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- 摘要
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- 实验方案
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Size and shape control of monoclinic vanadium dioxide thermochromic particles for smart window applications
摘要： Monoclinic vanadium dioxide (VO2 (M)) was synthesized by the thermolysis of vanadyl ethylene glycolate, which was obtained easily by the precipitation of a vanadium precursor in ethylene glycol solution under atmospheric conditions. The particle size and shape were easily controlled by altering the molar concentration of the vanadium precursor. Thereafter, VO2 (M) composite films were prepared by mixing with poly(vinylpyrrolidone). A high concentration of the vanadium precursor produced small spherical nanoparticles ≈30 nm in size, while lower concentrations afforded large rod-like particles. The composite films fabricated with the VO2 (M) nanoparticles exhibited high luminous transmittance (Tlum = 79%) and IR modulation ability (ΔTIR = 5.6%). This work demonstrates that these VO2 (M) composite films show promise for application in smart windows.
关键词： solar modulation ability,Energy efficiency,size and shape tuning,high luminous transmittance,VO2 (M) particle,thermochromic coating
更新于2025-09-23 15:21:21
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Artificial optic-neural synapse for colored and color-mixed pattern recognition
摘要： The priority of synaptic device researches has been given to prove the device potential for the emulation of synaptic dynamics and not to functionalize further synaptic devices for more complex learning. Here, we demonstrate an optic-neural synaptic device by implementing synaptic and optical-sensing functions together on h-BN/WSe2 heterostructure. This device mimics the colored and color-mixed pattern recognition capabilities of the human vision system when arranged in an optic-neural network. Our synaptic device demonstrates a close to linear weight update trajectory while providing a large number of stable conduction states with less than 1% variation per state. The device operates with low voltage spikes of 0.3 V and consumes only 66 fJ per spike. This consequently facilitates the demonstration of accurate and energy efficient colored and color-mixed pattern recognition. The work will be an important step toward neural networks that comprise neural sensing and training functions for more complex pattern recognition.
关键词： optic-neural synaptic device,human vision system,pattern recognition,energy efficiency,h-BN/WSe2 heterostructure
更新于2025-09-23 15:21:21
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[IEEE 2019 IEEE 9th International Conference on Consumer Electronics (ICCE-Berlin) - Berlin, Germany (2019.9.8-2019.9.11)] 2019 IEEE 9th International Conference on Consumer Electronics (ICCE-Berlin) - Case Study of Photovoltaic Energy Surplus Absorption by Charging Lithium-Ion Batteries Considering Chargea??Discharge Energy Efficiency
摘要： In Autumn 2018, reductive control of photovoltaic surplus energy was performed in Kyushu, Japan. This was a lost opportunity to utilize renewable energy, which could have been otherwise stored in rechargeable batteries. In this study, we simulated the absorption of the photovoltaic energy surplus by charging battery systems of a working electric vehicle considering the energy efficiency of lithium-ion battery systems to reduce the operation cost. This study clarified the quantitative effects of a real-time energy efficiency diagnosis of lithium-ion battery systems. From the simulation results, we discovered that the improvements of the charge–discharge energy loss and the economic gain of the photovoltaic energy surplus absorption depended on the input–output power of the bidirectional vehicle- to-grid charger and the amount of surplus energy. When the input–output power is sufficiently high and the ratio of surplus energy to total capacity of the battery systems is sufficiently low, is the reasonable. The real-time degradation diagnosis of the battery systems and selection considering charge–discharge energy efficiency is necessary to improve the profit from surplus energy absorption.
关键词： charge – discharge energy efficiency,Lithium-ion battery,degradation diagnosis,photovoltaic surplus energy,working electric vehicle
更新于2025-09-23 15:21:01
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Resource and Power Allocation in SWIPT Enabled Device-to-Device Communications Based on a Non-Linear Energy Harvesting Model
摘要： Due to the limited battery capacity in mobile devices, simultaneous wireless information and power transfer (SWIPT) has been proposed as a promising solution to improving the energy efficiency (EE) in Internet of things (IoT) networks, i.e., device-to-device (D2D) networks, by allowing mobile devices to harvest energy from ambient radio frequency (RF) signals. However, the non-linear behavior of RF energy harvesters has largely been ignored in existing works on SWIPT. In this paper, we propose to maximize the sum EE of all D2D links in a D2D underlaid cellular network by optimizing the resource and power allocation based on a non-linear energy harvesting (EH) model. Toward this end, we first propose a pre-matching algorithm to divide the D2D links into a SWIPT enabled group and a non-EH group that cannot meet the EH circuit sensitivity. We then develop a two-layer iterative algorithm to jointly optimize the D2D transmission power and the power splitting ratio to maximize the EE for each SWIPT enabled D2D link. On this basis, we build the preference lists for both SWIPT enabled D2D links and cellular user equipment (CUEs), and propose a one-to-one constraint stable matching algorithm to maximize the sum EE of all SWIPT enabled D2D links by optimizing the spectrum resource sharing between D2D links and CUEs. The sum EE of non-EH D2D links is maximized through an iterative power control algorithm and a one-to-one stable matching algorithm. Simulation results show that our proposed algorithms achieve a much higher sum EE than the existing matching based energy-efficient resource allocation scheme for SWIPT enabled D2D networks.
关键词： Device-to-device,underlay,energy harvesting,power control,resource allocation,SWIPT,energy efficiency,matching theory
更新于2025-09-23 15:21:01
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A Reconfigurable and Extendable Single-Inductor Single-Path Three-Switch Converter for Indoor Photovoltaic Energy Harvesting
摘要： This article proposes a single-path three-switch (1P3S) single-inductor dual-input dual-output (SIDIDO) converter to manage power among a photovoltaic (PV) module, battery, and load for indoor PV energy harvesting. For low duty-cycle applications, the 1P3S converter increases efficiency in the PV-to-battery-to-load path by eliminating inductor-sharing power switches. This article also proposes a reconfigurable controller to achieve reconfigurability and extendibility that the 1P3S converter can be reconfigured as a dual-path three-switch (2P3S) SIDIDO converter, combined as a dual-path six-switch (2P6S) SIDIDO converter, or extended as a paralleled-1P3S converter for high energy efficiency in various applications with different PV and load power profiles. To identify each converter’s advantageous applications, the efficiencies of the 1P3S, reconfigured 2P3S, and combined 2P6S converters were analyzed under dynamic PV and load powers. The chip is fabricated in the 0.5-μm CMOS process with a 1.24-mm2 chip area. The measured peak efficiencies for the 1P3S, 2P3S, and 2P6S converters are 95.0%, 95.2%, and 90.0%, respectively, while the measured quiescent currents are 210, 130, and 140 nA, respectively. Compared with the state-of-the-art 2P3S and 2P6S converters, the reconfigured 2P3S and combined 2P6S converters with the proposed IC, respectively, achieve higher efficiency through appropriate switch sizes and ON-time optimizations.
关键词： Dual-path six-switch (2P6S),single-path three-switch (1P3S),dual-path three-switch (2P3S),maximum power point tracking (MPPT),photovoltaic (PV) energy harvesting,energy efficiency,reconfigurable controller
更新于2025-09-23 15:21:01
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Sustainable manufacturing: re-contouring of laser cladding restored parts by machining method with cutting energy management
摘要： Laser cladding has been commonly utilized for restoring high value-added parts. However, the poor surface quality becomes key technological barrier which restricts its widespread applications. In the paper, re-contouring strategies by machining method are explored for minimal energy consumption as well as required surface roughness. Firstly, the effect of structural characteristics of the laser-cladded workpiece on specific cutting energy was explored by means of layer-by-layer turning and orthogonal cutting. Results indicated that the specific cutting energy increased, and the machining chatter/vibration exacerbated with decreasing coating thickness under fixed cutting parameters. The reason can be summarized as a result of the effect of elastoplastic deformation behavior across the interface. Then, the influences of depth of cut and feed on specific cutting energy in finish turning were addressed. Results indicated that the specific cutting energy reduced with increasing depth of cut and feed in the form of power functions. In addition, energy efficiency decreased with an increase in uncut chip thickness and cutting speed. On basis of this work, large feed and low cutting speed with the adoption of wiper inserts were recommended for minimizing energy consumption within surface roughness requirement.
关键词： Energy efficiency,Sustainable manufacturing,Specific cutting energy,Laser cladding,Surface quality
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Dynamic Real-Time Simulation Approach to Power Management Modelling for CubeSat Applications
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2025-09-23 15:21:01
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Laser Pouch Motors: Selective and Wireless Activation of Soft Actuators by Laser-powered Liquid-to-gas Phase Change
摘要： A joint optimization problem of link-layer energy efficiency (EE) and effective capacity (EC) in a Nakagami-m fading channel under a delay-outage probability constraint and an average transmit power constraint is considered and investigated in this paper. First, a normalized multi-objective optimization problem (MOP) is formulated and transformed into a single-objective optimization problem (SOP), by applying the weighted sum method. The formulated SOP is then proved to be continuously differentiable and strictly quasiconvex in the optimum average input power, which turns out to be a cup shape curve. Furthermore, the weighted quasiconvex tradeoff problem is solved by first using Charnes–Cooper transformation and then applying Karush–Kuhn–Tucker (KKT) conditions. The proposed optimal power allocation, which includes the optimal strategy for the link-layer EE-maximization problem and the EC-maximization problem as extreme cases, is proved to be sufficient for the Pareto optimal set of the original EE–EC MOP. Moreover, we prove that the optimum average power level monotonically decreases with the importance weight, but strictly increases with the normalization factor, the circuit power and the power amplifier efficiency. Simulation results confirm the analytical derivations and further show the effects of fading severeness and transmission power limit on the tradeoff performance.
关键词： energy efficiency,weighted sum method,delay-outage probability constraint,Quality-of-service,effective capacity,multi-objective optimization problem
更新于2025-09-23 15:21:01
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Toward the energy efficiency of multi-pulse PPM signalling for optical communication
摘要： To improve information throughput conventional single-pulse M-ary pulse-position-modulation (PPM) scheme, multi-pulse PPM has been proposed on the optical intensity-modulated and direct-detection channel. Although the multi-pulse M-ary PPM scheme significantly enhances throughput performance, nevertheless, the symbol error rate (SER) increases due to the loss of orthogonality between different pairs of symbols. In this study, the authors first derive the SER performance of general L pulses M-ary PPM scheme under Poisson channel statistic. Moreover, as the green radio is essential in future network, energy efficiency becomes the major concern. Hence, they evaluate L pulses M-ary PPM scheme by the number of reliable bits transmitted per joule of energy consumed. They analyse the trade-off between throughput and power consumption.
关键词： optical communication,symbol error rate,Poisson channel,energy efficiency,multi-pulse PPM
更新于2025-09-23 15:21:01
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[IEEE 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Rome, Italy (2019.6.17-2019.6.20)] 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Characterization of Plasmonic Effects in AuNP+rGO Composite as a Sensing Layer for a Low-cost Lab-on-chip Biosensor
摘要： In this paper, we study the joint pilot assignment and resource allocation for system energy efficiency (SEE) maximization in the multi-user and multi-cell massive multi-input multi-output network. We explicitly consider the pilot contamination effect during the channel estimation in the SEE maximization problem, which aims to optimize the power allocation, the number of activated antennas, and the pilot assignment. To tackle the SEE maximization problem, we transform it into a subtractive form, which can be solved more efficiently. In particular, we develop an iterative algorithm to solve the transformed problem where optimization of power allocation and number of antennas is performed, and then pilot assignment optimization is conducted sequentially in each iteration. To tackle the first sub-problem, we employ a successive convex approximation (SCA) technique to attain a solvable convex optimization problem. Moreover, we propose a novel iterative low-complexity algorithm based on the Hungarian method to solve the pilot assignment sub-problem. We also describe how the proposed solution approach can be useful to address the sum rate (SR) maximization problem. In addition to the algorithmic developments, we characterize the optimal structure of both SEE and SR maximization problems. The numerical studies are conducted to illustrate the convergence of the proposed algorithms, impacts of different parameters on the SR and SEE, and significant performance gains of the proposed solution compared the conventional design.
关键词： Energy efficiency,multi-cell,massive MIMO,power allocation,pilot contamination,pilot assignment
更新于2025-09-23 15:21:01