单良 SHAN Liang’s scientific contributions

In view of the poor real-time performance and high cost of haze detection methods, a method based on contrast and image energy was proposed to detect the haze. Firstly, the images taken by the CMOS camera were preprocessed. The image has some slight swing because the camera has been disturbed by the external environment, so the images were registered. Secondly, in the critical region of the image, two contrast vectors of contrast and image energy were obtained. Thirdly, the contrast, image energy and ambient humidity were taken as input, and the real-time PM10 concentration measured by the laser particle counter was used as the output. The relational model between input and output was constructed by training support vector regression (SVR). Finally, the PM10 concentration of the image was calculated using the model. The PM10 concentration detected by this method was compared with that measured by laser particle counter. The average relative error was less than 10% and MSE was 0.006 2, which indicates that the fitting degree between the predicted value and the true value is good and the accuracy of the model was high. On this basis, increasing the training samples can improve the model accuracy. Moreover, the method can establish the corresponding relation model for different environment to be tested, which has strong flexibility. © 2018, Editorial Board of Journal of Infrared and Laser Engineering. All right reserved.

To reduce the effect of noise on inversion result of grain diameter in nano-particle diameter measurement using photon correlation spectroscopy, a nano-particle diameter computing method is proposed based on photon correlation spectroscopy with nonnegative least squares. Photon correlation spectroscopy itself is as the weight to derive discrete model of inversion algorithm and avoid the influence of data fluctuation close to zero. The 90 nm, 190 nm and mixed latex particles are measured by the photon correlation spectroscopy equipment and compared with the traditional nonnegative least squares. The 30 experimental data in 60 seconds indicate that in the inversion of unimodal paticle group, the results of present method is close to traditional nonnegative least squares but variance of multiple repeated measurement is smaller which proves good repeatability of present method; in the inversion of multimodal particles, the results of present method are much closer to true values of diameters, however, the results of nonnegative least squares deviate more from true values. Experimental data of different measurement time show that in a short period of time, variance of present method is smaller and it can obtain more accurate results in a shorter period of time.