Judith Kelner | Universidade Federal de Pernambuco (original) (raw)
Papers by Judith Kelner
OTC Brasil, 2015
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Multimedia Tools and Applications
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Proceedings of the 51st Hawaii International Conference on System Sciences, 2018
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The Cloud-to-Thing Continuum, 2020
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Proceedings of the Annual Hawaii International Conference on System Sciences, 2020
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2017 13th International Conference on Network and Service Management (CNSM), 2017
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2021 IEEE Symposium on Computers and Communications (ISCC), 2021
Modern telecommunications networks are characterised by increased dynamism and heterogeneity from... more Modern telecommunications networks are characterised by increased dynamism and heterogeneity from the cloud to the edge. To meet these requirements and remain competitive, network operators use software defined networking (SDN) and network functions virtualisation (NFV) to make networks programmable, flexible, and agile. Service function chaining (SFC) enables NFV through the ordered sequencing of VNFs and subsequent steering of flows through them to provide end-to-end services. SFCs must meet availability constraints while avoiding resource wastage due to unnecessary redundancy. This paper proposes a novel approach to evaluate the availability of SFC placement considering the associated redundancy strategies using Stochastic Petri Net (SPN) models. We propose an algorithm to generate and resolve relatively small SPN models for SFC availability in an automatic way and then compare baseline SPN models with this algorithm across five SFC placement scenarios. In all scenarios, the proposed algorithm outperformed baseline SPN models in runtime performance.
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Advanced Information Networking and Applications, 2019
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2017 IEEE Symposium on Computers and Communications (ISCC), 2017
Cloud computing has gained popularity in recent years due to its pay-as-you-go business model, hi... more Cloud computing has gained popularity in recent years due to its pay-as-you-go business model, high availability of services, and scalability. Service unavailability does not affect just user experience but is also translated into direct costs for cloud providers and companies. Part of this costs is due to SLA breaches, once interruption time greater than those signed in the contract generate financial penalties. Thus, cloud providers have tried to identify failure points and estimate the availability of their services. This paper proposes models to assess the availability of services running in a cloud data center infrastructure. The models follow the TIA-942 standard. We propose Tier I and IV models using the Reliability Block Diagram (RBD) to allow modeling of different types of applications, and Stochastic Petri Net (SPN) to represent the failure behavior of information technology (IT) components in a data center. We perform stationary analysis to measure the service availability, and sensitivity analysis to understand which metrics have major impacts on data center availability.
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ArXiv, 2020
Software defined networking (SDN) and network functions virtualisation (NFV) are making networks ... more Software defined networking (SDN) and network functions virtualisation (NFV) are making networks programmable and consequently much more flexible and agile. To meet service level agreements, achieve greater utilisation of legacy networks, faster service deployment, and reduce expenditure, telecommunications operators are deploying increasingly complex service function chains (SFCs). Notwithstanding the benefits of SFCs, increasing heterogeneity and dynamism from the cloud to the edge introduces significant SFC placement challenges, not least adding or removing network functions while maintaining availability, quality of service, and minimising cost. In this paper, an availability- and energy-aware solution based on reinforcement learning (RL) is proposed for dynamic SFC placement. Two policy-aware RL algorithms, Advantage Actor-Critic (A2C) and Proximal Policy Optimisation (PPO2), are compared using simulations of a ground truth network topology based on the Rede Nacional de Ensino ...
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International Journal of Intelligent Robotics and Applications, 2021
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International Journal of Network Management, 2021
SummaryMobile network traffic prediction is an important input into network capacity planning and... more SummaryMobile network traffic prediction is an important input into network capacity planning and optimization. Existing approaches may lack the speed and computational complexity to account for bursting, non‐linear patterns, or other important correlations in time series mobile network data. We compare the performance of two deep learning (DL) architectures, long short‐term memory (LSTM) and gated recurrent unit (GRU), and two conventional machine learning (ML) architectures—Random Forest and Decision Tree—for predicting mobile Internet traffic using 2 months of Telecom Italia data for Milan. K‐Means clustering was used a priori to group cells based on Internet activity, and the Grid Search method was used to identify the best configurations for each model. The predictive quality of the models was evaluated using root mean squared error and mean absolute error. Both DL algorithms were effective in modeling Internet activity and seasonality, both within days and across 2 months. We ...
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International Journal of Computational Science and Engineering, 2020
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Journal of Cloud Computing, 2018
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Computer, 2017
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Journal of Cloud Computing, 2016
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Anais do III Simpósio Brasileiro de Engenharia de Software (SBES 1989)
Este artigo apresenta alguns conceitos básicos de hipertexto, alguns dos principais progressos re... more Este artigo apresenta alguns conceitos básicos de hipertexto, alguns dos principais progressos realizados na área, no mundo, até agora, e algumas idéias sobre o que poderá vir no futuro próximo. Em particular, o texto é uma introdução ao trabalho sendo realizado no Grupo de Linguagens e Engenharia de Software (LinES) do Departamento de Informática da UFPE. O principal projeto em andamento na UFPE visa definir e implementar um sistema de hipertexto cuja fundamental aplicação deverá ser a gerência de processos de desenvolvimento de software. A curto prazo, um sistema de hipertexto voltado a aplicações de documentação eletrônica já está sendo implementado. Tal sistema é parcialmente descrito neste artigo.
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International Journal of Human-computer Interaction, Apr 16, 2018
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OTC Brasil, 2015
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Multimedia Tools and Applications
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Proceedings of the 51st Hawaii International Conference on System Sciences, 2018
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The Cloud-to-Thing Continuum, 2020
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Proceedings of the Annual Hawaii International Conference on System Sciences, 2020
Bookmarks Related papers MentionsView impact
2017 13th International Conference on Network and Service Management (CNSM), 2017
Bookmarks Related papers MentionsView impact
2021 IEEE Symposium on Computers and Communications (ISCC), 2021
Modern telecommunications networks are characterised by increased dynamism and heterogeneity from... more Modern telecommunications networks are characterised by increased dynamism and heterogeneity from the cloud to the edge. To meet these requirements and remain competitive, network operators use software defined networking (SDN) and network functions virtualisation (NFV) to make networks programmable, flexible, and agile. Service function chaining (SFC) enables NFV through the ordered sequencing of VNFs and subsequent steering of flows through them to provide end-to-end services. SFCs must meet availability constraints while avoiding resource wastage due to unnecessary redundancy. This paper proposes a novel approach to evaluate the availability of SFC placement considering the associated redundancy strategies using Stochastic Petri Net (SPN) models. We propose an algorithm to generate and resolve relatively small SPN models for SFC availability in an automatic way and then compare baseline SPN models with this algorithm across five SFC placement scenarios. In all scenarios, the proposed algorithm outperformed baseline SPN models in runtime performance.
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Advanced Information Networking and Applications, 2019
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2017 IEEE Symposium on Computers and Communications (ISCC), 2017
Cloud computing has gained popularity in recent years due to its pay-as-you-go business model, hi... more Cloud computing has gained popularity in recent years due to its pay-as-you-go business model, high availability of services, and scalability. Service unavailability does not affect just user experience but is also translated into direct costs for cloud providers and companies. Part of this costs is due to SLA breaches, once interruption time greater than those signed in the contract generate financial penalties. Thus, cloud providers have tried to identify failure points and estimate the availability of their services. This paper proposes models to assess the availability of services running in a cloud data center infrastructure. The models follow the TIA-942 standard. We propose Tier I and IV models using the Reliability Block Diagram (RBD) to allow modeling of different types of applications, and Stochastic Petri Net (SPN) to represent the failure behavior of information technology (IT) components in a data center. We perform stationary analysis to measure the service availability, and sensitivity analysis to understand which metrics have major impacts on data center availability.
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ArXiv, 2020
Software defined networking (SDN) and network functions virtualisation (NFV) are making networks ... more Software defined networking (SDN) and network functions virtualisation (NFV) are making networks programmable and consequently much more flexible and agile. To meet service level agreements, achieve greater utilisation of legacy networks, faster service deployment, and reduce expenditure, telecommunications operators are deploying increasingly complex service function chains (SFCs). Notwithstanding the benefits of SFCs, increasing heterogeneity and dynamism from the cloud to the edge introduces significant SFC placement challenges, not least adding or removing network functions while maintaining availability, quality of service, and minimising cost. In this paper, an availability- and energy-aware solution based on reinforcement learning (RL) is proposed for dynamic SFC placement. Two policy-aware RL algorithms, Advantage Actor-Critic (A2C) and Proximal Policy Optimisation (PPO2), are compared using simulations of a ground truth network topology based on the Rede Nacional de Ensino ...
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International Journal of Intelligent Robotics and Applications, 2021
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International Journal of Network Management, 2021
SummaryMobile network traffic prediction is an important input into network capacity planning and... more SummaryMobile network traffic prediction is an important input into network capacity planning and optimization. Existing approaches may lack the speed and computational complexity to account for bursting, non‐linear patterns, or other important correlations in time series mobile network data. We compare the performance of two deep learning (DL) architectures, long short‐term memory (LSTM) and gated recurrent unit (GRU), and two conventional machine learning (ML) architectures—Random Forest and Decision Tree—for predicting mobile Internet traffic using 2 months of Telecom Italia data for Milan. K‐Means clustering was used a priori to group cells based on Internet activity, and the Grid Search method was used to identify the best configurations for each model. The predictive quality of the models was evaluated using root mean squared error and mean absolute error. Both DL algorithms were effective in modeling Internet activity and seasonality, both within days and across 2 months. We ...
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International Journal of Computational Science and Engineering, 2020
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Journal of Cloud Computing, 2018
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Computer, 2017
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Journal of Cloud Computing, 2016
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Anais do III Simpósio Brasileiro de Engenharia de Software (SBES 1989)
Este artigo apresenta alguns conceitos básicos de hipertexto, alguns dos principais progressos re... more Este artigo apresenta alguns conceitos básicos de hipertexto, alguns dos principais progressos realizados na área, no mundo, até agora, e algumas idéias sobre o que poderá vir no futuro próximo. Em particular, o texto é uma introdução ao trabalho sendo realizado no Grupo de Linguagens e Engenharia de Software (LinES) do Departamento de Informática da UFPE. O principal projeto em andamento na UFPE visa definir e implementar um sistema de hipertexto cuja fundamental aplicação deverá ser a gerência de processos de desenvolvimento de software. A curto prazo, um sistema de hipertexto voltado a aplicações de documentação eletrônica já está sendo implementado. Tal sistema é parcialmente descrito neste artigo.
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International Journal of Human-computer Interaction, Apr 16, 2018
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