The Experts below are selected from a list of 204 Experts worldwide ranked by ideXlab platform
Paulo Cortez - One of the best experts on this subject based on the ideXlab platform.
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Operations research models and methods for safety stock determination: A review
Operations Research Perspectives, 2020Co-Authors: João N.c. Gonçalves, M. Sameiro Carvalho, Paulo CortezAbstract:Abstract In supply chain inventory management it is generally accepted that safety stocks are a suitable strategy to deal with demand and supply uncertainty aiming to prevent inventory stock-outs. Safety stocks have been the subject of intensive research, typically covering the Problems of Dimensioning, positioning, managing and placement. Here, we narrow the scope of the discussion to the safety stock Dimensioning Problem, consisting in determining the proper safety stock level for each product. This paper reports the results of a recent in-depth systematic literature review (SLR) of operations research (OR) models and methods for Dimensioning safety stocks. To the best of our knowledge, this is the first systematic review of the application of OR-based approaches to investigate this Problem. A set of 95 papers published from 1977 to 2019 has been reviewed to identify the type of model being employed, as well as the modeling techniques and main performance criteria used. At the end, we highlight current literature gaps and discuss potential research directions and trends that may help to guide researchers and practitioners interested in the development of new OR-based approaches for safety stock determination.
João N.c. Gonçalves - One of the best experts on this subject based on the ideXlab platform.
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Operations research models and methods for safety stock determination: A review
Operations Research Perspectives, 2020Co-Authors: João N.c. Gonçalves, M. Sameiro Carvalho, Paulo CortezAbstract:Abstract In supply chain inventory management it is generally accepted that safety stocks are a suitable strategy to deal with demand and supply uncertainty aiming to prevent inventory stock-outs. Safety stocks have been the subject of intensive research, typically covering the Problems of Dimensioning, positioning, managing and placement. Here, we narrow the scope of the discussion to the safety stock Dimensioning Problem, consisting in determining the proper safety stock level for each product. This paper reports the results of a recent in-depth systematic literature review (SLR) of operations research (OR) models and methods for Dimensioning safety stocks. To the best of our knowledge, this is the first systematic review of the application of OR-based approaches to investigate this Problem. A set of 95 papers published from 1977 to 2019 has been reviewed to identify the type of model being employed, as well as the modeling techniques and main performance criteria used. At the end, we highlight current literature gaps and discuss potential research directions and trends that may help to guide researchers and practitioners interested in the development of new OR-based approaches for safety stock determination.
Albert Banchs - One of the best experts on this subject based on the ideXlab platform.
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statistical multiplexing and traffic shaping games for network slicing
IEEE ACM Transactions on Networking, 2018Co-Authors: Jiaxiao Zheng, Gustavo De Veciana, Pablo Caballero, Seung Jun Baek, Albert BanchsAbstract:Next-generation wireless architectures are expected to enable slices of shared wireless infrastructure, which are customized to specific mobile operators/services. Given infrastructure costs and the stochastic nature of mobile services’ spatial loads, it is highly desirable to achieve efficient statistical multiplexing among such slices. We study a simple dynamic resource sharing policy, which allocates a “share” of a pool of (distributed) resources to each slice-share constrained proportionally fair (SCPF). We give a characterization of SCPF’s performance gains over static slicing and general processor sharing. We show that higher gains are obtained when a slice’s spatial load is more “imbalanced” than, and/or “orthogonal” to, the aggregate network load, and that the overall gain across slices is positive. We then address the associated Dimensioning Problem. Under SCPF, traditional network Dimensioning translates to a coupled share Dimensioning Problem, which characterizes the existence of a feasible share allocation, given slices’ expected loads and performance requirements. We provide a solution to robust share Dimensioning for SCPF-based network slicing. Slices may wish to unilaterally manage their users’ performance via admission control, which maximizes their carried loads subject to performance requirements. We show that this can be modeled as a “traffic shaping” game with an achievable Nash equilibrium. Under high loads, the equilibrium is explicitly characterized, as are the gains in the carried load under SCPF versus static slicing. Detailed simulations of a wireless infrastructure supporting multiple slices with heterogeneous mobile loads show the fidelity of our models and the range of validity of our high-load equilibrium analysis.
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statistical multiplexing and traffic shaping games for network slicing
arXiv: Networking and Internet Architecture, 2017Co-Authors: Jiaxiao Zheng, Gustavo De Veciana, Pablo Caballero, Seung Jun Baek, Albert BanchsAbstract:Next generation wireless architectures are expected to enable slices of shared wireless infrastructure which are customized to specific mobile operators/services. Given infrastructure costs and the stochastic nature of mobile services' spatial loads, it is highly desirable to achieve efficient statistical multiplexing amongst such slices. We study a simple dynamic resource sharing policy which allocates a 'share' of a pool of (distributed) resources to each slice-Share Constrained Proportionally Fair (SCPF). We give a characterization of SCPF's performance gains over static slicing and general processor sharing. We show that higher gains are obtained when a slice's spatial load is more 'imbalanced' than, and/or 'orthogonal' to, the aggregate network load, and that the overall gain across slices is positive. We then address the associated Dimensioning Problem. Under SCPF, traditional network Dimensioning translates to a coupled share Dimensioning Problem, which characterizes the existence of a feasible share allocation given slices' expected loads and performance requirements. We provide a solution to robust share Dimensioning for SCPF-based network slicing. Slices may wish to unilaterally manage their users' performance via admission control which maximizes their carried loads subject to performance requirements. We show this can be modeled as a 'traffic shaping' game with an achievable Nash equilibrium. Under high loads, the equilibrium is explicitly characterized, as are the gains in the carried load under SCPF vs. static slicing. Detailed simulations of a wireless infrastructure supporting multiple slices with heterogeneous mobile loads show the fidelity of our models and range of validity of our high load equilibrium analysis.
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WiOpt - Statistical multiplexing and traffic shaping games for network slicing
2017 15th International Symposium on Modeling and Optimization in Mobile Ad Hoc and Wireless Networks (WiOpt), 2017Co-Authors: Jiaxiao Zheng, Gustavo De Veciana, Pablo Caballero, Seung Jun Baek, Albert BanchsAbstract:Next generation wireless architectures are expected to enable slices of shared wireless infrastructure which are customized to specific mobile operators/services. Given infrastructure costs and the stochastic nature of mobile services' spatial loads, it is highly desirable to achieve efficient statistical multiplexing amongst network slices. We study a simple dynamic resource sharing policy which allocates a ‘share’ of a pool of (distributed) resources to each slice-Share Constrained Proportionally Fair (SCPF). We give a characterization of the achievable performance gains over static slicing, showing higher gains when a slice's spatial load is more ‘imbalanced’ than, and/or ‘orthogonal’ to, the aggregate network load. Under SCPF, traditional network Dimensioning translates to a coupled share Dimensioning Problem, addressing the existence of a feasible share allocation given slices' expected loads and performance requirements. We provide a solution to robust share Dimensioning for SCPF-based network slicing. Slices may wish to unilaterally manage their users' performance via admission control which maximizes their carried loads subject to performance requirements. We show this can be modeled as a "traffic shaping" game with an achievable Nash equilibrium. Under high loads the equilibrium is explicitly characterized, as are the gains in the carried load under SCPF vs. static slicing. Detailed simulations of a wireless infrastructure supporting multiple slices with heterogeneous mobile loads show the fidelity of our models and range of validity of our high load equilibrium analysis.
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Statistical multiplexing and traffic shaping games for network slicing
2017 15th International Symposium on Modeling and Optimization in Mobile Ad Hoc and Wireless Networks (WiOpt), 2017Co-Authors: Jiaxiao Zheng, Gustavo De Veciana, Pablo Caballero, Seung Jun Baek, Albert BanchsAbstract:Next generation wireless architectures are expected to enable slices of shared wireless infrastructure which are customized to specific mobile operators/services. Given infrastructure costs and the stochastic nature of mobile services' spatial loads, it is highly desirable to achieve efficient statistical multiplexing amongst network slices. We study a simple dynamic resource sharing policy which allocates a `share' of a pool of (distributed) resources to each slice-Share Constrained Proportionally Fair (SCPF). We give a characterization of the achievable performance gains over static slicing, showing higher gains when a slice's spatial load is more `imbalanced' than, and/or `orthogonal' to, the aggregate network load. Under SCPF, traditional network Dimensioning translates to a coupled share Dimensioning Problem, addressing the existence of a feasible share allocation given slices' expected loads and performance requirements. We provide a solution to robust share Dimensioning for SCPF-based network slicing. Slices may wish to unilaterally manage their users' performance via admission control which maximizes their carried loads subject to performance requirements. We show this can be modeled as a "traffic shaping" game with an achievable Nash equilibrium. Under high loads the equilibrium is explicitly characterized, as are the gains in the carried load under SCPF vs. static slicing. Detailed simulations of a wireless infrastructure supporting multiple slices with heterogeneous mobile loads show the fidelity of our models and range of validity of our high load equilibrium analysis.
Rui Valadas - One of the best experts on this subject based on the ideXlab platform.
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ptplan mpls a tool for mpls network Dimensioning
Modeling Analysis and Simulation On Computer and Telecommunication Systems, 2001Co-Authors: Luís Cardoso, J Patrao, Conceicao Lopes, A De Sousa, Rui ValadasAbstract:This paper presents a tool for MPLS network Dimensioning that allows for multi-hour Dimensioning of networks supporting simultaneously peer-to-peer and client-server services. The Dimensioning model is able to take into account several LSP attributes: degree of survivability (link disjoint and node disjoint cases), maximum hop count, usable colours and preferred routes. The Dimensioning Problem is a combined capacity design and routing Problem where the LSP sets are calculated in order to minimise the network operational costs. This Problem is formulated as an integer programming Problem, which is solved through an heuristic based on Lagrangean relaxation with sub-gradient optimisation. The network design tool, named PTPlan MPLS, includes a graphical interface for an easy introduction and edition of the network parameters. Results show that the tool can design networks of realistic size in seconds using a standard PC platform.
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MASCOTS - PTPlan MPLS: a tool for MPLS network Dimensioning
MASCOTS 2001 Proceedings Ninth International Symposium on Modeling Analysis and Simulation of Computer and Telecommunication Systems, 1Co-Authors: Luís Cardoso, J Patrao, Conceicao Lopes, A De Sousa, Rui ValadasAbstract:This paper presents a tool for MPLS network Dimensioning that allows for multi-hour Dimensioning of networks supporting simultaneously peer-to-peer and client-server services. The Dimensioning model is able to take into account several LSP attributes: degree of survivability (link disjoint and node disjoint cases), maximum hop count, usable colours and preferred routes. The Dimensioning Problem is a combined capacity design and routing Problem where the LSP sets are calculated in order to minimise the network operational costs. This Problem is formulated as an integer programming Problem, which is solved through an heuristic based on Lagrangean relaxation with sub-gradient optimisation. The network design tool, named PTPlan MPLS, includes a graphical interface for an easy introduction and edition of the network parameters. Results show that the tool can design networks of realistic size in seconds using a standard PC platform.
Luís Cardoso - One of the best experts on this subject based on the ideXlab platform.
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QofIS - Network Dimensioning with MPLS
Quality of Future Internet Services, 2001Co-Authors: Luís CardosoAbstract:This paper presents a procedure for MPLS network Dimensioning that allows for multi-hour Dimensioning of networks supporting simultaneously peer-to-peer and client-server services. The Dimensioning model is able to take into account several LSP attributes: degree of survivability (link disjoint and node disjoint cases), maximum hop count, usable colours and preferred routes. The Dimensioning Problem is a combined capacity design and routing Problem where the LSP sets are calculated in order to minimise the network operational costs. This Problem is formulated as an integer programming Problem, which is solved through an heuristic based on Lagrangean relaxation with sub-gradient optimisation. Results show that the procedure can design networks with realistic size in seconds using a standard PC platform.
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ptplan mpls a tool for mpls network Dimensioning
Modeling Analysis and Simulation On Computer and Telecommunication Systems, 2001Co-Authors: Luís Cardoso, J Patrao, Conceicao Lopes, A De Sousa, Rui ValadasAbstract:This paper presents a tool for MPLS network Dimensioning that allows for multi-hour Dimensioning of networks supporting simultaneously peer-to-peer and client-server services. The Dimensioning model is able to take into account several LSP attributes: degree of survivability (link disjoint and node disjoint cases), maximum hop count, usable colours and preferred routes. The Dimensioning Problem is a combined capacity design and routing Problem where the LSP sets are calculated in order to minimise the network operational costs. This Problem is formulated as an integer programming Problem, which is solved through an heuristic based on Lagrangean relaxation with sub-gradient optimisation. The network design tool, named PTPlan MPLS, includes a graphical interface for an easy introduction and edition of the network parameters. Results show that the tool can design networks of realistic size in seconds using a standard PC platform.
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MASCOTS - PTPlan MPLS: a tool for MPLS network Dimensioning
MASCOTS 2001 Proceedings Ninth International Symposium on Modeling Analysis and Simulation of Computer and Telecommunication Systems, 1Co-Authors: Luís Cardoso, J Patrao, Conceicao Lopes, A De Sousa, Rui ValadasAbstract:This paper presents a tool for MPLS network Dimensioning that allows for multi-hour Dimensioning of networks supporting simultaneously peer-to-peer and client-server services. The Dimensioning model is able to take into account several LSP attributes: degree of survivability (link disjoint and node disjoint cases), maximum hop count, usable colours and preferred routes. The Dimensioning Problem is a combined capacity design and routing Problem where the LSP sets are calculated in order to minimise the network operational costs. This Problem is formulated as an integer programming Problem, which is solved through an heuristic based on Lagrangean relaxation with sub-gradient optimisation. The network design tool, named PTPlan MPLS, includes a graphical interface for an easy introduction and edition of the network parameters. Results show that the tool can design networks of realistic size in seconds using a standard PC platform.