Emergent situations for smart cities: A survey

A smart city is a community that uses communication and information technology to improve sustainability, livability, and feasibility. As any community, there are always unexpected emergencies, which must be treated to preserve the regular order. However, a smart system is needed to be able to respond effectively to these emergent situations. The contribution made in this survey is twofold. Firstly, it provides a comprehensive exhaustive and categorized overview of the existing surveys for smart cities.  The categorization is based on several criteria such as structures, benefits, advantages, applications, challenges, issues, and future directions. Secondly, it aims to analyze several studies with respect to emergent situations and management to smart cities. The analysis is based on several factors such as the challenges and issues discussed, the solutions proposed, and opportunities for future research. The challenges include security, privacy, reliability, performance, scalability, heterogeneity, scheduling, resource management, and latency. Few studies have investigated the emergent situations of smart cities and despite the importance of latency factor for smart city applications, it is rarely discussed

New Electrode Profile for Machining of Internal Cylindrical Surfaces by Electrochemical Drilling

Abstract: Electrochemical machining (ECM) is one of non-traditional machining process. It offers the ability to machine extremely hard materials or materials that are difficult to be machined using conventional methods. Moreover, it is considered one of the most effective ways to machine the complex shapes of internal and external geometries . This paper introduces a new electrode tool drilling with insert tip instead of traditional die electrode tool shape used in machining of internal cylindrical shapes. It reviews the development of high efficiency and low cost electrode for electrochemical cylindrical machining. The effect of insert tool profile on current values, metal removal rate (MRR), conicity, and surface roughness is investigated. Based on the experiments, it is concluded that by using the proposed insert tip tool profile, the hole machining becomes more accurate with smoother surface roughness with a remarkable reduction in the value of the consumed current

Analysis of Equilibrium Points in Quantized Hill System

In this work, the quantized Hill problem is considered in order for us to study the existence and stability of equilibrium points. In particular, we have studied three different cases which give all whole possible locations in which two points are emerging from the first case and four points from the second case, while the third case does not provide a realistic locations. Hence, we have obtained four new equilibrium points related to the quantum perturbations. Furthermore, the allowed and forbidden regions of motion of the first case are investigated numerically. We demonstrate that the obtained result in the first case is a generalization to the classical one and it can be reduced to the classical result in the absence of quantum perturbation, while the four new points will disappear. The regions of allowed motions decrease as the value of the Jacobian constant increases, and these regions will form three separate areas. Thus, the infinitesimal body can never move from one allowed region to another, and it will be trapped inside one of the possible regions of motion with the relative large values of the Jacobian constant