OpenLLM-France/wikimedia huggingface dataset:
# How to Create a dvavi file [for use in a video editing program] from a DVD.
## You will need to install

* Virtual dub mod - http://sourceforge.net/project/showfiles.php?group_id=65889 download it - it has an installer for windows.
* Ac3 Codec - http://www.softpedia.com/get/Multimedia/Video/Codec-Packs-Video-Codecs/AC3-ACM-Decompressor.shtml download it - Uncompress the files from ac3acm.zip archive, right-click on the ac3acm.INF file and select Install. - You may encounter a prompt saying: "The software you are installing for this hardware... has not passed Windows Logo testing..."; click on the Continue Anyway button.
* Panasonic DV codec -
http://www.free-codecs.com/download/Panasonic_DV_Codec.htm download it</a>
- Uncompress the files from pdvcodec.zip archive, right-click on the PANADV.INF file and select Install. - You may encounter a prompt saying: "The software you are installing for this hardware... has not passed Windows Logo testing..."; click on the Continue Anyway button. - You should now be able to load DV-AVI Type-2 files with VirtualDub (and any other program that loads AVI files).

## How to do it!

Some information: DVD's have their video data on the disk in the format of *.VOB files. A film is often split into several VOB files. If you want these can be played in your media player if you open them up on at a time. It is good to do this to find out which VOB file the particular bit of footage you want is in.
If you want to do this with a bit of footage that is encrypted or spans more than one VOB you will need to use Gordian Knot to do this, http://sourceforge.net/projects/gordianknot</a>

### Video

Open up Virual Dub Mod.
File > Open File
Choose the *.VOB file that contains the bit of footage you want.
You can scan through the file with the Play head like in a video editing program[1]. And you can set the in and out points as well. with buttons [2].
Now we are going to set the Video settings.
In the Video Menu choose Compression.
Video > Compression.
Choose from the list Panasonic DV avi. Click ok

### Audio

Now we deal with the Audio. This is a "Stream" so we go to the Stream menu and select Stream list.
If your source video file has audio it should be listed as a grey bar with information as seen below. [if you are using Gordian Knot to do this process from a DVD you will need to click ADD and browse for the *.wav file created in that process]
Right hand Click on this bar and select "Full Processing mode".
Then Right hand click again and Select "Compression".
If Conversion is greyed out it's because you haven't selected full processing mode.
Choose the top option - No compression PCM. Then click ok.
Now you are ready to save your DV avi file.
File > Save as
Give your file a name choose where to save it and click ok.
You should be able to import that file into premiere or other video editing programs.
# Ripping subtitle files from DVDs for re-use - and Burning subs to Xvid Files from External files

This is a bit geeky so the documentation is a bit brief. But I learnt how to do it so I may as well document it. It may be useful for someone.

## Creating subtitles as an external file from dvd

   You can rip the video and subtitle information separately from a dvd and then create subtitle files in different languages which can be played over the top of the player using clever players like Video Lan or Media Player Classic.
   To do this you need to convert the sub files you can rip from the DVD information here
   Software - install a package with lots of tools for riping dvds called Gordian Knot - http://gordianknot.sourceforge.net/
   This has a programme attached to it called Vob Sub Rip
   IFO files can be opened from the DVD with this tool - Know which segment of the DVD you want to encode. Do this by previewing the VOB files that are on the DVD.
   There will be a screen listing languages. The default is to choose all of them. This seems fine stick with this.
   It will then strip the information of subtitles from the DVD and save it as an .idx file and a .sub files - and then you can either encode that to an external file or burn the subtitles directly into a file using Virtual Dub
   Actually .sub files are not text files... they are in graphic format.... They also come with an index file .idx
   TO convert an .sub file into an .srt you need to install a program called vobsub onto your virtual pc.... and use a program contained in that package called vobresync
   Open the programme - Open the *.sub file and then Save As and choose *.srt
   It works like a scanner ocr program... in which it attempts to identify the letters from the sub graphic text. Whatever it doesn't recognize it will prompt you to enter ... the more it does .. the more it learns...
   You can also create your own subtitle files with <a href="http://www.urusoft.net">Subtitle Workshop</a> -

## Creating subtitles burned into the xvid - using virtual dub

   Open Virtual Dub Mod and open the relevant VOB file that corresponds with ifo file.
   Add a filter Vob Sub - and choose the .sub file that you have just created, there is a choice of languages - choose the relevant one. You can then encode the file normally [see other files for how to encode to divx or dv avi]
   With an Srt file you can Add Filter > Subtitler and choose the styles options there.
# Video Production/Editing a subtitle file with a text editor
## Opening Editing and Saving Subtitle Files from a Text Editor

Video creators and distributors are starting to create subtitle files for their videos. These are transcripts with timecodes included. They are very useful as they can be played on a computer linked with the appropriate video file, so that the subtitles are displayed. They can also be used to create subtitles for DVDs. These subtitle files can be selected as needed when viewing a video, and do not need to be 'burnt on' to the video image as subtitles have been traditionally.
Translators can also use a simple text editor like NotePad, Word Pad, Text Edit etc to open, edit (ie translate) and save the timecoded transcription file to a different language version.

### Windows

In Windows the simplest way to do this is with the NotePad program. You can open it in the Applications section of the Programs Menu.
Open notepad
File:Opennotepad.jpg
When you have opened it you can select and substitute each line of text with the translation. Be careful not to alter any of the numbers listed in the first 2 lines of each caption.
becomes
When the translation is finished you can save the file once more with a different name. Be sure to select from File Type, "Text Documents *.txt" - and give the file a *.srt extension as shown below. Then, for example, if the original is called transmission_xvid_700kps_mp3_128_en.srt and you have translated it to dutch you could call it transmission_xvid_700kps_mp3_128_nl.srt. It's good to include as much information as you can in the title of files to make it easier for internet distribution.

### Other platforms

The same theory applies if you are using Word, or Word Pad, or a Mac Text Edit or similar programmes. Just make sure you save as a text file, with the language indicated in the name, and with the .srt extension.
The file can then be emailed to whoever needs it, or it may be possible to upload it to the page that the original was downloaded from.
# Video Production/Ffmpeg to theora

Conversion of Dv Avi file into the ogg theora video file using windows
The free software to convert videos into the Ogg Theora Format is called "ffmpeg2theora", you can download it here. http://www.v2v.cc/%7ej/ffmpeg2theora/download.html
You must have the program 'ffmpeg2theora' in the same folder as the video (video.dv or video.avi) that you want to convert (copy-past or drag and drop it in the right location).
Then you must start the Command Prompt', you can find it under : Start > Programs > Accessories > Command Prompt.
Imagine the where the video that you want to convert is on your harddrive with the name "E:" in a folder called "umwandeln".
You can navigate to the right harddisk by using commands like "E:" and Enter You can navigate to the right folder by using the "cd" command, for example: "cd umwandeln" and Enter (cd stands for 'change directory')
Other help: The command 'dir' shows a list of the content of that folder (directory)
The command 'cd ..' moves you up to one folder level
Then, you can start the conversion by giving the command:
"ffmpeg2theora -p pro video.dv" (or .avi) and Enter:
After some time, depending on your hardware, the ogg video is ready and available in the same folder.
Notes:
It is possible to create ogg videos in a lower quality, for example the preview version, the command for that is: "ffmpeg2theora -p preview video.dv". Next to that, it is also possible to code the video in a diffent quality, e.g.: Video Quality 7 and Audio Quality 3, then you use the command: "ffmpeg2theora -v 7 -a 3 video.dv"
ffmpeg2theora -p pro video.dv -> Video: 720x576 if fps ~ 25, 720x480 if fps ~ 30 Quality 7 - Sharpness 0 Audio: Max 2 channels - Quality 3
ffmpeg2theora -p preview video.dv -> Video: 384x288 if fps ~ 25, 320x240 if fps ~ 30 Quality 5 - Sharpness 2 Audio: Max 2 channels - Quality 1
The command "ffmpeg2theora -h" gives a list of the possible output parameters that can be used.
More information on Ogg Theora :: here http://www.v2v.cc/%7ej/ffmpeg2theora/
# Waves/1D Solutions

Waves : 1 Dimensional Waves 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 Examples - Problems - Solutions - Terminology
As you have learned in the previous sections, the linear waves you studied in the previous section tend to disperse. However, there are nonlinear waves described by nonlinear partial differential equations (PDE) which admits solutions with nondispersing wave packets.
Here are two primary examples:

## Sine-Gordon

This is described by the PDE
$\partial _{x}^{2}\phi -\partial _{t}^{2}\phi =\sin(\phi )$.
The equation of a wave travelling along the positive x direction is given by y=0.25 x 0.001sin(500t-0.025x)determine the angular frequence
# Waves/1D Terminology

Waves : 1 Dimensional Waves 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 Examples - Problems - Solutions - Terminology
* Terminology
* s = Displacement (unit = metre, m): Displacement is the position of a particle of the medium relative to its equilibrium position.
* T = Period (unit = second, s): Period is the time for one complete cycle or oscillation of the medium.
* φ = Phase (unit = degrees or radians): Phase is the position (with respect to time) of the oscillation taking zero disturbance as zero time. As the disturbance goes through a cycle the position in the cycle is called the phase and, since the mathematical expression for the disturbance usually involves a sine function of the time, the phase is measured in degrees or radians. A full cycle is 360° and a quarter of a cycle is 90°.
* A or a = Amplitude (unit = various): Amplitude is the maximum disturbance of the medium from its equilibrium position or state.
* f = Frequency (unit = hertz, Hz): Frequency is the number of waves passing any point per second or the number of oscillations of the medium per second.
* λ = Wavelength (unit = metre, m): Wavelength is the distance between two points on successive wave fronts that are in phase. A Wave Front is a line joining all points that are in phase. Successive wave fronts are drawn at the same phase and waves are one wavelength apart. Waves travel perpendicular to the wave front.
* I = Intensity (unit = W/m$^2$ = kg/s$^3$, W·m$^{−2}$ = kg·s$^{−3}$): Intensity is the energy passing through unit area (perpendicular to the area) per second.
* v = Speed (unit = m/s, m·s$^{−1}$): Speed is the distance travelled by a wave front per second.
Waves : 1 Dimensional Waves 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 Examples - Problems - Solutions - Terminology
# Waves/Beats

Waves : 1 Dimensional Waves 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 Examples - Problems - Solutions - Terminology

### Beats

Suppose two sound waves of slightly different frequencies impinge on your ear at the same time. The displacement perceived by your ear is the superposition of these two waves, with time dependence $A(t)=\sin(\omega _{1}t)+\sin(\omega _{2}t)=2\sin(\omega _{0}t)\cos(\Delta \omega t),$ (2.19)
where we now have $\omega _{0}=(\omega _{1}+\omega _{2})/2$ and $\Delta \omega =(\omega _{2}-\omega _{1})/2$. What you actually hear is a tone with angular frequency $\omega _{0}$ which fades in and out with period $T_{beat}=\pi /\Delta \omega =2\pi /(\omega _{2}-\omega _{1})=1/(f_{2}-f_{1}).$ (2.20)
The beat frequency is simply $f_{beat}=1/T_{beat}=f_{2}-f_{1}.$ (2.21)
Note how beats are the time analog of wave packets -- the mathematics are the same except that frequency replaces wavenumber and time replaces space.
Waves : 1 Dimensional Waves 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 Examples - Problems - Solutions - Terminology
# Waves/Anisotropic Media

Waves : Geometrical Optics 1 - 2 - 3 - 4 - 5 - 6 Problems

### Anisotropic Media

Notice that Snell's law makes the implicit assumption that rays of light move in the direction of the light's wave vector, i. e., normal to the wave fronts. As the analysis in the previous chapter makes clear, this is valid only when the optical medium is isotropic, i. e., the wave frequency depends only on the magnitude of the wave vector, not on its direction.
Certain kinds of crystals, such as those made of calcite, are not isotropic -- the speed of light in such crystals, and hence the wave frequency, depends on the orientation of the wave vector. As an example, the angular frequency in anisotropic medium might take the form
    $\omega =\left[{\frac {c_{1}^{2}(k_{x}+k_{y})^{2}}{2}}+{\frac {c_{2}^{2}(k_{x}-k_{y})^{2}}{2}}\right]^{1/2},$ (4.4)
where $c_{1}$ is the speed of light for waves in which $k_{y}=k_{x}$, and $c_{2}$ is its speed when $k_{y}=-k_{x}$.
Figure 3.3 shows an example in which a ray hits a calcite crystal oriented so that constant frequency contours are as specified in equation (3.4). The wave vector is oriented normal to the surface of the crystal, so that wave fronts are parallel to this surface. Upon entering the crystal, the wave front orientation must stay the same to preserve phase continuity at the surface. However, due to the anisotropy of the dispersion relation for light in the crystal, the ray direction changes as shown in the right panel. This behavior is clearly inconsistent with the usual version of Snell's law!
It is possible to extend Snell's law to the anisotropic case. We will not derive the equations here, but they are
    ${\frac {dx_{i}}{dt}}={\frac {\partial \omega }{\partial k_{i}}}\quad {\frac {dk_{i}}{dt}}=-{\frac {\partial \omega }{\partial x_{i}}}$
Later we will see a suggestive resemblance between these equation of geometrical optics and the equations of classical mechanics.
For now, though, we will assume that isotropic optical media are used, and discuss optical instruments.
Waves : Geometrical Optics 1 - 2 - 3 - 4 - 5 - 6 Problems
# Waves/Diffraction Grating

Waves : 2 and 3 Dimension Waves 1 - 2 - 3 - 4 - 5 - 6 - 7 Problems

### Diffraction Gratings

Since the angular spacing $\Delta \theta$ of interference peaks in the two slit case depends on the wavelength of the incident wave, the two slit system can be used as a crude device to distinguish between the wavelengths of different components of a non-sinusoidal wave impingent on the slits. However, if more slits are added, maintaining a uniform spacing $d$ between slits, we obtain a more sophisticated device for distinguishing beam components. This is called a diffraction grating.
Figures 2.17-2.19 show the amplitude and intensity of the diffraction pattern for gratings with 2, 4, and 16 slits respectively. Notice how the interference peaks remain in the same place but increase in sharpness as the number of slits increases.
The width of the peaks is actually related to the overall width of the grating, $w=nd$, where $n$ is the number of slits. Thinking of this width as the dimension of large single slit, the single slit equation, $\alpha _{max}=\lambda /(2w)$, tells us the angular width of the peaks.
Whereas the angular width of the interference peaks is governed by the single slit equation, their angular positions are governed by the two slit equation. Let us assume for simplicity that $\vert \theta \vert <<1$ so that we can make the small angle approximation to the two slit equation, $m\lambda =d\sin \theta \approx d\theta$, and ask the following question: How different do two wavelengths have to be in order that the interference peaks from the two waves not overlap? In order for the peaks to be distinguishable, they should be separated in $\theta$ by an angle $\Delta \theta =m\Delta \lambda /d$, which is greater than the angular width of each peak, $\alpha _{max}$:
    $\Delta \theta >\alpha _{max}.$ (3.24)
Substituting in the above expressions for $\Delta \theta$ and $\alpha _{max}$ and solving for $\Delta \lambda$, we get $\Delta \lambda >\lambda /(2mn)$, where $n=w/d$ is the number of slits in the diffraction grating. Thus, the fractional difference between wavelengths which can be distinguished by a diffraction grating depends solely on the interference order $m$ and the number of slits $n$ in the grating:
    ${\frac {\Delta \lambda }{\lambda }}>{\frac {1}{2mn}}.$ (3.25)
More information about diffraction and diffractive optics
# Adventist Youth Honors Answer Book/Computers/Ink jet printer

Most current inkjets work by having a print cartridge with a series of tiny electrically-heated chambers. To produce an image, the printer runs a pulse of current through the heating elements. A steam explosion in the chamber forms a bubble, which propels a droplet of ink onto the paper (hence Canon's tradename for its inkjets, Bubblejet). When the bubble condenses, surplus ink is sucked back up from the printing surface. The ink's surface tension pumps another charge of ink into the chamber through a narrow channel attached to an ink reservoir.
Compared to earlier consumer-oriented printers, ink jets have a number of advantages. They are quieter in operation than impact dot matrix or daisywheel printers. They can print finer, smoother details through higher printhead resolution, and many ink jets with photorealistic-quality color printing are widely available.
The disadvantages of inkjets include flimsy print heads (prone to clogging) and expensive ink cartridges (sometimes costing US$30 – $40 or more). This typically leads value-minded consumers to consider laser printers for medium-to-high volume printer applications.
A common business model for inkjet printers involves selling the actual printer at or even below production cost, while dramatically marking up the price of the (proprietary) ink cartridges.
# Adventist Youth Honors Answer Book/Computers/Keyboard

A computer keyboard is a peripheral modelled after the typewriter keyboard. Keyboards are designed for the input of text and characters, and also to control the operation of the computer. Physically, computer keyboards are an arrangement of rectangular or near-rectangular buttons, or "keys". Keyboards typically have characters engraved or printed on the keys; in most cases, each press of a key corresponds to a single written symbol. However, to produce some symbols requires pressing and holding several keys simultaneously, or in sequence; other keys do not produce any symbol, but instead affect the operation of the computer, or the keyboard itself.
    Roughly 50% of all keyboard keys produce letters, numbers or signs (characters). Other keys can produce actions when pressed, and other actions are available by simultaneously pressing more than one action key.
# Adventist Youth Honors Answer Book/Dairy cattle breeds

Brown Swiss :
* Description: Brown Swiss is the breed of dairy cattle that produces the second largest quantity of milk per annum. The milk contains on average 4% butterfat and 3.5% protein, making their milk excellent for production of cheese. The Brown Swiss is known for their immense size, large furry ears, and an extremely docile (though some would say lethargic) temperament.
Guernsey :
* Description: The Guernsey is a breed of cattle used in dairy farming. It is cream and brown in color and is particularly renowned for the rich flavor of its milk, the very rich yellow color that is richest color of any milk breed, as well as its hardiness and docile disposition.
Holstein :
* Description: The primary color pattern for this dairy breed is black and white, but a red and white variety, called "Red Holstein", is also maintained. They are the most common breed of milk cow in America, gives the highest amount of milk yet the lowest butterfat.
Jersey :
* Description: The Jersey cow is quite small, ranging from only 800 to 1200 pounds (360 to 540 kg), but by some measures it produces more milk per unit of body weight than any other breed, and has the highest feed-to-milk conversion efficiency of any dairy breed. The milk is highest of all breeds for butterfat. Milk is known for the high cream and rich taste. Bulls are also small, ranging from 1200 to 1800 pounds (540 to 820 kg), and are notoriously aggressive.
# Adventist Youth Honors Answer Book/Completed Honors Needing Work

These honors are listed as complete, but they also have a TODO item still included.
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# Adventist Youth Honors Answer Book/Computers/Hard drive

A hard drive is a nonvolatile data storage device. It works by the same principals as a floppy disc, except that it is much faster, has much greater storage capacity, and is usually not removable from the computer. Most hard drives consist of several aluminum platters stacked on a spindle. The platters (or disks) are coated with a material whose magnetic properties are easily detected (for reading) and changed (for writing). The computer's operating system is usually stored on the hard drive as are most of the other programs the computer runs. Data stored on a hard drive will not be destroyed if the computer is turned off.
# Adventist Youth Honors Answer Book/Computers/Laser printer

A laser printer is a common type of computer printer that produces high quality printing, and is able to produce both text and graphics.
An electric charge is first projected onto a revolving drum. The drum has a surface of a special plastic or garnet. Electronics drive a system that writes light onto the drum with a laser. The light causes the electrostatic charge to leak from the exposed parts of the drum. The surface of the drum passes through a bath of very fine particles of dry plastic powder, or toner. The charged parts of the drum electrostatically attract the particles of powder. The drum then deposits the powder on a piece of paper. The paper passes through a fuser, which, with heat and pressure, bonds the plastic powder to the paper.
Laser printers are the workhorse printer of the business world. They are capable of producing very high quality prints very cheaply. Although most laser printers only work in black and white, some models can also produce color prints. Because of their speed and economy, laser printers have largely replaced all other types of printers except ink jet and thermal printers.
# Adventist Youth Honors Answer Book/Computers/RAM

RAM is an acronym that stands for Random Access Memory. "Random access" means that the contents of the memory can be accessed in any random order. The term was originally coined to differentiate it from serial memory (such as data stored on a magnetic tape). The contents of a serial memory could only be accessed sequentially. RAM is a volatile memory, which means that when the power is turned off, the information stored there is lost.
RAM can be accessed very quickly by the computer. Its contents can be both read and written. Most programs on a computer are loaded into and executed from RAM. RAM is also used as "scratch space" where the computer stores the results of calculations.
# Adventist Youth Honors Answer Book/Computers/CPU

CPU is an acronym that stands for "Central Processing Unit." This is the "brain" behind a computer, and is where all the arithmetic, logic, and program flow is performed.