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461.
The first part of this article explores whether convergence has occurred in technology and income across EU regions during the period 1990-2002. The second part evaluates whether these two processes of convergence are related to each other. With respect to the first question, we find that all R&D indicators and patents have converged among regions during the 1990s and this has ran parallel to a real convergence in income per capita levels. Regarding the second question, we have identified a strong relationship between the distribution of technology indicators and the distribution of regional income in Europe. Our main result is that convergence in business R&D leads to convergence in patents, which in turn leads to convergence in income per capita. Although, we identify a role for government R&D and higher education spending in this process, the policy implications for these two variables are less clear. 相似文献
462.
Jesús Navarro-Moreno Rosa María Fernández-Alcalá José Domingo Jiménez-López Juan Carlos Ruiz-Molina 《Journal of The Franklin Institute》2019,356(5):3115-3138
The optimal widely linear state estimation problem for quaternion systems with multiple sensors and mixed uncertainties in the observations is solved in a unified framework. For that, we devise a unified model to describe the mixed uncertainties of sensor delays, packet dropouts and uncertain observations by using three Bernoulli distributed quaternion random processes. The proposed model is valid for linear discrete-time quaternion stochastic systems measured by multiple sensors and it allows us to provide filtering, prediction and smoothing algorithms for estimating the quaternion state through a widely linear processing. Simulation results are employed to show the superior performance of such algorithms in comparison to standard widely linear methods when mixed uncertainties are present in the observations. 相似文献
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464.
The role of information and communication technologies (ICT) in education is well recognised – learning environments where the ICT features included are being proposed for many years now. The Web Geometry Laboratory (WGL) innovates in proposing a blended learning, collaborative and adaptive learning Web-environment for geometry. It integrates a well-known dynamic geometry system providing an adaptive environment where face-to-face activities can be combined with computer-mediated activities, in a collaborative or stand-alone, synchronous or asynchronous, classroom or homework way. The WGL collaborative environment allows each student to capitalise on one another's resources and skills. Its adaptive module gives to each teacher the ability to assess the geometric level of each student, allowing the teacher to build the individual profile and/or learning paths. In this paper we begin describing what are the goals that support the development of such an environment, the goals that support our beliefs in the usefulness of such an environment for the teaching and learning of geometry, after which we describe the environment and the case studies already conducted. 相似文献
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466.
Alejandro Bastida Castillo Carlos D. Gómez Carmona Ernesto De la cruz sánchez José Pino Ortega 《European Journal of Sport Science》2018,18(4):450-457
There is interest in the accuracy and inter-unit reliability of position-tracking systems to monitor players. Research into this technology, although relatively recent, has grown exponentially in the last years, and it is difficult to find professional team sport that does not use Global Positioning System (GPS) technology at least. The aim of this study is to know the accuracy of both GPS-based and Ultra Wide Band (UWB)-based systems on a soccer field and their inter- and intra-unit reliability. A secondary aim is to compare them for practical applications in sport science. Following institutional ethical approval and familiarization, 10 healthy and well-trained former soccer players (20?±?1.6 years, 1.76?±?0.08?cm, and 69.5?±?9.8?kg) performed three course tests: (i) linear course, (ii) circular course, and (iii) a zig–zag course, all using UWB and GPS technologies. The average speed and distance covered were compared with timing gates and the real distance as references. The UWB technology showed better accuracy (bias: 0.57–5.85%), test–retest reliability (%TEM: 1.19), and inter-unit reliability (bias: 0.18) in determining distance covered than the GPS technology (bias: 0.69–6.05%; %TEM: 1.47; bias: 0.25) overall. Also, UWB showed better results (bias: 0.09; ICC: 0.979; bias: 0.01) for mean velocity measurement than GPS (bias: 0.18; ICC: 0.951; bias: 0.03). 相似文献
467.
Mota J Silva P Santos MP Ribeiro JC Oliveira J Duarte JA 《Journal of sports sciences》2005,23(3):269-275
The aims of this study were: (1) to observe participation in moderate-to-vigorous physical activity (MVPA) during school recess periods; (2) to determine the relative importance of physical activity during recesses to overall daily physical activity; and (3) to examine differences in physical activity between the sexes during unstructured recess periods. The participants were 22 school children (10 boys, 12 girls) aged 8 - 10 years (mean = 8.9, s = 0.7) in the third and fourth grades. Daily totals for the physical activity variables were calculated by summing the values for each hour of 14 h of physical activity measurements (08:00 to 22:00 h). Recess times (minutes) were as follows: morning 10:30 to 11:00 h and afternoon 15:30 to 16:00 h. We did not differences between boys and girls in daily total accelerometer counts or the overall time spent in MVPA. However, girls were significantly (P < 0.05) more involved (38%) in MVPA during recess time than boys (31%). Participation in MVPA during recess contributes significantly more (P < 0.05) for girls (19%) than boys (15%) to the total amount of physical activity suggested by international health-related physical activity guidelines, while the percentage of time engaged in MVPA during recess time at school accounts for a small amount of the daily MVPA (6% for boys and 8% for girls). The results of this study suggest that school recess time is an important setting to promote MVPA and contributes to daily physical activity in young children, especially in girls. 相似文献
468.
This comment considers the applicability of the Cyert and DeGroot model of adaptive utility in modeling consumer choice behavior with respect to arts goods. An illustration of the consumer’s choice behavior on expenditure shares is simulated as a simple Markov chain. This is followed by a discussion of policy implications regarding the pricing and subsidization of arts goods. 相似文献
469.
The major distinctive feature of cultural goods is that consumers must learn how to consume them, implying that preferences should be modelled as intertemporally dependent. The canonical model in the literature uses a habit formation analogy. In this paper, we discuss in detail, though in the simplest setup, a consistent preference structure for that model. Then, we derive the implications for the dynamics of two aggregate equilibrium models, a fixed price model and a flexible price model. The learning-by-consuming behaviour is characterised by a preference structure displaying bounded adjacent complementarity in the demand for the cultural good. This implies that there will be short run complementarity between the stocks of culture and financial wealth and that the adjustment of the demand for cultural goods, or of their relative price, will have some inertia. In the exogenous price model, we find that increases in income will raise the long run demand for cultural goods while increases in the relative price will decrease it. In the endogenous price model, an increase in the supply of cultural goods will imply an initial undershooting of the price of cultural goods followed by an upward transition process. Our results seem to be consistent with the empirical results on the demand for cultural goods and seem to offer an explanation for the Baumol and Bowen paradox.JEL Classification: Z1, E21Earlier versions of this paper have been presented at the 1st Conference of the Sociedade Portuguesa de Investigação em Economia (SPiE, 1997) and at the Xth Conference of the Association for Cultural Economics International, 1998, Barcelona. 相似文献
470.