Can I write a smart contract to access a database and verify details of a student?

Question: I have to write a smart contract to create a degree certificate of a student in the University. To generate the certificate, I have to clear all the dues in my University's library, Sport's department, Hostel and Department.So, I have to access the database of a students to verify the student's details and his dues and if everything is fine, I have to sign the verified details with the respective department's private key.Likewise ,it has to happen in every department. After all department's verification is done, I have to write a smart contract to generate a degree certificate and place it in public blockchain so that anyone can verify. My doubt is whether this assignment is possible or not using smart contracts.
Please help me. Any help would be appreciated.Sorry if I have asked something ridiculous.
Thank you
Answer: Most of the things you describe have to be performed outside the blockchain. The blockchain has no access to external systems (such as databases).
So your process could go something like this:
1) Process all the required things outside the blockchain
2) Use a previously deployed smart contract to issue a degree to a student with some form of identification (social security number?). The degree can't be anything big, just a few strings and numbers - you can't upload a PDF for example.
3) The degree stays in the smart contract where everyone can see it.
Your biggest problems will be:
1) How to identify the student in the blockchain. Using a SSN might sound like a good idea but you can't use that as everyone would see it there.
2) What information you can input to the smart contract as a "degree". Ethereum is very bad for storing lots of data - you might want to use something like IPFS to store the actual data.
3) Other problems not related to the blockchain: how can you use the private key of the departments, what would you sign and where, how would have access to settle all the accounts etc etc


Downspout repair (with the 6 inch section)

Question: I cut a 6 inch section out of a 3x4 inch downspout. How can i put it back together?  I was installing a rain diverter and placed it too high. Thought about using 2 adapters but having trouble finding them at that 3x4 size. Should i just buy a whole new downspout?
Answer: You can crimp your own ends with a crimping pliers available at most home stores in the heating duct work section or hand tools section. They are simple to use and not expensive to purchase. When using these for splicing you will lose 1 1/2" - 3" of overall length though so keep that in mind when deciding whether to replace the whole downspout or repairing it.
Answer: You'll need the fluted end so you can lap the sections properly. This will probably require that you purchase a new length of spout.


Razer Kraken with Pi 2

Question: Does the Razer Kraken work with a Pi 2? Is the sound card compatible or not?
Razer Kraken page
Comment: I suggest if you have the device to plug it into the Pi and see what happens. I suspect the drivers required to make the sound over USB work are not available for the Pi.
Answer: No.  From  the "TECH SPECS" section of the web page:

PC / Mac with USB port
Windows® 10 / Windows® 8 / Windows® 7 / Mac OS X (v10.8 - 10.11)
At least 100MB of free hard disk space

The last two points in particular imply this device requires a lot of software, which has exactly zero chance of being usable in any way, on any model of Pi, using any operating system.
Since the connector is USB and not a normal 3.5mm stereo jack, it could not be used as a normal set of headphones with the Pi's built-in sound system either.
Comment: how to know which microphone suit pi 2 driver? thanks
Comment: There's no microphone jack on any of the Pi's so you will have to get a USB "soundcard".  They're an inch or so long, usually cost $5-20 USD and have two 3.5mm jacks, one out (green) one in (pink) like traditional soundcard ports.  *Most* of those should work out of the box without requiring any driver installation, since USB sound is standardized.  But a device that requires 100 MB of free space almost certainly uses some non-standard proprietary software, which you will not be able to install in this context.

Razer Kraken with Pi 2


What is the origin of the surname Griffin?

Question: Different websites give conflicting opinions regarding this surname. What is the origin of Griffin when used as a surname?
Answer: Griffin is often incorrectly described as being simply of Welsh origin. For example:
http://genealogy.about.com/library/surnames/g/bl_name-GRIFFIN.htm
http://forebears.co.uk/surnames/griffin
In reality if we look at phonebook data, it is clear that Griffin is primarily of Irish origin.
<code>Dublin Ireland, 216/1,271,000 = 0.02%
Clare Ireland, 87/117,196 = 0.07%
Kerry Ireland, 201/145,502 = 0.1%

Cardiff Wales,  22/341,000 = 0.006%
Bangor Gwynedd Wales 2/18,808 = 0.01%
Wrexham Wales  2/65,692 = 0.003%

Birmingham England 40/1,074,000 = 0.004%
Leeds England 22/474,632 = 0.004%
Southampton England 4/253,651 = 0.001%
Manchester England 16/514,417 = 0.003%
</code>
I used the Eir phone book for Ireland and the BT phone book for Wales and England. I've divided the number of entries in the phonebook by the local population when arriving at the local percentage with the surname.
Additionally, note that many of Wales' and England's Griffins are of Irish extraction, due to large levels of migration from Ireland to Britain. Of course, the surname Griffin may well have unique sources in both Wales and England. For example, Griffin is probably an alternative spelling of Griffiths in some instances.
Here is a map showing the distribution of Griffin per capita for Britain and Ireland:

Source: http://www.celticfamilymaps.com/?link=Griffin&q=node/2
The surname Griffin has numerous sources in Ireland. For example, in Kerry the name comes from the Gaelic surname Ó Grifín while in Clare it comes from Ó Gríofa.
See also: Griffin Surname Maps
Comment: Modern geographical repartition can be a tool, but is not a sole indicator of a name's origin. For example if a welsh person named Greffin moved to south-western Ireland and had 10 boys, all Greffins, and that they themselves had lots of kids, etc,,, you could have the repartition shown in the image but still a name of Welsh origin. (That's just an example).
Answer: According to the Dictionary of British Surnames:

Griffin F/N A diminutive of Griffith; or a nickname for a fierce
  person ME griffin (gryphon, a heraldic beast); Irish: Anglicized form
  of Gaelic O' [descendant of) Griobhtha ('gryphon'). Gtiffing is a
  scarce scattered variant.

Personally this is my go to book for Surname origins.
Answer: The usual origin is a patronymic based on a diminutive of the Middle Welsh name Gruffudd, either transmitted directly from the Welsh, or via Breton immigrants who came over to England with William the Conqueror. (See Reaney & Wilson: A Dictionary of English Surnames, s.n. Griffin; for example Osbertus filius Griffini 1153-68.)
The same Welsh name is the source of the Irish surnames Grífin and Ó Grífin. (See Woulfe, Irish Names and Surnames s.n. Grífin: https://www.libraryireland.com/names/g/grifin.php.) However, there are other Irish surnames that end up looking and sounding like "Griffin" in English, and some of them are more likely derived from an Irish given name Gríobhtha, which Woulfe derives from words meaning "gryphon-like, fierce warrior" (https://www.libraryireland.com/names/og/o-griobhtha.php).
Either way, however, the surname Griffin originates as a patronymic or relationship-based byname, naming the father or other ancestor of the bearer.
Answer: Due to Y DNA testing, we now (since 2016) know that the Griffin surname in Ireland has several different origins:

O'Griffy in County Clare with an Irish Y haplogroup
Griffin in County Clare with a Lowland Scots Y haplogroup
Griffin in County Kerry with a Highland Scots Y haplogroup
Griffin in County Galway with an Irish Y haplogroup
Griffin in County Donegal that, to my knowledge, haven't yet been tested
Griffin from Welsh and English origins

The Griffins with a Scots haplogroup are probably descended from gallowglasses who left Scotland before surnames were fixed then received Griffin as an epithet for a warrior in Ireland.
The County Galway Griffins may be descended from the County Clare O'Griffy family.
It will be interesting to find out whether County Donegal Griffins have an Irish or a Scottish Y haplogroup.

From comments:
I don't think Y-DNA genealogy of Irish Griffins has made it into peer review journals yet but raw data can be seen in the Griffi(th)(n)(s)(ng) group at FTDNA.
Comment: Welcome to G&FH:SE.  Citing sources to support your assertions would greatly improve your answer.
Comment: Thanks and I agree.  I don't think Y-DNA genealogy of Irish Griffins has made it into peer review journals yet but raw data can be seen in the Griffi(th)(n)(s)(ng) group at FTDNA:
https://www.familytreedna.com/groups/griffith/about/background
Comment: I've taken the liberty of adding that to your answer.  I hope that's OK.


Can I make it always night time?

Question: I would like my world to be always night time, but there appears to be no option to change this. So is it possible to make it always night on my world?
Answer: As of 0.16.0, you can change the time to night one time by
/time set night

To make it night constantly, (or if you are on lower versions then 0.16) you can use a mod:

Simple Commands mod

Simple Commands mod adds a few new, simple text commands. Now, among the "standard" commands will have a new command that has the effect to your character. In total there are 23 different effects, such as speed and invisibility - it is the effects of potions. With these commands, you can affect the gamegame mode, weather, time, deceleration time, set the level of experience, and more in MCPE 0.11-0.15.7

pocketInvEditor mod (available on Google Play)

PocketInvEditor is an inventory editor for Minecraft Pocket Edition. With this tool, you can give yourself more blocks and items without writing a single hexadecimal digit or connecting to a computer.

the mod also allows locking the day/night cycle
Answer: It seems that as of the 1.1 update "The Discovery Update" (June 1st, 2017), it is possible with the gamerule doDaylightCycle. The command:
/gamerule doDaylightCycle false

will stop the cycle from day to night and night to day.  Just use it when it is night.  I believe that will do the trick.
Comment: If this answer is more helpful to you than the current accepted answer, @sun-solar-arrow, you can mark it as accepted instead.
Comment: @Fabian ok, I'll accept this answer
Comment: Happy to help!  I was looking for this solution too and this was one of the first google results.  Figured I'd post what I found to help you, and anyone else looking for this solution as well :)
Answer: Not possible without a mod. This is a good one:
http://mcpeuniverse.com/mods/always-night/
Answer: Get yourself a repeating command block and type in /time set night and let it be active, but run /gamerule commandblockoutput false first before you can activate it. If you don't run it, you will get bugged from the amount of lines outputted by the command block (unless you're okay with it).

Can I make it always night time?


How old is Romeo?

Question: While answering a different question, I wanted to find out Romeo's age in the Shakespeare play Romeo and Juliet. It's well known that Juliet is 13, and generally assumed that Romeo is older (hence the occasional modern-day accusation that he's a paedophile), but what's the actual evidence for the latter? I've looked up about this online and found various places saying essentially that we don't know Romeo's age, but I'd be interested to see all the textual (or extratextual) evidence regarding this.
What, if anything, do we know about Romeo's age?
Answer: Shakespeare's main sources for Romeo and Juliet were

Arthur Brooke's narrative poem The Tragical History of Romeus and Juliet (1562) and
William Painter's prose version of the story in the second volume of The Palace of Pleasure (1567).

There is no evidence that Shakespeare read any of the French or Italian sources for this story, such as Pierre Boaistuau or Matteo Bandello.
In Brooke's narrative poem, Juliet is sixteen years old ("At sixteen years I first did choose my loving fere," she says), while in Shakespeare's play, her mother says, "[s]he's not fourteen" (Act I, scene 3).
Brooke does not mention Romeus' age. Near the beginning of the poem, he introduces him as

One Romeus, who was of race a Montague,
  Upon whose tender chin, as yet, no manlike beard there grew,

so he's probably not much older than Juliet.
According to Painter, who follows Boaistuau, he is

of the age of .20 or .21 years

Both Brooke's and Shakespeare's Romeo seem younger than this. Based on Romeo's and Juliet's relative maturity, I would argue that Shakespeare's Romeo is not much older than Juliet. In the introduction to the New Cambridge Shakespeare edition of Romeo and Juliet (second edition, 2003), G. Blakemore Evans writes,

Critics have often pointed out that Juliet is a stronger personality than Romeo and that she wins through an almost frightening maturity more quickly. We sense this in her poised and playfully serious exchange with Romeo at their first meeting (1.5) and it is underscored in the famous window scene (2.2), where she shows herself more thoughtful, prudent and realistic than Romeo, though no less deeply engaged, in sensing the tragic threat involved in such 'sudden haste': (...)

(He then goes on to quote Act II, scene 2, 116-220: "Although I joy in thee, ...")
Comment: One notes that it was perfectly normal in those times for a man not to grow a beard until he was in his twenties.  Puberty was later owing to sparse diet and harsh conditions.  So he could easily be several years older than Juliet.
Comment: @Mary The impression of Romeo's young age is not merely based on his lack of a beard; there are many male lovers in Shakespeare's plays but none seems as young and impetuous as Romeo.
Answer: We don't know much. About the only concrete data is that he's described as a "youth". We also know that his parents and Juliet's parents are social peers, which implies that they're of roughly similar age, but leaves room for him to be considerably older without violating the text.
I think his flightiness and moodiness makes an interpretation of "mid to late teens" most justified, but I think you could justify a pedophile interpretation if you thought it made an interesting performance. I suspect that it would not, but I suppose it would be up to a director to try it and find out.
There is a more interesting question in the age of Paris, who is often portrayed as considerably older and a figure of disgust, but that isn't a requirement of the text. It is also possible to portray him as only slightly older and a sympathetic figure, one whom Juliet might have made a tolerable match were she not overcome by what she imagines to be true love. Setting up Romeo as a much older man could have some interesting implications for his unjustified murder of Paris.
It is noteworthy, I think, that Juliet is considerably younger than women were usually married in England at the time. Shakespeare's wife was in her late 20s, and that was much more the custom. Marrying Juliet off at 12 or 13 would not be impossible, but definitely unusual. Shakespeare often used foreign settings to gain some distance from everyday British customs. Romeo and Juliet are characters of exaggerated emotion, which fits well with the behavior of young teens, and less well with more mature characters.
Comment: I don't know the age of marriage in Italy at the time... but neither would most of Shakespeare's audience, and probably not Shakespeare either.
Comment: Was she also considerably younger than women were usually married in *Italy* at the time?
Comment: Also, this answer might be improved by comparing Shakespeare's play with the R&J story he ripped it off from. I've read that in that earlier story their ages were explicitly given.
Comment: @Randal'Thor we know that her father thinks it's too young, and that sixteen-ish would be better.

How old is Romeo?


Fuel mass required to heat a room

Question:
A room in a house measures 3.7 m × 4.7 m × 4.0 m. Assuming no heat or material losses, how many grams of natural gas (methane, CH4) must be burned to heat the air in this room from 15.0 degrees C to 25.0 degrees C. Assume that air is 78% N2 and 22% O2.
Comment: [Welcome to chemistry.SE!](http://chemistry.stackexchange.com/tour) If you have any questions about the policies of our community, please visit [the help center](http://chemistry.stackexchange.com/help). This is a [homework](http://meta.chemistry.stackexchange.com/q/141/7448) question. We have a policy which states that you should show your thoughts and/or efforts into solving the problem. It'll make us certain that we aren't doing your homework for you. Otherwise, this question may get closed. Please [edit] in your full reasoning or thoughts on this.
Comment: Related: [How much does a light heat the air around it?](http://chemistry.stackexchange.com/q/35534/7951)
Answer: In the first step, we calculate the energy that is needed
to heat the room by ten degrees.
To do that, you need the heat capacity of air:
$C_\text{air} = 1210~ \text{J} \cdot \text{m}^{-3}\cdot \text{K}^{-1} $
This is the energy that is needed per volume unit to increase the temperature by one Kelvin (i.e. one Degree).
To increase the temperature by $\Delta T = 10 ~\text{K}$ for a volume of $V_\text{room}=\text{3.7 m}\cdot\text{4.7 m}\cdot\text{4.0 m}=69.56 ~\text{m}^3$  you would thus need an energy of
$$ E = C_\text{air}\cdot  V_\text{room} \cdot \Delta T =
1210~ \text{J} \cdot \text{m}^{-3}\cdot \text{K}^{-1} \cdot 69.56~\text{m}^3 \cdot 10~\text{K} \approx 842~\text{kJ}$$
We can now calculate the amount of methane that needs to be burned to get that energy. For this, we take the enthalpy of combustion $\Delta H_\text{comb}$:
$$\Delta H_\text{comb} = −882.0 ~\text{kJ/mol} \equiv 55.1~\text{kJ/g}$$
Thus, we calculate the mass of methane to be
$$ m_\text{methane} = 842/55.1 ~\text{g} = 15.3~\text{g}.$$
So about 15 g of methane would be needed to increase the temperature of that room by 10 degrees. By the way, 15 g methane correspond to a volume of about 20 L.
Comment: Is that the upper heating value of methane or the lower heating value?
Comment: The upper heating value.

Fuel mass required to heat a room


how can I add more character space to the home page tagline in big cartel?

Question: Does anyone know how to edit the CSS in a Big Cartel theme (specifically the FOUNDRY theme) to allow for more text in the home page tagline? Currently, you can only type about 100 characters. I would like to be able to write a bit more (like a small paragraph about the shop and current product overview).
Answer: The text box is limited to 100 characters, so to edit that you'll need to change the code the Advanced > Home section of the Customize Design area. Find this code at the top:
{% if theme.home_tagline != blank %}

    {{ theme.home_tagline }}

{% endif %}

And replace the {{ theme.home_tagline }} with your own text.


How would one share data between a parent and forked child process in Haskell?

Question: How would I even go about forking a child process using Haskell in the first place?
Also, if pipes are an obvious solution to the data sharing question - is there any other way to do it besides using pipes? I'm familiar with the use of shared memory segments in C (the shmget, *shmat, shmdt and shmctl functions). Could Haskell be able to imitate this? If so, how?
I'd be very grateful for any help you could spare.
I must admit I'm very much new to functional programming languages, even more so when it comes to Haskell. So forgive me (and please correct me) if I said something silly.
Comment: Both answers here seem to be parsing "forking a child process" as "forking a user land thread". But given other context in the question this does not seem right.
Answer: Better yet, use Software Transactional Memory - that is, TVars and TChannels.
Will recommend the same book, different chapter: http://book.realworldhaskell.org/read/software-transactional-memory.html
Here is a good small example of this technique in action: http://sequence.complete.org/node/257
Answer: The OP asked about communicating with a subprocess, not a thread.  For that, pipes are a perfectly fine way of doing it.  You can also call the C library function directly from Haskell if you want to, although that could get tricky.
This question has a better answer over here: Is there some standard Haskell library dealing with process communication?
Answer: use MVars or Channels.  See chapter 24 of RealWorld Haskell:
  http://book.realworldhaskell.org/read/concurrent-and-multicore-programming.html
Answer: If you want to actually fork a process, Unix style, you need to use forkProcess as given by http://hackage.haskell.org/package/unix-126.96.36.199/docs/System-Posix-Process.html
In this case, MVars and TVars do not do interprocess communication, so you cannot use them to do IPC. All standard techniques for IPC (pipes, sockets, etc) still work. If you want something more high-level, check out Cloud Haskell http://www.haskell.org/haskellwiki/Cloud_Haskell


Grakn Error; trying to load schema for "phone calls" example

Question: I am trying to run the example grakn migration "phone_calls" (using python and JSON files).
Before reaching there, I need to load the schema, but I am having trouble with getting the schema loaded, as shown here:  https://dev.grakn.ai/docs/examples/phone-calls-schema
System:
-Mac OS 10.15
-grakn-core 1.8.3
-python 3.7.3
The grakn server is started. I checked and the 48555 TCP port is open, so I don't think there is any firewall issue. The schema file is in the same folder (phone_calls) as where the json data files is, for the next step. I am using a virtual environment. The error is below:
<code>(project1_env) (base) tiffanytoor1@MacBook-Pro-2 onco % grakn server start
Storage is already running
Grakn Core Server is already running
(project1_env) (base) tiffanytoor1@MacBook-Pro-2 onco % grakn console --keyspace phone_calls --file phone_calls/schema.gql
Unable to create connection to Grakn instance at localhost:48555
Cause: io.grpc.StatusRuntimeException
UNKNOWN: Could not reach any contact point, make sure you've provided valid addresses (showing first 1, use getErrors() for more: Node(endPoint=/127.0.0.1:9042, hostId=null, hashCode=5f59fd46): com.datastax.oss.driver.api.core.connection.ConnectionInitException: [JanusGraph Session|control|connecting...] init query OPTIONS: error writing ). Please check server logs for the stack trace.
</code>
I would appreciate any help! Thanks!
Answer: Nevermind -- I found the solution, in case any one else runs into a similar problem. The server configuration file needs to be edited: point the data directory to your project data files (here: the phone_calls data files) & change the server IP address to your own.


Can I edit a PCB in Altium, if I only have the Gerber files?

Question: I only have the Gerber files; can I open them in Altium, and somehow generate a .pcbdoc file that I can work with (route signal, pour copper planes, place components, etc.)?
Comment: Let us know when you find one, please.
Comment: Gerber files provide you with several layers of routing of a circuit and is mainly the end product of schematic design and PCB design. If you're looking at going "the other way" then it'll get very impractical and time consuming, not worth the trouble. Better to just start from scratch really ...
Answer: Not directly in Altium, however it's bundled with Camtastic which can be used:
<code>This is the simplified process.

File ► New ► CAM Document
File ► Import ► Gerber(s)
File ► Import ► Drill (Browse to drill file)
If you don't have a drill file you can create one by placing a via on a new PcbDoc then export it as NC drill
Tables ► Layers (assign the layer types)
Tables ► Layers Order (Confirm the logical & physical Layer order is correct)
Tables ► Layers Sets (ensure your drill span shows up here)
Tools ► Netlist ► Extract
File ► Export ► Export to PCB
</code>
Then a lot of work if you want it to be a normal set of Altium files.
Comment: That is already half way done! I gotta change to Altium.
Comment: @jay You can get a free trial and see if it's actually practical in your particular situation.
Answer: It isn't as simple as importing the files and editing them directly - Altium cannot, with gerber files alone, determine information such as which pads make up a single component footprint.
Altium does have a help page detailing how you can reverse engineer from the gerbers, though.. See this page for their documentation, as it's pretty involved.
Comment: Generally one can tell a pad vs trace by the soldermask or lack thereof.
Comment: @crasic I do agree that was a terrible example. Perhaps a better one would be ability to tell which pads/silkscreen elements make up a single footprint?
Comment: This is true, and a huge limitation of Gerber format even for its intended purposes. However modern production format ODB++ files is also supported by the reverse engineering tool of Altium. This is improvement on current process where  I think almost everywhere common practice is to provide cad files and Gerbers , so generally you will have access to that data in some other format. Exception is  when dealing with PCB fabrication only, that is, without assembly.
Answer: Altium PCB does not have a gerber import facility, it is possible to use an external tool and convert to DXF (for example using FlatCAM).
Comment: Welcome! Can you elaborate on your answer (e.g. by directing readers to the right menu option to start the process)? My last recollection of KiCAD (early 6.0) was that it had its own .kicad_pcb format that could be *exported* to Gerber, and it had the ability to *view* gerbers, but not edit them.
Comment: I just skimmed through the documentation. But I believe it may be possible using **Gerbview -> Export to Pcb Editor**, and then using **Pcb Editor** to edit the data. @RobAnderson can you confirm and/or elaborate on this?
Comment: Yes that is the way it works, use Gerbview->export to pcb editor. I just used it yesterday for editing a gerber. Of course it is only for editing the gerber, there are no links to a schematic representation. I used it to change the board shape.
Comment: @RobAnderson I didn't dislike your initial proposal of using KiCAD. The only issue was that it didn't contain much information. IMO you can still promote KiCAD, but then describe how exactly it can be done using KiCAD. That would be worth an upvote from me.
Comment: I am more used to Altium, I have used it for years. But it was easy to use Gerbview to convert the gerbers to a file that could be edited in Kicad. I spent quite a while trying to do this in Altium but didn't get anywhere. I have not used KiCAD for anything before this.
Comment: Gerbview is part of Kicad, I noticed I didn't mention this. FlatCAM is a separate program. These programs are open source and run on Windows or Linux.


Deferred 'lazy' loading of YouTube video content and SEO effect

Question: My site uses a fair amount of plugins / active content from YouTube videos, Facebook and SoundCloud.  The effect of these adds a fair amount to the load time of the page.
I developed code which populates a DIV with the embedded Iframe after the page is loaded, using the Jquery .ready() event.  It is nothing clever, but it makes a big improvement to the page load time:

From an SEO point of view, Google likes video content as long as it relates to the page content.  My code relies on Javascript to load the video after the page has loaded.  I know the Googlebot uses Javascript, but is this method safe to use and will it affect my SEO?
Answer: In general Google won't index stuff rendered with JS. The code for your video is fine since it helps to reduce page load time.
You can try including content that is relevant to the video within the #video element. This will help provide some SEO context around your video and help anyone without JS turned on.


LTspice 2 grounds for AC PWM control by mosfets

Question: I'm working on a AC PWM controller with 2 mosfets. It took me a long time to get this to work in LTspice but i still can't get it to work. I send pulses to the mosfets to generate the PWM modulation on the AC side. Everything works until i want to implement an optical galvanization. For this i would need to define 2 grounds in LTspice and this is the point where things start to get weird. I've already looked on the internet for more information about this topic. In LTspice you can only define 1 ground node, this is the reference voltage from where LTspice starts to calculate. If i want to use a second ground i have to use the COM node. I tried to do this but it still doesn't work. I know my mosfet part works and i know my opto coupler part works. When i try to connect both LTspice starts to behave strange. I've connected the COM node and GND node with a 99M resistor( this was a solution i found online) but this doesn't work at all. How can i get this simulation to run? Attached are 2 print screens. The first is a working mosfet switch, the second is with the opto coupler.
I hope somebody here can help me to get this to work.

Thank you all!
Comment: you need to simulate everything with one GND... there is no galvanic isolation in spice.
Comment: What do you hope to achieve with the 2nd schematic? Do you really intend to drive two power MOS with an optocoupler in series wth a `100k` resistor (connected to mains, by the look of it, even if rectified)?
Comment: @aconcernedcitizen  yes, the 100K and 10K resistor act as a voltage divider so my opto doesn't blow up. It's not going to be a product that i'm going to sell but i don't see a reason why this won't work? I might need to choose other voltage divider resistors that can deliver more current.
Comment: @MichielReyntjens Not only the optocoupler is strongly dependent on the current collector, but the time constants -- even without the transistor -- will be in the tens of microseconds, if not more. Think of what that will do to the power dissipation. Try reading [this](https://www.ti.com/lit/slua618) and other similar documents about this, because your words "*i don't see a reason why this won't work*" are on the worrying side.
Comment: @aconcernedcitizen i didn't thought about this. Rise time according to spice is 50ns so that shouldn't be a problem. Fall time is 250micro seconds so i should find a solution for that.
Answer: You need to use only one GND in LTSpice.
This makes it sound like a limitation, but it isn't. In the real world the grounds will be connected, just via a very high impedance link.
I have often done LTSpice simulations for isolated DC-DC converters, where you have the same issue: two isolated grounds.
The fix for this is to remember that LTSpice simulates the real world with models. In the real world the two side are linked via a very high resistance, and a very small capacitance. So, for the lack of any concrete numbers to use, I use a 1Meg resistor in parallel with a 1nF capacitor to link the two grounds (number are open to some debate, as I've been given some, I've updated these numbers used here). Then I call one ground "iso_gnd" or something so that I can use that as the ground reference for my probes.
So I have a V_IN and GND_IN, then a V_OUT and GND_OUT. I connect the proper ground to GND_IN, connect GND_OUT to GND_IN via a 1Meg resistor in parallel with a 1nF capacitor. And simulate. To get the output voltage, I plot the voltage of V_OUT minus GND_OUT.
Comment: Just a note, this is the behaviour of SPICE since 40+ years ago: everything needs to be referenced to the global node zero (`0`). Also, no need for such extreme values (`1G || 1p`), when even in real SMPS you find connections of `1Meg || 1n` (or similar) between  primary and secondary.
Comment: @aconcernedcitizen I used those figures as a finger in the air, as you've given something with a bit of backing, I'll update it.


intermittent wifi/LAN client connection issues with dhcpd and bind9 on ubuntu server

Question: I have a soho LAN with a gateway server running isc-dhcpd-server and bind9 on one NIC 192.168.0.3 for the LAN & wifi.
The client connects to the LAN but often can't see the server on 192.168.0.3 even to ping it.
I can see the client sets up its IP address with DHCP and on some clients e.g. the mac laptop, /etc/resolv.conf contains the correct name-server 192.168.0.3 entry.
On my linux laptop, when it's not connecting, the resolv.conf entry is not correct.
At some point from a minute to 30 mins later, the client will suddenly connect and for a while all will be fine.
Meanwhile the internet connection on the gateway server is consistently OK.
Here's the server's dhcpd.conf:
subnet 192.168.0.0 netmask 255.255.255.0 {
  range 192.168.0.4 192.168.0.250;
  option subnet-mask 255.255.255.0;
  option domain-search "localdomain";
  option domain-name-servers 192.168.0.3;
  option routers 192.168.0.3;
}

log-facility local7;
default-lease-time 600;
max-lease-time 7200;
authoritative;
option domain-name "localdomain";
option domain-name-servers gondolin.localdomain;
ddns-updates on;
ignore client-updates;
update-static-leases on;
ddns-update-style standard;
update-optimization off;

include "/etc/dhcp/ddns-keys/rndc.key";
# must be same as "/etc/bind/rndc.key";

zone localdomain. {
     primary 192.168.0.3;
     key "rndc-key";
}

zone 0.168.192.in-addr.arpa. {
     primary 192.168.0.3;
     key "rndc-key";
}

gondolin.localdomain is the gateway hostname.
I'm not getting any errors in /var/log/dhcpd.log and the lease entries in /var/lib/dhcp/dhcpd.leases look like this:
lease 192.168.0.233 {
  starts 0 2019/11/03 18:00:35;
  ends 0 2019/11/03 20:00:35;
  cltt 0 2019/11/03 18:00:35;
  binding state active;
  next binding state free;
  rewind binding state free;
  hardware ethernet 24:5b:a7:20:26:a2;
  uid "\001$[\247 &\242";
  set ddns-rev-name = "126.96.36.199.in-addr.arpa.";
  set ddns-dhcid = "\000\001\001x\341c*8-]\267\336\210;3d$\376#\203\273P\207\002\375=\3327\035[\241\307\262\374/";
  set ddns-fwd-name = "Sylvies-iPhone.localdomain";
  client-hostname "Sylvies-iPhone";
}

I can't find any errors on the gateway server, nor on the clients in  ubuntu /var/log/syslog or iOS /var/log/system.log files.
Answer: Turns out it was just the wifi access point. I did a power cycle and it was all fine.


Can I update a field using a Lookup in a Flow?

Question: I've read the implementation guide and a number of other resources.  I can't see how to use a flow screen to display an Account's name and Parent Account field, and then have the user select the Parent Account, using the Lookup. Is this not possible?
Answer: Absolutely.    You'll need to do the following after creating your new flow:

Create Screen item in your Flow and make it your "start" item
In the Screen settings, add a field with Input Type = Textbox and name it "ParentAccountSearchTerm" and mark as required.   your users will enter part of the name, or you can default to the current account name.
Now, create a Record Lookup item to Account and add a filter for "Account Name" contains "ParentAccountSearchTerm". Name it "ParentAccountSearchResults"
Create another Screen and add a field  with Type = Dropdown List and name it "SelectedParentAccount" and mark as required.  You will need to assign the ParentAccountSearchTerm to the Choices Settings
Now that you have the desired Parent Account, you can then assign the Account.Id to your Current Account using an Assignment and Record Update Item

you'll have to make sure your flow receives the current accountId as a variable.   to display the name, simply use a record lookup and sotre the result in text variables, which can then be displayed on a screen as "display text"
Comment: I thought something like this would be necessary. I was hoping to use the normal lookup that you get with an SObject field like Account.ParentId. I guess that isn't the *flow* way. Unless another answer turns up.
Comment: Yeah, there's always some tradeoff when things are easier, such as less robust features...


What do you call a person who always wants to make sure about things?

Question: A person who stops themselves to do something because they're not sure yet, so they wait for patterns or for it to recur. Basically what do you call a person who wants to make sure about things before doing anything?
Comment: I call him *maddeningly passive*.
Answer: Your person is meticulous.
The Latin root of meticulous is metus, which means "fear," so it's easy to see how eventually meticulous got its meaning. Someone who's meticulous is afraid of what will happen if they're not careful enough to get every detail right.
source: vocabulary.com
Comment: Does meticulous specifically imply fear of imprecision? I've worked with many people whose work ethic I would describe as meticulous, but who weren't in any way overcome with fear. They were simply devoted to their work. The Latin heritage of the word does not automatically carry over to English. Sinister used to mean "left" in Latin, but the meaning in English has changed completely.
Comment: See also: ad hoc, alter ego, quorum, per diem. Although their meaning evolved naturally and originated from the meaning in Latin (although alter ego is more a misunderstanding than a natural evolution), it no longer applies in the same context.
Answer: I would say they were of a hesitant character.
The OED definition of hesitant, with examples of its use is:
Hesitating; irresolute, undecided; stammering.
1647   J. Trapp Comm. Epist. & Rev. (2 Cor. v. 6)   Not haesitant, or halting, as Hadrian the Emperour was.
1651   R. Baxter Plain Script. Proof 278   Are you not here hesitant also?
1683   W. Kennett tr. Erasmus Wit against Wisdom 14   The delivery of Achilles was rough, harsh, and hæsitant.
1856   R. A. Vaughan Hours with Mystics (1860) I. iii. i. 52   The hesitant and conflicting conjectures of Philo.
Comment: Dear WS2, I see that you have a rather mind-boggling rep.  But still, it doesn't seem fair.  The rest of us normal mortals are expected to provide documentation in our answers, or else confine our contributions to comments.  Shouldn't those norms apply to you as well?
Comment: @aparente001 I've edited with the OED definition. Will that suffice?
Comment: I didn't make the rules. // Thank you.
Answer: I am struggling to find an appropriate adjective. However, I do think that analysis paralysis exactly fits what you are looking for.

analysis paralysis (noun)
Inability to respond effectively to a situation due to an over-analytical approach or to an excess of available information.

It's most commonly used in software development (as far as I'm aware); but it applies to a wide variety of situations.
I would say that this person is frequently overwhelmed by analysis paralysis.
I also want to add a Wikipedia link here. Not as a way to define the word, but it nicely lists common forms of analysis paralysis. I am not sure which context best applies to your case.
Comment: @thomj1332: I'm not questioning your logic, but using it as an adjective like that sounds wrong to my ears. Does paralytic as an adjective not state that it **causes** paralysis, rather than **suffers from** it? i.e. you can say that "his constant analysis is paralytic", because the constant analysis is the cause.
Comment: You could say they are an ***analysis paralytic***.  Or, since paralytic is an adjective.  They are ***analysis paralytic.***


How to tell when it's time to give up on tires?

Question: I work at a community organization that receives a lot of donations, including tires, in various condition. We inspect tires for obvious damage and wear, and signs of aging like hardening or cracking. Are there non-obvious reasons to be wary of donated rubber that looks fine, just a little old?
Comment: Did anyone else see the title and think someone was thinking of stopping using tyres at all?
Comment: Nice, donating tires. My policy is to replace a tire before it gets punctured, I hate it to switch a tire at the side of the road. I'm not in Boston, otherwise I'd be happy to send you my old tires. Keep up the good work!
Comment: @Criggie I added a tag "bike-coop." Thanks for the suggestion!
Comment: @Criggie is this really a relevant tag for this question? I mean, the question of when a tire gets too old is not really depending on whether it's for a bike-coop or not.
Comment: We receive a lot of nice, usable stuff in every category of component and accessory. There may be a bike co-op or bike kitchen near you that can accept donations! I'm finding the bicycling community to be quite generous. In fact, we could use a few more wrenches on the staff!
Comment: Even tires worn or damaged beyond use can be recycled into other materials.  One thing I've seen them do is chop them up into little pieces to use as a mulching material underneath playgrounds.  (I think that's mostly car and truck tires, but bike tires might provide some reusable materials as well.)
Comment: @SamA Should we add a "community groups" tag ?   There's nothing in the tag list at the moment I can spot.
Answer: For reference - tire parts names.

The "Anti-puncture strip" and "bead protection tape" are not found on most tires.
Bead, casing, sidewall, and tread are the most common components.
Worn tread is easy to spot.
Here are some pictures - things to look for in tires to evaluate if they need replacement:
Tire bubble - caused by a torn tire casing under the tread.
Often the tire must be inflated to find this issue.

Caused by a torn casing and sidewall at the bead allowing the sidewall to separate from the bead. Usually this issue can be found without inflating the tire.

Split tire - usually can be found without inflation
Dry rot

Time and sun are not kind to tires. This is an example of dry rot caused by oxidation and UV on both gum wall and black wall tires.
Dry rot makes a tire "crunchy" it loses it's flexibility and becomes brittle so that the casing, sidewall or tread can break allowing the tube to come through or the bead to separate.
You can feel dry rot with your hands by flexing the tire. A tire should be flexible. Sometimes you can actually hear the tire make crunching sounds as flexing breaks casing threads and makes tread crackle.
Comment: Thank you for these illustrated references!
Comment: If you see anything like the above photos, please dispose/recycle the tyre!
Comment: Excellent illustration, but readers should remember that tires in this condition are *well* past prime.
Answer: This is a great question and there are actually some good ways of approaching it.
Inconveniently, you need to see the tire installed and inflated to have high certainty that it's good for reuse. Until then, there could be casing issues (bulging, cracking that's worse than it looks deflated, distortion, etc) that aren't apparent when it's just a loose tire.
However, there are heuristics you can exploit that allow you to do some pretty good screening even on loose tires.
For commercial shops that save unwanted used parts and donate them to community shops or bike projects, a very common scenario is a customer that has a pair of old tires on their bike and wants to start fresh with two new ones. It is overwhelmingly common in this case that the rear is toast and the front still has life left. On the bike, the most direct symptoms to observe are the roundness profile at the contact patch. Worn out tires get pretty squared off, and if the front one was the same age you often have a good visual comparison between still-pretty-close-to-original in profile versus worn. (There is a tangential conversation here about the merits of rotating tires on bikes, but that is a religious question and most people don't do it so we'll leave it at that).
If you're presented with two of the same tire and one is way less worn down the middle, it's pretty likely it was a matched pair, the rear eventually started flatting or having other issues or was just worn out, and the front is still usable. For that situation, throw away the more worn one and give the other a shot.
Where it could be murkier is when whoever donates you the tires has done you the favor of already throwing away the rear and only giving you the front. There are pretty good odds that if it's a tire that seems weathered but not all that worn on the contact patch and with no other apparent issues, that is what's going on.
Another approach is observing the thickness of the middle of the tire compared to the adjacent areas, where it's reasonably assumable that the starting thickness was the same as the middle. If the contact patch is a lot thinner than the tread areas that started at the same thickness, the tire is probably toast.
Comment: This is an excellent set of practical advice for evaluating used tires. Thanks.
Comment: It's very important to ensure your front tyre is in good condition, if that fails then injury is pretty much inevitable whereas if the rear fails you are more likely to be able to stop safely. That's not to say the rear tyre condition isn't important.
Answer: This is tough to answer as it'll be different for different types of tires.
For my riding styles, a tire is shot when the side walls won't stop weeping (all bikes), when the knobs stop hooking up (MTB), or when punctures/gushers/flats are becoming increasingly common (road, commuting).
Weeping sidewalls might be apparent in a donated tire, but probably not. Roached knobs aren't an issue if the tire is going on a beater/around-town bike that simply needs to roll for someone on a tight budget.
But the increasingly common flats/punctures angle is really what counts. For that, I would try to qualitatively gauge the thickness of the non-knobby tread and make a judgement call based on my gut feeling. For the types of bikes I've helped build at a community center, I'd be pretty quick to throw out worn, non-rugged tires.
Comment: I  suspect a community organization will rely on old school tubes, so the weeping be a concern.
Comment: @PaulH that sort of minor wear and tear on the sidewalls of an MTB tyre won't be enough to stop it lasting a long time with a tube
Comment: @SamA yes. Sealant (or some component of it) eventually consistently pushes through the sidewall in a well-used tire subject to rocky terrain
Comment: @mattnz yes and no. In a MTB tire's case, to me the weeping is indicative that the side wall has taken some non-catastrophic damage, likely on Oregon chunky and sharp basalt
Comment: Is "weeping" a phenomenon of tubeless setups?
Answer: Short answer - if you wouldn't feel safe riding on the tyre yourself on a high-speed descent, then it is for the bin.
Add a mental safety-factor/margin of error of 20% and don't be hesitant to say "no thanks" to donations that don't meet the grade.  You don't want to become the dumping ground for literal rubbish at your group's expense.
Err on the side of caution - there's always more tyres in the donation stream.
Comment: @SamA understood.  Back when I was involved with a community group, there was one single qualified guy who handled classifying incoming bikes for repair or as parts donors.   That way the consistency was there.  The donors were stripped down as far as possible and all reusable parts were cleaned, bagged and sorted.  Leftovers were sorted to steel/aluminium/brass/general waste.    Repair bikes were given to the larger group of volunteers to learn-on.  Finally a two person team did a safety inspection before putting the completed bike in the "ready to go" store.  It was fairly well delineated.
Comment: It's hard to give volunteers and trainees subjective criteria like the first, as personal experience varies. But yes, we certainly can afford to be (and have some duty to be) choosy about what we put on the floor or onto someone's bike.


Can a tournament allowed to run if all players are allowed to cheat?

Question: I am interested to know whether money based online chess tournament would succeed if all players are allowed to cheat.
Answer: This concept is called advanced chess or freestyle chess.
There used to be an advances chess tournament in Leon already in the late nineties. Nowadays it has reverted to a normal rapid tournament.
And there have been freestyle tournaments online (for money), first organised by chessbase and nowadays apparently continued by Infinity Chess.


Assign Materials by UV Island

Question: Help needed. I am using Blender 2.79 - I have a dress that I modeled and then unwrapped in UV layout. The problem is that I never added any material zones. What I would like to do now is add materials by UV island without having to try to select all those proper polys in 3d menu. Is there a way to add material zones by uv? Any help is appreciated!
Answer: If you are in your UV Editor, you could select a Polygon Face of any island and then hit L on your keyboard to select the island , after that you could assing a material.

Hope that helps.
Good Luck
Answer: One way is to use Select Linked command in the viewport and constrain it by seams.
If there aren't seams already on the mesh choose UV > Seams From Islands in UV editor (when UV map is visible).
With seams available select a face of the mesh and press Ctrl+L (or L if mouse cursor is over the mesh) while in 3D viewport. In operator options (F6) choose Seams.

Now there will be selected only that part of mesh geometry corresponding to one of the islands.
Comment: @VictorCsakany it seems that you selected islands in the UV editor. What this answer assumes is selecting geometry in the viewport, then if there are more than 1 material faces will be assigned to chosen one.
Comment: Thanks. I tried that and it works to select the islands. But then when I try to assign the materials, they still all just assign to the entire mesh.

Assign Materials by UV Island


My nook HD won't charge

Question: Unlike similar posts about this issue, the light doesn't from green to red to nothing when I plug it in, but rather, it just goes to green for a few seconds, and then nothing. I hadn't used it in a few years, and I went to use it again and this happened. I'm using the nook brand block and cable. It is a BNTV400. holding the power button for 20 seconds, or any length of time does not turn it on.
Answer: oops, tried a different charger and it worked

My nook HD won't charge


is this sentence right? is it a slang? or is it wrong?

Question: If I want to say I am good at something but not very good can I say "I am about good" does this phrase considered slang.
Comment: Do you perhaps mean, "I am quite good" or "I am moderately good."?
Comment: "I am about good" would be confusing to many listeners.  You might say "I'm fairly good" or "I'm pretty good at framifying whatsits".
Comment: Along with @HotLicks suggestions there's also "sort of good" (in speech *sorta*), "okay", "adequate" which are all a little bit "less good" than his suggestions.
Comment: And there's always "I get along."
Answer: This wouldn't be standard, and I wouldn't use it formally. However, in response to the question "Are you good?", you could say "I am about good", with a lot of emphasis on the word about. However, "about" is an unnatural modifier for "good", because it "about" usually refers to a specific quantity, time, or place — which "good" isn't.
In American English, I think the normal response, if you want to say that you're good, but not perfect, would be "I am pretty good."
Comment: mattdm, I like this answer enough that I'd like to see you add some examples: It works for quantity (Do you have any money? *I'm **about** out), time (Are you finished? *I'm **about** done), and place (Are you home yet?  *I'm just **about** there.)  But it's not idiomatic with qualities:  **about** good, **about healthy**, **about tall** -- they don't work.  You have prior permission to use my examples if you wish.


Inserting a post in Wordpress using MySql

Question: Does anyone know how to insert a new post into Wordpress using sql?
Comment: I edited your question. If it's not what you are asking please revert it.
Answer: You can use the Post object:
<code>// Create post object
  $my_post = array();
  $my_post['post_title'] = 'My post';
  $my_post['post_content'] = 'This is my post.';
  $my_post['post_status'] = 'publish';
  $my_post['post_author'] = 1;
  $my_post['post_category'] = array(8,39);

// Insert the post into the database
  wp_insert_post( $my_post );
</code>
More info found here.
Comment: BTW, if you want to test this, create a "test.php" file in the root of your blog and use this line before this code: require('./wp-blog-header.php');
Comment: The category needs to be an array of category IDs. That's not easy to get, especially if you don't have posts associated yet with categories. The fix on the category assignment was this: $sCategory='Test';$asPost['post_category']=array($wpdb->get_var("SELECT term_id FROM $wpdb->terms WHERE name='$sCategory'",0,0));
Comment: And which files I have to include? Because I want to do a separate admin panel for wordpress
Comment: This is great! You saved the day :)
Comment: Hi, I'm trying to get this to work inside a plugin but it looks like the plugin code isn't able to use WordPress function. Does anybody have an idea on this? Including wp-load isn't really recommended if i'm right.
Answer: Your question asks how to insert a new post into WordPress using SQL. If you really wanted to do that, taking a look at the "wp" database tables and do a standard INSERT - this wouldn't be hard.
But I'd strongly recommend against doing this - even if you want to create a separate admin dashboard outside of the normal WP-provided one, you should use the core functions/API that they provide.  For example, the wp_insert_post function is what you want to use.
I believe you can use/load these functions by including /wp-load.php.
Comment: I am somewhat new to Wordpress and I am wondering why you recommend against using a basic SQL insert?
Comment: @ssergei because Wordpress provides you with an API.
Comment: +1 for link to the wp_insert_post function and the details of the file to include for standalone scripts
Comment: +1 to that advice. Simply inserting a new row in wp_posts, and adding to a category in wp_term_relationships, doesn't work: the post count updates, but those posts don't show. I'm not sure what else you need to do nowadays.
Answer: I started by exporting the "wp_post" table just to see the structure - then copied the first section and wrote the seccond;
1: Start with a variable you can use for your insert statement ($sql)
<code>$sql = "INSERT INTO `wp_posts` (`ID`, `post_author`, `post_date`, `post_date_gmt`, `post_content`, `post_title`, `post_excerpt`, `post_status`, `comment_status`, `ping_status`, `post_password`, `post_name`, `to_ping`, `pinged`, `post_modified`, `post_modified_gmt`, `post_content_filtered`, `post_parent`, `guid`, `menu_order`, `post_type`, `post_mime_type`, `comment_count`) VALUES ";
</code>
2: I took the content that i wanted to insert, from another table - but you can just set the variables either inside or outside of your statement just set the variable to what you desire -
<code>$sql .= "(' ','".$post_author."',"."'".$post_date."',"."'".$post_date_gmt."',"."'".$post_content."',"."'".$post_title."',"."'".$post_excerpt."',"."'".$post_status."',"."'".$comment_status."',"."'".$ping_status."',"."'".$posd_password."',"."'".$post_name."',"."'".$to_ping."',"."'".$pinged."',"."'".$post_modified."',"."'".$post_modified_gmt."',"."'".$post_content_filtered."',"."'".$post_parent."',"."'".$guid."',"."'".$menu_order."',"."'".$post_type."',"."'".$post_mime_type."',"."'".$comment_count."'),";
</code>
After that, use your standard query:
<code>$res = mysql_query($sql); if($res): print 'Successful Insert'; else: print 'Unable to update table'; endif;
</code>
Comment: It won't work, because no category has been assigned to the post, and thus it won't be shown correctly...
Comment: What if it's a CPT and doesn't support wp core categories?
Comment: Some good help in this article as well: https://linkstraffic.net/transfer-wordpress-posts-one-database/


Merge container disks

Question:
I want to merge the empty container disk3 to existing container disk2. How can I do it?
Answer: I think disk is both partitioned and has container inside partition Container disk2, which is in use. And second partition Container disk 3, which was created probably by accident:

So press Partition button when hard disk is selected (ST1000LM..) and choose Partition. Then select unused partition and click [-] (minus) sign.
Then select the main partition and increase its size to max:

Click apply and you are done.
Comment: i dont have points to upvote Arunas's answer but i couldnt pass without saying thanks. Really thanks mate
Comment: Pleasure to help :) welcome!

Merge container disks


Being redirected to IIS7 page

Question: When I try to access another computer across my home network through a browser by using its ip address I get routed to an iis7 page that says iis7 and then welcome in a bunch of languages.
Any help?
Comment: What do you expect to see?
Comment: Are you trying to access the file system on the other computer or a web site on the other computer?
Answer: That is expected behavior and everything is working correctly, if the site is not configured.
If you want to get rid of IIS, then you should go to control panel->programs and features-> operating system components (or something like that), find IIS (Internet Information Services) on the list and uncheck it. That was for Vista/7. On XP, it's on add/remove programs.
Answer: Enable sharing on the machine you are trying to access. Then go to Start >> run  and type <code>\\ipaddress</code>.
When you try it from the browser it goes to the webserver on the remote machine and will not list the file on the system.
Answer: This is because IIS by default runs on port 80 as a webserver, so I'm guessing you're either connecting to port 80 or not specifying a port when connecting, which defaults to connecting to port 80 (assumably by a web browser by the sound of it).
If this is unexpected behaviour, you can disable IIS.
Answer: We had this problem today with the Tally T2365 printer. We changed the speed of the network connection from 100 Mb to 10 Mb. Not sure if that helped. We had the printer connected to a PC and both devices connected to a small switch. I power cycled the switch but that did not seem to help.
When we disconnected the switch from the LAN the normal web page finally came up and we were able to access the web page normally.
When I reconnected the switch to the LAN, again it failed.
Using the command prompt we found that the dynamic IP address was assigned to another device at the same time it was assigned to the printer. Now that surprised me since I already removed the device from the DHCP server.
So bottom line, if you see the IIS, try to isolate the printer from the rest of your network and see if that helps. It might be an IP conflict.

Being redirected to IIS7 page


My /boot is too small for upgrade: Increase /boot size? Temporarily empty /boot?

Question: I'm using a no-longer-supported Ubuntu 13.10 and want to upgrade it to 14.04.
However, possibly because my predecessor set the boot partition with too small a size, when running do-release-upgrade I get the following error:

The upgrade has aborted. The upgrade needs a total of 56.8 M free
space on disk '/boot'. Please free at least an additional 8,059 k of
disk space on '/boot'. Empty your trash and remove temporary packages
of former installations using 'sudo apt-get clean'.

My current disk usage with df -h /boot is:
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda1        88M   34M   47M  43% /boot

Files in /boot are:

e9t@/$ ls -al /boot
drwxr-xr-x 5 root root 1.0K Sep 13  2014 [1]  grub
drwx------ 2 root root  12K Mar  5  2014 [2]  lost+found
-rw------- 1 root root 3.2M Oct 10  2013 [3]  System.map-3.11.0-12-generic
-rw-r--r-- 1 root root 983K Oct 10  2013 [4]  abi-3.11.0-12-generic
-rw-r--r-- 1 root root 160K Oct 10  2013 [5]  config-3.11.0-12-generic
-rw-r--r-- 1 root root  17M Apr  8  2014 [6]  initrd.img-3.11.0-12-generic
-rw-r--r-- 1 root root 173K Jun 17  2013 [7]  memtest86+.bin
-rw-r--r-- 1 root root 175K Jun 17  2013 [8]  memtest86+_multiboot.bin
-rw------- 1 root root 5.4M Oct 10  2013 [9]  vmlinuz-3.11.0-12-generic

Cleaning, or freeing up more space in /boot is NOT an option because my /boot is just big enough to fit the necessary files - grub, vmlinuz, and initrd.
So I'm left with the following options:

Increase the partition's size (But I have to use command line and have cannot use live CD/USB because I'm working remote.)
Temporarily empty /boot (or move a big file, e.g., initrd), upgrade the OS, then restore /boot (or move the big file back)

Which is the safer or preferred way?
Is there a better way to fix my problem than the two options I've mentioned?
Comment: I suggest a new install of 14.04 with normal partitioning without separate /boot.
Comment: @EricCarvalho No, it's not a matter of freeing space, because my /boot partition is too small in the first place.
Answer: Try this:
OLDCONF=$(dpkg -l|grep "^rc"|awk '{print $2}')
CURKERNEL=$(uname -r|sed 's/-*[a-z]//g'|sed 's/-386//g')
LINUXPKG="linux-(image|headers|ubuntu-modules|restricted-modules)"
METALINUXPKG="linux-(image|headers|restricted-modules)-(generic|i386|server|common|rt|xen)"
OLDKERNELS=$(dpkg -l|awk '{print $2}'|grep -E $LINUXPKG |grep -vE $METALINUXPKG|grep -v $CURKERNEL)
sudo apt-get remove --purge $OLDCONF
sudo apt-get remove --purge $OLDKERNELS

Comment: Thanks, but as I mentioned in the question, I have already removed all "OLDKERNELS", yet still not enough space.
Comment: Try move  small /boot partition to / partition with live-dvd/usb


Forwarding Meeting Invite From Outlook Mobile App

Question: I am trying to figure out who receives a notification when I forward a meeting invitation from the outlook mobile app and I am not the organizer. Essentially I forwarded the meeting to two participants and then included a message (which I would not want anyone else to see) . Would the organizer / rest of participants be able to see that message or that I forwarded it? After sending the forward, it's not showing up in my sent mail so I am not able to track it. Any insights would be very helpful, thank you!
Comment: Why don't you just ask the other participants and organiser?
Answer: Normally, when you forward a meeting , Organizer will receive an email about the forwarding. But other attendees in this meeting will not get a notification.


Optimisation test services allude to 'inline script block #5', what does this mean

Question: Optimisation text services like Gmetrix and Pingdom Tools often provide feedback like 'inline script block #5', what exactly does this mean and how do you go about identifying and solving this problem.
Comment: This means that there is a script blocking your page being redered. That's all that can be sait for now. Please provide a bit more details. Maybe Gmetrixs tells you about which script causes the blocking and what it is used for. Gmetrix does tell you at least "The following external CSS files were included after an external JavaScript file in http://www.yourdomain.com/. To ensure CSS files are
downloaded in parallel, always include external CSS before external JavaScript."
Answer: As noted in Seb's comment immediately under the question, this indicates there is a script or asset request blocking your page being rendered.
More than likely, it is a javascript or css call for a plugin or add-on tracking service. Many such services often recommend/instruct website owners to insert their scripts/css calls as close to the top of the  section as possible.  Depending on the plugin or script, you may be able to optimize page load by moving them to the end of the source code, following the closing  tag and before .
Examples of such scripts/services could be:

ShareThis or AddThis
Salesforce or Hubspot injected forms
Campaign/Marketing tracking services such as DoubleClick, Floodlight, CrazyEgg
3rd-Party Plugins and Embeds


OpenCV: Simulate FishEye

Question: I've read this: How to simulate fisheye lens effect by openCV? post very good and played around with the code.
I also read the Wiki Article for Distortion(optics) and understood the math behind it.
The only real problem I have, is the calc_shift-function and how the scaling works.
I want to implement fisheye and pincushion distortion in my litte opencv-project for videos. Do I have other options? With built-in functions of opencv i only can correct distortions.
I gonna test http://www.imagemagick.org/script/magick++.php?ImageMagick=jb73dabpkumd9niucm1hr5d893 this today.
Best Regards, Moltisanti
Answer: you can use intel ipp library with functions like ippiCreateMapCameraUndistort
Comment: perhaps a somewhat more verbose answer would prove better for future readers.

OpenCV: Simulate FishEye