Loading...
Search for: optimization
0.03 seconds
Total 4627 records

    CorrIndex: A permutation invariant performance index

    , Article Signal Processing ; Volume 195 , 2022 ; 01651684 (ISSN) Sobhani, E ; Comon, P ; Jutten, C ; Babaie Zadeh, M ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    Permutation and scaling ambiguities are relevant issues in tensor decomposition and source separation algorithms. Although these ambiguities are inevitable when working on real data sets, it is preferred to eliminate these uncertainties for evaluating algorithms on synthetic data sets. As shown in the paper, the existing performance indices for this purpose are either greedy and unreliable or computationally costly. In this paper, we propose a new performance index, called CorrIndex, whose reliability can be proved theoretically. Moreover, compared to previous performance indices, it has a low computational cost. Theoretical results and computer experiments demonstrate these advantages of... 

    A novel system for electricity and synthetic natural gas production from captured CO2: Techno-economic evaluation and multi-objective optimization

    , Article Journal of CO2 Utilization ; Volume 63 , 2022 ; 22129820 (ISSN) Beyrami, J ; Jalili, M ; Ziyaei, M ; Chitsaz, A ; Rosen, M. A ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    To mitigate global warming and fossil fuel shortages a novel oxy-fuel combustion power plant integrated with a power to gas system is proposed. A net-zero emission MATIANT cycle with inherent CO2 capture ability is selected as the power cycle also providing the CO2 and power demand of the power to gas system, which comprises a proton exchange membrane electrolyzer for hydrogen production and a Sabatier reactor for methanation. A techno-economic investigation, a multi-objective optimization, and a sensitivity analysis are carried out. A comprehensive economic method that covers all economic aspects is utilized, and a Sabatier reactor model which considers the possibility of the presence of... 

    Pave the way for sustainable smart homes: A reliable hybrid AC/DC electricity infrastructure

    , Article Electric Power Systems Research ; Volume 210 , 2022 ; 03787796 (ISSN) Ardalan, C ; Vahidinasab, V ; Safdarian, A ; Shafie khah, M ; Catalão, J. P. S ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    The development of emerging smart grid technologies has led to more and more penetration of renewable energy resources and electric energy storage in the residential sectors. Besides, owing to the significant evolution of power electronic devices, there is a rapid growth in penetration of DC loads and generations, such as PV and electric vehicles (EVs), into the buildings and homes as a building block of the future smart cities. This is despite the fact that the electricity infrastructure of the conventional buildings is designed based on AC electricity and as a result, there would be a lot of losses due to the frequent power conversion from AC to DC and vice versa. Besides, according to a... 

    Photocatalytic degradation of vancomycin using titanium dioxide and optimization by central composite design

    , Article International Journal of Environmental Science and Technology ; Volume 19, Issue 9 , 2022 , Pages 8957-8968 ; 17351472 (ISSN) Dehghani, F ; Yousefinejad, S ; Dehghani, M ; Borghei, S. M ; Javid, A. H ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2022
    Abstract
    Conventional wastewater treatment processes are not completely effective in removing vancomycin. In this study, affecting parameters on vancomycin degradation, such as pH, catalyst, initial vancomycin concentration, temperature, and reaction time were investigated simultaneously during a removal process based on titanium dioxide with ultraviolet irradiation in an aqueous solution. Titanium dioxide was synthesized and characterized using X-ray diffraction and scanning electron microscopy. The average size of the synthesized crystals was 4.7 (± 0.2) nm. Design of experiments was done by a central composite design based on the response surface methodology and multiple linear regression was... 

    A user-friendly transactive coordination model for residential prosumers considering voltage unbalance in distribution networks

    , Article IEEE Transactions on Industrial Informatics ; Volume 18, Issue 9 , 2022 , Pages 5748-5759 ; 15513203 (ISSN) Saber, H ; Ehsan, M ; Moeini Aghtaie, M ; Ranjbar, H ; Lehtonen, M ; Sharif University of Technology
    IEEE Computer Society  2022
    Abstract
    Designing transactive energy (TE) markets in distribution systems has been a hot topic due to the increased presence of residential prosumers. In the literature, several residential market platforms have been proposed; however, they usually have two main drawbacks: 1) ignoring the effect of single-phase distributed energy resources on the voltage unbalance (VU) in active distribution networks to develop a transactive coordination model that will effectively mitigate the VU and 2) inability in providing a user-friendly strategy for home occupants to adjust the willingness to pay/accept of responsive assets according to their comfort and economic purposes. This article amends the shortcomings... 

    Predicting the environmental economic dispatch problem for reducing waste nonrenewable materials via an innovative constraint multi-objective Chimp Optimization Algorithm

    , Article Journal of Cleaner Production ; Volume 365 , 2022 ; 09596526 (ISSN) Zhu, L ; Ren, H ; Habibi, M ; Mohammed, K. J ; Khadimallah, M. A ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    The usage of conventional fossil fuels has aided fast economic growth while also having negative consequences, such as increased global warming and the destruction of the ecosystem. This paper proposes a novel swarm-based metaheuristic method called Chimp Optimization Algorithm (ChOA) to tackle the environmental, economic dispatch issue and reducing the waste nonrenewable materials. In this regard, two objective functions named fuel cost function and emission cost function are proposed. Unique constrained handling also solves the challenge of multi-objective optimization. Standard IEEE 30 bus with six generators and a 10-unit system are used to demonstrate the usefulness of ChOA. The result... 

    Experimental and numerical investigation of thermal enhancement methods on rammed-earth materials

    , Article Solar Energy ; Volume 244 , 2022 , Pages 474-483 ; 0038092X (ISSN) Toufigh, V ; Samadianfard, S ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    The renewed attention paid to rammed earth materials in recent decades is related to their sustainability, high thermo-buffering capacity and relatively low cost. The energy performance of rammed earth materials can be enhanced with stabilization. However, some of thermal enhancement methods have destructive side-effects. In the current study, the effect of three different methods was investigated on thirteen different alternatives of rammed earth materials to improve energy efficiency of buildings. These methods include using phase change materials, cementitious admixtures and external insulators. Thermo-dynamic parameters such as time lag, thermal conductivity and heat flux were measured... 

    Performance evaluation of Omni-Channel distribution network configurations considering green and transparent criteria under uncertainty

    , Article Sustainability (Switzerland) ; Volume 14, Issue 19 , 2022 ; 20711050 (ISSN) Babaei, A ; Khedmati, M ; Akbari Jokar, M. R ; Babaee Tirkolaee, E ; Sharif University of Technology
    MDPI  2022
    Abstract
    Satisfying customer demand is one of the growing concerns of supply chain managers. On the other hand, the development of internet communications has increased online demand. In addition, the COVID-19 pandemic has increased the demand for online shopping. One of the useful concepts that help to address this concern is the omni-channel strategy, which integrates online and traditional channels with the aim of improving customer service level. For this purpose, this paper proposes an algorithm for evaluating Omni-channel Distribution Network Configurations (OCDNCs). The algorithm applies an extended Data Envelopment Analysis (DEA) model to evaluate OCDNCs based on cost, service, transparency,... 

    Optimal energy management system of IoT-Enabled large building considering electric vehicle scheduling, distributed resources, and demand response schemes

    , Article Sensors ; Volume 22, Issue 19 , 2022 ; 14248220 (ISSN) Fei, L ; Shahzad, M ; Abbas, F ; Muqeet, H. A ; Hussain, M. M ; Bin, L ; Sharif University of Technology
    MDPI  2022
    Abstract
    In the energy system, various sources are used to fulfill the energy demand of large buildings. The energy management of large-scale buildings is very important. The proposed system comprises solar PVs, energy storage systems, and electric vehicles. Demand response (DR) schemes are considered in various studies, but the analysis of the impact of dynamic DR on operational cost has been ignored. So, in this paper, renewable energy resources and storages are integrated considering the demand response strategies such as real-time pricing (RTP), critical peak pricing (CPP), and time of use (ToU). The proposed system is mapped in a linear model and simulated in MATLAB using linear programming... 

    Dynamic reconfiguration optimization of intelligent manufacturing system with human-robot collaboration based on digital twin

    , Article Journal of Manufacturing Systems ; Volume 65 , 2022 , Pages 330-338 ; 02786125 (ISSN) Zhu, Q ; Huang, S ; Wang, G ; Moghaddam, S. K ; Lu, Y ; Yan, Y ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    In Industry 4.0, the emergence of new information technology and advanced manufacturing technology (e.g., digital twin, and robot) promotes the flexibility and smartness of manufacturing systems to deal with production task fluctuation. Digital twin-driven manufacturing system with human-robot collaboration is a typical paradigm of intelligent manufacturing. When production task changes, manufacturing system reconfiguration with dynamic opeartion task allocation between operator (human) and robot is a key manner to maintain the production efficiency of intelligent manufacturing system with human-robot collaboration. However, the differences between operator and robot are neglected during... 

    Data-driven joint TEP-BESS co-planning scheme to relieve transmission lines congestion: A min-max regret method

    , Article Sustainable Energy Technologies and Assessments ; Volume 53 , 2022 ; 22131388 (ISSN) Mazaheri, H ; Moeini Aghtaie, M ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    Transmission lines congestion has recently been a vital challenge in power systems operation due to the intermittent outputs of renewable energy sources (RES). Therefore, an efficient transmission congestion management (TCM) method should be defined to deal with the congestion issue. This paper aims to propose a simultaneous linearized two-stage TEP-BESS co-planning optimization model to relieve transmission lines congestion. In doing so, a novel TCM structure is suggested in a pool-based deregulated data-driven optimal power flows (D-OPF) by the computationally effective min-max regret method to consider future scenarios of generating units and demanded loads. To improve the efficiency of... 

    A new scheme for the development of IMU-based activity recognition systems for telerehabilitation

    , Article Medical Engineering and Physics ; Volume 108 , 2022 ; 13504533 (ISSN) Nasrabadi, A. M ; Eslaminia, A. R ; Bakhshayesh, P. R ; Ejtehadi, M ; Alibiglou, L ; Behzadipour, S ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    Wearable human activity recognition systems (HAR) using inertial measurement units (IMU) play a key role in the development of smart rehabilitation systems. Training of a HAR system with patient data is costly, time-consuming, and difficult for the patients. This study proposes a new scheme for the optimal design of HARs with minimal involvement of the patients. It uses healthy subject data for optimal design for a set of activities used in the rehabilitation of PD1 patients. It maintains its performance for individual PD subjects using a single session data collection and an adaptation procedure. In the optimal design, several classifiers (i.e. NM, k-NN, MLP with RBF as a hidden layer, and... 

    The utilization of patients’ information to improve the performance of radiotherapy centers: A data-driven approach

    , Article Computers and Industrial Engineering ; Volume 172 , 2022 ; 03608352 (ISSN) Moradi, S ; Najafi, M ; Mesgari, S ; Zolfagharinia, H ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    The high demand for radiotherapy services, combined with the limited capacity of available resources, patient unpunctuality, and series of appointments, makes Patient Appointment Scheduling (PAS) in radiotherapy centers very challenging. Although most centers use a First-Come-First-Serve (FCFS) policy for appointment scheduling, this approach does not consider patients’ behaviors, and consequently, it performs poorly. This type of inappropriate scheduling usually leads to inefficiency at the center and/or patient dissatisfaction. This study provides a data-driven approach to patient appointment scheduling to deal with the challenges mentioned above, and it considers patients’ histories of... 

    Centralized optimal management of a smart distribution system considering the importance of load reduction based on prioritizing smart home appliances

    , Article IET Generation, Transmission and Distribution ; Volume 16, Issue 19 , 2022 , Pages 3874-3893 ; 17518687 (ISSN) Sanaei, S ; Haghifam, M. R ; Safdarian, A ; Sharif University of Technology
    John Wiley and Sons Inc  2022
    Abstract
    The distribution system's economic operation is significantly impacted by the management of distributed generation (DG) resources, energy storage (ES), and controllable loads. The paper employs a smart distribution system that incorporates dispatchable and non-dispatchable DG resources, as well as battery storage, in addition to the demand response (DR) scheme. New modelling was performed in hourly steps to achieve the optimal unit commitment. In smart homes, appliances are prioritized and classified into four types: adjustable, interruptible, shiftable, and uncontrollable loads. Load reduction in smart homes is also considered based on load prioritization and customer participation in the... 

    Competitive facility location problem with foresight considering discrete-nature attractiveness for facilities: Model and solution

    , Article Computers and Operations Research ; Volume 146 , 2022 ; 03050548 (ISSN) Latifi, S. E ; Tavakkoli Moghaddam, R ; Fazeli, E ; Arefkhani, H ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    This paper addresses a bi-level mixed-integer nonlinear programming (MINLP) model for the competitive facility location problem in a closed-loop supply chain (CLSC), in which a firm (i.e., leader) aims at entering a market by locating new distribution and collection facilities, where a competitor (i.e., follower) already exists. The goal is to find the location and attractiveness of each facility going to be established by the leader who seeks to maximize its profit while also taking the follower's response into account. The attractiveness of each facility is a function of integer variables related to the facility's characteristics. Customer behavior is considered to be probabilistic based... 

    Viable closed-loop supply chain network by considering robustness and risk as a circular economy

    , Article Environmental Science and Pollution Research ; Volume 29, Issue 46 , 2022 , Pages 70285-70304 ; 09441344 (ISSN) Lotfi, R ; Nazarpour, H ; Gharehbaghi, A ; Hosseini Sarkhosh, S. M ; Khanbaba, A ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2022
    Abstract
    The viable closed-loop supply chain network (VCLSCND) is a new concept that integrates sustainability, resiliency, and agility into a circular economy. We suggest a hybrid robust stochastic optimization by minimizing the weighted expected, maximum, and entropic value at risk (EVaR) of the cost function for this problem. This form considers robustness against demand disruption. Finally, CLSC components are located, and quantity flows are determined in the automotive industry. The results show that the VCLSCND cost is less than not considering viability and has a − 0.44% gap. We analyze essential parameters. By increasing the conservative coefficient, confidence level, and the scale of the... 

    A new supply chain distribution network design for two classes of customers using transfer recurrent neural network

    , Article International Journal of System Assurance Engineering and Management ; Volume 13, Issue 5 , 2022 , Pages 2604-2618 ; 09756809 (ISSN) Najjartabar Bisheh, M ; Nasiri, G. R ; Esmaeili, E ; Davoudpour, H ; Chang, S. I ; Sharif University of Technology
    Springer  2022
    Abstract
    Supply chain management integrates planning and controlling of materials, information, and finances in a process which begins from suppliers and ends with customers. Optimal planning decisions made in such a distribution network usually include transportation, facilities location, and inventory. This study presents a new approach for considering customers’ differentiation in an integrated location-allocation and inventory control model using transfer recurrent neural network (RNN). In this study, a location and allocation problem is integrated with inventory control decisions considering two classes of strategic and non-strategic customers. For the first time, a novel transfer RNN is applied... 

    BOT-MICS: Bounding time using analytics in mixed-criticality systems

    , Article IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems ; Volume 41, Issue 10 , 2022 , Pages 3239-3251 ; 02780070 (ISSN) Ranjbar, B ; Hosseinghorban, A ; Sahoo, S. S ; Ejlali, A ; Kumar, A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2022
    Abstract
    An increasing trend for reducing cost, space, and weight leads to modern embedded systems that execute multiple tasks with different criticality levels on a common hardware platform while guaranteeing a safe operation. In such mixed-criticality (MC) systems, multiple worst case execution times (WCETs) are defined for each task, corresponding to the system operation mode to improve the MC system's timing behavior at runtime. Determining the appropriate WCETs for lower criticality (LC) modes is nontrivial. On the one hand, considering a very low WCET for tasks can improve the processor utilization by scheduling more tasks in that mode, on the other hand, using a larger WCET ensures that the... 

    Implementation and intelligent gain tuning feedback–based optimal torque control of a rotary parallel robot

    , Article JVC/Journal of Vibration and Control ; Volume 28, Issue 19-20 , 2022 , Pages 2678-2695 ; 10775463 (ISSN) Tajdari, F ; Ebrahimi Toulkani, N ; Sharif University of Technology
    SAGE Publications Inc  2022
    Abstract
    Aiming at operating optimally minimizing error of tracking and designing control effort, this study presents a novel generalizable methodology of an optimal torque control for a 6-degree-of-freedom Stewart platform with rotary actuators. In the proposed approach, a linear quadratic integral regulator with the least sensitivity to controller parameter choices is designed, associated with an online artificial neural network gain tuning. The nonlinear system is implemented in ADAMS, and the controller is formulated in MATLAB to minimize the real-time tracking error robustly. To validate the controller performance, MATLAB and ADAMS are linked together and the performance of the controller on the... 

    On the explicit formulation of reliability assessment of distribution systems with unknown network topology: Incorporation of DG, switching interruptions, and customer-interruption quantification

    , Article Applied Energy ; Volume 324 , 2022 ; 03062619 (ISSN) Jooshaki, M ; Lehtonen, M ; Fotuhi Firuzabad, M ; Muñoz Delgado, G ; Contreras, J ; Arroyo, J. M ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    This paper presents an original approach for the evaluation of reliability of active distribution networks with unknown topology. Built upon novel reformulations of conventional definitions for distribution reliability indices, the dependence of system-oriented reliability metrics on network topology is explicitly formulated using a set of mixed-integer linear expressions. Unlike previously reported works also modeling mathematically the relationship between reliability assessment and network topology, the proposed approach allows considering the impact of distributed generation (DG) while accounting for switching interruptions. Moreover, for the first time in the emerging closely related...