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In this paper, an improved control strategy (ICS) based on the duty ratio modulation, by properly matching the positive voltage vectors with the new zero voltage vectors (ZVVs), is proposed in direct torque control (DTC) of brushless DC motor (BLDCM). The traditional voltage switching table for the six switches of the converter is modified according to this strategy to minimize the torque ripple....
This paper investigates two finite-time attitude tracking controllers for spacecraft with attitude dynamics presented by rotation matrix. With the use of rotation matrix, unwinding problem widely exists in controllers based on quaternion can be dealt with. Based on backstepping method, the first controller can be developed in the presence of external disturbance. However, the upper bound of the disturbance...
We accomplished the first demonstration of 25Gbit/s NRZ transmission for 100G-PON by leveraging state-of-art 25G Ge/Si APD. Measurement results prove that 35dB power budget is achievable. Comparisons between 25G and 10G APD receivers are performed.
The impact of sampling jitter and resolution of ADC on the performance of MLSD-based NG-EPON is analyzed. 30-dB loss budget is achieved in 25-Gb/s/λ applications using 25-Gb/s, 3-bit ADC with ±2.5-ps timing jitter tolerance.
This paper investigates a fixed-time anti-unwinding attitude controller for spacecraft. With the use of rotation matrix, unwinding problem, which widely exists in controllers based on quaternion can be dealt with. By means of a fixed- time sliding mode surface, the desired attitude command can be tracked in a fixed time, the bound of which can be estimated without knowing any information of the initial...
Two sliding-mode based fault tolerant control schemes are proposed for attitude dynamic tracking problem of re-entry reusable launch vehicle (RLV) under actuator fault, unknown uncertainty, external disturbances, and input limitation. Firstly, the mathematical model of reentry RLV with loss of actuator effectiveness fault is presented. Then, a novel control algorithm is provided for stable control...
A novel reduced-dimension (RD) MUSIC algorithm based on augmented correlation matrix is proposed to estimate the direction of arrival (DOA) and direction of departure (DOD) for the bistatic co-prime multiple-input multiple-output (MIMO) radar. Firstly, by reference to the difference co-array of receiving array, we construct an augmented receiving correlation matrix which is then utilized for the DOA...
Traditionally the voltage vector is defined as zero voltage vector (ZVV) when all power switches are off in direct torque control (DTC) system of brushless DC motor (BLDCM). However the study on the voltage and current of the conducting phase windings shows that the voltage vector is not actually zero by using the traditional ZVV. So it is redefined in this paper according to the definition of ZVV...
To satisfy the QoS requirements and improve the reliability of the network, we propose a load-balancing-based fault-tolerant mapping method (LFMM) in smart grid virtual networks. The process of LFMM is divided into two stages, one is node mapping stage, and the other is link mapping stage. During node mapping stage, we present a load-balancing-based virtual node mapping (LVNM) algorithm. We choose...
Currently, the requirements of service quality in the electric power data network are getting higher and higher, and traffic prediction is an important premise to promote service quality. In order to accurately predict the total traffic of communication channels, a Multi-Applications Comprehensive Traffic Prediction (MACTP) model is proposed in this paper. Differing from F-ARIMA and S-ARIMA models...
In this paper, the self-linear canonical functions (SLCFs) based on linear canonical transform (LCT) are discussed and proposed. We found that the SLCFs can be used to decompose an image into M complex images. Based on this property, a novel multi-focus image fusion method is proposed in this paper. The simulations are carried out to show the importance of parameters in application of the SLCFs decomposition...
Graph processing is increasingly used in a variety of domains, from engineering to logistics and from scientific computing to online gaming. To process graphs efficiently, GPU-enabled graph-processing systems such as TOTEM and Medusa exploit the GPU or the combined CPU+GPU capabilities of a single machine. Unlike scalable distributed CPU-based systems such as Pregel and GraphX, existing GPU-enabled...
With the increase in the number of satellites, the security time synchronization protocol between satellites and servers on the ground increasingly important. But, the time protocol that existing in space lack of security protections. Also, SEIEEE1588's author has gathered the advantage of both NTP and IEEE1588 protocol raise a security enhanced IEEE1588 protocol for deep-space environment (SEIEEE1588)...
The signal distortions of the microwave photonic bandpass filter based on stimulated Brillouin scattering is presented in this paper for the first time. We assume that modulated signal pulse propagates through a continuous-wave-pumped Brillouin fiber gain medium, where the carrier angular frequency of the pulse is tuned so that it's near to Stokes resonance. The decibel gain and broadening factor...
Graph processing is increasingly used in knowledge economies and in science, in advanced marketing, social networking, bioinformatics, etc. A number of graph-processing systems, including the GPU-enabled Medusa and Totem, have been developed recently. Understanding their performance is key to system selection, tuning, and improvement. Previous performance evaluation studies have been conducted for...
With the proliferation of Mobile SNS, understanding users' acceptance behavior has become an important issue for researchers and service providers. Relevant studies have focused on the relationship of different influence factors of acceptance, little research have been conducted to investigate the moderating effects of gender. This paper incorporates perceived enjoyment with UTAUT theory as research...
Micro-grid is the technique which could access the utility grid with combined renewable energy generation resources, loads, energy storage devices and control devices. It is generally agreed that, Micro-grid could reduce or avoid the impact of wide range failure to the users and improves the power supply reliability. This paper proposed a Monte Carlo method to evaluate the reliability of Micro-grid...
To permit the growth of robotic systems into new applications, e.g. rehabilitation, wearable (exoskeleton) and domestic/service robots, new actuators that can safely interact with humans and environments are greatly required. This paper designs a pneumatically powered actuator that has intrinsic compliance, and is able to extend and bend. A discretization method is utilized to model the continuum...
Online gaming, a large market with hundreds of millions of active players, is still struggling to scale without risky investments in infrastructure. In this work, we propose a cloudbased platform to massivize online gaming—the challenges and opportunities of scaling on-demand, while paying only for what is used. We discuss the major aspects of cloud-based gaming, virtual-world management, game-data...
Graph-processing platforms are increasingly used in a variety of domains. Although both industry and academia are developing and tuning graph-processing algorithms and platforms, the performance of graph-processing platforms has never been explored or compared in-depth. Thus, users face the daunting challenge of selecting an appropriate platform for their specific application. To alleviate this challenge,...
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