A bi-level mathematical model for logistic management considering the evolutionary game with environmental feedbacks

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Peiman Ghasemi ◽  
Fariba Goodarzian ◽  
Angappa Gunasekaran ◽  
Ajith Abraham

PurposeThis paper proposed a bi-level mathematical model for location, routing and allocation of medical centers to distribution depots during the COVID-19 pandemic outbreak. The developed model has two players including interdictor (COVID-19) and fortifier (government). Accordingly, the aim of the first player (COVID-19) is to maximize system costs and causing further damage to the system. The goal of the second player (government) is to minimize the costs of location, routing and allocation due to budget limitations.Design/methodology/approachThe approach of evolutionary games with environmental feedbacks was used to develop the proposed model. Moreover, the game continues until the desired demand is satisfied. The Lagrangian relaxation method was applied to solve the proposed model.FindingsEmpirical results illustrate that with increasing demand, the values of the objective functions of the interdictor and fortifier models have increased. Also, with the raising fixed cost of the established depot, the values of the objective functions of the interdictor and fortifier models have raised. In this regard, the number of established depots in the second scenario (COVID-19 wave) is more than the first scenario (normal COVID-19 conditions).Research limitations/implicationsThe results of the current research can be useful for hospitals, governments, Disaster Relief Organization, Red Crescent, the Ministry of Health, etc. One of the limitations of the research is the lack of access to accurate information about transportation costs. Moreover, in this study, only the information of drivers and experts about transportation costs has been considered. In order to implement the presented solution approach for the real case study, high RAM and CPU hardware facilities and software facilities are required, which are the limitations of the proposed paper.Originality/valueThe main contributions of the current research are considering evolutionary games with environmental feedbacks during the COVID-19 pandemic outbreak and location, routing and allocation of the medical centers to the distribution depots during the COVID-19 outbreak. A real case study is illustrated, where the Lagrangian relaxation method is employed to solve the problem.

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mahdieh Masoumi ◽  
Amir Aghsami ◽  
Mohammad Alipour-Vaezi ◽  
Fariborz Jolai ◽  
Behdad Esmailifar

PurposeDue to the randomness and unpredictability of many disasters, it is essential to be prepared to face difficult conditions after a disaster to reduce human casualties and meet the needs of the people. After the disaster, one of the most essential measures is to deliver relief supplies to those affected by the disaster. Therefore, this paper aims to assign demand points to the warehouses as well as routing their related relief vehicles after a disaster considering convergence in the border warehouses.Design/methodology/approachThis research proposes a multi-objective, multi-commodity and multi-period queueing-inventory-routing problem in which a queuing system has been applied to reduce the congestion in the borders of the affected zones. To show the validity of the proposed model, a small-size problem has been solved using exact methods. Moreover, to deal with the complexity of the problem, a metaheuristic algorithm has been utilized to solve the large dimensions of the problem. Finally, various sensitivity analyses have been performed to determine the effects of different parameters on the optimal response.FindingsAccording to the results, the proposed model can optimize the objective functions simultaneously, in which decision-makers can determine their priority according to the condition by using the sensitivity analysis results.Originality/valueThe focus of the research is on delivering relief items to the affected people on time and at the lowest cost, in addition to preventing long queues at the entrances to the affected areas.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mitra Salmaninezhad ◽  
S. Mahmood Jazayeri Moghaddas

PurposePier scour is one of the main causes of damage to the columns of the river bridges. It is essential to select the best method among various repair methods based on different evaluation indices. However, there is no procedure for ranking these repair methods based on their attributes. The present study seeks to set an approach for this ranking.Design/methodology/approachIn this paper, a multi-attribute decision-making (MADM) model is presented for ranking the repair techniques, in which alternatives are examined using the most important evaluation criteria. In addition, a combination of entropy and eigenvector methods has been proposed for weighting these attributes. A case study is then used to demonstrate the applicability and the validity of the method.FindingsThe execution of the model using two multi-criteria methods yielded similar results, which confirms its accuracy and precision. Moreover, the research findings showed the consistency of the objective and subjective weighting methods and the conformity of the weights obtained for the attributes from the combination of these methods to the nature of the problem.Originality/valueThe selection of the proper method for repairing the bridge columns plays an essential role in success of the bridge restoration. The proposed model introduces an approach for ranking repair methods and selecting the best one that has not been presented so far. Also, the weighing method for attributes is an innovative method for ranking restoration methods that has been proven in a case study.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Masoud Rabbani ◽  
Soroush Aghamohamadi Bosjin ◽  
Neda Manavizadeh ◽  
Hamed Farrokhi-Asl

Purpose This paper aims to present a novel bi-objective mathematical model for a production-inventory system under uncertainty. Design/methodology/approach This paper addresses agile and lean manufacturing concepts alongside with green production methods to design an integrated capacitated lot sizing problem (CLSP). From a methodological perspective, the problem is solved in three phases. In the first step, an FM/M/C queuing system is used to minimize the number of customers waited to receive their orders. In the second step, an effective approach is applied to deal with the fuzzy bi-objective model and finally, a hybrid metaheuristic algorithm is used to solve the problem. Findings Some numerical test problems and sensitivity analyzes are conducted to measure the efficiency of the proposed model and the solution method. The results validate the model and the performance of the solution method compared to Gams results in small size test problems and prove the superiority of the hybrid algorithm in comparison with the other well-known metaheuristic algorithms in large size test problems. Originality/value This paper presents a novel bi-objective mathematical model for a CLSP under uncertainty. The proposed model is conducted on a practical case and several sensitivity analysis are conducted to assess the behavior of the model. Using a queue system, this problem aims to reduce the items waited in the queue to receive service. Two objective functions are considered to maximize the profit and minimize the negative environmental effects. In this regard, the second objective function aims to reduce the amount of emitted carbon.


2019 ◽  
Vol 14 (1) ◽  
pp. 175-198 ◽  
Author(s):  
S.M.T. Fatemi Ghomi ◽  
B. Asgarian

PurposeFinding a rational approach to maintain a freshness of foods and perishable goods and saving their intrinsic attributes during a distribution of these products is one of the main issues for distribution and logistics companies. This paper aims to provide a framework for distribution of perishable goods which can be applied for real life situations.Design/methodology/approachThis paper proposes a novel mathematical model for transportation inventory location routing problem. In addition, the paper addresses the impact of perishable goods age on the demand of final customers. The model is optimally solved for small- and medium-scale problems. Moreover, regarding to NP-hard nature of the proposed model, two simple and one hybrid metaheuristic algorithms are developed to cope with the complexity of problem in large scale problems.FindingsNumerical examples with different scenarios and sensitivity analysis are conducted to investigate the performance of proposed algorithms and impacts of important parameters on optimal solutions. The results show the acceptable performance of proposed algorithms.Originality/valueThe authors formulate a novel mathematical model which can be applicable in perishable goods distribution systems In this regard, the authors consider lost sale which is proportional to age of products. A new hybrid approach is applied to tackle the problem and the results show the rational performance of the algorithm.


Kybernetes ◽  
2019 ◽  
Vol 48 (6) ◽  
pp. 1355-1372 ◽  
Author(s):  
Ying Huang ◽  
Nu-nu Wang ◽  
Hongyu Zhang ◽  
Jianqiang Wang

Purpose The purpose of this paper is to propose a model for product recommendation to improve the accuracy of recommendation based on the current search engines used in e-commerce platforms like Tmall.com. Design/methodology/approach First, the proposed model comprehensively considers price, trust and online reviews, which all represent critical factors in consumers’ purchasing decisions. Second, the model introduces the quantization methods for these criteria incorporating fuzzy theory. Third, the model uses a distance measure between two single valued neutrosophic sets based on the prioritized average operator to consolidate the influences of positive, neutral and negative comments. Finally, the model uses multi-criteria decision-making methods to integrate the influences of price, trust and online reviews on purchasing decisions to generate recommendations. Findings To demonstrate the feasibility and efficiency of the proposed model, a case study is conducted based on Tmall.com. The results of case study indicate that the recommendations of our model perform better than those of current search engines of Tmall.com. The proposed model can significantly improve the accuracy of product recommendations based on search engines. Originality/value The product recommendation method can meet the critical challenge from the search engines on e-commerce platforms. In addition, the proposed method could be used in practice to develop a new application for e-commerce platforms.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
James Richards ◽  
Vaughan Ellis

PurposeA retrospective action-research case study of one branch of the University and College Union (UCU) is used to show how threshold requirements of the Act can be systematically beaten.Design/methodology/approachThe paper responds to calls for “best practice” on how trade unions may react to member voting threshold requirements of the Trade Union Act 2016 (the Act). A broader aim is to make a theoretical contribution related to trade union organising and tactics in “get the vote out” (GTVO) industrial action organising campaigns.FindingsFindings are presented as a lead organiser's first-hand account of a successful GTVO campaign contextualised in relation to theories of organising. The findings offer “best practice” for union organisers required to beat the Act's voting thresholds and also contribute to theories surrounding trade union organising tactics.Research limitations/implicationsFurther development and adaptation of the proposed model may be required when applied to larger bargaining units and different organising contexts.Practical implicationsThe findings can inform the organising practices/tactics of trade unions in relation to statutory ballots. The findings also allow Human Resource (HR) practitioners to reflect on their approach to dealing with unions capable of mounting successful GTVO campaigns.Social implicationsThe findings have the potential to collectively empower workers, via their trade unions, to defend and further their interests in a post-financial crisis context and in the shadow of the Covid-19 pandemic.Originality/valueThis is the first known empirical account of organising to exceed voting thresholds of the Act, providing practical steps for union organisers in planning for statutory ballots. Further value lies in the paper's use of a novel first-hand account of a GTVO campaign, offering a new and first, theoretical model of organising tactics to beat the Act.


Kybernetes ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
İlker Gölcük

PurposeThis paper proposes an integrated IT2F-FMEA model under a group decision-making setting. In risk assessment models, experts' evaluations are often aggregated beforehand, and necessary computations are performed, which in turn, may cause a loss of information and valuable individual opinions. The proposed integrated IT2F-FMEA model aims to calculate risk priority numbers from the experts' evaluations and then fuse experts' judgments using a novel integrated model.Design/methodology/approachThis paper presents a novel failure mode and effect analysis (FMEA) model by integrating the fuzzy inference system, best-worst method (BWM) and weighted aggregated sum-product assessment (WASPAS) methods under interval type-2 fuzzy (IT2F) environment. The proposed FMEA approach utilizes the Mamdani-type IT2F inference system to calculate risk priority numbers. The individual FMEA results are combined by using integrated IT2F-BWM and IT2F-WASPAS methods.FindingsThe proposed model is implemented in a real-life case study in the furniture industry. According to the case study, fifteen failure modes are considered, and the proposed integrated method is used to prioritize the failure modes.Originality/valueMamdani-type singleton IT2F inference model is employed in the FMEA. Additionally, the proposed model allows experts to construct their membership functions and fuzzy rules to capitalize on the experience and knowledge of the experts. The proposed group FMEA model aggregates experts' judgments by using IT2F-BWM and IT2F-WASPAS methods. The proposed model is implemented in a real-life case study in the furniture company.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zoraya Roldán Rockow ◽  
Brandon E. Ross

PurposeThis paper aims to describe and demonstrate a quantitative areal openness model (AOM) for measuring the openness of floor plans. Creation of the model was motivated by the widely reported but rarely quantified link between openness and adaptability.Design/methodology/approachThe model calculates values for three indicators: openness score (OS), weighted OS (WOS) and openness potential (OP). OS measures the absence of obstructions (walls, chases, columns) that separate areas in a floor plan. WOS measures the number of obstructions while also accounting for the difficulty of removing them. OP measures the potential of a floor plan to become more open. Indicators were calculated for three demolished case study buildings and for three adapted buildings. The case study buildings were selected because openness – or lack thereof – contributed to the owners' decisions to demolish or adapt.FindingsOpenness indicators were consistent with the real-world outcomes (adaptation or demolition) of the case study buildings. This encouraging result suggests that the proposed model is a reasonable approach for comparing the openness of floor plans and evaluating them for possible adaptation or demolition.Originality/valueThe AOM is presented as a tool for facility managers to evaluate inventories of existing buildings, designers to compare alternative plan layouts and researchers to measure openness of case studies. It is intended to be sufficiently complex as to produce meaningful results, relatively simple to apply and readily modifiable to suit different situations. The model is the first to calculate floor plan openness within the context of adaptability.


Author(s):  
Jiajia Chen ◽  
Yuhan Ma ◽  
Shiyou Yang

Purpose The purpose of this paper is to provide an accurate model and method to simulate the transient performances of an insulated gate bipolar transistor (IGBT) in an arbitrary free-carrier injection condition. Design/methodology/approach A numerical model and method for solving the physics-based model, an ambipolar diffusion equation-based model, of an IGBT is proposed. Findings The results of the proposed model are very close to the tested ones. Originality/value A mathematical model for an IGBT considering all free-carrier injection conditions is introduced, and a numerical solution methodology is proposed.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Vahid Shahabi ◽  
Adel Azar ◽  
Farshad Faezy Razi ◽  
Mir Feyz Fallah Shams

PurposeCOVID-19 has become a global challenge with a significant rate of prevalence, and it has exerted devastating consequences in epidemic, economic and social terms. Therefore, a number of studies have already been, or are now being, conducted on the detrimental effects of the virus. In this respect, a question may arise: Is there any possibility to turn the threat of the virus outbreak into an opportunity in some sectors such as the banking industry? In this research, the effects of COVID-19 outbreak as an intervening element on the acceptance of branchless banking were studied.Design/methodology/approachIn this research, the factors affecting the acceptance and development of branchless banking in Iran at the time of COVID-19 outbreak were identified by systematically studying the theoretical framework, conducting further research and interviewing the experts; then, a causal loop diagram of the problem in the proposed case study and the flow rate model were presented.FindingsThe simulation results showed that banking transactions and a bank's financial resources would increase by implementing the package policy of reducing the number of branches, promoting incentive policies and increasing the budget rate of the bank in Information Technology (IT). Further, by promoting customers' acceptance of new technologies, the spread of COVID-19 can be viewed as a positive factor, or even a catalyst, in the acceptance and development of branchless banking in Iran.Originality/valueBased on the proposed model, the difficulties faced by individuals during the spread of COVID-19 could act as justifiable incentives to boost appropriate organizational preparations for making changes to the classic working processes. Processes such as telecommuting, job rotation and so on are among these changes.


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