A study of quadratic cost functions for vehicle headway control

This paper shows that minimizing a quadratic cost function is not particularly useful for selecting a small number of controller gains in vehicle headway control. For cases in which a large number of controller gains are to be selected, the quadratic cost function may be useful, but the weighting parameter values cannot usually be chosen a priori if transient performance measures are of a particular interest. Examples illustrate how values of weights in a simplified cost function can be selected to yield acceptable transient performance. This performance is compared with that for a system containing only a few gains and optimized without recourse to a cost function.     

Representations of ethnic minorities in China's university media

This paper examines the representation of ethnic minorities in China through a review of campus newspapers, a major print medium in which universities exercise power over the discourse of cultural recognition. Three universities attended by minority students were selected. A two-dimensional mode (content and configuration) is established to analyze ethnic representations. A combination of content analysis and discourse analysis is used to categorize and analyze text and photographs relevant to ethnicity. The study concludes that (1) different discursive practices are employed to construct ‘images’ of ethnic groups as ‘Others’ or ‘Us’; (2) representations of ethnic minorities and the Han generate three discursive dichotomies between minority and majority: minority groups are distinctive, potentially separatistic, and visible; and the Han people are normative, patriotic, and invisible, respectively; (3) the university media reflects an ideology of ‘state multiculturalism’ that constructs a reflexive representation of the relationship between majority and minority.     

The influence of serve characteristics on performance in men's and women's high-standard beach volleyball

The precise influence of serve type and serve ball speed on beach volleyball performance is unclear. We examined the relationship between serve type and speed and their effectiveness during the 2008 Men's and Women's Open World Tour Tournament. Three hundred and seventy-eight and 375 serves performed by men and women respectively from the main draw tournament were analysed. Serve speed was recorded using a radar gun. Two expert observers recorded serve speed, serve mode, serve effectiveness and rally outcome. There was no relationship between serve speed and its effectiveness for men (r = -0.047, P > 0.05) and for women (r = -0.048, P > 0.05). However, there was a relationship between serve ball speed and its effectiveness both for men and women, when speed was categorised into three groups. There was a better balance between negative and positive outcomes at medium speeds for men and at low and high speeds for women. There was a relationship between ranking and serve ball speed only for women and between ranking and type of serve for both genders. There was no relationship between rally outcome and serve effectiveness. The combination of high ball speed and jump serve is characteristic of high ranking women but not of men.     

A Model for Using Triadic Supervision in Counselor Preparation Programs

The Council for Accreditation of Counseling and Related Educational Programs (2001) has approved the use of triadic supervision as an alternative to individual supervision in clinical instruction. However, literature describing this mode of supervision is very limited. A model for triadic supervision is described, including presession planning, in‐session strategies, and administrative considerations and supervisee evaluation. An evaluation of the model from 2 recent studies is also discussed, and recommendations are provided for using triadic supervision in counselor preparation.     

Academic Libraries and Autism Spectrum Disorder: What Do We Know?

This paper examines the rising rates of autism spectrum disorder (ASD) in children in the United States (1 in 59), and explores the role academic libraries can play in helping college students with ASD. A literature review of how different types of libraries (school, public, academic) support students with ASD indicates research in this area in general is lacking. Findings point to lack of adequate training and awareness for librarians and staff, resources, services and spaces are universal challenges. Several initiatives that academic libraries and librarians may consider in helping students with ASD are identified and described.     

Small-sided games can discriminate perceptual-cognitive-motor capability and predict disposal efficiency in match performance of skilled Australian footballers

This study determined if small-sided games could discriminate perceptual-cognitive-motor skill in Australian Rules Footballers. Higher skilled Western Australian Football League (WAFL) (n = 17) and lesser skilled Amateur (n = 23) players were recruited. Participants played three small-sided games of three minutes. Each disposal was scored for decision-making and motor skill execution, with these scores combined for a total score. Mann-Whitney U tests indicated significantly superior mean decision-making by higher skilled (Median = 2.90, Range = 0.30) over lesser skilled (Median = 2.80, Range = 0.73) (p = .012) players. Execution score was not significantly different between groups. Linear mixed model analysis found higher skilled players (M = 5.32, SD = 1.19) scored significantly higher than lower skilled players (M = 4.90, SD = 1.52) on total score (p = .009). Large effect sizes were found for decision-making and total score relative to games and position played in WAFL players. High agreement of scoring was observed for an elite (inter-rater) and a novice (intra-rater) coaches. Linear mixed model analysis indicated mean total scores of WAFL players significantly predicted disposal efficiency in match performance (p = .011). Small-sided games can be easily implemented to identify talented players and assess perceptual-cognitive-motor skill.     

Some Common Teaching Practices and their Effectiveness in Foreign Language Reading Instruction

This article shows that some rather common foreign‐language‐teaching reading practices are questionable. Very often, the emphasis is on the content of the text used in the instruction, and only rarely on developing reading skills. Questioning, one of the most frequently observed teaching strategies, hardly contributes to better reading achievement. Neither does teaching the content or explaining words. Explanations for this are proposed to be found in educational tradition, teacher values, teacher needs, desired teaching comfort and the influence of the testing format as used in examinations. In fact, teaching reading is to a large extent no more than sustained comprehension assessment. Some alternative types of exercises, materials and teacher activities, are presented, based on an analysis of crucial characteristics of the reading process and on some clues from learning theory.     

Determinants of countermovement jump performance: a kinetic and kinematic analysis

Abstract

This study aimed to investigate the contributions of kinetic and kinematic parameters to inter-individual variation in countermovement jump (CMJ) performance. Two-dimensional kinematic data and ground reaction forces during a CMJ were recorded for 18 males of varying jumping experience. Ten kinetic and eight kinematic parameters were determined for each performance, describing peak lower-limb joint torques and powers, concentric knee extension rate of torque development and CMJ technique. Participants also completed a series of isometric knee extensions to measure the rate of torque development and peak torque. CMJ height ranged from 0.38 to 0.73 m (mean 0.55 ± 0.09 m). CMJ peak knee power, peak ankle power and take-off shoulder angle explained 74% of this observed variation. CMJ kinematic (58%) and CMJ kinetic (57%) parameters explained a much larger proportion of the jump height variation than the isometric parameters (18%), suggesting that coachable technique factors and the joint kinetics during the jump are important determinants of CMJ performance. Technique, specifically greater ankle plantar-flexion and shoulder flexion at take-off (together explaining 58% of the CMJ height variation), likely influences the extent to which maximal muscle capabilities can be utilised during the jump.     

W5″ Test: A simple method for measuring mean power output in the bench press exercise

The aims of the present study were to assess the validity and reliability of a novel simple test [Five Seconds Power Test (W5″ Test)] for estimating the mean power output during the bench press exercise at different loads, and its sensitivity to detect training-induced changes. Thirty trained young men completed as many repetitions as possible in a time of ≈5?s at 25%, 45%, 65% and 85% of one-repetition maximum (1RM) in two test sessions separated by four days. The number of repetitions, linear displacement of the bar and time needed to complete the test were recorded by two independent testers, and a linear encoder was used as the criterion measure. For each load, the mean power output was calculated in the W5″ Test as mechanical work per time unit and compared with that obtained from the linear encoder. Subsequently, 20 additional subjects (10 training group vs. 10 control group) were assessed before and after completing a seven-week training programme designed to improve maximal power. Results showed that both assessment methods correlated highly in estimating mean power output at different loads (r range: 0.86–0.94; p?R²: 0.78). Good to excellent intra-tester (intraclass correlation coefficient (ICC) range: 0.81–0.97) and excellent inter-tester (ICC range: 0.96–0.99; coefficient of variation range: 2.4–4.1%) reliability was found for all loads. The W5″ Test was shown to be a valid, reliable and sensitive method for measuring mean power output during the bench press exercise in subjects who have previous resistance training experience.     

Psychomotor learning theory informing the design and evaluation of an interactive augmented reality hand hygiene training app for healthcare workers

Education and Information Technologies - Hand hygiene is critical for infection control, but studies report poor transfer from training to practice. Hand hygiene training in hospitals typically...