A new absorbing boundary condition (ABC) for frequency dependent finite difference time domain algorithm for the arbitrary dispersive media is presented. The concepts of the digital systems are introduced to the (F...A new absorbing boundary condition (ABC) for frequency dependent finite difference time domain algorithm for the arbitrary dispersive media is presented. The concepts of the digital systems are introduced to the (FD) 2TD method. On the basis of digital filter designing and vector algebra, the absorbing boundary condition under arbitrary angle of incidence are derived. The transient electromagnetic problems in two dimensions and three dimensions are calculated and the validity of the ABC is verified.展开更多
The design of industrial floors will be presented in this paper. In the first part of this article the calculation methods of the TR34 British guideline will be discussed. In the second part the state of the art desig...The design of industrial floors will be presented in this paper. In the first part of this article the calculation methods of the TR34 British guideline will be discussed. In the second part the state of the art design methods using advanced finite element methods will be presented. The design itself may seem as slow considering the actual computer efficiency, however comparing the results to theoretical analysis and to designing methods, precision and economical nature of the method can be justified. A large number of foreign industrial floor designs were made by this method;some of them will be shown as reference at the end of the article.展开更多
本文基于FVCOM(Finite Volume Community Ocean Model)构建了一个覆盖中国渤海、黄海和东海的数值模型,采用NCEP-CFSR风场数据对1509号台风“灿鸿”产生的风暴潮进行模拟,与实测水位数据的对比表明该模型可靠、模拟结果合理。基于此模型...本文基于FVCOM(Finite Volume Community Ocean Model)构建了一个覆盖中国渤海、黄海和东海的数值模型,采用NCEP-CFSR风场数据对1509号台风“灿鸿”产生的风暴潮进行模拟,与实测水位数据的对比表明该模型可靠、模拟结果合理。基于此模型,本文对非线性作用和地形在风暴潮增水过程中的作用进行了研究。首先,重点分析了增水过程中潮汐与风暴潮的非线性作用,结果表明:高潮时非线性作用使增水值降低;低潮时非线性作用使增水值升高。另外,开边界处分别只添加M2、S2和K1分潮,分析天文潮的潮高和周期对非线性作用的影响,结果表明:潮高越高,非线性作用越明显;半日潮的非线性作用较全日潮更明显;并且,增水极值附近出现的半日周期的波动也与非线性作用有关。其次,除了非线性作用,地形对风暴潮的增水也有一定影响,本文改变地形的实验结果表明:坡度越大,增水极值越小。琉球群岛的存在使得东南沿海出现风暴潮增水的面积减小,但使得风暴潮增水的高值区域扩大。展开更多
有限状态机(Finite State Machine,FSM)是时序电路设计中经常采用的一种方式,尤其适用于设计数字系统的控制模块。有限状态机不是孤立的一个状态,它依赖于输入输出关系,系统需求,编程语言的条件限制以及其他诸多因素。本文主要介绍了有...有限状态机(Finite State Machine,FSM)是时序电路设计中经常采用的一种方式,尤其适用于设计数字系统的控制模块。有限状态机不是孤立的一个状态,它依赖于输入输出关系,系统需求,编程语言的条件限制以及其他诸多因素。本文主要介绍了有限状态机的原理及实际应用。展开更多
Nonlinear dynamic analysis of rotating machinery system has always been the hot spot of the rotational dynamics re-search. This article sets up a rotating machinery condition monitoring system to realize the measureme...Nonlinear dynamic analysis of rotating machinery system has always been the hot spot of the rotational dynamics re-search. This article sets up a rotating machinery condition monitoring system to realize the measurement of system dynamic charac-teristic parameters based on NI(National Instruments) virtual instruments technology. The measurement of vibration signal of rotating machinery system is achieved by using NI company general data acquisition module of NI Company. Meanwhile, by analyzing and processing the acquired data using LabVIEW 2012, the dynamic characteristics, such as .the speed of the rotating machinery system, the axis trajectory, spectrum parameters, are attained. The measurement results show that the rotating machinery condition monitor-ing system based on LabVIEW is easy to operate, easy to realize the function extension and maintenance, and that it can be used in the industrial engineering projects with rotation characteristics. LabVIEW as the development tools used by virtual instrument func-tion is very powerful data acquisition software products support is one of the features of it, so using LabVIEW programming and data acquisition is simple and convenient.展开更多
To ensure the quality of Web applications, Web testing is one of the effective methods. The testing is a process of revealing errors that is used to give confidence that the implementation of a Web application meets i...To ensure the quality of Web applications, Web testing is one of the effective methods. The testing is a process of revealing errors that is used to give confidence that the implementation of a Web application meets its original specification. This work proposes a Web testing framework based on Stream X-Machines (SXMs), which provides a way to derive test cases for a Web application. It starts from constructing the SXM model, from which a test translator is employed to extract the test paths and then translates them into an XML-style test specification, which is the input of test engine. The test engine generates test cases and then executes them, and finally produces test report. This testing method is a significant contribution to informed research.展开更多
To enhance dynamic tracking performance and anti-disturbance capacity of finite impulse response(FIR) filters, variable discount factors are introduced to the recursive least squares(RLS) algorithm. By employing impro...To enhance dynamic tracking performance and anti-disturbance capacity of finite impulse response(FIR) filters, variable discount factors are introduced to the recursive least squares(RLS) algorithm. By employing improved FIR filters to conduct modelling of industrial robot drive systems, dynamic characteristics of the target systems are identified. Then the fault detection for a target system can be utilized by analyzing the coefficients of the FIR filter. Finally, an application of the fault detection scheme to a kind of brushless DC motor drive system is described. Compared with reference methods, the proposed scheme achieves effective fault detection and performs better in dynamic tracking and robustness according to the final simulation results.展开更多
文摘A new absorbing boundary condition (ABC) for frequency dependent finite difference time domain algorithm for the arbitrary dispersive media is presented. The concepts of the digital systems are introduced to the (FD) 2TD method. On the basis of digital filter designing and vector algebra, the absorbing boundary condition under arbitrary angle of incidence are derived. The transient electromagnetic problems in two dimensions and three dimensions are calculated and the validity of the ABC is verified.
文摘The design of industrial floors will be presented in this paper. In the first part of this article the calculation methods of the TR34 British guideline will be discussed. In the second part the state of the art design methods using advanced finite element methods will be presented. The design itself may seem as slow considering the actual computer efficiency, however comparing the results to theoretical analysis and to designing methods, precision and economical nature of the method can be justified. A large number of foreign industrial floor designs were made by this method;some of them will be shown as reference at the end of the article.
文摘本文基于FVCOM(Finite Volume Community Ocean Model)构建了一个覆盖中国渤海、黄海和东海的数值模型,采用NCEP-CFSR风场数据对1509号台风“灿鸿”产生的风暴潮进行模拟,与实测水位数据的对比表明该模型可靠、模拟结果合理。基于此模型,本文对非线性作用和地形在风暴潮增水过程中的作用进行了研究。首先,重点分析了增水过程中潮汐与风暴潮的非线性作用,结果表明:高潮时非线性作用使增水值降低;低潮时非线性作用使增水值升高。另外,开边界处分别只添加M2、S2和K1分潮,分析天文潮的潮高和周期对非线性作用的影响,结果表明:潮高越高,非线性作用越明显;半日潮的非线性作用较全日潮更明显;并且,增水极值附近出现的半日周期的波动也与非线性作用有关。其次,除了非线性作用,地形对风暴潮的增水也有一定影响,本文改变地形的实验结果表明:坡度越大,增水极值越小。琉球群岛的存在使得东南沿海出现风暴潮增水的面积减小,但使得风暴潮增水的高值区域扩大。
文摘Nonlinear dynamic analysis of rotating machinery system has always been the hot spot of the rotational dynamics re-search. This article sets up a rotating machinery condition monitoring system to realize the measurement of system dynamic charac-teristic parameters based on NI(National Instruments) virtual instruments technology. The measurement of vibration signal of rotating machinery system is achieved by using NI company general data acquisition module of NI Company. Meanwhile, by analyzing and processing the acquired data using LabVIEW 2012, the dynamic characteristics, such as .the speed of the rotating machinery system, the axis trajectory, spectrum parameters, are attained. The measurement results show that the rotating machinery condition monitor-ing system based on LabVIEW is easy to operate, easy to realize the function extension and maintenance, and that it can be used in the industrial engineering projects with rotation characteristics. LabVIEW as the development tools used by virtual instrument func-tion is very powerful data acquisition software products support is one of the features of it, so using LabVIEW programming and data acquisition is simple and convenient.
文摘To ensure the quality of Web applications, Web testing is one of the effective methods. The testing is a process of revealing errors that is used to give confidence that the implementation of a Web application meets its original specification. This work proposes a Web testing framework based on Stream X-Machines (SXMs), which provides a way to derive test cases for a Web application. It starts from constructing the SXM model, from which a test translator is employed to extract the test paths and then translates them into an XML-style test specification, which is the input of test engine. The test engine generates test cases and then executes them, and finally produces test report. This testing method is a significant contribution to informed research.
基金Supported by the Provincial Training Program of Innovation and Entrepreneurship for Undergraduates (202013571002Z)。
文摘To enhance dynamic tracking performance and anti-disturbance capacity of finite impulse response(FIR) filters, variable discount factors are introduced to the recursive least squares(RLS) algorithm. By employing improved FIR filters to conduct modelling of industrial robot drive systems, dynamic characteristics of the target systems are identified. Then the fault detection for a target system can be utilized by analyzing the coefficients of the FIR filter. Finally, an application of the fault detection scheme to a kind of brushless DC motor drive system is described. Compared with reference methods, the proposed scheme achieves effective fault detection and performs better in dynamic tracking and robustness according to the final simulation results.
