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A two-hop neighborhood information-based routing protocol is proposed for real-time wireless sensor networks. The approach of mapping packet deadline to a velocity is adopted as that in SPEED; however, our routing decision is made based on the novel two-hop velocity integrated with energy balancing mechanism. Initiative drop control is embedded to enhance(More)
Many of the interneuron cell types present in the adult spinal cord contribute to the circuits that control locomotion and posture. Little is known, however, about the embryonic origin of these cell types or the molecular mechanisms that control their differentiation. Here we provide evidence that V1 interneurons (INs), an embryonic class of interneurons(More)
Real-time wireless sensor networks are becoming more and more important by the requirement of message delivery timeliness in emerging new applications. Supporting real-time QoS in sensor networks faces severe challenges due to the wireless nature, limited resource, low node reliability, distributed architecture and dynamic network topology. There are(More)
The vision of pervasive computing is based on the idea that computers merge with their environment. Radio frequency identification (RFID) and wireless sensor network (WSN) are two important components of pervasive computing, since both technologies can be used for coupling the physical and the virtual world. However, RFID and WSN almost are under(More)
Reciprocal activation of flexor and extensor muscles constitutes the fundamental mechanism that tetrapod vertebrates use for locomotion and limb-driven reflex behaviors. This aspect of motor coordination is controlled by inhibitory neurons in the spinal cord; however, the identity of the spinal interneurons that serve this function is not known. Here, we(More)
The pathway mediating reciprocal inhibition from muscle spindle afferents (Ia axons) to motoneurons (MNs) supplying antagonist muscles has been well studied in adult cats, but little is known about how this disynaptic pathway develops. As a basis for studying its development, we characterized this pathway in mice during the first postnatal week, focusing on(More)
A multitude of applications of wireless sensor networks require that the sensor nodes be location-aware. Range-based localization schemes are sometimes not feasible due to hardware cost and resource restriction of the sensor nodes. As cost-efficient solutions, range-free localization schemes are more attractive for large-scale networks. This paper presents(More)
Barrier coverage is a critical issue in wireless sensor networks for security applications (e.g., border protection) where directional sensors (e.g., cameras) are becoming more popular than omni-directional scalar sensors (e.g., microphones). However, barrier coverage cannot be guaranteed after initial random deployment of sensors, especially for(More)
Node self-localization is a key research topic for wireless sensor networks (WSNs). There are two main algorithms, the triangulation method and the maximum likelihood (ML) estimator, for angle of arrival (AOA) based self-localization. The ML estimator requires a good initialization close to the true location to avoid divergence, while the triangulation(More)
Duty-cycling technique has been widely adopted in MAC protocols for wireless sensor networks to conserve energy. However, low duty-cycle also leads to limited throughput in most of existing solutions. In this paper, we propose iQueue-MAC to provide immediate yet energy-efficient throughput enhancement for dealing with burst or heavy traffic. Combined with(More)