OpenLLM-France/wikimedia huggingface dataset:
# Three way handshake
## Learning goals

* understand the concept of a logical connection (virtual communication channel) between two computers on the internet
* understand the importance of acknowledging received messages
* be able to understand the process of establishing a tcp / connection

## Script

TCP three-way handshake
One of the most important features of TCP is that we can make sure that packages really arrive at the other side when talking to host on the Internet. The basic ideas of achieving this goal is to acknowledge every send package. In order to do so we need to establish connection between the computers. This doesn’t mean physically interconnect the computers but rather to create virtual communication channel which can be used for reliable transmission of IP packages.
So when we wish to establish TCP-connection between 2 hosts on the WEB we need to make sure that both hosts can create this virtual cannel of communication and thereby establish the connection. This is achieved with 3-way handshake. As you want to establish a connection with another computer you could just send him IP package stating your interest to talk to each other. You do this by sending IP package in which you place a TCP package. Inside the TCP header you specify your wish to synchronize so you set the SYN-bit. Additionally you generate a random 32-bit number between 0 and 2^32 that is called sequence number and send this over to the other host. In the case the recipient successfully receiver the package it can answer back an Acknowledgment message (ACK). This message contains your sequence number +1. If you never receive this message (which can happen because your package was not delivered) you will receive an error message that the connection could not be established. In the case you received the data your connection is still not ready. A connection should be symmetric in a sense that both hosts could initialize to send data at any point of time.
Your communication partner not only sends an acknowledgment message to you but also generates his own sequence number and sends it together with SYN-flag set. So as you receive a response you know that your connection is established but you also have to acknowledge your partner request to establish the connection. So you take his sequence number and add 1 and put it as an acknowledgment number to the TCP package. You increase your own sequence number by 1 and put it together with the data that you want to transfer into your next TCP package. This is the 3rd message to be delivered (or at least send).
Now whenever one of the communication participants send data packages the sequence number is increased. This will be used later to assemble packages to the file and the numbers are acknowledged by the other side. If packages are not acknowledged, the host will send package again and again. In this way TCP creates a reliable way of communication.
--Jane Kruch (discuss • contribs) 17:10, 3 November 2013 (UTC)
# Web Science/Part1: Foundations of the web/Transmission Control Protocol/Three way handshake/script

TCP three-way handshake
One of the most important features of TCP is that we can make sure that packages really arrive at the other side when talking to host on the Internet. The basic ideas of achieving this goal is to acknowledge every send package. In order to do so we need to establish connection between the computers. This doesn’t mean physically interconnect the computers but rather to create virtual communication channel which can be used for reliable transmission of IP packages.
So when we wish to establish TCP-connection between 2 hosts on the WEB we need to make sure that both hosts can create this virtual cannel of communication and thereby establish the connection. This is achieved with 3-way handshake. As you want to establish a connection with another computer you could just send him IP package stating your interest to talk to each other. You do this by sending IP package in which you place a TCP package. Inside the TCP header you specify your wish to synchronize so you set the SYN-bit. Additionally you generate a random 32-bit number between 0 and 2^32 that is called sequence number and send this over to the other host. In the case the recipient successfully receiver the package it can answer back an Acknowledgment message (ACK). This message contains your sequence number +1. If you never receive this message (which can happen because your package was not delivered) you will receive an error message that the connection could not be established. In the case you received the data your connection is still not ready. A connection should be symmetric in a sense that both hosts could initialize to send data at any point of time.
Your communication partner not only sends an acknowledgment message to you but also generates his own sequence number and sends it together with SYN-flag set. So as you receive a response you know that your connection is established but you also have to acknowledge your partner request to establish the connection. So you take his sequence number and add 1 and put it as an acknowledgment number to the TCP package. You increase your own sequence number by 1 and put it together with the data that you want to transfer into your next TCP package. This is the 3rd message to be delivered (or at least send).
Now whenever one of the communication participants send data packages the sequence number is increased. This will be used later to assemble packages to the file and the numbers are acknowledged by the other side. If packages are not acknowledged, the host will send package again and again. In this way TCP creates a reliable way of communication.
--Jane Kruch (discuss • contribs) 17:10, 3 November 2013 (UTC)
# Web Science/Part1: Foundations of the web/Web Architecture/Web Content/Dynamic Content

* PART1: Week1: Ethernet · Internet Protocol · Week2: Transmission Control Protocol · Domain Name System · Week3: Internet vs world wide web · HTTP · Week4: Web Content · Dynamic Web Content
* PART2: Week5: How big is the Web? · Descriptive Web Models · Week6: Advanced Statistic Models · Modelling Similarity · Week7: Generative Modelling of the Web · Graph theoretic Web Modelling
* PART3: Week8 : Investigating Meme Spreading · Herding Behaviour · Week9: Online Advertising · User Modelling
* PART4: Week10 : Copyright · Net neutrality · Week11: Internet governance · Privacy
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* Video of the lesson: Interacting with HTML documents
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* Script for: Interacting with HTML documents
* What categories are relevant for interaction?
* Clicking on a 'link'
* widgets
* Typing text
* Speech input (e.g. http://slides.html5rocks.com/#speech-input )
* drag-and-drop
* text/image/video/audio display
* conversion, e.g. text-to-audio
* Server-side vs client-side code
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# Web Science/Part1: Foundations of the web/Transmission Control Protocol/Summary, further readings, homework

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* PART1: Week1: Ethernet · Internet Protocol · Week2: Transmission Control Protocol · Domain Name System · Week3: Internet vs world wide web · HTTP · Week4: Web Content · Dynamic Web Content
* PART2: Week5: How big is the Web? · Descriptive Web Models · Week6: Advanced Statistic Models · Modelling Similarity · Week7: Generative Modelling of the Web · Graph theoretic Web Modelling
* PART3: Week8 : Investigating Meme Spreading · Herding Behaviour · Week9: Online Advertising · User Modelling
* PART4: Week10 : Copyright · Net neutrality · Week11: Internet governance · Privacy
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* Further information, readings and exercises about Summary, Further readings, Homework
* exercises
* Use netstat to display protocol statistics.
* Use netstat to display all active connections and listening ports.
* Use Wireshark to capture and analyze User Datagram Protocol (UDP) traffic.
* Use Wireshark to capture and analyze Transmission Control Protocol (TCP) traffic.
* further reading
* Transmission Control Protocol
* User Data gram Protocol
* Transport layer lesson in Internet protocol analysis course
* Telnet
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# Web Science/Part1: Foundations of the web/Web Architecture

* PART1: Week1: Ethernet · Internet Protocol · Week2: Transmission Control Protocol · Domain Name System · Week3: Internet vs world wide web · HTTP · Week4: Web Content · Dynamic Web Content
* PART2: Week5: How big is the Web? · Descriptive Web Models · Week6: Advanced Statistic Models · Modelling Similarity · Week7: Generative Modelling of the Web · Graph theoretic Web Modelling
* PART3: Week8 : Investigating Meme Spreading · Herding Behaviour · Week9: Online Advertising · User Modelling
* PART4: Week10 : Copyright · Net neutrality · Week11: Internet governance · Privacy
Completing the second block of the first part of the Web Science MOOC you will
* learn that the basic form of the web consisted of 3 main technologies (URI, HTTP, HTML).
* see that the concepts and ideas of each of these technologies wasn't new but the combination of all of them created such a tremandous extra value.
* realize how there where similar systems like the web and why the open (licence) structure of the web as well as compatibility added to the success of the web.
* have implemented a simple web server and web client
* know the basic components of HTML
* understand the importance of the 404 for web scale
* know the most important historical events that influenced the rise of the web

### Theory

* protocol for requesting files (especially hypertext) from URIs
* HTTP header
* GET, POST,...
* status codes
* content negotiation
* request / response protocol (stateless)

#### Implementation

In order to get a better understanding we will implementing a web client and web server which understands HTTP 1.0 and only uses socket libraries.

#### Discussion

* the importance of 404 with respect to web scale
* what are the bad design issues of HTTP 1.0
* theoretical discussion of HTTP 1.0 and newer versions
* comparison: Stateless vs connection oriented vs connectionless protocols. Which part of the http protocol belong to which of the concepts?

### understanding HTML

* linked documents
* The link as a directed edge (again 404 and web scale)
* mark up language
* open format is included into the text to be displayed
* different HTML elements

## Web technologies
### REST

* RESTful services

### Cookies

as part of http or as a result of the flexibility of http?

### JavaScript

Hacked in by Netscape navigator.

## historical overview
### CERN

* information management systems at CERN
* ENQUIRE
* How the web was deleted

### Computing compatibility problems

* Compatibility problems of hardware: TimBL's NextStation

### Industry

* Microsoft's Internet Explorer (Why is it actually called internet explorer? What a stupid name!) (inventing cookies)
* Netscape (e.g. inventing java script)

### politics

* Bill Clinton's role in making the Web high priority.

## similar applications and technologies

* Goopher
* usenet
* Compuserve
* compatibility of HTTP with other protocols in order to have all the content accessible
* open, non commercial and free nature of HTTP
# Basic Terms and Definitions
## Learning goals
## Script

Tekim Akademi/Systems Engineering 101/Basic Terms and Definitions/script

## Quiz

Tekim Akademi/Systems Engineering 101/Basic Terms and Definitions/quiz
# History of Systems Engineering
## Learning goals
## Script

Tekim Akademi/Systems Engineering 101/History of Systems Engineering/script

## Quiz

Tekim Akademi/Systems Engineering 101/History of Systems Engineering/quiz
# Polynomial/Expansion/Taylor/z^3+3z^2-7z-4/2/Exercise

Write the polynomial
    $f(z)=z^{3}+3z^{2}-7z-4\,$
in the new variable $z-2$, using two different ways, namely
a) directly by inserting,
b) via the Taylor-polynomial in the point $2$.
# Polynomial/Formula for X^odd+1/Exercise

Prove the formula
    $X^{u}+1=(X+1){\left(X^{u-1}-X^{u-2}+X^{u-3}-\cdots +X^{2}-X+1\right)}\,$
for $u$ odd.
# Polynomial/Degree 3/Inverse function/Power series approach/Exercise

Let
    $f(x)=-3x+x^{3}\,.$
Because of
    $f'(x)=-3+3x^{2}\,,$
this function is on the open interval $]-1,1[$ strictly decreasing and therefore injective (with the image interval $]-2,2[$). Also, $f(0)=0$. Let
    $g(y)=\sum _{k=0}^{\infty }b_{k}y^{k}\,$
be the inverse function, which we want to understand as a power series. Determine from the condition
    $(g(f(x))=x\,,$
the coefficients $b_{0},b_{1},b_{2},b_{3},b_{4}$.
# Polynomial/Euclidean division/(4+3i)x^3+x^2+5i over (1+i)x^2+x -3+2i/Example

We perform the Euclidean division
    $P=(4+3{\mathrm {i} })X^{3}+X^{2}+5{\mathrm {i} }{\text{ divided by }}T=(1+{\mathrm {i} })X^{2}+X-3+2{\mathrm {i} }.$
The inverse of $1+{\mathrm {i} }$ is ${\frac {1}{2}}-{\frac {1}{2}}{\mathrm {i} }$, and therefore we have
    ${\begin{aligned}(4+3{\mathrm {i} })(1+{\mathrm {i} })^{-1}&=(4+3{\mathrm {i} }){\left({\frac {1}{2}}-{\frac {1}{2}}{\mathrm {i} }\right)}\\&=2+{\frac {3}{2}}-2{\mathrm {i} }+{\frac {3}{2}}{\mathrm {i} }\\&={\frac {7}{2}}-{\frac {1}{2}}{\mathrm {i} }.\end{aligned}}$
Hence, $Q$ starts with ${\left({\frac {7}{2}}-{\frac {1}{2}}{\mathrm {i} }\right)}X$, and we have
    ${\begin{aligned}((1+{\mathrm {i} })X^{2}+X-3+2{\mathrm {i} }){\left({\frac {7}{2}}-{\frac {1}{2}}{\mathrm {i} }\right)}X&=(4+3{\mathrm {i} })X^{3}+{\left({\frac {7}{2}}-{\frac {1}{2}}{\mathrm {i} }\right)}X^{2}+{\left(-{\frac {19}{2}}+{\frac {17}{2}}{\mathrm {i} }\right)}X\\\end{aligned}}$
We have to subtract this term from $P$ and we obtain
    ${\begin{aligned}P-{\left((4+3{\mathrm {i} })X^{3}+{\left({\frac {7}{2}}-{\frac {1}{2}}{\mathrm {i} }\right)}X^{2}+{\left(-{\frac {19}{2}}+{\frac {17}{2}}{\mathrm {i} }\right)}X\right)}&={\left(-{\frac {5}{2}}+{\frac {1}{2}}{\mathrm {i} }\right)}X^{2}+{\left({\frac {19}{2}}-{\frac {17}{2}}{\mathrm {i} }\right)}X+5{\mathrm {i} }\\\,\end{aligned}}$
We apply the same procedure to this polynomial (which we call $P'$). We compute
    ${\begin{aligned}{\left(-{\frac {5}{2}}+{\frac {1}{2}}{\mathrm {i} }\right)}{\left({\frac {1}{2}}-{\frac {1}{2}}{\mathrm {i} }\right)}&=-1+{\frac {3}{2}}{\mathrm {i} }\\\end{aligned}}$
Therefore, the constant term of $Q$ equals $-1+{\frac {3}{2}}{\mathrm {i} }$, and we obtain
    ${\left((1+{\mathrm {i} })X^{2}+X-3+2{\mathrm {i} }\right)}{\left(-1+{\frac {3}{2}}{\mathrm {i} }\right)}={\left(-{\frac {5}{2}}+{\frac {1}{2}}{\mathrm {i} }\right)}X^{2}+{\left(-1+{\frac {3}{2}}{\mathrm {i} }\right)}X-{\frac {13}{2}}{\mathrm {i} }\,.$
We subtract this from $P'$ and get
    $P'-{\left({\left(-{\frac {5}{2}}+{\frac {1}{2}}{\mathrm {i} }\right)}X^{2}+{\left(-1+{\frac {3}{2}}{\mathrm {i} }\right)}X-{\frac {13}{2}}{\mathrm {i} }\right)}={\left({\frac {21}{2}}-10{\mathrm {i} }\right)}X+{\frac {23}{2}}{\mathrm {i} }\,.$
This term is the remainder $R$, the Euclidean division altogether is
    ${\begin{aligned}(4+3{\mathrm {i} })X^{3}+X^{2}+5{\mathrm {i} }&=((1+{\mathrm {i} })X^{2}+X-3+2{\mathrm {i} }){\left({\left({\frac {7}{2}}-{\frac {1}{2}}{\mathrm {i} }\right)}X-1+{\frac {3}{2}}{\mathrm {i} }\right)}+{\left({\frac {21}{2}}-10{\mathrm {i} }\right)}X+{\frac {23}{2}}{\mathrm {i} }\\\,\end{aligned}}$
# Polynomial/K/Interpolation/Section

The following theorem is called theorem about polynomial interpolation and describes the interpolation of given function values by a polynomial. If just one function value at one point is given, then this determines a constant polynomial, two values at two points determine a linear polynomial (the graph is a line), three values at three points determine a quadratic polynomial, etc.

## Theorem

Let $K$ be a field, and let $n$ different elements $a_{1},\ldots ,a_{n}\in K$ and $n$ elements $b_{1},\ldots ,b_{n}\in K$ are given. Then there exist a unique
polynomial $P\in K[X]$ of degree $\leq n-1$, such that $P{\left(a_{i}\right)}=b_{i}$
$i$

### Proof

We prove the existence and consider first the situation where $b_{j}=0$ for all $j\neq i$ for some fixed $i$. Then
    $(X-a_{1})\cdots (X-a_{i-1})(X-a_{i+1})\cdots (X-a_{n})$
is a polynomial of degree $n-1$ which at the points $a_{1},\ldots ,a_{i-1},a_{i+1},\ldots ,a_{n}$ has value $0$. The polynomial
    ${\frac {b_{i}}{(a_{i}-a_{1})\cdots (a_{i}-a_{i-1})(a_{i}-a_{i+1})\cdots (a_{i}-a_{n})}}(X-a_{1})\cdots (X-a_{i-1})(X-a_{i+1})\cdots (X-a_{n})$
has at these points still a zero, but additionally at $a_{i}$ its value is $b_{i}$. We denote this polynomial by $P_{i}$. Then
    $P=P_{1}+P_{2}+\cdots +P_{n}\,$
is the polynomial looked for, because for the point $a_{i}$ we have
    $P_{j}(a_{i})=0\,$
for $j\neq i$ and $P_{i}(a_{i})=b_{i}$.
The uniqueness follows from fact.
$\Box$

## Remark

If the data $a_{1},\ldots ,a_{n}$ and $b_{1},\ldots ,b_{n}$ are given, then one can find the interpolating polynomial $P$ of degree $\leq n-1$, which exists by fact, in the following way: We write
    $P=c_{0}+c_{1}X+c_{2}X^{2}+\cdots +c_{n-2}X^{n-2}+c_{n-1}X^{n-1}\,$
with unknown coefficients $c_{0},\ldots ,c_{n-1}$, and determine then these coefficients. Each interpolation point $(a_{i},b_{i})$ yields a linear equation
    $c_{0}+c_{1}a_{i}+c_{2}a_{i}^{2}+\cdots +c_{n-2}a_{i}^{n-2}+c_{n-1}a_{i}^{n-1}=b_{i}\,$
over $K$. The resulting system of linear equations has exactly one solution $(c_{0},\ldots ,c_{n-1})$, which gives the polynomial.
# Polynomial/Insertion/2/Exercise

Insert into the polynomial $2X^{4}+X^{3}-3X^{2}+X+5$ the number ${\sqrt {2}}$.
# Polynomial/Euclidean division/6x^3+x+1 over 3x^2+2x-4/Example

We want to apply the Euclidean division (over $\mathbb {Q}$)
    $P=6X^{3}+X+1{\text{ divided by }}T=3X^{2}+2X-4.$
So we want to divide a polynomial of degree $3$ by a polynomial of degree $2$, hence the quotient and also the remainder have (at most) degree $1$. For the first step, we ask with which term we have to multiply $T$ to achieve that the product and $P$ have the same leading term. This is $2X$. The product is
    $2X{\left(3X^{2}+2X-4\right)}=6X^{3}+4X^{2}-8X\,.$
The difference between $P$ and this product is
    $6X^{3}+X+1-{\left(6X^{3}+4X^{2}-8X\right)}=-4X^{2}+9X+1\,.$
We continue the division by $T$ with this polynomial, which we call $P'$. In order to get coincidence with the leading coefficient we have to multiply $T$ with ${\frac {-4}{3}}$. This yields
    $-{\frac {4}{3}}T=-{\frac {4}{3}}{\left(3X^{2}+2X-4\right)}=-4X^{2}-{\frac {8}{3}}X+{\frac {16}{3}}\,.$
The difference between this and $P'$ is therefore
    $-4X^{2}+9X+1-{\left(-4X^{2}-{\frac {8}{3}}X+{\frac {16}{3}}\right)}={\frac {35}{3}}X-{\frac {13}{3}}\,.$
This is the remainder and altogether we get
    $6X^{3}+X+1={\left(3X^{2}+2X-4\right)}{\left(2X-{\frac {4}{3}}\right)}+{\frac {35}{3}}X-{\frac {13}{3}}\,.$
# Polynomial/Field/1/Definition

Let $K$ be a field. An expression of the form
    $P=a_{0}+a_{1}X+a_{2}X^{2}+\cdots +a_{n}X^{n}\,,$
with $a_{i}\in K$ and $n\in \mathbb {N}$, is called a polynomial in one variable over $K$.
# Evaluating a generative model
## Learning goals

* See that it makes sense to compare statistics
* Understand that comparing statistics is not a well defined task
* Be aware of the fact that very different models could lead to the same statistics

## Script

The slide deck can be found at File:Evaluating-a-generative-model.pdf
# Generative Models for the Web
## Learning goals
## Associated units

* Understand the principle methodology for building generative models
* Remember why people are interested in generative models
* Know why descriptive models are needed when evaluating a generative model
* Be aware of one way to create a model for text generation
* Understand how to sample values from an arbitrary probability distribution
* Have seen yet another application of the cumulative distribution function
* Understand that sampling from a distribution is just a coordinate transformation of the uniform distribution
* See that it makes sense to compare statistics
* Understand that comparing statistics is not a well defined task
* Be aware of the fact that very different models could lead to the same statistics
* See that one can always increase the model parameters
* Know that increasing model parameters often yields a more accurate model
* Be aware of the bigram and mixed models as examples for our generative processes
# Pittfalls when increasing the number of model parameters
## Learning goals

* See that one can always increase the model parameters
* Know that increasing model parameters often yields a more accurate model
* Be aware of the bigram and mixed models as examples for our generative processes

## Script

The slides can be found at File:Pittfalls-when-increasing-the-number-of-model-parameters.pdf
# Introduction to generative modelling.webm
## Learning goals

* Understand the principle methodology for building generative models
* Remember why people are interested in generative models
* Know why descriptive models are needed when evaluating a generative model
* Be aware of one way to create a model for text generation

## Script

The slides can be found at File:Introduction-to-generative-modelling.pdf
# Website administration

* Please help develop and classify this resource
* Learn how you can develop this resource to teach participants about Website administration. Choose a subject, education level, and resource type to classify the resource by. You may learn more about the topic to help you develop and classify the resource from:
Website administration is the process of maintaining a website. This process is done by the website administrator. Website administrators are responsible for running the site after completion. Tasks in maintaining a functional website may include any of the following:
On user-generated content sites, it is recommended to inform your contributors and visitors in advance of major changes, especially a possible shutdown. Ideally, inform users through a site notice at least three months before a planned shutdown so they have appropriate time to save what they wish, and at least one week before making the site read-only. Consider releasing users' text contributions as a compressed archive, since text compresses efficiently. Also consider sending users who have provided an email address an export of their account data.

## Course

System Administration

## Links

* Website information on wikipedia
* Webmaster information on wikipedia