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 Title: Analysis of MAP/PH/1 queueing system with discarding customers having imperfect service, single vacation, feedback and impatient customers Abstract: In this paper, we analyse a single server queueing model where the service time follows a phase type distribution and the arrival process follows a Markovian arrival process with corresponding representations (<i>D</i><SUB align="right"><SMALL>0</SMALL></SUB>, <i>D</i><SUB align="right"><SMALL>1</SMALL></SUB>) of order m and (<i>α</i>, <i>T</i>) of order <i>n</i>. When a customer enters for the service, a generalised Erlang clock with <i>r</i> stages is started concurrently. Due to the impatience the customers may balk the system if server is in vacation period. By using matrix analytic method, we find the steady state analysis in this model. Also, we derive the expected waiting time, system performance measures, cost function and busy period. By using some performance measures we provide the numerical results and graphical representations. Journal: Int. J. of Mathematics in Operational Research Pages: 411-440 Issue: 4 Volume: 29 Year: 2024 Keywords: Markovian arrival process; phase type service; imperfect service; Erlang clock; single vacation; Bernoulli feedback; balking. File-URL: http://www.inderscience.com/link.php?id=143389 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:4:p:411-440 Template-Type: ReDIF-Article 1.0 Author-Name: Subir Guin Author-X-Name-First: Subir Author-X-Name-Last: Guin Author-Name: Amit Sarkar Author-X-Name-First: Amit Author-X-Name-Last: Sarkar Author-Name: Brojeswar Pal Author-X-Name-First: Brojeswar Author-X-Name-Last: Pal Title: Pricing and return strategies in a dual-channel closed loop supply chain considering complementary products and sales effort Abstract: Waste materials are polluting the environment as they are being stored. Additionally, with a shortage of raw materials and energy sources, remanufacturing would be beneficial. In this paper, we discuss a dual-channel closed-loop supply chain of a pair of complementary products involving two manufacturers and one retailer. The manufacturer of main products distributes the products through both online and traditional retail channels, while the manufacturer of complementary products does so only through the online channel. For remanufacturing, two manufacturers collect their end-of-used products through only the online channels. Then the pricing and remanufacturing decision problem is modelled based on four-game (centralised, vertical Nash, manufacturer Stackelberg, and retailer Stackelberg) models, which differ in power structures. After that, the optimal results of the manufacturers and the retailer are analysed. Finally, a numerical result is proposed to analyse the analytical results and sensitivity to the respective parameters. Based on our research, we determined that channel and retailer profit along with return rate is highest for the centralised model, whether channel and retailer profit and sales effort are maximum for the manufacturer Stackelberg model under decentralised environment. Journal: Int. J. of Mathematics in Operational Research Pages: 482-510 Issue: 4 Volume: 29 Year: 2024 Keywords: dual-channel; closed loop supply chain; complementary products; sales effort; vertical Nash; Stackelberg. File-URL: http://www.inderscience.com/link.php?id=143390 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:4:p:482-510 Template-Type: ReDIF-Article 1.0 Author-Name: Biswajit Roy Author-X-Name-First: Biswajit Author-X-Name-Last: Roy Author-Name: Kousik Bhattacharya Author-X-Name-First: Kousik Author-X-Name-Last: Bhattacharya Author-Name: Sujit Kumar De Author-X-Name-First: Sujit Kumar Author-X-Name-Last: De Title: Solving an exploitation-based Marxian fuzzy EOQ model Abstract: This article deals with the clinical study of Marxian economic order quantity (M-EOQ) model under fuzzy environment. Initially the model has been viewed as multi-objective cost minimisation and profit maximisation problem under optimum rate of exploitation. Then we transform the multi-objective optimisation problem into single objective optimisation problem under suitable constraints. For optimising this objective function, we need to solve analytically a biquadratic equation where order quantity assumes as one of the decision variables. According to the nature of the roots of this biquadratic equation, we split the model into various sub models where the exploitation varies differently with the change of demand function. Incorporating the negative root of the biquadratic equation, we have formulated three different backlogging EOQ models. Considering a case study, we perform the numerical experimentation with the help of a solution algorithm. Moreover, to capture the non-random uncertainty of the model parameters, we construct an equivalent fuzzy shortage model. Our findings reveal that, shortage model is more beneficial than other sub-models for the decision maker all the time. Finally, numerical illustrations, sensitivity analysis, graphical illustrations and comparative study are done for justify the model followed by managerial insight, conclusion and scope of future work. Journal: Int. J. of Mathematics in Operational Research Pages: 511-541 Issue: 4 Volume: 29 Year: 2024 Keywords: EOQ model; Marx's theory; exploitation; fuzzy set; algorithm; optimisation. File-URL: http://www.inderscience.com/link.php?id=143391 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:4:p:511-541 Template-Type: ReDIF-Article 1.0 Author-Name: Meryem Cheraitia Author-X-Name-First: Meryem Author-X-Name-Last: Cheraitia Author-Name: Rewayda Razaq Abo Alsabeh Author-X-Name-First: Rewayda Razaq Abo Author-X-Name-Last: Alsabeh Title: A hybrid modified cuckoo search algorithm for the uncapacitated examination timetabling Abstract: In this study, we investigate the effectiveness of cuckoo search algorithm (CSA) for solving the uncapacitated examination timetabling problem (UETTP). CSA is a popular metaheuristic optimisation algorithm that mimics the behaviour of cuckoos. Compared with other nature-inspired algorithms, it is more generic and robust for many optimisation problems. The CSA is easy to understand and implement. Furthermore, it represents a powerful search method with few controllable parameters and can be combined with additional strategies to increase effectiveness. We proposed a modified version of CSA. Moreover, a local search strategy is utilised to reinforce the CSA and improve the exploitation phase to develop and provide high-quality solutions. Extensive experiments were conducted using Carter benchmark datasets consisting of 12 instances selected from several real-world universities. The obtained results confirm that the hybrid modified CSA outperforms the basic CSA and it has comparable performance in comparison with other algorithms proposed in the literature. Journal: Int. J. of Mathematics in Operational Research Pages: 40-59 Issue: 1 Volume: 28 Year: 2024 Keywords: examination timetabling; metaheuristic; cuckoo search algorithm; CSA; simulated annealing. File-URL: http://www.inderscience.com/link.php?id=138528 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:1:p:40-59 Template-Type: ReDIF-Article 1.0 Author-Name: Peter Tinashe Chinofunga Author-X-Name-First: Peter Tinashe Author-X-Name-Last: Chinofunga Author-Name: Broderick Oluyede Author-X-Name-First: Broderick Author-X-Name-Last: Oluyede Author-Name: Fastel Chipepa Author-X-Name-First: Fastel Author-X-Name-Last: Chipepa Title: The Topp-Leone-Marshall-Olkin-G power series class of distributions: properties and applications Abstract: This study introduces a new class of distributions known as the Topp-Leone-Marshall-Olkin-G power series (TLMO-GPS) distribution. TLMO-G family of distributions is compounded with the power series distribution to get TLMO-GPS distribution. Some statistical properties including quantile function, linear representation, order statistics, Rényi entropy, moments and probability weighted moments are developed. Parameter estimation is done using maximum likelihood estimation technique. To establish estimates consistency, we perform Monte Carlo simulation. By utilising real life datasets, the merits of a member of the new class of distributions are demonstrated. Thus, the Topp-Leone-Marshall-Olkin-G class of distributions is shown to be useful and applicable to real life data. Journal: Int. J. of Mathematics in Operational Research Pages: 441-462 Issue: 4 Volume: 29 Year: 2024 Keywords: Topp-Leone; Marshall-Olkin; generalised distributions; power series; moments; maximum likelihood estimation; goodness-of-fit statistics. File-URL: http://www.inderscience.com/link.php?id=143392 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:4:p:441-462 Template-Type: ReDIF-Article 1.0 Author-Name: Manoj Kumar Sharma Author-X-Name-First: Manoj Kumar Author-X-Name-Last: Sharma Author-Name: Divya Mandal Author-X-Name-First: Divya Author-X-Name-Last: Mandal Title: Preservation technology investment: a catalyst for sustainable two-warehouse inventory model and SDG achievement Abstract: Preservation technology investment in a two-warehouse inventory model can have a significant impact on the achievement of several United Nations Sustainability Development Goals (SDGs), including SDGs 2, 8, 12, and 13. In this article, we developed the two-warehouse inventory model and took the investment in preservation technology into account. An owned warehouse of finite size and a rented warehouse for storing excess items that exceed the capacity of the owned warehouse in practice were usded. The holding cost of a rented warehouse is greater than and distinct from that of an owned warehouse. Shortage is not permitted. The purpose of this study is to design a policy for deteriorating inventory when a store invests in preservation technology to slow the rate of product degradation. The model's utility and sensitivity examination of the appropriate resolution for a combination of features are illustrated mathematically. Journal: Int. J. of Mathematics in Operational Research Pages: 18-39 Issue: 1 Volume: 28 Year: 2024 Keywords: sustainability development goals; two warehouses; preservation technology; price dependent demand. File-URL: http://www.inderscience.com/link.php?id=138529 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:1:p:18-39 Template-Type: ReDIF-Article 1.0 Author-Name: Riya Dutta Author-X-Name-First: Riya Author-X-Name-Last: Dutta Author-Name: Prasun Kumar Nayak Author-X-Name-First: Prasun Kumar Author-X-Name-Last: Nayak Title: Ekeland variational principle on intuitionistic fuzzy quasi metric spaces Abstract: Utilising Brézis and Browder principle on partiality ordered sets, we formulate Ekeland variational principle and Takahashi's minimization theorem on intuitionistic fuzzy quasi metric spaces. The existence of solution of equilibrium problem (EP) is also given here. Moreover, Banach fixed point theorem and Caristi-Kirk fixed point theorem are provided in the setting of intuitionistic fuzzy quasi metric spaces. Journal: Int. J. of Mathematics in Operational Research Pages: 1-17 Issue: 1 Volume: 28 Year: 2024 Keywords: intuitionistic fuzzy quasi metric space; Ekeland variational principle; Banach contraction principle; Caristi-Kirk fixed point theorem; Takahashi's minimisation theorem; equlibrium point. File-URL: http://www.inderscience.com/link.php?id=138530 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:1:p:1-17 Template-Type: ReDIF-Article 1.0 Author-Name: Srabani Shee Author-X-Name-First: Srabani Author-X-Name-Last: Shee Author-Name: Tripti Chakrabarti Author-X-Name-First: Tripti Author-X-Name-Last: Chakrabarti Title: A marketing-oriented production inventory model under hybrid carbon policy with carbon emission origin-based green investments Abstract: This article studies an EPQ system for deteriorating products where demand rate is assumed to be a function of advertisement parameter and selling price under hybrid carbon regulation with green investment (GI). Here, we consider latest type of market demand which is a combination of sales-price and the rate of advertisement of the product in the news and electronic media. The proposed hybrid carbon strategy is a mix of carbon cap-trade and carbon tax (CT) regulations. Here, the carbon emission (CE) arises from three origins - setup, manufacturing, and stock carrying process. The production-house can spend money on green equipments in all CEs origin independently to decrease CE. This article helps retailers to maximise the total profit through determination of optimal production time, advertising variables and amount of GI in the three origins. The numerical illustration helps to compare the objective value under different environment. Lastly, sensitivity analysis is calculated to learn the effect of the various parameters. Journal: Int. J. of Mathematics in Operational Research Pages: 325-346 Issue: 3 Volume: 28 Year: 2024 Keywords: inventory; green investment; GI; advertisement and price sensitive demand; carbon tax policy; carbon cap and trade policy; hybrid carbon policy. File-URL: http://www.inderscience.com/link.php?id=140066 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:3:p:325-346 Template-Type: ReDIF-Article 1.0 Author-Name: Ritu Rathi Author-X-Name-First: Ritu Author-X-Name-Last: Rathi Title: Behavioural analysis of a fly ash bricks manufacturing system Abstract: This paper analysed the behaviour of reliability on fly ash bricks manufacturing system which having three subsystems such as pan mixing, belt conveyor, and bricks forming and they are organised in series manner. Both pan mixing and belt conveyor system contains single unit of machinery and the bricks forming subsystem contains two unit of machineries they are rotary press and hydraulic press. In bricks forming subsystem, both machineries are organised in parallel. Here, when the distribution of subsystem's repair time is taken as arbitrary, the distribution subsystem's failure time of the fly ash bricks manufacturing system is considered as exponential. The fly ash bricks manufacturing unit is investigated by utilising the supplementary variable technique. Here, the particular case is taken for discovering the availability, profit and mean time to system failure (MTSF) of the manufacturing system. Finally, the numerical analysis is performed to validate the impact of failure and repair rates on the availability and profit of the fly ash bricks manufacturing system. Journal: Int. J. of Mathematics in Operational Research Pages: 463-481 Issue: 4 Volume: 29 Year: 2024 Keywords: availability; profit; supplementary variable technique; mean time to system failure; MTSF; fly ash bricks manufacturing system. File-URL: http://www.inderscience.com/link.php?id=143394 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:4:p:463-481 Template-Type: ReDIF-Article 1.0 Author-Name: Vandana Y. Kakran Author-X-Name-First: Vandana Y. Author-X-Name-Last: Kakran Author-Name: Jayesh M. Dhodiya Author-X-Name-First: Jayesh M. Author-X-Name-Last: Dhodiya Title: A belief-degree-based two-stage multi-objective solid transportation problem in a green supply chain Abstract: In recent years, transport networks have been a significant source of greenhouse gas emissions that have provoked rapid growth in global warming and contamination of air. As a result, the proposed research has captivated our interest which focuses on a two-stage green supply multi-objective solid transportation problem (2-GrSMOSTP) under an uncertain environment where all the parameters are regarded as uncertain variables. Two mathematical models for the uncertain model of 2-GrSMOSTP are formulated using expected and optimistic value criteria for deterministic conversion of the uncertain model. After deterministic conversion, these models are solved directly in the Lingo 18.0 software using the minimising distance method and the fuzzy programming technique. Finally, a numerical illustration is provided to demonstrate the application and algorithm of the models. The sensitivity of the optimistic-criterion-based model is also examined using confidence levels in order to investigate variation in the objective functions. Journal: Int. J. of Mathematics in Operational Research Pages: 78-104 Issue: 1 Volume: 28 Year: 2024 Keywords: multi-objective; green supply chain network; GrSCN; solid transportation problem; STP; uncertain programming; fuzzy programming technique. File-URL: http://www.inderscience.com/link.php?id=138531 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:1:p:78-104 Template-Type: ReDIF-Article 1.0 Author-Name: Mounesh Marali Author-X-Name-First: Mounesh Author-X-Name-Last: Marali Author-Name: R. Dhanalakshmi Author-X-Name-First: R. Author-X-Name-Last: Dhanalakshmi Author-Name: Narendran Rajagopalan Author-X-Name-First: Narendran Author-X-Name-Last: Rajagopalan Title: A hybrid transformer-based BERT and LSTM approach for vulnerability classification problems Abstract: Industrial control systems (ICSs) are vulnerable to cyberattacks due to the growing corporate network and internet connectivity. Ensuring proper security and response to cyberattacks is critical as they can impact ICS performance, reliability, safety, and availability, leading to catastrophic losses. Cyber threat intelligence (CTI) helps companies avoid cyberattacks by relying on vulnerability databases such as CVEs from national vulnerability databases (NVDs). However, these databases may include flaws that compromise security solutions and hinder attack mitigation. To address this issue, automated categorisation of vulnerability data using deep learning (DL) is proposed. The study found that LSTM-tuned BERT designs outperform standard models in precision, F1 score, accuracy, and recall. Implementing DL vulnerability categorisation can enhance ICS security and decrease the threat environment. Journal: Int. J. of Mathematics in Operational Research Pages: 275-295 Issue: 3 Volume: 28 Year: 2024 Keywords: vulnerability; classification; LSTM; BERT; cyber threat intelligence. File-URL: http://www.inderscience.com/link.php?id=140067 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:3:p:275-295 Template-Type: ReDIF-Article 1.0 Author-Name: Sudha Rana Author-X-Name-First: Sudha Author-X-Name-Last: Rana Author-Name: Deepak Kumar Author-X-Name-First: Deepak Author-X-Name-Last: Kumar Author-Name: Anita Kumari Author-X-Name-First: Anita Author-X-Name-Last: Kumari Title: Tetracontatetragonal fuzzy number with application of fuzzy transportation problem Abstract: The objective of this paper is to introduce a new fuzzy number with 44 points called as tetracontatetragonal fuzzy number. Here, we derived a new ranking method for tetracontatetragonal fuzzy numbers. In this research work, we have investigated the results by implementing tetracontatetragonal fuzzy number to an unbalanced fuzzy transportation problem and we used four methods like Vogel's approximation method (VAM), Russel's approximation method (RAM), least cost's approximation method, and Modi's approximation method, to investigate the minimum cost transportation problem using tetracontatetragonal fuzzy numbers. We also calculated the minimum cost from a set of origins to a set of destinations in fuzzy transportation problem. Journal: Int. J. of Mathematics in Operational Research Pages: 214-233 Issue: 2 Volume: 29 Year: 2024 Keywords: fuzzy number; tetracontatetragonal fuzzy number; crisp values; ranking function; fuzzy transportation problem; Russel's approximation method; RAM; Vogel's approximation method; VAM. File-URL: http://www.inderscience.com/link.php?id=142115 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:2:p:214-233 Template-Type: ReDIF-Article 1.0 Author-Name: C.K. Anjali Author-X-Name-First: C.K. Author-X-Name-Last: Anjali Author-Name: Sreekanth Kolledath Author-X-Name-First: Sreekanth Author-X-Name-Last: Kolledath Title: Survey on queuing models with discouragement, policies and vacation Abstract: Queuing models with discouragement, policies, and vacation have been extensively investigated due to its wide range of applications in real-life scenarios. The effectiveness of a queuing system is questioned when customers balk or renege. However, the loss of customers can be prevented up to some extent by using customer retention strategies. Also, implementing vacation and threshold policies appropriately in the system improves the servers' capacity for providing service effectively. Based on these concepts many surveys have been made on finite and infinite population queuing models. But we have observed from the queuing theory literature that surveys have not been done by combining both the finite and infinite population models. The main objective of this survey is to provide an overview of the relevant research works done on finite and infinite population models with impatience, policies and vacation. By taking into account the models and methodologies used in various research articles, we also attempt to provide an outline of the works discussed in tabular format. Journal: Int. J. of Mathematics in Operational Research Pages: 105-145 Issue: 1 Volume: 28 Year: 2024 Keywords: machine repair problem; discouragement; balking; reneging; N-policy; F-policy; vacation; working vacation. File-URL: http://www.inderscience.com/link.php?id=138532 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:1:p:105-145 Template-Type: ReDIF-Article 1.0 Author-Name: Jency Leona Edward Author-X-Name-First: Jency Leona Author-X-Name-Last: Edward Author-Name: Palanivel Kaliyaperumal Author-X-Name-First: Palanivel Author-X-Name-Last: Kaliyaperumal Title: Assignment model for employing skilled IT professionals for appropriate job roles under uncertainty with different ranking approaches using membership functions Abstract: Assignment problems (AP) have a wide range of practical applications because they are widely used in business, management science, and other professions. Due to the inapplicability of traditional and classical APs, particularly complicated real-world issues can be addressed using fuzzy APs which are more effective. Selecting the best candidate for the job can be challenging due to uncertainty and limited data, especially in the IT sector. The AP is one of the most important factors in decision-making for any kind of allocation or assignment. In this article, the assignment model has been employed in order to deal with the job assignment for skilled IT professionals by means of conventional approaches using fuzzy membership functions (FMF) with different ranking methods. Additionally, the model explains the mathematical formulation, outlines, and methodology with numerical illustrations. Moreover, the considered problem is converted into a crisp AP using the different ranking indexes and also the problem has been resolved using the existing traditional assignment methods which enhances the model efficiency. Lastly, the model concludes that the best candidate for the job was recruited and results were compared that the effective application of placement for the right candidate for the right job. Journal: Int. J. of Mathematics in Operational Research Pages: 296-324 Issue: 3 Volume: 28 Year: 2024 Keywords: fuzzy assignment problem; FAP; ranking methods; robust ranking technique; magnitude ranking method; centroid ranking method; ranking function; Hungarian method; matrix one's assignment; MOA method; direct methods. File-URL: http://www.inderscience.com/link.php?id=140068 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:3:p:296-324 Template-Type: ReDIF-Article 1.0 Author-Name: Mathew P. Sindu Author-X-Name-First: Mathew P. Author-X-Name-Last: Sindu Author-Name: Narayanan C. Viswanath Author-X-Name-First: Narayanan C. Author-X-Name-Last: Viswanath Title: Study of a birth-death process with population independent death rate Abstract: Birth-death processes are extensively used in modelling several real-world phenomena. For example, the widely used exponential growth model is a pure birth model. This paper presents a birth-death process with time-inhomogeneous birth and death rates, where the death rate is independent of the population size. Transient analysis of the process is conducted using the generating function method. Mean, variance, and extinction probability are obtained by solving Volterra integral equations using numerical methods. A comparison, in terms of average, with the deterministic counterpart of the birth-death model shows that the influence of the initial population size separates the averages. A numerical study reveals that the new model outperforms the exponential growth model and could be its substitute in several real-world applications, including tumour growth modelling. Journal: Int. J. of Mathematics in Operational Research Pages: 60-77 Issue: 1 Volume: 28 Year: 2024 Keywords: birth-death process; transient analysis; Volterra integral equation; deterministic model; exponential growth model. File-URL: http://www.inderscience.com/link.php?id=138533 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:1:p:60-77 Template-Type: ReDIF-Article 1.0 Author-Name: K. Senthamarai Kannan Author-X-Name-First: K. Senthamarai Author-X-Name-Last: Kannan Author-Name: V. Parimyndhan Author-X-Name-First: V. Author-X-Name-Last: Parimyndhan Title: Forecasting the stock direction using ensemble random forest Abstract: Predicting stock prices is a challenging task due to market fluctuations and the nonlinear nature of stock markets. Forecasting errors can increase investment risk, so reducing them is essential. In this study, financial data including high, low, open, and close prices of stocks were used to generate new variables. Here TCS stock data is employed to construct a Random forest model. This model predicts whether a stock will close positively or negatively based on past values of technical indicators. The findings in this work demonstrate that, using random forest for stock forecasting is beneficial for both institutional and retail stock investors. The unique contribution of our work is the utilised of technical indicators as high-accuracy features for predicting the direction of stock prices. The performance accuracy rate of 74% for the model is obtained by increasing the number of training cycles for the algorithm. Journal: Int. J. of Mathematics in Operational Research Pages: 396-407 Issue: 3 Volume: 28 Year: 2024 Keywords: forecasting; random forest; RF; technical indicators; indicators; machine learning; ML; stock. File-URL: http://www.inderscience.com/link.php?id=140069 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:3:p:396-407 Template-Type: ReDIF-Article 1.0 Author-Name: R. Kalyanaraman Author-X-Name-First: R. Author-X-Name-Last: Kalyanaraman Author-Name: G. Janani Author-X-Name-First: G. Author-X-Name-Last: Janani Title: Finite population and finite capacity single server batch service queues with compulsory working vacation Abstract: A finite population Poisson queue with fixed batch service rule has been considered. After completion of each service the server takes vacation independent of the number of customers in the queue. During vacation, the server serves the customers in a slower rate. For this model, the system size probabilities are computed. Some system performance measures are derived. Also instead of finite population, infinite population model with finite waiting room capacity has been considered as a second model. The steady state results are obtained for this model. The two models are compared. Cost and profit structure are defined. Some numerical examples are given. Journal: Int. J. of Mathematics in Operational Research Pages: 163-190 Issue: 2 Volume: 29 Year: 2024 Keywords: finite population queue; batch service; steady state probability; performance measures; compulsory vacation. File-URL: http://www.inderscience.com/link.php?id=142117 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:2:p:163-190 Template-Type: ReDIF-Article 1.0 Author-Name: Tadeusz Antczak Author-X-Name-First: Tadeusz Author-X-Name-Last: Antczak Author-Name: Kalpana Shukla Author-X-Name-First: Kalpana Author-X-Name-Last: Shukla Title: Optimality and duality results for non-smooth vector optimisation problems with K-V-type I functions via local cone approximations Abstract: In the paper, local cone approximations are used to introduce new notions of generalised convexity and to prove optimality conditions and duality results for a new class of non-smooth vector optimisation problems with inequality constraints. Namely, several concepts of (generalised) <i>K</i>-<i>V</i>-type I are gathered in a general scheme by means of the concepts of <i>K</i>-directional derivative and the <i>K</i>-subdifferential. Then, optimality conditions and several Mond-Weir duality theorems are established for the considered non-smooth vector optimisation problem. The results established in the paper for aforesaid non-convex non-differentiable vector optimisation problems generalise similar results existing in the literature. Journal: Int. J. of Mathematics in Operational Research Pages: 374-395 Issue: 3 Volume: 28 Year: 2024 Keywords: non-smooth multi-objective programming; local cone approximations; K-directional derivative; K-subdifferential; K-V-type I function. File-URL: http://www.inderscience.com/link.php?id=140071 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:3:p:374-395 Template-Type: ReDIF-Article 1.0 Author-Name: Wellington Fredrick Charumbira Author-X-Name-First: Wellington Fredrick Author-X-Name-Last: Charumbira Author-Name: Broderick Oluyede Author-X-Name-First: Broderick Author-X-Name-Last: Oluyede Author-Name: Fastel Chipepa Author-X-Name-First: Fastel Author-X-Name-Last: Chipepa Author-Name: Lesego Gabaitiri Author-X-Name-First: Lesego Author-X-Name-Last: Gabaitiri Title: The Harris-G power series class of distributions with applications Abstract: This study introduces a novel class of distributions (CoD) called the Harris-G power series (H-GPS) CoD. The model is obtained by compounding the Harris-G distribution with the power series distribution (PSD). Some statistical properties including quantile function, linear representation, distribution of order statistics, moments, probability weighted moments and Rényi entropy are developed. Four special cases including the Harris-log-logistic distribution, Harris-log-logistic logarithmic distribution, Harris-Weibull Poisson distribution and the Harris-Weibull logarithmic distribution are presented. Parameter estimation is done using maximum likelihood estimation technique. A simulation study is carried out for the special case of Harris-Weibull Poisson (H-WP) distribution. Finally the Harris-Weibull Poisson is applied to two real datasets to illustrate the usefulness and applicability of the model. Journal: Int. J. of Mathematics in Operational Research Pages: 234-257 Issue: 2 Volume: 29 Year: 2024 Keywords: Harris-G; power series; generalised distribution; maximum likelihood estimation; MLE; moments; order statistics; entropy. File-URL: http://www.inderscience.com/link.php?id=142119 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:2:p:234-257 Template-Type: ReDIF-Article 1.0 Author-Name: R. Sengothai Author-X-Name-First: R. Author-X-Name-Last: Sengothai Author-Name: R. Sivaraman Author-X-Name-First: R. Author-X-Name-Last: Sivaraman Title: Water distribution networks leak detection using graph theory and optimised LSTM Abstract: Water supply issues are made worse by leakage in the water distribution network (WDN). Because there is a higher chance of contamination from leaky openings, leakage lowers the quality of water. It also results in pressure drops and power losses. These drawbacks are worse in undeveloped nations because of the substandard design quality and advanced age of distribution systems. Identification of the WDN leak is crucial due to the limited supply of water resources. In this research work, a graph theory and artificial network-based leak detection method are proposed to address the problem of leakage in WDNs. The proposed method is designed to detect leaks in WDNs with high accuracy. The technique uses graph theory to split the WDN into two sections, and then pressure loggers and the optimised long short-term memory (O-LSTM) algorithm are used for determining which section leaks. Journal: Int. J. of Mathematics in Operational Research Pages: 347-373 Issue: 3 Volume: 28 Year: 2024 Keywords: water distribution networks; WDNs; long short-term memory algorithm; long short-term memory; LSTM; leak detection; African vulture optimisation algorithm; AVOA; graph theory. File-URL: http://www.inderscience.com/link.php?id=140072 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:3:p:347-373 Template-Type: ReDIF-Article 1.0 Author-Name: Shubha Agnihotri Author-X-Name-First: Shubha Author-X-Name-Last: Agnihotri Author-Name: Jayesh M. Dhodiya Author-X-Name-First: Jayesh M. Author-X-Name-Last: Dhodiya Title: Fuzzy multi-objective solid transportation problem: genetic algorithm-based solution approach Abstract: This article addresses the structure of the fuzzy multi-objective solid transportation problem (FMOSTP) under the aegis of a hybrid genetic algorithm. Here, solid transportation problems (STP) are three-dimensional transportation problems in the sense that the mode of transportation is taken into account along with demand and supply constraints. Furthermore, the data structure considered in this article is assumed to be fuzzy because of the argument that the crisp data, in principle, is nearly hypothetical, and for this reason, the theory of fuzzy numbers is employed to account for the inherent impreciseness/uncertainty of the underlying system. Against this backdrop, the authors propose a matrix-based stochastic algorithm that efficiently generates an initial population. In this connection, two STPs are also posed for illustration purposes and solved using a hybrid genetic algorithm. In addition, the obtained results are compared with the fuzzy programming technique (FPT). Journal: Int. J. of Mathematics in Operational Research Pages: 271-290 Issue: 2 Volume: 29 Year: 2024 Keywords: multi-objective solid transportation problem; fuzzy theory; fuzzy programming technique; FPT; genetic algorithm; hybrid GA. File-URL: http://www.inderscience.com/link.php?id=142121 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:2:p:271-290 Template-Type: ReDIF-Article 1.0 Author-Name: Samia Ourari Author-X-Name-First: Samia Author-X-Name-Last: Ourari Author-Name: Farouk Yalaoui Author-X-Name-First: Farouk Author-X-Name-Last: Yalaoui Title: New conditions of dominance and optimality for single-machine scheduling problems with nested execution intervals Abstract: In this paper, we consider the problem of scheduling a set of n + 1 jobs on a single disjunctive machine. Each job has a fixed processing time and a temporal execution interval. Pre-emption is not allowed. Temporal execution intervals are assumed to have a perfect pyramidal structure, i.e., the execution intervals of the jobs are nested within each other, or none two of them are contained within each other. The objective is to find a feasible sequence that minimises the maximum lateness under some particular constraints. In order to do so, new dominance properties under known necessary and sufficient conditions are established, and optimality conditions of certain job sequences are given. Journal: Int. J. of Mathematics in Operational Research Pages: 191-213 Issue: 2 Volume: 29 Year: 2024 Keywords: single-machine scheduling; nested or perfect intervals; dominance conditions; optimality condition; scheduling rules. File-URL: http://www.inderscience.com/link.php?id=142135 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:2:p:191-213 Template-Type: ReDIF-Article 1.0 Author-Name: Udemezue Ndubisi Nnakee Author-X-Name-First: Udemezue Ndubisi Author-X-Name-Last: Nnakee Author-Name: Chi Aloysius Ngong Author-X-Name-First: Chi Aloysius Author-X-Name-Last: Ngong Author-Name: Chinyere C. Onyejiaku Author-X-Name-First: Chinyere C. Author-X-Name-Last: Onyejiaku Author-Name: Josaphat U.J. Onwumere Author-X-Name-First: Josaphat U.J. Author-X-Name-Last: Onwumere Title: Do asymmetric effect and volatility persistence exist in the Nigerian stock market? Abstract: Volatility modelling in Nigeria is limited to non-Gaussian models, as many researchers apply the Gaussian process. This paper investigates the leverage effect and volatility persistence in the Nigerian stock market. The generalised autoregressive conditional heteroscedasticity models with asymmetric extensions are employed for the analysis. The findings show no leverage effect with high volatility in the stock market. The model indicates explosive volatility and persistence. The high volatility weakens investors' confidence and prevents market growth and development. The policy-makers should enhance investors' awareness and education to ensure positive risk-taking behaviours that reduce volatility. Institutional quality should be improved to give confidence to investors in the market. The market infrastructure should be improved, and a variety of securities should be offered to attract rational investors. The government should tackle the prevalent activities of terrorists, herdsmen, and kidnappers, which engender uncertainty in the market. More attractive variety of securities should be offered in the market for rational and informed investors. The Nigerian stock market should be diversified via trading in financial derivatives instruments. Journal: Int. J. of Mathematics in Operational Research Pages: 145-162 Issue: 2 Volume: 29 Year: 2024 Keywords: stock market; leverage effect; volatility persistence; GARCH; error distributions. File-URL: http://www.inderscience.com/link.php?id=142136 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:2:p:145-162 Template-Type: ReDIF-Article 1.0 Author-Name: Vaibhav Ghildiyal Author-X-Name-First: Vaibhav Author-X-Name-Last: Ghildiyal Title: An intelligent chatbot using deep learning with bidirectional GRU and CNN model Abstract: Chatbots can be an important tool for guiding users through various processes or providing information on a particular topic. One of the main benefits of chatbots is their ability to provide personalised and real-time assistance to users, without requiring them to navigate through complex interfaces or search for information on their own. In this paper, an intelligent chatbot is designed for guiding the person who came for interview in an organisation, it is maintained at the human resource (HR) department in the company. The questions asked by the candidate is first pre-processed using stop word removal, stemming, tokenisation. Then the features present in the pre-processed data are extracted using the POS bagging and bag of words (BOW) representation. The chimp optimisation algorithm is introduced for selecting the required features. Finally, the chatbot uses the hybrid convolutional neural network (CNN) with bi-directional gradient recurrent unit (Bi-GRU). The implementation of this deep learning based chatbot is performed using the PYTHON platform with accuracy of 93.12%. Journal: Int. J. of Mathematics in Operational Research Pages: 258-270 Issue: 2 Volume: 29 Year: 2024 Keywords: chatbots; human resource; stop word removal; stemming; tokenisation; bi-directional gradient recurrent unit; Bi-GRU. File-URL: http://www.inderscience.com/link.php?id=142137 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:2:p:258-270 Template-Type: ReDIF-Article 1.0 Author-Name: G. Ayyappan Author-X-Name-First: G. Author-X-Name-Last: Ayyappan Author-Name: S. Nithya Author-X-Name-First: S. Author-X-Name-Last: Nithya Title: Analysis of M[X1], M[X2]/G1, G2/1 retrial queue with priority services, differentiate breakdown, delayed repair, Bernoulli feedback, balking and working vacation Abstract: In this study, we construct a single server retrial queueing system with two types of breakdowns, delayed repair, Bernoulli feedback, balking and working vacation. Two different categories of customers like priority and ordinary are to be considered. This model proposes non-pre-emptive priority discipline. Ordinary and priority customers arrive as per Poisson processes. For both ordinary and priority customers, the server consistently affords a single service that follows to general distribution. During certain periods, an arriving ordinary customer may balk the system. When the orbit and priority queue are empty after the service is ended, the server takes a single working vacation. In this study, we used probability generating function and supplementary variable technique to solve the Laplace transforms of time-dependent probabilities of system states. In order to accelerate the sensitivity analysis of system descriptions, numerical data are obtained and also examined. Journal: Int. J. of Mathematics in Operational Research Pages: 491-513 Issue: 4 Volume: 28 Year: 2024 Keywords: retrial queues; batch arrivals; priority queues; working vacation; balking; differentiate breakdown; Bernoulli feedback; delayed repair. File-URL: http://www.inderscience.com/link.php?id=140347 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:4:p:491-513 Template-Type: ReDIF-Article 1.0 Author-Name: R. Sengothai Author-X-Name-First: R. Author-X-Name-Last: Sengothai Author-Name: R. Sivaraman Author-X-Name-First: R. Author-X-Name-Last: Sivaraman Title: Early prediction of chronic kidney disease via ensemble-deep-learning approach and improved dimensionality reduction approach Abstract: This research proposes an ensemble-deep-learning approach and an enhanced dimensionality reduction method to predict chronic kidney disease (CKD) in its early stages. The proposed model has four major phases: pre-processing, feature extraction, feature selection, and CKD prediction. The pre-processed data is subjected to data cleaning and standardisation. Features are then extracted using PCA, statistical and higher-order statistical approaches, and the Spearman's rank correlation coefficient. Optimal features are selected using the hybrid optimisation model, which combines lemurs optimisation and harmony search algorithm. The CKD prediction phase uses an ensemble-deep-learning approach, including a transformer network, autoencoder, and feedforward neural network. The proposed model's accuracy, precision, F1 score, recall, FNR, FPR, and FDR are compared with existing models, showing its superiority. The proposed model aims to predict CKD in its early stages, potentially reducing its growth rate and associated issues. Journal: Int. J. of Mathematics in Operational Research Pages: 431-454 Issue: 4 Volume: 28 Year: 2024 Keywords: chronic kidney disease; CKD; hybrid optimisation model; ensemble-deep-learning approach; transformer network; autoencoder; feedforward neural network. File-URL: http://www.inderscience.com/link.php?id=140348 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:4:p:431-454 Template-Type: ReDIF-Article 1.0 Author-Name: Kalaivani Kaspar Author-X-Name-First: Kalaivani Author-X-Name-Last: Kaspar Author-Name: Palanivel Kaliyaperumal Author-X-Name-First: Palanivel Author-X-Name-Last: Kaliyaperumal Title: A neutrosophic application to the transportation problem with mixed constraints using single-valued trapezoidal neutrosophic numbers Abstract: Fuzzy transportation problems have been developed to address the uncertainty in real-world problems. Neutropsohic set plays a vital role in solving uncertainty which is the extension of fuzzy and the intuitionistic set. The defuzzification approach using a proposed ranking function has been considered to convert the fuzzy and neutrosophic data into crisp data. Moreover, this research is proposed a single-valued neutrosophic transportation problem with mixed constraints. The work aims to deal with the transportation problem in terms of neutrosophic nature to obtain optimal results by using a proposed ranking function. The problem explains mixed constraints by employing a conventional approach through numerical illustrations and the obtained results are compared with other ranking approaches. Lastly, it shows the justification of the results and efficiency of the ranking function which gives the optimal transportation cost. Lastly, MATLAB software has been used to show higher accuracy results for various ranking functions, and the proposed ranking function yields the most efficient optimal solution. Journal: Int. J. of Mathematics in Operational Research Pages: 514-525 Issue: 4 Volume: 28 Year: 2024 Keywords: transportation problem; TP; neutrosophic set; NS; single-valued trapezoidal neutrosophic number; SVTNN; mixed constraint transportation problem. File-URL: http://www.inderscience.com/link.php?id=140349 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:4:p:514-525 Template-Type: ReDIF-Article 1.0 Author-Name: Srabani Shee Author-X-Name-First: Srabani Author-X-Name-Last: Shee Author-Name: Tripti Chakrabarti Author-X-Name-First: Tripti Author-X-Name-Last: Chakrabarti Title: Impact of carbon emission policies on a production inventory model with stock and demand dependent production rate and preservation technology related deterioration Abstract: This article considers an EPQ model for deteriorating items assuming price dependent demand with different carbon emission regulations. Most of the researchers have taken production rate as constant or independent of demand. However, in this model production rate has been taken to be linear combination of on-hand inventory and demand. Also, we consider that the producing and holding items in storage can generate CO<SUB align="right"><SMALL>2</SMALL></SUB> emission. Moreover, we all know preservation machinery be able to change the rate of deterioration of produced item. So it is important to study the preservation strategy under carbon policies. For minimising the total cost in a production cycle, inventory systems are developed in carbon tax and cap-trade policies. Also, we made a comparison between the optimum results of the proposed inventory articles without carbon constraint and with two carbon strategies. At last, numerical example has been calculated to conclude the theoretical property of these articles and the effects of different parameters have been illustrated through sensitivity analysis. Journal: Int. J. of Mathematics in Operational Research Pages: 409-430 Issue: 4 Volume: 28 Year: 2024 Keywords: inventory; EPQ model; preservation technology; carbon emission; carbon tax policy; carbon cap-trade policy. File-URL: http://www.inderscience.com/link.php?id=140350 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:4:p:409-430 Template-Type: ReDIF-Article 1.0 Author-Name: S. Palaniammal Author-X-Name-First: S. Author-X-Name-Last: Palaniammal Author-Name: S. Pradeep Author-X-Name-First: S. Author-X-Name-Last: Pradeep Title: Cost benefit analysis for non-Markovian bulk queue with server failure Abstract: The queueing system is significantly impacted by a breakdown, which also has complex consequences. The queueing system's functioning and dysfunction as a consequence of on-going server failure are discussed in this paper. This study investigates the server's uninterruptible failure in the presence of numerous breaks and state-dependent arrivals. The distinctive qualities and distinguishing characteristics of the queueing system are given, along with a cost model and an application example that demonstrates how the model has developed theoretically. Along with a thorough study of performance measures, the lowest overall average cost is also provided by figuring out the ideal batch size for the service. Journal: Int. J. of Mathematics in Operational Research Pages: 455-474 Issue: 4 Volume: 28 Year: 2024 Keywords: cost benefit; bulk queue; server breakdown; supplementary variable technique; total average cost. File-URL: http://www.inderscience.com/link.php?id=140351 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:4:p:455-474 Template-Type: ReDIF-Article 1.0 Author-Name: Babita Chaini Author-X-Name-First: Babita Author-X-Name-Last: Chaini Author-Name: Narmada Ranarahu Author-X-Name-First: Narmada Author-X-Name-Last: Ranarahu Title: Solving fuzzy shortest path problem with vertex transfer penalties under type-2 fuzzy environment Abstract: Shortest path problems have many applications in the field of graph theory. However, the traditional shortest path algorithms only work in a situation where an edge penalty is a real number. In real-world situations like the shipping and transportation industry, the edge weight from a source node to the destination node often could not be defined through a real number due to incompleteness or inexactness, this can be challenging in some cases and can be defined through a fuzzy number. In this scenario, finding the shortest path between two nodes has already been solved in the past. In this paper, we are trying to find the shortest path between two nodes where the graph has transfer penalties at the node and the transfer penalties are defined by a type-2 trapezoidal fuzzy number. This problem has a go-to solution, i.e., to use a Kirby-Potts expansion to add parallel edges and then use the standard Dijkstra algorithm to find the shortest path. In this paper, we have not used any graph extension technique, but we have used a modified Dijkstra algorithm to manage the vertex penalty and find the shortest path in between the nodes. A numerical example is provided to explain the usefulness of the approach. Journal: Int. J. of Mathematics in Operational Research Pages: 526-548 Issue: 4 Volume: 28 Year: 2024 Keywords: fuzzy shortest path problems; IT2TrFN; modified Dijkstra algorithm; transfer penalties. File-URL: http://www.inderscience.com/link.php?id=140352 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:4:p:526-548 Template-Type: ReDIF-Article 1.0 Author-Name: Dharma Lesmono Author-X-Name-First: Dharma Author-X-Name-Last: Lesmono Author-Name: Taufik Limansyah Author-X-Name-First: Taufik Author-X-Name-Last: Limansyah Author-Name: Ignatius A. Sandy Author-X-Name-First: Ignatius A. Author-X-Name-Last: Sandy Title: A backorder inventory model considering price-sensitive and stock-dependent demand Abstract: In the inventory management system, time and quantity are crucial factors to be considered in relation to inventory costs. Demand is another external factor that influences the availability of goods for customers. In fact, demand varies from time to time, being dependent on price, time, stock or other relevant factors. The dynamics of this condition can be described by developing a mathematical model. In this paper, we develop a backorder inventory model considering price-sensitive and stock-dependent demand. From the model, we determine the cycle length and the time when the inventory drops to zero as decision variables in order to minimise the total inventory cost. Based on the sensitivity analysis, we found that generally speaking, changes in certain parameter values will substantial affect the decision variables of the model. Having this information at their disposal, retailers can determine which specific parameters should be managed in order to minimise the total inventory cost. Journal: Int. J. of Mathematics in Operational Research Pages: 291-304 Issue: 3 Volume: 27 Year: 2024 Keywords: inventory; price-dependent demand; stock-dependent demand; backorder. File-URL: http://www.inderscience.com/link.php?id=138053 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:3:p:291-304 Template-Type: ReDIF-Article 1.0 Author-Name: Yu Wu Author-X-Name-First: Yu Author-X-Name-Last: Wu Title: Decision-making analysis for a new variant of the classical secretary problem Abstract: In this paper, a new variant of the classic secretary problem is studied, in which the interviewer has a look-ahead privilege to observe partial future candidates before making a decision each time. Different from the classic problem, a decision can be deferred till some subsequent candidates are interviewed in this variant. We define the degree of look-ahead privilege on one candidate as how many candidates are sequentially interviewed from when this candidate is interviewed to when its decision is made. We first propose a general optimal decision strategy framework that can maximise the probability of successfully selecting the best candidate. Then, focusing on one specially structured look-ahead privilege, we apply the proposed strategy framework and obtain the probability of success in a closed function, to which an explicit solution will give the concrete optimal strategy; and further, through computational experiments, we study relationships between related parameters. Journal: Int. J. of Mathematics in Operational Research Pages: 305-316 Issue: 3 Volume: 27 Year: 2024 Keywords: secretary problem; look-ahead privilege; optimal strategy. File-URL: http://www.inderscience.com/link.php?id=138054 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:3:p:305-316 Template-Type: ReDIF-Article 1.0 Author-Name: Sukarna Dey Mondal Author-X-Name-First: Sukarna Dey Author-X-Name-Last: Mondal Author-Name: Dipendra Nath Ghosh Author-X-Name-First: Dipendra Nath Author-X-Name-Last: Ghosh Author-Name: Pabitra Kumar Dey Author-X-Name-First: Pabitra Kumar Author-X-Name-Last: Dey Title: Statistical-based multi-criteria decision making approach for prediction of the grade of an institution in NAAC Abstract: In the modern era, innumerable colleges and universities have been established in India but sometimes quality education is not imparted by the authority of colleges/universities. It has been a major challenge for the Indian government to assess the quality education in India. Through a well-versed assessment procedure, National Assessment and Accreditation Council (NAAC) was established to assist higher education institutions in identifying their assets, strengths, and weaknesses. In this paper, an innovative mathematical model is proposed to calculate and justify the NAAC grading of a well-known engineering college while taking into consideration the NAAC grading of nine other well-known affiliated colleges/autonomous colleges/universities. This model is making a prediction based on the data obtained from the self-study report (SSR) after data validation and verification (DVV). The result of the model is found to be very accurate when comparing the overall NAAC grade of the college given by NAAC. Journal: Int. J. of Mathematics in Operational Research Pages: 317-327 Issue: 3 Volume: 27 Year: 2024 Keywords: NAAC grade; MCDM techniques; ANOVA test; P-test; combined MCDM techniques; linear regression method. File-URL: http://www.inderscience.com/link.php?id=138055 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:3:p:317-327 Template-Type: ReDIF-Article 1.0 Author-Name: Prokash Mondal Author-X-Name-First: Prokash Author-X-Name-Last: Mondal Author-Name: Pritha Das Author-X-Name-First: Pritha Author-X-Name-Last: Das Author-Name: Sudhansu Khanra Author-X-Name-First: Sudhansu Author-X-Name-Last: Khanra Title: An EOQ model for seasonal product with ramp-type time and stock dependent demand, shortage and partial backorder Abstract: This study analyses an EOQ model for a seasonal product with ramp-type time and stock dependent demand function under permissible shortages. In the model, deterioration of seasonal products is considered with partial backlog, variable backlog rate, and backlog rate as a function of time until the next replenishment partial backlogging and the backlogging rate is variable and is dependent on waiting time for the next replenishment. Using the optimal control approach, we analytically derive the optimal total average cost and inventory strategy for the retailer over a finite time horizon. We analytically determine the best total average cost and inventory strategy for the merchant over a limited time horizon using the optimal control approach. A numerical application and sensitivity analysis demonstrate practical applicability. Journal: Int. J. of Mathematics in Operational Research Pages: 393-413 Issue: 3 Volume: 27 Year: 2024 Keywords: inventory; time-stock dependent demand; backlogging; deterioration. File-URL: http://www.inderscience.com/link.php?id=138057 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:3:p:393-413 Template-Type: ReDIF-Article 1.0 Author-Name: K. Sikdar Author-X-Name-First: K. Author-X-Name-Last: Sikdar Title: A single server finite buffer Geom/ G/1/ K queue with L limited service and multiple vacation policy Abstract: This paper investigates a <i>Geom</i>/ <i>G</i>/1/ <i>K</i> queueing system with <i>L</i> limited service and multiple vacation in which the packets arrive under the Bernoulli process. The lengths of service and vacation times are integral multiples of the slot duration. The server goes for a vacation if either the system is empty or <i>L</i> packets have been served during each busy period. The queue length distribution at service completion and vacation termination epochs is obtained using the imbedded Markov chain technique. Based on the supplementary variable technique, we develop the system of difference equations to derive the queue length distribution at random epoch. The waiting-time analysis for an arrival packet and other performance measures are also examined. We execute several numerical results, but only a few of them are added in the form of tables and graphs. The results of this research could be useful in understanding the performance of a service system. Journal: Int. J. of Mathematics in Operational Research Pages: 328-353 Issue: 3 Volume: 27 Year: 2024 Keywords: discrete-time queue; finite-buffer; limited service discipline; imbedded Markov chain; multiple vacation policy. File-URL: http://www.inderscience.com/link.php?id=138058 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:3:p:328-353 Template-Type: ReDIF-Article 1.0 Author-Name: Gollapudi Prathyusha Author-X-Name-First: Gollapudi Author-X-Name-Last: Prathyusha Author-Name: K.N. Udaya Kumar Author-X-Name-First: K.N. Udaya Author-X-Name-Last: Kumar Author-Name: G.A. Vatsala Author-X-Name-First: G.A. Author-X-Name-Last: Vatsala Title: Multi-goal multi-product fuzzy solid transportation problem via goal programming technique Abstract: This paper investigates a multi-goal multi-product solid transportation problem (MGMPSTP) with fuzzy coefficient variables for the objective functions and, therefore, the constraints under linear and nonlinear membership functions. The primary objective is to analyse the multi-goal multi-product fuzzy solid transportation problem (MGMPFSTP) using the goal programming (GP) technique through the membership functions and compare the results among the compromise solutions to obtain an optimal compromise solution of multi-objectives. The uncertain cost coefficients of the fuzzy numbers are initially defuzzified to the equivalent crisp MGMPSTP using the <i>α</i>-cut method. Finally, a numerical illustration has been examined to support the tactic. Journal: Int. J. of Mathematics in Operational Research Pages: 354-376 Issue: 3 Volume: 27 Year: 2024 Keywords: goal programming; fuzzy solid transportation problem; α-cut method; triangular fuzzy numbers; trapezoidal fuzzy numbers. File-URL: http://www.inderscience.com/link.php?id=138059 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:3:p:354-376 Template-Type: ReDIF-Article 1.0 Author-Name: Itishree Rout Author-X-Name-First: Itishree Author-X-Name-Last: Rout Author-Name: Trailokyanath Singh Author-X-Name-First: Trailokyanath Author-X-Name-Last: Singh Author-Name: Ameeya Kumar Nayak Author-X-Name-First: Ameeya Kumar Author-X-Name-Last: Nayak Title: An EOQ inventory policy varying with exponential-constant-exponential demand and shortages Abstract: In real market situations, it is often seen that most demands of the seasonal commodities run through three different phases, e.g., growth, steady and decline. The demand and the deterioration are taken as exponential-constant-exponential functions of time and constant, respectively. The model is divided into three policies according to the occurrence of the shortages period. The main purpose of the present paper is to investigate the effect of exponential-constant-exponential demand with seasonal commodities within the economic order quantity (EOQ) framework. Shortages as well as complete backlogged demand have been taken into consideration. A simple analytical procedure is presented to compute the optimal solutions of each policy. The model is well-explained with the help of three numerical examples. Finally, sensitivity analyses of all examples have also been performed to study the effectiveness of several system parameters on optimal solutions. Journal: Int. J. of Mathematics in Operational Research Pages: 145-166 Issue: 2 Volume: 27 Year: 2024 Keywords: backlogging; deterioration; economic order quantity; EOQ; exponential-constant-exponential type; replenishment. File-URL: http://www.inderscience.com/link.php?id=137037 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:2:p:145-166 Template-Type: ReDIF-Article 1.0 Author-Name: A. Baskar Author-X-Name-First: A. Author-X-Name-Last: Baskar Author-Name: M.A. Sai Balaji Author-X-Name-First: M.A. Sai Author-X-Name-Last: Balaji Author-Name: Jitendra Kumar Katiyar Author-X-Name-First: Jitendra Kumar Author-X-Name-Last: Katiyar Author-Name: Bharti Nagpal Author-X-Name-First: Bharti Author-X-Name-Last: Nagpal Author-Name: J. Rajesh Babu Author-X-Name-First: J. Rajesh Author-X-Name-Last: Babu Title: New population-based simple algorithms for solving global optimisation problems Abstract: Heuristic algorithms have effectively been used for solving global optimisation problems in a continuous space. It can be applied to both constrained and unconstrained problems. Presently, several population-based algorithms were proposed by researchers and are available in the literature but those are not enough to solve the issues. Therefore, this study has proposed five new population-based simple algorithms that do not require any tuning parameter. A different strategy was used for updating the solution set. Unlike other algorithms, the solution set is constructed using three or four expressions to ensure an effective search and move towards the optimal/near-optimal solution. Each expression is used to build the population partially and the best one is selected for the next iteration. Further, it is compared with the recent popular arithmetic optimisation algorithm (AOA) using different benchmark functions and test suites of CEC2019. The dimensions are varied from 2 to 1,000. The results demonstrate the better performance of new algorithms over AOA. However, five real-world problems with constraints are also analysed to further validate their efficacy. Journal: Int. J. of Mathematics in Operational Research Pages: 199-222 Issue: 2 Volume: 27 Year: 2024 Keywords: population-based; benchmark function; arithmetic optimisation algorithm; AOA; trigonometric algorithm; constrained optimisation; unconstrained optimisation. File-URL: http://www.inderscience.com/link.php?id=137039 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:2:p:199-222 Template-Type: ReDIF-Article 1.0 Author-Name: Qusay Mohammed Abdulateef Author-X-Name-First: Qusay Mohammed Author-X-Name-Last: Abdulateef Author-Name: Syariza Abdul-Rahman Author-X-Name-First: Syariza Author-X-Name-Last: Abdul-Rahman Author-Name: Hazem Sabri Abedalhammed Author-X-Name-First: Hazem Sabri Author-X-Name-Last: Abedalhammed Title: Cyprinus carpio feed cost optimisation using the linear programming technique: a case study in Iraq Abstract: Common carp (<i>Cyprinus carpio</i>) is the usual dietary meat in Iraq, as it is reasonably priced for consumers compared to other high-cost fish. However, the relative price increment in recent times has alienated some consumers. The high price is due to the feed, an essential component of the fish farming project. The main ingredients of fish feed consist of concentrated animal protein, yellow corn, soy flour, barley, and wheat bran. Moreover, the feed additive enhancer, i.e., barley sprout powder is also incorporated into the feed, since it can increase fish weight significantly. Therefore, this study proposed a linear programming formulation to ascertain the optimal cost of fish feed. The optimal total feed cost was 41 cents per kilogramme, and the amount of the ingredients in the mixture was: animal protein concentrates (0.10114); yellow corn (0.17077); soybean meal (0.39521); barley (0.12037); wheat bran (0.2); premix (0.01); and barley sprout powder (0.0025). Journal: Int. J. of Mathematics in Operational Research Pages: 377-392 Issue: 3 Volume: 27 Year: 2024 Keywords: Cyprinus carpio; feed formulation; optimisation; aquaculture; linear programming; Iraq. File-URL: http://www.inderscience.com/link.php?id=138063 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:3:p:377-392 Template-Type: ReDIF-Article 1.0 Author-Name: K. Preethi Sowndharya Author-X-Name-First: K. Preethi Author-X-Name-Last: Sowndharya Author-Name: J. Ebenesar Anna Bagyam Author-X-Name-First: J. Ebenesar Anna Author-X-Name-Last: Bagyam Title: Optimal server analysis of M/M/c queueing model to reduce the waiting time of patients in healthcare service Abstract: Queueing system is a mathematical design known to be the theory of overcrowding. Healthcare organisation is one of the applications for queueing theory. This paper provides about the healthcare setting at the Arathana ortho local hospital at Pollachi. The proposed queuing model has used the multi-server system with a first come, first server queue discipline. The arrival rate follows Poisson distribution and service rate follows an exponential distribution. The actual data were collected in the ortho hospital and examined using the windows-based TORA optimisation technique. Performance measures and optimal number of servers were found. The result shows that the optimal server to serve the patients and also to reduce the waiting time of patients. The technique is manageable to utilise in the hospital. Journal: Int. J. of Mathematics in Operational Research Pages: 254-266 Issue: 2 Volume: 27 Year: 2024 Keywords: service cost; patients waiting time cost; optimal server level; service time. File-URL: http://www.inderscience.com/link.php?id=137041 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:2:p:254-266 Template-Type: ReDIF-Article 1.0 Author-Name: Sudha Rana Author-X-Name-First: Sudha Author-X-Name-Last: Rana Author-Name: Suneel Kumar Author-X-Name-First: Suneel Author-X-Name-Last: Kumar Author-Name: Deepak Kumar Author-X-Name-First: Deepak Author-X-Name-Last: Kumar Author-Name: Anita Kumari Author-X-Name-First: Anita Author-X-Name-Last: Kumari Title: A novel approach for analysis fuzzy reliability of washing system using q-rung orthopair fuzzy set theory Abstract: One of the most crucial areas of reliability engineering is reliability modelling when discussing the symmetry between two or more objects. In reliability evaluation process, the innovative idea of a q-rung orthopair fuzzy set over dual universes is more flexible than the traditional idea of a Pythagorean fuzzy set and intuitionistic fuzzy set. The washing system is a sophisticated technical system that requires the creation of reliable maintenance plans in order to improve performance. Here, a new method for analysing fuzzy system reliability using q-rung orthopair fuzzy set theory is presented, where the reliability of the components of a complex system are represented by q-rung orthopair fuzzy number for modelling uncertainty in data which is common in real life situation. The suggested approach can more intelligently model and analyse the reliability of complex systems. The score function and accuracy function are also used to compare various complicated systems. Journal: Int. J. of Mathematics in Operational Research Pages: 475-490 Issue: 4 Volume: 28 Year: 2024 Keywords: q-rung orthopair fuzzy set; q-ROFS; fault tree; washing system; fuzzy reliability; parallel system; series system; bridge configuration. File-URL: http://www.inderscience.com/link.php?id=140370 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:4:p:475-490 Template-Type: ReDIF-Article 1.0 Author-Name: Ibrahim Yusuf Author-X-Name-First: Ibrahim Author-X-Name-Last: Yusuf Author-Name: Muhammad Sagir Aliyu Author-X-Name-First: Muhammad Sagir Author-X-Name-Last: Aliyu Author-Name: Mus'abu Musa Author-X-Name-First: Mus'abu Author-X-Name-Last: Musa Title: Mean time to failure modelling and sensitivity analysis of mixed standby serial systems Abstract: In this article, we investigate and compare the mean time to failure (MTTF) of series-parallel systems. This paper considers four different configurations with each having exponential failure and repair time. Each configuration consisting of the main, warm and cold standby units. A cold standby unit is included in Configuration 1 together with two warm standby units. Two cold standby units and one warm standby unit make up Configuration 2. In Configuration 3, there are four primary units, two warm standby units, and one cold standby unit. The Configuration 4 consists of six primary units, one warm standby unit, and two cold standby units. First order linear differential difference equations are used to produce a mathematical formula for MTTF for each configuration, which is then verified through analytical and numerical testing. Through the analytical and ranking experiment, Configuration 1 is found to be optimal. Journal: Int. J. of Mathematics in Operational Research Pages: 267-289 Issue: 2 Volume: 27 Year: 2024 Keywords: mean time to failure; MTTF; mixed standby; redundancy; series-parallel. File-URL: http://www.inderscience.com/link.php?id=137043 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:2:p:267-289 Template-Type: ReDIF-Article 1.0 Author-Name: Chaitali Kar Author-X-Name-First: Chaitali Author-X-Name-Last: Kar Author-Name: Manoranjan De Author-X-Name-First: Manoranjan Author-X-Name-Last: De Author-Name: Manoranjan Maiti Author-X-Name-First: Manoranjan Author-X-Name-Last: Maiti Author-Name: Pritha Das Author-X-Name-First: Pritha Author-X-Name-Last: Das Title: Multi-objective perishable multi-item green inventory models with uncertain finite time horizons and constraints by neutrosophic optimisation approach Abstract: The business period of seasonal products, such as mango, broccoli, etc., is finite over the years due to their availability, which is again uncertain for seasonal variations. According to FAO, about 40% of India's fruits and vegetables perish before reaching consumers. Due to global warming, firms have incorporated carbon management into business decisions. The resources in business are always limited and uncertain. Considering these facts, multi-objective perishable multi-product EOQ models with stock-dependent demand are formulated under crisp, uncertain (fuzzy, random, rough and neutrosophic) time horizons and constraints. The objective is to maximise total profit while minimising wastage costs and carbon emissions. Proposed models are solved using neutrosophic optimisation approach. The multi-objective problems are transformed into single ones using the weighted-sum method and solved through GRG (LINGO 11.0) method. Models are illustrated with numerical examples, and some sensitivity analyses are presented. A trade-off between profit and carbon emission is depicted. Journal: Int. J. of Mathematics in Operational Research Pages: 167-198 Issue: 2 Volume: 27 Year: 2024 Keywords: inventory; seasonal products; uncertain time horizon; carbon emission; neutrosophic optimisation. File-URL: http://www.inderscience.com/link.php?id=137053 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:2:p:167-198 Template-Type: ReDIF-Article 1.0 Author-Name: Aniket Todkar Author-X-Name-First: Aniket Author-X-Name-Last: Todkar Author-Name: Jayesh M. Dhodiya Author-X-Name-First: Jayesh M. Author-X-Name-Last: Dhodiya Title: Aspiration level-based non-dominated sorting genetic algorithm-II and III for multi-objective shortest path problem in a trapezoidal environment Abstract: The present article provides aspiration level (AL)-based non-dominated sorting genetic algorithm (NSGA)-II and AL-based NSGA-III utilising an exponential membership function (EMF) with possibility distribution to tackle fuzzy multi-objective shortest path problem (FMOSPP). In this study, fuzzy judgement for trapezoidal fuzzy number is classified for the decision-maker (DM) to optimise fuzzy objective function scenarios like optimistic, most likely lower, most likely upper, and pessimistic at the same time, utilising <i>α</i>-level sets. A numerical demonstration and a dataset have been offered to portray the application of the recommended methodologies. This study suggests that AL-based NSGA-II and AL-based NSGA-III can handle FMOSPP effectively and efficiently with optimal outputs. These methods provide solutions as per DM's AL. Thus it is very effective to manage real-world multi-objective shortest path problems (MOSPPs). Journal: Int. J. of Mathematics in Operational Research Pages: 223-253 Issue: 2 Volume: 27 Year: 2024 Keywords: multi-objective shortest path problem; MOSPP; aspiration level; exponential membership function; EMF; α-level set; trapezoidal fuzzy number; genetic algorithm. File-URL: http://www.inderscience.com/link.php?id=137054 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:2:p:223-253 Template-Type: ReDIF-Article 1.0 Author-Name: Prokash Mondal Author-X-Name-First: Prokash Author-X-Name-Last: Mondal Author-Name: Sriparna Chowdhury Author-X-Name-First: Sriparna Author-X-Name-Last: Chowdhury Author-Name: Pritha Das Author-X-Name-First: Pritha Author-X-Name-Last: Das Author-Name: Sanat Kumar Majumder Author-X-Name-First: Sanat Kumar Author-X-Name-Last: Majumder Author-Name: Kajal De Author-X-Name-First: Kajal Author-X-Name-Last: De Title: An EOQ model for deteriorating item with backorder and time dependent exponential demand Abstract: In this article, we have developed an economic order quantity (EOQ) model over a finite time horizon for an item with time dependent demand rate with a constant rate of deterioration in consideration of shortages (SFI policy) in inventory under permissible delay in payments and partial backlogging. The demand rate considers hare exponential to address the increment of demand, which greatly impacts the introduction of a new product in the market. Also, the backlogging rate is considered dependent on the hanging time duration of the customers instead of waiting in line of the customers. The model is solved analytically to obtain the optimal solution to the problem. It is then illustrated with the help of numerical examples. A sensitivity analysis of the optimal solution concerning the parameters of the inventory system is given. Journal: Int. J. of Mathematics in Operational Research Pages: 291-308 Issue: 3 Volume: 29 Year: 2024 Keywords: inventory; economic order quantity; EOQ; deterioration; delay in payment; trade credit; backorder dependent. File-URL: http://www.inderscience.com/link.php?id=142446 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:3:p:291-308 Template-Type: ReDIF-Article 1.0 Author-Name: G. Ayyappan Author-X-Name-First: G. Author-X-Name-Last: Ayyappan Author-Name: S. Sankeetha Author-X-Name-First: S. Author-X-Name-Last: Sankeetha Title: Achieving optimal resources utilisation in industrial environments: combining polling methods and an exhaustive service discipline with an unreliable service Abstract: Two types of queues, type I queue with infinite capacity and type II queue with a finite capacity, are both taken into account. While the service time distribution adheres to phase type, each queue's input process operates in line with the Markov arrival process (MAP). The server cycles through the line, starting with the type I queue, and provides standard service to everyone while also offering optional service based on the demands of the client. During the visiting period of each queue, a strict service discipline is observed. Working breakdown and repair are distributed exponentially, whereas many vacations are distributed according to a phase type. The entire number of consumers in the system are investigated using matrix analysis under the steady state probability vector. We analyse busy period analysis, an invariant probability vector, and few performance indicators in our model. The proposed model's numerical and graphical findings are also examined. Journal: Int. J. of Mathematics in Operational Research Pages: 309-344 Issue: 3 Volume: 29 Year: 2024 Keywords: Markovian arrival process; MAP; phase type service; vacation; exhaustive discipline; optional service. File-URL: http://www.inderscience.com/link.php?id=142447 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:3:p:309-344 Template-Type: ReDIF-Article 1.0 Author-Name: R. Suvetha Author-X-Name-First: R. Author-X-Name-Last: Suvetha Author-Name: K. Rangarajan Author-X-Name-First: K. Author-X-Name-Last: Rangarajan Author-Name: P. Rajadurai Author-X-Name-First: P. Author-X-Name-Last: Rajadurai Title: Recent trends of economic production quantity models (2000-2022) - a literature review Abstract: This article presents a literature review of recent trends in economic production quantity models from 2000 to 2022. It examines several recent studies on EPQM focused on a production level, production cost, carbon emissions, product recycling, and imperfect production system. Also, it identified prospective research gaps and investigates the existing research trend of the justifiable economic production quantity models. Established on the potential exploration, it offers a direction for future research that could lead to the creation of a realistic and long-term economic production quantity system. We also surveyed the literature on optimising production through the use of integrated inventory models, multi-level production, and additive manufacturing. Journal: Int. J. of Mathematics in Operational Research Pages: 377-409 Issue: 3 Volume: 29 Year: 2024 Keywords: economic production quantity; demand; carbon emission; additive manufacturing; fuzzy EPQ models. File-URL: http://www.inderscience.com/link.php?id=142448 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:3:p:377-409 Template-Type: ReDIF-Article 1.0 Author-Name: Anjaneyulu Mekala Author-X-Name-First: Anjaneyulu Author-X-Name-Last: Mekala Author-Name: U. Vijaya Chandra Kumar Author-X-Name-First: U. Vijaya Chandra Author-X-Name-Last: Kumar Author-Name: R. Murali Author-X-Name-First: R. Author-X-Name-Last: Murali Title: On independent domination topological indices of graphs Abstract: A dominating set (<i>ds</i>) <i>D</i> of a graph <i>G</i> = (<i>V</i>, <i>E</i>) is an independent dominating set (<i>Ids</i>), if the induces subgraph 〈<i>D</i>〉 has no edges. The independent domination number <i>i</i>(<i>G</i>) of graph <i>G</i> is the minimal cardinality of an <i>Ids</i>. In this paper we define a new independent degree domination (<i>Idd</i>) of each vertex <i>k</i> ∈ <i>V</i>(<i>G</i>), called an <i>Idd</i> of <i>k</i> and denoted by <i>d<SUB align="right"><SMALL>id</SMALL></SUB></i>(<i>k</i>) are introduced, as well as certain domination indices based on this <i>Idd</i> and also fundamental properties are investigated. We establish exact value for the <i>Idd</i> Zagreb indices of book graph, windmill graph, middle graph of cycle. Journal: Int. J. of Mathematics in Operational Research Pages: 345-353 Issue: 3 Volume: 29 Year: 2024 Keywords: independent domination number; independent minimal dominating number; independent domination degree Zagreb indices. File-URL: http://www.inderscience.com/link.php?id=142449 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:3:p:345-353 Template-Type: ReDIF-Article 1.0 Author-Name: Sonia Dua Author-X-Name-First: Sonia Author-X-Name-Last: Dua Author-Name: Sandeep Kumar Mogha Author-X-Name-First: Sandeep Kumar Author-X-Name-Last: Mogha Author-Name: Himani Dem Author-X-Name-First: Himani Author-X-Name-Last: Dem Title: A sustainable inventory system under the impact of partial trade credit Abstract: In the present scenario, countries are required to focus more on reduction of carbon emissions, as it is one of the key factors of global warming. This article considers the approaches to decrease emissions arising from production, storage and transportation. Suppliers offer ample opportunities to overcome the burden of holding costs from retailers by adopting the permissible delay method. We have developed a mathematical model for sustainable inventory system involving deteriorating items with a partial trade credit policy. The long-term best ordering tactics are for retailers that maximise total annual profit while reducing carbon emissions is provided. An efficient algorithm is also proposed to obtain the solution with numerical example. Sensitivity analysis is also performed to study how the model behaves against the changes in some key parameters. Journal: Int. J. of Mathematics in Operational Research Pages: 354-376 Issue: 3 Volume: 29 Year: 2024 Keywords: inventory model; partial trade credit; carbon emission cost; volume flexibility. File-URL: http://www.inderscience.com/link.php?id=142450 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:3:p:354-376 Template-Type: ReDIF-Article 1.0 Author-Name: Julia T. Thomas Author-X-Name-First: Julia T. Author-X-Name-Last: Thomas Author-Name: Mahesh Kumar Author-X-Name-First: Mahesh Author-X-Name-Last: Kumar Title: Optimal inventory economic order quantity model for inventory system with imperfect inspection processes Abstract: Inventory management is the core of supply and demand chain management. The economic order quantity (EOQ) model is the fundamental inventory management model that is assumed to bring only perfect items out of the ordered lot. A lot undergoes a single acceptance sampling plan with an imperfect inspection process before being placed in the inventory. The traditional inventory management process fails to address real-world situations where each type of product is handled in a unique way by manufacturers. This paper formulates an EOQ model in a fuzzy environment while considering: 1) shortages and backorders; 2) the chance of misclassification; 3) fuzziness in the model parameters. An optimisation problem is developed to maximise the total profit. The existence and uniqueness of the optimal solutions are proved with the help of a theorem established for concavity conditions of the total expected profit function. A sensitivity analysis study is also conducted to examine the effect of inspection error on order quantity, backorder level, and total profit. Finally, several numerical examples are presented to illustrate the model derived. Journal: Int. J. of Mathematics in Operational Research Pages: 195-208 Issue: 2 Volume: 28 Year: 2024 Keywords: economic order quantity; EOQ; imperfect quality; shortages; backorders; acceptable inspection level; acceptance sampling plan. File-URL: http://www.inderscience.com/link.php?id=138899 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:2:p:195-208 Template-Type: ReDIF-Article 1.0 Author-Name: Abhinav Goel Author-X-Name-First: Abhinav Author-X-Name-Last: Goel Author-Name: Anshika Singh Author-X-Name-First: Anshika Author-X-Name-Last: Singh Title: Decaying inventory model with different rates and varying costs under preservation technology investment Abstract: Decay, damage, or spoilage of any item is referred to as deterioration. Maintaining the product in excellent shape is a big problem for many retailers because the product loses value with increasing deterioration. Many papers have considered constant deterioration but in real life, the deterioration rate varies depending on the type of stock. This paper assumes that the item stored in the warehouse initially depletes due to demand and then, it decays at a constant and exponential rate, which is evident in the food and textile industries. With the utilisation of preservation technologies, the pace of degradation can be reduced. A mathematical framework with eventually decaying products is formed where demand depends on products and has variable carrying costs as the inventory's expense rises over time. A sample as a numerical analysis is presented to verify the outcome of the suggested model. An optimal solution for the cost function is calculated. Evaluation of sensitivity is done to determine how a modification of parameter affects the optimum solution, including and excluding preservation technology investment. Furthermore, the study's findings are used to generate several insightful managerial observations. Journal: Int. J. of Mathematics in Operational Research Pages: 230-252 Issue: 2 Volume: 28 Year: 2024 Keywords: inventory; constant deterioration; exponential deterioration; stock-dependent demand; variable carrying cost; preservation technology; optimisation; non-instantaneous deterioration; EOQ. File-URL: http://www.inderscience.com/link.php?id=138900 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:2:p:230-252 Template-Type: ReDIF-Article 1.0 Author-Name: Hisham M. Khudhur Author-X-Name-First: Hisham M. Author-X-Name-Last: Khudhur Author-Name: Hind H. Mohammed Author-X-Name-First: Hind H. Author-X-Name-Last: Mohammed Title: A new three-term conjugate gradient method for unconstrained optimisation and its applications in image restoration Abstract: Conjugate gradient methods (CGM) are generally used to solve unconstrained optimisation problems. In this research, the three-term CGM was developed depending on the conjugate coefficient of the Fletcher and Reeves (FR) conjugate descent method and the second condition of the Wolfe's strong search line, and the strong Wolfe condition was used to obtain the step length. According to some assumptions, the properties of descent and global convergence have been achieved for the new proposed method. Finally, we used the proposed method to solve the unconstrained optimisation functions to show its efficiency, and it was actually superior to the FR and three-term Fletcher and Reeves (TTFR) methods. Hence, we used the proposed new conjugate gradient algorithm in image restoration and image denoising. According to the numerical results, the recently proposed algorithm outperforms both FR and Fletcher and Reeves (TTFR) algorithms. Journal: Int. J. of Mathematics in Operational Research Pages: 253-273 Issue: 2 Volume: 28 Year: 2024 Keywords: algorithms; CG; optimisation; FR and TTFR; restoration; three-term Fletcher and Reeves; TTFR. File-URL: http://www.inderscience.com/link.php?id=138901 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:2:p:253-273 Template-Type: ReDIF-Article 1.0 Author-Name: Luay Aljasim Author-X-Name-First: Luay Author-X-Name-Last: Aljasim Author-Name: Ferhan Al-Maliky Author-X-Name-First: Ferhan Author-X-Name-Last: Al-Maliky Title: Sensitivity analysis of the optimum solution to perturbations of the profit of an item in the multiple-choice knapsack problem Abstract: Sensitivity analysis of an optimisation problem is the task of studying the stability of a given optimal solution due to the modifications in the parameters data. In this paper, we study the sensitivity analysis for the optimum to the multiple-choice knapsack problem (MCKP), according to the perturbation of the profit of an arbitrary item. We study how much the profit of an arbitrary item in the original problem can vary without changing the optimal solution structure. The range of variations can be represented by the so-called sensitivity intervals that consist of lower and upper values (limits). The obtained results are explained through a simple example. Furthermore, the performance of the proposed methods is evaluated on a set of problem instances. Journal: Int. J. of Mathematics in Operational Research Pages: 147-162 Issue: 2 Volume: 28 Year: 2024 Keywords: knapsack; multiple choice; optimality; optimisation; perturbation; sensitivity analysis. File-URL: http://www.inderscience.com/link.php?id=138902 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:2:p:147-162 Template-Type: ReDIF-Article 1.0 Author-Name: Broderick Oluyede Author-X-Name-First: Broderick Author-X-Name-Last: Oluyede Author-Name: Neo Dingalo Author-X-Name-First: Neo Author-X-Name-Last: Dingalo Author-Name: Fastel Chipepa Author-X-Name-First: Fastel Author-X-Name-Last: Chipepa Title: The Marshall-Olkin exponentiated half logistic-type II Topp-Leone-G family of distributions with applications Abstract: In this work, we develop and present a new family of probability distributions called Marshall-Olkin exponentiated half logistic-type II Topp-Leone-G (MO-EHL-TII-TL-G) distribution. Statistical properties and the maximum likelihood estimates of the parameters of the proposed family of distributions were derived. Some special cases of the new family of distributions are presented. The performance of the maximum likelihood estimates is assessed by carrying out a simulation study. Two real-life datasets from different areas are applied on one special model, namely, the Marshall-Olkin exponentiated half logistic-type II Topp-Leone-Weibull (MO-EHL-TII-TL-W) distribution to demonstrate the usefulness and applicability of the new family of distributions. Journal: Int. J. of Mathematics in Operational Research Pages: 163-194 Issue: 2 Volume: 28 Year: 2024 Keywords: Marshall-Olkin-G distribution; exponentiated half logistic-G distribution; type II Topp-Leone-G distribution. File-URL: http://www.inderscience.com/link.php?id=138905 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:2:p:163-194 Template-Type: ReDIF-Article 1.0 Author-Name: Mayank Singh Author-X-Name-First: Mayank Author-X-Name-Last: Singh Author-Name: Madhu Jain Author-X-Name-First: Madhu Author-X-Name-Last: Jain Author-Name: A. Azhagappan Author-X-Name-First: A. Author-X-Name-Last: Azhagappan Title: Cost analysis of a transient Markovian queueing model with provision of options between regular and working vacation Abstract: A transient Markov queue is investigated that provides options for two types of server vacations. When the server becomes idle after serving the last customer, he has the choice to take a complete vacation (CV) or a working vacation (WV). New arrivals can join the system in CV or WV mode with different arrival rates, which are dependent on the state of the system. During CV, the server remains idle, while during WV, he serves at a slower rate. After returning from the CV (or WV), the server immediately starts the service if some customers are waiting in the system; otherwise, he waits for the arrivals. The transient queue size distribution and other queueing indices are determined using continued fractions and probability generating function techniques. The stationary distribution is also derived from the transient distribution. Numerical analysis is conducted using a practical application to display the analytical results in real-life scenarios. Journal: Int. J. of Mathematics in Operational Research Pages: 209-229 Issue: 2 Volume: 28 Year: 2024 Keywords: transient analysis; vacation; working vacation; continued fractions; probability generating function; queue size. File-URL: http://www.inderscience.com/link.php?id=138906 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:28:y:2024:i:2:p:209-229 Template-Type: ReDIF-Article 1.0 Author-Name: Gomolemo Jacqueline Lekono Author-X-Name-First: Gomolemo Jacqueline Author-X-Name-Last: Lekono Author-Name: Broderick Oluyede Author-X-Name-First: Broderick Author-X-Name-Last: Oluyede Author-Name: Lesego Gabaitiri Author-X-Name-First: Lesego Author-X-Name-Last: Gabaitiri Title: A new heavy-tailed exponentiated generalised-G family of distributions: properties and applications Abstract: In this paper, we introduce a new family of heavy-tailed distributions called the type-I heavy-tailed exponentiated generalised-G (TIHTEG-G) family of distributions. A special model of the proposed family, namely the type-I heavy-tailed exponentiated generalised-log-logistic (TIHTEG-LLoG) model is studied in detail. Statistical properties of the new family of distributions are presented. These include, among others, the hazard rate function, quantile function, moments, distribution of order statistics and Rényi entropy. The maximum likelihood method of estimation is used for estimating the model parameters and Monte Carlo simulation is conducted to examine the performance of the model. Actuarial measures are also derived and simulation study for these measures is done to show that the proposed TIHTEG-LLoG model is a heavy-tailed model. Real datasets are analysed to illustrate the usefulness of the proposed model. Journal: Int. J. of Mathematics in Operational Research Pages: 1-34 Issue: 1 Volume: 27 Year: 2024 Keywords: heavy-tailed; exponentiated generalised-G; family of distributions; properties; applications; simulation; actuarial measures. File-URL: http://www.inderscience.com/link.php?id=136860 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:1:p:1-34 Template-Type: ReDIF-Article 1.0 Author-Name: Faizan Danish Author-X-Name-First: Faizan Author-X-Name-Last: Danish Author-Name: S.E.H. Rizvi Author-X-Name-First: S.E.H. Author-X-Name-Last: Rizvi Title: Approximately optimum strata boundaries under super population model Abstract: In the present investigation, a methodology has been developed under super population model for obtaining approximately optimum strata boundaries (AOSB) on highly related variable with the variable under consideration which is applicable for the situation having more than one study variables with product estimator. Minimal equations have been obtained under certain assumptions by minimising the generalised variance expressions. Under this complex nature we developed Cum<SUP align="right"><SMALL>3</SMALL></SUP>√<i>R</i><SUB align="right"><SMALL>5</SMALL></SUB>(<i>x</i>) rule for obtaining the AOSB. Empirical studies have also been made on certain density functions, which showed remarkable gain in precision. Journal: Int. J. of Mathematics in Operational Research Pages: 63-74 Issue: 1 Volume: 27 Year: 2024 Keywords: product estimator; super population; optimum strata boundaries; optimum stratification. File-URL: http://www.inderscience.com/link.php?id=136861 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:1:p:63-74 Template-Type: ReDIF-Article 1.0 Author-Name: V. Karthick Author-X-Name-First: V. Author-X-Name-Last: Karthick Author-Name: V. Suvitha Author-X-Name-First: V. Author-X-Name-Last: Suvitha Author-Name: Rathinasabapathy Kalyanaraman Author-X-Name-First: Rathinasabapathy Author-X-Name-Last: Kalyanaraman Title: A single server Markovian differentiated working vacation queue with server breakdown Abstract: A single server Markovian queue with server breakdown has been considered here. In addition, the server goes on two types of vacation namely type-I and type-II. Type-I vacation is taken after the busy period of non-zero duration and type-II vacation occurs, at the completion of type-I vacation. When there are no customers in the system, both type-I and type-II vacations are working vacations. Also, on type-I vacation, the server may breakdown, and immediately the repair takes place. We analysed it as a quasi-birth-and-death (QBD) process, and using the matrix geometric method, the steady-state probability vector of the number of people in the queue and the stability conditions were produced. There are some system performance measures found. The effects of various parameters on the system performance measures are illustrated numerically. Journal: Int. J. of Mathematics in Operational Research Pages: 105-120 Issue: 1 Volume: 27 Year: 2024 Keywords: single server; differentiated vacation; breakdown; repair; QBD process. File-URL: http://www.inderscience.com/link.php?id=136862 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:1:p:105-120 Template-Type: ReDIF-Article 1.0 Author-Name: Shirsendu Nandi Author-X-Name-First: Shirsendu Author-X-Name-Last: Nandi Title: Risk analysis on product quality improvement and supply chain performance for return contract with warranty Abstract: Products which require after sales services and associated with a warranty clause often pass through a series of quality checks and quality control measures. Improvement of quality of the product is an ongoing exercise and the manufacturer and the channel coordinator are expected to explore the impact of any initiative for quality improvement on the profitability and performance of the supply chain. It is important to carry out a risk benefit analysis before undertaking such quality improvement initiatives since it requires major financial investment. It is necessary to redesign the contract parameters after successful implementation of any quality improvement programme. The paper analyses the impact of the quality improvement initiative upon the profitability of the supply chain and describes how to redesign the contract parameters when return contracts are practised. It also does a risk analysis of the parties and the entire supply chain when return contract is practised along with warranty. It examines how change in order quantity and warranty length impacts supply chain risk as measured by variance of profit. Journal: Int. J. of Mathematics in Operational Research Pages: 121-143 Issue: 1 Volume: 27 Year: 2024 Keywords: warranty; quality; risk analysis; supply chain contract; return contracts; supply chain performance; redesign; supply chain risk. File-URL: http://www.inderscience.com/link.php?id=136863 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:1:p:121-143 Template-Type: ReDIF-Article 1.0 Author-Name: Anup Khan Author-X-Name-First: Anup Author-X-Name-Last: Khan Author-Name: Sujit Kumar De Author-X-Name-First: Sujit Kumar Author-X-Name-Last: De Author-Name: Prasun Kumar Nayak Author-X-Name-First: Prasun Kumar Author-X-Name-Last: Nayak Title: Solving an EPQ model with Lagrange interpolating polynomial function via game theory approach Abstract: This article briefly discusses about classical economic production quantity (EPQ) model using game theoretic approach via Lagrange multiplier. It involves two stages of computations, in first stage, we develop a Mond-Weir dual of the EPQ cost minimisation problem with the help of weak and strong duality theory. Secondly, we have formulated an equivalent matrix game problem using Preda's framework. The problem has been solved under convex optimisation, the game theoretic approach and Lagrange interpolating polynomial optimisation respectively with the help of a novel solution algorithm. The numerical illustration shows that a saddle point exists locally but for global optimality some duality gaps have been found. However, this study explains the role of Lagrange multiplier towards optimising the objective function and its corresponding range of variations also. Finally, we have done sensitivity analysis and graphical illustration to justify the novelty of this new approach. Journal: Int. J. of Mathematics in Operational Research Pages: 1-24 Issue: 1 Volume: 29 Year: 2024 Keywords: EPQ model; matrix game; Lagrange interpolating polynomial; optimisation. File-URL: http://www.inderscience.com/link.php?id=141471 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:1:p:1-24 Template-Type: ReDIF-Article 1.0 Author-Name: Gautam Kumar Author-X-Name-First: Gautam Author-X-Name-Last: Kumar Author-Name: Sukhendu Bera Author-X-Name-First: Sukhendu Author-X-Name-Last: Bera Author-Name: Guruprasad Samanta Author-X-Name-First: Guruprasad Author-X-Name-Last: Samanta Author-Name: Manoranjan Maiti Author-X-Name-First: Manoranjan Author-X-Name-Last: Maiti Title: Optimal order quantity and credit period for a time-dependent deteriorated green item under two-level trade credit with reminder cost: a new approach Abstract: Nowadays, people prefer to buy green products. In the present competitive market, the wholesalers and retailers offer trade credit to their downstream customers. Against retailers' offers, some customers become defaulters. In rural India, money lenders engage some people to remind the defaulters for payment. Following this idea, we introduce reminder costs in trade-credited systems to reduce default risk, though this system negatively affects the demand. Along with the conventional approach, a new approach for a two-level trade-credited EOQ model with a time-dependent deteriorated green item is presented, solving default risk and reminder cost by using the generalised reduced gradient method through LINGO 19.0. The new approach gives better results than the conventional ones, and in both approaches, the introduction of reminder cost gives more profit. The nature of profit and its dissection concerning decision variables are presented. Some managerial decisions are derived. Journal: Int. J. of Mathematics in Operational Research Pages: 75-104 Issue: 1 Volume: 27 Year: 2024 Keywords: inventory? two-level trade credit? deterioration? default risk? reminder cost? new approach. File-URL: http://www.inderscience.com/link.php?id=136864 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:1:p:75-104 Template-Type: ReDIF-Article 1.0 Author-Name: Yunfeng Zhang Author-X-Name-First: Yunfeng Author-X-Name-Last: Zhang Author-Name: Ying Qin Author-X-Name-First: Ying Author-X-Name-Last: Qin Title: An inventory model and supply chain coordination for ameliorating items allowing for shortages under non-instantaneous replenishment Abstract: This study constructs an ameliorating item supply chain consisted of a single supplier and a single retailer. The replenishment from the supplier to the retailer takes a while to complete. The retailer is allowed to run out of stock. We analyse the order cycle, the profit of the supply chain system and the profit for each member under the cooperative and the non-cooperative decision-making conditions respectively. The results show that the profit of the supply chain system per unit time is higher under the cooperative decision making than under the non-cooperative decision making. However, compared with the latter, the former will lead to a decrease in the supplier's profit per unit time. To make up for the supplier's loss, a revenue-sharing contract is designed to coordinate the ameliorating item supply chain. The equilibrium solution is given by using the Nash bargaining theory. A numerical example is used to verify the main conclusions. Journal: Int. J. of Mathematics in Operational Research Pages: 25-50 Issue: 1 Volume: 29 Year: 2024 Keywords: ameliorating items; supply chain coordination; inventory; revenue-sharing contract. File-URL: http://www.inderscience.com/link.php?id=141472 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:1:p:25-50 Template-Type: ReDIF-Article 1.0 Author-Name: Emmanuel Oluseye Adeyefa Author-X-Name-First: Emmanuel Oluseye Author-X-Name-Last: Adeyefa Author-Name: Adewale Adeyemi James Author-X-Name-First: Adewale Adeyemi Author-X-Name-Last: James Author-Name: Adeyemi Sunday Olagunju Author-X-Name-First: Adeyemi Sunday Author-X-Name-Last: Olagunju Author-Name: Folake Lois Joseph Author-X-Name-First: Folake Lois Author-X-Name-Last: Joseph Title: Development of a block method for solving multiple order ODEs Abstract: In this work, a convergent hybrid block method (CHBM) with two off-grid points for direct integration of first, second, and third-order initial value problems (IVPs) is proposed. The development of a block method for the solution of IVPs has been considered overwhelmingly in the literature. However, using a block method to directly solve multi-order IVPs has not been so common. Thus, the formulation of a single numerical algorithm for the direct numerical integration of first, second and third-order IVPs is our focus. The method is formulated from a continuous scheme derived using collocation and interpolation techniques and implemented in a block-by-block manner as a numerical integrator for IVPs. To assess the method's applicability, efficiency, and accuracy, the convergence analysis has been investigated, and six test problems are considered. Journal: Int. J. of Mathematics in Operational Research Pages: 51-65 Issue: 1 Volume: 29 Year: 2024 Keywords: block method; collocation; convergence; interpolation; multiple order ODEs. File-URL: http://www.inderscience.com/link.php?id=141473 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:1:p:51-65 Template-Type: ReDIF-Article 1.0 Author-Name: Rebaz Bahram Mustafa Author-X-Name-First: Rebaz Bahram Author-X-Name-Last: Mustafa Author-Name: Nejamddin Abdulla Sulaiman Author-X-Name-First: Nejamddin Abdulla Author-X-Name-Last: Sulaiman Title: Solving triangular fully fuzzy linear fractional programming problem via parametric approach Abstract: In this paper, the fully fuzzy linear fractional programming (FFLFP) problem is considered. The important point of this study is to illustrate an adapted method of parametric optimisation, which is a repeat operation technique that can be used to find an optimal solution for any linear fractional optimisation problem of any coefficient, such as an ordinary interval, rough interval, or fuzzy number. Here, the coefficients of the objective function, constraints, and decision variables are triangular fuzzy numbers (TrFNs), and the FFLFP problem is converted into a comparable deterministic three-linear fractional programming (LFP) problem under some assumptions. However, it can be utilised for the trapezoidal fuzzy number linear fractional programming problem. Finally, the suggested method produces the best or optimum solutions. A test numerical example of a triangular fuzzy linear fractional programming problem is given to present the performance of the procedure. Journal: Int. J. of Mathematics in Operational Research Pages: 94-108 Issue: 1 Volume: 29 Year: 2024 Keywords: fully fuzzy linear fractional programming; FFLFP; linear fractional programming; LFP; parametric approach; triangular fuzzy number; TrFN. File-URL: http://www.inderscience.com/link.php?id=141474 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:1:p:94-108 Template-Type: ReDIF-Article 1.0 Author-Name: P. Indumathi Author-X-Name-First: P. Author-X-Name-Last: Indumathi Author-Name: K.`. Karthikeyan Author-X-Name-First: K.`. Author-X-Name-Last: Karthikeyan Title: Review the concepts of queues and inventory models Abstract: A queueing inventory system has been widely analysed due to its ubiquitous applications in the modern environment and ability to enhance accuracy in this field. The current investigation provides adequate knowledge about the queueing inventory systems. The main aim of the analysis is to reduce the waiting time and the total optimal cost of inventory. The queueing systems, along with the inventory models, such as production inventory, stochastic, perishable products, an assorted variety of demands with diverse service times, and deteriorating inventory systems, are discussed. Based on the existing literature, this article offers some suggestions for using queueing inventory models in a wide variety of contexts. Examples of this include medical systems, traffic flow, scheduling, networking, and facility designs. Journal: Int. J. of Mathematics in Operational Research Pages: 66-93 Issue: 1 Volume: 29 Year: 2024 Keywords: queueing inventory models; perishable inventory; production inventory; stochastic inventory; deteriorating inventory; demands. File-URL: http://www.inderscience.com/link.php?id=141475 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:1:p:66-93 Template-Type: ReDIF-Article 1.0 Author-Name: Kannan Nilakantan Author-X-Name-First: Kannan Author-X-Name-Last: Nilakantan Title: Workforce skill-enhancement policies in manpower systems: modelling, analysis, and structural control Abstract: This paper takes up the mathematical modelling of some recent skill-enhancement policies adopted in organisations for enhancing the skill levels of their employees using Markov modelling techniques. Three such policies or scenarios that organisations encounter or adopt are examined, viz.: 1) regular training of employees; 2) institution of 'time-bound promotions' in their lowermost echelons with a view to attract the best talent from the market; 3) adoption of 'periodic' policies to better adapt to seasonality and cyclic variations in their business requirements. These policies are mathematically modelled and their long-term behaviour and effect on the system structure are derived. A control analysis of the system structure under the influence of these policies is also presented. And concomitantly, it is found that 'proportionality-based recruitment control' policies show promise as a tool for structural control when such policies are in force. Journal: Int. J. of Mathematics in Operational Research Pages: 109-143 Issue: 1 Volume: 29 Year: 2024 Keywords: skill-enhancement policies; time-bound promotions; regular training policies; periodic policies; proportionality-based recruitment control; Markov manpower systems. File-URL: http://www.inderscience.com/link.php?id=141476 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:29:y:2024:i:1:p:109-143 Template-Type: ReDIF-Article 1.0 Author-Name: Ibrahim Yusuf Author-X-Name-First: Ibrahim Author-X-Name-Last: Yusuf Author-Name: Muhammad Kabeer Author-X-Name-First: Muhammad Author-X-Name-Last: Kabeer Title: RAMD approach to performance estimation of fog-to-fog collaboration using software-defined networking Abstract: The software-defined networking (SDN) is subject to a variety of adversarial assaults due to its logically centralised design. These assaults have the potential to damage the managed network's performance, or perhaps bring it down in the worst-case scenario. As a result, SDN performance must be examined and estimated in order to determine its dependability, strength, and efficacy. This study aimed to increase SDN dependability, reliability, maintainability, availability, and metrics like MTBF and MTTF by boosting dependability, reliability, maintainability, and availability. The Markovian birth-death process is used to construct the system regulating the differential difference equation from the state transition diagram for modelling and analysis. The rates of repair and failure of each subsystem are exponentially distributed and statistically independent. For several subsystems of the system, the findings for dependability, reliability, maintainability, and availability, all of which are crucial to system performance, have been acquired and shown in figures and tables. The SDN's performance was evaluated using the numerical data gathered. Furthermore, the results of this study reveal that the highest system performance and dependability may be achieved when the overall system failure rate is low. Journal: Int. J. of Mathematics in Operational Research Pages: 35-62 Issue: 1 Volume: 27 Year: 2024 Keywords: reliability; availability; collaboration; software-defined network. File-URL: http://www.inderscience.com/link.php?id=136871 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:1:p:35-62 Template-Type: ReDIF-Article 1.0 Author-Name: Abubakar Bawa Zarogi Author-X-Name-First: Abubakar Bawa Author-X-Name-Last: Zarogi Author-Name: Abdulkareem Lado Ismail Author-X-Name-First: Abdulkareem Lado Author-X-Name-Last: Ismail Author-Name: Nura Jibrin Fagge Author-X-Name-First: Nura Jibrin Author-X-Name-Last: Fagge Title: Dependability prediction of a hybrid multi client computer networking system using Gumbel-Hougaard family copula Abstract: This paper presents a Markov model of a computer networking system. It consists of four subsystems: z client, router, load balancer, and two distributed data-based servers. They are arranged in a series-parallel configuration and integrated with a switch. The paper research objectives include evaluating the system for various dependability metrics and to see the effect of the repairs. Unit failure is presumed to be continuous and follows exponential distribution, and two repairs are available: general repair addresses partially failed states while copula repair addresses the system failure. The derived equations are studied utilising supplementary variables techniques and Laplace conversion procedures in order to obtain dependability metrics expressions such as reliability, availability, MTTF, sensitivity, and costs. The results were justified using numerical examples and presented in the tables and figures. It was observed that copula repair produces better outcomes than general repair and therefore is recommended for optimal performance of the system. Journal: Int. J. of Mathematics in Operational Research Pages: 509-530 Issue: 4 Volume: 27 Year: 2024 Keywords: availability; reliability; cost implication; computer networking; system. File-URL: http://www.inderscience.com/link.php?id=138462 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:4:p:509-530 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 Title: Analysis of MAP/PH/1 queue with differentiated vacation, vacation interruption under N-policy, optional service, breakdown, repair, setup and discouragement of customers Abstract: This study looks at a single server queueing system with differentiated vacations, vacation interruption under N-policy, optional services, setup, discouragement, breakdown, and repair. For customers' arrival, the Markovian arrival process (MAP) is applied, while phase type distributions (PH) are used for service and repair times. The server offers essential services to customers who are logged into the system on a first-come, first-served basis. The customer has the option to request another service (an additional service), if necessary, from the server after the essential service is complete. Here, we consider two types of vacation such as single and multiple vacations with distinct durations. Customers' arrivals may be discouraged due to impatience during both vacation periods. The matrix analytical technique is used to determine the steady-state probability vector for this model. The stability condition, busy period analysis, cost analysis and system effectiveness are all found in this model. The outcome of numerical values and graphical representations are represented in the view of two dimensional and three dimensional graphs. Journal: Int. J. of Mathematics in Operational Research Pages: 415-457 Issue: 4 Volume: 27 Year: 2024 Keywords: Markovian arrival process; MAP; phase type distribution; vacation interruption under N-policy; optional service; setup; discouragement; breakdown; phase type repair. File-URL: http://www.inderscience.com/link.php?id=138463 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:4:p:415-457 Template-Type: ReDIF-Article 1.0 Author-Name: Uttam Kumar Sharma Author-X-Name-First: Uttam Kumar Author-X-Name-Last: Sharma Author-Name: Varun Mohan Author-X-Name-First: Varun Author-X-Name-Last: Mohan Author-Name: S. Sindhuja Author-X-Name-First: S. Author-X-Name-Last: Sindhuja Author-Name: Pervaiz Iqbal Author-X-Name-First: Pervaiz Author-X-Name-Last: Iqbal Title: Economic order quantity model for Pareto distributed decaying products with quadratic demand, shortage and salvage value Abstract: At the present time, estimating demand and deterioration for some products becomes difficult because these key components of any economic order quantity (EOQ) model become dependent on price, freshness level and many other factors. On the other hand, rising competition does not allow managers to dispose of deteriorated items. In this paper, we incorporated salvage value parameter in the EOQ model with quadratic time dependent demand and Pareto distributed deterioration. Also, the stock out condition is allowed and completely backlogged. With these axioms' expressions for total inventory cost, inventory cycle time and lot size value are derived and optimised. Proposed model findings are described with the help of numerical example. Sensitivity analysis supports the relevance of salvage value parameter, i.e., rise in salvage value reduces the total inventory cost. Journal: Int. J. of Mathematics in Operational Research Pages: 479-495 Issue: 4 Volume: 27 Year: 2024 Keywords: deterioration; variable demand; salvage value; variable holding cost. File-URL: http://www.inderscience.com/link.php?id=138464 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:4:p:479-495 Template-Type: ReDIF-Article 1.0 Author-Name: Ankan Bose Author-X-Name-First: Ankan Author-X-Name-Last: Bose Author-Name: Dipak Laha Author-X-Name-First: Dipak Author-X-Name-Last: Laha Title: Efficient clustering-based constructive heuristics for capacitated vehicle routing Abstract: In this paper, we address the capacitated vehicle routing problem, a generalised variant of vehicle routing problems, in which the routes are assigned to a fleet of vehicles to serve customers meeting their demands in order to optimise certain criterion. Here, we aim to minimise total length of the routes. Although a plethora of research on vehicle routing appeared in the literature over many decades, a few good construction heuristics exist, namely, the heuristics of Clark and Wright (1964), Segerstedt (2014, 2018), which are used for minimising the total length of routes in the capacitated vehicle routing problem. In this paper, we have modified the heuristics of Segerstedt (2014, 2018) using K-means++ clustering in conjunction with a route merging procedure to enhance the solution quality for this problem. The computational results reveal that the modified approaches significantly improve their performance while not affecting their time-complexity. Journal: Int. J. of Mathematics in Operational Research Pages: 458-478 Issue: 4 Volume: 27 Year: 2024 Keywords: vehicle routing; K-means clustering; K-means++ clustering; heuristics; optimisation. File-URL: http://www.inderscience.com/link.php?id=138465 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:4:p:458-478 Template-Type: ReDIF-Article 1.0 Author-Name: R. Sivasamy Author-X-Name-First: R. Author-X-Name-Last: Sivasamy Author-Name: Keamogetse Setlhare Author-X-Name-First: Keamogetse Author-X-Name-Last: Setlhare Author-Name: Olebogeng Mokgware Author-X-Name-First: Olebogeng Author-X-Name-Last: Mokgware Title: Quasi-birth-and-death processes to determine economic order quantity of a queueing inventory system with impatient customers Abstract: The proposed investigation is an inventory system tied to a single-server M/M/1/N facility that allows impatient customers according to the ordering policy (r, Q). The order is triggered when the stock level drops to a positive integer 'r < Q' for a fixed number 'Q' of units. Here: 1) queueing inventory system (QIS) with lost customers; 2) QIS with back-order are investigated. For each type, we study the long-run moments of the X variable representing the observed queue length, and the Y variable representing observed inventory level. We show that the combined sequence <b>Z</b> = (X, Y) constitutes a level-dependent quasi-birth and death process (LDQBD) in the state space <b>E</b> = {(n, j): n = 0, 1, ..., N, and j = 0, 1, ..., (Q + r)}. We obtain the general probability distribution of the <b>Z</b> process by matrix analysis. Numerical illustrations are provided to find the economic order quantity. Journal: Int. J. of Mathematics in Operational Research Pages: 531-549 Issue: 4 Volume: 27 Year: 2024 Keywords: queueing inventory; queue length; inventory level; customer impatience; stationary distribution; expected cost; economic order. File-URL: http://www.inderscience.com/link.php?id=138466 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:4:p:531-549 Template-Type: ReDIF-Article 1.0 Author-Name: Satakshi Author-X-Name-First: Author-X-Name-Last: Satakshi Author-Name: Vishal V. Henry Author-X-Name-First: Vishal V. Author-X-Name-Last: Henry Title: A novel approach to find simple, pragmatic solutions to transportation problems Abstract: The transportation problem is a special case of a linear programming problem (LPP), and its goal is to determine the least/optimal shipping cost that satisfies both the supply and demand constraints simultaneously. An initial basic feasible solution (IBFS) is used to determine the optimal solution. Many methods can be found in the literature to find IBFS. Some of them are Vogel's approximation method (VAM), least cost method (LCM), and North West corner method (NWCM). Among these methods, VAM provides a better solution than other existing methods. This paper proposes a new transportation method (SVAM), inspired by VAM to find IBFS. SVAM performs better than VAM with respect to computation time as it takes very less computation time compared to VAM. The SciLab (V6.1.1) programming is used to implement the algorithm for solving the examples and finding the computation times of all the methods. To establish the correctness of the proposed method, many examples are solved and checked for SVAM and compared with VAM and LCM. Journal: Int. J. of Mathematics in Operational Research Pages: 496-508 Issue: 4 Volume: 27 Year: 2024 Keywords: transportation problem; initial basic feasible solution; IBFS; Vogel's approximation method; VAM; least cost method; LCM. File-URL: http://www.inderscience.com/link.php?id=138467 File-Format: text/html File-Restriction: Access to full text is restricted to subscribers. Handle: RePEc:ids:ijmore:v:27:y:2024:i:4:p:496-508