PCGS may refer to:
* Parallel communicating grammar systems,
grammar systems working on their own string and communicating with other grammars in a system by sending their sequential forms on request.
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Preconditioned conjugate gradient
In mathematics, the conjugate gradient method is an algorithm for the numerical solution of particular systems of linear equations, namely those whose matrix is positive-definite. The conjugate gradient method is often implemented as an iterat ...
square method, a variant of the
preconditioned conjugate gradient method
In mathematics, the conjugate gradient method is an algorithm for the numerical solution of particular systems of linear equations, namely those whose matrix is positive-definite. The conjugate gradient method is often implemented as an iterativ ...
– an algorithm for the numerical solution of systems of linear equations whose matrix is symmetric and positive-definite.
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Professional Coin Grading Service
Professional Coin Grading Service (PCGS) is an American third-party coin grading, authentication, attribution, and encapsulation service founded in 1985. The intent of its seven founding dealers, including the firm's former president David Hall, ...
, an authentication and grading service for rare coins started by seven coin dealers in 1985 to standardize coin grading.
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