Optical transport networks (OTNs), while increasingly popular, can be affected in ways that are challenging to restore efficiently. This study investigates the problem of service restoration under OTNs with an optical...
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Optical transport networks (OTNs), while increasingly popular, can be affected in ways that are challenging to restore efficiently. This study investigates the problem of service restoration under OTNs with an optical channel data unit (ODU)-k switching capability (OTN-OSC) environment. An advantage actor-critic-based service restoration (A2CSR) algorithm is presented with the objective of increasing the service restoration rate. In our experimental setup, A2CSR uses the advanced image recognition model MobileNetV2 and an advantage actor-critic reinforcement learning algorithm. Simulation results show that the proposed A2CSR algorithm can achieve better blocking probability and resource utilisation than the benchmark algorithm (first fit (FF)), and the restoration time is within the acceptable range. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Data center interconnection with elastic optical networks is a promising scenario to meet the high burstiness and high-bandwidth requirements of data center services. We previously implemented enhanced software define...
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Data center interconnection with elastic optical networks is a promising scenario to meet the high burstiness and high-bandwidth requirements of data center services. We previously implemented enhanced software defined networking over elastic optical network for data center application [Opt. Express 21, 26990 (2013)]. On the basis of it, this study extends to consider the time-aware data center service scheduling with elastic service time and service bandwidth according to the various time sensitivity requirements. A novel time-aware enhanced software defined networking (TeSDN) architecture for elastic data center optical interconnection has been proposed in this paper, by introducing a time-aware resources scheduling (TaRS) scheme. The TeSDN can accommodate the data center services with required QoS considering the time dimensionality, and enhance cross stratum optimization of application and elastic optical network stratums resources based on spectrum elasticity, application elasticity and time elasticity. The overall feasibility and efficiency of the proposed architecture is experimentally verified on our OpenFlow-based testbed. The performance of TaRS scheme under heavy traffic load scenario is also quantitatively evaluated based on TeSDN architecture in terms of blocking probability and resource occupation rate. (C) 2014 Optical Society of America
Enduring the rapidly growing demand for high data rates is the main challenge for the current network providers. Super passive optical network (Super-PON), a prominent next generation Ethernet PON (NG-EPON) candidate,...
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Enduring the rapidly growing demand for high data rates is the main challenge for the current network providers. Super passive optical network (Super-PON), a prominent next generation Ethernet PON (NG-EPON) candidate, can suffice this exponentially increasing data rate requirements. However, to appease such requirements, it employs many transceivers and increases the power-consumption of the network. In this work, we focus on reducing the carbon footprint of Super-PON and propose power-efficient dynamic bandwidth and wavelength allocation (DBWA) algorithms, namely best fit bin-packing sleep mode aware (BF-SMA) and updated BF-SMA (UBF-SMA). The proposed algorithms use SMA for bandwidth scheduling and different bin-packing techniques for wavelength allocation. In bin-packing, the number of available wavelengths and their efficient allocation is based on the network load. For restricting the number of available wavelengths, we can switch off the non-essential transceivers at the OLT, which also helps in maximizing the wavelength utilization and increasing the power efficiency. The simulation results show that in comparison to the state-of-the-art DBWA algorithms, the proposed algorithms improve the power efficiency and reduce the average delay of a Super-PON system. Furthermore, we use Jain's fairness index to validate the fairness of the proposed DBWA algorithms. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
We address multicasting in a wavelength-routed WDM network in which each destination node has different, as opposed to the traditional uniform, weights for different multicast groups. The weight, in practice, may refl...
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In this Letter, we propose schemes to improve the per-formance of quantum batteries and provide a new, to the best of our knowledge, quantum source for a quantum bat-tery without an external driving field. We show tha...
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In this Letter, we propose schemes to improve the per-formance of quantum batteries and provide a new, to the best of our knowledge, quantum source for a quantum bat-tery without an external driving field. We show that the memory effect of the non-Markovian reservoir can play a significant role in improving the performance of quan-tum batteries, which originates from a backflow on the ergotropy in the non-Markovian regime, while there is counterpart in Markovian approximation. We find that the peak for the maximum average storing power in the non-Markovian regime can be enhanced by manipulating the coupling strength between the charger and the battery. Finally, we find that the battery can also be charged by non rotating wave terms without driving fields. (c) 2022 Optica Publishing Group
Feature Issue on Next-Generation WDM Network Design and Routing (WDMN) The optimal choice of routing and wavelength assignment (RWA) for the working and protection path-pair of the newly generated demand request is of...
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The dynamics of a three-level system is investigated within the rotating-wave approximation using the generalized pseudospin formalism of Hioe and Eberly [Phys. Rev. Lett. 47 , 838 (1981)]. The Cayley–Hamilton theore...
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The dynamics of a three-level system is investigated within the rotating-wave approximation using the generalized pseudospin formalism of Hioe and Eberly [Phys. Rev. Lett. 47 , 838 (1981)]. The Cayley–Hamilton theorem is used to obtain a matrix solution to the problem valid for arbitrary initial conditions. The pseudospin equations are phenomenologically extended to include relaxation effects, and solutions are also presented in this case. The von Neumann entropy of the system is introduced as a dynamic variable and is used to study the system’s irreversible approach to equilibrium when it is subjected to relaxation effects. An oscillatory behavior of the entropy is noted, and its origin is elucidated.
Presented here is a modification in the adjustment for refractive-index nonlinear regression through a Sellmeier expansion. It is free of the deficiencies inherent in the earlier nonlinear method and notably improves ...
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Presented here is a modification in the adjustment for refractive-index nonlinear regression through a Sellmeier expansion. It is free of the deficiencies inherent in the earlier nonlinear method and notably improves the adjustment without excessively complicating the mathematical procedures. The method is applied to CdS with the object of comparing the results with those obtained previously. In this manner, the best adjustment has been found for CdS dispersion. It has also allowed a physical explanation of some adjustment parameters.
作者：
KIRSCH, STMIT
DEPT ELECT ENGN & COMP SCI CAMBRIDGE MA 02139 USA MIT
ELECTR RES LAB CAMBRIDGE MA 02139 USA
A simple method of determining thin film parameters from mode indices measured using a prism coupler is described. The problem is reduced to doing two least squares straight line fits through measured mode indices vs ...
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A simple method of determining thin film parameters from mode indices measured using a prism coupler is described. The problem is reduced to doing two least squares straight line fits through measured mode indices vs effective mode number. The slope and y intercept of the line are simply related to the thickness and refractive index of film, respectively. The approach takes into account the correlation between as well as the uncertainty in the individual measurements from all sources of error to give precise error tolerances on the best fit values. Due to the precision of the tolerances, anisotropic films can be identified and characterized.
The curium spectrum emitted by electrodeless lamps was observed from 2400 to 11500 Å and the wavelengths of over 13 250 lines were accurately *** effect and spectrum-assignment plates were photographed from 2400 ...
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The curium spectrum emitted by electrodeless lamps was observed from 2400 to 11500 Å and the wavelengths of over 13 250 lines were accurately *** effect and spectrum-assignment plates were photographed from 2400 to 9000Å. From data obtained on the spectrum-assignment plates, over 6800 lineswere assigned to Cm i and over 4050 lines were assigned to the Cm ii spectrum. The analysis of the Cm i spectrum hasproduced 335 odd levels and 348 even levels that combine to classify over 5025Cm lines. Only the energy levels are presented here. The Landé g valuesof most levels have been obtained from the Zeeman effect data and isotope shiftswere determined for many levels. These data were useful in the assignment oflevels to electronic configurations of Cm i . The ground configurationof Cm i is [Rn]5 f 7 6 d 7 s 2 and the lowest level ofthe[Rn]5 f 8 7 s 2 configuration is only 1214 cm −1 above the ground level.
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