20+ Years of Analytics on Complex Data: Impact, Issues, Challenges and Contributions

Computer Science is a relatively young discipline, but in the last two decades the advances in hardware technology and software engineering has induced notable changes in the way users interact with computers. In particular, several processes involving data have changed in a radical manner. As a matter of fact, the amount of data stored in repositories has grown at impressive rates due to the rise of data sources, such as sensor networks, social networks or operational processes. Moreover, the heterogeneity of data has dramatically increased. In a word, data and their management have became more and more complex. Besides the data issues, new challenges have emerged from an application viewpoint, enabled by the informatization and digitalization of even the most trivial processes in the society. New applications span from real-time monitoring of dependable systems by means of cyber-physical sensors, to information diffusion at all levels by means of persistently connected devices, to the capability of tracking and delivering adhoc services to individuals.We're living in a connected world and the new technologies allow us with unforeseen possibilities. Along the recent years, new strategies (specifically, data loading, transformation and extraction, data management, and data mining approaches) have been proposed in order to deal with these unprecedented source of information. The advent of Big Data technologies has empowered the whole discipline of data analytics, by eventually creating even new professional figures which summarize skills in computer science and databases, statistics, machine learning and economics. However, the explosion of this new discipline is not new, and finds its path in the several contributions throughout the last 20 years. The Italian community has been particularly active in this scenario, by providing cutting-edge scientific results and prototypes in the field. As a proof of concept of this, this chapter tries to summarize some important contributions to the analysis of complex data both from the technological and the application point of view. In the following, we briefly recall the basic data types and methods that we have explored in the last years. In order to give the reader a more appealing view of the mentioned approaches, we also describe some applications that we have carried out with respect to some key important topics in the framework of the H2020 societal challenges.