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论网络教学的“复杂观”
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作者 陈卫东 李芒 《现代远距离教育》 北大核心 2003年第3期34-37,共4页
本文针对目前教育技术研究领域中存在的简单化倾向,运用现代复杂学理论,阐述了网络教学的“复杂观”。重点分析了网络教学的复杂性的构成原因,构成层面,具体表现,并根据理论和实践的需求提出了解决问题的方法。
关键词 网络教学 “复杂观” 教育技术 复杂学理论 形成原因 解决方案
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Effective Moduli of Two-Layered Spherical Inclusions Reinforced Composites
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作者 胡更开 《Journal of Beijing Institute of Technology》 EI CAS 1997年第1期59-66,共8页
A model is proposed to evaluate the,effective modufi of a composite reinforced by two-layered spherical inclusions.This model is based on the localisation problem of a two- layered spherical inclusion embedded in an i... A model is proposed to evaluate the,effective modufi of a composite reinforced by two-layered spherical inclusions.This model is based on the localisation problem of a two- layered spherical inclusion embedded in an infinite matrix.The interations of the reinforced phases are taken into account by using the average matrix stress concept.When the external layer vanishes,the proposed model reduces to the classical Mori-Tanaka's model for spherical inclusions.Theoretical results for the composite of polyester matrix filled by hollow glass spheres and voids show excellent agreement with experimental results. 展开更多
关键词 two-layered spherical inclusion effective moduli COMPOSITE MICROMECHANICS
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Canadian Agility and Movement Skill Assessment(CAMSA):Validity, objectivity, and reliability evidence for children 8–12 years of age 被引量:11
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作者 Patricia E.Longmuir Charles Boyer +6 位作者 Meghann Lloyd Michael M.Borghese Emily Knight Travis J.Saunders Elena Boiarskaia Weimo Zhu Mark S.Tremblay 《Journal of Sport and Health Science》 SCIE 2017年第2期231-240,共10页
Purpose: The primary aim of this study was to develop an assessment of the fundamental, combined, and complex movement skills required to support childhood physical literacy. The secondary aim was to establish the fea... Purpose: The primary aim of this study was to develop an assessment of the fundamental, combined, and complex movement skills required to support childhood physical literacy. The secondary aim was to establish the feasibility, objectivity, and reliability evidence for the assessment.Methods: An expert advisory group recommended a course format for the assessment that would require children to complete a series of dynamic movement skills. Criterion-referenced skill performance and completion time were the recommended forms of evaluation. Children, 8–12 years of age, self-reported their age and gender and then completed the study assessments while attending local schools or day camps. Face validity was previously established through a Delphi expert(n = 19, 21% female) review process. Convergent validity was evaluated by age and gender associations with assessment performance. Inter-and intra-rater(n = 53, 34% female) objectivity and test–retest(n = 60, 47% female) reliability were assessed through repeated test administration.Results: Median total score was 21 of 28 points(range 5–28). Median completion time was 17 s. Total scores were feasible for all 995 children who self-reported age and gender. Total score did not differ between inside and outside environments(95% confidence interval(CI) of difference:-0.7 to 0.6;p = 0.91) or with/without footwear(95%CI of difference:-2.5 to 1.9; p = 0.77). Older age(p < 0.001, η2= 0.15) and male gender(p < 0.001, η2= 0.02)were associated with a higher total score. Inter-rater objectivity evidence was excellent(intraclass correlation coefficient(ICC) = 0.99) for completion time and substantial for skill score(ICC = 0.69) for 104 attempts by 53 children(34% female). Intra-rater objectivity was moderate(ICC = 0.52) for skill score and excellent for completion time(ICC = 0.99). Reliability was excellent for completion time over a short(2–4 days; ICC = 0.84) or long(8–14days; ICC = 0.82) interval. Skill score reliability was moderate(ICC = 0.46) over a short interval, and substantial(ICC = 0.74) over a long interval.Conclusion: The Canadian Agility and Movement Skill Assessment is a feasible measure of selected fundamental, complex and combined movement skills, which are an important building block for childhood physical literacy. Moderate-to-excellent objectivity was demonstrated for children 8–12 years of age. Test–retest reliability has been established over an interval of at least 1 week. The time and skill scores can be accurately estimated by 1 trained examiner. 展开更多
关键词 Agility course CHILDREN Dynamic motor skill Locomotor skill Object manipulation Population assessment
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Feasibility Comparison of Reanalysis Data from NCEP-I and NCEP-II in the Himalayas 被引量:3
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作者 XIE Aihong REN Jiawen +1 位作者 QIN Xiang KANG Shichang 《Journal of Mountain Science》 SCIE CSCD 2009年第1期56-65,共10页
Mt. Everest is often referred to as the earth's 'third' pole. As such it is relatively inaccessible and little is known about its meteorology. In 2005, an automatic weather station was operated at North Col (28... Mt. Everest is often referred to as the earth's 'third' pole. As such it is relatively inaccessible and little is known about its meteorology. In 2005, an automatic weather station was operated at North Col (28°1′ 0.95" N, 86°57′ 48.4" E, 6523 m a.s.l.) of Mt. Everest. Based on the observational data, this paper compares the reanalysis data from NCEP/NCAR (hereafter NCEP-Ⅰ) and NCEP-DOE AMIP-Ⅱ (NCEP- Ⅱ), in order to understand which reanalysis data are more suitable for the high Himalayas with Mr. Everest region. When comparing with those from the other levels, pressure interpolated from 500 hPa level is closer to the observation and can capture more synoptic-scale variability, which may be due to the very complex topography around Mt. Everest and the intricately complicated orographic land-atmosphereocean interactions. The interpolation from both NCEP-Ⅰ and NCEP-Ⅱ daily minimum temperature and daily mean pressure can capture most synopticscale variability (r〉0.82, n=83, p〈0.001). However, there is difference between NCEP-Ⅰ and NCEP-Ⅱ reanalysis data because of different model parameterization. Comparing with the observation, the magnitude of variability was underestimated by 34.1%, 28.5 % and 27.1% for NCEP-Ⅰ temperature and pressure, and NCEP-Ⅱ pressure, respectively, while overestimated by 44.5 % for NCEP-Ⅱ temperature. For weather events interpolated from the reanalyzed data, NCEP-Ⅰ and NCEP-Ⅱ show the same features that weather events interpolated from pressure appear at the same day as those from the observation, and some events occur one day ahead, while most weather events and NCEP-Ⅱ temperature interpolated from NCEP-Ⅰ happen one day ahead of those from the observation, which is much important for the study on meteorology and climate changes in the region, and is very valuable from the view of improving the safety of climbers who attempt to climb Mt. Everest. 展开更多
关键词 Mt. Everest NCEP/NCAR (NCEP-Ⅰ) NCEP-DOE AMIP-Ⅱ (NCEP-Ⅱ) daily minimumtemperature (DMinT) daily mean pressure(DMeanP) High Himalayas
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Traffic Flow States in a Freeway with Bottleneck 被引量:2
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作者 PENG Zi-Hui SUN Gang ZHU Jing-Yi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第1期145-148,共4页
The system of mixture of single lane and double lane is studied by a cellular automata model, which is developed by us based on the Nagel and Schreckenberg's models. We justify that the model can reach a stable state... The system of mixture of single lane and double lane is studied by a cellular automata model, which is developed by us based on the Nagel and Schreckenberg's models. We justify that the model can reach a stable states quickly. The density distributions of the stable state is presented for several cases, which illustrate the manner of the congestion. The relationship between the outflow rate and the total number of vehicles and that between the outflow rate and the density just before the bottleneck are both given. Comparing with the relationship that occurring in the granular flow, we conclude that the transition from the free traffic flow to the congested traffic flow can also be attributed to the abrupt variation through unstable flow state, which can naturally explain the discontinuities and the complex time variation behavior observed in the traffic flow experiments. 展开更多
关键词 granular flow phase transition stochastic process
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An investigation on the Correlation between Unemployment and Living Conditions in Zambia: A Case Study of Kaunda Square Stage II
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作者 Jubert Twambo M. Kabubi 《Journal of Life Sciences》 2018年第1期64-73,共10页
Most of the Zambian population, the poor people in affluent society, are enmeshed in the net of poverty. The Zambian government seems to have failed in its contractual obligation to respect and sustain its social cont... Most of the Zambian population, the poor people in affluent society, are enmeshed in the net of poverty. The Zambian government seems to have failed in its contractual obligation to respect and sustain its social contract with the people. There is a seemingly total collapse of social security, increased unemployment rate and consequently decreased living conditions among the youth. This study sets out to investigate the correlation between unemployment and living conditions in Kaunda Square Stage II by analyzing the impact of unemployment and suggests strategic solutions to mitigate the levels of unemployment. The primary objective of this study is to investigate the impact on the living conditions caused by unemployment in Zambia specifically in Kaunda Square Stage II and adopt strategic solutions that will mitigate creation of jobs to improve the living conditions. The study underscores that unemployment is a universal phenomenon, not necessarily a peculiar characteristic of any segment of the society. Reducing poverty, preventing excessive inequality, and generating adequate employment are the three most important goals of a macroeconomic strategy that seeks to improve the living standards of the population. Inequality and employment are each a complex phenomenon and difficult to capture with a single measurement, particularly in a low-income economy undergoing change. It is in this context that the study intends to investigate the correlation between unemployment and living conditions in Kaunda Square Stage II and to provide strategic solutions that may improve living conditions in Kaunda Square Stage II. The study concludes that high unemployment in Kaunda Square Stage II increases poverty which subsequently affects living conditions. Therefore, when, unemployment rates increase the opportunities for earning income decreases which instigate individuals to be poor. The paper closes with reflections on how good strategic solutions can be used to underwrite more employment reduction strategies. 展开更多
关键词 UNEMPLOYMENT living conditions INEQUALITY poverty.
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