Purpose:Based on the understanding of the characteristics of mobile services(m-services)provided by libraries,we attempt to develop a multidimensional and hierarchical model and a specifically designed measurement sca...Purpose:Based on the understanding of the characteristics of mobile services(m-services)provided by libraries,we attempt to develop a multidimensional and hierarchical model and a specifically designed measurement scale for the assessment of libraries' m-service quality.Design/methodology/approach:The research has been conducted sequentially in two stages.At the first stage,a multidimensional and hierarchical model of library m-service quality and a measurement scale are developed through literature review and focus group interviews.At the second stage the model is tested using partial disaggregation technique for an analysis of the data collected from over 400 library users in 3 Chinese universities.Findings:The proposed model is shown to fit the data well.The empirical analysis provides strong support for the model,which includes 4 dimensions(service environment,service interaction,information control and service effect) and 12 corresponding sub-dimensions.Research limitations:The sample size needs to be enlarged and the user types need to be expanded to make the sample more representative.Practical implications:The study provides a conceptual framework and measurement tool that can help library managers understand the users' needs in the context of mobile network environment,and boost their libraries' competitiveness by carrying out better services to meet the user demands.Originality/value:The proposed model and measurement scale specifically designed for the assessment of libraries' m-service quality fully reflect the hierarchical structure of libraries' m-service quality.In addition,by using partial disaggregation technique for model testing,we believe our research can serve as a practical reference to those engaged in the development and examination of a multidimensional and hierarchical model.展开更多
Most recent satellite network research has focused on providing routing services without considering security. In this paper, for the sake of better global coverage, we introduce a novel triple-layered satellite netwo...Most recent satellite network research has focused on providing routing services without considering security. In this paper, for the sake of better global coverage, we introduce a novel triple-layered satellite network architecture including Geostationary Earth Orbit (GEO), Highly Elliptical Orbit (HEO), and Low Earth Orbit (LEO) satellite layers, which provides the near-global coverage with 24 hour uninterrupted over the areas varying from 75° S to 90° N. On the basis of the hierarchical architecture, we propose a QoS-guaranteed secure multicast routing protocol (QGSMRP) for satellite IP networks using the logical location concept to isolate the mobility of LEO and HEO satellites. In QGSMRP, we employ the asymmetric cryptography to secure the control messages via the pairwise key pre-distribution, and present a least cost tree (LCT) strategy to construct the multicast tree under the condition that the QoS constraints are guaranteed, aiming to minimize the tree cost. Simulation results show that the performance benefits of the proposed QGSMRP in terms of the end-to-end tree delay, the tree cost, and the failure ratio of multicasting connections by comparison with the conventional shortest path tree (SPT) strategy.展开更多
基金supported by the Social Science Foundation of China(Grant No.:12CTQ005)
文摘Purpose:Based on the understanding of the characteristics of mobile services(m-services)provided by libraries,we attempt to develop a multidimensional and hierarchical model and a specifically designed measurement scale for the assessment of libraries' m-service quality.Design/methodology/approach:The research has been conducted sequentially in two stages.At the first stage,a multidimensional and hierarchical model of library m-service quality and a measurement scale are developed through literature review and focus group interviews.At the second stage the model is tested using partial disaggregation technique for an analysis of the data collected from over 400 library users in 3 Chinese universities.Findings:The proposed model is shown to fit the data well.The empirical analysis provides strong support for the model,which includes 4 dimensions(service environment,service interaction,information control and service effect) and 12 corresponding sub-dimensions.Research limitations:The sample size needs to be enlarged and the user types need to be expanded to make the sample more representative.Practical implications:The study provides a conceptual framework and measurement tool that can help library managers understand the users' needs in the context of mobile network environment,and boost their libraries' competitiveness by carrying out better services to meet the user demands.Originality/value:The proposed model and measurement scale specifically designed for the assessment of libraries' m-service quality fully reflect the hierarchical structure of libraries' m-service quality.In addition,by using partial disaggregation technique for model testing,we believe our research can serve as a practical reference to those engaged in the development and examination of a multidimensional and hierarchical model.
文摘Most recent satellite network research has focused on providing routing services without considering security. In this paper, for the sake of better global coverage, we introduce a novel triple-layered satellite network architecture including Geostationary Earth Orbit (GEO), Highly Elliptical Orbit (HEO), and Low Earth Orbit (LEO) satellite layers, which provides the near-global coverage with 24 hour uninterrupted over the areas varying from 75° S to 90° N. On the basis of the hierarchical architecture, we propose a QoS-guaranteed secure multicast routing protocol (QGSMRP) for satellite IP networks using the logical location concept to isolate the mobility of LEO and HEO satellites. In QGSMRP, we employ the asymmetric cryptography to secure the control messages via the pairwise key pre-distribution, and present a least cost tree (LCT) strategy to construct the multicast tree under the condition that the QoS constraints are guaranteed, aiming to minimize the tree cost. Simulation results show that the performance benefits of the proposed QGSMRP in terms of the end-to-end tree delay, the tree cost, and the failure ratio of multicasting connections by comparison with the conventional shortest path tree (SPT) strategy.
