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Stochastic power injections may over load transmission lines. Probabilistic load flow (PLF) is a good methodology to assess these possible risks in the presence of uncertainty and stochasticity. With the help of Gaussian Mixture Model (GMM), this paper proves two important properties of GMM, and proposes a completely analytical method to compute the probabilistic density distribution (PDF) of active...
In conventional wind farm outgoing line protections, the fault characteristics of wind farms have been rarely considered and thus the protections may mal-operate or refusal-operation due to the integration of large-scale wind power. This paper analyzes fault characteristics of the outgoing transmission line from a DFIG-based wind farm with LVRT capability and indicates that the main frequency component...
As a new kind of social media, query log gains mass size of users and data. It's easy for people to post on query log. Also, the posts spread fast and can be easily seen by many other users. For the reasons above, users post various and large number contents on query log. Among these posts, we find numerous posts that express authors purchase wish for a certain product, in other words, consumption...
With the development of science and technology, the network education are becoming more and more popular, education under the current phase of hot issue is the network autonomous learning mode. In this paper, the concept of network autonomous learning mode, principle, design and development bottleneck of the corresponding elaboration, provide feasibility basis for autonomous learning mode.
Using a solution of the radiation transfer equation in the small angle approximation, we examine the effect of multiple scattering on the measurement of the light beam attenuation in an aquatic environment abundant in bubbles created by movement of ship or sea animals. According to the measurement condition, the correction coefficient denoting the extent of multiple scattering is introduced, which...
We have calculated and simulated B field along the radial of coil using MATLAB and MAXWELL. Then B field of the transmitting coil and the bucking coil of different radius are generated. Based on the results above, two methods of the magnetic offset are proposed, the B field offset method and magnetic flux offset method. Firstly, we talk about the magnetic field left along the radius of the coil. Secondly...
The simulation model and equivalent circuit of coaxial line for dielectric measurements are described. The calculation of coaxial line reflection method, the expression of dielectric constant part and the imaginary part of the relative complex permittivity are solved. By using the program HFSS, we analyzed the reflection coefficient of sample and compared the simulation with the actual value of the...
The all-time and late-time response of TEM over a homogeneous half space and layered half space are described. We analyzed the theoretical results and gave the differences between all-time resistivity and late-time resistivity. By using the program EMMA, the effects of three different models on TEM measurements are further discussed. Finally the advantages and disadvantages of three different models...
Overhauser magnetometer is a device for magetostatic field measurement, RF excitation is necessary for nitrogen oxygen free radical solution. In this paper, design methods coupled with simulations of a RF circuits used in Overhauser magnetometer are presented. Functionally, a RF circuit consists of three parts, namely RF signal source, RF power amplifier and the load. Generation of a 70MHz RF signal...
The design of a single component air cored time-domain electromagnetic (TEM) sensor with 34 kHz resonant frequency and 2000 m2 effective receiver areas for airborne exploration is described. A detailed fabrication process including coil making and coil shielding is presented. A center-tapped differential coil with a double layer shield is used to suppress environmental electric noise. Optimal linear...
Proton precession magnetometer is a high precision equipment which is used a variety of the complex applications measured magnetic field. The proton precession magnetometer consists of probe coil, containing water as the proton precession material, the polarization and receiving circuit which is controlled by the microprocessor. This paper mainly describes the analysis of the polarization circuit,...
This paper introduced chopping principle and presented a design of chopper stabilized pre-amplifier for magnetic sensor. Compared with auto-zeroing technique, chopping technique does not fold noise to DC and the noise performance is better. This chopper stabilized pre-amplifier used the integrated instrumentation amplifier AD620 as the main amplifier. It achieved low voltage noise about 10nV/¡ÌHz,...
Flat bottom of the first series cab flip part of the welding fixture on the application of the control of Siemens S7–200PLC, to achieve Upset of the cylinder clamp action and motor rotation direction, speed, control and protection of software and hardware equipment, the system has good accuracy and reliability. This article discusses the flat bottom of the first series of cab flip part of the control...
With the great development of automobile industry and road system, the pollution of automobile exhaust becomes more and more serious, also mercury pollution. Burning mercury-rich fuel oil was thought the essence of pollution source. It's found that elemental mercury (Hg0), divalent reactive gaseous mercury (RGM), and particulate mercury (Hg (p)) from gasoline. The content of mercury is LPG>;gasoline>;...
Search coil magnetometer is widely used in Magnetotellurics (MT) to measure weak magnetic field. In our design, magnetic feedback is used to flatten the frequency response near the resonance. We proposed a new model to investigate the system frequency response. Feedback coil was used in this new model to provide known external magnetic field. Theoretical and simulated transfer function is proposed...
Heavy metals are important factors influencing plants' growth and physiology, sustainable agriculture and ecological environment. Heavy metal research is thus an important topic in environmental sciences for soil eco-toxicological diagnosis and ecological risk assessment. In this chapter, Transmission Electron Microscope (TEM) was used to investigate the damage of wheat seedlings caused by lead and...
For expertise on detecting very weak signal, search coil magnetometer is widely used in Magnetotellurics (MT). Unfortunately, noise is a primary factor affecting the sensitivity. In this work, noise model of the magnetometer is presented based on measured parameters, where transfer function affected by core eddy current loss is considered. Calculation is imposed on the model, and noise frequency response...
The effect of equipment manufacture industry to zone and country economy is very important. However, poor new product development (NPD) capacity restricts its development. Complex characters of equipment manufacture industry include multi-discipline technology integration of product, cross-organization in management, tailor-made, special business processes. These complex characters cause management...
As a special economic organization, the financial risks of Enterprise Group have obvious conductivity and amplification. This paper firstly clarify mechanism of enterprise risk conduction, then analyze the financial risk conduction of China's Enterprise Group from the capital, information and personnel, and finally points out the measures of Enterprise Group financial risk management, that is to build...
For online accurate holes detection of the auto rack girders, this paper proposes a method of combination non-linear distortion correction and double-linear transformation, to calibrate internal parameters and correct geometric parameters. Firstly, in different angles, through 20 grabbing calibration templates images, carrying on non-linear distortion correction for grabbing images with Zhang Zhengyou...
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