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51.
The purpose of this study was to determine test-retest reliability for the 1-mile, 3/4-mile, and 1/2-mile distance run/alk tests for children in Grades K-4. Fifty-one intact physical education classes were randomly assigned to one of the three distance run conditions. A total of 1,229 (621 boys, 608 girls) completed the test-retests in the fall (October), with 1,050 of these students (543 boys, 507 girls) repeating the tests in the spring (May). Results indicated that the 1-mile run/walk distance, as recommended for young children in most national test batteries, has acceptable intraclass reliability (.83 less than R less than .90) for both boys and girls in Grades 3 and 4, has minimal (fall) to acceptable (spring) reliability for Grade 2 students (.70 less than R less than .83), but is not reliable for children in Grades K and 1 (.34 less than R less than .56). The 1/2 mile was the only distance meeting minimal reliability standards for boys and girls in Grades K and 1 (.73 less than R less than .82). Results also indicated that reliability estimates remained fairly stable across gender and age groups from the fall to spring testing periods, with the exception of the noticeably improved values for Grade 2 students on the 1-mile run/walk test. Criterion-referenced reliability (P, percent agreement) was also estimated relative to Physical Best and Fitnessgram run/walk standards. Reliability coefficients for all age group standards were acceptable to high (.70 less than P less than .95), except for Fitnessgram standards for 5-year-old girls on the 1-mile test for both fall and spring and for 6-year-old boys and girls on the 1-mile test administered in the spring.  相似文献   
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Zusammenfassung.   Die automatische Erkennung und Lokalisation von Objekten in digitalen Bildern ist ein wesentlicher Bestandteil vieler praktisch relevanter Anwendungen. In diesem Artikel wird ein erscheinungsbasiertes Verfahren zur Erkennung starrer zwei- oder dreidimensionaler Objekte vorgestellt, dem eine statistische Modellierung zugrundeliegt. Im Gegensatz zu segmentierungsbasierten Verfahren, wie sie vor allem im Bereich der 3D-Objekterkennung eingesetzt werden, erm?glicht der erscheinungsbasierte Ansatz aufgrund der Modellierung der Intensit?tswerte oder davon abgeleiteter lokaler Merkmale eines Bildes die Erkennung komplexer Objekte. Die statistische Formulierung der Problemstellung bildet den mathematischen Kontext zur Bestimmung optimaler L?sungen. Die Form der Modellierung erlaubt neben der Einzelobjekterkennung auch die Berücksichtigung von heterogenem Bildhintergrund und Mehrobjektszenen. Die dazu ben?tigten lokalen Merkmale entstehen durch r?umlich begrenzte Transformationen des Bildes, wie beispielsweise Gabor- oder Wavelet-Transformationen. Die statistische Modellierung beschreibt die Verteilung dieser lokalen Merkmale anhand einer Dichtefunktion, die sich bei der Hintergrund- und Mehrobjektmodellierung als Mischungsverteilung der Einzelobjektverteilungen ergibt. Die Aufgabenstellungen des Erlernens und Erkennens von Objekten sind damit als Parametersch?tzprobleme formal darstellbar. Dabei werden im einen Fall die Modellparameter und im anderen Fall die Lageparameter beziehungsweise die Klassen von Objekten gesch?tzt. Die experimentelle überprüfung des Ansatzes anhand realer Objektaufnahmen durch CCD-Kameras zeigt seine Brauchbarkeit zur Erkennung von 2D- und 3D-Objekten bei homogenem und heterogenem Hintergrund. Eingegangen am 5. April 2000 / Angenommen am 20. Juli 2001  相似文献   
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The aim was to examine cross-cultural variation in linguistic responsiveness to young children in 10 English-speaking mother–child dyads and 10 Italian-speaking mother– child dyads. All 20 children were late talkers who possessed delays in expressive vocabulary development but age-appropriate cognitive and receptive language skills. Dyads were filmed in 15 minute free play contexts, which were transcribed and coded for measures of maternal linguistic input (e.g. rate, MLU, labels, expansions) and child language productivity (e.g. utterances, different words used). The results revealed that the Italian mothers used more utterances, spoke more quickly and used a more diverse vocabulary than the Canadian mothers. The Italian children mirrored their mothers and also used more utterances and a more diverse vocabulary than the Canadian children. Mothers in both groups used similar percentages of responsive labels and expansions. However, Italian mothers responded to fewer of their children's vocalisations, using a smaller percentage of imitations and interpretations than the Canadian mothers. Correlations between maternal input and children's language productivity revealed that contingent language measures (e.g. imitations, interpretations, expansions) were related to high levels of productivity in children in both cultural groups. The results support the use of language interventions based on increasing maternal responsiveness for these children at the one-word stage of language development. They also point to differences that may be culturally based. For example, Italian mothers use faster rates of interaction and appear to have higher expectations for their children's verbal participation in interaction. This is reflected in higher rates of language production from their children, even though children in both cultural groups have similar vocabulary sizes.  相似文献   
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Archival theory in Italy has a long tradition, going back as far as the second half of the nineteenth century, and with roots in the 17th and 18th centuries. Central theme in the theory is themetodo storico, the principle of provenance, for the first time expressed in the late 19th century by Bonaini and Bongi. In the following decades archivists like Casanova and Cencetti were among the leading authors. Elio Lodolini assigned himself the task to synthesize ideas and notions, within a clear distinctions between records (registratura) and archives. One of the overall characteristics of the rich Italian literature is the stressing of the cultural value of archives. I have twice treated before the theme of archival theory in Italy from the fifties up to the nineties. The first time on the occasion of the 25th anniversary of theScuola speciale per Archivisti e Bibliotecari dell'Università degli Studi “La Sapienza” di Roma in 1989, when there was an international round table on archival science in the State Archives of Rome. My essay,Italian archival science today, has been published in the proceedings of the meeting (cfr. Donato Tamblé,L'archivistica in Italia oggi, inStudi sull'archivistica, by Roma: Elio Lodolini, 1992). Some years later, in 1993, I published a book on contemporary Italian archival theory (Donato Tamblé,La teoria archivistica italiana contemporanea (1950–1990). Profilo storico-critico (Roma, 1993) which was the sequel to the volume of Elio Lodolini on Italian archival history — (Lineamenti di storia dell'archivistica italiana (Roma, 1991). The purpose of my book was that of locating and identifying the scientific object of archival science as it developed and was clarified in the thinking and in the lucubration of the contemporary Italian Archivists.  相似文献   
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赛艇运动的项目特性及训练指导思想   总被引:13,自引:4,他引:9  
通过对赛艇运动项目决定成绩的因素,如供能系统、专项素质、生理特性的分析,确定了赛艇运动的特性及规律,并据此特性科学地提出了该项目的训练指导思想.  相似文献   
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试论“网球肘”的成因、诊断、预防与治疗   总被引:2,自引:0,他引:2  
“网球肘”是网球运动中常见的一种伤病。通过研究“网球肘”的成因、诊断、预防与治疗,预防伤病的发生。  相似文献   
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