8th International Workshop on ADVANCEs in ICT Infrastructures and Services (ADVANCE 2020), Jan 27, 2020
Software-Defined Networks (SDN) modified the way network traffic can be monitored and analyzed, a... more Software-Defined Networks (SDN) modified the way network traffic can be monitored and analyzed, allowing for new approaches for network optimization. This paper presents an approach for monitoring and analyzing context-based data flow considering the global state of the computational environment (users, presentation/communication devices, and network infrastructure). The proposed solution relays on the development and deployment of an API called Context-Aware Adaptive Routing Framework (CAARF-SDN). CAARF-SDN is a context-based service that provides the monitoring and optimization of the SDN traffic. In this paper we present the CAARF-SDN based monitoring through the implementation of a virtual network using Mininet in order to analyze contextual information such as Quality of Service (QoS), Quality of Device (QoD) and Quality of Experience (QoE). For this purpose, different scenarios are proposed in order to validate the so-called network Quality of Context (QoC) which is related to the global state of the computational environment and allows for the optimization of the network.
Anais do XXVI Workshop de Gerência e Operação de Redes e Serviços (WGRS 2021), 2021
Software-Defined Networking (SDN) é um paradigma de rede que permite a aplicação de novas técnica... more Software-Defined Networking (SDN) é um paradigma de rede que permite a aplicação de novas técnicas de engenharia de tráfego através da separação do plano de controle do plano de encaminhamento. De forma a dar suporte às características dinâmicas do ambiente computacional (tais como, condições dinâmicas de tráfego e variedade protocolos de rede, mobilidade do usuário, heterogeneidade de dispositivos, entre outros), técnicas inovadoras de engenharia de tráfego devem ser propostas para lidar com aplicações sensíveis às variações de atraso, tais como videoconferência e voz sobre IP. Neste trabalho apresentamos o arcabouço Context-Aware Adaptive Routing Framework SDN (CAARF-SDN), uma solução para otimização do tráfego de redes, compatível com qualquer controlador SDN, através de uma abordagem dinâmica e proativa baseada em contexto. Neste trabalho, está aplicado a otimização de tráfego de voz abordando a mudança da prioridade do fluxo e a mudança de topologia, baseando a noção de contexto...
Proceedings of the eighth ACM international conference on Multimedia, 2000
This paper presents the ongoing work using a formal approach for the design of Interactive Multim... more This paper presents the ongoing work using a formal approach for the design of Interactive Multimedia Documents (IMDs) based on the RT-LOTOS formal description technique. The present work extends this approach proposing the scheduling of IMDs based on a simple and operational model obtained as a result from the reachability analysis. One important breakthrough of this model is that it is a scheduling graph that provides the control of the occurrence of non-deterministic events, such as user interactions, within valid temporal intervals so that the global synchronization constraints of the document can be fulfilled during its presentation. Further on, some scheduling policies are also presented based on this model. Finally, we introduce some characteristics of the player actually available for the presentation of IMDs based on this new model.
Encyclopedia of Networked and Virtual Organizations
Virtual reality (VR) represents a modern human-computer interface consisting of a three-dimension... more Virtual reality (VR) represents a modern human-computer interface consisting of a three-dimensional (3D) environment generated by computer where the user can interact in different ways. VR can be applied in several applications domains such as medicine, education, entertainment, etc. In particular, interest is drawn to the application of VR in education since a student is able to interact and to be involved with a 3D environment, which simulates situations that are difficult or even impossible to be carried out in the traditional education process.
The methodologies applied in classroom and consequently the successful learning is a constant con... more The methodologies applied in classroom and consequently the successful learning is a constant concern and a focus of attention for the scientific community. This concern leads to the exhaustive search for more and better means to strengthen these two elements: methodology and successful learning. Therefore, different methodologies, paradigms, and tools have been proposed to provide an insight on the student's academic and professional development and to consolidate the content taught in classroom, such as e-Portfolios, Blended Learning and Peer-Assisted Learning (PAL). Based on the integration of these different approaches, this article introduces a Blended Peer-Assisted Learning platform based on Moodle which provides the implementation of an adaptive, synchronous, and collaborative learning environment able to adapt the students' learning experience according to their learning needs.
International Journal of Emerging Technologies in Learning (iJET), 2009
Most of the tools and languages for modeling Virtual Reality environments, such as VRML, X3D, Jav... more Most of the tools and languages for modeling Virtual Reality environments, such as VRML, X3D, Java3D, etc. do not provide means of describing the synchronized presentation of multimedia content inside these environments. Multimedia has demonstrated its capabilities of motivating users and capturing their attention, which are important characteristics when we want to provide a higher degree of immersion and learning capabilities inside Virtual Reality applications. This paper presents a robust and generic solution for the integrated presentation of different kinds of media objects inside virtual environments based on the Graphical Engine OGRE and how this solution can be applied broadly for providing customizable multimedia and virtual learning environments.
Christian Gütl Institute for Information Systems and Computer Media (IICM), Graz University of Te... more Christian Gütl Institute for Information Systems and Computer Media (IICM), Graz University of Technology, Austria School of Information Systems, Curtin University of Technology, Perth, Australia Infodelio Information Systems and GÜTL IT Research & Consulting, Austria ...
Journal of Information Systems Engineering & Management, 2018
Education professionals are always searching for new ways of promoting learning, either by modify... more Education professionals are always searching for new ways of promoting learning, either by modifying the pedagogical project of courses or by the adoption of new learning strategies. In particular, this paper presents the results of an effort in order to bridge the knowledge acquired by students within classroom in face-toface classes with technical skills required in real life situations. The contribution presented in this paper is the result of an assignment applied within an undergraduate Data Network Infrastructure Design course in a Brazilian university using an adapted Problem-Based Learning methodology (PBL), as a motivational tool. This paper also presents and discusses the resulting data related to the learning assessment.
2000 IEEE International Conference on Multimedia and Expo. ICME2000. Proceedings. Latest Advances in the Fast Changing World of Multimedia (Cat. No.00TH8532)
This paper presents a formal approach based on the RT-LOTOS formal description technique for the ... more This paper presents a formal approach based on the RT-LOTOS formal description technique for the semantic verification of SMIL documents. The reachability analysis of RT-LOTOS specifications provides the verification of consistency properties of a document and, later on, it also enables the generation of a valid scheduling graph for its presentation. This graph characterizes the reference behaviors for the presentation of a document. Also, some erroneous semantic interpretations of SMIL documents which are not conformant with their reference behaviors are illustrated using some currently available SMIL players.
2017 XLIII Latin American Computer Conference (CLEI), 2017
3D virtual environments provide a large potential for the development of applications in several ... more 3D virtual environments provide a large potential for the development of applications in several domains. Throughout the years different efforts have been done in order to enhance the development of these environments. In particular, the proposal of interaction metaphors applied to 3D environments which aim at replicating real world concepts into the virtual environment, facilitating user's interaction. However, the proposal and implementation of new interaction techniques is always challenging. Therefore, the importance of identifying the existing interaction metaphors and their taxonomy. This work proposes a literature review about the existing interaction metaphors within 3D environments, their classification and introduces a subset of gesture metaphors that can be implemented generically across different implementation platforms.
Virtual Reality has provided means to improve interface and user interaction with computational s... more Virtual Reality has provided means to improve interface and user interaction with computational systems. This improvement has affected directly the degree of immersion and user interaction with computer-generated synthetic environments, through the utilization of human senses such sight, hearing, touch, smell and taste. This work aims to present a usability assessment and the functionalities of an interactive and immersive virtual reality system based on the utilization of the panoramic Oculus Rift device and interaction through voice commands. The virtual environment adopted to be integrated to the solution is the Google Street View through which user can visualize and navigate on. Besides assessment, this paper also introduces the hardware and software integration carried out, as the different phases of the development of the virtual environment.
Proceedings of the seventh ACM international conference on Multimedia (Part 2), 1999
The paper generalizes previous works of the authors by revisiting the concept of temporal consist... more The paper generalizes previous works of the authors by revisiting the concept of temporal consistency of hypermedia documents. This generalization relies on the distinction of internal and external non-deterministic events.
Proceedings of the 2014 Summer Simulation Multiconference, Jul 6, 2014
The OpenFlow protocol is an example of a Software Defined Networking protocol proposed as a softw... more The OpenFlow protocol is an example of a Software Defined Networking protocol proposed as a software mechanism for controlling the network equipments. Nevertheless, the management of OpenFlow experiments can be a difficult task considering the programming languages and the configuration required for the resources involved. Nevertheless, this task would be straightforward with the use of a graphical tool. This paper presents the utilization of a graphical user interface called Visual Network Description (SDN version) for the authoring of OpenFlow scenarios. In order to demonstrate the potential of this tool a case study is presented illustrating the authoring and execution of an Openflow scenario.
Conference on Network and Service Management, Oct 24, 2011
To provide an integrated and optimized management of network modeling and simulation tools is a c... more To provide an integrated and optimized management of network modeling and simulation tools is a complex task. Indeed, the underlying information structures used by these tools are, most of the times, very distinct and it is not simple to relate them. Moreover, the re-utilization of network descriptions and other network related data among tools is not current. The use of a standard data structure, or language, to describe data networks would promote the interoperability among network tools, providing the users with the possibility of applying new platforms and tools to validate their network scenarios. This work proposes the modeling and simulation of Differentiated Services networks based on the Network Scenario Description Language Framework.
Proceedings of the Third International Conference on Computer Graphics Theory and Applications, 2008
Different languages and tools have been used for the modeling and building Virtual Reality applic... more Different languages and tools have been used for the modeling and building Virtual Reality applications which can be applied in different domains. These tools are each time more sophisticated providing means for the author of a 3D environment to build his model intuitively. However, these languages and APIs used for building virtual environments are still limited when it comes to integrate multimedia content inside these applications. This paper presents a generic and extensible solution for the presentation of integrated Interactive Multimedia Documents within Virtual Reality applications.
Most of the tools and languages for modeling Virtual Reality environments, such as VRML, X3D, Jav... more Most of the tools and languages for modeling Virtual Reality environments, such as VRML, X3D, Java3D, etc. do not provide means of describing the synchronized presentation of multimedia content inside these environments. Multimedia has demonstrated its capabilities of motivating users and capturing their attention, which is an interesting characteristic when we want to provide a higher degree of immersion inside Virtual Reality applications. This paper presents a robust and generic solution for the integrated presentation of different kinds of media objects inside virtual environments based on the Graphical Engine OGRE.
Proceedings of the Ninth International Conference on Enterprise Information Systems, 2007
The identification of use cases is one key issue in the development of interactive information sy... more The identification of use cases is one key issue in the development of interactive information systems. User participation in the development life cycle can be seen as critical to achieve usable systems and has proven its efficacy in the improvement of systems appropriateness. Indeed, the involvement of users in the requirements definition can add a significant improvement in both consecutive/interleaved tasks of: (i) understanding and specifying the context of use, and, (ii) specifying the user and organizational requirements, as defined in Human-Centered Design (HCD) (Organizations, 1999). Existing solutions provide a way to identify business processes and/or use cases in order to achieve system definition, but they don't do it in an agile and structured way that helps to efficiently bridge between Business Process Management and Software Engineering. Process Use Cases is a methodology, defined in the Goals software construction process, for the identification of use cases and information entities during the modeling and reorganization of business processes focusing the results in the identification of the functional requirements for the correct development of an interactive information system.
8th International Workshop on ADVANCEs in ICT Infrastructures and Services (ADVANCE 2020), Jan 27, 2020
Software-Defined Networks (SDN) modified the way network traffic can be monitored and analyzed, a... more Software-Defined Networks (SDN) modified the way network traffic can be monitored and analyzed, allowing for new approaches for network optimization. This paper presents an approach for monitoring and analyzing context-based data flow considering the global state of the computational environment (users, presentation/communication devices, and network infrastructure). The proposed solution relays on the development and deployment of an API called Context-Aware Adaptive Routing Framework (CAARF-SDN). CAARF-SDN is a context-based service that provides the monitoring and optimization of the SDN traffic. In this paper we present the CAARF-SDN based monitoring through the implementation of a virtual network using Mininet in order to analyze contextual information such as Quality of Service (QoS), Quality of Device (QoD) and Quality of Experience (QoE). For this purpose, different scenarios are proposed in order to validate the so-called network Quality of Context (QoC) which is related to the global state of the computational environment and allows for the optimization of the network.
Anais do XXVI Workshop de Gerência e Operação de Redes e Serviços (WGRS 2021), 2021
Software-Defined Networking (SDN) é um paradigma de rede que permite a aplicação de novas técnica... more Software-Defined Networking (SDN) é um paradigma de rede que permite a aplicação de novas técnicas de engenharia de tráfego através da separação do plano de controle do plano de encaminhamento. De forma a dar suporte às características dinâmicas do ambiente computacional (tais como, condições dinâmicas de tráfego e variedade protocolos de rede, mobilidade do usuário, heterogeneidade de dispositivos, entre outros), técnicas inovadoras de engenharia de tráfego devem ser propostas para lidar com aplicações sensíveis às variações de atraso, tais como videoconferência e voz sobre IP. Neste trabalho apresentamos o arcabouço Context-Aware Adaptive Routing Framework SDN (CAARF-SDN), uma solução para otimização do tráfego de redes, compatível com qualquer controlador SDN, através de uma abordagem dinâmica e proativa baseada em contexto. Neste trabalho, está aplicado a otimização de tráfego de voz abordando a mudança da prioridade do fluxo e a mudança de topologia, baseando a noção de contexto...
Proceedings of the eighth ACM international conference on Multimedia, 2000
This paper presents the ongoing work using a formal approach for the design of Interactive Multim... more This paper presents the ongoing work using a formal approach for the design of Interactive Multimedia Documents (IMDs) based on the RT-LOTOS formal description technique. The present work extends this approach proposing the scheduling of IMDs based on a simple and operational model obtained as a result from the reachability analysis. One important breakthrough of this model is that it is a scheduling graph that provides the control of the occurrence of non-deterministic events, such as user interactions, within valid temporal intervals so that the global synchronization constraints of the document can be fulfilled during its presentation. Further on, some scheduling policies are also presented based on this model. Finally, we introduce some characteristics of the player actually available for the presentation of IMDs based on this new model.
Encyclopedia of Networked and Virtual Organizations
Virtual reality (VR) represents a modern human-computer interface consisting of a three-dimension... more Virtual reality (VR) represents a modern human-computer interface consisting of a three-dimensional (3D) environment generated by computer where the user can interact in different ways. VR can be applied in several applications domains such as medicine, education, entertainment, etc. In particular, interest is drawn to the application of VR in education since a student is able to interact and to be involved with a 3D environment, which simulates situations that are difficult or even impossible to be carried out in the traditional education process.
The methodologies applied in classroom and consequently the successful learning is a constant con... more The methodologies applied in classroom and consequently the successful learning is a constant concern and a focus of attention for the scientific community. This concern leads to the exhaustive search for more and better means to strengthen these two elements: methodology and successful learning. Therefore, different methodologies, paradigms, and tools have been proposed to provide an insight on the student's academic and professional development and to consolidate the content taught in classroom, such as e-Portfolios, Blended Learning and Peer-Assisted Learning (PAL). Based on the integration of these different approaches, this article introduces a Blended Peer-Assisted Learning platform based on Moodle which provides the implementation of an adaptive, synchronous, and collaborative learning environment able to adapt the students' learning experience according to their learning needs.
International Journal of Emerging Technologies in Learning (iJET), 2009
Most of the tools and languages for modeling Virtual Reality environments, such as VRML, X3D, Jav... more Most of the tools and languages for modeling Virtual Reality environments, such as VRML, X3D, Java3D, etc. do not provide means of describing the synchronized presentation of multimedia content inside these environments. Multimedia has demonstrated its capabilities of motivating users and capturing their attention, which are important characteristics when we want to provide a higher degree of immersion and learning capabilities inside Virtual Reality applications. This paper presents a robust and generic solution for the integrated presentation of different kinds of media objects inside virtual environments based on the Graphical Engine OGRE and how this solution can be applied broadly for providing customizable multimedia and virtual learning environments.
Christian Gütl Institute for Information Systems and Computer Media (IICM), Graz University of Te... more Christian Gütl Institute for Information Systems and Computer Media (IICM), Graz University of Technology, Austria School of Information Systems, Curtin University of Technology, Perth, Australia Infodelio Information Systems and GÜTL IT Research & Consulting, Austria ...
Journal of Information Systems Engineering & Management, 2018
Education professionals are always searching for new ways of promoting learning, either by modify... more Education professionals are always searching for new ways of promoting learning, either by modifying the pedagogical project of courses or by the adoption of new learning strategies. In particular, this paper presents the results of an effort in order to bridge the knowledge acquired by students within classroom in face-toface classes with technical skills required in real life situations. The contribution presented in this paper is the result of an assignment applied within an undergraduate Data Network Infrastructure Design course in a Brazilian university using an adapted Problem-Based Learning methodology (PBL), as a motivational tool. This paper also presents and discusses the resulting data related to the learning assessment.
2000 IEEE International Conference on Multimedia and Expo. ICME2000. Proceedings. Latest Advances in the Fast Changing World of Multimedia (Cat. No.00TH8532)
This paper presents a formal approach based on the RT-LOTOS formal description technique for the ... more This paper presents a formal approach based on the RT-LOTOS formal description technique for the semantic verification of SMIL documents. The reachability analysis of RT-LOTOS specifications provides the verification of consistency properties of a document and, later on, it also enables the generation of a valid scheduling graph for its presentation. This graph characterizes the reference behaviors for the presentation of a document. Also, some erroneous semantic interpretations of SMIL documents which are not conformant with their reference behaviors are illustrated using some currently available SMIL players.
2017 XLIII Latin American Computer Conference (CLEI), 2017
3D virtual environments provide a large potential for the development of applications in several ... more 3D virtual environments provide a large potential for the development of applications in several domains. Throughout the years different efforts have been done in order to enhance the development of these environments. In particular, the proposal of interaction metaphors applied to 3D environments which aim at replicating real world concepts into the virtual environment, facilitating user's interaction. However, the proposal and implementation of new interaction techniques is always challenging. Therefore, the importance of identifying the existing interaction metaphors and their taxonomy. This work proposes a literature review about the existing interaction metaphors within 3D environments, their classification and introduces a subset of gesture metaphors that can be implemented generically across different implementation platforms.
Virtual Reality has provided means to improve interface and user interaction with computational s... more Virtual Reality has provided means to improve interface and user interaction with computational systems. This improvement has affected directly the degree of immersion and user interaction with computer-generated synthetic environments, through the utilization of human senses such sight, hearing, touch, smell and taste. This work aims to present a usability assessment and the functionalities of an interactive and immersive virtual reality system based on the utilization of the panoramic Oculus Rift device and interaction through voice commands. The virtual environment adopted to be integrated to the solution is the Google Street View through which user can visualize and navigate on. Besides assessment, this paper also introduces the hardware and software integration carried out, as the different phases of the development of the virtual environment.
Proceedings of the seventh ACM international conference on Multimedia (Part 2), 1999
The paper generalizes previous works of the authors by revisiting the concept of temporal consist... more The paper generalizes previous works of the authors by revisiting the concept of temporal consistency of hypermedia documents. This generalization relies on the distinction of internal and external non-deterministic events.
Proceedings of the 2014 Summer Simulation Multiconference, Jul 6, 2014
The OpenFlow protocol is an example of a Software Defined Networking protocol proposed as a softw... more The OpenFlow protocol is an example of a Software Defined Networking protocol proposed as a software mechanism for controlling the network equipments. Nevertheless, the management of OpenFlow experiments can be a difficult task considering the programming languages and the configuration required for the resources involved. Nevertheless, this task would be straightforward with the use of a graphical tool. This paper presents the utilization of a graphical user interface called Visual Network Description (SDN version) for the authoring of OpenFlow scenarios. In order to demonstrate the potential of this tool a case study is presented illustrating the authoring and execution of an Openflow scenario.
Conference on Network and Service Management, Oct 24, 2011
To provide an integrated and optimized management of network modeling and simulation tools is a c... more To provide an integrated and optimized management of network modeling and simulation tools is a complex task. Indeed, the underlying information structures used by these tools are, most of the times, very distinct and it is not simple to relate them. Moreover, the re-utilization of network descriptions and other network related data among tools is not current. The use of a standard data structure, or language, to describe data networks would promote the interoperability among network tools, providing the users with the possibility of applying new platforms and tools to validate their network scenarios. This work proposes the modeling and simulation of Differentiated Services networks based on the Network Scenario Description Language Framework.
Proceedings of the Third International Conference on Computer Graphics Theory and Applications, 2008
Different languages and tools have been used for the modeling and building Virtual Reality applic... more Different languages and tools have been used for the modeling and building Virtual Reality applications which can be applied in different domains. These tools are each time more sophisticated providing means for the author of a 3D environment to build his model intuitively. However, these languages and APIs used for building virtual environments are still limited when it comes to integrate multimedia content inside these applications. This paper presents a generic and extensible solution for the presentation of integrated Interactive Multimedia Documents within Virtual Reality applications.
Most of the tools and languages for modeling Virtual Reality environments, such as VRML, X3D, Jav... more Most of the tools and languages for modeling Virtual Reality environments, such as VRML, X3D, Java3D, etc. do not provide means of describing the synchronized presentation of multimedia content inside these environments. Multimedia has demonstrated its capabilities of motivating users and capturing their attention, which is an interesting characteristic when we want to provide a higher degree of immersion inside Virtual Reality applications. This paper presents a robust and generic solution for the integrated presentation of different kinds of media objects inside virtual environments based on the Graphical Engine OGRE.
Proceedings of the Ninth International Conference on Enterprise Information Systems, 2007
The identification of use cases is one key issue in the development of interactive information sy... more The identification of use cases is one key issue in the development of interactive information systems. User participation in the development life cycle can be seen as critical to achieve usable systems and has proven its efficacy in the improvement of systems appropriateness. Indeed, the involvement of users in the requirements definition can add a significant improvement in both consecutive/interleaved tasks of: (i) understanding and specifying the context of use, and, (ii) specifying the user and organizational requirements, as defined in Human-Centered Design (HCD) (Organizations, 1999). Existing solutions provide a way to identify business processes and/or use cases in order to achieve system definition, but they don't do it in an agile and structured way that helps to efficiently bridge between Business Process Management and Software Engineering. Process Use Cases is a methodology, defined in the Goals software construction process, for the identification of use cases and information entities during the modeling and reorganization of business processes focusing the results in the identification of the functional requirements for the correct development of an interactive information system.
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Papers by Paulo Sampaio