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This paper considers the application of finite-time control to a Cucker-Smale flocking model of autonomous agents with collision avoidance. A mathematical expression for the upper bound on the flocking time is derived. Previous results without considering collision avoidance showed that the flocking time decreases as the number of robots in the flock increases, which is counter-intuitive. We showed...
The migration and segregation of Bi atoms in Cu/Sn-Bi/Cu solder interconnects under electric current stressing usually induce the formation of Bi-riched layers at the anode side, which can cause the failure of solder interconnects easily. In our study, the microstructure evolution of the eutectic Sn-Bi solder in a Cu/Sn-Bi/Cu flip chip solder joint and a right-angle Cu/Sn-Bi/Cu solder interconnect...
This paper uses log data of teaching and learning activities in a web-based learning platform, selects two universities implementing different online learning promotion strategies as the cases, and conducts the group differences analysis based on the hypothesized structural equation modeling (SEM) to analyze group interactive activities in two universities' online learning environment. The results...
In order to analyze the difference between two kinds of engineering software-Matlab and LabVIEW in dealing with the issue of non-linear curve fitting, we study the implementation methods in the two kinds of software separately, without combining them. In Matlab the curve fitting toolbox is used to analyze the data, while in LabVIEW we use the “nonlinear curve fit” and “curve fitting” two kinds of...
The supersonic combustion chamber with Shuttle-type cavity was investigated numerically and experimentally. The symmetry of Shuttle-type cavity is discussed in this paper. Results show that the symmetry is determined by the number of low-pressure centre area. Mach number of main flow is the key factor that determines the symmetrical characteristic of Shuttle-type cavity flow field and the critical...
This paper presents a perturbation based method for small-signal stability analysis in microgrid based on the uncertainty of microgrid parameters. The small-signal state-space model is built including the dynamic characteristics of the controllers, the power measurement and the system circuit and load dynamics model. The system eigenvalues of operating point at a steady-state in microgrid are obtained...
The continuous-state fault tree (CSFT) is used for reliability analysis for the degradation performance of SLD. Firstly, the degradation performance of SLD is analyzed and the methods of building CSFT are proposed. Based on CSFT, the formula for reliability is deduced. Secondly, the reliability quantitative analysis of SLD is introduced based on the building CSFT of SLD. Thirdly, the reliability curve...
A novel wide-area fault location algorithm is proposed in this paper. Fault model is developed in super-imposed network, and then based on network correlation coefficient matrix (NCCM), location function is defined. Finally search technique with adaptive step is used to locate fault branch and fault distance. This method requires few PMUs, avoids modifying node admittance matrix and NCCM. It has less...
The binary state is the fundamental assumption to the traditional FTA. Hence, the traditional FTA gives only the binary logical analysis of product catastrophic failures. However, performance of Fiber Optical Gyroscope (FOG) will degrade with the time and it is able to perform its task with partial performance. To overcome this problem, multistate reliability analysis is presented. However, multistate...
Based on the basic law of tunnel rock deformation and distant affection law of tunnel excavation, the method to judge tunnel rock stability according to the state of tunnel rock deformation velocity was put forward. If the deformation velocity changers less and less with the time, the deformation develop to stability. If the deformation velocity does not changer with the time, the tunnel rock locates...
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