迷宫闯一闯

Lily和Tom组成了一个校园乐队,Lily是主唱,Tom是吉他手。请你帮Lily走出错综复杂的迷宫,来到搭档Tom的身边。他们要进行排练,准备参加学校的大型演出呢。     

Innovators and imitators: Organizational reference groups and adoption of organizational routines

Firms vary greatly in their rates of creating and adopting technological and organizational innovations, in part because of their choice of reference group. We argue that the selection of a reference group is a crucial and neglected source of firm heterogeneity. Comparisons to the average of other firms in a population cause most firms to adopt innovations once they are widely accepted. A distinctive feature of the minority of innovating firms that create innovations or adopt them early is that they compare themselves with, compete with, and try to differ from other innovating firms, whereas the majority of firms compare themselves with, and conform to, a broader group of firms. We elaborate this argument based on the behavioral theory of the firm and institutional theory, and test it on a two-period survey on adoptions of innovative organizational forms in Europe and the US. The analysis shows the predicted differences in the adoption patterns of innovating and imitating firms.     

Why do high jumpers use a curved approach?

Currently, all elite high jumpers use the Fosbury Flop technique with a curved approach. This suggests that the curved approach presents some clear advantage, although there is no general agreement upon the mechanism or the mechanics. This study aimed to determine the characteristics of the approach curve and to investigate how it contributes to the generation of somersault rotation. A simple theoretical model was used to demonstrate that a tightening approach curve would change the inward lean towards the centre of the curve into outwards lean. Three-dimensional video analysis was used to record the performances of two elite male high jumpers in competition. It was found that in each case the radius of the approach curve and the inward lean angle both decreased towards the end of the approach. The amount of outward lean angular velocity generated was shown to be a major proportion of the required somersault angular velocity for a jump. It was concluded that the main advantage of a curved approach was that it resulted in the generation of somersault velocity providing the curve tightened towards the end of the approach.     

Successfully Mentoring Undergraduates in Research: A How To Guide for Mathematicians

Abstract

Undergraduate research occurs in a variety of mathematical fields and in diverse settings, but all mentors of undergraduates face a number of common considerations. This article is a brief guide to help faculty with various levels of previous mentoring experience lead students in research projects. In particular, we discuss the issues of picking appropriate research problems, recruiting students, setting expectations, moving research forward, and helping students to communicate their work.     

Architektur Multimedialer Informationssysteme

Ohne Zusammenfassung

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Architektur Multimedialer Informationssysteme

     

跨越海洋的勇敢航行

《海洋奇缘》(Moana)是美国迪士尼动画公司的第57部动画长片. 故事讲述了主宰风和海的半神毛伊(Maui)偷走了女神特菲提(Te Fiti)之心,导致岩浆魔鬼厄卡(Te Ka)陷入疯狂的状态,南太平洋各小岛也面临着毁灭的威胁.一千多年后,某小岛上的酋长之女莫阿娜(Moana)在父母的呵护下渐渐长大,童年时她曾偶然捡到特菲提之心,亦曾受到大海的召唤,然而父亲却严厉禁止莫阿娜出海,即使小岛正遭受着毁灭的威胁.从奶奶那里,莫阿娜知晓了他们这一族人的历史.于是为了拯救小岛,她毅然出海去寻找被困在某地的毛伊,好让他归还特菲提之心.历经千辛万苦,莫阿娜终于见到了这个传说中高傲自大的半神.然而,毛伊却因为担心特菲提之心会带来霉运而拒绝完成这个使命.最后,在命运的指引下,毛伊不得不随着莫阿娜踏上了波澜壮阔的海洋冒险之旅.