Sharif Digital Repository

Masonry buildings are wide spread in Iran and some other countries . These buildings are highly vulnerable to seismic excitations if not constructed in accordance with engineering fundamentals . Thus it is necessary to retrofit these structures to flee from humanitarian and economical damages inflicted by earthquakes. One of the critical vulnerabilities of masonry buildings is due to transverse instability of it’s infills . Therefore to study out of plane behavior of these elements , an infilled frame is modeled and analyzed with ABAQUS , the results of which is in good congruence with the experimental one . In this model , stress distribution due to one way arching action in the confined... 

In nanometer technologies, the effect of process variation is observed in Multi-Processor System on Chip (MPSoC) in terms of variation in processors‟ frequency and leakage power. Traditionally, only worst case values of the system parameters were concerned and a worst-case optimization algorithm was employed for an application under design. As previous researches have shown these algorithms are not optimal in terms of parametric yield compared with newly employed statistical optimization algorithms. In this project, we have considered the problem of simultaneously selecting MPSoC architecture (which includes type and number of processors and the communication media) and task and... 

Process Variation is seen as statistical variations in leakage current and delay of transistors in nano-scale technologies. The amount of process variations increase as the size of transistors decrease by technology scaling such that those effects can be seen in frequency of MPSoC (Multi-Processor System-on-Chip) cores and their leakage power deviation. These variations cause the tasks duration and power consumption fluctuate in different processors in an MPSoC instance. Consequently, some chip instances of the same MPSoC may consume more time and power than their considered limitations. Hence considering the process variation is necessary and required for MPSoC optimization at different... 

Size and number of high-performance data centers are fast growing all over the world in recent years. The growth in the leakage power consumption of servers along with its exponential dependency on the ever increasing process variation in nanometer technologies have made it inevitable to move toward variation-aware power reduction strategies. In this thesis, we simultaneously apply thermal- and variation-aware server placement and chassis consolidation methods to reduce total power consumption of data centers. We introduce two server placement heuristics as well as an Integer Linear Programming (ILP)-based server placement method based on power consumption of each server and the data center... 

With the proliferation of Internet-based applications and malicious attacks, security has become one of the most influential aspects in the network and, it should be considered from the beginning steps of designing the network infrastructure. Based on the fact that pattern matching is considered as one of the most important roles of security devices or applications, it becomes an important procedure in firewalls that have been classified as security equipments which adopt a security mechanism in order to restrict the traffic exchanged between networks and particular users or certain applications. While the trend of using compressed traffic is drastically increasing, this type of traffic is... 

Mobile payment has already become an integral part of modern life for daily banking needs. Many payment systems are now providing financial services to customers. Most of these systems need and rely on online network access to provide their services. On the other hand, there are many regions in the world that have no network access or the network quality is poor with intermittent failures. Customers in these areas are unable to transfer money or buy goods and pay for it using their mobile devices by such above systems. This motivated us to find a way for transferring money without need for network availability. As a result we devised an offline peer-to peer mobile payment system (MobiPOS).... 

In the past few years, because of the high energy price in data centers, optimizing energy consumption has become of real importance. The disproportionate energy consumption of network devices to their utilization has led them to become one of the biggest consumers of energy inside data centers. On the other hand, the stochastic nature of network traffic among virtual machines has made the assumption of known or fixed communication volume superficial. In this research we considered a stochastic distribution of network traffic and communication volume among virtual machines trying to change the communication inside data center to communication inside hosts. Initially, we start by evaluating... 

Liquefaction has a profound effect on buildings, bridges, buried pipes and other engineering structures. This phenomenon can lead to the sliding of huge earth masses, submersion and bending of substantial structures, uplift of buried light structures and collapse of retaining walls. In recorded earthquakes, liquefaction has caused major damage to structures and deep foundations, proving that pile foundations are not designed to withstand at liquefaction condition. Considerable damages in pile foundations due to liquefaction in destructive earthquakes has called for extensive study and research concerning the behavior and response of piles under the influence of liquefaction, resulting in... 

Recently, The Earth has become warm rapidly over the past few years. This global warming is not only caused by natural phenomena, and further increased by humans and the amount of greenhouse gases in the atmosphere. Around 40 to 50 percent of energy consumption is related to information technology and communications. However, the rapid growth of electricity consumption in data centers, in addition to increased costs, data center challenges faced serious environmental pollution and more greenhouse gases. Use of renewable energy and reducing electricity costs in data centers are the important subjects for researchers around the world. Many researchers provide solutions to reduce environmental... 

Cloud computing is a way to increase capacity or add capabilities dynamically without investing in new infrastructure. The purpose of this project is the use of specialized algorithms for efficient energy management for cloud computing environments.One of the issues that is very important with respect to cloud computing is considering lifetime of servers or physical machines. Servers are some of the most important and critical elements of cloud computing. Server costseffect on the costs of the entire cloud computing system and the interference of serverseffects on entire system. Lifetime of each sever is dependent on a few factors, the most important of which is the number of switching... 

In this study, ternary metal oxide coating consisting of Ti, Ru, Ir were prepared by sol-gel method. In order to achieve optimal conditions, the effect of number of layers, temperature and velocity of the heat treatment, the amount of ruthenium and iridium, polymeric additive on the coating and also, comparisons of binary and ternary oxide coatings were studied. The corrosion behavior was examined by anodic polarization and cyclic voltammetry tests and accelerated stability test (AST), the morphology of coatings was studied by field emission scanning electron microscopy (FESEM), phase and elemental analysis was performed using X-ray diffraction (XRD) and energy dispersive spectroscopy... 

The ever increasing density and performance of FPGAs, has increased the importance and popularity of soft processors. One major research concern in this regard lays in the field of energy efficiency of the system on FPGA. This work is particularly focused on the energy efficiency of multiprocessor structures on FPGA using system level techniques. The growing gap between the speed of processors and memories can partly be compensated through memory hierarchy, i.e. caches. Since memory accesses follow a non-uniform distribution, and vary from one application to another, variable set-associative cache architectures have emerged. In this thesis, two novel cache architecture, primarily aimed at... 

Using accelerators inside high speed servers can reduce execution time of applications and total power usage of the system. Sharing accelerator between virtual machines of a server decrease both cost and power, however it won’t provide the gained speedup of using dedicated accelerator for each virtual machines. Creation of an appropriate set of accelerators required for virtual machines, management of accesses to the accelerator, prioritizing and scheduling of requests and reconfiguration type of accelerator are the most important challenges that this project has been dealt with. The main objective of this project is implementing the necessary infrastructure to share an FPGA-based... 

The fastest growing of data in the fields of economic, cultural and scientific quick analysis of this data is one of the needs of users. The inability of the traditional programming model for processing large data makes MapReduce programming model to be introduced. MapReduce model, processing big data in shorter time available. Users to analyze large data processing, rent necessary resources from infrastructure of cloud as one of the most popular are provided. Due to cloud resources acquired and run-time program on selected configurations, the cost of these resources are paid according to their use. So if resources are not proportionate with the needs of the program will be wasting money and... 

Today, we have witnessed many changes in computer science. Rapid and exponential growth of data volumes, increasing a variety of data structures and forms, increasing data generation ratio are some important revolutions in our digital world. Because of these changes, our traditional computing models and processing methods cannot solve new big and sophisticate problems. Big data concepts and big data processing methods come to help us for solving these problems. A lot of parallel and distributed processing platforms built for the applications execution on a huge volume of data. Apache spark and Hadoop are two powerful platforms that each has some advantage and disadvantage. With growth...