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Modulation of emissivity in the mid-infrared is experimentally realized using thin-film phase-transition material SmNiO3. Designs of variable emissivity coatings based on metasurfaces integrated with SmNiO3 are also reported.
We demonstrate a thermal emitter whose radiated power remains nearly constant over a temperature range of δT ∼ 30 °C, implemented using thermochromic samarium nickelate. This zero-differential thermal emitter can be used for infrared camouflage and obfuscation.
Traditional imaging methods and computer vision algorithms are often ineffective when images are acquired in scattering media, such as underwater, fog, and biological tissue. Here, we explore the use of light field imaging and algorithms for image restoration and depth estimation that address the image degradation from the medium. Towards this end, we make the following three contributions. First,...
With the development of electric vehicles, more and more attentions have been put on understanding and attenuating the noise, vibration, and harshness (NVH) of traction machines. NVH in machines are mainly caused by the electromagnetic force, which is complex vector functions of both time and space, and models are desired for accurately evaluating its characteristics. In this paper, analytical models...
In this paper, we propose a modified design of phase difference method based position sensitive system for linear motion orientation. The analytic and experimental results show that the phase difference of the output current of the metal electrode has good linear relationship with a position. Improvement of circuit design is also presented and implemented, and the experiment results show good performance...
This paper deals with the sensorless direct torque control (DTC) scheme for the permanent magnet synchronous motor (PMSM), where a new estimation algorithm is developed based on the polynomial chaos theory and the extended Kalman filter (EKF) for the sensorless obtaining of the rotor speed, stator flux and electromagnetic torque. The proposed estimator can effectively deal with parametric uncertainties...
The future 5G communication will bring about the surge of traffic. The traffic of cellular network has great non-uniformity and volatility in space and time, which brings opportunities and challenges to the planning and management of cellular network. The energy consumption on base station (BS) accounts for more than 50% of the total energy consumption of the cellular network. Due to the space-time...
The inevitable nonlinearity of beam flexure cannot be ignored, which poses challenges for large range tracking of compliant nanomanipulating systems with nanometric motion quality. In this paper, the nonlinear stiffness of a self-developed large range XY compliant nanomanipulator is analytical modeled and experimentally verified. Then a feedback linearization technique is adopted to compensate the...
In order to research cyclists ' extent of physical fatigue and seat pressure distribution under the different seat heights of bicycle during cycling. The sEMG activity was recorded from cyclists' biceps brachii, triceps brachii, forearm muscles, deltoideus, erector spinae and trapezius at 95%, 100% and 105% seat heights. Interface seat pressure distribution was monitored using Tekscan pressure distribution...
With the development of big data and multi-core processors technology, DRAM-only based main memory cannot satisfy the requirements of in-memory computing in high memory capacity and low energy consumption. The emerging memory technology-phase change memory (PCM) is proposed to break the bottleneck of the current memory system. However, its weaknesses in write endurance and long access latency make...
5G communication will bring a surge traffic in cellular network. The traffic in cellular network not only has strong variability by time, but also has strong spatio-temporal correlation, which brings large difficulty to predict. In order to make reasonable use of communication network resources, it is important to describe and predict the spatio-temporal information of traffic in cellular network...
The impact of stochastic excitation in the operation process of power systems is becoming more and more serious. In this paper, the stochastic model of the single machine infinite bus power systems with automatic voltage regulator (AVR) was established. The stability of the power system and the relationship between the parameters and stochastic excitations were discussed. The conditions for the mean...
Piezoelectric actuators (PEAs) are widely used in active vibration control engineering. Dynamic hysteresis nonlinearities existing in the PEAs reduce the control accuracy. Using accelerometers for vibration control makes dynamic hysteresis modeling more challenging. In this study, a Hammerstein dynamic hysteresis model for a PEA is proposed based on the acceleration signal. Then, a hysteresis inverse...
In this paper, a robust repetitive control for time delay systems is investigated supporting high precision tracking of nano-manipulating systems. To handle the time delay of such systems, the repetitive control structure is reformulated and the design of q filter is converted to the mixed sensitivity optimization of infinite dimensional systems, where Skew-Toeplitz based approach is used for controller...
Since the low SNR environment, generally the modulation recognition rate of signal modulation type is not very high. In this paper, we studied an automatic recognition method of communication signal modulation type in the low SNR. According to analyze the signal entropy as the feature, three characteristics are selected, and the random forest is as the classifier, finally we get a high recognition-rate...
Cognitive radio (CR) is the enabling technology for supporting dynamic spectrum access. This sort of communication paradigm can utilize increasingly scarce spectrum resources more efficiently and has become one of the the hot issues of wireless communication in recent years. With in-depth research, some unique security risks of the CR network has been revealed. A new method named RF "Distinct...
A two-stage decoupling identification method is developed for Hammerstein system containing the threshold-discrete Prandtl-Ishlinskii (TDPI) operator with non-local memories. In the first stage, a persistently exciting input is designed so that the linear subsystem can be made decoupled from the nonlinear element and linear subsystem identification is coped with using a least squares estimator. Then,...
Large-scale group decision making problems exist widely in human being's daily life. In this paper, a new approach to large-scale multi-attribute group decision making with multi-granular unbalanced linguistic information is developed. First, an algorithm is proposed to represent the initial multi-granular unbalanced linguistic information of decision makers with the use of unbalanced linguistic distribution...
With the fast development of distributed power generations, stability and security have attracted extensive attention in the recent years. As a representative of clean energies, Photovoltaic (PV) systems have been installed extensively worldwide. This drives grid-connected requirements to be continuously updated. In current active grid requirements/codes, PV systems should be more intelligent in the...
This paper proposes a novel fixed off-time control method for single-phase micro-inverter operating in discontinues conduction mode. In this method, the off-time of the active switch is fixed to a constant value over the whole power level. The on-time of the active switch is obtained for current shaping without sensing inductor current. The proposed method has two advantages. One is that the switching...
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