In this paper, we propose a method for global localization using an omni-directional camera. A robot position and angle are estimated by correlation coefficient between topological node-map images and input images. Near-node has the largest correlation coefficient in topological map images. The calculated correlation coefficient makes the mixtures of Gaussians density map. The highest value of ...

An electronic meter to measure surface seawater density is presented. It is based on the measurement of the difference in displacements of a surface level probe and a weighted float, which according to Archimedes' law depends on the density of the water. The displacements are simultaneously measured using a high-accuracy magnetostrictive sensor, to which a custom electronic board provides a wir...

The electrophysiological properties of sinoatrial (SA) node pacemaker cells vary in different regions of the node. In this study, we have investigated variation of the 4-aminopyridine (4-AP)-sensitive current as a function of the size (as measured by the cell capacitance) of SA node cells to elucidate the ionic mechanisms. The 10 mM 4-AP-sensitive current recorded from rabbit SA node cells was ...

A Wireless Sensor Network (WSN) is a collaboration of a large number of sensor nodes. The sensor node operates on small batteries with limited lifetime. Some sensors, acting as source nodes, transmit their sensed data to a sink node via multi-hop communication. Often nodes nearer to the sink expend more energy than the nodes farther from the sink. Therefore, it is highly desirable to have an ef...

In this paper, we first define level of tree connectivity for multicast routing schemes in wireless ad hoc networks. Then given the level of tree connectivity, we examine the relation between node density required for single and double tree schemes both analytically and experimentally. For high density wireless ad hoc networks and a given level of tree connectivity, our analysis shows that the ...

The aim of this study is to propose an efficient broadcasting method considering node density and to conduct a comparative evaluation with existing methods. In our proposed method, broadcasting is carried out efficiently using positional information attached to messages at the time of broadcasting and not by periodically exchanging positional information or routing tables. We run a simulation c...

Internet technology is advancing with increasing internet applications demands. However, most developing countries have poor internet experience. Thus, the Quality of Service, QoS of an internet technology, Third Generation, 3G in a developing country, Nigeria was studied. Voice over internet protocol, VoIP and Video Streaming were the internet applications while CODECs and node density were th...

We investigate the fundamental relationship between node density and transmission delay in Large-scale wireless networks with unreliable links from percolation perspective. Previous works[7][2][6] have already showed the relationship between transmission delay and distance from source to destination. However, it still remains as an open question how transmission delay varies in accordance with ...