Sharif Digital Repository

Due to their specific characteristics such as huge data loads, heavy processes, various quality of service requirements (delay, jitter and reliability), multimedia streams have different necessities in comparison with normal data streams. The challenges of wireless sensor networks (process power, storage capacity and power limitations) add up to the challenges faced in WMSNs. In order to improve the quality of service in wireless multimedia sensor networks, attention must be paid to all the network layers. In this study improvement of quality of service is sought through the design of a protocol for the network layer of the wireless multimedia sensor network.
This protocol tries to... 

Transportation problem is one of the most important parts in supply chain management and it offers great potential to reduce costs and improve service quality. So many research efforts, are considering the optimization of the transportation systems and its related aspects. In this thesis, a transportation system according to a real case study, with the aim of minimizing total cost is considered. It is assumed a fleet of vehicles with limited capacity and different fixed and variable costs are shipping different products from a manufacturing plant to their associated nationwide distribution storages. Certain number of storages or depots with deterministic demand is available and each has a... 

Quality of Service (QoS) has recently become one of the most important challenges in data storage systems due to the growing use of data intensive applications in enterprise and mainstream systems. Flash-based Solid-State Drives (SSDs) are high-performance storage devices used in data storage systems to fulfill the performance demands of different applications using shared data storage system. Flash-based storage systems have limited endurance and poor write performance, resulting in quality of service issues such as unfairness. Different techniques such as I/O caching can be used to address QoS in storage systems but they adversely affect system endurance. To our knowledge, previous studies... 

Content delivery networks play a significant role in improving the quality of internet services by placing the necessary content closer to users on servers. Currently, over half of internet traffic is delivered through these networks to end users. The efficiency of a content delivery network depends on various parameters, including the type of requested content, workload distribution methods, network topology, routing algorithms, caching policies, network server configurations, and resource allocation (shared or dedicated hardware resources). Additionally, the requests made to a content delivery network vary based on the type of service and even the time of day, making optimization a... 

Transportation is an essential part of the economic growth in every country in the nowadays industrial era by making the possibility of good’s consuming, far from its origin. Delivery of a final product to the customer’s needs transportation of raw materials from suppliers to producers, transportation of semi-final products between companies, and, finally, delivery of the final product to customers and destination markets. Transportation costs include the majority of logistic expenses because of their abundance (between 30-60 percent). Traveling salesman problem and after that vehicle routing problem have been proposed about 70 years ago. In the last few decades, mathematical models, precise...