in this paper, integrated direct and reverse logistics considering production, distribution, customer, devastation, retrieval centers under uncertainty are developed. in this model, cost parameters are not certain, thus the scenario-based robust optimization method is applied. the aim of this model is to minimize the total cost and obtain a robust solution. finally, a practical case study is pr...

In this paper we define and study Scenario Based P Systems, a model of computation inspired by the metabolic pathways and networks. Starting from the classical definition of P systems with symbol objects and multiset rewriting rules, we define regular expressions able to capture the causal dependencies among different executions of the rules. The results show the computational power of this model.

Like other user-centered approaches, scenario-based design changes the focus of design work from defining system operations (i.e., functional specification) to describing how people will use a system to accomplish work tasks and other activities. However, unlike approaches that consider human behavior and experience through formal analysis and modeling of well-specified tasks, scenario-based de...

A method for scenario based requirements engineering is described. The method uses two types of scenario, structure models of the system context and scripts of system usage. A modelling language is reported for describing scenarios, and heuristics are given to cross check dependencies between scenario models and the requirements specification. Heuristics are grouped into several analytic treatm...

Scenarios have proven useful to elicit, validate and document requirements but cannot be used in isolation. Our concern in this paper is to integrate scenario-based techniques in existing methods. We propose a set of operators to support such an integration. This set is classified in two sub-sets: the one dealing with the integration of the product models of the two initial methods and the one ...

This mini tutorial explains the concepts and process of scenario based requirements engineering. Definitions of scenarios are reviewed, with their informal and more formal representations, and roles in the requirements process. The relationships between scenarios, specifications and prototypes is explored, and set in the perspective of human reasoning about requirements. Methods for scenario ba...

Despite the recent interest in scenarios, the development of new methods and tools for Requirements Engineering integrating scenario based approaches has been limited. This paper reports on four different processes developed from research undertaken as part of the CREWS project which the authors believe will improve scenario use and make it more systematic. Furthermore CREWS aims to integrate t...

This paper deals with day-ahead programming under uncertainties in microgrids (MGs). A two-stage stochastic programming with the fixed recourse approach was adopted. The studied MG was considered in the grid-connected mode with the capability of power exchange with the upstream network. Uncertain electricity market prices, unpredictable load demand, and uncertain wind and solar power values, du...

imagine you have traveled to an unfamiliar city. before you start your daily tour around the city, you need to know a good route. in network theory (nt), this is the traveling salesman problem (tsp). a dynamic programming algorithm is often used for solving this problem. however, when the road network of the city is very complicated and dense, which is usually the case, it will take too long fo...