Journal of Modern Processes in Manufacturing and Production
Volume:7 Issue: 2, Spring 2018

Nowadays, the internet and social networks become more popular than ever. People in all ages use the internet and communicate by that. One of the most terrible events in our daily life is to disconnect from the internet and lose the connections. It may also influence on the economics; so the sustainability in this area is necessary. Internet service provider companies are the executors of selling and maintaining the internet bandwidth. Some activities perform to maintain the corrupted internet ports. In this paper, the effect of maintenance activities on the internet sustainability is analyzed. This paper also discusses the three important maintenance activities and compares each of them with two different methods. The aim of this paper is to illustrate whether these three factors effect on the internet sustainability or not. 2k design procedure was used to analyze the results.

A powerful optimization method is proposed in this study for the minimal dimensional design problem of gearbox. It is a general model that is suitable to use for any series of gear drives system and can extract both dimensional and layout of components-limited optimization design together. The objective function in this study has many local extremes so for avoiding this situation, various constraints have been determined Then, Particle swarm optimization algorithm has been implemented to speed up the convergence of optimization and elitist particles searched in problem space to find optimum value of goal function until all of them converge to the similar set of values. At the end, Results have been presented in the utilitarian diagrams to obtain optimal parameters from useful diagrams. The results display that the proposed method in this study is better than other reported in last works and it shows optimum volume of gearbox being related to a decrease of not just space but costs, material used to make gearbox component, etc.

This short note points out an improvement on the robust stability analysis for electrically driven robots given in the paper. In the paper, the author presents a FAT-based direct adaptive control scheme for electrically driven robots in presence of nonlinearities associated with actuator input constraints. However, he offers not suitable stability analysis for the closed-loop system. In other words, it does not consider the role of saturation function in both control design and stability analysis.

In this study, turning operation of Monel K500 copper-nickel super-alloy was evaluated. Ceramic cutting tools with two different cutting noses (conventional and wiper) were utilized. At first, the experimental tests were designed by using central composite design method. After implementation of the tests, the statistical models for output data (surface roughness, cutting force, and flank wear) have been developed. Furthermore, the effect of cutting parameters on output data was taken into account with help of analysis of variance. In third step, the optimal cutting condition was introduced for both cutting tools by using response surface method. In total, it was revealed that low depth of cut and feed rate coupled with high cutting speed is an optimal condition for turning of Monel super-alloy when ceramic tools are selected. In particular, the positive effect of wiper tool on output data was more when depth of cut has been lower than the length of wiper edge.

In this paper, we study the re-entrant no-wait flexible flowshop scheduling problem with makespan minimization objective and then consider two parallel machines for each stage. The main characteristic of a re-entrant environment is that at least one job is likely to visit certain stages more than once during the process. The no-wait property describes a situation in which every job has its own processing sequence with the constraint that no waiting time is allowed among operations within any jobs. This study develops a bottleneck-based heuristic (BBFFL) to solve a flexible flowshop problem including a bottleneck stage. Also, a genetic algorithm (GA) based on heuristics for the problem is presented. First, the mathematical model for the problem is proposed, and then the suggested algorithms are explained. For small-scale, the results of the BBFFL and GA are compared to the results derived from the GAMS. For large-scale problems, the results of the GA and BBFFL are compared with each other. For small-scale problems, the algorithms have a close performance but the BBFFL is likely to generate much better in finding solutions in large-scale problems.

The purpose of this research is to demonstrate the importance of extracting business process mappings as a prerequisite for the implementation of the PFMEA (Process Failure Mode and Effect Analysis). In the first stage, 30 production process failures were extracted in the meetings with factory managers. Then, a team was formed by the presence of process owners, and with the help of the project team, the production process map was drawn up according to the IDEF0 standard. In the next step, for the second time, potential failures were extracted according to the production process map. This time, 49 failures in the production process with the potential sources of failures were identified. The results of the study showed that by extraction of the production process map, more failures in the production process would be detectable. In fact, extraction of the process map is a prerequisite for the implementation of the PFMEA. In this research, in order to better describe the steps taken, all extracted processes are schematically illustrated in accordance with the IDEF0 Modeling Standard, so that other sugar-producing companies can also use them to implement the PFMEA. The innovative aspect of this research is to extract the production process failures before and after extracting the process map and compare them with each other.

Nowadays, the role of light weight materials has grown up in important industries such as aerospace and biomechanics, but before the appliance, their strength should be increased. A modern way to increase this factor along with the lightweight factoris using bimetal sheets, hence, the design of multilayer sheets has been very much considered recently. In this study, explosive welded Cu/St/Cu multilayer sheets were used in the incremental forming process to determine the springback phenomenon on different layers. The results indicated that rotational speed, feeding rate, and vertical step parameters can affect spring back in single point incremental forming process (SPIF).Three levels of vertical step size, tool rotational speed, and feed rate have been considered as the input process parameters and spring back as the output.In order to design a better experiment and analyze the data, the Taguchi method was selected on the basis of DOEin Mini-Tab software andthe results have been analyzed by two states. In the first state,the value which was closest to the nominal value is considered to be the optimal result which obtained for spring back angles with parameters of 0.75 mm for the vertical step down, 200 rpm for the rotational speed and 500 and 1000 mm/min for the feeding rate. In the second state, the least amount is considered as the optimal result in which the values of 0.5 and 1 mm of the vertical step down, 150 and 100 rpm of the rotational speed, and 1500 and 500 mm/min of the feeding rate formed the optimal outcome.