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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - Auto-Scaling Mechanism in the ICT Converged Cross Stratum Orchestration Architecture for Zero-Touch Service and Network Management
摘要： This paper is aimed to provide a novel approach for an auto-scaling mechanism that are applied in the ICT converged cross stratum orchestration (CSO) architecture. CSO refers to an end-to-end orchestration across Application orchestration, Data Center SDN orchestration, and WAN SDN orchestration so that applications can be created seamlessly and optimally for operators and their customers. The auto-scaling mechanism presented in this paper is built on active monitoring of both DC compute/storage/network resources and DCI Transport network resources and then provides dynamically configurable auto-scaling and resource re-allocation. This mechanism will help tremendously the operators to control and manage their networks in an automated fashion.
关键词： SDN,Orchestration,CSO,automation,ICT convergence,zero-touch service management,auto-scaling,ACTN
更新于2025-09-09 09:28:46
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Variance-Minimization Iterative Matching Method for Free-Form Surfaces-Part I: Theory and Method
摘要： Free-form surface matching that aligns measured points with a design model is a common problem in manufacturing automation. In this paper, an iterative variance-minimization matching (VMM) method is proposed to address measured points that have measuring defects, such as uneven/open point distributions and measuring noise. The basic idea is that the objective function is defined as the variance of the closest distance from each measured point to the design model, and the measuring defects are considered by incorporating an average distance item into the objective function. Using the defined average distance item, a strategy for analyzing the effect of measuring defects on VMM and existing methods is presented. It is shown that the VMM method does not easily become trapped in a local optimum when measuring defects exist. To consider convergence speed and convergence stability, a new distance based on the first-order point-to-point distance and point-to-tangent distance is developed and used in the objective function. To demonstrate the availability of the proposed method, quadratic convergence and positive definiteness are theoretically analyzed. The proposed method is efficient and insensitive to measuring defects and is useful for shape matching tasks involving free-form surface features.
关键词： variance-minimization matching (VMM),free-form surface,measuring defects,Convergence
更新于2025-09-09 09:28:46
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Dimension Reduction for the Landau--de Gennes Model: The Vanishing Nematic Correlation Length Limit
摘要： We study nematic liquid crystalline films within the framework of the Landau--de Gennes theory in the limit when both the thickness of the film and the nematic correlation length are vanishingly small compared to the lateral extent of the film. We prove \Gamma -convergence for a sequence of singularly perturbed functionals with a potential vanishing on a high-dimensional set and a Dirichlet condition imposed on admissible functions. This then allows us to prove the existence of local minimizers of the Landau--de Gennes energy in the spirit of [R. V. Kohn and P. Sternberg, Proc. Roy. Soc. Edinburgh Sect. A, 111 (1989), pp. 69--84] despite the lack of compactness arising from the high-dimensional structure of the wells. The limiting energy consists of leading order perimeter terms, similar to Allen--Cahn models, and lower order terms arising from vortex structures reminiscent of Ginzburg--Landau models.
关键词： gamma convergence,thin film,nematic,dimension reduction
更新于2025-09-09 09:28:46
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Robust precision motion control of piezoelectric actuators using fast nonsingular terminal sliding mode with time delay estimation
摘要： Background: Piezoelectric actuators are widely used in many micro/nano-manipulation applications, but their positioning accuracy are badly affected by their inherent nonlinear hysteresis and creep. To solve this problem, this paper presents a new robust motion-control method for piezoelectric actuators with fast nonsingular terminal sliding mode based on time delay estimation. Method: The proposed controller needs no detailed information about the hysteresis and other nonlinearities of the system, leading to a simple and model-free characteristic due to the time delay estimation and ensures fast convergence and high tracking accuracy thanks to the nonsingular terminal sliding-mode surface and fast terminal sliding mode -type reaching law. A robust exact differentiator is adopted to estimate the velocity and accelerationinformation online, and it overcomes the limitation of only available position measurements. The finite-time convergence and stability of the closed-loop system are proved by using a Lyapunov function. Results: Experimental results show that the proposed control strategy has faster convergence and higher tracking precision compared with a traditional time delay control. Conclusion: The proposed control strategy can be widely used as an effective control method for high-precision motion control of piezoelectric actuators.
关键词： finite-time convergence,Piezoelectric actuator,terminal sliding mode,time delay estimation
更新于2025-09-09 09:28:46
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Large-Scale Planar Block Adjustment of GaoFen1 WFV Images Covering Most of Mainland China
摘要： GaoFen1 (GF1) is the first high-resolution earth observation satellite built in China, and carries four wide field-of-view (WFV) cameras to achieve large-scale monitoring and mapping. However, the unstable attitude measurement accuracy of the satellite generally imparts low geopositioning accuracy and inconsistent geometric error in overlapping areas of WFV images. A feasible and effective large-scale planar block adjustment (PBA) method is presented that corrects the geometric errors of the vast WFV images integrally, further improving the geometric accuracy of these images. In addition, whether ground control points (GCPs) are needed, and the effect of different numbers of GCPs on PBA accuracy is also investigated. Two key technologies are used in this paper. First, a universal PBA error equation based on the virtual control points is presented to allow PBA with or without GCPs. Second, an adjustment method aided by a digital elevation model is adopted to overcome the weak convergence geometry among WFV images, further ensuring stable estimation of PBA. The effectiveness of the proposed method was verified by 664 WFV images covering most of mainland China. The satisfactory experimental results indicate that the method presented herein is reasonable and effective, but that a certain number of GCPs is needed to ensure the accuracy of large-scale PBA results for WFV images.
关键词： weak convergence geometry,planar block adjustment (PBA),wide field view (WFV),virtual control points (VCPs),GaoFen1 (GF1)
更新于2025-09-09 09:28:46
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Weak convergence rates for stochastic evolution equations and applications to nonlinear stochastic wave, HJMM, stochastic Schr?dinger and linearized stochastic Korteweg–de Vries equations
摘要： We establish weak convergence rates for noise discretizations of a wide class of stochastic evolution equations with non-regularizing semigroups and additive or multiplicative noise. This class covers the nonlinear stochastic wave, HJMM, stochastic Schr¨odinger and linearized stochastic Korteweg–de Vries equation. For several important equations, including the stochastic wave equation, previous methods give only suboptimal rates, whereas our rates are essentially sharp.
关键词： stochastic evolution equations,multiplicative noise,additive noise,linearized stochastic Korteweg–de Vries equation,stochastic Schr¨odinger,non-regularizing semigroups,weak convergence rates,HJMM,stochastic wave equation
更新于2025-09-04 15:30:14
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AIP Conference Proceedings [Author(s) SolarPACES 2017: International Conference on Concentrating Solar Power and Chemical Energy Systems - Santiago, Chile (26–29 September 2017)] - Where should beam down heliostat central rays intersect the final optical element axis?
摘要： A beam down solar system is adjusted to maximize the power collected through a final optical element concentrator. The power reaching the outlet of the final optical element is studied as a function of the reflectivity of its facets, and the height of the central ray convergence point of the beam down central reflector. A configuration that maximizes the energy fed to the solar receiver during the experimental campaign of the CSPonD Demo project is chosen and implemented at the beam down installation at the Masdar Institute Solar Platform.
关键词： final optical element,CSPonD Demo project,solar receiver,central ray convergence point,beam down solar system
更新于2025-09-04 15:30:14
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Uniform continuity bounds for information characteristics of quantum channels depending on input dimension and on input energy
摘要： We obtain continuity bounds for basic information characteristics of quantum channels depending on their input dimension (if it is finite) and on the input energy bound (if the input dimension is infinite). We pay special attention to the case in which a multimode quantum oscillator is an input system. First, we prove continuity bounds for the output conditional mutual information for a single channel and for n copies of a channel. Then we obtain estimates for the variation of the output Holevo quantity with respect to simultaneous variations of a channel and of an input ensemble. As a result, tight and close-to-tight continuity bounds for basic capacities of quantum channels, which depend on the input dimension, are obtained. They complement the Leung–Smith continuity bounds, which depend on the output dimension. Finally, we obtain tight and close-to-tight continuity bounds for basic capacities of infinite-dimensional energy-constrained channels with respect to the energy-constrained Bures distance generating the strong convergence of quantum channels.
关键词： strong convergence of quantum channels,ensemble of quantum states,the Holevo quantity,quantum conditional mutual information,quantum channel capacities,energy-constrained Bures distance,multi-mode quantum oscillator
更新于2025-09-04 15:30:14
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High-Speed and Uninterrupted Communication for High-Speed Trains by Ultrafast WDM Fiber-Wireless Backhaul System
摘要： We developed a high-speed and handover-free communication network for high-speed trains (HSTs) using an ultrafast and switchable wavelength-division multiplexing fiber-wireless backhaul system in the W band. We successfully transmitted approximately 20-Gb/s and 10-Gb/s signals over the in the downlink and uplink switched fiber-wireless directions, respectively. An ultrafast radio-cell switching of less than 10 μs was experimentally demonstrated in both downlink and uplink directions. Moreover, the possibility of connecting a central station to many remote radio cells was evaluated, confirming that an uninterrupted communication network up to several tens of kilometers can be achieved for HSTs. The proposed system can overcome the current challenges in mobile networks and can provide a potential solution for the provision of advanced services to users on HSTs in future 5G and beyond networks.
关键词： high-speed train,moving cell,fiber-wireless convergence,mobile backhaul,Radio-over-fiber
更新于2025-09-04 15:30:14
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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - XGPON Statistical Multiplexing Analysis with Heterogeneous Users
摘要： Optical access networks are rapidly evolving mainly driven by the higher bandwidth requirements. XGPON is one of the most cost-effective solutions to upgrade existing GPON since it reuses existing optical distribution networks. Thanks to the high XGPON capacity, these networks can connect heterogeneous users such as base stations (BS), residential users (RU) or business users (BU). Statistical multiplexing of XGPON allows assigning different bandwidth to the different users based on their demands and always guaranteeing the agreed service level agreements. This work aims at evaluating the impact of packet delay and throughput for different XGPON scenarios for different user distributions. Furthermore, the paper evaluates the flexibility to cope with extra traffic caused by existing protection schemes.
关键词： DBA,network convergence,packet delay,XGPON,protection,throughput
更新于2025-09-04 15:30:14