Sharif Digital Repository

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,... 

Recent studies show that the code-compliant structures have faced a lot of damages in earthquakes, and their performance could improve. The structure should have the least initial cost in this approach, which observes all of the code's limits regardless of the structure's life cycle cost. In recent years, value-based design has been considered as an alternative for code-based design procedures. In this method, some other parameters are considered as well as the initial cost of the structure, including risk, resiliency, reliability, and sustainability. In this paper, the structures' total cost is studied by Fema P-58, while it is equipped with viscous dampers. The structures are 4, 8, and 12... 

In recent decades, large economic losses and social impacts following earthquakes and hurricanes have revealed the need for improved design criteria intended to reduce consequences including economic impacts to an acceptable level along with life protection. So, it is tried to express the expected performance of structures as financial and social criteria. Any assessment on earthquake consequences requires estimations of structural responses to seismic excitations. Endurance Time (ET) method as a dynamic procedure requiring reasonably reduced computational effort compared to other common time-history based procedures, is used to estimate the response of the structure in all levels of hazard... 

The main purpose of this research is to evaluate the impact of mainshock and aftershocks on the response and fragility of power transmission towers and to provide an approach to assess the risk of transmission lines under mainshock-aftershock sequence. The transmission line studied in this research has 27 self-supported 400 kV transmission towers. The reason for choosing this line is the proximity of the line to the active faults of Tehran like Mosha and North-Tehran, as well as the service of the line to a large residential and industrial area, which, in case of damage by an earthquake, will cause considerable direct and indirect loss to the society. In the three-dimensional models... 

The growing amounts of generation of electronic wastes (e-waste) and their increasing environmental impacts require a special optimal waste management strategy. Many different methods have been developed to managing e-waste. To make the best choices according to the conditions of each system, having an adequate knowledge of all methods and comparing them is the most important point. This research aims to design a system for managing e-waste by selecting mobile phones as an example of electronic waste and find the optimal condition of the system to increase economic benefits and reduce environmental impact. Recycling and landfill are selected as the main methods in this project. Four lines... 

Rail transport system plays an important role in the development of the economies of the countries. This system is worn out over time by operating and weather conditions and requires maintenance and repair. One of the objectives of maintenance operations is to maintain tracks in an acceptable level and prevent their excessive deviation from the optimal situation. This deviation is called geometric irregular deviation. If these irregularities go away, they can cause traffic accidents and derailment in addition to losing travel convenience. So avoiding the deviation of the tracks is a very important. Maintenance management systems in the past few decades have been considered by the experts in... 

Every year, a lot of costs are incurred to dairy production sets for new product production or product improvement.cosidering to the high amount spent on this sector so if there is not any cost management and cost planning based on life cycle of projects , costs will increase .As a result today considering of life cycle in cost management is a Essential principle . In this study we consider kalleh dairy company as a case study and resuls of this study will be a complete economic model for cost management based on the life cycle of dairy projects  

Tehran is the most populated area in Iran and is one of the most densely populated cities in the world where almost 40 percent of all days have been classified as unhealthy for sensitive groups. According to emission inventory of Tehran over than 85 percent of emission are due to different types of vehicles. And light duty vehicles share more than 80 percent all vehicles and are responsible for most of carbon monoxide and nitrogen oxides emitted in Tehran atmosphere. In this study real emission factor of Hybrid Synergy vehicles which just have been introduced to Tehran fleet were tested under real conditions of streets. Data produced in this research have been combined with previous... 

The aim of this research is value based optimum design of structures to minimize the costs imposing on them during lifetime. For this purpose, an optimization procedure is used to get optimum solutions. Therefore, in this optimization problem, total costs are objective functions and required limits of codes are as the constraints. The costs include initial costs of constructing and life cycle costs. The weight of structural components and seismic consequences during the lifetime of structure are used as a criterion to assess initial costs and life cycle costs, respectively. In this research, seismic losses are determined based on the probabilistic seismic assessment framework, which depends... 

The aim of this study is to develop the value-based design approach using the endurance time method as a comprehensive and efficient framework in optimal seismic design of structures. Optimal resource allocation is an interesting and important subject in the seismic design of structures from the theoretical and practical viewpoint. Finding optimal solutions requires the use of a trial and error process that is accompanied by repetitive structural performance evaluation. The seismic design process will be efficient when it provides a comprehensive and reliable estimation of the earthquake effects and be cost-efficient in terms of computational demand. In this regard, the value-based design... 

Preserving and promoting the health of citizens in a society is one of the most important problems addressed in any country. The power sector discharges a huge volume of carbon dioxide which intensifies the climate change and consequent human health problems.The goal of this study is to evaluate the ultimate effect of climate change caused by power plant emissions on the human health using life cycle analysis approach for different provinces in Iran. An integrated model has been developed to evaluate the impact of climate change due to power plant emissions on the human health. This model includes the equations regarding the variations in carbon dioxide concentration in the atmosphere,... 

Industrial centrifuge fans operate in various industries, specifically heavy industries such as pelletizing plants, steel mills, and cement plants. These fans transfer process gas in the production cycle. In some cases, due to their off-design working conditions, asymmetrical wear and failure happen on one side of the impeller's blades more than the other side. The most important reason is the heterogeneity of the entrance fluid's properties. One of the many critical parameters in this issue is the asymmetric distribution of particles between the two entrances of the fan. This research investigates the asymmetric erosion problem of a specific centrifugal fan with a double-suction side... 

A set of infected computers which are coordinated in some manner by one’s willingness and can perform malicious activities and provide threats in the cyberspace forms a network of bots, namely botnet. Botnet threats are more important and significant than other malwares due to their huge scale. A lot of computers coming together in a network obeying one’s commands allows their controller to conduct, for example, DoS attacks larger than ever seen incidents. This thesis, introduces botnets, their various threats, and an effective technique for detecting them. For this reason, different probable states of bots will be studied and modeled as a coherent bot life-cycle. The bot life-cycle allows... 

The actual value of structures should not be evaluated only based on initial cost, because failure cost and economical losses due to corrosion and natural hazards can be catastrophic. The aim of this research is Comparative study of life cycle cost of steel and concrete building systems designed based on standard 2800 by Endurance Time Method. These costs include initial cost and life cycle cost Due to the aftermath of the earthquake in the life of the structure. In this research, because it requires a lot nonlinear dynamic time history analysis, Endurance Time Method used which is both good accuracy and also drastically reduces the cost of computing-off. Selected models for the study, four,... 

Construction is a vast industry. It is one of the vital and important industries in each country because of high financial turn over, creating many job opportunities and developments. Development has always been a great challenge to the environment due to using much of natural materials and resources. Studies show that construction projects produce the highest amount of waste among other industries. By continuing current situation and increasing rate of production of construction waste, nations and human beings will face a lot of problems in the future. Recently, an increasing attention has been focused worldwide to limit using natural resources in order to conserve the... 

The aim of this research is the utilization of seismic life cycle cost estimation procedures and their implementation in optimal structural design. The costs include initial costs of constructing and life cycle costs. The weight of structural components and seismic consequences during the lifetime of structure are used as a criterion to assess initial costs and life cycle costs, respectively. In this research, seismic losses are determined based on ATC13, FEMA-P58 and FEMA-NIBS frameworks. Also, according to the high computational time of required dynamic analyses, the Endurance Time method is used which decreases the computational time simultaneously the dynamic predicted responses are... 

The objective of this study is to design a real structure based on value using the endurance time method, which is designed according to common design codes. In the value-based design of this structure, a variation of the lateral load coefficient has been used for the design of the investigated structural specimens. The term "value" in this research refers to the total costs incurred over the lifespan of the structure. The initial construction costs of the structure and the life cycle costs are optimized in the value-based design process. The initial construction cost in this research consists of two parts: the first part is variable costs that arise from the consumed materials in the... 

The objective of this research is to evaluate the concept of a new design methodology based on the total value of the structure namely Value Based Design of structures (VBD) by the use of potential benefits of the ET method. While prescriptive and also performance based approaches of seismic design commonly try to find a structure with lower initial cost satisfying a number of requirements under seismic actions, a new design approach to incorporate directly the concept of value in design procedure have been formulated here to achieve an economical design with lower total cost in its life time. In this method the design sections of structural elements are considered as optimization parameters... 

In the present thesis, A Computer software has been developed to evaluate technical and economic aspects of photovoltaic systems, off-grid and on-grid configuration, in urban areas where the electricity grid is accessible. As a case study the building of Energy Engineering faculty with annual demand of electricity in lighting section equals to 80048 kWh was considered. Regarding incident radiation and PV system characteristics with the aid of utilizability concept, a technical evaluation has been performed then life-cycle saving index was considered as a criterion for choosing an optimum nominal size of the system. Results show that for current electricity tariff of educational buildings ... 

The construction industry is one of the important and driving sectors of every country's economy, and construction projects are one of the economic development factors of countries. These plans lead to economic growth and development through the mobility they create in public and private capital. Every year, a significant share of the government budget is spent on the implementation of public construction projects. Due to the key role of public construction projects in the development of the country on the one hand and spending huge national funds on the other hand, it is important to pay attention to their efficiency and productivity. Excess costs of public construction projects and delays...