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Logarithmic decrement
The logarithmic decrement is a measure of damping, defined as the natural logarithm of the amplitude ratio of two successive cycles of damped free vibration.
Logarithmic derivative
The logarithmic derivative of a function f is f′/f, equal to the derivative of ln f; it measures how fast f changes relative to its current size.
Logarithmic integral function
The logarithmic integral, li(x), is a special function defined as the integral of 1/ln t for x > 1, used as the standard approximation to the prime counting function π(x).
Logarithmic mean temperature difference
The logarithmic mean temperature difference, or log mean temperature difference, is the effective mean temperature difference between hot and cold fluids in a heat exchanger, used in sizing calculations.
Logarithmic negativity
Logarithmic negativity is an entanglement measure for bipartite quantum states, introduced by Vidal and Werner in 2002, computable exactly for any mixed state and upper bounding distillable entanglement.
Logarithmic potential
The logarithmic potential is the potential U(z) = ∫ log(1/|z−w|) dμ(w) for a compactly supported measure in the plane; its kernel is the Laplacian's two-dimensional fundamental solution, underlying logarithmic potential theory, capacity, and log gases.
Logarithmic scale
A logarithmic scale, or log scale, is a measurement scale where each equal step multiplies the measured quantity by a fixed factor, most often ten, allowing huge ranges like pH, decibels, and earthquake magnitudes.
Logarithmic spiral
The logarithmic spiral, or equiangular spiral, is a plane curve that cuts every ray from its pole at a constant angle, common in shells and galaxies.
Logarithmic transformation
A logarithmic transformation replaces each value of a variable with its logarithm, a statistical preprocessing step that stabilizes variance, reduces skewness, and turns multiplicative differences into additive ones.
Logic
Logic, also known as Logike, is the systematic study of valid inference, which patterns of reasoning preserve truth from premises to conclusion, now underpinning mathematics, philosophy, and computer science.
Logic Colloquium
The Logic Colloquium is the European Summer Meeting of the Association for Symbolic Logic, an annual logic conference first held in Oxford in 1956 and one of the ASL's two major meetings.
Logic in Computer Science (conference)
Logic in Computer Science (LICS) is an annual academic conference on logic in computer science, founded in 1986 and generally regarded as the field's most prestigious.
Logic model
A logic model, also called a theory of change or program theory, is a graphic depiction of a program linking resources, activities, and intended outcomes, widely used in program planning and evaluation.
Logical biconditional
The logical biconditional, also called biimplication, is the two-place propositional connective "P if and only if Q", true when P and Q have the same truth value.
Logical conjunction
Logical conjunction, also called logical and, is the two-place logical operation written ∧ that combines two statements into a compound true only when both are true.
Logical connective
A logical connective, or logical operator, is a symbol such as "and", "or", "not", or "if...then" that binds one or more sentences into a new compound sentence in formal logic.
Logical disjunction
Logical disjunction, also called the inclusive or, is the logical connective written ∨, a compound sentence true when at least one of its two disjuncts is true.
Logical NOR
Logical NOR, also called joint denial, is the logical connective true only when both of its statements are false; on its own it can express every truth-function of propositional logic.
Logical positivism
Logical positivism, also called logical empiricism or neopositivism, was a philosophical movement centered in 1920s Vienna and Berlin, whose Vienna Circle held that meaningful statements must be verifiable by observation.
Logical quantum processor based on reconfigurable atom arrays
A 2023 Nature experiment by a Harvard, MIT, and QuEra team that ran a quantum processor on error-corrected logical qubits, using up to 280 neutral atoms in a reconfigurable array.
Logical qubit
A logical qubit is an encoded qubit protected by quantum error correction, formed from multiple physical qubits so that quantum information survives errors in any of its components.
Logical reasoning
Logical reasoning is the process of drawing conclusions from premises by rules evaluated independently of subject matter, divided into deductive, inductive, and abductive modes, first formally studied by Aristotle.
Logical relations
A logical relation is a family of relations between program meanings, indexed by types and defined by recursion over type structure; it proves program equivalence and compiler correctness.
Logistic distribution
The logistic distribution, also known as the sech-squared distribution, is a continuous probability distribution with a sigmoid cumulative distribution function, resembling the normal distribution but with heavier tails.
Logistic function
The logistic function, also known as the Verhulst equation or logistic sigmoid, is the S-shaped function mapping real numbers into (0, 1), devised by Verhulst in 1838.
Logistic map
The logistic map, also called the discrete logistic equation, is a recurrence widely used in nonlinear dynamics, passing through stable states, period doubling, and chaos as the parameter r increases.
Logistic regression
Logistic regression, also called the logit or binary logit model, is a statistical method for modeling the probability of a binary outcome as a function of explanatory variables.
Logit
The logit, also called the log-odds, is a statistical function that converts a probability into the logarithm of its odds; it is the link function of logistic regression.
Loh Teck Peng
Loh Teck Peng (罗德平), often published as Teck-Peng Loh, is a Malaysia-born organic chemist and Distinguished University Professor at Nanyang Technological University, Singapore, known for green chemistry.
Lomustine
Lomustine (CCNU) is an oral nitrosourea chemotherapy drug that crosses the blood-brain barrier, used mainly for brain tumors and relapsed Hodgkin's lymphoma; approved in 1976, it is marketed as Gleostine.