Browsing by Author "Qi, Ji"

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    5G wireless directional networking based on pattern division multiple access: algorithms, protocols and test-bed
    (University of Alabama Libraries, 2018) Qi, Ji; Hu, Fei; University of Alabama Tuscaloosa
    With the development of mobile services, the increase of wireless trac data will lead to higher requirements for the wireless communication networks. As one of the latest promising antenna techniques, multi-beam smart antennas (MBSAs) can achieve concurrent transmissions/receptions in multiple directions/beams. Thus it can significantly improve the network throughput. In this paper, we first describe the framework of our next generation MBSA wireless network. In our network, Pattern division multiple access (PDMA)is used for multi-user communication system, while Dynamic Channel Bonding (DyB) protocol is adopted to optimize the distribution of spectrum resource. Secondly, we present a Riverbed simulator implementation with both routing and medium access control (MAC) protocols for mobile ad-hoc network wireless networks with MBSAs. We describe the simulation models with the implementation of MBSA antenna model in physical layer, MAC layer, and routing layer protocols, all in Riverbed Modeler. Then we compare two routing scenarios, i.e., multi-hop diamond routing scenario and multi-path pipe routing. At last, we will elaborate our design methodology of a testbed for the study of multimedia over cognitive radio networks (CRNs) with directional antennas. We use compressive sensing to sample the wide bandwidth and cyclostationary domain features to detect the band signals. We also propose a Markov decision based spectrum hando control scheme that can switch channels in the proper times.
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    The impact of organizational resources and employee gratitude on frontline employee engagement
    (University of Alabama Libraries, 2018) Qi, Ji; Baker, Thomas L.; University of Alabama Tuscaloosa
    Delivering and understanding the drivers of superior customer service can be a critical differentiator in service provision contexts. To this end, drawing from social exchange theory, this study investigates the antecedents of frontline employee engagement. In line with previous studies, our research identifies three types of organizational resources, motivational resources (perceived job autonomy), relational-contextual resources (perceived relationship investment), and socio-emotional resources (perceived organizational support), and suggests that these resources collectively contribute to employee engagement through the psychological mechanism of employee gratitude. In addition, we also explore the role of supervisory feedback as a moderator that enhances the relationship between employee gratitude and employee engagement.