Applied Mechanics and Materials Vols. 239-240

Abstract: Old giant cranes in corrosive environment are in serious hidden danger of structural instability and failure, the modal analysis is an important part of dynamics analysis in the Crane Safety Evaluation to guarantee the safety of cranes. A Modal Analysis of a 28-year old 100t giant shipbuilding tower crane was done using ANSYS. Comparing with the vibration frequencies and modal shapes, Modal analysis shows that the Natural Frequency of the crane reduces from 1.0024Hz to 1.0003Hz, beside all the Modal vibration frequencies (first 10 Order) of the crane are lower than the designed value, means the strength of the tower crane has decreased; the Modal Vibration Frequencies (first 10 Order) of the tower crane are between 1 Hz and 2 Hz. The Mmodal analysis provided theoretical basis for safe use, design and transformation of this crane.

Abstract: The detection of motor noise can be used to evaluate the condition of motor. Furthermore the detection of motor noise can be used to analyze the source of motor noise and is helpful to reduce the motor noise. Through analyzing the mechanism of motor noise, a laptop computer and LabVIEW software are used to design the experimental system. The hardware of noise detection system consists of an external microphone and sound card coming with the computer. LabVIEW is used to detect the noise signal and record the noise and realize the spectrum analysis. Through detecting and analyzing the noise of the permanent magnet DC motor and three-phase asynchronous motor, It is proved that the motor noise experimental system consisting of computer and LabVIEW can fully meet the requirements of electrical machine test and research.

Abstract: Noise source identification is the precondition and foundation of the noise reduction. There are some limitations while using some common method to analyze noise sources, so on the basis of partial coherence analysis and analytic hierarchy process, a method was proposed which can sort noise source contribution. When noise in the multi-source excitation system is coherent，this method can identify and sort noise source.

Abstract: Compared with fixed detection threshold, adaptive detection threshold substantially improves the reception sensitivities in high sensitivity receivers. The optimal detection threshold depends on probability distribution of the received signals. The out-of-phase auto correlation values and cross correlation values of Chinese Compass B1-I signal were analyzed, and the probability distribution of the signal with the differential correlation technique was provided. Then the optimal detection threshold and the sensitivity gain that can be obtained by the adaptive detection threshold were provided.

Abstract: A region-based regression model is presented to fuse a pair of panchromatic (PAN) and multispectral image (MS) in order to get a pansharpened image with high spectral fidelity. Firstly, the images from two different sensors are segmented into isolated regions respectively by the mean shift segmentation method with embedded edge confidence. Then, three segmentation maps got from two images are used as reference of the following segment-based modeling process. The regression model is established independently for each isolated region by considering the linear relationship between corresponding PAN and MS image pixel values in the region. Finally, a modulation-based fusion technique is employed to get the fusion result. Two pairs of images are used for evaluating the method in both qualitative and quantitative ways. The method shows the superior result.

Abstract: This paper discusses land utilization classification based on remote sensing technology. Taking the Xinjiang Kulja county bureau department area remote sensing images as the basic information, and using ERDAS IMAGINE, this paper discusses non-supervised classification and supervised classification methods. The results show that remote sensing technology applies to land utilization situation and land classification, which has reference value.

Abstract: With the widely application of large scale aerophotogrammetry ,the traditional measurement methods already can’t satisfy the efficiency requirements of Photocontrol Point Measurement. There are some obvious advantages in GPS RTK, so it’s applied to Photocontrol Point Measurement. This article takes Jiaozuo with an aerial survey of 1:2000 for example, and introduces the operation of GPS RTK, analysis the problems in the procedure of operation, and also offers solution. As a result, the article provides a good reference to the application of Photocontrol Point Measurement. It analysis the measurement accuracy in GPS RTK, precision analysis about spatial aerotriangulation and proves that it satisfies the demand for proportion of 1:2000.

Abstract: An impulse-based single-borehole radar prototype for well logging is presented. An armored multi-conductor well logging cable is used to connect subsurface sonde and surface equipment in the prototype which is well compatible with the other well logging instruments. The performance experiments of the prototype have been conducted in a test field. The results show that the prototype system is capable of detecting the target which is 8 meters away from the borehole.

Abstract: Unmanned aerial vehicle remote sensing (UAVRS) technique was applied to emergency monitor Cocktail Mountain landslip geological hazard in Wulong county of Chongqing. The paper analyzes methods of accessing and processing digital image data in mountainous area and its application to emergency response management of geological hazard. The conclusion shows that UAVRS can access quickly high-precision remote sensing digital map and supply newly and explicit data for emergency decision. Combing with GIS spatial analyst modeling, UAVRS can assess high-speed hazard and provide base of allocating relief supplies. UAVRS integrating GIS can bring up potential and secondary disaster points for guaranteeing safety of personnel and property. UAVRS can also provide hazard information timely and exactly for pacifying the public to avoid panic. So UAVRS technique can provide technical support for emergency response management of geological hazard.

Abstract: Position and Orientation System (POS) is a technology widely used for motional error compensation of airborne InSAR. The measurement errors of inertial sensor (accelerometers and gyros) are the chief influencing factors to the precision of POS. In order to enhance the accuracy of POS, an improved SINS error model should be used in POS. In this paper, a more precise error model for SINS is developed by augmenting random walks error, first-order Markov process error, scale factor error and installation error. To validate the accuracy of the improved error model, semi physical flight simulation based on the imitation of imaging-flight route of InSAR is made to compare with the traditional SINS error model which only considering the random constant error. The simulation results show that the accuracy of the improved SINS error model is one order higher than the traditional SINS error model.