Evolutionary Parsing Algorithm
The results of this algorithm outperform the conventional GP upon certain problems. The performance is measured by several metrics such as recall, precision, and accuracy.
The individuals in this system are parses of a sequence of words. The fitness function is based on the probability of the grammar rules used to build the parse. 에볼루션파워볼 커뮤니티
It is language independent
The goal of a parser is to take a part-of-speech tagged sentence and output a parse tree indicating word-word dependencies. Statistical models estimate the conditional probability of a parse tree and identify the most likely one.
The main problem with current parsing algorithms is that they are prone to errors, which limit their applicability to real-world text. This is especially true for log events, which can have complex structure and many interleaved variable parts. To overcome this limitation, the authors propose a new approach that uses an evolutionary algorithm to discover an optimal parse configuration for each log event.
The evolution parser consists of a population of individuals, each of which has a subtree corresponding to a grammar rule. Individuals that can parse a sequence of words are selected for crossover. If a candidate individual lacks a certain sequence of words, the cut operator replaces it with another individual whose chromosome contains that sequence. This process is repeated until a suitable parse configuration is obtained. 에볼루션 파싱알
It is a bottom-up parser
The evolution parser is a probabilistic natural language parser that uses evolutionary algorithms to optimize its performance. It compares favorably to classic parsers based on exhaustive search techniques. In addition, it is more flexible than top-first chart parsers in that it allows for the possibility of partial parses. It also allows for different lexical tags to be assigned to words in sentences. This is important because it can improve the quality of the results of the search.
The system is based on genetic operators such as crossover, which combines partial parses into new individuals. These individuals are stored in a population. The most complete individuals have a higher fitness than the rest, but incomplete individuals can be replaced with new ones. This process is accelerated using an elitism operator that selects the best individual in each generation. The final result is a parse tree with the highest fitness score. Caraballo and Charniak have investigated different figures of merit (FOM) for evaluating the likelihood of a constituent, and have shown that one particular FOM outperforms the others.
It is a genetic algorithm
A Genetic Algorithm is a search technique that finds solutions to a problem using a genetic algorithm. The search starts with the generation of potential solutions to a sequence, and then selects the best ones. This process is iterated until a target number of generations is reached or a criterion of convergence is reached.
Many different variations of genetic algorithms have been developed. These vary in their chromosome representation and the selection and replacement of individuals. They also use different genetic operators such as crossover and mutation to generate new parses.
Crossover randomly replaces an individual’s subtree with another one that parses the same sequence of words and satisfies the same grammar rule. Mutation, on the other hand, replaces a portion of an individual’s tree with another one that matches its syntactic category. The cut operator is similar, but it randomly removes a part of the tree instead of replacing it. Both are based on the same basic principle: a genetic algorithm tries to find a chromosome that is matched to a grammar rule.
It is a probabilistic parser
The evolutionary parsing algorithm uses genetic operators to improve the performance of top-down parsers. This method uses the same principles as natural selection or survival of the fittest, based on a fitness function that penalizes individuals that do not fully match grammar rules. It also uses a number of other genetic operators, such as cut and mutation. Cut randomly replaces a part of an individual’s parse tree with another one that is less complete. Mutation is a random substitution of an individual’s complete parse tree by another one that has the same sequence of words and syntactic category as the original.
This approach has been shown to be a viable method for improving the performance of chart parsers by incorporating probabilistic grammars. In addition, it can be easily extended to include semantic checks and subroutines for removing contexts that have incompatible variable types. Moreover, it can be combined with advanced deductive and learning components such as recurrent neural networks (RNNs) to increase the efficiency of the parsing process.