Auditory perceptual processing in reading disabled children

One hundred and three children attending Learning Assistance Centres due to reading difficulties and one hundred and three matched, average readers were administered a battery of auditory perceptual processing tasks. The battery was composed of auditory analysis and synthesis, auditory sequential memory, auditory discrimination, and phonemic segmentation tasks. A principal components analysis yielded four factors. These were determined to be advanced phonological awareness, sequential memory, discrimination, and simple phonological awareness. Discriminant analyses, using the factor scores, indicated that three of the four factors were able to discriminate between the able and disabled readers. Most notable among these was advanced phonological awareness. Auditory discrimination could not discriminate between the groups. The results suggest that there may not be one underlying phonological ability implicated in successful reading acquisition. Furthermore, it is clear that two levels of phonological awareness exist and that screening and diagnostic instruments should address both in order to have predictive validity.     

Performance of Montessori and traditionally schooled nursery children on tasks of seriation, classification, and conservation

It was hypothesized that the Montessori curriculum accelerates the acquisition of a number of concrete operational skills. To test this, eighty 4-year-old children were given three Piagetian problems—seriation, classification, and conservation. Half of the subjects were from Montessori schools, and the other half were from more traditional nursery settings. Within each type of school, half of the children were first year and the other half were second year enrollees. Results showed that significantly more Montessori than traditional children seriated and classified objects like concrete thinkers but that there were no differences on the conservation problem. Year of enrollment did not influence performance on any of the tasks. It was concluded that the hypothesis was confirmed and that the failure to find acceleration of conservation performance was due to its advanced nature relative to the other problems and/or the tangential manner in which Montessori exercises deal with the critical concepts that underly it.     

A Physical Interpretation of Factorization and Factor Modification in Structural Analysis

The physical interpretation of LDL^t factorization and Bennett's method for matrix factor modification applied to structural analysis are studied. The sparsity of the matrix factors and their effect on matrix modification are examined.     

下一代GPS系统

目前,经常使用全球定位系统(GPS)的人数已达2000万,24颗"导航之星"(NavStar)组成的地球同步轨道卫星群(轨道高度为2万千米)随时为这些用户提供信号.阿富汗战争和伊拉克战争都证明了GPS系统不可或缺.     

现代炼钛金术

踏破铁鞋无觅处，得来全不费工夫。发现之神将高科技材料的低成本生产工艺传授给我们。     

Studying mathematics learning in collective activity

This paper describes a study of the interplay between social and developmental processes in children's mathematics learning. The focus is on children's play of an educational game, Treasure Hunt, and the way children's interactions in play frame developmental processes involving arithmetic with base-10 blocks. Sixty-four third and fourth graders were grouped in same- and mixed-grade dyads. Analyses of interactions revealed that players were frequently involved with jointly structuring arithmetical problems involving base-10 blocks. However, the arithmetical goals that members of dyads created often differed as labor became divided in their activity. Two findings were of particular interest: (1) differences in divisions of labor as a function of players' grades and grades of their opponents led to construction of different arithmetical goals, and (2) differences in goals led to different sequences in children's strategic developments, sequences that differed from the developmental trajectory in our matched controls.     

Evaluating Visitor Conservation Research at the Monterey Bay Aquarium

Abstract In 1997 the Monterey Bay Aquarium refined its mission to one concise statement: The mission of the Monterey Bay Aquarium is to inspire conservation of the oceans. This has led to increased conservation content in exhibitions and more evaluation studies focused on visitors' conservation knowledge, understanding, attitudes and behavior. This article reviews conservation‐related findings from the aquarium's exhibition evaluation efforts over the last 14 years, summarizing the major themes that emerge from this body of work. Findings suggest that visitors to the Monterey Bay Aquarium are interested in and receptive to conservation content and learn new conservation information from exhibitions. Visitors' interest is most influenced by their personal involvement with conservation issues and previous visitation to the aquarium. After leaving the aquarium, there is evidence that visitors retain specific conservation information and maintain levels of concern about conservation topics for weeks, and even months, after their visit. Additionally, some visitors use the Seafood Watch pocket guide to choose sustainable seafood months after visiting the aquarium.