Managing items and knowledge components: domain modeling in practice     

Pelánek  Radek 《Educational technology research and development : ETR & D》2020,68(1):529-550

Educational technology research and development - Adaptive learning systems need large pools of examples for practice—thousands of items that need to be organized into hundreds of knowledge...  相似文献   

Are professional young rugby league players eating enough? Energy intake,expenditure and balance during a pre-season     

Nessan Costello  Kevin Deighton  Thomas Preston  Jamie Matu  Joshua Rowe  Ben Jones 《European Journal of Sport Science》2019,19(1):123-132

Abstract

Due to the unique energetic demands of professional young collision sport athletes, accurate assessment of energy balance is required. Consequently, this is the first study to simultaneously investigate the energy intake, expenditure and balance of professional young rugby league players across a pre-season period. The total energy expenditure of six professional young male rugby league players was measured via doubly labelled water over a fourteen-day assessment period. Resting metabolic rate was measured and physical activity level calculated. Dietary intake was reported via Snap-N-Send over a non-consecutive ten-day assessment period, alongside changes in fasted body mass and hydration status. Accordingly, energy balance was inferred. The mean (standard deviation) difference between total energy intake (16.73 (1.32) MJ^.day^?1) and total energy expenditure (18.36 (3.05) MJ^.day^?1) measured over the non-consecutive ten-day period was unclear (?1.63 (1.73) MJ^.day^?1; ES?=?0.91?±?1.28; p?=?0.221). This corresponded in a most likely trivial decrease in body mass (?0.65 (0.78) kg; ES?=?0.04?±?0.03; p?=?0.097). Resting metabolic rate and physical activity level across the fourteen-day pre-season period was 11.20 (2.16) MJ^.day^?1 and 1.7 (0.2), respectively. For the first time, this study utilises gold standard assessment techniques to elucidate the distinctly large energy expenditures of professional young rugby league players across a pre-season period, emphasising a requirement for equally large energy intakes to achieve targeted body mass and composition adaptations. Accordingly, it is imperative that practitioners regularly assess the energy balance of professional young collision-sport athletes to ensure their unique energetic requirements are achieved.  相似文献   

Single-parameter tuning of PI controllers: Theory and application     

Radek Matuš?  Roman Prokop 《Journal of The Franklin Institute》2011,348(8):2059-2071

The paper deals with the influence of a single tuning parameter on performance properties of the closed control loop which contains algebraically designed continuous-time PI controller while the response quality is evaluated by the size of first under- or overshoots. The controllers are obtained from general solutions of Diophantine equations in the ring of proper and stable rational functions and can be subsequently tuned via the only parameter. This article brings simple tuning rules, verifies their validity by means of simulation example and, moreover, it presents their possible practical application during control of real laboratory model assumed as system with parametric uncertainty.  相似文献