{"title":"A fuzzy approach to multi-objective mixed integer linear programming model for multi-echelon closed-loop supply chain with multi-product multi-time-period","authors":"Sema Akin Bas, B. Ozkok","doi":"10.37190/ord200102","DOIUrl":"https://doi.org/10.37190/ord200102","url":null,"abstract":"By the green point of view, supply chain management (SCM), which contains supplier and location selection, production, distribution, and inventory decisions, is an important subject being examined in recent years by both practitioners and academicians. In this paper, the closed-loop supply chain (CLSC) network that can be mutually agreed by meeting at the level of common satisfaction of conflicting objectives is designed. We construct a multi-objective mixed-integer linear programming (MOMILP) model that allows decision-makers to more effectively manage firms’ closed-loop green supply chain (SC). An ecological perspective is brought by carrying out the recycling, remanufacturing and destruction to SCM in our proposed model. Maximize the rating of the regions in which they are located, minimize total cost and carbon footprint are considered as the objectives of the model. By constructing our model, the focus of customer satisfaction is met, as well as the production, location of facilities and order allocation are decided, and we also carry out the inventory control of warehouses. In our multi-product multi-component multi-time-period model, the solution is obtained with a fuzzy approach by using the min operator of Zimmermann. To illustrate the model, we provide a practical case study, and an optimal result containing a preferable level of satisfaction to the decision-maker is obtained.","PeriodicalId":43244,"journal":{"name":"Operations Research and Decisions","volume":"10 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78657977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Inventory model for deteriorating items with negative exponential demand, probabilistic deterioration and fuzzy lead time under partial back logging","authors":"Nabendu Sen, S. Saha","doi":"10.37190/ord200207","DOIUrl":"https://doi.org/10.37190/ord200207","url":null,"abstract":"The effect of lead time plays an important role in inventory management. It is also important to study the optimal strategies when the lead time is not precisely known to the decision makers. The aim of this paper is to examine the inventory model for deteriorating items with fuzzy lead time, negative exponential demand, and partially backlogged shortages. This model is unique in its nature due to probabilistic deterioration along with fuzzy lead time. The fuzzy lead time is assumed to be triangular, parabolic, trapezoidal numbers and the graded mean integration representation method is used for the defuzzification purpose. Moreover, three different types of probability distributions, namely uniform, triangular and Beta are used for rate of deterioration to find optimal time and associated total inventory cost. The developed model is validated numerically and values of optimal time and total inventory cost are given in tabular form, corresponding to different probability distribution and fuzzy lead-time. The sensitivity analysis is performed on variation of key parameters to observe its effect on the developed model. Graphical representations are also given in support of derived optimal inventory cost vs. time.","PeriodicalId":43244,"journal":{"name":"Operations Research and Decisions","volume":"95 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75898638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Information gap in value propositions of business models of language schools","authors":"Z. Malara, P. Ziębicki","doi":"10.37190/ord200202","DOIUrl":"https://doi.org/10.37190/ord200202","url":null,"abstract":"The paper presents the results of the second stage of research on business models of language schools. It was assumed that there is a significant difference in the value propositions of schools and the expectations of their clients. An examination procedure was planned with the use of a questionnaire and statistical analysis such as factor analysis, on its basis. Respondents consisted of a group of school managers (representing the majority of enterprises in Lower Silesia) on the one hand and, on the other hand, a large group of former and current clients. The results of the research confirm the existence of a gap in the perception of the values of both groups. The analysis has been conducted in the convention of the business model canvas template. The distinctness of the offer’s perception is presented in the form of activity packages, responsible for creating value for the clients (the right side of the model canvas). The structure of the packages, as a picture of the gap, is discussed. The results of the first stage of the research, diagnosing the influence of the surrounding elements on the business models of language schools, are also referred to. Directional changes in the business models that result from both stages of the research are suggested. The strategic dimension of the gap results from the strategy-business model relation. In light of the literature review, it may be supposed that the research is unique due to the segment of subjects and research methodology.","PeriodicalId":43244,"journal":{"name":"Operations Research and Decisions","volume":"56 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82097162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Galanc, W. Kołwzan, J. Pieronek, Agnieszka Skowronek-Grądziel
{"title":"Risk estimation and decision making in management (in selected areas of science)","authors":"T. Galanc, W. Kołwzan, J. Pieronek, Agnieszka Skowronek-Grądziel","doi":"10.37190/ord200103","DOIUrl":"https://doi.org/10.37190/ord200103","url":null,"abstract":"Risk is a category that is inseparably connected with uncertainty and probability, which means that the nature of risk as a category of science is complex, and the concept of risk is very difficult to define by one conceptual system of modern science. Due to the above, the main research hypothesis of the work is oriented to the assumption that the complexity of the risk category is determined by the diversity (variety) of reality, as a result of which in science there is currently no uniform methodology for risk assessment and estimation. As a result, the main goal of the article is to describe the research area based on selected representative methods of risk estimation and logical decision-making schemes, as well as to systematise the knowledge about the methodology used in them. In the article, the authors illustrate risk estimation with examples developed by themselves and quoted from various fields of science, differing from one another in formal terms in quantitative and qualitative (numerical and content-verbally) dimensions. Strategic risk, risk of fraction estimation, Bayesian risk, Bayesian methods for estimation of population distribution parameters, risk of econometric model assessment, interest rate risk, banking risk, and adverse event as a measure of risk are here addressed. The article also focuses on the problem of risk estimation in terms of the theory of fractals. The work is to have not only cognitive but also practical meaning. The created source of knowledge should prove helpful for decision-makers in the area of management since effective process management requires the expertise of risk estimation in various dimensions and using various mathematical tools.","PeriodicalId":43244,"journal":{"name":"Operations Research and Decisions","volume":"31 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85916894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Intuitionistic fuzzy sets in assessing the marginal value of the elements of a multigraph","authors":"B. Gładysz, J. Mercik","doi":"10.37190/ORD200402","DOIUrl":"https://doi.org/10.37190/ORD200402","url":null,"abstract":"The paper presents a method of assessing the value of individual elements of the multigraph, i.e., the value of its vertices and arcs, considering the fuzziness of its parameters. The need to take into account the specificity of the existing types of vertices (including logical functions specified on them) and the possibility of multiple relationships between two neighbouring vertices make it necessary to use a multigraph. The assumed basis for the evaluation of the individual elements of the multigraph was their marginal value, which is the so-called contribution of a given element to the entire multigraph, assuming that the given element affects not only the adjacent elements directly related to it but in a way, perhaps indirect, every other element of the multigraph.","PeriodicalId":43244,"journal":{"name":"Operations Research and Decisions","volume":"37 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89780060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Application of fuzzy programming techniques to solve solid transportation problem with additional constraints","authors":"S. Halder, Biswapati Jana","doi":"10.37190/ord200104","DOIUrl":"https://doi.org/10.37190/ord200104","url":null,"abstract":"An innovative, real-life solid transportation problem is explained in a non-linear form. As in real life, the total transportation cost depends on the procurement process or type of the items and the distance of transportation. Besides, an impurity constraint is considered here. The proposed model is formed with fuzzy imprecise nature. Such an interesting model is optimised through two different fuzzy programming techniques and fractional programming methods, using LINGO-14.0 tools followed by the generalized gradient method. Finally, the model is discussed concerning these two different methods.","PeriodicalId":43244,"journal":{"name":"Operations Research and Decisions","volume":"10 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87248265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Governmental combat of migration between competing terrorist organisations","authors":"K. Hausken","doi":"10.37190/ord200302","DOIUrl":"https://doi.org/10.37190/ord200302","url":null,"abstract":"Each terrorist organisation is modelled with four coupled differential time equations for the evolution of ideologues, criminal mercenaries, captive participants, and capital sponsoring. Emigration of ideologues may cause unbounded growth of the organisation receiving ideologues. The organisation losing ideologues may reach a stationary state where ideologues are supported by capital sponsors and mercenaries. Emigration of mercenaries may cause the organisation losing mercenaries to experience growth. The organisation receiving mercenaries may lose capital sponsors permanently, allowing for the presence of mercenaries, or capital sponsors may rebound deterring mercenaries. Emigration of ideologues from one organisation to another requires more government intervention into the latter to ensure termination. Emigration of mercenaries from one organisation to another may require more government intervention into the latter, since mercenaries support ideologues. Competing terrorist organisations may facilitate their mutual extinction. Various intervention strategies are considered: the most threatening organisation is eliminated first, aided by competition from the least threatening, after which the remaining organisation is eliminated. The government’s instantaneous and accumulated utilities are analysed through time and compared, depending on emigration, competition, and government intervention strategies.","PeriodicalId":43244,"journal":{"name":"Operations Research and Decisions","volume":"11 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74248159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Game theoretic analysis of ideologically biased clickbait or fake news and real news","authors":"K. Hausken","doi":"10.37190/ord200203","DOIUrl":"https://doi.org/10.37190/ord200203","url":null,"abstract":"A decision and game theoretic model is developed for how one and two news organisations strike balances between producing clickbait or fake news, and real news. Each news organisation seeks to attract gullible consumers who consume more clickbait or fake news than real news, and non-gullible consumers who conscientiously consume only real news. Increasing a news organisation budget results in obtaining both more clickbait or fake news, and more real news. More clickbait or fake news is produced if the news organisation’s unit cost of effort to produce real news, the production efficiency for clickbait or fake news, and the fraction of consumers consuming clickbait or fake news, increase. In contrast, less clickbait or fake news is produced if a news organisation’s unit cost of effort to produce clickbait or fake news, and the production efficiency for real news, increase, and the gullible consumers consume real news with a higher frequency. Lower unit effort costs and higher budget and production efficiencies cause higher utility for a news organisation and lower utility for the competing news organisation. Higher weight assigned to the contest over clickbait or fake news induces both news organisations to exert higher effort to produce clickbait or fake news. When the gullible consumers of a news organisation consume a relatively large amount of real news in comparison to the consumers of another news organisation, then the first news organisation exerts higher effort to produce real news and obtains higher utility than the other news organisation.","PeriodicalId":43244,"journal":{"name":"Operations Research and Decisions","volume":"59 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88492077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Moving Average control charts for Burr X and Inverse Gaussian distributions","authors":"A. Shafqat, Muhammad Aslam, M. Albassam","doi":"10.37190/ORD200406","DOIUrl":"https://doi.org/10.37190/ORD200406","url":null,"abstract":"The Burr X and inverse Gaussian (IG) distributions have been considered to design an attribute control chart for time truncated life test with the moving average (MA) scheme w. The presentation of the MA control chart has been estimated in terms of average run length (ARL) by using the Monte Carlo simulation. The ARL is determined for different values of sample sizes, MA statistics size, parameters’ values, and specified average run length. The performance of this new MA attribute control chart has been compared with the usual time truncated control chart for Burr X and IG distributions. The performance of a new control chart is better than that of the existing control chart.","PeriodicalId":43244,"journal":{"name":"Operations Research and Decisions","volume":"91 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77340835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Solutions for network games and symmetric group representations","authors":"J. Sánchez-Pérez","doi":"10.37190/ord190405","DOIUrl":"https://doi.org/10.37190/ord190405","url":null,"abstract":"","PeriodicalId":43244,"journal":{"name":"Operations Research and Decisions","volume":"73 1","pages":""},"PeriodicalIF":0.4,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86420952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}