Judith Kelner | Universidade Federal de Pernambuco (original) (raw)

Papers by Judith Kelner

Research paper thumbnail of Real Time Radius of Curvature Measurement During DVC Operations Based on Flexible Pipe 3D Reconstruction

OTC Brasil, 2015

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Research paper thumbnail of Video object segmentation for automatic image annotation of ethernet connectors with environment mapping and 3D projection

Multimedia Tools and Applications

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Research paper thumbnail of How to Improve Cloud Services Availability? Investigating the Impact of Power and It Subsystems Failures

Proceedings of the 51st Hawaii International Conference on System Sciences, 2018

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Research paper thumbnail of Flying to the Clouds: The Evolution of the 5G Radio Access Networks

The Cloud-to-Thing Continuum, 2020

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Research paper thumbnail of Optimizing the Cloud Data Center Availability Empowered by Surrogate Models

Proceedings of the Annual Hawaii International Conference on System Sciences, 2020

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Research paper thumbnail of Modeling and analyzing power system failures on cloud services

2017 13th International Conference on Network and Service Management (CNSM), 2017

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Research paper thumbnail of Automating the Service Function Chain Availability Assessment

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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Research paper thumbnail of A Methodology for Automating the Cloud Data Center Availability Assessment

Advanced Information Networking and Applications, 2019

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Research paper thumbnail of Analyzing the IT subsystem failure impact on availability of cloud services

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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Research paper thumbnail of The Greatest Teacher, Failure is: Using Reinforcement Learning for SFC Placement Based on Availability and Energy Consumption

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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Research paper thumbnail of Correction to: Rbot: development of a robot‑driven radio base station maintenance system

International Journal of Intelligent Robotics and Applications, 2021

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Research paper thumbnail of Predicting short‐term mobile Internet traffic from Internet activity using recurrent neural networks

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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Research paper thumbnail of The internet of things for healthcare: optimising e-health system availability in the fog and cloud

International Journal of Computational Science and Engineering, 2020

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Research paper thumbnail of Analyzing the availability and performance of an e-health system integrated with edge, fog and cloud infrastructures

Journal of Cloud Computing, 2018

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Research paper thumbnail of Minimizing and Managing Cloud Failures

Computer, 2017

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Research paper thumbnail of High availability in clouds: systematic review and research challenges

Journal of Cloud Computing, 2016

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Research paper thumbnail of Hipertexto: O Projeto do Sistema H

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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Research paper thumbnail of Multi-Device Classification Model for Game Interaction Techniques

International Journal of Human-computer Interaction, Apr 16, 2018

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Research paper thumbnail of Uma Ferramenta de Suporte a Recuperação de Informação na Web focada em Vulnerabilidades e Anomalias Internet

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Research paper thumbnail of Avaliação de Mecanismos de Segurança em uma Plataforma para Redes de Sensores Sem Fio

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Research paper thumbnail of Real Time Radius of Curvature Measurement During DVC Operations Based on Flexible Pipe 3D Reconstruction

OTC Brasil, 2015

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Research paper thumbnail of Video object segmentation for automatic image annotation of ethernet connectors with environment mapping and 3D projection

Multimedia Tools and Applications

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Research paper thumbnail of How to Improve Cloud Services Availability? Investigating the Impact of Power and It Subsystems Failures

Proceedings of the 51st Hawaii International Conference on System Sciences, 2018

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Research paper thumbnail of Flying to the Clouds: The Evolution of the 5G Radio Access Networks

The Cloud-to-Thing Continuum, 2020

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Research paper thumbnail of Optimizing the Cloud Data Center Availability Empowered by Surrogate Models

Proceedings of the Annual Hawaii International Conference on System Sciences, 2020

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Research paper thumbnail of Modeling and analyzing power system failures on cloud services

2017 13th International Conference on Network and Service Management (CNSM), 2017

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Research paper thumbnail of Automating the Service Function Chain Availability Assessment

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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Research paper thumbnail of A Methodology for Automating the Cloud Data Center Availability Assessment

Advanced Information Networking and Applications, 2019

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Research paper thumbnail of Analyzing the IT subsystem failure impact on availability of cloud services

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.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of The Greatest Teacher, Failure is: Using Reinforcement Learning for SFC Placement Based on Availability and Energy Consumption

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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Research paper thumbnail of Correction to: Rbot: development of a robot‑driven radio base station maintenance system

International Journal of Intelligent Robotics and Applications, 2021

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Predicting short‐term mobile Internet traffic from Internet activity using recurrent neural networks

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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Research paper thumbnail of The internet of things for healthcare: optimising e-health system availability in the fog and cloud

International Journal of Computational Science and Engineering, 2020

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Analyzing the availability and performance of an e-health system integrated with edge, fog and cloud infrastructures

Journal of Cloud Computing, 2018

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Minimizing and Managing Cloud Failures

Computer, 2017

Bookmarks Related papers MentionsView impact

Research paper thumbnail of High availability in clouds: systematic review and research challenges

Journal of Cloud Computing, 2016

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Hipertexto: O Projeto do Sistema H

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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Research paper thumbnail of Multi-Device Classification Model for Game Interaction Techniques

International Journal of Human-computer Interaction, Apr 16, 2018

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Research paper thumbnail of Uma Ferramenta de Suporte a Recuperação de Informação na Web focada em Vulnerabilidades e Anomalias Internet

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Avaliação de Mecanismos de Segurança em uma Plataforma para Redes de Sensores Sem Fio

Bookmarks Related papers MentionsView impact