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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.
Jessica L. Ford Jacob S. Ford Seth S. Frei Andrew Pilny Brenda L. Berkelaar 《Journal of Applied Communication Research》2016,44(3):316-335
Persistent school shootings have generated ongoing pressure to assess and enhance crisis communication effectiveness via strategies such as resilience-building and post-crisis restoration. A network perspective offers a robust, multilevel approach for examining complex information flows among community, campus, and individual actors affected by crises. Drawing on relational and structural embeddedness and Uncertainty Management Theory, we offer nine propositions that help explain structural and relational changes in a network over time. Although theoretically driven, these propositions are primarily functional, offering practical implications for safety officials and administrators trying to understand, prepare for, and respond to crises. Thus, we suggest measures and recommendations to improve information flow, uncertainty management, and resilience before, during, and after a crisis. 相似文献
3.
High antenatal maternal anxiety is related to ADHD symptoms, externalizing problems, and anxiety in 8- and 9-year-olds 总被引：8，自引：0，他引：8
Associations between antenatal maternal anxiety, measured with the State Trait Anxiety Inventory, and disorders in 8- and 9-year-olds were studied prospectively in 71 normal mothers and their 72 firstborns. Clinical scales were completed by the mother, the child, the teacher, and an external observer. Hierarchical multiple regression analyses showed that maternal state anxiety during pregnancy explained 22%, 15%, and 9% of the variance in cross-situational attention deficit hyperactivity disorder symptoms, externalizing problems, and self-report anxiety, respectively, even after controlling for child's gender, parents' educational level, smoking during pregnancy, birth weight, and postnatal maternal anxiety. Anxiety at 12 to 22 weeks postmenstrual age turned out to be a significant independent predictor whereas anxiety at 32 to 40 weeks was not. Results are consistent with a fetal programming hypothesis. 相似文献
4.
Wassenberg R Feron FJ Kessels AG Hendriksen JG Kalff AC Kroes M Hurks PP Beeren M Jolles J Vles JS 《Child development》2005,76(5):1092-1103
The relation between cognitive and motor performance was studied in a sample of 378 children aged 5-6. Half of these children had no behavior problems; the others were selected for externalizing (38%) or internalizing problems (12%). Quantitative and qualitative aspects of motor performance were related to several aspects of cognition, after controlling for the influence of attention. No relation between global aspects of cognitive and motor performance was found. Specific positive relations were found between both aspects of motor performance, visual motor integration and working memory, and between quantitative aspects of motor performance and fluency. These findings reveal interesting parallels between normal cognitive and motor development in 5- to 6-year-old children that cannot be ascribed to attention processes. 相似文献
5.
The Internal Working Model of the Self, Attachment, and Competence in Five-Year-Olds 总被引：5，自引：0，他引：5
The present studies examine some of the correlates of the self in the lives of young children. In Study 1, the connection is tested between young children's internal working model of self and their competence, social acceptance, behavioral adjustment, and behavioral manifestations of self-esteem. Ninety-five kindergartners aged between 51 and 76 months ( M age = 5 years, 3 months) participated in the study. An adapted version of the Puppet Interview was used to assess the representation of self. Affective quality (positiveness) of self and openness to admit imperfections were rated independently. Results show significant and positive relations of the positiveness of self with competence and social acceptance, with behavioral adjustment to school, and with behavioral manifestations of self-esteem, all rated by the teacher. In Study 2, Bowlby's assumption was tested that the working model of self is closely intertwined with the working model of attachment to mother. Subjects were 50 children aged between 55 months and 75 months ( M age = 5 years, 5 months). The working model of child-mother attachment was assessed through an Attachment Story Completion Task. The working model of self was measured via the Puppet Interview. Results show a positive and strong connection between the security of the child-mother attachment representation and the positiveness of self. The results of the two studies contribute to the validation of the adapted Puppet Interview. The Puppet Interview seems to be a promising instrument for assessing the representation of self in young children. 相似文献
6.
Christine Bieri Buschor Christa Kappler Andrea Keck Frei Simone Berweger 《Gender and education》2014,26(7):743-758
The study examines the career decision-making of Swiss academic high school students opting for a career in a non-traditional, gender-typed area of work during the transition to higher education. Based on a longitudinal study, a qualitative study with 11 female students in Science, Technology, Engineering and Mathematics (STEM) and 13 male student teachers was conducted in order to analyse their perceptions of the career decision-making process. They felt supported by their parents and teachers. Women showed a strong sense of identity as future scientists without mentioning specific career goals. Men, by contrast, referred to job security-related considerations and emphasised the importance of role models for their choice. Female students emphasised their status of being ‘unique in a men's world' whereas male student teachers highlighted the role of ‘masculinity in the classroom'. 相似文献
7.
The aim of the current study is to better understand the decision-making of men considering teaching as a career option. By means of a longitudinal study (n = 226), we examined the persistence of male academic high-school students in Switzerland interested in teaching during transition to higher education. For 85 men attending information events for teacher education, using regression analysis we explore factors contributing to their decidedness and volition before enrolling for teacher education studies. The findings reveal that only a very small number of male academic high-school students are interested in teaching. Those who are, however, are persistent in their study choice. Results of the regression analysis show that an interest in working with children and youth, the importance of having free time for other things and having professional experience working with children contribute to the likelihood of men having decided to take up teacher education studies. 相似文献
8.
Acute impact of submaximal resistance exercise on immunological and hormonal parameters in young men 总被引：2，自引：0，他引：2
In this study, we examined the acute effects of submaximal resistance exercise on immunological and hormonal parameters in 7 resistance-trained and 10 non-resistance-trained males. The participants, who were aged 29.5 +/- 7.1 years (mean +/- s), performed submaximal resistance exercise at 75% of their one-repetition maximum. Blood samples were taken before, during, immediately after, and 30, 60 and 120 min after exercise and analysed for leukocyte subpopulations and stress hormones. Total leukocytes, neutrophils and monocytes increased during exercise, reaching their maximum 2 h after exercise. Lymphocytes increased during exercise, T-helper cells returned to resting values after exercise, and natural killer cells and T-suppressor cells decreased below resting values. The CD4/CD8 ratio decreased during exercise but increased during recovery. The resistance-trained participants tended to have lower T-helper cell counts before, during and immediately after exercise and a lower CD4/CD8 ratio during recovery than the non-resistance-trained participants. Plasma cortisol correlated positively with leukocytes during exercise (r = 0.572, P < 0.05), but negatively with T-helper cells 30 and 60 min after exercise (r = -0.573, P < 0.05; r = -0.642, P < 0.01, respectively). Our results indicate that resistance exercise leads to acute changes in leukocyte counts, despite moderate hormonal changes, independent of training status. Regular resistance exercise might lead to decreased T-helper cell counts and a lower CD4/CD8 ratio, which could increase susceptibility to infections. 相似文献
9.
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
10.