Undirected Epsilon Closure Generation for Finite State Automata
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for removing ε-transitions in finite state automata and transducers are direction-dependent, leading to increased processing time and inefficiency when reversing transition directions.
Innovation Solution
An information processing device that generates undirected ε-closures and selects the optimal ε-removal patterns to minimize transitions without depending on the direction of ε-transitions, using a combination of set generation and pattern combination units to perform ε-removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If ε-removal is performed using related art methods, then processing can be completed, but processing time increases and efficiency decreases when transition directions are reversed
Solution Approach 1:
The patent segments the ε-removal process into distinct functional units: an undirected ε-closure generation unit that computes closures without direction dependency, and an ε-removal pattern selection unit that chooses optimal removal patterns. This segmentation allows each unit to specialize and avoids redundant computations when directions are reversed.
Solution Approach 2:
The undirected ε-closure generation unit creates a universal data structure (undirected closure) that can be used regardless of transition direction. This universal representation eliminates the need to recompute closures when directions are reversed, making the system adaptable to different processing scenarios without additional computational overhead.
2Device complexity
If ε-removal is performed in both directions to minimize transitions, then the number of transitions is reduced, but processing time increases
Solution Approach 1:
The patent performs preliminary action by generating undirected ε-closures before the actual ε-removal process. These pre-computed undirected closures contain all necessary information about state reachability regardless of direction, allowing the system to efficiently select optimal removal patterns without needing to perform separate computations for different directions.
Solution Approach 2:
The patent changes the parameter representation from directed closures (which depend on transition direction) to undirected closures (which are direction-independent). This parameter change allows the same data structure to serve multiple purposes and eliminates the need for re computation when processing directions are reversed.
3Ease of manufacture
If direction-dependent ε-removal methods are used, then implementation is simpler, but adaptability to different processing directions is reduced
Solution Approach 1:
Instead of creating separate directed closure generation processes for each direction, the patent inverts the approach by creating a single undirected closure generation process. This undirected process naturally handles both directions simultaneously, providing direction independence while maintaining implementation simplicity through a unified approach.
Data Source
AI summary
According to an embodiment, an information processing device includes a first set generating unit that generates a first set of states reachable by following ε-transitions in a forward direction and a reverse direction among states included in a finite state automaton; a second set generating unit that generates a second set representing a set of states included in each of a plurality of first sets connected by one transition that is not an ε-transition and the first set that is not connected to another first set by one transition that is not an ε-transition; a combination generating unit that obtains, among combinations of ε-removal patterns to be respectively applied to the ε-transitions in the second set, a combination with which the number of transitions after removing ε-transitions is the smallest; and a removing unit that removes ε-transitions in the second set by the removal patterns included in the obtained combination.