OpenLLM-France/wikimedia huggingface dataset:
# Character Encodings/Code Tables/EBCDIC/EBCDIC 005

IBM code page 5 (CCSID 5) is an EBCDIC code page used in IBM mainframes in the United States to support the English language.

## Codepage layout

Characters are shown with their equivalent Unicode codes.
EBCDIC 005 :
| | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | A | B | C | D | E | F |
| 0x | NUL | SOH | STX | ETX | SEL | HT | RNL | DEL | GE | SPS | RPT | VT | FF | CR | SO | SI |
| 1x | DLE | DC1 | DC2 | DC3 | RES/ ENP | NL | BS | POC | CAN | EM | UBS | CU1 | IFS | IGS | IRS | ITB |
| 2x | DS | SOS | FS | WUS | BYP/ INP | LF | ETB | ESC | SA | SFE | SM/ SW | CSP | MFA | ENQ | ACK | BEL |
| 3x | | | SYN | IR | PP | TRN | NBS | EOT | SBS | IT | RFF | CU3 | DC4 | NAK | | SUB |
| 4x | SP | | | | | | | | | | | . 002E | | ( 0028 | + 002B | |
| 5x | & 0026 | | | | | | | | | | | $ 0024 | * 002A | ) 0029 | ; 003B | ¢ 00A2 |
| 6x | - 002D | / 002F | | | | | | | | | ½ 00BD | , 002C | % 0025 | _ 005F | | ? 003F |
| 7x | | | | | | | | | | ± 00B1 | : 003A | # 0023 | @ 0040 | ' 0027 | = 003D | " 0022 |
| 8x | | a 0061 | b 0062 | c 0063 | d 0064 | e 0065 | f 0066 | g 0067 | h 0068 | i 0069 | | | | | | |
| 9x | | j 006A | k 006B | l 006C | m 006D | n 006E | o 006F | p 0070 | q 0071 | r 0072 | | | | | | |
| Ax | | | s 0073 | t 0074 | u 0075 | v 0076 | w 0077 | x 0078 | y 0079 | z 007A | | | | | | |
| Bx | | | | | | | | | | | | | | | | |
| Cx | | A 0041 | B 0042 | C 0043 | D 0044 | E 0045 | F 0046 | G 0047 | H 0048 | I 0049 | | | | | | |
| Dx | | J 004A | K 004B | L 004C | M 004D | N 004E | O 004F | P 0050 | Q 0051 | R 0052 | | | | | | |
| Ex | ¼ 00BC | | S 0053 | T 0054 | U 0055 | V 0056 | W 0057 | X 0058 | Y 0059 | Z 005A | | | | | | |
| Fx | 0 0030 | 1 0031 | 2 0032 | 3 0033 | 4 0034 | 5 0035 | 6 0036 | 7 0037 | 8 0038 | 9 0039 | | | | | | EO |
| Differences from EBCDIC 500 |||||||||||||||||

## References

* ↑ "Code Page 5" (PDF). Archived from the original (PDF) on 2013-01-21.
# Character Encodings/Code Tables/EBCDIC/EBCDIC 004

IBM code page 4 (CCSID 4) is an EBCDIC code page used in IBM mainframes in the United States to support the English language.

## Codepage layout

Characters are shown with their equivalent Unicode codes.
EBCDIC 004 :
| | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | A | B | C | D | E | F |
| 0x | NUL | SOH | STX | ETX | SEL | HT | RNL | DEL | GE | SPS | RPT | VT | FF | CR | SO | SI |
| 1x | DLE | DC1 | DC2 | DC3 | RES/ ENP | NL | BS | POC | CAN | EM | UBS | CU1 | IFS | IGS | IRS | ITB |
| 2x | DS | SOS | FS | WUS | BYP/ INP | LF | ETB | ESC | SA | SFE | SM/ SW | CSP | MFA | ENQ | ACK | BEL |
| 3x | | | SYN | IR | PP | TRN | NBS | EOT | SBS | IT | RFF | CU3 | DC4 | NAK | | SUB |
| 4x | SP | | | | | | | | | | £ 00A3 | . 002E | | ( 0028 | + 002B | ! 0021 |
| 5x | & 0026 | | | | | | | | | | | $ 0024 | * 002A | ) 0029 | ; 003B | ¢ 00A2 |
| 6x | - 002D | / 002F | | | | | | | | | ‗ 2017 | , 002C | % 0025 | _ 005F | | ? 003F |
| 7x | | | | | | | | | | | : 003A | # 0023 | @ 0040 | ' 0027 | = 003D | " 0022 |
| 8x | | a 0061 | b 0062 | c 0063 | d 0064 | e 0065 | f 0066 | g 0067 | h 0068 | i 0069 | | | | | | |
| 9x | | j 006A | k 006B | l 006C | m 006D | n 006E | o 006F | p 0070 | q 0071 | r 0072 | | | | | | |
| Ax | | | s 0073 | t 0074 | u 0075 | v 0076 | w 0077 | x 0078 | y 0079 | z 007A | | | | | | |
| Bx | | | | | | | | | | | | | | | | |
| Cx | | A 0041 | B 0042 | C 0043 | D 0044 | E 0045 | F 0046 | G 0047 | H 0048 | I 0049 | | | | | | |
| Dx | | J 004A | K 004B | L 004C | M 004D | N 004E | O 004F | P 0050 | Q 0051 | R 0052 | | | | | | |
| Ex | | | S 0053 | T 0054 | U 0055 | V 0056 | W 0057 | X 0058 | Y 0059 | Z 005A | | | | | | |
| Fx | 0 0030 | 1 0031 | 2 0032 | 3 0033 | 4 0034 | 5 0035 | 6 0036 | 7 0037 | 8 0038 | 9 0039 | | | | | | EO |
| Differences from EBCDIC 500 |||||||||||||||||

## References

* ↑ "Code Page 4" (PDF). Archived from the original (PDF) on 2013-01-21.
# Character Encodings/Code Tables/EBCDIC/EBCDIC 009

IBM code page 9 (CCSID 9) is an EBCDIC code page used in IBM mainframes in France to support the French language.

## Codepage layout

Characters are shown with their equivalent Unicode codes.
EBCDIC 009 :
| | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | A | B | C | D | E | F |
| 0x | NUL | SOH | STX | ETX | SEL | HT | RNL | DEL | GE | SPS | RPT | VT | FF | CR | SO | SI |
| 1x | DLE | DC1 | DC2 | DC3 | RES/ ENP | NL | BS | POC | CAN | EM | UBS | CU1 | IFS | IGS | IRS | ITB |
| 2x | DS | SOS | FS | WUS | BYP/ INP | LF | ETB | ESC | SA | SFE | SM/ SW | CSP | MFA | ENQ | ACK | BEL |
| 3x | | | SYN | IR | PP | TRN | NBS | EOT | SBS | IT | RFF | CU3 | DC4 | NAK | | SUB |
| 4x | SP | | | | | | | | | | ° 00B0 | . 002E | < 003C | ( 0028 | + 002B | ! 0021 |
| 5x | & 0026 | | | | | | | | | | § 00A7 | $ 0024 | * 002A | ) 0029 | ; 003B | ^ 005E |
| 6x | - 002D | / 002F | | | | | | | | | ù 00F9 | , 002C | % 0025 | _ 005F | > 003E | ? 003F |
| 7x | | | | | | | | | | £ 00A3 | : 003A | # 0023 | à 00E0 | ' 0027 | = 003D | " 0022 |
| 8x | | a 0061 | b 0062 | c 0063 | d 0064 | e 0065 | f 0066 | g 0067 | h 0068 | i 0069 | | | | | | |
| 9x | | j 006A | k 006B | l 006C | m 006D | n 006E | o 006F | p 0070 | q 0071 | r 0072 | | | | | | |
| Ax | | ¨ 00A8 | s 0073 | t 0074 | u 0075 | v 0076 | w 0077 | x 0078 | y 0079 | z 007A | | | | | | |
| Bx | | | | | | | | | | | | | | | | |
| Cx | é 00E9 | A 0041 | B 0042 | C 0043 | D 0044 | E 0045 | F 0046 | G 0047 | H 0048 | I 0049 | | | | | | |
| Dx | è 00E8 | J 004A | K 004B | L 004C | M 004D | N 004E | O 004F | P 0050 | Q 0051 | R 0052 | ³ 00B3 | | | | | |
| Ex | ç 00E7 | | S 0053 | T 0054 | U 0055 | V 0056 | W 0057 | X 0058 | Y 0059 | Z 005A | ² 00B2 | | | | | |
| Fx | 0 0030 | 1 0031 | 2 0032 | 3 0033 | 4 0034 | 5 0035 | 6 0036 | 7 0037 | 8 0038 | 9 0039 | | | | | | EO |
| Differences from EBCDIC 500 |||||||||||||||||

## References

* ↑ "Code Page 9" (PDF). Archived from the original (PDF) on 2013-01-21.
# Character Encodings/Code Tables/EBCDIC/EBCDIC 006

IBM code page 6 (CCSID 6) is an EBCDIC code page used in IBM mainframes in the Latin America to support the Spanish language.

## Codepage layout

Characters are shown with their equivalent Unicode codes.
EBCDIC 006 :
| | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | A | B | C | D | E | F |
| 0x | NUL | SOH | STX | ETX | SEL | HT | RNL | DEL | GE | SPS | RPT | VT | FF | CR | SO | SI |
| 1x | DLE | DC1 | DC2 | DC3 | RES/ ENP | NL | BS | POC | CAN | EM | UBS | CU1 | IFS | IGS | IRS | ITB |
| 2x | DS | SOS | FS | WUS | BYP/ INP | LF | ETB | ESC | SA | SFE | SM/ SW | CSP | MFA | ENQ | ACK | BEL |
| 3x | | | SYN | IR | PP | TRN | NBS | EOT | SBS | IT | RFF | CU3 | DC4 | NAK | | SUB |
| 4x | SP | | | | | | | | | | [ 005B | . 002E | ½ 00BD | ( 0028 | + 002B | ! 0021 |
| 5x | & 0026 | | | | | | | | | | ] 005D | $ 0024 | * 002A | ) 0029 | ; 003B | ¨ 00A8 |
| 6x | - 002D | / 002F | | | | | | | | | ñ 00F1 | , 002C | % 0025 | _ 005F | ¼ 00BC | ? 003F |
| 7x | | | | | | | | | | ´ 00B4 | : 003A | # 0023 | ¿ 00BF | ' 0027 | = 003D | " 0022 |
| 8x | | a 0061 | b 0062 | c 0063 | d 0064 | e 0065 | f 0066 | g 0067 | h 0068 | i 0069 | | | | | | |
| 9x | | j 006A | k 006B | l 006C | m 006D | n 006E | o 006F | p 0070 | q 0071 | r 0072 | | | | | | |
| Ax | | ° 00B0 | s 0073 | t 0074 | u 0075 | v 0076 | w 0077 | x 0078 | y 0079 | z 007A | | | | | | |
| Bx | | | | | | | | | | | | | | | | |
| Cx | £ 00A3 | A 0041 | B 0042 | C 0043 | D 0044 | E 0045 | F 0046 | G 0047 | H 0048 | I 0049 | | | | | | |
| Dx | ¡ 00A1 | J 004A | K 004B | L 004C | M 004D | N 004E | O 004F | P 0050 | Q 0051 | R 0052 | | | | | | |
| Ex | Ñ 00D1 | | S 0053 | T 0054 | U 0055 | V 0056 | W 0057 | X 0058 | Y 0059 | Z 005A | | | | | | |
| Fx | 0 0030 | 1 0031 | 2 0032 | 3 0033 | 4 0034 | 5 0035 | 6 0036 | 7 0037 | 8 0038 | 9 0039 | | | | | | EO |
| Differences from EBCDIC 500 |||||||||||||||||

## References

* ↑ "Code Page 6" (PDF). Archived from the original (PDF) on 2013-01-21.
# Character Encodings/Code Tables/EBCDIC/EBCDIC 010

IBM code page 10 (CCSID 10) is an EBCDIC code page used in IBM mainframes in Canada to support the English language.

## Codepage layout

Characters are shown with their equivalent Unicode codes.
EBCDIC 010 :
| | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | A | B | C | D | E | F |
| 0x | NUL | SOH | STX | ETX | SEL | HT | RNL | DEL | GE | SPS | RPT | VT | FF | CR | SO | SI |
| 1x | DLE | DC1 | DC2 | DC3 | RES/ ENP | NL | BS | POC | CAN | EM | UBS | CU1 | IFS | IGS | IRS | ITB |
| 2x | DS | SOS | FS | WUS | BYP/ INP | LF | ETB | ESC | SA | SFE | SM/ SW | CSP | MFA | ENQ | ACK | BEL |
| 3x | | | SYN | IR | PP | TRN | NBS | EOT | SBS | IT | RFF | CU3 | DC4 | NAK | | SUB |
| 4x | SP | | | | | | | | | | [ 005B | . 002E | £ 00A3 | ( 0028 | + 002B | ! 0021 |
| 5x | & 0026 | | | | | | | | | | ] 005D | $ 0024 | * 002A | ) 0029 | ; 003B | ¢ 00A2 |
| 6x | - 002D | / 002F | | | | | | | | | ½ 00BD | , 002C | % 0025 | _ 005F | ¶ 00B6 | ? 003F |
| 7x | | | | | | | | | | ± 00B1 | : 003A | # 0023 | @ 0040 | ' 0027 | = 003D | " 0022 |
| 8x | | a 0061 | b 0062 | c 0063 | d 0064 | e 0065 | f 0066 | g 0067 | h 0068 | i 0069 | | | | | | |
| 9x | | j 006A | k 006B | l 006C | m 006D | n 006E | o 006F | p 0070 | q 0071 | r 0072 | | | | | | |
| Ax | | ° 00B0 | s 0073 | t 0074 | u 0075 | v 0076 | w 0077 | x 0078 | y 0079 | z 007A | | | | | | |
| Bx | | | | | | | | | | | | | | | | |
| Cx | ² 00B2 | A 0041 | B 0042 | C 0043 | D 0044 | E 0045 | F 0046 | G 0047 | H 0048 | I 0049 | | | | | | |
| Dx | ³ 00B3 | J 004A | K 004B | L 004C | M 004D | N 004E | O 004F | P 0050 | Q 0051 | R 0052 | | | | | | |
| Ex | ¼ 00BC | | S 0053 | T 0054 | U 0055 | V 0056 | W 0057 | X 0058 | Y 0059 | Z 005A | | | | | | |
| Fx | 0 0030 | 1 0031 | 2 0032 | 3 0033 | 4 0034 | 5 0035 | 6 0036 | 7 0037 | 8 0038 | 9 0039 | | | | | | EO |
| Differences from EBCDIC 500 |||||||||||||||||

## References

* ↑ "Code Page 10" (PDF). Archived from the original (PDF) on 2013-01-21.
# Classroom Management and Discipline/Disruptive Behavior Defined

Dealing with disruptive behavior is one of the most stressful aspects of teaching (as if the responsibility of preparing a room full of children for a bright and successful future wasn't enough... not to mention the burden of preparing lessons and tests, satisfying curriculum requirements, marking papers, planning field trips, meeting with parents, and preparing for standardized student testing which could ultimately impact school funding and accreditation).
Again, disruption is stress upon an already stressful job.
In this situation, it is the easiest thing in the world to personalize the disruption, forming a dislike for the student in question, and coloring your responses and interactions with that student for the remainder of your relationship (and for that matter, predisposing yourself to deal similarly with future students who demonstrate similar behaviors). Regardless how justifiable your emotional reaction may be, the teacher, upon entering the classroom, agrees to remain an adult throughout these exchanges; that means you must focus on the issue (what was said or done), not on your feelings about it (even if what was said was intended to be hurtful to you).
It is important to consider that all behavior occurs in context. Rather than immediately feeding into the emotional response that a student's behavior evokes in you, consider what the source of the behavior might be.
| Behavior | Possible Source |
| Child daydreams in class | Material is too simple or too challenging |
| Child hoards food, eats in class | Child has past history of neglect |
| Child shouts at teacher when redirected | Child had a fight with his parent that morning |
| Child jokes when asked questions | Child doesn't understand or know the answer, makes a joke to avoid sounding stupid OR Child knows the answer but has been used to joking instead of answering |
| Child refuses to interact with teacher, peers | Child doesn't know how to make friends, has been rejected or ridiculed by peers and adults |
Unless you are the counselor or social worker, there isn't the time to explore underlying problems as the disruptive behaviors are demonstrating themselves, but it is still necessary to deal with them quickly and effectively for the room to function.
The disciplinary tone you set in your classroom over the first couple of weeks may determine how your room operates (or fails to operate) for the rest of the year. Your handling of discipline is noted not only by the student in question, but an audience of peers, who may gauge how far you can be pushed based on your handling of this incident. That is not to say that you should make students walk the plank of your pirate ship. Rather, you should strive to have a very even-tempered, firm delivery of your requests, and proceed with ordered steps of increasing consequence for continued non-compliance.
However, even if the responsibility of redirecting students and giving them consequences lies at your feet, while the job of finding out the underlying causes go to someone else, it is urgent that the process return back to you in a complete circle.
# Classroom Management and Discipline/Finding Things That Work
## Web Resources

See also Contemporary Educational Psychology/Chapter 7: Classroom Management and the Learning Environment—a discussion of major approaches to behavior management in classrooms.
# Classroom Management and Discipline/Handling Young Kids

* High five
* High five, down low, no, too slow
* Wax lips or the glasses that have the eyes pop out
* Pretend phone calls with a banana--hello, it is for you
* Be Gallagher—splat fruit with a hammer
* Play mad scientist—get bottles of things that look or smell cool and pour away—such as Alka-Selzer or those bath tablets
* Bob Marley (reggae is the backbone of having fun)
* Smoke from your finger tips—that you get from the same store that sells gum that turns your mouth blue and whoopee cushions
* Blow up a balloon, start to hand to child then let it go dance across the room crazily
* Those hair clips that are big now fit neatly on your wrist or a child's and make great teeth when you are a lion or tiger—they are also fun for "talking" when you squeeze and release them like a puppet
* Borrow magic tricks: pull a candy out of his ear.
* Electroshock (simulated please!): use your fists as 'shock pads' anywhere on his body - or have him do it to you and get very silly.
* Crack an egg on his head: no, not a real egg! - one fist on top, hit it with the palm of your other hand, then both hands 'dribble' down his face - yuk!
* Hot hands": his hands on yours, he has to pull them away before you can slap them.
* Hand game: hand over hand over hand over hand - flat or on a pole, as you would do when choosing 'firsts' with a baseball bat.
* Achey breaky heart
* Put tape over your mouth and try to talk—or pretend you're trying to keep your hand from covering your mouth but can't.
* Thumb wrestle
* Wear a hooded sweatshirt with a draw string and make your head disappear as you tighten string. ask child to help to get you out.
* Hand grenade deliverance of primary reinforcers. instead of giving an M&M, pretend to send it through the air with a whistling sound til it gets to child's mouth then explodes (i.e. you make exploding sound)
* Pick up telephone—it's for you, (child)—add in dialogue.
# Classroom Management and Discipline/Love and Logic

The Love and Logic model is based on the idea that teaching kids responsible behavior requires a mixture of the two core ideas: 'love' and 'logic'. By teaching our students (and our own children) that their actions have consequences, Fay asserts that we can better prepare them to make their choices about those actions intelligently.
The way the philosophy suggests we(educators and parents) can do this is by 'giving away control' by allowing kids to make their own choices while firmly standing by what we as individuals will do. A classic love and logic statement may illustrate this best.
"I will be glad to talk to you about this when your voice is as calm as mine"
The parent/educator has explained what he/she is willing to do (discuss the issue at hand), and also what behavior he/she expects from the child (when your voice as calm as mine).
As with many philosophies, some overlap exists with other philosophies or schools of thought. In the case of the Love and Logic philosophy some basic ideas are shared with both the Logical Consequences and the Restitution Model of Classroom management.
# Classroom Management and Discipline/Restitution Model

Restitution is a model for classroom management developed by Diane Chelsom Gossen based on Dr. William Glasser's concepts of Control Theory and Quality Schools. The Restitution Model has provided a guide for evaluating my management style, learning new skills and setting and maintaining limits within the classroom. The goal of Restitution is self-discipline. Using the Restitution Model is about helping children learn to become better people. Part of my job is to create the conditions in which a child can learn new behaviors that can be used in other situations; conditions where a child can be strengthened and develop self-understanding. Restitution is about helping an offending child become the kind of person she/he wants to be. It does not focus solely on the victim. Restitution helps a child reclaim their self-esteem through personal effort, taking action in making reparation, and strengthens the agreed upon beliefs and values about how we treat others. Restitution helps children evaluate what they can do to fix their own mistakes. (Restitution: Restructuring School Discipline, Diane Chelsom Gossen)
# Classroom Management and Discipline
## Classroom Management

* Starting Out
* Classroom Community
* Positive Reinforcement
* Handling Young Kids
* Challenging Behaviors
* Finding Things That Work

## Behavior Management

* Disruptive Behavior Defined
* Time Outs
* Therapeutic Holds
* Post-incident Processing

## Discipline Models

* Restitution Model
* Assertive Discipline
* Logical Consequences
* Transactional Analysis
* Teacher Effectiveness Training
* Reality Therapy/Choice Theory
* Judicious Discipline
* Democratic Classrooms
* Jones Model
* Love and Logic

## See also

* Contemporary Educational Psychology—discusses additional approaches to classroom management
# Classroom Management and Discipline/Classroom Community
## Getting Them In On It The First Day!

The first time you meet them, lay down the rules of the class. That way you get to know the different personalities you have. But do not rush too soon to start laying down the rules because you obviously will meet with your first rule breaker. Slacken a bit on the first day, but as the class progresses, show you mean business.
Also, find ways to warm up to them. Make them want to enjoy your class. Give them reasons why what you are teaching them is important to them. Of course not all of them will be glad that they are there. Who knows maybe when they hear something that interests them in your introduction, they will warm up to the class.

## Classroom Rules

You will have to keep saying the rules and applying the consequences of breaking them. But you also have to make it not too rigid or too lax. Let them know who is in charge. Do not lose your classroom.
# Circuit Theory/Extra Element

The Extra Element technique helps break down one complicated problem into several simpler ones like superposition. However the goal is to find impedance rather than current or voltage.
By removing the element that most complicates the circuit the overall circuit impedance can be obtained.
    $Z_{in}=Z_{in}^{\infty }\left({\frac {1+{\frac {Z_{e}^{0}}{Z}}}{1+{\frac {Z_{e}^{\infty }}{Z}}}}\right)$
where
    $Z\$ is the impedance chosen as the extra element to be removed
    $Z_{in}^{\infty }$ is the input impedance with Z removed (or made infinite)
    $Z_{e}^{0}$ is the impedance seen by the extra element Z with the source shorted (or made zero)
    $Z_{e}^{\infty }$ is the impedance seen by the extra element Z with the source opened (or made infinite)
Computing these three terms may seem like extra effort, but they are often easier to compute than the overall input impedance.

### Example

Consider the problem of finding $Z_{in}$ for the circuit in Figure 1 using the EET (note all component values are unity for simplicity). If the capacitor (gray shading) is denoted the extra element then
    $Z={\frac {1}{s}}$
Removing this capacitor from the circuit we find
* capacitor removed, looking at the input (source input)
* capacitor removed, reorganizing circuit so can see input impedance $Z_{in}^{\infty }$
    $Z_{in}^{\infty }=2\|1+1={\frac {5}{3}}$
Calculating the impedance seen by the capacitor with the input shorted we find
* shorted source, finding $Z_{e}^{0}$
* shorted source redrawn
    $Z_{e}^{0}=1\|(1+1\|1)={\frac {3}{5}}$
Calculating the impedance seen by the capacitor with the input open we find
* open source, finding $Z_{e}^{\infty }$
* open source redrawn
    $Z_{e}^{\infty }=2\|1+1={\frac {5}{3}}$
Therefore using the EET, we find
    $Z_{in}={\frac {5}{3}}\left({\frac {1+{\frac {3}{5}}s}{1+{\frac {5}{3}}s}}\right)$
Note that this problem was solved by calculating three simple driving point impedances by inspection.
# Circuit Theory/Examples

* Two resistors in series with DC power supply, find everything. One loop, no junctions.
* Two resistors in parallel with a current source, find everything. No loops, one junction.
* lots of random currents and directions .. figure out what is needed .. evaluate ... three junctions
* Many loops, many junctions, lots of equations
* Many power sources
* First differential equation
# Circuit Theory/Dangling Resistors

When opening capacitors, inductors or current sources during circuit analysis, sometimes a resistor is left connected to the circuit with only one wire. It can be removed from the circuit.
It can be removed because there is no current through it. This means that the electromotive force is the same through the resistor. The green and the red dot are part of the same node.
The original voltage between green and black is going to be the same voltage between red and black.
The total Resistance will be r1+r2.
# Circuit Theory/Decibel
## Decibel

Very large and very small numbers are hard to keep track of. Filters/amplifiers and test equipment all reduce or magnify signals. Even rounding to a factor 10 is hard to keep track of. It is easier to add and subtract powers of 10 rather than multiplying/dividing. Decibels have evolved as a way of doing this math in your head. Looking over a circuit is easier to see where inserting test equipment causes the signal to drop 3db rather than trying to remember whether one is dealing with power (and thus should translate this into one half) or voltage (which should be ... some uncomfortable number) at the moment.
In addition, the goal is magnify the very small and reduce the very large so that the most information can fit on a graph. Decibels also serve this purpose.
A decibel (dB) is one tenth of a bel (B). The bel represents a ratio between two power quantities of 10:1, and a ratio between two field quantities of √10:1. A field quantity is a quantity such as voltage, current, sound pressure, electric field strength, velocity and charge density, the square of which in linear systems is proportional to power. A power quantity is a power or a quantity directly proportional to power, e.g., energy density, acoustic intensity and luminous intensity.
The calculation of the ratio in decibels varies depending on whether the quantity being measured is a power quantity or a field quantity.
1 dB means a power ratio of 1.25892 (or $10^{\frac {1}{10}}\,$) and a voltage/current ratio of 1.12202 (or ${\sqrt {10}}^{\frac {1}{10}}\,$).
The problem is that logs are taken of unit-less ratios. How is a number like 5.7 Watt converted to dB? What is it to be divided by? For the purposes of this course, use P$_0$ = reference power = 1 Watt, V$_0$ = reference voltage = 1 volt, and I$_0$ = 1 amp. Decibels are then computed like this:
    $dB=10\log _{10}{\frac {P}{P_{0}}}$
    $dB=20\log _{10}{\frac {V}{V_{0}}}$
    $dB=20\log _{10}{\frac {I}{I_{0}}}$
Power goes as the square of the voltage, therefore the 10 log becomes 20 log.