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A vectored thruster based on 3-RRRR parallel manipulator for small-size AUVs is designed to solve some drawbacks of conventional AUVs, which the control surfaces become ineffective at zero or slow forward speeds. Though this method, the thrust from duck propeller is controlled by the parallel manipulator. This approach has advantages of high stiffness, high mobile and large payload capacity. The parallel...
Modern deep learning enabled artificial neural networks, such as Deep Neural Network (DNN) and Convolutional Neural Network (CNN), have achieved a series of breaking records on a broad spectrum of recognition applications. However, the enormous computation and storage requirements associated with such deep and complex neural network models greatly challenge their implementations on resource-limited...
Two-element serial-connected photodiode array (SC-PDA) and parallel-connected photodiode array (PC-PDA) were fabricated and tested. The novel PC-PDA shows a higher responsivity (0.32A/W), a smoother frequency response (14.0GHz) and a higher saturation current (66mA) comparing to the SC-PDA (0.24A/W, periodical patterned frequency response and 42mA).
WiFi-based Human activity recognition has attracted attention in the human-computer interaction, smart homes, and security monitoring fields. We first construct a WiFi-based activity dataset, namely WiAR, to provide a benchmark for existing works. Then, we leverage the moving variance of CSI to detect the start and end of activity. Moreover, we present K-means-based subcarrier selection mechanism...
Visual simultaneous localization and mapping (V-SLAM) based tracking method for moving cameras has drawn increasing attention. The unpredictability of road conditions and noise from the camera calibration, however, make conventional ground plane estimation unreliable and adversely affecting the tracking result. In this paper, we propose an adaptive ground plane estimation algorithm in a moving monocular...
We study an entangled QKD system using photons at 780nm, 1550nm and 4μm from a SPDC nonlinear crystal, over a 30km maritime channel. An analysis of the channel at each wavelength is performed and the QKD system is simulated for each wavelength.
The service-oriented paradigm offers support for engineering service-based systems based on service composition. QoS (Quality of Service)-aware service composition chooses a set of services to collectively construct a service-based system, while satisfying global QoS constraints and budget restriction. The service providers naturally are self-interested and strive to maximize their own utilities....
False data injection attack can bypass the bad data defense process in the power systems and affect the results of state estimation, so that the system security is in danger because of the wrong states obtained in the dispatch center. The traditional false data injection attack is based on the DC power flow model and has many limitations. In this paper, a global attack model and local attack model...
In this paper, asymmetric binary zero correlation zone (A-ZCZ) sequence sets are constructed. Based on zero correlation zone aperiodic complementary sequence (ZACS) sets obtained in [13], K binary ZCZ sequence sets are constructed, each set is a binary (2M2, M, M)-ZCZ and the K sets have a inter-set zero cross-correlation zone of length Z = M/K − 1, where K = pn. As a result, the K binary ZCZ sequence...
This paper attempts to study the effect of energy management strategy based on state machine on the performance of air-cooled fuel cell-battery hybrid system, for which the hybrid power system test platform composed of air-cooled fuel cell, lithium battery and DC converter was built. The reliability and stability of the hybrid system and the effectiveness of the energy management strategy based on...
In order to evaluate the mental workload of the pilots during the flight, a flight simulation platform for Electroencephalography (EEG) experiment is developed. The platform uses a distributed flight simulation framework, and the flight visual is driven by a real flight dynamics equation. A common simulation parameter architecture based on Extensible Markup Language (XML) is introduced to meet the...
As a global innovation capital and industrial cluster representative, Silicon Valley affects the whole world for its scientific and technological innovation. Patent co-citation can be used as information carrier to identify the core technology patents and evaluate technical similarities between enterprises in industrial clusters. In this paper, we carry out industrial clusters analysis of Silicon...
A vertically integrated device composed of Vertical-Cavity Surface-Emitting Laser (VCSEL) unit and Resonant Cavity Enhanced Photodiode (RCE-PD) unit is proposed, which has huge potential application perspectives for optical interconnects. The performance of the integrated device and the interaction of its two composing units are analyzed based on different structure optimization. As optimized, its...
In this paper, we studied the effect of mushroom-mesa structure on vertical incidence PIN photodiodes based on theory and experiments. A novel mushroom-mesa vertical incidence photodiode was fabricated. The 20-um-diameter mushroom-mesa photodiode with a 0.5-um absorption layer achieved a 3dB bandwidth of 24.1 GHz, which increased 39.3% compared with PIN photodiodes.
In this paper, the high-speed modified uni-traveling-carrier photodiode (MUTC-PD) was designed and fabricatedfor low reverse bias. The 3-dB bandwidth and responsivity of MUTC-PD with 24-μm mesa diameter at 1-V reverse bias is 22.5 GHz and 0.22 A/W at the wavelength of1550 nm, respectively. The dark current of the device is less than 4nA at 3.3 V reverse bias. The fabricated device can achieve high...
A phase-sensitive optical time domain reflectometry sensing system based on Ultra-weak FBG Array using double pulses is proposed. The principle of this sensing system is elaborated. A series of simulations are carried out to optimize the parameters to increase the sensing distance of this system. The parameters contain reflectivity of UWFBG, the interval between adjacent UWFBGs and pulse width. The...
Based on the existing communication links between UAVs, a short wave side tone ranging signal for UAV platform is constructed, based on the phase characteristic of side tone signal and the principle of bidirectional time comparison, this paper proposed a high-precision time synchronization method which can achieve the high-precision time synchronization for formation UAVs independently without GNSS...
The principle of predictable weighting algorithm is that a good clock is a predictable clock, we observed that deterministic signature such as frequency drift and ageing do not affect time scale stability if well predicted in studies of the algorithm. The clock difference is a non-stationary random process, in order to reduce noises of atomic clock, improve the stability of time scale, wavelet muti-scale...
A distributed vibration sensing technique using double optical pulse based on phase-sensitive optical time-domain reflectometry (Φ-OTDR) and ultra-weak FBG (UWFBG) array is proposed for the first time. The single mode sensing fiber is integrated with UWFBG array which has uniform spatial interval and ultra-weak reflectivity. The relatively high reflectivity of the UWFBG, compared with the Rayleigh...
Motivated by the interest in using light-emitting diode (LED) for underwater optical communication, experiments with low transmitting power and high receiving sensitivity are conducted. On-off keying (OOK) modulation is employed, and 7.5 Mbps and 500 kbps bit rates are achieved with transmitting distances of 10 m and 50 m respectively. For 10 m transmitting distance experiment, the bandwidth limitation...
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