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uncertainty-analysis
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Iterative sparsification-projection: Fast and robust sparse signal approximation
, Article IEEE Transactions on Signal Processing ; Volume 64, Issue 21 , 2016 , Pages 5536-5548 ; 1053587X (ISSN) ; Babaie zadeh, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
Abstract
In this paper, we address recovery of sparse signals from compressed measurements, and sparse signal approximation, which have received considerable attention over the last decade. First, we revisit smoothed L0 (SL0), a well-known sparse recovery algorithm, and give some insights into it that have not been noticed previously. Specifically, we re-derive the SL0 algorithm based on proximal methods, and using recent results in solving nonconvex problems by proximal algorithms, we provide a convergence guarantee for it. In addition, inspired by this derivation, we propose a general family of algorithms, which we call iterative sparsification-projection (ISP), having SL0 as a special member. Our...
Uncertainty analysis of wind-wave predictions in Lake Michigan
, Article China Ocean Engineering ; Volume 30, Issue 5 , 2016 , Pages 811-820 ; 08905487 (ISSN) ; Ataie Ashtiani, B ; Hamidi, S. A ; Sharif University of Technology
Springer Verlag
Abstract
With all the improvement in wave and hydrodynamics numerical models, the question rises in our mind that how the accuracy of the forcing functions and their input can affect the results. In this paper, a commonly used numerical third-generation wave model, SWAN is applied to predict waves in Lake Michigan. Wind data are analyzed to determine wind variation frequency over Lake Michigan. Wave predictions uncertainty due to wind local effects are compared during a period where wind has a fairly constant speed and direction over the northern and southern basins. The study shows that despite model calibration in Lake Michigan area, the model deficiency arises from ignoring wind effects in small...
Operation scheduling of battery storage systems in Joint energy and ancillary services markets
, Article IEEE Transactions on Sustainable Energy ; Volume 8, Issue 4 , 2017 , Pages 1726-1735 ; 19493029 (ISSN) ; Zareipour, H ; Amjady, N ; Rosehart, W. D ; Ehsan, M ; Sharif University of Technology
Abstract
This paper presents a risk-based approach for evaluating the participation strategy of a battery storage system in multiple markets. Simultaneous offering in day-ahead energy, spinning reserve, and regulation markets is considered in this paper. The uncertainties considered include predicted market prices as well as energy deployment in spinning reserve and regulation markets. A new nonprobabilistic model is introduced in this paper to handle the uncertain nature of spinning reserve and regulation markets. Robust optimization is implemented to model these uncertain parameters and manage their related risk. The proposed risk-based model is a max-min problem, which is converted to its...
Design and implementation of an online precise monitoring and performance analysis system for centrifugal pumps
, Article IEEE Transactions on Industrial Electronics ; 2017 ; 02780046 (ISSN) ; Emami, M. H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2017
Abstract
Development of design and production technology of centrifugal pumps for achieving better performance and less energy consumption in these devices has increasingly been taken into consideration. This is due to the fact that centrifugal pumps have an important contribution in industrial applications and energy consumption around the world. Accordingly, the international standards of centrifugal pumps, urge more precise analysis systems for obtaining the performance curves of these pumps. For this reason, a complete, precise and real-time monitoring and performance analysis system for centrifugal pumps is introduced in this paper. The pump characteristics are measured by precise measuring...
Day-ahead self-scheduling of a transmission-constrained GenCo with variable generation units using the incomplete market information
, Article IEEE Transactions on Sustainable Energy ; Volume 8, Issue 3 , 2017 , Pages 1260-1268 ; 19493029 (ISSN) ; Ehsan, M ; Shahidehpour, M ; Sharif University of Technology
Abstract
In this paper, a self-generation scheduling method for a power generation company (GenCo) with renewable generation units is presented. In the proposed method, locational market prices (LMPs) are calculated using the incomplete information on competing market participants by simulating the ISO's market clearing program and considering the effect of physical limitations of transmission lines. The errors associated with forecasted LMP and renewable production are modeled in the GenCo's generation scheduling using a robust optimization approach. The scheduling problem is modeled as a mixed-integer linear programming which is solved by a CPLEX solver in GAMS. An eight-bus system is employed to...
Robust D-stability testing function for LTI fractional order interval systems
, Article 2nd IEEE Conference on Control Technology and Applications, CCTA 2018, 21 August 2018 through 24 August 2018 ; 2018 , Pages 1277-1282 ; 9781538676981 (ISBN) ; Fathi Jegarkandi, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
This paper investigates the robust D -stability test of LTI fractional order interval systems (FOISes). The D stability includes the performance of an LTI system in addition to stability. The coefficients of the system transfer function are uncertain parameters that each adopts a value in a real interval. Firstly, the concept of the value set is extended to the FOISes, and a necessary and sufficient condition is presented to study the robust D-stability of FOISes. Secondly, the value set of the FOISes is obtained analytically, and based on it a robust D- stability testing function is introduced to check the presented condition. The results obtained are applicable to systems of both...
Behaviors of capacitive and Pirani vacuum gauges: Case study on time effect
, Article Vakuum in Forschung und Praxis ; Volume 30, Issue 5 , 2018 , Pages 39-44 ; 0947076X (ISSN) ; Arman, A ; Ghotbi, S. M. J ; Grayeli Korpi, A ; Salehi, M ; Mardani, M ; Hafezi, F ; Shafiekhani, A ; Ţăblu, Ş ; Afghan, A. S ; Sharif University of Technology
Wiley-VCH Verlag
2018
Abstract
Knowing the exact pressure of the process has a great impact on the validity of the results, product quality, energy efficiency, and in some processes, on the security of work with the system. Hence, the calibration of the barometers and the accuracy of the readings should be taken seriously. Choosing the appropriate time interval for re-calibration is done according to the extent and conditions of use, uncertainty, and the inaccuracy allowed in measurement, constructive suggestion, and some other things. Failure to pay attention to the importance of periodic calibration in vacuum gauges leads to some irreparable losses in the research project and the vacuum generator system. In this study,...
Reconfiguring a set of coverage-providing facilities under travel time uncertainty
, Article Socio-Economic Planning Sciences ; Volume 62 , 2018 , Pages 1-12 ; 00380121 (ISSN) ; Hajizadeh, I ; Krass, D ; Rahimi Vahed, A ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
We study networks of facilities that must provide coverage under conditions of uncertainty with respect to travel times and customer demand. We model this uncertainty through a set of scenarios. Since opening new facilities and/or closing existing ones is often quite expensive, we focus on optimal re-configuration of the network, that is finding a facility set that achieves desired thresholds with respect to expected and minimal coverage, while retaining as many of the existing facilities as possible. We illustrate our model with an example of Toronto Fire Service. We demonstrate that relocating just a few facilities can have the same effect as opening a similar number of new ones. We...
A geometric approach to fault detection and isolation in robotic manipulators
, Article Proceedings of the IEEE Conference on Decision and Control, 17 December 2018 through 19 December 2018 ; Volume 2018-December , 2019 , Pages 391-396 ; 07431546 (ISSN); 9781538613955 (ISBN) ; Namvar, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
We present a geometric approach for fault detection and isolation (FDI) in robotic manipulators in presence of model uncertainty. A systematic procedure is introduced for representing robotic system model being affine with respect to faults and disturbances. The proposed residual generator has smooth dynamics with freely selectable functions and it does not require high gains or threshold adjustment for the FDI purpose. No assumption on amplitude of faults and their rate is used. The solvability conditions for the FDI problem lead to a quotient observable subspace unaffected by all unknown inputs except the faults. Simulation example demonstrates localization of faults in presence of...
Robust D-stability analysis of fractional order interval systems of commensurate and incommensurate orders
, Article IET Control Theory and Applications ; Volume 13, Issue 8 , 2019 , Pages 1039-1050 ; 17518644 (ISSN) ; Fathi Jegarkandi , M ; Sharif University of Technology
Institution of Engineering and Technology
2019
Abstract
This study focuses on the robust D-stability analysis of fractional order interval systems (FOISes). The concept of interval means that the coefficients of the systems transfer functions are uncertain parameters that each adopts a value in a real interval. Initially, some new bounds on the poles of the FOISes are produced so that they reduce the computational burden in the case of the θ-stability. Then, the concept of the value set is extended to analyse the robust D-stability of the FOISes, and a new necessary and sufficient condition is presented. The value set of the FOISes is obtained analytically, and based on it an auxiliary function is introduced to check the condition. The obtained...
Robust D-stability analysis of fractional order interval systems of commensurate and incommensurate orders
, Article IET Control Theory and Applications ; Volume 13, Issue 8 , 2019 , Pages 1039-1050 ; 17518644 (ISSN) ; Fathi Jegarkandi, M ; Sharif University of Technology
Institution of Engineering and Technology
2019
Abstract
This study focuses on the robust D-stability analysis of fractional order interval systems (FOISes). The concept of interval means that the coefficients of the systems transfer functions are uncertain parameters that each adopts a value in a real interval. Initially, some new bounds on the poles of the FOISes are produced so that they reduce the computational burden in the case of the θ-stability. Then, the concept of the value set is extended to analyse the robust D-stability of the FOISes, and a new necessary and sufficient condition is presented. The value set of the FOISes is obtained analytically, and based on it an auxiliary function is introduced to check the condition. The obtained...
Investigating sensitivity of flow parameters and uncertainty analysis of nutrient transport and dispersion model in shallow water. (Case study: Peer-bazar river and anzali wetland)
, Article Desalination and Water Treatment ; Volume 174 , 2020 , Pages 204-214 ; Mirbagheri, S. A ; Borghei, S. M ; Abbaspour, M ; Sharif University of Technology
Desalination Publications
2020
Abstract
Accurate modeling of runoff in watersheds requires calibration and uncertainty analysis of effective flow parameters and identifying of their statistical characteristics based on inter-parameter relationships and model inputs. In this research, the transport and diffusion of pollution (nutrients) in the river were simulated through the two-dimensional finite-volume method using the shallow water equations. To numerically solve these equations, the governing equations were converted into linear equations. Uncertainty and sensitivity of the prepared pollution model were analyzed to achieve better results in estimating pollution concentrations in rivers within a reliable range. In this study,...
Stochastic framework for planning studies of energy systems: A case of EHs
, Article IET Renewable Power Generation ; Volume 14, Issue 3 , 2020 , Pages 435-444 ; Ghoraani, R ; Pasban, A ; Moeini-Aghtaie, M ; Safdarian, A ; Sharif University of Technology
Institution of Engineering and Technology
2020
Abstract
The substantial presence of different uncertainties in energy systems highlights the need for probabilistic analysis of operational and planning studies. Motivated by this fact, a new stochastic planning framework for energy hubs (EHs) is presented in this study based on the probability transformation concept. In the proposed framework, a measure of relative-likelihood impact is developed to estimate the importance of uncertainty sources in the studies, which, in turn, can remarkably reduce the overall complexity of stochastic problems. Step-by-step algorithm for implementation of the proposed framework on planning studies of an EH is also addressed in this study. Three different case...
Impulsive synchronization of different hyperchaotic (chaotic) systems
, Article Chaos, Solitons and Fractals ; Volume 38, Issue 1 , 2008 , Pages 120-131 ; 09600779 (ISSN) ; Dehghani, M ; Sharif University of Technology
2008
Abstract
The impulsive synchronization has been employed to synchronize two different hyperchaotic (chaotic) systems. Conditions on impulse distances are given in order to obtain stable synchronization in the nominal case and robust stability in the case that we experience uncertainties in the systems dynamic and/or measurement noise. Under the given conditions, it is guaranteed that the error dynamics is asymptotically stable for the nominal case and convergent to a predetermined level for uncertain and/or noisy circumstances. Computer simulations are provided to assess results of the given theorems in the paper. © 2006 Elsevier Ltd. All rights reserved
Chaos control via a simple fractional-order controller
, Article Physics Letters, Section A: General, Atomic and Solid State Physics ; Volume 372, Issue 6 , 2008 , Pages 798-807 ; 03759601 (ISSN) ; Haeri, M ; Sharif University of Technology
Elsevier
2008
Abstract
In this Letter, we propose a fractional-order controller to stabilize the unstable fixed points of an unstable open-loop system. Also, we show that this controller has strong ability to eliminate chaotic oscillations or reduce them to regular oscillations in the chaotic systems. This controller has simple structure and is designed very easily. To determine the control parameters, one needs only a little knowledge about the plant and therefore, the proposed controller is a suitable choice in the control of uncertain chaotic systems. © 2007 Elsevier B.V. All rights reserved
Optimum selection of "number of seats/Cargo volume" for transports in uncertain business environment
, Article Journal of Aircraft ; Volume 45, Issue 1 , 2008 , Pages 98-105 ; 00218669 (ISSN) ; Malaek, S. M. B ; Sharif University of Technology
American Institute of Aeronautics and Astronautics Inc
2008
Abstract
Increasing competition in the transport commercial market has resulted in many changes in the aircraft design process. There is a great tendency to include economic factors such as "affordability" In the design process. On the other hand, the so-called market dynamics are also getting complicated and a design team has to deal with many uncertainties as far as the business environment is concerned. This leads to the need for new decision-making tools in the early stages of the design process. This paper introduces a decision-making algorithm based on fuzzy logic systems which provides a structured approach to deal with uncertainties in the aircraft preliminary design. The developed tool leads...
Operational risk evaluation in competitive electricity market scheduling
, Article 2006 International Conference on Power System Technology, POWERCON2006, Chongqing, 22 October 2006 through 26 October 2006 ; 2006 ; 1424401119 (ISBN); 9781424401116 (ISBN) ; Ranjbar, A. M ; Fotuhi Firuzabad, M ; Samani, S. C ; Mozafari, B ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2006
Abstract
Electric power systems are typically operated at least cost subject to technical and reliability constraints. This paper presents a probabilistic approach for risk evaluation in competitive electricity market scheduling. A competitive structure is proposed which includes a purchasing agency with centrally optimized scheduling (MaxISO structure). Spinning and non-spinning reserves are considered in the proposed approach. The value of unit commitment risk is deduced from the generation model. The required generation model is constructed using the outage replacement rate (ORR) of units. The load forecast uncertainty is included in operational risk evaluation. This is due to the increased...
Adaptive synchronization of chaotic systems with uncertain parameters
, Article 2006 SICE-ICASE International Joint Conference, Busan, 18 October 2006 through 21 October 2006 ; 2006 , Pages 4419-4422 ; 8995003855 (ISBN); 9788995003855 (ISBN) ; Haeri, M ; Sharif University of Technology
2006
Abstract
In this paper, an approach for adaptive synchronization of uncertain chaotic systems is proposed using adaptive active control. According to the Lyapunov stability theorem, an adaptive control law is derived to make the states of two identical chaotic systems asymptotically synchronized. Simulation results are presented to show the effectiveness of the proposed method. © 2006 ICASE
Performance evaluation of Omni-Channel distribution network configurations considering green and transparent criteria under uncertainty
, Article Sustainability (Switzerland) ; Volume 14, Issue 19 , 2022 ; 20711050 (ISSN) ; Khedmati, M ; Akbari Jokar, M. R ; Babaee Tirkolaee, E ; Sharif University of Technology
MDPI
2022
Abstract
Satisfying customer demand is one of the growing concerns of supply chain managers. On the other hand, the development of internet communications has increased online demand. In addition, the COVID-19 pandemic has increased the demand for online shopping. One of the useful concepts that help to address this concern is the omni-channel strategy, which integrates online and traditional channels with the aim of improving customer service level. For this purpose, this paper proposes an algorithm for evaluating Omni-channel Distribution Network Configurations (OCDNCs). The algorithm applies an extended Data Envelopment Analysis (DEA) model to evaluate OCDNCs based on cost, service, transparency,...
Does a buyback contract coordinate a reverse supply chain facing remanufacturing capacity disruption and returned product quality uncertainty?
, Article Sustainability (Switzerland) ; Volume 14, Issue 23 , 2022 ; 20711050 (ISSN) ; Eslamipirharati, M ; Bakhshi, A ; Aghsami, A ; Jolai, F ; Yazdani, M ; Sharif University of Technology
MDPI
2022
Abstract
This paper studies a two-echelon reverse supply chain (RSC) involving a remanufacturer and a collector, in which the collector receives the used products by paying a reward to consumers. The reward amount given to customers is crucial for encouraging them to exchange used products. An exchanged item is accepted if it meets the minimum acceptable quality level (AQL). Both the remanufacturing capacity and the quality of exchanged products present uncertainties. Under the buyback contract, the remanufacturer purchases used products at a higher price than in the decentralized and centralized cases from the collector. In return, the collector undertakes to repurchase a certain number of used...