I had to recreate my computer and have installed Ubuntu 13.04 as my main OS. As a printer I would like to install a Canon iSensys LBP 2900 printer. The printer-setup recognizes the device, but it won'T allow me to install the proper driver for this device - simply because there seems to be none available. Is that true?  I checked the various similar topics about this issue, but they are either outdated and the data-packages (drivers) are not available anymore or about older/ earlier Ubuntu versions.  Thank you for any advice or help or support.  Best wishes! Liam
I am trying very hard to install Canon LBP2900b Printer in Ubuntu 13.10.  I have searched and googled a lot for the solution over fortnight but none of the site / link gave me the simple solution for me. How can accomplish my goal?
I'm making a Java application with an application-logic-thread and a database-access-thread. Both of them persist for the entire lifetime of the application and both need to be running at the same time (one talks to the server, one talks to the user; when the app is fully started, I need both of them to work).  However, on startup, I need to make sure that initially the app thread waits until the db thread is ready (currently determined by polling a custom method dbthread.isReady()). I wouldn't mind if app thread blocks until the db thread was ready.  Thread.join() doesn't look like a solution - the db thread only exits at app shutdown.  while (!dbthread.isReady()) {} kind of works, but the empty loop consumes a lot of processor cycles.  Any other ideas? Thanks. How do I overload the square-bracket operator in C#? DataGridView, for example, lets you do this:  DataGridView dgv = ...; DataGridViewCell cell = dgv[1,5];   but for the life of me I can't find the documentation on the index/square-bracket operator.  What do they call it?  Where is it implemented?  Can it throw?  How can I do the same thing in my own classes?  ETA: Thanks for all the quick answers.  Briefly: the relevant documentation is under the "Item" property; the way to overload is by declaring a property like public object this[int x, int y]{ get{...}; set{...} }; the indexer for DataGridView does not throw, at least according to the documentation.  It doesn't mention what happens if you supply invalid coordinates.  ETA Again: OK, even though the documentation makes no mention of it (naughty Microsoft!), it turns out that the indexer for DataGridView will in fact throw an ArgumentOutOfRangeException if you supply it with invalid coordinates.  Fair warning. Adjectives and nouns to describe an answer that doesn't answer the question? I've heard of the adjectives 'nonresponsive' or , but are they restricted to law^?     Collins Dictionary:  =       not responsive, not reacting to a stimulus   The definition above differs from the definitions of adjectives like 'equivocate,  evade' and nouns like , but these are negative and accusive; I prefer neutral connotation.  ^Only if you wish, please see: ,  by David Berg,  by Thomas A. Mauet. As the title says, I'm wondering if there is a continuous function such that $f$ is nonzero on $[0, 1]$, and for which $\int_0^1 f(x)x^n dx = 0$ for all $n \geq 1$. I am trying to solve a problem proving that if (on $C([0, 1])$) $\int_0^1 f(x)x^n dx = 0$ for all $n \geq 0$, then $f$ must be identically zero. I presume then we do require the $n=0$ case to hold too, otherwise it wouldn't be part of the statement. Is there ay function which is not identically zero which satisfies $\int_0^1 f(x)x^n dx = 0$ for all $n \geq 1$?  The statement I am attempting to prove is homework, but this is just idle curiosity (though I will tag it as homework anyway since it is related). Thank you! Error propagation with asymmetric uncertainties I red the Wikipedia  on error propagation. I get into some trouble when I want to calculate the error propagation in a specific case. I have real numbers $A$ and $B$ with related upper ($\Delta A_u$, $\Delta B_u$) and lower ($\Delta A_l$, $\Delta B_l$) uncertainties. I have two functions calculated as follows: $$F = \sqrt{A^2+B^2}$$ and  $$G = \tan^{-1}\frac{B}{A}$$ What are the related upper and lower errors of $F$ and $G$?  I found general formulae for Gaussian error distributions ($\Delta A_u = \Delta A_l$ and $\Delta B_u = \Delta B_l$), for instance the first formula of the first answer on . Is there a way to generalize that formula for arbitrary distributions with asymmetric errors as in my example? Is it safe to have laptop turned on 24/7? What order do triggered abilities happen in if multiple things trigger at the same time? I had several humans on the battlefield.  On turn three, I played . On turn four, I played . On turn five, during my upkeep, this question came up.  At this point, I need to draw/reveal three cards. If I reveal a human, Descendants' Path will allow me to cast it without paying its mana cost.  So, does it matter when I draw the human?  The static abilities state "at the beginning up your upkeep..." which leads me to believe that those two draws/reveals would happen before my normal draw. If that's the case, does the draw order happen in the same order that I played the enchantments?  In the end, that's how we decided to do it. I drew first for Triumph of Ferocity, then I revealed for Descendants' Path, then I drew for my turn. Did we do it right? How to inject Spring Bean for factory method requiring MyClass.class parameter Vectorize a PNG file in Adobe Illustrator CC 2017 I need to open a white PNG shape in Illustrator. I want to convert it into vector and change the color. In CS6 is very simple to do this. Can you help me to do this in CC? Why won't my computer go to sleep automatically? Windows 8 is set to sleep after 30 mins, and it used to work, but recently it's started refusing to sleep. (I can still manually ask it to go to sleep without any issue.)    I was having issues a while ago, but it was with my network adapter. That's since been disabled, so it's definitely not that:    I've checked to see what devices are able to wake up my machine, but it only appears to be my mouse:    Which is odd, because I haven't recently changed my mouse, and more confusing still: The monitor does go to sleep just fine. If it was actually the mouse keeping my system awake, I'm pretty sure the monitor wouldn't go to sleep.  I've checked my Wake Timers, and nothing:    I've also checked my existing requests...  UPDATE: I found something. What to do with it, I don't know...    Note: Even when /requests says that there's "NONE" under every category, my machine still won't sleep(!).    In short: How can I tell what's preventing my computer from Sleeping?    UPDATE: Ok, so I now have a few more pieces of the puzzle. I came back to my computer and it was ASLEEP! Lawks! It seems that the only times it doesn't sleep is if VLC Player is open, even if a video isn't actually playing.  UPDATE UPDATE: Ok, so it won't sleep sometimes when VLC Player ISN'T running, either. Bah! I have a 2-D probability distribution along the lines of this plot:  I know how to find the confidence interval for a 1-D probability distribution (by the definition of standard deviation or the 68-95-99 rule) but I don't know how to generalize that to 2-D to get a confidence region. I've been looking at Principle Component Analysis and covariance matrices, but most explanations or examples are for a 2D distribution of random vectors rather than a probability distribution so I'm not quite sure how to generalize it. How would I find the 1-$\sigma$/2-$\sigma$ regions for a 2D probability distribution? Edit: The question that was linked in the duplicate message refers to random vectors, whereas what I have is a probability distribution from data, with a continuous 2-D probability function as opposed to random vectors. As such, I cannot find the covariance matrix between two vectors because I DO NOT HAVE TWO VECTORS, and therefore cannot apply the process described in the linked question. If I were to analogize to 1-D, my issue is the difference between the standard deviation for a random distribution of samples, $\sigma=\sqrt{\frac{1}{N}\sum (x_{i}-\bar{x})^{2}}$, and the standard deviation for a probability distribution $\sigma=\sqrt{\sum (x_{i}-\bar{x})^{2}P(x_{i})}$. As far as I can tell, the method involving the covariance matrix is a generalization of the former. I need a generalization of the latter. If I'm wrong in my understanding, please let me know, but I don't think the other question gives me what I need. Benefits of using backtick (`) in MySQL queries? In MySQL we can create queries with or without the backtick (`) symbol. Example:   SELECT * FROM TEST; SELECT * FROM `TEST`;   Both works fine in mysql-console.  Is there any technical difference between them?  Is there any benefit using (`) over over simple queries? Given   $$ f_{XY}(x,y) = \frac{1}{2\pi \sqrt{1-\rho^2}} \exp \left( -\frac{x^2 +y^2 - 2\rho xy}{2(1-\rho^2)} \right) $$  $Y = Z\sqrt{1-\rho^2} + \rho X$  And   $$ f_{XZ}(x,z) = \frac{1}{2\pi } \exp \left( -\frac{x^2 +z^2}{2} \right) $$  Show that $P(X&gt;0,Y&gt;0)= \frac{1}{4}+\frac{1}{2\pi}(\arcsin \rho) $  I'm supposed to use the fact that X and Z are independent standard normal random variables, but I don't quite understand how. Any help would be greatly appreciated. Below is my code to create the component dynamically - The component is "ui:inputselect"  $A.createComponent(             RecoveryLineItem.Attributes[i].name,{                 "class" : "slds-input ",                 "aura:id" : 'ExampleId',                 "label" : RecoveryLineItem.Attributes[i].label,                 "multiple" : RecoveryLineItem.Attributes[i].multiple             }, ....   ..  console.log(component.find('ExampleId').get("v.value"))    Or console.log(component.find('ExampleId'))  is Giving as 'Undefined"  How to access the aura:id of the dynamically created components? When does SQLiteOpenHelper onCreate() / onUpgrade() run? How to access the Keyboard Layout Options in 13.10+ Microphone Not Working With FaceTime What are the various physical mechanisms for energy transfer to the photon during blackbody emission? By conservation of energy, the solid is left in a lower energy state following emission of a photon.  Clearly absorption and emission balance at thermal equilibrium, however, thermodynamic equilibrium is a statement of the mean behaviour of the system, not a statement that the internal energy is constant on arbitrarily short timescales.  The energy has to come from somewhere during emission, and go somewhere during absorption.  Energy in a solid can be stored as kinetic and potential energy of electrons and nuclei, either individually or in collective modes such as phonons and plasmons.  In thermal equilibrium energy will be stored more or less in various forms depending on the temperature and material.  However, even if most of the thermal energy in a particular solid at temperature $T$ is stored in the form of phonons, it could be that phonons primarily interact with light indirectly via electrons, e.g. a phonon excites an electron in a phonon-electron interaction, which can interact with light via the EM field.  Given that light is an EM field, it makes sense to me that it is emitted and absorbed by charged particles.  The electron-photon interaction is probably dominant for visible and ultraviolet light, given that metals are opaque, while semiconductors and insulators are transparent to (visible and UV) light with energy lower than their bandgap. However, once you get into energies in the IR and below, or X-rays and above, other mechanisms apparently take over.  For example, on the high-energy end of the spectrum I've heard that gamma rays can interact directly with nuclear degrees of freedom, which is reasonable considering that gamma rays are emitted during a lot of nuclear reactions.  A review of  might give clues to important light-matter interactions over a broad range of wavelengths.  Whether all of the these processes are involved in blackbody emission is a somewhat different question.  What physical processes mediate energy transfer during blackbody emission, and in which energy ranges are the various processes dominant? The integral $\int_0^\infty \dfrac{x \sin(x)}{x^2+1} dx$ How to calculate: $$\int_0^\infty \frac{x \sin(x)}{x^2+1} dx$$ I thought I should find the integral on the path  $[-R,R] \cup \{Re^{i \phi} : 0 \leq \phi \leq \pi\}$.  I can easily take the residue in $i$ $$  Res_{z=i} \frac{x \sin(x)}{x^2+1}  \quad = \quad \frac{i (e^{ii}-e^{-ii})}{2i}  \quad = \quad \frac{i(\frac1e-e)}{2i} \quad = \quad \frac1{2e}-\frac e2 $$ I know that the integral on $[-R,R]$ will get nearby the real value of $ \frac12\int_0^\infty \frac{x \sin(x)}{x^2+1} dx$. That means that I'm done if I show that the integral on the other part of the path will be small, here is an attempt to do so:  $$ \left|\frac{x \sin(x)}{x^2+1} \right|  \quad \leq \quad  R \cdot \frac{|\sin x|}{R^2-1} $$ I could rewrite $\sin x$ but it becomes nasty. Can you help me with this? C++ catching all exceptions