Sharif Digital Repository

Control and managing of fuel consumption is one of the most important issues facing man kind today. Locating gas stations has a great effect on fuel consumption. The gas station locating problem consists of selecting the optimal choice between the candidate nodes for constructing gas stations in such a way that minimizes the excess travel time that results from the gas station not being located on daily travel paths. The gas station locating model is presented for two conditions of either considering and not considering the gas station capacity. In the case of not considering the gas station capacity, a compact model is presented, too. Softwares for medium sized networks and the Simulated... 

Hub and Spoke networks come into play when considering direct link between all origins and destinations is either impossible or expensive in a transportation system. In this kind of problems, some nodes are chosen as hub from all origin and destination nodes to collect flows and then distribute them. Implementing hub network leads to minimizing transportation cost, sorting flows and conveying them in economies of scale. Otherwise, shipping flows directly may cause decreasing the travelling distance and the delivery time consequently. In this dissertation, combination of hub network and direct shipment is investigated. To obtain the optimal hub locations and direct links between non-hub nodes... 

Hub location problem arises where the flow has to be routed between a set of origins and destinations, but direct links between all nodes are impossible or too costly. In these situations, e.g. transportation and communication systems, hubs serve as transshipment points to collect, transfer, and distribute the flow. In hub location allocation problem, hubs are located and non-hub nodes are allocated to them. In this thesis, two different models of capacitated multiple allocation hub location problem are discussed. In the first model, flow collection of hubs from non-hub nodes and in the second model, sum of flow collection and distribution of hubs from/to non-hub nodes is addressed. The... 

In mobile ad hoc networks, having an efficient routing protocol to deal with dynamics in network topology, based on the user behavior learning, has a significant role in generating more accurate results. It is valuable to use a realistic mobility model in such networks so that the results from the simulation will reflect the actual reaction of mobile nodes in the real world. Using a realistic mobility model helps simulation to have more accurate results in comparison with other kinds of mobility models especially in a Vehicular Ad hoc Network (VANET). Before exchanging information between moving vehicles, the destination node should be located. However, the existing location service... 

In this research a joint location- inventory problem is analyzed. We assumed two kinds of inventories: fast-moving and slow-moving goods. These two kinds of goods can be observed in after sales service systems. In the real world fast moving goods are stocked in all dealers but for slow moving goods there is no force to stock in all dealers. Therefore an important decision in these systems is where and how much we should stock the slow moving goods and how each dealer can supplies its demand for slow moving goods. In this research we model this problem as a joint location-inventory model which locates some warehouses in the network to stock the slow moving goods and assigns the dealers to... 

In this research, the location-inventory problem is developed in order to design a distribution center considering customers behavior. We consider two groups of customers who have different behavior on purchase. The customers may order the product via internet and receive it at their location or go to the nearest store and buy the product at the store center. We model the problem as a multi-objective programming model. The objectives are maximizing the profit as well as maximizing the market share. The model locates the distribution centers (DC) and allocates the customers to DCs. Two heuristic algorithms developed to solve the model: non- dominated Sorting Genetic Algorithm (NSGA-II) and... 

High number of traffic accidents in Iran and its rate which is well above the world's average is a major issue of concern. The results of recent researches show a direct relation between survival rate of traffic accidents' injuries and the Emergency Response Time (ERT). The main objective of this research is to analyze different aspects of ERT in Tehran, Iran and to compare these results with the International standards. This study intends to compare the selected routes by ambulance drivers with the shortest paths recommended by EMME/2. Results of analysis show that when the travel time between accident scene and the emergency dispatch center is less than 8 minutes, the possibility of... 

A key driver of the overall productivity and profitability of a supply chain is its distribution network which can be used to achieve a variety of the supply chain objectives ranging from low cost to high responsiveness. Designing a distribution network consists of three subproblems: location–allocation problem, vehicle routing problem, and inventory control problem. Because of high dependency among these problems, in the literature there are several papers integrating two of the above problems: location–routing problems, inventory–routing problems, and location–inventory problems.
The three echelon location routing inventori problem (LRIP) is raised by the design of transportation... 

The Emergency Medical Services (EMS) have a major role in decreasing the mortality rate and reducing the non-reversible effects of injuries by on time care to patients and transporting them to hospitals if it is needed. Since there is an important goal directly related to the human life, any research or study to improve the performance of EMS is highly recommended. One of the most important parameters in evaluation of EMS is to measure the coverage time of a demand. The locations of EMS play substantial role to decrease the response time. So the locations of EMS stations are very important especially in large and populated cities. Mainly, there are three problems that EMS managers should... 

By progress of computer vision, many systems are produced for soccer analysis. These systems have been used in many applications such as 2D and 3D reconstruction in arbitrary view. In this circumstance, we need to detect and track players, referee and ball in whole matches. In a single view system there are problems such as occlusion. By having more views of game, when two objects are occluded in one view, we can detect and track them in the others. Objective of this project is multi-view detection and multi-view tracking players and ball in soccer. In recorded videos from multiple views, we track path of players and the ball.
Proposed player tracking system has two main parts. First... 

One of the most important stages to designing a process plant is layout of equipment in unit area. There are plenty of routine procedures to find out equipment arrangement and their separation distances based on process and cost criteria. Although some studies have been carried out to enter safety parameters to conventional procedures, the problem complexity because of the number of involved equipment is still of concern. To clear these ambiguities, the new approach presented in this thesis is aimed at quantifying the effects of adjacent equipment on each other. In this way, fire radiation and explosion have been selected as the major hazard that any equipment can expose on the other items,... 

Nowadays due to increasing environmental considerations and effort to reducing of the fossil fuels consumption, the necessity of hydroelectric power plants development is emerged. The purpose of this study is to suggest a method of spatial analysis for finding sites with appropriate potential for construction of these power plants, using TOPSIS and GIS. In this research, using the Python programming language, in software environment of Arc GIS version 9.3, local hydrological model was generated using the DEM layer and using of streams ordering methods, the overall situation along the river were processed. In the next step, with using of fuzzy TOPSIS algorithm implementation in software... 

Radio Frequency Identification (RFID) is a fast developing research area in the pool of analog RF circuit design. Its applications are growing rapidly, in very different sectors ranging from supply chain management to airport baggage handling or traffic management for non-stop toll collection, etc. RFID surpasses the conventional bar code system in so many fields such as, long read range, multiple tag identification, contactless, re-programmability of tags and no need for a line-of-sight.
Inthis projecta new approach for modeling and reducing the Multi Path Fading (MPF) error is proposed. It isbased on Direction of Arrival (DOA) technique in thepositioningofpassivetags in UHFRFID... 

Localization of a neutron point source using a designed computer program namely “MCMC-MATURE” is performed. The computer program analyses several detector responses in some certain media by Markov Chain Monte Carlo (MCMC) method and a new iteration algorithm. Identification of the possible regions of source position would be found by analyzing the initial fluxes generated by mesh tally of MCNPX computer code. The designed computer program is capable to generate the flux between detectors. “Regular-Sequential”, “Irregular-Sequential” and “Non-Sequential” are three methods used for sampling the generated random number in two dimensions. Each sample multiplied by a sampling function and lead to... 

Simultaneous localization and mapping (SLAM) is the action of detecting robot pose in an unknown environment and building the environment map by use of input data that captured from robot sensors. In visual SLAM, the input data for the robot, is limited to camera sensors. Nowadays, SLAM is one of the main challenges in robotic research.For autonomous action, we need robot pose in the map of the environment. The map production in the indoor environment, there is no GPS data, is one of the research issue in robotic community, in last decade. In this thesis, a new and efficient method is proposed for SLAM at the level of objects. The maps produced by state of the art methods don’t have a... 

This paper studies a multi-product, multi-period location- routing- inventory problem in a three-level supply chain including suppliers, cross-docks and customers. Each cross-dock could be supplied by more than one supplier and each customer could be supplied by more than one cross-dock. In the first phase we find the best locations for the cross-dock and allocate them to customers and suppliers by considering inventory costs. . Then, in the second phase Products are distributed from cross-docks towards customers using Heterogeneous vehicles. In this article the option for split delivery is enabled and furthermore, backlogging is allowable for each customer. The model presented in this... 

This Thesis presents a robust network design model for supplying blood during and after an earthquake disaster. A two stage optimization model based on several real-world scenarios is developed. The purpose of this research is to locate and allocate fixed and mobile facilities in probabilistic situation, in which Tehran city with 22 districts is considered as a case study. This model can be categorized as a probabilistic model which demand and supply rate for blood and its derivatives is uncertain. Furthermore the blood transition between different blood types and conversion to its derivatives such as Platelet and plasma are involved in the proposed model. The supply chain for blood consists... 

Efficient location of health centers is an essential decesion in healthcare strategic planning. Nowadays constructing multi-service health centers is highly paid attention because of multiple nature of most diseases. Concentrating patients' medical services in one center prevents them from traveling to different parts of cities, especially in mega cities. In this research we have developed a mathematical model for the location of multi-service health centers assuming probabilistic demand and service time. Medical services are divided in three groups: normal, emergency and preventive. Since patients may be referred to another service after recieving a service by doctors' order, health system... 

Naïve hardware implementation of encryption modules can cause leakage about the secret information. Attackers can use this information to extract the secret key. This approach is known as side channel attack (SCA). An example of such attacks is differential power analysis (DPA), which uses a number of traces of power consumption of the encryption device. One of the proposed methods to deal with such attack is using dual rail logic. In previous implementations based on a dual rail logic, symmetric complementary mapping with the cross coupling and pre-charging is being used. This method has relatively high delay and cost; however, significant increase in the level of security can be achieved.... 

Distribution is a necessary part of a supply chain. Location-routing problem is a problem that decide about location of facility , allocation and routing for vehicle. This research focus on modeling for multi-level and multi-product for perishable foods that include five suppliers, three plants, two depots and ten costumers. costumers and products classify according to their importance for the company and their quality into three batch. In order to decreasing of cost return orders and damaged products, a special system are Designed that products can be sent again. In real world we do not have any certain data for model’ parameters, then we consider uncertainty and use robust for showing...