Adaptive output-feedback control for nonlinear time-delay systems in pure-feedback form     

Sung Jin Yoo 《Journal of The Franklin Institute》2014

The main contribution of this paper is to develop an adaptive output-feedback control approach for a class of uncertain nonlinear systems with unknown time-varying delays in the pure-feedback form. Both the non-affine nonlinear functions and the unknown time-varying delayed functions related to all state variables are considered. These conditions make the controller design difficult and challenging because the output-feedback controller should be designed using only the output information. In order to overcome these conditions, we design an observer-based adaptive dynamic surface controller where the time-delay effects are compensated by using appropriate Lyapunov–Krasovskii functionals and the function approximation technique using neural networks. A first-order filter is added to the control input to avoid the algebraic loop problem caused by the non-affine structure. It is proved that all the signals in the closed-loop system are semi-globally uniformly bounded and the tracking error converges to an adjustable neighborhood of the origin.  相似文献   

Microfluidic electrical sorting of particles based on shape in a spiral microchannel     

John DuBose  Xinyu Lu  Saurin Patel  Shizhi Qian  Sang Woo Joo  Xiangchun Xuan 《Biomicrofluidics》2014,8(1)

Shape is an intrinsic marker of cell cycle, an important factor for identifying a bioparticle, and also a useful indicator of cell state for disease diagnostics. Therefore, shape can be a specific marker in label-free particle and cell separation for various chemical and biological applications. We demonstrate in this work a continuous-flow electrical sorting of spherical and peanut-shaped particles of similar volumes in an asymmetric double-spiral microchannel. It exploits curvature-induced dielectrophoresis to focus particles to a tight stream in the first spiral without any sheath flow and subsequently displace them to shape-dependent flow paths in the second spiral without any external force. We also develop a numerical model to simulate and understand this shape-based particle sorting in spiral microchannels. The predicted particle trajectories agree qualitatively with the experimental observation.  相似文献   

Middle school students' body mass index and physical activity levels in physical education     

Gao Z  Oh H  Sheng H 《Research quarterly for exercise and sport》2011,82(1):145-150

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Experimental intervention research on students with specific poor comprehension: a systematic review of treatment outcomes     

Sung Hee Lee  Shu-Fei Tsai 《Reading and writing》2017,30(4):917-943

Students with specific poor comprehension (SPC) can sound out words accurately, but have difficulty understanding what they read. However, most existing reading intervention studies on students with reading disabilities did not differentiate students with SPC from other types of students with reading disabilities who accompany with decoding difficulties. The purpose of this systematic review was to synthesize findings from 14 experimental intervention studies that have included students with SPC with the goal of increasing reading comprehension. Out of eight types of interventions identified, Reciprocal Teaching (g = .856) demonstrated the largest effect size. Metalinguistic intervention showed the effect size of above .50 (a medium effect size), suggesting that intervention that explicitly teaches high-level oral language strategies was positive to improve reading performances of students with SPC. Findings also suggest a need to specify the classification criteria of students with SPC to broaden an understanding about the evidence-based intervention for students with SPC. Practical implications for effective practice, limitations, and future directions are discussed.  相似文献   

Analytical method for promoting process capability of shock absorption steel     

Sung?Wen-Pei?Email author  Shih?Ming-Hsiang  Chen?Kuen-Suan 《浙江大学学报(A卷英文版)》2003,4(4):388-392

Mechanical properties and low cycle fatigue are two factors that must be considered in developing new type steel for shock absorption. Process capability and process control are significant factors in achieving the purpose of research and development programs. Often-used evaluation methods failed to measure process yield and process centering; so this paper uses Taguchi loss function as basis to establish an evaluation method and the steps for assessing the quality of mechanical properties and process control of an iron and steel manufacturer. The establishment of this method can serve the research and development and manufacturing industry and lay a foundation in enhancing its process control ability to select better manufacturing processes that are more reliable than decision making by using the other commonly used methods.  相似文献   

Integration of user profiles: models and experiments in information retrieval     

Sung H. Myaeng 《Information processing & management》1990,26(6)

One difficult problem in information retrieval (IR) is the proper interpretation of user queries. It is extremely hard for users to express their information needs in a specific yet exhaustive way. In an effort to alleviate this problem, two theoretical models have been proposed to utilize user characteristics maintained in the form of a user profile. Although the idea of integrating user profiles into an IR system is intuitively appealing, and the models seem viable, no research to date has established a foundation for the roles of user profiles in such a system. Aiming at the investigation of the roles of user profiles, therefore, this study first identifies and extends various query/profile interaction models to provide a ground upon which the investigation can be undertaken. From a continuum of models characterized on the basis of interaction types, metrics, and parameters, nearly 400 models are chosen to investigate the “model space.” New measures are developed based on the notion of user satisfaction/frustration. In addition, three different criteria are used to guide users in making judgments on the quality of retrieved items. Analysis of the data obtained from the experiments shows that, for a wide variety of criteria and metrics, there are always some query/profile interaction models that outperform the query alone model. In addition, preferable characteristics for different criteria are identified in terms of interaction types, parameters, and metrics.  相似文献   

Urban Youth Scholars: Cultivating Critical Global Leadership Development through Youth-Led Justice-Oriented Research     

Allen-Handy  Ayana  Thomas-EL  Shawnna L.  Sung  Kenzo K. 《The Urban Review》2021,53(2):264-294

The Urban Review - Educational researchers and practitioners have cited the need for new directions in youth leadership studies as it relates to globalization. Globalization is considered one of...  相似文献   

Robust ${\mathcal{H}}_{\infty }$ filtering of discrete-time nonhomogeneous Markovian jump systems with dual-layer operation modes     

Sung Hyun Kim 《Journal of The Franklin Institute》2019,356(1):697-717

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Bullying and repeated conventional transgressions in Swedish schools: How do gender and bullying roles affect students’ conceptions?          下载免费PDF全文

Robert Thornberg  Tiziana Pozzoli  Gianluca Gini  Jun Sung Hong 《Psychology in the schools》2017,54(9):1189-1201

Bullying is a moral transgression. Recognizing the importance of approaching bullying from a moral perspective, the present study examines whether children's judgments and reasoning to justify their judgments differ between bullying and repeated conventional transgressions. Our study also explores differences by gender and differences among bullies, victims, and uninvolved students. Participants included 381 students from 13 elementary schools in Sweden. Findings indicate that children judge bullying as more wrong than repeated conventional transgressions; use moral reasons more frequently in their justifications about bullying than about repeated conventional transgressions; and use conventional reasons more frequently to justify their judgments on repeated conventional transgressions as compared with bullying. Female students and nonbullies judged bullying and repeated conventional transgressions as more wrong and used moral reasons more frequently in their justifications of judgments of bullying than did male students and bullies. Male students reported bullying more than did female students. Implications for practice are also discussed.  相似文献   

Capitalizing on advances in mathematics and k-12 mathematics education in undergraduate mathematics: An inquiry-oriented approach to differential equations     

Chris Rasmussen  Oh Nam Kwon  Karen Allen  Karen Marrongelle  Mark Burtch 《Asia Pacific Education Review》2006,7(1):85-93

This paper provides an overview of the Inquiry-Oriented Differential Equations (IO-DE) project and reports on the main results of a study that compared students’ beliefs, skills, and understandings in IO-DE classes to more conventional approaches. The IO-DE project capitalizes on advances within mathematics and mathematics education, including the instructional design theory of Realistic Mathematics Education and the social negotiation of meaning. The main results of the comparison study found no significant difference between project students and comparison students on an assessment of routine skills and a significant difference in favor of project students on an assessment of conceptual understanding. Given these encouraging results, the theoretical underpinnings of the innovative approach may be useful more broadly for undergraduate mathematics education reform.  相似文献