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In this paper, the impedance matching and radiation performance of the SIW H-plane horn antenna is improved by the modification of the probe and the adoption of a capacitive post in the feeding structure. The simulation results show that using the capacitive post and the modified probe, the reflection coefficient can be reduced, and the gain of the design can be improved in H-plane in the operation...
Based on the peculiar refractive index feature of complementary split-ring resonator (CSRR), a low-RCS (LR) microstrip antenna is proposed. By loading CSRRs on the ground plane along two adjacent edges of the radiation patch, the scattering field is deflected and a spatial reduction of out-band radar cross section (RCS) is achieved. Due to the polarization selective characteristics of CSRR, each CSRR...
In urban mass transit railway system, the leaky rectangular waveguide is continuously mounted along the track, for both under- and on-ground environments, to realize a reliable wireless communication between trains and ground. The performance of the waveguide on ground is easily affected by the bad weather, especially for the heavy snowing weather. The available works only considered the effect of...
A novel high gain bidirectional circularly polarized array with the same rotation direction on both sides is proposed in this paper. The array consists of 4 bow tie antennas and operates at 900 MHz. The 4 bow tie antennas are arranged into two linearly polarized endfire sub-arrays which are placed orthogonally, the elements of the two sub-arrays are separated by a distance of one quarter of the free...
Among numerous theory models for describing the parametric array's near-field acoustic characteristics, the KZK equation is the most accurate theoretical model. However, the computation efficiency is low by using the frequency-domain method for the parametric array's sound field. The paper drew ideas from the time-domain method to separate the operator, and calculated the KZK equation's nonlinear...
In order to satisfy the requirement of high-power microwave system, a novel overmoded-waveguide directional coupler centred at 2.4 GHz, with low coupling of 40–50 dB, and with directivity greater than 20dB, is designed. A resonant cavity as the transition waveguide between main waveguide and sub-waveguide is introduced. This paper also proposes a correction of coupling coefficient calculation. Ultimately,...
Recognizing canonical vectors is seemingly trivial but actually a useful technique in practical computations. In this paper, some simple criteria for recognizing canonical vectors or scaled canonical vectors are proposed. The new criteria are easy to implement since they just depend on two invariants. Mechanism of the criteria are theoretically proved. Numerical experiment results demonstrate that...
In this paper, a class of distance functions are proposed to appropriately measure the distance between the vectors. First we build an elementary inequality, based on which we introduce the new distance functions combining some classic vector norms with the rearranging techniques. These distance functions could be helpful in eigenvalue computation or other scientific computations. Some basic and interesting...
The noises at the power lines limit the charge pump to provide large instantaneous current to PCM cells, which results in the number of bits can be written concurrently, i.e. the size of write unit, is restricted in PCM. When implementing PCM as the main memory, the inequality of cache line's size and write unit's size may result in many consecutive executed write units, which greatly decreases the...
To improve the accuracy of the vehicle-based SINS and reduce the time of calibration, it introduces a new multi-position calibration method in outfield conditions according to the using features of the Vehicle-based SINS based on extended observation. It raises a new filed calibration method with extended information of gyroscope and analyzes its observability, then conducts experiments. The test...
Global Navigation Satellite System (GNSS) provides consistently accurate position solutions when four or more GNSS satellites are observable. However, this condition is usually not satisfied under harsh conditions such as urban canyon, tunnels and other special application environment, and this case will lead to degradation of positioning precision or infeasibility of the positioning algorithm. This...
Because there are the following problems in the wireless sensor network: the collected data redundancy degree is higher, the node energy is limited, and the node storage is limited and so on, this paper puts forward an improved DP data compression algorithm, that is, the collected data is transmitted after they are firstly compressed. Adopt the method of automatically setting the compression threshold...
Concept lattice is an effective tool for knowledge discovery and has been applied to many fields successfully. The objects and attributes have clear relations in the classical formal context, but there are a lot of fuzzy information in real-life applications. Therefore, it is important to study the fuzzy formal context. As we know, the fuzzy set and the classical set can be transformed into each other...
Aimed at the study of multi-degree-of-freedom bionic eye drive problem, this paper puts forward a novel hybrid drive multi-degrees-of-freedom permanent magnet motor with liquid suspended bearing. The structure and working principle of the motor is introduced. The rotor's magnetic field of the air gap in this permanent magnet motor is analyzed using both the finite element method and analytical method...
The far field radiations by different parts of a dielectric rod antenna are analyzed by decomposing the near fields. A transition section is introduced to improve the radiation performance and impedance matching between the waveguide and the dielectric rod. The results show that using the transition, the backward radiation can be significantly reduced, and the gain can be increased. In addition, the...
This paper presents a new type of 3-DOF type combined drive motor, which can realize the rotation and deflection movement. The original type of 3-DOF type combined drive motor in the comparison between the basic structures is given with the working principle, etc. The air-gap magnetic field of the motor is calculated and the analysis is carried out under the spherical coordinates of the scalar magnetic...
The increasing learning materials on the Internet bring the learners a flood of educational resources, along with many difficulties in the learning process. It becomes much harder for the learners to find the required resources and get the right knowledge from these unsorted resources. To give the learners a better learning experience and improve the efficiency of the education based on the Internet,...
The increasing amount of services published on the Web makes it difficult to discover relevant services for users. Unlike the SOAP-based services that are described by structural WSDL documents, RESTful services, the most popular type of services, are mainly described using short texts. The keyword-based discovery technology for RESTful services adopted by existing service registries is insufficient...
To study firing signal propagation of hierarchical neuronal network, this paper investigates a neuronal network with FHN (FitzHugh-Nagumo) nodes. Average firing rate is applied to show the performance of the propagation. Signal raster plots in different layer demonstrate intuitively propagation process. Moreover, effects of the connection probability, the random connection number, the number of branches...
Telecommunication monitoring data requires the automation of data analysis workflows. A data mining tool provides data workflow management systems to process and perform analysis tasks. This paper presents an evaluation of two example data mining tools following the principles of design of experiment (DOE) to run forecasting and clustering workflows for telecom monitoring data. We conduct both quantitative...
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