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This paper discusses the time synchronization issue in wireless sensor networks. An event-triggered average consensus time synchronization algorithm is proposed. This algorithm uses the average time message from one node's one-hop neighbors to update the clock parameters of the node. And it achieved acceptable synchronization accuracy. We also proposed an event-trigger mechanism to reduce the communication...
As the penetration level of wind power increases, displacing conventional power generation with wind power will reduce the inertia of power system and decrease the frequency stability. Energy storage devices with only 5% energy storage of wind farm's rated capacity can produce the same virtual inertia as a same capacity synchronous generator. To reduce the additional costs of individual energy storage...
In this article, we present a target speaker dependent speech enhancement system, to enhance a specific target talker in presence of real life background noises. The proposed system uses a multi-channel processing stage to produce a noise reference signal. This noise reference signal is further used, to not only compute the residual noise statistics from the multichannel stage output, but also to...
Robot reaching ability serves as one of essential basis for many other manipulation skills, such as grasping, placing etc., and has been widely focused for decades. Inverse model, which plays a fundamental role within robot reaching ability, aims to produce motor commands to drive the system to the desired state. However, since the inverse model is always an one-to-many mapping, it suffers from the...
The strategies for important node detection according to topological structures are widely explored in complex networks. The diameter is a very important topological parameter among various network topological indicators. However, it is seldom utilized in important node searching methods. In this study, we defined the nodes on the diameter paths as central nodes and proposed a Diameter Center Detection...
A well known challenge in linearly-constrained beamforming is how to suppress multiple interferences when the degrees of freedom (DoF) provided by the array are fewer than the number of sources in the environment. In this paper, we propose a beamformer design to address this challenge. Specifically, we propose a min-max beam-former design that penalizes the spatial responses on all interferences'...
To solve the problem of low recognition rate which is the existing identification methods of partial discharge faults, a new method was designed with wavelet, singular value and improved particle swarm algorithm to optimize the BP neural network. First, using continuous wavelet and singular value decomposition to get the signal characteristic value; then combined with the significance of inertia weight...
In traditional wired or cellular communication, the communication scenario and channel are fixed. However, with an increasing interest in air-ground integrated communication network, communication scenario transition caused by dynamic and high-movement nodes happens frequently, resulting in deteriorating reliability of communication. In this paper, a time-varying channel model is proposed to describe...
Linear compressor is becoming more utilized in refrigeration for high efficiency, compared with the traditional rotary motor. Both stroke and frequency controls need to implement for steadiness and efficiency. In this paper, a strategy of resonant frequency tracking control based waveform fitting phase detection is presented to optimize the efficiency of the compressor. Compared with zero crossing...
In this paper a micro-nano Cu@Ag core-shell particles were synthesized by liquid phase reduction method based on 50nm, 5µm, 20µm spherical copper powders for enhancement of Sn-10Sb high temperature solder. The as-prepared Cu@Ag core-shell particles were characterized by XRD, TEM and SEM methods, result indicated that a layer of Ag was uniformly coated on the surface of Cu. 3wt.% Cu@Ag core-shell particles...
Nano Cu@Ag core-shell powders for electronic packaging were prepared by Liquid phase reduction method. The core-shell powders were characterized by XRD, SEM and TEM. The key problems in the experiment were presented some resolvable solution, and the coating process was optimized. The results showed that the dispersant PVP was added to make the dispersion effect better or the selection of stirring...
This paper focuses on parameter estimation for linear oscillatory actuator (LOA) utilized in linear compressor. A recursive least square (RLS) based method has been developed to estimate the resistance, inductance and thrust coefficient of the motor. Considering the time-varying effect of the system, a forgetting factor is introduced to improve the dynamic tracking precision. A mover displacement...
With the rapid development and application of distributed generation, more and more attention has been paid to the operation and control technology of the wind storage isolated network system. As a kind of new energy application, the operation of wind storage isolated network system has a great technical advantage in the process of operation. Aiming at the problem of self starting and stable operation...
With the rapid development of wireless technology, free or cheap voice communication has become more and more popular. But this cost-effective voice technology based on Wi-Fi, Voice over WIFI (VoWIFI), is lacking mature management and control system, especially there is still no relevant research on its RAN performance. This paper has three mainly contributes: 1) in the indoor environment, we studied...
There are billions of Internet of things (IoT) devices connecting to the Internet and the number is increasing. As a still ongoing technology, IoT can be used in different fields, such as agriculture, healthcare, manufacturing, energy, retailing and logistics. IoT has been changing our world and the way we live and think. However, IoT has no uniform architecture and there are different kinds of attacks...
This paper focuses on evaluation of the sampling strategy under different conditions. We first implement a framework for modeling and tracking spatio-temporal scalar fields with multiple robots, using Gaussian Process, Voronoi partition, discrete and continuous optimization algorithms. Then, the sampling conditions are divided into four cases from two perspectives (asynchronous / synchronous sampling...
The L-Band Digital Aeronautical Communication System (LDACS) is a typical pilot-aided orthogonal frequency division multiplexing (OFDM) communication system. With the performance of LDACS in the Unmanned Aerial Vehicle (UAV) over-water channel, the pilot is redesign based on Zadoff-Chu (ZC) sequence. The new periodic ZC-pilot could reduce the effects of noise by correlated calculation. Based on new...
The rapid development of the logistics industry promotes the nationwide circulation of the fresh agricultural products. The price of fresh agricultural product in different circulation modes is distinct. Aiming at this kind of phenomenon, this paper puts forward a model of selecting the best circulation mode according to the cost analysis. Use the fresh agricultural product's circulation structure...
The research of false alarm judgment method has great significance to identify real alarms timely, to response emergency rapidly and monitor network security status correctly. In this paper, in the point of view of alarm data distribution, several methods of false alarm decision are elaborated, and the advantages and disadvantages of each method are analyzed. Studying the false alarm judgment analysis...
The evaluation of small watershed management efforts is significantly meaningful to design and implement projects of protecting the water quality in water source area. In this paper, the images of GaoFen-1(GF1) and the China's first civilian high-resolution stereo mapping satellite, ZiYuan-3 (ZY-3) satellite, were used to get the land surface information in a small watershed in the water source area...
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