Shape optimization of golf clubface using finite element impact models     

Willem Petersen  John McPhee 《Sports Engineering》2009,12(2):77-85

To model the impact dynamics of a golf drive, finite element (FE) models of the ball and the clubhead are created and combined to simulate the collision of the two bodies. A three-piece golf ball is modelled using only solid elements, while the clubhead is modelled using solid elements for the crucial area of the impact, i.e. the clubface, and using shell elements for the rest of the clubhead to improve the computational efficiency of the simulation. The correct transfer of forces and moments in the transition area between the shell and solid elements is assured by introducing kinematic nodal constraints using rigid elements. The FE model is used to optimize the shape of the clubface in three steps to maximize the launch velocity of the golf ball for central impacts. A final clubface shape is reached and a total improvement of 4.8 m/s over the initial design is obtained. This is a 7% gain in launch velocity, which results in a driving length advantage of approximately 20 m (or 22 yards) until the first contact with the ground. During the optimization process, the mechanical impedances of the two colliding bodies were recorded and compared. It is shown that the optimal clubhead geometry does not agree with the impedance matching theory by comparing the optimization results to those obtained from a simple lumped parameter model.  相似文献   

The Academic Manifesto: From an Occupied to a Public University     

Willem Halffman  Hans Radder 《Minerva》2015,53(2):165-187

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A response to Carol Nash     

Willem H. Vanderburg 《Interchange》1989,20(1):65-67

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Designing innovative learning environments to foster communities of learners for students in initial vocational education     

Annoesjka Boersma  Geert ten Dam  Willem Wardekker  Monique Volman 《Learning Environments Research》2016,19(1):107-131

In this study, the concept of ‘community of learners’ was used to improve initial vocational education. The framework of a ‘community of learners for vocational orientation’ that we present offers both a theoretical understanding of teaching–learning processes in initial vocational education and heuristics for the design of innovative learning environments for optimising these processes. In a design research study, we investigated if, and how, learning environments designed on the basis of these heuristics fostered communities of learners for vocational orientation, in which students experience to learn in a shared, meaningful, reflective and transfer-oriented way. We examined students’ perceptions of the learning environment and their learning activities during eight curriculum units specifically designed to foster the communities of learners. During almost all of the units that we designed, students found themselves learning in a more shared, meaningful, reflective and transfer-oriented way than during regular units. We conclude that the proposed heuristics had been useful starting points for the design of innovative learning environments that foster communities of learners for vocational orientation. In addition, we show how the heuristics can be elaborated for a particular school, based on practical and pedagogical content knowledge of teachers, as well as students’ perceptions of the learning environment and their learning activities.  相似文献   

Peer teaching: Academic achievement of teacher-led versus student-led discussion groups   总被引：1，自引：0，他引：1  

Maurice L. De Volder  Willem S. De Grave  Wim Gijselaers 《Higher Education》1985,14(6):643-650

Problem-based small-group discussions are the cornerstone of health sciences education at the University of Limburg (The Netherlands). In each of three courses, fifteen discussion groups of about eight students were randomly assigned a staff-tutor (control condition) or student-tutor (experimental condition).In two of the courses no significant differences in cognitive test achievement between the two conditions were found. In one course students tutored by staff-tutors performed significantly better than students tutored by student-tutors. However, no significant differences in test performance were found between students tutored by high-achieving versus average-achieving student-tutors. These findings contradict the congruence hypothesis from information processing theory. Several other explanations are explored.  相似文献   

The use of mathematical symbolism in problem solving: An empirical study carried out in grade one in the French community of Belgium     

Annick Fagnant 《European Journal of Psychology of Education - EJPE》2005,20(4):355-367

This article relates to an empirical study based on the use of mathematical symbolism in problem solving. Twenty-five pupils were interviewed individually at the end of grade one; each of them was asked to solve and symbolize 14 different problems. In their classical curriculum, these pupils have received a traditional education based on a “top-down” approach (an approach that is still applied within the French Community of Belgium): conventional symbols are presented to the pupils immediately with an explanation of what they represent and how they should be used. Teaching then focuses on calculation techniques (considered as a pre-requisite for solving problems). The results presented here show the abilities (and difficulties) demonstrated by the children in making connections between the conventional symbolism taught in class and the informal approaches they develop when faced with the problems that are put to them. The limits of the “top-down” approach are then discussed as opposed to the more innovative “bottom-up” type approaches, such as those developed by supporters of Realistic Mathematics Educations in particular.  相似文献   

Learn to Lead: Mapping Workplace Learning of School Leaders     

Frank Arnoud Hulsbos  Arnoud Theodoor Evers  Joseph Willem Marie Kessels 《Vocations and Learning》2016,9(1):21-42

In recent years policy makers’ interest in the professional development of school leaders has grown considerably. Although we know some aspect of formal educational programs for school leaders, little is known about school leaders’ incidental and non-formal learning in the workplace. This study aims to grasp what workplace learning activities school leaders value most, what work-related questions incite them to learn, what outcomes they achieve through workplace learning and what conditions support workplace learning of school leaders. In order to generate answers to the research questions, we conducted semi-structured interviews with 20 Dutch school leaders in secondary education, which also served as a form of reflection for the respondents. Results show that school leaders mostly value workplace learning through working on improvement and innovation and through reflection. In addition to outcomes for the school leader, working on improvement and innovation also leads to learning outcomes for teachers, and seems to provide opportunities for teachers to influence changes in the school. On the other hand, teachers take little or no part in reflection. Here, school leaders find peace and stability to reflect with fellow school leaders. If adjusted to a specific context, the methods used in this study might be transferred to other contexts, to study workplace learning of all kinds of leaders.  相似文献   

Higher Education     

John Dyson  Willem Wamsteker 《Higher Education》2005,50(4):713-720

Instructions for authors

Higher Education  相似文献   

Can engineering education in South Africa afford to avoid problem-based learning as a didactic approach?     

F. J. Veldman  M. A. De Wet  N. E. Ike Mokhele  Willem Adriaan Johannes Bouwer 《European Journal of Engineering Education》2008,33(5-6):551-559

In this article, the authors support problem-based learning (PBL) based on its high level of alignment in addition to providing learners in engineering with an additional opportunity in learning process competencies, as contained within the South African National Critical Cross-field and Developmental Outcomes (COs). Constructive alignment describes a process in which the learning outcomes (LOs) become the objective for designing a curriculum that enables LOs to be achieved through appropriate activities and an assessment process that enables these LOs to be demonstrated. PBL applies problem-solving as a vehicle in achieving LOs. The degree to which a learner manages to achieve a given LO still serves as the authentic criteria for assessment. In addition, PBL provides learners an opportunity in acquiring non-subject-related skills, also referred to as process competencies, soft-skills, transferable skills, or graduate attributes. These skills are required especially for the management of human capital and are considered as crucial for successful practice in the engineering profession. It is therefore questioned why a PBL approach is not implemented by engineering faculties at South African Higher Education Institutions. The successful implementation of PBL, however, depends on a number of non-didactic issues that are highlighted in this paper. It is concluded that very few didactic methods can achieve the quality of learning we provide to engineering learners when using PBL, and therefore, it is proposed that South African Higher Education Institutions should also provide their academic staff with training opportunities in this regard.  相似文献   

The Platform for Responsible Editorial Policies: An initiative to foster editorial transparency in scholarly publishing     

Serge P.J.M. Horbach  Wytske M. Hepkema  Willem Halffman 《Learned Publishing》2020,33(3):340-344

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