Sharif Digital Repository

In distributed systems, a huge amount of data is dispersed among different nodes; centralization of this data is infeasible due to communication and storage costs. In addition, Databases with high dimensional data objects are becoming more prevalent is many areas. When the dimensionality increases, the volume of the space increases so fast that the available data becomes sparse. This sparsity is problematic from many aspects. In order to obtain a statistically sound and reliable result, the amount of data needed to support the result often grows exponentially with the dimensionality. Also organizing and searching data often relies on detecting areas where objects form groups with similar... 

Today, public-private-partnership (PPP) contracts are attracting attention of both public and private sectors. In these contracts public sector benefits from private sector’s money to overcome its budget limitations. It speeds up pace of the country’s development and brings value to the society. Plus, private sector gets new job during the construction phase and enjoys the benefit of its investment during the operation phase.
In Iran, PPP contracts have been used during last years. Many infrastructure projects in transportation, power, and lately in water sectors have been constructed using PPP delivery method. Despite many successful experiences in the past, there are still problems in... 

Infrastructure projects have an important role in the economic growth and development of countries. Sustainability approach takes into account environmental and social aspects of a project besides its economical development. In order to achieve sustainable development, executing a plan including different subsystems and influential aspects of sustainability is required. There is an increasing need for sustainability evaluation systems for infrastructure projects. This research emphasizes on sustainability evaluation of seaport infrastructure projects in Iran.
In this research, key factors for sustainability assessment in tourism and recreation seaport infrastructure projects were... 

Limited water resources in Iran have made dams an important part of the country’s infrastructure. As a result of the large number of in-progress and expected dam projects in the country, consideration of sustainability factors during planning, construction and operation phases of dam projects can create significant economical, social and environmental impacts in the long term. To come up with an inclusive sustainable development, new sustainability assessment approaches seek for sustainable development at the entire project’s life-cycle; they are looking for sustainable development at all design, construction, operation, maintenance and even demolition phases. In this research we have... 

For increasing longevity of a structure, it is not enough to notice only to designing aspects. In operation phase of a construction, we can increase the level of service and longevity. Asset-based Organizations, in addition to design their new assets, should maintain them. Infrastructures, such as road, bridge, dam, and water network, are important because of social and economic aspects. So they need special attention. There are efficient models for infrastructure maintenance that consider infrastructure element information, such as condition rate, weight, dimensions, deterioration rate, and cost of maintenance as inputs and give planning for maintenance in future. This planning, involves a... 

This dissertation proposes a new platform and a new software for evaluation of urban Water Distribution Network (WDN) resilience. Resilience is considerd as the ability of an infrastructure to come back to steady state after being affected by any environmental or man-made disturbance. WDN, as an essential infrastructure, has major role on resilience and sustainability of cities and communities. Today, uninterrupted performance of WDN is a basic need of people who live in cities. This uninterrupted performance becomes bolder in face of man-made or natural disasters like earthquake. The uninterrupted performance of a system is dependent on the system’s resilience. Majority of researchers... 

The increasing dependence of urban communities on infrastructure highlights the importance of resilience in the event of natural disasters, including earthquakes. Every society is made up of various infrastructures such as water supply, electricity, transportation, hospitals and so on.Every infrastructure to serve the community depends directly or indirectly on the electricity infrastructure.The power supply infrastructure consists of three main systems of electricity generation, transmission and distribution. Power substations, as nodes of the transmission and distribution network, are considered to be very vital nodes that it is important to maintain their serviceability after severe... 

The fundamental objective of this study is to present seismic hazard, risk and resilience assessment of a virtual city using sampling and agent-based simulation in two levels of refinement. In this context, hazard is the exceedance probability of ground shaking intensity, risk is exceedance probability of measures such as loss, and resilience is the ability to quickly recover after a hazard event. This study utilizes the Rtx risk and resilience assessment framework established at the Center for Infrastructure Sustainability and Resilience Research (INSURER) at Sharif University of Technology. This framework employs multiple interacting probabilistic models to quantify the risk and... 

This research proposes a probabilistic framework for decision support in emergency response. Currently, decision-making is traditionally based on data from reconnaissance teams, while there are other information sources that assist decision-making. These sources of information include social sensors, physical sensors, aerial imaging, and crowdsourcing. The information obtained from these sources is heterogeneous and uncertain, requires a probabilistic data fusion framework to be used in decision making. This research employs Bayesian Networks for this purpose. The outstanding feature of the Bayesian Network is its real-time nature, which set apart it from other methods. This feature makes... 

This research develops a probabilistic framework for evaluating community resilience subject to earthquake events by modeling the water distribution system and its prevailing inter- and intra-dependencies with other infrastructure systems of the community. This framework is entitled “Rtx,” which is under continuous development at the Center for Infrastructure Sustainability and Resilience Research (INSURER) at Sharif University of Technology, Tehran, Iran. It quantifies the community resilience by integrating hazard models, risk models, and recovery models within an agent-based simulation. Comprehensive modeling of the water distribution system requires a library of probabilistic models,... 

This thesis presents the seismic hazard and seismic risk analysis of the City of Golpayegan using reliability methods and multiple interacting probabilistic models. These models evaluate the seismic hazard intensity by simulating the hazard event and evaluate the seismic risk by simulating the building portfolio and infrastructure systems under the hazard event and quantifying the ensuing consequences. In this context, hazard is the exceedance probability of a ground shaking intensity measure, and risk is the exceedance probability of social and economic losses. This is the first time in the literature that reliability methods are applied in evaluating the seismic risk of a real-world city... 

What is the effect of access to paved roads on farmland rental rates? To answer this question, I estimate the impact of the increase in the share of people in counties that access asphalt roads on irrigated farmland rental rents between 2006 and 2011 in Iran. For this analysis, I construct a county-level panel dataset by combining 2006 and 2011 Iranian census and agricultural data on cropland as well as farmland rental rates and exploit a fixed effects approach. I show that the availability of rural asphalt roads, rural sanded roads, and railroad stations increased irrigated farmland rental rates by 3.4 percent, 4.0 percent, and 1.6 percent, respectively. I also show that the effect of... 

The provision of developmental infrastructure by governments and their various effects on the lives of citizens has always been the subject of discussion among researchers and policymakers. In particular, the infrastructure associated with access to modern energies causes changes in household economic behavior. The effects of pipeline gas connection on household behavior is the main subject of this research. By using micro level data, these effects compare the behavior of beneficiary households and lack of natural gas. The data includes households living in the entire geographical zone of Iran and between 1377 and 1394. First, we show that natural gas is a direct substitute for liquid fuels... 

In this study, reform strategies to enhance private sector participation in infrastructure projects is provided. The study is presented in the form of words that government institutions could use in the highest level. the pattern used for this study is based on system thinking in which all components are in causal relationship with each other. It was made effort to policies and upstream objectives of the country be respected. To provide research content, content analysis of successful experiences in the world was done. Finally, obtained strategies was presented to the experts, reformed and important cases was investigated. Lack of information and difficult access to country's infrastructure... 

Damming projects always have been important while construction, operation and even demolition due to their major effects on society, environment and economy. Although researchers have focused on one or a few phases of construction projects to develop sustainable infrastructures, the research community has to consider long term effects of developments too. There are a variety of such effects that ignoring them will cause construction of not convenient infrastructures i.e. air pollution and over-consumption of energy resources while construction, operation and demolition. Therefore, it is suggested to consider life cycle assessments to include all bad effects in all phases of a project. Dams... 

This thesis proposes a probabilistic modeling framework for networked infrastructure systems in community resilience analysis. In particular, the framework is presented for the electric power infrastructure. Models are proposed at two levels of refinement. The basic model only determines the connectivity of different elements in the network, whereas the refined model also quantifies the amount of the power transmitted through the network elements. In a community resilience analysis, the proposed basic model provides a rather simple tool to determine those buildings and infrastructure systems that suffer from power outage when the supplying power station loses connectivity with the network.... 

This thesis extends a probabilistic framework for evaluating the seismic resilience of communities by probabilistic modeling of the telecommunication infrastructure failure and recovery along with its interdependencies with other infrastructures. This framework, Rtx, that is being extended under continuous development at Sharif University of Technology, is based on modeling the community state from hazard incident until complete recovery by a combination of risk and agent-based simulation models. In this thesis the framework is extended with telecommunication infrastructure models. This infrastructure is modeled by developing a library of probabilistic models to predict damage to network... 

Estimation of indirect economic losses due to natural disasters, especially earthquakes, is one of the essential issues in disaster management. This study presents a framework that uses an economic model of the community under study and calculates the indirect economic losses caused by an earthquake. To this end, first, the earthquake-induced direct economic losses are quantified using appropriate risk analysis models. The direct losses are used to characterize the consequent shock to labor and capital. These shocks are then used as inputs to the regional economic model. In the proposed framework, a Computable General Equilibrium (CGE) model uses various data about the state of the community... 

The present survey study aims at investigating and comparing risk indices in highway and freeway projects implemented through Build-Operate-Transfer (BOT) and Design-Bid-Build (DBB) delivery methods. In this regard, two distinct questionnaires were developed (one for BOT and one for DBB delivery method) and interviews were conducted, too. The questionnaires were, then, sent to the target population, i.e. all the experts and agents involved in highway and freeway construction projects implemented through either BOT or DBB method. The collected data were then submitted to Statistical Package for Social Sciences (SPSS), version 22.00, to be analyzed. The results showed that risks had generally... 

This thesis proposes a probabilistic framework to increase situational awareness about serviceability of infrastructure systems, and extend and distribution of losses in the posthazard state of communities. Maintaining situational awareness is the first and foremost step in prioritizing search and rescue operations and organizing resources. This is a challenging task due to the uncertainties that exist in infrastructure systems’ performance after occurrence of a hazardous event. These uncertainties gradually diminish as further information is received. Therefore, a probabilistic framework is the necessary element for disaster management. This framework must be able to update initial beliefs...