Template-Type: ReDIF-Article 1.0 Author-Name: Henry Toledo Author-X-Name-First: Henry Author-X-Name-Last: Toledo Author-Name: Javier Martínez-Gómez Author-X-Name-First: Javier Author-X-Name-Last: Martínez-Gómez Author-Name: Juan Francisco Nicolalde Author-X-Name-First: Juan Francisco Author-X-Name-Last: Nicolalde Title: Selection of rear axle tip alternative material of a car by multi-criteria means Abstract: In Ecuador some automotive spare parts are not manufactured in the country and must be imported. The reason for this is that some materials cannot be found in the market, which is why this research aims to find an alternative material for the rear axle tip of a car. In order to find this material, first an original part is characterised under the ASTM E415 standard for chemical composition testing, where 0.577-0.603% of C was obtained. The hardness is determined with the ASTM E18 standard obtaining a hardness of 322.77 HB. Tensile strength is found through the ratio of hardness vs. tensile strength, obtaining 115.05 kg / mm<SUP align="right"><SMALL>2</SMALL></SUP>. Subsequently, a multi-criteria analysis is carried out with the entropy, simple management and CRITIC methods. The weights of each criterion are measured and with the EXPROM II, TOPSIS and VIKOR method the material is selected, where it was established that the optimal option is the AISI 5115 Steel compared to the original material characterised. Journal: Int. J. of Mathematics in Operational Research Pages: 46-66 Issue: 1 Volume: 21 Year: 2022 Keywords: automotive; multi-criteria; mechanics; materials; simulation. File-URL: http://www.inderscience.com/link.php?id=120320 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:1:p:46-66 Template-Type: ReDIF-Article 1.0 Author-Name: G. Ayyappan Author-X-Name-First: G. Author-X-Name-Last: Ayyappan Author-Name: G. Archana Alias Gurulakshmi Author-X-Name-First: G. Archana Alias Author-X-Name-Last: Gurulakshmi Author-Name: B. Somasundaram Author-X-Name-First: B. Author-X-Name-Last: Somasundaram Title: Analysis of MAP1I, PH2O/PH1I, PH2O/1 retrial queue with two-way communication, optional service, single vacation, closedown, setup and balking Abstract: A single server constant retrial queueing model with close down, vacation, setup, optional service and balking are studied in this article. There are two kinds of arrivals, namely incoming and outgoing calls. If the server is idle, arriving incoming calls will be served instantly. After completion of the service, the server becomes idle. The server goes on vacation, while the system is void. Before taking the vacation, the server will closedown the system and after completion of the vacation, the server will set up the system to give the service. The server will give optional service for incoming calls if the customer needs. The incoming calls follow the Markovian arrival process (MAP) and outgoing calls and service times follow PH-type distribution. We derived the busy period analysis and cost analysis. Also, some important performance measures are obtained which are illustrated graphically/numerically. Journal: Int. J. of Mathematics in Operational Research Pages: 427-455 Issue: 4 Volume: 23 Year: 2022 Keywords: retrial queues; two way communication; vacation; closedown; setup; optional service; balking. File-URL: http://www.inderscience.com/link.php?id=127751 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:4:p:427-455 Template-Type: ReDIF-Article 1.0 Author-Name: Seyed Omid Hasanpour Jesri Author-X-Name-First: Seyed Omid Hasanpour Author-X-Name-Last: Jesri Author-Name: Mohsen Akbarpour Shirazi Author-X-Name-First: Mohsen Akbarpour Author-X-Name-Last: Shirazi Title: Integrated centralised routing mechanism for optimising total travel time Abstract: Online vehicle routing is a fascinating and challenging topic in terms of research and functionality. Current approaches to routing generally suffer from two major problems which this paper attempts to resolve. Firstly, current approaches to routing primarily aim at user optimality, which does not lead to total system optimality. In this paper, we have presented the integrated centralised routing mechanism (ICRM), a holistic model that minimises the total travel time of all users via the central traffic control centre (CTCC), as a way to mitigate this problem. Gathering the origin and destination of all vehicles and the flow rates of all routes, the system calculates the optimum routes for all vehicles and directions thereof. The second problem has to do with the effects of the ongoing origin-destination (OD) demands on routing; current approaches show little regard for future demands while it strongly affects travel time. In our proposed model, future OD demands are considered as one of the main inputs of the system. The numerical test points to a significant improvement in total time travel in our proposed model vis-à-vis the existing models. Journal: Int. J. of Mathematics in Operational Research Pages: 509-527 Issue: 4 Volume: 23 Year: 2022 Keywords: integrated centralised routing mechanism; ICRM; system optimality; traffic management; urban planning; optimisation. File-URL: http://www.inderscience.com/link.php?id=127752 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:4:p:509-527 Template-Type: ReDIF-Article 1.0 Author-Name: Navdeep Kailey Author-X-Name-First: Navdeep Author-X-Name-Last: Kailey Author-Name: Sonali Author-X-Name-First: Author-X-Name-Last: Sonali Author-Name: Vikas Sharma Author-X-Name-First: Vikas Author-X-Name-Last: Sharma Title: Parametric approach for a class of fractional variational programs involving support functions Abstract: In this paper, a pair of non-differentiable second-order multi-objective symmetrical dual fractional variational programs over arbitrary cones is constructed. We have introduced the concept of second-order (<i>F</i>, <i>α</i>, <i>ρ</i>, <i>d</i>)-pseudoconvexity and an example of a function which is second-order (<i>F</i>, <i>α</i>, <i>ρ</i>, <i>d</i>)-pseudoconvex but not second-order <i>F</i>-pseudoconvex has been constructed. Further, to relate the objective function value of primal and dual, we proved weak, strong, and converse duality theorems under second-order (<i>F</i>, <i>α</i>, <i>ρ</i>, <i>d</i>)-pseudoconvexity suppositions. Moreover, to validate the results of the weak duality theorem, an example of a multi-objective variational fractional problem and its dual model has been constructed. Several known results are also discussed as special cases. Journal: Int. J. of Mathematics in Operational Research Pages: 481-508 Issue: 4 Volume: 23 Year: 2022 Keywords: fractional programs; support functions; parametric approach; variational programs; (F, α, ρ, d)-pseudoconvexity. File-URL: http://www.inderscience.com/link.php?id=127756 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:4:p:481-508 Template-Type: ReDIF-Article 1.0 Author-Name: Totan Garai Author-X-Name-First: Totan Author-X-Name-Last: Garai Author-Name: Arpita Paul Author-X-Name-First: Arpita Author-X-Name-Last: Paul Author-Name: Dipankar Chakraborty Author-X-Name-First: Dipankar Author-X-Name-Last: Chakraborty Title: Pricing strategy of competing retailers in a two layer supply chain under nonlinear stochastic demand Abstract: This paper develops mechanisms to deal the strategic issue that arises in a two-echelon closed-loop supply chain comprising of one manufacturer and two competing retailers. The chain works under stochastic nonlinear demand. Here the manufacturer works as the supplier and the retailers compete with each other on the basis of their retail price. The prime objective is to investigate a news-vendor model to govern the optimal order quantity. A buyback contract between the manufacturer and retailer has been considered and scenario of shortage has also been contemplated. The profit functions of manufacturer and two retailers are analysed following centralised approach. A numerical example is given to illustrate the theoretical results. Computational results show that it is always beneficial in integrated system for the members of the chain. Journal: Int. J. of Mathematics in Operational Research Pages: 528-544 Issue: 4 Volume: 23 Year: 2022 Keywords: pricing; news vendor; stochastic nonlinear demand; supply chain. File-URL: http://www.inderscience.com/link.php?id=127757 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:4:p:528-544 Template-Type: ReDIF-Article 1.0 Author-Name: Binay Kumar Author-X-Name-First: Binay Author-X-Name-Last: Kumar Title: Transient analysis of M/M/C queuing model with reneging, finite capacity and population Abstract: The present paper deals with multi-server Markovian queuing model with impatient behaviour of units. The server work in two modes: slow mode and fast mode; and changes its state from slow to fast or vice versa with some exponential distributed time parameters. When the server works in slow mode, the units may leave the system due to impatient behaviour of units. We investigate the present model by two variant, one with finite capacity and other with finite population. Transient probabilities of various states are obtained by solving the set of governing equation via Runge-Kutta method. The various system performance measures are established in terms of transient probability of the system states. The system behaviour for different parameter are analysed by using the graphs and tables. Journal: Int. J. of Mathematics in Operational Research Pages: 1-25 Issue: 1 Volume: 21 Year: 2022 Keywords: Markovian model; transient probability; multi-server; reneging; Runge-Kutta. File-URL: http://www.inderscience.com/link.php?id=120339 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:1:p:1-25 Template-Type: ReDIF-Article 1.0 Author-Name: Prabhujit Mohapatra Author-X-Name-First: Prabhujit Author-X-Name-Last: Mohapatra Author-Name: Santanu Roy Author-X-Name-First: Santanu Author-X-Name-Last: Roy Author-Name: Kedar Nath Das Author-X-Name-First: Kedar Nath Author-X-Name-Last: Das Author-Name: Saykat Dutta Author-X-Name-First: Saykat Author-X-Name-Last: Dutta Author-Name: M. Sri Srinivasa Raju Author-X-Name-First: M. Sri Srinivasa Author-X-Name-Last: Raju Title: A review of evolutionary algorithms in solving large scale benchmark optimisation problems Abstract: Optimisation problems containing huge total of decision variables are termed as large scale global optimisation problems which are often considered as abundant challenges to the area of optimisation. With presence of large number of decision variables, these problems also used to have the property of nonlinearity, discontinuity and multi-modality. Hence, the nature-inspired optimisation algorithms based on stochastic approaches are termed as great saviours than the deterministic approaches to handle these problems. However, the nature inspired optimisation algorithms also suffer from the jinx of dimensionality in the decision variable space. With increase of dimensions in the decision variable space, the complexity of the problem also increases exponentially. Hence, there is an immense need of proper guidance of choosing capable nature inspired algorithms to solve real-life large scale optimisation problems. In this paper, an attempt has been made to select the elite algorithm with proper justification. Hence, a number of works have been presented to analyse the results and to tackle the difficulty. Journal: Int. J. of Mathematics in Operational Research Pages: 104-126 Issue: 1 Volume: 21 Year: 2022 Keywords: swarm intelligence; large scale global optimisation; evolutionary algorithms. File-URL: http://www.inderscience.com/link.php?id=120340 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:1:p:104-126 Template-Type: ReDIF-Article 1.0 Author-Name: Mohamed Abd Allah El-Hadidy Author-X-Name-First: Mohamed Abd Allah Author-X-Name-Last: El-Hadidy Author-Name: Hamdy M. Abou-Gabal Author-X-Name-First: Hamdy M. Author-X-Name-Last: Abou-Gabal Title: On the linear cooperative search technique for a lost target with multiple searchers Abstract: We discuss the linear cooperative search model to detect a hidden and randomly located target on one of the <i>n</i>-intersected roads (real lines). The searching process starts from the origin with <i>n</i> searchers. Each one of these roads has one unit speed searcher. We get the expected value of the searching time until the (<i>n</i> - 1) searchers return to the origin after the target has been detected by the other searcher. We obtain the optimal distances for these <i>n</i> searchers to get the optimal search strategy which minimises the expected time of return. An interesting case with numerical results is studied when the target's position has a truncated normal distribution. Journal: Int. J. of Mathematics in Operational Research Pages: 221-231 Issue: 2 Volume: 21 Year: 2022 Keywords: cooperative search model; probability of detection; truncated normal distribution; optimal search plan. File-URL: http://www.inderscience.com/link.php?id=121112 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:2:p:221-231 Template-Type: ReDIF-Article 1.0 Author-Name: K.A.M. Kotb Author-X-Name-First: K.A.M. Author-X-Name-Last: Kotb Author-Name: Hassnaa A. El-Ashkar Author-X-Name-First: Hassnaa A. Author-X-Name-Last: El-Ashkar Title: Quality control of feedback machining system with finite source and standbys Abstract: This paper provides the quality control policy to improve the performance and the effectiveness of the machining system with standbys (spares) from the viewpoint of the queuing theory. The unit in the system is called a customer to whom the service should be rendered. An inspector is used to control the inspection process of the serviced unit. Under steady-state situation and the feedback concept, we obtained some performance measures and the probability when the system is empty or it has <i>n</i> units. Some important special cases and some analysis about the economic optimisation model with illustrative numerical examples are performed. Journal: Int. J. of Mathematics in Operational Research Pages: 141-170 Issue: 2 Volume: 21 Year: 2022 Keywords: quality control; spares; feedback machining system; steady-state solution; economic optimisation model. File-URL: http://www.inderscience.com/link.php?id=121113 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:2:p:141-170 Template-Type: ReDIF-Article 1.0 Author-Name: Jacob Muvingi Author-X-Name-First: Jacob Author-X-Name-Last: Muvingi Author-Name: Arshad Ahmud Iqbal Peer Author-X-Name-First: Arshad Ahmud Iqbal Author-X-Name-Last: Peer Author-Name: Farhad Hosseinzadeh Lotfi Author-X-Name-First: Farhad Hosseinzadeh Author-X-Name-Last: Lotfi Author-Name: Volkan Soner Özsoy Author-X-Name-First: Volkan Soner Author-X-Name-Last: Özsoy Title: Hierarchical groups DEA cross-efficiency and TOPSIS technique: an application on mobile money agents locations Abstract: Ranking of efficient decision-making units (DMUs) allows a further analysis of the data envelopment analysis (DEA) efficient DMUs, where otherwise a high number of efficient DMUs can be identified. The current research seeks to segregate the efficient DMUs through the use of seven cross-efficiency (CE) ranking approaches. The choice of using those CE approaches was meant to reduce bias associated with the use of a single criterion. The seven approaches were extended to suit a situation were DMUs are structured in a two-level hierarchical grouping. The CE of level 1 DMUs was adjusted with the performance of the level 2 DMUs. Variations in the seven adjusted CE ratings were observed. In a bid to ensure complete ranking, the technique for order preference by similarity to ideal solution (TOPSIS) ranking method was combined with the adjusted CE ratings. The results from a real-world example revealed complete ranking for all the DMUs. Journal: Int. J. of Mathematics in Operational Research Pages: 171-199 Issue: 2 Volume: 21 Year: 2022 Keywords: data envelopment analysis? DEA? hierarchical? groups? cross-efficiency? TOPSIS? locations? mobile money agents. File-URL: http://www.inderscience.com/link.php?id=121114 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:2:p:171-199 Template-Type: ReDIF-Article 1.0 Author-Name: Maryam Radman Author-X-Name-First: Maryam Author-X-Name-Last: Radman Author-Name: Kourosh Eshghi Author-X-Name-First: Kourosh Author-X-Name-Last: Eshghi Title: A novel decomposition approach to set covering problems by exploiting special structures Abstract: The set covering problem (SCP) has quite a large coefficient matrix in practical problems, but due to its low density, most of its entries are zero. Drawing on this observation, some methods can be developed to exploit special structures of the coefficient matrix of an SCP in such a way that they contain smaller dense subproblems. Against this backdrop, in this paper, three structures, namely 'partitioned', 'semi-block angular', and 'block angular', are proposed. To begin with, some heuristic methods are presented to exploit these structures of the coefficient matrices of SCPs; then, by optimally solving the smaller subproblems of these structures, their solutions are used to solve the whole problem based on the proposed theorem. Our approach has been tested using well-known instances from OR-Library and shown to be comparable with some of the recently-developed methods to solve SCPs. Journal: Int. J. of Mathematics in Operational Research Pages: 254-279 Issue: 2 Volume: 21 Year: 2022 Keywords: set covering problem; SCP; constraint partitioning; decomposition techniques; special structures; clustering methods. File-URL: http://www.inderscience.com/link.php?id=121115 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:2:p:254-279 Template-Type: ReDIF-Article 1.0 Author-Name: Rubi Das Author-X-Name-First: Rubi Author-X-Name-Last: Das Author-Name: Abhijit Barman Author-X-Name-First: Abhijit Author-X-Name-Last: Barman Author-Name: Pijus Kanti De Author-X-Name-First: Pijus Kanti Author-X-Name-Last: De Title: A two-echelon supply chain contract under advertisement and retail price-dependent demand Abstract: In this study, we have considered the coordination issues of a supply chain system composed of a supplier and a retailer. The supplier offers a single product to the retailer, and the customer demand for the product at the retailer's end is advertisement and retail price dependent. We have investigated the behaviour of the two-layered supply chain under the integrated and non-integrated scenario. Both models' nature provides significant perceptions to an organisation's manager to achieve optimum strategy under price and advertisement dependent demand. The main objective is to maximise the supply chain's overall profit by optimising selling price, wholesale price, order quantity, and replenishment time. We have established the decentralised structure under the Stackelberg game approach to find the optimal values of each channel member. A numerical example and study of sensitivity analysis are provided to validate our proposed model. Journal: Int. J. of Mathematics in Operational Research Pages: 232-253 Issue: 2 Volume: 21 Year: 2022 Keywords: inventory? advertisement? price? supply chain? centralised? decentralised? Stackelberg game. File-URL: http://www.inderscience.com/link.php?id=121117 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:2:p:232-253 Template-Type: ReDIF-Article 1.0 Author-Name: Neelanjana Rajput Author-X-Name-First: Neelanjana Author-X-Name-Last: Rajput Author-Name: R.K. Pandey Author-X-Name-First: R.K. Author-X-Name-Last: Pandey Author-Name: Anand Chauhan Author-X-Name-First: Anand Author-X-Name-Last: Chauhan Title: Fuzzy optimisation of a production model with CNTFN demand rate under trade-credit policy Abstract: The presented article deals with an economic production quantity model with a trade-credit policy. The classical (crisp) model presented with a fuzzy demand rate under a cloudy fuzzy environment. The concept of fuzziness affects the inventory model as well as inventory cost, profit, lot size, and all other factors. The centroid method has been used for the defuzzification of the model with triangular fuzzy demand in a general fuzzy environment. To avoid the effect of non-random uncertainties of demand rate in the production, the cloudy fuzzy model has been used here to provide a profitable business under several circumstances. And the Yager's ranking method has been used for defuzzification for the cloudy fuzzy model. The cloudy fuzzy model gives better results instead of deterministic models for the long-run production cycle. Finally, the sensitivity analysis and graphical illustrations of a numerical example justify the model. Journal: Int. J. of Mathematics in Operational Research Pages: 200-220 Issue: 2 Volume: 21 Year: 2022 Keywords: fuzzy optimisation? cloudy normalised triangular fuzzy number? CNTFN? EPQ inventory model? trade-credit scheme? triangular fuzzy number? TFN? centroid method? extended Yager' s ranking index method. File-URL: http://www.inderscience.com/link.php?id=121118 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:2:p:200-220 Template-Type: ReDIF-Article 1.0 Author-Name: Nemat Allah Taghi-Nezhad Author-X-Name-First: Nemat Allah Author-X-Name-Last: Taghi-Nezhad Title: A revisit of the proposed model for solving fuzzy linear fractional programming problem Abstract: Linear fractional programming (LFP) problem is used worldwide in solving real world problems. In real life situations the parameters of the problem are imprecise instead of fixed real numbers. So, a procedure for modelling these impreciseness in mathematical form is required. Fuzzy set theory is a best tool to deal with such situations. In this paper LFP problem with fuzzy parameters are studied. A fuzzy linear fractional programming (FLFP) problem is considered by Das et al. (2018) where a simple ranking approach between two triangular fuzzy numbers is provided. Then, in their study a tri-objective LFP problem is formulated to calculate the upper, middle and the lower bounds of the fuzzy optimal value. There are some errors and shortcomings in Das et al. method. Hence, in this study errors and shortcomings of Das et al. method are pointed out. Also, to overcome these errors, a simple method is presented to obtain optimal solution and fuzzy optimal value of the objective function. Moreover, by solving some numerical examples these errors are demonstrated and using the new proposed algorithm the correct optimal solution and the fuzzy optimal value of objective function are obtained. Journal: Int. J. of Mathematics in Operational Research Pages: 215-231 Issue: 2 Volume: 23 Year: 2022 Keywords: linear fractional programing problem; fuzzy number; fuzzy linear fractional programing problem; fuzzy optimal value. File-URL: http://www.inderscience.com/link.php?id=127051 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:2:p:215-231 Template-Type: ReDIF-Article 1.0 Author-Name: L.N.P. Kumar Rallabandi Author-X-Name-First: L.N.P. Kumar Author-X-Name-Last: Rallabandi Author-Name: Ravindranath Vandrangi Author-X-Name-First: Ravindranath Author-X-Name-Last: Vandrangi Title: A method for improving cosine consistency index of pairwise comparison matrix in analytic hierarchy process Abstract: In analytic hierarchy process (AHP), pairwise comparison matrix (PCM) is used to rank the alternatives in the decision-making problem. The priority vector, derived from the PCM, is accepted only when the PCM is consistent. However, in many practical situations the PCM obtained by the judgments of expert may be inconsistent. Several indices have been proposed to measure the consistency level of PCM over the years and one among them is cosine consistency index (CCI). In this paper, an algorithm is proposed to improve the consistency of PCM in terms of CCI. For examining the consistency of the given PCM, the new threshold values for CCI are proposed. Correlation and regression analysis is used to derive the relation between CCI and consistency ratio (CR) from which the threshold values of CCI for PCMs of order 3 to 15 are determined. The derived regression models have been validated by using statistical techniques. Journal: Int. J. of Mathematics in Operational Research Pages: 259-283 Issue: 2 Volume: 23 Year: 2022 Keywords: cosine consistency index; CCI; pairwise comparison matrix; PCM; consistency ratio; analytic hierarchy process; AHP. File-URL: http://www.inderscience.com/link.php?id=127052 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:2:p:259-283 Template-Type: ReDIF-Article 1.0 Author-Name: G. Ayyappan Author-X-Name-First: G. Author-X-Name-Last: Ayyappan Author-Name: K. Thilagavathy Author-X-Name-First: K. Author-X-Name-Last: Thilagavathy Title: Analysis of MAP/PH1E, PH2O/1 queue with standby server, second optional service, variant arrival rate, Bernoulli schedule vacation, impatient behaviour of customers, breakdown, essential and optional repair Abstract: In this article, we examine a single-server queueing model in which customers arrive at one of three different rates depending on the system's current state as determined by a Markovian arrival process. After obtaining the server's essential service, customers have the option of pursuing the second optional service. The service time is distributed in a phase-type manner. If the main server successfully completes an essential repair, the server may choose an optional repair option or return to the service station. We examined the total number of customers existing in the system using the matrix-analytic method (MAM) under the steady-state probability vector. We analyse the features of system performance measures. We discussed the stability condition, the analysis of the busy period, and the distribution of waiting times. For a better understanding of our suggested model, numerical results and graphical representations are provided. Journal: Int. J. of Mathematics in Operational Research Pages: 147-214 Issue: 2 Volume: 23 Year: 2022 Keywords: variant arrival rate; phase type distributions; Markovian arrival process; standby server; impatient behaviour; second optional service and repair. File-URL: http://www.inderscience.com/link.php?id=127054 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:2:p:147-214 Template-Type: ReDIF-Article 1.0 Author-Name: Manisha Pant Author-X-Name-First: Manisha Author-X-Name-Last: Pant Author-Name: Seema Sharma Author-X-Name-First: Seema Author-X-Name-Last: Sharma Author-Name: Anand Chauhan Author-X-Name-First: Anand Author-X-Name-Last: Chauhan Title: Optimal replenishment and preservation investment policy for hybrid demand with trade credit schemes Abstract: A safe and sustainable environment has become a top priority for all kind of businesses. This research is to develop a sustainable model of frozen products for hybrid price-stock-dependent demand with preservation technology. Generally, the consumption rate is often affected by the price and stock levels for some types of consumer products. In this study, the demand of the product depends on the price and stock of the product as well, and the retailer invests in preservation technology to decrease the occurrence of deterioration of seasonal goods. This results in high demand of products, which encourage both the retailer and the consumer. A massive pile of items in the supermarket is typically found to lead the consumer to buy more creating high demand. The objective is to optimise the replenishment cycle and preservation technology investment cost with hybrid price-stock dependent demand, time-varying carrying cost, and trade-credit policy under shortages for dairy and frozen products. These factors will improve and encourage the purchaser's judgment to buy more products with the appropriate amount. The model is illustrated numerically and validated by sensitivity analysis. Journal: Int. J. of Mathematics in Operational Research Pages: 232-258 Issue: 2 Volume: 23 Year: 2022 Keywords: inventory management; hybrid price-stock dependent demand; deterioration; trade credit scheme; preservation technology; inflation. File-URL: http://www.inderscience.com/link.php?id=127055 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:2:p:232-258 Template-Type: ReDIF-Article 1.0 Author-Name: Mohamed Abd Allah El-Hadidy Author-X-Name-First: Mohamed Abd Allah Author-X-Name-Last: El-Hadidy Title: Detection model for a suitable waiting list with maximising the discount effort reward search under the quality control process Abstract: The economic benefits of the company are increased by improving the quality of its services. At the same time, the customers aimed to get the service with minimum cost. In this paper, we provide a detection model which satisfies these purposes. The customer chooses the suitable engineering consultancy company from independent companies. Each company has a Markovian waiting list of customers with size <i>N</i>. The customer arrives to the waiting list with Poisson process and its service time has an exponential distribution. Under the quality control process and some concepts like balking and reneging of each waiting list, we provide the optimal decision to consider the suitable company. We consider the searching effort is bounded by a random variable with a known probability distribution. After applying the discount effort reward search function, we solve a difficult stochastic optimisation problem to get the maximum values of the service rate, discount effort reward and the minimum value of the detection cost. A case study is provided to get these optimal values and the optimum performance measures which give the optimal expected profit. Journal: Int. J. of Mathematics in Operational Research Pages: 423-448 Issue: 4 Volume: 22 Year: 2022 Keywords: detection model; services quality; waiting list; performance measures; decision-making; maximum discount effort reward. File-URL: http://www.inderscience.com/link.php?id=126042 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:4:p:423-448 Template-Type: ReDIF-Article 1.0 Author-Name: Amirmasoud Soltanzadeh Author-X-Name-First: Amirmasoud Author-X-Name-Last: Soltanzadeh Author-Name: Vahid Baradaran Author-X-Name-First: Vahid Author-X-Name-Last: Baradaran Author-Name: Faezeh Soltanzadeh Author-X-Name-First: Faezeh Author-X-Name-Last: Soltanzadeh Title: Develop an optimisation model for relief facility location in disaster Abstract: This research was conducted to study the issue of relief facility location hierarchically by consideration of possible road closure during the disaster, road safety, and arrival time of relief facility under disaster circumstances. A multi-objective model was developed to minimise the pre-disaster and pro-disaster costs. The main contribution of this study is road safety and reduction in time taken to have a critical facility in affected areas. To investigate the functional accuracy of the mathematical model, a numerical example with small dimensions was solved using CPLEX solver, and required sensitivity analysis was described. As the facility location-allocation is an NP-hard issue, three metaheuristic algorithms were used to solve numerical representations in real dimensions to examine numerical analyses effectively. Results showed that the grey wolf algorithm had the highest efficiency compared to other developed algorithms. The obtained results can be used as an efficient managerial tool in management organisations involved in the disaster. Journal: Int. J. of Mathematics in Operational Research Pages: 449-467 Issue: 4 Volume: 22 Year: 2022 Keywords: hierarchical location; disaster management; multi-objective optimisation model; metaheuristic algorithms. File-URL: http://www.inderscience.com/link.php?id=126043 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:4:p:449-467 Template-Type: ReDIF-Article 1.0 Author-Name: Mahmud R. Siamizade Author-X-Name-First: Mahmud R. Author-X-Name-Last: Siamizade Author-Name: Theodore B. Trafalis Author-X-Name-First: Theodore B. Author-X-Name-Last: Trafalis Title: A robust global optimisation framework for stochastic integrated refinery planning with demand and price uncertainties Abstract: This study presents a global optimisation framework for the strategic planning of an integrated oil refinery while accounting for the uncertainties in the crude oil and final product demand and market prices. To model the uncertainties, three modelling schemes have been utilised: 1) a robust optimisation framework; 2) a fuzzy possibilistic programming approach; 3) a risk aversion two-stage stochastic model with financial risk management. These methodologies are applied to an industrial case study, comprising an integrated oil refinery with tasks spanning from unloading crude oil at the refinery's front to distributing refined products to distribution centres by pipelines. The notable feature of this study is developing an optimisation approach with a multi-period mixed-integer nonlinear programming (MINLP) model and solving it through an aggregation/disaggregation linearisation algorithm and obtaining ε-global optimal solutions. The results indicate significant economical and operational advantage of the robust optimisation scheme depending on the decision maker's risk attitude. Journal: Int. J. of Mathematics in Operational Research Pages: 496-527 Issue: 4 Volume: 22 Year: 2022 Keywords: integrated refinery planning; global optimisation algorithms; uncertainty appraisal; robust programming; fuzzy possibilistic programming; stochastic programming; financial risk management; mixed-integer nonlinear programming; MINLP. File-URL: http://www.inderscience.com/link.php?id=126044 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:4:p:496-527 Template-Type: ReDIF-Article 1.0 Author-Name: André Gonçalves Medeiros Author-X-Name-First: André Gonçalves Author-X-Name-Last: Medeiros Author-Name: Leandro Colombi Resendo Author-X-Name-First: Leandro Colombi Author-X-Name-Last: Resendo Title: Mixed integer linear programming approaches to optimising oil production in offshore petroleum fields Abstract: In this work, mathematical models were developed to maximise oil production in offshore petroleum fields. The wells considered can be equipped with continuous gas-lift, electrical submersible pumps and naturally flowing, and connected by manifold or satellite. Platforms' fluid processing capacity and operational condition were considered as well. Two nonlinear models were developed: one model that considered the pipeline network as a fixed parameter, analysing the system configuration; and another that allows the assignment of wells to manifolds, analysing production improvement with network changes. Using piecewise linearisation for multidimensional functions, four mixed-integer linear formulations were proposed. Two-variable functions were linearised using the diagonal method and triangle method and three-variable functions were linearised using plane method. Using a real scenario, there were investigated the piecewise refinement, computational complexity, and solutions error. Results shown the model's applicability for daily adjustments and indicates the necessity of new investments in pipeline connections. Journal: Int. J. of Mathematics in Operational Research Pages: 468-495 Issue: 4 Volume: 22 Year: 2022 Keywords: mixed integer linear programming; MILP; offshore oilfield; linearisation; diagonal method; triangle method; plane method; production optimisation; continuous gas lift; electrical submersible pumps; ESP. File-URL: http://www.inderscience.com/link.php?id=126045 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:4:p:468-495 Template-Type: ReDIF-Article 1.0 Author-Name: Zeina Mueen Mohammed Author-X-Name-First: Zeina Mueen Author-X-Name-Last: Mohammed Title: Modelling time-series process of an agricultural crop production process by EWMA quality control chart Abstract: Control charts are considered to be one of the main tools for analysing and controlling the steps of a product chain process. This research emphasises the control charts' versatility not only in manufacturing, but in taking enough actions for maintaining the quality of the crops with more flexibility. The time-series quality proceedings for crops that utilised the statistical process control (SPC) method serve as a case study in the EWMA control chart. One week of 168 hours of observation data is analysed with a sampling time of one hour. These measurements have been investigated over three models: AR, MA, and ARMA. The results of plotting EWMA for autoregressive (AR), moving average (MA), and ARMA models included eight points at which the process is out of control. It is found that a higher order of AR or MA model shows a lower out-of-control process. This satisfies the concluded point that higher order of the ARMA model means lower out-of-control process points. Journal: Int. J. of Mathematics in Operational Research Pages: 76-95 Issue: 1 Volume: 23 Year: 2022 Keywords: statistical process control; SPC; control chart; EWMA; AR; MA; ARMA. File-URL: http://www.inderscience.com/link.php?id=126046 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:1:p:76-95 Template-Type: ReDIF-Article 1.0 Author-Name: Elham Shadkam Author-X-Name-First: Elham Author-X-Name-Last: Shadkam Title: The problem of resource levelling in multi-project mode by cuckoo optimisation algorithm Abstract: Project resource levelling is very important and project managers need a schedule based on the optimal use of resources needed to complete their projects. Most resource levelling research has been done in a single project, while in many organisations several projects are done simultaneously. For this purpose, a mathematical model with the aim of minimising the level of change in various resources of consumption by all projects is presented in this paper. The cuckoo optimisation algorithm has been used for this model, which is one of the newest and most efficient evolutionary optimisation algorithms. The obtained results by solving the problem with the cuckoo optimisation algorithm and comparing it with the exact approach indicate that the exact approach is more appropriate in low dimensions and as the dimensions of the problem increase, the cuckoo optimisation algorithm solves the problem faster and in less elapsed time with the same accuracy. Therefore, this algorithm is more suitable for large-scale problems that are close to the real world problem. Journal: Int. J. of Mathematics in Operational Research Pages: 25-54 Issue: 1 Volume: 23 Year: 2022 Keywords: resource levelling problem; cuckoo optimisation algorithm; COA; multi-project control; meta-heuristic algorithms; multi-resources. File-URL: http://www.inderscience.com/link.php?id=126047 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:1:p:25-54 Template-Type: ReDIF-Article 1.0 Author-Name: Miron Vinarskiy Author-X-Name-First: Miron Author-X-Name-Last: Vinarskiy Title: Multi-queue system with finite shared buffer under batch Poisson and/or interrupted batch Poisson arrivals: a computational analysis Abstract: This paper studies a model of a multi-queue system with a finite common buffer shared by queues with batch arrivals. The study is performed for a few buffer-sharing policies. For batch Poisson arrivals with an arbitrary batch size distribution, the analysis benefits from the fact that the stationary state distribution has a product form. For the special case of geometrically distributed batches, closed form solutions for normalisation constant are obtained. They lead to efficient computational procedures. For bursty interrupted batch Poisson arrivals, it is shown that an exact numerical analytic analysis is only possible for very small models. For real-life sized systems, an approximation method has been developed. Journal: Int. J. of Mathematics in Operational Research Pages: 1-24 Issue: 1 Volume: 23 Year: 2022 Keywords: queuing; multi-queue; batch arrivals; finite buffer; losses. File-URL: http://www.inderscience.com/link.php?id=126048 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:1:p:1-24 Template-Type: ReDIF-Article 1.0 Author-Name: Shweta Upadhyaya Author-X-Name-First: Shweta Author-X-Name-Last: Upadhyaya Author-Name: Geetika Malik Author-X-Name-First: Geetika Author-X-Name-Last: Malik Author-Name: Richa Sharma Author-X-Name-First: Richa Author-X-Name-Last: Sharma Title: Neuro-fuzzy computing and optimisation results for batch discrete time retrial queue Abstract: The present investigation involves the application of discrete time bulk entrance recurrent queuing model on asynchronous transfer mode (ATM) technology. This analysis includes the concept of Bernoulli feedback along with priority and impatient customers wherein server may undergo starting failure. Once a service is accomplished, the service provider/server either waits for succeeding customer or leave for a vacation of random time span. The service period, vacation period and retrial period all are presumed to follow general distribution. Firstly, we calculate necessary performance indices using <i>generating function</i> method. Thereafter, we approximate all calculated results with the help of adaptive neuro-fuzzy interface system (ANFIS). Furthermore, we discuss how this model can solve issues related to traffic management and control in ATM networks. Lastly, to make the system more economical, we have computationally analysed the model via particle swarm optimisation (PSO) and genetic algorithm (GA) techniques. Journal: Int. J. of Mathematics in Operational Research Pages: 119-146 Issue: 1 Volume: 23 Year: 2022 Keywords: batch arrival; Bernoulli vacation; starting failure; ATM network; adaptive neuro-fuzzy interface system; ANFIS; cost optimisation. File-URL: http://www.inderscience.com/link.php?id=126049 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:1:p:119-146 Template-Type: ReDIF-Article 1.0 Author-Name: Nabajyoti Bhattacharjee Author-X-Name-First: Nabajyoti Author-X-Name-Last: Bhattacharjee Author-Name: Nabendu Sen Author-X-Name-First: Nabendu Author-X-Name-Last: Sen Title: A multi-item sustainable production inventory constrained model to study and analyse the effective green investment and replenishment quantity Abstract: In the study of supply chain management (SCM) of bioethanol, it is a challenging problem for the manager to regulate the flow of raw material in the production unit and the finished products in the market. Apart from that, the several other decision-making processes like the implementation of preservation technologies, green investment, ordering optimum replenishment quantities, etc. are some relevant issues which demand a profound industrial framework to lead the decision-making process, especially when we are dealing with multi-items. In our present research we propose multi-item supply chain production inventory model to study the effect of green investment and optimum replenishment quantity on production cost. Preservation cost is a linear function of time. Energy cost and labour cost is considered together with finite energy supply and definite production capacity. In order to solve the model, we apply weighted PSO with statistical verification. We perform sensitivity analysis and provide managerial implication of the proposed model. Journal: Int. J. of Mathematics in Operational Research Pages: 528-554 Issue: 4 Volume: 22 Year: 2022 Keywords: multi-item; production inventory; preservation technology cost; carbon emission; green investment; optimisation; supply chain management; SCM. File-URL: http://www.inderscience.com/link.php?id=126050 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:4:p:528-554 Template-Type: ReDIF-Article 1.0 Author-Name: Dinesh K. Sharma Author-X-Name-First: Dinesh K. Author-X-Name-Last: Sharma Author-Name: S.K. Yadav Author-X-Name-First: S.K. Author-X-Name-Last: Yadav Title: Optimal generalised Searls estimation procedure of population mean under ranked set sampling scheme Abstract: Searls (1964) concluded that some constant multiple of a sample mean is an improved estimator of the study variable's population mean. Further, it is well established that the proper use of auxiliary information elevates the estimator's efficiency. In this study, a novel, more generalised family of Searls type estimators is suggested to enhance the estimation of the main variable's population mean utilising known auxiliary parameters under ranked set sampling (RSS) scheme. The bias and mean squared error (MSE) expressions are studied up to first-order approximation. The optimal values of Searls constants are derived, which minimises the MSE of the introduced estimator. The minimum MSE of the proposed estimator is also obtained. The introduced family of estimators is compared with the competing estimators of the population mean. The efficiency conditions of the proposed class over the competing estimators are also derived. These efficiency conditions are verified through numerical and simulation studies. The comparison is made based on the estimators' MSEs, and the estimator with the least MSE is recommended for practical applications. Journal: Int. J. of Mathematics in Operational Research Pages: 305-320 Issue: 3 Volume: 21 Year: 2022 Keywords: ranked set sampling; RSS; main variable; auxiliary variable; Searls estimation; bias; mean squared error; MSE; percentage relative efficiency. File-URL: http://www.inderscience.com/link.php?id=122211 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:3:p:305-320 Template-Type: ReDIF-Article 1.0 Author-Name: Warut Boonphakdee Author-X-Name-First: Warut Author-X-Name-Last: Boonphakdee Author-Name: Peerayuth Charnsethikul Author-X-Name-First: Peerayuth Author-X-Name-Last: Charnsethikul Title: Column generation approach for solving uncapacitated dynamic lot-sizing problems with time-varying cost Abstract: This study proposes the column generation approach for generating the uncapacitated dynamic lot-sizing problem solution under time-varying cost. The dynamic programming approach is also applied to calculate the cost function value. However, this column generation approach generates only an optimal lot size at period 1. Therefore, using the consistent arc method, search the connecting arc from period 1 to period N. Comparing the lot sizes generated by the proposed and the dynamic programming methods, they are the same value. Therefore, they are an optimal solution. Using GUROBI's simplex method can enhance to reduce the running time on dense matrices to be less than the original simplex method, about 25.4% and 26.1% for 12 and 24 periods. The lowest raw material fluctuation price period is selected obviously to order so that the total inventory cost will still be minimal. Therefore, the raw material price significantly influences procurement decision-making. Journal: Int. J. of Mathematics in Operational Research Pages: 55-75 Issue: 1 Volume: 23 Year: 2022 Keywords: dynamic programming; network inventory; column generation; maximum problem size. File-URL: http://www.inderscience.com/link.php?id=126051 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:1:p:55-75 Template-Type: ReDIF-Article 1.0 Author-Name: Mrudul Y. Jani Author-X-Name-First: Mrudul Y. Author-X-Name-Last: Jani Author-Name: Heta A. Patel Author-X-Name-First: Heta A. Author-X-Name-Last: Patel Author-Name: Manish R. Betheja Author-X-Name-First: Manish R. Author-X-Name-Last: Betheja Author-Name: Urmila Chaudhari Author-X-Name-First: Urmila Author-X-Name-Last: Chaudhari Author-Name: Bhargav Pandya Author-X-Name-First: Bhargav Author-X-Name-Last: Pandya Title: Effect of producer's innovation and vendor's sales promotion activities for perishable items under quadratic demand: a centralised vs. decentralised approach Abstract: This research focuses on a single producer-vendor supply chain. To increase the revenue and demand of the product, the producer employs innovation and the vendor employs sales promotion. In this article, demand for the product is predetermined to be quadratic. This paper examines a supply chain for innovation activity, sales promotion activity, and replenishment time, using both centralised and decentralised approaches, with products deteriorating at a constant rate. As the centralised approach reduces the vendor's total profit, the producer tries to convince the vendor by offering a credit facility, discount and profit sharing. The key ambition is to calculate the optimum replenishment time, producer's innovation activity, and vendor's sales promotion activity by using the classical optimisation algorithm that helps to maximise the total profit of a supply chain. The numerical example is solved for both centralised and decentralised approach, and the sensitivity analysis of major parameters are eventually analysed. Journal: Int. J. of Mathematics in Operational Research Pages: 96-118 Issue: 1 Volume: 23 Year: 2022 Keywords: centralised and decentralised decisions; credit period; deterioration; innovation activity; sales promotion activity. File-URL: http://www.inderscience.com/link.php?id=126053 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:1:p:96-118 Template-Type: ReDIF-Article 1.0 Author-Name: Moslem Fatahi Savadjani Author-X-Name-First: Moslem Fatahi Author-X-Name-Last: Savadjani Author-Name: Shohreh Ajoudanian Author-X-Name-First: Shohreh Author-X-Name-Last: Ajoudanian Title: Modelling and analysis of cascading failures in interoperable critical infrastructure systems Abstract: Studying the behaviour and structure of the critical infrastructure systems (CISs) and the interdependency among them is of special significance, and if it is not determined properly, in addition to failure and cascading failure, there will be a national catastrophe. One of the reasons for not using the proper technique for critical infrastructure modelling is not to specify the entire sample space of the system and express all its limitations so that in addition to displaying accurate infrastructure behaviour, cascading failures can be prevented to an acceptable extent. Therefore, there is a need for a CIS formal specification modelling to develop different instances of a CIS, and selecting the best and the failure-free instance of it. In this paper, we provide a formal declarative specification of CIS that supports detection and prevention of failure and cascading failure automatically in using Alloy. Since failures and cascading failures occur in dynamic and time-dependent environments, the proposed model considered dynamic aspects of CISs. The results show that using Alloy Analyser, all the models made and the current failures in infrastructure are determined using counter-examples and the best instance in terms of minimum and even without failure can be selected. Journal: Int. J. of Mathematics in Operational Research Pages: 380-410 Issue: 3 Volume: 21 Year: 2022 Keywords: critical infrastructure system; CIS; formal modelling; cascading failure; Alloy modelling language. File-URL: http://www.inderscience.com/link.php?id=122215 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:3:p:380-410 Template-Type: ReDIF-Article 1.0 Author-Name: Kamel Meziani Author-X-Name-First: Kamel Author-X-Name-Last: Meziani Author-Name: Fazia Rahmoune Author-X-Name-First: Fazia Author-X-Name-Last: Rahmoune Author-Name: Mohammed Said Radjef Author-X-Name-First: Mohammed Said Author-X-Name-Last: Radjef Title: Service pricing and customer behaviour strategies of Stackelberg's equilibrium in an unobservable Markovian queue with unreliable server and delayed repairs Abstract: In this paper, we model as a Stackelberg game with the service pricing of server and the strategic behaviour of customers in a totally unobservable <i>M</i>/<i>M</i>/1 queueing system subject to random breakdowns and delayed repairs, under a reward-cost structure. For this, we first use the partial generating functions to determine the steady-state condition and the sojourn time of a customer in the considered queueing system. The analytical forms of the service price and the customer entrance strategies of the Stackelberg equilibrium of the game are given. Through numerical examples, we illustrate the effect of the price and the reliability parameters on the entrance probability of customers and the server profit. Finally, we define and solve the corresponding social welfare problem. This study has not only a theoretical aspect, but also a practical one, and it can be adapted to several real-life situations. Journal: Int. J. of Mathematics in Operational Research Pages: 281-304 Issue: 3 Volume: 21 Year: 2022 Keywords: unreliable queue; delayed repairs; pricing; strategic behaviour; Stackelberg game; equilibrium. File-URL: http://www.inderscience.com/link.php?id=122216 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:3:p:281-304 Template-Type: ReDIF-Article 1.0 Author-Name: Hudson Henrique De Souza Lopes Author-X-Name-First: Hudson Henrique De Souza Author-X-Name-Last: Lopes Author-Name: Ricardo Bruno Osés De Oliveira Author-X-Name-First: Ricardo Bruno Osés De Author-X-Name-Last: Oliveira Author-Name: Flávio Geraldo Coelho Rocha Author-X-Name-First: Flávio Geraldo Coelho Author-X-Name-Last: Rocha Title: A load balancing algorithm inspired by the honey bee behaviour to reduce waiting time in a perinatal network Abstract: This article proposes a solution to a problem of mixed-integer linear programming for efficient resource allocation in the admission and scheduling process of pregnant women to a perinatal network composed of two maternity hospitals with heterogeneous capacities. For this, a load balancing algorithm based on the metaheuristic of honey bee behaviour is used. It is shown, through the results obtained in the simulations, that the proposed algorithm reduces the mean turnaround time of the system and the waiting time for pregnant women who enter the perinatal network, in comparison with other load balancing algorithms, based on classic queue theory, that are found in the literature. Journal: Int. J. of Mathematics in Operational Research Pages: 338-354 Issue: 3 Volume: 21 Year: 2022 Keywords: load balancing; honey bee behaviour; perinatal; maternity. File-URL: http://www.inderscience.com/link.php?id=122217 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:3:p:338-354 Template-Type: ReDIF-Article 1.0 Author-Name: Rafael De Freitas Souza Author-X-Name-First: Rafael De Freitas Author-X-Name-Last: Souza Author-Name: Luiz Paulo Fávero Author-X-Name-First: Luiz Paulo Author-X-Name-Last: Fávero Author-Name: Michel Ferreira Cardia Haddad Author-X-Name-First: Michel Ferreira Cardia Author-X-Name-Last: Haddad Author-Name: Hamilton Luiz Corrêa Author-X-Name-First: Hamilton Luiz Author-X-Name-Last: Corrêa Title: Multilevel evidence on how policymakers may reduce avoidable deaths due to COVID-19: the case of Brazil Abstract: We propose a hierarchical linear method to investigate the effectiveness of social distancing measures. By considering the COVID-19 data as a two-level structure, we are able to demonstrate a significant reduction of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases as a direct consequence of lockdown measures adopted by some states in Brazil. The multilevel modelling is the most appropriate method for the case of Brazil due to the fact that political battles between federal and State government leaders have led to the adoption of lockdown measures with distinct levels of flexibility adopted by each of its 27 states. During the outbreak of such a novel and highly contagious disease, decisions made by policymakers either prevent or increase the number of avoidable deaths. Thus, our results are also potentially useful to convince policymakers to adopt reasonable policy measures to shorten the COVID-19 pandemic in the biggest Latin American country. Journal: Int. J. of Mathematics in Operational Research Pages: 321-337 Issue: 3 Volume: 21 Year: 2022 Keywords: COVID-19; emerging countries; lockdown; multilevel modelling; SARS-CoV-2. File-URL: http://www.inderscience.com/link.php?id=122218 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:3:p:321-337 Template-Type: ReDIF-Article 1.0 Author-Name: Fatemeh Jalalkamali Author-X-Name-First: Fatemeh Author-X-Name-Last: Jalalkamali Author-Name: Faranak Hosseinzadeh Saljooghi Author-X-Name-First: Faranak Hosseinzadeh Author-X-Name-Last: Saljooghi Title: Investigating a multi-objective programming method with common weights for a two-stage efficiency evaluation Abstract: In this article, two stage data envelopment analysis (DEA) models are reviewed initially and then two methods of sum weighted and product in efficiency combination are presented. In this two models, the weight of intermediate data are presumed to be the same whereas the results of implementing these two models show different weights for intermediate data. Hence, in the second section, a multi-objective model for each stage, considering an ideal unit, is used which computes the intermediate data weight for two stages uniformly and the efficiency of stages are accordingly calculated. Furthermore, considering the homogeneous nature of input, intermediate and output data for all units, it seems allocating various weights for these factors, is not fair. Thus in Section 3, a model for evaluation of two stage process, considering a common weight for input, intermediate and output factors of different stages is presented and the stage and overall efficiency and inefficiency values for each decision making unit using common weight is calculated. Finally, the relationship of these two models with respect to previous models was investigated and the results were explained using some examples. Journal: Int. J. of Mathematics in Operational Research Pages: 355-379 Issue: 3 Volume: 21 Year: 2022 Keywords: data envelopment analysis; DEA; two stage model; multi-objective model; common weight; ideal unit; nadir unit. File-URL: http://www.inderscience.com/link.php?id=122220 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:3:p:355-379 Template-Type: ReDIF-Article 1.0 Author-Name: Alka Choudhary Author-X-Name-First: Alka Author-X-Name-Last: Choudhary Author-Name: D.C. Sharma Author-X-Name-First: D.C. Author-X-Name-Last: Sharma Title: Analysis of Markovian queue model with unreliable service station and a vacation after fixed services Abstract: In this study, we have investigated a Markovian queue system with infinite capacity with a single service station which is unreliable. A vacation has been introduced in which service station takes vacation after some fixed services. In this paper, service station has decreasing service rate because of continuous service and service station takes vacation after each fixed services. To calculate the system performance measures, we figured out the steady state equations and solved these equations using matrix geometric method. Condition on parameters is also defined for which the system is stable. Cost function is constructed and sensitivity analysis is done. Journal: Int. J. of Mathematics in Operational Research Pages: 411-428 Issue: 3 Volume: 21 Year: 2022 Keywords: Markovian queue; unreliable server; fixed services; working vacation; cost analysis. File-URL: http://www.inderscience.com/link.php?id=122233 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:3:p:411-428 Template-Type: ReDIF-Article 1.0 Author-Name: Salim Bavandi Author-X-Name-First: Salim Author-X-Name-Last: Bavandi Author-Name: Seyed Hadi Nasseri Author-X-Name-First: Seyed Hadi Author-X-Name-Last: Nasseri Title: A hybrid fuzzy stochastic model for fractional multi-commodity network flow problems Abstract: In this paper, we aim to introduce a class of multi-commodity network flow problems. Here, we deal with a multi-commodity flow problem with a fractional objective function that is investigated in a fuzzy random hybrid environment. This paper aims to provide a model that manages unknown coefficients in fractional multi-commodity networks. In this problem, the coefficients of the objective function in the numerator of the fraction and the arc capacity are assumed to be fuzzy random variables and the coefficients of the objective function in the denominator of the fraction are assumed to be fuzzy variables. Since this problem is investigated simultaneously in both random and fuzzy environments, we use a probability-possibility approach to convert the problem to a deterministic form. Next, we get the problem out of the fractional mode using the variable transformation method and finally, examine the efficiency of the proposed method by providing some numerical examples. Journal: Int. J. of Mathematics in Operational Research Pages: 195-215 Issue: 2 Volume: 22 Year: 2022 Keywords: fractional programming; fuzzy random variable; multi-commodity flow problem; probability-possibility approach; decision making under uncertainty. File-URL: http://www.inderscience.com/link.php?id=124038 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:2:p:195-215 Template-Type: ReDIF-Article 1.0 Author-Name: A. Akilbasha Author-X-Name-First: A. Author-X-Name-Last: Akilbasha Author-Name: G. Natarajan Author-X-Name-First: G. Author-X-Name-Last: Natarajan Title: Optimising fully interval integer two-stage transportation problems Abstract: The study proposes a novel technique namely, divided-united method which is framed based on the zero point method in order to optimise the fully interval integer two-stage transportation problem (FIITSTP). The proposed method offers more than one optimal solution to fully interval integer two-stage transportation problems. The optimal values of decision variables and the objective function of the fully interval integer two-stage transportation problems provided by the proposed method are interval integers. A numerical example is illustrated for a better understanding of the solution procedure of the proposed method. Since the proposed method offers more than one optimal solution, therefore it is highly helpful for the decision-makers when they are handling logistic models of real life situations involving interval integer parameters. Further, this method is likely to determine the perfect and effective optimal solution for fully interval integer transportation problems in a simple manner. Journal: Int. J. of Mathematics in Operational Research Pages: 216-234 Issue: 2 Volume: 22 Year: 2022 Keywords: two-stage transportation problem; optimal solution; interval integers; divided-united method. File-URL: http://www.inderscience.com/link.php?id=124039 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:2:p:216-234 Template-Type: ReDIF-Article 1.0 Author-Name: K. Jeganathan Author-X-Name-First: K. Author-X-Name-Last: Jeganathan Author-Name: S. Selvakumar Author-X-Name-First: S. Author-X-Name-Last: Selvakumar Title: An optional arrival process of the oscillatory demands in the inventory system with queue dependent service rate Abstract: In this paper, we study a classical retrial queueing-inventory system (CRQIS) with an optional arrival process of an oscillatory customer (OC) who may enter into the waiting hall or an infinite orbit directly under Bernoulli trials. The orbital customer emulates their requirements through the waiting hall only over the classical retrial policy (ClRP) whenever it is less than its capacity and the service rate of customer depends on the queue length at an epoch. This system contains a perishing item too, and replenishment can be done following the (<i>s</i>, <i>Q</i>) ordering policy. The server can do an orbital search which follows Bernoulli process. Neuts approach is applied for the matrix-geometric approximation (MGA) to find a stationary probability vector and the Laplace-Stieltjes transform method (LSTM) is used to derive waiting time of both arrivals. Also, sufficient numerical problems are to be explored for the assumed model. Journal: Int. J. of Mathematics in Operational Research Pages: 162-194 Issue: 2 Volume: 22 Year: 2022 Keywords: optional arrival process; oscillatory customer; queue dependent service rate; QDSR; classical retrial policy; waiting time. File-URL: http://www.inderscience.com/link.php?id=124040 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:2:p:162-194 Template-Type: ReDIF-Article 1.0 Author-Name: Tuhin Bera Author-X-Name-First: Tuhin Author-X-Name-Last: Bera Author-Name: Nirmal Kumar Mahapatra Author-X-Name-First: Nirmal Kumar Author-X-Name-Last: Mahapatra Title: Neutrosophy-based transportation problem and its solution approach Abstract: This study designs a transportation problem (<i>Tp</i>-problem) by taking the transportation cost, availabilities, demands and quantity of goods to be transported as single valued trapezoidal neutrosophic number (<i>svtn</i>-number). Then experts can include their hesitancy in decision making independently in an uncertain climate. The proposed form of <i>Tp</i>-problem is solved in four distinct methods, and optimality test of their initial outcomes are performed. The respective algorithms are developed with the help of existing crisp notions. A parameter-based linear ranking function of <i>svtn</i>-number is drawn here. This parameter of ranking function helps to incorporate the relevant characters involved indirectly in a <i>Tp</i>-problem beside the provided constraints in its solution approach. The way of treatment of uncertainty and the incorporation of relevant character in a <i>Tp</i>-problem designed here make its outcome more realistic and acceptable to the experts. The efficiencies of proposed concepts are tested in real ground. The optimal values are analysed to opt the better method applicable for that problem. Journal: Int. J. of Mathematics in Operational Research Pages: 252-281 Issue: 2 Volume: 22 Year: 2022 Keywords: single valued trapezoidal neutrosophic number; svtn-number; ranking of svtn-numbers; neutrosophy-based transportation problem; Nt-problem. File-URL: http://www.inderscience.com/link.php?id=124041 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:2:p:252-281 Template-Type: ReDIF-Article 1.0 Author-Name: S.K. Yadav Author-X-Name-First: S.K. Author-X-Name-Last: Yadav Author-Name: Dinesh K. Sharma Author-X-Name-First: Dinesh K. Author-X-Name-Last: Sharma Author-Name: Madhulika Dube Author-X-Name-First: Madhulika Author-X-Name-Last: Dube Title: A simulation approach to modified Searls estimation of population mean under two-phase random sampling Abstract: A new extended Searls type estimator is suggested in this paper to assess the population mean of an essential variable more efficiently. The suggested estimator utilises a known supplementary variable in a two-phase (double sampling) design for improved estimation. The bias and mean squared error (MSE) of the introduced estimator are retained to approximate degree one for studying the sampling distribution properties. The Searls constants' optimal values that provide minimum MSE of the novel introduced estimator have also been acquired. The MSE of the introduced estimator was compared with the MSEs of other estimators in competition under double sampling, and the conditions of efficiency are obtained. The efficiency conditions obtained in theoretical comparison for the proposed estimator are verified using four natural datasets. A simulation study has also been performed using the natural populations' parameters to see the results' consistency. Journal: Int. J. of Mathematics in Operational Research Pages: 235-251 Issue: 2 Volume: 22 Year: 2022 Keywords: main variable; Searls type estimator; auxiliary variable; bias; mean squared error; MSE; percentage relative efficiency; PRE. File-URL: http://www.inderscience.com/link.php?id=124042 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:2:p:235-251 Template-Type: ReDIF-Article 1.0 Author-Name: Ramasamy Uthayakumar Author-X-Name-First: Ramasamy Author-X-Name-Last: Uthayakumar Author-Name: Balasubramani Malleeswaran Author-X-Name-First: Balasubramani Author-X-Name-Last: Malleeswaran Title: A sustainable inventory model for setup and ordering cost reduction under a controllable lead time Abstract: In this study, we consider an integrated vendor-buyer supply chain (SC) model. This paper investigates the impact of setup and ordering cost reduction in a continuous review inventory policy with controllable lead time. The probability distribution is the most aspect of this model, within free distribution, including as mean and standard deviation. We obtain the annual minimum cost by considering setup and ordering cost reductions. The solution procedure is used to determine the optimal solutions of order quantity, setup cost, ordering cost, lead time, and the number of shipments from the single vendor (SV)-single buyer (SB) in one production run. This model has vital perspectives to present a venture by considering with and without distribution under a controllable lead time. Journal: Int. J. of Mathematics in Operational Research Pages: 143-161 Issue: 2 Volume: 22 Year: 2022 Keywords: supply chain management; SCM; logarithmic investment; integrated approach; probability distribution; controllable lead time. File-URL: http://www.inderscience.com/link.php?id=124043 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:2:p:143-161 Template-Type: ReDIF-Article 1.0 Author-Name: Olusola Ezekiel Abolarin Author-X-Name-First: Olusola Ezekiel Author-X-Name-Last: Abolarin Author-Name: Bamikole Gbenga Ogunware Author-X-Name-First: Bamikole Gbenga Author-X-Name-Last: Ogunware Title: New hybrid method for direct numerical solution of nonlinear second, third and fourth orders ordinary differential equations Abstract: A novel and efficient algorithm for the concurrent numerical solution of second, third and fourth orders of ordinary differential equations is studied in this article. Collocation and interpolation technique was employed in the derivation of the method and power series approximate solution was used as the interpolating polynomial. The fourth derivative of the power series was collocated at the entire grid and off-grid points, while the fifth and sixth derivatives of the polynomial were collocated at the endpoint only. Proper investigation of the basic properties of the method was done. The results showed that the new block method applied on a nonlinear second, third and fourth orders of ordinary differential equations were better in terms of accuracy than the existing methods. The proposed method takes away the burden of developing a separate method for the solution of second, third and fourth order initial value problem of ordinary differential equations. Journal: Int. J. of Mathematics in Operational Research Pages: 285-315 Issue: 3 Volume: 23 Year: 2022 Keywords: hybrid block method; collocation; higher order ODEs; interpolation; power series. File-URL: http://www.inderscience.com/link.php?id=127378 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:3:p:285-315 Template-Type: ReDIF-Article 1.0 Author-Name: Bouremani Touffik Author-X-Name-First: Bouremani Author-X-Name-Last: Touffik Author-Name: Benterki Djamel Author-X-Name-First: Benterki Author-X-Name-Last: Djamel Author-Name: Slimani Yacine Author-X-Name-First: Slimani Author-X-Name-Last: Yacine Title: Optimal control of an epidemic by vaccination using dynamic programming approach Abstract: In this paper, we are interested in solving a SIR epidemic model which can be reformulated as a control problem. We use some recent developments of the dynamics programming method to obtain a rigorous solution of the optimal control problem formulated in Trélat (2019). We use some refinement of Cauchy's method of characteristics for stratified Hamilton-Jacobi equations to describe a large set of admissible trajectories and identify a domain on which the value function exists and is generated by some admissible controlsm, and their optimality is justified by using one of the well-known verification theorems as an argument for sufficient optimality conditions. Journal: Int. J. of Mathematics in Operational Research Pages: 372-393 Issue: 3 Volume: 23 Year: 2022 Keywords: optimal control; differential inclusion; Pontryagin's maximum principle; dynamic programming; Hamiltonian flow; value function; verification theorem. File-URL: http://www.inderscience.com/link.php?id=127379 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:3:p:372-393 Template-Type: ReDIF-Article 1.0 Author-Name: Madhu Jain Author-X-Name-First: Madhu Author-X-Name-Last: Jain Author-Name: Anshul Kumar Author-X-Name-First: Anshul Author-X-Name-Last: Kumar Title: Effect of disaster and balking on M/M/1 driven fluid queue with working vacation Abstract: The fluid models are suitable for modelling traffic when individual arrival units have little effect on the system's performance. This paper aims to study the fluid model for the queueing scenario driven by the features of vacationing server, disaster, and balking. By introducing vacation strategy to the fluid model, we can provide greater flexibility for the design and control of input and output rates. By introducing the multiple working vacation strategy to the fluid model, we can provide greater flexibility to design and control the server's vacationing time and output. Continuing fraction and generating function methodologies are used to solve the fundamental framework of differential-difference equations that regulates the operation. The steady state probabilities for the different states of the fluid model have been found explicitly. The stationary distribution of the buffer content has also been derived in terms of the modified Bessel function of the first kind. Journal: Int. J. of Mathematics in Operational Research Pages: 359-371 Issue: 3 Volume: 23 Year: 2022 Keywords: fluid queue; working vacation; disaster; balking; generating function; continued fraction. File-URL: http://www.inderscience.com/link.php?id=127380 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:3:p:359-371 Template-Type: ReDIF-Article 1.0 Author-Name: Sukanta Nayak Author-X-Name-First: Sukanta Author-X-Name-Last: Nayak Author-Name: J. Pooja Author-X-Name-First: J. Author-X-Name-Last: Pooja Title: Numerical optimisation technique to solve imprecisely defined nonlinear system of equations with bounded parameters Abstract: This paper includes an optimisation algorithm to estimate the solution of interval nonlinear system of equations. First, the proposed optimisation algorithm converts interval nonlinear system of equations to unconstrained multivariable optimisation problem with interval uncertainties. Then the interval unconstrained multivariable optimisation problem is investigated by using inner-outer direct search approach. Finally, the obtained solutions are assembled and using the regularity principle, interval solutions are obtained. Considering these steps together, this method is named as inner outer direct search (IODS) algorithm for interval unconstrained multivariable optimisation. Example problems are investigated to demonstrate the IODS algorithm and compared the obtained results with the results by using Krawczyk, vertex and Newton's methods. Journal: Int. J. of Mathematics in Operational Research Pages: 394-411 Issue: 3 Volume: 23 Year: 2022 Keywords: uncertainty; interval nonlinear system of equations; unconstrained multi-variable optimisation; inner-outer direct search; uncertain width. File-URL: http://www.inderscience.com/link.php?id=127381 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:3:p:394-411 Template-Type: ReDIF-Article 1.0 Author-Name: Lawrence Osa Adoghe Author-X-Name-First: Lawrence Osa Author-X-Name-Last: Adoghe Author-Name: Ezekiel Olaoluwa Omole Author-X-Name-First: Ezekiel Olaoluwa Author-X-Name-Last: Omole Author-Name: Sunday Emmanuel Fadugba Author-X-Name-First: Sunday Emmanuel Author-X-Name-Last: Fadugba Title: Third derivative method for solving stiff system of ordinary differential equations Abstract: A continuous integration method based on the hybrid third derivative block method is constructed and used to generate solution for stiff systems of first order ordinary differential equations. The hybrid third derivative method are applied simultaneously to integrate stiff initial value problems by combining them into a single block matrix known as block hybrid third derivative method. The basic properties of block method were examined and were found to be zero-stable, consistence, convergence and A-stable. Some numerical results produced by the block method show that it is competitive with some existing ones in the literature. The results and comparison are presented in tables and curves. Journal: Int. J. of Mathematics in Operational Research Pages: 412-425 Issue: 3 Volume: 23 Year: 2022 Keywords: first order system of equations; ordinary differential equations; hybrid third-derivative; block method; stiff problems; A-stability; zero-stability; convergences. File-URL: http://www.inderscience.com/link.php?id=127382 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:3:p:412-425 Template-Type: ReDIF-Article 1.0 Author-Name: Rima Guerbane Author-X-Name-First: Rima Author-X-Name-Last: Guerbane Author-Name: Mohand Ouamer Bibi Author-X-Name-First: Mohand Ouamer Author-X-Name-Last: Bibi Title: Primal-dual method for a linear program with hybrid direction Abstract: In linear programming, the combination of primal and dual methods is of great importance in the search of efficient resolution algorithms. In the present paper, we are interested to the adaptive method with hybrid direction for the linear programs with bounded variables. After calculating the increment of the dual function with this hybrid direction, an optimality criterion for the dual problem is proved. Using this criterion and the initial speed of change for the dual function, a primal-dual algorithm with hybrid direction is suggested for solving linear programs with bounded variables. In this algorithm, the suboptimality estimate is used as a stopping criterion. A numerical example is presented and to compare the suggested method with three other methods, we have developed an implementation under the MATLAB programming language on randomly generated problems with precision <i>ε</i> ≥ 0, chosen in advance. Journal: Int. J. of Mathematics in Operational Research Pages: 316-343 Issue: 3 Volume: 23 Year: 2022 Keywords: linear programming; duality; hybrid direction; optimality criteria; primal-dual algorithm; numerical results. File-URL: http://www.inderscience.com/link.php?id=127383 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:3:p:316-343 Template-Type: ReDIF-Article 1.0 Author-Name: S.K. Yadav Author-X-Name-First: S.K. Author-X-Name-Last: Yadav Author-Name: Amit Kumar Misra Author-X-Name-First: Amit Kumar Author-X-Name-Last: Misra Author-Name: Tarushree Bari Author-X-Name-First: Tarushree Author-X-Name-Last: Bari Title: Searls estimation strategy for population mean of a sensitive study variable harnessing non-sensitive auxiliary information Abstract: In this study, we present a Searls type regression estimator for elevated estimation of the population mean of a sensitive study variable in the presence of a known non-sensitive supplementary variable under the simple random sampling scheme. The first order of approximation is used to obtain the bias and mean square error expressions. The suggested family of estimators is compared to competing estimators both theoretically and numerically. The findings verified through the real and simulated data show that the suggested estimator is preferably chosen over many of the existing competing estimators. Journal: Int. J. of Mathematics in Operational Research Pages: 344-358 Issue: 3 Volume: 23 Year: 2022 Keywords: sensitive variable; scrambled variable; Searls type estimator; response bias; mean square error; MSE; simulation study. File-URL: http://www.inderscience.com/link.php?id=127384 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:3:p:344-358 Template-Type: ReDIF-Article 1.0 Author-Name: Ashish Sharma Author-X-Name-First: Ashish Author-X-Name-Last: Sharma Author-Name: Amit Kumar Saraswat Author-X-Name-First: Amit Kumar Author-X-Name-Last: Saraswat Title: Optimal procurement and pricing policy for deteriorating items with price and time dependent seasonal demand and permissible delay in payment Abstract: In practice, items like food, nursery plants, medicines, etc. are seasonal and deteriorating in nature. For this type of products, permissible delay in payment is a common business policy, which is used to increase in the sell volume and to develop trust in buyer-seller relationship. In this paper, we developed an inventory model for time dependent deteriorating seasonal items with the permission of delay in payment. Shortages are permitted and partially back ordered. Our aim is to find optimal selling price and ordering quantity simultaneously. Concavity of profit function with respect to decision variables has been discussed analytically. A solution procedure followed by a numerical example and sensitivity analysis along with managerial insights are provided. Numerical analysis predicts that delay in payment profit policy is a better decision in order to maximise the profit or in order to get more profit. Journal: Int. J. of Mathematics in Operational Research Pages: 515-528 Issue: 4 Volume: 21 Year: 2022 Keywords: inventory; deterioration; price and time dependent demand; delay payment; seasonal demand. File-URL: http://www.inderscience.com/link.php?id=122802 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:4:p:515-528 Template-Type: ReDIF-Article 1.0 Author-Name: Hassan Bagheri Author-X-Name-First: Hassan Author-X-Name-Last: Bagheri Author-Name: Javad Behnamian Author-X-Name-First: Javad Author-X-Name-Last: Behnamian Author-Name: Samaneh Babaei Morad Author-X-Name-First: Samaneh Babaei Author-X-Name-Last: Morad Title: Fuzzy multi-criteria lead and zinc plant site location considering environmental criteria (a case study in Iran) Abstract: The aim of this study is to determine the location of the lead and zinc site considering environmental criteria. Within a radius of 5 km-10 km of the province under study, there are about 150 lead and zinc plants, which increase the pollution of the city and various diseases. If the plants are closed, about 3,500 people will be unemployed, with the industry mines, and national capital severely affected. Another option is to move these plants to a radius of 100 km in the province, which will cost a lot. Since the fuzzy sets theory method has been widely applied to uncertain decision-making problems in the real-world, in this study and for the first time, to select the appropriate option according to the criteria affecting environmental pollution, disease prevalence, income, unemployment rate, corruption, and cost, a multi-criteria decision-making technique with a hybrid fuzzy approach has been used. The proposed method is a hybrid of the TOPSIS fuzzy technique and a fuzzy hierarchical process that takes advantage of both of them. The results obtained in the case study show that using the proposed method, the best option is moving plants within a radius of 100 km from the city. Journal: Int. J. of Mathematics in Operational Research Pages: 480-496 Issue: 4 Volume: 21 Year: 2022 Keywords: location problem; fuzzy multi-criteria decision-making; lead; zinc; hybrid approach; Iran. File-URL: http://www.inderscience.com/link.php?id=122803 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:4:p:480-496 Template-Type: ReDIF-Article 1.0 Author-Name: Faiza Saadi Author-X-Name-First: Faiza Author-X-Name-Last: Saadi Author-Name: Ahmed Chibat Author-X-Name-First: Ahmed Author-X-Name-Last: Chibat Title: A simple way to enhance the efficiency of Nguyen-Widrow method in neural networks initialisation Abstract: The choice of the initial values of neural network parameters is of crucial importance for the conduct and successful completion of training. The most known and most used method to perform this task is the Nguyen-Widrow method. It has brought a well-established advantage over the traditional method of purely random choice. However, this advantage is not always guaranteed. A hidden defect can appear in some situations leading to a quality deteriorate of training. In this work, the existence of this hidden defect is revealed and the way to remedy this is proposed. We show how a simple procedure, built on conditional resets, eliminates unsuitable starting conditions and ensures the steadiness of good training quality. In this way, the search for the optimal architecture of a network when processing any given problem becomes faster and more reliable. Journal: Int. J. of Mathematics in Operational Research Pages: 497-514 Issue: 4 Volume: 21 Year: 2022 Keywords: neural networks; weight initialisation; function approximation; regression. File-URL: http://www.inderscience.com/link.php?id=122804 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:4:p:497-514 Template-Type: ReDIF-Article 1.0 Author-Name: John Olusola Kuboye Author-X-Name-First: John Olusola Author-X-Name-Last: Kuboye Author-Name: Bamikole Gbenga Ogunware Author-X-Name-First: Bamikole Gbenga Author-X-Name-Last: Ogunware Author-Name: Ezekiel Olusola Abolarin Author-X-Name-First: Ezekiel Olusola Author-X-Name-Last: Abolarin Author-Name: Chika O. Mmaduakor Author-X-Name-First: Chika O. Author-X-Name-Last: Mmaduakor Title: Single numerical algorithm developed to solving first and second orders ordinary differential equations Abstract: A potent numerical algorithm for solving first and second orders initial value problems is examined in this paper. Interpolation and collocation approach was applied in the derivation of the new method with the use of power series approximate solution as interpolating polynomial. The two numerical integrators that formed the block were derived by evaluating the non-interpolating points within the selected interval of integration. To examine the effectiveness of the block, it was tested on some first and second orders ordinary differential equations and results generated performed better when compared with existing methods in terms of accuracy. Journal: Int. J. of Mathematics in Operational Research Pages: 466-479 Issue: 4 Volume: 21 Year: 2022 Keywords: block method; collocation; hybrid; interpolation; power series; first order IVP; second order IVP. File-URL: http://www.inderscience.com/link.php?id=122805 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:4:p:466-479 Template-Type: ReDIF-Article 1.0 Author-Name: R.P. Tripathi Author-X-Name-First: R.P. Author-X-Name-Last: Tripathi Title: Establishment of EOQ strategy for time-sensitive deterioration and non-increasing time-linked demand under trade credits Abstract: The retailer makes a decision, the initial holding cost at the beginning of each replenishment cycle and then concludes whether and how to change the carrying costs during the cycle. Thus, during each cycle, items are sold before and after the carrying cost modification at two costs: the initial holding cost and the used holding cost. Of course, the two prices may be the same if the retailer chooses not to change prices. In this study, an inventory model is established under time linked demand and deterioration. Carrying cost is considered exponential time dependent. Mathematical formulation is given to build up the model. The numerical examples are discussed to authenticate the model projected in this study. Some results based on optimal solution are also discussed. We then show that the total cost is curved upward by means of cycle time. The sensitivity investigation is also established. Journal: Int. J. of Mathematics in Operational Research Pages: 429-443 Issue: 4 Volume: 21 Year: 2022 Keywords: inventory; deterioration; demand; exponential holding cost; credit period. File-URL: http://www.inderscience.com/link.php?id=122806 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:4:p:429-443 Template-Type: ReDIF-Article 1.0 Author-Name: Ahmed R. Abubakar Author-X-Name-First: Ahmed R. Author-X-Name-Last: Abubakar Author-Name: Hamisu A. Adamu Author-X-Name-First: Hamisu A. Author-X-Name-Last: Adamu Author-Name: Asuku Abdulsamad Author-X-Name-First: Asuku Author-X-Name-Last: Abdulsamad Author-Name: Yusuf A. Sha'aban Author-X-Name-First: Yusuf A. Author-X-Name-Last: Sha'aban Title: Development of a polynomial model for power prediction of miniature neutron source reactors Abstract: This paper presents the development of a second-order polynomial model for the prediction of power of a typical miniature neutron source reactor (MNSR). Using the least-squares method, the model coefficients were generated from thermal power and reactor core coolant temperature as dependent and independent variables, respectively. Operational data were collected at 1-minute intervals, for a total of 100 minutes each for 6.20 kW, 15.50 kW, and 31.0 kW. The mean absolute deviation (MAD) obtained during validation using the developed model (QModel), at 6.2 kW, 12.4 kW, 15.5 kW, 18.6 kW, 24.8 kW and 31 kW were: 0.51, 0.25, 0.38, 0.29, 0.44, and 0.50 respectively while the corresponding results from earlier work were 3.03, 3.36, 3.49, 2.24, 1.24, and 5.71. The QModel gave a better power prediction with an error deviation of less than ±5%. Journal: Int. J. of Mathematics in Operational Research Pages: 554-567 Issue: 4 Volume: 21 Year: 2022 Keywords: miniature neutron source reactor; MNSR; Nigeria research reactor-1; NIRR-1. File-URL: http://www.inderscience.com/link.php?id=122807 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:4:p:554-567 Template-Type: ReDIF-Article 1.0 Author-Name: Renu Sharma Author-X-Name-First: Renu Author-X-Name-Last: Sharma Author-Name: Anubhav Pratap Singh Author-X-Name-First: Anubhav Pratap Author-X-Name-Last: Singh Author-Name: Ritu Arora Author-X-Name-First: Ritu Author-X-Name-Last: Arora Author-Name: Anand Chauhan Author-X-Name-First: Anand Author-X-Name-Last: Chauhan Title: Optimisation of an inventory model for conclusive and inconclusive cost parameters using triangular and trapezoidal fuzzy numbers Abstract: Volatility in the prices of crude oil creates a very complicated situation for the management of an inventory system. As a result, an unexpected shift in cost parameters occurs. A model of economic order quantity (EOQ) is developed to control the inventory in that situation when a decision-maker is not able to clearly express the cost parameters at the beginning of a system design. Such type of situation is created due to volatility in the price. The purpose of the article is to study the impact of inconclusive cost parameters on total average cost. The holding cost, ordering cost, deterioration cost, and shortage cost are assigned by fuzzy numbers. Then, graded mean integration method (GMIM) is used to defuzzified the total average cost. A comparative study in a crisp environment and fuzzy environment is validated as an explicit condition to control the inventory for reducing the optimum cost. Journal: Int. J. of Mathematics in Operational Research Pages: 529-553 Issue: 4 Volume: 21 Year: 2022 Keywords: economic order quantity; EOQ; trapezoidal fuzzy number; triangular fuzzy number; graded mean integration method. File-URL: http://www.inderscience.com/link.php?id=122808 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:4:p:529-553 Template-Type: ReDIF-Article 1.0 Author-Name: S. Maragathasundari Author-X-Name-First: S. Author-X-Name-Last: Maragathasundari Author-Name: S. Kishore Eswar Author-X-Name-First: S. Kishore Author-X-Name-Last: Eswar Author-Name: R.S. Somasundaram Author-X-Name-First: R.S. Author-X-Name-Last: Somasundaram Title: A study on phases of service and multi-vacation policy in a non-Markovian queuing system Abstract: This paper manages the queuing issue of various vacation policies. Clients showing up in clumps follow a Poisson distribution. Administration, on the other hand, follows a general distribution, rendered in two phases in which the second phase of administration is discretionary. Here, during the vacation period, the support work of the server is completed. Also 'get-away' is presented in two classifications, viz. compulsory vacation and broadened vacation, both following general conveyance. Expanded vacation is regarded to have two phases, in which the second phase of broadened get-away is of the server's decision. Set up time arrange is presented on the early stage of expanded vacation and with the idea of reneging occurring during the second phase of broadened vacation. The issue is solved by strengthening the variable technique and queue measures with the force parameter, mean inactive time, mean number of clients, and mean waiting time in the queue, determined in the system. The paper contains the numerical depiction and graphical appraisal that supports the model. Journal: Int. J. of Mathematics in Operational Research Pages: 444-465 Issue: 4 Volume: 21 Year: 2022 Keywords: multi vacation; composite materials; reneging; extended vacation; two stages of service. File-URL: http://www.inderscience.com/link.php?id=122809 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:4:p:444-465 Template-Type: ReDIF-Article 1.0 Author-Name: Peter O. Peter Author-X-Name-First: Peter O. Author-X-Name-Last: Peter Author-Name: Broderick Oluyede Author-X-Name-First: Broderick Author-X-Name-Last: Oluyede Author-Name: Nkumbuludzi Ndwapi Author-X-Name-First: Nkumbuludzi Author-X-Name-Last: Ndwapi Author-Name: Onkabetse Mabikwa Author-X-Name-First: Onkabetse Author-X-Name-Last: Mabikwa Author-Name: Huybrechts F. Bindele Author-X-Name-First: Huybrechts F. Author-X-Name-Last: Bindele Title: The new family of Ristić-Balakhrishnan Marshall Olkin-G distributions with properties and applications Abstract: In this paper, we develop and study in detail a new family of distributions called Ristić-Balakhrishnan Marshall Olkin-G (RBMO-G) distribution. We obtain some mathematical and statistical properties of this distribution such as hazard and reverse hazard functions, quantile function, moments and incomplete moments, moment generating functions, Rényi entropy and order statistics. The model parameters are obtained through method of maximum likelihood. We finally illustrate the usefulness of this family of distributions via simulation experiments. Furthermore, we apply a special case of this family of distributions to some real data to assess and compare its performance with other non-nested models. Journal: Int. J. of Mathematics in Operational Research Pages: 283-312 Issue: 3 Volume: 22 Year: 2022 Keywords: Ristić-Balakhrishnan; Marshall-Olkin; distributions; moments; maximum likelihood; simulations. File-URL: http://www.inderscience.com/link.php?id=124135 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:3:p:283-312 Template-Type: ReDIF-Article 1.0 Author-Name: G. Ayyappan Author-X-Name-First: G. Author-X-Name-Last: Ayyappan Author-Name: R. Gowthami Author-X-Name-First: R. Author-X-Name-Last: Gowthami Title: A MAP/PH1, PH2/1 system with two types of heterogeneous service, setup, closedown, vacation, immediate feedback, breakdown and repair Abstract: In this article, we examine a classical queueing model with single unreliable server which can offer two types of heterogeneous services namely, types I and II. Customers reach the system by following the Markovian arrival process (MAP). The service times of both types of services are considered to be phase-type (PH) distributed. We have considered a service clock which begins at the commencement of the service after the setup/repair process and immediate feedback for the unsatisfied customers. If the service clock expires, the server will start the closedown process and consequently goes on vacation. The assumptions of our model have greater significance on small-scale industries. By utilising the matrix-analytic method, we have examined our model and investigated the active period and the waiting time distribution of our model. We have also carried out the cost analysis for our model. At the end, some numerical and graphical exemplifications are presented for clear insight into our model. Journal: Int. J. of Mathematics in Operational Research Pages: 313-348 Issue: 3 Volume: 22 Year: 2022 Keywords: PH distribution; Markovian arrival process; MAP; two types of services; vacation; service clock; setup; closedown; immediate feedback; breakdown; repair. File-URL: http://www.inderscience.com/link.php?id=124136 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:3:p:313-348 Template-Type: ReDIF-Article 1.0 Author-Name: Suresha Kharvi Author-X-Name-First: Suresha Author-X-Name-Last: Kharvi Author-Name: T.P.M. Pakkala Author-X-Name-First: T.P.M. Author-X-Name-Last: Pakkala Title: Inventory policies for monotonic change in the purchase price Abstract: This article considers an optimal inventory policy for monotonic change in the purchase price where price change depends on the number of orders made. The planning horizon is considered as finite and yearly demand is assumed to be constant and known. A closed-form solution is obtained for the optimal order lengths. These closed-form solutions will be very useful to business managers. An algorithm is given to determine the optimal number of orders during the planning horizon. Some of the interesting properties of the optimal order quantities are discussed. A numerical example and sensitivity analysis are carried out to support the theoretical results. Journal: Int. J. of Mathematics in Operational Research Pages: 349-362 Issue: 3 Volume: 22 Year: 2022 Keywords: inventory; monotonic price change; optimal policy; optimal cost; optimal order lengths. File-URL: http://www.inderscience.com/link.php?id=124137 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:3:p:349-362 Template-Type: ReDIF-Article 1.0 Author-Name: Nedjma Aiane Author-X-Name-First: Nedjma Author-X-Name-Last: Aiane Author-Name: Fazia Rahmoune Author-X-Name-First: Fazia Author-X-Name-Last: Rahmoune Author-Name: Djamil Aïssani Author-X-Name-First: Djamil Author-X-Name-Last: Aïssani Title: Modelling and performance evaluation in the (R, s, lnQ) inventory system Abstract: In this work, we propose to analyse a periodic review inventory model with an (<i>R</i>, <i>s</i>, <i>l<SUB align="right"><SMALL>n</SMALL></SUB>Q</i>) policy and an instant replenishment via a discrete Markov chain approach. Then, we adopt the strong stability method to evaluate the characteristics of the considered model in the case of the perturbation of some of its parameters (demand rate and demand law). Thus, we find the approximation bounds of the stationary distribution, with an exact computation of the constants, to evaluate the error generated by this approximation. Finally, we study numerically the effect of the perturbation of the arrival rate and the demand law respectively on the average stock and the total cost of the considered inventory model. Several numerical examples have been performed to illustrate the performance of this approach. Journal: Int. J. of Mathematics in Operational Research Pages: 363-402 Issue: 3 Volume: 22 Year: 2022 Keywords: inventory control; (R, s, lnQ) policy; Markov chains; transition kernel; strong stability; stability inequalities; stationary distributions; relative error; the error on the average stock; total cost. File-URL: http://www.inderscience.com/link.php?id=124139 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:3:p:363-402 Template-Type: ReDIF-Article 1.0 Author-Name: Anamika Jain Author-X-Name-First: Anamika Author-X-Name-Last: Jain Author-Name: Komal Shekhawat Author-X-Name-First: Komal Author-X-Name-Last: Shekhawat Author-Name: Bhoopendra Pachauri Author-X-Name-First: Bhoopendra Author-X-Name-Last: Pachauri Title: ANFIS computing and analysis of cost optimisation by upgrading service rate with N-policy, server vacation in M/M/1/∞ model Abstract: This study investigates an <i>M</i>/<i>M</i>/1/∞ model that emphasises the effect of various system parameters on the cost factor, with respect to upgraded service rates when the system follows <i>N</i>-policy and server vacation. Most often, the reason for customer dissatisfaction is the annoyingly protracted wait for the service. Therefore, given the customer's total satisfaction with the service, an upgrading in service rates is required. As a result, this study investigates the effect of different parameters on cost factors by considering the upgraded service rates, which help in better decision making. The well-known QBD process of the Markov chain is analysed using a matrix-geometric approach, and the steady-state probabilities are also observed. The system will continue in a working vacation state until the <i>N</i> threshold value is applied, as it follows <i>N</i>-policy. The adaptive neuro-fuzzy inference system (ANFIS) is utilised to approximate the nonlinear function. Journal: Int. J. of Mathematics in Operational Research Pages: 403-421 Issue: 3 Volume: 22 Year: 2022 Keywords: optimisation; balking; working vacation; matrix-geometric method; N-policy. File-URL: http://www.inderscience.com/link.php?id=124140 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:3:p:403-421 Template-Type: ReDIF-Article 1.0 Author-Name: Mahsa Ghandehari Author-X-Name-First: Mahsa Author-X-Name-Last: Ghandehari Author-Name: Mohsen Karimi-Lenji Author-X-Name-First: Mohsen Author-X-Name-Last: Karimi-Lenji Title: An optimal inventory model for a deteriorating item with multivariate demand function Abstract: Managing the inventory of perishable items is a vital task in the supply chain. The demand for some deteriorating items is influenced by many factors that make their management a complicated task. Therefore, it is important to take multiple key factors into account to develop a more realistic model. In this paper, an inventory model for non-instantaneous deteriorating items is proposed, for the case where the quality and quantity of the item decrease over time. The demand is an additive, continuous, and differentiable function of price, stock level, and also age of the product. The deterioration starts after a fixed period with a constant rate and the shortage is not allowed. Permissible delay in payment and time value of money are also considered in the model. First, we formulate the problem in a piecewise mixed-integer nonlinear programming model. We then propose an algorithm to solve a number of examples. Journal: Int. J. of Mathematics in Operational Research Pages: 1-25 Issue: 1 Volume: 22 Year: 2022 Keywords: replenishment policy; deteriorating items; multivariate demand function; delay in payment. File-URL: http://www.inderscience.com/link.php?id=123117 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:1:p:1-25 Template-Type: ReDIF-Article 1.0 Author-Name: Lanndon Ocampo Author-X-Name-First: Lanndon Author-X-Name-Last: Ocampo Author-Name: Enrico Enriquez Author-X-Name-First: Enrico Author-X-Name-Last: Enriquez Author-Name: Carmelita Loquias Author-X-Name-First: Carmelita Author-X-Name-Last: Loquias Author-Name: Reuella J Bacalso Author-X-Name-First: Reuella J Author-X-Name-Last: Bacalso Author-Name: Grace Estrada Author-X-Name-First: Grace Author-X-Name-Last: Estrada Title: On multi-objective extensions of the classical assignment model with fuzzy parameters and fuzzy goals Abstract: This study advances the limitations of current fuzzy multi-objective assignment models by exploring some formulations with fuzzy parameters and fuzzy goals. The first formulation expresses the coefficients of the objective functions and constraints as fuzzy sets. Two crucial fuzzy transformations were adopted, along with the computational process of the epsilon-constrained multi-objective optimisation. On the other hand, the second formulation assumes the fuzzy coefficients of objective functions and constraints and extends such fuzziness by introducing fuzzy constraints. Lastly, the coefficients of the objective functions and the constraints are expressed as crisp sets while allowing permissible constraint violations. The symmetric fuzzy linear programming solution concepts in the domain literature were adopted as part of the computational process in arriving at a model solution. Actual case examples aided these formulations to gain insights into their computational complexity, efficiency, scalability, and flexibility. Journal: Int. J. of Mathematics in Operational Research Pages: 93-126 Issue: 1 Volume: 22 Year: 2022 Keywords: assignment; multi-objective optimisation; fuzzy optimisation. File-URL: http://www.inderscience.com/link.php?id=123118 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:1:p:93-126 Template-Type: ReDIF-Article 1.0 Author-Name: Sapna Gahlot Author-X-Name-First: Sapna Author-X-Name-Last: Gahlot Author-Name: Ram Naresh Saraswat Author-X-Name-First: Ram Naresh Author-X-Name-Last: Saraswat Title: Fuzzy information inequalities and application in pattern recognition Abstract: In mathematics, an inequality is a relation that compares two numbers or other mathematical expressions in a non-equal way. Inequalities play an important role in finding relationships and solving real-life problems. Although there are many fuzzy inequalities exist in the literature, which are unable to provide solutions for specific cases. The prime objective of this paper is to establish new fuzzy information inequalities under Jensen's inequality and Csiszar's <i>f</i>-fuzzy divergence measure. A new fuzzy relative information of type k and its cases is proposed. Using the proposed fuzzy inequalities, some new bounds of well-known fuzzy information divergence measures in terms of fuzzy chi-square measure, fuzzy Kullback-Leibler measure and fuzzy Hellinger measure are obtained. The direct applications of the proposed fuzzy inequalities in pattern recognition is discussed in this paper. Fuzzy information inequalities also play an important role in medical diagnosis, decision making, etc. and can be extended to Chebyshev's inequality, holder's inequality, and so on, and by this we can solve any other real-life related issues. It is a more convenient and reliable method than others. Journal: Int. J. of Mathematics in Operational Research Pages: 456-480 Issue: 4 Volume: 23 Year: 2022 Keywords: fuzzy set; fuzzy f-measures; inequalities; pattern recognition. File-URL: http://www.inderscience.com/link.php?id=127731 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:4:p:456-480 Template-Type: ReDIF-Article 1.0 Author-Name: Shashi Bhushan Author-X-Name-First: Shashi Author-X-Name-Last: Bhushan Author-Name: Anoop Kumar Author-X-Name-First: Anoop Author-X-Name-Last: Kumar Author-Name: Sumit Kumar Author-X-Name-First: Sumit Author-X-Name-Last: Kumar Title: Efficient classes of estimators for population variance using attribute Abstract: This article deals with the problem of estimating population variance of study variable by using information on auxiliary attribute in simple random sampling. We have adapted the procedure of Kadilar and Cingi (2006) and established some efficient classes of estimators for population variance. The performance of the proposed estimators have been assessed by an empirical study using two real populations and the results demonstrate that the proposed estimators present an extensively greater efficiency when compared with the usual mean estimator, classical ratio, regression and exponential estimators suggested by Singh and Kumar (2011), Singh and Malik (2014) estimators, Zaman and Kadilar (2019) type estimators, Zaman (2020) type estimator and Cekim and Kadilar (2020) type estimator. Journal: Int. J. of Mathematics in Operational Research Pages: 74-92 Issue: 1 Volume: 22 Year: 2022 Keywords: bias; mean square error; efficiency; auxiliary attribute. File-URL: http://www.inderscience.com/link.php?id=123124 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:1:p:74-92 Template-Type: ReDIF-Article 1.0 Author-Name: K. Suriyapriya Author-X-Name-First: K. Author-X-Name-Last: Suriyapriya Author-Name: Jagadeeswari Murugan Author-X-Name-First: Jagadeeswari Author-X-Name-Last: Murugan Author-Name: V. Lakshmana Gomathi Nayagam Author-X-Name-First: V. Lakshmana Gomathi Author-X-Name-Last: Nayagam Title: Solution of linear programming problem with trapezoidal fuzzy coefficients using score functions Abstract: Numerous real-life problems depend on incomplete and implausible information. To overcome the enigma and obscurity, Zadeh promoted fuzzy set theory in 1965. After introducing fuzzy set theory, many researchers have made numerous developments in engineering and medicine. Different ranking principles on trapezoidal fuzzy numbers are established and are applied by eminent authors in multi-criteria decision-making problems in the literature. Linear programming models are essential tools to solve optimisation problems in healthcare, production planning, financial sectors, etc. The ranking principle plays a vital role in the constraints. Recently, a complete ranking principle on the class of trapezoidal fuzzy numbers was suggested in 2018. This study proposes a method to solve the fuzzy linear programming problem whose coefficients are trapezoidal fuzzy numbers using the total ordering principle by score functions defined in 2018. Here, we formulate an equivalent multi-objective linear programming problem for the given fuzzy linear programming problem to attain the optimal solution. Furthermore, the proposed method's efficiency is illustrated through numerical examples and comparison with the existing techniques is also discussed. Journal: Int. J. of Mathematics in Operational Research Pages: 41-73 Issue: 1 Volume: 22 Year: 2022 Keywords: linear programming problem; trapezoidal fuzzy coefficients; total ordering principle. File-URL: http://www.inderscience.com/link.php?id=123126 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:1:p:41-73 Template-Type: ReDIF-Article 1.0 Author-Name: B.S. Surya Prabhavati Author-X-Name-First: B.S. Surya Author-X-Name-Last: Prabhavati Author-Name: V. Ravindranath Author-X-Name-First: V. Author-X-Name-Last: Ravindranath Title: A simple and efficient method to solve fully interval and fuzzy transportation problems Abstract: One of the prime goals of an organisation is to establish good transportation and supply chain network to optimise the delivery costs. In practice network parameters are often expressed in either intervals or fuzzy numbers which are difficult to deal with the classical methods. In this paper, we have proposed modified minimum supply demand method to solve interval transportation problem and extended it to fully fuzzy transportation problems (FTP), where the supply, demand and the transportation cost parameters are either triangle or trapezoidal fuzzy numbers. The interval solution for the FTP has been proved to lie within the interval range of the corresponding optimum fuzzy solution. If the parameters are either triangle or trapezoidal fuzzy numbers, our solution coincides with the optimal solution and the method is demonstrated with a numerical example of logistics problem in the field of pharmaceutics. Journal: Int. J. of Mathematics in Operational Research Pages: 545-567 Issue: 4 Volume: 23 Year: 2022 Keywords: interval transportation problem; ITP; fuzzy transportation problem; FTP; optimum interval solution; minimum supply demand; trapezoidal fuzzy number; triangular fuzzy number. File-URL: http://www.inderscience.com/link.php?id=127734 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:23:y:2022:i:4:p:545-567 Template-Type: ReDIF-Article 1.0 Author-Name: Anusha Vulimiri Author-X-Name-First: Anusha Author-X-Name-Last: Vulimiri Author-Name: Sireesha Veeramachaneni Author-X-Name-First: Sireesha Author-X-Name-Last: Veeramachaneni Title: Estimating weight of stocks using ambiguity index and its application to type-2 intuitionistic fuzzy portfolio selection Abstract: In this paper a method to find the weight of stock in the portfolio is developed when the stock preferences are given in type-2 intuitionistic fuzzy numbers. Taking into the fact that ambiguity can significantly bring the outcome of weight; in this paper we compute ambiguity in the valuation of each stock and then used in weight determination process. The proposed technique allows the decision maker to assign the weights for stocks, which leads to select reliable portfolio for investment. The advantages are discussed by citing appropriate numerical examples. Journal: Int. J. of Mathematics in Operational Research Pages: 26-40 Issue: 1 Volume: 22 Year: 2022 Keywords: portfolio selection; stock weights; ambiguity index; type-2 intuitionistic fuzzy set; T2IFS; Jaccard distance measure. File-URL: http://www.inderscience.com/link.php?id=123127 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:1:p:26-40 Template-Type: ReDIF-Article 1.0 Author-Name: Gadde Srinivasa Rao Author-X-Name-First: Gadde Srinivasa Author-X-Name-Last: Rao Author-Name: Evodia Andreas Mnyanga Author-X-Name-First: Evodia Andreas Author-X-Name-Last: Mnyanga Title: Queuing systems in the cafeterias at the University of Dodoma, Tanzania Abstract: Queuing is a common practice to all public service centres where the demand surpasses the supply. The purpose of this study is the performance of queuing systems in the cafeterias at the University of Dodoma, Dodoma Tanzania. Data were recorded in a period of seven days to find the distribution pattern of the arrival and the service time through fitting them in poison and exponential distribution respectively, to determine the average waiting time in a queue by using the M/M/1 mathematical model, and to analyse the waiting time in a system by using statistical quality control chart. The results of the findings showed that the arrival time and service time for all queues in all sessions follows poison and exponential distribution respectively. Also the findings showed that the expected waiting time was high during breakfast, whereas during lunch and dinner the expected waiting time was low compared to breakfast. Journal: Int. J. of Mathematics in Operational Research Pages: 127-141 Issue: 1 Volume: 22 Year: 2022 Keywords: queue; restaurant; waiting lines; M/M/1 mathematical model; arrival time and service time; Tanzania. File-URL: http://www.inderscience.com/link.php?id=123128 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:22:y:2022:i:1:p:127-141 Template-Type: ReDIF-Article 1.0 Author-Name: Sandeep Prasad Author-X-Name-First: Sandeep Author-X-Name-Last: Prasad Author-Name: Monika Panghal Author-X-Name-First: Monika Author-X-Name-Last: Panghal Author-Name: Tesfamichael Molla Ali Author-X-Name-First: Tesfamichael Molla Author-X-Name-Last: Ali Title: Developing a cost-effective and heuristic tool to solve cut order planning problems in the apparel industry Abstract: Cut order planning (COP) plays a vital role in the proper utilisation of fabric in the garment manufacturing process. It is because its major goal is to develop the most effective cutting plan considering the various decision variables in a purchase order, namely quantity, size and colour. However, the major challenge faced by SMEs is to develop the best mix of cut plans while ensuring the optimum use of the material, machine, and labour in the absence of any sophisticated software. This result in under-utilisation of fabric because of 'intuitive' or 'ballpark figure' approaches adopted to develop a COP, which has negligible scientific validity. The researchers have developed a simple, yet powerful, and cost-effective tool based on a mixed-integer linear programming decision-making model using 'simplex' method with embedded automation powered by macros. The researchers tested the tool and validated the results on two sets of real cutting data. Journal: Int. J. of Mathematics in Operational Research Pages: 26-45 Issue: 1 Volume: 21 Year: 2022 Keywords: cut order planning; COP; Solver®; macros; Python; area; marker efficiency; garment industry; marker planning; optimisation; Open Computer Vision; OpenCV. File-URL: http://www.inderscience.com/link.php?id=120314 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:1:p:26-45 Template-Type: ReDIF-Article 1.0 Author-Name: Deepak Kumar Author-X-Name-First: Deepak Author-X-Name-Last: Kumar Author-Name: S.B. Singh Author-X-Name-First: S.B. Author-X-Name-Last: Singh Author-Name: Pawan Kumar Author-X-Name-First: Pawan Author-X-Name-Last: Kumar Title: Fuzzy reliability appraisal of a system using probabilistic dual hesitant fuzzy element emphasising score function Abstract: Present paper introduces a new technique for analysing fuzzy reliability of a system under probabilistic fuzzy environment, where the reliability of a component/unit of a system is represented by probabilistic dual hesitant fuzzy element for handling uncertainty like hesitancy in real life situation. With the help of the proposed approach, in this study, we have evaluated the fuzzy reliability of some complex systems having series, parallel and bridge configurations using score function and deviation degree. Additionally, a numerical example is taken for better demonstration of the proposed technique. Journal: Int. J. of Mathematics in Operational Research Pages: 67-82 Issue: 1 Volume: 21 Year: 2022 Keywords: fuzzy reliability; probabilistic dual hesitant fuzzy element; bridge configuration; score function; deviation function. File-URL: http://www.inderscience.com/link.php?id=120315 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:1:p:67-82 Template-Type: ReDIF-Article 1.0 Author-Name: Varun Mohan Author-X-Name-First: Varun Author-X-Name-Last: Mohan Author-Name: Mahadev Ota Author-X-Name-First: Mahadev Author-X-Name-Last: Ota Author-Name: Ashok Kumar Author-X-Name-First: Ashok Author-X-Name-Last: Kumar Title: An inventory model for decaying items with Pareto distribution, time-dependent demand and shortages Abstract: In this paper, we develop an EOQ model for time-varying demand with deterioration. We assumed that the deterioration of commodity follows a generalised Pareto distribution. Also, the shortage is allowed and fully backlogged. Keeping these assumptions under consideration, the mathematical expressions are obtained for carrying cost, shortage cost and deterioration cost. Inventory costs were used to constitute the total cost function. Subsequently, optimal time to consume physical stock, cycle time, and total cost per cycle were determined. The results are discussed with the help of numerical examples followed by a comparative analysis between quadratic demand rate and equivalent linear demand rate. A comparison of results obtained from numerical examples concludes that the optimum cost for quadratic demand is less than that of the linear demand model. Finally, sensitivity analysis is presented to describe the influence of changes in the parameters on optimal policies. Journal: Int. J. of Mathematics in Operational Research Pages: 83-103 Issue: 1 Volume: 21 Year: 2022 Keywords: EOQ model; inventory; shortages; stock out cost; cycle time; deteriorated units; positive stock. File-URL: http://www.inderscience.com/link.php?id=120316 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:1:p:83-103 Template-Type: ReDIF-Article 1.0 Author-Name: Halima Boudada Author-X-Name-First: Halima Author-X-Name-Last: Boudada Title: A non-parametric estimation of the conditional quantile for truncated and functional data Abstract: In this paper, we propose a local linear estimator for the conditional distribution function in the case where the real response variable is subject to left-truncation by another random variable (r.v.) and the covariate is of functional type. Under regular assumptions, both of the pointwise and the uniform almost sure convergences, of the proposed estimator, are established. Then, we deduce the uniform almost sure convergence of the obtained conditional quantile estimator. A simulation study is used to illustrate the performance of our estimator with respect to the kernel method. Journal: Int. J. of Mathematics in Operational Research Pages: 127-140 Issue: 1 Volume: 21 Year: 2022 Keywords: truncation; functional type covariate; local linear method; conditional quantile function; rate of almost-sure convergence; simulation. File-URL: http://www.inderscience.com/link.php?id=120318 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:21:y:2022:i:1:p:127-140