- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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A novel optical fiber Macha??Zehnder interferometer based on the calcium alginate hydrogel film for humidity sensing
摘要： Diverse models have been proposed over the past years to explain the exhibiting behavior of memristors, the fourth fundamental circuit element. The models varied in complexity ranging from a description of physical mechanisms to a more generalized mathematical modeling. Nonetheless, stochasticity, a widespread observed phenomenon, has been immensely overlooked from the modeling perspective. This inherent variability within the operation of the memristor is a vital feature for the integration of this nonlinear device into the stochastic electronics realm of study. In this paper, experimentally observed innate stochasticity is modeled in a circuit compatible format. The model proposed is generic and could be incorporated into variants of threshold-based memristor models in which apparent variations in the output hysteresis convey the switching threshold shift. Further application as a noise injection alternative paves the way for novel approaches in the fields of neuromorphic engineering circuits design. On the other hand, extra caution needs to be paid to variability intolerant digital designs based on nondeterministic memristor logic.
关键词： neuromorphics,threshold-based devices,Memristor,stochasticity,memristor model,stochastic electronics
更新于2025-09-16 10:30:52
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[IEEE 2019 Workshop on Recent Advances in Photonics (WRAP) - Guwahati, India (2019.12.13-2019.12.14)] 2019 Workshop on Recent Advances in Photonics (WRAP) - Displacement sensing using terahertz metasurfaces
摘要： As green communication becomes an inevitable trend for future 5G wireless networks, how to maximize the energy efficiency (EE) of device-to-device (D2D) communication has drawn extensive attention recently. However, most of existing works only optimize the EE in the single-cell scenario, while little attention is paid to maximizing the EE of the whole cellular network underlaid with D2D communication with randomly distributed users on multiple bands. In this paper, we first consider the whole cellular network underlaid with D2D communication on multiple bands and derive the exact expressions of the successful transmission probabilities, the average sum rate and the EE based on stochastic geometry theory. Then, we formulate the optimization problem of maximizing the EE subject to four constraints regarding to transmission power and outage probabilities, and the non-convexity of this problem is also verified. After that, by exploiting the objective function property of being the sum of several functions, we propose a derivative-based algorithm to solve this non-convex optimization problem. Our theoretical analysis shows that the computational complexity of the proposed algorithm is significantly lower than that of the conventional branch and bound algorithm. Finally, simulation results demonstrate that the proposed algorithm can achieve the near-optimal EE with much better performance than the conventional algorithm.
关键词： 5G,D2D communication,energy efficiency,stochastic geometry
更新于2025-09-16 10:30:52
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[IEEE 2019 26th IEEE International Conference on Electronics, Circuits and Systems (ICECS) - Genoa, Italy (2019.11.27-2019.11.29)] 2019 26th IEEE International Conference on Electronics, Circuits and Systems (ICECS) - FPGA-Based Tactile Sensory Feedback System with Optical Fiber Data Communication Link for Prosthetic Applications
摘要： Evidence indicates that requesting video clips on demand accounts for a dramatic increase in data traffic over cellular networks. Caching part of popular videos in the storage of small-cell base stations (SBS) in cellular networks is an efficient method to reduce transmission latency and mitigate redundant transmissions. In this paper, we propose a commercial caching system consisting of a video retailer (VR) and multiple network service providers (NSPs). Each NSP leases its SBSs, with some price, to the VR for the purpose of making profits, and the VR, after storing popular videos in the rented SBSs, can provide better local video services to the mobile users, thereby gaining more profits. We conceive this system within the framework of a Stackelberg game by treating the SBSs as a specific type of resources. Then, we establish the profit models for both the NSPs and the VR based on stochastic geometry. We further investigate the Stackelberg equilibrium by solving the optimization problems in two cases, i.e., whether or not the VR has a budget plan on renting the SBSs. Numerical results are provided for quantifying the proposed framework by showing its efficiency on pricing and resource allocation.
关键词： small-cell networks,content-centric communications,Stackelberg game,Wireless caching,stochastic geometry
更新于2025-09-16 10:30:52
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[IEEE 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Paris, France (2019.9.1-2019.9.6)] 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Flexible control of broadband terahertz radiations from laser plasmas
摘要： This paper presents a novel energy-management method for a microgrid that includes renewable energy, diesel generators, battery storage, and various loads. We assume that the microgrid takes part in a pool market and responds actively to the electricity price to maximize its pro?t by scheduling its controllable resources. To address various uncertainties, a risk-constrained scenario-based stochastic programming framework is proposed using the conditional value at risk method. The designed model is solved by two levels of stochastic optimization methods. One level of optimization is to submit optimal hourly bids to the day-ahead market under the forecast data. The other level of optimization is to determine the optimal scheduling using the scenario-based stochastic data of the uncertain resources. The proposed energy management system is not only bene?cial for the microgrid and customers, but also applies the microgrid aggregator and virtual power plant. The results are shown to prove the validity of the proposed framework.
关键词： microgrid,Controllable load,risk management,smart grid,stochastic optimization,electricity market,renewable energy,energy management
更新于2025-09-16 10:30:52
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Velocity controlled pattern writing: An application of stochastic resonance
摘要： In the present work, the concept of stochastic resonance is employed for pattern fabrication. In particular, the interplay of noise amplitudes and intrinsic system time scales is investigated. This interplay enabled us to obtain preordained patterns. Experiments were performed galvanostatically in a two electrode electrochemical cell onto a n-type Si substrate using a coherent wavelength laser source of 5 mW intensity. A focused laser beam was swept along the silicon substrate unidirectionally by moving the electrochemical cell at different velocities. By systematic tuning of the velocity, we have observed a unimodal variation in the contrast of the pattern. This indicates the occurrence of the stochastic resonance phenomena. Corresponding numerical simulations, performed on a spatial array of diffusively coupled FitzHugh-Nagumo oscillators in the presence of external noise, reveal good agreement with the experimental observations.
关键词： FitzHugh-Nagumo oscillators,pattern fabrication,electrochemical cell,stochastic resonance
更新于2025-09-12 10:27:22
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Empirical stochastic model of detected target centroids: Influence on registration and calibration of terrestrial laser scanners
摘要： The target-based point cloud registration and calibration of terrestrial laser scanners (TLSs) are mathematically modeled and solved by the least-squares adjustment. However, usual stochastic models are simplified to a large amount: They generally employ a single point measurement uncertainty based on the manufacturers’ specifications. This definition does not hold true for the target-based calibration and registration due to the fact that the target centroid is derived from multiple measurements and its uncertainty depends on the detection procedure as well. In this study, we empirically investigate the precision of the target centroid detection and define an empirical stochastic model in the form of look-up tables. Furthermore, we compare the usual stochastic model with the empirical stochastic model on several point cloud registration and TLS calibration experiments. There, we prove that the values of usual stochastic models are underestimated and incorrect, which can lead to multiple adverse effects such as biased results of the estimation procedures, a false a posteriori variance component analysis, false statistical testing, and false network design conclusions. In the end, we prove that some of the adverse effects can be mitigated by employing the a priori knowledge about the target centroid uncertainty behavior.
关键词： stochastic model,target centroid detection,calibration,registration,terrestrial laser scanner
更新于2025-09-12 10:27:22
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Stochastic Soliton Quantization in Mode-Locked Fibre Laser
摘要： Soliton quantization is a natural, intrinsic and random consequence property of localized pulses in nonlinear systems. It is formed in the fiber laser in the form of dissipative solitons due to the gain competition between the solitons in the laser cavity. The observation of quantized separations between the solitons was predicted either due to the interaction between far separated solitons or due to the interaction between weakly overlapping pulses [1, 2]. It was first found experimentally in a nonlinear amplified loop mirror mode-locked fiber laser [3] and then in a nonlinear polarization rotation mode locking fiber laser [4, 5] with a requirement of high pump power of >400 mW. Here, we report for the first time the experimental demonstration of the stochastic temporal soliton quantization state regimes at a low range of the pump powers (~41 mW) using a carbon nanotube’s saturable absorber mode-locked fiber laser [6]. We found that the regimes and the total number of pulses in the cavity are highly sensitive to the pump power and the state of the polarization which could lead to several distinct regimes of pulse formation. However, for certain pumping powers which were 41 mW and specific orientation of the laser cavity polarization controller (PC), we observed pulse trains of several tenths of pulses as shown in the real-time spatiotemporal measurements in Fig. 1a. The pulse train consists of a stochastic quantized distribution with separation between pulses starting from about 3 ns to tenths of ps with a nonlinearly quantized separation, behaving between the localized soliton pulses as shown in Fg. 1b. The pulses are localized with a much broader temporal separation far from the main soliton pulse and condensed to a very narrow seperations nearer to it. By slightly increasing the pump power to ~88 mW and varying the PC, we obtained the second order of the stochastic soliton which also have a quantized temporal distribution without any undesirable distribution of types or interactions between neighboring solitons along 5000 roundtrip pulse train. The quantized soliton, actually, has formed intrinsically in the form of dissipative solitons due to large binding soliton states.
关键词： Soliton quantization,stochastic soliton,carbon nanotube saturable absorber,mode-locked fibre laser
更新于2025-09-12 10:27:22
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An optimal switching approach toward cost‐effective control of a stand‐alone photovoltaic panel system under stochastic environment
摘要： The operation of a stand-alone photovoltaic (PV) system ultimately aims for the optimization of its energy storage. We present a mathematical model for cost-effective control of a stand-alone system based on a PV panel equipped with an angle adjustment device. The model is based on viscosity solutions to partial differential equations, which serve as a new and mathematically rigorous tool for modeling, analyzing, and controlling PV systems. We formulate a stochastic optimal switching problem of the panel angle, which is here a binary variable to be dynamically controlled under stochastic weather condition. The stochasticity comes from cloud cover dynamics, which is modeled with a nonlinear stochastic differential equation. In finding the optimal control policy of the panel angle, switching the angle is subject to impulsive cost and reduces to solving a system of Hamilton-Jacobi-Bellman quasi-variational inequalities (HJBQVIs). We show that the stochastic differential equation is well posed and that the HJBQVIs admit a unique viscosity solution. In addition, a finite-difference scheme is proposed for the numerical discretization of HJBQVIs. A demonstrative computational example of the HJBQVIs, with emphasis on a stand-alone experimental system, is finally presented with practical implications for its cost-effective operation.
关键词： stochastic optimal switching,cloud cover dynamics,Hamilton-Jacobi-Bellman quasi-variational inequalities (HJBQVIs),stand-alone photovoltaic system
更新于2025-09-11 14:15:04
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Extreme Events Generation via Cascaded Stimulated Brillouin Scattering in Self-Pulsing Fiber Lasers
摘要： Extreme-amplitude events and rare instabilities are observed for more than a decade in various optical systems. Specifically in dissipative systems, such as Raman fiber lasers, laser diodes or mode-locked lasers, to name a few, long-tailed statistics and highly-localized temporal structures have been observed [1,2]. Recent studies showed that stimulated Brillouin scattering (SBS) can also trigger the generation of extreme events in various configurations, from self-pulsing fiber lasers [3,4] to Q-switched random fiber lasers [5]. It is indeed known that the stochastic nature of SBS can promote the emergence of randomly distributed giant pulses which can induce irreversible damages in fiber laser systems. In order to understand and open the possibility to harness such extreme events, numerical models have then to be developed and refined. In the context of self-pulsed fiber lasers, a few studies taking into account only one or two fundamental Stokes orders have already been reported [6]. Such models describe well the large pulse-to-pulse intensity fluctuations observed in Erbium-doped fiber lasers Q-switched through SBS but they however did not predict any extreme event [6]. We propose here an extension of the model proposed in Ref. [3] by generalizing it to higher Stokes orders to study their impact on extreme dynamics in a self-pulsing laser. Our model is based on the coupled amplitudes equations describing the spatiotemporal dynamics of both the laser and Brillouin waves with their corresponding acoustic fields, as well as the temporal variations of the gain for each wave. We also consider a matter equation to account for the saturable absorption effect which can occur in the un-pumped segment of the active fiber. We show that increasing the number of SBS orders interacting with the gain medium reveals new dynamics enabling the generation of extreme events which are not predicted by the single SBS order model. Pulses with amplitudes 27 times the so-called significant wave height are indeed predicted, which attest of the presence of extreme-amplitude events, as shown in Fig. 1. Such giant pulses could then reach the threshold of irreversible damage in optical fibers. We also provide a comprehensive study on the different parameters influencing the dynamics, including the number of Stokes orders that strongly affect the laser dynamical behavior and then allow to somehow control the highest intensity of the laser instabilities. The influence of other parameters, such as the input noise, on the system’s dynamics will be discussed and we will show that our simplified model can pave the way towards a better understanding of the complex stochastic dynamics under the influence of SBS.
关键词： stimulated Brillouin scattering,stochastic dynamics,Extreme events,optical systems,self-pulsing fiber lasers
更新于2025-09-11 14:15:04
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[IEEE 2019 IEEE Milan PowerTech - Milan, Italy (2019.6.23-2019.6.27)] 2019 IEEE Milan PowerTech - Stochastic optimization framework for online scheduling of an EV charging station in a residential place with photovoltaics and energy storage system
摘要： House and building energy management systems (HEMS) are becoming key when it comes to assure grid stability and to offer flexibility. At the same time, energy systems technology has evolved to enable energy storage systems and electric vehicles to be managed together with local generated energy taking into consideration the preferences of the household owner. Contributing to this tendency, this work presents a stochastic optimization platform (SOFW) for optimal control using dynamic programming and stochastic optimization models. A stochastic optimization model involving a household composed of photovoltaics, energy storage system and an electric vehicle is designed and tested within SOFW. The uncertainties of the plug-in time and state of charge of the battery of the electric vehicle are modeled using a Markovian process and a Monte-Carlo simulation. The results showed that the proposed stochastic optimization model can be solved using dynamic programming and deployed as a continuous optimal control within SOFW. The system will be deployed shortly in Italy within one use case of the Storage4Grid (S4G) project.
关键词： stochastic dynamic programming,optimization framework,energy storage systems,Markov processes,electric vehicle charging
更新于2025-09-11 14:15:04