Claudio Gutiérrez-Soto

University of Bío-Bío | UBB · Department of Information Systems

This paper addresses the challenge of preserving user privacy in location-based services (LBSs) by proposing a novel, complementary approach to existing privacy-preserving techniques such as k-anonymity and l-diversity. Our approach implements collaborative caching strategies within a mobile ad hoc network (MANET), exploiting the geographic of loca...

Deriving insight from data is a challenging task for researchers and practitioners, especially when working on spatio-temporal domains. If pattern searching is involved, the complications introduced by temporal data dimensions create additional obstacles, as traditional data mining techniques are insufficient to address spatio-temporal databases (S...

Social networks such as Twitter provide thousands of terabytes per day, which can be exploited to find relevant information. This relevant information is used to promote marketing strategies, analyze current political issues, and track market trends, to name a few examples. One instance of relevant information is finding cyclic behavior patterns (i...

Nowadays, people can access a wide range of applications and services for mobile device users. Among them, location-based services (LBS), where the application needs the user’s position to provide the service. Some examples of these applications are Uber and Waze. Nevertheless, the repetitive use of an LBS can reveal confidential user information;...

Big Data is a generic term that involves the storing and processing of a large amount of data. This large amount of data has been promoted by technologies such as mobile applications, Internet of Things (IoT), and Geographic Information Systems (GIS). An example of GIS is a Spatio-Temporal Database (STDB). A complex problem to address in terms of p...

Web search users are likely to face problems related to the availability of large amounts of data. As the quantity of online content grows, the risk of missing relevant information during search can only increase. Moreover, external variables such as the users’ reading proficiency level can further complicate the task. This article proposes an onli...

Location-based services (LBSs) have become a profitable market because they offer real-time and local information to their users. Although several benefits are obtained from the usage of LBSs, they have opened up many privacy and safety challenges because a user needs to release his/her location. To tackle these challenges, many location-cloaking t...

When using information retrieval systems, information related to searches is typically stored in files, which are well known as log files. By contrast, past search results of previously submitted queries are ignored most of the time. Nevertheless, past search results can be profitable for new searches. Some approaches in Information Retrieval explo...

This paper presents a subscription-based overlay network that supports file parallel downloading for cloud collaboration. First, our system lets users to register to a central server and allows this server to incrementally build a topology graph containing the network connections among the subscribers. With this topology graph in place, we plan to...

When using information retrieval systems, information related to searches is typically stored in files, which are well known as log files. By contrast, past search results of previously submitted queries are ignored most of the time. Nevertheless, past search results can be profitable for new searches. Some approaches in Information Retrieval explo...

When using information retrieval systems, information related to searches is typically stored in files, which are well known as log files. By contrast, past search results of previously submitted queries are ignored most of the time. Nevertheless, past search results can be profitable for new searches. Some approaches in Information Retrieval explo...

In this paper, a new Monte Carlo algorithm to improve the precision using past search results is presented. Experiments were carried out to compare our algorithm with traditional retrieval on a simulated dataset. In this dataset, documents, queries, and judgments of users were simulated. Exponential and Zipf distributions were used to build docu- m...

Past search results can be an useful source of information in response to a new query. Nevertheless, just a few works exploit the advantages of queries executed previously in an information retrieval sys- tem (IRS). In this paper, we propose a Monte Carlo algorithm, which takes advantage of queries submitted previously in an IRS. The algo- rithm us...

In Information Retrieval, past searches are a source of useful information for new searches. This paper presents an approach for reusing past queries submitted to an information retrieval system and their returned results to build the result list for a new submitted query. This approach is based on a Monte Carlo algorithm to select past search resu...

In this paper we present two contributions: a method to construct simulated document collections suitable for information retrieval evaluation as well as an approach of information retrieval using past queries and based on result combination. Exponential and Zipf distribution as well as Bradford's law are applied to construct simulated document col...

Spatio-temporal databases have achieved a high attention. Nevertheless, there is a little work on this kind of databases in distributed environment. This paper presents an on-line parallel algorithm to workload using MVR-tree index on the CREW RAM parallel model. The algorithm makes a distribution of the objects that more frequently change either t...

Nowadays XML have reached a great interest, because it is possible to share information through the Web. Moreover, the Web can be conceived as a huge Database. Therefore, like DBMS traditional, the Web needs efficient algorithms to detect changes on the Database. In this paper we present an efficient algorithm to detect change in XML documents. Alg...

This work presents a new algorithm to detect RDF graph isomorphism. Furthermore, we show that isomorphic RDF graphs issue can be solved in an efficient manner using graphs information. Algorithm efficiency resides in the detection of RDF subgraphs isomorphism. The theoretical complexity of algorithm is O(nlogn+e_G), where n is the number...

Spatio-temporal databases have achieved a high attention. However there is little work on this kind of databases in distributed environments. This paper presents a parallel strategy for the MVR-tree spatio-temporal access method and extends the model defined for a sequential environment. Experiments comparing our strategy with the sequential approx...

This paper presents a software sensor algorithm to estimate states under model uncertainty, which is capable of estima te states of nonlinear process models with parameter uncertainty. The algorithm is based on IMHSE method, which is an optimization- based method that relies on interval analysis, whic h provides it with global convergent properties...

Spatio-temporal databases have reached great interest. However, there is a scarce work of these databases in distributed environments. This paper describes two parallel strategies for the MVR-tree spatio-temporal access method on CREW PRAM parallel model. Experiments to compare our strategies with sequential approximation were carried out. Prelimin...