The Experts below are selected from a list of 4977 Experts worldwide ranked by ideXlab platform
Biswanath Mukherjee - One of the best experts on this subject based on the ideXlab platform.
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Mathematical formulation of provisioning of connections with advance reservation in metro WDM ring networks using reconfigurable OADMs (ROADMs) with Tuning Constraint
Photonic Network Communications, 2007Co-Authors: Hongyue Zhu, Anpeng Huang, Biswanath MukherjeeAbstract:Optical add/drop multiplexers (OADMs) can significantly reduce the cost of metro optical wavelength-division multiplexing (WDM) ring networks by allowing traffic to bypass intermediate nodes without expensive opto-electro-opto (O-E-O) conversion. Some traditional OADMs, called fixed OADMs (FOADMs), can only add/drop traffic on a specific wavelength. Reconfigurable Optical Add/Drop Multiplexers (ROADMs) are emerging, which can add/drop traffic onto/from different wavelengths at different time. ROADMs provide desirable flexibility, enable fast provisioning of dynamic traffic, and save capital expenditure (CapEx) and operational expenditure (OpEx). In order to be cost-effective, some ROADMs employ architectures that tune the ROADM continuously from one wavelength to another, crossing through all the wavelengths in-between, which may cause interference to the connections, if any, on those wavelengths being crossed. In order to prevent existing connections from being interrupted, a Constraint needs to be imposed that ROADMs cannot cross working wavelengths when Tuning. In this study, the design and the benefits of metro optical WDM network architectures using ROADMs and the impact of this Tuning Constraint on the performance of the network are investigated. Mathematical formulation of the problem of provisioning of connections with advance reservation, in which the arrival time and departure time of all the connections are known in advance, is presented, and results for a small network are shown.
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Online connection provisioning in metro optical WDM networks using reconfigurable OADMs
Journal of Lightwave Technology, 2005Co-Authors: Hongyue Zhu, Biswanath MukherjeeAbstract:Optical add/drop multiplexers (OADMs) can significantly reduce the cost of metro optical wavelength-division multiplexing (WDM) ring networks by allowing traffic to bypass intermediate nodes without expensive opto-electro-opto (O-E-O) conversion. Some traditional OADMs, called fixed OADMs (FOADMs), can only add/drop traffic on a specific wavelength. Reconfigurable OADMs (ROADMs) are emerging, which can add/drop traffic onto/from different wavelengths at different time. ROADMs provide desirable flexibility, enable fast provisioning of dynamic traffic, and save capital expenditure (CapEx) and operational expenditure (OpEx). In order to be cost effective, some ROADMs employ architectures that tune the ROADM continuously from one wavelength to another, crossing through all the wavelengths in between, which may cause interference to the connections, if any, on those wavelengths being crossed. In order to prevent existing connections from being interrupted, a Constraint needs to be imposed that ROADMs cannot cross working wavelengths when Tuning. In this paper, the design and the benefits of metro optical WDM network architectures using ROADMs and the impact of this Tuning Constraint on the performance of the network are investigated. The dynamic traffic provisioning problem is analyzed and divided into two subproblems: 1) a traditional one on resource allocation; and 2) a new subproblem on Tuning-head positioning (TP). Several heuristics for each subproblem are developed to combat the Tuning Constraint. Results from our simulation experiments show that the Tuning Constraint can significantly affect the network performance in terms of overall connection blocking probability, and good heuristics for network control and management are needed to overcome this Tuning Constraint.
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Optical wdm networks: traffic grooming in mesh networks and metro networks using roadms
2005Co-Authors: Hongyue Zhu, Biswanath MukherjeeAbstract:Optical Fiber technology employing wavelength-division multiplexing (WDM) has and continues to be investigated and commercially deployed to meet our ever-increasing bandwidth demands. WDM partitions the huge bandwidth of an optical fiber into many non-overlapping wavelength channels, each of which can operate at the data rate of 10 Gbps (or 40 Gbps or higher). This dissertation investigates design and modeling issues of optical WDM mesh networks, as well as ring networks. This dissertation first proposes a novel generic graph model for traffic grooming in heterogeneous WDM mesh networks so that low-speed traffic streams can be "groomed" (or carried) by high-capacity wavelength channels. This model uses an auxiliary graph to represent the network state, which can accommodate various resource Constraints. It can achieve different grooming policies by employing a simple shortest-path algorithm, and it can be applied to both static and dynamic traffic-grooming scenarios. A grooming policy determines how to carry the traffic in a certain situation. It reflects the intention of a network operator. Different grooming policies are explored in both static and dynamic traffic environments in this dissertation. Various architectures and technologies can be employed when building optical crossconnects (OXCs). Thus, different OXCs might have different switching granularities and different OXC port costs. This dissertation investigates how to cost effectively design a network using OXCs of different switching granularities to leverage the advantages of various OXCs. We significantly enhance the graph model to cover the characteristic of switching granularity, and propose a network design procedure, which reduces the network-wide port costs. Optical Add/Drop Multiplexers can significantly reduce the cost of metro optical WDM ring networks by allowing traffic to bypass intermediate nodes without expensive opto-electro-opto conversion. Reconfigurable Optical Add/Drop Multiplexers (ROADMs) are emerging which can add/drop traffic onto/from different wavelengths at different times. ROADMs provide desirable flexibility, enable fast provisioning of dynamic traffic, and save capital expenditure and operational expenditure. This dissertation investigates the design and the benefits of metro optical WDM network architectures using ROADMs, identifies the Tuning Constraints of certain architectures, and studies the impact of this Tuning Constraint on the performance of the network.
Hongyue Zhu - One of the best experts on this subject based on the ideXlab platform.
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Mathematical formulation of provisioning of connections with advance reservation in metro WDM ring networks using reconfigurable OADMs (ROADMs) with Tuning Constraint
Photonic Network Communications, 2007Co-Authors: Hongyue Zhu, Anpeng Huang, Biswanath MukherjeeAbstract:Optical add/drop multiplexers (OADMs) can significantly reduce the cost of metro optical wavelength-division multiplexing (WDM) ring networks by allowing traffic to bypass intermediate nodes without expensive opto-electro-opto (O-E-O) conversion. Some traditional OADMs, called fixed OADMs (FOADMs), can only add/drop traffic on a specific wavelength. Reconfigurable Optical Add/Drop Multiplexers (ROADMs) are emerging, which can add/drop traffic onto/from different wavelengths at different time. ROADMs provide desirable flexibility, enable fast provisioning of dynamic traffic, and save capital expenditure (CapEx) and operational expenditure (OpEx). In order to be cost-effective, some ROADMs employ architectures that tune the ROADM continuously from one wavelength to another, crossing through all the wavelengths in-between, which may cause interference to the connections, if any, on those wavelengths being crossed. In order to prevent existing connections from being interrupted, a Constraint needs to be imposed that ROADMs cannot cross working wavelengths when Tuning. In this study, the design and the benefits of metro optical WDM network architectures using ROADMs and the impact of this Tuning Constraint on the performance of the network are investigated. Mathematical formulation of the problem of provisioning of connections with advance reservation, in which the arrival time and departure time of all the connections are known in advance, is presented, and results for a small network are shown.
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Online connection provisioning in metro optical WDM networks using reconfigurable OADMs
Journal of Lightwave Technology, 2005Co-Authors: Hongyue Zhu, Biswanath MukherjeeAbstract:Optical add/drop multiplexers (OADMs) can significantly reduce the cost of metro optical wavelength-division multiplexing (WDM) ring networks by allowing traffic to bypass intermediate nodes without expensive opto-electro-opto (O-E-O) conversion. Some traditional OADMs, called fixed OADMs (FOADMs), can only add/drop traffic on a specific wavelength. Reconfigurable OADMs (ROADMs) are emerging, which can add/drop traffic onto/from different wavelengths at different time. ROADMs provide desirable flexibility, enable fast provisioning of dynamic traffic, and save capital expenditure (CapEx) and operational expenditure (OpEx). In order to be cost effective, some ROADMs employ architectures that tune the ROADM continuously from one wavelength to another, crossing through all the wavelengths in between, which may cause interference to the connections, if any, on those wavelengths being crossed. In order to prevent existing connections from being interrupted, a Constraint needs to be imposed that ROADMs cannot cross working wavelengths when Tuning. In this paper, the design and the benefits of metro optical WDM network architectures using ROADMs and the impact of this Tuning Constraint on the performance of the network are investigated. The dynamic traffic provisioning problem is analyzed and divided into two subproblems: 1) a traditional one on resource allocation; and 2) a new subproblem on Tuning-head positioning (TP). Several heuristics for each subproblem are developed to combat the Tuning Constraint. Results from our simulation experiments show that the Tuning Constraint can significantly affect the network performance in terms of overall connection blocking probability, and good heuristics for network control and management are needed to overcome this Tuning Constraint.
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Optical wdm networks: traffic grooming in mesh networks and metro networks using roadms
2005Co-Authors: Hongyue Zhu, Biswanath MukherjeeAbstract:Optical Fiber technology employing wavelength-division multiplexing (WDM) has and continues to be investigated and commercially deployed to meet our ever-increasing bandwidth demands. WDM partitions the huge bandwidth of an optical fiber into many non-overlapping wavelength channels, each of which can operate at the data rate of 10 Gbps (or 40 Gbps or higher). This dissertation investigates design and modeling issues of optical WDM mesh networks, as well as ring networks. This dissertation first proposes a novel generic graph model for traffic grooming in heterogeneous WDM mesh networks so that low-speed traffic streams can be "groomed" (or carried) by high-capacity wavelength channels. This model uses an auxiliary graph to represent the network state, which can accommodate various resource Constraints. It can achieve different grooming policies by employing a simple shortest-path algorithm, and it can be applied to both static and dynamic traffic-grooming scenarios. A grooming policy determines how to carry the traffic in a certain situation. It reflects the intention of a network operator. Different grooming policies are explored in both static and dynamic traffic environments in this dissertation. Various architectures and technologies can be employed when building optical crossconnects (OXCs). Thus, different OXCs might have different switching granularities and different OXC port costs. This dissertation investigates how to cost effectively design a network using OXCs of different switching granularities to leverage the advantages of various OXCs. We significantly enhance the graph model to cover the characteristic of switching granularity, and propose a network design procedure, which reduces the network-wide port costs. Optical Add/Drop Multiplexers can significantly reduce the cost of metro optical WDM ring networks by allowing traffic to bypass intermediate nodes without expensive opto-electro-opto conversion. Reconfigurable Optical Add/Drop Multiplexers (ROADMs) are emerging which can add/drop traffic onto/from different wavelengths at different times. ROADMs provide desirable flexibility, enable fast provisioning of dynamic traffic, and save capital expenditure and operational expenditure. This dissertation investigates the design and the benefits of metro optical WDM network architectures using ROADMs, identifies the Tuning Constraints of certain architectures, and studies the impact of this Tuning Constraint on the performance of the network.
James D. Wells - One of the best experts on this subject based on the ideXlab platform.
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Predictions for constrained minimal supersymmetry with bottom-quark- tau mass unification.
Physical review. D Particles and fields, 1994Co-Authors: Christopher Kolda, Leszek Roszkowski, James D. Wells, Gordon L. KaneAbstract:We examine the constrained minimal supersymmetric standard model (CMSSM) with an additional requirement of strict [ital b]-[tau] unification in the region of small tan[beta]. We find that the parameter space becomes completely limited below about 1 TeV by physical Constraints alone, without a fine-Tuning Constraint. We study the resulting phenomenological consequences, and point out several ways of falsifying the adopted [ital b]-[tau] unification assumption. We also comment on the effect of a Constraint from the nonobservation of proton decay.
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Study of constrained minimal supersymmetry.
Physical review. D Particles and fields, 1994Co-Authors: Gordon L. Kane, Christopher Kolda, Leszek Roszkowski, James D. WellsAbstract:Taking seriously the phenomenological indications for supersymmetry we have made a detailed study of unified minimal SUSY, including many effects at the few percent level in a consistent fashion. We report here a general analysis of what can be studied without choosing a particular gauge group at the unification scale. Firstly, we find that the encouraging SUSY unification results of recent years do survive the challenge of a more complete and accurate analysis. Taking into account effects at the 5--10 % level leads to several improvements of previous results and allows us to sharpen our predictions for SUSY in the light of unification. We perform a thorough study of the parameter space and look for patterns to indicate SUSY predictions, so that they do not depend on arbitrary choices of some parameters or untested assumptions. Our results can be viewed as a fully constrained minimal SUSY standard model. The resulting model forms a well-defined basis for comparing the physics potential of different facilities. Very little of the acceptable parameter space has been excluded by CERN LEP or Fermilab so far, but a significant fraction can be covered when these accelerators are upgraded. A number of initial applications to the understandingmore » of the values of [ital m][sub [ital h]] and [ital m][sub [ital t]], the SUSY spectrum, detectability of SUSY at LEP II or Fermilab, [ital B]([ital b][r arrow][ital s][gamma]), [Gamma]([ital Z][r arrow][ital b[bar b]]), dark matter, etc., are included in a separate section that might be of more interest to some readers than the technical aspects of model building. We formulate an approach to extracting SUSY parameters from data when superpartners are detected. For small tan[beta] or large [ital m][sub [ital t]] both [ital m][sub 1/2] and [ital m][sub 0] are entirely bounded from above at [similar to]1 TeV without having to use a fine-Tuning Constraint.« less
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Upper Bounds in Low-Energy SUSY
arXiv: High Energy Physics - Phenomenology, 1994Co-Authors: Gordon L. Kane, Christopher Kolda, Leszek Roszkowski, James D. WellsAbstract:In the constrained MSSM one is typically able to restrict the supersymmetric mass spectra below roughly 1-2\tev\ {\em without} resorting to the ambiguous fine-Tuning Constraint.
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Dark Matter from Supersymmetric Grand Unification
arXiv: High Energy Physics - Phenomenology, 1994Co-Authors: Gordon L. Kane, Christopher Kolda, Leszek Roszkowski, James D. WellsAbstract:In constrained minimal supersymmetry the lightest neutralino of bino-type is the only neutral candidate for dark matter. As a result, one is typically able to restrict all the supersymmetric mass spectra below roughly 1-2\tev\ {\em without} imposing an ill-defined fine-Tuning Constraint.
Gordon L. Kane - One of the best experts on this subject based on the ideXlab platform.
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Predictions for constrained minimal supersymmetry with bottom-quark- tau mass unification.
Physical review. D Particles and fields, 1994Co-Authors: Christopher Kolda, Leszek Roszkowski, James D. Wells, Gordon L. KaneAbstract:We examine the constrained minimal supersymmetric standard model (CMSSM) with an additional requirement of strict [ital b]-[tau] unification in the region of small tan[beta]. We find that the parameter space becomes completely limited below about 1 TeV by physical Constraints alone, without a fine-Tuning Constraint. We study the resulting phenomenological consequences, and point out several ways of falsifying the adopted [ital b]-[tau] unification assumption. We also comment on the effect of a Constraint from the nonobservation of proton decay.
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Study of constrained minimal supersymmetry.
Physical review. D Particles and fields, 1994Co-Authors: Gordon L. Kane, Christopher Kolda, Leszek Roszkowski, James D. WellsAbstract:Taking seriously the phenomenological indications for supersymmetry we have made a detailed study of unified minimal SUSY, including many effects at the few percent level in a consistent fashion. We report here a general analysis of what can be studied without choosing a particular gauge group at the unification scale. Firstly, we find that the encouraging SUSY unification results of recent years do survive the challenge of a more complete and accurate analysis. Taking into account effects at the 5--10 % level leads to several improvements of previous results and allows us to sharpen our predictions for SUSY in the light of unification. We perform a thorough study of the parameter space and look for patterns to indicate SUSY predictions, so that they do not depend on arbitrary choices of some parameters or untested assumptions. Our results can be viewed as a fully constrained minimal SUSY standard model. The resulting model forms a well-defined basis for comparing the physics potential of different facilities. Very little of the acceptable parameter space has been excluded by CERN LEP or Fermilab so far, but a significant fraction can be covered when these accelerators are upgraded. A number of initial applications to the understandingmore » of the values of [ital m][sub [ital h]] and [ital m][sub [ital t]], the SUSY spectrum, detectability of SUSY at LEP II or Fermilab, [ital B]([ital b][r arrow][ital s][gamma]), [Gamma]([ital Z][r arrow][ital b[bar b]]), dark matter, etc., are included in a separate section that might be of more interest to some readers than the technical aspects of model building. We formulate an approach to extracting SUSY parameters from data when superpartners are detected. For small tan[beta] or large [ital m][sub [ital t]] both [ital m][sub 1/2] and [ital m][sub 0] are entirely bounded from above at [similar to]1 TeV without having to use a fine-Tuning Constraint.« less
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Upper Bounds in Low-Energy SUSY
arXiv: High Energy Physics - Phenomenology, 1994Co-Authors: Gordon L. Kane, Christopher Kolda, Leszek Roszkowski, James D. WellsAbstract:In the constrained MSSM one is typically able to restrict the supersymmetric mass spectra below roughly 1-2\tev\ {\em without} resorting to the ambiguous fine-Tuning Constraint.
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Dark Matter from Supersymmetric Grand Unification
arXiv: High Energy Physics - Phenomenology, 1994Co-Authors: Gordon L. Kane, Christopher Kolda, Leszek Roszkowski, James D. WellsAbstract:In constrained minimal supersymmetry the lightest neutralino of bino-type is the only neutral candidate for dark matter. As a result, one is typically able to restrict all the supersymmetric mass spectra below roughly 1-2\tev\ {\em without} imposing an ill-defined fine-Tuning Constraint.
Khaled Zabet - One of the best experts on this subject based on the ideXlab platform.
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Pole-placement Predictive Functional Control for over-damped systems with real poles
ISA transactions, 2015Co-Authors: John Anthony Rossiter, Robert Haber, Khaled ZabetAbstract:This paper gives new insight and design proposals for Predictive Functional Control (PFC) algorithms. Common practice and indeed a requirement of PFC is to select a coincidence horizon greater than one for high-order systems and for the link between the design parameters and the desired dynamic to be weak. Here the proposal is to use parallel first-order models to form an independent prediction model and show that with these it is possible both to use a coincidence horizon of one and moreover to obtain precisely the desired closed-loop dynamics. It is shown through analysis that the use of a coincidence horizon of one greatly simplifies coding, Tuning, Constraint handling and implementation. The paper derives the key results for high-order and non-minimum phase processes and also demonstrates the flexibility and potential industrial utility of the proposal.
