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This paper presents the design and fabrication of an ultra-narrow band-pass HTS filter with FBW of 0.02% in C band. Novel approaches to solve the weak coupling and unwanted parasitic coupling problems in narrowband filter design were introduced. The filter shows band rejection better than 23 dB at frequencies 500 kHz away from the center frequency. The measured minimum insertion loss is 3.8 dB, corresponding...
Air-Breathing Hypersonic Vehicles (AHVs) are kind of winged or wingless aerospace vehicles, which could fulfill cruising flight in the atmosphere 20∼100 kilometers above the ground and travel five times faster than sound. The AHVs' dynamic model manifests such characteristics as nonlinearity, quick time-variance, uncertainty, strong couplings and non-minimum phase, et al, which make the controller...
IR images are widely used many image process applications. Different with visible image, IR images are typically low-contrast, contains blurred edges and a lot of noise, which would bring many difficulties to further analyses. To solve those difficulties, we proposed a new framework for IR image enhancement. The framework not only improves both the global and local contrast of the IR image but also...
Aiming at the problem of small infrared target detection, improved structural collaborative sparseness (ISCS) detection algorithm which combined sparseness and edge-preserve smoothing was put forward. Firstly, in order to improve the background, component of bigger gradient was extracted based on zero norm of gradient; Secondly, background sparseness was modeled by row norm; At last, small dim infrared...
Focused ultrasound (FUS) exposure with the presence of microbubbles has shown its promise in temporally and targeted open the blood-brain barrier (BBB), and brings potential in delivering therapeutic agents into the brain for CNS disease treatment. Feasibility in using neuronavigation system to guide the FUS-BBB procedure in large animals has been demonstrated successfully, and the guidance precision...
This paper proposes a 3D path tracking method for a class of torpedo-type AUVs (autonomous underwater vehicles) with general form of dynamics. For this kind of AUV, there are only three control inputs are available for its 6DOF 3D motion, and therefore it's a typical underactuated system. First, we introduce certain two spherical coordinate transformations so as to transform the vehicle model into...
For underwater control and localization of an unmanned underwater vehicle (UUV), we have used vision information of a suggested pattern image. The pattern is based on suggested criteria. From the pattern specialized on direction information we extracted directional lines and had done Double Hough Transform (DHT) method on them. Once Hough Transform (HT) is usually done for extracting lines from an...
The localization of unmanned underwater vehicle (UUV) is important for the UUV to inspect or manipulator objects. We assume that there is an UUV with a camera sensor and the UUV uses the underwater floor pattern for localization. Because the pattern is known beforehand, the pattern matching between the pattern image and the camera image lets the UUV know its position. The pattern matching algorithm...
A novel longitudinal-bending (L-B) hybrid ultrasonic motor using vibration coupling is proposed. Different with the previous L-B ultrasonic motors, only longitudinal PZT plates are used; and the longitudinal-bending hybrid vibrations of the motor are excited synchronously. Fixed boundary condition is applied on one side surface of the flange, which locates at the wave node of a longitudinal transducer...
This paper considers the initial alignment problem for underwater robot's strapdown inertial navigation system. In general, initial alignment can be roughly divided into three types; coarse alignment, gyro compassing, and aided alignment. For underwater robot, gyro compassing is not suitable for its initialization, since it is difficult to accurately rotate the robot platform in the water. In this...
As a new biometric identification technology, finger-vein recognition technology is gathering more and more attention because it has some advantages such as: Non-contact, Live body identification, High security. In the finger-vein recognition system, there are many different characteristics matching algorithms after that the finger-vein vessel network has been segmented in the matching stage. In this...
The stability of the cascaded power converters system is an important design consideration, since the interaction among the individual converters in the cascaded system can lead to the degradation of the system stability and dynamical performances, even make the system unstable. In this paper, the stability analysis methods for the cascaded power conversion system are reviewed at the beginning. Following,...
Focused ultrasound (FUS) has been discovered its utility in targeted increase blood-to-brain permeability in the brain and capable of enhancing drug delivery for CNS disease treatment. To achieve successful treatment, the overall FUS exposure process relies on employing a sophisticated treatment planning procedure to precisely target the ultrasound energy to the aim and compensate the skull-induced...
Maximum likelihood estimation (MLE) has been used in direct position estimation in the global navigation satellite system (GNSS) receivers. It can be used for anti-spoofing because it utilizes the consistency between different satellites. In the method, how to find the optimal MLE solution is a challenge, because the likelihood function of the MLE is multimodal. In the paper, particle swarm optimization...
Millimeter-wave communication is deemed to be one of the promising solutions to meet the growing traffic explosion for the next generation wireless communication system. The compact design of millimeter-wave antenna makes it possible to form large number of narrow beams to cover a certain area. However, the number of beams that can be scheduled simultaneously is not as many as possible due to the...
In this paper, the hybrid implicit-explicit finite-difference time-domain (HIE-FDTD) method is proposed for efficient simulation of graphene-based absorbers at THz; there the graphene model is incorporated into the numerical methods with auxiliary differential equation (ADE) technique for solving the Maxwell's equations. Numerical simulations show that the absorption peaks of the absorbers can be...
Mn doped ferroelectric (Ba, Sr)TiO3 (Ba0.05Sr0.95Ti0.95Mn0.05O3, BSTM) thin films were prepared on the MgO single crystal substrate by using pulsed laser deposition technique. The dielectric properties of the varactor composed by this thin film was investigated by using a superconductor resonator at the liquid nitrogen temperature. Measurement results indicated that the thin film showed high quality-factor...
An improved one-step leapfrog alternating direction implicit finite difference time domain (leapfrog ADI-FDTD) method is proposed for simulating graphene-based filters operating at THz band, with the Drude model of monolayer graphene and associated auxiliary differential equation (ADE) technique implemented. Numerical results show that the S-parameters of the filter can be adjusted effectively by...
This paper presented a YBCO/Ba0.05Sr0.95TiO3 (BST-0.05) heterostructure thin film interdigital varactor grown on a MgO substrate by pulsed laser deposition (PLD). The microwave properties of the BST film were characterized at cryogenic temperature. The dielectric constant changed 78 % from 1160 to 252 and loss tangent was in the range of 0.01–0.02. An L-band four pole tunable high temperature superconductor...
This paper proposes an innovation thought based on the individualized teaching and classified cultivation to solve the problems which exist in the basic computer courses teaching. Through the conversion of teaching concept, the integration of teaching content, the optimization of teaching methods, the reform of evaluation form, teachers could leave more time for students to think, learn and practice...
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