A Two-hop Wireless Network (TWN) is the basic topology structure that provides network coding opportunity for improving throughput. Network coding on a homogeneous TWN, in which all the data flows have the same packet...A Two-hop Wireless Network (TWN) is the basic topology structure that provides network coding opportunity for improving throughput. Network coding on a homogeneous TWN, in which all the data flows have the same packet size and all the links have the same transmission rate, has been extensively investigated. In this paper, network coding on more practical heterogeneous TWNs, featured by various packet sizes and transmission rates, is studied. Based on the Markov model, the throughput of the proposed network coding scheme, together with the throughput gain, is derived, which matches the simulation results very well. Numerical analyses indicate that, encoding the packets with close size and close transmission rate and enlarging buffer size at the relay node help in improving the throughput gain.展开更多
In order to explore collocational usage competence across two different contexts,NS and NNS,in the current study,I investigated usage and frequency of collocation of Taiwan Residents learners of English(TWN),Indonesia...In order to explore collocational usage competence across two different contexts,NS and NNS,in the current study,I investigated usage and frequency of collocation of Taiwan Residents learners of English(TWN),Indonesian learners of English(IND) and English native speakers(NS),and found collocations statistically overused or underused by learner groups,which had not been studied before.Collocation is defined here as the word clusters composed of three and four words which occur 2 times and above,seen in English essays in the ICNALE corpus.All the collocations in the three corpora have been classified into 17 patterns based on the lexical and grammatical collocation categorization of Benson et al(1997).The results suggest that NNS have mastered different types of collocations to write essays,but use them differently from NS,as 27%in TWN and 38%in IND of the 150 most frequently used collocations are significantly overused or underused(p<0.0001).These findings obtained from a quantitative data analysis suggest that teachers in Taiwan and Indonesia should not only try to arouse students ' awareness of collocations but also do a pre-writing exercise of listing collocations related to a certain topic.These implications may also be useful for other Asian EFL countries.展开更多
基金Supported by the National Natural Science Foundation of China(No.61070190 and 61001126)Zhejiang Provincial Natural Science Foundation of China(No.Z1100455)Ph.D.Programs Foundation of Ministry of Education of China(No.20123317110002)
文摘A Two-hop Wireless Network (TWN) is the basic topology structure that provides network coding opportunity for improving throughput. Network coding on a homogeneous TWN, in which all the data flows have the same packet size and all the links have the same transmission rate, has been extensively investigated. In this paper, network coding on more practical heterogeneous TWNs, featured by various packet sizes and transmission rates, is studied. Based on the Markov model, the throughput of the proposed network coding scheme, together with the throughput gain, is derived, which matches the simulation results very well. Numerical analyses indicate that, encoding the packets with close size and close transmission rate and enlarging buffer size at the relay node help in improving the throughput gain.
文摘In order to explore collocational usage competence across two different contexts,NS and NNS,in the current study,I investigated usage and frequency of collocation of Taiwan Residents learners of English(TWN),Indonesian learners of English(IND) and English native speakers(NS),and found collocations statistically overused or underused by learner groups,which had not been studied before.Collocation is defined here as the word clusters composed of three and four words which occur 2 times and above,seen in English essays in the ICNALE corpus.All the collocations in the three corpora have been classified into 17 patterns based on the lexical and grammatical collocation categorization of Benson et al(1997).The results suggest that NNS have mastered different types of collocations to write essays,but use them differently from NS,as 27%in TWN and 38%in IND of the 150 most frequently used collocations are significantly overused or underused(p<0.0001).These findings obtained from a quantitative data analysis suggest that teachers in Taiwan and Indonesia should not only try to arouse students ' awareness of collocations but also do a pre-writing exercise of listing collocations related to a certain topic.These implications may also be useful for other Asian EFL countries.
