Sharif Digital Repository

Path planning is essential for unmanned aerial vehicles (UAVs) to navigate complex and hazardous environments. Many algorithms have been proposed to solve this problem, but heuristic, meta-heuristic, and hybrid algorithms have recently gained attention due to their ability to find approximate solutions quickly. In this thesis, we propose using the Late Acceptance Hill Climbing (LAHC) algorithm for UAV path planning. We compare LAHC's performance to classical and state-of-the-art optimization algorithms, including simulated annealing (SA), grey wolf optimization (GWO), symbiotic organisms search (SOS), and simplified grey wolf optimizer-modified symbiotic organisms search (SGWO-MSOS).... 

5G networks are going to support a variety of vertical services, with a diverse set of key performance indicators (KPIs), by using enabling technologies such as software-defined networking and network function virtualization. It is the responsibility of the network operator to efficiently allocate the available resources to the service requests in such a way to honor KPI requirements, while accounting for the limited quantity of available resources and their cost. A critical challenge is that requests may be highly varying over time, requiring a solution that accounts for their dynamic generation and termination. With this motivation, we seek to make joint decisions for request admission,... 

Graph Labeling is one of the most active initiatives in graph theory which was introduced in the early 1960’s. One of the most prominent kind of labeling in literature is magic-type labeling inspired by defining magic numbers and magic squares. It also encompasses various types. Total edge magic labeling of Graph G, is a bijection f from V(G)∪E(G) on the set of {1,2,…,|V(G) |+|E(G) |}, on this condition that the summation of each edge label and its vertices’ labels is constant for all edges. Since introducing total edge magic labeling, numerous researches is done that mostly are dedicated to prove mathematical theorems and depicting a whether a distinct graph is magic or not. Therefore, it... 

Location-allocation problem is known as one of the classical problems in industrial engineering. The goals of these problems are finding optimal location of facilities and assigning these facilities to service demands from a given set of point. Location-allocation decisions are widespread through all organization in the world concerning private and public businesses. Therefore, in this study, a practical mathematical model is formulated and solved.In this paper we present a new approach for a budgeted constraint capacitated location-allocation problem integrated with cellular layout approach containing cell formation and group scheduling. Main decisions are composed of formation of... 

Nowadays, radiation therapy is one of the most common methods for the cancer treatment. Intensity Modulated Radiation Therapy(IMRT) is a novel technique of radiation therapy that aims to delivere sufficient dose to cancerous tissues while sparing healthy organs. There are various uncertainties in radiation therapy problems, including uncertainty about device setup, device errors, interfraction and intrafraction motions. One of the most important uncertainties is the movement of the tumor during the treatment process(intrafraction motion), as this displacement may cause the cancer tissue to not receive sufficient dose and also to damage the healthy tissue due to a violation of their dose... 

Portfolio is a collection of different stocks for investment. The investors' objectives in portfolio formation are to get the highest return against exposure to the lowest risk. Portfolio Optimization Problem is one of the most complicated problems in investment and finance. It may be simply explained as follows: Let's imagine a set of N stocks for selection. We would like to see what percentage of the total amount of investment should be dedicated to each stock to maximize portfolio's total return and minimize its total risk.
Portfolio Optimization Problem is a NP-Hard problem and generally there exists no polynomial-time deterministic algorithm to find a precise solution to such a... 

Cross docking is a novel docking method which importance in supply chain management has been underlined in recent decades. Two main operations of regular docking centers, including storage and picking up are eliminated in cross docking facilities in order to decrease inventory holding costs, shorten lead times and at the same time increase service level. Although inbound and outbound flow at each cross dock are determined by the flow of shipments through the network, overwhelming majority of papers in this field have addressed each of local and network-wide cross docking problems mutually in isolation. That being so, the problem dealt with in this research, is to how determining the flow of... 

Thus far, there has been a great attraction toward the optimal flight path planning problem. Terrain following/avoidance (TF/TA) flight is one of the most significant applications of this issue. To prevent from detection by the radars, fighter aircrafts, cruise missiles and helicopters often have to fly as close as possible to the surface during the operations. Such types of maneuvers are much more demanding and effortful than to be designed and implemented by human. The optimal TF/TA guidance system design comprises three phases: optimal path planning, closed-loop control system design for trajectory tracking and sensor blending to match the onboard and measured terrain data. So far, the... 

This thesis presents an inventory control system which is based on Meta-heuristic Algorithms.In this thesis we will optimize the input values of our tree-echelon inventory model (keeping costs,stock worth,reorder costs,...) with these Algorithms. The presented method is able to determine the optimal stock level, costs of system and number of shipments in the system. The method is basically a decision support system (DES) and it is able to provide the order scheduling parameters of goods at operational level. The aim of the current research is to demonstrate that a Meta-heuristic algorithmis capable of solving complex inventory problems and with future improvements it is able to achieve... 

Around 20 to 50 percent of the operation costs occurs in manufacturing is related to facility layout. Efficient design would reduce these costs by 10 to 30 percent. Facility layout consists of design of material handling system and plant layout. Design of material handling system includes determining, the flow network and locations of Pick-up and Delivery stations which are defined regarding to the kind of material handling equipment. Today, Automated Guided Vehicles are considered as the basic material handling equipment due to their potentials in production planning and controls, high safety and flexibility and low expenses.
In this thesis, we first discuss the design of the shortest... 

This thesis is about multidisciplinary design optimization of MRI ¬controlled robots with a nonlinear model approach in the cardiovascular system and simulates its behavior to reach cancer cells. Such robots, designed to perform medical procedures with minimal side effects to the patient, include a set of ferromagnetic nanoparticles attached to the polymer and disposable drugs such as cancer drugs.The disciplines considered in this issue include structure, hydrodynamics, propulsion, controllability, and trajectory. The proposed model in this study, in addition to the main forces acting on the robot such as magnetic force, hydrodynamics, and apparent weight, also examines other forces due to... 

The Dynamic Maximal Covering Location Problem (DMCLP), is one of the classes of Facility Location Problem (FLP) with a wide raneg of applications in real-life situations. In order to solve this problem, this research presents a sufficient greedy heuristic algorithm, which is capable of solving the DMCLP in large scales of 2500 demand nodes and potential facilities of 200 in 5 periods in a negligible computation time in comparison to those with exact algorithms such as branch and cut. Furthermore, in this research DMCLP is also modified to reach reach a more realistic model. In this new model, a cost behaviour is defined according to the number of facilities located. Subsequently, the new... 

Civil engineering structures and infrastructures including buildings and bridges are exposed to various externally applied loadings such as traffic, wind and earthquake during their operational lifetime. In this regards, structural static/dynamic displacement monitoring and their charactristics by mounted transducers is the mostly utilized and popular strategy. This may provide quantitative information for both structural safety evaluation and maintenance purposes. Such practice, however, is highly expensive to be operateddue to wiring, power signal transmission issues, limitations of sensor configuration to capture the entire structural response, and so forth. In addition, this may affect... 

This study discusses about mass customization and optimization of supply network in which both goal considering to set the flow of raw material and final product to satisfy the customer demand. The mass customization is more important concept in this study, so that this goal is placed to the first objective. In this research, the model which contained both goal is presented. The model focus on mass customization and try to satisfy various products demand, which constitute 3 kind of speed demands. Each product can satisfy in 3 way: fast, normal, slow.In the first model the new approach present in which the speed affects all of supplying, manufacturing and distributing system. The system try... 

Human blood is a valuable and scarce product which is only produced by human body. There is no replaceable material for our blood and there has always been a constant need to donors and blood products in societies. Like every other product, blood has to be transfused to patients after it is donated and this process requires a complete and effective blood supply chain. Considering all properties, complexities and uncertainties of a blood supply chain, we need to develop stable methodologies in order to simplify decision making in blood supply chain. In this research, we develop a novel blood distribution system from a regional blood center (RBC) to its nearby hospitals. It helps RBCs plan the... 

Pricing and Revenue Management in systems that offer services in subscription as well as pay-per-use format simultaneously is one of the most significant challenges in service companies. One of the main criteria in these systems is keeping the loyal customers and attracting more subscribers. Pricing and capacity allocation are decisions to be made in such systems considering customer’s behavior. In this research, we consider a service system with subscription and pay per use options to analyze the price and capacity allocation based on customer’s bahvior. The Loss Aversion theory is assumed for customer’s behavior and its effect on decisions is analyzed. A greedy algorithm as well as a smart... 

This research investigates permutation flow shop scheduling problems with sequence-dependent setup times with minimizing the number of tardy jobs as criterion (Fm|prmu, Sijk|ΣUj). A mixed integer linear programming model has been developed for the research problem. As the problem is shown to be NP-hard, several meta-heuristic algorithms based on tabu search (TS) and imperialist competitive algorithm are developed to heuristically solve the problem. In order to find the best meta-heuristic algorithm, random test problems, ranging in size from small, medium, to large are created and solved by the meta-heuristic algorithms. Then, a detailed statistical experiment, based on split-plot design is... 

Operating rooms (ORs) are considered as the most valuable resource in hospital, which are the largest revenue generator and, at the same time, the largest cost center of hospitals. Hospital managers have been interested in improving the efficiency and effectiveness of ORs by developing modern planning and scheduling tools. This research studies the stochastic operating room (OR) scheduling problem integrated by Post-Anesthesia Care Unit (PACU), named the operating theater room (OTR) problem. Due to the inherent uncertainty in surgery duration and its consecutive PACU time, the completion time of the operation of a patient should be modeled as the sum of a number of random variables. Several... 

It is well known that data centres consume high amounts of energy, which has become a major concern in the field of cloud computing. Therefore, energy consumption could be reduced by using intelligent mechanisms work to adapt the set of network components to the total traffic volume. SDN is an efficient way to do so because it has many benefits over traditional approaches, such as centralised management, low capex, flexibility, scalability and virtualisation of network functions. In our work will we use the heuristic energy-aware routing (HEAR) model, which is composed of the proposed heuristic algorithm and the energy-aware routing algorithm. This work identifies the unused links and... 

One of the complex problems is routing. This problem becomes more difficult and important in certain situations, which cannot be solved straightforwardly. In this thesis, a model for vehicle (ambulance) routing problem during hospital evacuation in disaster conditions is described and solved using Gray Wolf Optimization (GWO) algorithm in combination with a local search algorithm called Great Deluge Algorithm (GDA). It is shown that the combination of GWO and GDA can improve the efficiency of GWO and avoid local optima. The results are compared with some metaheuristic algorithms. To test the model of 11 hospitals in Tehran, three different modes have been considered, and in each mode, 7...