Catálogo de publicaciones - libros

Several studies have applied genetic programming (GP) to the task of forecasting with favourable results. However, these studies, like those applying other techniques, have assumed a static environment, making them unsuitable for many real-world time series which are generated by varying processes. This study investigates the development of a new “dynamic” GP model that is specifically tailored for forecasting in non-static environments. This Dynamic Forecasting Genetic Program (DyFor GP) model incorporates methods to adapt to changing environments automatically as well as retain knowledge learned from previously encountered environments. The DyFor GP model is realised and tested for forecasting efficacy on real-world economic time series, namely the U.S. Gross Domestic Product and Consumer Price Index Inflation. Results show that the DyFor GP model outperforms benchmark models from leading studies for both experiments. These findings affirm the DyFor GP’s potential as an adaptive, non-linear model for real-world forecasting applications and suggest further investigations.

The most serious difficulty in developing a QA system is a lack of knowledge. In this paper, we first discuss three problems of developing a knowledge base by which a QA system answers How-type questions. Then, we propose a method of developing a knowledge base by using mails posted to a mailing list. Next, we describe a QA system which can answer How-type questions based on the knowledge base. Our system finds question mails which are similar to user’s question and shows the answers to the user. The similarity between user’s question and a question mail is calculated by matching of user’s question and a significant sentence in the question mail. Finally, we show that mails posted to a mailing list can be used as a knowledge base by which a QA system answers How-type questions.

In recent years, there has been a tremendous need for the ability to query and process vast quantities of musical data. Automatic content extraction is clearly needed here, relating to various aspects of music. One of desirable options is the ability of identifying musical pieces representing different types of emotions, which music clearly evokes. This paper focuses on scrupulous planning of experiments on automatic recognition of emotions in music. Collecting and labelling of data, extraction of objective features, as well as classification and cross-validation methods are proposed and discussed.

Increasing growth and popularity of multimedia resources available on the Web brought the need to provide new, more advanced tools needed for their search. However, searching through multimedia data is highly non-trivial task that requires content-based indexing of the data. Our research is focused on automatic extraction of information about the sound timbre, and indexing sound data with information about musical instrument(s) playing in a given segment. Our goal is to perform automatic classification of musical instrument sound from real recordings for broad range of sounds, independently on the fundamental frequency of the sound.

The mobile agent systems have been well known for years, but recent developments in the mobile technology (mobile phones, middleware) and the artificial intelligence created new research directions. Currently being widely used for the e-commerce and network management are entering into more personal areas of our life, e.g., booking airline tickets, doing shopping, making an appointment at the dentist. Future agents are becoming more like our representatives in the Internet than simple software. To operate efficiently in their new role they need to have the same capabilities as we do, showing their credentials when required and being anonymous when needed. Still they have to fulfill all security requirements for agent systems, including confidentiality, integrity, accountability, and availability. This paper focuses on providing mobile agents with anonymity and privacy. The proposed schemes are based on different cryptographic primitives: the secret sharing scheme and the zero-knowledge proof. The paper also includes a discussion of security of the proposed schemes.