Pub Date : 2023-05-22DOI: 10.24200/sci.2023.61217.7205
Vahid Yahyapour-Ganji, A. Ghodratnama, R. Tavakkoli-Moghaddam
. This study investigates a three-level hierarchical hub problem considering numerous features, such as congestion and reliability. This relates to ground and air hubs as high layers in this hierarchical network. A four-objective model is presented; it lowers the number of routes, network-related costs, and hub queue waiting times while raising the network’s route reliability. Due to the impact of service time on customer satisfaction in this issue, a time frame that a penalty is assigned for the amount of delay is considered. Both the airport and the ground are hub facilities in this regard. M/M/C/K queue systems are those found in the airport and ground hubs. Due to the multi-objective nature of the problem, the LP-metric and goal attainment (GA) approaches are used to resolve it and verify multiple samples with varying weight values provided by the decision-maker. The results from the above-mentioned methods are ranked using a simple additive weighting (SAW) method. A few parameters are treated as fuzzy numbers to make the model more realistic, and the Jimenez’s model and chance-constrained programming are used to present the findings. Considering numerous weights for each objective function and solving two methods, Pareto solutions are obtained.
{"title":"A multi-objective three-level hierarchical hub location-queue problem with congestion and reliability under uncertainty: A case study","authors":"Vahid Yahyapour-Ganji, A. Ghodratnama, R. Tavakkoli-Moghaddam","doi":"10.24200/sci.2023.61217.7205","DOIUrl":"https://doi.org/10.24200/sci.2023.61217.7205","url":null,"abstract":". This study investigates a three-level hierarchical hub problem considering numerous features, such as congestion and reliability. This relates to ground and air hubs as high layers in this hierarchical network. A four-objective model is presented; it lowers the number of routes, network-related costs, and hub queue waiting times while raising the network’s route reliability. Due to the impact of service time on customer satisfaction in this issue, a time frame that a penalty is assigned for the amount of delay is considered. Both the airport and the ground are hub facilities in this regard. M/M/C/K queue systems are those found in the airport and ground hubs. Due to the multi-objective nature of the problem, the LP-metric and goal attainment (GA) approaches are used to resolve it and verify multiple samples with varying weight values provided by the decision-maker. The results from the above-mentioned methods are ranked using a simple additive weighting (SAW) method. A few parameters are treated as fuzzy numbers to make the model more realistic, and the Jimenez’s model and chance-constrained programming are used to present the findings. Considering numerous weights for each objective function and solving two methods, Pareto solutions are obtained.","PeriodicalId":21605,"journal":{"name":"Scientia Iranica","volume":"53 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84825699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-22DOI: 10.24200/sci.2023.60134.6617
Gunisetty Ramasekhar, P. Bala, A. Reddy
The proficiency of hybrid nanoparticles in increasing heat transfer has impressed many researchers to further analyze the working of those fluids. In the current study, the impact of entropy generation on electromagnetohydrodynamic (EMHD) hybrid nanofluid (copper-aluminium oxide) flow over a rotating disk in the presence of the porous medium, Darcy ‐ Forchheimer, heat generation, viscous dissipation, and thermal radiation. By applying the self-similarity variables, the partial differential equations are converted into ordinary differential equations. After that, the dimensionless equations are numerically solved by using the Runge-Kutta technique, and also the comparison is done between the numerical technique (R-K method) and the homotopy perturbation method (HPM) where HPM yields a more effective and dependable conclusion. To highlight their physical significance, unique characteristic graphs are shown for the profiles of velocity, temperature, entropy generation, and bejan number along with a suitable explanation. The hybrid nanofluid velocity decreases with larger values of the magnetic parameter, but the velocity profile increases with the higher electric field. The findings are novel and innovative, with several modern industrial applications and the results are in excellent concurrence with the relevant literature. Applications of the current research are refrigeration, electronics, heat exchangers, and lubricants.
{"title":"Entropy generation on Darcy–Forchheimer flow of Copper-Aluminium oxide/Water hybrid nanofluid over a rotating disk: Semi-analytical and numerical approaches","authors":"Gunisetty Ramasekhar, P. Bala, A. Reddy","doi":"10.24200/sci.2023.60134.6617","DOIUrl":"https://doi.org/10.24200/sci.2023.60134.6617","url":null,"abstract":"The proficiency of hybrid nanoparticles in increasing heat transfer has impressed many researchers to further analyze the working of those fluids. In the current study, the impact of entropy generation on electromagnetohydrodynamic (EMHD) hybrid nanofluid (copper-aluminium oxide) flow over a rotating disk in the presence of the porous medium, Darcy ‐ Forchheimer, heat generation, viscous dissipation, and thermal radiation. By applying the self-similarity variables, the partial differential equations are converted into ordinary differential equations. After that, the dimensionless equations are numerically solved by using the Runge-Kutta technique, and also the comparison is done between the numerical technique (R-K method) and the homotopy perturbation method (HPM) where HPM yields a more effective and dependable conclusion. To highlight their physical significance, unique characteristic graphs are shown for the profiles of velocity, temperature, entropy generation, and bejan number along with a suitable explanation. The hybrid nanofluid velocity decreases with larger values of the magnetic parameter, but the velocity profile increases with the higher electric field. The findings are novel and innovative, with several modern industrial applications and the results are in excellent concurrence with the relevant literature. Applications of the current research are refrigeration, electronics, heat exchangers, and lubricants.","PeriodicalId":21605,"journal":{"name":"Scientia Iranica","volume":"52 6","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72412682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-22DOI: 10.24200/sci.2023.60125.6608
Z. Mohammadnazari, R. Tavakkoli-Moghaddam, M. Alipour-Vaezi
. With the growing use of flexible manufacturing systems (FMSs), it became more important to optimize them. Scheduling is one of the critical problems in FMS optimization. This study presents a new application of multi-criterion decision-making (MCDM) methods for scheduling problems of automated guided vehicles (AGVs). Designation of AGVs to job shops is the major concern of this study. The research methodology consists of two steps. We first identify the criteria for finding the importance of jobs and then apply several MCDM methods (i.e., TOPSIS, VIKOR, and PROMRTHEE) to assign AGVs to the jobs. At last, we highlight the scheduling plan for AGVs using the mathematical formulation. This paper can bring some managerial insights not only for those who use an FMS but also for anyone who is working in the field of smart management. By the scrutiny, we highlight that the travel distance is significantly correlated with utilities. In other words, the more important are the jobs, the less distance is between jobs and AGVs. The findings support the minimization premise of the travel by AGVs and utility maximization of sending AGVs to the jobs simultaneously. This is achieved through assignment of two AGVs to seven jobs for multiple periods.
{"title":"A new application of multi-criteria decision-making methods for the scheduling of flexible manufacturing systems: A case study","authors":"Z. Mohammadnazari, R. Tavakkoli-Moghaddam, M. Alipour-Vaezi","doi":"10.24200/sci.2023.60125.6608","DOIUrl":"https://doi.org/10.24200/sci.2023.60125.6608","url":null,"abstract":". With the growing use of flexible manufacturing systems (FMSs), it became more important to optimize them. Scheduling is one of the critical problems in FMS optimization. This study presents a new application of multi-criterion decision-making (MCDM) methods for scheduling problems of automated guided vehicles (AGVs). Designation of AGVs to job shops is the major concern of this study. The research methodology consists of two steps. We first identify the criteria for finding the importance of jobs and then apply several MCDM methods (i.e., TOPSIS, VIKOR, and PROMRTHEE) to assign AGVs to the jobs. At last, we highlight the scheduling plan for AGVs using the mathematical formulation. This paper can bring some managerial insights not only for those who use an FMS but also for anyone who is working in the field of smart management. By the scrutiny, we highlight that the travel distance is significantly correlated with utilities. In other words, the more important are the jobs, the less distance is between jobs and AGVs. The findings support the minimization premise of the travel by AGVs and utility maximization of sending AGVs to the jobs simultaneously. This is achieved through assignment of two AGVs to seven jobs for multiple periods.","PeriodicalId":21605,"journal":{"name":"Scientia Iranica","volume":"7 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82342768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-14DOI: 10.24200/sci.2023.59944.6508
M. Farrokh, Reza Yousefi-Zenouz, Aboozar Jamalnia
Sourcing resilience has become a primary concern in most closed-loop supply chains (CLSC). Companies face the option of sourcing their raw materials from suppliers or recycling centers though the latter can be disrupted sometimes. In this study, a multi-stage, stochastic programming (MSSP) model is developed to analyze how a company can proactively employ sourcing strategies along with pricing policies to enhance sourcing resilience in a CLSC, where the return of end-of-life (used) products into recycling centers is stochastic and sensitive to the purchasing price. The stochastic return is modelled using a scenario-tree-based approach. Since the sample average approximation algorithm (SAA) in scenario generation can lead to an increased number of scenarios and make the model hard to solve, a backward scenario reduction algorithm is employed to efficiently reduce the problem size. The findings indicate that an effective pricing policy can help determine the resilient sourcing strategy in the CLSC network design problem and, therefore, maximize the total profit and mitigate the disruption risks.
{"title":"A resilient closed-loop supply chain network design through integrated sourcing and pricing strategies","authors":"M. Farrokh, Reza Yousefi-Zenouz, Aboozar Jamalnia","doi":"10.24200/sci.2023.59944.6508","DOIUrl":"https://doi.org/10.24200/sci.2023.59944.6508","url":null,"abstract":"Sourcing resilience has become a primary concern in most closed-loop supply chains (CLSC). Companies face the option of sourcing their raw materials from suppliers or recycling centers though the latter can be disrupted sometimes. In this study, a multi-stage, stochastic programming (MSSP) model is developed to analyze how a company can proactively employ sourcing strategies along with pricing policies to enhance sourcing resilience in a CLSC, where the return of end-of-life (used) products into recycling centers is stochastic and sensitive to the purchasing price. The stochastic return is modelled using a scenario-tree-based approach. Since the sample average approximation algorithm (SAA) in scenario generation can lead to an increased number of scenarios and make the model hard to solve, a backward scenario reduction algorithm is employed to efficiently reduce the problem size. The findings indicate that an effective pricing policy can help determine the resilient sourcing strategy in the CLSC network design problem and, therefore, maximize the total profit and mitigate the disruption risks.","PeriodicalId":21605,"journal":{"name":"Scientia Iranica","volume":"97 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85772168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-10DOI: 10.24200/sci.2023.60369.6762
M. Vaezi, H. Bagheri
The effects of synthesis time and the number of synthesis layers were investigated on the synthesis of Na-X zeolite sublayer for fabricating a PEBA/Na-X hybrid membrane. The CO 2 /N 2 separation was considered as the objective function to obtain an effective Na-X sublayer. SEM and AFM studies of the synthesized sublayers reveal that 6 hour synthesis time and one synthesis layer give an Na-X sublayer (ZSL6-1) with sub-micron thickness (< 1µm), and roughness of 13 nm. The N 2 permeation ( 11900 GPU) shows the low mass transfer resistance through the ZSL6-1 sublayer. The ZSL6-1 sublayer in the hybrid structure of the membrane leads to the high stability of the multilayer structure via the anchoring effect of the polymer. Hydroxyl groups, along with positive and negative charges on the surface of the Na-X sublayer, cause to strong bonding of the polymer layer and prevent its delamination. The surface coverage of the sublayer by polymer has increased the mass transfer resistance just for N 2 and increase the perm-selectivity. These properties, along with the high affinity of the Na-X to the adsorption of CO 2 , results in a 56% increase in the perm-selectivity of CO 2 /N 2 ( ~ 70 ) compared to net PEBA ( ~ 40-50 ) and the recently reported hybrid membranes.
{"title":"PEBA/Na-X Multilayer Hybrid Membrane for CO2 Separation: Influence of Na-X Zeolite Layer Synthesis Condition","authors":"M. Vaezi, H. Bagheri","doi":"10.24200/sci.2023.60369.6762","DOIUrl":"https://doi.org/10.24200/sci.2023.60369.6762","url":null,"abstract":"The effects of synthesis time and the number of synthesis layers were investigated on the synthesis of Na-X zeolite sublayer for fabricating a PEBA/Na-X hybrid membrane. The CO 2 /N 2 separation was considered as the objective function to obtain an effective Na-X sublayer. SEM and AFM studies of the synthesized sublayers reveal that 6 hour synthesis time and one synthesis layer give an Na-X sublayer (ZSL6-1) with sub-micron thickness (< 1µm), and roughness of 13 nm. The N 2 permeation ( 11900 GPU) shows the low mass transfer resistance through the ZSL6-1 sublayer. The ZSL6-1 sublayer in the hybrid structure of the membrane leads to the high stability of the multilayer structure via the anchoring effect of the polymer. Hydroxyl groups, along with positive and negative charges on the surface of the Na-X sublayer, cause to strong bonding of the polymer layer and prevent its delamination. The surface coverage of the sublayer by polymer has increased the mass transfer resistance just for N 2 and increase the perm-selectivity. These properties, along with the high affinity of the Na-X to the adsorption of CO 2 , results in a 56% increase in the perm-selectivity of CO 2 /N 2 ( ~ 70 ) compared to net PEBA ( ~ 40-50 ) and the recently reported hybrid membranes.","PeriodicalId":21605,"journal":{"name":"Scientia Iranica","volume":"17 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91074268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-10DOI: 10.24200/sci.2023.60399.6778
M. Rastegar, Mitra Faraji
The banking system tend to internalize scoring according to Basel II & III and their Central Bank regulations. Consequently, these banking systems are in dire need of credit scoring models. In this study, first, we present a probabilistic neural network (PNN) algorithm for credit scoring of bank customers optimized by means of a genetic algorithm. Based on data from legal customers of one Iranian bank, its performance is compared with seven common machine-learning algorithms. Then we developed a new hybrid performance metric, called probabilities of credit scoring correctness, by combining several performance metrics. The banking system has proposed several credit-scoring models. Models such as single classifiers, hybrid models, and ensemble models determine the class of customers (good or bad). In order to calculate the expected loss and unexpected loss, banks need the probability of default. In general, the proposed model can utilize m performance metrics and n classifiers; the larger m and n , the more reliable the customer class estimates will be. In fact, the purpose of this paper is to create a hybrid approach for credit scoring Iranian banks' clients, thus obtaining the probability of default and credit risk models for the banking system, especially the weak banking system.
{"title":"Development of a Hybrid Credit Scoring Model for the Banking System","authors":"M. Rastegar, Mitra Faraji","doi":"10.24200/sci.2023.60399.6778","DOIUrl":"https://doi.org/10.24200/sci.2023.60399.6778","url":null,"abstract":"The banking system tend to internalize scoring according to Basel II & III and their Central Bank regulations. Consequently, these banking systems are in dire need of credit scoring models. In this study, first, we present a probabilistic neural network (PNN) algorithm for credit scoring of bank customers optimized by means of a genetic algorithm. Based on data from legal customers of one Iranian bank, its performance is compared with seven common machine-learning algorithms. Then we developed a new hybrid performance metric, called probabilities of credit scoring correctness, by combining several performance metrics. The banking system has proposed several credit-scoring models. Models such as single classifiers, hybrid models, and ensemble models determine the class of customers (good or bad). In order to calculate the expected loss and unexpected loss, banks need the probability of default. In general, the proposed model can utilize m performance metrics and n classifiers; the larger m and n , the more reliable the customer class estimates will be. In fact, the purpose of this paper is to create a hybrid approach for credit scoring Iranian banks' clients, thus obtaining the probability of default and credit risk models for the banking system, especially the weak banking system.","PeriodicalId":21605,"journal":{"name":"Scientia Iranica","volume":"20 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84280561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-10DOI: 10.24200/sci.2023.58148.5589
Mohammad Tavakkoli Nabavi, Masoud Azadi Moghaddam, F. Kolahan
. This paper considers a multi-objective model in which operation planning and tool assignment are simultaneously in a Flexible Manufacturing System (FMS). In this regard, the main characteristics of FMS have been analyzed. Then, a comprehensive model, including major system parameters and cost components, has been designed and presented. The proposed model contains cost factors, including machining cost, earliness or tardiness penalties, tool and part movement or switch costs, and idle time costs of tools and machines. Then, a multi-objective model for the problem has been proposed, in which the relative importance of each cost through weighting these costs based on the decision-making goals and the sum of the mentioned costs have been considered simultaneously. Based on the complex nature of the problem, standard solution techniques have yet to be employed. Therefore, to reduce computational times, the Simulated Annealing (SA) algorithm has been used for about 30 minutes (10,000 movements). The total production costs have been decreased from 7,000 to 4333 units using the SA algorithm. Based on the results, a 38% reduction in total production costs has been achieved. Computational results revealed that the proposed method is quite e(cid:14)cient in the multi-objective optimization of FMS within a short computational
{"title":"Application of simulated annealing algorithm for multi criteria operation planning in flexible manufacturing systems","authors":"Mohammad Tavakkoli Nabavi, Masoud Azadi Moghaddam, F. Kolahan","doi":"10.24200/sci.2023.58148.5589","DOIUrl":"https://doi.org/10.24200/sci.2023.58148.5589","url":null,"abstract":". This paper considers a multi-objective model in which operation planning and tool assignment are simultaneously in a Flexible Manufacturing System (FMS). In this regard, the main characteristics of FMS have been analyzed. Then, a comprehensive model, including major system parameters and cost components, has been designed and presented. The proposed model contains cost factors, including machining cost, earliness or tardiness penalties, tool and part movement or switch costs, and idle time costs of tools and machines. Then, a multi-objective model for the problem has been proposed, in which the relative importance of each cost through weighting these costs based on the decision-making goals and the sum of the mentioned costs have been considered simultaneously. Based on the complex nature of the problem, standard solution techniques have yet to be employed. Therefore, to reduce computational times, the Simulated Annealing (SA) algorithm has been used for about 30 minutes (10,000 movements). The total production costs have been decreased from 7,000 to 4333 units using the SA algorithm. Based on the results, a 38% reduction in total production costs has been achieved. Computational results revealed that the proposed method is quite e(cid:14)cient in the multi-objective optimization of FMS within a short computational","PeriodicalId":21605,"journal":{"name":"Scientia Iranica","volume":"30 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76353144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-10DOI: 10.24200/sci.2023.59998.6542
Arya Russel, S. Taghipour, M. Sharifi
Despite prominent scholarly advancements in operations research, limited literature has been reported on mathematical and heuristic approaches for scheduling low-volume low-variety production systems. This paper proposes a new approach for modeling and solving large-scale sequencing and scheduling problems in Low-Volume, Low-variety production systems. The proposed non-linear mathematical programming models and genetic algorithms are subject to time and resource constraints, aimed at maximizing the number of activities completed in-station or intended to minimize the positive deviation to the aspiring time and resources budgets in scenarios where the allocated work package must be completed in-station. The proposed algorithms are compatible with discrete and continuous-time scheduling problems and are found to be effective in modeling characteristics and constraints inherent in Low-Volume, Low-Variety production systems. To validate the proposed models, a real-world case study of a work center in the final assembly line of a private jet aircraft is conducted.
{"title":"Mathematical Programming and Metaheuristics for Solving Continuous-Time Scheduling Optimization Problems in Low-Volume Low-Variety Production Systems","authors":"Arya Russel, S. Taghipour, M. Sharifi","doi":"10.24200/sci.2023.59998.6542","DOIUrl":"https://doi.org/10.24200/sci.2023.59998.6542","url":null,"abstract":"Despite prominent scholarly advancements in operations research, limited literature has been reported on mathematical and heuristic approaches for scheduling low-volume low-variety production systems. This paper proposes a new approach for modeling and solving large-scale sequencing and scheduling problems in Low-Volume, Low-variety production systems. The proposed non-linear mathematical programming models and genetic algorithms are subject to time and resource constraints, aimed at maximizing the number of activities completed in-station or intended to minimize the positive deviation to the aspiring time and resources budgets in scenarios where the allocated work package must be completed in-station. The proposed algorithms are compatible with discrete and continuous-time scheduling problems and are found to be effective in modeling characteristics and constraints inherent in Low-Volume, Low-Variety production systems. To validate the proposed models, a real-world case study of a work center in the final assembly line of a private jet aircraft is conducted.","PeriodicalId":21605,"journal":{"name":"Scientia Iranica","volume":"7 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85428286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-10DOI: 10.24200/sci.2023.56722.4874
Scientia Iranica, M. H. Korayem, S. F. Dehkordi, M. Aghajari
. In this study, the new mobile robot structure with N parallel axles was designed and developed, as well as its motion equations derived. It uses several parallel axes, which increase its mobility at di(cid:11)erent surface conditions compared to similar ones. The number of parallel axes in such robotic systems makes studies of the e(cid:11)ect of slip mandatory due to the increase in the wheels’ contact area. These e(cid:11)ects make a di(cid:11)erence in the mobile robot kinematic constraints equations. On the other hand, added parallel axels prepare the capability for motion on rough and uneven surfaces. But the mobile platform requires a suspension system to reduce the e(cid:11)ects of oscillations due to the (cid:13)oor. Finally, the dynamics model of a mobile robot obtains by considering the e(cid:11)ect of wheels’ slips, suspension, and parallel axles using Lagrange equations. The concluded model is simulated for a two-axis mobile robot with four wheels in di(cid:11)erent surface conditions. It can be seen that the deviation of the robot is eminent, besides that the wheel’s slips a(cid:11)ect the system performance based on the (cid:13)oor conditions. Consequently, the robot deviation on ice is less than that on loose gravel
{"title":"Dynamic modeling of the extended mobile robot: Composed N parallel axles, suspension system, and wheels slippage","authors":"Scientia Iranica, M. H. Korayem, S. F. Dehkordi, M. Aghajari","doi":"10.24200/sci.2023.56722.4874","DOIUrl":"https://doi.org/10.24200/sci.2023.56722.4874","url":null,"abstract":". In this study, the new mobile robot structure with N parallel axles was designed and developed, as well as its motion equations derived. It uses several parallel axes, which increase its mobility at di(cid:11)erent surface conditions compared to similar ones. The number of parallel axes in such robotic systems makes studies of the e(cid:11)ect of slip mandatory due to the increase in the wheels’ contact area. These e(cid:11)ects make a di(cid:11)erence in the mobile robot kinematic constraints equations. On the other hand, added parallel axels prepare the capability for motion on rough and uneven surfaces. But the mobile platform requires a suspension system to reduce the e(cid:11)ects of oscillations due to the (cid:13)oor. Finally, the dynamics model of a mobile robot obtains by considering the e(cid:11)ect of wheels’ slips, suspension, and parallel axles using Lagrange equations. The concluded model is simulated for a two-axis mobile robot with four wheels in di(cid:11)erent surface conditions. It can be seen that the deviation of the robot is eminent, besides that the wheel’s slips a(cid:11)ect the system performance based on the (cid:13)oor conditions. Consequently, the robot deviation on ice is less than that on loose gravel","PeriodicalId":21605,"journal":{"name":"Scientia Iranica","volume":"14 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87719362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-10DOI: 10.24200/sci.2023.60421.6789
Mohammad Amin Mianroodi, Reza Akbari-Hasanjani, R. Sabbaghi‐Nadooshan
Quantum-dot cellular automata (QCA) technology is one of the candidate technologies to replace CMOS in multi-valued logic (MVL) circuit designs, to overcome the problems of binary systems. One of the advantages of MVL systems is that they can process more information. Some techniques are essential to simulate and evaluate new multi-valued designs and their performance. This article introduces a new software platform for simulating Quaternary QCA (QQCA) circuits that can be run on computers on Windows and Linux computers is powerful and can run simulations with high accuracy. The presented tool provides the results in two formats. The first format is waveform and the second one is truth table. The presented software has a user-friendly interface that allows users to easily implement their QQCA circuits. Furthermore, the electrostatic energies for all cases in which the basic gates assume four values are determined and the step-by-step simulation process is described. The basic NOT, AND, and OR gates have already been simulated and validated by the relevant software.
{"title":"QQCAsim: a new simulation tool for quaternary logic in QCA technology","authors":"Mohammad Amin Mianroodi, Reza Akbari-Hasanjani, R. Sabbaghi‐Nadooshan","doi":"10.24200/sci.2023.60421.6789","DOIUrl":"https://doi.org/10.24200/sci.2023.60421.6789","url":null,"abstract":"Quantum-dot cellular automata (QCA) technology is one of the candidate technologies to replace CMOS in multi-valued logic (MVL) circuit designs, to overcome the problems of binary systems. One of the advantages of MVL systems is that they can process more information. Some techniques are essential to simulate and evaluate new multi-valued designs and their performance. This article introduces a new software platform for simulating Quaternary QCA (QQCA) circuits that can be run on computers on Windows and Linux computers is powerful and can run simulations with high accuracy. The presented tool provides the results in two formats. The first format is waveform and the second one is truth table. The presented software has a user-friendly interface that allows users to easily implement their QQCA circuits. Furthermore, the electrostatic energies for all cases in which the basic gates assume four values are determined and the step-by-step simulation process is described. The basic NOT, AND, and OR gates have already been simulated and validated by the relevant software.","PeriodicalId":21605,"journal":{"name":"Scientia Iranica","volume":"79 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86331540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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