In this paper,the generalized bounds are derived on the partial periodic correlation of complex roots of unity sequence set with zero or low correlation zone(ZCZ/LCZ)as the important criteria of the sequence design an...In this paper,the generalized bounds are derived on the partial periodic correlation of complex roots of unity sequence set with zero or low correlation zone(ZCZ/LCZ)as the important criteria of the sequence design and application.The derived bounds are with respect to family size,subsequence length,maximum partial autocorrelation sidelobe,maximum partial cross-correlation value and the ZCZ/LCZ.The results show that the derived bounds include the previous periodic bounds,such as Sarwate bound,Welch bound,Peng-Fan bound and Paterson-Lothian bound,as special cases.展开更多
Direction is a common spatial concept that is used in our daily life. It is frequently used as a selection condition in spatial queries. As a result, it is important for spatial databases to provide a mechanism for mo...Direction is a common spatial concept that is used in our daily life. It is frequently used as a selection condition in spatial queries. As a result, it is important for spatial databases to provide a mechanism for modeling and processing direction queries and reasoning. Depending on the direction relation matrix, an inverted direction relation matrix and the concept of direction pre- dominance are proposed to improve the detection of direction relation between objects. Direction predicates of spatial systems are also extended. These techniques can improve the veracity of direction queries and reasoning. Experiments show excellent efficiency and performance in view of direction queries.展开更多
In contemporary entrepreneurial environment based on customer retention, the growth of the internet has pushed the most dynamic businesses to compete in the electronic market. In literature, there are many studies sho...In contemporary entrepreneurial environment based on customer retention, the growth of the internet has pushed the most dynamic businesses to compete in the electronic market. In literature, there are many studies showing how a company＇s brand affects customer loyalty. Less attention has been paid to the relationship between e-commerce website loyalty and e-customer loyalty. This paper can be included in a stream of research that applies the construct of loyalty to e-commerce. Thus, this study aims to analyze, within the electronic market, the elements influencing and determining the trust and loyalty of the e-customers. This research consists of a descriptive study carried out utilizing the survey method. The population in this study includes 421 e-customers of Italian online multi-brand portals. The instrument of data gathering was a web-questionnaire and the data analysis was based on regression. Findings show a positive relationship between three factors （website technological level, e-service quality, and brand） and e-customer trust. Furthermore, the correlation, among the three variables, trust as mediating variable, and e-customer＇s loyalty, has been revealed. Therefore, it can be basically assumed that trust builds e-customer loyalty.展开更多
基金Project supported by the National Natural Science Foundation of China (Nos. 60772087 and 90604035), the 111 Project the Foundation for the Author of National Excellent Doctoral Dissertation of China (No. 200341)
文摘In this paper,the generalized bounds are derived on the partial periodic correlation of complex roots of unity sequence set with zero or low correlation zone(ZCZ/LCZ)as the important criteria of the sequence design and application.The derived bounds are with respect to family size,subsequence length,maximum partial autocorrelation sidelobe,maximum partial cross-correlation value and the ZCZ/LCZ.The results show that the derived bounds include the previous periodic bounds,such as Sarwate bound,Welch bound,Peng-Fan bound and Paterson-Lothian bound,as special cases.
文摘Direction is a common spatial concept that is used in our daily life. It is frequently used as a selection condition in spatial queries. As a result, it is important for spatial databases to provide a mechanism for modeling and processing direction queries and reasoning. Depending on the direction relation matrix, an inverted direction relation matrix and the concept of direction pre- dominance are proposed to improve the detection of direction relation between objects. Direction predicates of spatial systems are also extended. These techniques can improve the veracity of direction queries and reasoning. Experiments show excellent efficiency and performance in view of direction queries.
文摘In contemporary entrepreneurial environment based on customer retention, the growth of the internet has pushed the most dynamic businesses to compete in the electronic market. In literature, there are many studies showing how a company＇s brand affects customer loyalty. Less attention has been paid to the relationship between e-commerce website loyalty and e-customer loyalty. This paper can be included in a stream of research that applies the construct of loyalty to e-commerce. Thus, this study aims to analyze, within the electronic market, the elements influencing and determining the trust and loyalty of the e-customers. This research consists of a descriptive study carried out utilizing the survey method. The population in this study includes 421 e-customers of Italian online multi-brand portals. The instrument of data gathering was a web-questionnaire and the data analysis was based on regression. Findings show a positive relationship between three factors （website technological level, e-service quality, and brand） and e-customer trust. Furthermore, the correlation, among the three variables, trust as mediating variable, and e-customer＇s loyalty, has been revealed. Therefore, it can be basically assumed that trust builds e-customer loyalty.
