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    An integrated vendor-buyer model with stock-dependent demand

    , Article Transportation Research Part E: Logistics and Transportation Review ; Volume 46, Issue 6 , November , 2010 , Pages 963-974 ; 13665545 (ISSN) Sajadieh, M. S ; Thorstenson, A ; Akbari Jokar, M. R ; Sharif University of Technology
    2010
    Abstract
    We develop an integrated vendor-buyer model for a two-stage supply chain. The vendor manufactures the product and delivers it in a number of equal-sized batches to the buyer. The items delivered are presented to the end customers in a display area. Demand is assumed to be positively dependent on the amount of items displayed. The objective is to maximize total supply chain profit. The numerical analysis shows that buyer-vendor coordination is more profitable in situations when demand is more stock dependent. It also shows that the effect of double marginalization provides a link between the non-coordinated and the coordinated case  

    Probabilistic optimization of networked multi-carrier microgrids to enhance resilience leveraging demand response programs

    , Article Sustainability (Switzerland) ; Volume 13, Issue 11 , 2021 ; 20711050 (ISSN) Azimian, M ; Amir, V ; Habibifar, R ; Golmohamadi, H ; Sharif University of Technology
    MDPI AG  2021
    Abstract
    Microgrids have emerged as a practical solution to improve the power system resilience against unpredicted failures and power outages. Microgrids offer substantial benefits for customers through the local supply of domestic demands as well as reducing curtailment during possible disruptions. Furthermore, the interdependency of natural gas and power networks is a key factor in energy systems’ resilience during critical hours. This paper suggests a probabilistic optimization of networked multi-carrier microgrids (NMCMG), addressing the uncertainties associated with thermal and electrical demands, renewable power generation, and the electricity market. The approach aims to minimize the NMCMG... 

    Reliability and Probabilistic Seismic Assessment of Fixed Jacket Type Offshore Platforms

    , M.Sc. Thesis Sharif University of Technology Tabandeh, Armin (Author) ; Golafshani, Ali Akbar (Supervisor)
    Abstract
    This thesis encompasses a number of issues in earthquake engineering which may appear quite diverse in nature. Several methodological aspects of both conventional and novel approaches to probabilistic seismic hazard assessment are discussed here along with subjects more strictly pertinent to structural and geotechnical engineering. This work, however, has a unique, ultimate goal: to provide procedures for an effective and practical probabilistic estimation of structural demand of offshore platforms due to seismic ground shaking. In modern multi-level design and rehabilitation procedures, structural performance is in fact quantified by deformation demand levels exceeded with a specified... 

    The Effect of Exact and Approximate Distribution of Conditional Spectrum in Probabilistic Estimation of Structural Demands

    , M.Sc. Thesis Sharif University of Technology Shokouhirad, Sahar (Author) ; Golafshani, Ali Akbar (Supervisor)
    Abstract
    In this thesis several methodological aspects of both conventional and novel approaches to probabilistic seismic hazard assessment are discussed here along with subjects more strictly pertinent to structural and geotechnical engineering. This work, however, has a unique, ultimate goal: to provide procedures for an effective and practical probabilistic estimation of structural demand of offshore platforms due to seismic ground shaking.In modern multi-level design and rehabilitation procedures, structural performance is in fact quantified by deformation demand levels exceeded with a specified annual frequency of structural life. We refer to this as Probabilistic Seismic Demand Analysis (PSDA).... 

    Imperialist competitive algorithm for solving non-convex dynamic economic power dispatch

    , Article Energy ; Volume 44, Issue 1 , 2012 , Pages 228-240 ; 03605442 (ISSN) Mohammadi Ivatloo, B ; Rabiee, A ; Soroudi, A ; Ehsan, M ; Sharif University of Technology
    Abstract
    Dynamic economic dispatch (DED) aims to schedule the committed generating units' output active power economically over a certain period of time, satisfying operating constraints and load demand in each interval. Valve-point effect, the ramp rate limits, prohibited operation zones (POZs), and transmission losses make the DED a complicated, non-linear constrained problem. Hence, in this paper, imperialist competitive algorithm (ICA) is proposed to solve such complicated problem. The feasibility of the proposed method is validated on five and ten units test system for a 24 h time interval. The results obtained by the ICA are compared with other techniques of the literature. These results... 

    Designing time-of-use program based on stochastic security constrained unit commitment considering reliability index

    , Article Energy ; Volume 41, Issue 1 , May , 2012 , Pages 541-548 ; 03605442 (ISSN) Nikzad, M ; Mozafari, B ; Bashirvand, M ; Solaymani, S ; Ranjbar, A. M ; Sharif University of Technology
    2012
    Abstract
    Recently in electricity markets, a massive focus has been made on setting up opportunities for participating demand side. Such opportunities, also known as demand response (DR) options, are triggered by either a grid reliability problem or high electricity prices. Two important challenges that market operators are facing are appropriate designing and reasonable pricing of DR options.In this paper, time-of-use program (TOU) as a prevalent time-varying program is modeled linearly based on own and cross elasticity definition. In order to decide on TOU rates, a stochastic model is proposed in which the optimum TOU rates are determined based on grid reliability index set by the operator. Expected... 

    A stochastic security approach to energy and spinning reserve scheduling considering demand response program

    , Article Energy ; Volume 36, Issue 5 , 2011 , Pages 3130-3137 ; 03605442 (ISSN) Partovi, F ; Nikzad, M ; Mozafari, B ; Ranjbar, A. M ; Sharif University of Technology
    Abstract
    In this paper a new algorithm for allocating energy and determining the optimum amount of network active power reserve capacity and the share of generating units and demand side contribution in providing reserve capacity requirements for day-ahead market is presented. In the proposed method, the optimum amount of reserve requirement is determined based on network security set by operator. In this regard, Expected Load Not Supplied (ELNS) is used to evaluate system security in each hour. The proposed method has been implemented over the IEEE 24-bus test system and the results are compared with a deterministic security approach, which considers certain and fixed amount of reserve capacity in... 

    A decision support system for demand management in healthcare supply chains considering the epidemic outbreaks: A case study of coronavirus disease 2019 (COVID-19)

    , Article Transportation Research Part E: Logistics and Transportation Review ; Volume 138 , June , 2020 Govindan, K ; Mina, H ; Alavi, B ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    The disasters caused by epidemic outbreaks is different from other disasters due to two specific features: their long-term disruption and their increasing propagation. Not controlling such disasters brings about severe disruptions in the supply chains and communities and, thereby, irreparable losses will come into play. Coronavirus disease 2019 (COVID-19) is one of these disasters that has caused severe disruptions across the world and in many supply chains, particularly in the healthcare supply chain. Therefore, this paper, for the first time, develops a practical decision support system based on physicians' knowledge and fuzzy inference system (FIS) in order to help with the demand... 

    Nonlinear seismic behavior of elliptic-braced moment resisting frame using equivalent braced frame

    , Article Steel and Composite Structures ; Volume 40, Issue 1 , 2021 , Pages 45-64 ; 12299367 (ISSN) Ghasemi Jouneghani, H ; Haghollahi, A ; Talebi Kalaleh, M ; Beheshti Aval, B ; Sharif University of Technology
    Techno-Press  2021
    Abstract
    Recently, the elliptic-braced moment resisting frame (ELBRF) which is a new lateral bracing system installed in the middle bay of the frame in the facade of buildings is introduced. This system not only prevents a solution for opening space problem in view of architectural aspects, but also improves the structural behavior. The main drawback of its using in view of numerical modeling in multistory buildings is lack of curved frame element in design and analysis software. To overcome this shortcoming, in this paper, for the first time, an equivalent element for elliptic brace is presented for ELBRF through a laboratory program and nonlinear finite element analysis, which will contribute to... 

    Assessment of Existing Jaket-Type Offshore Platforms in the Persian Gulf Region for Service Life Extension or Operative Conditions

    , Ph.D. Dissertation Sharif University of Technology Ebrahimian, Hossein (Author) ; Golafshani, Ali Akbar (Supervisor)
    Abstract
    Assessment of existing jacket-type offshore platforms in Persian Gulf for life extension or operative conditions is a major concern for oil offshore companies in recent years. Significant damage to offshore platforms as well as their contents will induce significant losses such as financial losses, fatalities and casualties. On the other hand, extreme waves or earthquakes are low-probability, large-consequence and large-uncertainty hazards that can affect these critical facilities; therefore, the assessment of existing offshore platforms subjected to each of these sources can be successfully carried out by a probabilistic approach. In this dissertation, a unique probabilistic... 

    Probabilistic Seismic Demand Analysis Using Endurance Time Method

    , Ph.D. Dissertation Sharif University of Technology Bazmooneh, Amir Ali (Author) ; Esmail Pourestekanchi, Homayoon (Supervisor)
    Abstract
    In the field of estimating the expected performance of structures under the excitation of earthquakes of different magnitudes, the Endurance time method has been introduced as a fast method in recent years. What is needed now in this method is to study the assumptions and definitions used in this method, to choose more logical definitions, to unify them, and to prove the statistics of this method in the overlapping and generalizable range of different structures. For this purpose, in this dissertation, different definitions have been evaluated in the process of using the Endurance time method and IDA. The results of different definitions for the target time equivalent to each earthquake... 

    Load commitment in a smart home

    , Article Applied Energy ; Vol. 96, issue , 2012 , p. 45-54 ; ISSN: 03062619 Rastegar, M ; Fotuhi-Firuzabad, M ; Aminifar, F ; Sharif University of Technology
    Abstract
    Although demand response (DR) potentially brings miscellaneous advantages, it is currently faced with challenges in its implementation due to customers' difficulty in manually responding to the time-varying prices. This paper presents an optimal and automatic residential load commitment (LC) framework to achieve the household minimum payment. Problem decision variables are the operating status of responsive appliances and charging/discharging cycles of battery storage and plug-in hybrid electric vehicles (PHEVs). Storage capability in residential centers provide the customers with this opportunity to not only supply the local demand during the high price hours but also sell the energy back... 

    Load commitment in a smart home

    , Article Applied Energy ; Volume 96 , 2012 , Pages 45-54 ; 03062619 (ISSN) Rastegar, M ; Fotuhi Firuzabad, M ; Aminifar, F ; Sharif University of Technology
    Abstract
    Although demand response (DR) potentially brings miscellaneous advantages, it is currently faced with challenges in its implementation due to customers' difficulty in manually responding to the time-varying prices. This paper presents an optimal and automatic residential load commitment (LC) framework to achieve the household minimum payment. Problem decision variables are the operating status of responsive appliances and charging/discharging cycles of battery storage and plug-in hybrid electric vehicles (PHEVs). Storage capability in residential centers provide the customers with this opportunity to not only supply the local demand during the high price hours but also sell the energy back... 

    Constrained single period problem under demand uncertainty

    , Article Scientia Iranica ; Volume 18, Issue 6 , December , 2011 , Pages 1553-1563 ; 10263098 (ISSN) Taleizadeh, A. A ; Shavandi, H ; Haji, R ; Sharif University of Technology
    2011
    Abstract
    In this paper, we develop the multi-product, multi-constraint, Single Period Problem (SPP) with uncertain demands, considering an incremental discount situation. Three new models are presented for multi-product, multi-constraint SPP in fuzzy, stochastic and rough environments. We consider constraints, such as service rate, restriction on order quantity and restrictions on warehouse space and budget. We also consider that the order quantity is a multiplier of predefined batch size. Furthermore, three kinds of solution algorithm, (1) harmony search, (2) hybrid intelligent based on harmony search and fuzzy simulation and (3) hybrid intelligent based on harmony search and rough simulation, are... 

    Nitrogen removal from high organic loading wastewater in modified Ludzack-Ettinger configuration MBBR system

    , Article Water Science and Technology ; Volume 72, Issue 8 , October , 2015 , Pages 1274-1282 ; 02731223 (ISSN) Torkaman, M ; Borghei, S. M ; Tahmasebian, S ; Andalibi, M. R ; Sharif University of Technology
    IWA Publishing  2015
    Abstract
    A moving bed biofilm reactor with pre-denitrification configuration was fed with a synthetic wastewater containing high chemical oxygen demand (COD) and ammonia. By changing different variables including ammonium and COD loading, nitrification rate in the aerobic reactor and denitrification rate in the anoxic reactor were monitored. Changing the influent loading was achieved via adjusting the inlet COD (956-2,096 mg/L), inlet ammonium (183-438 mg/L), and hydraulic retention time of the aerobic reactor (8, 12, and 18 hours). The overall organic loading rate was in the range of 3.60-17.37 gCOD/m2·day, of which 18.5-91% was removed in the anoxic reactor depending on the operational conditions.... 

    Dynamic optimization of natural gas networks under customer demand uncertainties

    , Article Energy ; Volume 134 , 2017 , Pages 968-983 ; 03605442 (ISSN) Ahmadian Behrooz, H ; Bozorgmehry Boozarjomehry, R ; Sharif University of Technology
    Abstract
    In natural gas transmission networks, the efficiency of daily operation is strongly dependent on our knowledge about the customer future demands. Unavailability of accurate demand forecasts makes it more important to be able to characterize the loads and quantify the corresponding uncertainty. A planning strategy for natural gas transmission networks under future demand uncertainty is addressed, which involves coupling of a gas transmission network dynamic simulator with the stochastic optimization framework. Loads from a gas-fired power plant are studied where the loads are characterized by a number of uncertain parameters, and unscented transform is utilized for uncertainty propagation.... 

    Capacity and output power estimation approach of individual behind-the-meter distributed photovoltaic system for demand response baseline estimation

    , Article Applied Energy ; Volume 253 , 2019 ; 03062619 (ISSN) Li, K ; Wang, F ; Mi, Z ; Fotuhi Firuzabad, M ; Duić, N ; Wang, T ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    Accurate customer baseline load (CBL) estimation is critical for implementing incentive-based demand response (DR) programs. The increasing penetration of grid-tied distributed photovoltaic systems (DPVS) complicates customers’ load patterns, making the CBL estimation more difficult because the volatile actual load and the intermittent PV output power are coupled together. A PV-load decoupling framework is proposed in this paper to address the above issue. The basic idea is to decouple the actual load power and the PV output power, then estimate them separately. To this end, historical PV output power data of each individual DPVS is required. However, pure historical PV output power data is... 

    Fuzzy hierarchical queueing models for the location set covering problem in congested systems

    , Article Scientia Iranica ; Volume 15, Issue 3 , 2008 , Pages 378-388 ; 10263098 (ISSN) Shavandi, H ; Mahlooji, H ; Sharif University of Technology
    Sharif University of Technology  2008
    Abstract
    In hierarchical service networks, facilities at different levels provide different types of service. For example, in health care systems, general centers provide low-level services, such as primary health care, while specialized hospitals provide high-level services. Because of the demand congestion at service networks, the location of servers and their allocation of demand nodes can have a strong impact on the length of the queue at each server, as well as on the response time to service calls. This study attempts to develop hierarchical location-allocation models for congested systems by employing a queueing theory in a fuzzy framework. The parameters of each model are approximately... 

    Disaggregate mode choice analysis for work trips using genetic-fuzzy and neuro-fuzzy systems

    , Article 10th IASTED International Conference on Artificial Intelligence and Soft Computing, ASC 2006, Palma de Mallorca, 28 August 2006 through 30 August 2006 ; 2006 , Pages 250-255 ; 0889866104 (ISBN); 9780889866102 (ISBN) Shafahi, Y ; Nazari, S ; Sharif University of Technology
    2006
    Abstract
    This paper applies the genetic-fuzzy and neuro-fuzzy systems to analyze a disaggregate mode choice problem for work trips. These two artificial intelligence methods have been widely used in many complex engineering problems recently. Some key points in developing genetic-fuzzy and neuro-fuzzy systems to analyze the mode choice problem for a large city are explained. Shiraz urban trips database is applied to prepare the data needed for the models. Results show that the developed models have good ability to estimate the existing situation and also to present reliable predictions for the future conditions of an urban transportation system  

    Evaluation of long-term steel demand in developing countries- Case study: Iran

    , Article Resources Policy ; Volume 77 , 2022 ; 03014207 (ISSN) Kolagar, M ; Saboohi, Y ; Fathi, A ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    The present study evaluates the application of top-down steel demand estimation in developing countries. The anticipated steel demand for the case of Iran is calculated by three methods, including the growth model (GM), the intensity of use hypothesis (IUH), and the fixed stock paradigm (FCP). GM shows a broad range of apparent steel demand based on the assumed growth factor. When the gross domestic product (GDP) per capita reaches 13,000 dollars per person (constant 2010 US$), the IUH method estimates the consumption peak consumption at around 500 kg steel per capita per year, which is being expected between 2040 and 2060 depending on the economic growth assumptions. Since fluctuations in...