By axial compression tests on 6 reinforced concrete slender columns wrapped with carbon fiber-reinforced plastic (CFRP),with slenderness ratio(SR) from 4.5 to 17.5,the results show that when SR increases the retrofitt...By axial compression tests on 6 reinforced concrete slender columns wrapped with carbon fiber-reinforced plastic (CFRP),with slenderness ratio(SR) from 4.5 to 17.5,the results show that when SR increases the retrofitting effect declines. In the case of same SR,the stability coefficient (SC) for the reinforced concrete(RC) columns with CFRP is much less than that without CFRP. There is 20% increase of stable bearing capacity to the former as compared with the latter when the SR in less than 17.5. The study summarized the simplified formula for SC,which provides a reference for engineering designers.展开更多
Secure and private authentication protocol is important in Radio Frequency Identification (RFID) technology.To date,researchers have proposed many RFID authentication protocols.However,these protocols have many flaws ...Secure and private authentication protocol is important in Radio Frequency Identification (RFID) technology.To date,researchers have proposed many RFID authentication protocols.However,these protocols have many flaws due to lack of theoretical support in designing these protocols.In this work,first we present the security and privacy requirements in RFID authentication protocols.Then we examine related works and point out problems in designing RFID authentication protocols.To solve these problems,we propose and briefly prove three theorems.We also give necessary examples for better understanding these theorems with concrete protocols.At last,we give our suggestions on designing secure and private authentication protocols.The security and privacy requirements,theorems,and suggestions will facilitate better understanding and designing of RFID authentication protocols in the future.展开更多
While there is lots of empirical evidence showing that grammar consciousness raising tasks （GCRTs） have an edge over the traditional modes of grammar instruction, there is very little qualitative evidence reflecting...While there is lots of empirical evidence showing that grammar consciousness raising tasks （GCRTs） have an edge over the traditional modes of grammar instruction, there is very little qualitative evidence reflecting learners＇ perceptions of externally imposed educational changes including GCRTs. To extrapolate the previous findings and fill in this gap, this study aims to： （I） test the alleged superiority of GCRTs in grammar instruction and （2） explore learners＇ perceptions of learning grammar through GCRTs. To this end, this study used a mixed-method design including a quantitative and a qualitative dimension. The former dimension aimed at testing the superiority of GCRTs on a random sample of intermediate learners from Simin language school in Karaj, Iran through the robust Solomon-four-group design and the latter dimension aimed at collecting and analyzing qualitative interview data on learners＇ perceptions of GCRTs. The quantitative results clearly showed that learners being taught through GCRTs significantly outperformed those instructed through the traditional mode of grammar instruction and the qualitative analysis of learners＇ perspectives showed that the participants had a positive perception of GCRTs and this positive perception was rooted in GCRTs＇ potential to： （1） facilitate the internalization of grammar and （2） involve learners in discovery learning. The findings have clear implications for syllabus designers and practitioners.展开更多
文摘By axial compression tests on 6 reinforced concrete slender columns wrapped with carbon fiber-reinforced plastic (CFRP),with slenderness ratio(SR) from 4.5 to 17.5,the results show that when SR increases the retrofitting effect declines. In the case of same SR,the stability coefficient (SC) for the reinforced concrete(RC) columns with CFRP is much less than that without CFRP. There is 20% increase of stable bearing capacity to the former as compared with the latter when the SR in less than 17.5. The study summarized the simplified formula for SC,which provides a reference for engineering designers.
基金supported in part by the Natioual Natural Science Foundation of China(Grant No.60933003)the High Technical Research and Development Program of China(Grant No.2006AA01Z101)+1 种基金Shaanxi ISTC(Grant No.2008KW-02)IBM Joint Project
文摘Secure and private authentication protocol is important in Radio Frequency Identification (RFID) technology.To date,researchers have proposed many RFID authentication protocols.However,these protocols have many flaws due to lack of theoretical support in designing these protocols.In this work,first we present the security and privacy requirements in RFID authentication protocols.Then we examine related works and point out problems in designing RFID authentication protocols.To solve these problems,we propose and briefly prove three theorems.We also give necessary examples for better understanding these theorems with concrete protocols.At last,we give our suggestions on designing secure and private authentication protocols.The security and privacy requirements,theorems,and suggestions will facilitate better understanding and designing of RFID authentication protocols in the future.
文摘While there is lots of empirical evidence showing that grammar consciousness raising tasks （GCRTs） have an edge over the traditional modes of grammar instruction, there is very little qualitative evidence reflecting learners＇ perceptions of externally imposed educational changes including GCRTs. To extrapolate the previous findings and fill in this gap, this study aims to： （I） test the alleged superiority of GCRTs in grammar instruction and （2） explore learners＇ perceptions of learning grammar through GCRTs. To this end, this study used a mixed-method design including a quantitative and a qualitative dimension. The former dimension aimed at testing the superiority of GCRTs on a random sample of intermediate learners from Simin language school in Karaj, Iran through the robust Solomon-four-group design and the latter dimension aimed at collecting and analyzing qualitative interview data on learners＇ perceptions of GCRTs. The quantitative results clearly showed that learners being taught through GCRTs significantly outperformed those instructed through the traditional mode of grammar instruction and the qualitative analysis of learners＇ perspectives showed that the participants had a positive perception of GCRTs and this positive perception was rooted in GCRTs＇ potential to： （1） facilitate the internalization of grammar and （2） involve learners in discovery learning. The findings have clear implications for syllabus designers and practitioners.
