Applied Mechanics and Materials Vols. 556-562

Abstract: High stability and constant-temperature crystal oscillator as time standard, microcontroller as control core, the countdown frequency measuring electric circuit, rapidly and timely surveying the transmitting frequency during the constant radar transmitted pulse, is a digital frequency measurement module. This module is an important constituent part in digital automatic radar frequency control system, having been successfully applied in a self-adaption frequency control system of meter wave warning radar.

Abstract: In the light of application requirements for non-contact measurement, this paper puts forward a non-contact measuring device. It generates the ultrasonic through electrical way with SCM detecting echo, the timer detecting ultrasonic transmitting and receiving time difference. Then it carries out the non-contact measurement of distance, and displays on LCD. The device can be used in many aspects, such as alarm, data monitoring, etc

Abstract: The prevalence of Android makes it face the severe security threats from malicious apps. Many Android malware can steal users’ sensitive data and leak them out. The data flow analysis is a popular technique used to detect privacy leakages by tracking the sensitive information flow statically. In practice, an effective data flow analysis should employ inter-procedure information tracking. However, the Android event-driven programming model brings a challenge to construct the call graph (CG) for a target app. This paper presents a method which employs the inter-procedural and context-sensitive data flow analysis to detect privacy leakage in Android apps. To make the analysis accurate, a flow-sensitive and points-to call target analysis is employed to construct and improve the call graph. A prototype system, called PDroid, has been implemented and applied to some real malware. The experiment shows that our method can effective detect the privacy leakages cross multiple method call instances.

Abstract: The maintenance efficiency of Chinese railway turnout is closely related to the accuracy of its fault diagnosis method. A proper method will provide great help to railway staff in maintaining turnouts. The research introduced in this paper built a model based on Support Vector Machine (SVM) and Grid Search and later than tested its effect with the data from experiments. Result of that test shows that the method can achieve a diagnosis accuracy as high as 98.33%.

Abstract: The co-author networks are important type of social network. In this paper, we establishes the Erdös co-author network and proves that the Erdös co-author network is a complex network which has three main properties, including small world, scale-free and clustering properties. Besides, this article gives the calculation formulas for degree centrality, closeness centrality and betweenness centrality of a network. According to the calculation result we give a ranking order for authors within Erdös co-author network.

Abstract: Vehicle detection in the traffic monitoring system has been widely studied in recent years. This paper presents a vehicle detection method based on different object motion characteristics to track the moving vehicles. Firstly, we use the frame different method to detect the moving objects. Secondly, we do binarization and filtering processing with the adaptive threshold segmentation technique to extract the moving vehicles in the traffic video. Then we determine centroid displacement to recognize the vehicle motion characteristics for retrograde judgment. Finally, we draw the vehicle trajectory and make the vehicle motion statistics. Experiment results show that the method can real-time track the moving vehicles and accurately get the vehicle retrograde detection.

Abstract: A new rolling bearing fault diagnosis approach is proposed. The original vibration signal is purified using the second generation wavelet denoising. The purified signal is further decomposed by an improved ensemble empirical mode decomposition (EEMD) method. A new selection criterion, including correlation analysis and the first two intrinsic mode functions (IMFs) with the maximum energy, is put forward to eliminate the pseudo low-frequency components. Experimental investigation show that the rolling bearing fault features can be effectively extracted.

Abstract: To meet the comprehensive maintenance demand of optical fiber transportation networks, an integrated optical cable on-line monitoring system is designed in this research. The researched employs modular structure, integrated function, and blended multiple communication interfaces for the key technologies of monitoring 128 modules. By using the technologies, speech path and signaling are able to transmit simultaneously. Then the research establishes the on-line monitoring system which integrates the functions of real-time monitoring of terminal offices on optical cable line and end machine, automatic dispatching of circuits, and maintenance test for optical transportation equipment. By applying the system on-line, the research verifies that the functions and technical indexes of the system meet its design requirements.

Abstract: The health of MOVA is very important for power system reliability and insulation coordination studies.MOVA is subjected to different kinds of stresses in services, which will cause degradation at early stage or in the long run.This paper present evidence theory for fault diagnosis of MOVA. Evidence theory can simultaneously analyze information from different sources,draw comprehensive conclusions,reduce single information misjudgment. In this paper, resistive leakage current and infrared imaging make up two types of evidence body for judge. Analysis of experimental data shows that this method can effectively detect early fault of the MOVA.

Abstract: During induction voltage test, the changes of data such as output voltage and output current reflects the changes of the equivalent parameters of the transformer. Through the analysis of testing data, diagnosis of winding deformation of the transformer can be made. Transformer condition evaluation can be provided on the basis of these data. In this paper, induction voltage test data is analyzed after a transformer tripping. Winding deformation of the transformer is judged. Relevance judgment is confirmed by disassembling inspection.