A Reaction-Diffusion-Based Coding Rate Control Mechanism for Camera Sensor Networks

A wireless camera sensor network is useful for surveillance and monitoring for its visibility and easy deployment. However, it suffers from the limited capacity of wireless communication and a network is easily overflown with a considerable amount of video traffic. In this paper, we propose an autonomous video coding rate control mechanism where each camera sensor node can autonomously determine its coding rate in accordance with the location and velocity of target objects. For this purpose, we adopted a biological model, i.e., reaction-diffusion model, inspired by the similarity of biological spatial patterns and the spatial distribution of video coding rate. Through simulation and practical experiments, we verify the effectiveness of our proposal

Experiments and considerations on Reaction-Diffusion based Pattern Generation in a Wireless Sensor Network

Taking into account requirements of sensor networks, we need fully-distributed and self-organizing control mech-anisms which are scalable to the size of a network, ro-bust to failures of sensor nodes, and adaptive to different and dynamically changing topology and changes in wire-less communication environment. To accomplish this goal, our research group focuses on behavior of biological sys-tems, which inherently are scalable, adaptive, and robust. In this paper, we first verify the practicality of control mech-anisms adopting a reaction diffusion equation, which ex-plains emergence of patterns on the surface of body of fishes and mammals, and then propose two methods for faster pat-tern generation to save energy consumption. From simula-tion and practical experiments on a prototype, it was shown that a stable pattern could be generated in a wireless sensor network in several minutes, even when packets were lost for collisions in wireless communication.

Multifocal intraoral ductal ectasia with metaplasia and focal epithelial proliferation: a case report

Ductal ectasia with metaplasia and focal epithelial proliferation in the oral cavity does not correspond to any existing salivary gland lesion. A 72-year-old man presented with a mass in the buccal mucosa, which was excised and initially diagnosed as a cystadenoma. An upper lip mass on the right side, which developed later, was also excised. The lesions were histologically similar, and since they were multifocal and in non-contiguous and independent sites with multiple dilated cystic structures that did not destroy the lobar architecture, the final diagnosis was confirmed as ductal ectasia with metaplasia and focal epithelial proliferation. This condition may mimic various neoplastic lesions. Keywords: Salivary ducts, salivary gland disease, salivary gland neoplasm, mucocele, metaplasia