Theory of nonlinear systems

This paper gives a general review of the Theory of Nonlinear Systems. In 1960, the author presented a paper “Theory of Nonlinear Control” at the First IFAC Congress at Moscow. Professor Norbert Wiener, who attended this Congress, drew attention to his work on the synthesis and analysis of nonlinear systems in terms of Hermitian polynomials in the Laguerre coefficients of the past of the input.Wiener's original idea was to use white noise as a probe on any nonlinear system. Applying this input to a Laguerre network gives u₁, u₂,…, u_s, and then to a Hermite polynomial generator gives V(α)'s. Applying the same input to the actual nonlinear system gives output c(t). Putting c(t) and V(α)'s through a product averaging device, we get $\text{c(t)V(α)}\text{=}\text{A}{}_{\mathrm{\alpha }}\text{2л}{}^{\mathrm{<mtext>s</mtext><mtext>2</mtext>}}$, where the upper bar denotes time average and A_α's can be considered as characteristic coefficients of the nonlinear system. A desired output z(itt) may replace c(itt) to get a new set of A_α's.The Volterra functional method suggested by Wiener in 1942 has been greatlydeveloped from 1955 to the present. The method involves a multi-dimensional convolution integral with multi- dimensional kernels. The associated multi-dimensional transforms are given by Y.H. Ku and A.A. Wolf (J. Franklin Inst., Vol. 281, pp. 9–26, 1966). Wiener extended the Volterra functionals by forming an orthogonal set of functionals known as G-functionals, using Gaussian white noise as input. Volterra kernels and Wiener kernels can be correlated and form the characteristic functions of nonlinear systems.From an extension of the linear system to the nonlinear system, the input-output crosscorrelation φ_xy can be shown to be equal to the convolution of system impulse response h₁ with the autocorrelation φ_xx. Using the white noise as input, where its power density spectrum is a constant, say, A, the crosscorrelation is given by φ_xy(σ) = Ah₁(σ), while the autocorrelation is φ_xx(τ) = Au(τ). This extension forms the basis of an optimum method for nonlinear system identification. Measurement of kernels can be made through proper circuitry.Parallel to the Volterra series and the Wiener series, another series based on Taylor-Cauchy transforms developed since 1959 are given for comparison. The Taylor-Cauchy transform method can be applied in the analysis of simultaneous nonlinear systems. It is noted that the Volterra functional method and the Taylor-Cauchy transform method give identical final results.A selected Bibliography is appended not only to include other aspects of nonlinear system theory but also to show the wide application of nonlinear system characterization and identification to problems in biology, ecology, physiology, cybernetics, control theory, socio- economic systems, etc.     

Reader,Word, and Character Attributes Contributing to Chinese Children’s Concept of Word

Concept of word—the awareness of how words differ from nonwords or other linguistic properties—is important to learning to read Chinese because words in Chinese texts are not separated by space, and most characters can be productively compounded with other characters to form new words. The current study examined the effects of reader, word, and character attributes on Chinese children’s concept of word in text. A total of 164 fifth-grade Chinese children participated in this study. Concept of word was measured by children’s lexical decisions about words and nonwords embedded in strings of characters. Cross-classified multilevel logistic models showed that reader attributes, including reading comprehension, vocabulary knowledge, and morphological awareness, interacted with certain word or character attributes in predicting children’s lexical decisions about words or nonwords. This study sheds light on the complex relationships between reader, word, and character attributes in the formation of concept of word in Chinese.     

直线电磁抽油机关键技术研究

针对石油在开采过程中消耗电能很大,能耗在采油成本中占有相当大的比重等问题,以直接驱动为目的的直线电磁抽油机的研究逐渐成为热点。本研究提出了提高直线电磁抽油机系统效率的三种途径,即：优化电动机、改善载荷负载的示功图以及采取适当的控制策略。该项技术研究为解决油田高能耗问题探索出一条新的途径。     

Assemble Collocation and Colligation in Chinese Writing Web Tools for New Immigrants in Taiwan

CSL （Chinese as a second language） learning is an emergency task in Taiwan, especially when more and more new immigrants joined in Taiwan. However, there are just a few new immigrants who can finish all language courses. For this reason, this research intends to provide a training system to assist new immigrants observing and learning the phrase structure. In this paper, the researchers design a system which can help new immigrants to form Chinese sentences by applying colligation and collocation technology.     

The introduction of electronic portfolios to teach and assess english as a foreign language in Taiwan

Conclusion The use of electronic portfolios to teach and assess EFL affects both teachers and students who are accustomed to traditional methods of teaching and learning English in Taiwan. This new innovation also stimulates teachers and students to think about ways to connect their work, their school and the island communities of Taiwan. Ultimately, it will help teachers and students to look beyond the Taiwan community to interact with a more globalized world community.     

Development of an instrument for exploring preservice technology teachers’ maker-based technological pedagogical content knowledge

With the development of the maker movement, more and more teachers are applying a broad range of technological tools in their pedagogy, instead of only information technology. This study details the development and validation of the Teachers Maker-based TPACK Survey Instrument (TMTSI), a revised model designed to measure technology teachers’ maker-based technological pedagogical content knowledge (TPACK) in utilizing maker-based tools to support their teaching. We recruited 165 preservice secondary technology teachers in Taiwan for this study and confirmatory factor analysis was applied to validate the instrument. Our findings suggest that TMTSI provided a valid and highly reliable research-based instrument that also serves as a professional development model to help scaffold the development of K-12 technology teachers. This paper details the theoretical foundations of TMTSI, reports on its reliability and validity, and discusses the application and implications of TMTSI for teacher education and professional development.     

基于NFI-CMAC的系统参数智能辨识

基于牛顿前向插值公式,提出一种对任意阶多维函数可实现无差逼近的新型CMAC神经网络———NFI-CMAC,详细阐述了基本原理、插值算法及训练规则。基于NFI-CMAC,提出了一种快速、高精度的控制系统参数在线智能辨识方案,仿真实例表明了该方案的可行性与有效性。     

Measuring active learning to predict course quality

This study investigated whether active learning within computer‐based training courses can be measured and whether it serves as a predictor of learner‐perceived course quality. A major corporation participated in this research, providing access to internal employee training courses, training representatives, and historical course evaluation data. Twenty sample courses were subdivided into 1,884 time‐based instructional events and categorized by eight design principles for learner engagement: attend, organize, recall, practice, interact, apply, explore, and absorb. This analysis produces a quantitative pattern for the cognitive activity a course encourages within the learner, summarized as the active learning index. A regression model, with the active learning index as a predictor variable for learner‐perceived course quality, resulted in a correlation coefficient of .83 (r²=.69) and a p‐value <.0001. These results suggest a framework for quantifying the active learning components in computer‐based training courses and guiding the work of instructional designers toward higher‐quality courses.     

Acknowledgement of contributions by reviewers

Given the immense power of the mass media, how they selectively represent the world requires investigation and critique. Selective representation refers basically to the promotion and reinforcement of certain ways of thinking (Fairclough 1995b, Lull 1995). This paper examines, by way of linguistic analysis, particular representations of the school experience in three popular English teenage magazines in Singapore. It concentrates on the implicit ‘commonsense’ assumptions about school which underlie common teenage discourse on such popular topics as having fun, being cool, looking good, etc.     

Using Rogers's Diffusion of Innovation Model to Examine the Willingness to Pay for Public Television in Taiwan

This study adopts Rogers's diffusion of innovation model to examine the factors affecting the willingness of the Taiwanese to pay a license fee to watch public television. A telephone survey was used, and 506 valid questionnaires were obtained, representing a response rate of 58.6%. The data analysis showed that most findings of this study were not congruent with the prediction of Rogers's model, indicating that the Taiwanese do not consider paying a license fee a feasible means to support public television. However, this study found that the frequency of public television viewing was the most powerful factor positively affecting people's intention to pay for public television.