GLOBAL KNOWLEDGE ARK

Reference library

Foundations

Explore concepts, laws, equations and methods, with clear explanations of their use and sources. Choose an area of study or find a specific entry.

More filters

Reference entries

Showing 1–30 of 204 reference entries

Physics · Information · MeasurementScientific records

Build an inspectable physics record, test and revise a bounded cart model, preserve processing history, and plan findable data with appropriate sharing conditions.

Method
Mathematics & logic · InformationClassical propositions and connectives

Classical logic combines truth-valued propositions using defined connectives.

Definition
Mathematics & logic · InformationSets, membership and basic operations

A set specifies membership without counting duplicate listings.

Definition
Mathematics & logic · InformationFunctions, domain and codomain

A function assigns exactly one output to each input in its domain.

Definition
Mathematics & logic · InformationMathematical induction

A base case and general successor step establish a predicate on all nonnegative integers.

Method
Mathematics & logic · InformationComplex numbers

A complex number has real coordinates a and b and an imaginary unit satisfying i²=−1.

Definition
Mathematics & logic · Information · PhysicsLinear maps and matrix representation

A linear map preserves linear combinations and has a matrix once bases are chosen.

Definition
Mathematics & logic · InformationProbability space and axioms

A probability assigns nonnegative, normalised, countably additive weights to events.

Definition
Mathematics & logic · InformationConditional probability and independence

Conditioning restricts attention to an event of positive probability.

Definition
Mathematics & logic · InformationExpected value of a discrete random variable

Expected value weights possible values by their probabilities.

Definition
Information · Mathematics & logicBits and unsigned binary encoding

A bit has two possible states; a fixed-width unsigned binary word encodes an integer.

Definition
Information · Mathematics & logicShannon entropy of a discrete distribution

Shannon entropy measures uncertainty in a specified probability distribution.

Definition
InformationAlgorithm and decision procedure

An algorithm specifies effective steps; a decision procedure must terminate on every permitted input.

Method
Information · Mathematics & logicUndecidability of the halting problem

No total algorithm decides halting for every program and input in a general computation model.

Mathematical statement
Information · Mathematics & logicAsymptotic upper bounds and big O

Big O bounds eventual growth up to a fixed constant factor.

Definition
InformationFinite-alphabet mutual information

Mutual information measures statistical dependence in bits.

Definition
InformationNear-lossless source coding threshold

Entropy bounds asymptotic compression for an iid source.

Mathematical statement
InformationDiscrete memoryless channel capacity

Capacity is the maximal asymptotically reliable rate.

Mathematical statement
InformationHamming distance and error correction

Separated codewords permit bounded symbol-error recovery.

Mathematical statement
InformationInternet protocol layers

Protocol layers divide communication responsibilities.

Definition
InformationTCP reliable byte-stream transport

TCP orders bytes and retransmits detected losses.

Method
InformationEncryption, hashes and message authentication

Cryptographic primitives serve distinct security properties.

Definition
InformationPublic-key digital signatures

A signing key and a verification key have different roles.

Definition
InformationComputable reductions and undecidability

Reduction direction determines which impossibility transfers.

Mathematical statement
InformationDecision classes P and NP

Polynomial solving and polynomial verification differ.

Definition
InformationNP-hardness and NP-completeness

NP-completeness combines verification and reduction hardness.

Definition
InformationBounded-error randomized computation

Random choices permit a stated probability of error.

Definition
InformationFinite graphs and trees

Graphs represent pairwise connections; trees impose acyclicity.

Definition
InformationData-structure interfaces and operation costs

An interface defines operations; an implementation determines costs.

Method
InformationLoop invariants and total correctness

An invariant establishes correctness only with its proof obligations.

Method
DefinitionSource checked

Bits and unsigned binary encoding

InformationMathematics & logic

A bit has two possible states; a fixed-width unsigned binary word encodes an integer.

Key knowledge

A binary digit takes a value 0 or 1. In an n-bit unsigned positional encoding, bit i contributes bᵢ2ⁱ, with the rightmost bit at i=0. The n-bit word represents an integer from 0 to 2ⁿ−1.

Values and equations

N = Σᵢ₌₀ⁿ⁻¹ bᵢ2ⁱ; 0 ≤ N ≤ 2ⁿ−1

N
Encoded nonnegative integer
n
Positive word length bits
bᵢ
Digit at position i, either 0 or 1
i
Bit position, counted from zero at the right

Conditions and scope

  • n is a positive integer and bᵢ is 0 or 1.
  • This is unsigned positional interpretation; signed numbers, text and other data require an explicitly specified encoding.
  • Stored bit count does not by itself specify Shannon entropy.
Sources · 2

References

Sources retain their recorded scope. A source link alone does not establish verification of every statement.

  1. Introduction to Computer Science, 5.3: Machine-level information representationOpenStaxTextbook chapteropenstax.orgRead source
  2. COMP1521 · Integers (23T2)UNSW SydneyTeaching resourcecgi.cse.unsw.edu.auRead source

Evidence and review

Unsigned positional encoding and its representable range.

2026-10-10 · Checked bit positions and the distinction between a bit pattern and its interpretation.

Foundational review

2026-10-10 · Fresh primary-source inspection of the complete compact record, including every statement, equation, quantity and material condition, followed by independent AI editorial review. This check does not certify all linked lessons or every passage of every cited publication.

Sources from other places

Scope or convention differs

Binary digits carry powers-of-two positional weights.

The repository finite-width range and entropy distinction are additional explicit qualifications.

  • UNSW Sydney, School of Computer Science and Engineering

Entry detailsPermanent link to this entry ↗
Record identity
info-binary-encoding
Revision
core.1
Structured reference record
Essential core · first collection