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resilience
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Total 174 records
Identifying and Ranking Supply Chain Risk Factors and Calculating Reliability in 3 Level Supply Chain
, M.Sc. Thesis Sharif University of Technology ; Eshraghnia Jahromi, Abdolhamid (Supervisor)
Abstract
Since 1990, supply chains get affected by business environment changes and become more vulnerable. Changes such as globalization, decrease of inventory levels, out sourcing, etc. in this thesis after reviewing some paper, researches are categorized in 8 group. Then 30 risk factor identified from this papers. Because of basic differences in industries and different importance of risk factors in them, a case was studied in one industrial area and risk factors was evaluated in a two-step evaluation. Eventually some advices presented for increasing reliability for that case
A Novel Manufacturing Service Composition Model Focusing on Enabling a Resilient Supply Chain Network
, M.Sc. Thesis Sharif University of Technology ; Haji, Alireza (Supervisor) ; Fatahi Valilai, Omid (Co-Supervisor) ; Khaleghparast, Sharif (Co-Supervisor)
Abstract
With the advent of the Industry 4.0 and advances in Information Technology, the manufacturing systems have experienced great evolution and transition in their production paradigms. Among these developments, we can refer to the globalization process of resources and a diversion from mass production to the production that is based on customized orders. Likewise, a movement from product-based manufacturing towards service-based production is taking place. Such changes expose supply networks to new opportunities and threats and encourage them to exploit advanced production systems. Cloud manufacturing, as an approach to fulfill the state-of-the-art opportunities, has been recently considered by...
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...
Seismic Damage Prediction for Non-Structural Building Systems: a Framework Based on Building Information Modeling and Machine Learning
, M.Sc. Thesis Sharif University of Technology ; Alvanchi, Amin (Supervisor)
Abstract
Despite the vulnerability of non-structural systems in buildings to disasters, their resilient design has received minimal attention from the practitioners of the construction industry. However, interruption in the performance of these systems jeopardizes the functionality of the buildings and threatens the resilience of the whole community. To address this issue, the present study proposes a novel framework for predicting possible damage states of non-structural building systems under disasters. The proposed framework benefits from an automated combination of Building Information Modeling (BIM) as a visualized 3D database of the building's components and the Machine Learning (ML)...
Developing a Data Envelopment Analysis (DEA) Model to Evaluate the Performance of Countries ‘Healthcare System during Corona Virus Pandemic’
, M.Sc. Thesis Sharif University of Technology ; Khedmati, Majid (Supervisor)
Abstract
Since the start of Covid-19 pandemic lately in 2019 from Wuhan in China, a lot of countries encountered it. Healthcare sysytems are the most important system against pandemics so it is needed to measure the efficiency of healthcare systems against Covid-19 in order to find best practices. In this research, a 3-phased method is proposed to evaluate the performance of the healthcare systems. In the first phase, countries are clustered, in the second phase the DEA model is applied in 2 separate parts, in one part with considering clusters and in another without it. In the third phase resilience is introduced for Covid-19 and then it is used as a criterion beside two other criteria, DEA result...
Evaluation of the Cyclic Performance of Buckling Restrained Braces with Sliding Friction Connection
, M.Sc. Thesis Sharif University of Technology ; Mofid, Masood (Supervisor)
Abstract
In today’s world, the use of lateral load-bearing systems, such as bracings, has become a pretty common practice. Often showing axial deformation behavior, these members exhibit proper performance under tensile loads but tend to become unstable under compressive loads. In contrast to common bracing systems, the buckling-restrained bracing (BRB) systems perform well under not only tensile loads but also compressive loads. Recent studies have paid greater deals of attention to the application of short-core BRB systems in different structures. The bracing core has been shortened to increase the core deformation and hence the energy dissipation capacity of the bracing system. In this condition,...
Defining a Resiliency Index for Urban Roadway Networks
, M.Sc. Thesis Sharif University of Technology ; Nassiri, Habibollah (Supervisor)
Abstract
Urban transportation infrastructure due to the emergency forces' access during and after the earthquake is one of the most important arteries in the face of crisis. The resilience of this infrastructure is a crucial factor that should control before an event, such as an earthquake, to prioritize segments for improving their conditions and prevent system disruption. In this research, a model presents for evaluating urban roads' resilience based on four characteristics of robustness, redundancy, resourcefulness, and rapidity. The fuzzy inference is employed to construct the model. Due to the expert opinion dependence of these models, the AHP questionnaire is used to train the model. In this...
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...
Design and assessment of seismic resilient structures by the endurance time method
, Article Scientia Iranica ; Volume 23, Issue 4 , 2016 , Pages 1648-1657 ; 10263098 (ISSN) ; Vafai, A ; Basim, M. Ch ; Sharif University of Technology
Sharif University of Technology
Abstract
A framework to calculate a quantitative measure of seismic resilience using the Endurance Time (ET) method is introduced. ET method is a response-history based analysis procedure where structures are subjected to gradually intensifying dynamic excitations and their performance is assessed based on their response at different excitation levels, reducing the required computational effort. First, a prototype hospital building is optimally designed through three distinct design philosophies: prescriptive design code, performance based design criteria, and value based seismic design method. In value based design method, the design sections of structural elements are assumed as optimization...
Upcoming challenges of future electric power systems: Sustainability and resiliency
, Article Scientia Iranica ; Volume 23, Issue 4 , 2016 , Pages 1565-1577 ; 10263098 (ISSN) ; Safdarian, A ; Moeini Aghtaie, M ; Ghorani, R ; Rastegar, M ; Farzin, H ; Sharif University of Technology
Sharif University of Technology
2016
Abstract
Going back and taking a quick glance at the history of developed countries prove that prosperity of any society is tightly intertwined with resiliency and sustainability of its preliminary infrastructures. Surely, in modern societies, electricity is among the most important infrastructures whose resiliency and sustainability are a key driving force toward development of the society. This is verified by the fact that since the industrial revolution, per capita electricity consumption has been taken as a key index showing the level of economic development and standard of living in a country. This paper focuses on the concept of resiliency and sustainability of electric power systems. The...
Reliability-aware design to suppress aging
, Article 53rd Annual ACM IEEE Design Automation Conference, DAC 2016, 5 June 2016 through 9 June 2016 ; Volume 05-09 , June-2016 , 2016 ; 0738100X (ISSN); 9781450342360 (ISBN) ; Khaleghi, B ; Gerstlauerz, A ; Henkel, J ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
Due to aging, circuit reliability has become extraordinary challenging. Reliability-aware circuit design flows do virtually not exist and even research is in its infancy. In this paper, we propose to bring aging awareness to EDA tool flows based on so-called degradation-aware cell libraries. These libraries include detailed delay information of gates/cells under the impact that aging has on both threshold voltage (Vth) and carrier mobility (μ) of transistors. This is unlike state of the art which considers Vth only. We show how ignoring μ degradation leads to underestimating guard-bands by 19% on average. Our investigation revealed that the impact of aging is strongly dependent on the...
Joint intra and multiple description coding for packet loss resilient video transmission
, Article IEEE Transactions on Multimedia ; 2017 ; 15209210 (ISSN) ; Iqbal, R ; Shirmohammadi, S ; Sharif University of Technology
Abstract
Multiple Description Coding (MDC) is a technique for video transmission over error prone networks where the descriptions are routed over multiple paths. Intra coding like MDC provides error resiliency but coding in this mode must be decided with care since it degrades the compression ratio. In this paper, we present our investigation results for a new intra coding approach in MDC. We have found that, in MDC streams, the best policy is to encode selective frames as I-frame instead of coding some macroblocks of frames in intra mode. In order to find the most suitable I-frame positions within a given video stream, we developed a cost function based on which intra/inter frame type is decided....
Increasing the resilience of distribution systems against hurricane by optimal switch placement
, Article 2017 Electrical Power Distribution Networks Conference, EPDC 201717 August 2017, Article number 8012732, Pages 7-11 ; 2017 , Pages 7-11 ; 9781538630105 (ISBN) ; Abbaspour, A ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Sharif University of Technology
Abstract
Due to increasing the intensity and frequency of natural disasters in recent years, power system decision makers are seeking cost efficient methods to improve the resilience of power grids against low probability, high impact natural disasters such as hurricanes, floods, and earthquakes. In this paper, a new algorithm is presented for switch placement problem with the main goal of improving the resilience of distribution grids. To reach this goal, at first, a model is presented to simulate the effects of hurricane on availability of system components. Then, this model is involved in optimization model of switch placement problem. A new criterion is introduced as objective function of switch...
PUF-based solutions for secure communications in advanced metering infrastructure (AMI)
, Article International Journal of Communication Systems ; Volume 30, Issue 9 , 2017 ; 10745351 (ISSN) ; Mirzakuchaki, S ; Ameri, M. H ; Mohajeri, J ; Sharif University of Technology
John Wiley and Sons Ltd
2017
Abstract
Advanced metering infrastructure (AMI) provides 2-way communications between the utility and the smart meters. Developing authenticated key exchange (AKE) and broadcast authentication (BA) protocols is essential to provide secure communications in AMI. The security of all existing cryptographic protocols is based on the assumption that secret information is stored in the nonvolatile memories. In the AMI, the attackers can obtain some or all of the stored secret information from memories by a great variety of inexpensive and fast side-channel attacks. Thus, all existing AKE and BA protocols are no longer secure. In this paper, we investigate how to develop secure AKE and BA protocols in the...
Topology exploration of a thermally resilient wavelength-based ONoC
, Article Journal of Parallel and Distributed Computing ; Volume 100 , 2017 , Pages 140-156 ; 07437315 (ISSN) ; Karimi, R ; Koohi, S ; Hessabi, S ; Sharif University of Technology
Academic Press Inc
2017
Abstract
With the growing number of cores, high-performance systems face power challenges due to dominating communication power. Thus, attaining energy efficient high-bandwidth inter-core communication nominates photonic network-on chip as the most promising interconnection paradigm. Although photonic networks pave the way for extremely higher performance communications, their intrinsic susceptibility to thermal fluctuations intimidates reliability of system. This necessitates the development of methodologies to analyze and model thermal effects on network behavior. In this paper, we model temperature fluctuations of optical chips and analyze photonic networks in a holistic approach. We present a...
Optimized design procedure for coupling panels in steel plate shear walls
, Article Structural Design of Tall and Special Buildings ; Volume 26, Issue 1 , 2017 ; 15417794 (ISSN) ; Dolatshahi, K. M ; Mofid, M ; Sharif University of Technology
John Wiley and Sons Ltd
2017
Abstract
Coupling beams have had a widespread application as performance enhancing devices within concrete structures and more recently also in steel structures. However, the conventional coupling beams are not so efficient in coupling distant walls. In this paper, a novel form of coupling members, namely, coupling panels is proposed and, then, the application for a nine-story building is investigated. Coupling panels are steel plates which are exerted in the intermediate spans between adjacent shear walls and act as a mega-coupling beam. First, a verified finite element model is constructed to demonstrate coupling panel behavior along with its global structural mechanism. Subsequently, a nine story...
Two novel shear fuses in moment resting frames
, Article Journal of Constructional Steel Research ; Volume 144 , May , 2018 , Pages 198-210 ; 0143974X (ISSN) ; Dolatshahi, K. M ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
Based on the code specifications, in moment-resisting frames the span-to-depth ratio has to be larger than a minimum value to make sure of adequate plastic hinging at beam-ends. This provision poses a restriction on the use of deep beams with short spans, especially for the framed-tube system in tall buildings. In this paper, a new energy dissipation method is introduced for moment-resisting frames by modifying the mid-span of the beam by two different methods, resulting in: (i) Perforated Shear Links (PSLs) and (ii) Slit Shear Links (SSLs). The links dissipate energy through shear yielding of the web, weakened by perforation or slitting, respectively. A thorough study is conducted on the...
Using Web-GIS technology as a smart tool for resiliency management to monitor wind farms performances (Ganjeh site, Iran)
, Article International Journal of Environmental Science and Technology ; 2018 ; 17351472 (ISSN) ; Abbaspour, M ; Radfar, R ; Mohammadi, A ; Sharif University of Technology
Center for Environmental and Energy Research and Studies
2018
Abstract
Considering the wide spread locations of wind farms in Iran, it is important to develop a suitable decision support system (DSS) to fulfill proper management of wind farms. Extensive literature survey indicates that there are no integrated forms of DSS to manage a set of wind farms. The existing wind farms are performing independently, and there is no practical method for exchanging the online data. DSS can contribute to optimal operation of wind farms, operation and maintenance scheduling, pricing policy, etc. In this study, a geographic information system and RETSCREEN software were linked to the designed DSS to achieve a more suitable result. Also, a huge number of data are constantly...
PPMN: a resilient public peer-to-peer mesh network of IEEE802.16 users
, Article 2009 International Conference on Signal Processing Systems, ICSPS 2009, Singapore, 15 May 2009 through 17 May 2009 ; 2009 , Pages 488-492 ; 9780769536545 (ISBN) ; Habibi, J ; Sharif University of Technology
2009
Abstract
In these days, IEEE802.16 protocol is being developed and in the next years, 802.16 modems will be used in every house to connect to the Internet through base-stations in both urban and rural areas. Since user bandwidth for connection to the Internet is limited, a large fraction of each modem's bandwidth is not used. In this paper, we propose an architecture to construct a public peer-to-peer mesh network using the non-utilized bandwidth of independent 802.16 users. The architecture is composed of a routing algorithm, a forwarding incentive mechanism, and a security-resiliency scheme. Design challenges are discussed in each case. © 2009 IEEE
A thermally-resilient all-optical network-on-chip
, Article Microelectronics Reliability ; Volume 99 , 2019 , Pages 74-86 ; 00262714 (ISSN) ; Koohi, S ; Tinati, M ; Hessabi, S ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Optical networks-on-chip are introduced as an alternative for electrical interconnects in many-core systems, due to their low delay and power consumptions, as well as their high bandwidths. Despite these advantages, physical characteristics of the photonic components are highly sensitive to thermal variations, which results in optical data misrouting through the optical networks at the presence of temperature fluctuation. In this paper, we propose a thermally-resilient all-optical communication approach which improves reliability, as well as performance of the optical networks. For this purpose, we take advantages of auxiliary waveguides and a novel wavelength assignment approach to avoid...