Interaction information is a concept used in information theory that quantifies the amount of information that is gained about a system when considering the joint distribution of multiple random variables, compared to when the variables are considered independently. It often addresses the interactions or dependencies among variables. In more technical terms, interaction information can be defined as a measure of how much more information about the joint distribution of two or more random variables can be obtained by knowing the values of the variables compared to knowing them independently.

Roman Jakobson, a prominent linguist, introduced a model of communication that identifies six distinct functions of language. These functions describe different aspects of human communication and how language can be used in various contexts. Here’s a brief overview of each of the six functions: 1. **Referential Function**: This function conveys information and describes the world around us. It is associated with the context or the referent being discussed.

Joint source and channel coding (JSCC) is an approach in information theory and telecommunications that combines source coding (data compression) and channel coding (error correction) into a single, integrated method. The goal of JSCC is to optimize the transmission of information over a communication channel by simultaneously considering the statistical properties of the source and the characteristics of the channel.

The Krichevsky-Trofimov estimator is a statistical method used in the context of estimating the probability distribution of discrete random variables. Specifically, it is used for estimating the probability mass function (PMF) of a multinomial distribution based on observed data. This estimator is particularly noteworthy for being a nonparametric estimator that performs well in situations where traditional estimates (like the maximum likelihood estimator) might be biased, especially when the sample size is small or when some outcomes have not been observed.

Kullback's inequality, often referred to in the context of Kullback-Leibler (KL) divergence, is an important concept in information theory and statistics. Although it is not necessarily framed as an "inequality" in traditional terms, it relates to the KL divergence between two probability distributions.

Lempel–Ziv complexity, also known as Lempel-Ziv (LZ) complexity, is a measure of the complexity of a string (or sequence) based on the concepts introduced by the Lempel-Ziv compression algorithms. It serves as an indication of the amount of information or the structure present in a sequence. The Lempel-Ziv complexity of a string is defined using the notion of "factors," which are contiguous substrings that the original string can be broken down into.

MIMO-OFDM stands for Multiple Input Multiple Output - Orthogonal Frequency Division Multiplexing. It is a technology used in wireless communication systems that combines two advanced techniques: MIMO and OFDM. 1. **MIMO (Multiple Input Multiple Output)**: This technique involves the use of multiple antennas at both the transmitter and receiver ends. MIMO technology enhances data transmission rates and improves the reliability of communication by exploiting multipath propagation, where transmitted signals take multiple paths to reach the receiver.

A Multicast-Broadcast Single-Frequency Network (MBSFN) is a technology used in telecommunications, specifically within mobile communication systems such as LTE (Long Term Evolution) and beyond. It is designed to efficiently transmit the same content simultaneously to multiple users over a network, utilizing a single frequency channel. ### Key Features of MBSFN: 1. **Single Frequency**: In MBSFN, multiple cells (or base stations) transmit the same data on the same frequency at the same time.

Network throughput refers to the rate at which data is successfully transmitted over a network from one point to another in a given amount of time. It is often measured in bits per second (bps) or its multiples, such as kilobits per second (Kbps), megabits per second (Mbps), or gigabits per second (Gbps).

The Noisy-Channel Coding Theorem is a fundamental result in information theory, established by Claude Shannon in the 1940s. It addresses the problem of transmitting information over a communication channel that is subject to noise, which can distort the signals being sent. The theorem provides a theoretical foundation for the design of codes that can efficiently and reliably transmit information under noisy conditions.

A measure-preserving dynamical system is a mathematical framework used in ergodic theory and dynamical systems that captures the idea of a system evolving over time while preserving the "size" or "measure" of sets within a given space.

Metcalfe's Law is a principle that states the value of a network is proportional to the square of the number of connected users or nodes in the system. In simpler terms, as more participants join a network, the overall value and utility of that network increase exponentially. The law is often expressed mathematically as: \[ V \propto n^2 \] where \( V \) is the value of the network and \( n \) is the number of users or nodes.

Per-user unitary rate control is a network management technique that regulates the amount of data transmitted to and from individual users or devices within a network. This concept is often used in telecommunications and internet service provision to ensure fairness, avoid congestion, and maintain quality of service (QoS) across all users. ### Key Aspects of Per-user Unitary Rate Control: 1. **Unitary Rate Limiting**: Each user is assigned a specific data transmission rate or limit.

Rényi entropy is a generalization of Shannon entropy that provides a measure of the diversity or uncertainty of a probability distribution. It was introduced by Alfréd Rényi in 1960 and is particularly useful in information theory, statistical mechanics, and various fields dealing with complex systems.

A one-way quantum computer, also known as a measurement-based quantum computer, is a model of quantum computation that relies on the concept of entanglement and a sequence of measurements to perform calculations. The key idea of this model is to prepare a highly entangled state of qubits, known as a cluster state, which then serves as a resource for computation.

The Principle of Least Privilege (PoLP) is a security concept that dictates that any user, program, or system should be granted the minimum level of access—or permissions—necessary to perform its tasks. The goal is to limit the potential damage or misuse of systems and data by minimizing the access rights for accounts, processes, and applications.

Privilege revocation in computing refers to the process of removing or changing a user's permissions or access rights within a system or application. This is a crucial aspect of security and access control in computing environments, as it ensures that users have only the privileges necessary to perform their tasks, helping to mitigate the risk of unauthorized access or actions by either legitimate users or attackers.

The Theil index is a measure of economic inequality that assesses the distribution of income or wealth within a population. It is named after the Dutch economist Henri Theil, who developed this metric in the 1960s. The Theil index is part of a family of inequality measures known as "entropy" measures and is particularly noted for its ability to decompose inequality into within-group and between-group components.

The term "phase factor" is commonly used in various fields such as physics, particularly in quantum mechanics and wave physics. It typically refers to a complex factor that affects the phase of a wave or wavefunction.

Pointwise Mutual Information (PMI) is a measure used in probability and information theory to quantify the association between two events or random variables. It assesses how much more likely two events are to occur together than would be expected if they were independent. PMI can be particularly useful in areas such as natural language processing, information retrieval, and statistics.