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fuzzy-decision-makings
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Iteration Control in Design Process
, Ph.D. Dissertation Sharif University of Technology ; Malaek, Mohammad Bagher (Supervisor)
Abstract
The main goal of this research is to reduce aircraft design cycle period, by reducing the necessary number of design cycle iterations. The Design cycle period is one of the main characteristics of the design process and design cycle iterations play a major role in the design cycle period. To achieve the above mentioned goal, we present a mathematical model of iterations for the aircraft design process. This model describes the design coupled tasks as a discrete-linear time invariant dynamic system. This model also helps identify tasks which are the most important for generating iterations. This new method basically helps break information cycles that create iterations among important tasks....
Phase Identification and Balancing in LV Distribution Networks Using Smart Meters Data
, M.Sc. Thesis Sharif University of Technology ; Safdarian, Amir (Supervisor)
Abstract
With the rapid proliferation of residential rooftop photovoltaic (PV) systems, current and voltage unbalance issues have become a matter of great concern in low voltage (LV) distribution feeders. This, however, necessitates identification of the hosting phase of the connected single-phase customers and PV panels. Both of the challenges have been addressed in this thesis. In the first place, this thesis proposes a mixed integer linear programming (MILP) model for phase identification problem. The model considers potential error in the input data provided by smart meters. To mitigate negative impacts of the error, the data associated with several consecutive time intervals are taken into...
Intelligent mobile robot navigation in an uncertain dynamic environment
, Article Applied Mechanics and Materials ; Volume 367 , 2013 , Pages 388-392 ; 16609336 (ISSN) ; 9783037857885 (ISBN) ; Entesari, F ; Osgouie, K. G ; Cheragh, M ; Sharif University of Technology
2013
Abstract
This paper presents a modified sensor-based online method for mobile robot navigation generating paths in dynamic environments. The core of the navigation algorithm is based on the velocity obstacle avoidance method and the guidance-based tracking algorithm. A fuzzy decision maker is designed to combine the two mentioned algorithms intelligently. Hence the robot will be able to decide intelligently in various situations when facing the moving obstacles and moving target. A noble noise cancellation algorithm using Neural Network is designed to navigate the robot in an uncertain dynamic environment safely. The results show that the robot can track a moving target while maneuvering safely in...
A scenario-based multi-objective model for multi-stage transmission expansion planning
, Article IEEE Transactions on Power Systems ; Volume 26, Issue 1 , May , 2011 , Pages 470-478 ; 08858950 (ISSN) ; Hosseini, S. H ; Oloomi Buygi, M ; Shahidehpour, M ; Sharif University of Technology
2011
Abstract
The unbundling of the electricity industry introduced new uncertainties and escalated the existing ones in transmission expansion planning. In this paper, a multi-stage transmission expansion methodology is presented using a multi-objective optimization framework with internal scenario analysis. Total social cost (TSC), maximum regret (robustness criterion), and maximum adjustment cost (flexibility criterion) are considered as three optimization objectives. Uncertainties are considered by defining a number of scenarios. To overcome the difficulties in solving the nonconvex and mixed integer optimization problem, the genetic-based Non-dominated Sorting Genetic Algorithm (NSGA II) is used....
Probabilistic multi-objective transmission investment and expansion planning
, Article International Transactions on Electrical Energy Systems ; Volume 25, Issue 9 , September , 2015 , Pages 1884-1904 ; 20507038 (ISSN) ; Hosseini, S. H ; Moeini Aghtaie, M ; Sharif University of Technology
John Wiley and Sons Ltd
2015
Abstract
In market-based planning studies, the financial aspects of transmission grids have been posed as a major challenge since these are important keys to provide a non-discriminative and competitive environment for energy market participants. In this respect, this paper proposes a probabilistic multi-objective transmission expansion planning algorithm considering private investors' preferences, technical concerns, and random nature of power system uncertainties. The combination of Non-Dominated Sorting Genetic Algorithm II, as a widely-used robust multi-objective optimization technique, and point estimation method is employed to handle non-commensurable probabilistic objective functions. The IEEE...
A multi-objective framework for enhancing the reliability and minimizing the cost of PMU deployment in power systems
, Article Scientia Iranica ; Volume 23, Issue 6 , 2016 , Pages 2917-2927 ; 10263098 (ISSN) ; Safdarian, A ; Fotuhi-Firuzabad, M ; Shahidehpour, M ; Sharif University of Technology
Sharif University of Technology
2016
Abstract
Wide-Area Monitoring, Protection, And Control (WAMPAC) is a key factor in the implementation of smart transmission grids. WAMPAC has a crucial role in detection and prevention of widespread events with an ultimate goal of improving the electricity service reliability. Several mathematical techniques were proposed for the Optimal Phasor Measurement Units (PMU) Placement (OPP) problem which represents the first step toward the development of WAMPAC. These techniques consider either the solution to the network observability or realization of specific PMU applications. This paper proposes a multi-objective framework for OPP which emphasizes the reliability of power systems. The objective...
Application of fuzzy decision making in mobile robot navigation in dynamic environments
, Article IEEE International Conference on Fuzzy Systems, 20 August 2009 through 24 August 2009 ; 2009 , Pages 877-881 ; 10987584 (ISSN) ; 9781424435975 (ISBN) ; Seifipour, N ; Sharif University of Technology
Abstract
This paper presents a modified sensor-based online method for mobile robot navigation generating paths in dynamic environments. The intelligent part of the algorithm is a Fuzzy Decision Maker (FDM) which enables the robot to do both the guidance-based tracking algorithm and the obstacle avoidance simultaneously. The output of FDM is a weighted combination of velocity vectors generated by velocity obstacle algorithm and guidance based tracking algorithm. The results prove that the robot can track a moving target while maneuvering safely in dynamic environment and avoids stationary and moving obstacles
A multi-objective framework for transmission expansion planning in deregulated environments
, Article IEEE Transactions on Power Systems ; Volume 24, Issue 2 , 2009 , Pages 1051-1061 ; 08858950 (ISSN) ; Hosseini, H ; Oloomi Buygi, M ; Shahidehpour, M ; Sharif University of Technology
2009
Abstract
Deregulation of power system has introduced new objectives and requirements for transmission expansion problem. In this paper, a static transmission expansion methodology is presented using a multi-objective optimization framework. Investment cost, reliability (both adequacy and security), and congestion cost are considered in the optimization as three objectives. To overcome the difficulties in solving the nonconvex and mixed integer nature of the optimization problems, the genetic based NSGA II algorithm is used followed by a fuzzy decision making analysis to obtain the final optimal solution. The planning methodology has been demonstrated on the IEEE 24-bus test system to show the...
A two-phase linear programming methodology for fuzzy multi-objective mixed-model assembly line problem
, Article International Journal of Advanced Manufacturing Technology ; Volume 44, Issue 9-10 , 2009 , Pages 1010-1023 ; 02683768 (ISSN) ; Javadi, B ; Sahebjamnia, N ; Mahdavi Amiri, N ; Sharif University of Technology
2009
Abstract
We develop a fuzzy multi-objective linear programming (FMOLP) model for solving multi-objective mixed-model assembly line problem. In practice, vagueness and imprecision of the goals in this problem make the fuzzy decision-making complicated. The proposed model considers minimizing total utility work, total production rate variation, and total setup cost, using a two-phase linear programming approach. In the first phase, the problem is solved using a max-min approach. The max-min solution not being efficient, in general, we propose a new model in the second phase to maximize a composite satisfaction degree at least as good as the degrees obtained by phase one. To show the effectiveness of...
Unbalance mitigation by optimal placement of static transfer switches in low voltage distribution feeders
, Article IET Generation, Transmission and Distribution ; Volume 14, Issue 20 , 2020 , Pages 4612-4621 ; Safdarian, A ; Lehtonen, M ; Sharif University of Technology
Institution of Engineering and Technology
2020
Abstract
With the rapid proliferation of residential rooftop photovoltaic (PV) systems, current and voltage unbalance issues have become a matter of great concern in low voltage (LV) distribution feeders. To overcome the issues, this study proposes a model to optimally rephase customers and PVs among the three phases via static transfer switches (STSs). The optimal STS placement is also considered in the model to achieve a cost effective solution with optimum number and location of STSs. The objective is to minimise total energy losses caused by current unbalance, minimise the number of STSs, and keep voltage unbalance along the feeder within the acceptable range. The model is solved via a...
A heuristic trade off model for integration of distributed generations in deregulated power systems considering technical, economical and environmental issues
, Article 2008 IEEE 2nd International Power and Energy Conference, PECon 2008, Johor Baharu, 1 December 2008 through 3 December 2008 ; 2008 , Pages 1275-1279 ; 9781424424054 (ISBN) ; Nasiri, R ; Bagheri, M ; Tehrani, A. A ; Sharif University of Technology
2008
Abstract
With the introduction of restructuring concepts to traditional power systems, a great deal of attention is given to the utilization of distributed generation. Since the integration of DG units has been known as an alternative for main grid as a resource for energy supply, the determination of optimal sizing and sitting is an important issue in the planning procedure of DG. This work presents a comprehensive multi-objective model for integration of distributed generations into a distribution network, regarding various technical, economical and environmental issues such as reduction of carbon dioxide emissions and investment & running costs while the bus voltages shall be kept within...
Intelligent based trajectory planning in Terrain Following flight
, Article 25th Congress of the International Council of the Aeronautical Sciences 2006, Hamburg, 3 September 2006 through 8 September 2006 ; Volume 5 , 2006 , Pages 3169-3175 ; Malaek, S. M ; Sharif University of Technology
Curran Associates Inc
2006
Abstract
A novel approach in Terrain Following/Terrain Avoidance (TF/TA) flight is proposed that facilitates flying over unknown terrains. Intelligency is implemented using fuzzy decision making tools. This method can be used in offline design in trajectory planning which has wide applications in TF/TA. A relationship b etween slope of terrain and aircraft height with speed of aircraft is constructed by fuzzy approach
How does psychological empowerment affect knowledge management improvement in organizations? a study of cause-and-effect relationship using the fuzzy DEMATEL method
, Article IEEE Transactions on Engineering Management ; 2021 ; 00189391 (ISSN) ; Mohammadi, M ; Maleki, A ; Bonyadi Naeini, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
The present article aims to investigate the cause-and-effect relationship between the employees’ psychological empowerment (PE) and dimensions of knowledge management (KM) in an oil company, using the fuzzy decision-making trial and evaluation laboratory method. The study population consists of oil company experts. The sample size is determined based on the theoretical saturation limit. The present findings show that PE is the strongest causative factor with significant effects on knowledge creation (KC) and knowledge dissemination (KD). Among the KM dimensions, the most influential factors are the dimensions of KC, knowledge application, and knowledge capture (KCA). Of all KM dimensions,...