The Redundancy and Distribution of the PhraseLengths of the Fixed - Database
نویسنده
چکیده
The Fixed-Database version of the Lempel Ziv algorithm closely resembles many versions that appear in practice. In this paper, we ascertain several key asymptotic properties of the algorithm as applied to sources with nite memory. First, we determine that for a dictionary of size n, the algorithm achieves a redundancy n = H log log n log n + o(log log n log n), where H is the entropy of the process. This is the rst, non-trivial, lower bound on any Lempel-Ziv type compression scheme. We then nd the limiting distribution and all moments of the lengths of the phrases by comparing them to a random-walk like variable with well known behavior.
منابع مشابه
Reliability Optimization for Complicated Systems with a Choice of Redundancy Strategies (TECHNICAL NOTE)
Redundancy allocation is one of the common techniques to increase the reliability of the bridge systems. Many studies on the general redundancy allocation problems assume that the redundancy strategy for each subsystem is predetermined and fixed. In general, active redundancy has received more attention in the past. However, in real world, a particular system design contains both active and col...
متن کاملIncreasing the Reliability and the Profit in a Redundancy Allocation Problem
This paper proposes a new mathematical model for multi-objective redundancy allocation problem (RAP) without component mixing in each subsystem when the redundancy strategy can be chosen for individual subsystems. Majority of the mathematical model for the multi-objective redundancy allocation problems (MORAP) assume that the redundancy strategy for each subsystem is predetermined and fixed...
متن کاملCold standby redundancy optimization for nonrepairable series-parallel systems: Erlang time to failure distribution
In modeling a cold standby redundancy allocation problem (RAP) with imperfect switching mechanism, deriving a closed form version of a system reliability is too difficult. A convenient lower bound on system reliability is proposed and this approximation is widely used as a part of objective function for a system reliability maximization problem in the literature. Considering this lower bound do...
متن کاملStability Assessment of the Flexible System using Redundancy
In this study, dynamic behavior of a mooring line in a floating system is analyzed by probability approaches. In dynamics, most researches have shown the system model and environments by mathematical expression. We called this process as the forward dynamics. However, there is a limit to define the exact environments because of uncertainty. To consider uncertainty, we introduce the redundancy i...
متن کاملA redundancy allocation problem with the choice of redundancy strategies by a memetic algorithm
This paper proposes an efficient algorithm based on memetic algorithm (MA) for a redundancy allocation problem without component mixing (RAPCM) in a series-parallel system when the redundancy strategy can be chosen for individual subsystems. Majority of the solution methods for the general RAPCM assume that the type of a redundancy strategy for each subsystem is pre-determined and known a prior...
متن کامل