Which page range do you cite in an article in IEEE proceedings?

Question: In biblatex I have cited using @inproceedings with pages={3310--3317}. I myself only used a pdf of the article, which does not contain page numbers. Since I cite the article directly and not the book, do I cite the page range 1-7 or 3310-3317 in the text itself?
Comment: You cite in such a way that somebody else can actually find the article. Since it is in a proceedings volume, one would use that actual numbers used in the proceedings.
Answer: If the proceedings actually have page numbers, cite the page range in which the article appears.
However, it is becoming more and more common for many conferences to not have bundled proceedings with page numbers (also in electronic form), and so all the articles have no page numbers or they have the same fictitious page numbers (e.g. with starting page 1 for all the articles). In this case, page numbers don't matter, but the reader should be able to locate the article: therefore, whether you don't put any page range or you put the fictitious one, try to add other identifiers like the DOI, if supported. This is especially important if there are two version of the article with the same title, a short one published in the proceedings and an extended one published in a journal.
Comment: Ok, I see. Very interesting. I myself use the online PDFs, which do not have page numbers. But I am not able to find DOIs for those, as all citations show them in the Proceedings. So I'll stick to using the real numbers


In generating Midi Track using C# Code, how Can I make the tone being played, not fading out?

Question: I am building a small MIDI composer application, using the Stanford Library. It is almost complete, except for a small problem: sound vanishes after the NoteOn command, but I want notes to keep on playing until I release the button.
Answer: With MIDI, you should hear the note continue forever until you send a NoteOff command.  If you're hearing a note begin but then fade out (without having sent a NoteOff message), then it might be that the channel is set to an instrument that naturally fades out on its own - like a marimba or steel drum sound.
Comment: all answers are accepted! :) yes, I've piano as the instrument.
Answer: That would be down to the MIDI device that you are addressing. You might be able to tell it to increase the sustain level of the envelope via MIDI NRPN or SysEx, but this would be device specific. Generally a string or pad voice will maintain a high sustain, whereas a piano or other percussive sound will consistently fade to zero regardless of sustain level.
Comment: I don't quite understand what you means by MIDI Device. I just using plain sound card. No external midi devices attached. Am I right?
Answer: So, you are saying that when you play a note it decays normally (as if you head down a piano key) and you don't want that?
That is a feature of the synthesizer and has nothing to do with MIDI.  You will need to pick a patch that doesn't do this.  Organ patches should work fine.
If instead you are saying that your note stops immediately (as if you hit the key and immediately released) then you have something sending a note-off command or a note command with 0 velocity.  Check to make sure you are in fact sending 7-bit values for velocity and what not.
Comment: @swdev, yes, that's what I mean.


compile AMR-nb codec with RVCT for WinCE/Window Mobile

Question: I'm working on amr speech codec (porting/optimization)
I have an arm (for WinCE) optimized version from voiceage and I use it as a reference in performance testing. So far, binary produced with my lib beats the other one by around 20-30%! I use Vs2008 and I have limited access to ARM instruction set I can generate with Microsoft compiler. So I tried to look for alternative compiler to see what would be performance difference.
I have RVCT compiler, but it produces elf binaries/object files. However, I run my test on a wince mobile phone (TyTn 2) so I need to find a way to run code compiled with RVCT on WinCE.
Some of the options are
1) to produce assembly listing (-S option of armcc), and try to assemble with some other assembler that can create COFF (MS assembler for arm)
2) compile and convert generated ELF object file to COFF object (seems like objcopy of gnu binutils could help me with that)
3) using fromelf utility supplied by RVCT create BIN file and somehow try to mangle the bits so I can execute them ;)
My first attempt is to create a simple c++ file with one exported function, compile it with RVCT and then try to run that function on the smartphone.
The emitted assembly cannot be assembled by the ms assembler (not only they are not compatible, but also ms assembler rejects some of the instructions generated with RVCT compiler; ASR opcode in my case)
Then I tried to convert ELF object to coff format and I can't find any information on that. There is a gcc port for ce and objcopy from that toolset is supposed to be able to do the task. However, I can't get it working. I tried different switches, but I have no idea what exactly I need to specify as bfdname for input and output format. So, I couldn't get it working either.
Dumping with fromelf and using generated bin file seems to be overkill, so I decided to ask you guys if there is anything I should try to do or maybe someone has already done similar task and could help me.
Basically, all I want to do is to compile my code with RVCT compiler and see what's the performance difference. My code has zero dependencies on any c runtime functions.
thanks!
Comment: About ASR "opcode" - really, it's like a Macros. There are many of this "opcodes" used in RVCT arm asm. For example, POP/PUSH/RET/LDM/All shifts (like ASR, LSL) and maybe others. (ASR Rd, Rx, Y => MOV Rd, Rx,ASR y).
You can write MACRO in ms arm asm to compile them, e.g.:
 MACRO
 RET
 MOV PC,LR
 MEND
Answer: Just an update...
I compiled gnu binutils with support for arm-pe and arm-elf.
convert arm-elf to arm-coff:
objcopy.exe -I elf32-littlearm -O pe-arm-wince-little test.o test.obj
Now test.obj contains the same function: int add(int, int);
the problem is that ms compiler rejects the test.obj file: test.obj : fatal error LNK1136: invalid or corrupt file
I also tried another approach. I converted test.o to symbolsrec format (I have no idea about this format, but that's the only one that worked) and then I converted the generated file to arm-pe. In this case ms compiler linked to the generated test.obj, but the generated machine code isn't valid.
I also compiled the test.cpp with gcc-ce and tried to link to he generated .obj file and in this case it all worked.
Here's the assembly code as shown in VS debugger:
<code>        int X2 = add(X, Y);
00012068  ldr         r1, Y, #0x28
0001206C  ldr         r0, X, #0x2C
00012070  bl          00011000
</code>
In case when I was able to link to converted obj file it looked like this:
<code>        int X2 = add(X, Y);
00011068  ldr         r1, Y, #0x28
0001106C  ldr         r0, X, #0x2C
00011070  bl          |WinMain + 0xfffff000 ( 10000h )|
</code>
In that last instruction it jumps to some random location that has nothing to do with my int add(int, int); function.
Answer: You mention you're using Vs2008 and "... I have limited access to ARM instruction set I can generate with Microsoft compiler. So I tried to look for alternative compiler ..."
(Assuming you can target WM7...) I recommend you try the latest CTP SDK for Windows Mobile 7 (see here).
The C++ compiler has huge code generation improvements over previous releases. And can target latest ARM architectures. Believe me, code generation quality is very high.
PS: Maybe the fact that I have implemented some of those features makes me a little bit biased.  :)


What does select filter do?

Question: In the settings menu of the editor, there is a checkbox option titled "select filter." What does this do?
Answer: Enable this option. Select an item and go the trash tab. Now in the bottom right, click the "Custom" button. Now, if you go back to the edit tab, you can only select items that are of that first item's type. If you try to select another item it will just not select. This still works for swiping.
To be able to select any item again go back to the trash tab and click the "None" button.

What does select filter do?


Calculation of FPS on object detection task

Question: How to calculate mean speed in FPS for an object detection model like YOLOv3 or YOLOv3-Tiny? Different object detection models are often presented on charts like this:

I am using the DarkNet framework in my project and I want to create similar charts for my own models based on YOLOv3. Is there some easy way to get mean FPS speed for my model with the "test video"?
Answer: You can use the dataset test set as "frames" of video. Test the images with your model and calculate the images per second of the result and that is the same as frames per second. However you should set the batch size to 1 as in the real world scenario. You should also display each image with teh corresponding boxes after inference and remove the accuracy calculation as to imitate the real world situation.
Answer: @Clement Hui
Thanks for your answer, I ask AlexeyAB from Darknet the same question and he add now flag for Darknet for this type of model speed measurments:
https://github.com/AlexeyAB/darknet/issues/4627

I added -benchmark flag for detector demo, now you can use command 2652263
<code>./darknet detector demo obj.data yolo.cfg yolo.weights test.mp4 -benchmark</code>
But for very fast models the bottleneck will be in the Video Capturing from file/camera, >or in Video Showing (you can disable showing by using -dont_show flag).

I think that it is the best solution, you only need the newest version of Darknet (from AlexeyAB).


Concepts of God

Question: Is the concept of God in Jewish religious traditions often characterized by attributes like self-centeredness, a demand for worship, jealousy, and punishment for not adhering to beliefs?
Comment: G-d, blessed be He, isn't self-centred for He cares about us. He shared goodness by creating. He is jealous as a human-emotional term-translation indicating that He cares that we don't go astray for He does not wish to see His creations ruin themselves perpetually. He demands worship because it is good for us & it is the most appropriate form of interaction with Him for He is that Holy. All 'beliefs' in Judaism are there for good reasons, & not following them leads to ruin, so those who harm others by not following the beliefs must get punished (e.g. removing them from those who are good).
Comment: Not really, Judaism has far more of an "it's up to you attitude" than most people realise.
Comment: [Welcome to MiYodeya](https://judaism.meta.stackexchange.com/a/3887/11501) Manny and thanks for this first question. Great to have you learn with us!
Answer: Welcome to Mi Yodeya.
I am certain this question is being asked like it normally is: innocently. However, this is actually an old Christian trope, going back to at least Marcion of Sinope, and has a horrible history of being invoked in the prelude to horrific abuse of the Jewish community. As such I've voted to close it, as I am not sure Mi Yodeya is here to provide response to such things.
Answer: Marcion of Sinope: try our new bible! Tyrant free. Source
Given that this misconception is so widespread by now (Rabbi Sacks AH had to mention that this was an antisemitic trope to a very surprised Richard Dawkins, a complete atheist, in their debate, and Stephen Fry, another atheist, has made this point viral recently), and is therefore almost a legitimate question, I'll give it an answer if I may.
Well 2 answers: the first is just go and read the entire Tanach, or even 50% of it; that would be the minimum level of prerequisite research required to bring to a question like this, ideally! I will give a couple of quotes at the end, but putting Hashem in the full context the Tanach offers will go a long way towards educating oneself on what He is like, and dispelling this myth.
The main answer I would like to give, is that the Torah reveals Hashem to be real. Not simply in the sense of "existing" (when it comes to that, the philosophical understandings of Hashem are very rich and deep, but not really the main thing we discuss), but in the sense of being a real someone. He may not have a body, but He is there and He is in a very close and personal relationship with us, and He needs that relationship and us infinitely. This is His project, people and desire.
So He is real, we are real, and therefore this relationship we are in with Him is real. A real relationship has anger sometimes. It has demands. It has consequences, which come from the relationship, rather than self-centeredness. He Himself defines goodness as "considering you more important to Me than I am to Myself".
The western idea of Hashem is quite Aristotelean, and this view can lead us to think of Him as a perfect infinite unchanging rock, who is aloof and unaffected by us, and therefore the key context to understanding Hashem is missing. The reader will miss that Hashem is real and actually cares. We are made in His Image, as the Torah tells us at the very beginning, and therefore we shouldn't have fallen into this trap of viewing His heartfelt dynamic relationship with us as depicting some sort of uncaring tyrant, ch'v, in the same ways we shouldn't view our parents, or our spouses, as being tyrannically in their love and closeness to us. Alas, we are easily impressed by silly, cynical tropes, especially under the influence of Greek thinking...
How deeply He cares is actually quite a personal, private matter, and as the Tanach progresses, it gets more and more revealed. The Tanach is indeed the full story of a relationship between God and His people, and at the beginning, the closeness is less obvious as the relationship is still new... Indeed, in any close and personal relationship, there is a lot of mystery, especially when it is new and they are still figuring each other out (how much more so when you are in a relationship with Hashem).
Jewish Tradition is now a nearly-4000 year story of everything we have got to know about Hashem through alacritous study, and can't possibly be squeezed into 30,000 characters of a Stack Exchange answer. There's so much to know, and now that you know that OP's point is just a trope, you won't be surprised to find out what should indeed really be true: that He is absolutely wonderful in every way, the source of all goodness (everyone likes goodness, right?), and there is an endless amount of study to get to know Him properly.
Here are some quotes from Tanach, followed by a quote from the Talmud.
From Torah:
Shemot 34:6-7:

ויעבר יהוה  על־פניו ויקרא ה  ה אל רחום וחנון ארך אפים ורב־חסד
ואמת  נצר חסד לאלפים נשא עון ופשע וחטאה ונקה לא ינקה
And the Lord passed by before him, and proclaimed, The Lord, The Lord,
mighty, merciful and gracious, longsuffering, and abundant in love and
truth, keeping love to thousands, forgiving iniquity, and
transgression, and sin, but who will by no means clear the guilty.

Our tradition records that this is the highest name of Hashem, the Tetragrammaton, and this name is when we want to describe who He is in essence.  Basically, this verse in a nutshell: "I love you with my very being and therefore I have very high expectations of you which are no joke, however I know that it's very very hard so I will be extremely understanding and patient with you, and help you get there with all my love"
From Prophets:
Hashem cries over our suffering (Yirmiyahu 13:17):

וְאִם לֹא תִשְׁמָעוּהָ בְּמִסְתָּרִים תִּבְכֶּה־נַפְשִׁי מִפְּנֵי
גֵוָה וְדָמֹעַ תִּדְמַע וְתֵרַד עֵינִי דִּמְעָה כִּי נִשְׁבָּה עֵדֶר
ה׃
But if you will not hear it, my soul shall weep in
secret for your pride; and my eye shall weep sore, and run down with
tears, because the Lord's flock is carried away captive.

Hashem is in a real relationship with us, with its ups and downs, but the love is the real "face" of Hashem (Yishayahu 4-8):

אל־תיראי כי־לא תבושי ואל־תכלמי כי לא תחפירי כי בשת עלומיך תשכחי וחרפת
אלמנותיך לא תזכרי־עוד כי בעליך עשיך ה צבאות שמו וגאלך קדוש ישראל אלהי
כל־הארץ יקרא כי־כאשה עזובה ועצובת רוח קראך ה ואשת נעורים כי תמאס אמר
אלקיך ברגע קטן עזבתיך וברחמים גדלים אקבצך בשצף קצף הסתרתי פני רגע ממך
ובחסד עולם רחמתיך אמר גאלך ה
Fear not; for you shall not be ashamed: neither be confounded; for you
shall not be put to shame: but you will forget the shame of your
youth, and will not remember the reproach of your widowhood any more.
For your Maker is your Husband: the Lord of hosts is His name; and
your redeemer is the Holy One of Yisrael; The God of the whole earth
He is called. For the Lord has called you as a woman forsaken and
grieved in spirit; but a wife of youth, can she be cast off? says your
God. For a small moment have I forsaken you; but with great mercies
will I gather you. In the overflowing of anger I hid my face from you
for a moment; but with everlasting faithful love will I have mercy on
you, says your redeemer, the Lord.

From Writings
This is a basic tenant of Judaism (Tehillim 23:6):

אך  טוב וחסד ירדפוני כל־ימי חיי ושבתי בבית־ה לארך ימים
Only goodness and steadfast love shall pursue me all the days of my
life, and I shall dwell in the house of the Lord for many long years.

Hashem is intimate and deeply, passionately loving (Shir HaShirim 7:7, 11, 8:6-7):

מה־יפית ומה־נעמת אהבה בתענוגים
How fair and how pleasant art thou, O love, for delights!
אני לדודי ועלי תשוקתו
I am my Beloved's, and His desire is towards me.
שימני כחותם על־לבך כחותם על־זרועך כי־עזה כמות אהבה קשה כשאול קנאה
רשפיה רשפי אש שלהבתיה מים רבים לא יוכלו לכבות את־האהבה ונהרות לא
ישטפוה אם־יתן איש את־כל־הון ביתו באהבה בוז יבוזו לו
Set Me as a seal upon thy heart, as a seal upon thy arm: for love is
strong as death; jealousy is cruel as She᾽ol: the coals thereof are
coals of fire, which have a most vehement flame. Many waters cannot
quench love, nor can the floods drown it: if a man would give all the
substance of his house for love, it would be utterly scorned.

Here we learn that such an intense love, such a passionate real relationship is "strong as death" and involves "jealousy as cruel as hell". We have this in the west; we view parental love as "controlling", martial bonding as "stifling", jealousy as a "red flag". Indeed if such a jealous love is as hot as hell, it's no wonder that hearing of a new testament that tells us that God's love is cool (so much so that He wouldn't mind if you go to hell forever if you don't love Him back) would be appealing. The Jews would rather withstand the temporary "hell" of this intensely real, vulnerable love, than the eternal hell of His love not being real, and wish everyone else would have the strength and courage to do so as well, in their personal lives and in their relationship with God.
From Talmud
Chagiga 5b (with Steinsaltz translation):

״וארא והנה רוח סערה באה מן הצפון ענן גדול ואש מתלקחת ונוגה לו סביב
ומתוכה כעין החשמל מתוך האש״. להיכן אזל? אמר רב יהודה אמר רב: שהלך
לכבוש את כל העולם כולו תחת נבוכדנצר הרשע. וכל כך למה? שלא יאמרו אומות
העולם: ביד אומה שפלה מסר הקדוש ברוך הוא את בניו. אמר הקדוש ברוך הוא:
מי גרם לי שאהיה שמש לעובדי פסילים — עונותיהן של ישראל הן גרמו לי.
The verse states: "And I looked and, behold, a stormy wind came out of
the north, a great cloud, with a fire flashing up, so that a
brightness was round about it; and out of its midst was like the color
of electrum, out of the midst of the fire" (Ezekiel 1:4). The Gemara
poses a question: Where did that wind go? Rav Yehuda said that Rav
said: It went to conquer the entire world under the wicked
Nebuchadnezzar. And why was all of this necessary? Why was it
necessary that the entire world be subjected to his dominion? So that
the nations of the world would not say: The Holy One, Blessed be He,
delivered His children into the hands of a lowly nation. Since it was
already decreed that the kingdom of Israel would fall into the hands
of Nebuchadnezzar, God made him into a great conqueror, so that Israel
would not be ashamed of being defeated by him. The Holy One, Blessed
be He, said with regard to this: Who caused Me to be an attendant to
worshippers of molten images, forcing Me to wage their wars? It was
the sins of Israel that led Me to do so.

This really answers your question most directly. It clearly demonstrates that all acts of suffering inflicted upon us by Hashem are only for our own very best good, and do not reflect any cruel feelings on His part. On the contrary, it goes against His very being, so much so that He goes to the trouble of actually helping idolators for the "small" concern of His people's dignity.

There is much endless further reading in the Jewish tradition on the subject of who is Hashem and what is He like/about. Rabbi Heschel (God in Search of Man) and Rabbi Sacks (Covenant and Conversation) come to mind. Chabad Chassidus is a recommendation of mine, and Rabbi Manis Friedman's lectures especially.
Comment: All terms referring to G-d having emotions are metaphorical, just like terms referring to G-d having physical body parts.
Answer: The only Jewish tradition of God that has those characteristics is those whose concept of God is limited to just the Biblical text. As far as I know all Rabbinate and Karaite Jews interpret God through traditions that do not teach God as having negative characteristics. Portions of the Torah that may not show God in a positive light are reinterpreted and validated with outside traditions to not make God "look so bad."
Thats the thing about the Jews though. They aren't going to censor their books because of problematic verses. And so yes, if you treat certain Biblical verses as devoid of any outside tradition you can come away with the impression that the Biblical God may resemble such negative characteristics.

Concepts of God


Sign Up vs. Add to Cart CTA for different product types' product detail pages

Question: So we have a webinar business that offers users the option to sign up for an upcoming webinar as well as a purchase a recording of a past webinar. Every webinar (upcoming and recorded) has it's own product detail page.
I am curious if it would be considered a best practice or intuitive to change the "sign up" CTA on the product detail page for upcoming webinars to "add to cart" for past webinar recording detail pages. My thought is that customers aren't actually "signing up" for a recorded webinar... they're just purchasing access to the recording.
Does this make sense to implement or am I only adding potential for confusion by having 2 different CTAs on these detail pages? I haven't seen any examples of this in the wild, so I was hoping for some thoughts/examples/direction from the group here.
Thanks!
Answer: welcome. Your instincts are correct that "Add to cart" is definitely a better CTA than "sign up". You'll want to hide the "sign up" button if the user can't sign up. "Add to cart" is fine for the remaining button if there are cues on the page that the webinar happened in the past, and the user can purchase a recording. If that's not possible, you might consider a CTA such as "Add recording to cart" or "Purchase recording".


M2 PCIe NVMe SSD driver

Question: I´m wondering if or what Ubuntu version supports my shiny new M2 PCIe 3.0 NVMe SSD (Samsung PM951 MZVLV 1TB), so Ubuntu will see it when I boot it from USB.
Answer: OK, I asked Mr. Google and dug around a little bit.
Seems that recent versions, at least 14.04 LTS (maybe 13) support the NVMe protocol. I´ll try this.

M2 PCIe NVMe SSD driver


Who are the "alternate" bosses?

Question: I have seen tweets from Killing Floor 2 and interviews in which they said they are hidden secret bosses in Killing Floor 2. Aside from the Patriarch, who are these bosses? I've been playing the beta extensively the past day and haven't yet seen any boss besides from the Patriarch.
Answer: Right now Patriarch and Hans Volter are the only bosses in the game, with (as far as I have seen) no announcements of new ones being planned
Answer: From what I've seen, Hans Volter is currently the only boss in the game.
The Patriarch hasn't even been revealed yet (though it has been confirmed).
Doesn't mean there aren't secrets to be found, though :D
Answer: It's too soon to tell, the game is still in beta phase, perhaps there will be announcements on this anytime soon.

Who are the "alternate" bosses?


OK to tin soldering tip prior to shutdown?

Question: I usually clean my soldering iron's tip before turning it off. Yesterday I read an article where someone suggested to tin the tip before turning off the iron. Is this a good idea? And how would it help? My station is a Weller WSM-1 if it makes any difference.
Comment: The impression I got from the article is that it somehow protects/prolongs the life of the tip.
Comment: http://electronics.stackexchange.com/a/1427/14004
Answer: An experienced colleague told me that having some solder on the tip protects it from oxidation. Following his advice, I have found that my tips tend to last longer than they used to.
I would guess that the solder protects the tip by keeping it from being exposed to the air.
Answer: Yes, tin your tip when turning off the iron.
Actually I usually turn the iron off first, then tin the tip with the residual heat.  The iron will still be hot enough to melt solder for a while.  You don't need extra heat to tin the tip, just enough to melt some solder.  The lower temperature reduces the oxidation of the solder so that the thin coating of soler you are putting on your tip is more useful.  That will also make the tip more usable when you turn it on again.  A thin layer of solder on the tip helps because of its wetting action, but oxidized solder does the opposite, and leaves the tip itself exposed to oxidation.


How can I further prevent my Fiddle Leaf Fig plant from growing slanted?

Question: As my plant grows, it slants forward. It is getting taller and I'm assuming that this is why, but is their a way to prevent this? Or a way to get it straight by using some type of item?
Answer: This plant is growing towards the light.  Some solutions:

easiest, rotate the plant pot a quarter turn every week
stake it
take it out of the pot, trim off the roots on the side it is leaning towards and repot straight.  Of course it will lean again so....

Providing more light and rotating the plant will give the best results with least work.
Comment: Love the composition of your photograph with the violin in the background!  Cute!!
Comment: The first answer is the absolute best!  Don't stake it unless you want wimpy stems and have to always stake this plant.  Right now it is turned so those leaves will be changing direction soon, I'd do a quarter turn back so those rotations aren't 180 degrees of work.  And Kevinsky's third solution although absolutely viable is just silly when you have a movable pot.  Great, simple, straight forward answer, Kevinsky.  I am working to emulate you guys honest!
Comment: @stormy Well, thank you very much :)


How Should I Store Brown Sugar?

Question: How can I store brown sugar as it always gets hard before I can use it all. How do you store brown sugar? Does it need to be refrigerated?  Also, How can you make hard brown sugar soft again?
Comment: See https://cooking.stackexchange.com/q/3935/67 and https://cooking.stackexchange.com/q/8902/67
Answer: I always store brown sugar in an airtight, ziplock bag. That works pretty well for preventing it from getting hard. It does not need to be refrigerated.
However, if your brown sugar is already hard, there are a few techniques that people often recommend for resoftening it. These include: storing it in a closed container for a short period of time with apple slices (which will impart moisture); doing the same with a slice of bread (which will also impart some moisture); or, briefly microwaving it.
Here is a cooking blog which discusses some of these approaches:
https://www.thekitchn.com/4-ways-to-soften-brown-sugar-and-keep-it-that-way-195922
Comment: Dani, good info but beware of just giving links for information -- they often suffer from 'link rot' when a website shuts down or decides to reorganize their content without setting up redirection.  I suggest giving them credit by linking to them, but also copying out the relevant parts.  (if you put a '`> `' (greater-than and a space)  at the beginning of each paragraph, it'll get formatted as a block quote)
Answer: Just put it in the microwave.  One minute at a time to make sure it doesn't melt.  Softens it right up.
If you store it in an airtight container at room temperature that's good enough.

How Should I Store Brown Sugar?


a question about Gromov-Witten invariant

Question: Do the Gromov-Witten invariants count the morphisms from a curve to a variety over $\mathbb{C}$?
Comment: fpqc, don't be a jerk.  I'm sure you're aware that many mathematicians and grad students aren't native English speakers, cut them some slack.
Comment: @fpqc: there are many non-native speakers of English in the site, myself included. Instead of making fun of people, you could suggest a way of rewriting it in a manner that is more correct.
Comment: You're right. I was trying to point out that the way the question was worded didn't make any sense while trying to also be funny. I'm sorry, HYYY and Alberto.  I didn't mean anything by it.
Answer: To further qualify Charles's yes: that these moduli spaces are orbifolds instead of manifolds does result in rational numbers, but this is quite natural and not much of a problem.  The orbifolds here are just resulting because we're counting things that have automorphisms, here, for instance, the map from P^1 to P^1 given by the polynomial z^d has Z_d as its automorphisms: we can multiply a point in P^1 by a dth root of unity and not change where it maps to).  Whenever you count things with automorphisms it's quite natural to count each thing weighted by 1/(the size of its automorphism groups), or to rigidify the things we're counting by adding some kind of extra structure so they no longer have automorphisms.
As an example: Cayley's formula that there are n^(n-2) trees on n labeled vertices - the labeling of the vertices guarantees that the objects we're counting do not have automorphisms, and we get an integer - we've rigidified the problem.  If we wanted to count the number of trees on n unlabeled vertices, the problem is much more difficult.  However, if we weight each such tree by the inverse of its automorphism group, then the problem has a nice answer again: it's simply n^(n-2)/n!.  My point is: the rationality is not the ugly part of what's going on.
The ugly part is that these moduli spaces of maps are not even orbifolds: they have much worse singularities, and can have different components of different dimension.  From deformation theory, we expect these moduli spaces to have a certain dimension.  To get a finite number, we put conditions on the map that cut this dimension down until its zero.  Geometrically, you should think of each of these conditions as a cycle on the moduli space, and we want to intersect them.  Doing this intersection naively doesn't work when the space is singular, and furthermore the moduli space might be smooth but have a dimension different than what we were expecting.  But a lot of hard work shows that these spaces have a "virtual fundamental class" of the dimension that we expect, and using this we can proceed as above to get a number.  But in doing this, we've lost the sense in that we're counting something.
But it strikes me that perhaps that's not necessarily what the questioner was after; most typically this is done for smooth, projective varieties of C, but somehow the part that really matters is the symplectic structure: Gromov-Witten invariants can be defined for any symplectic manifold - they will all have almost complex structures J that "play nicely" with the symplectic form omega, and we're "counting" these maps.  Or: all this works for orbifolds (which are really smooth objects), but not singular spaces.
The over $\mathbb{C}$ bit is pretty necessary, I think - people have looked a little at doing in positive characteristic, but one big problem is that the orbifold stuff, which I was just telling you isn't really a problem, can be a big problem in positive characteristic if the order of your automorphisms aren't coprime with the characteristic.
Comment: Paul, my understanding is that it's still conjectural that algebraic GW and symplectic GW give equivalent info, along with pretty much every other curve-counting scheme.  If they've been shown to be the same (even, say, for genus 0, where things don't get SO bad) could you provide a reference?
Comment: Charles: See this paper by Siebert http://arxiv.org/abs/math/9804108 and this paper by Li-Tian http://arxiv.org/abs/alg-geom/9712035
Comment: Charles: I think there has been a lot of recent progress in showing equivalence of Gromov-Witten, Donaldson-Thomas, and Pandharipande-Thomas theories, but I don't know much about this stuff and I don't know any references off the top of my head.
Comment: The equivariant GW/DT correspondence has been proven for toric 3-folds in MOOP:
http://front.math.ucdavis.edu/0809.3976.

There's been a huge explosion in the study of the DT-type sheaf theories recently - the names here are Joyce and Kontsevich-Soibelman - but I know less about this than I should, and any link I'd give you would be almost random.
Answer: HYYY, the answer is a qualified "yes." I'm not an expert (read a few papers at the beginning of the year before deciding that enumerative geometry wasn't going to be my area) and I know that the answer is a definitive yes for rational curves in homogeneous spaces.  However, more generally than that, the Kontsevich moduli space of stable maps isn't a manifold, but merely an orbifold, and so has rational cohomology but not integral.  So you get rational numbers.  Worse, if your curves aren't rigid, they might count negatively, so there will be rational and negative Gromov-Witten invariants, in general.
This paper is a great introduction, and works out the first big theorem that GW invariants proved, in a case where they do, in fact, count curves.
Comment: For more on negative GW invariants, see this question http://mathoverflow.net/questions/7823/negative-gromov-witten-invariants


Office 365 .NET Languages

Question: General Question: What .net language should I be learning since my organization has me learning and developing on SharePoint for Office 365. Not sure if there a difference. I was partial to VB or C#.
Answer: Generally, if you're working with Microsoft products and/or web-based applications, you probably want to go with C#. For the  most part, if you know VB or C#, it's fairly easy to translate back and forth from one to the other. And although either language will work quite nicely with SharePoint, the product itself is built using C#.
In fact, there are three languages you probably should learn when working on any kind of SharePoint or web-based application:

C# : Used for workflows, adding ribbon functionality, menu actions, etc. in SharePoint
JavaScript : Used heavily throughout SharePoint (usually for interface functionality)
jQuery : SharePoint 2013 and SP Online allow you to customize your web parts using jQuery. In many ways, this replaces the XSLT coding found in previous versions.
Answer: If you don't have a preference then go with C#. Not because it's better than VB but because all of the code in documentation, training, blogs, videos, etc. is going to be written in C#.

Office 365 .NET Languages


What is the difference between Root Hash and Block Hash?

Question: I was reading about how Bitcoin works from Satoshi's original paper. I had a query while going through the 7th paragraph. What is the difference between Root Hash and Block Hash? Isn't the block hash same as the hash of the root of its Merkle Tree? I have studied Merkle tree and understand how it works.
Answer: First, all transactions are hashed along a Merkle tree. The root of that tree is the Merkle root.
Then the block header is created with 6 fields: version number, the hash of the previous block, the time, the difficulty, and the Merkle root computed in the previous step.
Then that block header (which contains the Merkle root) is hashed, resulting in the block hash.
Comment: hashed* you mean? Thank You, solved my query.
Comment: @VaradBhatnagar You can help the site by marking answers as accepted if they are correct and address the question so that the question does not remain as "unanswered".
Comment: genius answer :)
Answer:
Isn't the block hash same as the hash of the root of its Merkle Tree?

No

What is the difference between Root Hash and Block Hash?

The root hash is a 'Merkle Tree' of all the transactions in the block.
The block hash is a separate hash derived from data in the block header. Data in the block header includes the Merkle Tree hash, but also includes:

the block version number
the 256-bit hash of the previous block header
the current timestamp expressed as seconds since 1970-01-01T00:00 UTC
the current target in compact format
a random 32-bit 'nonce'.

Source: https://en.bitcoin.it/wiki/Block_hashing_algorithm


Identify probability distributions

Question: Given a sample data set of floating point numbers, how do we determine its probability distribution and prove it?
Also generate random numbers of the same distributions thereafter.
Comment: This question is perhaps overly broad.  Do you have a specific problem you want to address?  If so, please describe it and how you are generating the data, because those are crucial pieces of information for selecting probability distributions.
Comment: If all you have are the data, you can neither determine the distribution from which they were drawn, nor - even if you guessed it correctly - could you prove it. In some restricted situations, you can get somewhere.
Answer: The short answer is that you can't.
The longer answer is that you really need to think about what you are trying to accomplish and what question(s) you are trying to answer.
Tests on distributions are not designed to prove a particular distribution, but to disprove (they are not perfect for that, you still have type I and type II errors).  But, often establishing an exact distribution is less important than finding a reasonable approximation.  With round-off error and machine precision, you can not tell the difference between whether the data came from a normal distribution or another distribution that is only slightly different from the normal without an infinite amount of data (and still maybe not then due to the round-off).  But treating such data as normal is probably still reasonable.  The CLT tells us that we can often model using the normal distribution even when the data is clearly not from a normal distribution (provided we are modeling the behavior of the sample mean, not the population).
What is more important than the statistical tests and proofs is knowledge of the science that generated the data.  Is a particular distribution (and the assumptions that go with it) reasonable from the science?
I prefer a visual test rather than the exact test for looking at distributions, generate data from the hypothesized distribution and create several plots, one with the original data, the rest with the generated data, then see if you can pick out which is different (the vis.test function in the TeachingDemos package for R does this).  If you can't tell which is different then the hypothesized distribution is probably "close enough".  Even if you can tell the difference you may decide that the differences are not that important.
If you want to generate new data from a distribution similar to your existing data then you can take bootstrap samples, or bootstrap samples plus some random noise (this is sampling from the kernel density estimate), or you can do a logspline fit and generate from that distribution (see the logspline package for R as one tool for this).
Answer: The only way to "prove" that data comes from a certain distribution (without an infinite number of samples) is to know precisely how that data is generated.  For example, if you know that the data came from the magnitude of a circular bivariate normal random variable, it has a Rician distribution.  Or if the data came from the time between events in a Poisson process, then it has an exponential distribution.
Lacking a precise definition of the generating process, there are a number of empirical measures you can use to determine the underlying distribution.  First, look at the data itself: Is it discrete or continuous?  Is it supported on (-inf,inf), [0,inf),(0,1), or another interval?  This knowledge can be used to narrow down the possible univariate parametric distributions that could fit your data.  Examples include the Gaussian distribution, Cauchy, Exponential, Gamma, Generalized Extreme Value, Rician, Wrapped Cauchy, Von Mises, Binomial, and Beta.  Once you have determined the support of the distribution, test the potential univariate distributions with an information criterion - such as Akaike information criterion (AIC) or Bayesian information criterion (BIC).  These balance the number of parameters in a given distribution with the likelihood of the data fitting a given distribution.  Visually check the best-scoring distribution(s) to see if they appear to fit the data.
An alternative is to construct a kernel density estimate of the data.  This is basically a sophisticated version of creating a histogram of the data, where a small Gaussian (or other) distribution is placed at each data point, and the estimated distribution is constructed from the sum of these.  For more information, see Kernel Density Estimation.  This has the advantage of being able to fit arbitrary distributions in the data, but sampling from this distribution has a large computational cost, especially with large data sets.
Another option is to construct a Gaussian Mixture Model (GMM) from the data, where a small number of Gaussian distributions are used to approximate the underlying distribution.  For more information, see Mixture Models.
The method appropriate for your application depends on the application itself.  If you can determine the distribution from the generating process, great, estimate the parameters and your done!  If not, the next-best scenario is finding a univariate parametric distribution that accurately describes the data.  Lacking that, mixture models, KDEs, or other methods can be used to approximate the distribution.
Answer: If you're trying to do Exploratory Data Analysis, you could use some graphical techniques.
I can suggest chapter 1.3.4 in the NIST handbook. In particular, any of the probability graphs might be insightful (e.g. Probability Plot Correlation Coefficient Plot, Quantile-Quantile Plot, etc.).
For a number of common distributions, you could try fitting to the Tukey-Lambda distribution, and extracting the distribution information from the fitted value of the lambda shape parameter.
Comment: Also check out [the worked example there](http://www.itl.nist.gov/div898/handbook/eda/section4/eda424.htm). (not enough rep. to add this link in the original answer...)-;
Comment: (+1) These recommendations look sufficiently constructive to be posted as an answer, especially since (as has been remarked in other answers) the request to "prove it" is misguided.  Thank you for visiting our site and contributing!
Comment: Thanks, @whuber. I guess some visitors put more emphasis on a theoretical approach to statistics than addressing more pragmatic needs. That might even be a decent 'meta' post...

Identify probability distributions


What is the difference of engineering and true stress?

Question: What is the difference of engineering and true stress? Also, why does the engineering stress decrease after the ultimate tensile  strength point?
Answer: In tensile testing, Stress is usually measured indirectly by measurement of the applied force over strain $\epsilon$.
If you divide that force $F$ by the cross-section of your specimen at the start of testing, $A_0$, you gain a value $\sigma_e$ with the dimension of a stress. $$\sigma_e=\frac{F}{A_0}$$ This is the engineering stress.
If, instead of $A_0$, you use the cross section corresponing with the elongation of the Probe, $A$, you get the true stress $\sigma$. $$\sigma=\frac{F}{A}$$
$\epsilon$ is defined by $$\epsilon=\frac{\Delta L}{L_0}$$ with $\Delta L$ being the Elongation and $L_0$ being the starting length. Because the solid material of the specimen is incompressible, its Volume $V$ has to stay constant in spite of strain. $$V=L_0*A_0=\int _0^L A(x)dx=const.$$
As a result of an increase in $L$ with constant $V$, A is changing throughout the whole Experiment. Even before reaching ultimate tensile strength, $\sigma$ differs from $\sigma_e$.
For many ductile materials we see the development of a constriction at a random point on the specimen. The reason for this is that the minimum-energy direction of plastic deformation is in a direction at an angle of 45° in relation to the direction of $F$. Now, at this constriction point, $A$ is drastically reduced which results in a large $\sigma$. $\sigma_e$, on the other hand, usually declines, due to the reduction in necessary $F$. This is the behaviour you've described in your question.
Engineering Stress is a measure for the applied force during tensile testing, rather than the actual stress. However, for many applications with elastic behaviour, it is deemed "close enough". The main reasons for this are the increased cost in having $A$ measured additionally and that the remaining uncertainty of testing can be higher than the difference between $\sigma$ and $\sigma_e$ (before reaching ultimate tensile strength).
In forming technology, though, true stress is very relevant, since the main interest is plastic behaviour, where larger differences between engineering stress and true stress appear.
Comment: Except that solids are _not_ incompressible and the volume changes under stress (See bulk modulus). The fact is, that it is _nearly_ incompressible as extension in one direction results in contraction in other directions, but $$\frac{\Delta V}{V} \approx \frac{\sigma}{E} (1-2 \nu) $$
Comment: @ja72 Initially, I was going to write _nearly_ incompressible but I decided to leave it out in order to avoid confusion.


How to decide on the ending of a story?

Question: I've been writing a short story about a boy who accidentally killed his brother and went through a serious trauma that he even started taking drugs (knowing that he is only 12 y.o).
In this story, I tackle the way he responded to the tragedy especially that he lives within a dysfunctional family and how his mother struggles to help him. The problem is that I have in mind three endings, two of them are sad and one is happy. How can I know which one will satisfy mostly my readers?
Comment: There might be some helpful discussion in the Related questions tagged 'Ending'…. i don't think there's any way for us to advise you based only on what you've asked here (other than preferring 'happy' or 'sad' endings in general). Things to maybe consider: your protagonist is 12, but are your readers 12 or are they adults? Also short stories do not always 'resolve' the main conflict, so there is middle-ground for an ambiguous or un-resolved ending.
Comment: You could consider writing all three endings, and then decide which one is best (or even publish all three).
Comment: I do not think that a serious trauma need happen for a 12 year old or any other age person to start taking addictive drugs.  Anyone who takes an addictive drug a few times, perhaps finding the stash of a relative ,or friend, has a chance of becoming addicted to it, whether they have any traumas in their past or not.  Yes, 12 years old is young to start using drugs, but not unheard of - see Drew Barrymore, as one example out of many.  And tobacco,tough legal, is very addictive, and I once heard my brother say he started smoking when aged 11.
Answer: Satisfaction of the reader depends on what the reader deems useful or seeks to find. If this story is about survival and overcoming then a happy ending could be satisfying, but if clarification and knowledge needs to be pointed out, then perhaps more adversity can do that, even if it's not a happy ending.
Before you choose which ending, maybe ask yourself, what do I want to achieve with this work ? is it to have an impact or just to get consumed. Do you want to only sell as much or want to tell as much ?.

How to decide on the ending of a story?


Is there a WordPress document on how to set up on this page?

Question: Is there a clear answer to a question that asks "how to install WordPress?" or is that kind of question on-topic here?
Answer: While this kind of question seems on topic to me, I think it's borderline too basic and realm of official documentation https://codex.wordpress.org/Installing_WordPress
Comment: …unless you start talking about Phing, Composer and other build systems. I would consider it being on topic if there's a specific task and effort shown and where it fails or lacks convenience.
Comment: Sure, such would make on topic and interesting question most of the time. :)


Sound and video are slow

Question: Whenever I opened google chrome today, everything seemed normal. I played one of my favorite games, and that's when stuff got weird. The sound on the game was slow. Not a major problem. I muted the sound. But then, I went to youtube on google chrome (everybody needs their daily Game Theories, right?) and when I went to watch a video, the video was slow AND the sound was slow. Okay, so I couldn't use youtube. But THEN, I opened Skype and tried talking. The sound was in slow-motion and it's messed up! (I wasn't actually talking to someone, I just used the Skype sound tester). I need help badly! I want to have normal video and normal sound D:
Answer: It seems Google Chrome is not as good as it was only four months ago.
Not many months ago, perhaps August of last year, back when Firefox became hopelessly problematic, I became an outspoken advocate of using the Google Chrome browser.  Since then I've encountered unexplained total lockups of Google Chrome, and in later discussions discovered that both my girlfriend and another friend had been having the same experiences.
At the moment, my solution is to use a third, and much more difficult to install web browser known as Opera.  Since installing it, I've discovered that my home security system software works better with Opera than either Firefox or Chrome, so now I feel I need to have it on any computers I intend to use.  It is not uncommon to find me using two browsers concurrently, and sometimes three.
There are many tutorials on how to install it, some even on this site, and I've discovered that not all of them appear to work for me.  The one I continually return to is linked here.
https://help.ubuntu.com/community/OperaBrowser
I realize that one might say this isn't a direct answer to your question, I mean I can't tell you how to make the Chrome browser work properly, and I doubt anyone can.  I would advise you to try another browser for a while and return in a few more months to see if Chrome has been fixed yet.

Sound and video are slow


Why is it rare to combine Reformed/Calvinist doctrine and Dispensationalism?

Question: I've been told that it's rare to find someone who combines Dispensationalism and Reformed/Calvinistic doctrine (such as John MacArthur).  Why is this?  What ideas don't mesh well?
Comment: @JonEricson - A valid answer would be "That's wrong."  But here is a link: http://rcsprouljr.com/blog/ask-rc/rc-reformed-view-eschatology/
Comment: I don't know about rare but it is certainly not the norm and that is because the two constructs don't mesh well. This will take some careful thinking to articulate well...
Comment: Could you elaborate on where you heard this?  Ideally with a link or quote from some written source.  (I don't have the impression that the assertion is true at all.)
Comment: For John, he holds on Reformed (R) **soteriological** view and Dispensational (D) **ecclesiological** and **eschatological** views. R and D doctrines covers wide aspect of Christian doctrine (the "logical"s I've mentioned). When we start comparing Covenant Theology (dominant view among reformed circle) and Dispensational since these tell us how to interpret the Bible, and this is where the stark differences arise.
Answer: The reason these two are seldom found together seems to be primarily because of the difference of the view of the church between covenant theology and dispensationalism. Although some (like MacArthur) continue to maintain the distinction between the church and Israel (as in dispensationalism), most 5 point Calvinists follow covenant theology which denies this distinction - placing the beginning of the church at least back to Abraham, and logically back to Adam. Therefore, although dispensationalism maintains that everyone has always been saved by grace through faith, the specific object of that faith in Reformed theology is understood to be Christ - while dispensationalism would recognize the role of the progress of revelation such that the basis for salvation was the Cross, the object was not as clearly seen as the incarnate Son of God. Actually, it is even more complex than this, but this gets you going in the right direction.
Comment: Decent answer/nice first post.  Just for your information, Stack Exchange discourages the use of signature lines.  Such information can be placed on your [user page](http://christianity.stackexchange.com/users/4638/david-james).  As a new user you might want to check out the [about page](http://christianity.stackexchange.com/about) and the [FAQ](http://christianity.stackexchange.com/faq).
Answer: As an ex-Calvinist turned mid-Acts dispensationalist, I find there are two primary points of contention that lead to all the rest:

Covenant/Reformed theology's tendency to allegorize or spiritualize various parts of Scripture vs dispensationalism's tendency to take it literally where it seems literally intended.
Covenant/Reformed folk (and others, to varying degrees) general belief that God is forever done with national Israel, having replaced her with the Body of Christ which has inherited the covenants and promises, and even some of warnings, God gave to Israel. Dispensationalists, on the other hand, believe God is not finished with Israel but has only set her aside in blindness temporarily during this dispensation of grace (Romans 9-11). Once this dispensation ends, God will once again take up dealing with Israel as His covenant nation, kicking off the apocalyptic end times events.

Point #1 alone is enough to keep the two systems from EVER synchronizing or harmonizing. Sad to say, it basically results in reading two different Bibles.
Answer: One reason could be that Reformed doctrine takes covenantal thinking into account; this allows for quite a bit of continuity between the two Testaments, with also some very distinct discontinuities. Reformed doctrine, for example, would see the covenants in the OT as building, one upon the other, in scope, until you have the New Covenant with Jesus Christ, which is so powerful it's retroactive in including the OT saints. Dispensationalism, on the other hand, allows for very few continuities between the testaments, if any.
Answer: Calvinism is historically linked with covenant theology, which stresses St. Paul's account of God's plan in the New Testament: the promise was given to Abraham and his Seed through faith and that promise belongs to all the people of God through Christ.  Faithful people of the Old Testament era did not receive the entirety of what God promised because only with us could they reach that completion (since it is through Christ).  This point is mentioned in the book of Hebrews.  In other words, continuity in God's plan, according to St. Paul, is the significant element, not the distinctions or changes that served as a part of that grand plan.  It's a matter of seeing the big picture and understanding that the differences through time become irrelevant, more or less.  Dispensationalists prefer to focus on those differences and to hold onto them in spite of St. Paul's conclusion.  They foresee a further working out of God's plan even though St. Paul's argument is that all things climax or culminate with the cross.  Dispensationalists are usually not Calvinistic because these two systems are not historically linked.  Dispensationalists usually stress freewill when it comes to whether or not people believe the gospel.  In my opinion it is not necessarilyt unreasonable to mix and match beliefs here and it does happen at times, as with the case of John MacArthur.  But it is my belief that Dispensationalism represents a misunderstanding of the overall plan of God.
Comment: This answer is O.K., but it would be a lot better if you could add references.  See  [How we are different than other sites?](http://meta.christianity.stackexchange.com/questions/1808/how-we-are-different-than-other-sites) and [What makes a good supported answer?](http://meta.christianity.stackexchange.com/questions/692/what-makes-a-good-supported-answer)
Answer: There are a number of sharp distinctions, but they are definitely not impossible to put together. The most important criteria in being able to mix belief systems is how much we are willing to stretch (as is not stick loyally to) the potentially less truthful parts of one belief system so that they may be covered by the more truthful parts of another belief system. At the very least, we need to be able to see the truthful parts in any belief system we encounter and be willing to adapt our own beliefs to conform to new-found truth.
In the case of Calvinism and Dispensationalism, Calvinists focus on the Covenant, which has continued from Abraham into today, only through different forms. Dispensationalists stress the divisions between time periods and the different ways God deals with his people throughout time. The also strongly disagree on the idea of "God's people"; Calvinists tend to put the Israelites and Christians together as part of the same promise, while dispensationalists will see the two as completely different.
If someone on either sides refuses to see the truth in the other perspective, they can't mesh. One way in which they could work together is to see that God has indeed been using covenants in different forms throughout time, as the Calvinists believe. Then add onto that the realization that the primary interaction between God and humanity has varied through history (there was indeed a time when people primarily relied on their conscience for morality, a time when the patriarchs lived by faith in God's promise, a time when the Israelites obeyed God by following His written law, and now we are in a time where we see that God saves His people through grace).
However, in order for this mixing to even start working, a dispensationalist would need to be able to suspend his belief that those dispensations were the method of salvation for God's people in favor of the idea that all of God's people are saved through faith. In turn, a Calvinist would need to be willing to divide history into stages in the first place. From my experience, people are often unwilling to drop the beliefs they grew up with (or beliefs they came upon during their own research), which is why it's so hard for Calvinists and dispensationalists (which come from very different perspectives) to compromise.
Answer: Why is it rare to combine Reformed/Calvinist doctrine and Dispensationalism?
Adam Smith (who was no fan of religion) thought different denominations were great. He saw that in order to coexist in the marketplace of ideas, they would eventually have to drop those things that were distinctive so that they would not produce discord and thus become impotent.
It is the nature of denominations (the word for divisions or disunity in the Greek is hairesis from which we get heresy) to function as an organizational systems or franchise brands. This by itself (definition by distinction) tends to prevent what might be called a harmonization.
There are doctrinal differences that are difficult to surmount. For example the idea that Israel has been replaced or subsumed by the church is not compatible with the idea that a faithful remnant of Israel will be used of God for an eventual kingdom of God on earth.
While at first glance covenants and dispensations might be seen as similar divisions of time, however, what is meant by and what happens in those divisions becomes an insurmountable obstacle.
In addition to the doctrinal distinctions, there are cultural distinctions that not only create barriers but can at times become vitriolic. Covenant (Calvinist) people sometimes come unglued when considering dispensational people because they can see them as lazy and just waiting for God to do something when they think Christians should be actively making things better.
One reason these distinctions are such barriers is that they are often mastered after much study and often those who make such an effort come to be the staunchest defenders of their mastered distinctions.

1 Corinthians 8:1  Now as touching things offered unto idols, we know
  that we all have knowledge. Knowledge puffeth up, but charity
  edifieth.

They key to Christian unity is humility (not being "puffed up"). Christian denominations are maintained by those who have gone through an approval process such that they can be counted upon to defend the denominational distinctives. Once a person can make allowance for the fact that he does not understand everything and may in fact understand some things poorly, he is less likely to condemn others for their beliefs.

1 Peter 5:5  Likewise, ye younger, submit yourselves unto the elder.
  Yea, all of you be subject one to another, and be clothed with
  humility: for God resisteth the proud, and giveth grace to the humble.

The reason that many if not most Christians cannot get past denominational distinctives can be accounted for by the following;

Lack of maturity.

1 Corinthians 3:1-3  And I, brethren, could not speak unto you as unto
  spiritual, but as unto carnal, even as unto babes in Christ.   I have
  fed you with milk, and not with meat: for hitherto ye were not able to
  bear it, neither yet now are ye able.  For ye are yet carnal: for
  whereas there is among you envying, and strife, and divisions, are ye
  not carnal, and walk as men?

Worldly entanglements.

James 4:1-4  From whence come wars and fightings among you? come they
  not hence, even of your lusts that war in your members?   Ye lust, and
  have not: ye kill, and desire to have, and cannot obtain: ye fight and
  war, yet ye have not, because ye ask not.   Ye ask, and receive not,
  because ye ask amiss, that ye may consume it upon your lusts.   Ye
  adulterers and adulteresses, know ye not that the friendship of the
  world is enmity with God? whosoever therefore will be a friend of the
  world is the enemy of God.

Diverted faith.

Galatians 3:1-3  O foolish Galatians, who hath bewitched you, that ye
  should not obey the truth, before whose eyes Jesus Christ hath been
  evidently set forth, crucified among you?   This only would I learn of
  you, Received ye the Spirit by the works of the law, or by the hearing
  of faith?   Are ye so foolish? having begun in the Spirit, are ye now
  made perfect by the flesh?

Living in the flesh.

Galatians 5:17  For the flesh lusteth against the Spirit, and the
  Spirit against the flesh: and these are contrary the one to the other:
  so that ye cannot do the things that ye would.
Answer: First, keep in mind that neither Dispensationalism nor Reformed/Calvinism fit neatly into tight boxes. There's a great deal of theological/philosophical diversity/variation in both realms. Clarity is important, so I'll strive to keep it as simple as possible.
The best approach to answering the question might be to mention what core beliefs they share in common, before proceeding to their CORE difference(s). (PS. I've spent nearly 55 years exploring these realms. When I reference "Dispensationalism," I historically trace the doctrinal distinctions to the extraordinary John Nelson Darby (JND) and his Classical Pauline view(s). The most definitive resources here are the extensive works of the late Roy A. Huebner.) Say what you will, but Darby was both a stalwart and a warrior for our Lord Jesus Christ.
COMMON: Both Reformed/Calvinism and Classical Pauline Dispensationalism share a belief in the Sovereignty of God (in contrast to the sovereignty of Man) and the epistemological foundation of the Inerrant Word of God--the 66 Books of the Bible. Both believe that Election and Salvation are based on God's Grace and Mercy, apart from ANY form of merit.
DIFFERENCE: Reformed/Calvinism follows traditional Christendom in the use of God's covenants made with earthly Israel to superimpose a forced continuity to the 66 books of Scripture. By contrast, Dispensationalism held this obfuscated the clear evidence of discontinuity and made Christianity an interloper in Israel's unique promises, the prime example being Catholicism.
A marked split with traditional Christendom, Classical Pauline Dispensationalism (JND) held that the covenants (including the briefly-mentioned "New Covenant") exclusively pertained to the earthly Elect Nation of Israel(1). Further, the Church/Body of Christ (whose advent was recorded in Acts 2) was the "heavenly people of God" and a separate group having a level of discontinuity from Israel.
(1) See An Introduction to the NEW COVENANT, Christopher Cone, General Editor.
Comment: I went to another computer where I wasn't signed into my account and looked at this question. My answer to it wasn't shown, i.e., was missing. Why is that?


Spreading-out integers via multiplication

Question: Let $a_1,...,a_n\in [0,m]$ be a set of $n$ positive integers, where $n<<m$, $m=poly(n)$.
One can assume $m$ is prime.
Is there an efficient, possibly randomized, way to find an integer $N=poly(n)$, such that
$(a_i \cdot N) (mod \ m)$ is approximately uniform on $[0,m]$.
The value of $N$ may also depend on the approximation parameter.
Comment: Should there be some additional hypothesis to prevent, for example, the situation where all the $a_i$ are equal?
Comment: Yes, let's assume they are all different.
Comment: "All different" won't work because there are $n$ of the integers $a_i$'s, all in $[0,m]$ with $m < n$
Comment: Of corse! - fixed the mistake above.
Answer: Choosing $N$ at random and checking should work. Put $e(t)=e^{2\pi i t/m}$. Then we have
\begin{eqnarray*}
\sum_{N=1}^m\sum_{k=1}^K\left|\sum_{i=1}^ne(k N a_i)\right|^2 & = &
\sum_{N=1}^m\sum_{k=1}^K\sum_1\leq i,j\leq n e(kN(a_i-a_j))\\
 & = & m\sum_{k\leq K} \#\{(i,j)|a_i\equiv a_j\pmod{\frac{m}{(m, k)}}\}.
\end{eqnarray*}
Since the $a_i$ are all different and in $[0, m]$, for fixed $a_i$ the number of $a_j$ satisfying the last congruence is $(m,k)$ at most, and the last sum is bounded above by $mn\sum_{k\leq K}(k,m)\leq mnK^2$.
Denote by $D_N$ the discrepancy of $a_iN\bmod m$. Then we have
$$
D_N\ll \frac{n}{K}+\sum_{k\leq K}\frac{1}{k}\left|\sum_{i=1}^n e(kNa_i)\right|,
$$
thus
$$
\frac{1}{m}\sum_{N=1}^m D_N \ll \frac{n}{K} + \sqrt{nK}\log K.
$$
Hence for most $N$ we have $D_N\ll n^{2/3}\log n$, which is reasonable good equidistribution.
Checking whether for a random $N$ we have that $D_N<n$ is small requires between $n^{1+\epsilon}$ and $n^{3/2}$ steps, depending on how small $D_N$ has to be.


Structure of content and assets table of joomla

Question: Can anyone explain structure of content and assets table. I m adding articles by API so how i can insert data into that two tables. In which table i have to add first. Please guide.
Comment: Thanks for your answer and i will implement it but how i can upload image or how i can specify image url. Can anyone guide?
Comment: I discovered your comment purely by chance. Don't expect others to be notified after commenting under your question. Please read the [help] section of JSE to find out how the site works. Also read the small help section of the comments. Regarding your comment, this is not directly related with the title of your question, which is the Assets table. Consider asking another question - explaining clearly your current problem. Regarding this question - if the answers below answered it, then consider accepting it - http://joomla.stackexchange.com/help/someone-answers
Answer: 1. Adding Joomla Content via the API
Not sure how you are using the API to create articles and why it doesn't create the assets entries for you - assuming you have already tried to do so - as, adding Joomla content through the API will handle this for you.
So you don't actually need to do anything extra in order to create the corresponding assets entries for your articles.
In short the procedure is:
1. Instatiate the JTableContent Object
    $item = JTable::getInstance('Content');

2. Create your article's properties:
    $item->title     = $myTitle;
    $item->alias     = JFilterOutput::stringURLSafe($myAlias);
    $item->introtext = $articleText;
    //... and so on

3. Save the article:
    $item->store();

2. The Assets Table
In brief the foreach article there should be a related assets record which will hold ACL information about the article.
The assets table follows the Nested Set Model to store data Hierhically, similar to how data are represented in XML, where every item has a Parent Item and 0 or more Children - except of the Root Item that has no parent.
Read this answer on an old question related with issues with com_tags in the assets table, where if I can recall right there is an example explanation of how left/righ/level values are calculated, with an example diagram: Unexpected parent tag association.
In that answer there is also a link to a great post that explains the Nested Set Model
Update
I just remembered there was some docs in Joomla.org about using nested set model, which can be found here: https://docs.joomla.org/Using_nested_sets

3. Docs

JTableContent Documentation
JTable_class Documentation
JTable API
Comment: Just tried your code and I confirm it works and creates the correct entries in the asset table. Thanks so much!!!
Comment: I used this method and that got the assets table entry inserted correctly. I still had to insert the content and workflow_associations records myself, but the assets table was the hard part. Thanks for this!


What does the mean of pairwise differences of two distributions tell use

Question: Pretty naive question here. If we have two paired large (>1000) samples and are interested in a paired Cohen's d then why not take the pairwise difference of the two samples and consider its mean divided by standard deviation?
$$\frac{\overline{{X}_1 - {X}_2}}{SD_{X_1-X_2}}$$
To my meager knowledge this seems like a good paired version of Cohen's d.
Answer: This is one way of computing a d-like measure for dependent samples. If the paired measurements are repeated measurements as in a pre-test post-test design, this is called the standardized mean change/gain and this uses change score standardization: $$d = \frac{\bar{D}}{SD_D} = \frac{\bar{X}_1 - \bar{X}_2}{SD_D}.$$ Alternatively, one can standardize the mean difference using one of the two SDs (typically the pre-test), so: $$d = \frac{\bar{D}}{SD_1} = \frac{\bar{X}_1 - \bar{X}_2}{SD_1}.$$ This is called the standardized mean change/gain using raw score standardization.
Comment: This doesn't use pairedness. I added a formula to my question.
Comment: $\bar{D}$ is the mean of the differences and $SD_D$ the SD of the differences, so this is the same as in your question.
Comment: OK great. Do you know of any reference on this subject (for citation)? Thank you.
Comment: A place to start: Morris, S. B., & DeShon, R. P. (2002). Combining effect size estimates in meta-analysis with repeated measures and independent-groups designs. Psychological Methods, 7(1), 105-125.


Can spinal injury occur from rear naked choke

Question: When putting your opponent  into the position for a rear naked choke it is common practice to open up the submission by bending the opponents  spine backwards. Is there any realistic possibility of injury to the spine from this technique?
Comment: You especially need to detail the position you were in. The basic answer is "Yes, anything is possible". I'm not sure that this question is really answerable, however, since we would just be relying on a description, which brings us back to the basic answer.
Comment: Rewording applied
Comment: What if I instead asked 'Should you tap when your back is taken, your opponent is trying to apply a rear naked choke, you have your neck protected and can breathe normally, but there is an uncomfortable amount of pressure from the back bend ?'
Comment: Am not sure about RNC, but twister / zombie twister will definitely have an impact on spine.
Comment: Related: https://martialarts.stackexchange.com/a/9312/8910
Answer: If you are uncomfortable with something that is happening to you, then tap. If your partner taps, then stop and let go with no questions asked. All questions wait until after disengagement. This is basic safety.
Crazy things happen. I have seen something done safely 10,000 times, but also one time that resulted in a significant injury. If pain is telling you that the low probability event may be occurring, then tap and stop.
Do NOT mess around with spine injuries. These can result in permanent paralysis.
I would guess if there is uncomfortable pressure on your spine from a rear naked choke, then you are face down. In this position, some of your vertebrae may be restricted in movement, and force can be concentrated a few joints.
Answer: Yes, it is common to bend the spine backwards. It's called "hipping in." You pull their lower body down with your legs (your "hooks"), and pull their neck backward, forcing them to bend backward. This opens the person's neck up even more, and makes them extremely uncomfortable, increasing the likelihood of getting the tap.
A couple bonuses to make your RNC extra deadly: go belly down. There's no escaping a belly down RNC one you hip in! And of course, wear a cup. Few things feel worse than a cup digging in to your spine while you're already being choked to death.
As for a spinal injury, I've never heard of spine injuries from a RNC, but anything is possible! If you're just training in the gym and something doesn't feel right, tap!


Is it good practice to design UX tailored to specific audiences or just use the general UX guidelines regardless?

Question: I work for a company where our users are generally older and less computer efficient ( based on user studies). Is it good UX practice to tailor the website experience taking that fact into account (larger fonts, more informative walkthroughs, etc). or should a UX be "good UX" universally and be focused for all audiences
Answer: As you mentioned you are already sure about the audience then going for a trailered UX is always a better plan. Whereas if I talk about the normal/general case, I personally prefer not going for a universal idea.
Comment: +1 You should design for your audience.  However to do that you really have to know them pretty well ( and not just make assumptions based on age).  An example of this is determining the language you can use on the website: a specialist site for doctors can use language which Joe Public won't want to read.
Answer: YES, You are referring to accessibility. It's about inclusively providing a good UX for all audiences. This includes not just older people but also people with disabilities and those with solver internet connections.

Accessibility is the practice of making your websites usable by as
many people as possible. We traditionally think of this as being about
people with disabilities, but the practice of making sites accessible
also benefits other groups such as those using mobile devices, or
those with slow network connections. You might also think of
accessibility as treating everyone the same, and giving them equal
opportunities, no matter what their ability or circumstances. Just as
it is wrong to exclude someone from a physical building because they
are in a wheelchair (modern public buildings generally have wheelchair
ramps or elevators), it is also not right to exclude someone from a
website because they have a visual impairment. We are all different,
but we are all human, and therefore have the same human rights.
Accessibility is the right thing to do. Providing accessible sites is
part of the law in some countries, which can open up some significant
markets that otherwise would not be able to use your services or buy
your products.

source
https://developer.mozilla.org/en-US/docs/Learn/Accessibility/What_is_accessibility#:~:text=Accessibility%20is%20the%20practice%20of,those%20with%20slow%20network%20connections.
Comment: In terms of Accessibility, it is important that whatever tailoring you do the same content is available to all types of Users, because you cannot really distinguish between Users of each "group" that are or aren't blind (at least you shouldn't). Having some content only available to Golf-loving-20-20-eyesight users and not others = Accessibility failed.


How to run the cron within specified timebound only?

Question: I have a requirement which needs to be done via cron.
Some of the jobs should run only in time frame of 9AM-7PM everyday. So how I can schedule a cron for this type of requirements in the crontab.I surfed around it, but didn't get any solutions so please anybody help me in this regard.
Answer: To run cron you have to have something that triggers the cron since php is a scripting language and only fires off when executed. What that means is you either need an outside resources to fire off the cron or you need to set it up server side.  You can set up a cron service on linux by following the guide on Drupal.org. If a scheduled cron task is not set up on the server side or some other mechanism then cron will simply run the next time a user goes to your site. This could have performance issues and unreliable cron runs.
Custom Module
If you don't want your cron task to run every single time cron runs then in your code you would set it up to check the current time and whether or not to run. This would require use of the date functions in php and allow you to decide whether or not to execute your code based off the time
Elysia Cron
Elysia cron will allow you specifically set which cron tasks run at certain times. This will require you to still set up a cron task so that cron can still fire.
Comment: Thanks fro your suggestions. I installed Elysia Cron but I am not getting settings to  reach my requirement, which is between 9AM to 7PM only it should run the cron. am I missing something in configuration or that functionality is not there?
Comment: I think I may have misunderstood the original requirement. Do you want it to run every single time cron runs between that time, or how many times do you want it to run?


Find which Debian packages are only installed because they are recommended or suggested

Question: On Debian I can use apt-get autoremove to remove packages that are no longer needed, i.e., that are not a dependency of any "manually installed" package. However, this does not remove packages that are merely "suggested" or "recommended" by manually installed packages. How can I find out the list of such packages on my system?
Answer: You can also tell apt-get autoremove to ignore "Recommends" and "Suggests":
sudo apt-get autoremove -o Apt::AutoRemove::RecommendsImportant=false -o Apt::AutoRemove::SuggestsImportant=false

Use -s to get a list of the removals this would lead to without actually changing anything:
sudo apt-get autoremove -s -o Apt::AutoRemove::RecommendsImportant=false -o Apt::AutoRemove::SuggestsImportant=false

Comment: Thanks a lot! I think this is a much better solution than the one I proposed. Somehow, though, this does not return the same set of packages (it mostly returns more, but it also misses a few that deborphan found).
Comment: The difference in output should be explained by your manual selections: `deborphan` ignores those, so it will find packages you no longer need but that are marked as manually installed. Basically that means you need to periodically review the output of `apt-mark showmanual` and mark packages you don't explicitly need as automatically installed; then if they are in practice no longer necessary, `autoremove` will suggest their removal.
Comment: Sure, thanks! (In fact, I already have scripts that periodically compare how `apt-mark showmanual` differs from a list that I maintain separately.) However, my point was that the output of your method is not the same as the output of my method even when I take the output of deborphan and specifically remove the manually installed packages (as per the command that I suggested). So I guess there must be some difference in how these two commands compute their output.
Comment: Ah, OK, I see! I'm mostly curious about the extra packages which `deborphan` finds. Perhaps they match the auto-removal configuration in `/etc/apt/apt.conf.d/01autoremove*`...
Comment: Here's the list, along with the `aptitude why` of each package:  https://zero.crans.org/?34e8bda1f03afebb#7WoQakPrmoHByhleNwJzQWYNPyiI9BKDZUOO+syF0zo=
Answer: This can be done using the deborphan -n command, or deborphan -an, but paying attention to the fact that this does not seem to really exclude manually installed packages (see here), so they have to be filtered separately. I use:
comm -3 -1 <(apt-mark showmanual | sort) <(deborphan -na | awk '{print $2}' | cut -d':' -f1 | sort)

See also another solution in a related question.


What happens when you cast the Disguise Self spell again while currently under its effects?

Question: Let's say you are a human warlock with the Mask of Many Faces invocation. You cast disguise self and alter your form to that of an elf. While under the effect of this first illusion (before it expires), you cast it again to change your form to a dragonborn. What happens?
Do you go from elf > dragonborn? Do you temporarily revert to your base human form?
Comment: Related: [How do you determine the 'most potent effect' for overlapping spells?](https://rpg.stackexchange.com/questions/93114/how-do-you-determine-the-most-potent-effect-for-overlapping-spells)
Answer: You don't revert to your original form, but beyond that it's up to the DM
The rules for Combining Magical Effects (PHB pg 205) come into play here:

The effects of different spells add together while the durations of those spells overlap. The effects of the same spell cast multiple times don't combine, however. Instead, the most potent effect—such as the highest bonus—from those castings applies while their durations overlap.
For example, if two clerics cast bless on the same target, that character gains the spell's benefit only once; he or she doesn't get to roll two bonus dice.

So what is important here is to determine which effect is the most "potent".
There is no clear guidance in the rules on how to determine potency when two spells have the same effect. There are some reasonable options in this case:

If the spells have the same effect, the one with the longest remaining duration is most potent (think a sorcerer who has used their extended spell meta magic to double the duration of the first casting)
The spell cast last is the most potent
The first spell effect remains the most potent until it ends, at which point the second effect takes over.

My ruling from the games I DM is that the players can choose when they cast the second spell if they want to use either #1 or #2, but only if they are casting it on an ally. If they are casting the spell on an enemy I apply #2.
In your case these two options are functionally equivalent, so you would look like an Elf that turned into a Dragonborn.
Answer: You'd look like a Dragonborn
As has been stated elsewhere, there would be no "overlapping" effects from the two castings of this spell.

'The effects of the same spell cast multiple times don't combine,
  however. Instead, the most potent effect—such as the highest
  bonus—from those castings applies[...].' (PHB p. 205)

This has been further clarified by Jeremy Crawford on Twitter (emphasis added):

The effects of the same spell don't stack; use the most potent effect
  (PH, 205). If equal, use the most recent.

Both castings of this spell were definitely equally potent (they required no spell slots, and were cast by the same magic user). So only the most recent one would apply. Now let's consider whether there was ever a period when you appeared human.
Spells (or their effects) end only when conditions are met which end them. The only thing which made the effect of the first spell (Elf disguise) end was the effect of the more recent casting of the same spell (Dragonborn disguise). So there was no time when neither spell was in effect, so you never looked like your base human form.
Of course, if someone saw you casting the spell (which has verbal and somatic components) and changing into a Dragonborn, they would likely come to the conclusion that your appearance was a the result of a spell. But they would never have seen your true form.
Answer: You'll probably turn into a Dragonborn immediately, but it depends which spell your DM considers 'more potent'.

As long as the spells duration's overlap, you won't revert to your original form.

If you dismiss your first casting before casting the spell a second time, then your normal form would be visible. Both dismissing and casting Disguise Self requires an Action and you cannot use two Actions simultaneously. Even when a feature allows you to take two Actions in a combat round, the actions are still understood to occur consecutively, not concurrently.
If you dismiss the first Disguise before Casting a second Disguise Self spell then they aren't concurrent spells.

Even if the two spell's durations overlap they still wouldn't overlap visually. Disguise Self doesn't simply produce a magical hologram.

While it might be amusing to think about the intangible hat you can create with disguise self, it isn't simply a magical hologram. If Disguise Self worked like a hologram then it would be impossible to disguise yourself as someone shorter or thinner than your original form - your head or your stomach would end up poking through the disguise.

'The effects of the same spell cast multiple times don't combine, however. Instead, the most potent effect—such as the highest bonus—from those castings applies[...].' (PHB p. 205)

So, while it might be funny to imagine two overlapping holograms, a shorter stockier dragonborn, with an elf's head sitting on top, delicate fingers semmingly extending from the dragonborn's finger tips, magic disguises don't work like holograms. While both spells are active, one would simply take precedence over the other.

But which disguise would be the dominant one? Which spell would be the 'most potent'? In this case it's up to the DM

Let's refer back to that rule again...:

'the most potent effect—such as the highest bonus—from those castings applies while their durations overlap.' (PHB p. 205)

Diguise Self requires an Intelligence (Investigation) Check against spell save save DC, from a creature that wishes to work out whether or not you are disguised.
If two different casters had cast Disguise Self on the same target, it seems logical that the spell cast by the one with the higher spell save DC would be considered more potent and take precedence, until it was dismissed or its duration expired.
However, when the spell save DC is the same, either between two different casters, or because the same caster has cast Disguise Self twice, there is no guidance as to how 'the most potent' spell should be adjudicated.
A DM should choose a method, make sure the players understand it, and then ensure they apply it consistently.
I personally would rule that the most recent spell cast takes precedence, effectively overlaying the previous casting.

Is there anywhere else I could look for guidance on this?

For evidence of a similar (but not definitive) ruling, that some might choose to consider authoratative, you might be interested in this tweet from Mike Mearls:

Q: Could you use multiple castings of Disguise Self to layer a disguise and force multiple checks against DC?
A: No, I'd only apply most recent casting.

See also, this tweet from Jeremy Crawford, which agrees with this general principle but isn't specific to Disguise Self.

So, when does the Elf turn into a Dragonborn?

If the second spell is ruled by the DM as more potent, then the PC will change into a dragonborn as soon as the second spell is cast. This is what I would rule happens.
If the DM rules that the first spell is 'more potent', the PC would only appear to change from an Elf into a Dragonborn when the first spell's duration expires.
Answer: You would just change from an elf to a dragonborn
It states on page 234 of the Player's Handbook,

You make yourself-including your clothing, armor,
  weapons, and other belongings on your person-look
  different until the spell ends or until you use your action
  to dismiss it. You can seem 1 foot shorter or taller and
  can appear thin, fat, or in between. You can't change
  your body type, so you must adopt a form that has the
  same basic arrangement of limbs. Otherwise, the extent
  of the illusion is up to you.

But then on page 205 it says that spells don't overlap and that the player keeps the most potent of the two spells that is cast on it.
So that means the first disguise self spell that was in affect on you would end if you recast disguise self to make yourself like a dragonborn.


Foot pedals as modifier keys for Mac

Question: I am hoping to buy a couple of foot pedals that I could use as Ctrl and Shift for my MacBook Pro. Is this at all possible with an OS X machine? I have read that Kinesis foot pedals (e.g. this one) cannot be used as modifiers in combination with other keyboards. Is this correct? If so, why?
Comment: Apparently the other option is Karbriner: https://www.reddit.com/r/emacs/comments/7remed/has_anybody_used_foot_pedals/dw462sj/ I wish I knew whether this will work or not before I spend $180 on an online purchase.
Comment: Karabiner works for me as you would expect on Mojave
Answer: I created my own "keyboard combiner". It lets me use the Kinesis Savant Elite Triple Foot Pedals for shift, alt, and command modifiers on a Mac.
https://github.com/davidbkemp/KeyboardCombinerArduinoSketch/wiki
It is quite easy to assemble, but I cannot guarantee that it will work for you. It certainly does not work with some pedals and some keyboards.  For the Kinesis pedals, you will initially need to configure them to act as shift, alt, and command keys, and that means using a PC to do the initial configuration.
Comment: I think (newer versions of?) the Kinesis pedal configuration allow you to specify the basic bindings without a PC.
Comment: NOTE: you need an Adruino / Raspberry Pi for this. Having had a negative experience with Raspberry Pi I'm not so motivated by this. Though I applaud the endeavour.
Answer: Definitely possible, there's this great ControllerMate software that lets you assign keys and keyboard shortcuts to various pedals. Take a look at the following SuperUser answer: https://superuser.com/a/1486751

Foot pedals as modifier keys for Mac


What makes a rectifier diode and an LED

Question: In an LED the electric circuit causes the electrons and holes in the P-N Junction to neutralize each other to produce light energy. Whereas in a rectifier diode, if I am not wrong, the electric circuit does not cause the electrons and holes to neutralize each other. Why is this so? Also, do the electrons in a circuit flow through the diode? If they do, why dont the electrons neutralize the hole?
Answer: In a rectifier diode, there will still be some e-h pairs that recombine. However there are reasons why they don't produce light
Firstly, Silicon is an indirect band-gap semiconductor. What this means is that the energy levels in the band-gap don't line up nicely making it very inefficient at emitting photons. Generally recombination will take place in a way which results in either vibration/heating of the silicon lattice, or other means (e.g. transferring the energy to other carriers). It is possible for silicon to emit light, however it is very inefficient.
Secondly, the band-gaps in rectifier diodes will not have the right energy level for photon production. Remember that the frequency of a photon is proportional to its energy (\$E_{ph}=h\nu\$). To produce a photon of a given colour, the semiconductor band-gap energy must be approximately equal to this energy (i.e. \$E_g = E_{ph}\$).
Thirdly, the doping levels of rectifier diodes will be much to low. Lower doping levels means fewer carriers which in turn means there will be less recombination of e-h pairs than, say, a heavily doped LED p-n junction. This is evident from the fact that the forward voltage of the rectifier diodes is much less than an LED (doping levels determine the built in potential).
Finally, LEDs are fabricated in a way that there is an emission surface from which photons can be emitted (a so-called "heterostructure"). Without this, the emitted photons would just be re-absorbed. This surface is then encapsulated in a transparent lens to get the light out efficiently - and to minimise the number of photons which reflect off the semiconductor/air interface back into the device. Rectifier diodes do not have any of this - they are sealed in opaque epoxy packages.
Comment: Things get more complicated and blurry when you go into the labs. Schottky barrier LEDs exist there, and electroluminescence effects have been observed in schottkys too. I think the most important point is that LEDs are specifcially manufactured to produce as many photons as possible in a wavelength band as narrow as possible, wherein other types of diodes nobody cares what happens to the energy, and the few photons that are produced in wavelengths all over the place get absorbed anyways.
Comment: Does the re-absorption of the photons cause the efficiency of the diode to decrease? "nobody cares what happens to the energy" doesn't seem right in these days of very low powered devices - but if the energy gets re-absorbed with a net of not really any change, then I guess it doesn't matter...
Comment: @Steve Reabsorption will basically just produce new e-h pairs.
Comment: All current results in e-h recombination in the junction. And, I will point out that III-V transistors light up quite nicely in operation, you just don't normally notice because they are usually in a package without a window.
Comment: Thanks for the help. However I would also like to ask: Do electrons in a circuit flow through a rectifier diode? If so why do these electrons not recombine with the holes in the P-N junction?
Comment: @RaphaelLow of course current flows through the diode - how else can it conduct in one direction. As to the recombination, see points 1 and 2 of my post.
Answer: All diodes essentially work the same, but different kinds of diodes have different forward voltages.
Diodes with higher forward voltage generate electromagnetic radiation with a smaller wavelength.
LEDS generate visible light (and are constructed so that the light can escape). 'Normal' diodes generate infrared radiation, so they just heat up.

What makes a rectifier diode and an LED


Stability of lattice or mesh supports for printing

Question: Support structures like lattice supports, tree supports or wire supports are being widely used in metal printing or FDM as they minimise the wastage of material and power consumption. In addition, they are easy to remove.
But compared to volume support, are these structures stable enough to stand firm against the build tray during the printing process?
How these structures avoid buckling depending on the height of supported zones?
Answer: It is a fast evolving industry.
I have been looking into some printers and it seems at the present time the limit of the size is 30cm cube roughly, but it is changing every day.
Many of the shapes don't even need support, some printers can bridge spans of up to 25mm. Vertical angles less than 45degree don't need support.
There are new ways of printing that don't need any support at all, such as laser printing, however some those are not publicly available.
All hardware manufacturers have manuals and recommend what to do as for support and filler. considering the fact that filaments get cold and hard fast after printing, the structural strength of support is not of primary concern. Also digital model makers are trying to design the model with least need for lattice or any support and make it easy to release the support with least post processing.
Here is an article about the methods and manufacturers of both software and hardware.
3d metal fuse deposition modeling