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The performance of an optical system with sensitive line-of-sight (LOS) is influenced by rotational vibration. In view of this, a design methodology is proposed for a passive vibration isolation system in an optical system with sensitive LOS. Rotational vibration is attributed to two sources: transmitted from the mounting base and generated by modal coupling. Therefore, the elimination of the rotational vibration caused by coupling becomes an important part of the design of the isolation system. Additionally, the decoupling conditions of the system can be obtained. When the system is totally decoupled, the vibration on each degree of freedom (DOF) can be analyzed independently. Therefore, the stiffness and damping coefficient on each DOF could be obtained by limiting the vibration transmissibility, in accordance to actual requirements. The design of a vibration isolation system must be restricted by the size and shape of the payload and the installation space, and the layout constrains are thus also discussed.

Background The aim of this study was to clarify the most suitable sampling force for OP swabs. Methods Thirty healthy subjects were continuously included in this study. The quantitative relationship between sampling force and the quality of OP swabs (CT values of GAPDH in OP swab specimens) has been explored. Results No significant relativities between the median sampling forces and qualities of OP swab were found in this study (r=-0.079, P = 0.547). The median and maximum sampling forces were remarkedly differed from different sampling doctors (P 40 g)of sampling force (P = 0.873). However, it was observed that the incidence of side effects was significantly increased in the middle and high level groups, compared to the low level group (P

In order to improve the performance in the practical engineering applications including so called low-speed video tracking and large-angle swing scanning imaging at the same time for a three-axis universal inertially stabilized platform (UISP), we propose an adaptive nonsingular fast terminal sliding mode control (ANFTSMC) strategy subjected to the uncertain disturbances and input saturation constraints. First of all, a second-order dynamic model is established with uncertain disturbances and input saturation constraints. Secondly, a nonsingular fast terminal sliding mode controller (NTSMC) is constructed to ensure the system error converges to zero fast in a finite time, meanwhile, a novel reaching law based on a modified normal distribution function is designed to adjust the control gain. Thirdly, an adaptive control law is designed to online estimate the parameters of the lumped uncertain disturbances. Additionally, the stability of the control system is proved by Lyapunov theory. Finally, extensive comparative simulations and experiments are carried out, the results comprehensively show the effectiveness and superiority of the proposed control method, which can accelerate convergence, weaken the chattering, and has the better control accuracy and robust performance both in the low-speed tracking and large-angle swing scanning applications. Moreover, the exact dynamic model and the prior knowledge of the upper bounds of the disturbances are not required during the procedure of the controller design, which make it have more extensive application value in practical engineering.

As one of the main approaches to acquire geographic data, aerial remote sensing is of great significance to the development of the geographic information industry in the era of big data. By taking the domestic three-line stereo aerial photography system as the main research object, this chapter analyses the information application demands for the development of aerial photography system by geographic big data acquisition, introduces the development status of aerial remote sensing equipment, describes the working principles and technical indexes of three-line stereo aerial photography system, and discusses the information application prospect of the aerial photography system in aspects such as digital urban construction, earthquake relief works, resource aerial remote control, environmental protection, and homeland security.

Digital mapping camera is an important tool for modern airborne photogrammetry. Monochromic area CCD which is full frame transfer is selected as image sensor in this paper. Electronic shutter is utilized to eliminate the opening delay of mechanical shutter which will affect the precision of exterior orientation elements acquisition. The equation for calculation displacement of principal point is proposed for TDI forward image motion compensation to compensate principal point shift. Imaging pose control system is designed in order to meet the need for airborne stereo mapping.

Task allocation is an essential strategy to achieve effective cooperation for swarm robots. Self-organized task allocation strategy is studied and efficient labor division and regulation is realized through local interactions among individual robots based on response threshold model. Local communication mechanism is proposed for the purpose of sharing local sensation information, and the simulation experiments verify that the efficiency of task allocation is improved significantly.

A centralized three dimensional localization algorithm is proposed with the name of NMDS-MEEF, which is based on the location requirements of wireless sensor network used for monitoring large electrical equipment fault. The localization algorithm adopts a changed nonmetric multidimensional scaling in which the iterations process only makes use of the correlated data of one-hop neighbor nodes. The algorithm is more straightforward and practical. The simulation results demonstrate that the algorithm is of great advantages in improving localization accuracy, decreasing the dependence on the density of anchor nodes and reducing the influence by the accuracy of position estimation.

To resolve the problem of complex operation of the linear approximation distance threshold (LADT) algorithm, some improved researches were made to the algorithm by taking the characteristic of electrocardiograph (ECG) signal and the advantages of field programmable gate arrays (FPGA) into account. The paper puts forward a real time compression method with much less mathematical operation and much easier real-time implementation. With the artificial and experimental verification, it turned to be that the arithmetic has the advantages of low distortion and in real time. In the application of improved fast LADT algorithm, the paper designed the hardware system of ECG data compression based on FPGA and the program of the algorithm based on very high speed integrated circuit hardware description language (VHDL). And the experiment results of this system turned to be good performance. The approach can be easily extended to other similar applications.

This paper studies the characteristics of denoised partial discharge (PD) signals and then puts forward a new method to extract features from distribution of PD energy against relevant phase position. The analysis results to field measured data shows the efficiency and practicability of the new method.