A mathematical model for power output in rowing on an ergometer

A mathematical model relating power output of rower to stroke rate on an ergometer (the Concept II Indoor Rower TM, Model C) is studied. The model is used to analyse the ergometer performance of a particular rower. It is determined that he can be more efficient (i.e. decrease power output while maintaining fixed velocity) by decreasing stroke rate, but at the expense of increasing force during the drive. It is also shown that he can be more efficient by increasing the drag factor (using higher vent setting) without increasing force. Dependence of power output on rowing style (the shape of the force curve) is also examined. It is shown that variation of force during the drive has little effect on efficiency, but efficiency is reduced by asymmetry of the force curve that favours the legs.     

关于有氧健身操的调查与研究

通过对有氧健身操、有氧操的锻炼内容、强度及音乐的调查,认为目前参与有氧健身操不乏其人．但大多数人都进行得较盲目。建议规范健身组织以及健全健身指导员组织。     

Entwicklung gro?er Systeme mit generischen Methoden – Eine übersicht über den Sonderforschungsbereich 501

Ohne Zusammenfassung     

The impact of attending after-school care schemes on science achievement in primary school: A Norwegian study

Accompanying the rise in the number of working parents is a growing demand for after-school care schemes for children. After-school care schemes, in addition to school, provide pupils with more learning opportunities than the experiences that school provides. The hypothesis is that after-school care schemes offer a better knowledge-basis for learning science than the school and home environments only. This article investigates how after-school care schemes affect learning in grades 5 and 8. While taking into account the socio-economic and ethnic backgrounds of pupils, results indicate that after-school care is of significance. The influence of after-school care is roughly explained by the increased number of learning opportunities. We discuss the implications for research and the limitations of this survey.     

Themenheft: Softwaretechnik '98

Ohne Zusammenfassung