Computer Science Basics

Study Notes

A bit is a contraction of "Binary Information Digit" or "Binary Digit".
8 bits equal 1 byte, 2 nibbles (a nibble being a group of 4 bits), and a word is a continuous group of bytes of any size.

Binary and decimal are called positional numbering systems because each position is weighted by a power of the radix (base).

A double-precision number under the IEEE-754 floating-point standard uses 64 bits, divided into 11 bits for the exponent and 52 bits for the significand, to represent 3 parts.

A Hamming code is an adaptation of the concept of parity, used in situations where random errors are likely to occur, to increase error detection and correction capabilities.
Hamming distance is the number of bit positions that two code words differ, and it is important for error detection.
The minimum Hamming distance is the smallest distance found among all pairs of code words in the code, which determines error detection and correction capabilities.

Normalization is the process of organizing a database to reduce redundancy and improve data integrity, or the rule that the first digit of the significand must be 1.
Normalization is necessary to:
Minimize data redundancy (duplicate data)
Minimize null values
Result in a more compact database (due to less data redundancy/null values)
Minimize/avoid data modification issues
Simplify queries
Make the database structure cleaner and easier to understand
Allow for easier extension of the database without impacting existing data
Make searching, sorting, and creating indexes faster

Unicode characters require different numbers of bits depending on the encoding used, with UTF-8 being the most commonly used encoding, which uses variable-length encoding.
In UTF-8, a Unicode character can require anywhere from 8 to 32 bits.
Unicode was created to address the limitations of traditional character encoding systems like ASCII, which only supported a limited range of characters.
Unicode provides a standardized way to represent text in virtually any language, allowing for universal text processing and communication across different platforms and systems.

Systematic error is a consistent or proportional difference between the observed and true values of something (e.g., a miscalibrated scale consistently registers weights as higher than they actually are).