Sharif Digital Repository

In the present work, trajectory optimization of the Dual-Arm Cam-Lock robot considering kinematic and dynamic redundancy is performed. First, the optimal control problem is solved only considering kinematic redundancy and then is solved considering dynamic redundancy. General form of the dynamic model for the system is developed using Lagrangian relations. Global optimization method is used for redundancy resolution problem. A performance index is defined based on the consumed kinetic energy and is minimized through a desired trajectory using the global optimization method. Formulations of optimal control problem are derived and initial boundary problem is changed to two point boundary value... 

In cloud computing services, high availability is one of the most quality requirements that it is necessary to maintain customer confidence. This requires various fault tolerance mechanisms for coping with software and hardware failures.In this thesis, after reviewing previous research, eight different scenarios was designed for availability evaluation of redundant openstack private clouds, represented by RBDs and Markov chains, hierarchically assembled.Based on the availability and downtime results obtained from the scenarios and cost consideration of company, best architecture for openstack is implemented.For real world modeling, we tried to collect and analyze the hardware and... 

Data center performance is a function of three features; bandwidth, latency, and reliability. The issue of increasing bandwidth and reducing power consumption for scalability is one of the things that can be accessed with optical technology and it has been used in recent designs. However, the problem of fault tolerance and dealing with failures in optical interconnection networks have been raised less. Data center failures fall into two categories of links and switches. The design of these networks is mainly done at two levels: the hardware design and the design of routing methods. Also, some parts may be added to control and establish connections between the routing and network hardware... 

Nowadays, the use of redundancy components on chips is the best method for replacing defective components on chip. This method improves yield parameter and thus reduces the manufacturing cost of a chip. However, in most of yield improvement methods, redundancy is used when the main components of a chip are defective, which is called cold redundancy. In this project, the manufacturing cost and yield parameters of chips, when using hot redundancy in SIMT processors is investigated. In the case of occurring defect on the chip, the hot redundant components are used for improving yield. Otherwise, they are used in order to improve the performance of chip. In this project, we examine systems,... 

The design and planning of resilient supply chains is a major challenge due to the increasing complexity of these systems that operate in a global market and therefore are more exposed to disruptions. Present work aims to apply principle of resiliency in a supply chain by simulation. A case study of Shahab Company is used to illustrate the effect of redundancy and agility on its resiliency. We simulate the relationships of Shahab Company with its suppliers, and the suppliers with their sources and investigate the effects of disruptions in the model. Shahab Company has two main supplier and they own sources. To evaluate the designed model, two performance measures were defined, inventory and... 

The primary goal of this thesis is to develop a Fault Tolerant Control (FTC) system for a flexible satellite in presence of actuators fault and failure. The actuators of the satellite are including three magnetorquers and three reaction wheels on each principal axis. At first, the three-degree-of-freedom rotational motion of a rigid satellite with two flexible solar panels is modeled. The flexible panels are modeled through the assumed mode approach by a finite set of bending modal motion. The ordinary differential equations of their generalized coordinates are found using the Lagrange’s equation. Then, the dynamic model is validated by comparing the simulation results of the model to the NX... 

With the advent of the Industry 4.0 and advances in Information Technology, the manufacturing systems have experienced great evolution and transition in their production paradigms. Among these developments, we can refer to the globalization process of resources and a diversion from mass production to the production that is based on customized orders. Likewise, a movement from product-based manufacturing towards service-based production is taking place. Such changes expose supply networks to new opportunities and threats and encourage them to exploit advanced production systems. Cloud manufacturing, as an approach to fulfill the state-of-the-art opportunities, has been recently considered by...