Search

To improve the evaluating ability of the electrical contact properties of the materials, a test device with a good comprehensive performance is designed based on eddy current repulsion mechanism. The working principle, mechanical structure and driving circuit of the device are introduced. A prototype of the device is made and tested. The result shows that the device has a wide range of speed regulation, wide application scope and small volume.

In order to solve the problems such as violent contact bounce, low utilization rate of core and coil materials of traditional AC contactor ， the dynamic characteristics and contact bounce of AC contactors with different inclined angles surface are simulated and analyzed based on electromagnetics and multi-body dynamics. On this basis, the improved pigeon colony optimization algorithm is used to optimize the electromagnetic mechanism of AC contactor, and the movement process of the armature and contact are captured by high-speed camera to verify the simulation results. Experimental results show that the contact bounce of AC contactor with inclined pole surface is effectively restrained, the core and coil materials are greatly reduced, and the economic benefits are improved.

Gas medium (N 2 , H 2 or N 2 -H 2 mixtures) and magnetic field are usually applied to extinguish the arc in high-voltage direct current (HVDC) relays. The presence of hydrogen will increase the probability of arc restriking, and when the arc extinguishing chamber is poorly sealed, it may also cause an explosion. The nitrogen reduces the probability of arc restriking, but the arc extinguishing time is similar to air. Therefore, in order to enhance the ability of arc extinguishing, avoid the arc restriking and increase the lifetime of the HVDC relay, the characteristics of the arc in the metal splitter plate and that of the arc root motion in the magnetic field are simulated by means of magnetohydrodynamics (MHD). The voltage and images of the arc are obtained by DC Arc Test System. The results show that increasing the external magnetic field is beneficial to the motion of the arc and shortens the time of arc movement on the contact surface. At the same time, the addition of the metal splitter plate on both sides of the contact is beneficial to increase the arc voltage and accelerate the arc extinguishing.

The Enhanced Super-Resolution Generative Adver-sarial Networks (ESRGAN) is the state of the art deep learning based image Super-Resolution (SR) and has the best performance in perceptual quality. However, we find it is time-consuming, which makes it impractical for SR at clients' side during video delivery since SR usually uses clients' computing resources (the computational power at the clients' side should not be as powerful as GPU) and videos often require real-time playback. While Efficient Sub-Pixel Convolutional Neural Network (ESPCN) has the best real-time performance, it is still not capable of offering a smooth watching experience and has much lower perceptual quality. In order to simultaneously meet the demands on the real-time performance and the resulting pleasant artifacts of SR at the clients' side, we propose RTSRGAN to exploit the advantages of ESRGAN in image perceptual quality and ESPCN in real-time performance. Our experimental results indicate that RTSRGAN has the fastest reconstruction speed, on the average, 15 images per second on a single 2.3GHz CPU (only 6 images per second by ESPCN), and reconstructs images of a relatively acceptable perceptual quality, which validates that our proposed RTSRGAN can be used for SR at clients' side to enhance the real-time performance and ensure the image perceptual quality.

In view of the flight characteristics of cruise missiles, a new path planning area map, slant distance map, is proposed on the premise that cruise missiles move at constant speed at a certain altitude. The path planning diagram is compared with the one without improvement. Particle swarm optimization (pso) is used to build a mathematical model for intelligent path planning and simulation of multiple cruise missiles. The results show that slant distance graph and particle swarm optimization can solve the path planning problem of multiple cruise missiles.

A very compact triple-band antenna with rectangular ring for wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) applications is designed in this article. The antenna has a simple structure and it consists of a rectangular ring, a fork-shaped strip, a modified 1-shaped stub, and a coplanar waveguide(CPW) which induces proposed antenna has the advantage of simple structure with a single metallic level, and it is easier to integrate into the microwave integrated circuit. It can be adjusted the position and length of these structures to achieve the three-different frequency and bandwidth, respectively. As a result, the triple-band antenna has been designed, and simulated, and then obtaining a high antenna performance.

In this paper, a novel multi-physics analysis method is proposed to quantify the temperature drift of microwave filters. Accurate correlation of electro-magnetic, thermal, and mechanical can be obtained without linear hypothesis. The approach is applied to design temperature compensation for waveguide filter. The multi-physics analysis procedure and the novel structure for temperature compensation are also presented. The simulation results show the efficiency of the analysis method.

Compact planar crossovers with single and dual band application are proposed. The crossovers are derived from the conventional two-section branch-line crossover by equivalent quarter-wavelength transmission-line with stubs, which reduces the circuit size and complexity. The crossover geometries and design procedure are discussed in detail according to the derived formulas. For verification, a single-band crossover working at 2.4 GHz and a dual-band crossover applied at 2.2/3.4 GHz are fabricated and tested. The proposed crossovers feature planar implementation with moderate line impedance, compact size and good performance. Both simulated and measured results are consistent with each other.

The feature extraction was analyzed and matching algorithms of object tracking, then we develop an object tracking method based on local feature matching in this paper. First we introduce about the existing feature extraction algorithms and the basic idea of Shape Context. then we propose the tracking algorithm based on local characteristics. in this algorithm, we evaluate the similarity between the two feature points by histogram distance statistics based on ¦O2-test and we determine the tracking trajectory by votes and prediction to the matching points. It is better matched in target deformation, rotation and occlusion by using this method. the experiment results show that our object matching method is effective.

This paper based on the RF chip of nRF24LE1 achieves the design of electronic license plate (E-Plate) recognition terminal system. Hardware and software design and implementation of this system is given. the 32-bit high performance processor of LM3S8962 of TI Company used as the main controller to achieve communication with the RF chip, the high performance can effectively improve the performance of the reader. at the same time, the implementation of Low-power design was achieved in the software to ensure the electronic tag can work stably for a long time.

The reliability of distribution system, which is one of three major components of electric power system, is influenced enormously by connection modes of itself. Combined reliability-network-equivalent with set theory, a connection mode based on primitive element, abstracting and generalizing the connection modes of distribution network, which constructs graphic and mathematic models of itself, is proposed in the paper, while the reliability can be analyzed. It is proved that the proposed method is effective and corrective by example results.

In accordance with the waveform characteristics of sonic waves which have different experience of propagation paths, a method based on energy operator for detecting the sonic logging signal arrival was proposed. This method can well achieve the extraction of each wave's arrival. While, for the actual logging signal, it is required to pass through an ideal low-pass filter. Fourier inverse transform is used to obtain the signal envelope and the local maximum's method is applied to find the trough positions of this signal, which are the arrivals of each wave. By using the method, we can precisely implement the extraction of signal arrival for the real drilling acoustic signal.

Qaidam Basin is one of the largest arid regions in the middle latitude Asia, which is surrounded by high mountains. The ecosystem of this region is fragile due to limited annual precipitation amounts in the interior basin and large temperature differentia between winter and summer on the surrounding mountains. Several researchers have reported vegetation cover in this area had degraded in the past several decades with the climate changes and human activity. In this study, we use 1-km resolution moderate-resolution imaging spectroradiometer (MODIS) normalized difference vegetation index (NDVI) to explore land cover changes in Qaidam area from 2000 to 2008 based on combine decision tree (DT) and spectral angle (SA) classification methods. An accuracy test illustrates the classification are of credible accuracy for both time periods. Analysis results indicate that vegetation cover has increased for the past 9 years in the Qaidam Area, and lake areas and multi-year snow/ice cover areas have also increased significantly, while barrenland has decreased.

An novel object detection and segmentation algorithm is proposed based on contour information and inference. The scheme proceeds in mo stages, in the first stage, some prototypes are learned automatically from their 3D models and training images. Firstly, aiming to viewpoint invariance, a two-layer structural of multi-views is built, secondly, the corner-polygon (CP), which is combination of 3 features, is proposed for describing templates. In the second stage, the generated framework is used for detecting category-given object. A new Dynamic Bayesian network (DEN) model is built to infer detection probability, based on corresponding patch matching and inference computing, the candidate window s should be found out, then thin plate spline (TPS) technique is used to segment object from background. Experimental results demonstrate that our proposed approach is able to identify and accurately detect and segment the objects with better performance than the existing methods.

There is an increasing interest in the identification and quantification of proteomic markers for biological and medical research. Experimental techniques utilizing liquid chromatography with mass spectrometry (LC- MS) provide one method of directly observing protein expression, but a substantial amount of computational work is needed to go from the raw LC-MS data to a matrix format analogous to gene expression studies in which the columns are samples and rows are proteins. One critical step in this pipeline is the extraction of peptide features from the LC-MS signal data. We present a complete solution to LC-MS feature detection that combines a model-based approach to feature extraction on the MS scans with techniques for robust estimation to build LC-MS features from the individual scans. We show that using our approach, we find significantly more features, more matches, and better correlation between replicated LC-MS experiments than are found using the current state-of-the-art software.