Mario Dantas

• Phd
• Professor at Universidade Federal de Santa Catarina

Neste artigo são apresentados um modelo e uma arquitetura para construção e estruturação de ambientes que necessitam realizar, eficientemente, armazenamento, busca e análise de grandes volumes de dados. Para a implementação do modelo foi utilizado o projeto ParticipACT Brasil. Este projeto visa implantar na cidade de Florianópolis o processo de ciê...

The increased use of IoT has contributed to the popularization of environments that monitor the daily activities and health of the elderly, children or people with disabilities. The requirements of these environments, such as low latency and rapid response, corroborate the usefulness of associating fog computing with healthcare environment since on...

Neste artigo s˜ao apresentados um modelo e uma arquitetura para construção e estruturaç˜ao de ambientes que necessitam realizar, eficientemente, armazenamento, busca e an´alise de grandes volumes de dados. Para a implementaç˜ao do modelo foi utilizado o projeto ParticipACT Brasil. Este projeto visa implantar na cidade de Florian´opolis o processo d...

The IoT (Internet of Things) has emerged to increase the potentiality of pervasive monitoring devices. However, the implementation and integration of IoT devices, data storage and the development of applications are still considered challenging. This paper presents an infrastructure for aggregating and storing data from different sources from IoT d...

O conceito de qualidade de experiência (QoE) não é uma novidade per se, mas sua definição em termos de métricas mapeáveis para qualidade de serviço (QoS), e em especial tal abordagem aplicada ao contexto de bases de dados distribuídas (BDDs), é um novo conceito. Novos trabalhos formalizando QoE como completude de QoS permitem se lidar com decisões...

This paper presents an architecture for robots as a service (RaaS) in the cloud, implemented over the MQTT, an open and lightweight protocol for message exchange based on publish/subscribe methods. The system is composed by the cloud layer, hosting the MQTT Broker, Gateway layer, composed by the IoT gateway to interface Zigbee to Internet, and a lo...

A maioria das pesquisas sobre a Biometeorologia Humana usa dados de provedores de dados da saúde e do clima, para correlacionar e inferir os impactos das variáveis climáticas sobre as morbidades. Embora possam gerar indicadores para a gestão da saúde, as pesquisas precisam ser refinadas no sentido de considerar as leituras das variáveis meteorológi...

The early theoretical studies that presented conceptual definitions for the mapping of Quality of Experience (QoE) through Quality of Service (QoS), in an approach focused on Distributed Databases (DDBs), showed the directions to be threshed in a way to accomplish a hybrid DDBs’ QoE-QoS set of evaluation criteria. That evaluation set being classifi...

This paper presents an approach for Web service (WS) composition that enables the automatic adjustment of the composition at run-time to deal with WS execution flaws, e.g., WS unavailability, failure to execute properly or to produce desired results. The WS composition problem is converted into a nondeterministic planning problem which, by its turn...

This paper presents an enhanced approach to the evaluation of Quality of Context (QoC) parameters in a ubiquitous Ambient Assisted Living (AAL) e-Health platform, supporting the care of people with special needs (elderly or with health problems) thus improving their quality of life. At the outset, the study presents a literature review of QoC. Then...

Provision and delivery of services with quality is a classic research problem, however the computational resources available in the network infrastructure of providers are, usually, managed with conventional Quality of Service (QoS) parameters. This paper presents an approach of Quality of Experience (QoE) management for providing services aware of...

In the context of distributed databases (DDBs), the absence of mathematically well defined equations to evaluate quality of service (QoS), especially with statistical models, seems to have taken database community attention from the possible performance guarantees that could be handled by concepts related to quality of experience (QoE). In this art...

This paper investigates WSN (Wireless Sensor Networks) applications in health, and proposes implementation of IoT (Internet of Things) with ZigBee for Ambient Condition Monitoring in a Ubiquitous AAL (Ambient Assisted Living) environment. The data obtained from sensors (temperature and humidity) were combined so as to obtain the dew point temperatu...

In the mobile wireless environment portable computers can cache data to reduce the contention on the bandwidth and to save energy. Caching data items frequently access has been considered as a very useful and effective mechanism to minimize the amount of data transferred. However, maintenance of the cache consistence is a complex task because the d...

Nowadays the studies of how to store massive amounts of data is a constant concern for the entire scientific community. In this paper is presented a data storage approach for DICOM medical image in distributed environments, using the distributed file systems CEPH, FhGFS, PVFS and Lustre versus a traditional RDBMS. The main contribution behind this...

This research work investigates the performance impact of virtualizing parallel file systems’ (PFS) environments. Through an extensive experimental analysis, using three distinct computing platforms and considering 11 factors with relevant impact on systems’ performance, we demonstrate how PFS’ write throughput is affected by network and disk conte...

The trend of grid computing available on the Internet has generated challenges to the allocation of resources provided by this type of environment. Many of these challenges can be solved by the quality of experience paradigm that takes into account several context parameters. In this context, this paper presents the proposal of a new quality of exp...

This research work presents an investigation of the impact of a wide range of factors on the performance of parallel file systems (PFSs). It is the result of an extensive test campaign with three distinct computing platforms and value variations for eleven factors that advance the understanding of PFSs’ behavior under different conditions. Our main...

This paper proposes a Quality of Experience (QoE) management architecture for the provision of experience-aware services using Software Defined Networks. The architecture is enriched with an Autonomic Semantic Engine which is able to detect and perform policy adaptation actions in case of QoE degradations.

This research work investigates the performance impact of operating systems' (OS) caching parameters on a parallel file system (PFS). Through an extensive experimental analysis, an analytical performance model is proposed in order to reflect caching effects on performance of file write operations. A qualitative and quantitative evaluation of 855 te...

Cloud computing configurations became the major facility to support execution and storage of different types of applications. The fact that the diversity of requirements for executions became too much complex, an understanding of load index characterization and knowledge of existing approaches lead us to research these two topics. Load balancing is...

Cloud computing configurations became the major facility to support execution and storage of different types of applications. The fact that the diversity of requirements for executions became too much complex, an understanding of load index characterization and knowledge of existing approaches lead us to research these two topics. Load balancing is...

This paper provides an approach to assessing Quality of Context (QoC) parameters in a ubiquitous Ambient Assisted Living (AAL) environment. Initially, the study presents a literature review on QoC, generating taxonomy. Then it introduces the context management architecture used. The proposal is verified with the Siafu simulator in an AAL scenario w...

This paper presents a broad overview of Knowledge Engineering (KE). This is a research area that aims to develop methodologies, techniques and tools to support the construction of knowledge-based systems, supporting management and dissemination of knowledge. The objective of this paper is to bring together, in a single document, important definitio...

A well-known problem faced by any organization nowadays is the high volume of data that is available and the required process to transform this volume into differential information. In this study, a case-comparison study of automatic document classification (ADC) approach is presented, utilizing both serial and parallel paradigms. The serial approa...

Cloud configurations can be computational environment with interesting cost efficiency for several organizations sizes. However, the indiscriminate action of buying servers and network devices may not represent a correspondent performance number. In the academic and commercial literature, some researches highlight that these environments are idle f...

Petroleum reservoir engineering is a complex and interesting field that requires large amount of computational facilities to achieve successful results. Usually, software environments for this field are developed without taking care out of possible interactions and extensibilities required by reservoir engineers. In this paper, we present a researc...

Advanced reservation has been used in grid environments to provide quality of service (QoS) and to guarantee resources available at the execution time. However, in grid subtypes, such as opportunistic grid computing, it is a challenge provides QoS and guarantee of availability resources. In this article, we propose a new advanced reservation approa...

This paper provides an approach to evaluating Quality of Context (QoC) parameters in a ubiquitous Ambient Assisted Living (AAL) environment. Lack of quality can lead assisted systems to respond inappropriately, resulting in errors related to assistance or support, or putting the user at risk. QoC assessments can improve these systems and set them t...

This paper provides an approach to assessing Quality of Context (QoC) parameters in a ubiquitous Ambient Assisted Living (ALL) environment. Lack of quality can lead assisted systems to respond inappropriately, resulting in errors related to assistance or support, or putting the user at risk. QoC assessments can improve these systems and set them to...

Energy consumption has been a constant concern for high-performance computing (HPC). Recently, this concern has gained attention from the research community, which is aiming to reduce its costs. The performance gain in such an environment is usually proportional to cost. Examples of such environments are computational grids, which are used in the a...

A Qualidade da Experiência (QoE – Quality of Experiency) refere-se à avaliação subjetiva das percepções e expectativas dos usuários no uso de um serviço. A fim de compreendê-la para um determinado serviço e como instrumentalmente estimá-la, é preciso conhecer os diferentes fatores e parâmetros, relacionados aos agentes tecnológicos e humanos. Este...

Opportunistic high performance computing environments have been widely used, especially by the academic community owing to the possibility of obtaining high processing power with low cost, considering that this type of distributed high performance environments uses idle computing resources of personal machines. However, excessive requests of resour...

Due to increasing hardware capacity, computing grids have been handling and processing more data. This has led to higher amount of energy being consumed by grids; hence the necessity for strategies to reduce their energy consumption. Scheduling is a process carried out to define in which node tasks will be executed in the grid. This process can sig...

The increasing use of portable devices has generated a demand for information about the environment and the user's context. The use of context can provide more dynamic and personalized services – an important point to guarantee Quality of Context (QoC) and users’ satisfaction. Lack of quality can lead assisted systems to respond inappropriately, re...

This paper provides an approach to evaluating Quality of Context (QoC) parameters in a ubiquitous Ambient Assisted Living (ALL) environment. The study presents the proposed context management architecture, which is then verified with the Siafu simulator in an ALL scenario where the user's health is monitored with information about blood pressure, h...

As perspectivas da educação no futuro têm sido intensamente debatidas. As questões sobre a educação e seus desafios são múltiplas e complexas, apontando a necessidade de busca por outros modelos educacionais. O desenvolvimento e a capilaridade das TIC (Tecnologias de Informação e Comunicação) geraram uma nova conformação social que impacta o am...

We present a new approach for the development of a data persistency layer for a Digital Imaging and Communications in Medicine (DICOM)-compliant Picture Archiving and Communications Systems employing a hierarchical database. Our approach makes use of the HDF5 hierarchical data storage standard for scientific data and overcomes limitations of hierar...

he growing demand for performance observed in many organisations can still be considered the main motivator for the evolution of HPC (High Performance Computing) and, more recently, cloud environments. Part of this demand regards the need to deal with large and complex data sets, called big data. Performance improvement in such environments begins...

Resumo: A convergência tecnológica permite que empresas de diferentes áreas do conhecimento operem de modo integrado e colaborativo com o menor número de plataformas possíveis, para ofertar serviços. Para atingir objetivos comuns do negócio as organizações criam alianças ofertando serviços (Internet, VoIP, IPTV), incluindo mobilidade, utilizando um...

O processo de seleção de recursos é um dos mecanismos mais importantes de um ambiente distribuído. A abordagem utilizada no processo influencia na eficiência da distribuição dos recursos para o atendimento das requisições dos usuários. Esse artigo apresenta uma abordagem semântica de seleção de recursos sensível ao contexto. O objetivo dessa propos...

Opportunistic grid computing is an interesting paradigm when it is necessary to obtain high performance computing with low cost investment. On the other hand, advance reservation is very useful when QoS and efficient scheduling are desired in a multi-scheduling environment. However, it is not conventional to use advance reservation with opportunist...

In ubiquitous environment context awareness approach plays a vital role in adaptability to users requirements. Context-sensitive systems meet specific requirements correctly, only if context information possesses the desired quality of context (QoC). Context data can be unreliable or inaccurate, thus undermining the potential of context-aware servi...

This paper approaches Context Knowledge Representation and Quality of Context (QoC) through the development of an ontology in this domain. It is thereby intended to improve knowledge sharing between humans and machines, and allow knowledge reuse between applications. A QoC assessment can contribute in order to enable context-aware applications to d...

This paper presents a research study consisting of a comparison analysis of replication and retrieval of medical image data which use the Digital Imaging and Communications in Medicine (DICOM) standard. These data are stored in a relational database management system (RDBMS) and in the Hierarchical Data Format (HDF) using a distributed file system...

The new trend in the process of data-intensive management indicates the importance of a distributed file system for both Internet large scale services and cloud computing environments. I/O latency and application buffering sizes are two of a number of issues that are essential to be analysed on different class of distributed file systems. In this p...

Context-sensitive systems can use geographical position at a specific time to extract knowledge and determine patterns in user trajectories. However, this data can be unreliable or inaccurate, thus undermining the trajectories pattern inference process. Some researches adopts a procedure to eliminate redundancy and conflicts through the utilization...

Este artigo tem por objetivo fazer uma revisão de literatura sobre as técnicas de Engenharia do Conhecimento (EC) como apoio aos processos de Memória Organizacional (MO) - aquisição, armazenamento, manutenção, busca e recuperação de conhecimento. A metodologia de estudo consistiu das etapas de coleta de dados na literatura, análise, síntese e estru...

RESUMO O objetivo deste artigo é fazer um levantamento na literatura sobre Qualidade de Contexto (QoC), propondo uma taxonomia dos temas abordados pelos trabalhos pesquisados, além de identificar alguns desafios. O aumento da utilização de dispositivos portáteis gerou uma demanda de informações do ambiente e do usuário, para que aplicações possam o...

Abstract. Conceptual aspects of cloud computing are presented in this article and a bibliometric survey is developed about this subject. Different issues of cloud computing discussed in some of the cited articles from the bibliometric survey are commented in this article. The results leads to an increasing research subject, with considerable amount...

Software Projects in general tend to get more software reuse and componentization in order to reduce time, cost and new products resources. The need for techniques and tools to organize projects of higher quality in less time is one of the greatest challenges of Software Engineering. The Software Product Line is proposed to organize and systematica...

Telemedicine is a very important area in medical field that is expanding daily motivated by many researchers interested in improving medical applications. In Brazil was started in 2005, in the State of Santa Catarina has a developed server called the CyclopsDCMServer, which the purpose to embrace the HDF for the manipulation of medical images (DICO...

The spread of telemedicine systems increases every day. The systems and PACS based on DICOM images has become common. This rise reflects the need to develop new storage systems, more efficient and with lower computational costs. With this in mind, this article discusses a study for application in NetCDF data format as the basic platform for storage...

This paper presents the development of a control system for learning environments specialized in special education. Amongst its various possible uses, the system focuses on managing the class attendance of special education students, teachers and other classroom users through the use of pervasive and ubiquitous technologies. For developing tests an...

Resumo O aumento da utilização de dispositivos portáteis vem gerando uma necessidade de informações do ambiente e do usuário, o contexto. O uso do contexto pode prover serviços mais personalizados e dinâmicos, sendo um ponto importante à garantia da Qualidade de Contexto (QoC). Este artigo apresenta diversas abordagens de representação de conhecime...

Mobile devices using traditional authentication processes are vulnerable and inadequate. New approaches must be considered for solving this problem: environmental characteristics, device limitations and information obtained from sensors. This paper presents a recommendation system approach for information systems based on user behavior and informat...

Mobile devices use traditional authentication processes, which are vulnerable and unsuitable for highly dynamic environments, such as ubiquitous and pervasive environments. Therefore, new approaches are necessary in such environments. These approaches must be (i) context-aware by considering environmental and operational characteristics, restrictio...

The interaction between mobile and grid environments in building a transparent infrastructure for mobile users, involves several factors from both wired and wireless networks. These include the following: coordinated application executions, the management of inherent characteristics of mobile devices (disconnections and the problem of a reduced bat...

Mobile devices are becoming mandatory equipment in modern life. However, the connections are usually based on traditional authentication processes, which do not consider the environmental characteristics, restrictions of devices, and information provided by sensors within the pervasive space. In this paper, it is presented a novel adaptive authenti...

Novel telemedicine and picture archiving and communication systems (PACS) are enabling research for unique data storage and retrieval mechanisms. This paper presents an improved proposal that considers the HDF5 paradigm as a high performance environment for the storage and retrieval of medical images via PACS. Specifically, the previous proposal ha...

Novel telemedicine and picture archiving and communication systems (PACS) are enabling research for unique data storage and retrieval mechanisms. This paper presents an improved proposal that considers the HDF5 paradigm as a high performance environment for the storage and retrieval of medical images via PACS. Specifically, the previous proposal ha...

This paper proposes a method for fraud detection in automated selection exams, using knowledge engineering tools for identifying groups of answers with a strong indication of fraud, based on probabilistic evidence. Founded on an analysis of the wrong answers of the various candidates, the proposed method enables identification of suspicions, and ev...

The great number of information available in different data sources requires increasingly of search engine system to retrieve as many relevant documents as possible. Clinical medical records contain a great number of information, normally written in free-text form and without a linguistic standard. The physicians do not write the patient's reports...

Mobile grid environments can be broadly divided into two different types of configurations. In the first case, devices are used as grid interfaces. In the second configuration, mobile devices are considered to be grid resources. However, the interaction between mobile devices and wired networks still has to overcome several difficulties before it c...

Advance reservation is an important mechanism for a successful utilization of available resources in distributed multi-cluster environments. This mechanism allows, for example, a user to provide parameters aiming to satisfy requirements related to applications' execution time and temporal dependence. This predictability can lead the system to reach...

In this research, a knowledge-based architecture for a mobile emergency medical assistance system is presented. It is based on the France SAMU model and dopts the ontology and mobile computing approaches. The contribution is characterized for providing routines and medical protocol specifications for specialists through the use of their natural lan...

Communities of Practice make intensive use of information and communication technologies (ICT) to meet their needs of interaction among their members. At present, the main supporting tool for these communities is the Internet and the software tools available for their users. With the advent of digital TV, however, new resources have become availabl...

Distributed team-based collaboration is an established trend in modern organisations. Commodity-off-the-shelf cluster architectures have become common in providing computational resources for a large number of complex applications. Clusters are often gathered into multicluster network configurations within and among organisations. These configurati...

The classical solution of electromagnetic problems using the finite element (FE) method needs to assemble, store and solve an Ax = b matrix system. A new technique for solving FE cases, considered much simpler than traditional methods, shows that the assembling of the matrix A is unnecessary. The difference between these two techniques is the compu...

Mobile devices are becoming mandatory equipment in modern life. However, the available interfaces are usually not suitable for accepting data input in a friendly and reliable fashion. Accordingly, a context- based approach can represent a useful alternative for circumventing threats in a mobile computing scenario. In this paper, we present a propos...

Wireless Sensor Networks (WSN) can be used to monitor hazardous and inaccessible areas. In these situations, the power supply (e.g. battery) in each node can not be easily replaced. One solution is to deploy a large number of sensor nodes, since the lifetime and dependability of the network can be increased through cooperation among nodes. In addit...

This article presents an approach for providing automated and coordinated features for applications execution in mobile grid configurations. Therefore, in this article is proposed and implemented an architecture that provides an execution flow adjustment, in disconnection cases, matching requirements of submitted application and options defined by...

Fiber tracking is a technique that determines the location of fiber bundles in a human brain. Sequential implementations of fiber tracking usually require a large execution time, which hinders both the interactivity currently experienced by physicians and its applications to large collections of data sets. In this paper we present the design and im...