Applied Mechanics and Materials Vols. 513-517

Abstract: In this paper, the idea of manifold learning is introduced into Stepped Frequency Radar (SFR) target recognition, a new method based on Locality Preserving Projections (LPP) algorithm and k-nearest neighbour classification for Stepped Frequency Radar target recognition is proposed. LPP is a subspace analytical method based on manifold learning, which is used to reduce the dimension of the High Resolution Range Profile (HRRP) and extract features from HRRP. The feature extraction method by LPP not only preserves the global topology structure, but also captures the local information of the different targets. Then three kinds of target are classified by k-nearest neighbour classification after the LPP. Experimental results on the three different targets suggest that the proposed method has the capability of finding the low-dimensional manifold structure embedded in the high-dimensional HRRP space and can provide a higher recognition rate in Stepped Frequency Radar target recognition.

Abstract: The vortex structure of two-dimensional flow in a cavity is calculated using the differential quadrature method. The numerical simulation focuses on investigating the effects of Reynolds number on vortex structure evolution of the flow in a square cavity with two opposite and equal speed moving lids. The streamline patterns and bifurcation diagrams are determined. The numerical results show that the flow in the cavity takes on the streamline pattern of completely symmetric vortex structure when the Reynolds number approaches zero. With the Reynolds number increasing, the sizes and center positions of the sub-vortexes appear to be affected, whereas the saddle point is still located at the cavity center, resulting in a skewed flow pattern in the cavity. It is observed that one large vortex occupies the entire cavity and the shape of the large vortex becomes more circular after a critical value of the Reynolds number is exceeded. If the Reynolds number is increased further, two secondary eddies emerge simultaneously on the upper left corner and the lower right corner near the sidewalls. The center of the large vortex is invariably located at the cavity centre. For different Reynolds numbers, the streamline patterns are symmetric about the cavity center which is always a stagnation point.

Abstract: This paper presents the concept of defect classification model, which is based on the technology of similarity. Defect classification model can analyze software defect more efficiently and provides the basis of solving problems quickly. This paper applies this model to GUI project and gives a GUI defect classification model based on large number of interface defects. Experiments show that the model is useful to improve the process of defect management and be used for test planning and implementation.

Abstract: The continental shale of Yanchang Formation in Ordos Basin is in complex facies. Being high in mud and low in brittle mineral, the reservoir quality is poor. Therefore multi-stage fracture stimulation has been applied there in horizontal wells. The fracture interval in horizontal well is a critical parameter and it has a great influence on the fracture interaction. Since the fracture interaction can directly determine the extent to which the stimulated reservoir volume (SRV) expands, its most necessary to study the mechanism of the effect. For this, a mathematical model based on elastic mechanics would be given. By using this model, we analyzed the influences on the fracturing work. An analysis of field data from Yanchang Oilfield shows that proper fracture interval can take good advantage of the fracture interaction so as to reduce the horizontal differential principal stress. However, exceeded fracture interaction may raise the fracture pressure. So the effect must be controlled by optimizing the fracture interval. To optimize the fracture interval, the results can be used to instruct the application of multi-stage fracture stimulation.

Abstract: Based on the supply chain managements theory and method of Customer Relationship Management, Customer Service Management and Demand Management to study Chongqing-Sinkiang-Europe International Railway logistics process, put forward the countermeasures of one center and three key points, thus base on Chongqing and organize source of goods from the National,improve logistics operational connection efficiency, play a role in collaborative management by IT information management system.

Abstract: Many studies suggest that air-transportation networks contribute a lot to the spatiotemporal dynamics of infectious diseases. The mobility of individuals over the networks has greatly speeded up the spreading processes of the epidemics and pushed the population in non-epidemic areas into the risk of infection. To figure out the underlying interactions between the air-transportation networks and the transmission of the epidemics, we have (i) analyzed the air-routes and the statistical data on the passenger throughput of the civil aviation of China and (ii) carried out a computer simulation based on the assumption that a novel influenza outbreaks in Southeast Asia. The results show that the topology of the air-transportations networks has a typical structure of heterogeneities. We also find that the epidemics will soon strike China after the initial outbreaks and rapidly spread throughout the whole networks without air-travel restrictions even the reproductive number () is small.

Abstract: Based on M language offered by Comsol Multiphysics analysis platform, a 3-D finite element model of a high arch dam was established. In this paper, a practical engineering was taken to be as a case.The coupled seepage-stress field was compared with uncoupled condition under normal storage level. The seepage, stress and displacement fields of the dam were analyzed for discussing the coupled effect. The results show the similar distribution of seepage, stress and displacement fields in the two conditions. However, compared to the uncoupled one, the potential distribution of seepage field is close to downstream, each displacement component increases at different rates, the tensile stress of the upstream rock and the compressive stress of the downstream rock both increases in the coupled condition, which enhances the uplift pressure in the foundation. So the coupled effect of seepage and stress is not beneficial for the dam safety, which cannot be ignored under high water pressure.

Abstract: Temperature is an important factor for affecting the accuracy of quartz flexible accelerometer. The relationship of quartz flexible accelerometers drift to temperature should be established accurately which can improve the precision of inertial navigation system. In order to reduce the temperature sensitivity and improve the sensor performance, temperature drift compensation method based on artificial fish swarm (AFS) algorithm is established and the steps and methods are given. The traditional modeling method of stepwise regression is also investigated to provide a comparison with the AFS algorithm. The result shows that the temperature compensation model by AFS algorithm is accurate. The drift instability of accelerometer output is reduced from 160.2ug to 18.0ug over the temperature range from-20°Cto +50°C. The results of the stochastic temperature tests show that this method has reduced the influence of temperature variation effectively and improved the accelerometer accuracy.

Abstract: This paper designs an RFID-based reader of which functional module and hardware design are also comprehensively described. The interface circuit between MCU and MF RC500 which is also the invitation point effectively solves the difficulty in RF interface circuit design. The proposed reader is applied in the smart-card system of campus and property management system and has great performance.

Abstract: This temperature measurement system is based on the control of AT89S52 single chip microcontroller, with temperature display function. Temperature information is changed into digital signal directly by a single bus digital temperature sensor DS18B20, and the digital signal is sent into microcontroller for real-time acquisition. The results are displayed through LCD module 1602 in real time. The system is with the characteristics of low cost, high precision, stable performance and convenient operation. The system can be extended to multi-point temperature detecting system easily, and adding temperature transfinite alarm function.