Breeze memory use

Question: I develop the SPA using Breeze, ASP.NET Web API and MySQL database. The main entity of database (Code First EF) have 4 one-to-many relations and 20 simple properties. When I've downloaded ~ 500 this entities (the total quantitity of objects with related entities ~ 2000), the Chrome tab process use 250+ Mb of RAM (without loading UI). And this value grown if I save some entitites. Is it normal? How can I reduce this value?
Answer: As of breeze v 1.1 we did fix some memory leaks in breeze and reduced some of the memory pressure while processing large queries.  In addition, the latest version of the Q library, which breeze uses has also fixed some leaks.  Hopefully, you should see a smaller footprint now. Please post any further findings.... and thanks for commenting on this.
Answer: So far I have been unable to repro this result, so can I get a little more information? Just to make sure that I am clear, your query is for 500 root entities, each with 20 simple properties, and 4 navigation properties and the total number of entities queried is only 2000 ( so each navigation property has on average on 1 related entity? (2000/(500*4)).
What are the sizes of the related entities?
Are you using 'EntityQuery.expand' to retrieve the relation properties or are you using 'entityAspect.loadNavigationProperty'?
Each breeze entityManager stores a single copy of each entity by key, so memory use should not expand unless you are retrieving more entities ( or using more than one entityManager.).
Comment: I was a little wrong in description of my model, sorry. The root entitiy have six 1-to-many properties. But in 5 of them max quantity of related entities doesn't exceed 5. The 6th relation has the folowing scheme of 1-to-many relations: 1 Root Entity -> 1st Navigation Entity (14 simple and 8 1-to-1 properties, max quantity is unlimited, ~ 10 by this moment) -> 2nd Navigation Entity (11 simple and one 1-to-1 properties, max quantity ~ 5) -> 3rd Navigation Entity (20 simple and 3 1-to-1 properties, max quantity ~ 50). The "->" symbol indicates 1-to-many relation.
Comment: I use one entityManager and 'EntityQuery.expand' expression.
Comment: So how many entities in total are you bringing down? and how many properties ( on average ) for each entity type. Ideally you could give me an estimate of the total memory that you 'expect' the entities that you are retrieving to take; assuming that each unique entity is only counted once.
Comment: The total quantity of entities is ~5000 with 15 simple properties (on average) for each by this moment. I think that 250-300 Mb per 50000 such uniq entities would be an ideal (or at least per 25k =).

Breeze memory use


Viewing distance in Google Fit

Question: I can't figure out how to view distances in Google Fit. When I walk, it only shows steps and duration. Is it possible to see the distance? How?
Answer: Good news! As of May 13, 2015, Google Fit was updated to show more kind of data: calories burned and distance. Note that the distance is approximated.
On the main screen, select the right drop-down list to change from active time/steps to distance, or tap/slide the big circle diagram to the second point.
You can also set the units to kilometers/miles in the settings.

(Image courtesy of Google)
Comment: Tip: I could only change from US units to normal units on my phone, not on the website. The good news is that you can switch it to kilojoules, too.
Answer: At current there is no way to view distance, however it will probably come in a future update.
However you could calculate it by multiplying your steps by your average stride.
You can get your average stride by walking 10 metres, counting how many steps you take, and divide 10 by the number of steps.
One thing to bear in mind about google fit, is that it isn't designed to track say, where you went on a run, it is designed to do low power, background tracking and this is probably why there was no distance feature to begin with.
Answer: The km is not calculated correctly in Google Fit.
It should calculate 1400 steps = 1 km
When there us a break it does not take the previous stros into account.
The calculation should be in a day how many steps walked and it should calculate 1 KM at 1400 steps.
By the process we come to know from 12 am to 12 pm how much we walked in a day in e
Steps
KM
Calories
Heart beat

Viewing distance in Google Fit


How know space disk left WITHOUT root

Question: I'd like to know if there is a way to get free space disk of a unix (debian) system without root (sudo) and if possible in only one command ?
Comment: What is your research effort? How do you do it *with* root? Have you tried the same command without root? Usually `df` does not require root access.
Comment: Can you clarify what you mean by "disk free space"? There is more than one kind of free space: partition space, file system space, etc. If you only want to know "is there enough disk space in my /home/username directory to download an ISO image file", try "df -h /home/username" (the -h option tells df to output "human readable" size units).
Answer: Depends on what "free space" are you trying to get.
df provides information about free space for mounted filesystems and it doesn't require root:
$ df -h
Filesystem                           Size  Used Avail Use% Mounted on
devtmpfs                             717M     0  717M   0% /dev
tmpfs                                737M     0  737M   0% /dev/shm
tmpfs                                295M  1,3M  294M   1% /run
/dev/mapper/fedora-root               17G   11G  5,4G  67% /
tmpfs                                737M  9,5M  727M   2% /tmp
/dev/sda1                            976M  285M  625M  32% /boot

If you want to know how much free/unallocated space is on each disk (space not occupied by partitions), you need to use tools like parted or fdisk and you need root privileges for that. lsblk can help, but it doesn't print free space:
$ lsblk /dev/sdb
NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sdb      8:16   0    1G  0 disk
├─sdb1   8:17   0  100M  0 part
├─sdb2   8:18   0  512B  0 part
└─sdb3   8:19   0  100M  0 part

But you can assume from its output that sdb here has approximately 800 MiB of free space for a new partition.
You can get better picture with UDisks, which also has information about partition layout, GNOME Disks uses this data to display free space on disks:

UDisks doesn't have a simple way to display this. You'd need to use its DBus API and calculate the free space yourself.

How know space disk left WITHOUT root


I can't find LINE IN - Audio Input Problem with a Mac Book pro early 2015

Question: I'm trying to record on my Mac book pro early 2015,  but the Line-In port does not appear. I only have the "built in Mic" option. I have plugged different kinds of mini jack in the only in/out port, with the device already turned on...and NADA.
Answer: You don't have a line in.
Per the Technical Specifications for your MacBook, it has support for a line out, but not line in.

Audio

Stereo speakers
Dual microphones
3.5 mm headphone jack

Support for Apple iPhone headset with remote and microphone
Support for audio line out (digital/analog)

Emphasis mine
To get a Line-In, I suggest using a USB-DAC or a USB Mixer so you can get a proper line level input and output.  In fact, I try not to use any of the built in audio ports due to their poor shielding and "economy grade" components.  You'll get better results with a proper audio interface.
Comment: Thank you so so much. I switched from a Mac 2012 to this and the previous one had it. Crazy- I will buy an external usb adaptor or a Focusrite audio
Comment: If the answer worked, please [vote up and/or accept this answer](https://apple.stackexchange.com/help/privileges/vote-up).  It's how you indicate an answer worked for you.
Comment: @allan Wouldn't plugging in a 3.5mm headphone with a built in microphone, act as the line in though? Or are you saying the sound input is inferior to using a USB-DAC/Mixer? I thought all TRRS headphones (3 rings on the headphone jack) would produce the same input quality? I know Macs are compatible with the TRRS standard so it should act as both output and input.


What file format should my fledgling animator use to create a "logo sequence" that precedes my movie?

Question: What file format (ex: GIF, mov, etc) should my graphics artist/fledgling animator use to create the logo sequence for my new movie production company, please? I submitted a storyboard of .png images to him to animate.
Answer: I would say that you'd want an uncompressed video of the animation; typically, those are wrapped in a MOV container.


Do pilots of commercial aircraft have ready access to a map or data showing nearest airports in case of a need to make an emergency landing?

Question: As a passenger I often wonder that if a pilot had to make an emergency landing, do they have access to live information to direct them to the nearest airport or is this something that they have to rely on from air-traffic controllers?  I'm thinking that seconds could mean the difference between life and death and having information as such on-board could be a life saver, rather than rely on others to figure out where to go during a crisis.
Answer: Since you asked about commercial aircraft, I will answer for a modern airliner: The Boeing 777. The details will differ between aircraft models, but the general functionality should be available in every modern airliner.
With a modern airliner equipped with an EFIS (Electronic Flight Instrument System), there is no need to carry paper maps with possible diversion airports any more. Selecting a suitable alternate and navigating there can be done with the FMC (Flight Management Computer).
On the 777, the FMC has a page with alternate airports that are selected automatically from the navigation database, but can also be overridden by an uplink (where the airline dispatch sends suitable alternate airports to the aircraft) or manually (e.g. required for ETOPS flights with selected ETOPS alternates). This page looks something like this:

(Boeing 777 FCOMv2 11.43.21 - Flight Management, Navigation - FMC Descent and Approach)
The list of four airports is shown in 1 and the estimated time of arrival (ETA) as well as the fuel at the diversion airport is shown in 4 and 5 respectively. 2 allows a request of alternate airports from the airlines dispatch via ACARS. In order to divert to one of these airports, you select the respective line from 1 and the press DIVERT NOW (9). This will set up the flight plan with a direct line towards the selected airport.

Alternate Airport Diversions
ALTN page 1/2 data aids the flight crew in finding a suitable alternate airport.
The page displays up to four airports in ETA sequence. Each airport on the list has an XXXX ALTN page with more data. [...]
Three alternate airport uplinks can be received. ALTN LIST page 1/2 can get an uplink for the entire page or just the ALTN INHIB line. ALTN LIST page 2/2 can receive an uplink of alternate airport names.

(Boeing 777 FCOMv2 11.43.20 - Flight Management, Navigation - FMC Descent and Approach)
These four diversion airports can also be displayed on the Navigation Display (ND):

(Boeing 777 FCOMv2 10.10.35 - Flight Instruments, Displays - Controls and Indicators)
This is particularly helpful if adverse weather is in the area (e.g. thunderstorms) because the weather radar would depict areas with large amounts of precipitation on the ND as well. Should an alternate diversion airport be out of display range, it will be shown like this:

Displays the FMC or pilot selected primary alternate airport. Displays up to four alternate airports when the EFIS control panel ARPT map switch is selected on.
Offscale airports (those beyond 640NM with 640 scale selected), directional arrow relative to the airplane position or PLAN center point and distance (distance remove in PLAN).

(Boeing 777 FCOMv2 10.40.20 - Flight Instruments, Displays - Navigation Displays)
All of this allows a fast decision for an alternate diversion airport. Nonetheless, communication with ATC (Air Traffic Control) is of course essential in an emergency and ATC will assist in finding a suitable diversion airport if necessary. I don't quite agree with

I'm thinking that seconds could mean the difference between life and death [...].

If you only have seconds to make such a decision, it means you are at very low altitude, meaning either just after takeoff from your departure airport or already very close to your destination airport. In this case, the usual choice in case of an emergency is to return to the departure airport or continue to the destination. There are exceptions of course, like e.g. a takeoff alternate:

A take-off alternate aerodrome should be specified in the operational flight plan if either the meteorological conditions at the departure aerodrome are below the applicable landing minima or in case it should not be possible to return to the departure aerodrome for some other reason.

(SKYbrary - Alternate Aerodrome)
In this case the takeoff alternate would however be chosen before even departing, so no quick decision is necessary.
Comment: @BeginnerBiker for concerns about flying over water, do some investigation into [tag:ETOPS] (Extended-range Twin-engine OPerationS). There are a boat... er... plane-load of rules and regulations about how far you can be from a diversion airport based on the individual aircraft you're in and what that particular aircraft is certified for.
Comment: Much appreciated, thanks.  This level of sophistication increases my feelings of security while flying.  I generally feel quite safe flying over land, knowing that there is usually an airport nearby in case of an emergency.  But flying over water always worries me.  Cheers.
Answer: Generally, yes. The FMS will have a database, updated every few weeks, that contains all possible navigational data that one might need within the selected region(s). This is needed so that pilots are able to enter any possible route they might need, including ATC rerouting them or diverting to other airports due to weather or emergencies.
I don't know airliner FMSes in particular, but even GA planes have a single button that will show you all the nearest airports and key data like runway lengths, and you can select and start navigating directly to any of them in one or two clicks specifically to address the exact scenario you mention.
There are even apps for phones and tablets with the same capabilities; they aren't legal for IFR navigation, but VFR pilots use them for that every day, and IFR pilots do use them for other reasons or at least have them in their bag as an emergency backup.
Since these databases are large and rather expensive, you don't load data that clearly isn't needed. For instance, a US domestic carrier would still load the Canadian regions since they might overfly it between US cities, but they wouldn't load regions on other continents since their planes couldn't get there anyway. And GA pilots might only load the region they live in.
Answer: Maps and charts are always available in all aircraft flying for scheduled commercial carriers. They used to be in the big leather flight cases that pilots used to drag through the airports. General Aviation aircraft are not required to have maps and charts for VFR flight. But, it is highly recommended. Regardless, each pilot in command, before beginning a flight, is required to become familiar with all available information concerning that flight. This may include emergency landing options and alternate airports. Technology has made it a lot easier to have charts and maps available as well as having all information concerning each flight.
In a "glass panel" aircraft, maps and charts are loaded into the aircraft's onboard navigation system. These maps and charts can be geo-referenced to provide a moving map showing the aircraft's location based on GPS. In addition, pilots can now use apps loaded on their tablets with the capability of storing maps and charts of the entire world. Although, just the US would take anywhere from 30-50 gigs including the app software itself.
In an emergency where landing at an airport is an option the nearest airport can be found fairly quickly. Most glass panels and tablets have a nearest function that will direct the pilots to airports fitting preselected parameters. These parameters are usually based on airports able to accommodate the aircraft based on runway dimensions, available instrument approaches, etc. For reference, the nearest functions of the Garmin G1000 are shown below. One of which is activated by the push of one button on the Primary Flight Display.
Luckily, the higher the aircraft is flying, the further it can glide to a suitable airport for landing. This may take a surprisingly long time from over 30,000 feet. If the aircraft is in an uncontrolled and rapid descent, it may be pointless to attempt a landing at an airport no matter how near it is.
One such flight that landed successfully was Air Transat Flight 236 that glided without power for 75 miles in almost 20 minutes.


Where in Old Testament is said something like we must be cautious reading it because prophets can make mistakes?

Question: A week ago I was reading Matthew, and at Mt 2:15 and 2:17 he write about Old Testament prophecies. Searching for it, maybe in Jeremiah, I read something like  'we must be cautious reading the Holy Scriptures because prophets can make mistakes'. I found it a beautiful message, but at the time, when I was searching for the prophecy referenced by Matthew, I don't pay too much attention to it, and today I'm not able to find it again.
Can someone point me the location of some versicle that could be that?
Comment: Welcome to Christianity.SE. For a quick overview, please take the [Site Tour](http://christianity.stackexchange.com/tour). I looked up Matthew 1:15, 17, and they are verses in a genealogy rather than references to Old Testament prophecies. Can you give us the correct verses you were referring to? Also, about asking questions here, please see: [What topics can I ask about here?](http://christianity.stackexchange.com/help/on-topic) and: [How do I ask a good question?](http://christianity.stackexchange.com/help/how-to-ask)
Comment: @LeeWoofenden , I'm sorry, it is Matthew 2:15,17. I'll edit may question.
Comment: Can you  tell us what Bible version you are using?
Comment: @DickHarfield it's a Catholic Bible, in Portuguese, from 1962, _IMPRIMATUR_ given by _Curia Archiepiscopalis Mediolani_.
Answer: I think the passage you are asking about is:

Jeremiah 14:13 through 17 KJV  Then said I, Ah, Lord GOD! behold, the prophets say unto them, Ye shall not see the sword, neither shall ye have famine; but I will give you assured peace in this place. 14  Then the LORD said unto me, The prophets prophesy lies in my name: I sent them not, neither have I commanded them, neither spake unto them: they prophesy unto you a false vision and divination, and a thing of nought, and the deceit of their heart. 15  Therefore thus saith the LORD concerning the prophets that prophesy in my name, and I sent them not, yet they say, Sword and famine shall not be in this land; By sword and famine shall those prophets be consumed. 16  And the people to whom they prophesy shall be cast out in the streets of Jerusalem because of the famine and the sword; and they shall have none to bury them, them, their wives, nor their sons, nor their daughters: for I will pour their wickedness upon them. 17  Therefore thou shalt say this word unto them; Let mine eyes run down with tears night and day, and let them not cease: for the virgin daughter of my people is broken with a great breach, with a very grievous blow.

If this is the passage it must be noted that it is referring to False Prophets as stated in verse 14.
If these are not the verses you are asking about let me know and I will do some more research.
Hope this helps.
Comment: I've appreciate your help, but is not this passage. The passage, I remember,  is not about **False Prophets**, but about something like the recognition of the fragility of the prophecies itself by the prophet himself. I guess I read it on Jeremiah, but I'm not 100% sure, but I'm sure it is on the Old Testament.
Comment: @LeandrosLópez I'll do some more research and if I find anything I'll let you know.
Answer: I can't think of any passage where God (through the inspired writers of the Bible) would be saying that true prophets of God or the written word of God itself might be mistaken, so you should pick and choose carefully what you believe.
Here's a list of all word forms of "prophet" or "prophecy" from Jeremiah.  You'll notice that the theme of almost all these verses is God's condemnation of all the false prophets of Judah.  Time and time again God warns his people not to listen to them because He has not sent them.  The clear implication is that true prophets, like Jeremiah, prophecy the true word of God, and therefore refusing to believe them would be foolish.
In fact one of the signs of a true prophet of God is that what he prophecies comes true.  A prophecy that does not come true is a sign of a false prophet.  Read about Jeremiah's encounter with Hananiah in Jeremiah 28 to see how that played out, especially verse 9:

As for the prophet who prophesies peace, when the word of that prophet comes to pass, then it will be known that the LORD has truly sent the prophet."
  (Jeremiah 28:9 ESV)


How to Implement Breadcrumbs for nested Categories

Question: My categories can be nested about 6 levels deep at most. The problem I am having is getting the breadcrumb array or list from the database (sql server 2005). My sql skills are not that great. Once I get the breadcrumb from the database what would be the best way to present it.
Answer: Why are you storing the users history in the database?  Wouldn't a breadcrumb be more of where the user has been?
In that case you'd probably want to store the page each time a user navigates to it, dropping off the first item when you have reached your maximum length.
the issue then becomes one of where to store that history and yeah a database may be an option.  You might also want to store that with the users session data if available.  there are stacks of ways to implement storage of history.
EDIT
This is added info to what mjv said.
Answer: There are several ways you could represent breadcrumb information in your markup.  There isn't a <breadcrumb> element in HTML so its debatable if any approach is semantically correct.  Look here for a discussion of some of the approaches that people use.
I prefer using lists, then you could style it as shown in this example.


How to make to tables in InDesign to flow horizontally (in other words be side-by-side and not one after the other like normally happens)?

Question: How to make to tables in InDesign to flow horizontally (in other words be side-by-side and not one after the other like normally happens)?
I would need to put 2 tables like this:
|----|   |----|
|    |   |    |
|----|   |----|

Instead of:
|----|
|    |
|----|

|----|
|    |
|----|

I intend to maintain the header cells on both pages (when it breaks). I also intend to export the data at some point, so table nesting is not desirable.
How to do it without an extra table? thanks a lot!
Comment: Can I ask why you want to do this without creating another table? You could create a third table with 2 columns and 1 row, set the stroke to none, and copy paste the 2 tables into the cells.
Answer: There are three ways depending on how (if at all) the two tables are interelated.
1. Continuous columns from one table to the next
Meaning: you get the side-by-side effect, with headers and footers appearing correctly at the top of both tables sitting next to each other, but the pair are one continuous table split across two columns, so you can select cells down the columns in both halves at once, paste data into both at once, etc (rather than being one table, then another, extra table).
Probably the simplest way is with two linked frames and a frame break pushing the second half of the table into the second frame (steps below).

Set up your table in a text frame in the left position. Make any rows you want to be above / below both sides set as Header / Footer rows (using Table > Convert Rows while they're selected)
Set up the table as one long table, with the rows you want to be on the right below the rows you want on the left (one header / footer for the whole two-tables-combined). If you need it the other way round, top on the right, that's fine too, just move this first table to the right.
Click the 'Out' port in the bottom right end of the table's text frame to create a second linked frame that excess rows can overspill into. Place it to the right of your table as desired.
Put the cursor in the start of the first row that you want to be in the right-hand section of the table, and insert a frame break (Type > Insert break character > Frame break, or shift+enter), sending it to the second frame.
If you need these two tables to sit side-by-side in the main body text, so they move as the text changes, see 3. below.

If you want it to flow from one to the other so that when you delete one row on the left, another row moves to replace it from the right, don't add the frame break and instead just shrink down the text frame until half the table is pushed into the second frame.

2. Different columns, continuous rows
This is assuming you want continuous columns. If what you actually want is left and right tables with different columns but the same row headings, lined up horizontally, just make one wide table with extra columns on the left and include a blank column - no fill, no stroke other than sides if needed, no content, etc - to make the 'gap' between left and right.

3. Separate tables, sitting in the same position in the main body text
(just re-read the question: I think this might be what you mean but I don't see where the 'extra' table would come from)
If they really are completely separate tables (or split into separate frames), and you've got a two column layout and you simply want to put them into the layout so one is after the other in the document flow but fixed to the right instead of dropping below, you can do that while keeping the tables within the flow of the text, by nesting a text frame in the main text frame:

Create a text frame a bit taller than the taller of the two tables, and as wide as the two columns.
Create a text frame the size of the right table, cut and paste the right table into it.
Cut it, put the type cursor in the wide frame, and paste it (so it's inline with the text). Use the type tool to select this nested table frame like it was text.
Set it to right align. It should jump to the right of the frame.
Do the same with the left table, but keep it as left aligned. You've now got the two tables side by side in a frame. (if ever need more than two, you can have them all on one line and place them using tabs and the Type > Tabs window)
Select this text frame, cut it, put the Type cursor in the position in your main body text where you want the side-by-side tables, and paste.
It's probably sitting on top of text in the right hand column. Select the frame, and in the Text Wrap window (Window > Text Wrap), set it to "Wrap around bounding box" (second icon) so that it pushes the text in the opposing column out the way.

You've now got two tables that are fixed to be side by side, and are sat in a set position in the flow of your document and will move with that position as the document text changes.
Don't forget to keep an eye on it to make sure it doesn't end up in the wrong column or in an awkward position on the page.


Should Oracle *online* redo logs be backed up?

Question: Obviously archived redo logs are backed up as frequently as required, but does it make any sense to backup online redo logs? Is the online redo log an open and active file such that copying it in this state is a waste of time (same as backing up an open database)?
If the online redo log hasn't switched for 20 minutes (so that the log was available for archiving) then if the system fails and media recovery is required and you haven't backed up the online redo log, surely you've just lost the last 20 minutes of transactions?
I know there are other, more robust ways of transporting redo information to ensure nothing is lost, but I'm still interested in the state of the online redo log files.
Thanks for your time.
Clarifying Update...
There is a regular background process running regularly that ships off archived log files and online log files. I don't have much control of this process. Are the online log files usable, or could they be corrupt if the log was being written to when the backup was taken?
Answer: The recommendation is that you duplex / multiplex your online redo logs. That way they are written to two different physical disks. If one fails, your database will stop (as it can't write to the redo logs). You shutdown abort, then bring up the database on the surviving redo log(s), then you can restart the database with all the multiplexing when you've resolved the problem.
Comment: Thanks for the reply - my redo logs are in groups and group members spread across multiple locations so I'm not worried about not having the file available. My question was whether the current online redo log can be backed up while it is being written to - the backup is offsite so gives an extra level of confidence.
Comment: +1, this is your best protection against disk failure. If the system goes completely belly up, then you're in for restore/recovery on another box (see my answer about standby databases).
Answer: If you want to 'flush' the current redo log to ensure you have an archive of it you can issue an
<code>alter system switch logfile;
</code>
from SQLPLUS or RMAN
This will force the archival of the current log which you can then backup off site.
Another option would be to use smaller redo logs so that the natural transaction rate of your database causes a log switch and archive at in interval you are more comfortable with.
"alter system switch logfile" does not force the archival of the current log, it only switches to the next log from the current making it available for archival. "alter system archive log current" does force the archive of the current log.
Answer: Another thing to consider is a standby database. You can configure that to have the log writer write redo to the listener on a remote system with a standby database (real-time apply). This is done in near real time. The benefit is minimal downtime in the case of a system failure with no recovery needed. Just activate the standby database and go.
The recommendations about mirroring your redo log groups on separate disks are excellent advice. Typically, only one of your log groups is active at a time - the rest are either archived already or waiting for archival. You wouldn't want to copy the active one - it would likely be useless in a recovery scenario.
In short, no you can't copy live redo logs while the db is running and hope to have anything of value when you're done.
Comment: Thanks for the detailed reply. Your last sentence answered the question.
Answer: It depends what you mean by Backup.  If you mean it in the traditional sense then DCookie gave the correct answer of "short, no you can't copy live redo logs while the db is running and hope to have anything of value when you're done.".  On the other hand there are newer backup type technologies that can take a point in time snap of volumes.  If they can snap your data files, control files, and redo logs as of the time point in time then you do have something useful.  If this data were to be restored when the database is brought up it would behave as though the power were pulled at the time of the snap.  Any uncommitted transactions would be rolled back, but no committed transactions would be lost up to the point at which the snap was made.
Answer: If your online logs are available upon restart and they are not corrupted, Oracle should be able to recognise them and replay them as well as the archived ones.
The only things that will be lost are the transactions not yet commited at the time of the crash.
Of course if your hard drives crash, you will lost everything that has not be backed up.
That's why you should have some mirroring or better have the redo logs stored on different disks/controllers/computers.


Yosemite not displaying external HDMI monitor at full resolution

Question: I have an HP Pavilion 22xi, which is 1920 x 1080, but my external display settings only go up to 1080p, even with the option click trick on the scaled button.
Answer: 1080p = 1920x1080 so you are already getting the highest resolution available on your monitor.
Are you missing the menu bar at the top of the screen and the dock at the bottom? If so, moving the underscan slider beneath the resolution section in the Displays preference pane should resolve your problem.
If you are still having trouble, try a PRAM reset (instructions below). Display resolution settings are stored there.
1.Turn off your computer.
2. Locate Command+Option+P+R keys and be ready to press them simultaneously.
3. Press the power button then immediately press and hold the keys until you hear the startup chime a second time.
Comment: No, the whole thing just looks blurry. When I connect my PC to the monitor it goes perfect.


Advantages of using business logic in model

Question: In an MVC framework i have often heard that use business logic in a model. But i think using the business logic in controller would run faster as view is directly connected to controller. I want to know what are the advantages of using a business logic in model?
Comment: If you put your business logic in the controller, what would be left in the model then? :)
Comment: model interacts with the database and runs the query required... thats my opinion which might be wrong...
Answer: The key is:
Separation of concerns
In an ideal world you want any given piece of code to do one thing and to do that well. So you want to try and avoid mixing up display logic and business logic and storage logic and everything else.
This separation provides a variety of benefits - testability (as suggested) is an important one (though to my mind it's almost a bonus), but also the fact that the code should be easier to understand at any given level and hence easier to maintain, that the business model/logic (in particular) is more portable (from web to native app) or that you can change the UX (say from MVC pages to a fully separated javascript app using a web API) - finally, if nothing else, the cummulative experience of a huge number of programmers tells us that it - separation of concerns - is a good thing.
On contemporary server hardware performance just shouldn't be an issue unless you're doing seriously funky stuff and then you don't want to have bound up in the user interface layers because you can't then attempt to deal with the performance issues in isolation.
Comment: Its all the same code running in the same place. The overhead of object instantiation and the method calls should negligble or you're doing something seriously wrong. Whilst you shouldn't be blind to performance considerations they really shouldn't be something you worry about in the first instance (in the general case) and more importantly anything that is purely *in code* is unlikely to be a bottleneck. You will get far more value (and have more time to look at performance if needed) if you have a well structured application with appropriate automated tests
Comment: My concren is whenever end user uses our application it hits our controller so its better to validate the data according to business rules in a controller rather than validating in a model
Answer: First, it is almost every time a mistake to argue about the place of the business logic in terms of program speed (at least, when your model and controller layers are part of the same program with no network communication between them). If you have speed issues, you can optimize them in your model layer as well as in your controller layer.
Much more important than speed is typically the goal to give your program a good structure, where you know about the responsibility of each component, where you can test things in isolation, where you avoid code repetition when the same part of business logic is needed twice, and so on.
Thus, the question for the best place should be guided by the question "what kind of business logic?"

business logic controlling the user interactions of your views belong typically into a controller
small parts of business logic dealing with primarily one business object typically belong to that object and so are best placed in the model. Example: having an object "Person" with attributes "FirstName" and "LastName", and you need to get the "full name" as concatenation of FirstName and LastName, then a property "FullName" of "Person" may be a good idea.
for bigger parts of your logic, independent from your views, you should introduce separate controller classes.

Where exactly to draw the line is up to you. There is a long-lasting and open-ended discussion in the community about how much logic should be in the model and how much in controllers, see, for example, here: http://www.martinfowler.com/bliki/AnemicDomainModel.html
Comment: if i am not wrong you are saying that it depends on the type of business rules and its developer who decide where to put the particular logic
Answer:
Testability.

Decoupling user interface from the model makes it easier to write tests against just the model. You just test against the core functionality, without having to worry about User Interface getting in the way (which you may test as well, and there are ways to do that, but this is not what you are asking :).
Comment: i didnt catch your point it would be good if you provide some details
Comment: I added some details, hope it helps :)
Answer: Model Concept....
The model manages the behavior and data of the application domain, responds to requests for information about its state (usually from the view), and responds to instructions to change state (usually from the controller). In event-driven systems, the model notifies observers (usually views) when the information changes so that they can react.
View Concept....
The view renders the model into a form suitable for interaction, typically a user interface element. Multiple views can exist for a single model for different purposes. A view port typically has a one to one correspondence with a display surface and knows how to render to it.
Controller Concept...
The controller receives user input and initiates a response by making calls on model objects. A controller accepts input from the user and instructs the model and a view port to perform actions based on that input.
MVC
also see the screenshot

Please read carefully and reply me if you have any Query regarding this @shayan
Comment: read my question carefully i haven't ask the concepts of mvc framework....
Comment: first you have to clear your concept then ask Question
Comment: your Question is belong to this Concept first you have to read carefully and reply me
Comment: In the original MVC pattern the Controller does not direct the View, it only observes the view.


Oil pressure to high?

Question: So last night I did a oil change on my 2005 Chevy Silverado 1500 and I put 15w40 in because it's over 230000 miles and that's what my mechanic told me to And the oil pressure is around 60, should I be concerned?
Comment: Welcome to Motor Vehicle Maintenance & Repair!
Answer: My oil pressure is that high when I first start the motor, but slowly drops as the motor heats up. I drive it to warm it up, careful not to overload it beyond 80 before it's warm. I don't think you should worry about it, but in the future, I would not put that oil in it.
Old timer mechanics would often change the oil weight with mileage and/or weather conditions, but technology has come a long way in both oil and engine manufacturing, tightening tolerances. I don't think engines these days are as tolerable to oils that they were not designed for. They make, "high mileage" SAE 5W 30, that I would use for high-mileage vehicles, rather than using an oil that's not spec'd by the manufacture.
Answer: Partly depends on what pressure was with the correct oil. 60 psi sounds high depending on RPM. However modern engines are designed with close tolerances. Engineers who designed the engine intended a certain amount of oil flow across the bearings to cool them. Shear in the oil film causes heating. There is less cooling oil flow across the bearings with high viscosity oil. Ambient temperature also has an influence. I use the oil viscosity the engineers designed for rather than hearsay.

Oil pressure to high?


How to force SharePoint Office 365 to show new item form in a dialogue instead of full window?

Question: Clicking on new item link on a list for most of my lists are showing popup but one of the list, which actually is exact copy of other lists, shows new item form in full window instead of a dialogue.  I checked list settings and the new form in dialogue option is set to "YES".  Any other idea?  Any help is greatly appreciated.
Comment: is there any customization in your forms? maybe you can provide some screenshots about this issue to understand this issue better.
Answer: Are you trying to create a "New Form" in the Dialog, from the "Standard View"?
Because in SharePoint OOB, the option "Launch forms in a dialog" is applicable only for the "Standard View".


Problem with understanding the application of the Intermediate Value Theorem in the proof of the Mean Value Theorem for Integrals

Question:
I am struggling to understand the last parts of this proof because I know that the IVT states that on the interval $[a,b]$ of $f$, where it is continuous, there exists a value $L$ between $f(a)$ and $f(b)$ such that $f(c)=L$. Now, while I understand that, I do not singularly understand how a single value of a function, $f(k)$, can be equal to the the area of our function multiplied by $\frac{1}{b-a}$, for, as I know, the IVT can be applied only to points of a function and not integrals. Can anyone tell where I have gone wrong in my understanding?
Answer: The IVT does not say "there exists a value $L$ between $f(a)$ and $f(b)$ such that $f(c)=L$". It says that if $L$ is any value between $f(a)$ and $f(b)$ then there exists $c\in(a,b)$ such that $f(c)=L$. Note the "any".
Consider the interval $[m,M]$. Let $L=\frac{1}{b-a}\int_a^b f(t)\,dt$. Then $L$ is a value between $f(m)$ and $f(M)$ (one of the inequalities above says so). So IVT says exactly that there exists $k\in(m,M)$ with $f(k)=L$. (And now $k\in(a,b)$ since $(m,M)\subset(a,b)$.
(I assumed here that $m<M$ just so I could use the notation (m,M)$. If $M
Answer: The function in question here is the anti-derivative of $f(x)$ starting at $a$.
$$F(x) = \int_a^x f(x) dx$$
This function is zero at $F(a)$ and equal to $\int_a^b f(x) dx$ at $F(b)$.  At an intermediate value between $a$ and $b$ it will have differing values, but  there is a point in between ($k$) where everything balances out:
$$\int_a^b f(x) dx = f(k)(b-a)$$


I have a Fujifilm HS25 EXR and its minimun aperture is F2.8. Is there a way of getting a lower aperture for my camera?

Question: I have a Fujifilm HS25 EXR and its minimum aperture is F2.8, but I want it to be F1.8 (my dream is to achieve the bokeh effect) Is there a way of getting a lower aperture for my camera; maybe a lens or something like that? Thanks a lot!
Answer: No. The only way to use a conversion lens to make the aperture faster is if you can put it between the lens and the sensor. But of course you can't do that with a fixed-lens camera. But take a look at How can I take shallow depth of field photos with a point-and-shoot camera? to see what you can do. If that isn't enough, you will need to buy a camera with a larger sensor and faster lens.
Answer: The aperture can not be any bigger (faster) than the smallest opening through which the light passes.  No matter what you put on the lens, you can't remove the opening through which the light must pass, so there is no way to change it.


ExactTarget - Send email to group via Fuel SDK?

Question: Can an email be sent to a Group via the Fuel SDK?  If not, how can it be done with another API or SDK?
Comment: test the sample in this url: http://salesforce.stackexchange.com/questions/107419/reviewed-why-i-see-the-count-of-completed-queued-errored-on-triggered-sends-to
Answer: The way I am sending email using FuelSDK php, I have created DataExtension then using this (search for SendEmailToDataExtension sample code)
<code>$response = $myclient->SendEmailToDataExtension($EmailIDForSendDefinition, $SendableDataExtensionCustomerKey,$SendClassificationCustomerKey);
</code>
Where
$EmailIDForSendDefinition: is your email ID which you can get by getting email properties.
$SendableDataExtensionCustomerKey: is you DataExtension Key again you can get this by looking into properties of Data Extension.
$SendClassificationCustomerKey: This is you Send Classification e:g DefaultTransactional
To send email to List have same procedure and function used for this in fuelsdk is "SendEmailToList".
Using one of these code, instead of listid/DataExtension id provide group Id and and send email.
Regards
Answer: If you are using the PHP version of the SDK, check out the example for sending to a List at:
https://github.com/ExactTarget/FuelSDK-Ruby/blob/master/samples/sample-email.senddefinition.rb
A group is basically just a special type of List, it has an ID which can be used interchangeably with a standard List ID.
Comment: Thanks Mac, that's great to know.  How do you find the ID for the group though?  With no access to the Groups via the SDK, it still feels like a dead-end.
Comment: That looks like a link to the Ruby SDK.
Comment: By the way, I did try getting all Lists, but my group wasn't included in them.
Comment: I also tried using an ID I found via the web interface, but the get() against ET_List() failed to return anything but an empty stub object.


Is port forwarding an ssh server safe?

Question: I am using an Ubuntu desktop at my house, and I want to access my computer from school on my Ubuntu laptop and on termux with my Android phone. I heard that I have to use port forwarding. Is this safe for my desktop and other computers on my network? What are some precautions I could take?
Comment: If you have an SSH service accessible from the Internet, it *will* be attacked, so you need to make sure it's properly locked down. See [this previous question](https://unix.stackexchange.com/questions/21639/internet-ssh-server-security-considerations) (which this might be considered a duplicate of) and [this security.SE question](https://security.stackexchange.com/questions/39/what-methods-are-available-for-securing-ssh) (which is closed, but nonetheless has some good recommendations). One I'll add: make sure you use hard-to-guess passwords on your accounts!
Comment: You don't necessarily need Port Forwarding. A safer option would be to use VPN. Some routers offer to run a builtin VPN Server. Regarding your questions: Letting a computer to be accessed from the Internet is not safe. You have to care a lot about the security. Harden your ssh-server. Keep up with updates ... If your computer can be hacked, the other computers in the network are also under attack.
Comment: I am not sure how what you mean by using VPN, I just want my desktop to be accessible on other networks.
Answer: Unless you know the IP address/range used by your school, you will need to allow access (either port forwarding or VPN) for any IP address, and as a result, anything on the internet may attempt to access the forwarded port or the VPN server.
Yes, anything. That includes numerous worms and hacked systems that spend their time scanning the internet to find new systems to break into. If you look at your system logs after enabling port forwarding, you'll soon see login attempts from various locations all over the world.
Whether they will be successful or not will depend on how secure you can make the service you're allowing: long and complex passwords are better than easily-guessable ones, and certificate or SSH-key-based authentication is probably better than any password-based authentication.
If you decide to port forward the SSH service, I would recommend that you first set up SSH key authentication between the desktop and the laptop+phone, edit /etc/ssh/sshd_config to add the setting:
PasswordAuthentication no

and then restart the SSH service.
With this setting, no password at all will grant SSH access to your system, although the SSH server may still ask for one, just to make an intruder waste their time. Only key-based authentication will actually work.
Comment: I changed tried changing that file, but how do I connect to it?
Comment: It firstname.lastname@example.com: permission denied (publickey).```
Comment: Nevermind I figured it out

Is port forwarding an ssh server safe?


Update Panels in Repeaters - Why can't multiple callback at the same time?

Question: I have an update panel in a repeater
(Edit: I removed Runat and Id attributes to make the post look cleaner)
<asp:Repeater>
    <ItemTemplate>
        <asp:UpdatePanel UpdateMode="Conditional">
            <ContentTemplate>
                 <asp:LinkButton onclick="btnCallback_Click" />
            </ContentTemplate>
        </asp:UpdatePanel>
        <asp:UpdateProgress DisplayAfter="0">
            <ProgressTemplate>

            </ProgressTemplate>
        </asp:UpdateProgress>
    </ItemTemplate>
</asp:Repeater>

The idea is here that you click the LinkButton and it calls back and performs a server side action for that data item. This works perfectly fine for one item. However, if I click the button for every item without waiting for the previous update panel to finish the call back, it appears to cancel the previous callback.
Can UpdatePanels not perform call backs at the same time? Is there anyway I can make it so you don't need to wait before clicking on the next button?
Answer: Every AJAX request performed via UpdatePanel cancels any previous one (if previous is still running). This is how it is built. UpdatePanel AJAX request passes portions of ViewState along with request. It is impossible (at least very hard) to reconcile multiple arbitrary viewstates brought back by concurrent ajax calls. I heard that this was the primary reason MS chose to build it that way.
EDIT: use jQuery and have fun :-)
Comment: Crap, I was really hoping not to hear that... I think I will use jQuery to disable the other buttons until a request is finished. Thansk!
Answer: I had the same problem before. But i finded out that making some tricks can allow you to implement multiple ajax calbacks in different microsoft update panels.
function ProcessCallBack(uniqID)
{
    var prm = Sys.WebForms.PageRequestManager.getInstance();
    //checking if there is somewhere perforimg of callback
    if (prm.get_isInAsyncPostBack())
    {
        setTimeout("ProcessCallBack()", 1000); //here we move execution of callback
        //for 1 sec forward
    }
    else
    {
        __doPostBack(uniqID,'');
    }
    return false;
}

So you must add calling of that function to your button or control on client-side click. uniqID is the unique identifier of server control, you can get it on server side.
So enjoy, and remember that everything is possible, but for some is needed a lot of time todo :-)
I was thinking about that, why guys from microsoft didn't implement such thing :-)


Discharging a capacitor conceptual question

Question: When a capacitor is discharging, why is the potential difference across it at any time $t$ equal to that of the resistor? Do  the two potential difference's not have to add up to the EMF of the supply (the supply is the capacitor, right?) When we charge the capacitor, eventually the potential difference across the capacitor is the EMF and the potential difference across the resistor is $0$. Then when we discharge, initially the potential difference across both components is the EMF? How did the resistor gain so much voltage?
Answer: The potential difference (pd) across the resistor is the same as the pd across the capacitor since they are wired together, and we model the wires as having zero resistance. When the capacitor is charging, the resistor may or may not be in the circuit, but when it is fully charged there is no current flowing so there is no potential difference across the resistor, because the pd across the resistor is proportional to the current, $V=IR$. The pd across the capacitor is proportional to charge $Q$, $V=Q/C$, where $C$ is the capacitance, so if the circuit is open, that is current cannot flow, it retains its charge.
Answer: Imagine a series circuit consisting of a charged capacitor $C$, potential difference  $\mathcal E$, a switch and a resistor $R$.
The switch is open so there is no current in the circuit and hence the potential difference across the resistor is zero.

How did the resistor gain so much voltage [instantaneously]?

You are asking, how is it that when the switch is closed the potential difference across the resistor instantaneously becomes $\mathcal E$ with a current in the circuit of $\mathcal E/R$.
In the real world the potential difference across the resister changes from zero to $\mathcal E$ as does the current change from zero to $\mathcal E/R$ in a finite amount of time which usually is very small compared with the time constant $CR$ of the circuit.
The reason is that the circuit has some (parasitic) inductance as the circuit is in the form of a loop, which prevents an instantaneous change in the current.
The inductance is small which means that the change of current from zero to $\mathcal E/R$ occurs over a very short interval of time and is often neglected.


I don't know why object has changed color

Question:
Why is the color on the area near the mouth and nose of my model more dark? I can't change it and I don't know what is it. Even when I add texture it is visible.
Comment: check to make sure your [normals](http://blender.stackexchange.com/q/27117/2217) are correct.
Answer: From looking at your screenshot, it seems that your normals are inconsistent. To fix this,  Tab  into edit mode, then select everything by pressing A  twice,(assuming nothing is already selected in the scene) and press  Ctrl +  N to make your normals consistent.
You can usually tell if your normals have been flipped because the shading on your object will darken.


How do I achieve an "old" distressed poster effect in Illustrator, Photoshop or Pixelmator?

Question: I am looking to create some graphics that look like modernism vintage style.
Examples here:

Any thoughts here?
Comment: *Which* application you use effects *how* you'd achieve this. Asking for 3 separate applications makes this a bit broad.
Answer: There are many ways to do this and to achieve this effect very easy you can just use a ready-made texture (search for example for "vintage" or "letterpress").
If I wanted to make my own texture I would use photoshop and start with a new black layer on top of my image.
Then i would add a low amount of Noise to it (Filter > Noise > Add Noise …)

Now press cmd/ctrlF a few times to add new instances of the effect on top and make the noise overlap in some places. This way you will get some dots that are brighter than others and therefore more variance in the noise. You can adjust this effect by using Curves or Brightness/Contrast.

Now add a Layermaskand select it.

Use Filter > Render > Cloudson the Layermask (Clouds will use your selected fore- and background color, so don't forget to reset them to black and white by pressing D). This will make the noise visible in random patches.
Now you just have to set the blend mode to Screen.

I bet if you play around a little with the settings and maybe also try out some of the airbrush brushes in Photoshop, you can get a good result.
Comment: Thank You very very much, great explanation, this was very helpful for me.
Answer: Those aren't distressed per se. They are emulating offset printing on lower quality substrates. Photocopies, or newsprint.
Essentially, it's an effect that you'd see when printing solid blocks of color where you get uneven ink coverage.
The most typical way to achieve this is scanning in the actual texture you want to use. If you Google "print textures" you'll find plenty of examples. Another term to search for is "print grunge" (which hearkens back to the aesthetic of the mid-90s that paralleled music ala David Carson and Art Chantry.
Once you have the texture you like, you'd bring it in to your image editing software (typically your raster-based software such as Photoshop or Pixelmator) and play with layer blending until it looks the way you like it.
I have no personal affiliation, nor have I personally used it, but perhaps the easiest way to achieve this is to purchase a commercial package that does exactly this. Mister Retro's products do just this.
Final note: If you want to be accurate, note that you'd rarely see this effect all by itself. In other words, if you have poor ink coverage on press, you likely also have bad line definition...meaning your edges are going to be a bit rough, your corners will fill in due to ink bleed. You may also have splotches of ink outside if your defined image or large spots of no ink inside of your defined image (often referred to as spots and hickeys). Essentially, the effect is 'cheap and/or poor quality printing' and that can include a range of things that people would not want to see in higher end printing projects.


How do I set up three tethered cameras to dump photos onto one computer into the same folder?

Question: This is for product photography. I would like to have three cameras tethered to one computer via USB. Camera 1 is handheld (say canon powershot) and first, photos are taken of the subject box. Then the box is placed on a scale and weighed. At this point, cameras 2 and 3 are positioned overhead to take a photo of the box barcode (camera 2) and a photo of the scale weight readout (camera 3). Photos from cameras 2 and 3 don't need to happen exactly simultaneously but should happen nearly at the same time because I would like to rig cameras 2 and 3 to one trigger. Next, I would like all photos to appear in one folder in the proper sequence in which they were taken, e.g. in lightroom. But I don't edit my photos so I'd prefer to just move the files with windows explorer to keep things simple.
What would be the easiest way to do this?
Comment: Wouldn't it be much simpler to have a USB scale and a USB barcode reader that puts the weigh and barcode directly in a text file?
Comment: The photo of the barcode/sku must go into the photo set of the item as a redundancy for my single sku inventory system. So if there's a typo or blank sku, I can refer to the sku photo in the sales page as the true sku number
Answer: Set your tethering software to assign file names based on the date and time taken, with the date in MMDD, YYMMDD, or YYYYMMDD format and the time in 24Hr format so it is HH:MM:SS. If you want camera sequence numbers, then have them included after the time & date portion of the file name. Be sure the time on all of your cameras is synchronized and have the same time zone set.
If you captured an image on March 9, 2023 at 22 seconds after 3:47 p.m. (15:47 in 24H format) using YYYYMMDDHHMMSS it would be named:
20230309154722.jpg
For instance, I use a file naming convention that goes like this:
YYMMDDxxxxMC54zzzz.CR2
In my case, xxxx is a sequence number I assign when editing so that images from a particular shoot will appear in the order I desire when uploaded to my website or social media, or when viewed in a slideshow that displays images in file name order.
MC54 is the prefix I've changed from IMG_ in my Canon EOS 5D Mark IV camera's settings (My 5D Mark III is set to MC53, my 7D Mark II is MC72), and zzzz is the original camera assigned 4 digit file number.
The image I want displayed third in the sequence from the fourth album/event on March 9, 2023 would look like this:
2303094003MC547863.CR2 (Where the original in-camera file name would be MC547863, or IMG_7863 if I had not changed the prefix from IMG_ to MC54 in the camera's internal settings)
The exported full (high) resolution JPEG would be named:
2303094003MC547863HR.jpg
The exported lower resolution file intended for web viewing would be named:
2303094003MC544786LR.jpg
If I shot using multiple bodies, as I often do, then the 18th image from the second shoot/album which was taken using my 7D Mark II might be:
2303092018MC723257.CR2 (Where the original in-camera file name would have been IMG_3257 had I not changed the prefix from IMG_ to MC72 in the camera's internal settings)
You would use the time stamp in HHMMSS for the six places to the immediate right of the date, then whatever other info you wanted to include to the right of that. Any file system set to display file order based on file name ascending would arrange the images in the order they were taken.


Can subterranean termites live on wet wood only without access to the ground?

Question: I didnt know that my sink was leaking making the woods under it wet which made it ideal for termites. When I check under the sink there were mud tubes and termites. The house/sink is made of concrete and the only wood was the cabinet under the sink. No wood is in contact with the soil. So my question is can a subterranean termite colony live without access to the soil? There were swarmers that got inside the house a few months back which I guess found the wet wood under the sink and started a colony. Is that even possible?
Answer: You should ask a professional, well established pest control company.  I can tell you only about my experience in Florida that Subterranean termites can establish colonies by building mud tubes up the sides of concrete block, to reach wood inside your home. In Fl. A lot of the big companies use Termidor, which is injected into the ground surrounding your home.  They treat your house every ten years and will offer a warranty if you pay about $125. Per year and they inspect your house yearly for signs of damage.  What we call dry-wood termites fly into your house through openings and colonize after they drop their wings. Often they can be treated with a type of heat gun and other means if the infestation is localized.  If they are all through your house they usually treat by tenting the entire house and gassing them.
I'm sure there are other opinions and treatments, esp. in different climates.


MT-135 Sounding Rocket info / design

Question: I'm searching for any design file or deep-info on the MT-135 rocket, the fuel used, engines, engines info, any thing really. I have deep-searched on tons of sites but I just find few missions that used this rocket;  I would like all the possible info. Thanks and regards.
Comment: @RussellBorogove yes, i check that page, but im searching info more technical, for example, the name of engines, fuel type, etc..
Comment: Are you looking for info beyond what's on [this JAXA page?](https://www.isas.jaxa.jp/en/missions/sounding_rockets/mt-135.html) It is more detailed than what I usually expect to find about sounding rockets.
Answer: According to the JAXA page about the rocket, it's a solid-fuel motor:

The propellant, a pre-formed grain, polyurethane composite with a low burning rate...

By polyurethane composite I assume they mean HTBP plus ammonium perchlorate and aluminum powder, since that's what JAXA generally uses for solid rockets. Since it's a solid rocket stage, the motor itself doesn't have its own name or an identity outside of the MT-135.
The page gives quite a bit of information about the construction as well:

The [combustion] chamber is built up by welding tubes made of chromium-molybden steel, and the outer edge of the nozzle is welded to it. The throat insert material is graphite, and the exit cone is made of ablative silica-phenolic FRP [fiber-reinforced phenolic, i.e. fiberglass]

The motor casing in the later MT-135P is recoverable by parachute, but the nozzle materials are ablative, so would be replaced after each flight.
Comment: Very usseful info! Thanks for that. And other thing, you have any idea to improve this rocket? i mean, this rocket is from 60's and, maybe a new fuel or something, you have something in mind? just guessing, this answere help me a lot!

MT-135 Sounding Rocket info / design


What lenses should I use for bird photography

Question: I am looking for lenses to use with my Nikon D5600 that would be good for bird photography. I recently bought it and was wondering what lenses would be good. My budget is up to $400. Thanks in advance
Comment: You could try too look for a used sigma 150-500mm they are in your budget range on ebay.
Answer: Birds are small and far away.  You need a long focal length to overcome this.  The APS-C sensor gives you a 1.6 multiplier, but I can't imagine using a focal length less than 600 mm effective.  I fought with a 420mm for some years before moving up to 600mm and now I have 2000mm effective on a P900 and love it.  You can buy a shorter lens and add a teleconverter, but that slows down the lens and may ruin your autofocus.  That is a killer if you have birds that move around.  Buy the cheapest 400mm real lens or lens plus teleconverter that will autofocus, take pictures, and see where you have problems.  Manual focus will help a lot when the birds are behind some brush, which is common.  The shorter lens you have, the closer you have to get.
Comment: APS-C sensor gives 1.5x multiplier on Nikon cameras (1.6x is for Canon APS-C), but it's a little detail :).


Phonegap app to send data via wifi

Question: I have an idea about an app. This app will simply send data from my ipad to iphone via wifi. My question is that is it possible to make app that sends data through wifi using phonegap?
Answer: Assuming that your devices are on the same WiFi network, this is achievable.  If there is no WiFi AP available, you're looking at more difficulty because iOS devices cannot create ad-hoc networks.
Take a look at this plugin, which uses Bonjour to discover the IP address of other devices running your app, and can then establish a TCP connection between the devices.

Phonegap app to send data via wifi


Is there a future for a closed question?

Question: I want to know , Is there a future for a closed question. Means what can be done after a question is closed? I know we can comment on closed question but what about other aspects about the question like "answering them", "up-voting or down-voting them" or "accepting answers for it" ?
Comment: [These](http://meta.stackoverflow.com/posts/77880/revisions) and [these](http://meta.stackoverflow.com/posts/77690/revisions). Anything that is above the ``.
Comment: Whatever you do: please DO NOT remove the auto-inserted duplicate links, which you did twice at another question.
Comment: what auto inserted duplicate links?
Comment: is there a way to officially VETO a close vote on your question???
Answer: Closed questions follow three general paths:

They are reopened by other community members,
They are closed but not deleted,
They are deleted.

When a question is deleted, all of the rep earned becomes null and void.  So if you recalc your reputation, all those votes are removed from your rep calculation.
You can still accept an answer on a closed question, but no further answers can be posted on it.  Obviously, you can't do anything else with a deleted question except, under certain circumstances, you can undelete it if you are the owner and have more than 10K of rep.  Community members with over 10K rep can also vote to undelete a question.
And so on.
Users with 10K rep can see deleted posts.  Most deletions are really "soft" deletions; the post remains in the database, but is not viewable by the majority of community members.
Answer: Anyone with sufficient reputation can vote to reopen questions.
Also, if you've edited/improved your question and want to reopen it, you can probably ask moderators. That shouldn't be a lot of trouble for them.
Comment: Or if you edited it you could visit the chat and ask for members of sufficient standing where present to reopen it. You'll probably be asked to demonstrate that you've made an effort to improve it (but a sufficient edit will usually demonstrate that)
Comment: I tried once to remove my errors from my question and asked the moderators to reopen it but they just roll-backed it to previous state
Comment: @Pankaj If some moderator's actions confused you, feel free to ask here. They have a lot of power, but they still answer to the community. Naturally, I can't say more about your problem without knowing details.
Answer: Even if a question stays closed, it can be useful.
If it has been closed as a duplicate, or when it has been closed and moved to another site, then it can still serve as an entry point for people who happen to find it through Google or some other search. Those can then follow the "duplicate of" links to get to a similar question which is still open (and probably has answers), or are automatically taken to the other site when browsing to the the migrated question. Other closed questions tell people what questions are not welcome on the site.
In short: some closed questions stay closed, and have a future in helping people find their way.


relationshipName - Parent child relationship dynamic query

Question: I'm trying to get relationshipName for standard childobject to build dynamic query.
Is there any function that returns the queryable name of the standard sObject for SOQL query. Example : Contact->Contacts // ActivityHistory -> ActivityHistories
Answer: You can use DescribeFieldResult class getRelationshipName() method to dynamically obtain relationship name for any lookup field (standard or custom).
Answer: Have a play with the Workbench, particularly the functionality under the info tab. You can see fields, relationships and also use the Queries tab to prepare and try out SOQL and SOSL.


Can I use .NET core with only F# or will I need to learn C# too?

Question: F# has recently caught my eye as something I'd like to learn more about, but I have never used the .NET platform and know very little about it. If I want to write a small website in .NET core can I do that with only F# or will I need to expand my learnings to include C#?
Comment: If you do anything .NET related, you'll inevitably come across C# every now and again, so it's probably helpful not to be entirely oblivious to it. As a rule of thumb, I'd say it's a good idea to know C# well enough to understand why you'd rather use F#.
Comment: The BCL is object-oriented and implemented in C# but you don't need to know C# to use it.
Comment: Don't forget [the Stack Overflow F# Chat Room](https://chat.stackoverflow.com/rooms/51909/f)
Answer: You can definitely use .NET Core with pure F#. There is no C# knowledge required, though it can be beneficial to familiarize yourself with it enough to understand usage and library documentation.
The official Getting Started with F# guide has a section on using .NET Core with "just F#", which you can use as a starting point.
As for writing a website, I highly recommend looking at the SAFE Stack intro, docs, and samples. It shows how you can use only F# for full stack web development, all using .NET Core.
Answer: This depends on your learning and working style.
Technically, F# does not need any support from C#. You can write complete programs of any kind whatsoever without ever touching C#.
However, a lot of F# resources online are geared towards migrating from C# to F#, and as a result are phrased in terms of the differences between the two. Something like "you've been doing this thing in C# before, but here's how it can be done way better in F#".
Additionally, a lot of .NET libraries are written in C#. The binaries are, of course, completely compatible with F#, so you don't need to do any sort of special tricks to use C#-written libraries. However, if you ever want to look at the source code, that's where C# knowledge would come in handy.
To be fair, there is quite a large number of F#-exclusive libraries out there, but the majority of .NET libraries are still in C#. So chances are, you will end up using some of them. Whether you would actually want to look at their source - that depends on your style.
Answer: There are some libraries that I could never get working nicely in F#, so I tend to have some C# projects built into my solution to handle things that I just could not find an elegant way of doing in F# - like using the high level "Nest" Elasticsearch driver. It is designed to give you very elegant code in C# but I found it was the exact opposite in F#, sort of defeating the point of using a high level driver.
C# is nothing to fear though, it is readable and intuitive for the most part. I came into F# with no knowledge of .NET and have learned what I've needed as I've gone along without any troubles.


Installing Java but being blocked by Permission Denied

Question: I am trying to install java on my raspberry pi following the instructions on: http://www.oracle.com/technetwork/articles/java/raspberrypi-1704896.html, but at the instruction ./bin/java -version, I get Permission denied. I tried doing sudo ./bin/java -version, but I get command not found. I am logged in on the root, so I'm not sure what's happening.
Comment: I think the problem when using sudo is that the java environment variable is not set for the root user.
Comment: So you are really using Debian and not Raspbian? Instead of using Java with Raspbian with more Performance. Java from Oracle for Raspbian is only available at the moment as java 8 "beta" release.
Comment: @SteveRobillard For some reason, typing in `./bin/java`, even though it goes to an elf file, it doesn't execute it which is the problem
Comment: @otakun85 Sorry for the confusion, I'm running raspian (from the raspberry pi website) and I'm trying to run a Java application on it. Preferably something that would run java files the same on a desktop (or as similar) that it does on another device with java
Answer: Java 8 is available as an early release for the Raspberry Pi.  This includes JDK8 and JavaFX 8 early release.
Checkout http://jdk8.java.net/fxarmpreview/
johnma@raspbmc:~$ /opt/jdk1.8.0/jre/bin/java -version
java version "1.8.0-ea"
Java(TM) SE Runtime Environment (build 1.8.0-ea-b36e)
Java HotSpot(TM) Client VM (build 25.0-b04, mixed mode)
johnma@raspbmc:~$

Also, I suspect that you received program not found because the version of the executable was not compatible with the platform that you tried to run the executable on.  I accidentally downloaded a JDK7 preview for ARM instead of the most current JDK8 preview and received the same "command not found" error that you did.
Answer: Ok, I found a way around it. It's probably very silly, but it seems to work.
I run apt-get install openjdk-6-jre, which bundles java and now I am able to call java -jar TCA.jar and it does the same io reading and writing as done on my desktop version (which helps with my debugging), but I am still testing the other objects in it. So far, I haven't found any issues.
Comment: Damn it, didn't really work. Most of the libraries I want to use (like a lot of the System) doesn't work. Think I need one tailored for raspberry pi


Evidence for a chemical reaction

Question: I know that the emission of light is evidence for a chemical reaction.  However, are there any instances where emission of light can also be considered a physical reaction?
Comment: An Edison-style *light bulb*? LEDs? ;-) Actually chemical rections emitting light are rather rare, esp. if you take out those that simple become *very hot*. If you don't live in a rural area (fireflies) or have had a good chemistry teacher, you probably have never even seen a light that would qualify as "chemical".
Comment: [Synchrotron radiation](https://en.wikipedia.org/wiki/Synchrotron_radiation)? [Czerenkov radiation](https://en.wikipedia.org/wiki/Cherenkov_radiation)? [Bremsstrahlung](https://en.wikipedia.org/wiki/Bremsstrahlung)? What you are searching for?
Answer: Most light doesn't result from chemical reactions
While there are many chemical reactions that can emit light and many related reactions where the emission is related to chemistry (for example the light from some flames is caused by electronic transitions), most light you see isn't.
An incandescent light bulb emit light because of black-body radiation produced because it is hot (this is not normally though of as having anything to do with chemistry). Fluorescent tubes emit light because of electronic transitions in gases or phosphors (both of which might be considered closer to chemistry because they involve electronic transitions but not the sort that indicate a reaction as they are entirely reversible). LEDs are similar.
A well set up Bunsen burner emits a small amount of light from the chemical reactions occurring in the flame but most well-regulated flames don't emit much light. A candle, on the other hand, has a relatively bright flame. but most of the light comes not from chemical emissions but from the incandescent emission from small soot particles produced from the (deliberately) inefficient burning. Ultimately that heat come from chemistry but most of the light comes from the basic black-body physics of hot objects.
So, in short, most light is physical not chemical.
Comment: I was initially thinking about the light bulb as an example of light emission as a physical change. Because I know that electricity passing through the filament in a light bulb causes a physical change.  Heat and light are produced, yet no chemical change. But the Introductory Chemistry textbook I have presents emission of light as evidence of a chemical reaction (example of glow sticks and fire flies) and no mention that it could also be physical change. But the light bulb made me think otherwise and, thus, I wanted to reach out to others for additional input/confirmation.
Comment: There are a number of places where it might be appropriate to write "*visible* light" rather than just light.
Comment: @user72414 Can you give the name of this book, so others might be warned about it?
Comment: Introductory Chemistry (6th Ed) by Nivaldo J. Tro (pg. 209-210).  It's interesting that the author does point out how gas evolution is not always an indication of a chemical change (physical change of liquid water to gas for example).  The book also stresses that the changes only provide evidence but not definitive evidence (which is true).  But I think it would have been less confusing had the author included something about how emission of light can be from chemical changes AND physical changes.  I guess that will come about in the 7th edition?;-)

Evidence for a chemical reaction


Can a Boggart affect another Boggart?

Question: Can a boggart affect another? Or, more generally, can they affect non-human beings?
I can't quite remember if this is addressed in the books (I've never read Fantastic Beasts and where to find them). If so, what form would they take?
Comment: Why the downvotes? Perfectly legitimate and interesting question
Comment: I never read any canon about this, but 1+ anyway due to possible interesting answers. It might be on pottermore, you should try there.
Comment: Boggarts don't appear in "Fantastic Beasts", presumably because they aren't beasts
Comment: There's nothing on pottermore that answers this question
Comment: I don't have any references, but my guess is that a Boggart can affect some non-human beings that can have fear; but that a Boggart most likely won't affect another Boggart, either because it is immune to its own type of magic, or because it recognizes others of its kind and will not attack them.
Answer: To answer your question:
Probably yes. This was never addressed in the books or elsewhere.
Here are my theory's based on Pottermore, the site said that Boggarts are non-beings..
From Pottermore

The more generally fearful a person is, the more susceptible they will
  be to Boggarts. Mugggles, too, feel their presence and may even
glimpse them, although they seem less capable of seeing them plainly
  and are usually easily convinced that the Boggart was a figment of
  their imagiantion.
Like a poltergeist, a Boggart is not and never has been truly alive.
  It is one of the strange non-beings that populate the magical world,
  for which there is no equivalent in the muggle realm. Boggarts can be
made to disappear, but more Boggarts will inevitably arise to take
  their place. Like poltergeists and the more sinister Dementors, they
  seem to be generated and sustained by human emotions.

I have never read anything canon about this and it is not in any other literature if I am not mistaken.
Here is my theories based on canon:

If a boggart saw itself it could possibly just turn into regular form. I mean when we are alone we behave normally, we don't affect ourselves or anything. So the Boggart could possibly do the same, its in a relax atmosphere so why do anything?
The Boggart could get scared. A lot of animals get scared when seeing themselves(in the mirror), so the Boggart could possibly get scared and die or try to change or something. Or they could get hopelessly confused and just change shape rapidly. Lupin did say that it was best to travel in pairs around them as that confuses them. So maybe having no fear confuses them.
The Boggart could cease living when it gets in the presence of the same matter.
The Boggart could become nothing. I mean the Boggart is always turning into something so I think it would make sense if the Boggart was scared of nothing or becoming nothing, so to scare each other they would turn into nothing.

The theory I put the most stock into is #1. 1# makes the most sense to me, but then I could be wrong. A lot of antisocial(to humans) creatures don't attack their own kind. I mean take Dementors, Thestrals, Unicorns, etc. They don't seem to want to attack each other so that rules out that.
Things they would do around non-human beings.
It is not known. But I would hazard to guess that they would scare them as well. I mean creatures that are sentient or have a humans level of consciousness would be fair game(centaurs, etc). I would say that a Boggarts ability to shape shift is like a Jellyfish's tentacles, a squid's ink, or a dog's teeth's it is purely defensive. And since it has to be defensive against everyone that is capable of hurting it it would affect a dog, whale or other animal. I say hurt, but if that is not possible I would say scare it.
But then again it might do nothing as Pottermore said:

they seem to be generated and sustained by human emotions.
"So the boggart sitting in the darkness within has not yet assumed a
  form. He does not yet know what will frighten the person on the other
  side of the door. Nobody knows what a boggart looks like when he is
  alone, but when I let him out, he will immediately become whatever
  each of us most fears."

Professor Lupin to his Third year class in 1993.
Definition

A boggart is an amortal shape-shifting non-being that takes on the
  form of the viewer's worst fear. When facing a boggart, it is best to
  have someone else along, to try to confuse it, since facing more than
  one person at once would make it indecisive as to what form it must
  take, usually a mixed-up amalgam of the victims' fears. Because of
  their shape-shifting ability, no one knows what a boggart looks like
  when it is alone,........

Things they might do:

Attack each other with something. But I think they are non-being so that rules that out.
Change rapidly.
Explode.
Get scared and flee.
Change into nothing.
Change into their true form.
Answer: "What kills a boggart is laughter". We can infer that boggarts would be scared of laughter (If they had any feelings at all). So if two boggarts came face to face then one either on of them could turn into the sound of laughter thereby killing themselves and the boggart in front of them (this might be why there were never more than one boggart at a time in a particular place). As far as other non humans are concerned we can apply the same logic. Boggart will take the form of the entity's( that is standing in front of it) fear. So if a dementor approached a boggart then the boggart would turn into a patronus. If the boggart approached an animal then the boggart would take the shape of the hunter of that animal and so on and so forth.

Can a Boggart affect another Boggart?


Desktop application automation

Question: I need to automate desktop application i.e Bluetooth PTS tool. But can't find any good way to do. I have no exposure to scripting.
Comment: What operating system? You tagged it Python, does it need to be in Python?
Comment: **Scripting is programming.** Learn programming first. Automating it using convenient programming language is the only way to do it. As Niels said, Python is **excellent** first language for programming beginners, with many free online resources. Good luck!
Answer: Talking about UI testing you can try Sikuli - great tool which uses image recognition.
Also it is a lib which can be installed with Sikuli: Tesseract which allows to grab/recognize text.
It supports Python(Jython), Java, etc.
Answer: AutoIt works great for simple automation tasks.
It doesn't require scripting if you use it in it's basic form of record-play.
Answer: automating any application requires programming experience. The best way to learn automation testing is to start with learning programming language,then frame works using the programming language and finally tools.
Mostly as testers we first focus on tools that help us in picking up automation quickly.
To automate desktop applications, there  are a lot of tools available. Try Sahi,Sikuli,TestComplete(Commercial),AutoIT etc.
As you are new to scripting, I suggest to start with Python language(which is easy to learn and implement) and you can do many things with the available libraries. I would recommend you to use your research skills to identify what exactly you need in test lab to achieve the automation need at hand.
I wish you best of luck in automating.

Desktop application automation


What spells does Arcane Protection protect from?

Question: The spell Arcane Protection means "hostile powers suffer a −2 penalty". Now, what qualifies as hostile powers? Obviously powers like Mind Reading and in general anything with an opposed roll should be affected. OTOH, indirect spells like Smite don't seem to qualify. What about Bolt? Is bolt's damage the spell effect (in which case protection applies), or is it caused by something that was enchanted or called into existence by the spell (the protection probably does not work then)? What about area-effect spells like Havoc?
Answer: Any power being used against the character.
Healing is not a hostile power, so would not be penalized by arcane protection, but lower Trait, stun, entangle, havoc, bolt, burst, blast, puppet and most other powers would be hostile.
GM adjudication is required for some corner cases. Such as the shrink component of growth/shrink. It is possible that shrink could be a beneficial power for infiltration, escape, disguise, or a number of other uses. It is equally possible that it could be a hostile power when used by a foe to make the character weaker during combat.
Similarly, mind link could be a beneficial power used to communicate with allies. Or mind link could be a hostile intrusion to steal the character's thoughts. GM adjudication is required for such cases.
It's important to note that the Savage Worlds rules are consistent about marking rules terms (other than Action). Hostile has no markings to tie it to a technical definition in the rules (it is not capitalized, italicized, bold, underlined, or otherwise marked as a rules term), so hostile is being used in the common form.

adjective
      unfriendly; antagonistic.

If the power use is "unfriendly" or "antagonistic" then arcane protection protects from it.
As for non-power "magical" effects, like dragon breath weapons, GM adjudication is required. One creature's breath weapon may be purely magical while another creature's breath is purely scientific - but Savage Worlds trust the GM to make and track such distinctions.
Edit: In the case of area effect powers, the official answers recently clarified that the arcane protection characters can be unaffected by a successful power. In the case of havoc, a total of 4 or more successfully places the blast template but the total is reduced by the arcane protection (-2 or -4, depending) to determine the effect on the protected character. If the modified total is less than 4 then the protected character is unaffected by havoc. If the modified total is four or higher then the protected character is affected and needs to roll Strength (with -2 if the modified total is 8 or higher).
In the case of damaging powers, like smite, the second clause of arcane protection is relevant.

If the power causes harm, damage is also reduced a like amount.

Because smite makes the weapon attack a magical effect, the final damage of the attack is reduced by arcane protection.
Comment: Can you please elaborate why Havoc (or other area-spells) are included, but Smite is not (or is it)? In neither case the character is direct target, and in both cases the spell is most often meant to harm the character? If there are more characters to be affected by the spell, some protected, some not, what does it mean that the spell "suffers -2 to affect this character"?
Comment: Added. How to adjudicate the math is outside the scope of your original question, which is why I excluded it. I hope the addition is useful.
Comment: I agree with your point of view, it makes quite a lot of sense. It just makes me think that Arcane Protection is a pretty powerful spell given its cost, but that's another story.
Comment: It's a good power when dealing with magic. It's useless when you're being eaten by a swarm of beetles, shot by a mundane crossbow, falling off a cliff, being swept underwater by a rapid river, or any of a dozen other threats that have nearly killed by caster with *arcane protection*. But when you're being attacked by magic, *arcane protection* is pretty great.


Problem for Procedural Texture of Donut

Question: I am trying to make a procedural texture for donut, I want the white dots ( sugar ) to be only on top instead of all over the donut, How can I do ?
Comment: weight paint maybe?
Answer: To get a mask of the top of the model, you can use the Normal output of the Texture Coordinate node. This gives a map of colors -1 to 1 along the X Y and Z axis. You can use a separate XYZ node to use only the Z axis, which can be used as a mask of the top of the model.

This gives a nice result

I used the Subtract node to control how high the mask was on the donut. Because the output from separate XYZ is a black and white image, you can manipulate it easily.

Then I added the Sugar texture onto black using the Z Normal as a mask, giving a black and white texture with the white dots acting as sugar.

Problem for Procedural Texture of Donut


Why isn't my periwinkle flowering?

Question: Here is my periwinkle. I watered it twice a day. Its hot weather here it Bangladesh. This plant is producing a lots of seeds but no flowers.
Comment: What kind of [periwinkle](http://en.wikipedia.org/wiki/Periwinkle)? You wouldn't happen to have a picture for us? Welcome to the site, btw.!
Answer: Depends which periwinkle you've got - there are two plants that are often called periwinkle. The first is Vinca (V. major or V. minor) and this one is a sprawly perennial which does well in shade, and flowers in early to mid spring. If this is the one you have, its likely its done flowering for this year, in which case, pull all the stems up into the air and chop them off to about 4/5 inches from the ground. This may induce a bit more flower as the stems grow again, or you'll get some more around autumn - just not so many as in spring.
The second periwinkle is Catharansus rosea - this is usually treated as an annual and flowers from spring through to summer. If this is the one you have, and you've only recently planted it, it will need frequent watering until its established, so if its short of water, that might be why its not flowering. Cut off spent flowerheads to save the plant putting energy into producing seed.
If you've recently planted the first type, Vinca, again, that will need watering during dry spells till its settled in, but more to keep the plant thriving rather than inducing further flowering now.
UPDATED ANSWER;
Now you've added a pic, I can say its Catharansus rosea - this plant prefers full sun, or half a day's sun at the least - without that, it flowers less readily. Your picture is out of focus in the centre of the top 3 leaves, where I can see what might be either seed pods or buds for flowers, hard to tell. Bear in mind that, for your plant to have produced seeds, it must have flowered, one follows from the other. If those are seed pods in the centre and not flower buds, then you've obviously had flowers recently.
If you've had this plant a while, just check its not root bound and needs a bigger pot - its not looking particularly lush and healthy.
Comment: Bamboo have u seen my morning glory flower? It has bloomed. Its so big !!

Why isn't my periwinkle flowering?


Is there a Tor-Browser-Bundle for the armhf /Beaglebone Black?

Question: Trying to bring it up on the Beaglebone Black running Debian. Loaded the bundle for debian but it fails with a code of 126 and seems to be stalled at running firefox. IceWeasel, for example, runs fine on the Beaglebone Black but I'm guessing the firefox in the bundle is a different build. Or maybe it's something else...
Answer: Beaglebone is ARM architecture, there is no build of the browser bundle for that.
You need to install Tor and configure your browser yourself, you can get the same addons and such as the browser bundle has, to get as close to the bundle's setup as possible.
Comment: OK. Well, I had already built tor from source and configured IceWeasel but given the warnings about using anything other than the Browser Bundle ( and my lack of confidence that I could replicate the bundle's setup) I was hoping for a native version. I have a bridge and a hidden site running on the Beaglebone, maybe I'll just do my browsing elsewhere.
Comment: This is a bit of a silly suggestion, but if your Beaglebone is only for Tor browsing you might install Android with Orbot, give it superuser access, and tell it to route all traffic through Tor (if you're not comfortable dealing with iptables and what not in Debian, the Android version may be a bit more user friendly).
Comment: I don't know about the Beaglebone Black, but I know for sure that my system isn't going to tolerate the notion of building an entire firefox build -- I have 2GB of RAM and 4 x Cortex A7 1.3GHz cores.  According to the firefox build instructions, you need 8GB RAM and a 64-bit OS.  Does anyone have a cross-compilation setup they can use to build an appropriate package?


Any idea for two transmitters one receiver wireless communication module?

Question: I am undergraduate electrical engineering student. I have a project for Analog Electronics course. I should design a system which tries to equate the heat of two stations with a controlled cooler with wirelessly received heat information. The system basicly will look like as the picture in attachments. The confising point is that I am supposed to implement two transmitters one receiver wireless communication module. And the minimum distance should be at least 1 meter. What do you think to best way for wireless communication for this project. There may be lots of choses lik using two speaker and a microphone or using two laser and an LDR. I tried to use two laser (with changable duty cycle respect to changing temperature). I can transmit that square wave to my receiver (LDR). But I could not find a solution transmitting two information to a single receiver. Any idea?
Comment: Sorry for that, it was my first post. I've just edited
Comment: Is there a reason why you can only have one receiver?  Can you just have separate receivers?  What is the controller?
Comment: Using a single receiver is indicated in he project definition. So it is forbidden to use more than one receiver. Controller basically should do that, if the second station's is hotter than first station the cooler should start to work and cool the second station. The main aim is equalize the heats of the stations.
Answer: There's lots of different ways multiple transmitters can share a receiver or a medium.
Classically, we organize these in four categories:

Time-based multiple access (the different transmitters simply don't transmit at the same time)
Frequency-based multiple access (information is coded onto oscillations of different frequency, which don't interfere with each other)
Spatial multiplexing (the receiver is able to tell signals coming from different directions apart)
Code multiplexing (You find sets of functions which are orthogonal under some dot product, and each of your transmitters uses a different one. The superposition of multiple signals can be losslessly deconstructed into the original data by applying that dot product)

All these methods work with any signal – they're most prominently used in digital radio communication, but there's no reason why Code Division would not work for e.g. infrared comms. In fact, I think there's multiple IR data communication standards that do that. And, for example, infrared remote controls avoid interference with normal sources of light (like lightbulbs) and other infrared-based comm systems by employing basically frequency division principles.
I'd drop the laser idea – a laser typically generates a focussed beam, and you don't need that – a simple LED that illuminates a larger region is much easier to handle.
Comment: But especially at ranges of 1 meter, it will be extremely difficult for a newbie to detect such a low level signal from an LED..
Comment: @WhatRoughBeast aside from that newbie absolutely having the chance to simply use eg. existing infrared remote ICs? Also, no, it's really not that hard for an EE undergrad to come up with a digital or analog filter that would be able to allow for frequency multiplex. The CDMA approach would in fact not be much harder.
Comment: (of course, assuming the EE undergrad student already had some minimal lecture on signals and systems – but from the project description, it would seem that way)