This paper presents an optimization method to solve a non-linear separable programming problem with coefficients and variables as generalized trapezoidal intuitionistic fuzzy numbers. Such optimization problems are known as fully intuitionistic fuzzy non-linear separable programming problems. The optimization method is based on the linear approximation of fully intuitionistic fuzzy non-linear separable functions. The concept of an intuitionistic fuzzy line segment between two intuitionistic fuzzy points is introduced to find the required linear approximation. In this way, a fully intuitionistic fuzzy non-linear programming problem is converted into an intuitionistic fuzzy linear programming problem. The defuzzification and component-wise comparison techniques are then used to convert the fully intuitionistic fuzzy linear programming problem to a linear programming problem with crisp coefficients which can then be solved by using traditional optimization techniques. The application of the proposed approach in an investment problem faced by a businessman has been presented.
{"title":"An optimization method to solve a fully intuitionistic fuzzy non-linear separable programming problem","authors":"Kirti Sharma, VISHNU PRATAP SINGH, Bhavin Poojara, Ali Ebrahimnejad, Debjani Chakraborty","doi":"10.1051/ro/2023152","DOIUrl":"https://doi.org/10.1051/ro/2023152","url":null,"abstract":"This paper presents an optimization method to solve a non-linear separable programming problem with coefficients and variables as generalized trapezoidal intuitionistic fuzzy numbers. Such optimization problems are known as fully intuitionistic fuzzy non-linear separable programming problems. The optimization method is based on the linear approximation of fully intuitionistic fuzzy non-linear separable functions. The concept of an intuitionistic fuzzy line segment between two intuitionistic fuzzy points is introduced to find the required linear approximation. In this way, a fully intuitionistic fuzzy non-linear programming problem is converted into an intuitionistic fuzzy linear programming problem. The defuzzification and component-wise comparison techniques are then used to convert the fully intuitionistic fuzzy linear programming problem to a linear programming problem with crisp coefficients which can then be solved by using traditional optimization techniques. The application of the proposed approach in an investment problem faced by a businessman has been presented.","PeriodicalId":54509,"journal":{"name":"Rairo-Operations Research","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136155443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Modular architecture design can not only increase the product variety and thus make mass customization (MC) easier, but also improve interchangeability and then lower the remanufacturing cost. This paper models a remanufacturing MC supply chain with one manufacturer and one retailer. The manufacturer, as a Stackelberg game leader, designs and then sells the new and modular MC products via its brand retailer, and meanwhile the remanufacturing of used MC products would be carried out by either the manufacturer or the retailer. We study the optimal modular design for new MC products and the best remanufacturing mode for used MC products. One centralized and two decentralized decision models are formulated, and the equilibrium solutions of proposed models are compared and analyzed. Findings show that, compared to the retailer-remanufacturing mode, the manufacturer-remanufacturing mode can be superior in terms of the ability to cope with customer customization requirements (i.e., the modularity level), total supply chain profit, and consumer surplus. Moreover, both supply chain members and consumers would prefer the manufacturer-remanufacturing mode when the parameters meet certain conditions. We also extend the model to two scenarios: the remanufacturing is bounded by cores supply and the retailer acts a leader, so as to verify the robustness of main results. Numerical examples demonstrate the theoretical results.
{"title":"Modular design of new products and remanufacturing of used products under mass customization","authors":"Honglin Yang, Lan Jiang","doi":"10.1051/ro/2023151","DOIUrl":"https://doi.org/10.1051/ro/2023151","url":null,"abstract":"Modular architecture design can not only increase the product variety and thus make mass customization (MC) easier, but also improve interchangeability and then lower the remanufacturing cost. This paper models a remanufacturing MC supply chain with one manufacturer and one retailer. The manufacturer, as a Stackelberg game leader, designs and then sells the new and modular MC products via its brand retailer, and meanwhile the remanufacturing of used MC products would be carried out by either the manufacturer or the retailer. We study the optimal modular design for new MC products and the best remanufacturing mode for used MC products. One centralized and two decentralized decision models are formulated, and the equilibrium solutions of proposed models are compared and analyzed. Findings show that, compared to the retailer-remanufacturing mode, the manufacturer-remanufacturing mode can be superior in terms of the ability to cope with customer customization requirements (i.e., the modularity level), total supply chain profit, and consumer surplus. Moreover, both supply chain members and consumers would prefer the manufacturer-remanufacturing mode when the parameters meet certain conditions. We also extend the model to two scenarios: the remanufacturing is bounded by cores supply and the retailer acts a leader, so as to verify the robustness of main results. Numerical examples demonstrate the theoretical results.","PeriodicalId":54509,"journal":{"name":"Rairo-Operations Research","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136155435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ana Luísa C. Furtado, Miguel Alfredo Del Rio Palma, Simone Dantas, Celina M. H. de Figueiredo
The coloring game is played by Alice and Bob on a finite graph $G$. They take turns properly coloring the vertices with $t$ colors. The goal of Alice is to color the input graph with t colors, and Bob does his best to prevent it. If at any point there exists an uncolored vertex without available color, then Bob wins; otherwise Alice wins. The game chromatic number $chi_g(G)$ of $G$ is the smallest number $t$ such that Alice has a winning strategy. In 1991, Bodlaender showed the smallest tree $T$ with $chi_g(T)$ equal to $4$, and in 1993 Faigle et al. proved that every tree $T$ satisfies the upper bound $chi_g(T) leq 4$. The stars $T = K_{1,p}$ with $pgeq 1$ are the only trees satisfying $chi_{g}(T)=2$; and the paths $T= P_n$, $ngeq 4$, satisfy $chi_{g}(T)=3$. Despite the vast literature in this area, there does not exist a characterization of trees with $chi_g(T) = 3$ or $4$. We answer a question about the required degree to ensure $chi_g(T) = 4$, by exhibiting infinitely many trees with maximum degree 3 and game chromatic number 4.
{"title":"On the degree of trees with Game Chromatic Number 4","authors":"Ana Luísa C. Furtado, Miguel Alfredo Del Rio Palma, Simone Dantas, Celina M. H. de Figueiredo","doi":"10.1051/ro/2023150","DOIUrl":"https://doi.org/10.1051/ro/2023150","url":null,"abstract":"The coloring game is played by Alice and Bob on a finite graph $G$. They take turns properly coloring the vertices with $t$ colors. The goal of Alice is to color the input graph with t colors, and Bob does his best to prevent it. If at any point there exists an uncolored vertex without available color, then Bob wins; otherwise Alice wins. The game chromatic number $chi_g(G)$ of $G$ is the smallest number $t$ such that Alice has a winning strategy. In 1991, Bodlaender showed the smallest tree $T$ with $chi_g(T)$ equal to $4$, and in 1993 Faigle et al. proved that every tree $T$ satisfies the upper bound $chi_g(T) leq 4$. The stars $T = K_{1,p}$ with $pgeq 1$ are the only trees satisfying $chi_{g}(T)=2$; and the paths $T= P_n$, $ngeq 4$, satisfy $chi_{g}(T)=3$. Despite the vast literature in this area, there does not exist a characterization of trees with $chi_g(T) = 3$ or $4$. We answer a question about the required degree to ensure $chi_g(T) = 4$, by exhibiting infinitely many trees with maximum degree 3 and game chromatic number 4.","PeriodicalId":54509,"journal":{"name":"Rairo-Operations Research","volume":"143 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135059495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A graph is called split if its vertex set can be partitioned into a stable set and a clique. In this article, we studied two variants of split graphs. A graph G is polar if its vertex set can be partitioned into two sets A and B such that G[A] is a complete multipartite graph and G[B] is a disjoint union of complete graphs. A 2-unipolar graph is a polar graph G such that G[A] is a clique and G[B] is the disjoint union of complete graphs with at most two vertices. We present a minimal forbidden induced subgraph characterization for 2-unipolar graphs. In addition, we show that they can be represented as an intersection of substars of special cacti. Let G be a graph class, the G-width of a graph G is the minimum positive integer k such that there exist k independent sets N1,...,Nk such that a set F of nonedges of G, whose endpoints belong to some Ni with i = 1,...,k, can be added so that the resulting graph G0 belongs to G. We say that a graph G is k-probe-G if it has G-width at most k and when G is the class of split graphs it is denominated k-probe-split. We prove that deciding, given a graph G and a positive integer k, whether G is a h-probe-split graph for some h ≤ k is NP-complete. Besides, a characterization by minimal forbidden induced subgraphs for 2-probesplit cographs is presented.
{"title":"On two variants of split graphs: 2-unipolar graph and k-probe-split graph","authors":"Luciano N. Grippo, Verónica A. Moyano","doi":"10.1051/ro/2023149","DOIUrl":"https://doi.org/10.1051/ro/2023149","url":null,"abstract":"A graph is called split if its vertex set can be partitioned into a stable set and a clique. In this article, we studied two variants of split graphs. A graph G is polar if its vertex set can be partitioned into two sets A and B such that G[A] is a complete multipartite graph and G[B] is a disjoint union of complete graphs. A 2-unipolar graph is a polar graph G such that G[A] is a clique and G[B] is the disjoint union of complete graphs with at most two vertices. We present a minimal forbidden induced subgraph characterization for 2-unipolar graphs. In addition, we show that they can be represented as an intersection of substars of special cacti. Let G be a graph class, the G-width of a graph G is the minimum positive integer k such that there exist k independent sets N1,...,Nk such that a set F of nonedges of G, whose endpoints belong to some Ni with i = 1,...,k, can be added so that the resulting graph G0 belongs to G. We say that a graph G is k-probe-G if it has G-width at most k and when G is the class of split graphs it is denominated k-probe-split. We prove that deciding, given a graph G and a positive integer k, whether G is a h-probe-split graph for some h ≤ k is NP-complete. Besides, a characterization by minimal forbidden induced subgraphs for 2-probesplit cographs is presented.","PeriodicalId":54509,"journal":{"name":"Rairo-Operations Research","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135437003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In a globalized market, forest management plans play an important role in the sustainability of forest enterprises. Several optimization processes have therefore been developed to support decision-making in forestry operations. However, important issues remain to be addressed, such as planning the allocation of harvesting areas and scheduling the harvesting teams that are contracted for these purposes. Harvesting schedules include different time scales and natural constraints, so that finding optimal or even good quality ones constitutes a highly complex combinatorial optimization problem. Efficient planning of harvesting operations can significantly reduce the costs associated with logistics and improve the economic performance of companies in the sector. In Uruguay, almost 75% of total forest harvesting operations for pulp production are carried out by contractor companies, so they are an important player in the supply chain. This study aims to optimize the allocation and routing of the harvesting equipment of forest contractors, which must be located at the sites to be harvested during the year. Numerical experiments over a case study based on realistic data have shown that realistic-sized instances can be resolved by standard mathematical programming software in a reasonable time. The mathematical programming model can also be useful to evaluate potential gains in joint planning by several contractors with respect to the costs incurred by separate planning; as illustrated also with numerical examples over the same case study. This model can be used to support annual forest harvest scheduling and equipment allocation for corporate contractors, leading to better quality plans and improvement opportunities.
{"title":"Modelling the forest harvesting tour problem","authors":"Víctor Viana, Héctor Cancela, Lorena Pradenas","doi":"10.1051/ro/2023142","DOIUrl":"https://doi.org/10.1051/ro/2023142","url":null,"abstract":"In a globalized market, forest management plans play an important role in the sustainability of forest enterprises. Several optimization processes have therefore been developed to support decision-making in forestry operations. However, important issues remain to be addressed, such as planning the allocation of harvesting areas and scheduling the harvesting teams that are contracted for these purposes. Harvesting schedules include different time scales and natural constraints, so that finding optimal or even good quality ones constitutes a highly complex combinatorial optimization problem. Efficient planning of harvesting operations can significantly reduce the costs associated with logistics and improve the economic performance of companies in the sector. In Uruguay, almost 75% of total forest harvesting operations for pulp production are carried out by contractor companies, so they are an important player in the supply chain. This study aims to optimize the allocation and routing of the harvesting equipment of forest contractors, which must be located at the sites to be harvested during the year. Numerical experiments over a case study based on realistic data have shown that realistic-sized instances can be resolved by standard mathematical programming software in a reasonable time. The mathematical programming model can also be useful to evaluate potential gains in joint planning by several contractors with respect to the costs incurred by separate planning; as illustrated also with numerical examples over the same case study. This model can be used to support annual forest harvest scheduling and equipment allocation for corporate contractors, leading to better quality plans and improvement opportunities.","PeriodicalId":54509,"journal":{"name":"Rairo-Operations Research","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135981534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
João Domingos Gomes da Silva Júnior, Carla Silva Oliveira, Liliana Manuela G. C. da Costa
Let G be a graph with adjacency matrix A(G) and degree diagonal matrix D(G). In 2017, Nikiforov [1] defined the matrix Aα(G), as a convex combination of A(G) and D(G), the following way, Aα(G) = αA(G) + (1 − α)D(G), where α ∈ [0,1]. In this paper we present some new upper and lower bounds for the largest, second largest and the smallest eigenvalue of Aα-matrix. Moreover, extremal graphs attaining some of these bounds are characterized.
{"title":"Bounds for Aα-eigenvalues","authors":"João Domingos Gomes da Silva Júnior, Carla Silva Oliveira, Liliana Manuela G. C. da Costa","doi":"10.1051/ro/2023144","DOIUrl":"https://doi.org/10.1051/ro/2023144","url":null,"abstract":"Let G be a graph with adjacency matrix A(G) and degree diagonal matrix D(G). In 2017, Nikiforov [1] defined the matrix Aα(G), as a convex combination of A(G) and D(G), the following way, Aα(G) = αA(G) + (1 − α)D(G), where α ∈ [0,1]. In this paper we present some new upper and lower bounds for the largest, second largest and the smallest eigenvalue of Aα-matrix. Moreover, extremal graphs attaining some of these bounds are characterized.","PeriodicalId":54509,"journal":{"name":"Rairo-Operations Research","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135937977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We consider a green supply chain that consists of a traditional supplier, a green supplier, and a manufacturer. We investigate the optimal strategies for the suppliers' raw material prices, and the manufacturer's production and green raw material ordering. In particular, we consider three price competition models: the traditional supplier-led model, the green supplier-led model, and the Nash game model. The results indicate that the more dominant the green supplier, the more likely the green material price will be higher than the traditional material price. In addition, the manufacturers' product greenness level is the lowest under the green supplier-led model and the highest under the traditional supplier-led model. We also find that, as the manufacturer's yield uncertainty increases, the prices of traditional and green raw materials both decrease with respect to the manufacturer's product greenness level. Moreover, as customers' green preference increases, the price of green raw materials increases, the price of traditional raw materials decreases, and the product greenness level increases.
{"title":"Optimal strategies for green supply chains with competition between green and traditional suppliers","authors":"Jing Cong, Tao Pang, Hongjun Peng","doi":"10.1051/ro/2023141","DOIUrl":"https://doi.org/10.1051/ro/2023141","url":null,"abstract":"We consider a green supply chain that consists of a traditional supplier, a green supplier, and a manufacturer. We investigate the optimal strategies for the suppliers' raw material prices, and the manufacturer's production and green raw material ordering. In particular, we consider three price competition models: the traditional supplier-led model, the green supplier-led model, and the Nash game model. The results indicate that the more dominant the green supplier, the more likely the green material price will be higher than the traditional material price. In addition, the manufacturers' product greenness level is the lowest under the green supplier-led model and the highest under the traditional supplier-led model. We also find that, as the manufacturer's yield uncertainty increases, the prices of traditional and green raw materials both decrease with respect to the manufacturer's product greenness level. Moreover, as customers' green preference increases, the price of green raw materials increases, the price of traditional raw materials decreases, and the product greenness level increases.","PeriodicalId":54509,"journal":{"name":"Rairo-Operations Research","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135937973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper is devoted to the study of a class of nonsmooth programming problems with switching constraints (abbreviated as, (NMPSC)), where all the involved functions in the switching constraints are assumed to be locally Lipschitz. We investigate the properties of Frèchet normal cone of (NMPSC). In particular, we introduce two Guignard type constraint qualifications for (NMPSC) in terms of Michel-Penot subdifferential. Moreover, we derive two estimates for the Fr‘echet normal cone of (NMPSC) and further establish stationarity conditions at an optimal solution for (NMPSC). To the best of our knowledge, this is for the first time Frèchet normal cone for (NMPSC) have been studied in the setting of Euclidean spaces.
{"title":"On Frèchet normal cone for nonsmooth mathematical programming problems with switching constraints\u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000\u0000 ","authors":"Balendu Bhooshan Upadhyay, Zahra Jafariani, Nader Kanzi, Maryam Naderi Parizi","doi":"10.1051/ro/2023138","DOIUrl":"https://doi.org/10.1051/ro/2023138","url":null,"abstract":"This paper is devoted to the study of a class of nonsmooth programming problems with switching constraints (abbreviated as, (NMPSC)), where all the involved functions in the switching constraints are assumed to be locally Lipschitz. We investigate the properties of Frèchet normal cone of (NMPSC). In particular, we introduce two Guignard type constraint qualifications for (NMPSC) in terms of Michel-Penot subdifferential. Moreover, we derive two estimates for the Fr‘echet normal cone of (NMPSC) and further establish stationarity conditions at an optimal solution for (NMPSC). To the best of our knowledge, this is for the first time Frèchet normal cone for (NMPSC) have been studied in the setting of Euclidean spaces.","PeriodicalId":54509,"journal":{"name":"Rairo-Operations Research","volume":"3 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82113068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}