diff --git a/404.html b/404.html new file mode 100644 index 00000000..5123a7b5 --- /dev/null +++ b/404.html @@ -0,0 +1,4520 @@ + + + +
+ + + + + + + + + + + + + + + + +The 6LoWPAN (IPv6 over Low-power Wireless Personal Area Networks) is an +adaptation Layer that enables the use of IPv6 over low-power IEEE +802.15.4 radio links. In most cases, the 6LoWPAN network is connected to +the IPv6 network using an edge router.
+The 6LoWPAN protocol uses the first byte of the IEEE 802.15.4 +encapsulation header stack as a special Dispatch Byte. This Dispatch +Byte indicates that the following bytes are a LoWPAN header instead of +an IPv6 header.
+Bin | +Header | +Description | +
---|---|---|
00 xxxxxx |
+NLAP | +Not a LoWPAN frame. | +
01 000001 |
+IPv6 | +Uncompressed IPv6 | +
01 000010 |
+HC1 | +HC1 compressed IPv6 | +
01 1xxxxx |
+IPHC | +IPHC compressed IPv6 | +
10 xxxxxx |
+MESH | +Mesh header | +
11 000xxx |
+FRAG1 | +Fragmentation Header | +
IPHC/NHC compression was defined in RFC +6282 in 2011 and updates the older +HC1/HC2 compression.
+Structure of a typical 6LoWPAN frame with IPv6+UDP:
++--------+--- - - ---+----------+--- - - ---+--------
+| IPHC | Inline IPv6 | UDP NHC | Inline UDP | Payload
+|(2 byte)| (variable) | (1 Byte) | (variable) |
++--------+--- - - ---+----------+--- - - ---+--------
+
The frame starts with 2 IPHC bytes, where the first byte is the LoWPAN
+dispatch byte. Therefore the first byte starts with 011
to indicate
+IPHC compression. The remaining bits specify the IPv6 compression.
0 1
+ 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
++---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
+| 0 | 1 | 1 | TF |NH | HLIM |CID|SAC| SAM | M |DAC| DAM |
++---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
+
If SAC/DAC=1:
+In case CID = 1 in the IPHC bytes, an additional CIE byte directly +follows the two IPHC bytes. This CIE byte is used to identify previously +exchanged IPv6 contexts by a 4 bit Source Context Identifier (SCI) and a +4 bit Destination Context Identifier (DCI) instead of 128 bit for each +address.
+ 0 1 2 3 4 5 6 7
++---+---+---+---+---+---+---+---+
+| SCI | DCI |
++---+---+---+---+---+---+---+---+
+
Compression formats for different next headers are identified by a +variable-length bit-pattern (within one Byte) immediately following the +IPHC compressed header.
+Bits 0 through 4 represent the NHC ID and '11110' indicates the specific +UDP header compression ID.
+ 0 1 2 3 4 5 6 7
++---+---+---+---+---+---+---+---+
+| 1 | 1 | 1 | 1 | 0 | C | P |
++---+---+---+---+---+---+---+---+
+
The HC1/HC2 compression was defined in RFC +4944 in 2007 and is not +recommended anymore. It uses two bytes -- HC1 for IPv6 and HC2 for UDP +-- to specify how headers are compressed.
+With this compression it is possible to achieve a very small 7 byte +frame for IPv6 + UDP if all compression mechanisms are used:
+The HC1 byte is used to compress the IPv6 header.
+ 0 1 2 3 4 5 6 7
++---+---+---+---+---+---+---+---+
+| IP-SA | IP-DA |TF | NH |HC2|
++---+---+---+---+---+---+---+---+
+
The HC2 byte is used to compress the UDP header.
+ 0 1 2 3 4 5 6 7
++---+---+---+---+---+---+---+---+
+|SP |DP |LC | - | - | - | - | - |
++---+---+---+---+---+---+---+---+
+
6LoWPAN supports two routing methods on different layers.
+TeX4TUM is an Interactive Knowledge Platform for Engineers covering the +following topics:
+With TeX4TUM, we offer an interactive knowledge platform that adjusts
+the content to your individual needs. In contrast to all the forums,
+blogs, and wikis out there, we focus on the most important aspects first
+and only optionally offer you the details if you need them. Our articles
+are short, consistent and well structured making them ideal for
+efficiently looking up your study topics. Using interactive diagrams,
+you are not limited to static examples but can play around with
+different parameters and observe their effect on the result. This direct
+feedback will enable more intuitive understanding and helps to quickly
+learn or lookup even complex topics, reducing cognitive overload and
+letting you stay focused. Experience it for yourself. Hit tab
and type
+a term that you want to look up.
Intuitive design does not stop when it comes to writing an article. Our +goal is that authors do not need to bother about learning any complex +markup or programming language. As an author you simply write the +article following some format guidelines. Afterwards, our smart scripts +will process the article and figure out which content is visible by +default and which content will appear on demand. For example, symbol +explanations only appear when you click on the corresponding equation.
+TeX4TUM uses many different frameworks to achieve its goals.
+TODO draw image of the process github .md --> jekyll --> scripts --> +pandoc --> .html + head.html = webpage
+Tex4TUM should eveolve to be your swiss knive of engineering knowledge. +That is, we will focus on a few (\(\approx 200\)) high-quality articles +instead of having thousands of "OK" articles. First, we are completely +open to any suggestions, new articles, and improvements from anyone in +order to generate the content that matters most for the students. After +a few years when the articles are quite complete, the content should be +maintained by trusted student groups, tutors, or researches of the +university.
+To improve the quality of this platform your feedback is important. +Please report errors, bugs or improvements to our {% icon fa-bug %} +issue tracker or send an +email to {% icon fa-envelope %} {{ site.email +}}
+The content of this page is based on the cheatsheets from {% icon +fa-globe %} latex4ei.de
+{% for entry in site.data.social %} {{ entry.about_text }}: {% include +icon-social.html data=entry %} {% endfor %}
+ + + + + + + + + + + + + + + + +An actuator is a component of a machine that is responsible for moving +and controlling a mechanism.
+{{ FOLDER_TOC }}
+ + + + + + + + + + + + + + + + +Ada is a programming language intended for real-time safety-critical +systems.
+with Ada.Text_IO;
+
+procedure main is
+ message : String := "Hello World"
+begin
+ -- Print message
+ Ada.Text_IO.Put_Line( message );
+end main;
+
-- type declarations
+type Counter_Type is range 1 .. 10; -- constrained
+subtype Counter_Type is Counter_Type range 1 .. 3; -- further constrained
+type Vector_Type is array (1 .. 3) of Integer; -- 3 elements
+
+-- instanciations
+MyCounter : Counter_Type := 1;
+Velocity : Vector_Type := (1, 2, 3);
+
Integer
, Natural
, Positive
Float
Access
Array
, Record
, Task
type Day_type is range 1 .. 31;
+type Month_type is range 1 .. 12;
+type Year_type is range 1800 .. 2100;
+
+type Date is record
+ Day : Day_type;
+ Month : Month_type;
+ Year : Year_type;
+end record;
+
ISO/IEC 8652: Information technology---Programming languages---Ada
+The Advanced Encryption Standard (AES), (original name Rijndael) is a +specification for the encryption of electronic data established by the +U.S. National Institute of Standards and Technology (NIST) in 2001.
+AES operates on block sizes of \(32 \times 32\) bits.
+Key-length | +Number of Rounds | +
---|---|
128 bit | +10 | +
192 bit | +12 | +
256 bit | +14 | +
AES 128 High Level Overview
+Key Expansion: Create individual 128bit round keys from the + cipher key
+AddRoundKey: each byte of the block is combined with a block of + the round key using bitwise xor.
+Rounds:
+Final Round: (no MixColumns)
+Electronic Codebook (ECB)
+The message is divided into blocks, and each block is encrypted +separately.
+Electronic Codebook (ECB) Encryption Electronic Codebook (ECB) Decryption
+Cipher Block Chaining (CBC)
+Each block of plaintext is XORed with the previous ciphertext block +before being encrypted.
++
Cipher Feedback (CFB)
+A close relative of CBC. Transforms a block cipher into a +self-synchronizing stream cipher.
++
+
Output Feedback (OFB)
+Transforms a block cipher into a synchronous stream cipher. It generates +keystream blocks, which are then XORed with the plaintext blocks to get +the ciphertext.
++
Counter (CTR)
+Counter mode turns a block cipher into a stream cipher. It generates the +next keystream block by encrypting successive values of a "counter".
++
mode = ECB-AES128.Encrypt
+in = 6bc1bee22e409f96e93d7e117393172a
+key = 2b7e151628aed2a6abf7158809cf4f3c
+out = 3ad77bb40d7a3660a89ecaf32466ef97
+
+mode = CBC-AES128.Encrypt
+in = 6bc1bee22e409f96e93d7e117393172a
+key = 2b7e151628aed2a6abf7158809cf4f3c
+iv = 000102030405060708090a0b0c0d0e0f
+out = 7649abac8119b246cee98e9b12e9197d
+
{{ FOLDER_TOC }}
+ + + + + + + + + + + + + + + + +with function \(f\)
+Name | +Definition | +
---|---|
Function | +\(f:\mathbb D \rightarrow \mathbb W\) | +
Scalarfield | +\(\phi:\mathbb D^n \rightarrow \mathbb W\) | +
Curve | +\(\vec r: \mathbb D \rightarrow \mathbb W^m\) | +
Vectorfield | +\(\vec F:\mathbb D^n \rightarrow \mathbb W^n\) | +
Property | ++ |
---|---|
Bild | +\(f(D) := \{ f(x) \;\vert\; x\in D \}\) | +
Kern | +\(\ker f := \{ \vec x \;\vert\; \vec f(\vec x) = \vec 0 \}\) | +
Komposition | +\(f \circ g := f\bigl( g() \bigr)\) | +
Fixpunkt | +\(a := f(a)\) | +
Class | ++ |
---|---|
Injektiv | +\(f(x_1)=f(x_2) \Rightarrow x_1=x_2\) | +
Surjektiv | +\(\forall y\in \mathbb W \exists x\in \mathbb D:f(x)=y\) | +
Bijektiv | +if injective and surjective | +
Eine Funktion \(f\) ist eine Abbildung, die jedem Element \(x\) einer +Definitionsmenge \(D\) genau ein Element \(y\) einer Wertemenge \(W\) +zuordnet.
+Achsensym.(\(g\)): \(f(-x)=f(x)\) Punktsym.(\(u\)): \(f(-x)=-f(x)\)
+\(g_1 \pm g_2 = g_3\) | +\(u_1 \pm u_2 = u_3\) | +
---|---|
\(g_1 \cdot g_2=g_3\) | +\(u_1 \cdot u_2 = g_3\) | +
\(f''(x_0)=0 \text{ und } f'''(x_0) \ne 0 \rightarrow x_0\) Wendepunkt
+\(f'(x) \stackrel{_\ge}{_{(>)}}\!\! / \!\! \stackrel{_\le}{_{(<)}} 0 \ \rightarrow\) + \(f\) (streng) Monoton steigend/fallend. \(x\in[a,b]\)
+\(f''(x) \stackrel{_\ge}{_{(>)}}\!\! / \!\! \stackrel{_\le}{_{(<)}} 0 \ \rightarrow\) + \(f\) (strikt) konvex/konkav. \(x\in[a,b]\)
+Horizontal: \(c_\pm =\lim\limits_{x\ra \pm \infty} f(x)\) Vertikal: +\(\exists\,\text{Nullst. } a \text{ des Nenners }\)\ Polynomasymptote +\(P(x)\): \(f(x):=\frac{A(x)}{Q(x)}=P(x)+ \Big(\frac{B(x)}{Q(x)}\ra 0\Big)\)
+Regel von L'Hospital: +\(\lim\limits_{x \rightarrow a} \frac{f(x)}{g(x)} \rightarrow \left[ \frac{0}{0} \right]\!/\!\left[ \frac{\infty}{\infty} \right] = \lim\limits_{x \rightarrow a} \frac{f'(x)}{g'(x)}\)
+Wichtige Grenzwerte | ++ |
---|---|
\(\lim\limits_{x \ra \infty} \frac{1}{x^n} = 0\) | +\(\lim\limits_{n \ra \infty} \sqrt[n]{n} = 1\) | +
\(\lim\limits_{x \ra \infty} x \cdot e^{-x} = 0\) | +\(\lim\limits_{x \ra 0} \frac{\sin(x)}{x} = 1\) | +
Zwischenwertsatz: +\(\forall y \in [f(a),f(b)]\ \exists x\in [a,b]:f(x)=y\)
+Mittelwertsatz: Falls \(f\) diffbar, dann +\(\exists x_0:f'(x_0)=\frac{f(b)-f(a)}{b-a}\)
+Satz von Rolle: Falls \(f(a)=f(b)\), dann \(\exists x_0: f' (x_0) = 0\)
+{{ FOLDER_TOC }}
+ + + + + + + + + + + + + + + + +