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alikhani--hamed
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Using genetic algorithms for long-term planning of network of bridges
, Article Scientia Iranica ; Volume 26, Issue 5 A , 2019 , Pages 2653-2664 ; 10263098 (ISSN) ; Alvanchi, A ; Sharif University of Technology
Sharif University of Technology
2019
Abstract
Bridge maintenance activities are often budgeted, scheduled, and conducted for networks of bridges with different ages, types, and conditions, which can make bridge network maintenance management challenging. In this study, we propose an improved maintenance planning model based on genetic algorithm for a network of bridges to bring a long-term perspective to the lifespan of bridges. To test the applicability and efficiency of the model, it was applied to a network of 100 bridges in one of the south-western provinces of Iran. The results of the model implementation showed considerable potential for improvement over the currently adopted model for bridge maintenance planning. © 2019 Sharif...
Using genetic algorithms for long-term planning of network of bridges
, Article Scientia Iranica ; Volume 26, Issue 5 A , 2019 , Pages 2653-2664 ; 10263098 (ISSN) ; Alvanchi, A ; Sharif University of Technology
Sharif University of Technology
2019
Abstract
Bridge maintenance activities are often budgeted, scheduled, and conducted for networks of bridges with different ages, types, and conditions, which can make bridge network maintenance management challenging. In this study, we propose an improved maintenance planning model based on genetic algorithm for a network of bridges to bring a long-term perspective to the lifespan of bridges. To test the applicability and efficiency of the model, it was applied to a network of 100 bridges in one of the south-western provinces of Iran. The results of the model implementation showed considerable potential for improvement over the currently adopted model for bridge maintenance planning. © 2019 Sharif...
Developing a Sustainable Model for Bridge Maintenance in Big Organisations
, M.Sc. Thesis Sharif University of Technology ; Alvanchi, Amin (Supervisor)
Abstract
For increasing longevity of a structure, it is not enough to notice only to designing aspects. In operation phase of a construction, we can increase the level of service and longevity. Asset-based Organizations, in addition to design their new assets, should maintain them. Infrastructures, such as road, bridge, dam, and water network, are important because of social and economic aspects. So they need special attention. There are efficient models for infrastructure maintenance that consider infrastructure element information, such as condition rate, weight, dimensions, deterioration rate, and cost of maintenance as inputs and give planning for maintenance in future. This planning, involves a...
Air pollution concentration near sensitive urban locations: A missing factor to consider in the grade separation projects
, Article Journal of Cleaner Production ; Volume 228 , 2019 , Pages 824-832 ; 09596526 (ISSN) ; Rahimi, M ; Alikhani, H ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
The high vehicle congestion is the main contributing factor to air pollution originated from the engine's combustion in many urban areas. Grade separation projects have been used to solve this problem and have resulted in overall air pollution reduction in many cases. Many grade separation projects are constructed near sensitive urban locations accommodating susceptible individuals. This research argues that in such cases in addition to the overall air pollution reduction, air pollution concentration near sensitive locations is an influential factor for deciding the appropriate scenario. This research proposes a complementary simulation-based method for assessing the resulting pollution...
In-depth investigation of project planning and control software package application in the construction industry of iran
, Article International Journal of Engineering, Transactions A: Basics ; Volume 33, Issue 10 , 2020 , Pages 1817-1825 ; Shiri, N ; Alikhani, H ; Sharif University of Technology
Materials and Energy Research Center
2020
Abstract
Inefficient project planning and control have been identified as the main contributor to the reduced performance of the construction industry in Iran. Meanwhile, improper use of planning and control software packages (PPCSPs) in these projects can be a key factor in this reduced performance. This study investigates different aspects of the PPCSP applications to draw the role of PPCSPs in the planning and control processes of construction projects in the country using a survey-based method. It is found that only 32.5% of the construction companies in Iran highly or very highly use PPCSPs. The low level of skill and the lack of management support are two main contributing factors to this...
An efficient tabu search algorithm for the single row facility location problem [electronic resource]
, Article European Journal Of Operational Research ; Vol. 205, No. 1, pp. 98-105 ; Eshghi, Kourosh ; Sharif University of Technology
Abstract
The general goal of the facility layout problem is to arrange a given number of facilities to minimize the total cost associated with the known or projected interactions between them. One of the special classes of the facility layout problem is the Single Row Facility Layout Problem (SRFLP), which consists of finding an optimal linear placement of rectangular facilities with varying dimensions on a straight line. This paper first presents and proves a theorem to find the optimal solution of a special case of SRFLP. The results obtained by this theorem prove to be very useful in reducing the computational efforts when a new algorithm based on tabu search for the SRFLP is proposed in this...
Sensitivity analysis of matching pennies game [electronic resource]
, Article Mathematical and Computer Modelling ; Volume 51, Issues 5–6, March 2010, Pages 722–735 ; Eshghi, Kourosh ; Sharif University of Technology
Abstract
In this paper, we have discussed the results of sensitivity analysis in a payoff matrix of the Matching Pennies game. After representing the game as a LP model, the sensitivity analysis of the elements of the payoff matrix is presented. The game value and the optimal strategies for different values of parameters are determined and compared
Construction schedule, an influential factor on air pollution in urban infrastructure projects
, Article Journal of Cleaner Production ; Volume 255 , 2020 ; Rahimi, M ; Mousavi, M ; Alikhani, H ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Urbanization growth and aging infrastructures necessitate new infrastructure construction projects in congested urban areas. Urban construction projects interrupt the regular on-road vehicle traffic flow that affects air pollution concentration in the adjacent areas. The project schedule, however, is a possible contributor to the air pollution which has been neglected to date. This research proposes a new framework to account for the impact of different urban project schedule alternatives on air pollution emission near the construction zones. The proposed framework uses the capabilities of vehicle traffic simulation to evaluate air pollution emission of different construction schedule...
Spacecraft Attitude Estimation Via Nonlinear Filtering Using Thermal Sensors
, Ph.D. Dissertation Sharif University of Technology ; Pourtakdoust, Hossein (Supervisor) ; Alikhani, Alireza (Supervisor)
Abstract
The problem of spacecraft attitude determination (AD) using thermal data is investigated. Given the Solar space environment, the key dominant mechanism of heat transfer will be radiation, in which the Sun and Earth are the major contributing heat sources that affect the satellite external surface temperatures. In this sense, the net heat fluxes (NHF) of a satellite surface that is insulated against any internal heat communication will only be related to these main radiating sources. In order to utilize the satellite temperature data for AD, a heat attitude model (HAM) that relates the satellite surfaces NHF to its attitude is developed using three orthogonal satellite surfaces. Assuming...
DOA Estimation in Communication Systems Using Deep Neural Networks
, M.Sc. Thesis Sharif University of Technology ; Behrouzi, Hamid (Supervisor) ; Karbasi, Mohammad (Supervisor)
Abstract
The purpose of Direction-of-arrival(DOA) estimation in MIMO communication networks is to find the direction of signals that are mixed together and mixed with noise by using an array of multiple receiving antennas. DOA estimation is an important issue in array signal processing. The traditional methods for DOA estimation try to solve this problem with mathematical algorithms. For example, some of these methods are based on parameter estimation; such as DOA estimation methods using maximum likelihood estimation methods. Some of other traditional methods are based on subspace decomposition; Like the famous MUSIC method. The traditional methods of DOA estimation usually have a drawback, and that...
Stabilizing a DG-fed islanded system through load shedding on the basis of the rate of change of frequency and voltage drop
, Article International Transactions on Electrical Energy Systems ; Volume 25, Issue 10 , June , 2015 , Pages 1976-1991 ; 20507038 (ISSN) ; Reza Alikhani, H. R ; Mortazavi, S. M ; Sharif University of Technology
John Wiley and Sons Ltd
2015
Abstract
The islanding of a distributed generation (DG)-fed distribution system generally results in frequency drop, which means less power is generated than it is needed. The only way of dealing with this problem is shedding loads as the system cannot generate any more electricity. Load shedding is intended to restore balance between generated and consumed power. This paper proposes a new method for load shedding based on the rate of change of frequency (RoCoF) at the first step and on voltage drop at subsequent steps. For this purpose, three lookup tables were created in order to prioritize loads to be shed according to the willingness of subscribers to pay and the RoCoF. The strength of the...
Development of a radiation based heat model for satellite attitude determination
, Article Aerospace Science and Technology ; Volume 82-83 , 2018 , Pages 479-486 ; 12709638 (ISSN) ; Pourtakdoust, S. H ; Alikhani, A ; Fourati, H ; Sharif University of Technology
Elsevier Masson SAS
2018
Abstract
This paper is focused on the development and verification of a heat attitude model (HAM) for satellite attitude determination. Within this context, the Sun and the Earth are considered as the main external sources of radiation that could effect the satellite surface temperature changes. Assuming that the satellite orbital position (navigational data) is known, the proposed HAM provides the satellite surface temperature with acceptable accuracy and also relates the net heat flux (NHF) of three orthogonal satellite surfaces to its attitude via the inertial to satellite transformation matrix. The proposed HAM simulation results are verified through comparison with commercial thermal analysis...
Design of a large-scale cable-driven robot with translational motion
, Article Robotics and Computer-Integrated Manufacturing ; Vol. 27, Issue 2 , April , 2011 , Pages 357-366 ; ISSN: 07365845 ; Behzadipour, S ; Alasty, A ; Sadough Vanini, S. A ; Sharif University of Technology
2011
Abstract
The design of a new cable-driven robot for large-scale manipulation is presented with focus on the tension condition in the cables. In this robot, the arrangement of the cables is such that the moving platform has three translational motions. The robot has potentials for large-scale robotic manipulations, machining of large parts and material handling. The design analysis presented here is towards the synthesis of the robot as well as the sizing of the actuators and cables. The synthesis of this robot is dependent on the results of the tensionable workspace analysis previously published by the Alikhani et al. [6]. The analysis of the cable forces is presented in detail, which is then used to...
Workspace analysis of a three dof cable-driven mechanism
, Article Journal of Mechanisms and Robotics ; Volume 1, Issue 4 , 2009 , Pages 1-7 ; 19424302 (ISSN) ; Behzadipour, S ; Sadough Vanini, A ; Alasty, A ; Sharif University of Technology
2009
Abstract
A cable-driven mechanism based on the idea of BetaBot (2005, "A New Cable-Based Parallel Robot With Three Degrees of Freedom, " Multibody Syst. Dyn., 13, pp. 371-383) is analyzed and geometrical description of its workspace boundary is found. In this mechanism, the cable arrangement eliminates the rotational motions leaving the moving platform with three translational motions. The mechanism has potentials for large scale manipulation and robotics in harsh environments. A detailed analysis of the tensionable workspace of the mechanism is presented. The mechanism, in a tensionable position, can develop tensile forces in all cables to maintain its rigidity under arbitrary external loading. A...
Binding Affinity Prediction Between Antibody and Antigen using Self-Supervised Learning
, M.Sc. Thesis Sharif University of Technology ; Sharifi Zarchi, Ali (Supervisor)
Abstract
In recent years, monoclonal antibodies have gained attention as highly effective drugs for treating diseases, especially cancer. The high binding affinity between an antibody and its corresponding antigen is one of the key factors in triggering an effective immune response. Modeling binding affinity using machine learning is considered a promising and cost-effective computational approach; however, due to the lack of training data, the performance of these models is often poor and limited. In contrast, recent advances in geometric learning have demonstrated that incorporating the three-dimensional geometry of protein structures in the learning process can significantly impact 3D...
Parametric study and computation of seismic performance factors of braced shear panels
, Article Scientia Iranica ; Volume 23, Issue 2 , 2016 , Pages 460-474 ; 10263098 (ISSN) ; Mofid, M ; Sharif University of Technology
Sharif University of Technology
2016
Abstract
By locating a steel shear panel on the intersection point of the X-braces, concentrically or eccentrically braced shear panel (CBFSP or EBFSP) is formed. In this paper, to perform parametric study, 1-story CBFSP and EBFSP models with span length greater or less than height are considered. Using linear static analyses, the effects of size and location of the shear panel on the lateral stiffness of the frame with respect to the moment resisting frame with the same member sections are investigated. Next, for 1- And 3-story models, maximum displacement, along with base shear, and the ratio between the dissipated energy and input energy are examined under 4 ground motion records. Behavior of the...
Assessment of Seismic Retrofit Policies for Buildings
, M.Sc. Thesis Sharif University of Technology ; Kashani, Hamed (Supervisor)
Abstract
Occurrence of natural disasters such as earthquake could seriously damage most buildings especially those with insufficient resistance located in urban worn-out textures. In order to reduce unpleasant consequences of an earthquake, appropriate policies need to be considered to persuade the beneficiaries to follow retrofitting standards in the process of planning, designing, and construction of buildings. These policies shall be implemented through institutions in arbitrary or obligatory forms, by encouragement or penalty mechanisms. In order to consider these policies, first of all we need to identify the beneficiaries and their particulars. By studying and considering subjects discussed in...
Optimal-Robust Control of Drug Delivery in Cancer Chemotherapy
, M.Sc. Thesis Sharif University of Technology ; Moradi, Hamed (Supervisor)
Abstract
Chemotherapy is a proven and effective systematic approach to treat various types of cancers. Despite its advantages, chemotherapy would kill healthy as well as cancer cells. To overcome this problem, different controlling strategies are implemented. This study aims to provide a medicine drug delivery schedule for chemotherapy (by designing a proper controlling system) based on the verifiable mathematical models. First, the dynamic model is analysed and stability points are reviewed. The selected model has five state variables and two inputs. In this study, the focus is on dynamic model analysis and obtaining an effective and appropriate treatment pattern by designing a proper controller. To...
Real Options Analysis Framework for the Optimal Timing of Network Infrastructure Systems Retrofits
, M.Sc. Thesis Sharif University of Technology ; Kashani, Hamed (Supervisor)
Abstract
Natural disasters can damage the infrastructure of society. Damages to the infrastructure components of society can disrupt their service delivery. Disruption in providing services to society's infrastructure can disrupt social and economic activities and impose various significant costs on society. The cost of repairing the damaged infrastructure and reducing the income of households are among the economic damages of accidents. The decline in the quality of life, as well as the death and injury of people due to the breakdown of the infrastructure or the disruption in their services, are among the social damages caused by accidents. In the same way, natural disasters are considered a...
Analysis of Seismic Vulnerability Reduction Policies of Residential Buildings Using a Multi-agent Evolutionary Game Model Based on Prospect Theory
, M.Sc. Thesis Sharif University of Technology ; Kashani, Hamed (Supervisor)
Abstract
Due to the vulnerability of urban fabric and residential buildings to earthquakes and considering its destructive social and economic effects on society, the need to adopt appropriate policies to prevent and reduce vulnerability, has been increasingly considered by policy makers. Despite the laws, regulations, incentives and penalties that policymakers have envisioned to prevent unprincipled and unsafe construction, evidence shows that a significant number of new buildings being built in the country are not earthquake resistant and there are many violations in design, implementation and supervision that is done by the stakeholders. To solve this problem, research has been done on the...