David C. Ni

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This paper presents a real world case of implementing a sensor network for fulfilling the requirements of gas meter application. We propose a hierarchical network, which includes the functionalities such as receiving, transmitting, routing, auto-reconfiguring, scheduling, and deep-sleeping under the stringent requirement of power consumption. We are(More)
This paper proposes a compact printed quadrifilar helix antenna (PQHA) that has quarter wavelength inverted-F resonators at a low cost. The proposed PQHA is fed by a four-port quadrature phase system which consists of a 180°power splitter and two couplers implemented by lumped-element circuit. The fabricated and miniaturized PQHA measures only.The(More)
The rapidly growing web-based online services offered by new and traditional vendors have attracted the interests of massive consumers. These vendors provide or extend their services and products to the clients via the internet. As the service offers or related activities (e.g., merge) increase, they begin to scale up service infrastructure. For example,(More)
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