排序方式： 共有60条查询结果，搜索用时 140 毫秒
51.
Toward a systematic framework for research on dominant designs, technological innovations, and industrial change 总被引：1，自引：0，他引：1
The concept of a dominant design has taken on a quasi-paradigmatic status in analyses of the link between technological and industrial dynamics. A review of the empirical literature reveals a variety of interpretations about some aspects of the phenomenon such as its underlying causal mechanisms and its level of analysis. To stimulate further progress in empirical research on dominant designs, we advocate a standardization of terminology by conceptualizing products as complex artifacts that evolve in the form of a nested hierarchy of technology cycles. Such a nested complex system perspective provides both unambiguous definitions of dominant designs (stable core components that can be stable interfaces) and inclusion of multiple levels of analysis (system, subsystems, components). We introduce the concept of an operational principle and offer a systematic definition of core and peripheral subsystems based on the concept of pleiotropy. We also discuss how the proposed terminological standardization can stimulate cumulative research on dominant designs. 相似文献
52.
To identify performance characteristics that could help predict future elite field hockey players, we measured the anthropometric, physiological, technical, tactical, and psychological characteristics of 30 elite and 35 sub-elite youth players at the end of three consecutive seasons. The mean age of the players at the end of the first season was 14.2 years (s = 1.1). Repeated-measures analyses of covariance, with standard of performance and measurement occasion as factors and age as a covariate, showed that the elite players fared better than the sub-elite players on technical and tactical variables. Female elite youth players also scored better on interval endurance capacity, motivation, and confidence. Future elite players appear to have excellent tactical skills by the age of 14. They also have good specific technical skills and develop these together with interval endurance capacity better than sub-elite youth players in the subsequent 2 years. To verify our conclusions, we will be tracking these players into adulthood. 相似文献
53.
Elferink-Gemser MT Visscher C Lemmink KA Mulder TW 《Journal of sports sciences》2004,22(11-12):1053-1063
To determine the relationship between multidimensional performance characteristics and level of performance in talented youth field hockey players, elite youth players (n = 38, mean age 13.2 years, s = 1.26) were compared with sub-elite youth players (n = 88, mean age 14.2 years, s = 1.26) on anthropometric, physiological, technical, tactical and psychological characteristics. Multivariate analyses with performance level and gender as factors, and age as the covariate, showed that the elite youth players scored better than the sub-elite youth players on technical (dribble performance in a peak and repeated shuttle run), tactical (general tactics; tactics for possession and non-possession of the ball) and psychological variables (motivation) (P < 0.05). The most discriminating variables were tactics for possession of the ball, motivation and performance in a slalom dribble. Age discriminated between the two groups, indicating that the elite youth players were younger than the sub-elite players. In the guidance of young talented players to the top as well as in the detection of talented players, more attention has to be paid to tactical qualities, motivation and specific technical skills. 相似文献
54.
55.
56.
This paper aims to show that alliance networks can play an important role in facilitating large-scale strategic change projects. It focuses on the particular case of IBM, whose radical redirection from an exploitation strategy towards an exploration strategy was realized by major changes in its network strategy. We show that by involving new partners in the network and by loosening the ties with its existing partners, IBM managed to transform from a hardware manufacturing company to a global service provider and software company. The findings suggest that the traditional view of large firms as being slow to adapt may not be valid because alliance networks can be used to overcome inertia. 相似文献
57.
Sekeris Elke Verschaffel Lieven Luwel Koen 《European Journal of Psychology of Education - EJPE》2022,37(1):19-38
European Journal of Psychology of Education - Computational estimation is seen as an important mathematical competence. Little is known, however, about the mathematical skills that are predictive... 相似文献
58.
Marije Elferink-Gemser Chris Visscher Koen Lemmink Theo Mulder 《Journal of sports sciences》2013,31(11-12):1053-1063
To determine the relationship between multidimensional performance characteristics and level of performance in talented youth field hockey players, elite youth players (n = 38, mean age 13.2 years, s = 1.26) were compared with sub-elite youth players (n = 88, mean age 14.2 years, s = 1.26) on anthropometric, physiological, technical, tactical and psychological characteristics. Multivariate analyses with performance level and gender as factors, and age as the covariate, showed that the elite youth players scored better than the sub-elite youth players on technical (dribble performance in a peak and repeated shuttle run), tactical (general tactics; tactics for possession and non-possession of the ball) and psychological variables (motivation) (P <?0.05). The most discriminating variables were tactics for possession of the ball, motivation and performance in a slalom dribble. Age discriminated between the two groups, indicating that the elite youth players were younger than the sub-elite players. In the guidance of young talented players to the top as well as in the detection of talented players, more attention has to be paid to tactical qualities, motivation and specific technical skills. 相似文献
59.
Koen Put Johan Wagemans Jochim Spitz Manuel Armenteros Gallardo A. Mark Williams 《Journal of sports sciences》2013,31(18):1688-1697
AbstractWe examined whether the use of three-dimensional (3D) simulations in an off-field offside decision-making task is beneficial compared to the more widely available two-dimensional (2D) simulations. Thirty-three assistant referees, who were all involved in professional football, participated in the experiment. They assessed 40 offside situations in both 2D and 3D formats using a counterbalanced design. A distinction was made between offside situations near (i.e., 15 m) and far (i.e., 30 m) from the touchline. Subsequently, a frame recognition task was performed in which assistant referees were asked to indicate which of the five pictures represented the previous video scene. A higher response accuracy score was observed under 3D (80.0%) compared to 2D (75.0%) conditions, in particular for the situations near the touchline (3D: 81.8%; 2D: 72.7%). No differences were reported between 2D and 3D in the frame recognition task. Findings suggest that in highly dynamic and complex situations, the visual system can benefit from the availability of 3D information, especially for relatively fine, metric position judgements. In the memory task, in which a mental abstraction had to be made from a dynamic situation to a static snapshot, 3D stereo disparities do not add anything over and beyond 2D simulations. The specific task demands should be taken into account when considering the most appropriate format for testing and training. 相似文献
60.
Koen A. P. M. Lemmink Han C. G. Kemper Mathieu H. G. Greef Piet Rispens Martin Stevens 《Research quarterly for exercise and sport》2013,84(3):331-336
Abstract A growing concern for the establishment of a national system of education was clearly evident in France during the last decades of the eighteenth century. Physical education was afforded an important role in the educational projections of the period. Beginning with La Chalotais' Essai d'éducation nationale (1763) authors began to express more and more support for the inclusion of a comprehensive program of physical education. Gabriel Coyer's De l'éducation publique (1770), Louis Philipon de la Madelaine's Vues patriotiques sur l'education du peuple (1783) and De l'éducation des collèges (1784), and Jean Ver dier's Maison d'éducation physique et morale (1772) and Cours d'éducation à l'usage des eleves (1777) all contributed significantly to the concept that physical education must constitute an important and integral part of any comprehensive and viable plan for national education. Among the most important deliberations of the various French revolutionary assemblies between 1789 and 1795 were those dealing with education as a concern of the state. Legislators tried valiantly to establish a sound national plan for education. The educational reports and projects presented to the various revolutionary assemblies by Talleyrand, Condorcet, Lepelitier, Lakanal, Romme, and Daunou are usually considered by educational historians to be the most significant. Each of these specified that due attention must be devoted to physical education for children and youth. The proposals, the decrees and the debates which they precipitated did much to attract attention to the importance of the subject. It seems most likely that the period from 1763 to 1795 in France witnessed the establishment of a precedent in modem times for the concept of state concern and support for physical education. 相似文献