Inventing by combining pre-existing technologies: Patent evidence on learning and fishing out     

Matthew S. Clancy 《Research Policy》2018,47(1):252-265

I develop a model of innovation where new technologies are combinations of pre-existing technological components. The model captures two opposing forces. The best ideas are used up (knowledge is exhaustible). However, as firms learn which technologies can be combined, new ideas become feasible (knowledge accumulates). I test the model with more than 80 years of US patent data. Technological components are proxied by 13,517 patent office technology classifications. These are reused and recycled in 10,000 distinct three-component sets. Consistent with a learning/fishing-out dynamic, I show patenting in one set of components is correlated with a subsequent increase in similar patents (sharing two of three components), but a subsequent decrease in identical patents (sharing all three components). I use patent renewal data to show my results are not driven by changes in demand for various technology bundles. My results suggest the positive impact of learning on subsequent patenting is larger than the negative impact of fishing out.  相似文献   

Living with imperfect comparisons: The challenges and limitations of comparative paralympic sport policy research     

Mathew Dowling  Phil Brown  David Legg  Aaron Beacom 《Sport Management Review》2018,21(2):101-113

In this article, the authors explores the challenges and limitations of conducting cross-comparative management/policy research in the Paralympic sporting domain. The comparative sport policy debate in able-bodied sport has emerged, in part, due to the increasing complexity, uncertainty, and competitive nature of high performance sport environments and a desire to understand why some countries are more successful than others at international sporting competition. The same issues and questions have also emerged within the Paralympic context. As a precursor to establishing a research agenda in this area, however, it was deemed important to begin to address the epistemological, methodological, and practical issues in comparative sport research. The analysis draws upon the broader sociological literature and examples from the Paralympic sporting context to identify and discuss the challenges and limitations of the comparative approach as well as recommendations for mitigating against them.  相似文献   

Visiting Fortaleza: motivation,satisfaction and revisit intentions of spectators at the Brazil 2014 FIFA World Cup     

Graham Brown  Guy Assaker 《Journal of Sport Tourism》2018,22(1):1-19

The FIFA World Cup provides opportunities to attract visitors to host cities and for local residents to enjoy event-related celebrations. This paper directs attention to Fortaleza, in the north-east of Brazil, where a survey was conducted of 285 spectators to identify the relative importance of enjoyment and competitive outcomes as motives to attend games at the 2014 World Cup. The study also examined the relationship between motivation, event setting and event satisfaction and whether any differences in these relationships existed between local and visiting spectators. In the case of visitors to Fortaleza, factors that influence intentions to revisit the city were also examined. Although satisfaction did not have an impact on visitation intentions, visitors were strongly influenced by competitive motives associated with the team they support. In comparison, local residents were more motivated by event excitement. The need to recognize the propensities of different types of spectators and the complexity of the relationship between spectators and the event setting are discussed.  相似文献   

What resources do parents exchange in the VCLL?     

Sean F. Brown 《Sport in Society》2018,21(10):1544-1557

Abstract

When parent relationships form within the context of a youth baseball league, they can and often do facilitate the exchange of benefits to one or more parties, a phenomenon known as social capital. Based on 18 months of fieldwork, approximately 30 interviews, and innumerable casual conversations with parents and league officials, I explore the specific types of resources that were typically shared between parents of a youth baseball league in the American Southwest. I uncovered four specific types of benefits that parents offered and accepted as a result of the relationships they cultivated during baseball seasons: emotional support, information sharing regarding goods and services about town, job information sharing, and childcare.  相似文献   

Sleep and stress hormone responses to training and competition in elite female athletes     

Shannon O’Donnell  Steve Bird  Gregory Jacobson  Matthew Driller 《European Journal of Sport Science》2018,18(5):611-618

Stress hormone and sleep differences in a competition versus training setting are yet to be evaluated in elite female team-sport athletes. The aim of the current study was to evaluate salivary cortisol and perceptual stress markers during competition and training and to determine the subsequent effects on sleep indices in elite female athletes. Ten elite female netball athletes (mean?±?SD; age: 23?±?6 years) had their sleep monitored on three occasions; following one netball competition match (MATCH), one netball match simulation session (TRAIN), and one rest day (CONTROL). Perceived stress values and salivary cortisol were collected immediately pre- (17:15 pm) and post-session (19:30 pm), and at 22:00 pm. Sleep monitoring was performed using wrist actigraphy assessing total time in bed, total sleep time (TST), efficiency (SE%), latency, sleep onset time and wake time. Cortisol levels were significantly higher (p?p?p?相似文献   

Sex differences in wheelchair propulsion biomechanics and mechanical efficiency in novice young able-bodied adults     

Dhissanuvach Chaikhot  Matthew J. D. Taylor 《European Journal of Sport Science》2018,18(5):650-658

An awareness of sex differences in gait can be beneficial for detecting the early stages of gait abnormalities that may lead to pathology. The same may be true for wheelchair propulsion. The aim of this study was to determine the effect of sex on wheelchair biomechanics and mechanical efficiency in novice young able-bodied wheelchair propulsion. Thirty men and 30 women received 12 min of familiarisation training. Subsequently, they performed two 10-m propulsion tests to evaluate comfortable speed (CS). Additionally, they performed a 4-min submaximal propulsion test on a treadmill at CS, 125% and 145% of CS. Propulsion kinetics (via Smart^wheel) and oxygen uptake were continuously measured in all tests and were used to determine gross mechanical efficiency (GE), net efficiency (NE) and fraction of effective force (FEF). Ratings of perceived exertion (RPE) were assessed directly after each trial. Results indicated that CS for men was faster (0.98?±?0.24?m/s) compared to women (0.71?±?0.18?m/s). A lower GE was found in women compared to men. Push percentage, push angle and local RPE were different across the three speeds and between men and women. NE and FEF were not different between groups. Thus, even though their CS was lower, women demonstrated a higher locally perceived exertion than men. The results suggest sex differences in propulsion characteristics and GE. These insights may aid in optimising wheelchair propulsion through proper training and advice to prevent injuries and improve performance. This is relevant in stimulating an active lifestyle for those with a disability.  相似文献   

Singing it for “us”: Team passion displayed during national anthems is associated with subsequent success     

Matthew J. Slater  S. Alexander Haslam  Niklas K. Steffens 《European Journal of Sport Science》2018,18(4):541-549

The present research examined the link between passion displayed by team members during the singing of national anthems at UEFA Euro 2016 and team performance in the tournaments’ 51 games. Drawing on social identity theorising, we hypothesised a positive relationship between passion and performance. Consistent with this hypothesis, results showed that teams that sang national anthems with greater passion went on to concede fewer goals. Moreover, results provided evidence that the impact of passion on the likelihood of winning a game depended on the stage of the competition: in the knockout stage (but not the group stage) greater passion was associated with a greater likelihood of victory. Extending recent reviews that highlight the importance of social identity processes in sporting contexts, these results suggest that team members’ identity-based expression of passion for the collective can be an important predictor of subsequent performance.  相似文献   

Prevalence and correlates of resistance training skill competence in adolescents     

Jordan J. Smith  Matthew DeMarco  Sarah G. Kennedy  Mark Kelson  Lisa M. Barnett  Avery D. Faigenbaum 《Journal of sports sciences》2018,36(11):1241-1249

The aim of this study is to examine the prevalence and correlates of adolescents’ resistance training (RT) skill competence. Participants were 548 adolescents (14.1 ± 0.5 years) from 16 schools in New South Wales, Australia. RT skills were assessed using the Resistance Training Skills Battery. Demographics, BMI, muscular fitness, perceived strength, RT self-efficacy, and motivation for RT were also assessed. The proportion demonstrating “competence” and “near competence” in each of the six RT skills were calculated and sex differences explored. Associations between the combined RT skill score and potential correlates were examined using multi-level linear mixed models. Overall, the prevalence of competence was low (range = 3.3% to 27.9%). Females outperformed males on the squat, lunge and overhead press, whereas males performed better on the push-up (p < .05). Significant associations were seen for a number of correlates, which largely differed by sex. Muscular fitness was moderately and positively associated with RT skills among both males (β = 0.34, 95%CIs = 0.23 to 0.46) and females (β = 0.36, 95%CIs = 0.23 to 0.48). Our findings support a link between RT skills and muscular fitness. Other associations were statistically significant but small in magnitude, and should therefore be interpreted cautiously.  相似文献   

Technical determinants of tackle and ruck performance in International rugby union     

Sharief Hendricks  Tiffany van Niekerk  Drew Wade Sin  Mike Lambert  Steve den Hollander  James Brown 《Journal of sports sciences》2018,36(5):522-528

The most frequently occurring contact events in rugby union are the tackle and ruck. The ability repeatedly to engage and win the tackle and ruck has been associated with team success. To win the tackle and ruck, players have to perform specific techniques. These techniques have not been studied at the highest level of rugby union. Therefore, the purpose of this study was to identify technical determinants of tackle and ruck performance at the highest level of rugby union. A total of 4479 tackle and 2914 ruck events were coded for the Six Nations and Championship competitions. Relative risk ratio (RR), the ratio of the probability of an outcome occurring when a characteristic was observed (versus the non-observed characteristic), was determined using multinomial logistic regression. Executing front-on tackles reduced the likelihood of offloads and tackle breaks in both competitions (Six Nations RR 3.0 Behind tackle, 95% confidence interval [95% CI]: 1.9–4.6, effect size [ES] = large, P < 0.001); Championship RR 2.9 Jersey tackle, 95% CI: 1.3–6.4, ES = moderate, P = 0.01). Fending during contact increased the chances of offloading and breaking the tackle in both competitions (Six Nations RR 4.5 Strong, 95% CI: 2.2–9.2, ES = large, P = P < 0.001; Championship RR 5.1 Moderate, 95% CI: 3.5–7.4, ES = large, P < 0.001). For the ruck, actively placing the ball increased the probability of maintaining possession (Six Nations RR 2.2, 95% CI: 1.1–4.3, ES = moderate, P = 0.03); Championship RR 4.0, 95% CI: 1.3–11.8, ES = large, P = 0.01). The techniques identified in this study should be incorporated and emphasised during training to prepare players for competition. Furthermore, these techniques need to be added to coaching manuals for the tackle and ruck.  相似文献   

The physical education predisposition scale: Preliminary tests of reliability and validity in Australian students     

Toni A. Hilland  Trent D. Brown  Stuart J. Fairclough 《Journal of sports sciences》2018,36(4):384-392

The main aim of this study was to psychometrically test the Physical Education Predisposition Scale (PEPS) with a cohort of Australian students, to assess secondary school students’ perceived PE ability and PE worth. Secondary aims were to explore how the two variables were related and to investigate age and gender differences. Altogether, 266 Year 7, 8, 9 and 10 students (aged 12–16 years), from four schools within the South Eastern region of Melbourne, completed the PEPS at both time points. Principal components analysis revealed the presence of a simple two-factor structure explaining 66.9% of the variance. Factor 1 (labelled perceived PE worth) reflected enjoyment and attitude (α = .91), and factor 2 (labelled perceived PE ability) represented perceptions of competence and self-efficacy (α = .92). Significant positive correlations were observed between the two factors (r = .50–.82, P < .001). Boys scored significantly higher than girls on perceived PE ability (P = .01), and year 7 students scored significantly higher compared to Year 9 students (P = .002). Our results support the potential of the PEPS as a concise measurement tool for use in the PE setting, for both teachers and researchers.  相似文献