通用的说，熵(Entropy)被用于描述一个系统中的不确定性(the uncertainty of a system)。在不同领域熵有不同的解释，比如热力学的定义和信息论也不大相同。要想明白交叉熵(Cross Entropy)的意义，可以从熵(Entropy) -> KL散度(Kullback-Leibler Divergence) -> 交叉熵这个顺序入手。当然，也有多种解释方法[1]...
Entropy, the measure of a system’s thermal energy per unit temperature that is unavailable for doing useful work. Because work is obtained from ordered molecular motion, entropy is also a measure of the molecular disorder, or randomness, of a system.
The Beretta equation of motion describes the time evolution of the state of a system via a density operator which is uniquely based on an unambiguous preparation of an ensemble of identical systems, i.e. the so-called homogenous or irreducible ensemble, and does so both for unitary and non-...
The entropy of a system is defined to be the logarithm of the total weight, (1.10)S=kB ln W. This equation may be regarded as the basis of thermodynamics and statistical mechanics. If the microstates are equally likely, then this reduces to Boltzmann's original definition: the entr...
The goal of quantum key distribution (QKD) is to establish a secure key between two parties connected by an insecure quantum channel. To use a QKD protocol in practice, one has to prove that a finite size key is secure against general attacks: no matter the adversary’s attack, they canno...
We obtain an implicit equation for the correlation dimension of dynamical systems in terms of an integral over a propagator. We illustrate the utility of t... M Wilkinson,B Mehlig,K Gustavsson - Epl 被引量: 24发表: 2010年 Entropy dimension of topological dynamical systems. We introduce the ...
Enthalpy cost and entropy gain in a disordered system are characterized through the thermodynamic density of states, Ω(E)δE, measuring the number of configurationally excited states within\([E,E+\delta E]\). For our large number of chemical compounds, to obtain Ω, we find more precise ...
In engineering, the method of identification and reduction of thermodynamic irreversibilities is commonly called entropy generation analysis (EGA). Its optimization counterpart, i.e. entropy generation minimization (EGM), aims at minimizing the losses of a system subject to a specified set of ...
b, The distribution of the radius of the cavity B obtained from a bulk crystal phase of S = 0.52 system (Clath I – A0B1) at three different pressures. Source data Extended Data Fig. 3 Free energy calculation. A schematic diagram of the free energy calculation of the guest and host ...
The master equation and, more generally, Markov processes are routinely used as models for stochastic processes. They are often justified on the basis of randomization and coarse-graining assumptions. Here instead, we deriventh-order Markov processes and the master equation as unique solutions to an...