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951.
A previous study showed that pairs of students interacting in a second language produced more words when they were assigned a fictitious expert position in a specific competence dimension than when they were assigned a nonexpert position. It has also been shown that the usual level of expertise has an impact on the assigned fictitious expertise effect. The present study was designed to determine whether the processing capacity allotted to the current task could partly determine performance. A given position of expertise may demand a large or small attentional capacity. Two experiments were conducted using a dual-task paradigm. As expected, the different expertise positions led to different reaction times on the secondary task. The second experiment showed that the impact of assigning a position of expertise to students depends on their usual academic standing. This study supports the idea that in interactive situations, performance variations as a function of the expertise position can be partially explained by differences in the processing resources allocated to the task. Implications for teaching are discussed.  相似文献   
952.
基于到达时间差的无线传感器网络中Sybil攻击检测方案   总被引:1,自引:0,他引:1  
As wireless sensor networks (WSN) are deployed in fire monitoring, object tracking applications, security emerges as a central requirement. A case that Sybil node illegitimately reports messages to the master node with multiple non-existent identities (ID) will cause harmful effects on decision-making or resource allocation in these applications. In this paper, we present an efficient and lightweight solution for Sybil attack detection based on the time difference of arrival (TDOA) between the source node and beacon nodes. This solution can detect the existence of Sybil attacks, and locate the Sybil nodes. We demonstrate efficiency of the solution through experiments. The experiments show that this solution can detect all Sybil attack cases without missing.  相似文献   
953.
A profilometer used for 3 dimension measurement of micro-surface topography is presented. The instrument is based on the vertical scanning microscopic interferometry (VSMI). A Linnik type interference microscope is used and the interferograms which present changes of surface profile are recorded with a CCD camera. A developed nano-positioning work stage with an integrated optical grating displacement measuring system realizes the precise vertical scanning motion during profile measurement. By a white-light phase shifting algorithm of arbitrary step, frames of interferograms are processed by a computer to rebuild and evaluate the measured profile. Because of the specialty of VSMI, the profilometer is suitable for both smooth and rough surface measurement. It can also be used to measure curved surfaces, dimension of micro electro mechanical systems (MEMS), etc. The vertical resolution of the profilometer is 0.5 nm, and lateral resolution 0.5 μm.  相似文献   
954.
讨论了抽样调查在港口吞吐量调查中的应用前景,分析了港口吞吐量抽样调查方案设计的各个环节,包括:方案设计的原则、技术方法、抽样公式、调查时间、分层确定、季节变动处理和非抽样误差控制等。  相似文献   
955.
江苏省部分竞走运动员个性特征的研究   总被引:1,自引:0,他引:1  
运用卡特尔16种性格因素测量表对江苏省部分竞走运动员的性格类型进行了调查,按性别、运动成绩分组对照,并进行分析和研究,以期为竞走运动员的心理选材、心理训练提供一些参考依据。  相似文献   
956.
提高软件质量的有效途径——个体软件过程(PSP)   总被引:1,自引:0,他引:1  
信息时代,软件质量的重要性越来越为人们所认识,个体软件过程(PSP)为提高软件质量提供了具体而有效的途径.本文主要介绍了PSP的相关技术,讨论了PSP的质量管理,阐述了CMM/PSP/TSP的体系结构.  相似文献   
957.
The present study examines the treatment of the Prophet's mount in Shī‘ite tradition. We discuss the different opinions concerning the ass's name, ‘Ufayr or Ya‘fūr and present various traditions concerning utterances spoken by it, including utterances addressed to the Prophet, and other cases of human-like behaviour on its part, such as an ability to distinguish Muslims from Jews. We then go on to compare the Prophet's ass to those of other prophets, and find a number of similarities between them, in particular their ability to speak a human language. We also discuss the ass's death, which according to Shī‘ite tradition was by suicide, occasioned by the ass's fear following his master's death that someone else, not a prophet, would use it as a mount. We compare the Prophet's ass to those of Noah, and Solomon's Hoopoe, and show how Shī‘ite tradition has focused on similarities among them and utilized those to support the idea of the Imāmate as the Prophet's legacy in Shī‘ite doctrine. We further discuss the preference which Shī‘ite Imāms had for asses as against other mounts, a preference based on their wish to follow in the Prophet's footsteps.  相似文献   
958.
为探讨垂盆草对训练大鼠不同组织ATPase活性的影响,以SD雄性大鼠为实验对象,建立跑台运动训练模型.测定了大鼠力竭运动时间和Ca2 ,Mg2 -ATPase、Na ,K -ATPase活性.实验结果显示,垂盆草可以显著延长大鼠跑台运动力竭时间;使运动大鼠心脏、肝脏、肾脏、脑、股四头肌组织中Na ,K -ATPase 和Ca2 ,Mg2 -ATPase活性显著升高;结论认为,补充垂盆草冲剂可以提高大鼠不同组织ATPase活性,延长大鼠跑台运动力竭时间,提高大鼠的运动能力.  相似文献   
959.
LDAP(轻型目录存取协议)服务器是 PKI(公钥基础设施)中存放公钥、证书等重要信息的常见载体,它自身的安全性问题也越来越受到关注。文章以 Java 为实现手段,研究增强 LDAP 系统安全性的多种方式,最终能够满意地解决各种不同情况下的安全验证要求。  相似文献   
960.
Expected shortfall(ES) is a new method to measure market risk. In this paper, an example was presented to illustrate that the ES is coherent but value-at-risk(VaR) is not coherent. Three formulas for calculating the ES based on historical simulation method,normal method and GARCH method were derived. Further, a numerical experiment on optimizing portfolio using ES was provided.  相似文献   
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