Sharif Digital Repository

Astransportation networksbecome larger and more congested, designers are seeking more precise, efficient and general algorithms that could use large memoryand powerfulCPUs efficiently. In thisthesis we evaluate Bar-Gera and Dial’sorigin-based algorithms thatsolvethe traffic assignment problem based on the user-equilibrium principal and compare them withthe path-based complementarity algorithm which has been improved in this study. Dial’s algorithm has been implemented in C++ programming language but for Bar-Gera’s algorithm we have usedan executable code that was implemented by him.Networks that have been used in this study are a small hypothetical network, Sioux Falls network, generated... 

Endurance Time Method (ET) is a dynamic analysis in which structures are subjected to intensifying accelerograms and performance of them are assessed based on their response at different excitation levels. Duration consistency of current ET accelerograms has not been directly considered. Strong motion duration can strongly influence the response of structures and foundations especially when they encounter degrading characteristics in their materials. In this study, duration related properties of ET accelerograms and ground motions are compared. These properties consist of strong motion duration, cycles number of motion and number of nonlinear cycles which a structure should sustain when it... 

The Energy Dissipating Restraint (EDR) is a friction device which can be used to dissipate the energy introduced to a structure by a seismic event.A special characteristic of this device is that it is self-centering, which makes it preeminent among other friction dampers. As a result of high nonlinearity associated with the behavior of the EDR, the analysis and performance assessment of the structures which are outfitted with EDR entail quite a few nonlinear time-history analyses. Regarding the substantial computational cost of this method, the existing provisions have authorized the use of more economical alternative methods for the analysis of the structures whose motions are controlled... 

Financial losses and casualties due to the collapse of the masonry facade and the infill walls of the building in recent earthquakes were motivators of this research to study seismic performance assessment of masonry facade. One of the main reasons for the collapse of buildings facade is their inadequate connection to the infill walls and structure frame. The mentioned item caused when earthquakes such as Kermanshah earthquake occurred, although a large number of buildings remained undamaged in terms of their structural, facades of these buildings collapsed. The details of the masonry facade, such as the metal wires mentioned in the codes, are not usually applied in Iran, and the connection... 

The ultimate objective of this project is to evaluate and present various signal processing tools, including wavelet transform, for application in the analysis of structures using the endurance time method. Currently, in the endurance time method, only the maximum displacement values of structures over time are utilized. However, the output signals from this method contain additional information about the dynamic properties of the structure. In recent years, there has been increasing interest in using signal processing methods to detect damage and monitor the health of structures, aiming to enhance their safety and reliability. One of the primary goals of these methods, particularly in... 

Using viscous dampers is one of the common techniques in the technical literature for seismic strengthening and rehabilitation of existing structures. The key step in dampers design is the distribution of damping coefficients along the height of the structure. For the distribution of damping coefficients along the height of the structure, no standard’s method has been proposed. Today, many researches have been done to introduce optimized pattern for distribution of damping coefficients by using optimization algorithms and iterative nonlinear dynamic analysis. However, the use of these methods is not common among designers and engineering offices due to the need for high expertise and high... 

The existing statistical studies implies that in Iran like most of developing countries, the great percent of houses are traditional. Statistics of the most disastrous current quakes also show damages caused by masonry structures in developing countries. The main problem of brick and masonry structures especially the unreinforced one is their weak performance against quake. Different methods are use to analyse the seismic performance of this structures. The modern endurance time method is a kind of time history analysis using standard increasing accelerograms which examines different parameters of structure behavior during excitation actions. In this project we analyse these structures using... 

In new method of performance-based design, the behavior of structure during earthquake is considered more realistically, and applying damage parameters like plastic ductility and inter-story drift to determine the seismic performance of structures is suggested. Damage indexes, the contribution of damage parameters to damage capacity of structural members, are defined to specify damage level of each element. In addition, damage spectrum which is the diagram of values of certain damage index versus natural period of single-degree-of-freedom system will be useful to seismic assessment of existing structures and seismic design of new ones. By the way, endurance time (ET) method can be... 

The sustainability of urban infrastructure is assessed in three integral economic, social, and environmental dimensions. This study focuses on advancing a design approach based on value through the optimization of the life-cycle cost of steel moment frames, considering sustainability indicators by utilizing endurance time method analysis.In this path, the dimensional specifications of steel frame sections are selected optimally using an automated process with the objective of minimizing the cost of the structure's life cycle as the objective function and code specifications as optimization constraints. The cost of the life cycle, includes material extraction and production, transportation,... 

Dominance over the seismic behavior of structures leads to proper design and the cost reduction of structures according to the structures demand performance. In this regard, the issue of performance-based seismic design of structures has been proposed in which the nonlinear behavior of structures is the basis for the design and evaluation of structures during earthquakes. Moreover, regarding of soil under the structures will change the elastic and inelastic behavior of structures; also, the effects of soil-structure interaction on the seismic performance of structures should be considered to achieve the real behavior of structures. Hence, the purpose of this study is to evaluate the... 

Endurance Time (ET) method is a dynamic analysis in which structures are subjected to intensifying acceleration time histories. These excitations are also called Endurance Time Excitation Functions (ETEF). The reliability and accuracy of the ET method heavily depends on the accuracy of ETEFs. ETEFs are generated so that ETEFs dynamic characteristics must be consistent with dynamic characteristics of real ground motions. Since the number of ETEFs equations are considerably more than variables noninear optimization is used to generate ETEFs. In order to improve the accuracy of ETEFs two approaches can be used. First, modifying the objective function equations by considering more dynamic... 

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... 

Performance-based seismic design method, with a new look and a totally different philosophy, as an alternative design method instead of strength-based design method has been suggested in the new generation of seismic codes. Massive problems such as the need for complex dynamic analysis and consequently, spending high cost and time in researches forced researchers to seek more effective methods to evaluate seismic performance of structures. This idea in the optimal design of structures that require repeated analysis seems to be more effective. In the Endurance Time (ET) method, structures are subjected to specially designed intensifying acceleration functions and their response at various... 

Different structural systems have been declared and used in recent decades. To identify more about their performance, it's crucial that while evaluating their characteristic, the effect of miscellaneous natural phenomena would be evaluated. One of these phenomena is SSI or Soil effect actively on the structure performance. As modeling has serious effect on the results precision related with SSI effect, usage of 3D Models those that are more compatible with the real ones is important. So, in this research two 2 and 5 story building possessing real dimension in the format of 3D-Modeling with all effective details were modeled by finite element method. For seismic analysis, 7 couple records... 

In this research, probability distribution of structural demand is estimated using a simplified dynamic analysis which is named Endurance Time method. In this method, the structure is subjected to nonlinear dynamic time history analysis, which its acceleration increases in time. It can be extracted the median of structural demand for earthquakes with different return periods. In customary researches, this estimation is performed using Incremental Dynamic Analysis knowns as IDA. The significant computational effort of IDA is the dominant obstacle that researchers and engineers encounter with. The main advantage of Endurance Time method is the fast estimation of structural demands by reducing... 

In recent decades, the soil-structure effect has been considered in seismic studies. Most of these researches are based on the premise that the foundation is bonded to the ground. However, several examples of structures that experienced uplift have been reported. Uplift affects the soil-structure contribution and nonlinear behavior of the structure. It seems that a parametric study should be done for the simultaneous effects of the soil-structure interaction, foundation uplift and inelastic behavior of the superstructure. Although the most accurate methods to estimate the behavior of structures is the nonlinear time history analysis, this analysis is very time consuming. The endurance time... 

One of the main challenges in the design of wireless sensor networks (WSNs) is minimizing the energy consumption while simultaneously maximizing the performance of sensors. In this thesis, we have considered WSNs based on beacon enabled IEEE 802.15.4/Zigbee Standards with low rate applications like temperature, humidity and light sensing, which mainly have been used in a smart home environment, and proposed a cross-layer design to overcome this challenge. The design involves an optimizer module that captures the application layer and MAC sub layer behaviors. Based on these behaviors, the optimizer dynamically changes the rate of node’s traffic at the application layer and the priority of... 

We present a home energy management system that is able to manage home energy demand and resources to achieve minimum household payment in electricity dynamic pricing.Communication is used to collect needed data from the home energy system members and users in order toimprove demand and resources management. Some of the needed data comes from appliances and solar panels by wireless sensor network and some other is received from home users by a user interface.
Two algorithms are proposed that the first algorithm goal is to minimizing household payment and the second algorithm goals are flexible implementiation and decreasing household payment. To decrease household payment, these... 

Today, smart devices have become an integral part of everyday life. The Android operating system is also the most popular operating system of these devices, and as a result, various malwares are produced and distributed for this operating system every day. This makes it especially important to investigate these malwares. This includes finding people involved in the development and distribution of malware, as well as discovering other malwares created by them. Discovering other involved entities, such as social media accounts, websites, Android store accounts, and taking steps to prevent malware from being distributed by them is another aspect of this story. In order to deal with organized...