Storage management strategy can be expressed by a file system. Commercial file system for embedded application is generally complicated and resource wasted. In this paper, a specified file system adapted to embedded s...Storage management strategy can be expressed by a file system. Commercial file system for embedded application is generally complicated and resource wasted. In this paper, a specified file system adapted to embedded system with flash-based memory is developed. To guarantee the average usage of flash storage sectors, the strategy of wear leveling and adaptive damage management is introduced, in which a dynamic storage space management mode and the strategy of first in first out (FIFO) are adopted. Moreover, the strategy of redundancy design and fast-calculation and tracing is also adopted to extend the life of kernel sector, which can guarantee the reliable service of system booting. The practical application in an embedded CNC (computerized numerical control) platform proves that the file system has effective performance. Furthermore, the flash file system can be transplanted to different embedded platforms by changing a few bottom hardware parameters with universality.展开更多
Part of the difficulty in engineering education is to achieve aggregate theoretical knowledge to practice what therefore discourages the student. Trying to alleviate this difficulty, practical problems are created to ...Part of the difficulty in engineering education is to achieve aggregate theoretical knowledge to practice what therefore discourages the student. Trying to alleviate this difficulty, practical problems are created to encourage students to apply their knowledge in different ways; these problems can be computational order, resolved by programs through simulation, or physical, with the realization of models, prototypes, benches or interactive platforms with visual practical approach. From this, it was proposed to students of the Federal University of Pardi--Campus Tucurui through the Electric Power Systems and Mechanics Research Group, in order to apply knowledge arising from multidisciplinary fields of engineering in the construction of a prototype with reused materials and low cost enabling studies and analysis of vibrations in unbalanced motors. This system features an open source prototyping embedded platform Arduino to read values from the sensors used: accelerometers and potentiometers coupled to the engine, aiming to collect values and vary the supply voltage. The results are read by Arduino and computationally processed to be printed on an LCD display. Therefore, the aim of this is to provide an accessible way using simple techniques a prototype linking the theoretical and practical knowledge as the system of the bench that performs vibration analysis in an unbalanced motor interactively, and encourage research and development technologies in the Amazon region.展开更多
The indirect boundary element method(IBEM) was established to solve the problem of 3-D seismic responses of 2-D topographies,by calculating the free-field responses with the direct-stiffness method and simulating the ...The indirect boundary element method(IBEM) was established to solve the problem of 3-D seismic responses of 2-D topographies,by calculating the free-field responses with the direct-stiffness method and simulating the scattering wave fields with the dynamic Green's functions of moving distributed loads.The proposed method yields accurate results,because the 3-D dynamic stiffness matrixes used are exact and the fictitious moving distributed loads can be acted directly on the interface between the alluvial valley and the layered half-space without singularity.The comparison with the published methods verifies the validity of the proposed method.And the numerical analyses are performed to give some beneficial conclusions.The study shows that 3-D scattering by an alluvial valley is essentially different from the 2-D case,and that the presence of soil layer affects not only the amplitude value of surface displacements but also the distribution of surface displacements.展开更多
The system model of embedded reconfigurable system is discussed firstly, followed by the construction of the soft- ware and hardware platform. Based on the platform, the function trait and control models of digital si...The system model of embedded reconfigurable system is discussed firstly, followed by the construction of the soft- ware and hardware platform. Based on the platform, the function trait and control models of digital signal processing tasks are described. According the functional unit model and control model, a software/hardware integrating model with dataflow control infrastructure is constructed. The software/hardware partition is carded out in the experiments of ultrasonic signal processing, and the results show that the system model is practicable.展开更多
This paper introduces the hardware structure and software design of data acquisition system based on embedded Linux. In order to improve the real-time response performance and the ability of multi task for system, usi...This paper introduces the hardware structure and software design of data acquisition system based on embedded Linux. In order to improve the real-time response performance and the ability of multi task for system, using ARM9 microprocessor technology in hardware, and transplant the Linux operating system, and the system reliability and scalability can be improved. The design makes full use of the characteristics of embedded Linux. The system software module have data acquisition module, data processing module, data communication module and data diagnostic module. The embedded Linux operating system is transplant into data acquisition system, that can accelerate the development of the system and convenient to future expansion functions, improve the observation data timeliness and accuracy, and can realize automation observation.展开更多
基金Supported by National Natural Science Foundation of China (No50475117)Specialized Research Fund for the Doctoral Program of Higher Education of China (No20060056016)
文摘Storage management strategy can be expressed by a file system. Commercial file system for embedded application is generally complicated and resource wasted. In this paper, a specified file system adapted to embedded system with flash-based memory is developed. To guarantee the average usage of flash storage sectors, the strategy of wear leveling and adaptive damage management is introduced, in which a dynamic storage space management mode and the strategy of first in first out (FIFO) are adopted. Moreover, the strategy of redundancy design and fast-calculation and tracing is also adopted to extend the life of kernel sector, which can guarantee the reliable service of system booting. The practical application in an embedded CNC (computerized numerical control) platform proves that the file system has effective performance. Furthermore, the flash file system can be transplanted to different embedded platforms by changing a few bottom hardware parameters with universality.
文摘Part of the difficulty in engineering education is to achieve aggregate theoretical knowledge to practice what therefore discourages the student. Trying to alleviate this difficulty, practical problems are created to encourage students to apply their knowledge in different ways; these problems can be computational order, resolved by programs through simulation, or physical, with the realization of models, prototypes, benches or interactive platforms with visual practical approach. From this, it was proposed to students of the Federal University of Pardi--Campus Tucurui through the Electric Power Systems and Mechanics Research Group, in order to apply knowledge arising from multidisciplinary fields of engineering in the construction of a prototype with reused materials and low cost enabling studies and analysis of vibrations in unbalanced motors. This system features an open source prototyping embedded platform Arduino to read values from the sensors used: accelerometers and potentiometers coupled to the engine, aiming to collect values and vary the supply voltage. The results are read by Arduino and computationally processed to be printed on an LCD display. Therefore, the aim of this is to provide an accessible way using simple techniques a prototype linking the theoretical and practical knowledge as the system of the bench that performs vibration analysis in an unbalanced motor interactively, and encourage research and development technologies in the Amazon region.
基金Supported by National Natural Science Foundation of China (No. 50978156 and 50908183)Tianjin Research Programof Application Foundation and Advanced Technology(12JCQNJC04700)
文摘The indirect boundary element method(IBEM) was established to solve the problem of 3-D seismic responses of 2-D topographies,by calculating the free-field responses with the direct-stiffness method and simulating the scattering wave fields with the dynamic Green's functions of moving distributed loads.The proposed method yields accurate results,because the 3-D dynamic stiffness matrixes used are exact and the fictitious moving distributed loads can be acted directly on the interface between the alluvial valley and the layered half-space without singularity.The comparison with the published methods verifies the validity of the proposed method.And the numerical analyses are performed to give some beneficial conclusions.The study shows that 3-D scattering by an alluvial valley is essentially different from the 2-D case,and that the presence of soil layer affects not only the amplitude value of surface displacements but also the distribution of surface displacements.
基金supported by the Research Project of “SUST Spring Bud”under contract number 2008BW2046 fron Shandong University of Science and Technology,China
文摘The system model of embedded reconfigurable system is discussed firstly, followed by the construction of the soft- ware and hardware platform. Based on the platform, the function trait and control models of digital signal processing tasks are described. According the functional unit model and control model, a software/hardware integrating model with dataflow control infrastructure is constructed. The software/hardware partition is carded out in the experiments of ultrasonic signal processing, and the results show that the system model is practicable.
文摘This paper introduces the hardware structure and software design of data acquisition system based on embedded Linux. In order to improve the real-time response performance and the ability of multi task for system, using ARM9 microprocessor technology in hardware, and transplant the Linux operating system, and the system reliability and scalability can be improved. The design makes full use of the characteristics of embedded Linux. The system software module have data acquisition module, data processing module, data communication module and data diagnostic module. The embedded Linux operating system is transplant into data acquisition system, that can accelerate the development of the system and convenient to future expansion functions, improve the observation data timeliness and accuracy, and can realize automation observation.