Partial differential equationIn mathematics, a partial differential equation (PDE) is an equation which computes a function between various partial derivatives of a multivariable function. The function is often thought of as an "unknown" to be solved for, similar to how x is thought of as an unknown number to be solved for in an algebraic equation like x2 − 3x + 2 = 0. However, it is usually impossible to write down explicit formulas for solutions of partial differential equations.
Second derivativeIn calculus, the second derivative, or the second-order derivative, of a function f is the derivative of the derivative of f. Informally, the second derivative can be phrased as "the rate of change of the rate of change"; for example, the second derivative of the position of an object with respect to time is the instantaneous acceleration of the object, or the rate at which the velocity of the object is changing with respect to time. In Leibniz notation: where a is acceleration, v is velocity, t is time, x is position, and d is the instantaneous "delta" or change.
Individualist anarchism in the United StatesIndividualist anarchism in the United States was strongly influenced by Benjamin Tucker, Josiah Warren, Ralph Waldo Emerson, Lysander Spooner, Pierre-Joseph Proudhon, Max Stirner, Herbert Spencer and Henry David Thoreau. Other important individualist anarchists in the United States were Stephen Pearl Andrews, William Batchelder Greene, Ezra Heywood, M. E. Lazarus, John Beverley Robinson, James L. Walker, Joseph Labadie, Steven Byington and Laurance Labadie.
Types of socialismTypes of socialism include a range of economic and social systems characterised by social ownership and democratic control of the means of production and organizational self-management of enterprises as well as the political theories and movements associated with socialism. Social ownership may refer to forms of public, collective or cooperative ownership, or to citizen ownership of equity in which surplus value goes to the working class and hence society as a whole.
Higher-order singular value decompositionIn multilinear algebra, the higher-order singular value decomposition (HOSVD) of a tensor is a specific orthogonal Tucker decomposition. It may be regarded as one type of generalization of the matrix singular value decomposition. It has applications in computer vision, computer graphics, machine learning, scientific computing, and signal processing. Some aspects can be traced as far back as F. L. Hitchcock in 1928, but it was L. R. Tucker who developed for third-order tensors the general Tucker decomposition in the 1960s, further advocated by L.