Persistent homology group - A persistent homology group is the image of the homology map from an earlier stage of a filtration to a later stage.
Personal access token - A personal access token, or PAT, is a secret credential that software can present to a service when making authenticated requests.
Personal cloud - A personal cloud is a collection of remotely accessible storage and related services organized around an individual's information and devices.
Personal data - Personal data is information relating to an identified or identifiable person.
Personal knowledge base - A personal knowledge base is an organized collection through which an individual records, connects and retrieves knowledge useful to their work or life.
Personal pronoun - A personal pronoun is a pronoun associated with grammatical person, such as English “I,” “you,” “she,” “he,” “it,” “we,” or “they.
Personalization management system - A personalization management system is software used to organize, deliver and evaluate experiences tailored to different users or audiences.
Personalized search - Personalized search adapts search results to information about a particular user, such as stated interests, previous activity or task context.
Perspective projection - Perspective projection maps a three-dimensional point to a two-dimensional image through a camera center.
Perturb-and-MAP sampling - Perturb-and-MAP sampling generates random configurations by perturbing an objective or energy function and then optimizing the perturbed function.
Pessimistic description - A pessimistic description is a conservative description of a high-level action in angelic hierarchical planning.
Phase-based magnification - Phase-based magnification is a video-processing technique that makes small motions more visible by modifying temporal changes in the local phase of image...
Phase correlation - Phase correlation is a frequency-domain method for estimating the relative translation between two images.
Phase dispersion minimization - Phase dispersion minimization, usually abbreviated PDM, is a method for finding candidate periods in time-series data.
Phase (Fourier) - Fourier phase describes the positional alignment of a sinusoidal component in a Fourier representation.
Phase of Spectrum - The phase of a spectrum is the angle of each nonzero complex frequency component in a signal's Fourier representation.
Phillips - Perron test - The Phillips - Perron test is a time-series test whose null hypothesis is that a series has a unit root.
Phone - A phone is a speech sound considered as a phonetic unit.
Phoneme - A phoneme is a contrastive sound category in a language: replacing it with another phoneme can distinguish one word from another.
Phonetic search technology - Phonetic search technology finds candidate occurrences of spoken words or phrases by comparing representations of their sounds.
Phonetics - Phonetics is the study of speech sounds, including how people produce them, their physical acoustic properties, and how they are perceived.
Phonotactics - Phonotactics concerns the patterns and constraints governing how speech sounds can combine in a language.
Photon counting noise - Photon counting noise is the random variation in the number of photons detected during a measurement interval.
Phrasal template - A phrasal template is a reusable wording pattern containing fixed language and one or more slots that can be filled to produce particular expressions.
Phrasal verb - A phrasal verb is a construction in which a verb combines with a particle to function as a lexical unit, often with a meaning that cannot be predicted...
Phrase search - Phrase search retrieves text in which a sequence of query terms occurs with specified positional relationships, usually adjacent and in the same order for...
Phrase structure - Phrase structure is the hierarchical organization of a sentence into constituents, such as noun phrases and verb phrases.
Phrase structure grammar - A phrase structure grammar describes how smaller linguistic units combine into larger constituents, such as noun phrases, verb phrases, and sentences.
Physical artificial intelligence - Physical artificial intelligence is a broad term for AI used in systems that perceive, reason about or act within the physical world.
Physical Independence - Physical independence, usually called physical data independence in databases, is the ability to change physical storage or access arrangements without...
Physical neural network - A physical neural network uses controllable physical processes to carry out neural computation.
Physical schema - A physical schema describes how a database's data structures are implemented for a particular database system.
Physics-informed neural networks - Physics-informed neural networks, or PINNs, are neural models trained using physical equations or related scientific constraints as well as available...
PID controller - A PID controller is a feedback controller that combines proportional, integral and derivative contributions to produce a control command.
Pie chart - A pie chart is a circular chart divided into slices that show how categories contribute to one whole.
Pilot job - A pilot job is a job that acquires computing resources so an application-level system can subsequently schedule tasks within that allocation.
Pilot survey - A pilot survey is a preliminary survey conducted to test how a proposed survey works before full implementation.
Pinball loss - Pinball loss is an asymmetric error measure used to train and evaluate quantile predictions.
Pink noise - Pink noise is a random signal whose power spectral density is approximately inversely proportional to frequency over a specified range.
Pipe - In regular expressions, the pipe symbol, |, expresses alternation: a pattern can match one alternative or another.
Pipeline - A pipeline is the chain of steps that turns raw inputs into a finished result, where each step's output feeds the next: collect, clean, transform, train...
Pipeline architecture - Pipeline architecture organizes a system into processing stages whose outputs feed later stages.
Pipelining - Pipelining is the practice of overlapping the stages of work so that while one item is being processed by a later stage, the next item is already moving...
Pitch - Pitch is the perceptual quality that makes a sound seem relatively high or low.
Pitch accent - A pitch accent, in intonational analysis, is a tonal event associated with a prominent syllable in an utterance.
Pitch extraction - Pitch extraction is the computational estimation of pitch-related information from a sound recording, usually by estimating fundamental frequency, F0, over...
Pitch track - A pitch track is a time-indexed sequence of estimated pitch-related values, usually fundamental-frequency estimates from a sound recording.
Pivot table - A pivot table is a summary table that groups source records by selected categories and calculates measures such as sums, counts or averages.