Search for: effective-approaches
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    New encoding methods for SAT-based temporal planning

    , Article ICAPS 2013 - Proceedings of the 23rd International Conference on Automated Planning and Scheduling ; June , 2013 , Pages 73-81 ; 9781577356097 (ISBN) Rankooh, M. F ; Ghassem Sani, G ; Feyzbakhsh Rankooh, M ; Sharif University of Technology
    Although satisfiability checking is known to be an effective approach in classical planning, it has scarcely been investigated in the field of temporal planning. Most notably, the usage of ∃-step semantics for encoding the problem into a SAT formula, while being demonstrably quite efficient for decreasing the size of the encodings in classical planning, has not yet been employed to tackle temporal planning problems. In this paper, we define temporal versions of classical ∀-step and ∃-step plans. We show that when the casual and temporal reasoning phases of a SAT-based temporal planner are separated, these semantics can be used to translate a given temporal planning problem into a SAT... 

    A review on recent advances in humidification-dehumidification (HDH) desalination systems integrated with refrigeration, power and desalination technologies

    , Article Energy Conversion and Management ; Volume 196 , 2019 , Pages 1002-1036 ; 01968904 (ISSN) Faegh, M ; Behnam, P ; Shafii, M.B ; Sharif University of Technology
    Elsevier Ltd  2019
    Water and energy supply are two of the key issues human beings must address to attain sustainable development. Humidification-dehumidification technology has been proven to be a cost-effective approach to fulfill the freshwater demand. Particular attention has been given to coupling the humidification-dehumidification cycles with refrigeration, power and other desalination technologies with the aim of enhancing the performance of the combined cycle as well as increasing the amount of produced freshwater, cooling effect, power, etc. This paper provides a comprehensive review of the state-of-the-art investigations in terms of humidification-dehumidification technologies and their integration... 

    Network-Constrained transactive coordination for plug-in electric vehicles participation in real-time retail electricity markets

    , Article IEEE Transactions on Sustainable Energy ; Volume 12, Issue 2 , 2021 , Pages 1439-1448 ; 19493029 (ISSN) Saber, H ; Ehsan, M ; Moeini Aghtaie, M ; Fotuhi Firuzabad, M ; Lehtonen, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2021
    Uncoordinated adoption of plug-in electric vehicles (PEVs) imposes further load on the distribution network, and therefore may result in disruptive impacts on the grid. Transactive coordination of PEVs has been introduced as an effective approach to mitigate these negative consequences. This paper furthers efforts enabling PEVs to participate in a real-time retail electricity market under a transactive energy (TE) paradigm. In this regard, PEV owners will estimate their willingness to pay/accept using a user-friendly strategy and submit the estimated values to the retail market operator. Then using a network-constrained market clearing mechanism, the clearing prices, i.e., dual variables of... 

    Parametric study and design approach of off-center bracing systems

    , Article Structural Design of Tall and Special Buildings ; Volume 26, Issue 3 , 2017 ; 15417794 (ISSN) Sedaghati, P ; Lotfollahi, M ; Mofid, M ; Sharif University of Technology
    This paper presents an effective approach for the seismic design of off-center bracing systems (OBSs). The nonlinear behavior of an OBS can be specified by evaluation of two yielding stages representing tensile yielding of different bracings. This can be achieved when stiffness of the corner brace member is deliberately considered less enough to act as a fuse-like component. An accurate two-dimensional finite element modeling for the geometric and material nonlinearity of such systems considering buckling behavior of the brace members is developed. Through an extensive parametric study, the optimal ratios of the influential parameters of OBS are obtained, and their effects on the nonlinear... 

    A variables neighborhood search algorithm for solving fuzzy quadratic programming problems using modified Kerre’s method

    , Article Soft Computing ; Volume 23, Issue 23 , 2019 , Pages 12305-12315 ; 14327643 (ISSN) Ghanbari, R ; Ghorbani Moghadam, K ; Mahdavi Amiri, N ; Sharif University of Technology
    Springer Verlag  2019
    To solve a fuzzy optimization problem, we need to compare fuzzy numbers. Here, we make use of our recently proposed modified Kerre’s method as an effective approach for comparison of LR fuzzy numbers. Using our new results on LR fuzzy numbers, we show that to compare two LR fuzzy numbers, we do not need to compute the fuzzy maximum of two numbers directly. We propose a new variable neighborhood search approach for solving fuzzy number quadratic programming problems by using the modified Kerre’s method. In our algorithm, a local search is performed using descent directions, found by solving five crisp mathematical programming problems. In several available methods, a fuzzy optimization... 

    A closed-loop supply chain considering carbon reduction, quality improvement effort, and return policy under two remanufacturing scenarios

    , Article Journal of Cleaner Production ; Volume 232 , 2019 , Pages 1230-1250 ; 09596526 (ISSN) Taleizadeh, A. A ; Alizadeh Basban, N ; Akhavan Niaki, S. T ; Sharif University of Technology
    Elsevier Ltd  2019
    In today's competitive supply chains, providing products which can stimulate the customer's demand and enhance the revenues of companies is an important objective. Therefore, three stimulating factors, including the carbon emission reduction, return policy and quality improvement efforts are taken into consideration in a supply chain (SC). In line with reducing carbon emission, two possibilities in the forward flow, including the technologies investment and the trade and cap are employed. In the reverse flow, hybrid remanufacturing of the imperfect quality products under technology license is investigated. The impacts of collecting-remanufacturing processes on carbon reduction, quality... 

    Structural, microstructural and electrochemical studies of TiO2-Ag double layer coated NCM cathode for lithium-ion batteries

    , Article Materials Research Express ; Volume 6, Issue 8 , 2019 ; 20531591 (ISSN) Sharifi Rad, A ; Ghorbanzadeh, M ; Sharif University of Technology
    Institute of Physics Publishing  2019
    Lithium ion batteries as one of the most important energy storage equipments, have several challenges including capacity drop as number of cycles increases. Cathode particle coating is an effective approach in improvement of electrochemical performance of the batteries. In this study, TiO2-Ag coating was used to improve NCM cathode performance. The microstructure and crystal structure properties of coated NCMs were evaluated by the FE-SEM and XRD. Electrochemical behavior of the batteries was investigated by cycling performance analysis and EIS. TiO2 coating was deposited as a uniform layer and Ag coating was precipitated as dispersed nanoparticles. The results shows that using of TiO2-Ag... 

    Enhancement of pool boiling heat transfer using ferromagnetic beads in a variable magnetic field

    , Article Applied Thermal Engineering ; Volume 164 , 2020 Rahmati, P ; Ebrahimi Dehshali, M ; Hakkaki Fard, A ; Sharif University of Technology
    Elsevier Ltd  2020
    The pool boiling is one of the heat transfer mechanisms used in cooling systems. Using an external force to improve the efficiency of thermo-fluid systems is among the most effective approaches, and also highly applicable in enhancing heat transfer. In this study, the pool boiling of water, as the working fluid, in the presence of a variable magnetic field, is studied. To this end, ferromagnetic beads were placed on the boiling surface, and the effect of their movements due to a variable magnetic field was observed and measured. The number of beads was selected such that they would cover 1/3, 1/2 and 2/3 of the surface in different cases and the magnetic field was controlled by altering... 

    Automatic promotional specialization, generalization and analysis of extended feature models with cardinalities in Alloy

    , Article Journal of Logical and Algebraic Methods in Programming ; Volume 84, Issue 5 , September , 2015 , Pages 640-667 ; 23522216 (ISSN) Ajoudanian, S ; Hosseinabadi, S. H. M ; Sharif University of Technology
    Elsevier Inc  2015
    Abstract Software product line engineering is a method of producing a set of related products that share more commonalities than variability in a cost-effective approach. Software product lines provide systematic reuse within a product family. Extended feature models with cardinalities are widely used for managing variability and commonality in the software product line domains. In this paper, we use promotion technique in Alloy to formalize constraint based extended feature models with cardinalities and their specialization and generalization. This technique has a significant influence on applying analysis operations on feature models. To show the benefits of the promotion technique, we... 

    Development of an optimal process for friction stir welding based on GA-RSM hybrid algorithm

    , Article Frattura ed Integrita Strutturale ; Volume 12, Issue 44 , April , 2018 , Pages 106-122 ; 19718993 (ISSN) Mehri Khansari, N ; Berto, F ; Karimi, N ; Ghoreishi, S. M. N ; Fakoor, M ; Mokari, M ; Sharif University of Technology
    Gruppo Italiano Frattura  2018
    Performance of Friction Stir Welding (FSW) as a solid-state process is approved in several engineering applications, especially aluminum industries. Identification of mechanical behavior of the associated welded zone is necessary due to these extensive applications of FSW. In this study, considering the effect of rotational and forward speed of welding tool on the mechanical properties of welded region, a hybrid optimization method based on combination of Genetic Algorithm (GA) and Response Surface Method (RSM) named here as GA-RSM is proposed to achieve maximum tensile and ultimate strength. The results of GA-RSM are validated by per-forming necessary experimental tests on two wide-used... 

    Novel hot milling approach for the synthesis of fine PbZr0.95Ti0.05O3 powders

    , Article Ceramics International ; Volume 45, Issue 18 , 2019 , Pages 24176-24181 ; 02728842 (ISSN) Sayyadi Shahraki, A ; Hojaji Najafabadi, A. R ; Safaei, S ; Sadrnezhaad, Kh ; Sharif University of Technology
    Elsevier Ltd  2019
    A new and effective hot milling system was designed and applied to the synthesis of PbZr0.95Ti0.05O3 (PZT) powder. PbO, ZrO2 and TiO2 powders were used as starting materials and hot milled at various temperatures ranging from 10 ̊°C to 800 ̊°C. The obtained powders were characterized by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). Results indicated that pure, crystalline, and fine PZT powders with the average particle size of 170 nm can be successfully synthesized directly after a relatively short synthesis time of 12 h at lower temperature of 800 ̊°C by the hot milling technique. In contrast to this method, this study demonstrates that conventional solid-state... 

    The effects of viscous dampers on the reliability of steel structures using a PIF index

    , Article Proceedings of the Institution of Civil Engineers: Structures and Buildings ; Volume 172, Issue 4 , 2019 , Pages 289-300 ; 09650911 (ISSN) Rahimiasl, M ; Bakhshi, A ; Sharif University of Technology
    ICE Publishing  2019
    A new comparative performance measure based on a structure's seismic fragility curve is introduced. This factor, called the performance improvement factor (PIF), was used to compare the seismic performance and reliability of two structures. Using the PIF, the efficiency of viscous dampers on the behaviour of a weak mid-rise steel structure was investigated. A prototype five-span 12-storey steel frame was equipped with three patterns of viscous dampers and their seismic performance was studied. The distribution of dampers along the height of the structure was optimised in three hazard levels using a genetic algorithm and the structure was subjected to 12 ground motion records scaled to levels... 

    Numerical analysis of photovoltaic solar panel cooling by a flat plate closed-loop pulsating heat pipe

    , Article Solar Energy ; Volume 206 , 2020 , Pages 455-463 Alizadeh, H ; Alhuyi Nazari, M ; Ghasempour, R ; Shafii, M. B ; Akbarzadeh, A. A ; Sharif University of Technology
    Elsevier Ltd  2020
    Photovoltaic (PV) panels provide a suitable way for the direct conversion of solar energy into electricity. The electrical output and efficiency of PV modules are dependent on working temperature. The present study contributes to investigate the efficiency of utilizing a flat plate closed-loop pulsating heat pipe (CLPHP) to cool down a PV panel in both thermal and economic aspects. Accordingly, a numerical investigation is employed to obtain the surface temperature and electrical gain of the PV panel through four scenarios, including natural cooling without additional equipment, CLPHP-based passive cooling, CLPHP-based active cooling, and a conventional flat plate cooling methods. The... 

    Double layer mesoscopic electron contact for efficient perovskite solar cells

    , Article Sustainable Energy and Fuels ; Volume 4, Issue 2 , 2020 , Pages 843-851 Chavan, R. D ; Yadav, P ; Tavakoli, M. M ; Prochowicz, D ; Nimbalkar, A ; Bhoite, S. P ; Bhosale, P. N ; Hong, C. K ; Sharif University of Technology
    Royal Society of Chemistry  2020
    Interface engineering has emerged as a great strategy for fabrication of high efficiency and stable perovskite solar cells (PSCs). Here, we deposit a thin layer of ZnS as a buffer layer at the interface of the perovskite absorber and electron transporting layer (ETL) using the atomic layer deposition (ALD) process. The impact of the ZnS layer on the photovoltaic characteristics of PSCs was investigated by comparison of two mesoscopic configurations, in which the ZnS layer is grown on compact TiO2 and on mesoporous TiO2 surfaces. Our results revealed that the addition of an ultrathin ZnS layer between the perovskite and ETL drastically improves the charge extraction properties and reduces... 

    An effective approach for aid planning on multi-type transportation networks after a disaster

    , Article International Journal of Industrial and Systems Engineering ; Volume 34, Issue 3 , 2020 , Pages 342-364 Shiripour, S ; Mahdavi Amiri, N ; Sharif University of Technology
    Inderscience Publishers  2020
    We present a new approach for emergency response planning to the injured on a multi-type transportation network. We consider a three-type transportation network with separate connection links simultaneously: road, rail and air networks. In this study, a circle-based approach is presented where using concentric circles with various radiuses, different levels of the effect of a disaster are considered. After formulating the relations, we present an integer nonlinear programming model for the problem. The model is to determine the locations for establishment of temporary aid stations among the candidate locations, the type of aid stations, the percentage of the injured allocated to each...