In order to completely push on quality education,this requires college"courses" should meet and give service to reformation tendency.And its status must be strengthened and can’t be weakened."two cours...In order to completely push on quality education,this requires college"courses" should meet and give service to reformation tendency.And its status must be strengthened and can’t be weakened."two courses" is a basis link of college quality education.Under these new circumstances,we must build new teaching system and strengthen teaching reform.展开更多
A new intelligent control method for welding positioner is proposed. Applying an improved fuzzy controller and a variable PID controller, a two-mode intelligent coordinating controller ( TMICC ) is designed on basis o...A new intelligent control method for welding positioner is proposed. Applying an improved fuzzy controller and a variable PID controller, a two-mode intelligent coordinating controller ( TMICC ) is designed on basis of fuzzy logic and rules. The simulation and experimental results show that this control system can obtain better dynamic and static characteristics.展开更多
In this paper, the fabrication and testing results of a two-dimensional pin-cushion position sensitive detector (PSD) are presented. The obtained pin-cushion PSD with an 8×8 mm2 effective area presents a maximum ...In this paper, the fabrication and testing results of a two-dimensional pin-cushion position sensitive detector (PSD) are presented. The obtained pin-cushion PSD with an 8×8 mm2 effective area presents a maximum spectral response of 0.5 mA/mW at 850-nm wavelength, a 12-nA dark current at 5-V reverse voltage, a reverse breakdown voltage of 50 V, a nonlinearity of 2.175%, and a spatial resolution of 10 μm. The spatial resolution is relatively low and the slight pin-cushion concave distortion is generated due to the incompletely satisfied relationship between sheet resistivity of the anode and the resistance per unit length.展开更多
A 2D neutron detector based on 3He convertor and MWPC with an active area of 200 mmx200 mm has been successfully designed and fabricated. The detector has been tested with Am/Be neutron source and with collimated neut...A 2D neutron detector based on 3He convertor and MWPC with an active area of 200 mmx200 mm has been successfully designed and fabricated. The detector has been tested with Am/Be neutron source and with collimated neutron beam with the wavelength of λ=1.37A. The best spatial resolution of 1.18 mm （FWHM） and good linearity were obtained. This is in good agreement with theoretical calculations.展开更多
Track monitoring is a fast method of determining incorrect return-to-track and track-to-track assignments. An analytical method to evaluate the effectiveness of track monitoring was presented by reference [1]. In orde...Track monitoring is a fast method of determining incorrect return-to-track and track-to-track assignments. An analytical method to evaluate the effectiveness of track monitoring was presented by reference [1]. In order to reduce the probability of initiating or accepting the ghost track, two sequential track monitoring algorithms, which use the inclination angles to form test statistics, are proposed in this paper. Two decision rules are given and the corresponding thresholds are derived. The paper also gives the estimation methods of the noncentral parameter of noncentral chi-square distribution when the true value of it is unknown, the algorithms can adaptively estimate the decision thresholds and can make sequential track monitoring decision on line. Simulation is also made and the results show that the proposed algorithms are effective and feasible.展开更多
To improve the observability of strapdown inertial navigation system and the effectiveness of Kalman filter in the navigation system, the method of estimating the observability is analyzed based on eigenvalues and eig...To improve the observability of strapdown inertial navigation system and the effectiveness of Kalman filter in the navigation system, the method of estimating the observability is analyzed based on eigenvalues and eigenvectors which are proved to be availabe, on this basis two-position alignment technigue is applied. The simulation shows that two-position alignment really makes the system＇s observability change from being incomplete to being complete, and the test method based on eigenvalues and eigenvectors is available to determine the observability of every state vector.展开更多
The spontaneous emission of an excited atom embedded in photonic crystals with two atomic position-dependent bands is investigated.The distribution of the density of states between two bands depends on the atomic posi...The spontaneous emission of an excited atom embedded in photonic crystals with two atomic position-dependent bands is investigated.The distribution of the density of states between two bands depends on the atomic position in a unit cell of the photonic crystal and is described with an atomic position-dependent parameter.The result shows that the emitted field and the time evolution of the upper-level population are affected by the atomic position and the gap width.The spontaneous emission spectrum in free space can be shifted and narrowed with the photonic reservoir and the gap width.展开更多
In the measurement of automobile body-in-white, it has been widely studied to position the twodimensional (2D) visual sensors with high precision. In this paper a graphic positioning method is proposed, a hollow tetra...In the measurement of automobile body-in-white, it has been widely studied to position the twodimensional (2D) visual sensors with high precision. In this paper a graphic positioning method is proposed, a hollow tetrahedron is used for a positioning target to replace all the edges of a standard automobile body. A 2D visual sensor can be positioned through adjusting two triangles to be superposed on a screen of the computer, so it is very important to evaluate the superposition precision of the two triangles. Several methods are discussed and the least square method is adopted at last, it makes the adjustment more easy and intuitive with high precision.展开更多
文摘In order to completely push on quality education,this requires college"courses" should meet and give service to reformation tendency.And its status must be strengthened and can’t be weakened."two courses" is a basis link of college quality education.Under these new circumstances,we must build new teaching system and strengthen teaching reform.
文摘A new intelligent control method for welding positioner is proposed. Applying an improved fuzzy controller and a variable PID controller, a two-mode intelligent coordinating controller ( TMICC ) is designed on basis of fuzzy logic and rules. The simulation and experimental results show that this control system can obtain better dynamic and static characteristics.
文摘In this paper, the fabrication and testing results of a two-dimensional pin-cushion position sensitive detector (PSD) are presented. The obtained pin-cushion PSD with an 8×8 mm2 effective area presents a maximum spectral response of 0.5 mA/mW at 850-nm wavelength, a 12-nA dark current at 5-V reverse voltage, a reverse breakdown voltage of 50 V, a nonlinearity of 2.175%, and a spatial resolution of 10 μm. The spatial resolution is relatively low and the slight pin-cushion concave distortion is generated due to the incompletely satisfied relationship between sheet resistivity of the anode and the resistance per unit length.
基金supported by the National Natural Science Foundation of China(Grant No.11127508)
文摘A 2D neutron detector based on 3He convertor and MWPC with an active area of 200 mmx200 mm has been successfully designed and fabricated. The detector has been tested with Am/Be neutron source and with collimated neutron beam with the wavelength of λ=1.37A. The best spatial resolution of 1.18 mm （FWHM） and good linearity were obtained. This is in good agreement with theoretical calculations.
文摘Track monitoring is a fast method of determining incorrect return-to-track and track-to-track assignments. An analytical method to evaluate the effectiveness of track monitoring was presented by reference [1]. In order to reduce the probability of initiating or accepting the ghost track, two sequential track monitoring algorithms, which use the inclination angles to form test statistics, are proposed in this paper. Two decision rules are given and the corresponding thresholds are derived. The paper also gives the estimation methods of the noncentral parameter of noncentral chi-square distribution when the true value of it is unknown, the algorithms can adaptively estimate the decision thresholds and can make sequential track monitoring decision on line. Simulation is also made and the results show that the proposed algorithms are effective and feasible.
文摘To improve the observability of strapdown inertial navigation system and the effectiveness of Kalman filter in the navigation system, the method of estimating the observability is analyzed based on eigenvalues and eigenvectors which are proved to be availabe, on this basis two-position alignment technigue is applied. The simulation shows that two-position alignment really makes the system＇s observability change from being incomplete to being complete, and the test method based on eigenvalues and eigenvectors is available to determine the observability of every state vector.
基金supported by the Natural Science College Key Projects of Anhui Province (Grant Nos. KJ2010A335 and KJ2012Z023)the National Natural Science Foundation of China (Grant Nos. 41075027 and 61205115)the Key Project of Chinese Ministry of Education (Grant No. 212076)
文摘The spontaneous emission of an excited atom embedded in photonic crystals with two atomic position-dependent bands is investigated.The distribution of the density of states between two bands depends on the atomic position in a unit cell of the photonic crystal and is described with an atomic position-dependent parameter.The result shows that the emitted field and the time evolution of the upper-level population are affected by the atomic position and the gap width.The spontaneous emission spectrum in free space can be shifted and narrowed with the photonic reservoir and the gap width.
文摘In the measurement of automobile body-in-white, it has been widely studied to position the twodimensional (2D) visual sensors with high precision. In this paper a graphic positioning method is proposed, a hollow tetrahedron is used for a positioning target to replace all the edges of a standard automobile body. A 2D visual sensor can be positioned through adjusting two triangles to be superposed on a screen of the computer, so it is very important to evaluate the superposition precision of the two triangles. Several methods are discussed and the least square method is adopted at last, it makes the adjustment more easy and intuitive with high precision.
