Automatic path planning for an unmanned drone with constrained flight dynamics     

K. S. Yakovlev  D. A. Makarov  E. S. Baskin 《Scientific and Technical Information Processing》2015,42(5):347-358

In the article we solve path planning task for an agent being multirotor unmanned aerial vehicle (multicopter). We propose an approach of estimating path geometry constraints based on UAV flight dynamics model and control constraints. Than we introduce a new path finding method which takes into consideration those geometry constraints and study this method both theoretically and empirically.  相似文献   

Research on Teaching Thinking     

Calvin S. Kalman 《Science & Education》2017,26(6):743-745

  相似文献   

Demand for culture in Spain and the 2012 VAT rise     

Javier García-Enríquez  Cruz A. Echevarría 《Journal of Cultural Economics》2018,42(3):469-506

This paper analyzes the effects that the 2012 VAT rise in Spain had on household’ demand for cultural goods and services. Household’ demands are modeled as a two-stage QUAIDS. After estimating price and expenditure elasticities, and the pass-through parameter associated with the reform, our results show that the individual welfare loss and the increment in the tax bill increase, but less than proportionately, with income. Consequently, the reform can be considered as regressive. Relating the effects of the VAT reform to households’ incomes also implies a low quantitative effect, because of the low proportion of total household expenditure that cultural expenditure represents. From a social perspective, the size of the induced welfare loss would positively depend on society’s inequality aversion. Regardless of the latter, it cannot be concluded whether the reform would have increased or reduced inequality in the distribution of cultural spending. Our results prove qualitatively robust to alternative values of the pass-through parameter.  相似文献   

Orthographic-Phonological Mapping and the Emergence of Visual Expertise for Print: A Developmental Event-Related Potential Study     

Vera Varga  Dénes Tóth  Valéria Csépe 《Child development》2020,91(1):e1-e13

The N1 effect is an electrophysiological marker of visual specialization for print. The phonological mapping hypothesis (Maurer & McCandliss, 2007) posits that the left-lateralized effect reflects grapheme-phoneme integration. In this event-related potential study, first (age = 7.06 years, N = 32) and third-grade readers (age = 9.29 years, N = 28) were presented with pairs of pseudowords and Armenian character strings in a novel implicit same-different paradigm. To test the phonological mapping hypothesis, stimuli were presented in visual-only and audiovisual conditions. The results demonstrated that tuning for print already emerges in first grade. Moreover, the parallel presentation of auditory stimuli enhanced the N1 effect suggesting a role of orthographic-phonological mapping in the development of specialization for print.  相似文献   

School Education Through the Eyes of Parents     

Ia. M. Roshchina  T. N. Filippova 《Russian Education & Society》2014,56(1):70-86

Data from surveys of parents of students in Russian schools of various types in the years 2006 to 2011 show a high level of desire to invest in their children's education. There has been a high degree of stability in aspirations and investment in spite of the economic problems caused by global recession.  相似文献   

New cellulosic titanium dioxide nanocomposite as a protective coating for preserving paper-art-works     

Maryam Afsharpour  Fereshteh T. Rad  Hamid Malekian 《Journal of Cultural Heritage》2011,12(4):380

We investigate the TiO₂ role in the inherent protection of paper works of art to protect them against damaging effect of ultraviolet radiation, pollutant gasses, mold and bacteria. In this study a cellulosic nanocomposite of TiO₂ were used as protective coating on the surface of paper fibers. This layered nanocomposite can act as a consolidate materials too. Furthermore, to determine how well paper works screen objects from the damaging effects, two accelerated aging mechanisms due to light and heat are discussed. Results show good stability of papers with nanocomposite coating. Also, a good light stability was shown in the colored paper that treated with this nanocomposite. Furthermore, to demonstrate the degree of antifungal properties of coated papers, papers were treated with two common molds and the good preventive effect of coated paper against molds is described.  相似文献   

<Emphasis Type="Bold">Math: Old,New, and Equalitarian</Emphasis>     

William M. Briggs 《Academic Questions》2017,30(4):508-513

  相似文献   

Relationship between foot strike pattern,running speed,and footwear condition in recreational distance runners     

Roy T. H. Cheung  Rodney Y. L. Wong  Tim K. W. Chung  R. T. Choi  Wendy W. Y. Leung  Diana H. Y. Shek 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(2):238-247

Compared to competitive runners, recreational runners appear to be more prone to injuries, which have been associated with foot strike patterns. Surprisingly, only few studies had examined the foot strike patterns outside laboratories. Therefore, this study compared the foot strike patterns in recreational runners at outdoor tracks with previously reported data. We also investigated the relationship between foot strike pattern, speed, and footwear in this cohort. Among 434 recreational runners analysed, 89.6% of them landed with rearfoot strike (RFS). Only 6.9 and 3.5% landed with midfoot and forefoot, respectively. A significant shift towards non-RFS was observed in our cohort, when compared with previously reported data. When speed increased by 1 m/s, the odds of having forefoot strike and midfoot strike relative to RFS increased by 2.3 times and 2.6 times, respectively. Runners were 9.2 times more likely to run with a forefoot strike in minimalists compared to regular running shoes, although 70% of runners in minimalists continued to use a RFS. These findings suggest that foot strike pattern may differ across running conditions and runners should consider these factors in order to mitigate potential injury.  相似文献   

Stasis and change: the evolution of a philosopher     

Alan C. Love 《Metascience》2017,26(2):223-227

  相似文献   

MOOCs: The Director’s Cut     

Daniel A. Bonevac 《Academic Questions》2016,29(1):59-67

  相似文献