The exploitation of large data bases frequently implies the investment of large and, usually, expensive resources both in terms of the storage and processing time required. It is possible to obtain... Show More

The exploitation of large data bases frequently implies the investment of large and, usually, expensive resources both in terms of the storage and processing time required. It is possible to obtain equivalent reduced data sets where the statistical information of the original data may be preserved while dispensing with redundant constituents. Therefore, the physical embodiment of the relevant features of the data base is more economical. The author proposes a method where we may obtain an optimal transformed representation of the original data which is, in general, considerably more compact than the original without impairing its informational content. To certify the equivalence of the original data set (FD) and the reduced one (RD), the author applies an algorithm which relies in a Genetic Algorithm (GA) and a multivariate regression algorithm (AA). Through the combined application of GA and AA the equivalent behavior of both FD and RD may be guaranteed with a high degree of statistical certainty.

Sensor networks have perceived an extraordinary growth in the last few years. From niche industrial and military applications, they are currently deployed in a wide range of settings as sensors are... Show More

Sensor networks have perceived an extraordinary growth in the last few years. From niche industrial and military applications, they are currently deployed in a wide range of settings as sensors are becoming smaller, cheaper and easier to use. Sensor networks are a key player in the so-called Internet of Things, generating exponentially increasing amounts of data. Nonetheless, there are very few documented works that tackle the challenges related with the collection, manipulation and exploitation of the data generated by these networks. This paper presents a proposal for integrating Big Data tools (in rest and in motion) for gathering, storage and analysis of data generated by a sensor network that monitors air pollution levels in a city. The authors provide a proof of concept that combines Hadoop and Storm for data processing, storage and analysis, and Arduino-based kits for constructing their sensor prototypes.

The Babel File System is a dependable, scalable and flexible storage system. Among its main features the authors underline the availability of different types of data redundancy, a careful... Show More

The Babel File System is a dependable, scalable and flexible storage system. Among its main features the authors underline the availability of different types of data redundancy, a careful decoupling between data and metadata, a middleware that enforces metadata consistency, and its own load-balance and allocation procedure which adapts to the number and capacities of the supporting storage devices. It can be deployed over different hardware platforms, including commodity hardware. The authors' proposal has been designed to allow developers to settle a trade-off between price and performance, depending on their particular applications.

Public streams of geo-located social media information have provided researchers with a rich source of information from which to draw patterns of urban-scale human-mobility. However, most of the... Show More

Public streams of geo-located social media information have provided researchers with a rich source of information from which to draw patterns of urban-scale human-mobility. However, most of the literature relies on assumptions over the spatial distribution of this data (e.g., by considering only a uniform grid division of space). In this work the authors present a method that does not rely on such assumptions. They followed the social media activity of 24,135 Twitter users from Mexico City over a period of seven months (June 2013 - February 2014). The authors' method clusters user's geo-locations into a 19 zone data-driven division of Mexico City. These results can be interpreted from a graph theory-based perspective, by representing each division as nodes, and the edges between them as the number of people traveling between locations. Graph centrality reveals city's infrastructural key points. Without these gateways the authors can argue that mobility would either be radically transformed or break the city apart.

The widespread use of Mobile Intelligent Terminals and ubiquitous access to networks has enabled online information sources including Weibo and Wechat to bring huge impact to the society. Only a few... Show More

The widespread use of Mobile Intelligent Terminals and ubiquitous access to networks has enabled online information sources including Weibo and Wechat to bring huge impact to the society. Only a few words of network information can expand rapidly and catalyze the generation of a huge amount of information. The highly real-time content, fission-like spreading rate and enormous public opinion guiding forces created in this process will cast great influence on the society. Thus, semantic computing on online social networks and research on topics about emergencies have great significance. In this article, a numerical model of text semantic analysis based on artificial neural network is proposed, and a semantic computational algorithm for social network texts as well as a discovery algorithm for emergencies is provided with reference to the information provided by the social nodes itself and the semantic of the text. Through the numerization of text, the calculation and comparison of semantic distance, the classification of nodes and the discovery of community can be realized. In this article, semantic vector of micro-information for nodes and closure extension of semantic extensions are defined in order to build up an equivalence of short sentences, and in turn realize the discovery of emergencies. Then, huge quantities of Sina Weibo contents are collected to verify the model and algorithm put forward in this article. In the end, outlooks for future jobs are provided.