排序方式： 共有27条查询结果，搜索用时 15 毫秒
21.
Andrea De Mauro Marco Greco Michele Grimaldi Paavo Ritala 《Information processing & management》2018,54(5):807-817
The rapid expansion of Big Data Analytics is forcing companies to rethink their Human Resource (HR) needs. However, at the same time, it is unclear which types of job roles and skills constitute this area. To this end, this study pursues to drive clarity across the heterogeneous nature of skills required in Big Data professions, by analyzing a large amount of real-world job posts published online. More precisely we: 1) identify four Big Data ‘job families’; 2) recognize nine homogeneous groups of Big Data skills (skill sets) that are being demanded by companies; 3) characterize each job family with the appropriate level of competence required within each Big Data skill set. We propose a novel, semi-automated, fully replicable, analytical methodology based on a combination of machine learning algorithms and expert judgement. Our analysis leverages a significant amount of online job posts, obtained through web scraping, to generate an intelligible classification of job roles and skill sets. The results can support business leaders and HR managers in establishing clear strategies for the acquisition and the development of the right skills needed to leverage Big Data at best. Moreover, the structured classification of job families and skill sets will help establish a common dictionary to be used by HR recruiters and education providers, so that supply and demand can more effectively meet in the job marketplace. 相似文献
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The aim of this study was to assess the effects of nicotinamide adenine dinucleotide hydride (NADH) on maximal oxygen uptake (VO2max), maximal anaerobic running time, and mental performance. Eight men were exposed to a supplement treatment (30 mg NADH as ENACHI tablets per day) and to a placebo treatment, each of 4 weeks' duration, in a balanced, double-blind, and cross-over design. The two treatments were separated by a 14-week wash-out period. The results indicated that VO2max, maximal anaerobic running time, and the ability to concentrate were similar in the NADH and placebo conditions. There were also no differences in blood lactate, creatine kinase, reaction time or feelings of fatigue between the treatments. A counter-movement jump performed at rest and 2 min after the aerobic test differed significantly (P 相似文献
23.
Minna Torppa Anna-Maija Poikkeus Marja-Leena Laakso Asko Tolvanen Esko Leskinen Paavo H.T. Leppanen 《Scientific Studies of Reading》2013,17(2):73-103
The development of phonological awareness (PA) before school age was modeled in association with the development of vocabulary and letter knowledge, home literacy environment (HLE), children's reading interest, and beginning reading skill in children with and without familial risk of dyslexia. A total of 186 children were followed from birth to the age of 6.5 years. Of these children, about half had a familial background of reading difficulties (the at-risk group), and the other half came from families without such background (the control group). The data from several measures and assessment time points were analyzed within an SEM framework, and a latent analysis of growth curves was employed. Vocabulary and letter knowledge were found to predict PA development, and vice versa, PA predicted them. The effect of HLE on PA was mediated by vocabulary skills, and of the HLE variables, the only variable predicting vocabulary development was shared reading. In spite of the difference in level, favoring the controls, the pattern of effects of vocabulary and letter knowledge on PA development was highly similar in children with and without familial risk for dyslexia. However, in the at-risk group, the HLE variables and children's reading interest had stronger associations with each other and with skill development than in the control group, and vocabulary predicted parental reports on children's reading interest in the at-risk group only. 相似文献
24.
This paper provides a unique perspective on knowledge ecosystems by studying their organization. Grounded in empirical evidence, we propose that knowledge ecosystems consist of users and producers of knowledge that are organized around a joint knowledge search. A distinction is drawn between knowledge ecosystems searching for a knowledge domain and those searching within an identified knowledge domain, respectively characterized as prefigurative and partial forms of organizing. In a knowledge ecosystem organized in prefigurative form (to identify a knowledge domain), actors whose participation is affiliated, self-resourced, and unobliged probe that domain to identify and establish shared knowledge as a basis for collective actorhood, with no formal rules or coordination mechanisms. In a knowledge ecosystem organized in partial form (where a knowledge domain has already been identified), actors search and reveal problem- and solution-related knowledge, participating though formal membership and access to resources, and their contributions are monitored. The present study contributes to the literature by 1) specifying the distinct types of joint search performed by knowledge ecosystems; 2) considering how the nature of joint search affects how knowledge ecosystems are organized; and 3) distinguishing two forms of organizing knowledge ecosystems, with a focus on participation and coordination. 相似文献
25.
Electromyographic (EMG) activity of the leg muscles and the ground reaction forces were recorded in 17 elite male middle-distance runners, who performed isometric maximal voluntary contractions (MVC) as well as running at different speeds. Electromyograms were recorded from the gluteus maximus, vastus lateralis, biceps femoris, gastrocnemius and tibialis anterior. The results indicated that the averaged EMG (aEMG) activities of all the muscles studied increased (P?<?0.05) with increasing running speed, especially in the pre-contact and braking phases. At higher speeds, the aEMG activities of the gastrocnemius, vastus lateralis, biceps femoris and gluteus maximus exceeded 100% MVC in these same phases. These results suggest that maximal voluntary contractions cannot be used as an indicator of the full activation potential of human skeletal muscle. Furthermore, the present results suggest that increased pre-contact EMG potentiates the functional role of stretch reflexes, which subsequently increases tendomuscular stiffness and enhances force production in the braking and/or propulsive phases in running. Furthermore, a more powerful force production in the optimal direction for increasing running speed effectively requires increased EMG activity of the two-joint muscles (biceps femoris, rectus femoris and gastrocnemius) during the entire running cycle. 相似文献
26.
Jukka T. Viitasalo Paavo Rahkila Leo Österback Markku Alén 《Journal of sports sciences》2013,31(5):401-413
Abstract The purpose of this study was to examine the effects of calendar and skeletal age, anthropometric dimensions, training history and their interactions on vertical jumping height and horizontal overhead throwing velocity in a cross‐section of 318 young male athletes (age range 9–16 years) participating in cross‐country skiing (n = 70), basketball (n = 40), apparatus gymnastics (n = 19), ice hockey (n = 50), track and field (n = 89) and wrestling (n = 50). Vertical jumping height was measured with four different loads held on the shoulders and then interpolated for loads representing 0 and 40% body mass. Horizontal overhead throwing velocity using both hands was determined for seven balls of different weights and then interpolated for weights representing 1 and 5% body mass. Both vertical jumping height and overhead throwing velocity were found to increase (P< 0.01) from the skeletally youngest to the oldest cohort when the effects of body height and mass were controlled. The inter‐event comparisons did not reveal statistically significant differences in respect of vertical jumping height. Also in the overhead throwing tests, the inter‐event differences were small, although the analysis of variance revealed statistically significant (P< 0.001) differences for the skeletal age cohorts of 13 and 14 years. While the quantity of training had no effect on vertical jumping height, it explained the results in the overhead throwing test. The effects of training on vertical jumping and horizontal overhead throwing among adolescent athletes were considered to be small, while maturational processes and anthropometric development followed by increase in calendar age were deemed to be of greater importance. 相似文献
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