A standoff 3-D imaging radar for security body scan at 340 GHz has been described. This terahertz imager incorporates a multiple input output (MIMO) array as an electronic beam former in horizontal dimension and elliptic cylinder focusing reflector elevation. Frequency-modulated continuous-wave (FMCW) emission with 16-GHz bandwidth caused 10-mm-range resolution after calibration nonlinearities of the distorted signals. The MIMO contains 4 transmitters 16 receivers (4Tx-16Rx) to generate...

We demonstrated that attenuated total reflectance terahertz time-domain spectroscopy (ATR THz-TDS) is able to monitor oxidative stress response of living human cells, which proven in this work it an efficient non-invasive, label-free, real-time and situ monitoring cell death. Furthermore, the dielectric constant loss cultured breast epithelial along with their evolution under induced by high concentration H2O2, were quantitatively determined work. Our observation results finally confirmed...

Model-based fault diagnosis, using statistical hypothesis testing, residual generation (by analytical redundancy), and parameter estimation, has been an active area of research for the past four decades. However, these techniques are developed in isolation, generally, a single technique cannot address diagnostic problems complex systems. In this paper, we investigate hybrid approach, which combines model-based data-driven to obtain better performance than use alone, demonstrate it on...

Imperfect test outcomes, due to factors such as unreliable sensors, electromagnetic interference, and environmental conditions, manifest themselves missed detections false alarms. This paper develops near-optimal algorithms for dynamic multiple fault diagnosis (DMFD) problems in the presence of imperfect outcomes. The DMFD problem is determine most likely evolution component states, one that best explains observed Here, we discuss four formulations problem. These include deterministic...

A system wide prognostic process is required to fulfill the needs of expensive and high availability industrial systems. The recent advances in model-based design technology have facilitated integration diagnosis prognosis systems, leading condition-based maintenance. In this paper an integrated based on data collected from simulations under nominal degraded conditions described. Interacting Multiple Model (IMM) used track hidden damage. Remaining life prediction performed by mixing...

We proposed a three-dimensional model to simulate terahertz generation from LiNbO3 crystal under intense laser excition (up ~50 mJ/cm2). The impact of three-photon absorption, which leads free carrier and saturation (when pump fluence above ~10 mJ/cm2) on was investigated. And further with this model, we stated the optimized experimental conditions (incident postion, beam diameter, pulse duration, etc) for maximum efficiency in commonly-used tilted-pulse-front scheme. Red shift spectrum,...

The diagnosis of the initiation and growth detonation in high explosives (HEs) is important physics. We designed experimentally demonstrated a non-invasive high-precision free-space terahertz-wave Doppler interferometric velocimetry (TDV) design for diagnosing transient processes HEs. system can non-intrusively record propagation shock/detonation wavefront inside HEs continuously measure key parameters (position/displacement, velocity, etc.). A detailed quasi-optical TDV discussed. terahertz...

The competitive businesses' desire to provide "smart services" and the pace at which modern automobiles are increasing in complexity, motivating development of automated intelligent vehicle health management systems. Current On-Board Diagnosis (OBD II) systems use simple rules maps perform diagnosis, significant human intervention is needed troubleshoot a problem. More research on developing innovative, easy-to-use diagnostic approaches for incorporation into OBD In addition, remote...

Pulsed terahertz spectroscopy is suitable for spectroscopic diagnostics of ultrafast events. However, the study irreversible or single shot events requires ability to record transient properties at multiple time delays, i.e., resolved level, which not available currently. Here by angular multiplexing use femtosecond laser pulses, we developed and demonstrated a resolved, domain technique, where burst mode THz pulses were generated then detected in measurement manner. The contain 2 sub-THz...

One popular approach for fault diagnosis is based on reasoning about the behavior of a system in failure space. Diagnosis performed by considering set observations (or symptoms) and explaining it terms root causes. There are many modeling methods to capture system's faulty behavior, such as behavioral Petri nets, multi-signal flow graphs, Bayesian networks. In this paper, we will investigate equivalence these three formalism way application car engine problem, discuss advantages...

Smart homes have been shown to be one of the most important applications Internet Things (IoT); however, security issues are still main drawback improved, especially facing problem terminal power constraint and distributed network architecture. In this paper, we propose a novel secure group data exchange protocol in smart with physical layer approaches which retains benefit key sharing needless lightweight computation. As core technique, nested lattice coding is conduct each sensor node form...

This study proposes a method for analyzing magnetic devices such as inductors and wireless power transfer (WPT) systems based on Cauer equivalent circuit. The circuit parameters are determined computed or measured input impedance. It is possible to obtain dynamic response eddy-current loss in the time domain arbitrary drive voltage waveforms from synthesized Magnetic saturation core of an inductor could be accurately represented using Moreover, transient WPT device shown modeled by circuit,...

Networked embedded systems, such as modern automobiles, consist of a large number physically distributed nodes (subsystems). Each node communicates with other via network. With the rapid growth in control units, global diagnosis method, which collects diagnostic information from all subsystem controllers, is not practical because high communication requirements and time delays induced by centralized diagnosis. This paper presents algorithm based on digraph model local fault-test dependency...

The problem of current waveform distortion because dead-time inserted in power electronic applications is analyzed and researched this paper, the equivalent voltage source model set up to analyze low frequency harmonic effect. control strategy injection proposed compensate due Firstly, obtains application output amplitude phase mainly by Fourier transform, then calculates compensation instructive according connected inductor dc voltage. Based on H-bridges cascaded static synchronous...

Model-based fault diagnosis, using statistical techniques, residual generation (by analytical redundancy), and parameter estimation, has been an active area of research for the past four decades. However, these techniques are developed in isolation generally a single technique can not address diagnostic problems complex systems. In this paper, we investigate hybrid approach, which combines different to obtain better performance than use alone, demonstrate it on anti-lock brake system. first...

The set-covering problem has been widely used to model many real world applications. In this paper, we formulate a time-dependent set covering problem, viz., dynamic (DSC), which involves series of coupled problems over time. We motivate the DSC from viewpoint fault diagnosis wherein multiple faults may evolve time and fault-test dependencies are deterministic. objective is evaluate most likely evolution minimal columns (component states) rows (failed tests) constraint matrix at minimum cost...

With the increasing shortage of energy resources, wind power has gradually developed and become an emerging environment-friendly source. Now, a large number electric generated by turbines is transmitted DC transmission lines, which can better adapt to characteristics long distance capacity. However, at same time, addition DFIG weakens stability system, failure system may have greater impact, causing commutation or even blocking. In this paper, model added traditional HVDC several typical...

In order to realize rapid THz detecting and imaging, a line beam scanning-based ultra-fast imaging platform is designed combining simple optical components lightweight mechanical system. The has the resolution of 12 mm, scanning angle range ±10.5°, speed 0.17 s/frame, 2 m × 0.8 m; moreover, it can human body distinguish metallic objects. Considering its high-quality performance in detecting, believed proposed be used future various safe screening applications.