Dense network coding(NC) is widely used in wireless cooperative downloading systems. Wireless devices have limited computing resources. Researchers have recently found that dense NC is not suitable because of its high...Dense network coding(NC) is widely used in wireless cooperative downloading systems. Wireless devices have limited computing resources. Researchers have recently found that dense NC is not suitable because of its high coding complexity, and it is necessary to use chunked NC in wireless environments. However, chunked NC can cause more communications, and the amount of communications is affected by the chunk size. Therefore, setting a suitable chunk size to improve the overall performance of chunked NC is a prerequisite for applying it in wireless cooperative downloading systems. Most of the existing studies on chunked NC focus on centralized wireless broadcasting systems, which are different from wireless cooperative downloading systems with distributed features. Accordingly, we study the performance of chunked NC based wireless cooperative downloading systems. First, an analysis model is established using a Markov process taking the distributed features into consideration, and then the block collection completion time of encoded blocks for cooperative downloading is optimized based on the analysis model. Furthermore, queuing theory is used to model the decoding process of the chunked NC. Combining queuing theory with the analysis model, the decoding completion time for cooperative downloading is optimized, and the optimal chunk size is derived. Numerical simulation shows that the block collection completion time and the decode completion time can be largely reduced after optimization.展开更多
Due to the development of technology in medicine,millions of health-related data such as scanning the images are generated.It is a great challenge to store the data and handle a massive volume of data.Healthcare data ...Due to the development of technology in medicine,millions of health-related data such as scanning the images are generated.It is a great challenge to store the data and handle a massive volume of data.Healthcare data is stored in the cloud-fog storage environments.This cloud-Fog based health model allows the users to get health-related data from different sources,and duplicated informa-tion is also available in the background.Therefore,it requires an additional sto-rage area,increase in data acquisition time,and insecure data replication in the environment.This paper is proposed to eliminate the de-duplication data using a window size chunking algorithm with a biased sampling-based bloomfilter and provide the health data security using the Advanced Signature-Based Encryp-tion(ASE)algorithm in the Fog-Cloud Environment(WCA-BF+ASE).This WCA-BF+ASE eliminates the duplicate copy of the data and minimizes its sto-rage space and maintenance cost.The data is also stored in an efficient and in a highly secured manner.The security level in the cloud storage environment Win-dows Chunking Algorithm(WSCA)has got 86.5%,two thresholds two divisors(TTTD)80%,Ordinal in Python(ORD)84.4%,Boom Filter(BF)82%,and the proposed work has got better security storage of 97%.And also,after applying the de-duplication process,the proposed method WCA-BF+ASE has required only less storage space for variousfile sizes of 10 KB for 200,400 MB has taken only 22 KB,and 600 MB has required 35 KB,800 MB has consumed only 38 KB,1000 MB has taken 40 KB of storage spaces.展开更多
The sensitive data stored in the public cloud by privileged users,such as corporate companies and government agencies are highly vulnerable in the hands of cloud providers and hackers.The proposed Virtual Cloud Storag...The sensitive data stored in the public cloud by privileged users,such as corporate companies and government agencies are highly vulnerable in the hands of cloud providers and hackers.The proposed Virtual Cloud Storage Archi-tecture is primarily concerned with data integrity and confidentiality,as well as availability.To provide confidentiality and availability,thefile to be stored in cloud storage should be encrypted using an auto-generated key and then encoded into distinct chunks.Hashing the encoded chunks ensured thefile integrity,and a newly proposed Circular Shift Chunk Allocation technique was used to determine the order of chunk storage.Thefile could be retrieved by performing the opera-tions in reverse.Using the regenerating code,the model could regenerate the missing and corrupted chunks from the cloud.The proposed architecture adds an extra layer of security while maintaining a reasonable response time and sto-rage capacity.Experimental results analysis show that the proposed model has been tested with storage space and response time for storage and retrieval.The VCSA model consumes 1.5x(150%)storage space.It was found that total storage required for the VCSA model is very low when compared with 2x Replication and completely satisfies the CIA model.The response time VCSA model was tested with different sizedfiles starting from 2 to 16 MB.The response time for storing and retrieving a 2 MBfile is 4.96 and 3.77 s respectively,and for a 16 MBfile,the response times are 11.06 s for storage and 5.6 s for retrieval.展开更多
English speaking skill is one of the most important skills that senior high students need to obtain in learning English.However,there are still many problems existing in students’speaking practice.As a teaching and l...English speaking skill is one of the most important skills that senior high students need to obtain in learning English.However,there are still many problems existing in students’speaking practice.As a teaching and learning strategy,Chunking is now gradually used in English classroom and has received a positive feedback.Therefore,in this paper,the influence of Chunking on improving English speaking skill among senior high school students will be investigated and analyzed through the methods of questionnaire and the follow-up interview to answer four questions:(1)What effect does Chunking have on the oral fluency of high school students?(2)What effect does Chunking have on the oral accuracy of high school students?(3)What effect does Chunking have on the vocabulary?And(4)Does the English speaking performance relate to genders?After analyzing the results of questionnaire by the SPSS and summing up the interview record,we found that most of them agree the fact that the strategy of Chunking does benefit their oral fluency,oral accuracy,and vocabulary.Also,female students have higher scores than male students.展开更多
Listening is an important input way of language learning,and is closely related to language learning.Now,listening is still a weakness for English learners in colleges.In recent years,many experts and scholars have ex...Listening is an important input way of language learning,and is closely related to language learning.Now,listening is still a weakness for English learners in colleges.In recent years,many experts and scholars have explored the application of lexical chunks in teaching,trying to solve the problem of students’vocabulary acquisition.However,there are relatively few researches between lexical chunks and listening achievement.Based on the lexical chunks theory,the research finds that lexical chunks teaching can relieve students’anxiety in English listening,improve their English listening scores,and stimulate students’chunk consciousness.展开更多
This paper aims to demonstrate the pervasiveness of metaphor chunks in News English and introduce effective ways of understanding themcorrectly from the perspective of cognitive linguistics.Considering the difficulty ...This paper aims to demonstrate the pervasiveness of metaphor chunks in News English and introduce effective ways of understanding themcorrectly from the perspective of cognitive linguistics.Considering the difficulty in making out the accurate meaning of metaphor chunks in News Eng-lish,some translation strategies have also been proposed in hopes that it will benefit readers in their understanding and appreciation of News English.展开更多
Traditionally,language is considered to be a grammar vocabulary dichotomy system,and grammar and vocabulary seem to be independent of each other.This deep-rooted notion is particularly prevalent in Chinese English tea...Traditionally,language is considered to be a grammar vocabulary dichotomy system,and grammar and vocabulary seem to be independent of each other.This deep-rooted notion is particularly prevalent in Chinese English teaching and learning.Michael Lewis,the author of the Lexical Approach challenged the standard view of dividing language teaching into grammar and vocabulary.He believes that language is grammaticalised lexis,not lexicalized grammar,and lexis is the core of language learning while grammar is subordinate to it.This paper intends to explore its theoretical foundations and emphasize the great significance of the Lexical Approach to college English teaching in China.展开更多
Based on the concepts of Lexical Chunks and Multimodal Teaching,this paper focuses the input source of English vocabulary learning,integrating the advantages of Lexical Approach with Multimodal Teaching.As a new teach...Based on the concepts of Lexical Chunks and Multimodal Teaching,this paper focuses the input source of English vocabulary learning,integrating the advantages of Lexical Approach with Multimodal Teaching.As a new teaching exploration of English vocabulary,the teaching practice in classroom has shown that teachers should make full and reasonable use of various teaching means and resources to achieve multimodal teaching of lexical chunks,which is helpful to promote students to learn vocabulary quickly and effectively,and improve students'English language competence and performance.展开更多
Lexis Acquisition has increasingly been regarded as a crucial aspect of Second Language Acquisition(SLA).This thesis discusses some of the theoretical studies on L2 Lexis Acquisition and focuses on a newly-introduced ...Lexis Acquisition has increasingly been regarded as a crucial aspect of Second Language Acquisition(SLA).This thesis discusses some of the theoretical studies on L2 Lexis Acquisition and focuses on a newly-introduced theory,Prefabricated Chunks Theory,in the attempt to provide L2 learners with some enlightenment in their Lexis Acquisition.展开更多
基金supported by the National Natural Science Foundation of China(Nos.61370212,61402127,and 61502118)
文摘Dense network coding(NC) is widely used in wireless cooperative downloading systems. Wireless devices have limited computing resources. Researchers have recently found that dense NC is not suitable because of its high coding complexity, and it is necessary to use chunked NC in wireless environments. However, chunked NC can cause more communications, and the amount of communications is affected by the chunk size. Therefore, setting a suitable chunk size to improve the overall performance of chunked NC is a prerequisite for applying it in wireless cooperative downloading systems. Most of the existing studies on chunked NC focus on centralized wireless broadcasting systems, which are different from wireless cooperative downloading systems with distributed features. Accordingly, we study the performance of chunked NC based wireless cooperative downloading systems. First, an analysis model is established using a Markov process taking the distributed features into consideration, and then the block collection completion time of encoded blocks for cooperative downloading is optimized based on the analysis model. Furthermore, queuing theory is used to model the decoding process of the chunked NC. Combining queuing theory with the analysis model, the decoding completion time for cooperative downloading is optimized, and the optimal chunk size is derived. Numerical simulation shows that the block collection completion time and the decode completion time can be largely reduced after optimization.
文摘Due to the development of technology in medicine,millions of health-related data such as scanning the images are generated.It is a great challenge to store the data and handle a massive volume of data.Healthcare data is stored in the cloud-fog storage environments.This cloud-Fog based health model allows the users to get health-related data from different sources,and duplicated informa-tion is also available in the background.Therefore,it requires an additional sto-rage area,increase in data acquisition time,and insecure data replication in the environment.This paper is proposed to eliminate the de-duplication data using a window size chunking algorithm with a biased sampling-based bloomfilter and provide the health data security using the Advanced Signature-Based Encryp-tion(ASE)algorithm in the Fog-Cloud Environment(WCA-BF+ASE).This WCA-BF+ASE eliminates the duplicate copy of the data and minimizes its sto-rage space and maintenance cost.The data is also stored in an efficient and in a highly secured manner.The security level in the cloud storage environment Win-dows Chunking Algorithm(WSCA)has got 86.5%,two thresholds two divisors(TTTD)80%,Ordinal in Python(ORD)84.4%,Boom Filter(BF)82%,and the proposed work has got better security storage of 97%.And also,after applying the de-duplication process,the proposed method WCA-BF+ASE has required only less storage space for variousfile sizes of 10 KB for 200,400 MB has taken only 22 KB,and 600 MB has required 35 KB,800 MB has consumed only 38 KB,1000 MB has taken 40 KB of storage spaces.
文摘The sensitive data stored in the public cloud by privileged users,such as corporate companies and government agencies are highly vulnerable in the hands of cloud providers and hackers.The proposed Virtual Cloud Storage Archi-tecture is primarily concerned with data integrity and confidentiality,as well as availability.To provide confidentiality and availability,thefile to be stored in cloud storage should be encrypted using an auto-generated key and then encoded into distinct chunks.Hashing the encoded chunks ensured thefile integrity,and a newly proposed Circular Shift Chunk Allocation technique was used to determine the order of chunk storage.Thefile could be retrieved by performing the opera-tions in reverse.Using the regenerating code,the model could regenerate the missing and corrupted chunks from the cloud.The proposed architecture adds an extra layer of security while maintaining a reasonable response time and sto-rage capacity.Experimental results analysis show that the proposed model has been tested with storage space and response time for storage and retrieval.The VCSA model consumes 1.5x(150%)storage space.It was found that total storage required for the VCSA model is very low when compared with 2x Replication and completely satisfies the CIA model.The response time VCSA model was tested with different sizedfiles starting from 2 to 16 MB.The response time for storing and retrieving a 2 MBfile is 4.96 and 3.77 s respectively,and for a 16 MBfile,the response times are 11.06 s for storage and 5.6 s for retrieval.
文摘English speaking skill is one of the most important skills that senior high students need to obtain in learning English.However,there are still many problems existing in students’speaking practice.As a teaching and learning strategy,Chunking is now gradually used in English classroom and has received a positive feedback.Therefore,in this paper,the influence of Chunking on improving English speaking skill among senior high school students will be investigated and analyzed through the methods of questionnaire and the follow-up interview to answer four questions:(1)What effect does Chunking have on the oral fluency of high school students?(2)What effect does Chunking have on the oral accuracy of high school students?(3)What effect does Chunking have on the vocabulary?And(4)Does the English speaking performance relate to genders?After analyzing the results of questionnaire by the SPSS and summing up the interview record,we found that most of them agree the fact that the strategy of Chunking does benefit their oral fluency,oral accuracy,and vocabulary.Also,female students have higher scores than male students.
文摘Listening is an important input way of language learning,and is closely related to language learning.Now,listening is still a weakness for English learners in colleges.In recent years,many experts and scholars have explored the application of lexical chunks in teaching,trying to solve the problem of students’vocabulary acquisition.However,there are relatively few researches between lexical chunks and listening achievement.Based on the lexical chunks theory,the research finds that lexical chunks teaching can relieve students’anxiety in English listening,improve their English listening scores,and stimulate students’chunk consciousness.
文摘This paper aims to demonstrate the pervasiveness of metaphor chunks in News English and introduce effective ways of understanding themcorrectly from the perspective of cognitive linguistics.Considering the difficulty in making out the accurate meaning of metaphor chunks in News Eng-lish,some translation strategies have also been proposed in hopes that it will benefit readers in their understanding and appreciation of News English.
文摘Traditionally,language is considered to be a grammar vocabulary dichotomy system,and grammar and vocabulary seem to be independent of each other.This deep-rooted notion is particularly prevalent in Chinese English teaching and learning.Michael Lewis,the author of the Lexical Approach challenged the standard view of dividing language teaching into grammar and vocabulary.He believes that language is grammaticalised lexis,not lexicalized grammar,and lexis is the core of language learning while grammar is subordinate to it.This paper intends to explore its theoretical foundations and emphasize the great significance of the Lexical Approach to college English teaching in China.
文摘Based on the concepts of Lexical Chunks and Multimodal Teaching,this paper focuses the input source of English vocabulary learning,integrating the advantages of Lexical Approach with Multimodal Teaching.As a new teaching exploration of English vocabulary,the teaching practice in classroom has shown that teachers should make full and reasonable use of various teaching means and resources to achieve multimodal teaching of lexical chunks,which is helpful to promote students to learn vocabulary quickly and effectively,and improve students'English language competence and performance.
文摘Lexis Acquisition has increasingly been regarded as a crucial aspect of Second Language Acquisition(SLA).This thesis discusses some of the theoretical studies on L2 Lexis Acquisition and focuses on a newly-introduced theory,Prefabricated Chunks Theory,in the attempt to provide L2 learners with some enlightenment in their Lexis Acquisition.