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1.
Markus Keidl Alfons Kemper Donald Kossmann und Alexander Kreutz 《Informatik - Forschung und Entwicklung》2002,17(3):123-134
Zusammenfassung. Wir pr?sentieren in dieser Arbeit das ObjectGlobe-System, ein offenes und verteiltes Anfragebearbeitungssystem auf Internet-Datenquellen.
ObjectGlobe erweitert die begrenzten F?higkeiten des Internets bezüglich Anfragebearbeitung, indem es einen offenen Marktplatz
schafft, in dem eine Vielzahl von Anbietern Rechenzeit, Daten und Anfrageoperatoren bereitstellen. Den Schwerpunkt dieses
Beitrags bildet die im Rahmen des ObjectGlobe-Projekts entwickelte Metadatenverwaltung MDV, ein verteiltes Metadaten-Management-System.
Es besitzt eine 3-schichtige Architektur und unterstützt Caching und Replikation in der Mittelschicht, so dass Anfragen lokal
ausgewertet werden k?nnen. Benutzer spezifizieren die Informationen, die sie ben?tigen und die repliziert werden, mit Hilfe
einer besonderen Regelsprache. Um Replikate aktuell zu halten und die Replikation von neuen und relevanten Informationen anzusto?en,
verwendet das MDV-System einen neuartigen Publish & Subscribe-Algorithmus. Wir beschreiben diesen Algorithmus im Detail und
zeigen, wie er mit Hilfe eines normalen relationalen Datenbanksystems implementiert werden kann.
Eingegangen am 19. November 2001 / Angenommen am 30. Juli 2002 相似文献
2.
Dolores A. Stegelin Denise Anderson Karen Kemper Jennifer Wagner Katharine Evans 《Early Childhood Education Journal》2014,42(2):133-142
The purpose of this research project was to gain a greater understanding of daily routines of 4–7 year olds regarding physical activity and nutrition practices in typical early learning environments. The settings selected for this observational study included Head Start, primary, and after-school learning environments in a city in the southeast. Specifically, this exploratory study focused on the research question: What are typical daily physical activity and nutrition patterns in community-based early learning settings for young children 4–7 years of age in the United States? Two overarching themes were identified through data analysis: restriction of activity and restriction of physical movement. Results indicated that children in elementary school settings had fewer opportunities for indoor and outdoor physical activity than children in other settings and that children seek to be physically active and will do so when given the opportunity. Increasing time for both structured and unstructured physical activity and play for children ages 4–7 in early learning settings was recommended by the researchers. 相似文献
3.
Bortz Whitney Wall Gautam Aakash Tatar Deborah Lipscomb Kemper 《Journal of Science Education and Technology》2020,29(1):121-136
Journal of Science Education and Technology - Integrating computational thinking (CT) and science education is complex, and assessing the resulting learning gains even more so. Arguments that... 相似文献
4.
This study examined how Flesch Reading Ease and text cohesion affect older adults' comprehension of common health texts. All older adults benefited when high Flesh Reading Ease was combined with high cohesion. Older adults with small working memories had more difficulty understanding texts high in Flesch Reading Ease. Additionally, older adults with low verbal ability or older than 77 years of age had difficulty understanding texts high in text cohesion but low in Flesch Reading Ease. These results imply that writers must increase Flesch Reading Ease without disrupting text cohesion to ensure comprehension of health-related texts. 相似文献
5.
Kyle R. Lynch Han C. G. Kemper Bruna Turi-Lynch Ricardo R. Agostinete Igor H. Ito Rafael Luiz-De-Marco 《Journal of sports sciences》2017,35(24):2421-2426
The objective of the present study was to investigate the effects of different sports on stress fractures among adolescents during a 9-month follow-up period. The sample was composed of 184 adolescents divided into three groups (impact sports [n = 102]; swimming [n = 35]; non-sports [n = 47]). The occurrence of stress fracture was reported by participants and coaches. As potential confounders we considered age, sex, resistance training, body composition variables and age at peak of height velocity. There were 13 adolescents who reported fractures during the 9-month period. Bone mineral density values were higher in adolescents engaged in impact sports (P-value = 0.002). Independently of confounders, the risk of stress fracture was lower in adolescents engaged in impact sports than in non-active adolescents (hazard ratio [HR] = 0.23 [95% confidence interval (CI) = 0.05 to 0.98]), while swimming practice was not associated to lower risk of fracture (HR = 0.49 [95% CI = 0.09 to 2.55]). In conclusion, the findings from this study indicate the importance of sports participation among adolescents in the reduction of stress fracture risk, especially with impact sports. More importantly, these results could be relevant for recognising adolescents in danger of not reaching their potential for peak bone mass and later an increased risk of fractures. 相似文献
6.
Markus Keidl Alfons Kemper Donald Kossmann Alexander Kreutz 《Informatik - Forschung und Entwicklung》2002,10(1):123-134
Wir pr?sentieren in dieser Arbeit das ObjectGlobe-System, ein offenes und verteiltes Anfragebearbeitungssystem auf Internet-Datenquellen. ObjectGlobe erweitert die begrenzten F?higkeiten des Internets bezüglich Anfragebearbeitung, indem es einen offenen Marktplatz schafft, in dem eine Vielzahl von Anbietern Rechenzeit, Daten und Anfrageoperatoren bereitstellen. Den Schwerpunkt dieses Beitrags bildet die im Rahmen des ObjectGlobe-Projekts entwickelte Metadatenverwaltung MDV, ein verteiltes Metadaten-Management-System. Es besitzt eine 3-schichtige Architektur und unterstützt Caching und Replikation in der Mittelschicht, so dass Anfragen lokal ausgewertet werden k?nnen. Benutzer spezifizieren die Informationen, die sie ben?tigen und die repliziert werden, mit Hilfe einer besonderen Regelsprache. Um Replikate aktuell zu halten und die Replikation von neuen und relevanten Informationen anzusto?en, verwendet das MDV-System einen neuartigen Publish & Subscribe-Algorithmus. Wir beschreiben diesen Algorithmus im Detail und zeigen, wie er mit Hilfe eines normalen relationalen Datenbanksystems implementiert werden kann. 相似文献
7.
Mollie Rubin Susan Kemper Patrick Ellen B. Goldring 《Peabody Journal of Education》2017,92(5):609-626
This paper studies the early implementation of a school improvement effort in two high schools. We examine what explains variation in the teacher adoption of program practices. Our findings highlight the tension between encouraging immediate adoption of program practices and the longer term goals of schoolwide culture change. We find that highly structured practices and those that are already aligned with teachers' extant beliefs and classroom practices can be implemented with little preexisting capacity. These conditions could also lead to more consistent and quicker initial adoption. However, this type of implementation might not encourage sufficient understanding of program goals and may inhibit the diffusion of practices into the school culture. Findings highlight dilemmas associated with program practices when the goal is to bring educational reforms to scale. 相似文献
8.
Joya A. Kemper Paul W. Ballantine C. Michael Hall 《Environmental Education Research》2019,25(12):1751-1774
AbstractFaculty are key to bringing about ‘bottom-up’ change for sustainability education. Yet, research is still needed on the backgrounds and experiences of change agents in universities and the challenges they face. This study focuses on the marketing discipline, a field fraught with epistemological tensions in seeking to integrate sustainability, mainly revolving around profit maximisation and continuous consumption while living on a planet with finite resources. Semi-structured interviews were conducted with sustainability marketing academics in Australasia, Europe and North America. The contribution of this paper lies in the development of a sustainability educator typology linking why and how integration occurs. The sustainability ‘transformer’ wishes to engage in transformational learning, changing student mindsets, the ‘thinker’ wants to encourage critical thinking to bring about the discussion of worldviews, while the ‘actioner’ hopes ‘learning by doing’ (community projects) will provide an appreciation for sustainability. We discuss implications for those disciplines which struggle with philosophical tensions and colleague resistance to the integration of sustainability in the form of suggestions for professional development (i.e. creation of positive nature experiences) and pedagogical approaches (critical, transformative and community-service learning). 相似文献
9.
The study aimed to compare the differential effectiveness of explicit and implicit instruction of two Dutch spelling rules. Students with and without spelling disabilities were instructed a spelling rule either implicitly or explicitly in two experiments. Effects were tested in a pretest-intervention-posttest control group design. Experiment 1 suggested that explicit instruction of a morphological spelling rule led to instance-based knowledge in students with spelling disabilities and to rule-based knowledge in students without. Implicit instruction led to instance-based knowledge in students with spelling disabilities, and in the group without spelling disabilities no learning at all occurred. Experiment 2 revealed that explicit and implicit instruction of an orthographical spelling rule were equally effective in both groups and that the spelling knowledge they had acquired was instance-based. Findings suggest that explicit instruction is more effective than implicit instruction for the teaching of spelling rules when generalization is aimed at. 相似文献
10.
M. J. Themane K. D. Monyeki M. E. Nthangeni H. C. G. Kemper J. W. R. Twisk 《International Journal of Educational Development》2003,23(6):637-643
The purpose of this paper is to report the cross-sectional relationship between educational achievements and the ‘health status’ of the rural South African children in the Ellisras Longitudinal Study (ELS).The study followed a cohort design where 1033 children (569 boys and 464 girls) aged 7–14 were randomly sampled from 11 primary schools and one secondary school. Anthropometric measurements for height for age (HAZ), weight for age (WAZ), body mass index (BMI) and sum of skinfolds (SOS) were carried out to establish their ‘health status’. Educational achievement tests for Mathematics and English were administered to check their educational status.The results of the multilevel analysis showed that HAZ, WAZ and BMI were positively related to both English and Mathematics performance. HAZ was only positively related to mathematical performance and SOS was not related to educational achievement at all. Furthermore, age and gender only marginally influenced the observed relationships.The study recommends that other factors such as socio-economic status and learning environment should be looked into to find out whether these factors influence the observed relationships. 相似文献