Catálogo de publicaciones - libros

Extracting data from Web pages using wrappers is a fundamental problem arising in a large variety of applications of vast practical interest. There are two main issues relevant to Web-data extraction, namely wrapper generation and wrapper maintenance. In this paper, we propose a novel approach to automatic wrapper maintenance. It is based on the observation that despite various page changes, many important features of the pages are preserved, such as text pattern features, annotations, and hyperlinks. Our approach uses these preserved features to identify the locations of the desired values in the changed pages, and repairs wrappers correspondingly. Experiments over several real-world Web sites show that the proposed automatic approach can effectively maintain wrappers to extract desired data with high accuracy.

A set of 974 lexical symbols is defined which may appear in Polish text. Based on this set, a context-free grammar is constructed whose Chomsky normal form possesses 755 variables, 490 terminals and 1790 productions. Probabilities of these productions are estimated using over 40000 unparsed sentences. It turns out that a parsing algorithm using the resulting probabilistic context-free grammar parses correctly about 1/4 sentences.

In this paper we present the MAP language for expressing dialogues in multiagent systems. This is accomplished by defining patterns of communication between groups of agents, expressed by protocols. Our language is directly implementable and allows to specify the connection between communication and knowledge management in a way that is independent of the specific reasoning techniques used. Here we introduce MAP formal syntax and we point out added features with respect to its predecessor, the MAP language.

In this paper, I investigate anaphoric coreference as one of the sources of definiteness of NPs. The main focus here is how relative clauses influence the process of finding an antecedent for an NP in the standard DRT framework. Treelike indexes are adapted for this goal. The analysis is performed for article-free language (Polish). Other sources of definiteness are not considered.

Embedding a digital watermark in an electronic document is proving to be a feasible solution for multimedia copyright protection and authentication purposes. However, the balance between the watermark robustness and its invisibility has always been a challenge for watermarkers. Consequently, it was necessary to use a powerful computation system that can guarantee the watermarking requirements. In this end, we propose to apply genetic programming to digital watermarking. In this work, we are presenting a new watermarking scheme in DCT domain based on genetic programming (GP). It is an optimizing structure which permits to develop automatically the embedding equation of a DCT algorithm possessing a high PSNR value and a good robustness. Simulation results were satisfactory.

The paper presents simple methods for perfoming pattern search on annotated text corpora. Elementary text processing techniques are applied, based on the use of common text scanning tools: and . The methods allow to properly handle ambiguous annotation, as well as structured tags. Processing times for some types of queries are comparable to those attained by elaborated search engines using indexing techniques with query languages of similar expressiveness.

The paper presents an approach to anomaly detection problem based on self-nonself space paradigm. Hyperrectangular structure as description for self and nonself elements is proposed. Niching genetic algorithm is used for generation of detector set. Results of conducted experiments show a high quality of intrusion detection which outperforms the quality of recently proposed approach based on hypersphere representation of self-space.

The paper presents a concept of immune paradigm application to monitoring of company environment. Short-time prediction of stock rates is used as a basic tool to vigil relevant events, viewed as switching between “healthy” and “ill” behavior of the monitored quotations. Two predictive formulas are applied alternatively to recognize the behavior kind. “Illness” detection rules are proposed, based on the prediction efficiency evaluated in moving windows. Parameters of the predictors are modified according to the immune paradigm.

The problem of information exchange and communication in marine navigation is presented. The authors propose a sub-ontology for automatic intership communication as a supplement to the ontology of navigational information. The application of the sub-ontology enables the improvement of information exchange and co-operation between navigators steering the ships. The automation allows to reduce the impact of human errors resulting from the failure to effiectively communicate and coordinate actions. The human factor is often to blame for marine accidents. Applications in the ship communication and co-operation system are shown.

The article presents application of artificial immune algorithms in prediction of the arterial blood gasometry parameter, which is related to the infants respiration insufficiency. Artificial immune network algorithm created for this purpose allows for time series prediction of the vectorized data sets. Training data originates from the Infant Intensive Care Unit of the Polish – American Institute of Pediatry, Collegium Medicum, Jagiellonian University in Cracow.