Effect of verbal instructions and image size on visual search strategies in basketball free throw shooting

We assessed the effects on basketball free throw performance of two types of verbal directions with an external attentional focus. Novices (n = 16) were pre-tested on free throw performance and assigned to two groups of similar ability (n = 8 in each). Both groups received verbal instructions with an external focus on either movement dynamics (movement form) or movement effects (e.g. ball trajectory relative to basket). The participants also observed a skilled model performing the task on either a small or large screen monitor, to ascertain the effects of visual presentation mode on task performance. After observation of six videotaped trials, all participants were given a post-test. Visual search patterns were monitored during observation and cross-referenced with performance on the pre- and post-test. Group effects were noted for verbal instructions and image size on visual search strategies and free throw performance. The 'movement effects' group saw a significant improvement in outcome scores between the pre-test and post-test. These results supported evidence that this group spent more viewing time on information outside the body than the 'movement dynamics' group. Image size affected both groups equally with more fixations of shorter duration when viewing the small screen. The results support the benefits of instructions when observing a model with an external focus on movement effects, not dynamics.     

A new active R bandpass filter

A new active R filter which realizes a second order bandpass transfer function is given. The network employs only resistors and two operational amplifiers. Sensitivities to all passive and active circuit components are very low. Design equations are given and experimental results are also included.     

Student engagement scale: development,reliability and validity

In this study, the purpose was to develop a student engagement scale for higher education. The participants were 805 students. In the process of developing the item pool regarding the scale, related literature was examined in detail and interviews were held. Six factors – valuing, sense of belonging, cognitive engagement, peer relationships (emotional engagement-I), relationships with faculty members (emotional engagement-II) and behavioural engagement within the scope of the components of campus engagement and class engagement – made up of 41 items were identified. The total variance explained was 59%. A higher student engagement score was regarded as an indicator that the student had a high level of engagement with the university, campus and class, while a lower score demonstrated that the student’s engagement with the campus and class was weak or that disengagement could occur.     

A stochastic multi-parameters divergence method for online auto-tuning of fractional order PID controllers

This paper presents a stochastic multi-parameters divergence method for online parameter optimization of fractional-order proportional–integral–derivative (PID) controllers. The method is used for auto-tuning without the need for exact mathematical plant model and it is applicable to diverse plant transfer functions. The proposed controller tuning algorithm is capable of adaptively responding to parameter fluctuations and model uncertainties in real systems. Adaptation skill enhances controller performance for real-time applications. Simulations and experimental observations are carried on a prototype helicopter model to confirm the performance improvements obtained by the online auto-tuning of fractional-order PID structure in laboratory conditions.     

Networked feedback control for nonlinear systems with random varying delays

This paper discusses the controller synthesis problem of a nonlinear networked controlled system subject to delays in the measurement and actuation channels. The communication through the network also suffers non-stationary packet dropouts. The bounded nonlinearities in the plant state satisfy Lipschitz conditions. A Lyapunov function is developed for the closed-loop system considering dynamic output feedback and the resulting stabilization conditions are drawn in the form of linear matrix inequalities to ensure that the system is exponentially stable in the mean-square sense. The developed conditions are represented in the form of a convex optimization problem and the results are tested by simulation on a quadruple-tank process.     

The application of workflow management to digital heritage resources

Recent years have witnessed a noticeable proliferation in Digital Library Systems (DLSs) and their specialized form represented in Digital Heritage Resources (DHRs). DHRs usually manage a complex and varied mix of digital heritage objects of different types and formats. They tend to be complex in nature and usually involve complex, simultaneous and intersecting workflows. As a result, DHRs impose implementation challenges on any solutions that aim to manage their workflows. Thus, despite the proliferation of DHRs, it is a noteworthy trend that there is a general lack of workflow management solutions that can be utilized in such systems. As a research area that is rarely covered, this paper therefore presents the design and development of a novel Workflow Management System (WfMS) built to integrate with DHRs specifically, and DLSs in general. In this context, an experimental WfMS aimed to test the validity of workflow management integration with DHRs. The devised WfMS was built as a workflow management solution that can adequately address the specific hurdles imposed by DHR implementations. Additionally, a novel DHR implementation framework called DISPLAYS (Digital Library Services for Playing with Antiquity and Shared Heritage) is presented as a test bed for the proposed WfMS.