Efficient distribution of service requests between fog and cloud nodes considering user mobility and fog nodes’ overload is an important issue of fog computing. This paper proposes a heuristic method for task placement considering the mobility of users, aiming to serve a higher number of requested services and minimize their response time. This method introduces a formula to overload prediction based on the entry-exit ratio of users and the estimated time required to perform current requests that are waiting in the queue of a fog node. Then, it provides a solution to avoid the predicted overloading of fog nodes by sending all delay-tolerant requests in the overloaded fog node’s queue to the cloud to reduce the time required for servicing delay-sensitive requests and to increase their acceptance rate. In addition, to prevent requests from being rejected when the mobile user leaves the coverage area of the current fog node, the requests in the current fog node’s queue will be transferred to the destination fog node. Simulation results indicate that the proposed method is effective in avoiding the overloading of the fog nodes and outperforms the existing methods in terms of response time and acceptance rate.

In their study, Brenna and Spandonaro analyzed the mobility into Italian regions. In particular, it analyzes the situation of 5 regions, with very different backgrounds. With this paper, we try to better define the meaning of health mobility and to find its underlying causes. Furthermore, we propose a strategy that could help in controlling mobility flows that currently are the source of health inequalities.

Rip currents are the most visible features of surf zone that extend from the shoreline to the sea and are classified based on the mechanism of the controlling forces governing the surf zone. In this research, at first a pattern is presented to show the quality of the Channel rips mobility using the Mike21/3 software. In the next step, the presented pattern is verified and confirmed using the CERC equation. The results of the model are then compared with field observations of other researchers by examining the mean rip mobility rate (V) and alongshore current velocity (vl), which shows a very good agreement. The main finding of this study indicates that the longshore mobility of Channel rips depends on the bed slope and depth of the channels. In addition, it was found that the intermediate beaches are conducive to the formation of this particular type of rip currents.