Valéria C. Times

Federal University of Pernambuco | UFPE · Center of Informatics (CIn)

The health sector has demanded computational solutions from academia and the software industry that ensure data security, interoperability, and reliability in software systems. Blockchain technology has been used in healthcare, and numerous studies have used its foundations and characteristics to provide solutions for the ecosystem of healthcare or...

Marketplace systems for delivery food retain valuable sensitive data besides charging high fees for each order. On the other hand, Blockchain has being adopted as a distributed database to reduce costs and remove intermediary actors. We have developed FoodChain that is a blockchain based system, decentralizes the food delivery solution and keeps da...

The growing use of online social networks (OSNs) has encouraged users to share detailed information about places they have visited, resulting on a clear connection between the virtual world and the physical world. The functionality responsible for sharing location by users dubbed “check-in”. This paper describes social and spatiotemporal interactio...

Self-adaptation gives software systems the ability to adjust their behavior or structure in changing environments such as the health software domain. However, adaptability significantly complicates software implementation and brings great challenges to software engineering. This paper proposes an Adaptive Healthcare Software Architecture (AHSA), wh...

A cloud data warehouse (cloud DW) is a subject-oriented, integrated, time-variant, voluminous, nonvolatile and multidimensional distributed database that is hosted in a cloud. A solution to ensure data confidentiality for a cloud DW is cryptography. In this article, the authors propose an encryption methodology for a cloud DW stored according to th...

The healthcare sector requires computational solutions with reliable authenticity features for the storage and retrieval of electronic health record data. To address this important issue, this article proposes a service-based software architecture to extract data from different legacy databases, standardise the patient's clinical data requirements...

he healthcare sector requires computational solutions with reliable authenticity features for the storage and retrieval of electronic health record data. To address this important issue, this article proposes a service-based software architecture to extract data from different legacy databases, standardise the patient's clinical data requirements a...

Coupling is a challenge in software engineering, because errors or failures compromise the whole software execution. To address this issue in the healthcare domain, a Decoupled Health Software Architecture (DHSA) is proposed in this paper. This study presents the development of three components, a tool, and a formal metric. The Connector, Container...

Reusability is an essential attribute in a software lifecycle, as it improves the usefulness of applications and reduces maintenance and development costs. However, legacy health applications use software architecture models that hinder the reusability of its components. This paper proposes the Health Software Modelling Language (HSML), which enabl...

The constant evolution of software development technologies has provided new interactions mechanisms for improving the usability of software systems and increasing the productivity of healthcare professionals. In this sense, speech recognition uses methods and technologies that allow the capture and transcription of spoken language automatically. H...

The container retrieval problem (CRP) is a practical problem, as it enables high operational efficiency in a container terminal system. The CRP involves finding an optimal sequence of operations for the crane, making it possible to retrieve all the containers from the bay according to a predefined order. An optimal sequence of operations is obtaine...

The development of Health Information Systems (HIS) based on openEHR archetypes establishes interoperability mechanisms for the Electronic Health Record (EHR) and improves the flexibility of health applications. However, there is a lack of tools to dynamically build data schema and Graphical User Interfaces (GUI) using archetypes for the healthcare...

Data interoperability in the health sector is a current and important topic which has been the object of study in several research. Interoperability provides improved patient care quality, assists professionals in decision-making and enables healthcare organizations to remain competitive on the market. This work presents a cloud middleware based on...

Traditionally, legacy Health applications use software architecture models that make it difficult to reuse components. Reusability is an essential attribute in the software lifecycle, as it improves the quality of applications and reduces maintenance and development costs. This paper proposes the cloud tool Microservice4EHR, which dynamically gener...

This paper presents a computational tool to dynamically create data schemas and graphical user interfaces from data attributes, terminologies and constraints specified in archetypes. Template4EHR allows end users to build health applications based on the Electronic Health Record specifications defined in archetypes, thus minimizing their dependency...

Background: Obstetric telemonitoring can improve gestational care, reducing the need fortravel, and can be used in different contexts to enable early detection of complications and prevention of intercurrences, providing local intervention before hospitalization. Objective: This paper aims to identify advances, contributions and limitations of o...

Popular events are well reflected on social media, where people share their feelings and discuss their experiences. In this paper, we investigate the novel problem of exploiting the content of non-geotagged posts on social media to infer the users’ attendance of large events in three temporal periods: before, during and after an event. We detail th...

The use of openEHR archetypes facilitates the development of flexible and interoperable health applications and allows end users to specify Electronic Health Record (EHR) requirements. However, there are few tools and frameworks available on the market that support health-standard-based Health Information Systems (HIS) development. This work presen...

The container retrieval problem (CRP) is a very important issue for container terminals. The CRP seeks to find an optimal sequence of operations for the crane to retrieve all the containers from the bay according to a predefined order. An optimal sequence of operations is obtained by either reducing the number of container relocations or reducing a...

A cloud data warehouse (cloud DW) is a subject-oriented, integrated, time-variant, voluminous, nonvolatile and multidimensional distributed database that is hosted in a cloud. A solution to ensure data confidentiality for a cloud DW is cryptography. In this article, the authors propose an encryption methodology for a cloud DW stored according to th...

The development of archetype-based Health Information Systems (HIS) allows the creation of interoperable mechanisms for the Electronic Health Record (EHR) as well as improvements for application maintenance and upgrades. However, we identified a lack of an approach or tool to build dynamic archetype-based data schema in heterogeneous database. This...

People living in highly populated cities increasingly experience decreased quality of life due to pollution and traffic congestion. With the objective of reducing the number of circulating vehicles, we investigate a novel approach to boost ride-sharing opportunities based on the knowledge of the human activities behind individual mobility demands....

A first fundamental step in the process of analyzing movement data is trajectory segmentation, i.e., splitting trajecto-ries into homogeneous segments based on some criteria. Although trajectory segmentation has been the object of several approaches in the last decade, a proposal based on a semi-supervised approach remains inexistent. A semi-superv...

The creation of databases for Electronic Health Records (EHR) has traditionally been done through relational database management systems (RDBMS). Using relational databases guarantees a referential integrity of the data, however, it hinders the extension and evolution of the data schemas due to the constant changes in the clinical concepts of the h...

Electronic Health Record (EHR) data management in a Health Information System (HIS) has traditionally been done using a single database model. Due to the heterogeneity of such data, this practice increases the complexity in HIS development. This article presents a software architecture for a legacy HIS, which improves data management by using polyg...

Few studies about OpenEHR standards assess usability aspects. This paper aims to evaluate archetyped interfaces, built by a user interface building tool, with respect to usability requirements of health care professionals. Such an assessment is carried out by comparing two user interface building tools. We carried out experimental tests with Health...

Large popular events are nowadays well reflected in social media fora (e.g. Twitter), where people discuss their interest in participating in the events. In this paper we propose to exploit the content of non-geotagged posts in social media to build machine-learned classifiers able to infer users' attendance of large events in three temporal period...

Sistemas de processamento de consultas para bancos de dados criptografados têm sido propostos como uma solução para proteger a confidencialidade de dados armazenados em servidores não confiáveis, tais como provedores de computação em nuvem, e para reduzir o impacto da criptografia no desempenho de consultas sobre dados criptografados. Pouca atenção...

The use of archetypes in the development of health applications standardizes the data attributes, terminologies, and constraints of the electronic health record, as well as improves the flexibility of health information systems. However, we have noticed in the literature that little attention has been given to researching tools that dynamically bui...

The development of archetype-based Health Information Systems (HIS) allows the creation of interoperable mechanisms for the Electronic Health Record (EHR) as well as improvements for application maintenance and updates. However, we identified a lack of approach or tool to build dynamic archetype-based data schema in heterogeneous database. This art...

The creation of Graphical User Interfaces (GUI) for the Electronic Health Record (EHR) based on archetypes improves maintainability of Health applications and reduces dependence on a software team. However, we noticed there lacked approaches to build customizable GUIs for the EHR, and performed experimental tests to assess the usability of Health a...

The container retrieval problem (CRP) is an important issue to achieve high yard operational efficiency in a container terminal system. The CRP aims to find an optimal sequence of operations for the crane to retrieve all the containers from the bay according to a predefined order. An optimal sequence of operations is obtained by either reducing the...

Although spatial database applications and location based systems require the execution of several types of searching operations over spatial data, works related to encrypted spatial data address a limited set of searching operations, restricting their use in real applications. This article proposes an encryption scheme that enables circular range...

Development of Health Information Systems (HIS) based on dual models allows modifications and extensions to be conducted in the layer of archetypes, reducing dependencies on software developers and on system development tools. However, the literature on HIS has paid little attention to modeling tools that build conceptual data schemes based on dual...

The development of Health Information Systems based on dual models allows modifications to be conducted in the layer of archetypes, reducing dependencies on software developers. However, we identified a lack of conceptual models to represent two-level database entities. This paper proposes a novel conceptual data model, called ArcheER, which is a d...

Building data schemas for storage in the Electronic Health Record (EHR) has traditionally been done using a single data model. This practice increases the complexity in application development due to the heterogeneity of data in the health care sector, which consequently makes the data schema rigid. In addition, an approach that stores EHR from app...

ComeWithMe is an activity oriented carpooling service that enlarges the candidate destinations of a ride request by considering alternative places where the desired activity can be performed. It is based on the observation that individuals often move towards a place to perform an activity while the activity is often not strictly associated with a s...

The increasing availability of positioning data fostered a number of new applications where the knowledge about mobility patterns is essential. However, the research conducted so far on mobility analysis focused on the geometric aspect at the expenses of the semantics of the movement. In this paper, we offer a new vision of semantic trajectory data...

The interest in carpooling is increasing due to the need to reduce traffic and noise pollution. Most of the available approaches and systems are route oriented, where driver and passengers are matched when the destination location is the same. ComeWithMe offers a new perspective: the destination is the intended activity instead of a location. This...

Studies on the validation of minimum data sets from international information standards have drawn the attention of the academic community to the identification of necessary requirements for the development of Electronic Health Records (EHRs). The primary motivation of such studies is the development of systems using archetypes. The aim of this stu...

Cloud computing systems handle large volumes of data by using almost unlimited computational resources, while spatial data warehouses (SDWs) are multidimensional databases that store huge volumes of both spatial data and conventional data. Cloud computing environments have been considered adequate to host voluminous databases, process analytical wo...

Homomorphic encryption (HE) allows the execution of queries over encrypted data without requiring decryption. However, we found a lack of studies for investigating the use of HE in data warehouse (DW). In this article, we propose a framework that defines how a HE scheme can be used to encrypt numeric measures of a DW, and how sum aggregation functi...

With the increasing popularity of Location-based Social Networks (LBSNs), users have shared information about places they have visited, creating a link between the real world (their movements on the globe) and the virtual world (what they express about these movements on the LBSNs). In this article, we propose the SiST model, which contains informa...

An important problem in the knowledge discovery of trajectories is segmentation in subparts (subtrajectories). Existing algorithms for trajectory segmentation generally use explicit criteria to create segments. In this article, we propose segmenting trajectories using a novel, unsupervised approach, in which no explicit criteria are predetermined....

Several studies deal with mechanisms for processing transactional queries over encrypted data. However, little attention has been devoted to determine how a data warehouse (DW) hosted in a cloud should be encrypted to enable analytical queries processing. In this article, we present a novel method for encrypting a DW and show performance results of...

In recent years, the exponential growth of positioning-enabled devices have allowed us to study the mobility behavior of individuals analyzing their collected tracks. In this context, a small, but steadily increasing part of the literature is looking at the semantic aspects of mobility. This paper presents a contribution to this trend, and is conce...

Mobility crowdsourced data, like check-ins of the social networks and GPS tracks, are the digital footprints of our lifestyles. This mobility produces an impact on the places that we are visiting, characterizing them by our behavior. In this paper we concentrate on the loyalty of places, indicating the regularity of people in visiting a given place...

A major challenge in trajectory data analysis is the definition of approaches to enrich it semantically. In this paper, we consider machine learning and context information to enrich trajectory data in three steps: (1) the definition of a context model for trajectory domain; (2) the generation of rules based on that context model; (3) the implement...

Although many real world phenomena are vague and characterized by having uncertain location or vague shape, existing spatial data warehouse models do not support spatial vagueness and then cannot properly represent these phenomena. In this paper, we propose the VSCube conceptual model to represent and manipulate shape vagueness in spatial data ware...

A vague spatial data warehouse allows multidimensional queries with spatial predicates to support the analysis of business scores related to vague spatial data, crisp spatial data and conventional data. However, vague spatial data are often represented and stored as multiple geometries and impair the query processing performance. In this paper, we...

Mobility crowdsourced data, like check-ins of the social networks and GPS tracks, are the digital footprints of our lifestyles. This mobility produces an impact on the places that we are visiting, characterizing them by our behavior. In this paper we concentrate on the loyalty of places, indicating the regularity of people in visiting a given place...

A vague spatial data warehouse allows multidimensional queries with spatial predicates to support the analysis of business scores related to vague spatial data, addressing real world phenomena characterized by inexact locations or indeterminate boundaries. However, vague spatial data are usually represented and stored as multiple geometries and imp...

There are many commercial Extract-Transform-Load (ETL) tools, of which most of them do not offer an integrated platform for modeling processes and extending functionality. This drawback complicates the customization and integration with other applications, and consequently, many companies adopt internal development of their ETL systems. A possible...

Spatial data warehouses (SDWs) allow for spatial analysis together with analytical multidimensional queries over huge volumes of data. The challenge is to retrieve data related to ad hoc spatial query windows according to spatial predicates, avoiding the high cost of joining large tables. Therefore, mechanisms to provide efficient query processing...

Current commercial and academic OLAP tools do not process XML data that contains XLink. Aiming at overcoming this issue, this paper proposes an analytical system composed by LMDQL, an analytical query language. Also, the XLDM metamodel is given to model cubes of XML documents with XLink and to deal with syntactic, semantic and structural heterogene...

Currently, geographic data warehouses provide a means of carrying out spatial analysis together with agile and flexible multidimensional analytical queries over huge volumes of data. However, they do not enable the representation and neither the analysis over real world phenomena that have uncertain locations or vague boundaries, which are denoted...

The growth of data available on the Internet and the improvement of ways to handle them consist of an important issue while designing a data model. In this context, XML provides the necessary formalism to establish a standard to represent and exchange data. Since the technologies of data warehouse are often used for data analysis, it is necessary t...

The growth of data available on the Internet and the improvement of ways to handle them consist of an important issue while designing a data model. In this context, XML provides the necessary formalism to establish a standard to represent and exchange data. Since the technologies of data warehouse are often used for data analysis, it is necessary t...

Drill-across SOLAP queries (spatial OLAP queries) allow for strategic decision-making through the use of numeric measures from distinct fact tables that share dimensions and by the evaluation of spatial predicates. Despite the importance of these queries in geographic data warehouses (GDWs), there is a lack of research aimed at their study. In this...

Non-redundant geographic data warehouse (GDW) schemas have been recognized as an essential issue in the GDW design. However, little attention has been devoted to the study of how the handling of vague spatial data affects query performance and storage requirements in GDW. In this paper we investigate the query processing performance over nonredunda...

With the growth of mobile devices equipped with geographical localization services, it has become economical and technically feasible to capture moving object trajectories in real life. Many interesting applications are being developed based on trajectory analysis. For example, in a traffic management system, traffic jams may be determined by minin...

Spatial Data Warehouses (SDWs) enable the simultaneous processing of multidimensional queries and spatial analysis. In the literature, little attention has been devoted to the development of benchmarks for analyzing the performance of query processing over SDWs. In this paper, we propose a novel benchmark, called Spatial SSB, designed specifically...

Spatial data warehouses (SDW) enable analytical multidimensional queries together with spatial analysis. Mainly, three operations are related to SDW query processing performance: (i) joining large fact tables and large spatial and non-spatial dimension tables; (ii) computing one or more costly spatial predicates based on spatial ad hoc query window...

Existing works for semantic trajectory data analysis have focused on the intersection of trajectories with application important geographic information and the use of the speed to find interesting places. In this paper we present a novel approach to find interesting places in trajectories, considering the variation of the direction as the main aspe...

A number of proposals for integrating geographical (Geographical Information Systems—GIS) and multidimensional (data warehouse—DW and online analytical processing—OLAP) processing are found in the database literature. However, most of the current approaches do not take into account the use of a GDW (geographical data warehouse) metamodel or query l...

Data Warehouse (DW), On-Line Analytical Processing (OLAP) and Geographical Information System (GIS) are tools for providing decision-making support. Much research is aimed at integrating these technologies, but there are still some open questions, particularly regarding to the design of spatial dimensional schemas of Geographical DW (GDW) and the m...

Trajectory data are normally generated as sample points, which are very difficult to understand and to analyze because they are often collected with no semantic information. Several studies have been developed for trajectory data analysis. Recently, a new model was designed to reason over trajectories as stops and moves, where stops are the importa...

XLink are XML elements used for describing relationships and semantic information contained in valid XML documents. Thus, the structure of XLink can be navigated and their components (arcs, locators, resources and title) can be retrieved through a path language, like XPath. However, it was not specified to retrieve information from specific element...

The current commercial and academic OLAP tools do not process XML data that make use of XLink. To develop OLAP systems for helping in the analysis of such data, this paper proposes an analytical query language, namely LMDQL (Link-based and Multidimensional Query Language). Before presenting LMDQL, a multidimensional data model based on XLink is giv...