Sharif Digital Repository

Supply chain management aims to increase customer satisfaction and satisfy demand with the lowest cost by establishing coordination and cooperation among the chain members. However, considerable concerns along supply chain management are reported from both academicians and practitioners. Security, visibility, transparency and traceability are the main challenges confronting supply chain management. The emerging technology named Blockchain is able to address the mentioned challenges by integrating with supply chain management. A prominent point to consider is that whether it is absolutely necessary to adopt blockchain technology in a system or not. If yes, how blockchain should be implemented... 

Effect of discontinuities on shear behavior and shear strength of rock masses are very important. Infill materials found in natural rock discontinuities may cause a reduction in joint shear strength, influencing rock mass stability. Many researches have been done in the field of behavior of infilled and unfilled discontinuities. The models and relationships developed through such studies will be of immense help to mining and civil engineering projects in rock masses. Rough surfaces in rock masses are found in rock joints. In general this research includes studies on the effect of joint surface mechanical and geometrical characteristics, asperity orientation and infill materials mechanical... 

Security is an important issue in Vehicular Ad Hoc Networks (VANETs),which are mainly aimed at enhancing safety. Analysis of security mechanisms can help design and implement secure communication establishment methods in such networks. Formal verification is an analysis approach, with the purpose of proving the correctness of a system based on defined precise assumptions. Formal verification is applicable to a vast range of systems, such as time-critical reactive systems. Timed formal verification of cryptographic protocols is a subject that has gained a lot of attention in the recent two decades. The TESLA broadcast authentication protocol is on one hand an efficient, standardized method... 

In most places in the world as it is in our country, structural vibration caused by earthquakes are among the most destructive menaces for the building. For this reason one of the main goals for civil engineers is constructing structures that can perform properly in an earthquake-exposed situation. For moving toward this goal it is necessary to estimate structural responses considering probable earthquake excitation and use these data for design of new structures or retrofitting of existing ones. In this research, the capability of a new method named Endurance Time analysis in seismic assessment of concrete moment frame is investigated in nonlinear range. ET is a new dynamic time history... 

Different reasons, all structures have inside crack or surface crack when crack growth is more at the frequancy load and it is one of the main factor in the diagnosis of structural life that this sensitivity is much greater aerial parts industry. The aim of this project, designing a new structure for the auxiliary engine compartment of the aircraft with the damage tolerance theory for cargo aircraft within the country are making. In the first stage after reviewing activitation past, the evaluation design rules between each company design its obligations, standards in design and then conceptual plan to make. Then reload force plan to make. At this stage with regard to maneuver the airplane... 

Preventing critical damages to structures and hence saving the lives and money is an inevitable work which a designer has to do. During the earthquake, huge amount of energy applies to the structure and finding a way to reduce transfer of this energy to main structure is crucial. For this purpose, Structural Control systems may be used. Metallic Dampers are one of those systems which absorb the earthquake input energy by having nonlinear deformations. In this Thesis, one type of this dampers which is innovated by Estekanchi, have been studied .Indeed, this damper is a connection between bracing and main frame. In this damper a U shape part acts as a sacrificing portion and absorbs energy by... 

The purpose of this study is to evaluate the performance and seismic costs for pre-designed bridges according to the Iranian Bridge Code, which maps and details are available in Code 294. In order to evaluate performance, seismic costs of a structures are determined over its life cycle and these costs are compared eventually. Seismic costs are divided into two parts of the initial cost and life cycle cost of the structure. The initial costs depend on the cost of constructing the bridge, but life cycle costs are depends on seismic damage for structure and its users over the useful life of the bridge. These damages include the cost of maintenance of the bridge over its useful life and the... 

Elevated concrete tanks have a wide range of applications in storing drinking water, firefighting, sewage, oil, toxic chemicals, and similar fluids. Therefore, due to their usage, these tanks are usually placed in the category of very important structures and vital arteries. Consequently, their design against seismic loads and their proper performance during earthquakes are of great importance. The endeavor time Analysis is a seismic analysis method in which the structure is subjected to an increasing dynamic excitation whose intensity gradually increases over time. The structure's response over time is examined, and based on the corresponding response to various levels of excitation... 

In this thesis, the effect of cognition in wireless networks is studied. In a wireless communica-tion network, cognition is the ability of a device to sense the transmissions of neighboring nodes and adapt its own transmission to the sensed environment. Cognitive radios are very attractive be-cause of the increasing need for more efficient use of frequency spectrum. The goal of this thesis is the analysis of cognitive radio networks from an information theoretic perspective and to this end statistical models of the wireless medium with a limited and tractable number of devices are uti-lized. We consider three different models in three parts of the thesis. First, we consider a new... 

The use of Radio Frequency Identification is increasing rapidly. The reason is the capability to transfer data wirelessly without line-of-sight necessity, high data rate and long read range. The main advantage of barcode is its lower cost which has ensured its existence for many years. The applications and materials that are identified by RFID increase as the price of RFID tags decrease. This Project deals with the front-end of an Integrated RFID Reader for the UHF band. The bottleneck of the design is the presence of a large interferer just hundreds of kilohertz apart from the desired signal which is at about 900 MHz. The key idea of the design is utilizing feedback in order to cancel... 

This thesis investigates the dynamic response of a viscoelastic plate resting on a viscoelastic Winkler foundation subjected to the excitation of a moving mass. Through application of the Laplace transform, the governing equation of the problem is derived for a general viscoelastic material. Thereafter, an analytical-numerical method is proposed in order to determine the dynamic response of the viscoelastic plate. The method is based on transforming the governing partial differential equation into a new solvable system of linear ordinary differential equations. To that extent, the proposed solution proves to be applicable to plates made of any viscoelastic material and with various boundary...