José Moura | ISCTE - University Institute of Lisbon (ISCTE-IUL) (original) (raw)
Papers by José Moura
IEEE Access
The work of Jose Moura is funded by FCT/MCTES through national funds and when applicable co-funde... more The work of Jose Moura is funded by FCT/MCTES through national funds and when applicable co-funded EU funds under the project UIDB/50008/2020. The work of David Hutchison is funded by the NG-CDI project: UK EPSRC (EP/R004935/1) and British Telecom plc.
The fast growth of Internet-connected embedded devices demands for new capabilities at the networ... more The fast growth of Internet-connected embedded devices demands for new capabilities at the network edge. These new capabilities are local processing, efficient communications, and resource virtualization. The current work aims to address these capabilities by designing and deploying a new management proposal, which offers on-demand activation of offline Internet of Things (IoT) fog computing assets via a Software Defined Networking (SDN) based solution combined with containerization and sensor virtualization. We propose a testbed as a proof of concept for the main functionalities of this novel solution. The obtained results evidence that the current SDN-based solution can deploy with success activation policies on computational edge containers, which are located within the same network domain of the SDN controller. In addition, different application-level scenarios are also investigated.
Cyber-Physical Systems (CPSs) are increasingly important in critical areas of our society such as... more Cyber-Physical Systems (CPSs) are increasingly important in critical areas of our society such as intelligent power grids, next generation mobile devices, and smart buildings. CPS operation has characteristics including considerable heterogeneity, variable dynamics, and high complexity. These systems have also scarce resources in order to satisfy their entire load demand, which can be divided into data processing and service execution. These new characteristics of CPSs need to be managed with novel strategies to ensure their resilient operation. Towards this goal, we propose an SDN-based solution enhanced by distributed Network Function Virtualization (NFV) modules located at the top-most level of our solution architecture. These NFV agents will take orchestrated management decisions among themselves to ensure a resilient CPS configuration against threats, and an optimum operation of the CPS. For this, we study and compare two distinct incentive mechanisms to enforce cooperation amo...
ArXiv, 2019
Ideally, full integration is needed between the Internet and Cyber-Physical Systems (CPSs). These... more Ideally, full integration is needed between the Internet and Cyber-Physical Systems (CPSs). These systems should fulfil time-sensitive functions with variable levels of integration with their environment, incorporating data storage, computation, communications, sensing, and control. There are, however, significant problems emerging from the convergence between CPS and Internet of Things (IoT) areas. The high heterogeneity, complexity, and dynamics of these resource-constrained systems bring new challenges to their robust and reliable operation, which implies the need for novel resilience management strategies. This paper surveys the state of the art in the relevant fields and, discusses the research issues and future trends that emerge. Thus, we hope to provide new insights into the management of resilient CPSs, formed by IoT devices, modelled by Game Theory, and flexibly programmed using the latest software and virtualization platforms.
ArXiv, 2020
The fast growth of Internet-connected embedded devices demands for new capabilities at the networ... more The fast growth of Internet-connected embedded devices demands for new capabilities at the network edge. These new capabilities are local processing, fast communications, and resource virtualization. The current work aims to address the previous capabilities by designing and deploying a new proposal, which offers on-demand activation of offline IoT fog computing assets via a Software Defined Networking (SDN) based solution combined with containerization and sensor virtualization. We present and discuss performance and functional outcomes from emulated tests made on our proposal. Analysing the performance results, the system latency has two parts. The first part is about the delay induced by limitations on the networking resources. The second part of the system latency is due to the on-demand activation of the required processing resources, which are initially powered off towards a more sustainable system operation. In addition, analysing the functional results, when a real IoT proto...
Game Theory (GT) has been used with outstanding outcomes to formulate, and either design or optim... more Game Theory (GT) has been used with outstanding outcomes to formulate, and either design or optimize, the operation of a huge number of representative communications and networking scenarios, each one with distinct entities aiming at different and usually contradictory goals. This paper comprehensively surveys and updates, in a tutorial style, the literature contributions that have applied a diverse set of theoretical games to wireless networks, emphasizing scenarios of upcoming Mobile Edge Computing (MEC). MEC is a promising model that aims to offer cloud services at the network periphery, reducing service latency and backhaul load, and enhancing Quality of Experience. Our literature discussion of GT is structured according to a taxonomy that has three top-level groups: classical, evolutionary, and incomplete information. Then, the above groups are divided considering pertinent game aspects that have a great impact on players’ final decisions, namely: rational vs. evolving strategi...
The fast growth of Internet-connected embedded devices demands for new capabilities at the networ... more The fast growth of Internet-connected embedded devices demands for new capabilities at the network edge. These new capabilities are local processing, efficient communications, and resource virtualization. The current work aims to address these capabilities by designing and deploying a new management proposal, which offers on-demand activation of offline Internet of Things (IoT) fog computing assets via a Software Defined Networking (SDN) based solution combined with containerization and sensor virtualization. We propose a testbed as a proof of concept for the main functionalities of this novel solution. The obtained results evidence that the current SDN-based solution can deploy with success activation policies on computational edge containers, which are located within the same network domain of the SDN controller. In addition, different application-level scenarios are also investigated. Keywords— Management; Elastic Provisioning; Software-Defined Networking; Internet of Things; Edg...
Cyber-Physical Systems (CPSs) are increasingly important in critical areas of our society such as... more Cyber-Physical Systems (CPSs) are increasingly important in critical areas of our society such as intelligent power grids, next generation mobile devices, and smart buildings. CPS operation has characteristics including considerable heterogeneity, variable dynamics, and high complexity. These systems have also scarce resources in order to satisfy their entire load demand, which can be divided into data processing and service execution. These new characteristics of CPSs need to be managed with novel strategies to ensure their resilient operation. Towards this goal, we propose an SDN-based solution enhanced by distributed Network Function Virtualization (NFV) modules located at the top-most level of our solution architecture. These NFV agents will take orchestrated management decisions among themselves to ensure a resilient CPS configuration against threats, and an optimum operation of the CPS. For this, we study and compare two distinct incentive mechanisms to enforce cooperation amo...
Game Theory (GT) has been used with excellent results to model and optimize the operation of a hu... more Game Theory (GT) has been used with excellent results to model and optimize the operation of a huge number of real-world systems, including in communications and networking. Using a tutorial style, this paper surveys and updates the literature contributions that have applied a diverse set of theoretical games to solve a variety of challenging problems, namely in wireless data communication networks. During our literature discussion, the games are initially divided into three groups: classical, evolutionary, and incomplete information. Then, the classical games are further divided into three subgroups: non-cooperative, repeated, and cooperative. This paper reviews applications of games to develop adaptive algorithms and protocols for the efficient operation of some standardized uses cases at the edge of emerging heterogeneous networks. Finally, we highlight the important challenges, open issues, and future research directions where GT can bring beneficial outcomes to emerging wireles...
SN Applied Sciences, 2020
Cyber-Physical Systems (CPSs) are increasingly important in everyday applications including the l... more Cyber-Physical Systems (CPSs) are increasingly important in everyday applications including the latest mobile devices, power grids and intelligent buildings. CPS functionality has intrinsic characteristics including considerable heterogeneity, variable dynamics, and complexity of operation. These systems also typically have insufficient resources to satisfy their full demand for specialized services such as data edge storage, data fusion, and reasoning. These novel CPS characteristics require new management strategies to support the resilient global operation of CPSs. To reach this goal, we propose a Software Defined Networking based solution scaled out by Network Function Virtualization modules implemented as distributed management agents. Considering the obvious need for orchestrating the distributed agents towards the satisfaction of a common set of global CPS functional goals, we analyze distinct incentive strategies to enact a cooperative behavior among the agents. The repeated operation of each agent's local algorithm allows that agent to learn how to adjust its behavior following both its own experience and observed behavior in neighboring agents. Therefore, global CPS management can evolve iteratively to ensure a state of predictable and resilient operation.
Journal of Network and Computer Applications, 2020
Information, 2019
The current paper addresses relevant network security vulnerabilities introduced by network devic... more The current paper addresses relevant network security vulnerabilities introduced by network devices within the emerging paradigm of Internet of Things (IoT) as well as the urgent need to mitigate the negative effects of some types of Distributed Denial of Service (DDoS) attacks that try to explore those security weaknesses. We design and implement a Software-Defined Intrusion Detection System (IDS) that reactively impairs the attacks at its origin, ensuring the “normal operation” of the network infrastructure. Our proposal includes an IDS that automatically detects several DDoS attacks, and then as an attack is detected, it notifies a Software Defined Networking (SDN) controller. The current proposal also downloads some convenient traffic forwarding decisions from the SDN controller to network devices. The evaluation results suggest that our proposal timely detects several types of cyber-attacks based on DDoS, mitigates their negative impacts on the network performance, and ensures ...
IEEE Communications Surveys & Tutorials, 2019
Game Theory (GT) has been used with significant success to formulate, and either design or optimi... more Game Theory (GT) has been used with significant success to formulate, and either design or optimize, the operation of many representative communications and networking scenarios. The games in these scenarios involve, as usual, diverse players with conflicting goals. This paper primarily surveys the literature that has applied theoretical games to wireless networks, emphasizing use cases of upcoming Multi-Access Edge Computing (MEC). MEC is relatively new and offers cloud services at the network periphery, aiming to reduce service latency backhaul load, and enhance relevant operational aspects such as Quality of Experience or security. Our presentation of GT is focused on the major challenges imposed by MEC services over the wireless resources. The survey is divided into classical and evolutionary games. Then, our discussion proceeds to more specific aspects which have a considerable impact on the game's usefulness, namely: rational vs. evolving strategies, cooperation among players, available game information, the way the game is played (single turn, repeated), the game's model evaluation, and how the model results can be applied for both optimizing resource-constrained resources and balancing diverse trade-offs in real edge networking scenarios. Finally, we reflect on lessons learned, highlighting future trends and research directions for applying theoretical model games in upcoming MEC services, considering both network design issues and usage scenarios.
Handbook of Research on Trends and Future Directions in Big Data and Web Intelligence
This chapter details how Big Data can be used and implemented in networking and computing infrast... more This chapter details how Big Data can be used and implemented in networking and computing infrastructures. Specifically, it addresses three main aspects: the timely extraction of relevant knowledge from heterogeneous, and very often unstructured large data sources; the enhancement on the performance of processing and networking (cloud) infrastructures that are the most important foundational pillars of Big Data applications or services; and novel ways to efficiently manage network infrastructures with high-level composed policies for supporting the transmission of large amounts of data with distinct requisites (video vs. non-video). A case study involving an intelligent management solution to route data traffic with diverse requirements in a wide area Internet Exchange Point is presented, discussed in the context of Big Data, and evaluated.
Handbook of Research on Trends and Future Directions in Big Data and Web Intelligence
This chapter revises the most important aspects in how computing infrastructures should be config... more This chapter revises the most important aspects in how computing infrastructures should be configured and intelligently managed to fulfill the most notably security aspects required by Big Data applications. One of them is privacy. It is a pertinent aspect to be addressed because users share more and more personal data and content through their devices and computers to social networks and public clouds. So, a secure framework to social networks is a very hot topic research. This last topic is addressed in one of the two sections of the current chapter with case studies. In addition, the traditional mechanisms to support security such as firewalls and demilitarized zones are not suitable to be applied in computing systems to support Big Data. SDN is an emergent management solution that could become a convenient mechanism to implement security in Big Data systems, as we show through a second case study at the end of the chapter. This also discusses current relevant work and identifies...
Sono iniziate dieci anni fa le infuocate polemiche fra joyciani, al di qua e al di là dell'Atlant... more Sono iniziate dieci anni fa le infuocate polemiche fra joyciani, al di qua e al di là dell'Atlantico, sull'edizione critica dell'Ulisse ; da allora, i critici non joyciani di professione hanno cominciato a diffidare di certe ricerche filologiche che appaiono al servizio non tanto della "sacralità " del Testo quanto dell'interesse economico dei diversi editori. Chi abbia mai scorso, infatti, il James Joyce Archive 1 , i 63 monumentali volumi che raccolgono in riproduzione gli scritti di Joyce, dai meticolosi appunti linguistici alle varie versioni e bozze delle sue opere, sa bene come non ci si dovrebbe sorprendere di scoprire varianti anche minime in qualche foglio sperduto; e ciò è vero soprattutto per quanto riguarda le prime opere joyciane, visto che, come osserva Hans Walter Gabler, note, appunti e prime stesure di quelle ci sono giunti in modo molto frammentario 2. Le poche righe che si possono, dunque, scoprire sono magari ininfluenti dal punto di vista critico, eppure ricche quanto mai dell'emozione di chi, nella scoperta, si sente partecipe non tanto di una verità letteraria quanto di un salvataggio della memoria e del recupero di un tormentato processo di elaborazione creativa. E` stato durante una ricerca bibliografica a caccia di scritti joyciani dimenticati che ci si è imbattuti in una di queste pagina. Una circostanza che potrebbe apparire fortuita, se non fosse stata invece caparbiamente inseguita. E la prima emozione è toccata a una laureanda 3 che ha scoperto ciò che-si fa per dire-era già, come la lettera rubata di Poe, sotto gli occhi di tutti. Così, un nuovo titolo, Petali d'arancio , si candida per l'accettazione nel consistente corpus dell'autore irlandese: rimarrà ora il difficile compito di stabilire se si tratti di una traduzione prevaricante o di una vera e propria variante italiana. Il caso Su Il Popolo di Trieste del 3 gennaio 1929 appare Petali d'arancio con la firma "James Joyce"; si tratta della versione italiana di un racconto di Dubliners (Gente di Dublino) intitolato "The Boarding House" ("Pensione di famiglia"), scritto da Joyce a Trieste nel 1905. Di questa variante italiana-come ci 1 Cfr.
Seventh International Conference on Networking (icn 2008), 2008
Lecture Notes in Computer Science, 2008
The apparently never ending widespread of wireless networks requires an enhanced multimedia appli... more The apparently never ending widespread of wireless networks requires an enhanced multimedia application support. In this paper, we show how to improve the performance of EDCA in terms of throughput, frame delay and station scalability, through the effective cooperation of two backoff mechanisms: EDM and CWD. Simulation results confirm our previous analytical study and enable the discussion about how to improve relevant Quality of Service metrics, considering different channel bit rate and network load.
IEEE Access
The work of Jose Moura is funded by FCT/MCTES through national funds and when applicable co-funde... more The work of Jose Moura is funded by FCT/MCTES through national funds and when applicable co-funded EU funds under the project UIDB/50008/2020. The work of David Hutchison is funded by the NG-CDI project: UK EPSRC (EP/R004935/1) and British Telecom plc.
The fast growth of Internet-connected embedded devices demands for new capabilities at the networ... more The fast growth of Internet-connected embedded devices demands for new capabilities at the network edge. These new capabilities are local processing, efficient communications, and resource virtualization. The current work aims to address these capabilities by designing and deploying a new management proposal, which offers on-demand activation of offline Internet of Things (IoT) fog computing assets via a Software Defined Networking (SDN) based solution combined with containerization and sensor virtualization. We propose a testbed as a proof of concept for the main functionalities of this novel solution. The obtained results evidence that the current SDN-based solution can deploy with success activation policies on computational edge containers, which are located within the same network domain of the SDN controller. In addition, different application-level scenarios are also investigated.
Cyber-Physical Systems (CPSs) are increasingly important in critical areas of our society such as... more Cyber-Physical Systems (CPSs) are increasingly important in critical areas of our society such as intelligent power grids, next generation mobile devices, and smart buildings. CPS operation has characteristics including considerable heterogeneity, variable dynamics, and high complexity. These systems have also scarce resources in order to satisfy their entire load demand, which can be divided into data processing and service execution. These new characteristics of CPSs need to be managed with novel strategies to ensure their resilient operation. Towards this goal, we propose an SDN-based solution enhanced by distributed Network Function Virtualization (NFV) modules located at the top-most level of our solution architecture. These NFV agents will take orchestrated management decisions among themselves to ensure a resilient CPS configuration against threats, and an optimum operation of the CPS. For this, we study and compare two distinct incentive mechanisms to enforce cooperation amo...
ArXiv, 2019
Ideally, full integration is needed between the Internet and Cyber-Physical Systems (CPSs). These... more Ideally, full integration is needed between the Internet and Cyber-Physical Systems (CPSs). These systems should fulfil time-sensitive functions with variable levels of integration with their environment, incorporating data storage, computation, communications, sensing, and control. There are, however, significant problems emerging from the convergence between CPS and Internet of Things (IoT) areas. The high heterogeneity, complexity, and dynamics of these resource-constrained systems bring new challenges to their robust and reliable operation, which implies the need for novel resilience management strategies. This paper surveys the state of the art in the relevant fields and, discusses the research issues and future trends that emerge. Thus, we hope to provide new insights into the management of resilient CPSs, formed by IoT devices, modelled by Game Theory, and flexibly programmed using the latest software and virtualization platforms.
ArXiv, 2020
The fast growth of Internet-connected embedded devices demands for new capabilities at the networ... more The fast growth of Internet-connected embedded devices demands for new capabilities at the network edge. These new capabilities are local processing, fast communications, and resource virtualization. The current work aims to address the previous capabilities by designing and deploying a new proposal, which offers on-demand activation of offline IoT fog computing assets via a Software Defined Networking (SDN) based solution combined with containerization and sensor virtualization. We present and discuss performance and functional outcomes from emulated tests made on our proposal. Analysing the performance results, the system latency has two parts. The first part is about the delay induced by limitations on the networking resources. The second part of the system latency is due to the on-demand activation of the required processing resources, which are initially powered off towards a more sustainable system operation. In addition, analysing the functional results, when a real IoT proto...
Game Theory (GT) has been used with outstanding outcomes to formulate, and either design or optim... more Game Theory (GT) has been used with outstanding outcomes to formulate, and either design or optimize, the operation of a huge number of representative communications and networking scenarios, each one with distinct entities aiming at different and usually contradictory goals. This paper comprehensively surveys and updates, in a tutorial style, the literature contributions that have applied a diverse set of theoretical games to wireless networks, emphasizing scenarios of upcoming Mobile Edge Computing (MEC). MEC is a promising model that aims to offer cloud services at the network periphery, reducing service latency and backhaul load, and enhancing Quality of Experience. Our literature discussion of GT is structured according to a taxonomy that has three top-level groups: classical, evolutionary, and incomplete information. Then, the above groups are divided considering pertinent game aspects that have a great impact on players’ final decisions, namely: rational vs. evolving strategi...
The fast growth of Internet-connected embedded devices demands for new capabilities at the networ... more The fast growth of Internet-connected embedded devices demands for new capabilities at the network edge. These new capabilities are local processing, efficient communications, and resource virtualization. The current work aims to address these capabilities by designing and deploying a new management proposal, which offers on-demand activation of offline Internet of Things (IoT) fog computing assets via a Software Defined Networking (SDN) based solution combined with containerization and sensor virtualization. We propose a testbed as a proof of concept for the main functionalities of this novel solution. The obtained results evidence that the current SDN-based solution can deploy with success activation policies on computational edge containers, which are located within the same network domain of the SDN controller. In addition, different application-level scenarios are also investigated. Keywords— Management; Elastic Provisioning; Software-Defined Networking; Internet of Things; Edg...
Cyber-Physical Systems (CPSs) are increasingly important in critical areas of our society such as... more Cyber-Physical Systems (CPSs) are increasingly important in critical areas of our society such as intelligent power grids, next generation mobile devices, and smart buildings. CPS operation has characteristics including considerable heterogeneity, variable dynamics, and high complexity. These systems have also scarce resources in order to satisfy their entire load demand, which can be divided into data processing and service execution. These new characteristics of CPSs need to be managed with novel strategies to ensure their resilient operation. Towards this goal, we propose an SDN-based solution enhanced by distributed Network Function Virtualization (NFV) modules located at the top-most level of our solution architecture. These NFV agents will take orchestrated management decisions among themselves to ensure a resilient CPS configuration against threats, and an optimum operation of the CPS. For this, we study and compare two distinct incentive mechanisms to enforce cooperation amo...
Game Theory (GT) has been used with excellent results to model and optimize the operation of a hu... more Game Theory (GT) has been used with excellent results to model and optimize the operation of a huge number of real-world systems, including in communications and networking. Using a tutorial style, this paper surveys and updates the literature contributions that have applied a diverse set of theoretical games to solve a variety of challenging problems, namely in wireless data communication networks. During our literature discussion, the games are initially divided into three groups: classical, evolutionary, and incomplete information. Then, the classical games are further divided into three subgroups: non-cooperative, repeated, and cooperative. This paper reviews applications of games to develop adaptive algorithms and protocols for the efficient operation of some standardized uses cases at the edge of emerging heterogeneous networks. Finally, we highlight the important challenges, open issues, and future research directions where GT can bring beneficial outcomes to emerging wireles...
SN Applied Sciences, 2020
Cyber-Physical Systems (CPSs) are increasingly important in everyday applications including the l... more Cyber-Physical Systems (CPSs) are increasingly important in everyday applications including the latest mobile devices, power grids and intelligent buildings. CPS functionality has intrinsic characteristics including considerable heterogeneity, variable dynamics, and complexity of operation. These systems also typically have insufficient resources to satisfy their full demand for specialized services such as data edge storage, data fusion, and reasoning. These novel CPS characteristics require new management strategies to support the resilient global operation of CPSs. To reach this goal, we propose a Software Defined Networking based solution scaled out by Network Function Virtualization modules implemented as distributed management agents. Considering the obvious need for orchestrating the distributed agents towards the satisfaction of a common set of global CPS functional goals, we analyze distinct incentive strategies to enact a cooperative behavior among the agents. The repeated operation of each agent's local algorithm allows that agent to learn how to adjust its behavior following both its own experience and observed behavior in neighboring agents. Therefore, global CPS management can evolve iteratively to ensure a state of predictable and resilient operation.
Journal of Network and Computer Applications, 2020
Information, 2019
The current paper addresses relevant network security vulnerabilities introduced by network devic... more The current paper addresses relevant network security vulnerabilities introduced by network devices within the emerging paradigm of Internet of Things (IoT) as well as the urgent need to mitigate the negative effects of some types of Distributed Denial of Service (DDoS) attacks that try to explore those security weaknesses. We design and implement a Software-Defined Intrusion Detection System (IDS) that reactively impairs the attacks at its origin, ensuring the “normal operation” of the network infrastructure. Our proposal includes an IDS that automatically detects several DDoS attacks, and then as an attack is detected, it notifies a Software Defined Networking (SDN) controller. The current proposal also downloads some convenient traffic forwarding decisions from the SDN controller to network devices. The evaluation results suggest that our proposal timely detects several types of cyber-attacks based on DDoS, mitigates their negative impacts on the network performance, and ensures ...
IEEE Communications Surveys & Tutorials, 2019
Game Theory (GT) has been used with significant success to formulate, and either design or optimi... more Game Theory (GT) has been used with significant success to formulate, and either design or optimize, the operation of many representative communications and networking scenarios. The games in these scenarios involve, as usual, diverse players with conflicting goals. This paper primarily surveys the literature that has applied theoretical games to wireless networks, emphasizing use cases of upcoming Multi-Access Edge Computing (MEC). MEC is relatively new and offers cloud services at the network periphery, aiming to reduce service latency backhaul load, and enhance relevant operational aspects such as Quality of Experience or security. Our presentation of GT is focused on the major challenges imposed by MEC services over the wireless resources. The survey is divided into classical and evolutionary games. Then, our discussion proceeds to more specific aspects which have a considerable impact on the game's usefulness, namely: rational vs. evolving strategies, cooperation among players, available game information, the way the game is played (single turn, repeated), the game's model evaluation, and how the model results can be applied for both optimizing resource-constrained resources and balancing diverse trade-offs in real edge networking scenarios. Finally, we reflect on lessons learned, highlighting future trends and research directions for applying theoretical model games in upcoming MEC services, considering both network design issues and usage scenarios.
Handbook of Research on Trends and Future Directions in Big Data and Web Intelligence
This chapter details how Big Data can be used and implemented in networking and computing infrast... more This chapter details how Big Data can be used and implemented in networking and computing infrastructures. Specifically, it addresses three main aspects: the timely extraction of relevant knowledge from heterogeneous, and very often unstructured large data sources; the enhancement on the performance of processing and networking (cloud) infrastructures that are the most important foundational pillars of Big Data applications or services; and novel ways to efficiently manage network infrastructures with high-level composed policies for supporting the transmission of large amounts of data with distinct requisites (video vs. non-video). A case study involving an intelligent management solution to route data traffic with diverse requirements in a wide area Internet Exchange Point is presented, discussed in the context of Big Data, and evaluated.
Handbook of Research on Trends and Future Directions in Big Data and Web Intelligence
This chapter revises the most important aspects in how computing infrastructures should be config... more This chapter revises the most important aspects in how computing infrastructures should be configured and intelligently managed to fulfill the most notably security aspects required by Big Data applications. One of them is privacy. It is a pertinent aspect to be addressed because users share more and more personal data and content through their devices and computers to social networks and public clouds. So, a secure framework to social networks is a very hot topic research. This last topic is addressed in one of the two sections of the current chapter with case studies. In addition, the traditional mechanisms to support security such as firewalls and demilitarized zones are not suitable to be applied in computing systems to support Big Data. SDN is an emergent management solution that could become a convenient mechanism to implement security in Big Data systems, as we show through a second case study at the end of the chapter. This also discusses current relevant work and identifies...
Sono iniziate dieci anni fa le infuocate polemiche fra joyciani, al di qua e al di là dell'Atlant... more Sono iniziate dieci anni fa le infuocate polemiche fra joyciani, al di qua e al di là dell'Atlantico, sull'edizione critica dell'Ulisse ; da allora, i critici non joyciani di professione hanno cominciato a diffidare di certe ricerche filologiche che appaiono al servizio non tanto della "sacralità " del Testo quanto dell'interesse economico dei diversi editori. Chi abbia mai scorso, infatti, il James Joyce Archive 1 , i 63 monumentali volumi che raccolgono in riproduzione gli scritti di Joyce, dai meticolosi appunti linguistici alle varie versioni e bozze delle sue opere, sa bene come non ci si dovrebbe sorprendere di scoprire varianti anche minime in qualche foglio sperduto; e ciò è vero soprattutto per quanto riguarda le prime opere joyciane, visto che, come osserva Hans Walter Gabler, note, appunti e prime stesure di quelle ci sono giunti in modo molto frammentario 2. Le poche righe che si possono, dunque, scoprire sono magari ininfluenti dal punto di vista critico, eppure ricche quanto mai dell'emozione di chi, nella scoperta, si sente partecipe non tanto di una verità letteraria quanto di un salvataggio della memoria e del recupero di un tormentato processo di elaborazione creativa. E` stato durante una ricerca bibliografica a caccia di scritti joyciani dimenticati che ci si è imbattuti in una di queste pagina. Una circostanza che potrebbe apparire fortuita, se non fosse stata invece caparbiamente inseguita. E la prima emozione è toccata a una laureanda 3 che ha scoperto ciò che-si fa per dire-era già, come la lettera rubata di Poe, sotto gli occhi di tutti. Così, un nuovo titolo, Petali d'arancio , si candida per l'accettazione nel consistente corpus dell'autore irlandese: rimarrà ora il difficile compito di stabilire se si tratti di una traduzione prevaricante o di una vera e propria variante italiana. Il caso Su Il Popolo di Trieste del 3 gennaio 1929 appare Petali d'arancio con la firma "James Joyce"; si tratta della versione italiana di un racconto di Dubliners (Gente di Dublino) intitolato "The Boarding House" ("Pensione di famiglia"), scritto da Joyce a Trieste nel 1905. Di questa variante italiana-come ci 1 Cfr.
Seventh International Conference on Networking (icn 2008), 2008
Lecture Notes in Computer Science, 2008
The apparently never ending widespread of wireless networks requires an enhanced multimedia appli... more The apparently never ending widespread of wireless networks requires an enhanced multimedia application support. In this paper, we show how to improve the performance of EDCA in terms of throughput, frame delay and station scalability, through the effective cooperation of two backoff mechanisms: EDM and CWD. Simulation results confirm our previous analytical study and enable the discussion about how to improve relevant Quality of Service metrics, considering different channel bit rate and network load.