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151.
Soo Jin Lee Jaehong Shin 《International Journal of Science and Mathematics Education》2015,13(2):329-355
In the present study, we describe a participating student’s (Carol’s) distributive partitioning scheme and operations along with Steffe’s and his colleagues’ studies about children’s constructions of fraction knowledge as a particular model of mathematical learning. Analysis of Carol’s mathematical behaviors indicates that an operationally common mathematical behavior (distributive partitioning operation) was revealed in various mathematical problem situations such as fraction multiplication, fraction division, and multiplicative transformation between fractional quantities. It both provides a rationale for why becoming versed in one mathematical subject could facilitate working with another mathematical subject and also implies the necessity of describing and defining students’ mathematical behaviors from an operational view of knowledge, which might lead to building foundations of a substantial cognitive map for students’ mathematical development. 相似文献
152.
Higher Education - Literature offers a theoretical framework exemplifying the inherent tensions between “becoming Chinese” and “remaining global” in the evolution of the... 相似文献
153.
Kwon Wonju Ha Jung Hee Jang Hansori Lee Donghun 《International journal for the advancement of counseling》2022,44(2):283-297
International Journal for the Advancement of Counselling - The current study investigated the mediation effect of self-focused attention on the relationship between South Korean novice... 相似文献
154.
Li Zhao Yi Zheng Junbang Zhao Guoqiang Li Brian J. Compton Rui Zhang Fang Fang Gail D. Heyman Kang Lee 《Child development》2023,94(4):922-940
Academic cheating is common, but little is known about its early emergence. It was examined among Chinese second to sixth graders (N = 2094; 53% boys, collected between 2018 and 2019) using a machine learning approach. Overall, 25.74% reported having cheated, which was predicted by the best machine learning algorithm (Random Forest) at a mean accuracy of 81.43%. Cheating was most strongly predicted by children's beliefs about the acceptability of cheating and the observed prevalence and frequency of peer cheating at school. These findings provide important insights about the early development of academic cheating, and how to promote academic integrity and limit cheating before it becomes entrenched. The present research demonstrates that machine learning can be effectively used to analyze developmental data. 相似文献
155.
Guan-Cheng Li Ronald Lai Alexander D’Amour David M. Doolin Ye Sun Vetle I. Torvik Amy Z. Yu Lee Fleming 《Research Policy》2014
Research into invention, innovation policy, and technology strategy can greatly benefit from an accurate understanding of inventor careers. The United States Patent and Trademark Office does not provide unique inventor identifiers, however, making large-scale studies challenging. Many scholars of innovation have implemented ad-hoc disambiguation methods based on string similarity thresholds and string comparison matching; such methods have been shown to be vulnerable to a number of problems that can adversely affect research results. The authors address this issue contributing (1) an application of the Author-ity disambiguation approach (0170 and 0175) to the US utility patent database, (2) a new iterative blocking scheme that expands the match space of this algorithm while maintaining scalability, (3) a public posting of the algorithm and code, and (4) a public posting of the results of the algorithm in the form of a database of inventors and their associated patents. The paper provides an overview of the disambiguation method, assesses its accuracy, and calculates network measures based on co-authorship and collaboration variables. It illustrates the potential for large-scale innovation studies across time and space with visualizations of inventor mobility across the United States. The complete input and results data from the original disambiguation are available at (http://dvn.iq.harvard.edu/dvn/dv/patent); revised data described here are at (http://funglab.berkeley.edu/pub/disamb_no_postpolishing.csv); original and revised code is available at (https://github.com/funginstitute/disambiguator); visualizations of inventor mobility are at (http://funglab.berkeley.edu/mobility/). 相似文献
156.
On the Semantic Web, the types of resources and the semantic relationships between resources are defined in an ontology. By using that information, the accuracy of information retrieval can be improved. 相似文献
157.
This paper addresses synchronization problem for discrete-time complex dynamical networks with interval time-varying delays. In order to achieve the synchronization, a feedback controller subjected to randomly occurring perturbations will be considered. The randomly occurring perturbations are assumed to belong to the Binomial sequence. By constructing a suitable Lyapunov–Krasovskii functional, and utilizing reciprocally convex approach and Finsler?s lemma, the synchronization criteria for the networks are established in terms of linear matrix inequalities (LMIs) which can be easily solved by various effective optimization algorithms. The networks are represented by the use of Kronecker product technique. The effectiveness of the proposed methods will be verified via numerical examples. 相似文献
158.
In this study, we simulated deformation and surfactant distribution on the interface of a surfactant-covered droplet using optical tweezers as an external source. Two optical forces attracted a single droplet from the center to both sides. This resulted in an elliptical shape deformation. The droplet deformation was characterized as the change of the magnitudes of surface tension and optical force. In this process, a non-linear relationship among deformation, surface tension, and optical forces was observed. The change in the local surfactant concentration resulting from the application of optical forces was also analyzed and compared with the concentration of surfactants subjected to an extensional flow. Under the optical force influence, the surfactant molecules were concentrated at the droplet equator, which is totally opposite to the surfactants behavior under extensional flow, where the molecules were concentrated at the poles. Lastly, the quasi-equilibrium surfactant distribution was obtained by combining the effects of the optical forces with the extensional flow. All simulations were executed by the lattice Boltzmann method which is a powerful tool for solving micro-scale problems. 相似文献
159.
Red blood cells (RBCs) are important to dictate hemorheological properties of blood. The
shear-thinning effect of blood is mainly attributed to the characteristics of the RBCs. Variations
in hemorheological properties alter flow resistance and wall shear stress in blood vessels. Therefore, detailed
understanding of the relationship between the hemorheological and hemodynamic properties is of great
importance. In this study, blood viscosity and blood
flow were simultaneously measured in the same microfluidic device by monitoring the
flow-switching phenomenon. To investigate blood flows according to hemorheological variations, the flow rate of blood samples (RBCs
suspended in autologous plasma, dextran-treated plasma, and in phosphate buffered saline solution)
was precisely controlled with a syringe pump. Velocity profiles of blood flows were measured by using a micro-particle image
velocimetry technique. The
shape of velocity profiles
was quantified by using a curve-fitting equation. It is found that the shape of the velocity profiles is highly correlated with
blood viscosity. To
demonstrate the relationship under ex vivo conditions, biophysical properties and
velocity profiles were
measured in an extracorporeal rat bypass loop. Experimental results show that
increased blood viscosity seems to induce blunt velocity profile with high velocity component at the wall of the microchannel. Simultaneous
measurement of blood viscosity and velocity profile would be useful for understanding the effects of hemorheological
features on the hemodynamic
characteristics in capillary blood vessels. 相似文献
160.
E. Schreuders M. van Buuren R. J. Walsh H. Sijtsma M. Hollarek N. C. Lee L. Krabbendam 《Child development》2024,95(2):368-390
Longitudinal changes in trusting behavior across adolescence and their neural correlates were examined. Neural regions of interest (ROIs) included the medial prefrontal cortex (mPFC), dorsal anterior cingulate cortex (dACC), left anterior insula (AI), bilateral ventral striatum (VS), and right dorsal striatum (DS). Participants (wave 1 age: M = 12.90) played the investor in a Trust Game with an uncooperative trustee three times (1-year interval). Analyses included 77 primarily Dutch participants (33 females). Participants decreased their investments with wave. Furthermore, activity was heightened in mPFC, dACC, and DS during investment and repayment, and in right VS (investment) and AI (repayment). Finally, DS activity during repayment increased with wave. These findings highlight early–middle adolescence as an important period for developing sensitivity to uncooperative behavior. 相似文献