Sprinting analysis of elite soccer players during European Champions League and UEFA Cup matches   总被引：1，自引：1，他引：0  

Di Salvo V  Baron R  González-Haro C  Gormasz C  Pigozzi F  Bachl N 《Journal of sports sciences》2010,28(14):1489-1494

It has been suggested that assessment of high-intensity activities during a match is a valid measure of physical performance in elite soccer. Recently, sprinting activities have been analysed in more depth. The aim of this study was to develop a detailed analysis of the sprinting activities of different playing positions during European Champions League and UEFA Cup competitions. Altogether, 717 elite outfield soccer players were evaluated throughout 2002-2006 using ProZone? (Leeds, UK). Sprinting (explosive and leading) was analysed for each playing position. To compare positional differences, a Kruskal-Wallis analysis was performed. Differences were found among positions for total number of sprints and total sprint distance covered: wide midfielders > (attackers = wide defenders) > central midfielders > central defenders (P < 0.001), as well as for explosive sprints: (wide midfielders = attackers = wide defenders) > central defenders, wide midfielders > central midfielders > central defenders and attackers = wide defenders = central midfielders (P < 0.001), and leading sprints: wide midfielders > (attackers = wide defenders) > central midfielders > central defenders (P < 0.001). For each group, there were no differences in ratio of explosive to leading sprints. Wide midfielders performed a higher number of sprints in all five distance categories than all other positions. This study showed that sprinting characteristics are influenced by position. Wide midfielders have to complete additional high-intensity activities during training sessions compared with the other positions to achieve the performance level required during the match.  相似文献   

Almost sure weak exponential stability with a certain decay function of semilinear stochastic evolutionequations     

David Castillo Fernández 《Journal of The Franklin Institute》2010,347(10):1814-1824

In this paper the weak exponential stability with decay function of sample path, which are given by mild solution to a class of semilinear stochastic evolution equations, are presented. The analyses consist in using exponential martingale formula, Lyapunov functional and some special inequalities derived for our stability purposes. Two examples are given to illustrate the theory.  相似文献   

Integrating educational institutions to produce intellectual capital for sustainability in Caguas,Puerto Rico     

Lillian V?Ortiz-FournierEmail author  Eulalia?Márquez  Felix Rogelio?Flores  Juan C?Rivera-Vázquez  Pablo A?Colon 《知识管理研究与实践》2010,8(3):203-215

This research is part of a broader investigation to analyse the processes followed by the Caguas Municipality at the Commonwealth of Puerto Rico in an effort to develop the characteristics of a ‘Smart City’ as an example of sustainable development. We describe the integration of the educational institutions’ initiatives and the municipal government strategic plan to contribute to the knowledge and intellectual capital that brings sustainability to the city. An actor's model was designed to represent this integration. The conceptual framework was based on the concepts of knowledge production and sharing as applied to the collaboration between critical representative actors. Field research consisting of in-depth interviews was performed to ascertain the integration processes and their relationship with such processes of knowledge production and sharing. The results showed that the governance paradigm implemented is already empowering the citizens to contribute with intellectual capital that brings sustainability to Caguas.  相似文献   

Assessing Quality and Evaluating Performance in Higher Education: Worlds Apart or Complementary Views?     

Cláudia S. Sarrico  Maria J. Rosa  Pedro N. Teixeira  Margarida F. Cardoso 《Minerva》2010,48(1):35-54

This paper reflects on quality assessment and performance evaluation in higher education, namely by analysing the insufficient link between those two aspects. We start by reviewing the current state of the art regarding different processes and mechanisms of quality assessment and performance evaluation and discuss some of the major issues regarding the implementation of some of them. In particular, we analyse the current limitations regarding data collected, available and publicised on the performance of HEIs and the problems those limitations bring to a fair evaluation of higher education. Through this analysis we intend to contribute to a better understanding of the mechanisms of evaluation in higher education and the way these may lead to the promotion of better quality assessment practices and institutional management.  相似文献   

A practical approach to making accurate 3D layouts of interesting cultural heritage sites through digital models     

Pedro Martín Lerones  José Llamas Fernández  Álvaro Melero Gil  Jaime Gómez-García-Bermejo  Eduardo Zalama Casanova 《Journal of Cultural Heritage》2010,11(1):1-9

On many occasions, the graphic information handled by people working in the cultural heritage sector is still bidimensional. Layouts showing elevations and cross sections are the most widespread tools. However, there is an increased need for carefully detailing the complexity of valuable sites with an improved accuracy. This implies the measuring and handling of three-dimensional data, using both commercial and turn-key hardware and software solutions. Taking the usual traditional process as a reference, in the present paper a new effective methodology for carrying out computer assisted delineation of layouts from cultural heritage sites, using 3D digital models, is described. The proposed procedure has been tested in five intervention projects on representative churches within the “Merindad de Aguilar de Campoo” medieval area, in the north of Spain.¹ This area has the largest collection of Romanesque art in the world, and is currently under European Heritage Site and World Heritage Site declaration process by the UNESCO.  相似文献   

Effect of the addition of hydroxyl-terminated polydimethylsiloxane to TEOS-based stone consolidants     

Ramón Zárraga  Jorge Cervantes  Carmen Salazar-Hernandez  George Wheeler 《Journal of Cultural Heritage》2010,11(2):138-144

Hybrid stone consolidants prepared from tetraethoxysilane (TEOS) and α,ω-hydroxyl-terminated polydimethylsiloxane (PDMS-OH) have been considered as one of the most promising approaches to improve the effectiveness of traditional alkoxysilane-based formulations. They have emerged as response to the negative reports commonly found in the literature: the resulting silica gel phase (SiO₂) tends to develop fractures and fissures inside the stone as the gel shrinks during the drying stage. In this work, we employed SEM, solid-state ²⁹Si NMR spectroscopy and compressive tests to characterize SiO₂-PDMS hybrid gels. We report the morphological characteristics exhibited by gels prepared in vitro and in situ. It was found an appreciable reduction of gel fracture for hybrids prepared from 5% w/w of PDMS. As TEOS polycondenses, PDMS-OH is chemically incorporated into the gel matrix via Si-O-Si bonds. The inclusion of these elastic chains provides the necessary flexibility to resist the stress imposed by capillary pressure. Additionally, an important hydrophobic character is imparted to the stone.  相似文献   

An evaluation of daylight distribution as an initial preventive conservation measure at two Smithsonian Institution Museums, Washington DC, USA     

Julio M. del Hoyo-Melndez  Marion F. Mecklenburg  María Teresa Domnech-Carb 《Journal of Cultural Heritage》2011,12(1):54

This paper presents the results of a light levels survey conducted at the Donald W. Reynolds Center for American Art and Portraiture in Washington DC. The museum space is shared by the National Portrait Gallery and the Smithsonian American Art Museum. After six years of extensive renovations, the building reopened to the public in July 1, 2006. The structure was not originally designed to house a museum collection since it contains numerous openings such as windows, doors and skylights, which provide a path for natural radiation to enter the building and come in contact with the artworks. From a preventive conservation standpoint, this is an important problem since sensitive works of art in the collection may be subjected to damage caused by light exposure. Environmental data loggers installed throughout the museum were programmed to take successive measurements every 10 min for 24 h a day, 7 days a week and 52 weeks a year. This light levels assessment started in November 1, 2007 and finished in October 31, 2008. This study presents a new method for determining natural radiation exposures registered in exhibition spaces that rely on both electric lighting and natural lighting, considering the growing trend of using daylight illumination in museums.  相似文献   

Progress in aviation     

Theodore von Kármán 《Journal of The Franklin Institute》1948,246(6):451-452

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Dyestuffs     

Louis Joseph Mátos 《Journal of The Franklin Institute》1918,186(2):187-209

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Education,social structure and styles of development     

Germán W. Rama 《Prospects》1978,8(3):306-319

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