Step characteristic interaction and asymmetry during the approach phase in long jump

The aim of this study was to investigate the relative influence of step length (SL) and step frequency (SF) on step velocity (SV) during the approach run of high-level long jumpers and to quantify the asymmetry of these step characteristics. Spatiotemporal data of the approach run were collected during national competition from 10 long jumpers (age 26.2 ± 4.1 years, height 1.84 ± 0.06 m, mass 72.77 ± 3.23 kg, personal best performance 7.96 ± 0.30 m). Analyses were conducted for total approach, early approach and late approach. For the total approach 4/10 athletes were SF reliant and 6/10 athletes favoured neither characteristic. At the early approach, 3/10 athletes were SF reliant and 7/10 athletes favoured neither. During late approach 2/10 athletes demonstrated SL reliance, 7/10 athletes were SF reliant and 1/10 athletes favoured neither. Four athletes displayed significant asymmetry for SL and three for SF. However, no athletes demonstrated significant asymmetry for SV indicating that the asymmetrical demands of take-off do not have a marked influence on step characteristic asymmetry, probably due to the constraints of the event. Consideration should be given to the potentially conflicting demands between limbs for individual athletes.     

基于结构形状的印刷体数字识别方法

从数字的结构形状着手,通过分析印刷体数字的形状,提出了一种基于结构形状的印刷体数字识别方法。该方法不用对字符图像进行复杂的细化处理,减少了因细化带来的误差问题,因而识别速度非常快,实验证明了该方法的有效性。     

“写长法”在涉外旅游专业英语写作教学中的应用研究

将"写长法"的教育理念引入到涉外旅游专业的英语写作教学当中,并采用SPSS11.5对实验数据进行了分析解释。分析结果表明,"写长法"对实验组学生的写作成绩产生了积极的影响,实验组和控制组的学生在后测的写作成绩上呈现明显差异。     

Prediction of shelled shrimp weight by machine vision

The weight of shelled shrimp is an important parameter for grading process. The weight prediction of shelled shrimp by contour area is not accurate enough because of the ignorance of the shrimp thickness. In this paper, a multivariate prediction model containing area, perimeter, length, and width was established. A new calibration algorithm for extracting length of shelled shrimp was proposed, which contains binary image thinning, branch recognition and elimination, and length reconstruction, while its width was calculated during the process of length extracting. The model was further validated with another set of images from 30 shelled shrimps. For a comparison purpose, artificial neural network (ANN) was used for the shrimp weight predication. The ANN model resulted in a better prediction accuracy (with the average relative error at 2.67%), but took a tenfold increase in calculation time compared with the weight-area-perimeter (WAP) model (with the average relative error at 3.02%). We thus conclude that the WAP model is a better method for the prediction of the weight of shelled red shrimp.      

我国优秀游泳运动员途中游速度、划频、划幅变化的研究

竞技游泳途中游的速度取决于划频和划幅两个因素。通过实验观测和比较,分析了我国最高水平游泳运动员成绩及途中游速度、划频、划幅的现状与变化情况,并结合身材、动作效率等因素,对如何调控划频、划幅以促进我国游泳运动员水平的进一步提高提出了参考意见。     

Sequence-length variation of mtDNA HVS-I C-stretch in Chinese ethnic groups

The purpose of this study was to investigate mitochondrial DNA (mtDNA) hypervariable segment-I (HVS-I) C-stretch variations and explore the significance of these variations in forensic and population genetics studies. The C-stretch sequence variation was studied in 919 unrelated individuals from 8 Chinese ethnic groups using both direct and clone sequencing ap-proaches. Thirty eight C-stretch haplotypes were identified, and some novel and population specific haplotypes were also detected. The C-stretch genetic diversity (GD) values were relatively high, and probability (P) values were low. Additionally, C-stretch length heteroplasmy was observed in approximately 9% of individuals studied. There was a significant correlation (r=-0.961, P<0.01) between the expansion of the cytosine sequence length in the C-stretch of HVS-I and a reduction in the number of up-stream adenines. These results indicate that the C-stretch could be a useful genetic maker in forensic identification of Chinese populations. The results from the Fst and dA genetic distance matrix, neighbor-joining tree, and principal component map also suggest that C-stretch could be used as a reliable genetic marker in population genetics.     

Length awareness predicts spelling skills in Finnish

Abstract. The main type of phonemic analysis skill considered to affect spelling acquisition has been awareness of phoneme quality. However, it is also important to find out whether other measures of phoneme awareness might contribute to literacy acquisition. Thus, the influence of phoneme length and phoneme quality awareness on spelling in Finnish was compared. The Oddity task was used to assess phonemic awareness and spelling skills were investigated by a spelling-to-dictation task. The results showed that length awareness predicted spelling better than quality awareness did. Moreover, length awareness was more strongly related to spelling of long phonemes, which specifically require analysis of phoneme length, than to spelling of phoneme clusters not involving length analysis. Additionally, only length awareness predicted children's general spelling skills. These findings suggest that awareness of length, which is a phonemic attribute of the Finnish language, is connected to children's spelling skills more strongly than awareness of phoneme quality is.     

Reading development and dyslexia in a transparent orthography: a survey of Spanish children

Spanish-speaking children learn to read words printed in a relatively transparent orthography. Variation in orthographic transparency may shape the architecture of the reading system and also the manifestation of reading difficulties. We tested normally developing children and children diagnosed with reading difficulties. Reading accuracy was high across experimental conditions. However, dyslexic children read more slowly than chronological age (CA)-matched controls, although, importantly, their reading times did not differ from those for ability-matched controls. Reading times were significantly affected by frequency, orthographic neighbourhood size and word length. We also found a number of significant interaction effects. The effect of length was significantly modulated by reading ability, frequency and neighbourhood. Our findings suggest that the reading development of dyslexic children in Spanish is delayed rather than deviant. From an early age, the salient characteristic of reading development is reading speed, and the latter is influenced by specific knowledge about words.     

二项式模型在标准参照性语言测验长度研究中的应用

随着国内外教育测量理念的转变,传统的常模参照测验所提供的相对性评价信息已无法满足考试用户和考生的需求,标准参照测验(CriterionReferenced Test,CRT)的社会价值越来越受到重视。在对被试掌握程度进行分类决策的CRT测验中,如何确定恰当的测验长度和合格分数是影响测验分类误差的重要因素。本文在对CRT测验研究的现状、原理和用途进行考察的基础上,专门介绍了二项式概率模型在CRT测验长度决策研究中的理论和过程,并以误差控制为原则,对二项式模型在综合性标准参照语言测验长度和合格分数决策中的应用过程进行了研究。     

文本长度、T单位长度与英语写作成绩的相关分析及启示--一项基于非英语专业学生英语写作的实证研究

文本长度、T单位长度是影响二语写作质量的两个重要因素.通过对49名非英语专业学生英语写作进行实验研究,得出写作的文本长度、T单位长度与写作成绩呈显著相关,并且高分组和低分组在写作的文本长度、T单位长度两个变量上都存在显著差异.实验结果进一步验证了目前国内盛行的"写长法"教学,为外语写作教学提供了一些启示.