Bilateral practice improves dominant leg performance in long jump

Benefits of bilateral practice both for the non-dominant and for the dominant body side have been shown in several studies. Thereby, most of the studies included movement tasks of the upper extremity or investigated sports games in which the ability of acting bilaterally is an essential basis for success and, thus, a bilateral practice is reasonable anyway. Individual unilaterally performed sports including movement tasks of the lower extremity are rarely investigated. Therefore, the aim of our study was to test if contralateral transfer due to bilateral practice can be found in an unilaterally performed sport including the lower extremity. We trained and tested 61 adolescent athletes in long jump to compare the jumping performance of the dominant leg after a 12-week practice period between two groups: a bilateral practice group that practiced specific long jump exercises with both the dominant and non-dominant leg and an unilateral practice group that practiced specific long jump exercises only with the dominant leg. Results showed a superior effect of bilateral practice compared to unilateral practice regarding the jumping performance of the dominant leg. The performance increase at post-test and retention-test for the dominant limb was significantly higher for the bilateral practice group (pre-to-post: 5.2%, pre-to-retention: 7.4%) compared to the unilateral practice group (pre-to-post: 3.4%, pre-to-retention: 4.5%). Thus, bilateral practice should be established in the early practice programmes of track and field athletes to improve the performance of the dominant take-off leg.     

玉米在近现代长江下游山区的种植与传播

长江下游是中国最早传入玉米并大面积种植的地域之一。自清代康乾年间始至当代,玉米日渐在杭嘉湖、皖南、皖西南和皖东苏西山区传播种植,先后形成约40个县域种植区;玉米在长江下游的传播路径有一点两线;清代和民国时期的传种者以棚民为主、土著为辅,当代则是土著和地方政府。     

调整完善教学内容体现"特色+精品"理念

为充分体现我校“特色加精品”的办学理念,应着重调整完善课堂教学内容,增加地质专业基础课程学时,注重少而精;对周口店地区教学实习内容再次进行重大改革,野外实习过程中减少由教师带领的路线,增加学生自主观察路线;把地学类学生独立填图时间延长至十天或更长,每人填图面积不少于3km2,培养学生动手能力;实习报告以填图范围的说明书形式编写。以达到使学生既学到专业知识,又初步掌握野外工作能力的目的。     

A novel method for mobile robot simultaneous localization and mapping

INTRODUCTION A key prerequisite for a truly autonomous robot is that it can simultaneously localize itself and accu-rately map its surroundings (Kortenkamp et al., 1998), which is known as Simultaneous Localization and Mapping (SLAM), which, when phrased as a state estimation problem, involves a variable number of dimensions. Murphy and Russell (2001) adopted Rao-Blackwellized particle filters (RBPFs) as an effective way for representing alternative hypotheses on robot paths and ass…     

渐近非扩张映象的具误差的修正Reich迭代收敛性

在实Banach空间中,研究具误差的修正Reich迭代序列的收敛问题,获得了第一型和第二型具误差的修正Reich迭代序列强收敛到不动点的充要条件,所得结果改进和推广了已有文献的相关结果.     

巧用迭代法

基于不动点原理的迭代法,有很广泛的应用.本文运用迭代方法,在代数与几何问题中进行了有趣的实践.     

EBF网络特征映射和恢复及其在鲁棒话者识别中的应用

The performance of speaker verification systems is often compromised under real-world environments. For example, variations in handset characteristics could cause severe performance degradation. This paper presents a novel method to overcome this problem by using a non-linear handset mapper. Under this method, a mapper is constructed by training an elliptical basis function network using distorted speech features as inputs and the corresponding clean features as the desired outputs. During feature recuperation, clean features are recovered by feeding the distorted features to the feature mapper. The recovered features are then presented to a speaker model as if they were derived from clean speech. Experimental evaluations based on 258 speakers of the TIMIT and NTIMIT corpuses suggest that the feature mappers improve the verification performance remarkably.     

用保角变换法计算单芯偏心电缆单位长度的自感

文章利用分式线性变换计算单芯偏心电缆单位长度的自感,并对结果进行讨论。     

Banach空间中一类广义集值拟变分包含的迭代解

本文引入Banach空间中一类广义集值拟变分包含问题,利用集值预解的技巧,建立起Banach空间一类广义集值拟变分包含问题与预解方程及不动点问题间的等价关系,并给出了其解的存在性及其迭代逼近问题.这些结果改进、推广、统一了文[1-15,17-24,27-33]的相应结果.     

一类含参广义变分不等式组的灵敏性分析

本文应用新的方法研究了一类含参广义变分不等式组解的灵敏性 ,得到了一些新的结果 .