Higher vocational college-students’ verbal expression is quite poor.The main reason is their fragile language basis,teachers and students’ indifference and irrationality of curriculum offering.In order to change this situation,two aspects should be taken.One is college-teacher-student changing concept to understand its urgency.The other is to create conditions and take effective approaches to strengthen verbal expression training.
This article focuses on stepper motor control, and introduces the hardware structure of position control system design based on LabVIEW. Steps and methods of software design are expounded emphatically, and then test data are given. Tests show that the system has small steady-state error, short adjusting time, friendly interface, excellent portability, good control effect and other characteristics.
Radar signal sorting is a process of detecting and identifying the target radar emitter. This paper presents an extract pulse clustering algorithm based on support vector clustering, which tremendously reduces the CPU run time without loss of accuracy. The basic idea of the algorithm is to extract part of the radar signal pulses randomly and analyze the extracted pulses. Simulation results show the effectiveness of the proposed method.
In recent years-the fractal image compression becomes an attractive method for its ability of high compression ratio. In this article-the history and present status of the development of fractal image compression are studied;the characteristic and deficiency of fractal image compression are analyzed;some better methods are given out.
In this paper, the virtual instruments software LabVIEW and its simulation interface toolkit are introduced at first. With visualization technology, LabVIEW can simulate an industry plant with better effect. The LabVIEW simulation interface toolkit (SIT) provides a seamless integration between MATLAB/Simulink software and LabVIEW. A method is presented to implement real-time digital simulation with no hardware-in-the-loop and a pure software real-time digital simulation example of a lever process control system using LabVIEW simulation interface toolkit is given. It can get better effect in teaching or training of industry process control system with minimal cost.
With the development of remote sensing technology,using the remote sensing images for monitoring land and resources has become a hotspot.Image difference and post-classification analysis are two normal change detection methods.However,there are many disadvantages in these methods.A novel remote sensing image change detection algorithm based on Fuzzy C-Means is presented.The improved FCM algorithm is employed to classify remote sensing image.Then a multi-band integration change mask method is employed to execute change detection.Experiments show that the method is effective,and improves the veracity of change detection.The change detection results can offer an important reference for land and resources survey.
This paper designs a pinhole defects detection scheme of aluminum foil based on machine vision. After linear contrast stretch and image binary segmentation on captured production lines image, it analyzes the light/dark pixels collected domain, combined with image calibration technique and script, it realizes effectively inspect of aluminum foil product that doesn't meet the national standard. The experimental results verify that the system can take effective real-time online pinhole detection of aluminum foil.
Sensor and detecting technology is one of the important backbone technical courses in automation and electrical engineering automation specialty.Under system analysis of the important position in the training of the specialty and the shortcomings in present teaching,the teaching method is presented in this paper,which combines theory and practice and integrates the teacher's classroom teaching with the students' practical abilities.The teaching aims at strengthening the student interest and improving practical abilities by abstracting keystone from the teaching material.Undergraduates teaching quality is improved by the improvement of teaching method and the enhancement of the teacher and students relationships because of the students' enthusiasm has been brought into play.
The application of real-time precise point positioning (PPP) requires real-time precise orbit and clock products that should be predicted within a short time to compensate for the communication delay or data gap. Unlike orbit correction, clock correction is difficult to model and predict. The widely used linear model hardly fits long periodic trends with a small data set and exhibits significant accuracy degradation in real-time prediction when a large data set is used. This study proposes a new prediction model for maintaining short-term satellite clocks to meet the high-precision requirements of real-time clocks and provide clock extrapolation without interrupting the real-time data stream. Fast Fourier transform (FFT) is used to analyze the linear prediction residuals of real-time clocks. The periodic terms obtained through FFT are adopted in the sliding window prediction to achieve a significant improvement in short-term prediction accuracy. This study also analyzes and compares the accuracy of short-term forecasts (less than 3 h) by using different length observations. Experimental results obtained from International GNSS Service (IGS) final products and our own real-time clocks show that the 3-h prediction accuracy is better than 0.85 ns. The new model can replace IGS ultra-rapid products in the application of real-time PPP. It is also found that there is a positive correlation between the prediction accuracy and the short-term stability of on-board clocks. Compared with the accuracy of the traditional linear model, the accuracy of the static PPP using the new model of the 2-h prediction clock in N, E, and U directions is improved by about 50%. Furthermore, the static PPP accuracy of 2-h clock products is better than 0.1 m. When an interruption occurs in the real-time model, the accuracy of the kinematic PPP solution using 1-h clock prediction product is better than 0.2 m, without significant accuracy degradation. This model is of practical significance because it solves the problems of interruption and delay in data broadcast in real-time clock estimation and can meet the requirements of real-time PPP.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)