Loading...
Search for:
mathematical-optimization
0.013 seconds
Removal of Cu (ll) from industrial wastewater using poly (acrylamide-co-2-acrylamide-2-methyl propane sulfonic acid)/graphene oxide/sodium alginate hydrogel: Isotherm, kinetics, and optimization study
, Article Journal of Water Process Engineering ; Volume 42 , 2021 ; 22147144 (ISSN) ; Ghasemi, S ; Khosravi, A ; ZabihiSahebi, A ; Hasan Zadeh, A ; Borghei, S. M ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Here, Graphene oxide/poly (acrylamide -2-acrylamide-methyl-propanesulfonic acid)/sodium alginate (GO/PA-AMPS/SA) hydrogel was synthesized through a free-radical polymerization approach. The impact of Graphene Oxide (GO) content on mechanical strength, swelling behavior, and the adsorption performance of prepared hydrogel was studied. The operating parameters, including contact time, solution pH, and initial Cu(II) content on the adsorption capacity of the hydrogel, were studied. The maximum Cu(II) adsorption capacity of 230.8 mg/g was obtained for GO/PA-AMPS/SA under a pH of 5, the contact time of 270 min, and adsorbent content of 0.5 g/L at 25 °C. The high value of adsorption capacity after...
Design, operation, performance evaluation and mathematical optimization of a vermifiltration pilot plan for domestic wastewater treatment
, Article Journal of Environmental Chemical Engineering ; Volume 8, Issue 1 , 2020 ; Mirzaie, M ; Hasan Zadeh, A ; Ashrafnejad, M ; Hashemian, S. J ; Shahnemati, S. R ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
The present study shows the approach developed and employed to wastewater treatment utilizing the vermifiltration technique in a region with a population of approx. 280 people. The domestic sewage from the residential area accumulated in the septic tank was fed into the system designed based on the combination of the sand filter and the vermifilter with the optimum loading rate of 2m2 per day for 45 days. The pH, electrical conductivity, chemical oxygen demand, turbidity and nitrate concentration of wastewater were measured before and after vermitreatment for the mentioned period. The results demonstrated that the unique combination of the vermifiltration system with the sand filter was able...
Efficient Service Placement and Request Routing in Cooperative Mobile Edge Computing for Data Intensive Systems
, M.Sc. Thesis Sharif University of Technology ; Movaghar, Ali (Supervisor)
Abstract
Routing requests to cloud service providers has been increasingly used to provide powerful computations for users. In order to reduce the long delays of cloud computations, mobile edge computing architecture has been proposed, where computing nodes are placed in the vicinity of the network edge. Data-driven applications such as IoT, remote virtual reality, and self-driving cars require not only computational resources but also memory resources in edge service providers. Since service providers in mobile edge computing architecture have much more limited resources compared to cloud space, in this research, we propose a solution to maximize the profit of service providers while providing...
Hydrogen distribution in refinery with non-linear programming
, Article International Journal of Engineering, Transactions B: Applications ; Volume 18, Issue 2 , 2005 , Pages 165-176 ; 1728-144X (ISSN) ; Kashi, E ; Rashtchian, D ; Sharif University of Technology
Materials and Energy Research Center
2005
Abstract
Growth of the world population, increasing demand for fossil fuel consumption and consequently increasing threat of global warming, has extended the need for production and use of clean fuels and normal hydrogen is an important utility in the production of clean fuels. In this paper, a mathematical optimization method is applied which is based on non-linear programming of superstructure for minimizing the consumption of hydrogen. The method considers all the pressure constraints and is suited for revamping industrial systems. The optimum placement of new equipments like purification unit has been also considered. It is tried to verify the method adopted, in addition, an industrial case study...
Integration Operation Management for Outpatient Clinics Case Study: Milad Hospital
,
M.Sc. Thesis
Sharif University of Technology
;
Eshghi, Kourosh
(Supervisor)
;
Delavari, Vahid
(Supervisor)
Abstract
Outpatient clinics always encounter a huge deal of demand and due to the variety of the services they provide and the existence of uncertainties, operation management is such a difficult task. This issue has made problems related to this issue popular among scientists and researchers. In this research, we are going to address several popular problems related to outpatient appointment scheduling. Initially, an M/M/c/K queuing system is developed in order to obtain the optimum scheduling window for different sub clinics. Secondly, the real demand for each sub clinics will be estimated using data analysis techniques for each 24-hour period. Having the results of the previous section, we build a...
Constructing a Robust Least Squares Support Vector Machine Based on Lp-norm and L∞-norm
, M.Sc. Thesis Sharif University of Technology ; Mahdavi Amiri, Nezamoddin (Supervisor)
Abstract
In the last decades, Support Vector Machine (SVM) has been used for supervised classification due to its wide applications. In addition, SVM is a mathematical programming tool, that as other optimization-based approaches, turns to be useful for a successful development of supervised classification. Based on current research in the literature, we explain the extension of a developed method for SVM using L2-norm to the more general case of Lp-norms with p > 1. The Kernel function is used frequently in the L2-SVM model, but the multidimensional Kernel is used as a general function in Lp-SVM. Finally, we use Lp-LSSVM model, with 0
Dynamic Optimization Model for Electric Vehcile Routing in Ridesharing
, M.Sc. Thesis Sharif University of Technology ; Shafahi, Yousef (Supervisor)
Abstract
In the past few decades, a considerable number of researches is devoted to study different challenges of ridesharing systems. Thus, this paper presents a mathematical optimization model to find the exact solution of the dynamic dial-a-ride problem with a fleet of electric autonomous vehicles and charging stations. Furthermore, time windows at which model strives to serve trip requests, are defined over origin and destination of passengers. Contrary to many previous works, charging behavior of vehicle battery at charging station is modeled to follow the actual nonlinear function in real world. In addition, vehicles are able to charge the battery whether fully or partially, whichever is more...
A web-based methodology for convergent product fuzzy networks using the Steiner tree
, Article Journal of Industrial and Production Engineering ; Volume 30, Issue 7 , 2013 , Pages 415-432 ; 21681015 (ISSN) ; Mahdavi, I ; Mahdavi Amiri, N ; Sharif University of Technology
2013
Abstract
An important manufacturing technology spectrum is to consider rapid and sensitive assemblies through convergent product (CP) in digital environment. We integrate functions and sub-functions using a comprehensive mathematical optimization process. To form the CP, a web-based fuzzy network is considered in which a collection of base functions and sub-functions configure the nodes and each arc in the network is to be a link between two nodes. The aim is to find an optimal tree of functionalities in the network adding value to the product in the web environment. First, a purification process is performed in the product network to assign the links among bases and sub-functions. Then, fuzzy...
A Hybrid Multi-Objective and Multi-Criteria Approach to Develop an Assignment Optimization Model in Car Sharing Networks
, M.Sc. Thesis Sharif University of Technology ; Akbari Jokar, Mohammad Reza (Supervisor)
Abstract
In this study, given the increasing challenges urban and intercity transportation face in the modern world, including population growth, urban development, and environmental concerns, an innovative approach to optimize the use of car-sharing vehicles is presented. The research aims to develop a multi-objective mathematical programming model for the optimal allocation of car-sharing vehicles, considering key factors such as transportation costs, travel time, and environmental pollution. This seeks to reduce costs, increase efficiency, shorten travel times, and contribute to environmental sustainability. Initially, a thorough literature review was conducted to provide a comprehensive...
Thermodynamic analysis of combustion processes and pollutants emission using nonlinear optimization approach
, Article Asia-Pacific Journal of Chemical Engineering ; Volume 7, Issue 1 , AUG , 2012 , Pages 80-85 ; 19322135 (ISSN) ; Zolfaghari Sharak, A ; Zolfaghari Shahrak, A ; Sharif University of Technology
2012
Abstract
Mathematical formulation and modeling of combustion processes is an important tool in the understanding of this phenomenon. Determination of equilibrium temperature and composition is often the first stage in calculation of combustion characteristics. There are number of different techniques for simulation of combustion process. In this study a basic model has been developed based on the minimization of Gibb's free energy to simulate the combustion processes. A nonlinear mathematical optimization has been developed based on Lagrange multipliers and solved using Quasi-Newton method written in MathCAD environment. The effect of various parameters such as initial temperature, pressure, and...
Optimal behavior of hot water heating coils at steady conditions
, Article 2008 ASME International Mechanical Engineering Congress and Exposition, IMECE 2008, Boston, MA, 31 October 2008 through 6 November 2008 ; Volume 10, Issue PART B , 2009 , Pages 1427-1432 ; 9780791848715 (ISBN) ; Saldi, M. H ; Sharif University of Technology
2009
Abstract
Hot water heating coils are key components in air conditioning systems undergo heat transfer. The most widely used exchangers (coils) take the form of fin and tube configuration in association with the application of air conditioning systems. In this research, thermodynamic modeling and mathematical optimization of hot water heating coils at steady conditions, approaching minimum energy consumption are achieved. The modeling procedure for heating coils is done based on the log mean temperature difference (LMTD) method. The objective function for optimization is pressure drop of air crossing coil per heating load of the system. This unction comprises all thermal and geometrical parameters of...
Multi-Attribute decision making on Inter-Basin Water Transfer projects
, Article Scientia Iranica ; Volume 16, Issue 1 E , 2009 , Pages 73-80 ; 10263098 (ISSN) ; Szidarovszky, F ; Ardakanian, R ; Sharif University of Technology
2009
Abstract
One of the best ways to control water shortages in the central region of Iran is Inter-Basin Water Transfer (IBWT). Efficient decision making on this subject is, however, a real challenge for the water authorities in Iran. These decisions should include multiple attributes, model uncertainty and, also, the optimistic/pessimistic view of the decision makers. The Ordered Weighted Averaging (OWA) operator can be used as an efficient Multi-Attribute Decision Making (MADM) method. This paper will introduce a new method to obtain the order weights of this operator. The new method is based on a combination of fuzzy quantifiers and neat OWA operators. Fuzzy quantifiers are usually applied in soft...