User talk:Oleg Alexandrov

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[edit] Re: your RfA

Hi Oleg,

Regarding your RfA, I was just a bit puzzled by your comment that you want to delete old revisions of your files. There is not really any reason to do this, since deleted files are still kept in storage - so it doesn't save any space. cheers, pfctdayelise (说什么?) 03:30, 14 April 2007 (UTC)

OK. I must confess I did not do my homework for this RfA. :) Thank you for your note. I may try my luck later should I feel that having admin privileges at commons would be useful. Oleg Alexandrov 05:20, 14 April 2007 (UTC)

No prob. :) BTW, my personal feeling is that admins here should be part of the community here, regardless of where else they edit. So although appealing to your experience on enwp might be one way to show that you're trusted, it's not such a convincing demonstration that you're trusted here. The reason is that we have distinct policies and maybe a distinct community feeling. Personally I want admins that are going to carry out actions in a "Commons way", not an "English Wikipedia way" (or any other wiki). cheers, pfctdayelise (说什么?) 06:20, 14 April 2007 (UTC)

[edit] Image links

Hi Oleg. You've recently changed Image:Finite Differences.png and some more. Firstly: thanks, it looks better now. Secondly: I wanted to ask how can I check the usage of an Image on commons in other wiki project, because the page on Commons sais: "There are no pages that link to this file." Thanks, Mintz l 15:33, 24 May 2007 (UTC)

You're welcome. Usually I like to make the details larger, so that they can be seen in a thumb, so the lines thicker, fonts bigger, etc.

Now, to see the usage, visit the image, say Image:Finite Differences.png, and look at the top there is a "check usage" tab. Note that that tool does not always give very accurate results since the database it searches can be a few hours or days out of date for non-English Wikipedias (and a few months for the English Wikipedia). Cheers, Oleg Alexandrov 02:13, 25 May 2007 (UTC)

[edit] Image:Simple harmonic oscillator.gif

Hi Oleg, I saw the image you made, well done, could you do one with damped oscillations ? that could be useful to train students. Thanks Dingy 02:58, 24 June 2007 (UTC)

Good idea. Will do. I am still tweaking the undamped one now. Oleg Alexandrov 03:08, 24 June 2007 (UTC)

Done, Image:Damped spring.gif. Thanks for the idea! Oleg Alexandrov 04:00, 24 June 2007 (UTC)

[edit] Travelling wave

Hello Oleg, I saw with interest , and would like to mention the use of travelling waves to explain voltage variations on a line when a switch interrrupts (on the left side of the line) a fault due to a fault (on the right side of the line). There are similar reflections at the fault point and at the open point (although the amplitude is doubled there), you can see that on page 35 of [1]. Do you think an image could be done as you did with Wave equation 1D fixed endpoints, as there are two waves moving in opposite directions maybe several images are necessary ? Dingy 03:15, 24 August 2007 (UTC)

I will think about how I could implement this. Oleg Alexandrov 03:09, 30 August 2007 (UTC)

Thanks. Dingy 05:08, 1 September 2007 (UTC)

I looked at that paper. I must say I don't understand very well what is going on there, and how to apply the wave equation to get the kind of behavior you would like to see (I don't completely understand the behavior you need either).

Also, on what Wikipedia page could this figure be used?

If you know better these things, you could perhaps be able to adapt the code to the picture above (it is available on the picture page), to do the movie you want. Or, if you could tell me the exact mathematical equations, I could modify the code myself. Oleg Alexandrov 04:15, 4 September 2007 (UTC)

I made this image,

for the en:Transmission coefficient (optics) article. It is not quite what you wanted I guess, but I made it inspired by your suggestion. Thanks! Oleg Alexandrov 06:05, 26 November 2007 (UTC)

Hi, that's good ! you could combine it with

to have the reflection at the open point Dingy 02:32, 2 December 2007 (UTC)

But where is the open point? Oleg Alexandrov 05:58, 2 December 2007 (UTC)

In the case I am interested in, it is the point on the left. When the wave coming from the right reaches an infinite impedance it does not change sign and is doubled in amplitude, it then goes on like the one you just did Partial transmittance with oposite sign. Dingy 07:29, 2 December 2007 (UTC)

[edit] Image:Improperintegral1.png

Image deletion warning

Image:Improperintegral1.png has been listed at Commons:Deletion requests so that the community can discuss whether it should be kept or not. We would appreciate it if you could go to voice your opinion about this at its entry.

If you created this image, please note that the fact that it has been proposed for deletion does not necessarily mean that we do not value your kind contribution. It simply means that one person believes that there is some specific problem with it, such as a copyright issue. If the file is up for deletion because it has been superseded by a superior derivative of your work, consider the notion that although the file may be deleted, your hard work (which we all greatly appreciate) lives on in the new file.
In all cases, please do not take the deletion request personally. It is never intended as such. Thank you!

Moloch981 09:47, 25 November 2007 (UTC)

[edit] Fourier Wave on a Disc

Hey Oleg,

I noticed this image on the Fourier Series page:

Its description indicates that a Fourier series is the solution to the wave equation on a disc. The problem of finding the solutions to the wave equation on a disc is typically solved in cylindrical coordinates. The solution in that particular coordinate system would be a Bessel function. You could of course write that solution as a Fourier series (this amounts to a simple change of basis), but that wouldn't really serve the purpose of demonstrating to the reader what a Fourier series in 2-dimensions looks like. It seems like it really should be replaced with a similar image showing solutions to the wave equation on a square or removed entirely.

Let me know if I should give a more detailed response or a proof. Thanks.

I am fully aware of what you are saying. I did not put the picture on the Fourier series page. I suggest you raise this at en:talk:fourier series. Oleg Alexandrov 04:11, 24 May 2008 (UTC)

[edit] Image:UCLA Bruin.jpg

Oleg, I've deleted this image as it is a two dimensional representation of a three dimensional work of art. Per US Copyright Act of 1976, § 106(2), who owns copyright of the original has the exclusive right to authorize derivative works. The statue was dedicated in 1985 [2], so it is not PD by way of age. Thought you'd like to know, --Durin (talk) 15:28, 22 August 2008 (UTC)

[edit] Vibrations of drums

Just a word of gratitude for putting up the vibrational modes of circular membranes. I intend to use them in my General Chemistry 101 course as a step up to atomic orbitals. I think it will help a lot to get idea of nodal lines and nodal circles (and implicitly: quantum numbers) across. Any visual support for that is very welcome because freshmen find atomic orbitals very puzzling and difficult to grasp.

Besides they love a cool simulation... Jcwf (talk) 18:58, 22 August 2008 (UTC)

You're welcome. Oleg Alexandrov (talk) 00:19, 2 September 2009 (UTC)

[edit] Please link images

Hello Oleg Alexandrov!

Thank you for providing images to Wikimedia Commons. Commons images are used by editors on many projects in many languages. Each image is put into categories. This helps other editors find them. Please add categories to each image you upload.

To add an image to a category, add the following code to the end of the page.

[[Category:Category Name]]

For example, if you are uploading a diagram showing the orbit of comets, add the following to the image description page:

[[Category:Astronomy diagrams]]

[[Category:Comets]]

This will make the diagram show up in the categories: Astronomy diagrams, Comets.

For further information on categories read Commons:Categories.

The CommonSense Tool often helps you find the best category for your image.

Here is a gallery of your images. Please check that each image has a category. If you have any questions, please feel free to ask them at the help desk. Thank you.

BotMultichillT 06:07, 30 May 2009 (UTC)

Image:Lick Observatory2.JPG is uncategorized since 29 May 2009.
Image:Xemacs-21.5.b29.png was uncategorized on 19 August 2009.
Image:AVALONIA.jpg was uncategorized on 6 September 2009.
Image:Phase-shift illustration.png was uncategorized on 6 September 2009.

User talk:Oleg Alexandrov

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Contents

[edit] Re: your RfA

[edit] Image links

[edit] Image:Simple harmonic oscillator.gif

[edit] Travelling wave

[edit] Image:Improperintegral1.png

[edit] Fourier Wave on a Disc

[edit] Image:UCLA Bruin.jpg

[edit] Vibrations of drums

[edit] Please link images

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