Sharif Digital Repository

In project management context, the Earned Value Management (EVM) is a well-known technique. Despite its popularity, the standard EVM suffers from the absence of some features that require being focused further on to make this method more efficient. This paper is addressing such features specifically the financial aspects of cost control system. These aspects that have been absent in the standard EVM include the time value of money, delay in client payment and contractor cash flow in uncertain environment. The proposed model here utilizes fuzzy sets to deal with the uncertain conditions of real projects. It attempts to extend the theoretical framework of EVM to evaluate and control the... 

We consider the design of an optimal natural-gas network. Our proposed network contains two echelons, Town Broad Stations (TBSs), and consumers (demand zones). Here, our aim is a two-stage cost minimization. We first determine locations of the TBS so that the location-allocation cost is minimized. Then, we show how to distribute the flow of gas among the TBS minimizing the flow cost by using Minimum Spanning Tree (MST). A case study in Mazandaran Gas Company in Iran is made to assess the validity and effectiveness of our proposed model  

In the present work, a thermal modeling is conducted for optimal design of compact heat exchangers in order to minimize cost and entropy generation. In this regard, an εNTU method is applied for estimation of the heat exchanger pressure drop, as well as effectiveness. Fin pitch, fin height, fin offset length, cold stream flow length, no-flow length, and hot stream flow length are considered as six decision variables. Fast and elitist nondominated sorting genetic algorithm (i.e., nondominated sorting genetic algorithm II) is applied to minimize the entropy generation units and the total annual cost (sum of initial investment and operating and maintenance costs) simultaneously. The results for...