Understanding the role of shaft stiffness in the golf swing

Theoretically, shaft stiffness can alter shot distance by increasing clubhead speed or altering clubhead orientation at impact. A 3D forward dynamics model of a golfer and flexible club simulated the downswing. A genetic algorithm optimized the coordination of the model’s muscles (four torque generators) to maximize clubhead speed. The maximum torque output and maximum rate of torque development from the torque generators were varied to simulate the swing of golfers that generate different clubhead speeds. Four shafts of varying stiffness (flexible, regular, stiff, and completely rigid) were entered into these simulations to examine the role that shaft flexibility had on clubhead speed and orientation at impact. Shaft stiffness was found to have a meaningful effect only on clubhead orientation (dynamic loft and dynamic close) at impact. There was no evidence to support the premise that matching the stiffness properties of the shaft with the golfer would improve clubhead speed.     

Determination of the swing technique characteristics and performance outcome relationship in golf driving for low handicap female golfers

Abstract

Previous studies on the kinematics of the golf swing have mainly focused on group analysis of male golfers of a wide ability range. In the present study, we investigated gross body kinematics using a novel method of analysis for golf research for a group of low handicap female golfers to provide an understanding of their swing mechanics in relation to performance. Data were collected for the drive swings of 16 golfers using a 12-camera three-dimensional motion capture system and a stereoscopic launch monitor. Analysis of covariance identified three covariates (increased pelvis–thorax differential at the top of the backswing, increased pelvis translation during the backswing, and a decrease in absolute backswing time) as determinants of the variance in clubhead speed (adjusted r ² = 0.965, P < 0.05). A significant correlation was found between left-hand grip strength and clubhead speed (r = 0.54, P < 0.05) and between handicap and clubhead speed (r = ?0.612, P < 0.05). Flexibility measures showed some correlation with clubhead speed; both sitting flexibility tests gave positive correlations (clockwise: r = 0.522, P < 0.05; counterclockwise: r = 0.711, P < 0.01). The results suggest that there is no common driver swing technique for optimal performance in low handicap female golfers, and therefore consideration should be given to individual swing characteristics in future studies.     

Relative efficiency of R&D activities: A cross-country study accounting for environmental factors in the DEA approach

This paper applies the production framework associated with the data envelopment analysis (DEA) method to evaluate the relative efficiency of R&D activities across countries. R&D capital stocks and manpower are treated as inputs while patents and academic publications are considered as outputs. A three-stage approach, which involves using DEA for evaluating efficiency and using Tobit regressions for controlling the external environment, is applied to 30 countries in recent years. The results show that less than one-half of the countries are fully efficient in R&D activities and that more than two-thirds are at the stage of increasing returns to scale. Most countries have a more significant advantage in producing SCI cum EI publications than in generating patents.     

A Survey of Families in a Charter Hybrid Homeschool

“Hybrid homeschools” generally operate as formal schools 2–3 days per week. The rest of the week students are homeschooled. These entities therefore share some aspects of conventional schooling along with some aspects of homeschooling and are classified in a variety of ways by their states, local districts, and even their own administrations. Most hybrid homeschools around the nation tend to be private and religiously affiliated, though some public models have emerged. The purpose of this study was to better understand parents’ stated preferences for choosing to enroll their children in a charter school that is organized as a hybrid homeschool network in southern California. An electronic survey was sent through the network’s CEO to all enrolled families asking questions regarding demographics, stated values, and desired sources of information. The results of this survey find that these hybrid homeschool families are on average slightly more ethnically diverse, less wealthy, and less educated compared to private, religious hybrid homeschoolers, but are also more ethnically diverse, more wealthy, and more educated compared to their sponsoring school district. These families tend to place more value on individualized attention and the learning environment than on religion, safety, or formal academic issues when choosing a hybrid homeschool compared to their private, religious counterparts.     

Left Behind: District Secession and the Re-segregation of American Schools

ABSTRACT

Sixty-five years after the Brown v. Board decision, American schools are re-segregated and re-segregating. The mechanisms of this re-segregation are legal action, voluntary moves towards unitary status, unintended consequences of integration-oriented strategies, and an increasing trend towards the fracturing, or splintering of school districts. Both economic and political theory would indicate that splintering districts would work to pull racial and economic advantage out of the remaining district and into their own. To test this theory, we created a dataset that captures the fiscal and demographic status of U.S. school districts between 2000 and 2014 and analyzed the effect of district separation on the remaining districts in terms of student body composition, overall integration and local, state, and federal resources. Our findings indicate that separating districts are less diverse than the districts left behind. We further find that separating districts gain resources from local revenue and that remaining districts gain federal revenue in insufficient amounts to account for the loss of local funds. We find that these relative disadvantages for left behind districts and relative advantages for seceding districts persist when compared to the general population of school districts.     

Changes in the Multi‐Level Effects of Socio‐Economic Status on Reading Achievement in Sweden in 1991 and 2001

This study examines the changes in educational inequality at the school‐ and individual‐levels in 1991 and 2001. Comparisons are made between the IEA Reading Literacy Study 1991 and the so called 10‐Year Trend Study in PIRLS 2001. The between‐school differences in reading achievement variance and the size of the relationship between SES and reading achievement at school‐level are the two main focuses. Applying a two‐level structural equation modeling technique, it was found that the between‐school differences in reading achievement were greater in RLS 2001 than in RLS 1991, and the school SES effect has been strengthened over time. These changes indicate that educational inequality in Sweden has increased over time. Some possible explanations to these changes are discussed with reference to school reforms and demographic changes.     

An International Orientation on Institutional Strategies and Governmental Policies for the Use of ICT in Higher Education

This article provides an international comparative overview of institutional strategies, collaboration patterns and governmental policies related to the use of ICT in higher education. It has been produced as part of an international comparative study on the use of ICT in higher education. A study commissioned by the Dutch Ministry of Economic Affairs and the Ministry of Education, Culture and Science and published as: “The Use of Information and Communication Technology in Higher Education: An International Orientation on Trends and Issues”, B. Collis and M. van der Wende (Eds). University of Twente, CHEPS, 1999. It covers the following range of countries: Belgium, Finland, the United Kingdom, Australia and the United States of America. Additionally some main initiatives at the European level have been taken into account. On the basis of this international comparison, the following main conclusions were drawn. Due in part to the fact that in many cases institutional strategies for ICT are still lacking, interesting experimentation does not generally lead to successful dissemination and adoption on a wider scale. In many cases, the push for a substantial use of ICT in distance learning programs has come from new educati onal markets, life-long learning and international education in particular. The response of higher education to these markets is leading in many countries to a convergence of distance and traditional (on-campus) education. Inter-institutional and inter-sectoral collaboration between universities and companies are characteristics of many successful ICT initiatives, although they do not generally continue into sustainable implementation in the individual institutions. Governments facilitate the use of ICT through the establishment of infrastructure, networks and inter-institutional and public–private partnerships, and try to create the right regulatory environment. Further deregulation will enable institutions to respond to new market demands and will inspire the necessary organizational change in higher education institutions.     

PRESERVICE TEACHERS’ THOUGHTS AND FEARS ABOUT DISCIPLINING CHILDREN

The purposes of this study were threefold: (1) to determine if fears and concerns about guiding children's behavior and misbehavior is a generalized feeling, or more related to specific circumstances and scenarios; (2) to determine which situations may give students the greatest and least amounts of anxiety; and (3) to explore the relationship between students’ beliefs about the causes of children's misbehavior and their anxiety about specific discipline situations.

After completing a questionnaire, preservice teachers in this study rated children's challenges to their authority as the most difficult. Discipline situations involving conflicts between children (e.g., refusing to share, not joining in activities) were rated as the least difficult to handle. Most of the preservice teachers believed children misbehaved because of a lack of social skills and developmental sophistication rather than because of bad parenting, inherent personality characteristics, or too many adult restrictions. Preservice teachers rated the difficulty of the discipline issues similarly regardless of their beliefs concerning the causes of misbehavior. Implications of this study are discussed.     

MAGIS: mobile augmented-reality games for instructional support

ABSTRACT

We present Mobile Augmented-Reality Games for Instructional Support (MAGIS), a framework for the development of mobile augmented-reality (AR) games for education. The framework supports off-the-shelf, state-of-the-art technologies that enable AR tracking and rendering on consumer-level mobile devices, and integrates these technologies with content-generation tools that simplify the development of educational AR games, especially those that extensively use narrative-based game design and player-location tracking such as location-based historical or museum adventure games. We use Igpaw: Intramuros, a proof-of-concept game developed using MAGIS, to help describe the current state of the framework and to show its efficacy for implementing outdoor location-based educational games, and we briefly outline future development plans to improve MAGIS’ AR support (especially those involving indoor scenarios) as well as to improve the instructional design and authoring phases of AR applications written using this framework.