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Application of endurance time method in seismic analysis of bridges
, Article Scientia Iranica ; Volume 27, Issue 4A , 2021 , Pages 1751-1761 ; 10263098 (ISSN) ; Estekanchi, H. E ; Vafai, A ; Sharif University of Technology
Sharif University of Technology
2021
Abstract
In this paper, the application of Endurance Time (ET) method to the seismic analysis of bridges is elaborated. ET method is a novel seismic analysis method based on time history analysis in which a structure is subjected to a predefined intensifying acceleration function. First, six concrete bridges were modeled in this study. Three Endurance Time Acceleration Functions (ETAFs) were applied to the models, and the average of responses was calculated. Next, the time history analysis was conducted using seven real accelerograms that are scaled using the method recommended by Federal Highway Administration (FHWA) to be compatible with the design spectrum of American Association of State Highway...
Electricity distribution grids resilience enhancement by network reconfiguration
, Article International Transactions on Electrical Energy Systems ; Volume 31, Issue 11 , 2021 ; 20507038 (ISSN) ; Doroudi, A ; Fotuhi Firuzabad, M ; Bashiri, M ; Sharif University of Technology
John Wiley and Sons Ltd
2021
Abstract
Electric power systems try to maximize resilience by various enhancement strategies as preventive and corrective actions against extreme weather events. This paper presents an operational network reconfiguration strategy during a high wind event to strengthen the resiliency of distribution networks. In the proposed resilience enhancement strategy, a bi-level optimization problem is formulated with two conflicting objectives (i) maximizing grid resilience and (ii) realize the primary objective by a minimum number of out-of-service lines (OSLs) switching operations. Furthermore, the algorithm considers the priority of loads, which is an important characteristic of modern distribution grids....
Distribution system resilience enhancement via mobile emergency generators
, Article IEEE Transactions on Power Delivery ; Volume 36, Issue 4 , 2021 , Pages 2308-2319 ; 08858977 (ISSN) ; Safdarian, A ; Moeini Aghtaie, M ; Lehtonen, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
Natural calamities always have been a serious threat to energy systems. In this regard, this paper constitutes a stochastic mixed integer linear programming (SMILP) model to enhance the resilience of power distribution systems to deal with disastrous events. In particular, the proposed model is developed to enhance both survivability and restoration capability of distribution systems. In this regard, to increase the preparedness of the power distribution system, the system operator reconfigures the network by utilizing remote-control switches (RCSs), manual switches (MSs), and distributed generations (DGs) before the natural calamity hits. The proposed model contemplates the traveling time...
The lake urmia environmental disaster in Iran: a look at aerosol pollution
, Article Science of the Total Environment ; Volume 633 , 2018 , Pages 42-49 ; 00489697 (ISSN) ; Khaghani, A ; MacDonald, A. B ; Nguyen, P ; Karimi, N ; Heidary, P ; Karimi, N ; Saemian, P ; Sehatkashani, S ; Tajrishy, M ; Sorooshian, A ; Sharif University of Technology
Abstract
Lake Urmia (LU) once was the second largest hypersaline lake in the world, covering up to 6000 km2, but has undergone catastrophic desiccation in recent years resulting in loss of 90% of its area and extensive coverage by playas and marshlands that represent a source of salt and dust. This study examines daily Aerosol Optical Depth (AOD) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) between 2001 and 2015 over northwestern Iran, which encompasses LU. Intriguingly, salt emissions from the LU surface associated with ongoing desiccation do not drive the study region's AOD profile, whereas pollution transported from other regions and emissions around LU are more important....
A distributed topology control algorithm for P2P based simulations
, Article 11th IEEE International Symposium on Distributed Simulation and Real-Time Applications, DS-RT 2007, Chania, 22 October 2007 through 24 October 2007 ; November , 2007 , Pages 68-71 ; 15506525 (ISSN); 0769530117 (ISBN); 9780769530116 (ISBN) ; Shirmohammadi, S ; Pakravan, M. R ; Sharif University of Technology
2007
Abstract
Although collaborative distributed simulations and virtual environments (VE) have been an active area of research in the past few years, they have recently gained even more attention due to the emergence of online gaming, emergency simulation and planning systems, and disaster management applications. Such environments combine graphics, haptics, animations and networking to create interactive multimodal worlds that allows participants to collaborate in real-time. Massively Multiplayer Online Gaming (MMOG), perhaps the most widely deployed practical application of distributed virtual environments, allows players to act together concurrently in a virtual world over the Internet. IP...
Optimal Network Hardening to Enhance Distribution Networks Resiliency Against Hurricane
, M.Sc. Thesis Sharif University of Technology ; Safdarian, Amir (Supervisor)
Abstract
Back then and still now natural calamities have been a serious threat for energy systems. On that front, this thesis constitutes a three-stage mixed integer linear programming (MILP) model to enhance the resilience of power distribution systems to deal with disas-trous events. The proposed model involves in pre-, mid-, and post-event stages. In this con-text, to increase the preparedness of the power distribution system, system operator recon-figures the system by taking benefit of remote-control switches (RCSs), manual switches (MSs), and distributed generations (DGs) before the natural calamity hits. The proposed model contemplates the traveling time of crew teams to the MS sites in order...
Optimal Enhancement of Community Resilience through Prioritization of Recovery Operations for Interdependent Infrastructures
, M.Sc. Thesis Sharif University of Technology ; Mahsuli, Mojtaba (Supervisor)
Abstract
In this study, community resilience after a disaster is optimally enhanced for interdependent infrastructures through prioritization of recovery operations considering limited resources. Optimal enhancement of community resilience can be performed at two levels: Pre-disaster and Post-disaster. In the pre-disaster level, resilience enhancement is achieved through optimization of long-term decision making that includes optimized allocation of resources to retrofit of buildings. However, in the post-disaster response and recovery period, allocating resources to retrofit or backup systems is infeasible. Therefore, in the post-disaster level considered in this study, resilience enhancement is...
Blood Supply Chain Robust Network Design Model for the Supply of Blood in Disaster
, M.Sc. Thesis Sharif University of Technology ; Haji, Alireza (Supervisor)
Abstract
This Thesis presents a robust network design model for supplying blood during and after an earthquake disaster. A two stage optimization model based on several real-world scenarios is developed. The purpose of this research is to locate and allocate fixed and mobile facilities in probabilistic situation, in which Tehran city with 22 districts is considered as a case study. This model can be categorized as a probabilistic model which demand and supply rate for blood and its derivatives is uncertain. Furthermore the blood transition between different blood types and conversion to its derivatives such as Platelet and plasma are involved in the proposed model. The supply chain for blood consists...
A Machine Learning Model for Simplified Damage and Loss Assessment of the Buildings After an Earthquake
, M.Sc. Thesis Sharif University of Technology ; Mohtasham Dolatshahi, Kiarash (Supervisor)
Abstract
This study presents a Machine Learning framework for post-earthquake structural damage state and economic loss estimation. The framework is proposed to rapidly determine whether a structure is safe or unsafe to be occupied following a seismic event, to predict the detailed structural response, and finally to evaluate the economic loss of the buildings. An extensive database is developed by analyzing twelve low-rise, mid-rise, and high-rise eccentrically braced frames (EBFs) under 44 scaled ground motion records through incremental dynamic analysis (IDA) to train the Machine Learning algorithms. Machine Learning algorithms are employed to classify the structural damage state of the buildings...
Co-Planning of Transmission Expansion Planning and Distributed Energy Resources Considering Power System Resiliency
, Ph.D. Dissertation Sharif University of Technology ; Hosseini, Hamid (Supervisor)
Abstract
The loads in power systems are increasing mainly due to the development of new technologies, population growth, and the arrival of new consumers. This load growth necessitates the planning for expansion of power systems to meet the future load. Transmission expansion planning (TEP) is one of the main power system planning studies that is performed to meet the future load with an acceptable reliability level. On the other hand, in recent years, the integration of distributed energy resources (DERs) into power systems is growing, mainly driven by energy policies and the associated incentives. The impact of the growing integration of DERs into power grids on distribution network planning is...
Hardening Strategies for Enhancing the Resilience of Electrical Distribution Networks against Earthquake
, M.Sc. Thesis Sharif University of Technology ; Vakilian, Mehdi (Supervisor)
Abstract
During natural disasters, especially an earthquake the distribution systems operation is severely affected and interrupted by facing many failures. More than 80% of these outages are due to failures in distribution Systems. Therefore, it is crucial to enhance the resilience of the distribution systems (DSs) against these disasters. However, nowadays, due to limitation of resources for investment in these networks, only the most efficient measures should be implemented. In this work, studying the recent earthquakes in different countries, we have tried to identify the fundamental causes of failure of important network equipment, including distribution substations equipment and network...
Vibration-based Structural Damage State Identification by Image-based Two-dimentional Convolutional Neural Network
, M.Sc. Thesis Sharif University of Technology ; Mohtasham Dolatshahi, Keyarash (Supervisor)
Abstract
This paper proposes a novel image-based two-dimensional convolutional neural network for identifying damage level of the structures after an earthquake. The acceleration of the structure is the input data that is converted into an image, and the corresponding damage level is the output of the network. The superiority of the proposed method in comparison to the signal-based one-dimensional convolutional neural network method is the incorporation of the high and low frequency of the input data into the kernel of the convolution. Rows of the input image show short period high frequency of the signal and the column represent long duration and low frequency of the response time history...
Modeling and Evaluation of the Role of Authorities in Enhancing the Effectiveness of Seismic Vulnerability Reduction Policies
, M.Sc. Thesis Sharif University of Technology ; Kashani, Hamed (Supervisor)
Abstract
The purpose of study is the modeling and evaluation of the role of authorities in enhancing the effectiveness of seismic vulnerability reduction policies. Seismic vulnerability reduction of infrastructures depends on the measures that must be taken before a disaster occurrence. In addition to increasing disaster preparedness, an important part of the pre-disaster measures is taken to increase the robustness of the infrastructure. In some cases, measures to reduce the vulnerability of infrastructure, such as the resilience of residential buildings, require the coordinated role’s implementation of relevant organizations. Evidence shows that in many cases, policies to reduce the vulnerability...
A prioritization model for locating relief logistic centers using analytic hierarchy process with interval comparison matrix
, Article Knowledge-Based Systems ; Volume 86 , September , 2015 , Pages 173-181 ; 09507051 (ISSN) ; Asvadi, S ; Sharif University of Technology
Elsevier
2015
Abstract
When natural disasters happen, relief logistic centers (RLCs) and the quality of their services become absolutely important. In other words, choosing proper locations for RLCs has a direct impact on operating costs and timeliness of responses to the rising demands. This paper aims at proposing a decision support system for prioritizing RLC's locations to facilitate providing emergency helps when natural disasters occur. The present study, focuses on considering availability, risk, technical issues, cost and coverage in locating RLCs. It is assumed that applying analytic hierarchy process (AHP) can facilitate the problem of locating these centers. The most important step in this process is...
Is really NACK protocol secure to be employed in MANETs?
, Article Proceedings - 17th IEEE International Conference on Computational Science and Engineering, CSE 2014, Jointly with 13th IEEE International Conference on Ubiquitous Computing and Communications, IUCC 2014, 13th International Symposium on Pervasive Systems, Algorithms, and Networks, I-SPAN 2014 and 8th International Conference on Frontier of Computer Science and Technology, FCST 2014, 19 December 2014 through 21 December 2014 ; 2015 , Pages 1644-1647 ; 9781479979813 (ISBN) ; Mackvandi, A ; Taghavi, M ; Zare Bidoki, M ; Ghasemi, M ; Neshati, A ; Liu, X ; El Baz, D ; Kang, K ; Hsu, C. H ; Chen, W ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
MANET, which stands for Mobile Ad-hoc Network, is composed of a group of self-organized and wireless nodes that do not possess any predictable and fixed infrastructure. When nodes want to communicate with each other, they have to pass on their messages directly or indirectly. In case the destination node is out of the transmission range, the source node has to rely on intermediate nodes, which, in this case, is called indirect transmission. On the other hand, if the destination node is the neighboring node, there is no need to employ intermediate nodes, which, in this case, is called direct transmission. Over the past years, security issues in MANETs have received a great deal of attention...
Nonlinear dynamic analysis of a concrete gravity dam considering an elastoplastic constitutive model for the foundation
, Article Scientia Iranica ; Volume 20, Issue 6 , 2013 , Pages 1676-1684 ; 10263098 (ISSN) ; Ghaemian, M ; Sharif University of Technology
Sharif University of Technology
2013
Abstract
Dam failure can result in a catastrophic break followed by a ood wave, often with considerable loss of life or property. One of the main causes of dam failure is loss of shear strength and the existence of discontinuity within the foundation. Dynamic analysis of concrete dams usually considered concrete behavior to be nonlinear and the foundation rock is assumed to be linear. In this study, seismic analysis of a concrete gravity dam was conducted to investigate the effect of the foundation on the nonlinear response. A finite element model of a dam-reservoir-foundation was considered to properly model the foundation as well as dam body nonlinear behaviors. An elasto-plastic formulation was...
Dynamic risk assessment of decommissioning offshore jacket structures
, Article Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE, 17 June 2018 through 22 June 2018 ; Volume 3 , 2018 ; 9780791851227 (ISBN) ; Khorasanchi, M ; Kurt, R. E ; Ocean, Offshore and Arctic Engineering Division ; Sharif University of Technology
American Society of Mechanical Engineers (ASME)
2018
Abstract
The need to develop an integrated dynamic safety and risk analysis model for decommissioning offshore jacket structures is driven by the risky, expensive and complex nature of the operation. Many of the existing risk analysis techniques applicable to offshore assets failed to recognise and capture evolving risks during different stages of the decommissioning operation. This paper describes risk-based safety model to conduct quantitative risk analysis for offshore jacket decommissioning failure. First, a bow-tie technique is developed to model the accident cause-consequence relationship. Subsequently, a Bayesian belief network is used to update the failure probabilities of the contributing...
Countries’ classification by environmental resilience
, Article Journal of Environmental Management ; Volume 230 , 2019 , Pages 345-354 ; 03014797 (ISSN) ; Garna, R. K ; Sharif University of Technology
Academic Press
2019
Abstract
Rapid population growth, urbanization, and industrialization affect countries’ vulnerability to future disasters. This study investigates the vulnerability of 141 countries to natural and anthropogenic hazards using six environmental indicators including air pollution, greenhouse gas (GHG) emissions, access to drinking water, access to improved sanitation, environmental risks (total death and affected people), and energy use. Results confirm that the resilience varies by the location. Furthermore, this work delineates the World countries using the environmental resilience score. The most resilient countries are located in Europe and North America and the least resilient countries are in...
An effective approach for aid planning on multi-type transportation networks after a disaster
, Article International Journal of Industrial and Systems Engineering ; Volume 34, Issue 3 , 2020 , Pages 342-364 ; Mahdavi Amiri, N ; Sharif University of Technology
Inderscience Publishers
2020
Abstract
We present a new approach for emergency response planning to the injured on a multi-type transportation network. We consider a three-type transportation network with separate connection links simultaneously: road, rail and air networks. In this study, a circle-based approach is presented where using concentric circles with various radiuses, different levels of the effect of a disaster are considered. After formulating the relations, we present an integer nonlinear programming model for the problem. The model is to determine the locations for establishment of temporary aid stations among the candidate locations, the type of aid stations, the percentage of the injured allocated to each...
Toward operational resilience of smart energy networks in complex infrastructures
, Article Advances in Intelligent Systems and Computing ; Volume 1123 , 2020 , Pages 203-228 ; Jalilian, A ; Safdarian, A ; Moeini Aghtaie, M ; Lehtonen, M ; Sharif University of Technology
Springer
2020
Abstract
Smart energy systems can mitigate electric interruption costs provoked by manifold disruptive events via making efforts toward proper pre-disturbance preparation and optimal post-disturbance restoration. In this context, effective contingency management in power distribution networks calls for contemplating disparate parameters from interconnected electric and transportation systems. This chapter, while considering transportation issues in power networks’ field operations, presents a navigation system for pre-positioning resources such as field crews and reconfiguring the network to acquire a more robust configuration in advance of the imminent catastrophe. Also, after the occurrence of the...