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2D electric-double-layer phototransistor for photoelectronic and spatiotemporal hybrid neuromorphic integration
摘要： The hardware implementation of neuromorphic computing has attracted growing interest as a promising candidate for confronting the bottleneck of traditional von Neumann computers. However, most previous reports are focused on emulating the synaptic behaviors by a mono-mode using an electric-driving or photo-driving approach, resulting in a big challenge to synchronously handle the natural photoelectric information. Herein, we report a multifunctional photoelectronic hybrid-integrated synaptic device based on the electric-double-layer (EDL) MoS2 phototransistor. Interestingly, the electric MoS2 synapse exhibits a potentiation filtering effect, while the photonic counterpart can implement both potentiation and depression filtering effects. Most importantly, for the first time, photoelectronic and spatio-temporal four-dimensional (4D) hybrid integration was successfully demonstrated by the synergic interplay between photonic and electric stimuli within a single MoS2 synapse. An energy band model is proposed to further understand such a photoelectronic and spatio-temporal 4D hybrid coupling mechanism. These results might provide an alternative solution for the size-scaling and intellectualization campaign of the post-Moore era, and for more sophisticated photoelectronic hybrid computing in the emerging neuromorphic nanoelectronics.
关键词： neuromorphic computing,electric-double-layer,synaptic device,MoS2 phototransistor,photoelectronic hybrid integration
更新于2025-11-25 10:30:42
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Small Aircraft Infrared Radiation Measurements Supporting the Engine Airframe Aero-thermal Integration
摘要： The large, EU Supported ESPOSA (Efficient Systems and propulsion for Small Aircraft) project has developed new small gas turbines for small aircraft. One of the important tasks was the engine - airframe aero-thermal radiation integration that included task of minimizing the infrared radiation of the small aircraft, too. This paper discusses the factors influencing on the aircraft infrared radiation, its possible simulation and measurements and introduces the results of small aircraft infrared radiation measurements. The temperature of aircraft hot parts heated by engines were determined for validation of methodology developed and applied to engine - aircraft thermal integration.
关键词： aircraft,engine - airframe thermal integration,radiation measurements,infrared radiation
更新于2025-09-23 15:23:52
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[IEEE 2017 14th IEEE India Council International Conference (INDICON) - Roorkee (2017.12.15-2017.12.17)] 2017 14th IEEE India Council International Conference (INDICON) - Impact of intermittent wind and solar resources on the dynamics of power system under different loading conditions
摘要： This paper presents the impact of renewable energy systems i.e. wind and solar on the load frequency control aspects of power system. An interconnected two area power system is modeled with backlash in the governor and generation rate constraint (GRC) in the turbine dynamics. The system is integrated with wind and solar resources in the form of a time series data with a resolution of one fifth of a second. The impact of these two renewable energy resources on the frequency response of power system is analyzed in terms of maximum overshoot (MP) and settling time (ts).
关键词： frequency deviation,peak overshoot,renewables integration,settling time,two area model.
更新于2025-09-23 15:23:52
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Coordinated control of MPPT and voltage regulation using single-stage high gain DC–DC converter in a grid-connected PV system
摘要： In general, grid-connected PV system uses two stages of DC-DC converter to accomplish Maximum Power Point Tracking (MPPT) and DC voltage regulation. In order to overcome the two stage conversion, a single stage high gain DC-DC converter is presented in this paper. The operation of three switches with two different duty ratio is the main advantage of this converter to accomplish the coordinated control of MPPT and DC voltage regulation. This coordinated control also helps to provide constant DC voltage to the DC loads though the inverter is disconnected from the DC bus. A 1KW grid-connected PV system with the proposed DC-DC converter is developed and is validated using OP4500 Real-Time test platform. In addition, a decoupled control strategy with fractional order proportional-integral (FOPI) controller is implemented at the inverter end. Also, the reactive power compensation, harmonic reduction (less than 5% as per the IEEE 519 standard) and the grid power factor close to unity is obtained and the results are validated using the real-time simulator.
关键词： Solar photovoltaics,LCL filter,Coordinated control of MPPT and voltage regulation,High gain DC-DC converter,Grid integration and power quality
更新于2025-09-23 15:23:52
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A dynamic model based on response factor method and seasonal performance analysis for integration of flat plate solar collector with building envelope
摘要： Integrating solar thermal collectors into building envelopes (e.g. walls or roofs) is very promising due to no need of additional site to place solar collectors. When a solar collector is integrated with a building, the working conditions for both the solar collector and the building envelope are changed. This paper proposed a new dynamic thermal model based on the response factor method. The new model combines the conventional analysis method for solar collectors with building envelopes, therefore it is easy to be understood and is more convenient to be realized by programming in a computer than state space model. The calculated results by the dynamic model agreed well with those calculated by the state space model and the measured experimental data, suggesting a satisfying validity of the model proposed. The seasonal performance of a solar wall (integrating of solar collectors and walls) in Beijing was studied by the new model. The results showed that: (1) In winter, the useful heat gain by the solar wall was always a little higher than the separate wall by about 6.7–8.8%, and the heat loss through solar wall is reduced by 90% or more, this is very favorable to reduce space heating load. (2) In summer, the useful heat gain of solar wall was higher than the separate collector by about 2.1–10.2%, the heat transferred through walls was less or higher than the separate wall depending on the inlet water temperature.
关键词： Dynamic model,Building heat transfer,Response factor method,Integration of solar collector with building,Useful heat gains
更新于2025-09-23 15:23:52
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Frequency Hopping and Parallel Driving with Random Delay Especially Suitable for the Charger Noise Problem in Mutual-Capacitive Touch Applications
摘要： Charger noise can cause inaccurate touch points and fake touch points to appear; this can cause a device to behave incorrectly. The intensity of charger noise could be much larger than the intensities of the original touch signals. Furthermore, the frequency of charger noise varies for each different charger. Therefore, industry experts have identified charger noise as the most difficult problem in capacitive touch applications. The demand for a solution to this problem has become crucial for the mobile market. In this paper, we prove that a particular combination of frequency hopping and repeated integration is an effective method to handle the problem. In addition, we propose an efficient discrete Fourier transform (DFT)-based algorithm to select an effective sensing frequency. We propose parallel driving with random delay to enhance signal-to-noise ratio (SNR). We show an efficient hardware-software co-design that facilitates the application of our methods in touch ICs. Experimental results show that our methods can increase SNR by over 45 dB and can find an effective sensing frequency fast and dynamically.
关键词： repeated integration,frequency hopping,mutual-capacitive touch,parallel driving,Charger noise
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Portland, OR, USA (2018.9.23-2018.9.27)] 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Comparative Analysis of Non-Isolated and Isolated Type Partial-Power Optimizers for PV-Battery Series Inverter Architecture
摘要： A seamless battery integration with higher power conversion efficiency and lower system power rating can be achieved by adopting the DC-series battery integration topology into a photovoltaic (PV) string inverter system, the PV-battery series inverter. The PV-battery series inverter uses the partial-power processing technique to achieve flexible current control between PV string and battery. In the process of designing the partial-power DC-DC optimizer, different types of DC-DC converters and different size of batteries can be considered, and the system efficiency and the power rating vary based on the system design. This paper presents a comparative analysis of the different type partial-power optimizers for the PV-battery series inverter in residential rooftop applications (< 10kW PV output power, < 500V DC-bus voltage), in consideration of the DC-DC converter topology. Non-isolated and isolated bidirectional DC-DC converters are considered and selection of battery voltage in each case is made to have the optimized system design. The operation of the designed DC-DC optimizer is verified through controller hardware-in-the-loop test.
关键词： pv-battery series inverter,residential rooftop PV application,comparative analysis,non-isolated and isolated bidirectional dc-dc converters,partial-power dc-dc optimizer,PV-battery integration,dc-series
更新于2025-09-23 15:23:52
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Position-free monte carlo simulation for arbitrary layered BSDFs
摘要： Real-world materials are often layered: metallic paints, biological tissues, and many more. Variation in the interface and volumetric scattering properties of the layers leads to a rich diversity of material appearances from anisotropic highlights to complex textures and relief patterns. However, simulating light-layer interactions is a challenging problem. Past analytical or numerical solutions either introduce several approximations and limitations, or rely on expensive operations on discretized BSDFs, preventing the ability to freely vary the layer properties spatially. We introduce a new unbiased layered BSDF model based on Monte Carlo simulation, whose only assumption is the layer assumption itself. Our novel position-free path formulation is fundamentally more powerful at constructing light transport paths than generic light transport algorithms applied to the special case of flat layers, since it is based on a product of solid angle instead of area measures, so does not contain the high-variance geometry terms needed in the standard formulation. We introduce two techniques for sampling the position-free path integral, a forward path tracer with next-event estimation and a full bidirectional estimator. We show a number of examples, featuring multiple layers with surface and volumetric scattering, surface and phase function anisotropy, and spatial variation in all parameters.
关键词： BSDF,Monte Carlo integration,layered materials
更新于2025-09-23 15:23:52
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Outlier Events of Solar Forecasts for Regional Power Grid in Japan Using JMA Mesoscale Model
摘要： To realize the safety control of electric power systems under high penetration of photovoltaic power systems, accurate global horizontal irradiance (GHI) forecasts using numerical weather prediction models (NWP) are becoming increasingly important. The objective of this study is to understand meteorological characteristics pertaining to large errors (i.e., outlier events) of GHI day-ahead forecasts obtained from the Japan Meteorological Agency, for nine electric power areas during four years from 2014 to 2017. Under outlier events in GHI day-ahead forecasts, several sea-level pressure (SLP) patterns were found in 80 events during the four years; (a) a western edge of anticyclone over the Pacific Ocean (frequency per 80 outlier events; 48.8%), (b) stationary fronts (20.0%), (c) a synoptic-scale cyclone (18.8%), and (d) typhoons (tropical cyclones) (8.8%) around the Japanese islands. In this study, the four case studies of the worst outlier events were performed. A remarkable SLP pattern was the case of the western edge of anticyclone over the Pacific Ocean around Japan. The comparison between regionally integrated GHI day-ahead forecast errors and cloudiness forecasts suggests that the issue of accuracy of cloud forecasts in high- and mid-levels troposphere in NWPs will remain in the future.
关键词： outlier events,regional integration,global horizontal irradiance (GHI),photovoltaic (PV) power generation,numerical weather prediction (NWP),day-ahead forecast
更新于2025-09-23 15:23:52
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Incoherent Range Walk Compensation for Spaceborne GNSS-R Imaging
摘要： Global navigation satellite system reflectometry (GNSS-R) receivers produce delay-Doppler maps (DDMs) by incoherently integrating coherent integration results. Due to system dynamics, during incoherent integration, the receiver aligns each coherent result by tracking the delay and Doppler of the specular point. This is known to cause a blurring of the spatial footprint of the Woodward ambiguity function (WAF) on the reflecting surface. In this paper, we demonstrate that the blurring of the WAF varies over the glistening zone (GZ), and even if a fixed point on the ground is tracked, blurring still occurs. We derive the expressions for the delay and Doppler change rates over the GZ and then predict the error introduced by range walk for typical GNSS-R scatterometry configurations. We find that ≈6 dB of loss is expected for a point scatterer near the edge of the GZ when a fixed point on the surface is tracked. The incoherent range walk compensation (IRWC) method is then presented for GNSS-R receivers to mitigate this loss. The IRWC method focuses the power in the DDM to the isodelay and iso-Doppler configuration occurring at the midpoint of the integration time. DDMs produced by tracking a fixed point with and without IRWC are simulated, and errors are found to be in agreement with those predicted. Spatial domain GNSS-R products will be improved with IRWC. Target detection will benefit from a larger usable swath, allowing longer tracking and detection times as a result of the increased target to clutter and noise ratio. At the same time, imaging applications will no longer suffer from a spatially variant blurring of the WAF, which limits the resolution of the estimated products. IRWC is shown to mitigate the range migration losses and improve the SNR of an imaging GNSS-R receiver by ≈6 dB near the edge of the GZ.
关键词： integration,global navigation satellite system reflectometry (GNSS-R),reflectometry,imaging,target detection,receiver,incoherent range walk compensation (IRWC),Dynamic corrections
更新于2025-09-23 15:23:52