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991.
The purpose of this study was to assess the sources of award-wining research professors’ (six women; six men) teaching self-efficacy through the framework of Bandura’s (1986) social cognitive theory. Semi-structured interviews revealed that mastery experiences and social persuasions were particularly influential sources of self-efficacy and that these sources tended to be closely related. Professors reported that their self-efficacy had generally stabilized within their first few years of assuming a tenure-track position. Participants framed negative events in adaptive ways that had little cost to their teaching self-efficacy. 相似文献
992.
Grisham W Schottler NA McCauley LM Pham AP Ruiz ML Fong MC Cui X 《CBE life sciences education》2011,10(2):222-230
Zebra finch song behavior is sexually dimorphic: males sing and females do not. The neural system underlying this behavior is sexually dimorphic, and this sex difference is easy to quantify. During development, the zebra finch song system can be altered by steroid hormones, specifically estradiol, which actually masculinizes it. Because of the ease of quantification and experimental manipulation, the zebra finch song system has great potential for use in undergraduate labs. Unfortunately, the underlying costs prohibit use of this system in undergraduate labs. Further, the time required to perform a developmental study renders such undertakings unrealistic within a single academic term. We have overcome these barriers by creating digital tools, including an image library of song nuclei from zebra finch brains. Students using this library replicate and extend a published experiment examining the dose of estradiol required to masculinize the female zebra finch brain. We have used this library for several terms, and students not only obtain significant experimental results but also make gains in understanding content, experimental controls, and inferential statistics (analysis of variance and post hoc tests). We have provided free access to these digital tools at the following website: http://mdcune.psych.ucla.edu/modules/birdsong. 相似文献
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995.
Dacai Liu Zhi Liu C.L. Philip Chen Yun Zhang 《Journal of The Franklin Institute》2021,358(3):1782-1811
The existing studies on prescribed-time control cannot directly deal with nonlinear functions which don’t satisfy Lipschitz growth conditions. No results are available for prescribed-time containment control of pure-feedback UNMASs with prescribed performance. Therefore, completely unknown nonlinear function, prescribed-time tracking of system states and prescribed performance of containment errors are simultaneously considered in this paper. Fuzzy logic systems are utilized to approximate completely unknown nonlinear function. Prescribed-performance function is introduced and further incorporated into a novel speed function. Combining the proposed speed function and barrier Lyapunov function, this article presents a novel adaptive fuzzy prescribed-time containment control method which can guarantee, under prescribed performance, all followers converge to a convex formed by dynamic leaders in a prescribed time. Moreover, all tracking errors converge to predefined regions in a prescribed time. The effectiveness of the proposed prescribed-time containment control method are confirmed by strict proof and simulation. 相似文献
996.
Robert B. Anderson Julius A. Marshall Andrea L’Afflitto 《Journal of The Franklin Institute》2021,358(12):6281-6308
In classical model reference adaptive control (MRAC), the adaptive rates must be tuned to meet multiple competing objectives. Large adaptive rates guarantee rapid convergence of the trajectory tracking error to zero. However, large adaptive rates may also induce saturation of the actuators and excessive overshoots of the closed-loop system’s trajectory tracking error. Conversely, low adaptive rates may produce unsatisfactory trajectory tracking performances. To overcome these limitations, in the classical MRAC framework, the adaptive rates must be tuned through an iterative process. Alternative approaches require to modify the plant’s reference model or the reference command input. This paper presents the first MRAC laws for nonlinear dynamical systems affected by matched and parametric uncertainties that constrain both the closed-loop system’s trajectory tracking error and the control input at all times within user-defined bounds, and enforce a user-defined rate of convergence on the trajectory tracking error. By applying the proposed MRAC laws, the adaptive rates can be set arbitrarily large and both the plant’s reference model and the reference command input can be chosen arbitrarily. The user-defined rate of convergence of the closed-loop plant’s trajectory is enforced by introducing a user-defined auxiliary reference model, which converges to the trajectory tracking error obtained by applying the classical MRAC laws before its transient dynamics has decayed, and steering the trajectory tracking error to the auxiliary reference model at a rate of convergence that is higher than the rate of convergence of the plant’s reference model. The ability of the proposed MRAC laws to prescribe the performance of the closed-loop system’s trajectory tracking error and control input is guaranteed by barrier Lyapunov functions. Numerical simulations illustrate both the applicability of our theoretical results and their effectiveness compared to other techniques such as prescribed performance control, which allows to constrain both the rate of convergence and the maximum overshoot on the trajectory tracking error of uncertain systems. 相似文献
997.
Biomechanics and visual-motor control: how it has, is, and will be used to reveal the secrets of hitting a cricket ball 总被引:1,自引:0,他引:1
Sarpeshkar V Mann DL 《Sports biomechanics / International Society of Biomechanics in Sports》2011,10(4):306-323
Cricket batting is an incredibly complex task which requires the coordination of full-body movements to successfully hit a fast moving ball. Biomechanical studies on batting have helped to shed light on how this intricate skill may be performed, yet the many different techniques exhibited by batters make the systematic examination of batting difficult. This review seeks to critically evaluate the existing literature examining cricket batting, but doing so by exploring the strong but often neglected relationship between biomechanics and visual-motor control. In three separate sections, the paper seeks to address (i) the different theories of motor control which may help to explain how skilled batters can hit a ball, (ii) strategies used by batters to overcome the (at times excessive) temporal constraints, and (iii) an interpretation from a visual-motor perspective of the prevailing biomechanical data on batting. 相似文献
998.
T. Le Sage A. Bindel P. P. Conway L. M. Justham S. E. Slawson A. A. West 《Sports Engineering》2011,14(1):1-14
The research outlined in this paper was conducted to allow real-time processing, transmission and presentation of data to
swimming coaches and subsequently their swimmers in a training environment, focused on providing information relevant to strokes
in free swimming. This was achieved using a wearable wireless sensor and embedded programming techniques, using accelerations
involved in the swimming stroke to provide relevant features for coaches. Current methods used do not offer real-time response
to coaches, which results in the lack of real-time feedback and significantly increased post-session analysis time. Filtering
and signal processing algorithms are described here, which allow real-time data analysis to be embedded within a wireless
sensor node. The system significantly reduces the time for processing acquired data and has delivered a novel monitoring device
suitable for operation within the harsh environment of the pool. 相似文献
999.
吕冬梅 《大学图书情报学刊》2011,29(6):15-18
文章对图书馆在实施馆员绩效考核过程中面临的诸多困境进行了分析,认为这主要是由思想观念出现偏差、图书馆作为不完全行为能力主体的尴尬地位、馆员素质层次不齐、考核实践模式不健全等原因造成的,进而从绩效考核的准备、实施、监控等阶段论述了破解困境的策略。 相似文献
1000.
Many user-centred studies of electronic information resources include a think-aloud element – where users are asked to verbalise their thoughts, interface actions and sometimes their feelings whilst using these resources to help them complete one or more information tasks. These studies are usually conducted with the purpose of identifying usability issues related to the resource(s) used or understanding aspects of users’ information behaviour. However, few of these studies present detailed accounts of how their think-aloud data was collected and analysed or provide detailed reflection on methodological decisions made. In this article, we discuss and reflect on the methodology used when planning and conducting a think-aloud study of lawyers’ interactive information behaviour. Our discussion is framed by Blandford et al.’s PRET A Rapporter (‘ready to report’) framework – a framework that can be used to plan, conduct and describe user-centred studies of electronic information resource use from an information work perspective. 相似文献