Breaking of diffeomorphism invariance after fixing a background metric

Question: The Lagrangian for the gravitational field in absence of matter is the following $$L=1/k\int dx^4 \sqrt g R,$$ where $k=\sqrt G$, $g$ is the determinant of the metric and $R$ the Ricci scalar. It's possible to fix a background metric like $\eta_{uv}$ and then study the perturbations $h_{uv}$ around it by $$g_{uv}=\eta_{uv}+kh_{uv}$$
The Lagrangian becomes $$L=L^{0}+kL^{1}+k^{2}L^{2}+.......$$
which can be interpreted as an effective field theory of self-interacting particles called gravitons.
Now, given the transformation law of $h_{uv}$, how is it possible to say the entire Lagrangian is invariant, order by order, under local diffeomorphisms? Of course the symmetry is still there, but I was wondering if there is some kind of Spontaneus Symmetry Breaking associated with the perturbation field $h_{uv}$ and the diffeomorphisms group.
The procedure resemble the SSB for the Higgs Boson, where the Lagrangian is $$L=\partial_{u}\phi\partial^{u}\phi - m^{2}\phi^{2}+\lambda\phi^{4}$$
This Lagrangian is invariant under parity in $\phi$, but after the redefinition around the vacuum $v$, the minimum of the potential, you deal with $\phi=v+\delta\phi$ and the Lagrangian in δϕ is no more parity invariant. Does this happen in the previous example after fixing a background?
Comment: @Yildiz you cannot lose symmetries by field redefinitions. In this case, the redefinition $g=\eta+h$ is linear; this makes the symmetry less obvious/manifest but it is there.
Comment: This post has been discussed on Meta, see [here](http://meta.physics.stackexchange.com/questions/9451/downvotes-without-explanation/9457?noredirect=1#comment35467_9457).
Comment: See [Schwartz's Quantum Field Theory and the Standard Model](http://www.schwartzqft.com/index.html), section 8.7.2. (and maybe section 22.4)
Comment: I have received only a partial answer to my previous question, so I tried to explain myself in a better way.
Comment: Ok, I' ll try to look at Schwartz. Anyway, It seems to me that fixing a background metric breaks diffeomorphism invariance of the Lagrangian.
Comment: Doing a perturbation approach does not fix the metric. It defines orders of magnitude effects and if you do it right the expanded series defines a metric, and it still needs to be, invariant, to each order. The perturbation expansion should not work for a strong gravitational field on top of your flat initial metric. The problem might be if you have nothing to set the scale
Comment: Ok, but how is it possible to prove in a rigorous way that there is no breaking of diffeomorphisms invariance using a perturbative approach? I have read a lot of times your statement, but I have never seen a formal proof.
Comment: @AccidentalFourierTransform I was wondering if there is some kind of SSB after this redefinition $g=\eta+h$; it's not evident that the Lagrangian described by $g$ and then by $h$ is invariant under the same symmetry group.
Answer: No, there is no SSB after a field redefinition. Recall that SSB is a dynamical effect. You cannot trigger dynamical effects by changing your coordinates. In the scalar case the SSB is triggered by a quadratic term with "the wrong sign", not by the change of variables $\phi=v+\delta\phi$. The new physics are more transparent in the new coordinates; but the SSB is not caused by changing into  the new coordinates: the symmetry breaks whether you define $\phi=v+\delta\phi$ or not.
In other words, physics are independent of coordinates. Using $g\to\eta+h$ leaves the physics invariant. You can also change $g\to g_0+g_1$, and choose any background $g_0$. The flat background is convenient, but in the literature you'll also find people that consider more general backgrounds; for example, $g_0$ can be taken to be the metric of an asymptotically flat space-time. In any case, the dynamics are determined by the Lagrangian, not by the coordinates.
Comment: I understand what you are saying, anyway  you will agree with me that when I quantize a system in order to deal with particles I have to work around a minimum of the potential, and while using $\delta\phi$ I have to be careful because is not true that the Lagrangian is parity invariant when "reads" in the perturbations: of course the initial symmetry is still there, but is less manifest like in the case of the Higgs Boson. I was wondering if the same happens in my case
Comment: Yes, I agree with you: when written in terms of $g_{\mu\nu}$ the gauge symmetry is obvious, but when written in terms of $h_{\mu\nu}$ the symmetry is no longer obvious. The symmetry is not manifest but it is there. The analysis of the diff. inv. of the Einstein-Hilbert Lagrangian is analysed in detail in Schwartz's book. See also [General Covariance and Background Independence in Quantum Gravity](https://arxiv.org/abs/1207.0340v1), by M. Bärenz.
Comment: I have taken a look at Barenz and Schwartz, but I didn't find an answer. My main problem is the following: the transformation law $h_{uv}^{'}=h_{uv}+\partial_{u}\xi_{v}-\partial_{v}\xi_{u}$ is it the diffeomorphism symmetry applied naively to $h_{uv}$, or is it the hidden symmetry, the correct one, which preserves the diff. invariance for $g_{uv}$?
Comment: In the Higgs Boson example is the same as transforming $\delta\phi$ in $-\delta\phi$ or $-\delta\phi-2v$: the first is parity applied naively to perturbations which is violated, the second one is the hidden symmetry which ensures that parity is preserved for the Lagrangian in $\phi$. It could appear a game of words, but it's not, please let me know if you understand me and I'll try to be clearer.
Comment: For sure the transformation law that I wrote for $h_{uv}$ is not the hidden one, because it's only the linearization of the true hidden one $h_{uv}^{'}=g_{uv}^{'}-\eta_{uv}$ where $g_{uv}$ transforms in the usual way. If so it seems that diffeomorphism invariance is violated.
Answer: Schematically, the Einstein-Hilbert action is given by,
$$S \sim \int d^D x \, \sqrt{|\det g_{\mu\nu}|} \, \mathcal R$$
for a metric, $g_{\mu\nu}$. Now, as noted in previous questions and by the OP, one can expand the field as,
$$g_{\mu\nu} = \eta_{\mu\nu} + h_{\mu\nu}$$
and since the inverse metric is an infinite series in $h_{\mu\nu}$, one obtains an infinite number of terms in the Einstein-Hilbert action expressed in this form. This procedure does not violate diffeomorphism invariance, as it is a mere field redefinition and we know all the terms sum to give $S$.
We can express any metric in the form $\eta_{\mu\nu} + h_{\mu\nu}$, it is as trivial as expressing a scalar $\phi$ in terms of two scalars, one of which we can choose completely freely, e.g. $\phi = \eta + h$.
Comment: @Yildiz The division between string theory and LQG has nothing to do with that, because string theory makes no attempt to quantise a theory of $g_{\mu\nu}$; Einstein gravity emerges as the renormalisation group flow of the string in a non-linear sigma model.
Comment: I agree that a symmetry remains after field redefinition, anyway it could be less manifest. The same happen with Spontaneuos Symmetry Breaking for the Higgs Boson: the Lagrangian has $\phi$ as field and it's invariant under parity, but after the redefinition $\phi=v+\delta\phi$, the Lagrangian in $\delta\phi$ is not parity invariant: of course the symmetry still exist but is hidden. Does this happen in our case? Not only this: in the Higgs Boson example $v$ was the minimum of a potential, but here we don't have a potential, so why choosing $\eta_{uv}$ and not another metric?
Comment: Of course, $\eta_{uv}$ is a natural choice as a background, anyway there is no dynamical procedure which gives it as a background. It's not derived as minimum from a potential in our Lagrangian unlike the vacuum $v$ for the Higgs Boson and other fields.
Comment: @Yildiz It is simply convenient to expand around $\eta_{\mu\nu}$. In gravitational perturbation theory, we actually expand around a general metric, $g_{\mu\nu} = {g_{0}}_{\mu\nu} + h_{\mu\nu}$. Things simplify for $ {g_{0}}_{\mu\nu}=\eta_{\mu\nu}$.
Comment: For sure it's convenient in many situations, but usually this field redefinition is accompanied in many books (e.g. Schwartz) with the claim that GR is not renormalizable, and that in order to resolve this problem we have to find a UV completion.
Comment: There is nothing wrong with this claim, but I would also offer another point of view: maybe the procedure of choosing $\eta_{uv}$ has a background is simply wrong, non dynamical, and this could suggest we have to quantize the entire $g_{uv}$ in order to obtain a consistent theory. I would say that this different point of view on the problem is a the basis of the division between string theory and LQG approaches on quantum gravity.
Comment: I know that string theory doesnt' attempt to quantize $g_{uv}$ and this is at the basis of its perturbative approach. LQG has another approach: it quantizes the metric using canonical quantization, leading to a non-perturbative approach. At the basis of this difference I think there is what I said.


How to prevent android from auto-sync'ing gmail contacts and photos etc

Question: I just got a Samsung Galaxy Note 3 and when I go into my settings then add an account and add a gmail account, it gives me an option to choose what I want to sync. I unchecked 'photos' and 'contacts' and everything else except for 'gmail', but it still auto sync'ed my photos and contacts (and my apps and app data, even though I told it not to). I then deleted the account and tried again but this time, I didn't check anything at all (not even gmail) and it did not sync anything, which is good. But I want to sync only my mail, so then I went into the settings for my account and checked only the 'sync gmail' box and it synced everything again (app, app data, contacts, photos).  How do I make it stop syncing everything? I just want to sync my inbox.
Comment: You can **Hack it**

- Go to Settings -> Accounts
- Click on Top RIGHT Icon (Settings) and then UNCHECK **Auto-Sync Data***
- Add your Google Account
- Turn the phone on **Air Plane Mode**
- Go to Settings -> Accounts -> Google -> Your Account
- Selectively turn sync only for things that you would like sync (e.g gmail)
- Turn off Air plane mode.
- Turn On 'Auto-Sync Data' option.

Now not all of the data will be synced except the ones that you selected!
Answer: To turn off syncing of everything to google, except mail then you can try the following steps:

Go to "Settings" on your phone -> "General" -> "Accounts" -> "Google" -> click your email address in the top. From here, you can uncheck checkboxes on everything you don't want to sync with Google.
Google+ also has its own syncing options -> Go to "Settings" on your phone -> "General" -> "Accounts" -> "Google" -> "Google+" -> "Auto backup". In the top, you can choose "Off" to turn off the backup of pictures and files to Google+.

I hope this helps.
Comment: okay so I tried adding an account again and it worked, I'm not sure what I did differently but just in case someone comes across this same problem in the future, I think if you go to the GMAIL app (don't click on settings -> accounts), just if you go to the GMAIL app, click settings inside the gmail app and then click 'ADD ACCOUNT', then it won't sync anything except the gmail. If you go to your phone settings -> Accounts and add accounts from there and tell it not to sync, then it might sync regardless of what you tell it (like what it was doing for me).
Comment: problem is, even when I tried to do this, it still synced the photos and the photos are all there. It's annoying how when I first link my account and say to not sync photos and anything else except for email, it still does it :/
Comment: Also, to clear already downloaded online galleries from your Gallery on the phone: Go to Gallery Application in application manager and clear data.
Comment: Also the program photos has its own sync service. To stop it just entrr the program, go into settings and turn it off there
Answer: you turn off the sync and open the mail app if it is gmail then it is easy as gmail app has its swipe down to refresh mails. but the android email app has no features like this so go to its settings to change it
Comment: That's a reasonable workaround, but only if you don't want new-mail notifications.


How to show on screen the cursor position on an android tablet or smartphone?

Question: I would like to be able to show on the screen something like the mouse cursor on PC's. Does anyone know how to do it with an app or by modifying the options on the device?
Comment: Can you give any more information? Many Android tablets will provide a mouse cursor system-wide if you connect a Bluetooth mouse. Or do you mean something different, using either the touch controls or D-pad/trackball somehow?
Answer: On Android 4.0, go to Settings > Developer Options > Pointer Location and toggle that on. This is very handy for presentations.
I am not aware of a solution for this on previous versions of Android.
Answer: Indeed the setting is in Developer Options as in @CommonsWare's answer. On Jelly Bean, the location of it started being even trickier.


How to Magento Debug

Question: I have an extension that is giving me an endless loop, and I can't figure out the cause. I tried to follow this (Fundamentals for debugging a Magento store) but can't understand how to do it ? Can anyone help me ?
Answer: Your question is a little broad, but in general.

Figure out which controller and action method corresponds to the URL that triggers an endless loop
Look at the controller action and figure out how it is calling code in your extension
Add a series of exit(__FILE__ . '::' . __LINE__); lines until you pinpoint the section of code that's an endless loop.

How to Magento Debug


How to prevent Flash components from blocking Firefox's keyboard shortcuts?

Question: Whenever a flash code takes control in Firefox, Firefox's keyboard shortcuts stop functioning. Is there a way to fix this?
Answer: From the Flash Player FAQ

Keyboard shortcuts can not be used when Flash Player is loaded
This is a known problem with all plugins, not just Flash Player.
There are several bugs filed on this issue. [Bug List]
Answer: Unless you are having this problem when you are specifically trying to look at flash, you should definitely install the Flash Block extension.  It's one of the best as it means you only have to look at the flash you want to see, when you want to see it.
Answer: I've researched this recently, and if you're running Linux, you can follow the somewhat complicated instructions to create your own extension, which monitors the system keyboard input.


Is it possible to allow mysql connection only from specific folder?

Question: Is it possible to allow mysql connection only from specific folder? I want to make sure that connection to database is only from my secure folder. This folder has php script which will make mysql connection. The folder is created with root user and it has read only permission for PHP process (apache).
Answer: No
As far as I know the current working directory is not something you can use as a security / authentication attribute in MySQL.


Relationship between SSE with GLS and OLS

Question: I have been trying to derive if there is any relationship between the sum of squared residuals (SSE) from a model estimated with GLS, and the same model estimated with OLS. Professor Chung-Ming Kuan, on his lecture notes, states that the first is always the equal or greater than the second (bottom of page 80). This seems to come from a projection standpoint, but I am not able to grasp it, and cannot find this statement in any econometrics textbook. Is this relationship true, and may someone explain the reasoning behind it?
Answer: Hi: Maybe if you think of it this way it might might make more sense. By the gauss-markov theorem, when the assumptions of the theorem are satified,  OLS is efficient. This means that the OLS estimate has the smallest possible variance of all linear unbiased estimators.
But, in the notes, author clearly shows that the GLS model can be transformed to an OLS model using the square root of the covariance matrix. See the section on Aitken.
So, if you view that that transformed model as an OLS model, which it is, then that model also has to satisfy the guass-markov theorem. ( assuming the assumptions hold. which they do ).  So, it's variance has to be the smallest of all linear unbiased estimators also.
<code>                                            Mark
</code>
Addendum: Although the above is true, it does NOT address What the OP was asking. Now that I understand what he-she is asking,  I will think about his question and try to develop an answer but anyone is welcomed to also. My apologies to community for providing an answer that has very little to do with the question.
Comment: Actually, I went back to your notes and figured out what page 80 was. Now I realize that I made a mistake in interpreting your question. What you are asking is not what I was answering so let me delete my answer and comment and I ( or maybe someone else) can think about it some and give you a good answer. My apologies for the confusion. Originally, I couldn't find page 80 and just assumed that you were asking something that you weren't asking. My mistake.
Comment: Thank you for your answer. However, you mention the variance of the estimator, and I cannot see the connection between the fact that the variance is lower and a higher SSE.
Comment: Thank you very much. I believe Baer's answer is correct, since when calculating the sum of squared residuals we are not considering the matrix omega that is crucial when finding the GLS estimates.
Comment: A very nice answer by Baer. My intuition  is that OLS is a projection so this is why it has to be a minimizer. Hopefully Baer or you can confirm that. So, the omega matrix works on the variance of the estimates but has to make a sacrifice by adding some bias. Thanks to Baer for great answer.
Answer: The least squares estimator $\hat{\beta}_T$ is defined to be the minimizer of the sum of squared residuals; this is expressed as: $$\|y - X \hat{\beta}_T\|_2^2 \leq \|y - X \beta\|_2^2$$ for all coefficients $\beta$. In particular, this holds for $\beta = \hat{\beta}_\textrm{GLS}$.


Xray mode for selected object only?

Question: I am trying to find a way to have only my selected object go into xray mode so that I can edit it while the other objects in the scene are still fully opaque. Xray mode functionality currently seems to turn everything transparent, and when adjusting the transparency setting, it applies it to all objects in the scene globally. Is there a way to do this without having to create materials and such? This is something I would just like to be able to toggle on and off via shortcut for editing purposes without having to go through a convoluted process. Thanks!
Answer: In the Object panel > Viewport Display > Display As > Wire?
Answer: Thanks, I was aware of that but I wanted a simple toggle for ease of use. I have attached a script that works to that effect. If you install this via an addon, it will create a toggle button that will appear in the 3dviewport as a tab labelled Toggle Wireframe, which you can then assign as a keyboard shortcut.
Save the following code as toggle_wireframe.py using notepad. Save it under your Blender user directory: C:\Users\"your username"\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons
In blender, install it as an addon and enable it. Once enabled, the button will pop up in your viewport. Right click and create shortcut. I hope this is helpful to others. Ignore the weird formatting here on the post and just copy all of the text into that notepad file.

import bpy

class OBJECT_OT_toggle_wireframe(bpy.types.Operator):
    """Toggle Wireframe Display"""
    bl_idname = "object.toggle_wireframe"
    bl_label = "Toggle Wireframe"
    bl_options = {'REGISTER', 'UNDO'}

    def execute(self, context):
        mode = context.mode
        if mode == 'OBJECT':
            for obj in context.selected_objects:
                obj.display_type = 'WIRE' if obj.display_type != 'WIRE' else 'SOLID'
        elif mode == 'EDIT_MESH':
           for obj in context.selected_objects:
                obj.display_type = 'WIRE' if obj.display_type != 'WIRE' else 'SOLID'

        return {'FINISHED'}

class VIEW3D_PT_custom_panel(bpy.types.Panel):
    """Creates a Panel in the Object properties window"""
    bl_label = "Toggle Wireframe"
    bl_idname = "VIEW3D_PT_custom_panel"
    bl_space_type = 'VIEW_3D'
    bl_region_type = 'UI'
    bl_category = 'Toggle Wireframe'

    def draw(self, context):
        layout = self.layout
        layout.operator(OBJECT_OT_toggle_wireframe.bl_idname)

def register():
    bpy.utils.register_class(OBJECT_OT_toggle_wireframe)
    bpy.utils.register_class(VIEW3D_PT_custom_panel)

def unregister():
    bpy.utils.unregister_class(OBJECT_OT_toggle_wireframe)
    bpy.utils.unregister_class(VIEW3D_PT_custom_panel)

if __name__ == "__main__":
    register()

Comment: So Im having a different issue. Blender crashed on me while I was working and now the addon doesnt load. I tried uninstalling it and reinstalling it and still no luck. Blender says it added it but it does not show up under addons in preferences like it did before the crash.

Xray mode for selected object only?


why are patents granted that do NOT solve the problem they describe

Question: As part of researching patents I came across one that claims to solve a problem that does actually exist. https://register.epo.org/application?tab=doclist&number=EP14188074&lng=en
In broad terms a fire resistant door leaf made of "intuemecent transparent Gel Filled" fire resisting glass has "L" shaped trims bonded to the glass edges to conceal the internal seal within the glass that keeps the Gel in place. It is claimed that trims hide the internal seal if the side legs (bonded to the faces of the glass) extend 2mm past the seal. However in practice this only works when the glass is viewed "face on" perpendicular to the trim. If you stand prependicular to the leading edge of the door leaf (near the door handle) the seals are visible across the top and base of the door leaf and down the hinge edge of the glass door leaf. Another claim is that if the trims were bonded to the glass with a fire resitant adhesive, they would distort in a fire and break the glass. The invention says that by utilising an adheisive that debonds at high temperatures, the trims will fall off thus preventing the glass breaking. However it is a well known fact that glass in a fire goes into thermal shock, particulalry if the edges are covered (this forms a thermal shadow) keeping the glass edges cool and as the exposed central area of glass heats up the glass shatters. As this happens about 2 minutes into a fire test,the trims would not have expanded enough to break the glass before it was broken by the thermal shock effect, there is no benefit in the trims debonding as the glass still breaks anyway. So both the claimed improvements 1. concealment of the internal glass seal  and 2. the prevention of the glass breaking are not achieved in practice. The EPO have however granted this. I cannot understand why as the inventive step appears to not have achieved the claimed improvments ? It appears that a patent does NOT have to work in practice for it to be granted. Seems pretty odd to me ?
Logikman
Answer: Patent claims do not need to be for a production-ready version and do not even need to be a better solution than existing solutions, just different,
It needs to, at least minimally, be useful; it needs to be new; and in most places to have an inventive step beyond the state of the art. (In the US the similar requirement is non-obviousness.)
Other than in medical domains, short of a perpetual motion or time machine, an application is taken at face value. If a fairly useless invention is patented it's not the end of the world. A patent is not supposed to be an endorsement by the government that something is a good solution.
If it doesn't work very well it will not be infringed by others and it will not necessarily inhibit better solutions getting patented.
The work load to judge the practical value of patent applications would be very impractical and not really objective without universal criteria of merit.
Comment: The glass described is gel filled glass that normally uses standard glass. It always goes into thermal shock after 2 minutes in a fire test. A video https://www.youtube.com/watch?v=MyXJ8qgvmHY and patents GB1451932 GB 2195136A describe this. The trim cannot expand enough in the first two minutes to break the glass earlier (simple expansion theory based on the temperature rise in a fire test over the first two minutes). There really is no way the trim falling off will stop the glass breaking. It is the Gel becoming opaque that gives the glass its fire performance as each glass layer breaks.
Answer: The document has had a long prosecution history and as far as I can tell still not granted as a patent. That said, I agree with George White, there are many patents which have little value and if they really don't work, then they should pose little difficulty to other products. In this case, the assignee has pursued the patent for the better part of 9 years and doubtlessly poured much money in to the prosecution. It is hard to believe they would do so if the invention has no value.
I would like to suggest, however, that you really dismiss the invention a bit too easily. Assuming that the glass will shatter before the trim falls off is assuming a lot. The adhesive might debond at far cooler temperatures than when glass might shatter. Also regular window glass likely acts far differently than specialized tempered glass used in fire doors.
Engineering is full of examples where mechanisms work in ways counter to intuition. Unless you have actually tested the invention, it is perhaps too much to claim it couldn't possibly work.


How do you say "on" as in "The book is on the table."?

Question: So, how do you say "on" in Latin, as in "The book is on the table.". Would you say "Liber super mensa est."? I have a feeling that would imply that the book is hovering above the table, rather than that it is directly on the table. Or would you simply say "Liber mensa est."? Wouldn't that mean that the book is inside a drawer in the table?
Answer: My first instinct was to use Liber in mēnsā est.
In fact, there are several sentences of this exact form in Hans Ørberg's introductory Latin reader, Lingua Latina per se illustrata, capitulum quartum:

Dāvus sacculum suum in mēnsā ponit. Iam sacculus eius in mēnsā est.

I can't find a sentence of this exact form in the PHI Latin texts corpus, but there are 19 examples of in mēnsā (often in combination with a form of pōnere).
Here is an example describing a book on a table:

Cum inter suos convivaretur, aut Ulpianum aut doctos homines adhibebat, ut haberet fabulas litteratas, quibus se recreari dicebat et pasci. Habebat, cum privatim convivaretur, et librum in mensa et legebat, sed Graece magis; Latinos autem poetas lectitabat.

(Scriptores Historiae Augustae, Alexander Severus Aeli Lampridii 34.7.2)
Obviously, you would not be able to read from a book inside of a drawer.
Super mēnsā doesn't have any hits in the PHI corpus. I agree it doesn't seem like a good choice, although I'm not sure if it would suggest a book "hovering above the table". Super + ablative, according to Lewis and Short, is rarely used to refer to literal physical position.
Super mēnsam might be possible. It occurs in what seems like a relevant context in the following sentence by Petronius:

inter haec tres pueri candidas succincti tunicas intraverunt, quorum duo Lares bullatos super mensam posuerunt, unus pateram vini circumferens 'dii propitii' clamabat . . .

(Petronius, Satyrica 60.8.2)


passphrase failed for encrypted disk after GRUB menu

Question: I have a dual boot system with Windows 7 and Kubuntu 13.10 on two separate physical disks (SSD).
I have two partitions for Ubuntu: an unencrypted "/boot" and an encrypted "/".
Everything was working as expected (booting on both OS) until I unfortunately unplugged the Windows disk and rebooted with the Ubuntu Disk alone.
I had a "bootmgr is missing" message. I immediately replugged the Windows disk but still had the same message.
So I tried to "boot-repair" and succeeded in getting the Grub menu back to choose between Windows and Ubuntu again. Windows boot is working but when trying to boot on Ubuntu the passphrase for the encrypted disk just after the Grub menu is consistantly failing.
Exact message being: "cryptsetup: cryptsetup failed, bas password or options?"
When launching a ubuntu installation CD I'm able to connect to the encrypted disk (the passphrase is working from Dolphin file manager and I can access the files) so the encrypted volume is still accessible even though I'm not able to launch Ubuntu on it.
I guess that when I unplugged the Windows disk the BIOS switched to the Ubuntu disk as primary boot device and failed to find the "bootmgr". Hence the "Bootmgr is missing" message.
Later when I ran "boot-repair" it overwrote my initial Grub files and I lost some information to decrypt the disk from Grub (?).
Now I'm not able to boot on Ubuntu anymore. :(
I tried to run "boot-repair" a second time with only the Ubuntu disk (mono boot) to see if any progress but I still have the same issue with the passphrase step.
Any Idea how I can get my system working back? I browsed the web for hours with no answer to this specific issue.
Answer: I think you could have solved this if you kept a copy of master boot record. So that you can copy it where it needed to be.
Comment: I'm learning Linux... painfully. :-) Don't even know if Grub is installed in the MBR or not in my configuration (I let the installation wizard do everything for me blindly)


canon pixma mg2440 scanner not working with xsane

Question: I have got the canon pixma printer/scanner , tried installing drivers from cd, it didn't work, from canon website, i couldn't install ,  xsane doesn't see the scanner , however the printer is working. any solution for fixing this? thank you
Comment: thank you , I downloaded the drives from canon and now it's opening from gimp.
Comment: you should give yourself a detailed answer below and mark it as definitive. you could provide a link or other details on the Canon drivers you used. I think they would work in my case, I have a similar problem in this question [here](http://askubuntu.com/q/723592/47206). I have also used  Canon drivers for the scanner - scangearmp-common and scangearmp-mg2400series - and the scanner is not seen)
Answer: If you have installed the drivers from Canon, the ScanGear application is there too, and that's all you need.
Run scangearmp. That command can be added into a .desktop file, like so.
It can be run from within Gimp, but scanning is not dependent on that.


Origin of delta

Question: Why does delta mean change? What is the origin of delta? I understand that upper-cased delta is used in this way and that delta is the fourth letter of the Greek alphabet. I also read that delta is the first letter of a Greek word that means "difference." The question remains: why does delta now symbolize change?
Comment: If it's the first letter of a word that means "difference", then that would seem to explain it. $\qquad$
Comment: Perhaps one should add that although that would seem to explain it, that doesn't prove that it's historically what happened.  Sometimes the actual history is a colorful story that doesn't seem like the immediately plausible explanations. $\qquad$
Comment: That is true. While this is a plausible story, some evidence would be nice, to elevate it from folk etymology. It can be hard to track such things down. In this case, I'd probably start with accounts of Newton's &/or Leibniz's work.
Comment: @MichaelHardy As "difference" (Eng., Fr.) and "διαφορά" (Greek) are words that mean difference, and all have the first letter 'd', err $\delta$, ... :) @ OP, what more needs to be said? The change in something is the difference between two of its states. Why uppercase $\Delta$ rather than $\delta$? There's no accounting for taste, and perhaps It's easier to write if you don't write Greek.
Comment: Cauchy used $\delta$ for différence, or "difference".
Comment: "why does delta now symbolize change": because difference and change are near synonyms.
Comment: 200 yrs ago higher education in Europe almost always included Latin and classical Greek and science students  were not exempt. Publishing in Latin had the advantage of not needing translation to local languages. Some terms persist today: Inf (infimum),Sup (supremum)......
Answer: The origin of the symbol $dx$ for the differential is with Leibniz.
See:

Gottfried Wilhelm Leibniz, The Early Mathematical Manuscripts, (J.M. Child editor, 1920, Dover ed), Elementa calculi novi pro differentiis et summis, tangentibus et quadraturis, Ms. no date (ca.1680)  page 137:

Let $CC$ be a line, of which the axis is $AB$, and let $BC$ be ordinates perpendicular to this axis, these being called $y$, and let $AB$ be the abscissae cut off along the axis, these being called $x$. [see figure]
Then $CD$, the differences [latin: differentia] of the abscissae, will be called $dx$.

The first Leibniz's publication using it is Nova methodus pro maximis et minimis (1684).
Compare with a "mature" explanation (1710):

Hic $dx$ significat elementum, id est incrementum vel decrementum (momentaneum)
  ipsius quantitatis $x$ (continue) crescentis. Vocatur et differentia [...].

According to the historian Florian Cajori, History of Mathematical Notations (1928–1929 - Dover ed.), II vol., page 222:

§593. Partial derivatives appear in the writings of Newton, Leibniz, and the Bernoullis, but as a rule without any special symbolism. To be sure, in 1694, Leibniz, in a letter to De l'Hospital, wrote "$\delta m$" for the partial derivative [...].
in 1776 Euler" uses $\dfrac {\delta^{\lambda}} p V$ to indicate the $\lambda$th derivative, partial with respect to the variable $p$.

And page 225:

The use of the rounded letter $\delta$ in the notation for partial differentiation occurs again in 1786 in an article by A.M. Legendre.

For Cauchy:

§610. More fully developed is [Cauchy] notation of 1844. Taking $s$ as a function of many variables, $x, y, z, \ldots, u, v, w$, Cauchy designates:

Partial increments $\Delta_1 s, \Delta_{11}s,\ldots$.
Différentielles partielles $d_1 s, d_{11}s, \ldots$.

For finite difference, see:

§640. In place of Leibniz' small Latin letter $d$, [Euler] used the corresponding Greek capital letter $\Delta$ which Johann Bernoulli had used previously for differential coefficient

Origin of delta


import sharepoint 2007 web site

Question: I have sharepoint 2007 site and i export this site and i want to import it to another site can i import it to existing site not create new one?
Answer: You'll need to use stsadm.
To export:
stsadm -o export -url [URL HERE] -filename [path] -versions 4
ststadm -o import -url [NEW URL] -filname [path]
Those should work.

import sharepoint 2007 web site


Copying User Settings

Question: Is there a way to copy every setting of an admin account to another admin account. I am currently using the default administrator account, but since it doesn't show in the welcome screen, I want to switch to a new account. But I don't want to loose all files and settings on  the previous account. Obviously they'll be available in the another account always. But can I just copy them in some few steps?
Will copying and replacing the user folder works?
Answer: many ways, but i would prefer to copy the whole profile... 1) logon with your new administrator user and than logoff... 2) logon with a 3rd admin user and copy the 1rst userprofile over the 2nd one (if files are in use of the 2nd one try to restart first) - 3) right click the profile folder of the 2nd one an change the permission and owner settings for all subfolders.
(this procedure does not work >xp, after xp there is a different way)
Answer: You can use the Windows XP Migration Wizard (also called Windows Easy Transfer) to save the data and settings of the first account into a file and use the same tool to import it back into the second account.
I only found the article for Windows Vista but the Functionality is the same:
http://support.microsoft.com/kb/928634/en-us
If it is not part of your Windows XP CD then you can download it from Microsoft here:
http://windows.microsoft.com/en-US/windows7/products/features/windows-easy-transfer
to start it just run migwiz.exe

Copying User Settings


Is 壁橱 (as opposed to 衣柜) only a colloquial word for "closet"?

Question: I apologize if this is very elementary: I've never heard of closet referred to as 壁橱, only as 衣柜, but the direct translation doesn't seem appropriate. I've also heard 衣柜 used to reference cupboard as well. Is this for colloquial reasons?
Answer: 壁橱 can refer to a small closet, a wardrobe embedded in a wall, a cupboard hanging on a wall, a chest placed against a wall or something else. As the characters go (壁=wall, 橱=case), it can be a container for anything not limited to clothes. Note, as an imported concept, 'walk-in closet' is not translated into 壁橱 but something along the line of 储衣间 (clothes storage room) or 更衣室 (dressing room).
衣柜 (衣=clothes, 柜=cabinet) means a wardrobe, either built-in in the wall or a standalone piece of furniture. A general-purpose cupboard should never be called 衣柜.
In Chinese, the distinction between built-in in the wall vs. standalone furniture is not made by first-class words or affixes. Both 壁橱 and 衣柜 can refer to either a closet or something else.
For the similarities/differences between 橱 and 柜, please refer to @Question Overflow's answer here.
Comment: Excellent answer!
Comment: I think chest should be 柜子 or 箱 instead of 橱. Agree with the rest though. +1
Comment: @QuestionOverflow Good point. Your answer has very good explanation for 橱 and 柜, I'll refer to that and change the inline to 'case' which is more accurate than 'chest'.
Answer: I believe a wardrobe is a kind of closet for storing clothes, and depending on your locale, people may also loosely call it a cupboard (sometimes also known as a cabinet). You may like to look up these terms on Wikipedia. What I want to focus here is more on 橱 and 柜. Since I can't find a precise definition for these two on the internet, I shall describe them based on my experience.
Similarities:

橱 and 柜 are a kind of furniture, usually rectangular in shape used mainly for storage purpose.

Differences:

橱 is usually full-height and placed against the wall, with doors that
open outwards. Most of them are made of wood.
柜 is usually half-height and can have drawers or a lid instead of
doors. A good portion of them are for display purpose.

Examples:

壁橱 (cupboard placed against the wall)
衣橱 (wardrobe)
冰橱 (refrigerator)
电视柜 (TV cabinet)
衣柜 (cabinet for storing clothes)
陈列柜 (showcase)
鞋柜 (shoe cabinet)

A similar kind of furniture with open compartments and no doors is known as 架 or a shelf.
Comment: "Refrigerator" is "冰箱" in Chinese. "箱" means a box or a trunk.
Comment: 冰箱 is the generic word for a fridge. Sometimes it is also known as 冰橱 or 雪柜.
Comment: The question also asked about 衣柜 referring to a cupboard, which doesn't store clothes. Can you comment on this usage?
Comment: @Claw, I wouldn't say it is totally wrong, just that 衣柜 is a subset of a cabinet which is sometimes also known as a cupboard. People with good vocabulary would normally call it a wardrobe since the purpose is well defined.
Comment: @QuestionOverflow FYI 雪柜 is originated in Cantonese and is rarely used in Northern China. http://baike.baidu.com/view/1798723.htm
Comment: @NS.X., yes, you are right. But Mandarin is spoken worldwide, not just in Northern China. Those are the ones that I heard, spoken in Mandarin.
Answer:  壁 = wall
 橱 = cupboard/wardrobe

So, from there it's very clear. That a wall cupboard. In Mandarin, a word can remain very much of meaning. So, if only by a word, we can't know actually what they want to mean, after combine these words. We can actually know what it's mean. Actually if you uses these word to combine to other, it won't mean closet, but will mean other as what the sentences mean.
and 衣 = clothes 柜 = something like a place to store things. So, combine it can became CUPBOARD
Comment: No. Here is a [picture of a closet](http://www.diyinahour.com/images/folding-closet-doors.jpg). It's a small room for storing clothes in.


Why is this question off topic

Question: Why is this question off topic on an expat site : Does Australian Medicare cover me internationally? ?
Answer: It's about your 'trips abroad' - it'd be a great travel question.  If it was 'does it cover me while LIVING abroad', that'd be different.
That's my view, at least.  In these early days of beta, we need to be strict and precise.
Comment: +1 Question clearly belongs on Travel.SE.
Comment: Anybody with enough knowledge of Australian Medicare to answer authoritatively would have to know both, I don't see much value in the distinction. The best is to (re)formulate the question more broadly and to describe under what conditions you might be covered or not.

Why is this question off topic


Applying multiple CSS styles to an element

Question: I've been thinking about doing this:
<code><button class="ui-button ui-widget ui-state-default ui-corner-all ui-button-text-only">Blah</button>
</code>
Is there a way you can define a single class in CSS that comprises all these classes and then define the button to have the single class?
Like:
<code>.myclass {ui-button ui-widget ui-state-default ui-corner-all ui-button-text-only}

<button class="myclass">Blah</button>
</code>
?
Answer: No, nothing in CSS lets you reference another rule-set.
Answer: You could do something similar if you used something like LESS ( http://lesscss.org/ )
Example from their website:
<code>.rounded_corners (@radius: 5px) {
  -moz-border-radius: @radius;
  -webkit-border-radius: @radius;
  border-radius: @radius;
}

#header {
  .rounded_corners;
}

#footer {
  .rounded_corners(10px);
}
</code>
There is also SASS (http://sass-lang.com/) and LessJS (http://github.com/cloudhead/less.js/tree/)
If you don't want to use these libs, there is no possibility to do such a thing using only CSS
Answer: Very sadly, CSS doesn't allow that kind of thing. The 'CSS way' is to would put all relevant classes into the element's class attribute.
There are a few tools that allow you to write CSS in this style (eg Less), but you still have to run the tool on your 'shorter' CSS to generate the full CSS file that would end up on your site.
And in fact, these tools, because of the way they work, generally end up resulting in you actually having a larger CSS file in the end. So even though they can make your styles easier to work with when you're developing, if your aim is to reduce filesizes on your site, they're not the best option.


How can I transfer my driver to another garage?

Question: I've bought another garage because I didn't like the location of the previous one but the game doesn't let me transfer my controlable character to it. I can do that with hired people. The old garage has only one slot in which my player is and the new one has 3 slots.
I'm also level 4 if it matters.
So is it possible to transfer my own character to another garage and if it is how can I do it?
Answer: In short - No it's not possible.
I had the same problem and at Steam Forum people also confirmed that. Your created character is fixed to your the base you selected at the start. You can quick jump between garages you own, but you can't change your homebase.
Comment: According to [this blogpost](http://blog.scssoft.com/2014/06/digging-deeper-into-ets2-111-update.html) the option to sell a garage or relocate your headquarters to another city will come with version 1.11.


Does it matter what order I place my workers when brewing?

Question: Some works have abilities like 25% chance of 25% faster brew time.  Does it matter if I place this worker first in the task order (i.e. cleaning), or last (bottling)?  Will it reduce the overall brew time or is it just for their task that they have a chance in reducing?
Answer: No, the craft bonuses are applied regardless of where you place them in the production line. The important statistic that you should base your consideration on are as follows;
This means that you should assign your workers to the roles they're best suited to based on the statistics bonuses for each role below;

Cleaning - Patience
Cooking - Intelligence and Dexterity
Fermenting - Intelligence and Patience
Packaging - Dexterity

Choosing a worker with statistics that match the role requirements will improve the quality of your brew in addition to the craft bonuses.
Comment: I think you were right the first time, I put a double brewing speed guy at the packaging and the entire process went super fast.
Comment: just to clarify, so if my packager has the increase brew speed by 25%, then it'll affect the entire brewing time, not just the bottling part?
Comment: "brew" in this game refers to the entire process
Comment: I know, but usually you don't see them apply their 'bonus' until its their turn to do something
Comment: Still testing... the speed bonus seems to drop off once that worker becomes inactive, although putting a worker in the role of cooking instead of cleaning does seem to reduce the duration of the brew slightly (I think this is because cooking is a slightly longer process than cleaning or packing though since cleaning comes before cooking during a brew)


How does stokes theorem generalize to sets rather than manifold.

Question: I learned the Stokes theorem in the context of differential topology, it says that if I have a $n-1$ form $w$ with compact support on an oriented smooth n-manifold, then $
\int_{\partial M} w = \int_M dw$. However I was asked to prove the following fact using the stokes theorem: given a compact set $K \subset \mathbb C$, and a holomorphic function on $\mathbb C$, $\int_{ \partial K} f =0 $, how should I use the stokes theorem since $K$ here is necessarily a manifold? May be it involves arguing that $\partial K$ can be realized as the boundary of some manifold?
Comment: It isn't true: let $K$ be the closed real interval $[0, 1]$ and let $f(z) = z$ be the identity function. $K$ is a compact subset of $\mathbb{C}$, and it also is a oriented smooth 1-manifold, but the integral equals 1.
Comment: Hmm. Is it possible that the asker of the question meant to assume that $K$ is a nice set?
Answer: The result is true if we suppose that a compact set $K$ is a smooth oriented 2-manifold over $\mathbb{C}$, and that it's boundary, $\partial K$, is a smooth 1-manifold. Then we are integrating the 1-form $w = f(z)dz$, whose exterior derivative is known to be $0$ (because $f$ is holomorphic).
We can, without loss of generality, suppose that $K$ is connected. Being compact, $K$ is also closed and limited. Now, if we can prove that the boundary points of $K$ (topological boundary points, not the same thing as the boundary of a manifold) form a connected subset (which I believe to be true), then the theorem should become true under the following two hypothesis:

$K$ doesn't have an empty interior
Every open ball centered on a boundary point of $K$ intersects an interior point of $K$

Actually, (2) implies (1), but I'm leaving it there to emphasize it. I think that using this hypothesis, we can prove that $K$ is actually a (sufficiently smooth) 2-manifold. (1) rules out the example $K = \{x + 0i \in \mathbb{C}| x \in [0,1]\}$ that I gave on the comments, and (2) rules out other weird compact sets such as:
$K = \{z \in \mathbb{C} | |z + 1| \leq 1\} \cup \{x + 0i \in \mathbb{C}| x \in [0,1]\}$
The set above is the union of the closed disk centered on $z = -1$ and radius $1$ with the real line segment $[0, 1]$. The first part can be realized as a smooth oriented 2-manifold and satisfies property (2), while the second one can't. This is still informal though, I'm not sure how laborious or technical it is to prove
Theorem Every non-empty compact set $K$ satisfying (1) and (2) can be realized as a smooth oriented 2-manifold over $\mathbb{C}$.
EDIT: Maybe even this won't be enough - try to imagine the unitary disk $|z| \leq 1$, but create a perturbation on it's boundary using something like the Weierstrass function, a function continuous everywhere but differentiable nowhere. It may even be a continuous manifold, but I don't think it will be differentiable, let alone smooth enough.
EDIT2: It is true that the interior points of $K$ form a differentiable oriented 2-manifold (they are simply a submanifold of $\mathbb{C}$). It's boundary is precisely the closure of it's interior, which is contained in $K$ (and if $K$ satisfies (2), it is all of $K$). It doesn't need however to be a smooth nor even a differentiable manifold - google Koch Snowflake , center it on the origin and let it be your $K$. Stronger hypothesis are needed then, and I think this can't be done with nothing less than "supposing $K$ satisfies (2) and it's boundary points are a smooth 1-manifold".
Comment: Thank you very much that is a very detailed answer!!!!! Is there a stokes theorem more of a computational essence? I am pretty sure people do not have to deal with smooth manifold in calc 3.
Comment: @z.z while the machinery involved in the generalized Stokes' Theorem is pretty abstract (differential forms and smooth manifolds are, at first, counter-intuitive notions and formalism-heavy), the work done internalizing those ideas pays off on the long run. It generalizes all the big multi-variable calculus theorems such as the Gauss-Ostrogradsky's, the Kelvin-Stokes', the Green's, the Gradient's, and it also gives a unified language for vector fields, scalar fields, parametrization, the $dx$, $dy$, $dA$, $dS$, orientation, etc. It is, really, the most modern way to learn it. But...
Comment: @z.z not all calculus courses teach it that way and it isn't necessarily a bad thing. Most references in applications (engineering, physics, social sciences, etc) still do multi-variable calculus the old way, using more intuitive notions but broken down to several specific cases. You could see the four theorems cited above for alternatives to the generalized Stokes' Theorem, as they cover basically all the most usual applications of the theorem.
Comment: @z.z computationally speaking, differential forms and manifolds aren't very complicated either. You take a manifold, which is essentially a parametrized set, you use this parametrization to pullback your differential form, which is (or should be) a purely mechanical process, and then you have iterated single-variable integrals which you can then solve trough your favorite single-variable techniques. You're welcome to ask around the forum with a specific example or calculation, should you have questions regarding computational aspects of Stokes' Theorem!
Comment: really really thank you!!!! That is really very helpful!!!


Do I need return air ducting to a new upstairs furnace?

Question: I am ripping my entire house apart and will be making almost an entire wall out of windows and doors,(glass). I will be changing all of the floor plans, (walls), so at the moment I am adding HVAC to the upstairs. I want to install a furnace upstairs, along with an electrical sub-panel. I plan on making a separate "mechanical s" room for the furnace and electrical, which will be placed in the center of the existing chimney. I plan on installing exposed spiral ducting down the center of the upstairs vaulted ceiling.
Do I need to run  cold air return ducting back to this secondary furnace? Can I have a gap on the bottom of all doors, instead of running ducting?
Thank You
Comment: Do you have permits for this project? If you did, then you would likely already know the answer to these questions.
Comment: Have you already spoken to an HVAC guy or two? My gut says that they'll be able to answer your question better than us.
Comment: In my area, if someone is "ripping" their entire house apart, permits are required. One of the reasons permits are required is so that the work performed is completed to meet all codes, mainly for safety. Thus the reason I have asked this question. Building permits in my area are nothing more than a form notifying the city that work will be performed in compliance of codes set. When a homeowner obtains a permit does not mean that they are a professional in all the work being performed. If everyone on this site would hire a professional, I do not see much reason to have this website up?
Answer: A Manual D load calculation will give you each room's airflow and return air path requirements. Those return air paths can be provided by dedicated return ducts, jump-ducts, or undercut doors. Undercut doors represent the least desirable approach because the amount of airflow that can pass under a door is about 50 CFM per inch, and a one inch undercut is pretty big but 50 CFM may not come close to the airflow going into the room. A one inch undercut also creates privacy concerns and may look just plain ugly.
By far the superior solution if you don't want to use dedicated return air ducting is to use jump ducts that allow air to pass through common walls and into the central hallway, and then you can have your simple central hallway return. The preferred approach is to do the ducts through the wall, not over the ceiling, which would put them in the unconditioned attic.
I am assuming you did a Manual J calculation to size the equipment correctly and determine whether or not a second furnace needed in the first place, right? And that you did the calculation with the assumption that all air sealing and insulation work were done first so when when you eventually do them later, this equipment won't be hugely oversized and create comfort problems, right? And that the results of this calculation convinced you that a second ducted furnace was actually required and cost-effective vs a single unit with zoning, a mini-ducted mini-split heat pump, or a series of ductless mini-split heat pumps? And that you were able to find a furnace with a small enough output that it won't short-cycle all season?
The reason why I ask is that if the answers to most or all these questions are all "No", then it's time to go back to the drawing board, because you could be setting yourself up for disappointment.
Answer: You can have a centrally located Return Air grille and raise the bottom of the doors to have 1.5" or so off the finished floor or carpeting.


How to Filter Null Values inside SOQL query

Question: I am trying to filter out the null values of Account Id related to the corresponding child contacts in the following query, but it is not happening.
When I update the active__c checkbox field in the contact object for the record which doesn't have any associated parent account Id in the Account object, The column Count(Account.Name) is giving the problem by returning the null record having 0 value.
SELECT Account.Id, Count(Account.Name) Namecount FROM Contact WHERE Active__c = true AND
Account.Id != NULL AND Account.Name != NULL GROUP BY Account.Id ORDER BY Account.Id

The same query when I run separately in the query editor is working fine and giving the expected results. (only Non zero Non-null values)
But, when I use this same query inside the SOQL in apex method, it is returning the Null values also(0 count record), and the output is impacted.
Can anyone please suggest how to get rid of these null value records inside SOQL queries?
Answer: I think, this is giving correct results in execute anonymous apex -
List<AggregateResult> cons = [SELECT Account.Id, Count(Account.Name) Namecount
FROM Contact WHERE Active__c = true AND Account.Id != NULL
AND Account.Name != NULL GROUP BY Account.Id
ORDER BY Account.Id];
System.debug(cons);


What is the fix for class file for com.google.common.base.predicate not found?

Question: A sselenium program I have been developing for a while now comes up with
com.google.common.base.Predicate not found when I open it in Netbeans.
It appears that some Java update has removed or changed that library. Does it have to be reinstalled or is there some replacement for it?
Answer: This class is part of the Guava library. It must be in your classpath. But libraries do not magically disappear from the classpath of a project when upgrading Java. Some one must have removed it.
Comment: I am certain I did not remove it. After adding Guava I had to add the ApacheHttpClient because something depending on com.gargoyle.xxx now depended on org.apache.xxxx
Answer: This class is normally located in a jar file called something like google-*.jar. Try to find it on your filesystem and if you do, make sure it is pointed to by the CLASSPATH environment variable (the variable should point to the jar file, not the directory which contains it). If you don't find it in your file system, you need to download it (it's free) and then ensure the correct CLASSPATH. Alternatively, you can use you system's package management tool to download it, in which case there is a chance it will update CLASSPATH automatically (you may need to log out and in again or restart you shell etc to make the last change effective).
If you want to confirm the jar file you find/download contains the class, you can do something like this (Unix/Linux):
jar -tf file.jar | grep 'com.google.common.base.Predicate'

where you should substitute the name of the file you've found/downloaded for file.jar.


Frank W. Jandl Engineer

Question: I'm trying to find out about patents involving my Father, Frank William Jandl. He is long deceased, and I'm his daughter and I'm doing the family genealogy hoping to include information on my Father. He was a mechanical engineer mostly based in the Los Angeles CA area during the years 1945-1980.
I'd appreciate any and all information!
Thank You,
Camilla
Answer: Camila, doing an inventor search on the USPTO website, I found Frank W. Jandl listed as a co-inventor on US Patent No. 4,110,977.
You can download a copy of the patent in PDF form here.

Frank W. Jandl Engineer


How to transfer data from one list to another and then update it automatically

Question: Just a little background on how the problem originated - we've been running a bunch of tables on local drives and decided to move them to sharepoint in order to work with those tables simultaniously and automate the the filling of tables somehow. So now we have a bunch of tables transfered to lists, and already started filling them in. The management decided to use PowerBI to build dashboards based on those new lists by directly uploading from Sharepoint, but it turned out to be problem since the lists contained AdvancedLookUp columns and PowerBi cannot read them (even through oData).
So now to my problem - I decided to try to create a copy of all those lists (shadow copy) so it would be first fully copied and then updated aotumatically upon new entries in original table.
So for example we have List1 with columns 1 2 3 and a bunch of elements already created in this list.
1) First I want to copy all the existing data from List1 to ListCopy1.
2) Secondly after there is an element created in List1 it would create the same element with all columns filled from List 1 in ListCopy1. It would be even better if the data copied would be in plain text for easier management in PowerBI.
I'm using Sharepoint 2013 and have access to SharepointDesigner 2013, but my knowledge in running SD2013 is really low, so please go in a bit more details in explanation if possible.
Thank you!
Answer: There are multiple options for this.
1. Workflow ( add to other list when item created & update item when it has been changed )
2. Event Recevier


Do the simplest bacteria have ribosomes and helicase?

Question: I find it interesting that all life on earth use DNA. I've seen video on how helicase and ribosomes work together to copy DNA sequences (to RNA) with helicase then recreate them using ribosomes. Does this process work the same way in the simplest life forms? Bacteria and other unicellular life that reproduce through mitosis, for example?
Comment: Although the definition of life is complicated, there's general agreement that viruses aren't alive. Furthermore, there seems to be a misconception about the mechanism of DNA replication: no intermediate step via RNA is involved. Maybe you could clarify what you mean here? Still, I think this is a good question.
Comment: You seem to have got confused between translation (making proteins from RNA templates using ribosomes) and DNA replication (direct DNA-DNA copying)
Comment: I'm voting to close this question as off-topic because it is based on the false premise that ribosomes are involved in transcription.
Answer: I've had a direct look at Carsonella rudii, which is I believe is the bacterial genome with the smallest number of genes so far - 184 as well as being only 160 kb in length.   It has a putative DNA helicase encoded in it.  37 of those genes encode for ribosomal components as well.
If there was ever a bacterium or any living cell (non virus that is) discovered without a ribosome, you would have heard about it.  nobel prizes all around.
So I would say that your answer is yes.
Answer: First, mitosis is a eukaryotic process where not only genome replication and cell division is involved but quite a few more processes, not the least because there is a nucleus in eukaryotes. Bacteria simply divide after replication. And yes, even the simplest bacteria (and even some symbionts) use ribosomes for protein production. Example:
The smallest bacteria are from species Mycoplasma. The Mycoplasma species with the smallest annotated proteome on UniProt is Mycoplasma genitalium (strain ATCC 33530 / G-37 / NCTC 10195, with 484 genes. I have attached links to the set, as well as to its helicase. (For the 16S gene you would look that up in a gene not protein database)
http://www.uniprot.org/uniprot/?query=taxonomy:243273
http://www.uniprot.org/uniprot/P47340


VShadow.exe for Vista

Question: I need the VShadow or its equivalent for Vista (Business).
All the VShadows I am trying are giving errors. I need to use it from Command Prompt.
The procedure entry point ClusterGetVolumeNameForVolumeMountPoint could not be located in the dynamic link library RESUTILS.dll."
or
VSHADOW.EXE 2.2 - Volume Shadow Copy sample client
Copyright (C) 2005 Microsoft Corporation. All rights reserved.
(Option: Create shadow copy set)
ERROR: COM call "CreateVssBackupComponents(&m_pVssObject)" failed.
- Returned HRESULT = 0x80070005
- Error text: Access is denied.
Answer: This particular error means that you need to be elevated - run as administrator.
However there are multiple versions of this app for various windows versions.  I'm trying to find one for Windows 8.1 - which I understand uses a whole different engine.  So far I have only found versions - which has a link to a 2010 zip of various versions.
Note - you are using a compiled version of the VSS Tools 7.2 - which says in the documentation only works with Windows Server 2003 (NT 5.2) and Vista is NT 6.0.

VShadow.exe for Vista


How did Thomson come with his "Plum Pudding" Model?

Question:
Why couldn't he not think of something like a triangular or any distorted shaped atom (and why only a spherical one)?
Can't the positive charge be in some other fashion which is not evenly distributed?
Can't it be that positive protons are present in a sea of negatively charged electrons?
Comment: You'd have to ask Thomson. You would probably be better off asking this on the [History of Science SE](https://hsm.stackexchange.com/) since it isn't a physics question.
Comment: @Divyanshu He was a physicist. If you're a physicist, absent evidence otherwise, everything is a sphere or a plane or a straight line.
Answer: The honest reasoning in favor of the so-called "plum pudding" model is available in a number of public-domain sources from that time period. You might enjoy the 1914 article The Structure of the Atom in Nature No. 2308.
It was known at the time that corpuscles of negative charge (now called "electrons") could be extracted from an atom, leaving a positively-charged particle (now called an "ion") of approximately the same mass as the neutral. Both the neutral and its ion, if they had a shape at all, must have been spherical in shape, since they showed no angular dependence in interactions with other particles. No fundamental corpuscle of positive charge could be extracted from a neutral. Therefore, the reasoning goes, the atom must consist of its "electrons" as well as a heavy positively-charged part. What's more, since positive and negative charges attract one another, these charges must pull themselves into a compressed, isotropic volume. The simplest model (for we do so love simplicity) then has the electrons distributed throughout a positively-charged sphere.


OLE DB Exception - database/user/password is too large

Question: I'm trying to connect to a database using OleDbConnection and a connection string, the error given within the try-catch statement is 'database/user/password is too large'. What does that statement mean, and how can I solve this problem so I can connect to my database? My database is using a SQLBase driver.
Answer: The connection string probably can have a database, user, and/or password in it. One or more of them is too large.
Answer: SQLBase has restrictions on the length of the database, user, and password parameters. The database name has a maximum of 16 characters, and the user and password fields have a maximum length of 8 characters.


What type of modulation goes from D♭ to A?

Question: In Scott Joplin's Gladiolus Rag near the end there is a brief modulation from D♭ to A then back to D♭.    I know a composer can modulate to any key at any time as he likes, but I suspect this is a common pattern in ragtime and perhaps even some classical pieces.  Is this modulation some kind of identified type?
Answer: By definition, a modulation must reach a cadence in the new key. Since there is no cadence on B♭♭ here, it's technically incorrect to call this a modulation.
Instead, he's simply using a B♭♭ chord right here. We understand this from a theory standpoint by calling this a "borrowed" chord or a "mode mixture" chord. What we mean by this is that Joplin is "borrowing" a chord found not in D♭ major, but in D♭ minor; in order to create a colorful harmony, he's mixing these modes (hence "mode mixture"). In Roman numerals, this would be a ♭VI chord in D♭.
But he does make this even more interesting by prolonging this B♭♭ chord by means of its own V, F♭ major. So not only is he using mode mixture, he's actually tonicizing this mode mixture! Great example.
PS: The cadential six-four that comes after this chord is, from a textbook standpoint, "supposed" to be on the downbeat of the measure. Interesting that it isn't!
Comment: Thank you.  Part of my confusion stemmed from the fact that D♭ minor isn't a key signature (because it would have double flats), but I learned here that D♭ minor can still transiently exist and be borrowed from.  I also assumed all the double flats used here were just a notational preference over other accidental changes.  But its really great to learn that the double flats are actually communicating useful information.
Comment: I was also assuming incorrectly that the F♭ was enough to make a cadence for the B♭♭ and therefore it was a modulation, but I suppose it has to come at the end of a phrase or section to be a cadence.
Comment: @J.Lenthe The presence of a modulation tends to be considered in terms of duration: are we in the new key area long enough for the ear to adopt it as the new tonal center. Here it's short enough that, in context, it's not really heard as a change of key; just a change of color. Richard and Laurence are correct in this; my answer should have avoided the term.
Comment: As a gratuitous sidenote, I played in a ragtime quartet for years, and this was one of our favorite numbers.  Joplin pulled out all the harmonic stops in this piece, but so elegantly that it's all coherent. It's one of his lovliest rags.
Answer: You're enharmonically correct that Joplin modulates to A, but that's misleading. Joplin is very careful to notate the passage as Bbb, which is the bVI of Db major. This is a reasonably common borrow from the parallel minor, leading to the dominant, which it does (Ab, in this case).
Answer: There's no modulation here.  Just a chromatic chord, the very common ♭VI.   As we're in D♭major, that's correctly spelled as B♭♭.
I'm not too fond of 'borrowing'  as a justification for a chromatic chord.  Just look at it as an an alternative harmonisation of the tonic note.
(Now, if we respell it as A, the theory DOES get confusing!   It's B♭♭.)
Comment: To be Bbb7, an Abb is required, and to be an Aug6, a G is required.
Answer: I always try to explain a progression-  or like in this example - a borrowed chord by transposing the music to C major key:
When the tonic C is extending to Ab, we have a lowered bVI degree: Ab-C-Eb, borrowed from Cm, the parallel key of the C.
As you see all other answers are correct! But I find it is more obvious or insightful explained the situation in C major or even in the language of solfege - for those who know it: I = Do Mi So (tonic) and bVI = Lu Do Ma, the VI of Cm.
Now in Db - this makes it more complicate to understand, the parallel is Dbm and the VI of Dbm is Bbb-Db-Fb (and not its enharmonic equivalent A-C#-E). But modern pop music notation isn't as 'careful' handling harmonic relations.
Comment: Thank you.  I agree that it is easier to understand something like this in C major and that is a helpful technique I will use in the future.
Comment: I wonder what your teacher thinks about the movable do ... my experience is that we become more flexible and movable ourselves ;)
Comment: Our professor told us it isn't very good to think in C major for two reasons: (a)students aren't flexible enough when it comes to writing a, what we called, dictation, (b) people with an absolute sense of hearing, even though there are very few of them in a generation, can't help but feel what is written and that is C major. Just her words, not mine.
Answer: This just seems like a temporary modulation to Cb Major. The only scale with both a Cb and a Fb


Removing summoned ender dragon (Minecraft.)

Question: I summoned an ender dragon in minecraft realms (in the overworld) and it just sits there and makes a lot of noise. I have tried many things to remove it but it will not work. (Cheats are on!) It does not move or shoot fireballs it just makes a lot of noise and stays in one place. Please someone help me I really need to remove this...
Comment: @Molley Jones could you please tell us what you've done so far to try to fix the problem? It's hard to tell you an answer if we don't know that you have tried what we are suggesting.
Answer: First, Please provide more information next time, which will aid us in helping you - Such as what you have tried, or game specs - modded etc.
This is intended behavior in the game, because the dragon's code causes it to go to 0,0 - Like in the enderdragon fight. - Detailed Here: https://bugs.mojang.com/browse/MC-95601
Since you have not told us what you have done, Here are a few things you can try -
Try and kill it manually, with a sword.
You could also try
<code>/kill @e[type=minecraft:ender_dragon]
</code>
Please let us know if neither of these work, or if you require more help.
Comment: None of those work, and i'm sorry i did not provide much information, i thought people would know you can't mod realms, and if I had cheats on, i would be able to change game specs, and that you can't kill it with a sword. Sorry I just assumed people that read what i wrote would know.
Comment: Hi Molly,
I said modded as an example. Game specs cannot be altered by having cheats on or off, so I don't see how that could affect it.

Seeing that you have tried killing ender_dragon, the other possible command is ` /kill @e[type=!Player].` Be aware it will kill ALL entities except for the player, INCLUDING boats itemframes, villagers, minecarts and other. This command will kill any bugged out entities as well.

Please ensure you have run both kill commands. (ender_dragon) (!player)


Trouble saving graduated color style in Spatialite db in QGIS

Question: When I attempt to save a style with graduated colors for a vector layer in a Spatialite db, I receive the following error:

Error looking for style. The query was logged

I had success saving single symbol and categorized color styles following the workflow shown here. How can I save my graduated color class in the spatialite db?
QGIS: 2.12.1. Spatialite: 4.1.1
Answer: Maybe this have to do with data type involved, graduated color is sometime quite glitchy when it come to real number with a lot of decimals. Look more like a bug than something you can actually resolve.
As a workaround you can try to convert your graduated renderer to a rule based renderer.
Adjust your rendering using graduated color then switch the top left drop-down list to use rule-based renderer.
BUT make sure the generated class limit don't overlap, last time I used this trick some weird <= >= definition was produced when converting graduated to rule.


When does electrical charges cancel each other?

Question:
If we have a wire with equal amount of positive and negatvie charges, will the total charge of the wire then be neutral?
If the first statement is true. Then a positiv charge will cancel with a negative charge. Does this mean that a positive charge can only "focus/attract" one negative charge at a time? For example if we had three isolated charges. One positive, and two negative. Will the positive charge then attract one of the negative charges. And the last negative charge will stay stationary and will not feel any attraction?
If the second statement is true. Can we then put a positive charge outside a wire, and let one of the negative charges inside the wire focus on the charge outside. Will the wire then be positive?
Answer: To complement QuirkyTurtle89's answer, in any system, a charged particle will feel interactions from all the other charged particles, positive or negative.
The total charge of a system or subsytem is sometimes a useful concept in physics. But if you want to talk about particles attraction/repulsion, what you need to calculate is the force that each particle feels from its interaction with the others. Let's see what the difference is by using a three particles example:
Assume the particles at positions $\vec{r_1}$, $\vec{r_1}$ and $\vec{r_3}$, with respective charges $q_1 e$, $q_2 e$ and $q_2 e$.
The force that the particle 1 feels from the others is the sum of the Coulomb forces with each of the other particles:
$$\vec{F_1} = \frac{q_1 q_2}{4 \pi \epsilon_0}\frac{\vec{r_2} - \vec{r_1}}{||\vec{r_2} - \vec{r_1}||^3} + \frac{q_1 q_3}{4 \pi \epsilon_0}\frac{\vec{r_3} - \vec{r_1}}{||\vec{r_2} - \vec{r_1}||^3}$$
Let's assume particles 1 and 2 have a charge $-e$ and particle 3 has $+e$. The force on particle 1 becomes
$$\vec{F_1} = \frac{1}{4 \pi \epsilon_0} \left( \frac{\vec{r_2} - \vec{r_1}}{||\vec{r_2} - \vec{r_1}||^3} - \frac{\vec{r_3} - \vec{r_1}}{||\vec{r_2} - \vec{r_1}||^3} \right)$$
Here you see the funny thing: Particles 2 and 3 have opposite charges, so the total charge of the two particles is zero. But by summing forces from particles 2 and 3 rather than charges you obtain a force feeled by the first particle that is generally not zero. In other words, to talk about attraction and repulsion of charges, you need to consider the charges between the particles but also their positions, as the further away particles are, the lower the interaction.
If you want to look further into this three-particle system, I suggest you read about electrostatic dipoles, as they are a typical example of a system of two particles with not net charges.
Answer:
Yes, there is an equal amount of electrons -negative charges- and protons -positively charged. Therefore the net charge, which is the sum of all charges, will be zero.
No! In the example of two negative charges and one postive charge. The postive charge will attract both negative charges and the force on the positive charge will be the vectorsum of the force exerted by negative charge 1 and negative charge 2.  This force can be easily calculated by Coulomb's law:
$$\vec{F}=\frac{q_1q_2\vec{r}}{4\pi\varepsilon_0r^3}$$


Airplane data for thriller novel

Question: I've written a legal thriller. One scene involves the antagonist lawyers hiring someone at O'Hare to sabotage some other lawyers' private jet so that it crashes. But I don't know enough about aviation to write a plausible scene, as in what could someone on the ground do to down a plane that the pilots wouldn't see. So far, I've heard about someone deliberately installing the wrong size screws in the windshield because the pilot could miss them in pre-flight checks. This could cause the windshield to fail at altitude, either crashing the plane or ending in an emergency landing at the closest field. But are the screws are visible from the cockpit? And if so, would the pilot detect a problem before takeoff? Any guidance would be great. Thanks!
Comment: **Does this have to look like a accident, especially afterwards?** Something which looks like a vibration fatigue failure maybe work in this case, but  is probably fatal and require some kind of access to plane and have to look like maintenance. If you don't need to hide you can manipulate the fuel in one of the tanks, can be done quickly, which will only be used later during flight (depends on plane type?) and cause all engines to fail. Here is the chance much higher for the pilots to save the situation. Of course your free to serve the pilots *decaffeinated* coffee, serious harm ;)
Answer: I would suggest to look into Wikipedia overview on Category:Airliner accidents and incidents caused by maintenance errors, immediately focusing on the "Investigation" sections. Some errors could be reproduced deliberately.
Answer: Depends on the plane. On many the windshields are sandwiched in place between riveted strips of metal - no screws.
Might have better luck messing with the O2 system, reference the golfer Payne Stewart's jet plane accident.
From Wikipedia:

On October 25, 1999, a month after the American team rallied to win the Ryder Cup and four months after his U.S. Open victory, Stewart was killed in the crash of a Learjet flying from his home in Orlando, Florida, to Texas for the year-ending tournament, The Tour Championship, held at Champions Golf Club in Houston. National Transportation Safety Board (NTSB) investigators concluded that the aircraft failed to pressurize and that all on board were incapacitated due to hypoxia as the aircraft passed to the west of Gainesville, Florida. The aircraft continued flying on autopilot until it ran out of fuel and crashed into a field near Mina, South Dakota.

Airplane data for thriller novel


Sync files between desktop and laptop for free

Question: I want to modify some python or C or whatever files using an IDE on my desktop, then I want to use my laptop to continue the work on the same files but on a updated version without having to download the files myself (like I would have to on google drive for example), just turn on the PC and open the IDE. I've tried Resilio but the free version doesn't allow sync between pc's. How can I do that?
Comment: Going to have to be more specific.  There are a lot of tools out there:  Google Drive, MS One Drive, Dropbox, GitHub, etc.
Comment: What kind of network setup do you imagine?  Do you need a central server or can PC and laptop talk to each other directly?
Answer: Based on your question, it sounds like you want near-real-time synchronization between the two systems.  The best option I've found for this is called Syncthing.  It's essentially an equivalent to Resilio, but open source (and therefore free).  It's not trivial to set up initially, but once you have it working, it's rock solid in my experience.  The one downside is that there's no central location you sync to, so both systems need to be on at the same time to synchronize data between them, although you can work around this by just keeping your desktop on all the time, or getting a cheap VPS to run it on (it works just fine running on the smallest offerings from most cloud hosting providers).


Rally App SDK 2.0 / SharePoint integration

Question: I have created a series of custom apps, using the 2.0pX SDK, which I would like to distribute to others within the company using SharePoint. In all the examples I have found on how to do this, version 1.XX of the SDK is being used. Is it a possibility at this point to share 2.0 apps via SharePoint? If not, is this integration planned for a future release of the SDK?
Answer: At this time, AppSDK2 Preview doesn't provide "LoginKey-like" functionality. Right now the focus for Rally engineering is on getting the finishing touches on AppSDK2 in order to get the toolkit to GA.
AppSDK2 "LoginKey-like" capability is definitely on the radar screen for AppSDK2 since being able to "surface" Rally data to external web pages without the need for end user authentication is very popular - so this will likely be on the roadmap once the toolkit is GA.


Practical use of expression trees

Question: Expression trees are a nice feature, but what are its practical uses? Can they be used for some sort of code generation or metaprogramming or some such?
Comment: possible duplicate of [What are some instances in which expression trees are useful?](http://stackoverflow.com/questions/27726/what-are-some-instances-in-which-expression-trees-are-useful)
Answer: As Jon notes, I use them to provide generic operators with .NET 3.5. I also use them (again in MiscUtil) to provide fast access to non-default constructors (you can't use Delegate.CreateDelegate with constructors, but Expression works fine).
Other uses of manually created expression trees:

object cloning
dynamic LINQ sorting
as a compiler

But really, Expression is a very versatile way of writing any dynamic code. Much simpler than Reflection.Emit, and for my money, simpler to understand than CodeDOM. And in .NET 4.0, you have even more options available. I show the fundamentals of writing code via Expression on my blog.
Comment: Thanks. the blog not showing up!!!
Comment: @pixparker I just tested it: working fine
Answer: Marc Gravell has used them to great effect in MiscUtil to implement generic operators.
Comment: Darn, beat me to it ;-p
Answer: I just created a generic filter function using an Expression Tree that I want to share with you guys...
Start
var allFiltered= Filter(AllCustomer, "Name", "Moumit");

public static List<T> Filter<T>(this List<T> Filterable, string PropertyName, object ParameterValue)
{
    ConstantExpression c = Expression.Constant(ParameterValue);
    ParameterExpression p = Expression.Parameter(typeof(T), "xx");
    MemberExpression m = Expression.PropertyOrField(p, PropertyName);
    var Lambda = Expression.Lambda<Func<T, Boolean>>(Expression.Equal(c, m), new[] { p });
    Func<T, Boolean> func = Lambda.Compile();
    return Filterable.Where(func).ToList();
}

One More
string singlePropertyName=GetPropertyName((Property.Customer p) => p.Name);

public static string GetPropertyName<T, U>(Expression<Func<T, U>> expression)
{
        MemberExpression body = expression.Body as MemberExpression;
        // if expression is not a member expression
        if (body == null)
        {
            UnaryExpression ubody = (UnaryExpression)expression.Body;
            body = ubody.Operand as MemberExpression;
        }
        return string.Join(".", body.ToString().Split('.').Skip(1));
}

Make it more expandable
string multiCommaSeparatedPropertyNames=GetMultiplePropertyName<Property.Customer>(c => c.CustomerId, c => c.AuthorizationStatus)

public static string GetMultiplePropertyName<T>(params Expression<Func<T, object>>[] expressions)
{
        string[] propertyNames = new string[expressions.Count()];
        for (int i = 0; i < propertyNames.Length; i++)
        {
            propertyNames[i] = GetPropertyName(expressions[i]);
        }

        return propertyNames.Join();
}

I know it also can be done using reflection, but this one is tremendously fast or, I can say, equivalent to a lambda after first compilation. The very first iteration takes just an average of 10 milliseconds. So this is Expression Tree magic. Simple and fantastic (I think)!
Comment: Nice! Thanks for the examples.
Comment: Maybe I'm not reading this right but, does GetPropertyName only work for first order properties? Would it find the name of Baz if I gave it GetPropertyName((Foo f) => f.Bar.Baz); ?
Comment: @JoshGust .. I guees yes ... you will get `Bar.Baz` as `string`
Comment: @Moumit, in that case a simple change `string.Join(".", body.Split('.').Last()` would do the trick, no?
Comment: @JoshGust .. this is example given ... you can customize as per your need ....
Answer: I use them to create dynamic queries, whether it be for sorting or filtering the data. As an example:
IQueryable<Data.Task> query = ctx.DataContext.Tasks;

if (criteria.ProjectId != Guid.Empty)
      query = query.Where(row => row.ProjectId == criteria.ProjectId);

if (criteria.Status != TaskStatus.NotSet)
      query = query.Where(row => row.Status == (int)criteria.Status);

if (criteria.DueDate.DateFrom != DateTime.MinValue)
      query = query.Where(row => row.DueDate >= criteria.DueDate.DateFrom);

if (criteria.DueDate.DateTo != DateTime.MaxValue)
     query = query.Where(row => row.DueDate <= criteria.DueDate.DateTo);

if (criteria.OpenDate.DateFrom != DateTime.MinValue)
     query = query.Where(row => row.OpenDate >= criteria.OpenDate.DateFrom);

var data = query.Select(row => TaskInfo.FetchTaskInfo(row));

Answer: Implementation of LINQ providers is mostly done by processing expression trees. I'm also using them to remove literal strings from my code:

Monorail
NHibernate
Answer: You can use them to build your own linq provider for a website like Google or Flickr or Amazon, your own website or another data provider.
Answer: Originally by Jomo Fisher, Gustavo Guerra published a revised version of
the static string dictionary.
Where through Expression trees, a dynamic expression that provides a really (read: ridiculously) Dictionary.
The implementation creates a dynamic decision tree that select the corrent value according to the length of the input string, then by the first letter, then the second letter and so on.
This ultimately runs much faster than the equivalent Dictionary.

Practical use of expression trees


Make VOIP-phone Cisco SPA504G to receive only 1 call

Question: I don't want the phone to receive more that 1 call. So if an operator have one ongoing call, a new incoming call will received busy signal. As far as I understand, there is no option to set this behaviour using Web Admin of the phone.
Answer: If you are using a Cisco PBX, you can configure this directly on the system.
the "ephone-dn" config section is used for configuring phone extensions, if you make the primary extension of the phone a single-line extension, as in "ephone-dn 1" instead of "ephone-dn 1 dual-line", the phone will only take one call, and the call-forward busy handler will be used for additional calls.
If you are using the SIP firmware for the phone and not using a Cisco PBX, this is not configurable directly on the phone. If you are connecting the phone directly to a SIP provider, they may be able to accommodate this. If not, you'd have to review the options of the PBX you are using.


PHP include() for WordPress plugin- Error/Warning Message

Question: This is my first post on stack overflow, so I apologize if I have violated etiquette or otherwise did something dumb. I'm also a novice programmer as well, so I apologize in advance if this question seems dumb.
Now on to the main point: I'm trying to create a WordPress plugin for a website while our main programmer is on vacation. I've had some success, and now what I need to do is call simplemodal-login from the plugin after the user does a certain action on the webpage. Currently, I am trying this in order to include the files, which are in a separate directory one level up from the plugin in file(I'm going to block out files names to preserve anonymity):
include ("../simplemodal-login/simplemodal-login.php");

I've also tried prefixing the simplemodal-login directory part with /../, ../../, and /../../  . I've also tried
include ("{$_SERVER['DOCUMENT_ROOT']}/[project name]/wp-content/plugins/simplemodal-login");

and some variations of it. Nothing has worked. I keep on getting variations of this error message:
Warning: include(../simplemodal-login/simplemodal-login.php) [function.include]: failed to open stream: No such file or directory in /home/[user name]/public_html/[website name]/[project name]/wp-content/plugins/[my plugin]/[plugin file] on line 29
Warning: include() [function.include]: Failed opening '../simplemodal-login/simplemodal-login.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/[user name]/public_html/[website name]/[project name]/wp-content/plugins/[plugin name]/[plugin file].php on line 29

What am I doing wrong? I simply want to run the simplemodal-login plugin after the user sees the webpage a certain amount of times. How can I include the file properly? I apologize for my inexperience - I've taken an intro course in Java at college (which I did well in) and I've learned a little (I mean LITTLE) bit of PHP this summer as an intern. If anyone could guide me so I don't get that error message when I try to include the files, it would be very helpful.
Thanks!
Comment: Have you tried using an absolute path instead of relative?  i.e.: require('/path/to/simplemodal-login/simplemodal-login.php');
Answer: If the file you are trying to include is one directory level up from the plugin file you are writing the code in, a portable solution would be to use:
include dirname(__FILE__) . '/../file.php';

dirname(__FILE__) returns the path of the file that that statement is executed in (regardless of whether or not it has been included itself).  I use this in Wordpress plugins without any issues.
Hope that helps.
Comment: That worked! Thank you so much! I would vote you up if I could.
Comment: @AndrewAnon Glad that worked, you are able to accept the answer by clicking the checkmark to the left of the answer.  That will build up your rep so you can soon vote on questions.


Intuition behind ambiguity of direction using linear array

Question: I have recently started studying array signal processing. I am struggling to understand the intuition behind ambiguity of direction using a single linear array and how it is solved using two parallel linear arrays. Can anyone please explain me?
Comment: With two arrays you can use differential processing to give you more accurate results. Common mode reflections can be cancelled out, etc. Doppler effects such as motion become more clear.
Answer: Consider a linear array of sensors aligned in a North-South direction. This array cannot distinguish between a signal arriving from the East versus a signal arriving from the West. Either signal will arrive at all of the sensors at the same time. Now consider what happens if there are two parallel arrays designated A and B with array A to the West of array B.  A signal arriving from the East will reach the sensors in array B before the sensors in array A.  Similarly a signal arriving from the West will reach the sensors in array A before those in array B. Thus the directional ambiguity no longer exists.


Sync Google Calendar Tasks with Evolution

Question: I am running Ubuntu 12.04 and prefer Evolution to Thunderbird as my mail manager and organiser. I run a gmail account and use the calendar a lot to organise future meetings,appointments and tasks.I have synced the calendar, contacts and meetings, but cannot get tasks to sync.
Does anyone know how to do that?
Comment: Not with Evolution tasks, but you could maybe use [google-task-indicator](http://www.webupd8.org/2012/03/google-tasks-indicator-quick-access-to.html)
Answer: Tasks are currently not supported in Evolution due to missing support for Google Tasks in underlying library (libgdata).See the bug here.
But it can be done using third party tool syncevolution & web service memotoo.
Google <----------> Memotoo <-----------> Evolution.
First enable universe & multiverse repo.
Then open terminal & type: sudo apt-get update.
Install syncevolution: sudo apt-get install syncevolution sync-ui. Sync-ui is the gtk-gui for syncevolution.
Now go to https://www.memotoo.com/ & U can sign up there for free or choose premium version (1 Euro/Month).Free version has some limitation (max 50 tasks).
Sign in & go to "My Tasks" & select "syncronize my task". See image below.

Select Google Task from the list.Authorize memotoo to access your google account.Select type of synchronization "both ways". You can set sync schedule as per your preference.

On the same page click "synchronize google task" to start syncing manually.At this point you can see your google task on memotoo (default task category). Now you need to sync memotoo with evolution.
Open dash, type sync-ui & from the search open syncevolution.If you open it for first time you need to select the sync service.

Click on select sync service, Select memotoo from the list. Provide memotoo username & password. De-select appointments & contacts check-boxes & finally click "save & use".

Clicking Sync-Now under action will start syncing.If you are syncing for first time it may offer slow-sync.Click on "slow sync" to perform a slow-sync.You can also enable "Automatic   sync" to sync automatically(syncevolution will be running in background). At this point, it will sync to your default task list.You can view default task list by typing "syncevolution" in the terminal.

Extra Tweaks:
You can choose to sync only uncompleted task between memotoo & evolution. To do that open syncevolution, edit memotoo, under server settings change task uri from "task" to "task.uncompleted".

DONE!
Comment: I got the following error in sync-ui when trying to sync with memotoo (own translation):
"There was a problem with the local database. Restarting the syncronization or restarting program may solve the problem"
Comment: Its a coomon bug in syncevolution. To fix it go to `~/.config/syncevolution/default/peers/memotoo/sources/calendar+todo` & open the config.ini file with gedit.Make sure 'sync' is not set to "disabled". If that is case, change it to "two-way" or "slow"(i.e sync=two-way or sync=slow).Relaunch syncevolution.It should work now.Also you could try latest sync evolution from ppa.Add the repository to /etc/apt/sources.list as: `deb http://downloads.syncevolution.org/apt stable main`.Open synaptic & install the 'syncevolution-evolution' package.
Comment: @wouter205 Also you can explicitly set your local database to evolution database(**This is NOT recommended**).First make a backup of `~/.config/syncevolution/sources/calendar+todo/config.ini` file. Then open it with gedit & change the database value to Personal, (i.e database=Personal).It will sync to your task-list named "Personal" which is default task-list in evolution.
Answer: It is 2022 and it seems Google Tasks in Evolution are now supported (I am not sure since).  Assuming you already have your Gmail connected via IMAP account, go to Evolution > Tasks > Edit > Accounts > Task Lists > Add > Task List, fill in the form as shown bellow and it should work.
Type: Google
Name: Tasks
User: email@example.com