The BaumWelch algorithm finds the unknown parameters in a construct named for this man. When a finite number of steps leads to a state that is impossible to leave, this scientist's namesake system is called "absorbing." This man names the statement 
The BaumWelch algorithm finds the unknown parameters in a construct named for this man. When a finite number of steps leads to a state that is impossible to leave, this scientist's namesake system is called "absorbing." This man names the statement that the probability of a random variable being greater than or equal to a, is less than or equal to the expected value over a. That inequality can be used to derive (*) Chebyshev's. In his namesake matrices, the rows and/or columns sum to one. Those transition matrices describe a system named for this man in which future states depend only on the current state. For 10 points, name this Russian mathematician whose namesake systems are used to model random walks as "chains."
The BaumWelch algorithm finds the unknown parameters in a construct named for this man.
Andrey Markov [accept Markov chains or Markov networks; accept Markov's inequality]