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When pulse radar signal is applied in a range limited anechoic chamber for target probing, the transmitted and reflected signal are coupled at the receiver. Interrupted transmitting and receiving (ITR) method can be used to solve this problem. However, the ideal rectangle ITR control signal is difficult to be generated by radio frequency simulation (RFS) system and the period of ITR is unstable in...
Vacuum circuit breaker (VCB) is a mature technology which is commonly used in medium voltage power systems worldwide. However, it is still facing challenges to switch capacitive current, especially for back-to-back capacitor bank switching. The main reason is that the inrush current can cause serious damages to the contact surfaces and further deteriorate the high voltage withstand ability of the...
This article investigates the problem of fault detection for a class of uncertain systems by a new method. Based on the system's own uncertainty and external disturbances, a more effective fault detection method is designed by the method of homogeneous polynomial function. This detection method not only suppresses the effects of disturbances and uncertainties on the residual signal but also makes...
Corresponding to low targeting accuracy due to tissue deformation during the process of electrode insertion in sub-thalamic nucleus deep brain stimulation (DBS), biomechanical properties of brain tissue are essential to investigate. Elastic and viscoelastic biomechanical properties in post-puncture are investigated by indentation-relaxation experiment. In this paper the flat indenter with a diameter...
In this paper, the H∞ filtering problem for singular stochastic systems with Brownian motions is studies. The design of singular H∞ filter is focused such that the filtering error system is asymptotically mean square admissible and meet prescribed H∞ performance level. For design purpose, the existence condition of the proposed singular H∞ filter is formulated according to the linear matrix inequality...
Vulse radar signal is widely used in radar countermeasure and detection. When pulse radar signal is adopted in radio frequency simulation (RFS) for radar countermeasure, the target echo will return before the pulse signal is totally transmitted because the size of anechoic chamber is small. The reflected signal and transmitted signal will be coupling and the radar countermeasure cannot be implemented...
To extract the micro-motion parameters of the rotating targets, SFS (Stepped Frequency Signal) is usually adopted to obtain the HRRP (High Resolution Range Profile). To reduce the sub-frequency counts SFS needs to synthesize the wideband, RSFS (Random Stepped Frequency Signal) is raised. By randomly transmitting the sub-frequencies of SFS, the frequency counts are obviously reduced. Then HRRP reconstruction...
For a wideband radar system adopting stepped frequency signal (SFS), the micro-motion parameter is usually obtained by time-frequency analysis of the echo HRRPs (high resolution profiles). The data to be collected mainly includes each sub-frequency echo in the slow-time domain, which brings a great burden to the signal generation equipment and data storage on the radar system. Because of the sparseness...
The common researches for radar system modelling are mostly based on deductive methods, which forward simulate the radar working process according to the information of radar parameters and expert system. However, the radar prior information obtained is limited under battlefield background. So it is difficult to model the radar operating modes and schedule schemes accurately, especially for the multi-function...
Weight distribution of code is very important for error correction in the use of Turbo coding program in optical fiber communication. Input sequence need to pass convolutional encoder, Therefore, it is necessary that the weight of the output should be kept as large as possible. Although the interleaver can help to improve the output code weight, the higher the complexity of interleaving, the iterative...
In the paper, we propose a new method, namely Random Filtering Mapping (RFM), through which the peak-to-average power ratio (PAPR) of the Generalized frequency division multiplexing (GFDM) signal is reduced. Then, the improved signal is transmitted through the Radio Over Fiber (ROF) system of Single SideBand (SSB) modulation and optical fiber of 60Km. The simulation results show that the PAPR of the...
This paper presents a new type of Lyapunov function which is called composite homogeneous parameter dependent quadratic Lyapunov function. By using this function, a condition is derived in terms of an auxiliary feedback matrix for determining if a given convex hull is an estimation of attractive region for a system under a saturated linear feedback. Most of the cases, the shape of attractive region...
Crop injury from off-target herbicide application is of primary concern to farmers. Timely determination of crop injury is critical for farmers to take appropriate actions for remediation before it is too late. Traditionally, crop injury was determined by field sampling and measuring plant biological responses, making it difficult to provide timely information. We conducted studies to evaluate optical...
Disturbance and regrowth are vital processes in determining the roles of forest ecosystem in carbon and biogeochemical cycles. The vegetation change tracker (VCT) algorithm derives the spectral disturbance magnitude based on the time series observations. While these spectral disturbance magnitudes are indicative of physical changes in tree cover or biomass, their quantitative relationships have yet...
This paper is concerned with the H∞ filtering problem for a class of singular stochastic time-delay systems. The purpose is the design of a delay-independent filter such that the resulting error system is regular, impulse-free and mean-square stable. Sufficient conditions for solvability of this problem are formulated in terms of a set of linear matrix inequalities (LMIs), and stability theory of...
Considering a two-layer service supply chain consisting of a service provider and a service integrator, and given service demand is influenced by both price and advertising level, mathematical models of decentralized service supply chain, centralized service supply chain and modified decentralized service supply chain based on cost sharing contract are built. Comparing the optimal decisions of the...
Pulse sequence analysis is a crucial part in the research on multi-function radar (MFR) behaviours. It is the base for MFR behaviour recognition and prediction to extract radar words accurately from the intercepted radar pulse sequence. The common radar word extraction methods are only based on the time-of-arrival (TOA) of pulses, which perform not well when dealing with the complex signals with multiple...
Multiple-input multiple-output (MIMO) radars with wideband signals are useful to discriminate target in clutter. With wideband MIMO radar, the problem of extended target detection in compound-Gaussian clutter is considered in this paper. By obtaining target echoes from each antenna, the detector based on generalized likelihood ratio test (GLRT) is developed. It shows that the shape parameter of clutter,...
Metro emergency has always been the social concerned issues in which information diffusion is one of the most important concerns as sometimes it will decide the severity of the emergency. In the metro emergency, the passengers not only communicate with peers, but also be affected by the official information. Therefore, the opinion dynamic of passengers with the release of official information is mainly...
Cross-linked polyethylene (XLPE) insulation cable is the main type of cable in use now. Its main insulation is aging with the increasing of service years. Two methods are used to diagnose the condition of the cable insulation-polarization/depolarization current (PDC) and frequency domain spectroscopy (FDS). The PDC is a time domain method, while the FDS is frequency domain. In this paper, we put forward...
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