discrete topology on each copy of $K$.
To sum up, I believe you are asking the wrong question for whatever purpose you may have in mind (but since no motivation was given, I can only guess).  I conjecture that what you really want to ask is this: for a subset $\{y_{\lambda}\}_{\lambda \in \Lambda}$ of $\mathfrak{m}_A$ lifting a topological basis of $V_0$, is the unique continuous map
$$K[\![Y_{\lambda}]\!] \rightarrow A$$
of pseudo-compact $K$-algebras satisying $Y_{\lambda} \mapsto y_{\lambda}$ an isomorphism?
The answer is affirmative, but before I say anything more about that I'd like to get clear confirmation from you that this is actually addressing the question you want; if not then I likely will not have anything useful to say (and likely nor will anyone else).
Comment: Dear NFDC23, great thanks for your kind answer. The notation $K[[Y_{\lambda}]]$ in your definition implies ``the inductive limit" of all possible $K[[Y_{\lambda},...,Y_{\gamma}]]$, where $(Y_{\lambda},...,Y_{\gamma})$ is the finitely many subset of $V_0$. That is, we would like to represent $A$ as the ``attachment" of each finitely-many-variable formal power series ring. If this is the case, please teach me how can I show that the answer is affirmative. Many thanks.
Comment: Also I have one question. m_A is already closed. Then why is the square of m_A *not* closed? Also what I would like to do is that I can rewrite A as the inductive limit of finitely-many-variable formal power series ring, so I would like to get rid of inverse limit topology.
Comment: My point of view is that each finitely many variables consist of finitely many subset of V_0, but I believe that m_A/(m_A)^2 being a K-vector space makes sense. I am afraid that for the characteristic ch(K) = p > 0, such element as X_1 + (X_2)^p + (X_3)^{p^3} + (X_4)^{p^4} + ... disappears in V_0, although it will be a member of the generators of m_A. With these problems in mind, I am now proving that A can be written as the inductive limit of finitely-many-variable formal power series ring over $K$ by using generators of m_A, i.e. ω_{λ}'s such that (...,ω_{λ},...) = m_A.
Comment: After all, I think that the lifting of the topological bases of V_0 is *not* what I am thinking. That is, the L.H.S. must be union of finitely-many-variable formal power series ring with variables running over all generators of m_A. So, we need continuously many variables. Also, we need the presentation of inductive limit. My point of view is at least we have generators from the K-v.s. m_A/(m_A)^2, and will add more generators to V_0 to make up whole m_A. If we denote by Γ the index set, we have the presentation as A = lim K[[ω_λ,...,ω_ζ]] with (λ,...,ζ) running over all finite subset of Γ.
Comment: Since (i) you are confused about inductive vs. inverse limits, (ii) you say you are trying to get rid of inverse limit topologies but that is a serious technical error, (iii) your 3rd comment has serious mistakes, (iv) your 4th comment is most definitely wrong (either the 1st sentence is wrong or else you are trying to do something that makes no sense), I'm going to withdraw from the discussion here. I don't have time to explain away the many misconceptions you have.  I gave you the precise reference in SGA3, and urge you to read it to clear up the many misconceptions in your comments.
Comment: Dear nfdc23, probably you know general Neron-Popescu-Spivakovsky desingularisation. K[[X_1,...,X_N]] is the inductive limit of smooth sub-algebras of finite type over K. In the similar manner, you can show that A is also written as the inductive limit of smooth algebras of finite type over K. My K-vector space is V := m_A/(m_A)^2, where (m_A)^2 is *non-closed* ideal. So V is HUGE. Anyhow one can choose bases of V. This, however, will NOT sufficient to generate (or recover) m_A, for some dies in V. By complementing lost ones whole bases which generate m_A will give the presentation A = lim A_λ


How can I install Unity Player for Tor Browser 3.6.3?

Question: I have Tor Browser 3.6.3 (secure browser based on Firefox 24.7.0).
I want to run Unity3d game like : https://apps.facebook.com/dragons_world/
I've installed Unity Player promted, but it doesn`t appears on Tor restart.
What should I do?
Comment: This may pose an anonymity risk. Such plugins are basically separate programs with lots of privileges on your system, more than what your browser usually allows.
Answer: Tor does not support, nor will support any additional plugins for the browser.  I asked this questing a few months ago, and they dolt me the same thing.
Now, you can try this. I have no clue what registry tor takes, but I would guess that it is somewhat similar to the one firefox occupies.


Change order of images in icon file

Question: Is there an app that can change the order of images inside an icon?
Thanks!
Answer: What you'll need to do that is a resource editor. A google search will reveal many free ones out there. The restorator is a great one, but not free and over-priced IMO.
Any decent resource editor will allow you to see icons in the exe or dll and save them or replace them. I don't know of any that will allow you to reorder them, but just about any out there would allow you to save the icons out and then replace them back in the exe/dll in whatever order you'd like.
Answer: The only resource editor I know of that will allow you to re-order the embedded icons including png compressed vista icons is Resource Tuner Console.
Answer: You can change the image order using Pixelformer (an icon/bitmap editor). Import the icon, reorder the images as you wish, then export it back.
Answer: Using a resource editor is not an easy way to do this because you have to edit both ICON and ICON GROUP and I tried to do this with Resource Hacker and could not do it.
I found Easy Icon Maker is able to rearrange the order of the icons properly... it's the only icon editor that I found with this option, and I tried about half a dozen.  The editor itself is not nearly as good as IcoFX (http://portableapps.com/apps/graphics_pictures/icofx_portable)
Why would you want to do this?  Well there are certain times when Windows will use the first icon file that matches the size, but this may not be the color-depth that you want... for instance if you are on an older machine like Windows 2000 that doesn't support Alpha Channels then putting these at the beginning of your ICO file will cause Windows 2000 to try to render it so it results in black dots all over the image.

Change order of images in icon file


Mass SQL Wordpress Meta Key deletion

Question: hi i am newbie with SQL data base so forgive my dumbness i have installed KK Star rating plugin on my wp site which noticed its recording lot of entries and my db size is over 280 MB and 188MB is wp_postmeta table. uninstalled the plugin and i want to run sql query to delete all postmeta with kkstar recorcs. the meta key record is: kksr_fingerprint_default so please give me correct command line to run thanks in advance
Answer: DELETE FROM `{PREFIX}post_meta` WHERE meta_key = 'kksr_fingerprint_default'

{PREFIX} is the string $table_prefix defined in wp-config.php; of course be careful in run SQL DELETE, create a table backup and (maybe) execute first a single line deletion to check the result
DELETE FROM `{PREFIX}post_meta` WHERE meta_key = 'kksr_fingerprint_default' LIMIT 1

Answer: First, make sure you back up your database. :)
If you're wanting to run a SQL command directly - perhaps using phpMyAdmin - the query would be
DELETE FROM wp_postmeta WHERE meta_key = 'kksr_fingerprint_default'

Mass SQL Wordpress Meta Key deletion


Installing Genymotion Eclipse plug-in

Question: I have installed Genymotion on my Windows 7 , 32-bit machine. I am working with Eclipse to develop Android apps. I would like to ask what the proper way to install the Genymotion plug-in is.
Going by their website, they provide two JAR files for Eclipse and a note underneath which reads:

The installation of the plugin can be done by launching Eclipse and
  going to "Help / Install New Software" menu, then just add a new
  Update Site with the following URL:
  http://plugins.genymotion.com/eclipse. Follow the steps indicated by
  Eclipse.  Warning: to use this plugin, Genymotion must be installed on
  your system.

I have installed the plug-in from the Eclipse 'Help' menu. I havent downloaded any of the two files. Have I done it correctly ?
The two files are:
1. Genymotion Plug-in for Eclipse
2. Mandatory dependency for Eclipse plug-in
Comment: when you added the url as an "update site" and installed the plugins that where found there, than yes! Short question though, why don't you have tried to use the plugin?!
Comment: @WarrenFaith Doing that as I type this. Downloading the virtual device :)
Answer: Tutorials
This tutorial shows how you should do everything:
http://www.slideshare.net/scentsome/eclipse-genymotion
And this is the original website tutorial:
https://cloud.genymotion.com/page/doc/
Both explain it perfectly

Extra:
Android Studio:

Go to File/Settings on Windows and Linux or Android Studio/Preferences on Mac OS X.
Select Plugins and click Browse Repositories.
Right-click (double-click for Mac OS X) on Genymotion.
Click Download and install.
Click Yes.
Click Close.
Click OK.
Restart Android Studio by clicking Restart.

If you want to do the manual method or want to see the instructions from their website, this is the link: https://www.genymotion.com/#!/developers/user-guide#genymotion-plugin-for-android-studio
Eclipse:
If you want to have the genymotion virtual devices inside eclipse do this:
Go to help -> install new software -> add this link: https://dl.genymotion.com/eclipse
Answer: For those who face There are no categorized items on Eclipse
Uncheck Group items by category
Comment: That was the answer! Thank you!
Comment: Thanks a lot :) +1
Comment: Thanks you men !! +1
Answer: Follow this link, There you can see how to install genymotion eclips plugin.
Eclips>Help>Install new software>Add>
Type anything on Name box.
Inside Location box : http://plugins.genymotion.com/eclipse
Then follow the steps.
Answer: Below is a demonstration to show how to install Genymotion in Eclipse ADT
https://www.youtube.com/watch?v=3sBHQqZ5TKk
Note: sometimes after additions of the plugin from Help | Install new software it is not giving the checkbox to check or the ability to install. At this time uncheck "Group Items by category" to list all items without any grouping. Check all of items then press Next and proceed.
Answer: Yeah dude you done it perfectly after installing genymotion you will see an icon in your eclipse when you click it then a window with genymotion devices will be shown
(You must install genymotion virtual box and should have virtual devices in genymotion to run your app sucessfully)

Installing Genymotion Eclipse plug-in


How to Migrate SharePoint server 2013 to SharePoint server 2016?

Question: Please any link for this how to  Migrating SharePoint server 2013 to SharePoint  server 2016.Thanks in Advance.
Comment: There is no official instruction how to migrate as SharePoint 2016 is yet to be released to the public yet.
Comment: Hi , SharePoint 2016 is released or not yet release.Anyone know releasing date of SharePoint 2016  please share with me.
Answer: SharePoint Server 2016 will generally available on May 4th 2016( xcross fingers), you can join  Microsoft is hosting a live,
Right now, Trail version is available and you can download it from Microsoft site.
As far as Migration, In your case Database Upgrade approach is best. Same approach we did from 2010 to 2013 farm.
Also check: http://www.avepoint.com/community/avepoint-blog/choosing-upgrade-path-sharepoint-2016/


Im trying to download apps but it says insufficient storage but I have plenty of storage and an sd card

Question: I try to download apps like Vine and other apps but, it continuously says insufficient storage and I have an sd card and enough internal storage to download. It makes me angry. Please help, I need don't want but need some apps and it wont let me download.  I have a Samsung galaxy ace style and I got it June 13th. Thanks.
Comment: As you've correctly tagged your question `insufficient-memory`: have you checked with the [corresponding tag-wiki](http://android.stackexchange.com/tags/insufficient-memory/info)? That will give you some first-aid, and a.o. tell you the error has nothing to do with your SDCard (you could have Terabytes free there, it wouldn't matter). As this also is a somehow frequent question here, there are more answers already existing, see e.g. [How can I deal with "Low on Space" messages on my Android?](http://android.stackexchange.com/q/2305/16575)
Answer: I had the same problem on my Huawei Ascend P2, I did a factory reset and it seemed to work, though I highly recommend copying over to your computer every file on your phone before even trying to do so, I don't know the cause myself, the theories I have are:
Virus
Damaged internal memory
If it still doesn't work after the factory reset then you need to take it to a specialist (unless you are one) and take it apart and replace the memory.
P.S Don't treat this as a answer as such, I don't have the reputation to comment (which I think they should allow everyone to do instead of risking losing a ton of rep).
P.S.S Have you checked to see if your SD card is being read by your phone?
Answer: A simple solution, don't know you have tried or not.
Install any Cache Cleaner apps if possible. Some uncleaned cache may take GBs of data.
If its not possible, delete the files from the cache folders inside the folders in Android\data\< some_folder > \


Is it possible to replace a SQL table with a SQL view in an already created model in MVC 4?

Question: I have recently inherited a mess from the developer who used to sit in this chair over a year ago.  One of the many things he did is create nearly identical tables in many databases (such as having a Users table in each database that contains exactly the same information).  I am attempting to eliminate all the manual work that is currently being done every time a new employee is hired by eliminating these duplicate tables.
I have created a SQL view that represents data exactly as the old table did.  It pulls it's data from the master database, but all the tables I need (and this new view) are all on the same DB.  There is no need for the application I am working with to modify the users table, so it only needs read access (so a view should be fine, right?).
Is there any way to simply replace the table in code with the new view?  I would be happy to provide more information if needed.
Answer: if the created view has the same name and same columns as the original table, it will work without app modification.
It is also possible to modify data throught this view (with some restrictions...), see https://msdn.microsoft.com/en-us/library/ms180800.aspx .


Need some help in creating a query in SQL?

Question: I have 2 following tables :
Ticket(ID, Problem, Status,Priority, LoggedTime,CustomerID*, ProductID*);
TicketUpdate(ID,Message, UpdateTime,TickedID*,StaffID*);

Here is a question to be answered:
Close all support tickets which have not been updated for at least 24 hours. This will be records that have received at least one update from a staff member and no further updates from the customer (or staff member) for at least 24 hours.
My query is:
UPDATE Ticket SET Status = 'closed' FROM TicketUpdate
WHERE(LoggedTime - MAX(UpdateTime))> 24
     AND Ticket.ID = TicketUpdate.TicketID;

When I run this query on mysql it says that "<" does not exist.
Can you tell me  is my query right to for calculating the records which have not been updated for at least 24 hours and if it is right what should I do use instead of "<"?
Comment: What data type is the UpdateTime column? Is it a datetime, or a timestamp?
Comment: Possible duplicate of your earlier questions http://stackoverflow.com/questions/10195759/need-some-help-in-creating-a-query-in-sql and http://stackoverflow.com/questions/10192521/need-some-help-in-creating-a-query-in-sql
Comment: Why would you mention MySQL, when the question is tagged PostgreSQL? Can be solved with window functions in PostgreSQL but not in MySQL, which does not support this feature.
Answer: If you are working with postgreSQL then this should work
UPDATE Ticket SET Status = 'closed' FROM TicketUpdate
WHERE abs(extract(epoch from LoggedTime - MAX(UpdateTime))) >24
     AND Ticket.ID = TicketUpdate.TicketID;

Comment: I cannot use DATEDIFF as I don't have column day.The data type for UpdateTime is timestamp
Comment: cannot use aggregate function in UPDATE
LINE 2: WHERE abs(extract(epoch from LoggedTime - MAX(UpdateTime)))
Answer:
... records that have received at least one update from a staff member and
  no further updates from the customer (or staff member) for at least 24
  hours.

So, effectively, the last update must have been done by a staff member and be older than 24 hours. That covers it all.
(BTW, you have a typo: TickedID -> I use ticketid here.)
UPDATE ticket t
SET    status = 'closed'
FROM (
    SELECT DISTINCT ON (1)
           ticketid
          ,first_value(updatetime) OVER w AS last_up
          ,first_value(staffid)    OVER w AS staffid
    FROM   ticketupdate
    -- you could join back to ticket here and eliminate 'closed' ids right away
    WINDOW w AS (PARTITION BY ticketid ORDER BY updateTime DESC)
    ) tu
WHERE  tu.ticketid = t.id
AND    tu.last_up < (now()::timestamp - interval '24 hours')
AND    tu.staffid > 1 -- whatever signifies "update from a staff member"
AND    t.status IS DISTINCT FROM 'closed'; -- to avoid pointless updates

Note that PostgreSQL folds identifiers to lower case if not double-quoted. I advise to stay away from mixed case identifiers to begin with.


What is the connection between the Fundemental group and homotopy equivalent

Question: I am just beginning learning algebraic topology after finishing point-set topology. I did not have background in group theory(only know some basic fact about it).
For this question, can I just claim if torus and klein bottle do not have same fundemental group,then they are not homotopy equivalent?
This is the first time I have encountered such questions and if anyone can give explanations in details, then it may help me to learn greatly. Thank you.
Comment: $\pi_1$ of torus is abelian, but $\pi_1$ of a Klein bottle is not.  Alternatively, you can calculate the homology groups.  Or show that Klein bottle is not orientable. ....
Comment: @user10354138 showing non-orientability is not enough on its own. For example, the annulus is homotopy equivalent to the Möbius band, but the former is orientable while the latter is not.
Comment: In group-theory land, your two-sheeted cover just says that $\pi_1$ of your Klein bottle contains $\pi_1$ of your torus with index two. But this doesn't help you that much, as in fact both groups ($\pi_1$ of your Klein bottle and of your torus) each contain a copy of $\pi_1$ of your torus with index two.
Comment: The fundamental group is homotopy invariant, meaning that homotopy equivalent spaces have the same (isomorphic) fundamental group. That is not the same as saying non-homotopy equivalent spaces have non-isomorphic fundamental groups, which is not true.
Answer: It seems like the other answers are trying to prove that the Klein bottle and the torus don't have the same fundamental group which, as far as I understand, is not your question (EDIT : per Jason's comment : it's no longer your question, after an edit to the original one, which explains the other answers)
If I understand correctly, you know that and want to conclude from this that they are not homotopy equivalent. You are correct that one can conclude that way, indeed :

Let $f:X\to Y$ be a homotopy equivalence between spaces. Then for any $x\in X$, the induced morphism $f_* : \pi_1(X,x)\to \pi_1(Y,f(x))$ is an isomorphism

In particular, the contrapositive states that if the fundamental groups are different, the spaces are not homotopy equivalent.
The proof of the claim can be found in any introductory algebraic topology text. The idea is fairly easy, the only possible problem being a problem of basepoints. Indeed, the homotopy equivalences need not be basepoint preserving, and the homotopies $gf\simeq id_X$ need not be a pointed homotopy either.
There are various ways of dealing with that issue, a particularly nice one is to work with the fundamental groupoid instead of the fundamental group, and with this tool, the basepoint problem kind of goes away.
Comment: To be fair to the other answers, it looks like the precise question has been edited.
Comment: @JasonDeVito : you are correct, I hadn't noticed that !
Comment: @user1729 : yes, I noted Jason's comment and then went to check the edit history of the question, and my first paragraph was no longer adequate. I didn't alter it but added an edit to clarify the situation, I hope that's ok
Comment: Whoops, didn't see the other comment. Yes, that's better.
Answer: One way to think about this problem is by using cut and paste constructions of the torus and the Klein bottle to compute their fundamental groups and distinguish them as not homotopy equivalent. The torus (left) and Klein bottle (right) are built like so:

From the picture, we see that the non-trivial loops we can build on these spaces are given by "linear combinations" of $a$ and $b$, and hence these are the generators of the fundamental groups. To figure out their relations, we again turn to the picture and pay attention to the directions of the arrows to tell us whether we are using a generator or its inverse.
On the left, walking around the boundary over the top gives us that $bab^{-1} = a$. On the right however, that same walk over the boundary on the top gives us the relationship $bab^{-1} = a^{-1}$. Writing out these fundamental groups' presentations of the torus $T^2$ and Klein bottle $K$:
$$\pi_1(T^2) = \langle a,b | ba = ab\rangle \text{ and } \pi_1(K) = \langle a,b | bab^{-1}= a^{-1}\rangle$$
From the presentations, the torus has an abelian fundamental group because the generators commute, but this is not the case for the Klein bottle, hence they are not the same group and thus they are not homotopy equivalent. I hope this helped you visualize the problem better!
Answer: As far as I know, the only way to do this is to calculate some algebraic invariant of $T$ and $K$. I don't know if you've covered any algebraic topology, but there are very simple algorithms to calculate both the fundamental group and the homology groups of $T$ and $K$, by realising them as squares with side identifications. See the Wikipedia page on cellular homology, and this page on fundamental groups of CW complexes. It is a standard result of algebraic topology that if two spaces are homotopy equivalent, then their fundamental groups are isomorphic, and their homology groups are isomorphic. But we can check that
$$H_1T\cong\mathbb{Z}^2\ncong\mathbb{Z}\times\mathbb{Z}/2\mathbb{Z}\cong H_1K.$$
You can check $\pi_1$ and $H_2$ as well, but this is enough to show they cannot be homotopy equivalent.


Migrating MOSS 2007 to sharepoint 2010 giving the error "Invalid Object Name sites"

Question: I am migrating sharepoint 2007 publishing site to sharepoint 2010. These are the steps I have followed

Backup the content database from the SP2007 machine.
Restore that database in sql server 2008 (SP2010 machine).
Create a new web application in SP2010 and create a site collection type of publishing template.
I have run the following stsadm command for adding the content database to the web application
stsadm -o addcontentdb -url http://testsite -databasename WSS_Content_test

But I am getting the Invalid object name sites error. Could anyone help me to resolve this issue ?
Answer: Did you follow correct procedures? Did you do a pre-upgrade check?

Migrating MOSS 2007 to sharepoint 2010 giving the error “Invalid Object Name sites”


Prove that $\sum\limits_{n=1}^\infty(-1)^n\frac{x^2+n}{n^2}$ converges uniformly, but not absolutely

Question: My Work:
i) Uniform Convergence (By Weierstrass M-Test):
I am attempting to show that the series converges uniformly on the interval $I=[-a,a]$, in which:$$\sum_{n=1}^\infty(-1)^n\frac{x^2+n}{n^2}\le\sum_{n=1}^\infty(-1)^n\frac{a^2+n}{n^2}=\varepsilon_0$$
Suppose that $\sum\limits_{n=1}^\infty\frac{x^2+n}{n^2}$ will be called "A" and $\varepsilon_0$ will be called "B". By the M-test, if B converges, then A converges uniformly on the interval $I$ defined above.
I am having difficulty proving that B converges, however. I have tried both the root and ratio tests, and they have been unhelpful. For this segment, could someone confirm my logic / provide a hint towards the convergence of B?
ii) Absolute Convergence:
I believe that this function does not converge absolutely because$\sum\limits_{n=1}^\infty\frac{x^2+n}{n^2}$ is a divergent sum as n approaches infinity. Bit of a trivial solution here but I believe it's sufficient.
Comment: The $M$-test won't apply; but see [this](http://math.stackexchange.com/questions/136909/show-uniform-convergence-of-function-series).
Comment: Am I misunderstanding something, or can you not use the Alternating Series Test to demonstrate the convergence of "B"? Though this probably won't help, since the suggested inequality isn't true.
Answer: Your argument is correct for the non-absolute convergence. Indeed, the series $\sum_{n\geqslant 1}x^2/n^2$ is convergent while $\sum_{n\geqslant 1}1/n$ is divergent, hence $\sum_{n\geqslant 1}\left(x^2/n^2+1/n\right)$ is divergent.
For the uniform convergence, define $s_n(x):=\sum_{j=1}^n(-1)^j(x^2+j)/j^2$. Defining $S_n(x):=\sum_{j=1}^n(-1)^j\frac{x^2}{j^2}$, we have the equality
$$s_n(x)=S_n(x)+\sum_{j=1}^n(-1)^j/j.$$
Since the series $\sum_{j=1}^{+\infty}(-1)^j/j$ is convergent, it suffices to establish the uniform convergence of the sequence $\left(S_n\right)_{n\geqslant 1}$ on $[-a,a]$, which can be done by the Weierstrass $M$-test.


How do I add a meta tag inside the  tag?

Question: How can I add the following meta tag inside the  tag?
<meta http-equiv="X-UA-Compatible" content="IE=edge" />

I am trying to add it to a Drupal 8 site.
Answer: From different sources I found different way of adding meta tags in Drupal 8, hence compiling all ways.
Using a THEME.theme file
The same question has been asked on Add meta tag to . One of the answers provides the following code.
Just add the following code in the .theme file, and clear the cache.
The theme_preprocess_html() function should be already there in the .theme file; don't add another function with the same same, or PHP will throw an error.
function theme_preprocess_html(&$variables) {
  $xuacompatible = [
    '#tag' => 'meta',
    '#attributes' => [
      'http-equiv' => 'x-ua-compatible',
      'content' => 'ie=edge',
    ],
  ];

  $variables['page']['#attached']['html_head'][] = [$xuacompatible, 'x-ua-compatible'];
}

Through a template file
In How can I set/remove meta tags?, the user who asked the question mentioned that it's possible to add meta tags in the html.html.twig file. The template file used by Drupal core is core/modules/sytem/templates/html.html.twig. You can copy and paste its content in a theme's template folder.
The relevant part in that template file is the following one.
<!DOCTYPE html>

    <title>{{ head_title|safe_join(' | ') }}</title>
    <css-placeholder token="{{ placeholder_token|raw }}">
    <js-placeholder token="{{ placeholder_token|raw }}">
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />

    {#
      Keyboard navigation/accessibility link to main content section in
      page.html.twig.
    #}

      {{ 'Skip to main content'|t }}

    {{ page_top }}
    {{ page }}
    {{ page_bottom }}
    <js-bottom-placeholder token="{{ placeholder_token|raw }}">

Create your own custom module
If you follow Adding new HTML tags in the  in Drupal 8, it describes the general way of adding tag to head in Drupal 8. I have modified the code to adapt it to the question you asked.
/**
 * Implements hook_page_attachments().
 */
function module_name_page_attachments(array &$page) {
  $xuacompatible = [
        '#tag' => 'meta',
        '#attributes' => [
          'http-equiv' => 'x-ua-compatible',
          'content' => 'ie=edge',
        ],
      ];
  $page['#attached']['html_head'][] = [$xuacompatible, 'x-ua-compatible'];
}

Using a Drupal module
You can use the Metatag module for this, which requires the Token and the Chaos Tool Suite (ctools) modules.
Answer: When adding content to a controller, block, entity, field or other places you don't need to create a hook.
You can attach the meta tag directly to a render/build array. Any render array has at least one render child (containing #theme, #type, #markup, #plain_text), where you can place the attachment:
$build['username'] = [
  '#theme' => 'username',
  '#account' => \Drupal::currentUser(),
  '#attached' => [
    'html_head' => [
      [
        [
          '#tag' => 'meta',
          '#attributes' => [
            'name' => 'foo',
            'content' => 'bar',
          ],
        ],
        'my_module_foo',
      ],
    ],
  ],
];

When rendered the tag bubbles up to page level and is added to the ... section.
In a preprocess hook you can attach to the top level of $variables, see https://drupal.stackexchange.com/a/288989/47547
Answer: Custom Meta module is the way to go. It has a very straightforward configuration and allows adding any custom meta tag to the page head section.

The module allows you to define and manage custom meta tags. Simply select the Meta attribute (property, name, http-equiv) and set the value and content value in the format and the module will add your meta tags to all non-admin content for your site.
Answer: Here we can use the Metatag module.
We need to enable Metatag: Mobile & UI Adjustments submodule.
After doing this from metatag config page we would be able to see Windows & Windows Mobile under each metatag type and according to our requirement, we can add either globally or page-specific X-UA-Compatible content.
Answer: Drupal 7 answer
Recently had to implement some Open Graph <meta property="og:xxx" content="xxx"> tags for Facebook embedding.
Drupal 7 let's you also do the following (not sure about Drupal 8 though):
$ogTitleElement = array(
    '#type' => 'html_tag',
    '#tag' => 'meta', // The #tag is the html tag -
    '#attributes' => array( // Set up an array of attributes inside the tag
        'property' => 'og:title',
        'content' => 'My Custom Title',
    ),
);
drupal_add_html_head($ogTitleElement, 'facebook_title');

Code can be added inside your custom module, or inside the <themename>_preprocess_html function of your theme's template.php file.
Answer: The Mix module can be used to set title and meta tags for the front page and a description meta tag for the node page.
Set title and meta tags for the front page.
Install and enable the Mix module.
Goto /admin/config/mix, find and click the Meta tags link or goto /admin/config/mix/meta directly.
Fill the Frontpage form then click Save Configuration
Goto front page and inspect the page title and source code to see all the changes.

Set a description meta tag for the node page.
Install and enable the Mix module.
Goto /admin/config/mix, find and click the Meta tags link or goto /admin/config/mix/meta directly.
Fill the Node form then click Save Configuration
Goto any node page and inspect the source code to see the changes.

How do I add a meta tag inside the  tag?


parse_str on an object instead of global namespace

Question: Normally using parse_str('name=me&hungry=yes') will make a variable $name and hungry be equal to 'me' and 'yes' respectively.
The problem with using this function is that I'm running it through user input and feel uncomfortable making sure I can't get any attacks because of this, since the variables are being put on the global namespace.
Is there any way to make this functionality only put values into a given variable? For example something like parse_str('name=me&hungry=yes', $obj) will make obj be equal to
array('name' => 'me', 'hungry' => 'yes');

Comment: What's wrong with parse_str('name=me&hungry=yes', $obj):? On reading the manual it should work as you would like. The second argument will be passed by reference.
Answer: Not only for example, but exactly. See parse_strDocs, especially the examples.
Answer: The second argument to parse_str() will be an array of the params.
Answer: parse_str($string,$newarray)
$newarray is the array you can work on from there


Pokemon Go login help?

Question: I was randomly logged out of my account yesterday and had signed in the Pokemon site with a fake email. But now when I made a new account, I signed out then I was signed in perfectly but when I try to log in with my old account it says I need to activate my account with my fake email! But my new account doesn't have this problem. Could anybody help?
Answer: Go to the Pokemon website and update the email address associated with your Pokemon Trainer account to one that you can access. You can create a new one that you only use for this if you are concerned about using your regular email.

Pokemon Go login help?


How to check remote session enabled?

Question: If remote access session is enabled, I have to disable and later enable it. How to achieve this using Python code?.
Answer: I'm not completely sure what you mean by a remote access session.
To see all listening services / ports run one of the following commands:
sudo lsof -i -P -n | grep LISTEN
sudo netstat -tulpn | grep LISTEN

If you leave off the | grep LILSTEN part the same commands will also show active connections.
sudo lsof -i -P -n
sudo netstat -tulpn

Typically VNC connections will use ports of 5900 or so.
On my system I see:
systemd      1    root   33u  IPv4  17131      0t0  TCP *:111 (LISTEN)
systemd      1    root   41u  IPv6  17133      0t0  TCP *:111 (LISTEN)
cupsd     2071    root    6u  IPv6  43261      0t0  TCP [::1]:631 (LISTEN)
cupsd     2071    root    7u  IPv4  43262      0t0  TCP 127.0.0.1:631 (LISTEN)

So I know everything on that list.
I suppose it is possible for crackers to hide services, but that is a separate discussion.

How to check remote session enabled?


What dimensions should my Illustrator artboard be when designing for a wallpaper for the walls of my office?

Question: I am planning to design some patterned wall paper for the walls of my office and I was wondering if there are recommended dimensions for the artboard when designing it via illustrator.
Comment: Depends on the manufacturer, ask whoever is going to print it.
Answer: As long as you keep the proportion right it does not matter while you work on the design.
I prefer to work on a 1:1 scale.
And in the end you should adjust the resolution / DPI ... according to the printer you will use.
p.s: I assume the whole design is vector based :)
Answer: Your design in Illustrator should be in all vector, so the size doesn't really matter. I personally find it very helpful to put an image of the object I design for at the bottom of my layers.
So get an image of your wall(s), lock it and design above it. For printing/projecting it on the wall, you can resize your (vector)work in any size.
Answer: The other answers are correct, it doesn't matter that much as long as it is proportionally identical. Working on 1:1 scale, wall sized may give you performance issues though. You should be aware though that Illy only has an accuracy of 3DP. This can cause some problems with scaling when things need to be super accurate. Some effects and things (especially Warp and Mesh) do a lot better at larger sizes.


Logical Backup strategy in large Oracle Databases

Question: in Oracle databases, I would like to know if it is advisable to make logical backups with exp or expdp in large databases with large volumes of data, greater than terabyte, I have seen several systems with Oracle that have large sizes and only perform physical backups With RMAN, I wonder what the strategy would be if a table was deleted for some reason ...? What do you do in such cases? What would be a save strategy in these large Oracle?
Answer: With RMAN you can do point-in-time recovery (if properly) configured, so you could restore the database to the moment before the drop. Also, you can even restore just a single table from a backup. Other than that you have the recyclebin from which you can recover dropped tables and you have also Flashback Database. So to recover from a dropped table there are plenty of options - without an export.
In my career I have only once used daily exports as part of the backup strategy, but we stopped that once you could restore a single table from backup.
Regards,
Daniel


Which is the most well-known Esperanto movie?

Question: From La Sturmo de Johana Arimo to the animated short Cxapeloj, there are actually quite a few Esperanto movies out there. Which is the most well-known / most watched in Esperantujo? Would that be Gerda Malaperis? (Simply because it's the only one I have seen so far, I think.)
I guess criteria could be YouTube views or public displays at congresses where an estimated number of viewers is known.
Answer: That would certainly be Incubus (1966) starring William Shatner. No Esperanto movie has reached anywhere near its fame. After this, I would venture that either the films of Christopher Mihm like Atako de la lunaj zombioj (although some would disqualify this, since it's an English movie dubbed into Esperanto) or Gerda Malaperis. Unfortunately sales statistics for none of these films are public, so past Incubus, it is very difficult to guess what the second most popular Esperanto film would be.
Comment: Most (in)famous, probably yes. But could it really be the most well-known (in the sense of most watched) one? [According to Wikipedia](https://en.wikipedia.org/w/index.php?title=Incubus_(1966_film)&oldid=1039663683#Release) it was released to theaters _only_ in France and considered lost for quite some time afterwards. Have DVD sales made up for that since then?
Answer: Incubus is pretty much the only full length Esperanto movie so it wins by default. However, I'd say it's infamous due to the terrible Esperanto used.


How to deploy new ActiveX objects

Question: I am supporting some classic ASP pages. One of the core 3rd party components had a leak and was fixed with a new version of their CAB. For first time users or the ones who deleted the objects, browser prompts and downloads the object. How can new cab be made available for existing users with limited privileges?
Comment: I take it you mean getting through their user/browser security?
Answer: If their privileges don't include downloading/installing ActiveX, you will have to have a user with elevated permissions login and download the components.  We have our support center, login to the user's computer, and login into our website.  This downloads the components.
The only other option is to set up some sort of administrative deployment system, possibly packaging the objects for Windows "Run Advertised Programs" or something similar.

How to deploy new ActiveX objects


How can I separate two panels bonded with urethane glue?

Question: I glued a painting wood panel back to another small piece of wood to add hanging wire with gorilla glue.  I now want to take these two wood pieces apart.  What can I use?
Comment: A sharp chizzle or exactO knife will work gorilla glue is really tough once expanded and set.
Comment: Gorilla glue is polyurethane, so give a look for anything that will dissolve it without destroying your project. Ed's comment is probably the best bet, though. "Chizzle". :D
Comment: As they say in NJ, "Fuhgeddaboudit!"
Answer: A saw, a chisel, or brute force. Cured polyurethane glue is largely impervious to solvents, and if there are any exceptions to that, they are probably absurdly hazardous to people.
If you don't actually want the small piece, setting up a router jig to plane it off the painting would be a relatively tidy/controlled way of removing it.


Reuse an open EntityConnection used by previously ObjectContext

Question: I'm using EF 4.1 in a web application and i'm using the UnitOfWork pattern. I open a new ObjectContext by each request and it's used for all operations in the current request. I also open and close an EntityConnection manually.
It would be better if I would not close the EntityConnection and reuse it for future request. I know that it is a Connection Pool mechanism and my ask is:
Have EF this feature included?
and if not
Can I use an open EntityConnection (Used from previously ObjectContext) in another ObjectContext?
The Connection String is always the same.
Answer: No need to do that. Connection pooling is pretty fast. Just take a new connection.


Powering Raspberry Pi 4 'on the move' using power bank

Question: There are good official resources that state that recommended power supply must be 3 amps (e.g. official RPi power supply via mains). However, for use 'on the move' or remote locations this may not be practical. 5v 3 amp USB power banks exist, but are expensive (compared to 'standard' cousins). It seems that RPi doesn't need 3 amps for booting up or use minimal attached devices that are not power hungry (WiFi might still be okay), although I haven't tried this. I have a number of power banks around, one that outputs around 2.1 amps max. (12,500 mAh), 5v USB. Assuming no power hungry devices are required, could I boot up RPi and use GPIO (e.g. weather sensors) or USB webcam? There must be in no way any resulting damage to GPIO pins/modules/devices, SD card or RPi itself from insufficient power/amps; on-screen power warnings okay though. I have a multimeter to test devices if necessary. I assume it would NOT be recommended to attempt to boost amp output (i.e. to 3) using at least two power banks and correct circuitry to achieve this.
Comment: I'm voting to close this question because it lacks clarity of add-ons to be used (so restricting any advice to pure guess work), selection of kit before use case (user has selected Pi before researching needs), opinions will vary on if this is practicable or not and shopping recommendations are off-topic.
Comment: Multimeters are a rough guide only - brownouts that show up on a scope can 'kill' a pi very quickly.  As for your issue - its going to lead to very opinion based / shopping items - both of which are off-topic I'm afraid - even the USB webcam / 'weather sensors' need clarification and current draw to give a judges item.  Remember the foundation set requirements for good reasons not to be impractical - maybe the use case does not match the kit selection (as that seems to have been done first)...  Voting a close.
Comment: I would suggest that you setup the pi with all the sensors etc. that you want to use. Power it from the mains but with a USB power tester (https://www.amazon.co.uk/dp/B06XFZFZX6/ref=cm_sw_r_cp_apa_fabt1_kqOXFbWZ42TH4) between the source and the pi and see how many amps its using under your load. Then match that against what the power bank can deliver.
Answer: There are many questions here regarding powering the RPi from a battery. On the basis of your question, I will guess that you have not read many of them. For example, you don't seem to know how much current the RPi will draw in an "idle/doing-nothing* state. We welcome all contributors here at RPi, but we prize the ones who invest some time and effort to understand the subject matter. You should read some of these other questions, to familiarize yourself with the problems of powering the RPi from a battery.
In general, powering the RPi from a battery is not an easily viable proposition. Why? Because what you need is energy - power delivered over a period of time long enough to accomplish "something useful". The difference may be understood by reading a good explanation, or with some relatively simple math:
Power = V × I ; where V is dc volts, and I is dc current
Energy = P × t ; where P is power, and t is time
These two simple equations allow you to calculate how much energy you need for your "on the move or remote" Raspberry Pi application.
Figuring batteries is a bit more more complex. Batteries generate power from a chemical reaction. There are limits on the amount of power this chemical reaction can produce, and increasing this limit with any given "chemistry" inevitably involves increases in battery volume, weight and cost. There are also "wear-out" mechanisms involved in all (current) batteries that limits their useful life. However, one need not master all of these details to understand the limits for powering a Raspberry Pi from a battery!
Most batteries have various ratings. One of these ratings is amp-hour capacity. If we assume the battery has a constant voltage, Amp-hours may be used as a substitute for an energy rating. Consider this battery for example:

Battery Capacity (mAh)       26000    (or, 26 Amp-hours)

The rating implies that this battery has the capacity to produce 1 Ampere of current for 26 hours. Unfortunately, it's not quite that simple. You may wish to read this article at Battery University to gain more insight into this battery rating. But to keep things simple, we will apply an estimated de-ratiing at 75% of the manufacturer's claim:
Adjusted battery capacity = 26 Ah × 0.75 = 19.5 Ah
At 6 volts, this yields:
Energy = V × I × t = 6 × 19.5 = 117 watt-hours
You can now take this figure, and use it to estimate how much battery you need for your application. Of course you will need to know the Raspberry Pi's energy requirements to compare against a particular battery. From all of the above, it should be clear that requirement may be estimated from the equation for Energy; e.g. 5V × 1A × 24 hours = 120 watt-hours.
Hopefully, this gives you some insight into the subject, and an approach to use for answering your own question. But please do not assume this is all that needs to be done to power an RPi from batteries... we have not even touched on the subjects of regulating battery voltage to feed to the RPi, how to execute a graceful shutdown before the battery is depleted or battery re-charging techniques. Once again: The RPI was designed to run from a mains-powered USB/5V power supply; powering it from a battery is not an easily viable proposition. It can be done of course, but you will need to work through some details.


Publish Failing for pages in Tridion 2013 in "Committing Deploy" phase

Question:
My page contains four components. All the components are more or less similar. The first three components is working fine and the last component creating the issue.
I checked the Component template and its TBB everything is fine but due to this component only the page is getting failed at the Committing Deployment stage kindly help to resolve the issue.
Comment: Can you please share the deployer logs? That will provide insight into what is happening.
Comment: And the deployer and storage configuration also as we'll very likely want to see these next...
Answer: Given the age of this question I'm hoping you've already figured out your issue, but, for the sake of anyone who finds this question with the same issue in the future, I wanted to highlight the cause that I have found to be the most common in my experience.
Duplicate binaries, as mentioned by Raj, are a fairly common issue arising from situations where two different binary items in Tridion share a file name and are being published from the same publication. Since Tridion attempts to place all files into the same folder on the file system by default in many implementations there will obviously be a unique filename conflict with the second binary. I wouldn't be surprised if the component blocking publishing in this case contains a duplicate binary. The deployer logs would show this pretty clearly. There are ways to get around this programmatically if you're running into the issue repeatedly, but the simplest solution is to just make sure all binary filenames are unique.
For more detail you can check out Chris Summers' comprehensive blog post here.
Answer: as mentioned by Hiren, Bj0rn. do check the logs in debug/verbose mode. also check following in respect to  problematic component

Write Permission on the all the folders are correct, images, binary and other folders
Duplicate binary already exists in respective folder.
Paths in storage config
Check JDK version
check any hotfix available for this error if any


Icon vs Text Editing Table

Question: In the context of a table in which each row represents a user, what is better to use? An edit icon at the end of each row, or the Edit text underlined as a hyperlink?
Comment: I think we would need to know more about the rest of the visual language for your product and the context of this table to answer with anything more than just opinion.
Answer: If space allows, try providing both icon and label. Icons alone are famous to have non-universal comprehension (except those that have being around for decades). Even the hamburger icon is notorious to be confusing to users.
If providing icons alone, labels alone or both on each row becomes too repetitive down the rows, maybe you should consider some other approaches such as:

Highlighting each cell when hovered, or some other visual indication that allows the user to click and directly edit the cell like in excel.
Allowing the user to click into the row, and on the user detail page, allow users to simply click on an attribute value (e.g. Last name) and edit it. This automatically activates the edit state, providing a save button.
Answer: An Edit icon - because they are universal and cross language. To avoid crowding or repetition, you could show the icon only upon hover.
Comment: But if you show it only upon hover, how would users know that they can actually edit something? They have to move around a little to figure out that there is a hover option.

Icon vs Text Editing Table


Could a solid metal, tapered, segmented whip with a tip of equal mass to a 5.56 round produce fire arm like ballistics if cracked? (Not on the ground)

Question: The whip would be around 10–11 feet long and most likely made from some steel alloy. If we were to ignore the strength limitations of humans and assume that someone could actually effectively use this theoretical whip as they would a normal one, would it be able to crack the same way that a whip usually does. Could this solid metal whip produce firearm like ballistics if the tip had the same mass as a rifle caliber round, and would the whip be able to survive the forces at play and not destroy itself. (plz ignore my horrible grammar, I'm an engineer in training and should probably be studying for my exam instead of asking this question).
Comment: Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking.
Answer: No.
And the reason I say no will come across as quite nit-picky, but I think it's rather relevant.
Assuming for the moment that at the moment the Whip cracks, the tip departs the whip with the same velocity/energy as your 5.56 round - there are 3 immediate problems which is why I say the ballistics will not be the same.
1: The direction of travel vs the shape of the whip tip.
So with your bullet - it's shaped to be aerodynamic (ignoring WW1 inverted rounds) in the direction of travel. Pointy at one end, spitzer'd at the other - nice.
Your whip crack tip however - assuming one is able to crack it in such a manner as to accurately in the desired direction would most likely shear off the end - even if this is by design - you first have the problem of uneven breakage - but worst of all - you don't have a means of controlling exactly when the break will be and what angle the now projectile will have relative to it's trajectory. It could be nice and aligned - but more likely it's going to be at an angle - this is going to impact your Ballistics.
2: Barrel length vs indeterminacy of the above.
So, for a rifle - we have Barrel length and the sight radius and various other things to try and make sure that everything is as tightly aligned as possible 1 degree offset at 100 yards is 5.2 feet - that's more than a Human's width. Realistically - a good quality 5.56 platform with 1 MOA is accurate to 0.16 degrees.
I don't think it's feasible that someone could crack a whip and have a projectile detach within such a narrow window.
3: Spin!
The big thing about Rifles is that they are... Rifled! those grooves in the Barrel aren't there to increase manufacturing costs - nope - they spin the projectile and impart a degree of stability for the projectile that leads to predictability - the Bullet goes in approximately the direction you want it.
Your Whip crack, if it's going to spin at all, it likely to spin/tumble in the direction of flight, rather than perpendicular to it (like a rifle round) - this combined with the angle of the projectile when it breaks relative to the direction of travel means your projectile will probably be similar enough as makes no difference within a short distance - but air drag and tumbling and lack of stability  etc. etc. will mean significantly different Ballistics
Comment: @sam_phillips_1628534640: As far as I understand, _this_ is the question the OP wanted to ask. I've re-read the question a few times, and at no point to they ask about a whip "firing" a bullet.
Comment: @MatthieuM. - I think the question OP wanted to ask is about **terminal** Ballistics - however, that's a completely different question. FWIW - answer is still no, but for completely different reasons.
Comment: So I did not think of the idea that the tip breaking off would be intentional, but that is a very interesting idea. I should have explained better, but I meant that if the whip is cracked would it be able to inflict the same if not greater damage than a rifle as the metal tip would be moving at approximately twice the speed of sound and have the same mass as the rifle projectile. If the whip was made of say s7 shock steel could is realistically in the hands of some super human be used repeated the same way that a normal whip functions
Comment: @MatthieuM. Ballistics refers to the science of projectiles, which implies disconnected from the whip. I can see the original intention, but as written this answers the question.
Comment: @TannerFerguson If you want to know whether a metal tipped whip could deal comparable damage to a bullet _at normal whip range_, that would be a good follow-up question to ask.
Comment: Poor control could be fixed by computer driving the whip and releasing the bullet, with feedback from accelerometers along the whip. Getting a spinning projectile is tricky but doable with some clever engineering like having whip twisted at rest and untwisting when fired.
Answer: Here is a supersonic trebuchet video. It has a fair amount of physics in it if you are interested. So, the speeds are possible. It does not spin what it launches, but this was never the aim of the thing. But at least the velocity part of the problem has been comprehensively answered.


Position of 不 in a sentence

Question: Is there a difference between these two sentences?

他不在学院学习。
他在学院不学习。
Answer: Generally, 不 negates the word(s) right after it.
Therefore sentence 1 can be interpreted in two ways depending on the context:

不 negates 在学院, so he does study, not in the school(but elsewhere).
不 negates 在学院学习, so he doesn't study in the school(we don't know if he studies elsewhere, or doesn't study at all).

Sentence 2 is simpler, 不 negates only 学习, so he is in the school, but doesn't study.
And you can add sentence 3: 他学习不在学院, which clearly indicates he does study elsewhere.
Comment: `他学习不在学院` isn't valid Chinese. should be `他没在学院学习`
Comment: @imkzh I think it is, like 他学习不在学校,在家里。 / 他上班不在白天,在晚上。
Comment: `他学习不在学校,在家里。` should be `他不是在学校里学习,而是在家里`. And `他上班不在白天,在晚上。` should be `他不在白天上班,` or more precisely  `他的班不在白天,是在晚上` / `他上晚班不上白班`
Answer: Yes there is a big difference between them.
The first sentence means:
He is not studying in the school.
The second sentence means:
He is in the school but not studying.
Answer: 他不在学院学习。// He won't study in the school. It implies he will do something else in the school, e.g. play. And it can also imply that he is not the student in the school.
他在学院不学习。// The sentence implies a condition as if saying if he's in school he won't study. It also implies that the way to get him study is to make him somewhere else. E.g. 他在学院不学习, (在其他地方可能会学习). It can also be that the purpose he is in school is not for study but something else.
So, both sentences can be interpreted differently. We need context to understand the true meaning.
Have fun!
Answer:
他不在学院学习。 This sentence needs a "tense" to clearly indicate the person's status - 他已不在学院学习了。 Also, I think 讀書 (study) is a better choice than 学习(learning).

他在学院不学习。 This sentence needs conjunction in between the phrases and a modifier before 不学习 to make it sounds complete - 他在学院但不好学习。

It is clear that the subjects following "不" are completely different, so the meanings of the sentences.

Position of 不 in a sentence


Why am I having trouble with lettuce germination?

Question: I want to grow lettuce. I used fresh Grand Rapids variety seeds but the problem is that they would not germinate. Day temperature there is between 26° to 29° C (78° to 84° F) and night temperature is between 19° to 23° C (66° to 73° F). Now, what is the reason that they would not germinate?.
Comment: Additional information would be helpful.  Are you growing them inside or outside.  Are you planting them in pots or in the ground?  Did you use any kind of seeding mix to start the germination process or just put them in the ground?  How many days has it been?
Comment: Growing inside and in pots. No, i am not using seedling mix. After three days of sowing when i see the seed they swell too much but cannot germinated. Can water also affect germination?.
Answer:
Lettuce, while now bred into dozens on varieties, originally comes from the Mediterranean, an area with hot and dry summers. A mechanism called thermo-inhibition prevents the seeds to sprout when the soil is warmer than ca. 27C / 80F. In the wild, this protects the seeds to grow in conditions when they have virtually no chance of survival; for a gardener, this means germinating lettuce in summer often can be difficult.
Air temperature is less critical, btw., but remember that soil in direct sunlight can get really hot. Plus this can mean the top layer of soil (and the seeds) is prone to drying out.
Some lettuce seeds need light to germinate, so sowing too deep can also be a problem.

For temperatures that are just a bit too warm, soaking the seeds in cool water for 16-24 hours can help overcome the temperature inhibition.
For more reliable and temperature-independent results, consider germinating your seeds in wet paper towels and then planting the tiny seedlings. Of course that means you must protect them from the summer sun and keep them constantly moist during the initial growth stages.

Side note:
Hot temperatures also encourage bolting, which may also lead to more bitter leaves, and possibly less developed heads. Make sure you choose appropriate breeds or grow your lettuce primarily in spring and autumn. They are a short time crop anway.
Answer: That is a little warm for lettuce seed germination.  A more useful number to know would be your soil temperature.  There could be a variety of factors involved though.  Did you keep the seed bed moist?  Did you sow the seeds too deep into the soil?  Hard to answer your question without more information.
Comment: Yes, i keep the seed bed moist and i spread it on the surface of soil. Can water also effect the seed germination?. When i see the seeds after 3 days they only swell too much. Is 28 C temperature is not suitable for germination?.


What is the difference between MethodChannel, EventChannel & BasicMessageChannel?

Question: In Flutter, there are three types of platform channels, and I want to know about the difference between them.
Answer: These channels are used to communicate between native code (plugins or native code inside of your project) and the Flutter framework.
MethodChannel
A MethodChannel is used for "communicating with platform plugins using asynchronous method calls". This means that you use this channel to invoke methods on the native side and can return back a value and vise versa.
You can e.g. call a method that retrieves the device name this way.
EventChannel
An EventChannel is used to stream data. This results in having a Stream on the Dart side of things and being able to feed that stream from the native side.
This is useful if you want to send data every time a particular event occurs, e.g. when the wifi connection of a device changes.
BasicMessageChannel
This is probably not something you will want to use. BasicMessageChannel is used to encode and decode messages using a specified codec.
An example of this would be working with JSON or binary data. It is just a simpler version because your data has a clear type (codec) and you will not send multiple parameters etc.
Comment: can eventChannel send stream from flutter to platform ?
Answer: Here is a link to a good explanation for you https://medium.com/flutter-io/flutter-platform-channels-ce7f540a104e
Basically there are two main types:
Method Channels: designed for invoking named pieces of code across Dart and Java/Kotlin or Objective-C/Swift. (From flutter to the platform)
Event Channels: specialized platform channel intended for the use case of exposing platform events to Flutter as a Dart stream. (From the platform to flutter)
Comment: Method Channels can *also* be used to call methods (and return values) in the Dart side from native.
Comment: @Alexufo see: https://stackoverflow.com/questions/50187680/how-to-call-methods-in-dart-portion-of-the-app-from-the-native-platform-using-m/50188557#50188557
Comment: @RichardHeap any example?
Comment: @RichardHeap can we use it to send data from native to dart? I want to send data from button on native screen
Answer: @creativecreatorormaybenot answer clears the things, let me add more to this.
Method Channel
This is more like RPC call. You invoke a method from your Flutter app to the native code, the native code does something and finally responds with a success or error. This call could be to get the current battery status, network information or temperature data. Once the native side has responded, it can no longer send more information until the next call.
Method Channel provides platform communication using asynchronous method calls.

Note:- If desired, method calls can also be sent in the reverse
  direction, with the platform acting as client to methods implemented
  in Dart.

Event Channel
This is more like reactive programming where platform communication using asynchronous event streams. These events could be anything that you need streamed to your Flutter application.Streaming data from the native code to Flutter app like continuously updating BLE or WiFi scanning results, accelerometer and gyro, or even periodic status updates from intensive data collection.
Basic Message Channel
It provides basic messaging services similar to BinaryMessages, but with pluggable message codecs in support of sending strings or semi-structured messages. Messages are encoded into binary before being sent, and binary messages received are decoded into Dart values. The MessageCodec used must be compatible with the one used by the platform plugin.


What happens when Lee Sin uses Resonating Strike on a Vlad using Sanguine Pool?

Question: Basically, here's the situation: Lee Sin uses Sonic Wave, hitting Vlad. Vlad pools to get away. Can Lee Sin use Resonating Strike?
Answer: Lee will be teleported to Vlad, but will not damage him. Works the same as twisted advance, Maokai will be teleported to Vlad location, but will not deals any damage.
Answer: It seems from that LoL forum thread [1] that once Lee Sin has a lock on a target, he can dash to him even if he became untargetable, thanks to the lock. This does make the damage unless the enemy champion abilities cancel received damage.
In the detailed abilities on wikia [2] and [3] we can read that

Resonating Strike is the follow-up ability to Sonic Wave. If Sonic Wave has hit a target, Lee Sin will be able to charge them while they are revealed, dealing physical damage and an additional amoung of damage equal to 10% of their missing health.

Morgana's Black Shield does not block Sonic Wave nor Resonating Strike, but Resonating strike can be blocked by other spell shields.
No patch note ever noticed that this has been corrected so far (V188.8.131.52) so it should be the same at the moment.


Should Archive Tables have their own Surrogate Identity Key

Question: Should archive tables have their own surrogate identity id/key? For a customer sales table example:

We have original table, and then an additional archive table with surrogate archive id.
Rules for primary clustered indexes are:

Ever Increasing
Narrow
Unique
Static

Reference: Effective Clustered Indexes (Red-Gate Hub)
At the last company I worked for, there was a thought, that if we accidentally missed a day or period of importing, e.g. imported data for May 3, accidentally skipped May 4 (issue with system), and imported May 5, that without the new archive id, we would have to reinsert data between the pages, causing fragmentation, and slower inserts.
With the archive id, we can just add on in an ever-increasing manner.
Just inquiring if adding archiveid column is a standard industry practice.
Original Table:
create table dbo.CustomerSalesId
(
    CustomerSalesId bigint primary key identity(1,1),
    CustomerId bigint not null,
    PurchaseDate datetime not null,
    Amount decimal (10,2) not null,
    .........
}

Archive Table:
create table dbo.ArchiveCustomerSalesId
(
    ArchiveCustomerSalesId bigint primary key identity(1,1),
    CustomerSalesId bigint,
    CustomerId bigint not null,
    PurchaseDate datetime not null,
    Amount decimal (10,2) not null,
    .........
}
create unique index ux_CustomerSalesId on ArchiveCustomerSalesId(CustomerSalesId)

Answer: Fragmentation is not as bad as you think it is. Page fullness (internal fragmentation) is much more important than the physical order of the pages (external fragementation).
Having rows inserted out of order might affect the performance of scans when the pages are read from disk. When reading pages from memory, it is not important whether the pages are in the correct order or not. Also, you are probably not working with a physical server and your disk is likely a LUN sitting on a SAN, so the advantage of page contiguity is negligible.
A good visual description of internal vs. external fragmentation can be found here: http://www.sqlservercentral.com/blogs/practicalsqldba/2012/04/05/sql-server-index-fragmentation-understanding-fragmentation/
A great article on why fragementation is not what you think can be found on Brent Ozar's blog: https://www.brentozar.com/archive/2012/08/sql-server-index-fragmentation/
That said, using an additional surrogate key just for avoiding fragmentation is not a good idea. A good clustered index is, first of all, the key that you use the most to locate the data, so that you don't have to perform additional lookups. If you alter the clustering key when you archive the data, to locate the rows you would have to use a unique nonclustered index on the column(s) of the previous clustering key. A nonclusterd index is a copy of the data that requires additional space and also requires lookups to extract columns that are not part of the index.
Wrapping up: no, you don't need an additional "archiveId" surrogate key.
Comment: just wanted to add, I forgot to add in original CustomerSalesId on Archive table, don't think it makes a difference to answers, thanks-
Answer: Recently I went through this exercise for the system on which I'm currently working. I chose to retain the current surrogate IDs.
Mostly this was to retain historical references. We have various secondary processes which use the ID as an external reference. This may not be best practice, but it's the way it is. Internal logging captures the ID, too. For these reasons I'd want to retain the active table's ID in the archive table's values. It seemed redundant to include another column which performed the same purpose.
As for fragmentation, this is not an issue. These rows will be used in two circumstances - point lookup (what was row X's value of column Y?) or broad aggregates (how many Zs did we have in January?). Either way, having a bit of fragmentation will not hurt us.
As and when our volumes grow significantly, and our analytics become more complicated, I may need to re-visit this. Likely I'd use partitions and online rebuilds (SQL Server 2014+).