Can I buy another set of round trip tickets if I already have one for a later date?

Question: I bought a round-trip ticket from Vancouver to Toronto. I am now in Toronto, but due to family emergency I need to go back to Vancouver and then come back to Toronto. In this case, can I purchase a new round-trip ticket in Toronto, or do I NEED to reschedule my ticket (going to Vancouver) and once I am in Vancouver buy another round-trip ticket? I am purchasing WestJet for both round-trip tickets. Isn't it more convenient to buy another round-trip ticket back to Vancouver?
Comment: It looks like a domestic trip, buy tickets as you please
Comment: It's called a nested trip/itinerary and is perfectly fine.
Comment: Airlines love repeat customers. Buy as many tickets as you want. You don't have to buy the ticket starting in the place you live.
Answer: If I understand you correctly, you're flying four legs in total:
<code>A: Vancouver to Toronto
B: Toronto to Vancouver
C: Vancouver to Toronto
D: Toronto to Vancouver
</code>
You already have a round-trip ticket for A+D, and you have just discovered that you need B+C.
Buying A+D and B+C instead of A+B and C+D fits the pattern of back-to-back ticketing, and airlines have been known to frown on that.
However this is mostly in cases where buying A+D and B+C is cheaper -- such as if there's a Saturday night between B and C and the airline offers cheap round-trip fares when there's such a night between the outbound and inbound leg (because that way they can attract pleasure travelers who wouldn't otherwise go, without needing to offer the same low price to business travelers on short trips within the working week).
If the airline you're flying with does not offer such deals in the first place (they have become less common than they were 10 or 15 years ago) -- or if you're not getting a good deal for B+C anyway, such as if you need to buy it on short notice -- it is unlikely that the airline would have any problem with it.
In any case, even if the airline does take offense, it is extremely unlikely they would refuse to transport you. At worst they may get stingy with frequent-flier points, or demote any preferred status you may have in their bonus program -- but if you're not a frequent traveler anyway you could just decide not to care about that.
Comment: As the OP did not buy the tickets at the same time, rather is buying the second ticket after flying leg 1 in response to an emergency, his situation would not be considered back to back ticketing by any airline.
Comment: @Tom: Yes, that is what I meant by "if you're not getting a good deal for B+C anyway ..."
Comment: I don't think any airline even claims to prohibit this practice, even if they technically or legally had the means to do so. These days they would be happy to see you are a repeat customer. It's perfectly fine. That said, have an upvote for the clear explanation of the practice.
Comment: Airlines typically only frown on bookings where you do not intend to fly one or more legs like hidden city ticketing or booking two opposite round trips and only using the  first leg of each (because of the stupid Sat night rule). As long as you fly what you booked, no one will take issue.
Answer: You can buy a new Toronto to Vancouver return ticket and use it. There are no rules that force you to reschedule your original flight.


OP_CHECKSIG: reasoning behind construction of message to be signed

Question: I've closely studied the deservedly famous OP_CHECKSIG explanation found here, including the diagram found here. That explanation details how to construct the message that is signed via ECDSA, producing the digital signature for SigScript. All good.
By way of summary, the aforementioned message is an amalgamation of the new transaction under construction (with its ScriptSigs nulled out) and the scriptPubKey from the sourcing transaction output. For clarity, the "sourcing transaction output" is the one identified in the transaction input under construction by its Transaction Hash field and its Output Index field. All good.
MY QUESTION: in the new transaction under construction, its Transaction Hash field already "fingerprints" the sourcing transaction output. Why go to the effort of inserting the aforementioned scriptPubKey from the sourcing transaction output into the message? That seems redundant, given that the hash digest in the Transaction Hash field fingerprints the entire sourcing transaction.
I ask this question in order to more thoroughly understand the logic behind the intricate construction of the message that is signed via ECDSA.
Answer: I think, since with some sighash types, the scriptPubKey is not part of the txid. So it is not automatically taken into consideration when the txid is already part of the hash.


How to remove excerpts in joomla articles

Question: On my homepage, I am listing all my blog posts from a category. I don't want to show there any excerpt of articles neither full article instead of a title and featured image. How can I achieve that?
Comment: If you have made an attempt to self-solve, please provide that.  If you did some research before posting, please show us so that we don't suggest something that you have already seen.  Editing your question to include these important details will make your question more attractive to answer.
Comment: It seems that the volunteers wishing to help are not completely sure of your requirements.  Please use different wording to describe what you desire.  Alternatively, you might show a screenshot and use an image editor to indicate what you do and do not want.
Answer: It appears to me that you want to just show the title of the articles in your blog and not the Introduction Text or the Full text of the Article.
If you want the article list to appear in the body of your Homepage then you need to update the Menu Item Type for the Home page and select Articles->Category List.
If you want to display a list of the articles off to the side of your home page then look at the various Modules available under the Extension menu for listing Articles. i.e. Most Recent.
https://docs.joomla.org/Help39:Menus_Menu_Item_Article_Category_List
Answer: I'm really not sure what you're after, but what I think you're asking for is how to make the category blog that you have designated as your home page show a list of article titles, no intro text.
To do that, go to the "Blog Layout" tab of the menu itemand put zeroes in the boxes for Leading Articles and Intro Articles, then put in a number for how many link articles you want in your list. Then you'll want to adjust the values on the "Options" tab until you see what you want.
If that's not what you're after, please expand your original question to give us more specifics so we can figure out what you're trying to do.
If nothing else works, a template override can certainly get you what you're after.


Whose responsibility is it to advise impact to transit time due to flight changes by partner airline(s)

Question: Transiting from Dubai via Madrid to a local flight in Spain operated by Iberia. (Terminal 4S arrival, Terminal 4). All tickets issued by Emirates. Original transit time 2.5 hours, now down to 25 minutes. Iberia have advised me of the the flight change as a FYI (but have not mentioned the transit time might be an issue etc). I've heard nothing from Emirates although I can now see my itinerary has changes. Is it always upon the traveler to work out that there might be an issue (25 minutes is to short to transfer from 4S to 4 in Madrid) after changes in connecting flights (even if they are on a single ticket)?
Comment: Every airport publishes minimum transit time and 25 min will be too small of a transit time as per any airport. From what I know, airlines try to adhere to these published minimum transit times when they issue a hopping ticket. However, they aren't regulated by anyone and the onus of being able to connect is almost always on the passenger. But I would wait for other opinions too.
Comment: Yes Madrid airport has a minimum transit time of >1 hour from what I've read for transfer from International to EU zone flights (Which is terminal 4S to 4 in Madrid). You would think it would be simple batch program for an airline to run nightly looking for violations that have arisen due to changes in flights. They enforce it when booking a ticket, should be ongoing housekeeping
Answer: For a schedule change in advance it is always the ticketing carrier (in this case, Emirates) that is responsible for rebooking you after the change.
In a perfect world this would be handled automatically, but when multiple airlines are involved it generally doesn't - especially when those airlines are not part of the same alliance (Emirates is NOT OneWorld, despite your questions heading).  I would suggest reaching out to whoever you purchased your ticket from (either Emirates or the travel agent) and asking them to arrange an alternative. It is possible they will contact you, but the earlier you arrange the alternative the better the options may be.
Depending on how much notice you were given of this change and how much you need to change your arrival time, you may be able to claim compensation under EU261.
Comment: Compensation under EU261 is not obvious, given it's a trip To the EU rather than from the EU, and the carrier probably being non-EU. I'm not sure what the precedents are (if any) for a mixed-flight in that direction.
Comment: @jcaron Iberia rescheduled the flight, and are an EU carrier. Whilst the ticketing carrier is responsible for rebooking the passenger, the carrier that rescheduled the flight would be responsible for the compensation.
Comment: @Doc thanks I've updated the question to remove the statement that Emirates is part of OneWorld. Ticket purchased direct with Emirates BTW


Can we connect mobile to reverse cam display output

Question: My cars reverse camera's display break. I can see a mini USB cable was connected to the display. Can I connect my mobile phone to that output using mini USB female to micro USB male jack with any kind of USB streaming app?
Comment: So for the display that was an output or do you think it was an input? Then, can you actually send the data format the display expects? ie what was the output of the camera?
Answer: What are the outputs from the camera?
You could try something like this (from this question) and see if that'd work with an OTG cable. I can't guarantee that it'll work, but it seem like a really fun project to do imo.
However, buying a new screen might be the same price as there are tons on Amazon/Chinese websites
Edit
Are you sure the micro USB input to the display, was not just the power instead of actual video
Completely off topic
You can also get a Raspberry Pi / Arduino, accept video signal from camera, plug in a wi-fi dongle, connect with your phone to the IP (within the same network, so make sure you use your Pi/Arduino to host, rather than receive) and stream the video.
Pretty sure you'll have (lots) of delay. So be careful and don't hit anything behind you...
Comment: The display was connected to a micro USB port. The micro USB provided power as well as data to the screen. At this moment I just need only a screen. That screen is not available in the market. So I have to buy an entire module once again. So I think about my old mobile as a display. I can see some mini USB to micro USB converters in the market. But don't know if it will work or not.
Answer: reverse cameras are almost certainly analog signals.  That's probably the power cord for it.  However if you have an android-based deck, it's possible that it COULD actually be the camera.  There are a couple of external av adapters that hook up that way.  I have one myself.  usb-otg -> digital input device -> camera.  People use them a lot when doing heads-up flying of drones but they are also designed for reverse cameras (you can flip the image).  In Summary, follow that cable and it may lead to a device with a standard av input.


Going from individual elements back to to matrix/vector notation

Question:
Note: Moved to math.stackexchange.com. Sorry for the off-topic question!

[Context: I'm working through problem set one of Andrew Ng's Machine Learning course, question 2, trying to derive the Hessian myself. My trouble, though, is with the simple linear algebra. I'll ignore the regularization parameters in my question to keep things simple.]
I can find $H_{jk}$ by taking partial derivatives of the original function with respect to $j$ and $k$. I've worked it through to the point where I know that $H_{jk} = \sum_{i=1}^m d_i X_{ij} X_{ik}$, and I know the answer is that $H = X^TDX$.
($d$ is a vector of reals, $H$, $X$ and $D$ are $m \times m$ matrices, $D$ diagonal with $D_{ii} = d_i$.)
It's easy for me to verify that $H = X^TDX$ gives $H_{jk} = \sum_{i=1}^m d_i X_{ij} X_{ik}$. But I don't "see" how to go easily in the opposite direction.
1) Is there a method, or a set of rules to memorize, or a way of talking through it that would make it easy, or do I just need to do enough basic linear algebra homework to start to recognize patterns?
2) Am I doing it wrong by breaking it down and deriving $H_{jk}$? Are there tricks for taking these kind of derivatives (which involve logs and exponentials) over the whole matrix at once?
Comment: This question is not quite appropriate for MO; you might have better luck at math.stackexchange.com.
Answer: I'm not sure, but it seems to me you're done!:
$H_{jk}=\sum_{i=1}^m d_i X_{ij} X_{ik}=\sum_{i=1}^m X^T_{ji} D_{ii} X_{ik}$.
Where, as you mention $D_{ii}=d_i$, is a diagonal matrix, therefore:
$H_{jk} =\sum_{i=1}^m \sum_{l=1}^m \sum_{n=1}^m  X^T_{jl} D_{ln} X_{nk}=X^TDX$.


Loud fan: Tried many ways, but can't handle it

Question: hope you can help me, quite frustrating...
I used Windows 7 and had no problems with my fans at all. Using Linux in the university I decided to use it at home, too. When you boot your Computer, your fan starts to get loud, but then gets nearly silent. This does not happen, it keeps being loud.
I am quite sure the CPU-Fan is my problem. Settings in the Boot-menu did not help in any way; they had no influence on my fan.
Hardware:
Intel i5-3570 LGA 1155
MSI Z77A-G43
I have already searched a lot and tried to use fancontrol. But, as you probably know, you need to install lm-sensors first and configure pwmconfig.
Summary-Output of sensors-detect:
Driver `coretemp':   * Chip `Intel digital thermal sensor' (confidence: 9)

Driver `lm78':   * ISA bus, address 0x290
    Chip `National Semiconductor LM78' (confidence: 6)

Driver `f71882fg':   * ISA bus, address 0x295
    Chip `Fintek F71869A Super IO Sensors' (confidence: 9)

To load everything that is needed, add this to /etc/modules:
----cut here----  Chip drivers  coretemp  f71882fg  lm78
----cut here---- If you have some drivers built into your kernel, the list above will contain too many modules. Skip the appropriate ones!

Do you want to add these lines automatically to /etc/modules? (yes/NO)yes Successful!

Monitoring programs won't work until the needed modules are loaded. You may want to run 'service kmod start' to load them.

Unloading i2c-dev... OK Unloading i2c-i801... OK Unloading cpuid... OK

Output of sensors:
acpitz-virtual-0 Adapter:  Virtual device  temp1:        +27.8°C  (crit
= +106.0°C)  temp2:        +29.8°C  (crit = +106.0°C)

nouveau-pci-0100 Adapter:  PCI adapter  fan1:        4824 RPM temp1:
+42.0°C  (high = +95.0°C, hyst =  +3.0°C)
                       (crit = +105.0°C, hyst =  +5.0°C)
                       (emerg = +135.0°C, hyst =  +2.0°C)

coretemp-isa-0000 Adapter:  ISA adapter Physical id 0:  +36.0°C  (high
= +85.0°C, crit = +105.0°C) Core 0:         +28.0°C  (high = +85.0°C, crit = +105.0°C) Core 1:         +36.0°C  (high = +85.0°C, crit =
+105.0°C) Core 2:         +28.0°C  (high = +85.0°C, crit = +105.0°C) Core 3:         +32.0°C  (high = +85.0°C, crit = +105.0°C)

pkg-temp-0-virtual-0 Adapter:  Virtual device temp1:        +35.0°C

Now the reason, why I wrote "but"....
After I installed fancontrol, I did this sudo pwmconfig.
Output pwmconfig:
Found the following devices:     hwmon0 is acpitz     hwmon1 is nouveau  hwmon2/device is coretemp     hwmon3 is pkg-temp-0

Found the following PWM controls:    hwmon1/pwm1           current value: 100

Giving the fans some time to reach full speed... Found the following fan sensors:    hwmon1/fan1_input     current speed: 4483 RPM

Warning!!! This program will stop your fans, one at a time, for approximately 5 seconds each!!! This may cause your processor temperature to rise!!! If you do not want to do this hit control-C now!!! Hit return to continue:

Testing pwm control hwmon1/pwm1 ... /usr/sbin/pwmconfig: line 226: echo: write error: Operation not permitted Manual control mode not supported, skipping. Testing is complete. Please verify that all fans have returned to their normal speed.

The fancontrol script can automatically respond to temperature changes of your system by changing fanspeeds. Do you want to set up its configuration file now (y)? y What should be the path to your fancontrol config file (/etc/fancontrol)?

Select fan output to configure, or other action: 1) Change INTERVAL    3) Save and quit 2) Just quit           4) Show configuration select (1-n):

The last menu, showing 1), 2),... should show any fan, but, as you see, it does not.
Additional information about that:
It says "Warning!!! This program will stop your fans, one at a time, for
 approximately 5 seconds each!!!", but the fan didn't stop after pressing "Enter".
Do you have any idea, how I get control of my noisy problem?
Answer: Make sure that it is not your GPU fan that is causing all the racket.  I had an EVGA video card that would run at full fan by default, and would only quiet down once the appropriate driver had been loaded.
If it turns out to be your GPU fan, then you will probably have an easier time controlling that than controlling your CPU fan.
Good Luck.


Is there a minimum size that a Tallis Kattan has to be?

Question: Is there a minimum size that a Tallis Kattan has to be in order to be Yotzei the Mitzva of Tzitzis according to all Poskim? If there is a minimum size, what is it?
Comment: Are you just looking for the largest possible opinion brought in a serious posek (as your question currently reads), or are you looking for the different opinions suggested lemaaseh by modern poskim (significantly more interesting IMO)?
Comment: ...well? Will you take an answer with a Shittah in Achronim even if it isn't the most machmir?
Comment: @DoubleAA: My question was regarding a Shita that would be acceptable to all. I would accept an answer from any reliable Posaik even if it is not L'chumra.
Answer: The main shiur is that which will cover the head and most of the body of a child who can walk independently in the marketplace (menachos 41).  The Tur gives an age of 9.
There is a dispute about the second condition of the braisa that an adult would wear it in the street occasionaly.  The Tur holds this is a second precondition and so the Rema adds this even though the mechaber doesn't ((O.C. 16:1- see magen Avraham).  The 2nd precondition alone would not be enough of a shiur.  However, the Mishna Berura (16:2) says that it seems from the Bach that if an adult (13 y/o) would wear it on a regular basis, you wouldn't need the precondition of the child.
BOTTOM LINE: The Mishna Brura (ibid.) quotes a shiur of 3/4 Amah L x 1/2 Amah W, but then quotes the Artzos haChayim who say this shiur has no basis and says that "Anshei maase" are particular to have an Amah on each side, but you should have at least 3/4 of an Amah, since the "Mesamchei Lev" measured a 9 y/o and found him to be 1.5 Amos.
Answer: Twenty-four inches wide. Some poskim hold that it is eighteen inches.
Comment: That is based on the Artzos haChayim's recomendation of an amah.  There are, of course many shittos of amah in between.
Comment: This is also based on the [*shittot*](http://halachipedia.com/index.php?title=Reference_of_Measurements_in_Halacha#Amah.2C_Tefach.2C_Etzbah) of multiple Rabbanim as regards converting an *amah* to inches.
Answer: haRav David Yosef rules in Halacha Berura 16:1 (presumably based on a ruling of his father Hacham Ovadia) that unless a talit is 2 amot long (96 cm) and 1 amah wide (48 cm), not including the hole, one should not make a beracha.
Comment: How do you not include the hole when measuring a _talis katan_?
Answer: Basing himself on Ritva, Nemukey Yosef, and popular practice, the Aruch Hashulchan (OCH 16:5) writes that the minimum sizes are only required for ittuf; wrapping oneself. Since we don't do this with a normal tallit k'tanah, there is no minimum shiur:

ולענ"ד כל חקירה זו בחנם והעולם מקיימים מצות ציצת בטליתות הקטנים דכבר בארנו בר"ס ח' מהנמק"י ומהריטב"א ... ומן התורה כל בגד של ד' כנפות שנושא על גופו חייב בציצת ע"ש וגם דעת רבינו הב"י כן הוא כמ"ש שם והא דבעינן עיטוף רוב הגוף זהו בטלית העליון ... אבל טלית קטן שתחת הבגדים א"צ שיעור כלל דאם רק יש בו ד' כנפות חייב בציצת וכן מבואר להדיא מדברי הריטב"א והנמק"י שהבאנו בשם בסעיף ד' ע"ש

"In my humble opinion, this whole investigation [regarding the requisite size of a garment] is pointless, and the public fulfill their obligation to wear tzitzit with small garments, for we have already explained in the begining of ch. 6 on the basis of Ritva and Nemukey Yosef...every garment with four corners needs tzitzit, and this is the opinion of the Beit Yosef. And the requirement to fully wrap oneself with a tallit, is only with a tallit g'dolah." (Trans. my own).
Answer: Big enough that if you wore this over your torso in the street, you wouldn't be embarrassed.
(Now Groucho Marx would ask what your torso was doing in the street, but that's a different question ...)
Answer: To make it simple. It would be size 22 of Tzitzis.
Comment: Tzvi, Shavu'a Tov, welcome to Judaism.SE, and thanks very much for this recommendation! It would be much more valuable if you'd [edit] in the reasoning behind it.
Comment: Odd, because [other-Tzvi says](http://judaism.stackexchange.com/a/3556/759) there are multiple opinions.


Can tethered shooting be dangerous to my camera?

Question: I own a T6i and a 6D. I'm interested in tethered shooting for studio scenarios. However I've heard from a friend that if I tether my camera to my laptop and I a power surge happens in the USB port, that it can fry some board on the camera and I'll lose it. Can this actually happen, and if so, is there a safe way to perform tethered shooting?
Comment: The only real danger is someone tripping over the cable and damaging the USB sockets of the computer or the cam...
Answer: I wouldn't worry about it.
From my experience, power surges are not something you need to worry about with USB devices. If a power surge happens, it will most likely be from the power grid which is more likely to fry the computer you are tethering from, than the USB devices connected.
Usually the opposite happens. A USB device draws more power than the USB port allows, which is what is generally meant, when discussing USB power surges.
But that won't break anything, only potentially cause some of the other devices connected to not function properly until being hot-swapped.
Tethered shooting should not be a problem.
Answer: As another answer correctly states, power surges on computer USB ports are not very likely. Also, for such a surge to be harmful, it would need to be an actual overvoltage between pins on the USB port. Unlikely unless something manages to activate eg USB PD modes by accident.
There is slightly more likelyhood of the whole usb port having problematic potential differences with OTHER power supplies involved, or relative to ground.
For absolute maximum safety of expensive equipment, avoid connecting the camera to USB PD (Power Delivery) capable ports, avoid using less than trustworthy powered USB hubs, and avoid having anything else connected to the camera that is also indirectly, in any way, connected to the mains (eg studio strobes, HDMI monitors...). If there are multiple cables plugged into the camera, only one cable should be connected to anything that is plugged into the wall or connects to something plugged into the wall.
Comment: Whoever downvoted, knows more about common-mode and ground potential problems and dodgy grounding capacitors in PSUs than me ... or not enough :)
Comment: If someone does know more, then they should be well-placed to add a good answer of their own....


where is input.h located?

Question: I can't remember what directory this file is found in off hand.  Does anybody know?
Answer: After a more precise google search, I found the answer:
/usr/include/linux/input.h
Answer: you can also look in the system using the following command: $ sudo find / -type f -iname input.h; it'll take a while, or $ locate input.h =)
Answer: If you're looking for a header file from a dev package that isn't installed, you can use the search from (the non-official site) http://packages.ubuntu.com/ . So for example, you can see all the packages that provide input.h in maverick at http://packages.ubuntu.com/search?searchon=contents&keywords=input.h&mode=exactfilename&suite=maverick .
Alternatively, you can use the archive provided contents file in http://archive.ubuntu.com/ubuntu/dists/RELEASE/Contents-ARCH.gz , replacing RELEASE with the release (e.g. lucid, maverick) and ARCH (i386, amd64). Within that, you can search for the specific file and get the package from that.
If you know the file came from a package that's currently installed, you can use 'dpkg -S FILE' to find out what package and where the file is located.

where is input.h located?


Interactive spreadsheet survey

Question: I'm looking for an online survey platform which would allow participants to input information into a blank interactive online spreadsheet.
The spreadsheet would be blank for each individual participant and I would then be able to export the collected data into a CSV file. Does something like this exist?
Answer: Disclosure: I work for PollUnit.
I'm not sure I understood you right. By "blank" you mean a completely empty table without table header? If not PollUnit might be something for you.
If you create a poll of type "Free Table", you can define columns. Your users fill in the rows.
CSV and Excel export is only possible in the payed accounts.
At https://pollunit.com/en/table you will find some examples.
Comment: Thank you very much! Poll Unit looks nice. What I mean by 'blank' is that I want each participant's information that they put into the table to be private. I want each person who uses the table to be able to add information to it but I don't want them to see each other's work. Only I would be able to see everything. Do you know of any platform that could help with that?
Comment: @Wavetree With PollUnit you can choose between different private settings. But this is also only possible in the payed accounts. It's in the Advanced step of the wizard. There you can choose "hide participants".

And another idea would be to use a survey tool which allows multiple questions. I am sure, most of these tools can export those questions in a table form.

Interactive spreadsheet survey


Why is there increased dryer motor hum while powered by a generator?

Question: We have an off grid home, solar powered 120v. While running the home on the backup generator (also charging batteries), the drum motor on the propane dryer has an increasing noise, then gets to a point where it trips the breaker on the generator, but the breaker on the manual transfer box (30 amps) and the 20amp breaker in the main panel are unaffected. I have check voltage and frequency at the dryer outlet with the generator running (dryer not plugged in the outlet), 119-121 volts and 59-61 hz which should be very acceptable. Also in a possible related sense, we have 4 ceiling fans 2 of which also get the hum situation but no issue with breakers.
Answer: Is your generator producing true sine wave, modified sine wave, or square wave output?
The motor's designed to work on sine-wave AC, which is what large generators are happiest producing, and which is generally the most efficient form since all the energy goes into the single frequency and can be easily drawn back out.
Square wave is easier for small alternators to produce, but has a lot of high harmonics which can cause resonance in motors, sometimes to the point of being damaging. Square-wave alternators may also be damaging to some electronics, for similar reasons.
"Modified sine wave" is a compromise between the two -- it adds another few steps between the most-positive and most-negative outputs. This reduces the harmonics to a level that most motors and electronics can handle safely. There are still going to be some harmonics, which may be made audible by the motor, but they shouldn't be strong enough to be damaging.
If you've got a square-wave unit, consider replacing it. If you've got a modified-sine unit and are still having trouble... well, switching to true sine wave will probably solve it, but you might want to get someone with expertise in this system to take a look at your set-up before you commit to that purchase.
Comment: CEMF goes into making the motor work harder to turn the generator. Really. Run a generator with no load and it's just a spinning mass of metal; put a load on it and the back-EMF produces magnetic forces which resist that spin. (Remember that a generator and an electric motor are almost the same concept, just used backward.) Some of it is also lost as heat, of course, just as some of the power the load uses is lost as heat. In other words: It exists, it's normal operation, it's the nature of the beast, and it's designed for.
Comment: I'm assuming any sort of doohickey that smooths out the wave costs more than a new gen-set (or don't exist)? Also, what about feedback?
Comment: (1) Yes, a filter would be difficult. Simplest would be a motor-generator, at which point you might as well just drive the generator directly from the engine... (2) I don't know, what about feedback? I don't see where the concept is applicable to this question.
Comment: I guess I don't understand where [CEMF](http://en.wikipedia.org/wiki/Counter-electromotive_force) *goes*. I thought it would be bad for the gen-set and since you'd have to pay to upkeep it; a concern.
Comment: I can run tests again while the genset is running loads-inverter battery charger and the lights, etc that we use while charging which is mostly at night so we're charging AND running the house off the other leg of the generator. I haven't checked the purity of the sine wave (I believe it is from my research on B&S larger generators), I think I'll need an oscilloscope for that. I could see where the engine harmonics could affect the waveform too, if that is what some of the talk here is addressing. I as well thought that the dryer motor may not accept the distortions.
Answer: It sounds like the inverter is producing a cleaner sine wave than the generator.
Your TRMS meter might show 120 volts and 60Hz but isn't telling you the whole story. In other words, the sine wave is distorted with harmonics. The hum is telling you the story.
Answer: I am the one that posted the original issue. After research and consideration of what is happening, I believe that what is going on is that there is an imbalance in the way the generator/inverter is wired. I looked at the inverter/charger wire diagram and I am sure that the leg that feeds the charger is the same that is powering a larger portion of the home requirements, that being those kitchen lights, washer and dryer. The other leg is feeding a tv, a couple living room lights and a well pump that has a max of 1200 watts when running which should be a non-issue. We run the generator at night as most usage is lower at that time. I am going to swap the two feeds at the main breaker. Thinking is that what is being heard is the generator going into surge (the hum that starts low and increases) and then trips the breaker. A key thing happened is that I discovered the inverter generator was operating along with the circuits that run the dryer etc, and the twist lock had backed out some and there was no power to a portion of the home, that being the other leg from the generator...I thought the gen had an issue but it was the connection at the twist lock. I'll be back with the answer.
Comment: Hello, and welcome (back) to Stack Exchange. You should try to [merge your accounts](http://stackoverflow.com/help/merging-accounts), so that you can get your old reputation.


Manufactured home bathtub/shower wall installation

Question: We purchased a 15 yr old mfd. home. Master bath has an ABS(?) bathtub with separate shower walls. It's serviceable, but will eventually need to be replaced(ugly).
A: I would like an all in one insert tub with walls. I can see, without measuring, the walls are not square. Is an insert possible without a lot of finagling? We're on a limited budget.
B:If I cannot do an all in one insert, what r my best options for material for the tub and the separate walls. The shower walls right now are board with vinyl over them, doomed to fail. Again, not looking for Top of the line, something economical, easy, sturdy, easy to clean.
Thanks.
Answer: I have replaced dozens of older tub/shower units with nice fiberglass tubs with a three piece matching/interlocking surround wall kits. Since getting a one piece unit into old construction is usually impossible, these modular units work well. The better units are sturdy and will adapt well in situations where the walls are not perfect. Since the wall units interlock and overlap the tub flange, leaking is rarely a problem. The costs of these units run from about $500 to $800. I have good results with Kohler and American Standard units. Avoid the cheap units that have non-locking wall sides and require a lot of sealants and flimsy corner trims. This is not an easy DIY project for someone without experience. The process will include plumbing skills, leveling the tub unit and shimming the walls if the existing wall framing is really bad.  Sometimes it is necessary to remove existing wall sheathing (drywall etc) and attach tub and sides to studs, then use moisture/mold resist drywall to recover the walls.
Answer: Are you sure you can install a one-piece unit?  Measure your doorway and hallway clearance.  Often the one-piece units are installed during initial construction before the doors and drywall are installed.  You may not have enough clearance to get one in.
Answer: As Shirlock & Grunthos say, you're probably not going to be able to do a one-peice (unless you cut a large hole in the wall.) I did a tub and surround a few years back, tried a budget plastic surround, got it home, pulled it out of the box, put it back in the box, returned it and upgraded to a (3 peice) fiberglass surround that cost a bit more than the new tub - the cheap was was clearly too thin to actually last (or possibly even survive the install.) This was a limited project to get the house sold. I figured I would not want to buy a house with the cheap plastic surround, so who else would? Might as well leave the rusty leaking steel tub I was replacing in as use that piece of junk.
To make the most of DIY in a project where it's not just to make the bath look good enough to sell the house, I'd consider tiling it rather than even a "good" fiberglass surround. More DIY mileage and a nicer end product - potentially at less cost. If that sounds scary, try a few smaller tiling projects first - it's less daunting when you have done some (or you'll find out it's not your idea of a fun time on a smaller project.)
If you use a fiberglass (or other plastic) tub, bed the thing in plaster - it should be in the instructions, if not, well, find some elsewhere. It makes a world of difference in how the tub feels and holds up over time. Literally as simple as placing a pile of plaster on the floor, and then setting the tub, so the plaster fills the space between the tub bottom and the floor, fully supporting it. Nothing wrong with a fiberglass tub if you attend to that detail and don't scratch it up - cast iron is "more solid" out of the box, but also expensive and heavy - the only end benefit (to an annoying install experience dealing with the heavy thing) is that you have a harder porcelain finish.
I personally won't use even "moisture resistant" drywall around a tub. Tile backer (durock, hardi-backer - stuff comes in 3x5 sheets, normally) is far more moisture resistant and does not cost a lot more for the small area - so if anyone ever decided they don't like the fiberglass surround in the house we sold, they'll find tile backer behind it. There's also framing to support grab bars if ever needed.


How do I shoot a panorama with a Nikon D5200?

Question: I recently bought a Nikon D5200 and I was wondering how to shoot in panorama mode. I seem to find every other mode but panorama. Do I just need to pan the camera and take multiple pictures and stitch them together later? Or does the camera have a panorama mode built in?
Answer: The D5200 does not have a panorama mode built in. You will need to take multiple shots and stitch them in software like Photoshop or Hugin.
When you take your shots, do not simply stand still and twist at the waist. This will result in distorted panoramas. Instead, you need to imagine that the end of the lens is attached to a pole in the ground, and pivot around that. Here, have a diagram:

You can get special tripod heads that set the camera back so that the pivot point sits correctly at the front of the lens. Or you can do it more approximately by hand, using your tripod as a guide and keeping the lens over its central point.
Comment: Ah... I know some people who might object and suggest to rotate around the optical center and not the front lens (somewhere in between front lens and sensor plane :-). Anyway this is true if you have a short distance foreground or with a wide angle lens - which is not recommended for good stitching. Otherwise the impact will be minimized : I did "quick and dirty" panos that turned out good.
Comment: Where is the diagram from?
Answer: Because the D5200 has an optical viewfinder, they haven't thought to build in a way to overlap images.  P&S cameras typically use an LCD with liveview, so it's easier to implement a way to give a panorama-assist mode.  There is, of course, nothing stopping camera manufacturers from adding this to the SLR liveview modes, or creating a dot-matrix LCD overlay in the viewfinder to do this, but it could be cost-prohibitive, or they simply believe nobody needs the feature.
It is entirely possible to shoot a panorama without it.  As long as you do not have any nearby subjects, parallax is not critical, and you can rotate the camera by hand, and just visualize 1/3 to 1/2 of the frame overlapping (side to side for rows; top to bottom for columns) so you'll have enough matching detail to create a successful stitch.
Other basic panorama technique to keep in mind:

Manual exposure mode can keep the exposure of the member images from shifting as the lighting conditions shift with the view.
A manual (non-Auto) white balance mode can keep the color temperature of the member images from shifting as the lighting shifts with the view.
Manual focus can keep your DoF from moving between member images.
Shoot more coverage than you think you need--both for scene cropping and for horizon correction.
Consider shooting more coverage through time as well as space, if there are moving subjects going through the scene--you may need a "clean background plate" to erase ghosts or clones created by the stitching.
If you are using a wide-angle lens, also consider correcting in post for vignetting before you stitch, to avoid dark borders from showing up in the panorama.

Rotating the lens around its no-parallax point really only becomes an issue when you're shooting a panorama in small spaces (typically indoors), or you have subjects very close to the camera. The farther away the scene is you want to shoot, the less chance parallax will prevent a clean stitch.  For most landscape panoramas, you do not need a special panohead.
Answer: As you have already been advised, you can shoot multiple overlapping photos and then use software light Photoshop / Lightroom / AutoStitch / Hugin to stitch them in a single panorama.
In order to get a perfect panorama, though, you need to rotate the camera around its so-called "nodal point" - when rotating around it you virtually shoot all photos from the same position (the center of a virtual sphere you are trying to "wallpaper"); as opposed to shooting by rotating around yourself, or even rotating the camera on a standard tripod - in the first case the center of rotation is yourself, and in the second - the camera sensor. In both latter cases you get photos from slightly differing viewpoints (slightly offset spheres).
This might not have much, if any, impact if you are shooting distant objects only - the parallax effect might not be visible at all. But if you have an object (rock, tree, house) that is close to the shooting point, the object will have a visible offset (against the distant background) between the different photos, and might not stitch properly, if at all, in Photoshop.
There is gear (special panoramic heads for tripods) that can make it easier for you to rotate around the nodal point once you have found it for the particular lenses you are using (note that each lens has a different nodal point). But you still need to find it experimentally. Here is a video and an article that can help you with that:
https://www.youtube.com/watch?v=JpFzBq0g7pY
http://www.johnhpanos.com/epcalib.htm
Answer: From http://www.ifotosoft.com/resource/make-panoramic-photography.html:

Whatever your project, here are some guides and tips on how to take
  advantage of the panorama stitching software with your camcorder. And
  then you can blend the photos together in the best status as a
  panorama. Just learn the best method to stitch photos to panoramic
  photography.

Use consistent settings Change "White Balance" to a manual mode or at lest change from "auto-white balancing" to another settings. In the
  way you can create panorama files evenly.
Choose a center point Find the feature or area that looks good in the center and take steady aim, and then shoot the rest in the same
  zoom level. It'll help you align photos later in good status.
Shoot overlapping shots in ordered rows It is the last and the most important requirement. With 20-30 percent of the overlapping the last
  one in a steady row, it can help you keep the shots organized.


Research grants for international PhD candidates

Question: I recently came across a friend who is applying for a PhD in my lab. He happens to be from Brazil, on an F-1 visa. He was told by my advisor that his citizenship status affects the sources of funding available to support his work. I was always under an impression that the principal investigator applies for research grants and funding does not depend on visa status (if any) of the students under his guidance. Was I wrong in making this assumption?
Answer: It absolutely depends on the source of funding. Each organization has their own rules. By and large, the NSF (since you mentioned F-1 visas I assume this is US-centric) allows foreign students to receive funding from grants, but this intent has to be disclosed at the time of submitting the grant request.
DARPA has slightly tighter rules although I'm reasonably sure foreign nationals can be funded. But if you're from a "country of interest" like Iran, there can be other complications.
Finally, while these are not PI-requested grants, the NSF-Hertz graduate fellowships are exclusively for US citizens.
p.s This even applies to PIs. There's a large DARPA program that you're not eligible to apply for unless you have a SECRET clearance, for which a necessary but not sufficient condition is that you're a US citizen.
Comment: There are also restrictions for students supported from "industry affiliate" funds of a research center - in some cases, these funds are from defense contractors for defense-related projects and can only go to US citizens.
Comment: I figured DOD and DARPA would be exclusive about allocating their funds to international researchers, and understandably so. But my lab works on medical imaging (MR-PET, if you find yourself curious). Our source of funding is primarily from NIH and a few corporate giants who we are thankful for. Would the aforementioned restrictions still apply? I would think not. I mean, it's just healthcare after all.
Comment: I'm not familiar with NIH funding procedures. I know that NIH money can fund foreign students just by looking around my own department. Ultimately it depends on the particular program rules.
Answer: The question (or the supervisor's answer) does not indicate clearly if the supervisor is planning to incorporate your friend into one of his grants as support personnel, or is planning to have your friend write his own doctoral fellowship grant.
For the first option, the student's visa status does not matter in most of the cases. I have seen CDC and NIH grants used to fund foreign students. My PhD was also funded by NIH (I was not listed as an investigator) when I was holding an F1 visa.
The only wrinkle I can think of is that, the PI (principal investigator) might have budgeted a full time salary of, say, $50000 a year for an assistant. Due to F1 visa's limitation, the student has to be a full-time student, which means he cannot get full-time salary as a worker simultaneously. The usual approach is to resubmit a minor adjustment and change the budget into $25000 part-time salary and $25000 scholarly support. At this point, some problems can occur as some grants might have specified that they wouldn't fund school fee (which means your friend may have to look for scholarship to supplement his study. But he will have some stipend from the grant), and the agency may also question the feasibility of cutting a position's time in half. etc. Otherwise, I cannot think of other significant reasons.
For the latter case, then visa status matters a whole lot more. If your friend is going to write his own grants, it is true that a lot of grants do not accept proposal from non-US citizens. Try to scout around some grant websites such as Grants.gov and do a search. The site allows you to screen out grants by applicant's visa status. As far as I have seen, PhD fellowship grants mostly welcome all kinds of visa status.
So, in conclusion, clarify with the said supervisor, and start assessing the grant availability.


cake baking problem (white lumps of flour)

Question: I have a cake recipe called oil cake that has been in my family for a long time. It calls for flour and sugar and to make a well and add egg, buttermilk, cocoa, pinch of salt, cinnamon, and oil. Then add 1 cup of boiled water to which 2 tsps of baking soda have been added. Sometimes I mix it first and then add the water w/ b soda and sometimes I add it all together. My problem is sometimes I have white clumps in the batter and they are still there when the cake is done baking. I can't figure out what the problem is. Is the water too hot? Which is the correct way to add it, before I mix the rest of the ingredients or  after? Help I love this cake but sometimes it comes out perfect and other times not. I am at a loss. thanks for the advice
Answer: How it's supposed to be done
The lump problem is straightforward: your mixing technique is failing.
When you are using a well, you have to sift the flour first. Then you add a little bit of the homogenous liquid. So, you don't pour oil, eggs, etc. into the well, but first get them all into another bowl (including the water), and mix them well, preferably with an electric mixer, until they are very homogenous. Ideally, the eggs will emulsify the oil a bit.
For the actual ingredients mixing, you now pour just a little bit of your eggy mixture into the well, maybe 50 ml. Then you take a spoon or other utensil and start stirring the egg mixture without touching the flour with the spoon. A little bit of flour from the walls of the well will stick to the liquid surface and start sinking in, thickening the liquid. Once it is noticeably thicker than the pure mixture, you add some more of the egg mixture to thin it back, then continue back and forth, thickening the batter with the flour then thinning it, until you are done.
When you feel more comfortable and know well how the flour and liquid acts, you can start carefully spreading some flour from the far side of the flour "volcano hill" (not the well edge) onto the liquid, to get it a bit quicker. But in general, it is a finely tuned skill which you have to learn from experience, by doing it slowly and with concentration. If you impatiently stir too much flour into the liquid, it forms the lumps you described.
A more sensible alternative
This is how to execute the recipe correctly. It is a good, but very long method for even mixing. But frankly, there is no need to use it. Nowadays we have electric mixers, which will mix the flour for you into the liquid ingredients without creating lumps. And we have scales, so we can weigh the ingredients. So the second advantage of the well method - you stop mixing the moment the batter has the right consistency (which is necessary when you cannot measure the flour, or don't have a written recipe and are playing it by feeling) - is also moot. If you don't want to spend half an hour mixing your cake batter by your grandma's way, just emulsify the liquid ingredients with the mixer, then slowly add the sifted flour with the mixer turned on on low speed, and stop the moment it's mixed in. That's it.
Water temperature and boiling
As for the water, I see no good reason to boil it from a food science point of view. All the explanations I can think of make it seem unnecessary.

The recipe is so old, it comes from a time with bad water supply. The water was always boiled for safety and to precipitate scale, rust and other stuff present. Shouldn't be a concern today. (If your water is very hard, filter it instead).
The eggs and oil are meant to emulsify, to give you a smoother mouthfeel in the cake. It is like making mayonnaise, and works best when the eggs are warm - but fails completely when you make them so hot that they curdle. 72 Celsius would be optimal, but anything between 60 and 83 Celsius should work. If your water is warmer than that, it will curdle your eggs, doing more damage than good. So, if you are pouring the water in just after boiling, stop doing it (although it doesn't cause the lumps you described, it causes cruder texture overall). The best thing would be to warm it to 80 Celsius using a thermometer, then pour it into the eggs, beat, then add the oil. If you don't have a thermometer, take it off the heat the moment you see the first tiny bubble forming on the bottom, then let it cool for a minute before pouring.
The soda dissolves quicker in warm water. This is still not a reason to get it to a full boil - take it again to 80 Celisius, instead of boiling first and cooling it afterwards.
The whole ingredients are too cold when coming directly from the fridge, and the hot water is supposed to correct that. But in fact, this won't work well. Temperature shocks are not good for cake ingredients, especially for eggs. You should use room temperature eggs and buttermilk instead.
Answer: The boiling water is actually an integral part of the recipe - the heat insures that the cocoa powder fully dissolves and contributes to a richer, more chocolate-y cake - and adding the baking soda to the water first will probably have more to do with enriching the color of the final baked cake than it has to do with leavening.  It is NOT tied to sanitation issues.  Please do not neglect this part in your process!
Also, you need to be a little careful about the order in which you add your ingredients - for instance, you can't just mix-up your eggs in the boiling water because that would cook the eggs - the eggs need to go into the batter when the batter is cool enough to prevent coagulation.
I assume that what you are making is a good old-fashioned chocolate cake using cocoa. Here's a link to a recipe from Hershey's - I know that you want to perfect your family recipe so I'm not trying to suggest you abandon your link to the past - I include it here because you might find the directions (and the order of operations) helpful if you apply them to your cake.
https://www.hersheys.com/recipes/recipe-details.aspx?id=184&name=HERSHEY%27S-PERFECTLY-CHOCOLATE-Chocolate-Cake
Comment: You are probably thinking of making hot chocolate starting from plain cocoa powder (not instant drink mixes). There you really want to boil it quickly, because cocoa consists mostly of starch, and you have to cook the starch - not dissolve it, starch doesn't dissolve in water. Cooking is technically the same thing as making very thin pudding, it makes it homogenous. In the cake recipe however, there is no need for that. The starch in the cocoa will act exactly like the starch in the flour - it will get wet when mixed, and cook in the oven. No need for hot water before that.
Comment: I am not thinking about making hot chocolate.  Dissolving the cocoa powder in the boiling water is called "blooming" the cocoa powder - it is done to intensify the flavor of the chocolate.


Albums are split by artist

Question: When I had 2.2 on my Desire, the album view of the stock music player would show each of the albums on the device.  Now I've upgraded to 2.3 (CM7), albums which have tracks by more than one artist appear multiple times in the list, once for each artist.  I'm using the same SD card with the same files -- what do I need to do (preferably to the app, not the files) to have them appear in a similar way to the way they looked under 2.2?
Answer: It looks like the easiest way to fix this is to add albumartist tags to each album.

Albums are split by artist


Why is it more costly to discover a defect later in the process?

Question: Why is it more costly to discover a defect later in the process?
I've heard this a lot but I struggle to understand and put context/examples to this.
Comment: The more common statement is that "It is more costly to _fix_ a defect when it's discovered later in the process".
Comment: http://www.joelonsoftware.com/articles/fog0000000043.html #5
Answer: You're building a house.  You're laying the sewer pipes into the foundations, but unknown to you one of the pipes is blocked by a dead hedgehog.
Would you rather find out:

Just before you pour the concrete
After the house is finished and the new owner tries to use the toilet?

(There's a "Stack Overflow" joke somewhere in this analogy . 8-)
Comment: great analogy ! I frequently use the "house" analogy when explaining programming issues to the users at my job.
Comment: Stupid hedgehogs!!  At least its not a badger...
Comment: Hedgehogs and sewerage pipes is without doubt the strangest analogy I have ever heard. Beautiful work. Love it.
Comment: better a hedgehog than a family of skunks :-)
Comment: Personally, I don't like this analogy at all. It assume's that you are using the waterfall method and you a working from plans which will be correct when complete.

As we all know software is not like that, software is read and refactored more than written. You are always going to get it wrong the first time.
Answer: The longer it takes to find a bug, then:

the more the behavior of the bug may have been accepted as correct, and the more other things may have become dependent on that behavior (Windows is notorious for this).
the more tightly integrated the system is likely to have become, and the harder the bug will be to extract.
the higher the likelihood that the bug's erroneous behavior will be duplicated elsewhere by virtue of copy-pasting or in clients that use the erroneous code.
the longer it's been since the code was originally written and the harder it may be to understand it.
the less likely it will be for people who understand that original part of the system to be around to fix it.
Answer: The later you find out a bug, the worse. When you find a bug immediately after you code, you have all the behavior in mind, and know exactly what changes caused it. You will be able to focus on the problem, once you know where it resides.
When you take long, developers no longer remember exactly how it worked, and there are many more places to investigate to find the bug. Perhaps the developer who coded the bug is no longer working in the company also.
Also, as time goes by, more parts of the code will probably depend on the buggy code, and you may need to fix them as well.
Finally, there are issues involving users. If you find a bug after a release, more users will be frustrated by it, and your product image will be worse. Users may also be used to have a workaround for this bug, which may start to fail after you fix the bug.
Summary: When you take long to find a bug

Your scope to investigate is bigger
The developer who created the bug may not be there anymore, and the other developers will have to study the code more to find it, understand it, and fix it
You may also need to fix parts that depends on buggy code (and there will be more parts like that)
Users will already be frustrated by the bug, and the image of the product will be damaged
Answer: This can be illustrated in a simple (if not trivial) example.
Take a simple dialog with a message and just two buttons "OK" and "Cancel".
Assume that the error is a spelling mistake.
If this is found after the product is released then a new version of the product has to be released with all the costs associated with that. Manuals will need to be reprinted.
If this is found in final testing the manual will have to be reprinted. The code will need to be rewritten and tests re-run.
If this is found during development then there is just the cost of fixing the code.
If this is found during design then the code is written correctly first time - no cost.
Comment: +1: We actually encountered something like this.
The client gave us a bunch of labels in a language totally incomprehensible us. The only we we could verify it was to work over each whorl of each wriggly character, and confirm it was right.
The client rejected the work )+:
The first word in each label was the equivalent of 'Example'.
Answer:
No-one ever understands the code as well as you do as you are writing it.
People may have come to depend on the bug being there.
You may have to fix up lots of bad data that the bug has saved away.
You may have to roll out a new version or patch of your software.
Your helpdesk may have to field a whole heap of calls.
You may have to fill in bunches of paperwork explaining why that bug exists and what problems it causes, and what you are going to do to make sure it never, ever happens again.
Answer: Because more people will have spend time with the defective software.
If you fix a bug at early on you and maybe a code reviewer will spend a little time on it.
If it gets released to customers and reported as an error, you will have coded it, someone may have reviewed it, someone may have tested it, somebody may even have documented it and so forth ...
Answer: There may be other dependencies (internal or external) which will affect the fixing of a defect.
For example - If I resolve this defect, I may have to fix something else
Answer: Imagine you're writing an essay on why it's more costly to discover a defect later in the process, and you suddenly realise one of the premises on which most of your essay content is based is false.
If you're still planning, you only have the half a page of plan to change. If your essay is nearly finished, you suddenly need to scrap the lot and start over. If you've already handed it in, the error is gonna cost you your grade.
Same reason.
Answer: For a shrink-wrapped software product:
If you find a bug after your product hits the stores, you will have to help users through support calls, suggest a workaround or even recall the product/issue a service pack.
For a website:
Site outages and delays cost you money.
Customer loss as a result of poor/malfunctioning site costs you more.
The debugging process is also costly itself.
Answer: It is probably an error by the question author, but the actual question is, "Why is it more costly to discover a defect later in the process"  Within that question is the cost to discover the bug and we can hope it also means to fix it.  Most of the answers do a good job at describing the cost to fix and why it is better to fix early versus fix later.  And, I really don't disagree with any of them.  But, that isn't the whole question.
I have a regular series of esoteric arguments with some about the discovery cost.  How much testing would have been required to find a specific bug (without hindsight).  Would it have take 3 man-months more of automated or manual testing before you would have been likely to find that test case and scenario ?
In practice, test as much as you can but finding that balance point isn't as easy as many would have you think.  Most programs are too big to have 100% code coverage.  And, 100% code coverage is usually just a fraction of all the possible scenarios the code must handle.
Another factor that comes into the cost of a bug is the business cost associated with the bug.  Are there 5 million boxes out there holding the bug ?  Would you have to do a product recall ?  Will it generate X calls to your warranty help desk ?  Will it trigger some clause in a contract holding you liable for damages.  In very simple terms, this is why software written in the medical field costs more per LOC than those for website development.
Answer: Because of the development process and all the work involved in fixing the defect.
Imagine you find a problem in the function you coded yesterday, you just check out, fix, check in, period. It's still fresh in your mind, you know what it is about and that your fix won't have any side effect.
Now imagine finding the same bug in six month from now. Will you remember why the function was coded that way ? Will you still be working on this project/company ? You have to open a defect report, a new version of your software have to be issued, QA needs to validate the correction. If the software has been deployed, then all instances have to be upgraded, customers will call support ...
Now it's true that the curve showing the cost are made up to illustrate the point; it actually depends on the development process.
Answer: I would say that the most costly is to find a defect and let it be. The longer you allow the defect to live the more costly it becomes.
I was at a company at a time, where they had the policy, that once they had taken a decision, they stick with it. The system I worked on was loaded with bugs because of a stupid corporate framework that we were forced to use, and a deep misunderstanding of the proper usage of web services.
To this day, I believe that the cheapest way for that company to get a working, usable system, would be to ditch the entire system and rewrite it from scratch.
So my point is, that I don't think that finding a defect at a late stage is that problematic. But ignoring a defect until a late stage is extremely problematic.


Meditation Into A Dream State

Question: Does anyone know if one can fall asleep into a dream while in the process of mindful insight practice and still maintain mindfulness and concentration? This would be different than establishing mindfulness while dreaming.
Answer: Before I became Buddhist I did a lot of random "spiritual" practices, including "astral travel". The later is when you try to retain "waking" consciousness as you fall asleep.
I only had mixed success with the various techniques for achieving that, but the one that worked more or less well was to relax the body and completely refrain from any movement until you lose all bodily sensations. So effectively you let the body "fall asleep" while keeping the mind awaken.
The major difficulty for me was (to avoid) getting overexcited at the moment the body falls asleep - which (overexcitement) resulted in hyperventilation and loss of control.
Eventually I realized that establishing lucid mind inside the dream was easier for me than carrying it over from the waking state, and so I dropped that frustrating practice.
Another related technique I had better success with was doing the Four Immeasurables type meditation at that same moment of falling asleep. This works better as you don't have to artificially restrict body movements, which seems to go counter to deep meditation in my experience.
Answer: When you are in deep sleep your Bhavanga consciousness is active and at this stage you are not mindful. If you are in a dream state there is some metal activity hence there can be some mindfulness and concentration, but this goes in hand with Sloth and Torpor hence the level of mindfulness and concentration would be weak.
Answer: I've experienced that several times. It took me around ~45 minutes up to an hour to enter a state of dreaming, while meditating. I did not fall asleep for sure as I was sitting up.
The experience was different from lucid dreaming. I experienced lucid dreaming over hundreds of times, so I am confident I am familiar to know a distinct state.
Just like with lucid dreaming, the very first times it is difficult to stay asleep yet mentally aware of your self. Resulting in either loosing self awareness of waking up from the dream.
With this I found the same, but this balance seems even more delicate to me. I was wakefully present in this dream while meditating, but as soon as I realized I was, it lasted only very short.
These dreams while meditating seem more close to wakeful life experiences in a sense that I have a goal, a mental concern or puzzle to solve. Whereas in dreams while being asleep, this tends to be more and more irrational.
How the two states differ in dynamics (wakeful dreaming while asleep/meditating) is not clear to me yet. With dynamics I mean some sort of mechanistic behavior, like gravity here in this physical reality, but then more mentally related. Like when becoming fearful it is more apparent that I am loosing control of the scenario in a lucid dream than in this physical reality because the whole scenario visually starts to mirror my state of mind. How that is different in these dreams while meditating, I am not sure yet.
Good luck with experimenting!

Meditation Into A Dream State


motor affecting time calculation between hardware interrupts

Question: My robot uses an Arduino Mega 2560. It has 6 IR receiver modules connected to its 6 external pins namely 2, 3, 18, 19, 20, and 21.I have connected the Pololu MC33926 dual motor driver arduino shield to my arduino(here is the connections diagram : https://www.pololu.com/docs/0J55/3.c ). I generate a 56KHz IR signal with an LED from another Arduino. The IR receiver modules convert the 56KHz signal into a active low digital signal. My signal consists of a signature bit followed by 32 bits of data. a binary 1 is represented by a signal of length 1200 uS and a binary 0 is represented by a 600uS signal with intervals of 600uS. I employed a state machine in my code which checks the duration of time between falling edge and rising edge. and vice versa and compares it to the duration expected. If anything is not expected it discards as noise and goes back to the idle state. If the duration is as expected it goes to the next state and then takes in the entire 32 bits and converts this binary format into a decimal value. I print this value on a 7 segment display on my robot. It works perfectly when the motor's are not running.
      Now this is the case when the motors are running. It does not receive the signal. I have tested every component individually and these are the results:

The receivers still receive the signal perfectly, and their output to the Arduino is also as expected. No problem there.
Earlier the Arduino was being powered through the Motor driver. Just to make sure that was not the problem I separated the Arduino's power supply from that of the motor driver. Still the same issue, i.e. the robot does not receive a valid signal(at this point i realized the arduino receives a valid signal but isnt able to decode it accurately).
We then printed out the values of time differences between each rising and falling edge on the interrupt pins. These values seem correct and within the tolerance range when the motors are switched off. But when the motors are switched on these values are not right. Of the 32 duration's measured, atleast two are not right(for eg. instead of 300 uS it calculated 88uS) due to which the signal is being discarded as invalid.
I thought that the PWM being generated to control the speed of the motors on digital pin 9 and digital pin 10(OC2B AND OC2A). Even though the PWM signals were being generated(without the motors connected) the signal was still being read as valid and the robot was receiving the signal. So its not that either.

The only anomaly I have found are the readings of the durations of the interrupt intervals. Can somebody please tell me what connection I have done wrong. Its mostly not with the program since it works otherwise. Something with the motor is making the Arduino act weirdly. Any help will be greatly appreciated. I have to scale up these robots to build a swarm and I am still stuck in the first step.
Thanks a lot.
Answer: Noise from electromagnetic sources is always an important issue that must be addressed. The aims are to minimise noise generation at source, reduce transmission of noise between source and the "target" affected circuitry and reduce noise impact at the target.
Motor controller circuit diagram here
The shield power supply link MUST have been removed.
Shield must have all own powering.
Coupling via a common eg 5V supply has a high chance of being problematic.
The two 5V supplies (arduino & shield) could have a common higher voltage source but need separate regulators and proper noise removal in each supply.
Placing extra capacitance across the arduino Vin or main power source MAY help.
I assume that the motors are driven in either direction during operation. If not then a reverse diode across the motors should help.
If bidirectional,  try reversed diodes from each motor lead to Vout (= V+ motor drive voltage).
The shield's Vout filter capacitors C7 & C8 care 47 uF each.
Vout could usefully have 1000 or so uF added somewhere on the board.
I do not know how much motor current is drawn and exact control strategy. This MAY interfere with motor drive but probably not: Identify one motor which "has issues". Add a small series resistance in each lead with a capacitor across the leads on the motor side. Here "small" means "does not noticeably affect performance". eg 1 Ohm if Imotor < to << 1 amp. Capacitor needs to be biplar for bidirectional motor control - eg a 1 uF ceramic or plastic (polyester, mylar, ...) cap.
'If all else fails'[tm] opto coupling the driver interface is possible BUT should not be needed.
Try above.
Report.
Ask more questions if needed.
Answer: Thanks for the above answer. It got me thinking on the right track. After some reading through the motor driver data sheet I realized that I forgot totally about the by-pass capacitors. After connecting a 0.1uF cap between two terminals of the motors and another two between the terminals and the casing the results are much better. It can receive a valid signal from another robot(though not as well as when the motors are turned off). Any suggestions where else I could place by pass cap's to further eliminate electrical noise?
Again,
Thanks a lot guys.
really appreciate the help.
Comment: In the other places I mentioned.


Home screen filled with app icons

Question: My ASUS Transformer tablets home screen is becoming filled with app icons, many being duplicates. Q: how do I get rid of the spare ones? How do I stop them getting there in the first place?
Answer: Hold on an icon and drag it over another icon should give you your the ability to create a folder. You can then drag other icons into this folder.
You could create various folders - one for games, one for apps, one for social, tools, etc.
If you've got duplicates, you should be able to hold the icon and drag it to an area of the screen that allows you to remove that particular icon. I'm not 100% sure where it is on a Transformer, but generally it's at the top of the screen.
Answer: Check Play Store > Settings > Auto-add widgets is checked, and uncheck it.

Home screen filled with app icons


When did the Pakistan army used tank for the first time during the 1971 Bangladesh war?

Question: I would like to know the first recorded case of usage of tank in the Bangladesh war which took place in 1971.
Comment: As they had tanks, I would assume they used them. Or do you have any reason to assume they did not use the tanks from the start? A little more context here would be helpful to understand the question.
Comment: @LennartRegebro depending on the terrain, using tanks might not be a good idea. A lot of Bangladesh being rather boggy makes it less than ideal tank country...
Comment: I have pledged to downvote any question that asks for historical analysis of "my friend said".  Those kind of questions are generally answerable from  wikipedia or google.
Comment: @LennartRegebro, One of my friends claimed that they didn't use tanks until India got involved. Later, I got two records of using tanks one on April 23rd and another on September 20th both before India got involved.  Thanks anyway.
Answer:
20 Baluch with some tanks had secured the area immediately around the cantonment in the morning.

This is the 26th of March during Operation Searchlight, the start of the war. As I suspected, they had tanks and used them from the beginning.
Answer: In the 1971 Bangladesh war in the eastern theaters pakistan had 1 armored regiment which consist of 75 US made M24 Chaffee tanks.
Tanks was used in Dakha during operation searchlite on March 25th. Chittagong also saw some tank actions dring the same operation.
During the operation searchlite which started on March 25 to April 10 Pakistani Army used Tanks to reduce the morale of the peoples of East Pakistan.
In the western Theaters, Pakistani tanks met an ill fate during the battle of Longewala.
Answer: Yes, there was a tank battle and some of the Pakistani tanks were capture by the Indian army. There were traitors in the Pakistan who was involved in breaking the East Pakistan with the help of the Indian army and government.
The M24 chaffee tanks took part in the operation that was started in march and ended in May. You may refer further at
Men In Black-The Armored Corps Of The Pakistan Army
Comment: When and where was the tank battle?


What additional conditions are there to make POVM measurement same as projective measurement?

Question: We know that POVMs are applied in the more general cases where the system is not necessarily closed. So mathematically, how does going from open to closed system change the scenario in case of POVM so that it becomes a projective measurement?
Comment: I don't understand the question. What do you mean exactly with "how does going from open to closed *change the scenario*"?
Comment: @glS.: We can't apply projective measurement when the system is not closed. In an open system the evolution of a state can't be described by unitary operation. We often hear that a general measurement will be projective measurement if it follows the additional condition that $$M_{m}^\dagger M_{m'}= \delta_{m,m'}M_{m}$$. I want to know if there is some relation holds between these two.
Comment: Are you aware of the concept of a Naimark dilation?
Comment: @Rammus.: Heard first time in my life a min ago from you.
Comment: sure you can do projective measurements when the system is not closed. The system being "open" or "closed" refers to its dynamics, i.e. how it evolves. That doesn't affect the types of measurements you can perform on the state itself. About the relation between POVMs and projective measurements, have you seen https://quantumcomputing.stackexchange.com/q/7004/55? See also https://quantumcomputing.stackexchange.com/q/12275/55
Answer: An $m$-outcome positive-operator value measure or POVM consists of $m$ positive operators $A_1,\ldots,A_m$ on $\mathbb{C}^n$ such that $$\sum_{i=1}^m A_i=I.$$ Each $A_i$ is positive iff $A_i=B_i^*B_i$ for some operator $B_i$ on $\mathbb{C}^n$, thus each POVM is a projection-valued measure or PVM iff each $B_i$ is an orthogonal projection, if so then  $B_i=B_i^*=B_i^2$ and $B_1,\ldots,B_m$ is a PVM since $$\sum_{i=1}^n B_i=\sum_{i=1}^n B_i^2=\sum_{i=1}^n B_i^*B_i=\sum_{i=1}^n A_i=I.$$ As mentioned in the comments, Naimarks dilation theorem shows that for any POVM on $\mathbb{C}^n$ there is an isometry $V:\mathbb{C}^n \rightarrow \mathbb{C}^{N}$ where $N\geq n$ and each positive operator $A_i$ gets mapped to an orthogonal projection $\widetilde{A_i}$ in the larger space where the "completeness relation" of summing to the identity still holds, thus turning any POVM into a PVM on the larger space.


Is that work of a web designer allowed?

Question: Assalamu alaikum,
I am working as a web designer and developer for 3 years.
I have intended recently to create general products that can be used in halal or haram and sell them worldwide.
One of these products is a template for "Our team" pages which has different layouts for the team of any company. The buyer is responsible for putting the images himself and of course in this time, a lot of companies have women in their team and they don't mind having their photos to be published online.
I want to ask is this halal or haram?
I don't upload the photos myself. Only the buyer.
Is this like selling weapons in time of fitnah (temptation) ?
and if it is not haram, what if someone comes to me to fix some issues on his website not related to the photos themselves and I found his site contains some haram photos of women but the requirements aren't related to the photos  and are related to design conflicts?
If this work is haram, then the money gained from it is haram also?
Answer: You just created a product to sell to the customers. What they will do with it is their responsibility, not yours.
Rest assured with the help of Allah.
Comment: If you sell a knife to someone who is going to kill some people. Will that be halal?
Comment: If you 100 % knew about it then yeah it would be halal. But that person can use it to cut his meat for all we know. People can't know everything about other people otherwise you should make up a profile of everyone you sell goods too.
Comment: @Anonymous I: *haram

Is that work of a web designer allowed?


How to reduce the noise from my household washing machine

Question: I have a washing machine in my home, once the spin cycle starts, the vibration is very annoying. I live above a tenant and he complains that he can hear the vibration above. Any suggestions on how to minimize the vibration during the spin cycle?
Answer: It sounds as though your washing machine needs to be balanced properly.
If you've never done it, it can be a bit of a black art. The machine will normally have 2 feet at the front which can be unscrewed with a spanner to make them longer (or vice versa) to make sure the machine is sitting firmly on all four feet. If one of the feet is too short, it's a bit like a chair sitting on an uneven floor (or a restaurant table) where it keeps wobbling on the 2 longest legs and onto each of the other 2 legs in turn.
I usually find it much easier to balance it by sliding thin material like plywood, cardboard or plastic under the suspect foot until it gets better. Do it while the machine is spinning to get instant feedback. Once you establish which foot needs to be longer, you can then make the fix permanent by adjusting the foot with a spanner.
Answer: If the tenant below is complaining, I would imagine the washing machine is perhaps shaking on a hard floor. The best way to reduce the sound of these humanoid washing machines is to place something underneath to dampen the vibrations and the sound. I suggest you use a piece of thick carpet/rug you don't care for or a rubber mat, or anything you can find that's well padded and lifts the washing machine from the floor.
It is also a god idea to ensure you have left a gap between worktops etc.
Answer: If it is making an extreme amount of noise, it probably needs balancing.There are feet under the washer that you can make come out farther or go in farther all the way around on four corners and you have to adjust those to get it level and you will hardly be able to hear it running at all,if that is the particular problem.
Comment: This answer has already been given.
Answer: I have same issue with my front loader washing machine and after balance a couple of day start to walk again.
Some friend recommend to check anti vibration pads, it is a small piece of rubber that are magical.
Check about it..!
Comment: Preferred responses here include something that you might already have around your house (for example, if one was asking how to remove blood stains, you might suggest hydrogen peroxide rather than a fancy cleaner from the store). If there is a common around-the-house item one can substitute for this, please feel free to add that and leave the link you posted as well in case they choose to buy something to fix the problem permanently later :)
Answer: Check the balance of the feet on each corner and adjust if required.
Check the machine is not overloaded and the contents are equally distributed when filling.
Place padding or foam spacers between the sides of the machine and housing unit in order to absorb any vibrations.
Comment: These answers have already been given.


Cron log to Notification bar

Question: I have a couple of cron jobs that I would like to log output to the Notification app in Mountain Lion. I've searched and and figured out how to log cron output by editing the plist file, but nothing specifically about how to integrate into the Notifications app.
Comment: Feel free to edit this to show why / how the liked question is different or what you didn't get from that Q&A to solve your problem. Once it's edited, you can flag it for review and potential re-opening.
Answer: You need to use a third party piece of software to send messages to the Notification Center from command line tools and scripts.
terminal-notifier appears to be a popular solution. OSXDaily has an article walking through how to set terminal-notifier up.

Alternative methods are covered in the answers to, how can I trigger a Notification Center notification from an AppleScript or shell script?

Cron log to Notification bar


Live Streaming Video Camera?

Question: Are there any video cameras (recording over 30 minutes of footage length) that have live streaming services (RTMP) built-in to the camera? I know there are a ton of cameras with YouTube (etc.) uploading capabilities with built-in Wi-Fi, but I'm asking specifically for live streaming.
Answer: The JVC  GY-HM200 has live streaming capabilities - http://pro.jvc.com/prof/attributes/features.jsp?model_id=MDL102319.
I've never used that particular model (so have no personal experience of the live streaming functions) but I do use the 170 and it's a solid little camcorder with a great range of options (including shooting in 4K and at high speed - though not at the same time), it's fairly robust and delivers great quality for the price.
Answer: Unless you're attempting to be out and about and live streaming from a hotspot, look into just outputting the camera directly to a computer (or a switchboard if you need it), and capturing that footage with something like OBS.
Provided you're on a budget, you can probably just connect whatever camera to your existing laptop with the right cords and use OBS to connect to the RTMP, and that works for both options.
Another option is to use a gopro, so the camera can be wirelessly connected to the hotspot, the footage can be displayed and window/monitor captured from the computer.
Comment: It wouldn't let me comment to clarify on your post so I laid some options for you, or more likely, other people that stumbled onto this looking for streaming on the go options.  Best of luck.
Comment: Thanks for the answer, but it doesn't answer the question. I'm fully capable of setting up a computer to publish a live feed. I'm looking for video recording and publishing in one unit.

Live Streaming Video Camera?


How do movie channels get movies to be in HD if they've not been released on an HD source?

Question: I just got a copy of the Twilight Time edition of Christine and the colors are a lot more vibrant than the other versions released on DVD. I believe Twilight Time was the first Blu-ray release of Christine. So how do cable channels get a DVD-like transfer and put it in HD? Yes, the aspect ratio is off, but I believe that's the only difference.
Comment: Your title and your question do not line up. You ask about how channels obtain a HD version, while you yourself talk about a Blu-ray (from 2013!). What does one thing have to do with another? And then you continue to talk both in general ("how do cable channels get a DVD-like transfer and put it in HD") and yet also specific ("Yes, the aspect ratio is off, but I believe that's the only difference.").
Comment: Cable channels don't go out and buy retail copies in order to show movies.
Comment: Adding someting to Paulie_D's comment. Sometimes old(er) shows get remastered in HD, digital remastering can do some improvements to colour and tone.
Comment: I would like to add that I saw it on cable back in 2011, before the TT release was out.
Answer: Taking Christine as an example the original film format was 35mm which is, essentially, better than HD quality.

Film is analog so there are no real "pixels." However, based on converted measures, a 35mm frame has 3 to 12 million pixels, depending on the stock, lens, and shooting conditions. An HD frame has 2 million pixels, measured using 1920 x 1080 scan lines. With this difference, 35mm appears vastly superior to HD.
Source

In this case TT have obtained a newly-mastered transfer of the 35mm film in HD format from Columbia-Sony

Christine is presented on Blu-ray courtesy of Twilight Time with an AVC encoded 1080p transfer in 2.39:1. Columbia-Sony continues to provide exceptional looking high definition masters to Twilight Time
Source

Basically, the original release may not have been in HD ( not available in 1983) but with 35mm film a new HD master can be obtained any time.
Comment: exactly this.  people forget how big movie screens are and how good the film quality has to be to look good blown up to that size
Comment: As opposed to television shows from that period, which were often shot in video quality (with exceptions like Star Trek: The Next Generation, shot in 35mm and downscaled for video).


Why is たばこ written in hiragana instead of katakana?

Question: While studying my Genki textbook I noticed that the word たばこ uses hiragana instead of katakana. I've always seen loan words to be in katakana, so this was interesting to me.  I saw in this answer that this is because its an older word. I was wanting to know if there was more information about this. Why is たばこ, a loan word, written in hiragana?
Comment: I've added the history of the term _tabako_ with references.  _Tenpura_ is outside the scope of your question as posted above, so I haven't added stuff for that.
Comment: Michael, what kind of sources are you looking for with your bounty?  Are you looking for specific documentation about why the spelling varies (kanji, hiragana, katakana)?  This is harder to find; there are numerous other older borrowed terms that are also written in kanji, hiragana, and katakana, but little explicit discussion (that I can find so far) about why this is so.  Or are you looking for documentation about when the term appeared in Japanese?  This is easier to find.
Comment: Since it boils down to the time it was imported, sources about when the term was introduced would work.
Answer: The simplest explanation is that たばこ is often written in hiragana because it was borrowed so long ago that it has nativized. (Sorry, in a rush -- details to be posted later.)
Update
There are a few words that are definitely borrowings, but that were borrowed so long ago that they are treated as native terms, and they might even have kanji spellings.

Tabako is one such word.  The substance was introduced to Japan by the Spanish and Portuguese missionaries in the late 1500s.  The source of the Japanese term is generally listed as Portuguese tabaco.  The term may be encountered in hiragana as たばこ, in katakana as タバコ, and in kanji as 煙草 (most common, even offered up by the MS IME), or as 烟草 or 莨 (less common, listed in some dictionaries).
Tenpura is another well-known Japanese term that was borrowed.  This too has kanji spellings, as 天麩羅 or 天婦羅, even though the term again comes from Portuguese.  See the Wiktionary entry for more detail.

As a general rule of thumb, borrowings are indeed spelled in katakana.  However, the older the borrowing, the less this rule applies.  For instance, this other question-and-answer thread lists several old borrowings from Korean that are treated as nativized Japanese words, complete with kanji spellings.  For newer borrowings, especially from English, katakana is the way to go.
Update 2
More details about the history of the term タバコ, with references (emphasis and translations mine).

Shogakukan's 国語大辞典 mentions the following:

原産地では古代から吸煙に利用され、一六世紀初頭にスペインに伝わり、世界じゅうに急速に普及、日本へは安土桃山時代に輸入された。
  Used in its place of origin since ancient times for smoking, reaching Spain in the early 1500s, rapidly spreading around the world, imported to Japan in the Azuchi-Momoyama period.

The 安土{あづち}桃山{ももやま}時代{じだい} (Azuchi-Momoyama period) dates from 1573 to 1603.
Daijirin explains:

日本へは近世初頭に南蛮船によってもたらされた。
  Brought to Japan by ships from Spain or Portugal in the early modern ages.

近世{きんせい} ("early modern ages") is further defined more specifically as:

日本史では,後期封建制の時期の安土桃山・江戸時代をいう。
  In Japanese history, refers to the late-feudal Azuchi-Momoyama and Edo periods.

Daijisen explains:

南アメリカの原産で、桃山時代に輸入。
  Originally from South America, imported in the Momoyama period.

Gogen Allguide explains:

日本には南蛮貿易を通して伝わり、慶長年間(1596~1615年)にはタバコの栽培が行われた。
  Reached Japan via trading with the Spanish and Portuguese, with tobacco then cultivated in the Keichō era (1596-1615).

Cultivation was preceded by importation of the product and the term, and this timing again coincides with the other sources.
Comment: I always (baselessly) assumed that since たばこ used to be frequently written in kanji, it could also be that hiragana was used simply as a reading of a kanji word, not unlike ねこ for 猫 or たけ for 竹. (This ties in with the sentiment that it is a "nativized" word, of course.)
Answer: History of smoking is pretty long in Japan to say たばこ is a borrowed word, though it's certainly foreign origin.
According to Wikipedia, there's two theories about the time of the tobacco coming to Japan. One is at the time guns were brought into Tanegashima by Portuguese for the first time in Japan in 1543, and the other, it was imported much earlier than that by westerners around 1600.
It's pretty new to come to write タバコ in Katakana. Before then, it was written in Kanji same with Chinese equivalent, 烟草. For examples, we can find "巻煙草 - cigarette," "刻煙草 - finely chopped tobacco," "嗅煙草 - sniffing tobacco," and "噛煙草 – chewing tobacco," in "毛吹草 - Kefukigusa," a commentary on 俳諧 ‐ Haiku written by Matsue Shgeyori and published in 1643. We also see the word, "煙草," in the line, "請願寺通の末なる煙草切の女といへり – She was said to be a dried tobacco-leaf chopper by her profession, who lives in the corner of Seiganji Teple Street in Kyoto" in "好色五人女 – Lecherous five women" of a famous novelist and play writer, 井原西鶴 – Ihara Saikaku in early Edo era.
In Showa-era, たばこ is written in Katakana. "タバコのみの歯磨スモカ – Sumoka, the toothpaste for heavy smokers" was a famous, long-life slogan invented by a genius of copywriting, Kataoka Toshio in early 19 century. Since then tobacco is written and indicated in three ways of タバコ, たばこ, and 煙草.
If you google "tabako" in romaji, you will get instantly "タバコ銘柄、値段、種類、"たばこ税," "たばこ事業法," "JT website 煙草商品一覧," and so on.
So you cannot say "たばこ uses hiragana instead of katakana." Actually たばこ、タバコ, 煙草 are all in parallel use today.
Comment: One minor point: any term of foreign origin is etymologically a borrowed word.  For instance, the English term _ball_ in reference to a dance is a borrowed word, borrowed from French.  Similarly, 明太{めんたい} is a borrowed word in Japanese, borrowed from Korean.  In both cases, the borrowed nature of the terms isn't important anymore -- the terms have effectively nativized, and are treated as regular English/Japanese words.


Access denied when user try to use Alert Me on a list - WSS v3

Question: I have some users who have contribute access on a list and read access on the site but anytime a user tries to alert himself he gets

Error: Access Denied

Why is this?
I even gave the user Full Control on the list, still the same issue!
Comment: Please mark an Answer if you found one useful. ;)
Answer: I had this problem recently. In my case, a user had Contribute access to a list but at the site level had Restricted Read. Restricted Read doesn't have the Create Alerts permission. Replacing the site permissions with Read resolved the issue.
Answer: To expand a little on @David Clarke's sound answer, let's discuss the following three scenarios and their minimum required permissions within the Role / Permission Levels:

Add Own Alert
Requires: Create Alerts
Manage Own Alerts
Requires: Open Items
Add / Manage Alerts of Other Users
Requires: Manage Alerts - at site level

Scenarios 1 & 2 may also require View Application Pages if not already granted via another role. Without this permission at or above the scope (site, list, item) where you want to create the Alert, you will not have the option. Furthermore, you may also be redirected to the notoriously obnoxious "Access Denied" page.
Confirmed (i.e. the same permissions exist) in SharePoint 2007 through SharePoint Online.
Answer: The permission to create alerts is actually at the site level.  By default, I don't think the OOTB Visitors/Readers group can do this.
Answer: Do the site permissions allow for persnalization permissions?  In the Shared Service Provider of Central Administration, do all authenticated users have personalization permissions defined in Personalization services permissions, assuming your on 2007?
Comment: PirateEric this is a WSS v3 - 2007 .I don't think i have a shared service provider in the Central Admin.
Answer: It is a known issue, you should give the users permissions on the paren web as well, as discussed here:

You can create the alert from the list ribbon via the application page
  SubNew.aspx, and manage them via the MySubs.aspx page, both of them
  are located in the _layouts folder. The code behind class for these
  pages are the SubNewPage and the MySubsPage classes respectively from
  the assembly Microsoft.SharePoint.ApplicationPages (and the same
  namespace). There is no security check in the OnLoad method of the
  SubNewPage class (nor in its base classes), however in the OnLoad
  method of the MySubsPage class the CheckRights method of the
  LayoutsPageBase class (Microsoft.SharePoint assembly,
  Microsoft.SharePoint.WebControls namespace ) is called. This method
  checks, if the current user has DefaultLayoutsRights permission (that
  means SPBasePermissions.EmptyMask | SPBasePermissions.ViewFormPages | SPBasePermissions.Open | SPBasePermissions.ViewPages) on the parent
  web, and not on the list. If not, the user is not able to manage the
  alerts she created earlier.


Wearing pieces from two different sets of tefillin

Question: Tefillin are usually thought of as coming in sets, one for the hand (shel yad) and one for the head (shel rosh). But is there any reason two sets can't be mixed and matched? May one wear tefillin where the shel yad and the shel rosh come from different sets, my shel rosh and some other guy's shel yad? Does it make a difference if this is a temporary measure?
Answer: It is permitted.
A problem of כסדרן may appear - Rm"a addresses this (OC 32:1) and says it should be taken care of לכתחילה, but if not it's not פסול.
Regarding Rashi & Rabenu Tam - it would be contradicting to wear Yad of one and Rosh of another. However, Rabbi Ya'akov Medan says it is לכתחילה to wear rashi for Yad and Rabenu Tam for Rosh.
Comment: A) It would not be contradicting to wear one of each RT and Rashi. The two tefillin aren't m'akeiv each other. B) I'm fairly certain R Medan said that as a theoretical suggestion, not that he or anyone follows that practically. It's actually a pretty interesting suggestion in terms of understanding how the machloket came about.
Comment: @DoubleAA, A) It's either one way or the other. If you would ask Rabenu Tam - someone wearing rashi isn't yotze. B) I understood that's his understanding of the gemara.
Comment: I agree with the above answers, but I wish to add a detail. In the case where the parchment in the Yad or the Rosh of a pair of tefilin is pasul (invalid) because there is a problem with the writing, you can still use the one that is kosher and make one of the two brachot (as appropriate) on that one.. this differs from what was told to me in a personal situation where the sofer said that the tefilin were pasul, could not be corrected or used...