appropriate scheduling and sequencing of tasks on machines is one of the basic and significant problems that a shop or a factory manager encounters; this is why in recent decades extensive studies have been done on scheduling issues. one type of scheduling problems is just-in-time (jit) scheduling and in this area, motivated by jit manufacturing, this study investigates a mathematical model for...

Nowadays, software systems are complex and large. To cope with this situation, teams of developers have to cooperate and work in parallel on software models. Thus, techniques to support the collaborative development of models are a must. To this end, several approaches exist to identify the change operations applied in parallel, to detect conflicts among them, as well as to construct a merged m...

this paper presents a new mathematical model for a bi-objective job shop scheduling problem with sequence-dependent setup times that minimizes the weighted mean completion time and the weighted mean tardiness time. for solving this multi-objective model, we develop a fuzzy multi-objective linear programming (fmolp) model. in this problem, a proposed fmolp method is applied with respect to the o...

This paper presents a multi-objective mixed-integer nonlinear programming model to design a group layout of a cellular manufacturing system in a dynamic environment, in which the number of cells to be formed is variable. Cell formation (CF) and group layout (GL) are concurrently made in a dynamic environment by the integrated model, which incorporates with an extensive coverage of important ...

Industrial hazardous materials (hazmat) are byproduct of industrial production and include hazardous goods, such as flammable, toxic and corrosive materials that pose a risk to the environment.Hazardous waste management includes collection, transportation, treatment, recycling and disposal of industrial hazardous material in an organized manner. With the increasing industrialization of countrie...

An invigilator is a person who supervises students during examinations in educational systems. Assigning invigilators to exams is an important phase in the exam scheduling process. The problem has its own constraints and a multi-objective structure. Hardly any mathematical models have been used in the past. Mostly, heuristic approaches are used to assign invigilators to exams. The Analytic Netw...

in this paper we have discussed the main features of a finite clement program which we have developed for nonlinear dynamic analysis of plates and shells with material and geometric nonlinear behaviour. for this purpose, initially, the finite element model which we have used is briefly described. afterwards, the nonlinear viscoplastic material model in one-dimensional and multi-dimensional medi...

estimation of parameters of a hydrologic model is undertaken using a procedure called “calibration” in order to obtain predictions as close as possible to observed values. this study aimed to use the particle swarm optimization (pso) algorithm for automatic calibration of the hec-hms hydrologic model, which includes a library of different event-based models for simulating the rainfall-runoff pr...

mobile-ad-hoc-networks (manets) are self-configuring networks of mobile nodes, which communicate through wireless links. the infrastructure of a mobile ad hoc network (manet) has no routers for routing, and all nodes must share the same routing protocol to assist each other when transmitting messages. the main issues in manets include the mobility of the network nodes, the scarcity of computati...

Nowadays, the necessity of accurate quantitative decision support methods is becoming a critical subject for managers as rivalry between organizations caused a more fragile economic environment and brand reputation is becoming more important. Furthermore, dealing with incidents after they happened is not accepted by customers anymore. Managers require powerful decision making tools to support t...