Online payments refer to the process of making financial transactions over the internet. This process allows users to pay for goods and services online using various methods, eliminating the need for cash or physical checks. Online payments are widely used in e-commerce, subscriptions, and various services, and they can be conducted through different platforms and devices, including computers, smartphones, and tablets. Common methods of online payment include: 1. **Credit and Debit Cards**: Users enter their card information to complete transactions.

Payment cards are financial cards that facilitate transactions between consumers and merchants, allowing users to pay for goods and services electronically. There are several types of payment cards, including: 1. **Credit Cards**: These allow consumers to borrow funds from the card issuer up to a certain limit to make purchases. Users are expected to pay back the borrowed amount, typically with interest, if not paid in full each month.

"Portal" can refer to a couple of different things in the context of computers and gaming, but it most commonly pertains to a critically acclaimed video game developed by Valve Corporation. Released in 2007 as part of the game bundle "The Orange Box," Portal is a puzzle-platform game that introduces a unique gameplay mechanic based around the use of a "portals" to solve puzzles and navigate through the game's environment.

A planisphere is a flat, rotating map of the stars and celestial objects that is used for stargazing. It typically consists of two parts: a circular star map that represents the night sky and a transparent overlay or rotating disk that covers the map. The user can adjust the overlay to display the stars visible at a specific date and time from a particular location on Earth.

Frederic C. Williams is a significant figure in the history of computer science, particularly known for his contributions to the development of early computing technologies. He was involved in the design of the Williams-Kilburn tube, which was an early form of computer memory that used cathode ray tubes to store data. The Williams tube was one of the first types of random-access memory, allowing computers to store and retrieve information much more quickly than previous methods, such as punched cards or magnetic tape.

IBM Hursley is an IBM development laboratory located in Hursley, near Winchester, England. Established in the 1960s, the facility has historically played a significant role in the development of various IBM software products and technologies. It is particularly known for its contributions to enterprise software, middleware, and cloud computing solutions. The Hursley lab has been involved in developing products like IBM WebSphere, IBM Integration Bus, and IBM MQ, among others.

The Kent Recursive Calculator, also known as the KRC, is a programming language and environment designed for exploring and demonstrating concepts in recursion and computation. It was developed in the context of educational use. KRC allows users to define recursive functions and perform computations that illustrate the principles of recursion, which is a fundamental concept in computer science and mathematics.

"Micro Men" is a 2009 BBC television film that tells the story of the rivalry between two toy manufacturers in the late 1970s: Chris Sievey, who created the infamous action figure "Cranky," and his competitor, Mattel's Big Jim line. The film revolves around the creation of the popular, tiny action figures known as "Micromen." It explores themes of innovation, creativity, and competition in the toy industry during that era.

Fictional dimensions generally refer to the conceptual space within storytelling—particularly in literature, film, and other narrative arts—where fictional worlds exist. These dimensions can encompass various aspects: 1. **Setting**: The physical location where the story takes place, which could include different landscapes, cities, and environments that may be entirely realistic, fantastical, or a blend of both. For example, Middle-earth in J.R.R.

Computer audition is a field of study and research that focuses on enabling computers to process, understand, and analyze audio signals, similar to how humans perceive and interpret sound. This multidisciplinary area encompasses aspects of signal processing, machine learning, artificial intelligence, and cognitive science, among others. Key objectives of computer audition include: 1. **Sound Recognition**: Identifying and classifying sounds or audio signals, such as speech, music, environmental sounds, and other audio events.

Infinite Impulse Response (IIR) is a type of digital filter used in signal processing. The key characteristic of an IIR filter is that its impulse response (the output when an impulse signal is applied) is infinite in duration, meaning the filter’s output will respond not just for a finite duration but indefinitely. This is typically achieved by using feedback in the filter's structure, which allows the output to depend on both current and past input values, as well as past output values.

A digital delay line is a circuit or device that delays a signal in the digital domain. It is commonly used in various applications, including audio processing, telecommunications, and digital signal processing (DSP). The primary function of a digital delay line is to store and playback a digital signal after a specified amount of time. ### How It Works: 1. **Sampling**: The incoming analog signal is first converted to a digital format through an analog-to-digital converter (ADC).

"Fast Algorithms for Multidimensional Signals" refers to a class of computational techniques designed to efficiently process and analyze signals with multiple dimensions (such as images, video, or 3D data). These multidimensional signals are often represented by arrays or tensors, where each dimension can correspond to different physical properties (such as time, space, frequency, etc.).

Discrete-time beamforming is a signal processing technique used in array signal processing where signals received from multiple sensors or antennas are combined in a way that enhances desired signals while suppressing unwanted signals or noise. This technique is particularly useful in applications such as telecommunications, radar, and sonar systems. ### Key Concepts: 1. **Array of Sensors**: Discrete-time beamforming relies on an array of sensors (e.g., microphones, antennas) that capture signals.

Effective Number of Bits (ENOB) is a metric used to describe the actual performance of an analog-to-digital converter (ADC) or a similar system, indicating the quality of the digitized signal. It provides an estimate of the actual number of bits of resolution that an ADC can achieve under real-world conditions, rather than just the theoretical maximum.

Encoding law generally refers to principles or rules that govern how information is transformed into a specific format for storage, transmission, or processing. While it’s not a term widely recognized in a particular field, it can intersect various areas such as: 1. **Information Theory**: In this context, encoding laws might refer to coding schemes used to efficiently represent data for storage or transmission.

The Nyquist frequency is a critical concept in the field of signal processing and is defined as half of the sampling rate of a discrete signal. It represents the highest frequency that can be accurately represented when a continuous signal is sampled at a given rate. According to the Nyquist-Shannon sampling theorem, in order to accurately reconstruct a continuous signal from its samples, the sampling frequency must be at least twice the highest frequency present in the signal.

The Finite Legendre Transform is a mathematical operation that generalizes the standard Legendre transform to finite-dimensional spaces or finite sets of points. It is often used in various fields such as physics, optimization, and numerical analysis, particularly in the context of convex analysis and transformation of functions.

Fourier analysis is a mathematical technique used to analyze functions or signals by decomposing them into their constituent frequencies. Named after the French mathematician Jean-Baptiste Joseph Fourier, this method is based on the principle that any periodic function can be expressed as a sum of sine and cosine functions (Fourier series) or, more generally, as an integral of sine and cosine functions (Fourier transform) for non-periodic functions.