At present, in the shear speckle interference technique for vehicle tire defect detection, the key is to accurately reflect the real phase of object motion when there are interference factors. Thus, this study proposes a discrete cosine transformation (DCT) unwrapping algorithm based on phase gradient smoothing correction, and analyzes the feasibility of the proposed method through several experiments and numerical simulation calculations. The proposed method replaces abnormal phase gradients caused by noise with calculated weighted moving average phase gradients, bringing phases closer to real values. Finally, the DCT unwrapping method is used to obtain the final solution of phase. A phase recovered using the proposed method is closer to the real value than that recovered using the traditional DCT unwrapping algorithm. Compared to the traditional DCT unwrapping algorithm, the root mean square error accuracy of the proposed method is improved by 10 to 100 times. And after many experiments to record the average running speed, it can be obtained that the time-consumption of the two algorithms only differs by similar to 0.1 to 0.3 s. (c) 2023 Society of Photo-Optical Instrumentation Engineers (SPIE)

LED的驱动电源性能会直接影响LED的使用性能和寿命,优化驱动电源性能是提高LED普及率的关键因素之一.本文基于LT3964芯片设计了LED驱动电源电路,利用LTspice软件对电路进行仿真测试,仿真结果显示该电路为恒流驱动方式,31 ～36 V电压输入下工作效率不低于94.73％.利用Altium Designer绘制PCB板并制作驱动电路实物,利用脉冲宽度调制(PWM)实现了100 W RGBW灯珠阵列的调光调色.实测中,在34V电压输入下电路实际工作效率为95.37％,与仿真结果相近.

对某粮仓采集到的数据进行仿真试验,将单棵C4.5决策树、随机森林、经过属性约简后的随机森林进行比较.结果表明经属性约简后的随机森林提高了计算精度且减少了时间消耗.

A method and an apparatus for receiving and transmitting configuration information, and a communication system. The method comprises: a terminal device receives first configuration information that is transmitted by a network device and is used for radio link monitoring, the first configuration information at least comprising threshold configuration of the radio link monitoring and/or resource configuration for the radio link monitoring. Therefore, not only the introduction of beams and different services having different requirements for radio link quality can be supported, but also the flexibility and accuracy in configuration of radio link monitoring can be improved.

This paper points out the main problems of on-line insulation monitoring system at present.A new on-line insulation monitoring system for HV apparatuses is presented in this paper， which consists of the low layer intellectual monitoring units in the substation field and the upper layer personal computers for the use of control and information management.A LonWorks field-bus technique is adopted in this monitoring system. Some fundamental equipment of this system is also specially described，including sensor，intelligent monitoring unit and fieldbus.

给出了悬挂式无间隙氧化锌避雷器(MOA)相对座式的优点,计算了悬挂在变电站门型构架上MOA的电压分布情况,设计了均压环的最佳尺寸,并反映了悬挂式MOA离地高度对其电压分布的影响.

This paper points out the main problems of an on-line insulation monitoring system at present. A new on-line insulation monitoring system for HV apparatus is presented in this paper, which consists of the lower intelligent monitoring units in substation field and the upper personal computers for the aim of control and information management. A kind of technology using LonWorks fieldbus is adopted in this monitoring system. Some fundamental equipment of this system is also specially described, including sensor, intelligent monitoring unit and fieldbus

The application of the BP neural network to the partial discharge patterns recognition of generator stator windings is discussed.Five types of simulation models for the insulation PD in the large generator stator windings are presented.The PD simulation models include the surface discharge at end windings,the discharge between two slots and the interior discharge in three different positions of the insulation.The recognition ability of the ANN is studied.A higher recognition rate for the partial discharge types of the large generator stator insulation is gained.

The technology character of 4 fieldbus control systems from application angle is analyzed in this paper. From these analysis we get the reason to choice the LONWorks network and design the net module of on-line system based on LONWorks in substation.

Mixing powdered conducting material in silicone rubber to make the semiconducting composite material and molding for tube parts, and applying it to improve the electric field distribution in end of bushing or cable, the effects is better than using traditionally semiconducting paint or band. The new material has advantages of simple in technology process and long life. It can adjust the field as well by changing the specific resistivity (ρ) as also by means of adjusting the relative permittivity (εr) which may be changed in large scope. Both ρ and εr have good non-linear characteristic with electric field strength. This paper presents the test results of this material and its application in high voltage bushing.

The method of rime formation in laboratory and artificial rime discharge tests of long insulator string were described. The test results confirm that there is a great difference of discharge phenomenon and electric insulation strength between the rime covered insulator and the glass covered one.

This paper describes the generation and development process of the carbon tracking fault in the fiber reinforced plastic rod and on the interface between the rod and housing in composite insulators in service. The possibility of the fault has been confirmed by the model tests in the laboratory and the analyses of early operated composite insulators. The fault can be detected on-line by measuring the electric field distribution along the composite insulators. The calculation result and the characteristics of the axial electric field distribution of the faulted insulator are described. Testing results in laboratory are given

The authors describe mixing powdered conducting material in silicone rubber to make a semiconducting composite material and molding it for tube parts. The material may be applied to improve the electric field distribution in the ends of bushings or cables, with better effect than using traditional semiconducting paint. The new material has the advantages of a simple technology process and long life. It is possible to adjust the field as well by changing the specific resistivity (/spl rho/) and also by adjusting the relative permittivity (/spl epsiv//sub r/). Both /spl rho/ and /spl epsiv//sub r/ have good non-linear characteristics with electric field strength. This paper presents the test results of this material and its application in high voltage bushings.

The dielectric strength of high voltage insulator string drops greatly because of ice coating. The outages on HV transmission lines due to flashover of ice coated insulators are frequently reported in many countries. This paper gives information of investigation in icing on insulators in icing regions of China, and results of artificial ice coating and discharge tests on HV line insulator strings. On the basis of these, some views on the types and forming process of icing on insulators, flashover process and discharge voltage performance of ice coated insulator string are provided.

本文以移动通信网络的发展为出发点，在介绍CDMA网络基本原理的基础上，着重分析了CDMA网络中的传播模型及其仿真。 本文首先介绍了无线传播环境和传播方式，鉴于CDMA网络规划要求有较为精确可靠的信道模型，所以还介绍了基本传播模型及其使用范围和具体使用。 由于适用频段的不同，所以本文将传播模型在具体环境下应用时进行修正，首先通过对ITU文档的学习得到所需的修正公式和参数，接着使用MATLAB对三种模型进行图形仿真。 最后将理论仿真与实测数据进行对比，得出结论。