Regularized Wasserstein Means for Aligning Distributional Data

We propose to align distributional data from the perspective of Wasserstein means. We raise the problem of regularizing Wasserstein means and propose several terms tailored to tackle different problems. Our formulation is based on the variational transportation to distribute a sparse discrete measure into the target domain. The resulting sparse representation well captures the desired property of the domain while reducing the mapping cost. We demonstrate the scalability and robustness of our method with examples in domain adaptation, point set registration, and skeleton layout

A meta-analysis: Gamification in education

“Gamification has been used in a variety of contexts including education. In order to understand the effects of gamification in education, a meta-analysis was conducted. A bottom-up approach was used to analyze the effects of game design elements on learning outcomes found in the literature search. The result suggests that gamification can enhance student learning outcomes. Elements such as points, leaderboards, competitions, progress bars, feedback, and collaboration have medium to large effect sizes. Gamification also has larger effects on young children in elementary education than learners at other education levels. The study offers suggestions and guidelines for educators on the use of design elements in gamification”--Abstract, page iii

Production forecast of China׳s rare earths based on the Generalized Weng model and policy recommendations

AbstractChina is currently the largest producer of rare earths in the world, mining at least 90% of world total production. Because of China׳s dominant position in global rare earths production and the constant development of rare earths terminal industries, the study of China׳s rare earth supply trends has gradually been a hot topic of world interest. However, the literature shows that previous research has mainly focused on the estimation of rare earth supply and its influence based on experiential judge of current and premonitory new rare earth production capacity, rather than on quantitative modeling. The results are usually estimations of the productions of near future rather than longer term. Forecasts by mine types are particularly rare. Considering the different applications and demands of different rare earth elements, the Generalized Weng model, a widely used quantitative model in exhaustible resource forecast, is adopted in this study to predict the production of the three major rare earths in China (namely, mixed rare earth, bastnasite and ion-absorbed rare earth) before 2050. The results show that production of mixed rare earth will peak in 2014 at 62,757t, followed thereafter by an annual decline of 2%; production of bastnasite will peak in 2018 at 32,312t, preceded by an annual increase of 1.67% and followed by an annual decrease of 4%; production of ion-absorbed rare earth will peak in 2024 at 45,793t, preceded by an annual increase of 1.72% and followed by an annual decrease of 4%. Based on these findings, Chinese government should enforce environmental and resource exhaustible taxes soon and different domestic regulations for different rare earths according to their different production potential. Countries without resource endowments should make efforts to develop rare earth recycling technologies and seek substitutes for rare earth resources, in addition to keeping good international trading relationships. Countries with some kind of rare earths should start or restart their rare earth mines to gradually reduce dependence on China׳s supply

Simulation of local head loss of drip-irrigation tape with integrated in-line emitters as a function of cross section

Aim of study: To investigate how the cross section of a drip-irrigation tape affects local head loss.Area of study: The work was carried out in the laboratory of Irrigation hydraulics, College of Water Conservancy and Environment, Three Gorges University, Yichang, Hubei province.Material and methods: Tapes with six different wall thicknesses were studied experimentally to determine the relationship between cross-section deformation, wall thickness, and pressure. Based on the experimental results, we determined the factors that influence local head loss in drip-irrigation tapes by numerical simulation and dimensional analysis.Main results: The cross-sectional shape of the drip-irrigation tape varied with pressure: under low pressure, the cross section was nearly elliptical. The cross-sectional shape of the tape strongly influenced the local head loss, which was inversely proportional to the 0.867th power of the flattening coefficient of the drip irrigation tape. We expressed the local head loss of a drip-irrigation tape equipped with integrated in-line emitters by considering the deformation of the cross section. Under the conditions used in this study, when the cross section is circular, the ratio of local head loss to frictional head loss was about 10% but, when the cross section is elliptical, this ratio increased to 15%.Research highlights: The shape of the cross section of a drip-irrigation tape is nearly elliptical under low pressure. Local head loss is inversely proportional to the 0.867th power of that is the flatting coefficient of the drip-irrigation tape. Local head loss is about 1.5 times for elliptical tape than circular tape