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In order to solve the problems such as the low degree of automation of concrete curing room temperature control, the difficulty for the temperature control to meet the requirements of national standard, the parameter self-tuning fuzzy PID control algorithm was put forward. The algorithm through the real-time correction PID parameters to ensure the system accuracy and stability. The Matlab simulation results showed that the parameter self-tuning fuzzy PID control system has better stability and robustness than the traditional PID. [ABSTRACT FROM AUTHOR]

In this study, we developed a fast and non-destructive technology for the prediction of the nitrogen content in lettuce leaves based on hyperspectral imaging technology which contains abundant spectral and spatial information in an object. First, hyperspectral images of lettuce leaves in the visible and near infrared (390-1050 nm) regions were acquired by the hyperspectral imaging system, and then the corresponding nitrogen content in the lettuce leaves were obtained by Kjeldahl method successively. The binary mask image was successfully determined by the method of dividing the image of very high reflectance intensity by the image of very low reflectance intensity with a certain threshold, and ROI (Region of Interest) in the sample of lettuce leaf was determined by removing the regions of noise using the acquired binary mask image. As the hyperspectral imaging technology provided much more information including spectral and spatial information for all the samples of lettuce leaves, and in which some information is noisy and redundant. In fact, this leads to the difficulty of meeting the needs for fast and efficient detection of some objects. So it is very hard to be directly used for on-line industrial application in our daily life. Therefore, effective selection of several characteristic wavelengths is necessary for the hyperspectral images. In this paper, the initial investigation was carried out by using a principal component analysis (PCA) to identify a number of potential characteristic wavelengths (662.9 nm, 711.7 nm, 735.0 nm, 934.6 nm) according to the weight coefficient distribution curve of the first three principal component images (PC1, PC2, PC3) under the full wavelengths. Both spectral data and texture data based on a co-occurrence matrix were extracted from the four characteristic wavelength images on the ROI, and the texture data of the first three principal component images were also extracted simultaneously. Then spectral data from four characteristic wavelength images, texture data (from four characteristic wavelength images, from the first three principle component images) and the combined data were utilized to develop different SVR (support vector machine regression) models to predict the nitrogen content in the lettuce leaves respectively. According to the performance of all the SVR models in the calibration set and the prediction set, the experiment results show that, from the calibration performance index, the model based on spectral data combined texture data from four characteristic wavelength images is the best with a coefficient of determination (R2C =0.996) and the root-mean-square error (RMSEC) of 0.034. From the prediction performance index, however the model based merely on spectral data is the best with a coefficient of determination (R2p=0.86) and the root-mean-square error (RMSEP) of 0.22. This study provides valuable information for rapid and non-destructive nitrogen detection in crops. [ABSTRACT FROM AUTHOR]

Combined with the vocational education and practical teaching characteristics, through the analysis of the importance of practical teaching and the existing problems, we analyze from the aspects of the top-level design, teaching methods, examination method reform, so as to provide policy reference for practical teaching of computer courses. [ABSTRACT FROM AUTHOR]

Population characteristics deserve closer study when two kinds of conflict information spread over social network at the same time. According to complexity theory and sociology achievement, we developed conflict information spreading model by using SIR model on network. Here we introduced three manners for individual to resolve conflict information involving "first impressions are strongest", "herd effect" and "leader opinion" into the spreading process, and then conducted contrastive experiments of the model corresponding different behaviors on the large-scale social network. The experiment results show that social network structure and individual manners significantly affect the information spreading. From local interactions to collective behavior, global feature has more diverse trends than local feature, and this study will contribute to the explanation of large-scale population characteristics such as go to extremes and diversification. [ABSTRACT FROM AUTHOR]

The rotor airfoil design has the characteristics of multi-point, multi-objective and strong constraints. Based on the evolutionary multi-objective optimization method, Kriging method and B-splines airfoil shape parameterization method, combined with the concept of Pareto optimality and constraint-handling mechanism, a rotor airfoil design and optimization system is built. In Kriging model the sample points are selected by using the uniform design, and the accuracy of the model is adjusted by the Expected Improvement criterion during the optimization procedure. The airfoil is parameterized by using the B-spline definition which has good flexibility. The airfoil performance is evaluated using Navier-Stokes code, and the transition model was added into the code to improve the computation accuracy of drag. The rotor airfoil design is studied using the design system, and the optimized airfoil was tested in a tunnel. The results show that the aerodynamic performance of optimized airfoil has been improved significantly, and the feasibility if the optimization method is validated. [ABSTRACT FROM AUTHOR]

As a complex logistics node, the container terminal is affected by many uncertainties. In order to make terminal operating plan implemented smoothly and improve its robustness, a scheduling strategy for berth and quay cranes based on robust and reactive policy is proposed, focusing on how to increase the plan robustness through the real-tithe scheduling of berth and quay cranes when the uncertainties occurs. The real-time scheduling strategy includes the berth real-time scheduling and the quay cranes real-time scheduling. The former adopts the ASAP strategy. The latter adopts MAS technology, makes full use of quay cranes, and designs a real-time scheduling model for quay cranes based on CNP. The simulation tests show that this real-time scheduling strategy can achieve more stable plan than that just considering the berth real-time scheduling. [ABSTRACT FROM AUTHOR]

Taking the total average friction work of crankshaft bearings and the mass of crankshaft as objectives, a multi-objective integrated optimization is conducted on the crankshaft bearings of a four-cylinder engine by using particle swarm optimization (PSO) algorithm with exponent decreasing inertia weight strategy. The results are compared with original engine and the results of single objective optimization, and it is shown that after multi-objective integrated optimization, the total average friction work of crankshaft bearings decreases by 26.2 % and the mass of crankshaft reduces by 5.3% compared with original engine, and it has also a slight improvement over the results of single-objective optimization. [ABSTRACT FROM AUTHOR]

Combined with the Meiliang Lake ecological dredging engineering project example in Taihu Lake, the total ecological dredging with double side interval such as piling, double side suspension safety net, unilateral fixed antiseepage geotextile and various construction technologies, we discussed the application of geotechnical tube bag dehydration curing technology in the cofferdam heightening project. Engineering practice proved that the method has great practical and promotion value. [ABSTRACT FROM AUTHOR]

The sapphire single crystal plate with size of 485 mm x 985 mm x 12 mm was successfully prepared by a large-size edgedefined film-fed growth (EFG) furnace designed and developed independently. After cutting and grounding, the crystal was formed into transparent armors composited with glass and polycarbonate. The surface density with the size of 352 mm x 351 mm x 33 mm is 79. 27 kg/m², and the surface density of the other is 79.38 kg/m² with the size of 351 mm x 342 mm x 33 mm. Targeting tests were conducted on the transparent armors using incendiary shells with diameters of 7.62 mm and 12.7 mm, respectively. The experimental results show that the transparent armor based on sapphire crystal plate has excellent impact resistance during firing at a normal angle of 0° and with a distance of 100 m which from target to the armors. [ABSTRACT FROM AUTHOR]

Vapor equilibrium transport method is used to prepare near stoichiometric lithium tantalate crystals with high quality. However, it is difficult to prepare large-thickness crystals by this method due to its low solid diffusion rate. In this paper, based on the diffusion mechanism of lithium tantalate crystal, the diffusion of lithium tantalate crystal was carried out by asymmetric diffusion process with lithium rich atmosphere on one side of the wafer and congruent composition atmosphere on the other side. The composition and domain inversion field were characterized. The results show that the asymmetric diffusion technique provides a channel for the diffusion of anti-tantalum ion and increases the diffusion rate of anti-tantalum ion and lithium ion in the crystal, which is beneficial to the preparation of large-thickness near stoichiometric lithium tantalate crystal. [ABSTRACT FROM AUTHOR]

The constant rate uniaxial tension tests and tension-recover tests are conducted to obtain the accurate mechanical property of the EPDM insulation material. A visco-hyperelastic constitutive model is developed based on the mechanical behavior characteristics of EPDM. The method is established by applying the hyperelastic theory which was established under finite deformation condition in combination with linear viscoelastic theory. Then the way to obtain the model parameters is proposed, which is simple and easy to be generalized. The results show that EPDM has the typical hyperelastic mechanical characteristics, and presents a rate-dependent effect. The visco-hyperelastic constitutive model proposed can describe the uniaxial mechanical property of EPDM accurately. The model can provide a theoretical reference for structural integrity analysis of solid rocket motor made of EPDM insulation material. [ABSTRACT FROM AUTHOR]

The design of automatic headlight adjustment system based on design for quality technique is presented in this paper. Firstly a modification design is conducted on the system to make it adapted to the structure of present step motors. Then the driving parameters of step motor are adjusted to effectively prevent the adjusting mechanism from getting stuck, and further a tolerance design is performed to achieve the uniformity of backlight adjustment and the reliable work of adjusting system under adverse conditions. Finally both bench and real vehicle tests validate the results of system improvement. [ABSTRACT FROM AUTHOR]

In order to remove the moisture and upgrade the quality of lignite with efficient methods, a specially-designed microwave equipment was used to remove water from the lignite and the key influencing factors during the process were analyzed. The effects of coal particle sizes, radiation powers and initial moisture contents on the dewatering process were investigated. The results indicate that there were conceptually four stages (preheating stage, pressurizing stage, constant-rate drying stage and falling-rate drying stage) during the whole drying process in microwave. The temperature of lignite rose quickly while the moisture content is nearly constant in preheating stage. The dehydration rate increases notably in the pressurizing stage as the seepage flow generated from the large pressure gradient between internal and external particles. The vapor pressure and dehydration rate is steady in the constant-rate drying stage. The dehydration rate decreases while the lignite temperature increases in the falling-rate drying stage. The peak drying rate could reach 11% per minute when the particle size is 0.6-3.0 mm. The drying rate increases with the increasing microwave output power when the power is less than 600 W. Generally, the high initial moisture content of coal would cause high drying rate, but slow increase in lignite temperature. [ABSTRACT FROM AUTHOR]

Considering the aviation cost and combat effect of aerocrafts team, this thesis investigated the way of aerocrafts' cooperative path planning based on task assignment, constructed aerocrafts team's cooperative path planning model and designed decomposition algorithm. This can effectively balance multiple objective presence, get reasonable task allocation and path planning schemes. The simulation results show that this method can not only guarantee the cooperative paths of aircrafts reasonable, but also get the best combat effect and effectively improve the combat benefit-cost ratio. [ABSTRACT FROM AUTHOR]