Sharif Digital Repository

Shipment of hazardous materials has got an important role in the world of today. Nowadays, sustainable development has got serious attention, and human health and environment are one of the sustainable development bases. The risk of hazardous materials for human health and environment, and also importance of this kind of materials in the industrial economy, make necessity of programming for shipment of hazardous materials more serious. This thesis, presents an optimiziation model for routing and scheduling for shipment of hazardous materials. This model is a multi criteria time varing mixed integer programming (MIP). The presented model, finds the optimal routs and scheduling of movement... 

Today with growth of wireless communications and progress of small and cheap sensors which have capability of communication and calculation, wireless sensor networks are important and useful topic. But due to energy restrictions, efficient use of resources and increasing network lifetime, have been considered as key factors in network design. In this regard, using efficient multicast routing in energy consumption, for an efficient data transmission to specific number of nodes instead of all nodes code updates, information requests, task assignments and etc., is necessary.On the other hand these networks use unlicensed spectrum and suffer from collision due to congestion caused by other... 

Modular Robots are group of robots which are made of small components called modules. The advantage of these robots to others is their ability to change physical configuration. Using of these robots in configuration changing due to environmental conditions is popular. While, reconfiguration is one of the most important features in modular robot, it’s the most important concern too. Path planning problem is one of the important problems in robotics .So far, most of presented path planning methods and algorithms are based on fixed-structure and they had little attention to path planning and configuration changing, simultaneously. In this thesis, the Genetic Algorithm is used to find path and... 

Control of many mechanical systems such as satellites lies on the control of space robots. Control of space robots has many theoric complexities because of the presence of non-holonomic constraints due to angular momentum conservation. Unlike fixed-base robots, any movement of space robots manipulator has a reaction on the robot base and moves it. Thus manipulator’s movement toward desired configuration rotates the robot base and as a result appropriate attitude may not be attained. Therefore an appropriate path is required to achieve the desired configuration and the base attitude reaches its desired value. In this thesis, first the dynamic of space robots and the interaction between the... 

In this project we present a method to support execution of multiple applications on an NoC simultaneously. To this end we are going to use resource sharing methods, especially Spacial Division Multiplexing (SDM). In this work we first present a mapping algorithm to map the nodes of a compound graph (a graph that is composed of all the task graphs that are supposed to work simultaneously) in to mesh nodes. We also present an architecture to support SDM. After that we present a routing and resource allocation algorithm to find a circuit for each communication flow in the task graph. Our results show that the proposed mapping algorithm reduces the average packet latency compared to NMAP... 

This project presents a routing algorithm to cope with the dynamic traffic pattern of network-on-chip (NoC) architectures aiming to distribute the on-chip traffic evenly across the network. In this algorithm, instead of relying solely on local congestion information, the routes are determined based on the global information about on-chip traffic. This is achieved by employing a light-weight and efficient control network which monitors the on-chip traffic and collects the required information for determining the appropriate path between any pairs of communicating nodes in such a way that the congestion is avoided and the NoC load is balanced. Our experiments show that the proposed method... 

Wireless mesh networks (WMN) appeared as popular communication networks supporting high speed and high throughput applications. They consist of mesh routers and mesh clients and they have unique characteristics like self organizing and self configuring of the mesh nodes that bring a great deal of efficiency, reliability and robustness to networks and decreases networks maintenance cost notably. Also WMNs provide an integration of different types of wireless networks by exploiting the gateway involvement. One of the important group communication technologies that offers high level of bandwidth conservation and efficiency is multicasting. It also decreases the cost of communication compared to... 

Network coding as an efficient approach for performance improvement of communication networks has been introduced by Ahlswede et al. Despite simple forwarding schemes, in network coding scenarios, intermediate nodes forward the encoded version of their received packets. In wireless Networks, resource allocation includes routing, network coding, flow control, scheduling and power control.In this dissertation a joint scheduling, routing, flow control and Inter-session NC formulation based on a convex optimization problem is studied. Our formulation integrates the optimal scheduling, flow control and Inter-session network coding with a modified version of minimum delay routing. We propose a way... 

Wireless sensor networks have many applications one of which in linear structure is used to control pipeline infrastructure. This thesis focuses on the routing of oil, gas, and water pipelines using wireless sensor networks. There are two algorithms one of which is Jump Always (JA) Algorithm and the other one is Redirect Always (RA) Algorithm. There are designed in Linear Structure of wireless sensor networks that are presented with a hierarchical addressing scheme. A Redirect Jump (RJ) routing protocol is our method that is designed for the hierarchical addressing scheme too. The RJ routing protocol has many benefits compared to the two methods (JA and RA). The RJ algorithm can increase the... 

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... 

Project in brief: reconfiguring the network according to application which has been run on the network is one of the ways to improve using resources in the network-on-chip. There is a hierarchical cluster based NOC. In this network, nodes are going to partition into clusters. Every cluster’s node can have its own configuration and the configuration of inside of each cluster is unchangeable however the relationship between clusters is configurable. This ability is made by some switches which are located between clusters and they can change the way that clusters are related. The number of nodes which is inside the cluster are cluster size and the number of switches between two adjacent... 

reparedness and emergency procedure be devised in the event of,and prior to,a disaster. One of these disastersoften accompanying byhuge damages, losses and casualtiesisanearthquake. After such a disaster, several governmental and non-governmental organizations usually start relief operations. They commonly pursue their own agendas and use their own facilities and capabilities to help the people affected without pursuing a central plan. These disintegrated behaviors of involved organizations generate contradictory responses and result in either wasted resources or preventing equitable service for all affected people. Due tothe abovefact, this dissertation proposes amodel for improving... 

Switching as one of important characteristics of on-chip network affects on power consumption and performance. In general there are two switching methods as circuit-switching and packet-switching. Hybrid switching includes both switching to have both resource utilization and scalability of packet switching and low power consumption and improved latency of circuit switching. Also topology is another network attribute that greatly affects the power, performance, cost, and design time/effort of NoCs. In this thesis, we propose a novel NoC architecture which holds both fixed connections between adjacent nodes and long connections virtually connecting non-adjacent nodes. Our proposed NoC... 

Due to the dynamic topology of vehicular ad hoc networks, routing of packets in these networks faces a lot of difficulties. The situation will become more challenging when we have to deal with Delay Tolerant Networks (DTN) which are also sparse and partitioned and we need to use some vehicles to store the packets and carry them from one partition to another. Despite all these difficulties, by looking through movements of vehicles in an urban environment, we can find out that the topology of the network does not change in a pure random way and we can bring the traffic models of streets into account for having better routing performance. In this thesis, we proposed an intelligent routing... 

Wireless Sensor Networks (WSNs) have attracted much attention in recent years for their unique characteristics and wide use in many different applications. WSNs are composed of many tiny sensor nodes that have limitations on energy level, bandwidth, processing power and memory. Therefore, reducing energy consumption and the increased network lifetime and scalability are the main routing challenges in sensor networks. Many algorithms were presented for routing in sensor networks; a class of theses algorithms is hierarchical algorithms based on clustering. Their main goals are to reduce energy consumption, distribution energy consumption in the whole network and increasing scalability. There... 

Wireless Sensor Networks (WSNs) has been a research topic for more than a decade, and the range of potential applications has spanned beyond the military domain into commercial domains. A key feature of current WSN solutions is operation in unlicensed frequency bands, for instance, the worldwide available 2.4 GHz band. However, the same band is shared by other wireless applications, such as Wi-Fi and Bluetooth, as well as other proprietary technologies. There is evidence that unlicensed spectrum is becoming overcrowded, to solve this problem, concept of cognitive radio has been introduced.
A main challenge for routing in cognitive radio wireless sensor networks is the collaboration... 

Cognitive Radio (CR) technology enables dynamic spectrum access (DSA) to overcome the problems of unlicensed bands which is becoming overcrowded. However, providing an acceptable quality of service (QoS) for cognitive users requiresmore sophisticated approachesdut to the existence of primary users (PU) with their high priority over licensed bands. Additionally, reducing interference with primary users so that they can communicate without interruption is of extreme importance. In order to meet cognitive user’s quality of service as much as possible and reduce interference with PUs, a new class-based multipath on-demand routing protocol for cognitive radio networks (CMORC) is proposed. CMORC... 

Path planning of a robot inside an environment with obstacles is to determine an appropriate path for moving from an initial point to a destination without colliding the obstacles. The main considerations in selecting such a path are its length and simplicity in terms of links or turn angles. In this paper, we study this problem for a point robot in the plane and our goal is to minimize the path length. We solve this problem by converting it to an optimization problem and solving the resulted optimization problem by a recurrent neural network. According to the implementation results, the obtained path is a proper approximation of the minimum length path, especially when obstacles are not too... 

Introductions: The routing Problem in SMS networks, start from subscriber called origin and end to other subscriber called destination. SMSs passed throw the switches, relay and routers. When the traffic of a SMS network increase, a global optimization is required to reduce the charge that SMS center must be paid meanwhile maximize total flow and minimize delivery time.
Methods: in this study after investigation in Short Message service, Routing Algorithms and letreture review, first we used our models for Telephone networks. The total model with Features and constrains was build. In order apply this model on Mobile networks, with using Latin Multy Plications Algorithms we develope a...