Data Mining Algorithm for Moving Object Trajectory

Aiming at the poor effect and long recognition time of data mining algorithm for moving target trajectory recognition, a data mining algorithm based on improved Hausdorff distance is proposed. The position and angle of abnormal trajectory data are detected by calculating the distance between trajectory classification and sub trajectory line segments, and the trajectory unit is established by using the improved Hausdorff distance algorithm to optimize the similarity matching structure. Experimental results show that the algorithm has low error pruning rate in identifying moving target trajectory, improves the detection efficiency of moving target trajectory recognition data, and ensures the quality of moving target trajectory recognition data mining

The Design of Terahertz Frequency Quadruplers Based on Discrete Schottky Diodes

On the basis of the W-band power source, a single-stage frequency quadrupler method was used to implement two 335 GHz frequency quadruplers. The two frequency quadruplers adopted a traditional binomial matching structure and an improved gradient line matching structure, respectively. An idle loop was added to the overall circuit in the design of the DC filter and low-pass filter. The improved gradient line matching structure reduced the circuit length while increasing the bandwidth, effectively reducing the power loss on the transmission line. A micro-strip circuit was fabricated with a 50 μm thick quartz circuit and was mounted onto a split waveguide block. The results showed that the output power of the quadrupler with the improved matching structure was better than that of the quadrupler with the conventional matching structure. The peak output power of the improved frequency quadrupler was 4.75 mW at 333 GHz when driven with 200 mW. In contrast, this improved structure broadened the bandwidth by 8 GHz and reduced the length of the substrate by 0.607 mm, effectively reducing the length of the traditionally designed circuit by 11.5%.

Study on Double-sided Impedance Matching of Spherical Focusing Transducer in Ultrasonic Abrasive Flow Polishing System

The impedance matching of ultrasonic focusing spherical transducer is one of the primary factors affecting its work efficiency in ultrasonic focusing flow polishing system. To realize the efficient utilization of the vibration energy of the transducer, there are different requirements for the front and rear matching structure of the transducer. That is, the front matching structure should have high transmittance, and the rear matching structure should have high reflectivity. Based on the acoustic impedance matching theory and Kirchhoff's theory, the Influence of the front & back impedance matching structure of spherical focusing ultrasonic transducer to the focus sound pressure is studied theoretically and experimentally. The new matching structure for spherical focusing transducer is proposed based on above research. The experimental result shows that the focus sonic pressure with the new matching structure is increased by 72.03% compared with the traditional structure.

UHF RFID Conductive Fabric Tag Design Optimization

This paper presents the design of a 920 MHz Ultra High Frequency (UHF) band radio frequency identification (RFID) conductive fabric tag antenna. The DC (Direct Current) resistance and impedance of the conductive fabric are measured by a DC multimeter and by a network analyzer at a UHF frequency band. The conductivities of the fabrics are calculated with their measured DC resistance and impedance values, respectively. The conductivities of the fabric are inserted into the CST simulation program to simulate the fabric tag antenna designs, and the results of the tag designs with two conductivities are compared. Two fabric UHF RFID tag antennas with a T-Matching structure, one with the name-tag size of 80 × 40 mm, and another with 40 × 23 are simulated and measured the characteristics of tag antennas. The simulated and measured results are compared by reflection coefficient S11, radar cross-section and reading range. The reading range of the 80 × 40 mm fabric tag antenna is about 4 m and 0.5 m for the 40 × 23 size tag. These fabric tags can be easily applied to an entrance control system as they can be attached to other fabrics and clothes.

Inferences about Structure

This chapter locates a few rules that govern our inferences about structure in physics, three in particular: inferring structure from the laws, minimizing structure, and matching structure. The chapter illustrates these rules by means of familiar inferences that rely on them. These inferences concern a variety of physical theories, from Aristotle’s physics and Newton’s laws to time reversal invariant laws and special relativity. The discussion contrasts these epistemic rules with other guiding principles in the literature. Along the way, the general idea of the structure presupposed by the laws, a theory’s dynamical structure, is elucidated. The chapter ends with a discussion of the extent to which coordinate systems and the form of an equation can tell us about the nature of physical reality.