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shirani--mohammad
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Designing a Multi-Level Supply Chain Model with Pricing and Marketing Considerations Based on Sales Contract Approach
, M.Sc. Thesis Sharif University of Technology ; Hajji, Alireza (Supervisor)
Abstract
Nowadays, with the development of various technologies and the competitive market environment, businesses must make great efforts to supply, produce, and distribute their goods and products. The design of the supply chain network, which includes distribution, has a significant impact on the chain's profitability and customer satisfaction. The supply chain network design decisions, which constitute the most important part of strategic level decisions of supply chain management, include determining the required product capacity, allocating them to different sources and markets, integrating facilities, and pricing. Pricing strategy is critical to determine the right price at different levels of...
An experimental review on microbubble generation to be used in echo-particle image velocimetry method to determine the pipe flow velocity
, Article Journal of Fluids Engineering, Transactions of the ASME ; Volume 135, Issue 3 , Feb , 2013 , Paper No: FE-12-1217 ; 00982202 (ISSN) ; Shafii, M. B ; Shirani, S ; Sharif University of Technology
2013
Abstract
Microbubbles are broadly used as ultrasound contrast agents. In this paper we use a low-cost flow focusing microchannel fabrication method for preparing microbubble contrast agents by using some surface active agents and a viscosity enhancing material to obtain appropriate microbubbles with desired lifetime and stability for any in vitro infusion for velocity measurement. All the five parameters that govern the bubble size extract and some efforts are done to achieve the smallest bubbles by adding suitable surfactant concentrations. By using these microbubbles for the echo-particle image velocimetry method, we experimentally determine the velocity field of steady state and pulsatile pipe...
New approach for strategic bidding of gencos in energy and spinning reserve markets
, Article Energy Conversion and Management ; Volume 48, Issue 7 , 2007 , Pages 2044-2052 ; 01968904 (ISSN) ; Ranjbar, A. M ; Shirani, A. R ; Sharif University of Technology
2007
Abstract
In restructured and de-regulated power systems, generating companies (Gencos) are responsible for supplying electricity for both energy and reserve markets, which usually operate simultaneously. In this condition, the question is how much and for what price must each Genco generate for each market to maximize its profit, so this paper intends to answer to this question. In this paper, first, the combined energy and reserve markets are considered, and the Nash equilibrium points are determined. Then, the bidding strategies for each Genco at these points will be presented. The bids for the energy and 10 min spinning reserve (TMSR) markets are separated in the second stage, and again, the...
New approach to bidding strategies of generating companies in day ahead energy market
, Article Energy Conversion and Management ; Volume 49, Issue 6 , 2008 , Pages 1493-1499 ; 01968904 (ISSN) ; Ranjbar, A. M ; Shirani, A. R ; Sharif University of Technology
2008
Abstract
In the restructured power systems, generating companies (Genco) are responsible for selling their product in the energy market. In this condition, the question is how much and for what price must each Genco generate to maximize its profit. Therefore, this paper intends to propose a rational method to answer this question. In the proposed methodology, the hourly forecasted market clearing price (FMCP) is used as a reference to model the possible and probable price strategies of Gencos. The forecasted price is the basis of the bidding strategies of each Genco, which can be achieved by solving a bi-level optimization problem using GAMS (general algebraic modeling system) language. The first...
Strategic bidding of generating units in competitive electricity market with considering their reliability
, Article International Journal of Electrical Power and Energy Systems ; Volume 30, Issue 3 , 2008 , Pages 193-201 ; 01420615 (ISSN) ; Ranjbar, A. M ; Shirani, A. R ; Sharif University of Technology
2008
Abstract
In the restructured power systems, they are typically scheduled based on the offers and bids to buy and sell energy and ancillary services (AS) subject to operational and security constraints. Generally, no account is taken of unit reliability when scheduling it. Therefore generating units have no incentive to improve their reliability. This paper proposes a new method to obtain the equilibrium points for reliability and price bidding strategy of units when the unit reliability is considered in the scheduling problem. The proposed methodology employs the supply function equilibrium (SFE) for modeling a unit's bidding strategy. Units change their bidding strategies and improve their...
A new structure for electricity market scheduling
, Article 2006 International Conference on Power Electronics, Drives and Energy Systems, PEDES '06, New Delhi, 12 December 2006 through 15 December 2006 ; 2006 ; 078039772X (ISBN); 9780780397729 (ISBN) ; Ranjbar, A. M ; Shirani, A. R ; Sharif University of Technology
2006
Abstract
On pool market structure, the generating units are typically dispatched in order of lowest to highest bid as needed to meet demand requirement as well as considering network constraints. Generally, no account is taken of generating unit's reliability when scheduling them. This paper proposes a new structure for electricity market to consider generating unit's reliability in the scheduling problem. GAMS (General Algebraic Modeling System) language has been used to solve the social welfare maximization problem using CPLEX optimization software with mixed integer programming. ©2006 IEEE
Strategic bidding with regard to demand elasticity
, Article Iranian Journal of Science and Technology, Transaction B: Engineering ; Volume 30, Issue 6 , 2006 , Pages 691-700 ; 03601307 (ISSN) ; Ranjbar, A. M ; Shirani, A. R ; Sharif University of Technology
2006
Abstract
This paper presents a new method to analyze the bidding strategies of Generating Companies (GENCOs) with regard to demand elasticity. It is assumed that the available information of each GENCO about its opponents is incomplete and only the minimum and maximum generation levels of their opponents, as well as their fuel type, are known. In the proposed methodology, GENCOs prepare their strategic bids according to a Supply Function Equilibrium (SFE) model. GENCOs will change their bidding strategies until Nash equilibrium points are obtained. The general Algebraic Modeling System (GAMS) has been used to solve the maximization modules using the MINOS optimization software with non Linear...
A new approach for distribution state estimation based on ant colony algorithm with regard to distributed generation
, Article Journal of Intelligent and Fuzzy Systems ; Volume 16, Issue 2 , 2005 , Pages 119-131 ; 10641246 (ISSN) ; Ranjbar, A. M ; Shirani, A. R ; Sharif University of Technology
2005
Abstract
Technology enhancement of Distributed Generations, as well as deregulation and privatization in power system industry, shows a new perspective for power systems and subsystems. When a substantial portion of generation is in the form of dispersed and small units, a new connection pattern emerges whereby the dispersed units are embedded in reticulation infrastructure. Now, the flow of power is no longer the same as in the conventional systems, since the dispersed generating plants contribute with generation also at the distribution grids level. Connection of generation to distribution grids cannot effectively be made, unless the some especial control and monitoring tools are available and...
An approach to Volt/Var control in distribution networks with distributed generation
, Article Scientia Iranica ; Volume 12, Issue 1 , 2005 , Pages 34-42 ; 10263098 (ISSN) ; Ranjbar, A. M ; Shirani, A. R ; Sharif University of Technology
Sharif University of Technology
2005
Abstract
Due to deregulation and restructuring in many countries, it is expected that the amount of small-scale generations connected to the distribution networks will increase. So, it is necessary that the impact of these kinds of generators on Volt/Var control should be investigated. This paper presents a new approach to Volt/Var control in distribution systems with Distributed Generation (DG). It has been shown that DG can improve the entire performance of a network system, by means of better control and decreasing losses. In this approach, the Genetic Algorithm (GA) has been used as the optimization method, where the amount of DG and its controlling parameters, the voltage regulators situation,...
Power system stability assessment during restoration based on a wide area measurement system
, Article IET Generation, Transmission and Distribution ; Volume 6, Issue 11 , 2012 , Pages 1171-1179 ; 17518687 (ISSN) ; Karimi, M. J ; Ranjbar, A. M ; Shirani, A ; Sharif University of Technology
2012
Abstract
Online power system stability assessment during restoration has not been strongly addressed yet. The introduction of wide area measurement systems (WAMS), however, made it possible to monitor the stability online. This study technically presents a detailed analysis of stability during restoration using WAMS. The power system build-up strategy is used as the restoration approach, based on which the early and the last stages of restoration are to divide the power system into islands and interconnect them, respectively. In fact, the practical use of WAMS at the early stages of restoration provides precise determination of generators loading steps. Moreover, unification of phase angle references...
Numerical investigation on the effect of the size and number of stages on the tesla microvalve efficiency
, Article Journal of Mechanics ; Volume 29, Issue 3 , 2012 , Pages 527-534 ; 17277191 (ISSN) ; Kolahdouz, E. M ; Shirani, E ; Shafii, M. B ; Sharif University of Technology
2012
Abstract
In the present study, the effect of the number of stages of Tesla Micro-Valve (TMV), as well as the dependency of Reynolds number, Re, on the valve performance has been analyzed. For this purpose, different layouts include one to four-stage with different sizes are investigated numerically. The main criterion for evaluation of valves performance is diodicity, Di. Unsteady and steady flow in valve have been simulated and compared. It is shown that although there are some difference but the trend is similar for both responses. Finally, 2-D and steady state computations of the fluid flow have been utilized that reveal a strong dependence of Di on Re and pressure drop, ΔP. The results showed...
Geometrical analysis of localization error in stereo vision systems
, Article IEEE Sensors Journal ; Volume 13, Issue 11 , 2013 , Pages 4236-4246 ; 1530437X (ISSN) ; Samavi, S ; Soroushmehr, S. M. R ; Shirani, S ; Sharif University of Technology
2013
Abstract
Determining an object location in a specific region is an important task in many machine vision applications. Different parameters affect the accuracy of the localization process. The quantization process in charge-coupled device of a camera is one of the sources of error that causes estimation rather than identifying the exact position of the observed object. A cluster of points, in the field of view of a camera are mapped into a pixel. These points form an uncertainty region. In this paper, we present a geometrical model to analyze the volume of this uncertainty region as a criterion for object localization error. The proposed approach models the field of view of each pixel as an oblique...
Numerical study on the performance of Tesla type microvalve in a valveless micropump in the range of low frequencies
, Article Journal of Micro-Bio Robotics ; Volume 8, Issue 3 , 2013 , pp 145-159 ; 21946418 (ISSN) ; Kolahdouz, E. M ; Shirani, E ; Shafii, M. B ; Sharif University of Technology
2013
Abstract
In this study, the performance of Tesla-type microvalves, used in micropumps for low frequency driving force, is examined. Three-dimensional and unsteady numerical analysis of fluid flow inside a valveless reciprocating micropump in the range of low working frequencies is carried out. Reciprocating movement of flow actuator provides the actuation and pumping of the working fluid. Ferrofluidic valveless micropump is one practical sample of this kind of micropumps that operate in the range of low working frequencies. To model the reciprocating movement of flow actuator, two time varying functions that includes sinusoidal and step excitation are employed. Also, the performance of...
Modeling self-assembly of the surfactants into biological bilayer membranes with special chemical structures using dissipative particle dynamics method
, Article Scientia Iranica ; Volume 23, Issue 3 , 2016 , Pages 942-950 ; 10263098 (ISSN) ; Pishevar, A. R ; Saidi, M. S ; Shirani, E ; Sharif University of Technology
Sharif University of Technology
2016
Abstract
The aim of this study is to simulate the self-assembly of the surfactant molecules with special chemical structure and bending stiffiness into bilayer membranes using a mesoscopic Dissipative Particle Dynamics (DPD) method. The surfactants are modeled with special chemical structure and bending stiffiness. To confirm that the novel model is physical, we determine the interaction parameters based on matching the compressibility and solubility of the DPD system with real physics of the uid. To match the mutual solubility for binary uids, we use the relation between DPD parameters and x-parameters in Flory-Huggins-type models. Unsaturated bonds can change the stiffiness of a lipid membrane,...
Optimal placement of phasor measurement units: Particle swarm optimization approach
, Article 2007 International Conference on Intelligent Systems Applications to Power Systems, ISAP ; 2007 ; 9860130868 (ISBN); 9789860130867 (ISBN) ; Ranjbar, A. M ; Amraee, T ; Shirani, A. R ; Sharif University of Technology
2007
Abstract
This paper is concerned about the optimal placement of phasor measurement units (PMUs) so as to make a system completely observable. Observability assessment is done by the aid of the topological observability rules. Moreover a new rule is added which can decrease the number of required PMUs for complete system observability. A modified binary particle swarm is used as an optimization tool for obtaining the minimal number of PMUs and corresponding configuration. In order to improve the speed of convergence, an initial PMU placement is provided by graph-theoretic procedure. The simulation results of proposed approach are presented for several IEEE test systems
A competitive market structure for reactive power procurement
, Article Iranian Journal of Science and Technology, Transaction B: Engineering ; Volume 30, Issue 2 , 2006 , Pages 259-276 ; 03601307 (ISSN) ; Ranjbar, A. M ; Amraee, T ; Shirani, A. R ; Sharif University of Technology
2006
Abstract
This paper first proposes a competitive market structure for reactive power procurement and then develops a methodology for incorporating voltage stability problems into the model. The owners of electric transactions should participate in this competitive framework and submit their own firmness bids in ($/MW) to the Independent/System/Market Operator (ISOIMO). ISO clears the market for reactive energy regarding the value of each transaction and utilization cost of reactive power on one hand, and the impact of transaction amount on the voltage security of the power system on the other hand. Here, the voltage stability margin is incorporated into the power flow equations so that the security...
Computing optimum bidding strategy of gencos using simulated annealing method
, Article 2006 IEEE International Conference on Industrial Technology, ICIT, Mumbai, 15 December 2006 through 17 December 2006 ; 2006 , Pages 2563-2568 ; 1424407265 (ISBN); 9781424407262 (ISBN) ; Ranjbar, A. M ; Shirani, A. R ; Sadati, N ; Sharif University of Technology
2006
Abstract
This paper describes a new method that uses Simulated Annealing (SA) method for analyzing the competition among Generating Companies (Gencos) where they have incomplete information about their opponents. Each Genco models its opponents with their generating cost coefficients. The proposed methodology employs the Supply Function Equilibrium (SFE) for modeling a Genco's bidding strategy. Gencos change their bidding strategies until Nash equilibrium points are obtained. Nash equilibrium constitutes a central solution concept in game theory. The task of detecting the Nash equilibria of a finite strategic game remains a challenging up-todate. This paper uses SA to compute Nash equilibria...
Reactive power management in a deregulated power system with considering voltage stability: Particle swarm optimisation approach
, Article Eighteenth International Conference and Exhibition on Electricity Distribution, CIRED 2005, Technical Reports - Session 1: Network Components, Turin, 6 June 2005 through 9 June 2005 ; Volume 6, Issue 2005-11034 , 2005 , Pages 55-58 ; 05379989 (ISSN) ; Ranjbar, A. M ; Shirani, A. R ; Mozafari, A ; Sharif University of Technology
2005
A new approach based on ant colony algorithm to distribution management system with regard to dispersed generation
, Article Eighteenth International Conference and Exhibition on Electricity Distribution, CIRED 2005, Technical Reports - Session 1: Network Components, Turin, 6 June 2005 through 9 June 2005 ; Volume 4, Issue 2005-11034 , 2005 , Pages 219-223 ; 05379989 (ISSN) ; Ranjbar, A. M ; Shirani, A. R ; Ostadi, A ; Sharif University of Technology
2005
A new approach based on ant algorithm for Volt/Var control in distribution network considering distributed generation
, Article Iranian Journal of Science and Technology, Transaction B: Engineering ; Volume 29, Issue 4 , 2005 , Pages 385-398 ; 03601307 (ISSN) ; Ranjbar, A. M ; Shirani, A. R ; Ostadi, A ; Sharif University of Technology
2005
Abstract
Recently, in many countries, power systems are moving towards creating a competitive structure for trading electrical energy. These changes, along with the numerous advantages of the Distributed Generators (DGs), have created more incentives for distribution companies to use these kinds of generators more than ever before. The Volt/Var control is one of the most important control schemes in distribution networks, which can be affected by DGs. This paper presents a new approach for the Volt/ Var control in distribution networks. The output reactive powers of the DGs, Static Var Compensators (SVCs), Load Tap Changers (LTCs) and the settings of the local controllers are chosen as the control...