{"title":"Decision making model for detecting infected people with COVID-19","authors":"S. Mahmood","doi":"10.2298/yjor221115009m","DOIUrl":"https://doi.org/10.2298/yjor221115009m","url":null,"abstract":"The detection of people that are infected with COVID-19 is critical issue due to the high variance of appearing the symptoms between them. Therefore, different medical tests are adopted to detect the patients, such as Polymerase Chain Reaction (PCR) and SARS-CoV-2 Antibodies. In order to produce a model for detecting the infected people, the decision-making techniques can be utilized. In this paper, the decision tree technique based Decisive Decision Tree (DDT) model is considered to propose an optimized decision-making approach for detecting the infected people with negative PCR test results using SARS-CoV-2 antibodies and Complete Blood Count (CBC) test. Moreover, the fever and cough symptoms have been adopted as well to improve the design of decision tree, in which the precision of decision is increased as well. The proposed DDT model provide three decision classes of Infected (I), Not Infected (NI), and Suspected (S) based on the considered parameters. The proposed approach is tested over different patients? samples in off and real-time simulation, and the obtained results show a satisfactory decision class accuracy ratio that varies from 95% to 100%.","PeriodicalId":52438,"journal":{"name":"Yugoslav Journal of Operations Research","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87810697","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}
Luka Ivanovic, S. Radovanović, G. Savić, Boris Delibasic, Milena Popovic
{"title":"Team-bounded DEA efficiency scores: The case of UEFA Champions League Players","authors":"Luka Ivanovic, S. Radovanović, G. Savić, Boris Delibasic, Milena Popovic","doi":"10.2298/yjor230615022i","DOIUrl":"https://doi.org/10.2298/yjor230615022i","url":null,"abstract":"Each player puts in time and effort to achieve results during a game, which can contribute to the team?s overall score. However, the combined effort of the whole team is a hidden factor that impacts a player?s outcomes. With this in mind, the aim of this study is to improve the DEA methodology by considering team performance when calculating efficiency scores. In this study, we introduce a new way to estimate efficiency using data envelopment analysis, which takes into account how the team performs. To achieve this, we use a single mathematical model that limits the player?s efficiency score based on the team performance. This ensures that the efficiency score cannot be more than ? times the average team efficiency score. The results from applying this new model to the UEFA Champions League 2021/22 season indicate that inefficient teammates significantly impact efficiency scores. However, when the entire team performs well, any decrease in efficiency scores is not substantial. The key advantage of these new efficiency scores is that they help pinpoint weak links within each team and identify areas that need improvement to enhance individual efficiency. Consequently, coaches and managers can utilize this model to identify areas for team enhancement, as well as players to improve their performance.","PeriodicalId":52438,"journal":{"name":"Yugoslav Journal of Operations Research","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76849549","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":"Entrepreneurs’ preferences towards online market research packages: A discrete choice analysis","authors":"Ognjen Nikolic","doi":"10.2298/yjor230815026n","DOIUrl":"https://doi.org/10.2298/yjor230815026n","url":null,"abstract":"Startups have become a buzzword in the last couple of years, and entrepreneurship became career path for a number of people in the world. With all the advances in education and government subsidizing all over the world, still, statistics shows only a small percentage of successful startups. Studies have shown that the one the leading reasons for startup failure is the misreading of market?s needs. The aim of this paper is to determine the approach to market research, knowledge of tools and methods, and preferences towards online market research tools of entrepreneurs by using Discrete Choice Analysis. The research gathered 187 valid responses from a panel of participants working on developing new products and business, using an online survey tool. In the paper it is shown that the most important attributes for entrepreneurs are the price of the market research tool, followed by the level of details in the report generated, with more in-depth analysis regarding segmentation, simulations, and Marginal Willingness to Pay in the further chapters. The results of the research imply the need for a market research business model optimized for those starting a new business, focused primarily on detailed reporting and analysis, with the pricing model adjusted to the lack of resources entrepreneurs face at the start of their ventures, which would help them better understand the market-fit at the beginning and raise the statistic of successful startups.","PeriodicalId":52438,"journal":{"name":"Yugoslav Journal of Operations Research","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135449560","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":"Metric on the space of systems behavior functions represented by fuzzy measures","authors":"V. Bocharnikov, S. Sveshnikov","doi":"10.2298/yjor230315012b","DOIUrl":"https://doi.org/10.2298/yjor230315012b","url":null,"abstract":"G. Klir proposed to describe the behavior of complex systems using behavior functions (BFs) - invariant constraints on the set of system states. BFs are one of the most productive tools for studying the functioning of systems. To study systems, it is necessary to have a metric for measuring of the difference between two BFs. To describe BFs modern researchers do not use distributions other than probability or possibility. But these distributions can be considered as special cases of Sugeno fuzzy measures, the use of which greatly expands the possibilities in the study of systems. However, metrics to measure the difference between fuzzy measures have not been developed. Therefore, in this article, the authors proposed a new metric and an algorithm for its calculation for the case when BFs are described by Sugeno fuzzy measures. This metric is based on the Cartesian product of fuzzy measures and the use of our proposed concentration function. The metric makes it possible to compare the behavior of systems in the case of describing BFs by Sugeno fuzzy measures with different modalities, as well as to ensure the priority of taking into account the set of the most significant states of the system.","PeriodicalId":52438,"journal":{"name":"Yugoslav Journal of Operations Research","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75289519","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":"Numerical integration approximations to estimate the Weitzman overlapping measure: Weibull distributions","authors":"Omar M. Eidous, Mervat Al-Hayja`a","doi":"10.2298/yjor221215021e","DOIUrl":"https://doi.org/10.2298/yjor221215021e","url":null,"abstract":"This paper deals with the problem of estimating the overlapping (OVL) Weitzman measure (?) when two independent random variables ?? and ?? are given by two-parameter Weibull distribution. The measure ? has been studied in the literature in the case of two Weibull distributions under the assumption that the two shape parameters are equal. In this work, a general expression for the Weitzmans measure is provided under the Weibull distribution without using any assumptions about the distribution parameters. Some new estimators for ? are developed depending on three numerical integration rules known as trapezoidal, Simpson 1/3 and Simpson 3/8 rules. The performance of the proposed estimators were investigated and compared with some existing estimators via simulation technique and real data. The results demonstrated the superiority of the proposed estimators over the existing one in almost all considered cases.","PeriodicalId":52438,"journal":{"name":"Yugoslav Journal of Operations Research","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81503839","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}
C. Ceylan, Hüseyin Başkurt, Yasin Erkan, Şeymanur Uğur
{"title":"Process analysis and optimal facility layout planning in manufacturing systems","authors":"C. Ceylan, Hüseyin Başkurt, Yasin Erkan, Şeymanur Uğur","doi":"10.2298/yjor2105015033c","DOIUrl":"https://doi.org/10.2298/yjor2105015033c","url":null,"abstract":"In this article, it is emphasized that the process analysis for companies is carried out by using the DISCO process mining program and the results are interpreted and developed. In the light of machine and worker occupancy information obtained as a result of process analysis, imbalances, if any, are detected. These imbalances are resolved by arranging job assignments. Another information that we obtain is the time elapsed until the processing of any workpiece on a machine is finished. This time consists of the time elapsed between the machines and the waiting time in the queue of the machine to be processed. The waiting time in the queue of the machine will be improved by adjusting the workload balance of the machines and the transportation times will be improved by creating the best plant layout suitable for the process. As a result, the facility layout of the factory was made considering the functional grouping. In the study, a layout is designed in accordance with the workflow of the products. With this newly designed plan, it has been determined that the products can be produced by covering 50% less transport distance. In addition, the workload imbalances of the machines and workers were corrected by changes in job assignments. This has reduced the cycle time of a product by eliminating bottlenecks at the factory.","PeriodicalId":52438,"journal":{"name":"Yugoslav Journal of Operations Research","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85599411","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":"Decision making in fuzzy closed loop dual channel supply chain","authors":"A. Mondal, J. Kumar, J. Kumar","doi":"10.2298/yjor230115014m","DOIUrl":"https://doi.org/10.2298/yjor230115014m","url":null,"abstract":"This paper discusses the optimal pricing and collecting decisions in a fuzzy environment of the three closed-loop dual-channel supply chain models where a manufacturer produces the original product from fresh materials and unfashionable products. The manufacturer sells the original products to the customers using direct and retail channels (forward dual channel). In the reverse channel, the manufacturer, third-party collector and retailer individually take responsibility for unfashionable products acquired from the market in the three models. Remanufacturing cost, product collecting cost and market demand are treated as fuzzy variables. The optimal decisions wholesale price, direct price, retail price and collection rate are derived using fuzzy set theory and game theory approach in the three decision models. Finally, numerical illustrations clarify the impact of the fuzzy degree parameters on the decision variables and the expected profits of the players. It is found that the manufacturer decision model is superior for receiving the maximum expected profits of the players and also being more convenient from the customer?s perspective.","PeriodicalId":52438,"journal":{"name":"Yugoslav Journal of Operations Research","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84765012","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":"Neutrosophic MAGDM based on critic-EDAS strategy using geometric aggregation operator","authors":"Rama Mallick, Surapati Pramanik, B. Giri","doi":"10.2298/yjor221017016m","DOIUrl":"https://doi.org/10.2298/yjor221017016m","url":null,"abstract":"Nowadays career choosing is a very difficult job for many students. This paper primarily addresses the concerns of those students who face difficulty in choosing the right career option for themselves, using multi-attribute group decision-making (MAGDM) methodologies based on CRITIC (Criteria Importance Through Inter criteria Correlation) and EDAS (Evaluation based on Distance from Average Solution) strategies under the single-valued neutrosophic set (SVNS) environment. First, the CRITIC strategy is used to calculate the weights of the attributes and then these weights are used to develop EDAS strategy in the SVNS environment. Since the usage of the geometric operator CRITIC-EDAS has not before been documented in the literature, this study is distinctive. A realistic example of commerce students? career selection problem is discussed.","PeriodicalId":52438,"journal":{"name":"Yugoslav Journal of Operations Research","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78647180","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":"A stochastic inventory model with price-sensitive demand, restricted shortage and promotional efforts","authors":"U. Khedlekar, Lalji Kumar, Mamta Keswani","doi":"10.2298/yjor220915010k","DOIUrl":"https://doi.org/10.2298/yjor220915010k","url":null,"abstract":"This paper is attempt to develop a stochastic inventory model with quadratic price-sensitive demand. Objective function is developed by incorporating promotional efforts to boost the market demand, preservation technology to reduce the rate of deterioration, proportionate shortage time and partial backloggings. The proposed work is to generalise the stochastic demand with different probability distributions and their comparisons. The objective is to find the optimal price, optimal replenishment, and optimal preservation technology investment while optimizing the total profit per unit time. In the case of partial backlogging and lost sale, we deduced the optimal replenishment schedules for respective price and preservation technology cost. Also, we shown analytically and graphically that the total profit per unit time is a concave function with respect to per unit time, price, and preservation cost. The theoretical implications have been validated by useful results and numericals. Also, we examine the impact of various parameters for the best course of action. The conclusions drawn from the assessment might be useful for managerial purposes.","PeriodicalId":52438,"journal":{"name":"Yugoslav Journal of Operations Research","volume":"142 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80307060","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}
Ines Ziad, Vijaya Laxmi, Girija Bhavani, A. Bouchentouf, Shakir Majid
{"title":"A matrix geometric solution of a multi-server queue with waiting servers and customers’ impatience under variant working vacation and vacation interruption","authors":"Ines Ziad, Vijaya Laxmi, Girija Bhavani, A. Bouchentouf, Shakir Majid","doi":"10.2298/yjor220315001z","DOIUrl":"https://doi.org/10.2298/yjor220315001z","url":null,"abstract":"This paper deals with a M/M/c queueing system with waiting servers, balking, reneging, and K-variant working vacations subjected to Bernoulli schedule vacation interruption. Whenever the system is emptied, the servers wait for a while before synchronously going on vacation during which services are offered with a lower rate. We obtain the steady-state probabilities of the system using the matrix-geometric method. In addition, we derive important performance measures of the queueing model. Moreover, we construct a cost model and apply a direct search method to get the optimum service rates during both working vacation and regular working periods at lowest cost. Finally, numerical results are provided.","PeriodicalId":52438,"journal":{"name":"Yugoslav Journal of Operations Research","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88665920","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}