Self-Configuration and Self-Optimization Process in Heterogeneous Wireless Networks

Self-organization in Wireless Mesh Networks (WMN) is an emergent research area, which is becoming important due to the increasing number of nodes in a network. Consequently, the manual configuration of nodes is either impossible or highly costly. So it is desirable for the nodes to be able to configure themselves. In this paper, we propose an alternative architecture for self-organization of WMN based on Optimized Link State Routing Protocol (OLSR) and the ad hoc on demand distance vector (AODV) routing protocols as well as using the technology of software agents. We argue that the proposed self-optimization and self-configuration modules increase the throughput of network, reduces delay transmission and network load, decreases the traffic of HELLO messages according to network’s scalability. By simulation analysis, we conclude that the self-optimization and self-configuration mechanisms can significantly improve the performance of OLSR and AODV protocols in comparison to the baseline protocols analyzed

Late results (up to 18 years) after parietal cell vagotomy

One hundred and two selected patients treated for duodenal ulcer disease by parietal cell vagotomy between 1975 and 1984, at the Department of Surgery of the Aegean University Faculty of Medicine were followed up for 1 to 18 years. The main indication for surgery was intractable pain (87%). A drainage procedure was employed in 12 patients, early in the study. During the first 10 years after parietal cell vagotomy (median follow-up 35 months), Visik 1+2 patients amounted to 82% of the series. There were five recurrences (5%) and 14% Visik 3 patients. Thirty-nine patients (38.6%) were lost for follow-up within the first 10 years of their operation. Among the 62 patients with 11 to 18 years follow-up (median follow-up 14 years), Visik 1+2 patients were 85%. The estimated cumulative recurrence rate was 9.8% for the entire series