Sharif Digital Repository

Management decisions, Enhanced Oil Recovery, and reservoir development plans in petroleum industries are based on predictions by reservoir simulation. Due to uncertainties in model parameters or engineering assumptions, the simulation results are not accurate, while they are correct. One remedy is to match simulation results with engineering measurements, typically pressure and flow rate, by adjusting model parameters. In Reservoir Engineering literature, this is called History Matching and is an optimization problem. Common methods of history matching are based on finite difference simulation, and therefore have a very low speed. In addition, these methods usually ignore Geostatistical... 

In this thesis a multi-mode resource constrained project scheduling problem with considering project robustness,length of critical path and total quality of project is solved. Also we tried to propose a new mathematical model for this problem and we used both renewable and non-renewable resource constrained.The function is multi-objective so we couldn’t use classic optimization methods to reach globally or locally optimum solutions,then we used a multi-criteria optimization method to solve the problem.with respect to the computational complexity of problem we proposed a multi-objective metaheuristic (DE) algorithm to get to dominated optimal solutions.in our metaheuristic method particular... 

One of the challenges of today's economy, is improving economic structures and reduce its dependence on oil revenues. Agricultural industry as an important part of the economy, is not dependent on oil revenues and improving its structure can have a significant impact on increasing revenues. Kerman province with a high proportion of horticultural products in the country, plays a significant role in Agricultural industry .However, the problem of water shortages in the country, highlighted the efficient use of water in economic purpose and crop-planning. By the problems with the current structure, lack of management of planting crops, lack of proper supply chain, redesign of agricultural supply... 

In this thesis a model of mixed integer programming to find the optimal solution of bi-objective facility layout problem in flexible bay structure according to uncertainty in flow material among departments and closeness rating is represented. In a facility layout problem based on flexible bay structure, departments with unequal areas are allocated to parallel bays. Also each department can only be allocated in one bay. The Goals are to minimize material handling cost and to maximize closeness rating. Uncertainty in flow material and closeness rating are modeled by fuzzy numbers. Due to the high complexity of the presented model, exact methods are only able to respond to maximize of 9... 

Among scientific fields of study, mathematical programming has high status and its importance has led researchers to develop accurate models and effective solving approaches to addressing optimization problems. In particular, meta-heuristic algorithms are approximate methods for solving optimization problems whereby good (not necessarily optimum) solutions can be generated via their implementation. In this study, we propose a population-based meta-heuristic algorithm according to chemotherapy method to cure cancers that mainly search the infeasible region. As in chemotherapy, Chemotherapy Science Algorithm (CSA) tries to kill inappropriate solutions (cancers and bad cells of the human body);... 

In the present work, a comprehensive economic, environmental and dynamic behavior analysis with multi-objective optimization for the unit 400 of BandarEmam aromatic plant are provided and the interaction between decision variables in these criterions is discussed. In the first part, potential of seven environmental features of the operational plant are qualified and normalized using life cycle assessement (LCA) for both process waste and utility environmental impacts. By choosing the number of trays and feed stage in three distillation columns as decision variables, optimization is performed to determine the best structural variables values based on the total annual cost and Environmental... 

Today, in order to keep up the competition in the market, companies need to use the latest technologies, methods, processes, applications, etc. to find the best services and products. For this, companies and organizations need more dynamism to make the best decisions that can accelerate business process changes. Cloud computing, which is one of the newest and most important business models, can contribute to their success by sharing information and production resources between organizations, as well as helping them compete globally with each other's capabilities. In this research, a multi-objective model is proposed to optimize customer decision-making in using cloud computing and the... 

This thesis focuses on the problem of large vocabulary continuous speech recognition (LVCSR).Numerous research results in recent years proved effectiveness of deep neural networks (DNN) for LVCSR. As a result, many methods were proposed to incorporate DNNs in LVCSR. From one perspective we can look at these methods from the viewpoint of objective functions used for training DNNs. A frame-level objective function is one that is defined on frames locally, whereas a sequence-level objective function is defined on whole sequences. Since speech recognition is essentially a sequentional problem, here we focus on designing and imroving sequencelevel objective functions for DNNs. The main proposed... 

In this research, the effect of variable stiffness and damping, in suspension system, on car performance was studied. The optimization of car performance was obtained by minimization of an objective function including the body acceleration, suspension travel and tire deflection. Firstly, considering the stochastic input for a quarter car model, minimization of the objective function was done by changing the stiffness and damping coefficients in the frequency domain. The Linear Quadratic Regulator (LQR) method was implemented to minimize the objective function. In order to supply the active force obtained by optimization, different semi-active designs, in which stiffness and damping were... 

Supply chain management seeks to coordinate supply chain processes to achieve certain goals; one of which is minimizing the overall cost of the system. In this study integration of different supply chain management decisions i.e. location, routing and inventory management is considered in a single model. The products are distributed in a two-echelon distribution system. One type of product is shipped from a single factory to multiple retailers with deterministic demands through a set of distribution centers. The products can be stored in second and third levels facilities. The product is perishable with a certain shelf life. The product is delivered in a way to be consumed before spoilage. A... 

Multicommodity network flow problem arises in the areas of transportation, logistics, and, telecommunication. The cost of each arc might be a linear or nonlinear function of the sum of commodity flows on that arc. Most of researches have worked on linear multicommodity flow problem. In addition, they consider the shared capacity constraints as the side constraints. In this thesis, we present a penalty-based algorithm for solving the multicommodity network flow problem with a linear or nonlinear objective function and considering the shared capacity constraints as the side. To solve multicommodity network flow problem, we relax the shared capacity constraints, and add a penalty term for the... 

The extensive use of nonlinear loads such as motor drives and new generation of home appliances has caused a deterioration of power quality in power systems. The use of active power filters due to the fast variation of the loads has been recommended by power engineering. In this method, the harmonic profiles are controlled by applying active filters in a distribution feeder. Optimal placement of active filters in a distribution system due to the increase of harmonic generation loads has attracted researchers. However placement of each filter is the major concern that researchers face. In this paper, a new objective function is introduced to determine the optimal number and location of active... 

Internet of Things (IoT) is one of the most emerging fields in the computer science context. It is predicted that more than 9 billion devices will be connected to IoT networks by 2025. Considering the specifications of IoT devices such as low battery capacity and small memory, these networks face major challenges in energy consumption and reliability. One of the most important elements which have an indisputable effect on network efficiency is routing protocol. In this manner, IETF presented RPL in 2012. It is designed to create a robust network among IoT devices.Although RPL performs well in static networks, it is not designed originally for mobile networks and it has serious flaws in that... 

This research intends to investigate the multi-skilled project scheduling problems (MSPSP) considering staffs’ dynamic efficiency. In doing so, a mixed-integer nonlinear programming (MINLP) model is proposed, considering the influence of personnel learning and forgetting on activities duration. The more the staff spends time on their various skills, the more learned and efficient they will be on that skill (according to personal learning curves) so that they can complete new tasks less costly and more quickly. Most project-based organizations want to maximize value by finishing the projects efficiently and developing their staff’s competence through projects. Inherently, any... 

Internet of Things (IoT) is a communicative infrastructure, which establishes IP-based connections between many smart devices with limited energy supplies. The gathering of such an enormous number of connected devices would impose many challenges, with routing the most important issue. Standardization of the IPv6 Routing Protocol for Low-power and Lossy Networks (RPL) was a major step towards fulfilling the IoT routing requirements. The key element in determining the routing policies and creation of the topology in RPL is the objective function. According to our studies, more than 97% of the consumed energy of a node in wireless networks is due to transceiver activities. On the other hand,... 

Internet of things (IOT) interconnects a system of low power embedded devices that each of them has a unique identifier, without human intervention. The number of devices of IOT increases every day, therefor routing in the network of IOT is an important challenge. So, Internet Engineering Task Force (IETF) propose a protocol for routing low power and lossy networks in 2012, which is named RPL. Considering the power supply limitation of devices in the network, utilizing energy-aware policies within the RPL is so important. Meanwhile, objective functions have a vital role in the consuming energy. Also, energy consumption determines the lifetime of nodes. Since many of devices are placed in... 

There are many limitations to determine relationships within biological systems. Among the limitations of these systems, one can consider the lack of sufficient information about them, such as the complete knowledge of many networks, the lack of reaction information, the complexity of the analysis of these reactions, etc. One of the methods to analyze these systems is called flux balance analysis. This method consists of three parts: objective function, equal constraints and unequal constraints. Among the features available in this method, we can mention less need for experimental information and no need for high processing systems. In order to determine the objective functions in this... 

The presence of IoT has been increased in different aspects of human life. Due to the increasing trend in the number of smart connected devices, routing has become a major challenge in loT systems. Furthermore, due to the energy-constrained embedded devices in the network, which are usually battery-powered, and considering that %97 of the node's energy consumption is due to activities associated with the transceiver module, the energy-aware routing is significantly important. In this regard, the IPv6 routing protocol for low-power and lossy networks (RPL) was standardized to be adopted in IoT infrastructure. Due to the increasing interest in mobile IoT applications in recent years and... 

In this thesis, equations related to large deformation of a polymer were derived by considering viscoelastic effects. To express type of material behavior which includes elastoplastic and viscoelastic property at the same time, two-layer viscoplastic model was used. An axisymmetric model was used for modeling problem in finite element software. By derivation of parameters related to two layer model and entering them in finite element software and also entering other properties required to model the forming process, modeling was performed by special profile connecting input and output sections. Due to favorable properties of spline functions, profiles used in die geometry, were selected from...