Template-Type: ReDIF-Article 1.0
Author-Name: G. Ayyappan
Author-X-Name-First: G.
Author-X-Name-Last: Ayyappan
Author-Name: N. Arulmozhi
Author-X-Name-First: N.
Author-X-Name-Last: Arulmozhi
Title: Analysis of MAP/PH/1 retrial queueing system with two-stage vacations with imperfect service, N-policy service, delayed feedback, unreliable server and discouragement customer
Abstract:
In the present study, we investigate a continuous-time single server constant retrial queueing with a limitless system of capacity, two-stage vacations that include single working vacation and multiple vacations with imperfect service, N-policy service, delayed feedback, unreliable server, and discouragement customer. Once the operating environment is empty during a normal busy period, it initially takes a working vacation, during which the server can still provide service but at a slower rate. If the system is empty after this working vacation, the server will take a vacation and stop serving entirely. Otherwise, the server resumes its normal service rate. If there are fewer than N customers in orbit after the vacation period ends, the server resumes normal operation. If not, the server starts another vacation. When approaching the system using the matrix-analytic method, steady-state vector, busy period, and cost analysis are generated for this model. Analytical performance indices are assessed numerically.
Journal: Int. J. of Mathematics in Operational Research
Pages: 81-110
Issue: 1
Volume: 30
Year: 2025
Keywords: multiple vacation; working vacation; unreliable server; imperfect service; delayed feedback.
File-URL: http://www.inderscience.com/link.php?id=144546
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:1:p:81-110
Template-Type: ReDIF-Article 1.0
Author-Name: Dharmesh K. Katariya
Author-X-Name-First: Dharmesh K.
Author-X-Name-Last: Katariya
Author-Name: Kunal T. Shukla
Author-X-Name-First: Kunal T.
Author-X-Name-Last: Shukla
Title: Optimal greening efforts, pricing and inventory strategies for non-instantaneous deteriorating perishable products under price, freshness and green efforts dependent demand with price discount
Abstract:
Nowadays, consumers who are concerned about their health prefer and expect nutritional and fresh sustainable products. Due to their freshness, healthfulness, and environmental friendliness, people are now using sustainable fresh perishable products. The price of products plays an important role in consumers purchasing behaviours. This article considers an inventory model for non-instantaneously deteriorating perishable fresh products with selling price, age of product (freshness), and greening efforts dependent demand. The quality of products reduces due to physical deterioration and degradation of the product's freshness, and hence, retailers offer a discount in the selling price to the buyer during a deteriorating period to boost demand. The objectives of the study are to determine the optimal selling price, an optimal period for replenishment cycle time, and an optimal value of greening efforts cost simultaneously while taking into account retailers total profit maximisation. A mathematical model is developed and validated using numerical results to reflect actual situations. To examine the reliability of the model, sensitivity analysis with regard to parameters is undertaken. Some keys managerial insights are presented, and the article concludes with a discussion of the future scope of related research.
Journal: Int. J. of Mathematics in Operational Research
Pages: 22-45
Issue: 1
Volume: 30
Year: 2025
Keywords: inventory; freshness index; greening efforts; non-instantaneous deterioration; price discount; perishable products.
File-URL: http://www.inderscience.com/link.php?id=144547
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:1:p:22-45
Template-Type: ReDIF-Article 1.0
Author-Name: P. Jayashri
Author-X-Name-First: P.
Author-X-Name-Last: Jayashri
Author-Name: S. Umamaheswari
Author-X-Name-First: S.
Author-X-Name-Last: Umamaheswari
Title: Supplier-retailer-customer trade credit policy for perishables
Abstract:
Perishable items have a relatively short shelf life and degrade naturally. In particular, managing perishable inventory can be challenging, since shortages and wastage are closely associated. Preservation techniques are incorporated to maintain the shelf life of perishable items. The objective of this paper is to optimise the total inventory costs by minimising the deterioration rate and free up working capital for entrepreneurs. Genetic algorithm with one-point crossover, swap mutation and random selection is used to determine the optimal credit period and cycle time by varying different upstream credit periods. An economic order quantity is derived to determine an optimal ordering quantity for a trade credit inventory model. The total profit corresponding to various credit periods and time intervals is illustrated numerically. The effect of changes in key parameters of the optimal solution is investigated using sensitivity analysis. The model is applicable for perishable items like fruits, vegetables, meat, dairy products, and so on which need preservation to increase shelf life.
Journal: Int. J. of Mathematics in Operational Research
Pages: 46-62
Issue: 1
Volume: 30
Year: 2025
Keywords: deteriorating; inventory; perishable; preservation technique; trade credit.
File-URL: http://www.inderscience.com/link.php?id=144548
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:1:p:46-62
Template-Type: ReDIF-Article 1.0
Author-Name: Gustavo Benitez Alvarez
Author-X-Name-First: Gustavo Benitez
Author-X-Name-Last: Alvarez
Author-Name: Rafael Guimarães de Almeida
Author-X-Name-First: Rafael Guimarães de
Author-X-Name-Last: Almeida
Author-Name: Cecília Toledo Hernández
Author-X-Name-First: Cecília Toledo
Author-X-Name-Last: Hernández
Author-Name: Patrícia Alves Pereira de Sousa
Author-X-Name-First: Patrícia Alves Pereira de
Author-X-Name-Last: Sousa
Title: The synthesis of the AHP as a well-posed mathematical problem and matrix norms appropriate for sensitivity analysis via condition number
Abstract:
The analytic hierarchy process (AHP) is a decision-making method, which has as its greatest criticism the rank reversal effect. This paper formulates the fourth step of the AHP (synthesis) as a 'well-posed' mathematical problem. A theorem guarantees the existence of the square condensed original formulation for the AHP. This means that any decision problem modelled by AHP with a different number of alternatives and criteria can be condensed into a model with an equal number of alternatives and criteria without loss of condensed information. This condensed formulation can be better conditioned than the original rectangular formulation of the AHP. The square condensed equivalent formulation is also a 'well-posed' mathematical problem. The concepts are applied to two practical cases from the literature, and sensitivity analysis is performed. Four classical matrix norms are reformulated to obtain theoretical bounds for the error estimate closer to actual error.
Journal: Int. J. of Mathematics in Operational Research
Pages: 111-134
Issue: 1
Volume: 30
Year: 2025
Keywords: multiple criteria analysis; rank reversal; linear systems of equations; sensitivity analysis.
File-URL: http://www.inderscience.com/link.php?id=144549
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:1:p:111-134
Template-Type: ReDIF-Article 1.0
Author-Name: Siti Salwana Mamat
Author-X-Name-First: Siti Salwana
Author-X-Name-Last: Mamat
Author-Name: Siti Rahmah Awang
Author-X-Name-First: Siti Rahmah
Author-X-Name-Last: Awang
Author-Name: Tahir Ahmad
Author-X-Name-First: Tahir
Author-X-Name-Last: Ahmad
Title: Fuzzy weak autocatalytic set for decision making and its application to the project manager selection
Abstract:
In decision-making procedures, the comparison of alternatives is often necessary to determine the most suitable option among a set of choices. One commonly used approach is pairwise comparison, where each alternative is compared to every other alternative based on certain criteria. FWACS method offers a way to represent the pairwise comparisons of alternatives as a directed graph with fuzzy edges. The FWACS is a technique used to address problems involving multiple criteria. In this study, a new ranking approach using FWACS is implemented on a previously published MCDM problem. The purpose of this implementation is to showcase the effectiveness of the FWACS method in addressing decision problems that involve multiple criteria.
Journal: Int. J. of Mathematics in Operational Research
Pages: 63-80
Issue: 1
Volume: 30
Year: 2025
Keywords: fuzzy weak autocatalytic set; FWACS; decision making; project manager selection; ranking; graph theory.
File-URL: http://www.inderscience.com/link.php?id=144550
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:1:p:63-80
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 batch arrival bulk service priority queue with multiple vacation, close down, setup, differentiate breakdown, and repair
Abstract:
This paper is a steady state analysis of a single server non-preemptive priority queueing system under multiple vacation, close down, setup, differentiate breakdown, and repair. Priority and ordinary customers arrive according to Poisson processes, and their service time based on the general distribution. The server constantly offers a single service for priority and bulk service for ordinary customers. Ordinary customers will only be served if the batch size is more than 'a' or less than or equal to 'b'. We compute the Laplace transforms of the time-dependent probabilities of system states using the probability generating function and supplementary variable technique. Numerical results are obtained which are also examined to facilitate the sensitivity analysis of system descriptions.
Journal: Int. J. of Mathematics in Operational Research
Pages: 1-21
Issue: 1
Volume: 30
Year: 2025
Keywords: bulk service; priority queues; batch arrivals; differentiate breakdown; multiple vacation; closedown; setup.
File-URL: http://www.inderscience.com/link.php?id=144552
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:1:p:1-21
Template-Type: ReDIF-Article 1.0
Author-Name: C. Vijayan
Author-X-Name-First: C.
Author-X-Name-Last: Vijayan
Author-Name: R. Manimaran
Author-X-Name-First: R.
Author-X-Name-Last: Manimaran
Author-Name: N. Racshitha
Author-X-Name-First: N.
Author-X-Name-Last: Racshitha
Title: Fractional Black-Scholes equation described by the conformable fractional derivative with three different methods
Abstract:
This study deals with the conformable fractional derivative (CFD) operator and three different methods for solving the fractional Black-Scholes equation (FBSE) and the generalised fractional Black-Scholes equation (GFBSE). They are the variation iteration method (VIM), reduced differential transform method (RDTM) and homotopy analysis method (HAM). The redefined proposed methods are the conformable variation iteration method (CVIM), conformable fractional reduced differential transform method (CRDTM), and conformable homotopy analysis method (CHAM). Finally, images and tables are used to display the results of FBSE and GFBSE. These methods can be used to accurately solve both the fractional Black-Scholes equation and the generalised fractional Black-Scholes equation.
Journal: Int. J. of Mathematics in Operational Research
Pages: 135-151
Issue: 2
Volume: 30
Year: 2025
Keywords: Black-Scholes equation; BSE; conformable fractional derivative; CFD; variational iteration method; VIM; reduced differential transform method; RDTM; homotopy analysis methods; HAM.
File-URL: http://www.inderscience.com/link.php?id=145604
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:2:p:135-151
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: A two-server tandem queueing model with Markovian arrival process, phase type service, working vacation, feedback, re-service, unreliable server, interrupted closedown and customers intolerance
Abstract:
This paper intends to focus on two-server tandem queue with working vacation, feedback, re-service, unreliable server, interrupted closedown and impatient customers. Input flow of customers arrival is modelled using a Markovian arrival process (MAP) and the service time is considered to follow a phase type distribution. Customers impatience has been studied under phenomena of reneging and balking of this model. The essential and sufficient conditions for system stability is found. By using the matrix analytical method, the queueing model's steady-state probability distribution was derived. Additionally, we derived some performance indicators for the model. Finally, certain numerical examples were used to evaluate the impact of system parameters both numerically and graphically.
Journal: Int. J. of Mathematics in Operational Research
Pages: 206-250
Issue: 2
Volume: 30
Year: 2025
Keywords: Markovian arrival process; MAP; phase type service; working vacation; re-service; interrupted closedown; reneging; balking; breakdown; repair.
File-URL: http://www.inderscience.com/link.php?id=145605
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:2:p:206-250
Template-Type: ReDIF-Article 1.0
Author-Name: Abdulkareem Lado Ismail
Author-X-Name-First: Abdulkareem Lado
Author-X-Name-Last: Ismail
Author-Name: Abdulhadi Aminu
Author-X-Name-First: Abdulhadi
Author-X-Name-Last: Aminu
Author-Name: Ibrahim Yusuf
Author-X-Name-First: Ibrahim
Author-X-Name-Last: Yusuf
Title: Copula approach to predict reliability factors of a wide range communication system
Abstract:
Information can be passed between people, groups, gadgets, organisations, continents, and the rest of the globe through communication. Focusing on the aforementioned, this study takes into account a communication system made up of five subsystems: three servers, two switches, a router, and three clients, which are all grouped together in a series-parallel categorisation. Given that this system is operational, failure is inevitable. As a result, the failure of these subsystems appears to be constant and in accordance with the exponential function, general and copula repairs are offered to fix both partial and whole system failures. The mathematical transition figure of the system is used to construct partial differential equations, which are then solved with the use of a supplementary variable and the Laplace transformation method. The expressions for availability, reliability, mean time to failure (MTTF), sensitivity, and costs are realised using a mathematical tool. The study's findings are supported by specific examples.
Journal: Int. J. of Mathematics in Operational Research
Pages: 185-205
Issue: 2
Volume: 30
Year: 2025
Keywords: availability; reliability; mean time to failure; MTTF; sensitivity; cost; communication; computer.
File-URL: http://www.inderscience.com/link.php?id=145606
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:2:p:185-205
Template-Type: ReDIF-Article 1.0
Author-Name: R.S. Yohapriyadharsini
Author-X-Name-First: R.S.
Author-X-Name-Last: Yohapriyadharsini
Author-Name: V. Suvitha
Author-X-Name-First: V.
Author-X-Name-Last: Suvitha
Author-Name: Rakesh Kumar
Author-X-Name-First: Rakesh
Author-X-Name-Last: Kumar
Title: A queueing system with heterogeneous arrivals, two kinds of vacations and impatient customers
Abstract:
We consider an <i>M</i>/ <i>M</i>/1 queueing system with two kinds of vacations and impatient customers. The server begins the 1st kind of vacation each time the system becomes empty after serving all the customers. If the system is empty, when returning from this vacation it takes the 2nd kind of vacation. When the server comes back from either 1st kind or 2nd kind of vacation, if there is at least one customer in the system, the server immediately starts the service. If the server is busy or on 1st kind of vacation when a customer arrives at the system, it activates an impatience timer. If the customer's service has not been finished before the customer's timer perishes, the customer leaves the system and never returns. The balance equations of the model are all derived using a state-transition diagram. Probability generating functions (PGFs) technique has been used to derive the steady-state probabilities. Various measures of performance are presented and numerical illustrations are also provided.
Journal: Int. J. of Mathematics in Operational Research
Pages: 152-166
Issue: 2
Volume: 30
Year: 2025
Keywords: busy state; vacations; steady state; performance measures.
File-URL: http://www.inderscience.com/link.php?id=145607
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:2:p:152-166
Template-Type: ReDIF-Article 1.0
Author-Name: Abdelkrim Rezzag
Author-X-Name-First: Abdelkrim
Author-X-Name-Last: Rezzag
Author-Name: Mohand Ouamer Bibi
Author-X-Name-First: Mohand Ouamer
Author-X-Name-Last: Bibi
Author-Name: Abdelhek Laouar
Author-X-Name-First: Abdelhek
Author-X-Name-Last: Laouar
Title: Reduction of bounded variables in integer linear programming problems
Abstract:
In this paper, we suggest a new technique for reducing the number of variables in general integer linear programming problems with bounded variables. This technique involves fixing certain variables of the problem's optimal solution at one of their bounds, either lower or upper. A numerical illustrative example is presented, numerical experiments have been conducted to compare the execution time of the original problem with the execution time of the reduced problem and the presolving procedure.
Journal: Int. J. of Mathematics in Operational Research
Pages: 251-265
Issue: 2
Volume: 30
Year: 2025
Keywords: integer linear programming; bounded variables; presolving procedure; numerical results and comparisons.
File-URL: http://www.inderscience.com/link.php?id=145608
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:2:p:251-265
Template-Type: ReDIF-Article 1.0
Author-Name: Sangeetha Nandigam
Author-X-Name-First: Sangeetha
Author-X-Name-Last: Nandigam
Author-Name: Perumali Sundarayya
Author-X-Name-First: Perumali
Author-X-Name-Last: Sundarayya
Title: Graph theory for data cryptography security
Abstract:
This paper explores the use of graph theory in data cryptography security, with a focus on encryption and decryption methods. The proposed approach utilises the double transposition column method with a graph as a key to enhance security and flexibility for various applications. To further improve the efficiency and effectiveness of the proposed algorithm, we introduce GEO and SMO optimisation techniques. GEO optimisation leverages geometric features of the graph to improve the security of the encryption process, while SMO optimisation uses support vector machines to enhance the accuracy of the decryption process. Experimental results show that the proposed approach with GEO and SMO optimisation outperforms traditional encryption methods in terms of security, efficiency, and accuracy. The use of graph theory and optimisation techniques provides a promising solution for secure data transmission and storage in various applications, including banking, electronic commerce, electronic voting, and more.
Journal: Int. J. of Mathematics in Operational Research
Pages: 167-184
Issue: 2
Volume: 30
Year: 2025
Keywords: graph theory; cryptography; encryption; decryption; secure data transmission; golden eagle optimiser; GEO; slime mould optimise; SMO.
File-URL: http://www.inderscience.com/link.php?id=145641
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:2:p:167-184
Template-Type: ReDIF-Article 1.0
Author-Name: Jerry L. Shaw
Author-X-Name-First: Jerry L.
Author-X-Name-Last: Shaw
Author-Name: Donovan Fuqua
Author-X-Name-First: Donovan
Author-X-Name-Last: Fuqua
Author-Name: Hansuk Sohn
Author-X-Name-First: Hansuk
Author-X-Name-Last: Sohn
Author-Name: Manuel Ivan Rodriguez Borbon
Author-X-Name-First: Manuel Ivan Rodriguez
Author-X-Name-Last: Borbon
Title: Introduction of an arc rank order statistic for analysis of optimal solutions in travelling salesman problems
Abstract:
This research provides an empirically derived and previously unreported insight into the actual composition and common features of optimal solutions in travelling salesman problems (TSPs). One unreported characteristic of these solutions is the frequency with which a vertex is connected to another relatively near or distant vertex. Based on a mathematical question on optimal solution arc lengths, we introduce an arc rank statistic and use it to analyse optimal solutions for a range of standard TSPs. The resulting analysis shows, with few exceptions, that the frequency with which low-ranked arcs appear is a decreasing function. Further, the frequency distributions of arc ranks generally have fat tails. Log/log transforms of the frequency distributions were analysed to show linear relations; suggesting that the distribution of arc ranks in optimal TSP solutions generally follows a power law distribution. This knowledge suggests that statistical information about a solution may be sufficient to inform an observer about the quality of a solution.
Journal: Int. J. of Mathematics in Operational Research
Pages: 308-328
Issue: 3
Volume: 30
Year: 2025
Keywords: optimisation; travelling salesman problem; TSP; graph theory; edge ranking.
File-URL: http://www.inderscience.com/link.php?id=145754
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:3:p:308-328
Template-Type: ReDIF-Article 1.0
Author-Name: Justin Chirima
Author-X-Name-First: Justin
Author-X-Name-Last: Chirima
Author-Name: Frank Ranganai Matenda
Author-X-Name-First: Frank Ranganai
Author-X-Name-Last: Matenda
Author-Name: Mabutho Sibanda
Author-X-Name-First: Mabutho
Author-X-Name-Last: Sibanda
Title: Pricing a guaranteed minimum maturity benefit in uncertain markets
Abstract:
This paper examines the problem of pricing a guaranteed minimum maturity benefit (GMMB) in uncertain markets. Several uncertainties are encountered in financial markets. The pricing process of a GMMB does not exhibit randomness alone, but also non-random uncertainties. We introduce uncertainty theory into pricing a GMMB. The assumption is that the stock price process, <i>S<SUB align="right"><SMALL>t</SMALL></SUB></i>, interpreted as an index for the fund assets, is driven by an uncertain differential equation (UDE). The solution to this UDE is regarded as a geometric canonical Liu process. We apply the UDE in pricing the GMMB problem and assume that the stock price evolution is driven by the canonical Liu process. Utilising the uncertain Liu option pricing approach, we formulate and examine a framework for pricing a GMMB in uncertain markets. Numerical computations are exemplified as well. The results of the study show that this approach is capable of pricing a GMMB.
Journal: Int. J. of Mathematics in Operational Research
Pages: 295-307
Issue: 3
Volume: 30
Year: 2025
Keywords: uncertainty; uncertainty distribution; canonical Liu process; guaranteed minimum maturity benefit; GMMB; insurance policyholders; stock price.
File-URL: http://www.inderscience.com/link.php?id=145755
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:3:p:295-307
Template-Type: ReDIF-Article 1.0
Author-Name: Reza Keykhaei
Author-X-Name-First: Reza
Author-X-Name-Last: Keykhaei
Title: Optimal mean-variance portfolio selection with uncertain time horizon in a regime-switching market when asset returns are market path-dependent
Abstract:
In a financial market, the state of the underlying economy and investors' mood affect market trends and consequently asset prices movements. Regime-switching models are used to describe changes in market states and trends. The main assumption in regime-switching models is that asset returns depend on the current state of the market. We generalise this assumption to the case where market states in the past, as well as the current state, affect asset returns. In fact, we assume that asset returns are market path-dependent. Under this assumption, we study a multi-period mean-variance portfolio selection problem in a Markovian regime-switching market when the time horizon is uncertain. Using the stochastic dynamic programming approach, we obtain the path-dependent optimal portfolio strategy and the mean-variance efficient frontier in a closed form. We show that the results obtained under conventional regime-switching model, can be obtained as special cases of the present model.
Journal: Int. J. of Mathematics in Operational Research
Pages: 392-414
Issue: 3
Volume: 30
Year: 2025
Keywords: mean-variance portfolio selection; regime-switching; market path-dependent; uncertain time horizon; stochastic dynamic programming.
File-URL: http://www.inderscience.com/link.php?id=145756
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:3:p:392-414
Template-Type: ReDIF-Article 1.0
Author-Name: Sunil B. Bhoi
Author-X-Name-First: Sunil B.
Author-X-Name-Last: Bhoi
Author-Name: Jayesh M. Dhodiya
Author-X-Name-First: Jayesh M.
Author-X-Name-Last: Dhodiya
Title: Uncertain multi-objective student project assignment problem by fuzzy programming technique
Abstract:
This paper presents mathematical 0-1 integer programming model of uncertain multi-objective student project assignment problem based on uncertain preferences of students and supervisor over projects or pairs of student and project. To develop this uncertain model, preferences are computed based on supervisor feedback and student result analysis, which are uncertain in nature. Two ranking criteria are utilised to deal with these uncertain preferences, which are expected value and optimistic value. Thereafter, uncertainty theory is applied to these uncertain model to transform uncertain models into deterministic form. Fuzzy programming technique with linear and exponential membership functions is utilised to solve deterministic multi-objective models and results are obtained using LINGO software. To check the strength and efficiency of proposed models, numerical data-based case is studied and results are discussed.
Journal: Int. J. of Mathematics in Operational Research
Pages: 329-349
Issue: 3
Volume: 30
Year: 2025
Keywords: student project assignment; multi-objective optimisation; 0-1 integer programming; uncertain programming; fuzzy programming technique.
File-URL: http://www.inderscience.com/link.php?id=145757
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:3:p:329-349
Template-Type: ReDIF-Article 1.0
Author-Name: Zuhair A. Al-Hemyari
Author-X-Name-First: Zuhair A.
Author-X-Name-Last: Al-Hemyari
Author-Name: Jamal N. Al Abbasi
Author-X-Name-First: Jamal N. Al
Author-X-Name-Last: Abbasi
Title: On the numerical solution and mathematical modelling of the global warming data from the years 1970 to 1994 and from 1995 to 2019
Abstract:
In this paper, the numerical method and modelling of a big data set related to global warming are developed using several techniques. The data of daily temperatures is collected from several cities over a 50-year period. To study the existence 8of the global warming precisely, the collected data is to be divided into two equal secondary periods. In addition, several methods of analysis and modelling will be applied in this paper. The analytical and modelling methods applied to the global warming in this paper are unique. In addition, the results on this paper are comprehensive, prominent and describe the essence of the problem and its perspective in the future. In specific, the results have shown that the changes occurring in the climate in the studied cities are significant and more severe than the changes occurring in the past (before 1970) and in other countries of Middle East region.
Journal: Int. J. of Mathematics in Operational Research
Pages: 267-294
Issue: 3
Volume: 30
Year: 2025
Keywords: numerical solution; modelling; global warming; fitting; mixture distributions; EM algorithm.
File-URL: http://www.inderscience.com/link.php?id=145758
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:3:p:267-294
Template-Type: ReDIF-Article 1.0
Author-Name: G. Ayyappan
Author-X-Name-First: G.
Author-X-Name-Last: Ayyappan
Author-Name: K. Thilagavathy
Author-X-Name-First: K.
Author-X-Name-Last: Thilagavathy
Author-Name: Rakesh Kumar
Author-X-Name-First: Rakesh
Author-X-Name-Last: Kumar
Title: Cost optimisation of MMAP/PH(1), PH(2)/1 pre-emptive priority retrial queueing model with standby server, orbital search, server breakdowns, phase type repairs and impatient customers
Abstract:
In this paper, we examine a single server queueing model in which priority customers arrive based on the marked Markovian arrival process (MMAP) and their corresponding service process is based on phase-type (PH) distribution. The primary server provides service to high priority or low priority customers, who may be affected by a breakdown, the standby server takes over service until the primary server has been repaired. Whenever either the primary or the standby server becomes idle, an orbital search of low priority customers is performed. We have established the stability condition for the model. Utilising the matrix-analytic method (MAM), the model is solved under steady state. Further, the busy period analysis of the model is carried out. Finally, the cost model is presented and the total cost of the system is analysed with the change in system parameters.
Journal: Int. J. of Mathematics in Operational Research
Pages: 350-391
Issue: 3
Volume: 30
Year: 2025
Keywords: MMAP; PH-distribution; standby server; impatient customers; busy period analysis; retrials.
File-URL: http://www.inderscience.com/link.php?id=145759
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:3:p:350-391
Template-Type: ReDIF-Article 1.0
Author-Name: Fastel Chipepa
Author-X-Name-First: Fastel
Author-X-Name-Last: Chipepa
Author-Name: Mavis Pararai
Author-X-Name-First: Mavis
Author-X-Name-Last: Pararai
Author-Name: Wilbert Nkomo
Author-X-Name-First: Wilbert
Author-X-Name-Last: Nkomo
Title: New Weibull-Pareto Poisson distribution: properties, actuarial measures and applications
Abstract:
A new power series distribution called the new Weibull-Pareto Poisson distribution is developed. The proposed model is very flexible in modelling heavy-tailed data. Some of the statistical properties are also derived and these include moments, moment generating function, and Rényi entropy. We derive the maximum likelihood estimates of the model parameters. We also derive risk measures, conduct and present their numerical simulations. Numerical simulations results for actuarial risk measures show that the new developed model is heavy-tailed compared to its nested models and some competing models. A Monte Carlo simulation study was also conducted to evaluate the consistency of the model parameter estimates. The results from this study confirm that the developed model produce consistent and reliable parameter estimates. Two heavy-tailed real data examples are used to demonstrate the usefulness of the new proposed model.
Journal: Int. J. of Mathematics in Operational Research
Pages: 415-434
Issue: 4
Volume: 30
Year: 2025
Keywords: Weibull-Pareto distribution; power series distribution; maximum likelihood estimation; risk measures; Poisson distribution.
File-URL: http://www.inderscience.com/link.php?id=146353
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:4:p:415-434
Template-Type: ReDIF-Article 1.0
Author-Name: Palak Mehta
Author-X-Name-First: Palak
Author-X-Name-Last: Mehta
Author-Name: Madhu Jain
Author-X-Name-First: Madhu
Author-X-Name-Last: Jain
Title: Joining strategy for double orbit retrial queue with imperfect service and vacation under N-policy
Abstract:
Optimal joining policy for Markovian retrial queueing system operating under N-policy and having ordinary and premium orbits, has been investigated. There is provision of additional service to the unsatisfactory ordinary orbit customers whereas unsatisfactory executive orbit customers may re-join the queue as a feedback customer. The proposed queueing system is investigated by implementing probability generating function (PGF) approach and evaluating various performance measures. Numerical experiments are performed to validate the analytical metrics obtained. The adaptive neuro fuzzy inference system (ANFIS) approach has also been implemented to authenticate the feasibility of intelligence computing for various metrics. The optimal joining probability is obtained by maximising the profit function value using particle swarm optimisation (PSO). The sensitivity of the queueing indices along with cost function has also examined by conducting the numerical simulation.
Journal: Int. J. of Mathematics in Operational Research
Pages: 435-469
Issue: 4
Volume: 30
Year: 2025
Keywords: double orbit retrial queue; N-policy; imperfect service; feedback; joining strategy; particle swarm optimisation; PSO.
File-URL: http://www.inderscience.com/link.php?id=146354
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:4:p:435-469
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: Integrated management and optimisation of vaccination and treatment processes in a batching system with observation and limited space
Abstract:
This study examines a single-server system that incorporates multiple vacations. Customer arrivals adhere to a Markovian arrival process (MAP), and two types of service are applied, both following a phase-type distribution. Upon arrival, customers are grouped into batches of size <i>L</i>. Following service, customers enter an observation room, waiting for a predetermined duration. Subsequently, customers either leave the system if comfortable, or they join queue 2 for further service if not. Queue 2 follows a non-preemptive policy guided by the server. In the absence of customers, the server experiences multiple vacations following an exponential distribution. The server remains idle if customers are in the observation hall or if the number of customers in queue 1 is below <i>L</i>. This intricate system is represented as a quasi-birth-and-death (QBD) process, which we analyse using matrix-based methods. Also analysing the busy period, invariant probability, and performance metrics through graphical and numerical approaches.
Journal: Int. J. of Mathematics in Operational Research
Pages: 60-94
Issue: 1
Volume: 31
Year: 2025
Keywords: Markovian arrival process; MAP; phase type service; multiple vacation; bulk service; non-preemptive priority.
File-URL: http://www.inderscience.com/link.php?id=146355
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:1:p:60-94
Template-Type: ReDIF-Article 1.0
Author-Name: Thatayaone Moakofi
Author-X-Name-First: Thatayaone
Author-X-Name-Last: Moakofi
Author-Name: Agolame Puoetsile
Author-X-Name-First: Agolame
Author-X-Name-Last: Puoetsile
Author-Name: Broderick Oluyede
Author-X-Name-First: Broderick
Author-X-Name-Last: Oluyede
Title: A new heavy-tailed generalised exponentiated half logistic-G distribution with actuarial measures and applications
Abstract:
This work introduces and investigates the new heavy-tailed generalised exponentiated half logistic-G (HT-GEN-EHL-G) family of distributions. The study involves the derivation and analysis of statistical properties associated with HT-GEN-EHL-G distribution. Employing the maximum likelihood estimation technique, we estimate model parameters and evaluate the consistency of these estimators through simulation studies. Additionally, we develop actuarial metrics (risk measures) tailored to this distribution. The practical utility of the HT-GEN-EHL-G family of distributions is demonstrated through the analysis of four real-life datasets from diverse fields. These applications emphasise the significance and versatility of the newly introduced HT-GEN-EHL-G family of distributions.
Journal: Int. J. of Mathematics in Operational Research
Pages: 501-538
Issue: 4
Volume: 30
Year: 2025
Keywords: heavy-tailed distribution; exponentiated half-logistic-G distribution; estimation; applicability.
File-URL: http://www.inderscience.com/link.php?id=146356
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:4:p:501-538
Template-Type: ReDIF-Article 1.0
Author-Name: Joshua Sunday
Author-X-Name-First: Joshua
Author-X-Name-Last: Sunday
Author-Name: Richard Olatokunbo Akinola
Author-X-Name-First: Richard Olatokunbo
Author-X-Name-Last: Akinola
Author-Name: Joshua Amawa Kwanamu
Author-X-Name-First: Joshua Amawa
Author-X-Name-Last: Kwanamu
Author-Name: Dominic Raymond
Author-X-Name-First: Dominic
Author-X-Name-Last: Raymond
Title: Optimised variable step-size algorithm for the solution of dynamical systems
Abstract:
This study focuses on the formulation of optimised variable step-size algorithm (OVSSA) for the solution of dynamical systems. In order to minimise the number of iterations and number of steps taken as well as improve the accuracy of the proposed algorithm, an embedded strategy was deployed in formulating the method using variable stepsize mode. One of the major advantages of the proposed OVSSA is that the algorithm automatically fine-tunes (or adjusts) the stepsize to suit the problem under consideration according to the variable stepsize strategy defined by the authors. Convergence properties of the OVSSA were also analysed theoretically in order to validate its stability and computational reliability. The OVSSA was employed in solving dynamical systems like the Van der Pol, Genesio-Tesi, Kepler and Lorenz systems. The results generated as a result of the application of the OVSSA on dynamical systems clearly showed that the method is convergent and computationally reliable.
Journal: Int. J. of Mathematics in Operational Research
Pages: 470-500
Issue: 4
Volume: 30
Year: 2025
Keywords: algorithm; chaos; convergence; dynamical system; fixed stepsize; initial value problem; optimise; stability; stiffness; variable stepsize.
File-URL: http://www.inderscience.com/link.php?id=146357
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Handle: RePEc:ids:ijmore:v:30:y:2025:i:4:p:470-500
Template-Type: ReDIF-Article 1.0
Author-Name: Kamlesh Kumar
Author-X-Name-First: Kamlesh
Author-X-Name-Last: Kumar
Author-Name: Madhu Jain
Author-X-Name-First: Madhu
Author-X-Name-Last: Jain
Title: A queueing model with balking, server vacation and working breakdown
Abstract:
This paper focuses on a single server queueing model that includes customer's balking, server vacation, and working breakdown. When there is no customer in the system or the system becomes empty, the server goes on a vacation and returns back when one or more customer available in the system. The server resumes service to the customers accumulated during its vacation period. There is always the possibility of a server breakdown while providing services to the customers, which may result in slower service rate. Slower service rate is considered as working breakdown state of the server or a defective mode of service. If the server is providing normal or defective service, customers may balk. For the system states, some practicable performance measures such as average number of customers in the system, average total cost function, and system throughput have been established for the various system states.
Journal: Int. J. of Mathematics in Operational Research
Pages: 41-59
Issue: 1
Volume: 31
Year: 2025
Keywords: Markovian queue; balking; server vacation; working breakdown; probability generating function; PGF; cost function.
File-URL: http://www.inderscience.com/link.php?id=146358
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:1:p:41-59
Template-Type: ReDIF-Article 1.0
Author-Name: Nabil Ait Yala
Author-X-Name-First: Nabil Ait
Author-X-Name-Last: Yala
Author-Name: Badredine Issaadi
Author-X-Name-First: Badredine
Author-X-Name-Last: Issaadi
Author-Name: Karim Abbas
Author-X-Name-First: Karim
Author-X-Name-Last: Abbas
Title: Strong perturbation bounds for the stationary distribution of the main multi-server retrial queue model
Abstract:
Many queuing models are represented by Markov chains with infinite countable state space and we will often want to know their stationary distributions in order to deduce their characteristics, but the calculation of these distributions is generally difficult, if not impossible, and do not have closed form solutions because of the infinite number of equations to solve. This is why researchers try to obtain approximations that converge quickly to these distributions. Perturbation theory for Markov chains addresses the question of what impact can occur on a stationary distribution of a Markov chain if its transition matrix is slightly disturbed. In this paper, we use the strong stability approach based on the drift condition to establish analytic error bounds for the generalised truncation of a main multi-server retrial queue model. At the end of this article, we give numerical examples in order to show the quality of the error bounds obtained.
Journal: Int. J. of Mathematics in Operational Research
Pages: 1-40
Issue: 1
Volume: 31
Year: 2025
Keywords: Markov chains; perturbation theory; truncation; strong stability; Lyapunov function; drift condition; retrial queueing systems.
File-URL: http://www.inderscience.com/link.php?id=146359
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:1:p:1-40
Template-Type: ReDIF-Article 1.0
Author-Name: Oladimeji Samuel Sowole
Author-X-Name-First: Oladimeji Samuel
Author-X-Name-Last: Sowole
Title: Solving the vehicle routing problem with search algorithms: a comparative analysis
Abstract:
The vehicle routing problem (VRP) is a well-known optimisation problem in operations research, with applications in logistics, transportation, and supply chain management. This paper offers a comparative analysis of search algorithms used to solve the VRP, focusing on their strengths and weaknesses. It introduces the VRP and its variants, highlighting the challenges and constraints involved. Various search algorithms, such as genetic algorithms, simulated annealing, and ant colony optimisation, are examined, discussing their principles, advantages, and limitations. Real-world case studies in package delivery, waste collection, and emergency response demonstrate the application of these algorithms. Factors influencing algorithm performance, including problem size, complexity, and parameters, are discussed. Recommendations for selecting appropriate search algorithms for different VRP instances are provided. The paper aims to provide readers with a comprehensive understanding of using search algorithms to solve the VRP, aiding decision-making in similar optimisation problems.
Journal: Int. J. of Mathematics in Operational Research
Pages: 110-141
Issue: 1
Volume: 31
Year: 2025
Keywords: vehicle routing problem; VRP; search algorithms; metaheuristics; ant colony optimisation; ACO; particle swarm optimisation; PSO; genetic algorithms; GAs; Tabu search; simulated annealing; heuristics; routing strategies.
File-URL: http://www.inderscience.com/link.php?id=146360
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:1:p:110-141
Template-Type: ReDIF-Article 1.0
Author-Name: N. Sujatha
Author-X-Name-First: N.
Author-X-Name-Last: Sujatha
Author-Name: G.V.S.R. Deekshitulu
Author-X-Name-First: G.V.S.R.
Author-X-Name-Last: Deekshitulu
Title: A study on transient solution of fractional M/M/2 queue with homogeneous and heterogeneous servers
Abstract:
In queuing models with multiple servers, all the servers may not be completely active and may not work with same efficiency. Keeping this in view, a multiserver fractional queue with heterogeneous servers has been analysed in the present paper. Transient state probablities and also performance measures of the model such as average number of customers in the system, average number of customers in the queue, etc. have been computed. Variations in these performance measures have been observed both numerically and graphically with respect to partial activity of the server. Further, efficiency of transient <i>M</i>/<i>M</i>/2 fractional queueing model consisting of heterogeneous servers is compared with efficiency of transient <i>M</i>/<i>M</i>/2 fractional queuing model with homogeneous servers.
Journal: Int. J. of Mathematics in Operational Research
Pages: 95-109
Issue: 1
Volume: 31
Year: 2025
Keywords: transient solution; fractional queue; Mittag-Leffler function; heterogeneous servers.
File-URL: http://www.inderscience.com/link.php?id=146361
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:1:p:95-109
Template-Type: ReDIF-Article 1.0
Author-Name: Meenakshi Sharma
Author-X-Name-First: Meenakshi
Author-X-Name-Last: Sharma
Author-Name: Sameer Sharma
Author-X-Name-First: Sameer
Author-X-Name-Last: Sharma
Author-Name: Nidhi Joshi
Author-X-Name-First: Nidhi
Author-X-Name-Last: Joshi
Title: A multi-machine bicriteria flow shop scheduling with sequence dependent setup time
Abstract:
Bicriteria flow shop scheduling problem with sequence dependent setup time (BPFSSP/SDST) is addressed in this paper. The objective of scheduling problem is to minimise weighted sum of makespan and system utilisation time, when both criteria are equal weighted. To solve the referred scheduling problem in small size machine-job environment, a mixed-integer programming model is developed and implemented. Since permutation flow shop scheduling problem with SDST is NP-complete in nature, therefore, the heuristic approach based on Nawaz, Enscore, Ham (NEH) neighbourhood structure and metaheuristic approach of hybrid iterated greedy algorithm with delay time, are proposed and implemented to optimise aforementioned scheduling bicriteria. The computation experiment is carried out to evaluate the performance of all developed heuristics and metaheuristics on varying size job-machine environment. The comparative analysis reported with response variable average relative percentage deviation (ARPD) verifies the effectiveness of proposed computation techniques over existing one's in solving the referred scheduling problem.
Journal: Int. J. of Mathematics in Operational Research
Pages: 182-215
Issue: 2
Volume: 31
Year: 2025
Keywords: scheduling; bicriteria; sequence dependent setup time; iterated greedy algorithms; local search.
File-URL: http://www.inderscience.com/link.php?id=147021
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:2:p:182-215
Template-Type: ReDIF-Article 1.0
Author-Name: S. Maragathasundari
Author-X-Name-First: S.
Author-X-Name-Last: Maragathasundari
Author-Name: K. Karthikeyan
Author-X-Name-First: K.
Author-X-Name-Last: Karthikeyan
Title: Recital facts of M X/G/1 queues with setup time, phases of service, and vacation
Abstract:
Researching group queueing systems that combine setup time and vacation work stages into a single server service is the aim of this <i>M</i><SUP align="right"><SMALL><i>X</i></SMALL></SUP>/<i>G</i>/1 queueing study. In this queueing system, arrival time follows the Poisson distribution and service time follows a general distribution. The model is well equipped with setup time phases to do both a key maintenance task during the break and the necessary server pre-processing job. Additionally, the system is unavailable during the disruption because service disruptions are inevitable. The aforementioned mathematical queueing problem is solved using the supplemental variable technique, and the system's performance metrics are obtained. From the calculated probability generation function of queue size at a random time for the different system states, we extract performance measures such as the server's probability of idle time, the utilisation factor, the average queue length, and the average wait time. It is backed by methods for numerical portrayal, graphic representation, and real-world applications. This paradigm is entirely legal due to its practical use and algebraic demarcation mechanism. The graph provides precise readings of the implemented limitations.
Journal: Int. J. of Mathematics in Operational Research
Pages: 241-262
Issue: 2
Volume: 31
Year: 2025
Keywords: non-Markovian queueing problem; batch arrival; supplementary variable technique; setup time stages; vacation; service interruption.
File-URL: http://www.inderscience.com/link.php?id=147022
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:2:p:241-262
Template-Type: ReDIF-Article 1.0
Author-Name: Mahmoud Dehghan Nayeri
Author-X-Name-First: Mahmoud Dehghan
Author-X-Name-Last: Nayeri
Author-Name: Roghayeh Haddad
Author-X-Name-First: Roghayeh
Author-X-Name-Last: Haddad
Title: Optimal joint dynamic pricing and inventory replenishment policy for perishable products with freshness-sensitive demand
Abstract:
This paper aims to propose a mathematical model for joint pricing and inventory replenishment decisions of a retailer who faces a freshness-sensitive demand. The retailer has the option to submit fast replenishment orders with lower profit margins to other peer retailers within the short lifecycle of the perishable products in addition to the regular replenishment orders that take place at the start of the lifecycle. Also, the retailer can sell the end-of-season perished product at lower prices. The proposed model is capable of handling different types of demand and freshness functions. To show the applicability of the proposed model, it is used to optimise pricing, discounting, inventory, and replenishment decisions of two product categories of a major retailer in Iran using real-world data. Results indicate that the retailer should pursue a specific joint pricing and replenishment strategy in each product category. A sensitivity analysis is also performed for initial inventory and initial price for each of the categories. Results revealed that each of the factors contributes differently to the total profit in each category. The total profit showed a different level of sensitivity to changes in the two aforementioned tweaked parameters.
Journal: Int. J. of Mathematics in Operational Research
Pages: 263-281
Issue: 2
Volume: 31
Year: 2025
Keywords: dynamic pricing; inventory management; perishable products; inventory replenishment.
File-URL: http://www.inderscience.com/link.php?id=147023
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:2:p:263-281
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 non-Markovian batch arrival retrial queue with priority services, vacation and vacation interruption under random environment, negative arrival, immediate feedback, differentiate breakdown, and repair
Abstract:
In this study, we construct a single server retrial queueing system with two classes of customers, vacation and vacation interruption under random environment, negative arrival, immediate feedback, differentiate breakdown and repair. Customers can be divided into two distinct categories, such as priority and ordinary. This concept emphasises non-preemptive priority discipline. Customers arrive according to Poisson processes for priority and ordinary. Both priority and regular customers can always receive the same service from the server, which is distributed arbitrarily. In this study, the time-dependent probabilities of system states using Laplace transforms are computed using the probability generating function and the supplementary variable technique. Numerical results are obtained which are also examined to facilitate the sensitivity analysis of system descriptions.
Journal: Int. J. of Mathematics in Operational Research
Pages: 143-163
Issue: 2
Volume: 31
Year: 2025
Keywords: batch arrivals; priority queues; vacation and vacation interruption under random environment; negative arrival; immediate feedback; differentiate breakdown; repair.
File-URL: http://www.inderscience.com/link.php?id=147024
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:2:p:143-163
Template-Type: ReDIF-Article 1.0
Author-Name: Aliakbar Montazer Haghighi
Author-X-Name-First: Aliakbar Montazer
Author-X-Name-Last: Haghighi
Author-Name: Dimitar P. Mishev
Author-X-Name-First: Dimitar P.
Author-X-Name-Last: Mishev
Title: A transient M[X]/M(k, K)/1 queue with reneging and setup time for service
Abstract:
In this paper, we analyse a transient queuing model, in which tasks arrival in bulks of varying sizes with compound Poisson process. There is a single server serving batches of tasks with limited sizes with a minimum and a maximum, according with exponential distribution, with setup times for service with also exponential distribution, and impatient tasks that may renege while the server is busy with also exponential distribution. The transient probability generating function for the number in the system, special cases to verify it and some performance measures have been found.
Journal: Int. J. of Mathematics in Operational Research
Pages: 164-181
Issue: 2
Volume: 31
Year: 2025
Keywords: transient queue; Markov process; Poisson; reneging; exponential service; setup time; probability generating function; moments.
File-URL: http://www.inderscience.com/link.php?id=147025
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:2:p:164-181
Template-Type: ReDIF-Article 1.0
Author-Name: Swapna Thota
Author-X-Name-First: Swapna
Author-X-Name-Last: Thota
Author-Name: D. Menaka
Author-X-Name-First: D.
Author-X-Name-Last: Menaka
Title: IoT-botnet attack detection and mitigation using ensembled-deep-learning-model
Abstract:
In this study, we propose an ensembled-deep learning model for robust IoT-botnet attack detection. The model comprises six phases: data preprocessing, data augmentation using SMOTE, feature extraction (central tendency, dispersion, and information gain), feature selection using the clan updated grasshopper optimisation algorithm (CUGOA), and attack detection. The detection model integrates DCNN, attention-based bi-LSTM, and optimised RNN, with fine-tuning using CUGOA. When an attack is detected, our new botnet traffic filter (BTF) mitigates it, enhancing network reliability. Our model outperforms existing approaches in terms of accuracy, sensitivity, specificity, and precision.
Journal: Int. J. of Mathematics in Operational Research
Pages: 216-240
Issue: 2
Volume: 31
Year: 2025
Keywords: botnet; internet of things; deep learning cyber security; intrusion detection.
File-URL: http://www.inderscience.com/link.php?id=147026
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:2:p:216-240
Template-Type: ReDIF-Article 1.0
Author-Name: Rosshairy Abd. Rahman
Author-X-Name-First: Rosshairy Abd.
Author-X-Name-Last: Rahman
Author-Name: Kean Heong Lee
Author-X-Name-First: Kean Heong
Author-X-Name-Last: Lee
Author-Name: Syariza Abdul-Rahman
Author-X-Name-First: Syariza
Author-X-Name-Last: Abdul-Rahman
Author-Name: Azhar Mahdi Ibadi
Author-X-Name-First: Azhar Mahdi
Author-X-Name-Last: Ibadi
Title: Job shop scheduling in Wafer Fab with random job arrivals using hybrid tabu search technique
Abstract:
Job shop scheduling (JSS) plays an important role in the manufacturing sector to minimise makespan and avoid bottleneck situations. Wafer fabrication (Wafer Fab) is a costly and complex manufacturing system that demands several billion dollars investment with many repeated processes. Scheduling of Wafer Fab is vital to produce wafers and to achieve on-time delivery to customers. As such, this study proposes a hybrid tabu search model to solve JSS problem by minimising makespan while concurrently maximising the average machine utilisation. Initially, the concept of bin packing was deployed to obtain the initial solution using random greedy algorithm. Tabu search algorithm (TSA) was then employed to enhance solutions around the neighbourhood area. The findings successfully improved the schedule of jobs in Wafer Fab manufacturing, where the enhancement of 6.2% in makespan minimisation was achieved. Thus, it shows the ability to utilise the machines equally and avoid bottlenecks in Wafer Fab manufacturing.
Journal: Int. J. of Mathematics in Operational Research
Pages: 397-412
Issue: 3
Volume: 31
Year: 2025
Keywords: job shop scheduling; JSS; random greedy bin packing; Wafer Fab; tabu search algorithm; TSA; makespan; manufacturing; tabu tenure size; metaheuristics; bottleneck; utilisation.
File-URL: http://www.inderscience.com/link.php?id=147858
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:3:p:397-412
Template-Type: ReDIF-Article 1.0
Author-Name: Abdulhadi Aminu
Author-X-Name-First: Abdulhadi
Author-X-Name-Last: Aminu
Author-Name: Sunday E. Olowo
Author-X-Name-First: Sunday E.
Author-X-Name-Last: Olowo
Author-Name: Salisu Usaini
Author-X-Name-First: Salisu
Author-X-Name-Last: Usaini
Title: On efficient solutions to bi-objective max-linear programming problems
Abstract:
A number of methods for determining solutions to max-linear programming problems with one objective function have been developed. In this work, we introduce the concept of a bi-objective max-linear programming problem subject to two sided constraints (BOMLP) for both minimisation and maximisation cases, then we proposed two methods for determining efficient solutions to the problem and developed improved algorithms based on an alternating and bisecting method of solving two sided max-linear system. Performance of the methods were compared based on effectiveness, user friendliness and task time, in fact the second method is found to be faster than the first method, some numerical examples were considered to test the problems using MATLAB software.
Journal: Int. J. of Mathematics in Operational Research
Pages: 339-371
Issue: 3
Volume: 31
Year: 2025
Keywords: bi-objective max-linear programming; two-sided system; optimal solution; efficient solution; pseudo-polynomial algorithms.
File-URL: http://www.inderscience.com/link.php?id=147859
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:3:p:339-371
Template-Type: ReDIF-Article 1.0
Author-Name: R. Kalyanaraman
Author-X-Name-First: R.
Author-X-Name-Last: Kalyanaraman
Author-Name: B. Anurathi
Author-X-Name-First: B.
Author-X-Name-Last: Anurathi
Title: A Markovian two server queue with state dependent hybrid service discipline
Abstract:
A Markovian two server model is constructed by assuming a new concept. The concept is that upto the service of <i>N</i> customers, the two servers act as homogeneous servers after which the servers act like heterogeneous servers. In practice, in particular, if the servers are human beings, they cannot serve in the same spirit till the end of the busy period. These practical situations lead to study of queues with heterogeneous servers. This model is analysed in steady state by deriving the difference equations and applying the recursive concept for solution. For this model the waiting time distribution and some system performance measures are obtained, particular cases are derived. The practical applicability of the model is tested by presenting some numerical illustrations. A cost model is developed by defining the total expected cost function and also sensitivity analysis is carried out to investigate the effect of system parameters on the expected cost function.
Journal: Int. J. of Mathematics in Operational Research
Pages: 413-434
Issue: 3
Volume: 31
Year: 2025
Keywords: two server queue; homogeneous server; heterogeneous server; performance measures.
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:3:p:413-434
Template-Type: ReDIF-Article 1.0
Author-Name: Manas Karak
Author-X-Name-First: Manas
Author-X-Name-Last: Karak
Author-Name: Tuhin Bera
Author-X-Name-First: Tuhin
Author-X-Name-Last: Bera
Author-Name: Mahendra Rong
Author-X-Name-First: Mahendra
Author-X-Name-Last: Rong
Author-Name: Nirmal Kumar Mahapatra
Author-X-Name-First: Nirmal Kumar
Author-X-Name-Last: Mahapatra
Title: An attempt on neutrosophic multi-attribute decision making based on generalised signed distance method
Abstract:
Decision making in today's uncertain scenario is the most challenging task for experts. To assist the decision-makers, this study deals with a ranking of neutrosophic number based on the generalised signed distance method. Some important definitions like level-1 neutrosophic points and level (<i>α</i>, <i>β</i>, <i>γ</i>)-neutrosophic intervals are drawn initially. Then a number of properties and theorems on ranking of neutrosophic numbers are developed here. Finally, to establish our theoretical idea on ranking, we consider a real life multi-attribute decision-making problem and find the desired result. After that we make some comparative study of our model with some existing decision-making models.
Journal: Int. J. of Mathematics in Operational Research
Pages: 372-396
Issue: 3
Volume: 31
Year: 2025
Keywords: neutrosophic number and its ranking; neutrosophic points; neutrosophic intervals; signed distance method.
File-URL: http://www.inderscience.com/link.php?id=147861
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:3:p:372-396
Template-Type: ReDIF-Article 1.0
Author-Name: Jitendra Kaushik
Author-X-Name-First: Jitendra
Author-X-Name-Last: Kaushik
Title: The inventory model for optimal replenishment policy with deterioration and various interest rates: two levels permissible delay in payment strategy
Abstract:
Here, I developed an 'EOQ' model for the deteriorating items considering the price and time-dependent ramp-type demand function. I considered two rates for interest charged and discussed four different possibilities according to the length of the time slots: 1) both the rates lie in the growing phase; 2) one lies in the growing, and another lies in the constant phase. Permissible delay in payment provides an opportunity for extra sales, which increases revenue for suppliers and retailers. Suitable numerical examples are provided to demonstrate the obtained results. The comparison of models is presented considering permissible delay and without permissible delay; our results highlight higher profit to retailers in case of permissible delay. Then, sensitivity analysis is performed, and its implication is discussed from a managerial perspective.
Journal: Int. J. of Mathematics in Operational Research
Pages: 314-338
Issue: 3
Volume: 31
Year: 2025
Keywords: economic order quantity; nonlinear demand function; permissible delay in payment; PDP: deterioration; shortage; inventory model.
File-URL: http://www.inderscience.com/link.php?id=147871
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:3:p:314-338
Template-Type: ReDIF-Article 1.0
Author-Name: Bijayini Mohanty
Author-X-Name-First: Bijayini
Author-X-Name-Last: Mohanty
Author-Name: Santi Lata Champati
Author-X-Name-First: Santi Lata
Author-X-Name-Last: Champati
Author-Name: Swadhin Kumar Barisal
Author-X-Name-First: Swadhin Kumar
Author-X-Name-Last: Barisal
Title: A novel approach to optimise fuzzy association rule by using evolutionary genetics algorithm
Abstract:
In data mining, extracting useful information from complicated and ambiguous datasets has remained a significant issue. To address such problems, the fuzzy logic approach is becoming increasingly very popular. The traditional association rule mining and clustering are two highly efficient approaches for finding underlying information in this discipline. This approach integrates the fuzzy logic theory to improve the efficiency of these two approaches. The integrated approach is more adaptive to dealing with real-world data. So, this study proposes a hybrid framework that effectively explores and optimises the number of generated rules. This work provides a unique cluster fuzzy association rules (CFARs) technique by combining fuzzy association rule mining and fuzzy C-means clustering. The proposed model generates three clusters for the fuzzy association rules for the considered 'online retail' dataset. This approach processes the primary set of CFAR to filter-out optimal number of rules. The optimisation process is carried out under the guidance of evolutionary genetics algorithm. The mining method extracts 5,000 fuzzy association rules from the considered data, which the optimisation process then reduces to 2,005 fuzzy association rules.
Journal: Int. J. of Mathematics in Operational Research
Pages: 283-313
Issue: 3
Volume: 31
Year: 2025
Keywords: data mining; fuzzy logic; association rule mining; ARM; C-means clustering; evolutionary genetics algorithm; EGA; apriori algorithm.
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:3:p:283-313
Template-Type: ReDIF-Article 1.0
Author-Name: Prokash Mondal
Author-X-Name-First: Prokash
Author-X-Name-Last: Mondal
Author-Name: Sudhansu Khanra
Author-X-Name-First: Sudhansu
Author-X-Name-Last: Khanra
Author-Name: Pritha Das
Author-X-Name-First: Pritha
Author-X-Name-Last: Das
Title: An inventory model with hybrid time-stock dependent demand for seasonal products with trade credit policy
Abstract:
This study examines an EOQ model with a hybrid time- and stock-dependent demand function for a seasonal product context of shortages. In several marketing strategies that have a strong connection to stock - time and stock both play a crucial role in customer decision-making - vendors always entice customers to buy more by displaying many products. This investigation aims to present the best inventory management technique for perishable products with hybrid demand that is time- and stock-dependent under partial backlog with a trade credit policy. The provided EOQ model is validated using a numerical illustration. Finally, sensitivity analysis has been employed to examine the effects of changes in the values of system factors using MATLAB software (Version 2014a).
Journal: Int. J. of Mathematics in Operational Research
Pages: 435-464
Issue: 4
Volume: 31
Year: 2025
Keywords: inventory; time-stock dependent demand; partial backlogging; deterioration; trade credit policy.
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:4:p:435-464
Template-Type: ReDIF-Article 1.0
Author-Name: G. Ayyappan
Author-X-Name-First: G.
Author-X-Name-Last: Ayyappan
Author-Name: N. Arulmozhi
Author-X-Name-First: N.
Author-X-Name-Last: Arulmozhi
Title: Optimising inventory in business environments: combining matrix analytic methods with a working vacation, cancellation policy and working breakdown
Abstract:
The inventory system of the single-server Markovian arrival process with working vacations, working breakdowns under a Bernoulli schedule, and cancellation policy are discussed. The server begins to go on a working vacation when there is no customer in the system even if the inventory level is positive. If any customers arrive while he is end of his working vacation time, a normal busy period begins. If not, he will simply remain idle in regular mode. When a system breaks down, it either offers slow service to the current customers with probability <i>p</i> or immediately undergoes a repair phase with probability <i>q</i>. We derive the invariant vector, busy period, waiting time distribution, total cost, and computation of performance measures using the matrix analytic technique.
Journal: Int. J. of Mathematics in Operational Research
Pages: 465-497
Issue: 4
Volume: 31
Year: 2025
Keywords: Markovian arrival process; MAP; phase-type service; (s, Q) policy; working vacation; working breakdown; cancellation policy.
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:4:p:465-497
Template-Type: ReDIF-Article 1.0
Author-Name: K. Navaz
Author-X-Name-First: K.
Author-X-Name-Last: Navaz
Author-Name: N. Muthuvairavan Pillai
Author-X-Name-First: N. Muthuvairavan
Author-X-Name-Last: Pillai
Author-Name: G. Shanmuga Sundaram
Author-X-Name-First: G. Shanmuga
Author-X-Name-Last: Sundaram
Author-Name: T. Rajesh Kumar
Author-X-Name-First: T. Rajesh
Author-X-Name-Last: Kumar
Author-Name: C. Jehan
Author-X-Name-First: C.
Author-X-Name-Last: Jehan
Title: An enhancing IOT security with a trinary deep learning paradigm and squirrel reptilian optimisation
Abstract:
This research work proposes a novel approach for IoT intrusion detection using a trinary deep learning paradigm. The proposed model aims to address the challenges of large data requirements and false positives commonly encountered in IoT network security. The model consists of four phases: pre-processing, multi-modal feature extraction, optimal feature selection, and intrusion detection. Initially, the collected raw data is pre-processed using data cleaning techniques and Z-score normalisation, which helps to standardise the data for further analysis. Following pre-processing, multi-modal feature extraction techniques are applied, including measures of central tendency, database features, statistical dispersion, and information entropy-based features. To select the most relevant features from the extracted set, the squirrel reptilian optimisation algorithm is employed. SRO combines the squirrel search algorithm and reptile search algorithm to optimise feature selection, ensuring that only the most informative features are utilised for intrusion detection.
Journal: Int. J. of Mathematics in Operational Research
Pages: 544-575
Issue: 4
Volume: 31
Year: 2025
Keywords: IoT; intrusion detection; multi-modal feature extraction; squirrel reptilian optimisation algorithm; SRO; trinary-deep-learning-paradigm; CNN; RBFN; RBM.
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:4:p:544-575
Template-Type: ReDIF-Article 1.0
Author-Name: Mukesh Kumar
Author-X-Name-First: Mukesh
Author-X-Name-Last: Kumar
Author-Name: Manoj Kumar Sharma
Author-X-Name-First: Manoj Kumar
Author-X-Name-Last: Sharma
Author-Name: Ajay Sharma
Author-X-Name-First: Ajay
Author-X-Name-Last: Sharma
Author-Name: Shalu Chaudhary
Author-X-Name-First: Shalu
Author-X-Name-Last: Chaudhary
Title: A healthcare divisions inventory model for deteriorating items with a variable deterioration rate under permissible delay in payments
Abstract:
The deterioration of medicines is an extensive trend in the healthcare sector. There are a lot of medicines and pharmaceutical products, such as generic injectables, caplets, ophthalmic liquids, ointments, tablets, etc., that have short expirations; therefore, there is a requirement to develop methods to use them within their expiration time. Most of the public health system encounters this problem frequently occurs. To solve this problem, the authors developed an inventory model based on four features of the healthcare sector: time-dependent demand rate, holding cost, deterioration rate, partially backlogged shortages in demand, and credit period offered by pharmaceuticals. We also considered the time duration, which is free from interest on credit, and the rate of interest. However, the hospitals have the reserve money to make the payments at the beginning, but they decide to take advantage of the credit period. We validated this model by using a numerical example and explaining the sensitivity analysis.
Journal: Int. J. of Mathematics in Operational Research
Pages: 498-517
Issue: 4
Volume: 31
Year: 2025
Keywords: inventory; demand; pharmaceutical products; deterioration and permissible delay payments.
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:4:p:498-517
Template-Type: ReDIF-Article 1.0
Author-Name: Broderick Oluyede
Author-X-Name-First: Broderick
Author-X-Name-Last: Oluyede
Author-Name: Kethamile Rannona
Author-X-Name-First: Kethamile
Author-X-Name-Last: Rannona
Title: The Ristić-Balakrishnan-exponentiated half logistic-G family of distributions with applications
Abstract:
In this paper, we introduce a new family of distributions called the Ristić-Balakrishnan-exponentiated half logistic-G (RB-EHL-G) family of distributions. Statistical properties of the new family including hazard function, quantile function, moments, distribution of the order statistics and Rényi entropy are derived. Some special cases of the new family are presented. The maximum likelihood estimation technique is used to estimate the model parameters. A Monte Carlo simulation study is conducted in order to examine the bias and mean square error of the maximum likelihood estimators. Finally, the new family is applied to real life datasets to illustrate the usefulness of the proposed distribution.
Journal: Int. J. of Mathematics in Operational Research
Pages: 518-543
Issue: 4
Volume: 31
Year: 2025
Keywords: Ristić and Balakrishan-G distribution; exponentiated half logistic-G distribution; maximum likelihood estimation.
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Handle: RePEc:ids:ijmore:v:31:y:2025:i:4:p:518-543
Template-Type: ReDIF-Article 1.0
Author-Name: G. Ayyappan
Author-X-Name-First: G.
Author-X-Name-Last: Ayyappan
Author-Name: S. Meena
Author-X-Name-First: S.
Author-X-Name-Last: Meena
Title: Analysis of MAP/PH/1 retrial inventory queueing system with phase type vacation and unreliable server
Abstract:
In this study, a retrial queueing inventory system with a fixed retrial rate, single vacation, breakdown, and repair is investigated. We have made the assumption that customers arrive through a Markovian arrival process and that the server will offer phase-type services to them. The (<i>s</i>, <i>S</i>) policy is used to replenish the inventory, and it is anticipated that the replenishing time will follow an exponential distribution. The server goes on vacation if there are no consumers in the orbit, or zero inventory, or both. When a server breaks down, it quickly starts the repair process, and the customer enters the infinite size of the orbit. In the steady state, it is possible to determine the number of customers in the orbit, the inventory level, and the status of the servers. The cost analysis is derived, and several significant performance measurements are established. Furthermore, a few numerical demonstrations are given to clarify our mathematical model.
Journal: Int. J. of Mathematics in Operational Research
Pages: 1-30
Issue: 1
Volume: 32
Year: 2025
Keywords: queueing-inventory; Markovian arrival process; phase-type distribution; (s, S)-type policy; retrial; single vacation; breakdown and repair; matrix analytic method.
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Handle: RePEc:ids:ijmore:v:32:y:2025:i:1:p:1-30
Template-Type: ReDIF-Article 1.0
Author-Name: Ameer Hassan Abdullahi
Author-X-Name-First: Ameer Hassan
Author-X-Name-Last: Abdullahi
Author-Name: Abdulhadi Aminu
Author-X-Name-First: Abdulhadi
Author-X-Name-Last: Aminu
Author-Name: Ibrahim Yusuf
Author-X-Name-First: Ibrahim
Author-X-Name-Last: Yusuf
Title: Enhancing reliability and performance of sequential chiller system using copula
Abstract:
Chiller systems play a pivotal role across various industries, providing essential cooling solutions. Ensuring their efficiency and reliability necessitates precise performance evaluation. The Gumbel-Hougaard family copula, an efficient approach for modelling multivariate dependencies, is used in this paper to carry out an in-depth examination of chiller machine systems. Through this method, we can capture intricate correlations between chiller system characteristics and performance metrics such as reliability, availability, mean time to failure (MTTF), cost and MTTF sensitivity. We further conducted sensitivity analysis using our copula-based model to identify key factors influencing chiller system performance. The efficacy of the copula-based approach in capturing intricate relationships between several chiller system features and critical performance measures is exemplified by numerical findings that are displayed in tables and graphs. We can make conclusions about the results since they have been validated using quantitative data and can be seen in tables and graphs. This deeper understanding will assist us in optimising system operations for improved cost-effectiveness and energy efficiency. Additionally, our copula-based approach enhances performance evaluation compared to traditional methods by allowing us to assess the system's resilience under varying operational conditions.
Journal: Int. J. of Mathematics in Operational Research
Pages: 123-144
Issue: 1
Volume: 32
Year: 2025
Keywords: availability; efficiency; chiller systems; series-parallel system; transition diagram.
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Handle: RePEc:ids:ijmore:v:32:y:2025:i:1:p:123-144
Template-Type: ReDIF-Article 1.0
Author-Name: Manoj Kumar Sharma
Author-X-Name-First: Manoj Kumar
Author-X-Name-Last: Sharma
Author-Name: Neha Rani
Author-X-Name-First: Neha
Author-X-Name-Last: Rani
Author-Name: Anshika Rajpal
Author-X-Name-First: Anshika
Author-X-Name-Last: Rajpal
Title: Balancing sustainability and profitability in inventory management: insights into carbon emissions, consumer demands, payment strategies, and green investments
Abstract:
Optimising inventory management practices is paramount in a world increasingly concerned with environmental stewardship. The present study focuses on four main aspects: a) reducing carbon emissions; b) responsiveness to price and freshness-dependent consumer demands; c) evaluation of payment schemes; d) assessment of investments in preservation and green technologies. By addressing these fundamental components of inventory management, the article offers valuable insights and practical recommendations for businesses striving to align their operations with sustainability goals. Achieving sustainability in inventory management contributes to environmental conservation and enhances competitiveness and long-term profitability. Payment methods wield significant influence in inventory management, impacting cash flow, supplier relations, and sustainability efforts. They serve as tools for sustainability, highlighting the trade-off between cash flow and environmental stewardship. Finally, a few computational instances and sensitivity analyses demonstrate the suggested model's features. The results and sensitivity analysis show that controllable carbon emissions favourably impact overall inventory model profit.
Journal: Int. J. of Mathematics in Operational Research
Pages: 31-89
Issue: 1
Volume: 32
Year: 2025
Keywords: inventory management; carbon emissions; price and freshness dependent demand; comparison of payment scheme; preservation technology investment; green technology investment.
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Handle: RePEc:ids:ijmore:v:32:y:2025:i:1:p:31-89
Template-Type: ReDIF-Article 1.0
Author-Name: Aniket S. Todkar
Author-X-Name-First: Aniket S.
Author-X-Name-Last: Todkar
Author-Name: Jayesh M. Dhodiya
Author-X-Name-First: Jayesh M.
Author-X-Name-Last: Dhodiya
Title: Enhanced non-dominated sorting genetic algorithms for fuzzy multi-objective multi-route shortest path problem
Abstract:
This study examines a fuzzy multi-objective multi-route short path problem (FMOMRSPP) by transforming it into a crisp multi-objective multi-route shortest path problem (MOMRSPP) using possibility distribution. Using <i>α</i>-level sets, fuzzy judgement is categorised for the decision maker (DM) to optimise fuzzy objective function scenarios. This paper proposes aspiration level (AL)-based non-dominated sorting genetic algorithm (NSGA)-II and AL-based NSGA-III to obtain a Pareto-optimal solution that meets DM AL for the FMOMRSPP. A numerical example has been provided to demonstrate the usage of the presented methodologies. A comparison is presented between the proposed and several other approaches. The sensitivity of objective functions is also investigated with ALs and shape parameters. The coverage is determined to evaluate the effectiveness of the proposed methods.
Journal: Int. J. of Mathematics in Operational Research
Pages: 90-122
Issue: 1
Volume: 32
Year: 2025
Keywords: multi-objective multi-route shortest path problem; MOMRSPP; NSGA-II; NSGA-III; aspiration level.
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Handle: RePEc:ids:ijmore:v:32:y:2025:i:1:p:90-122
Template-Type: ReDIF-Article 1.0
Author-Name: Yassine Adouani
Author-X-Name-First: Yassine
Author-X-Name-Last: Adouani
Title: A genetic algorithm combined with mathematical programming to solve generalised quadratic multiple knapsack problem
Abstract:
In this paper, the generalised quadratic multiple knapsack problem (GQMKP) is tackled with an efficient hybrid approach, called GA&IP, which combines a binary genetic algorithm (GA) with integer programming (IP) to solve the GQMKP problem. In the GA&IP approach, a linearisation technique is used to transform the GQMKP into a linear problem called LGQMKP. After that, the LGQMKP is transformed into several dependent classical knapsack problems using a GA. Finally, an IP algorithm is applied to optimally solve each knapsack problem. The effectiveness of the GA&IP approach is demonstrated through experimentation on 96 diverse benchmark instances that are commonly used in the field. Experimental results show the effectiveness of the proposed GA&IP in solving the GQMKP problem and the hybridisation with integer programming can enhance the genetic algorithm.
Journal: Int. J. of Mathematics in Operational Research
Pages: 199-213
Issue: 2
Volume: 32
Year: 2025
Keywords: generalised quadratic knapsack problem; genetic algorithm; integer programming.
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Handle: RePEc:ids:ijmore:v:32:y:2025:i:2:p:199-213
Template-Type: ReDIF-Article 1.0
Author-Name: Abdelhek Laouar
Author-X-Name-First: Abdelhek
Author-X-Name-Last: Laouar
Author-Name: Mohand Ouamer Bibi
Author-X-Name-First: Mohand Ouamer
Author-X-Name-Last: Bibi
Title: An adaptive hybrid direction algorithm for convex box-QP problems with enhanced pre-solving
Abstract:
In this paper, we propose a new algorithm for solving quadratic programming problem with box constraints. The principle of the algorithm is to apply a preprocessing procedure to reduce the original problem. Then the resulting reduced problem will be solved by applying the adaptive method with a hybrid direction. A post-processing step (post-solving) is necessary to deduce the optimal solution of the original problem. In order to test the algorithm of the proposed method and to make sure of its effectiveness, a comparative study of the proposed method is made with active-set quadprog algorithm, the interior-point-convex quadprog algorithm of the MATLAB optimisation toolbox and the modified proportioning with reduced gradient projections algorithm (MPRGP). The obtained results show that the proposed algorithm presents good performances, it always performs better than the active set method and appears to be very competitive with the interior point method and the MPRGP algorithm, mainly for the problems having |<i>b<SUB align="right"><SMALL>i</SMALL></SUB></i>| sufficiently large with many active variables at the optimal solution and for problems where <i>A</i> is generalised diagonally dominant. In these cases, the optimal solution is obtained only by the pre-solving procedure.
Journal: Int. J. of Mathematics in Operational Research
Pages: 251-275
Issue: 2
Volume: 32
Year: 2025
Keywords: quadratic programming; box constraints; pre-solving; adaptive method; hybrid direction.
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Handle: RePEc:ids:ijmore:v:32:y:2025:i:2:p:251-275
Template-Type: ReDIF-Article 1.0
Author-Name: K. Vasantha Lakshmi
Author-X-Name-First: K. Vasantha
Author-X-Name-Last: Lakshmi
Author-Name: K.N. Udaya Kumara
Author-X-Name-First: K.N. Udaya
Author-X-Name-Last: Kumara
Title: Graphical neural network-based MCDM for evaluating sustainable city logistics measures
Abstract:
This paper presents a novel approach to evaluate sustainable city logistics measures using a multi-criteria decision-making (MCDM) framework based on qualitative data. The proposed approach combines different weighing methods such as fuzzy DEMATEL, fuzzy AHP, to determine the weights of the criteria. The criteria are based on economic, environmental, social, and technical aspects, such as operational costs, energy consumption, revenues, air pollution, noise, land use, congestion, accidents, mobility, accessibility, freeing of public space, logistical efficiency, trip effectiveness, loading factor of vehicles, service quality, and customer coverage'. The study also proposes a graphical neural network (GNN) with weighted MCDM for artificial intelligence-based decision-making, which helps in achieving a better selection of city logistics measures for urban freight logistics. The approach is implemented in MATLAB and compared with other deep learning models such as CNN, ANN, and DNN, showing higher performance. Furthermore, the paper presents an extrapolation-enhanced approach for modelling travel decision-making based on MCDM with GNN and error calculation, which provides higher performance. The results demonstrate the effectiveness of the proposed approach in selecting sustainable city logistics measures, which can contribute to improving urban freight logistics.
Journal: Int. J. of Mathematics in Operational Research
Pages: 214-238
Issue: 2
Volume: 32
Year: 2025
Keywords: sustainable city logistics; social factors; multiple stakeholders; fuzzy logic methodology; normalised matrix; Pairwise similarity matrix; multi-criteria decision-making; MCDM; graphical neural network; GNN.
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Handle: RePEc:ids:ijmore:v:32:y:2025:i:2:p:214-238
Template-Type: ReDIF-Article 1.0
Author-Name: Sunita Sharma
Author-X-Name-First: Sunita
Author-X-Name-Last: Sharma
Author-Name: Vinod Kumar
Author-X-Name-First: Vinod
Author-X-Name-Last: Kumar
Author-Name: S.B. Singh
Author-X-Name-First: S.B.
Author-X-Name-Last: Singh
Title: Reliability measures of repairable k-out-of-n system using weighted exponential-Lindley distribution
Abstract:
This study focuses on the analysis of a <i>k</i>-out-of-<i>n</i>: <i>F</i> repairable system employing a novel lifetime distribution termed the weighted exponential-Lindley distribution (WXLD). The system under investigation assumes constant failure rates, while repair times follow the newly proposed WXLD. The repair process involves two personnel: a trainee for minor repairs and an expert for major repairs. Leveraging the supplementary variable technique and Laplace transformation, we derive key reliability measures for the system, including reliability, availability, expected profit, and sensitivity. To exemplify and validate the generalised results, the research employs a communication system as a practical application.
Journal: Int. J. of Mathematics in Operational Research
Pages: 179-198
Issue: 2
Volume: 32
Year: 2025
Keywords: k-out-of-n: F system; weighted exponential-Lindley distribution; WXLD; supplementary variable technique; SVT; reliability; availability; expected profit; sensitivity; Laplace transformation; LT.
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Handle: RePEc:ids:ijmore:v:32:y:2025:i:2:p:179-198
Template-Type: ReDIF-Article 1.0
Author-Name: Sudipta Mishra
Author-X-Name-First: Sudipta
Author-X-Name-Last: Mishra
Author-Name: Rashmi Ranjan Ota
Author-X-Name-First: Rashmi Ranjan
Author-X-Name-Last: Ota
Title: Lexicographic multi-objective geometric programming problems with pentagonal fuzzy parameters using robust method
Abstract:
Fuzzy logic is the most useful method for simulating complex real-world problems. In the process of creating models and coming up with solutions, it integrates ambivalence information. This paper outlines the process for resolving lexicographic multi-objective geometric programming problems with fuzzy parameters. After the introduction of pentagonal fuzzy parameters as the coefficients, the study utilises the robust method to defuzzify the programming problems. Finally, the solution is reached using the geometric programming technique. Two numerical examples have been given to illustrate our proposed methodology.
Journal: Int. J. of Mathematics in Operational Research
Pages: 239-250
Issue: 2
Volume: 32
Year: 2025
Keywords: geometric programming; multi-objective; lexicographic method; pentagonal fuzzy parameters; robust method.
File-URL: http://www.inderscience.com/link.php?id=148878
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Handle: RePEc:ids:ijmore:v:32:y:2025:i:2:p:239-250
Template-Type: ReDIF-Article 1.0
Author-Name: Joshua Sunday
Author-X-Name-First: Joshua
Author-X-Name-Last: Sunday
Author-Name: Joel Nimyel Ndam
Author-X-Name-First: Joel Nimyel
Author-X-Name-Last: Ndam
Author-Name: Anthony Chukwuemeka Onyekonwu
Author-X-Name-First: Anthony Chukwuemeka
Author-X-Name-Last: Onyekonwu
Title: Self-adjusting formulae for the solution of fuzzy differential equations with triangular fuzzy numbers
Abstract:
It is a known fact that in modelling real world phenomena, differential equations are indispensable. Uncertainty, unfortunately intervene with such real world problems. The uncertainty may arise from measurement error, determining initial/boundary conditions or even deficient data. Modelling these problems in the form of fuzzy differential equations (FDEs) helps address such setbacks. This research focuses on deriving self-adjusting formulae (SAF) through the variable stepsize strategy for the solution of FDEs with triangular fuzzy numbers. The SAF, which is in the form of implicit block backward differentiation formulae (BBDF) was derived in such a way that it automatically adjusts the stepsize to fit the FDE under consideration. The BBDFs have been known for their unbounded region of absolute stability, thus making them suitable for solving FDEs. The results obtained showed that the SAF is computationally efficient, robust and reliable.
Journal: Int. J. of Mathematics in Operational Research
Pages: 145-178
Issue: 2
Volume: 32
Year: 2025
Keywords: backward differentiation formulae; convergence; fuzzy differential equation; FDE; H-difference; Hukuhara derivative; interval differential equations; mathematical models; triangular fuzzy number; variable stepsize; uncertainty.
File-URL: http://www.inderscience.com/link.php?id=148879
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Handle: RePEc:ids:ijmore:v:32:y:2025:i:2:p:145-178
Template-Type: ReDIF-Article 1.0
Author-Name: K. Baby Saroja
Author-X-Name-First: K. Baby
Author-X-Name-Last: Saroja
Author-Name: V. Suvitha
Author-X-Name-First: V.
Author-X-Name-Last: Suvitha
Title: Analysis of Markovian queueing model with two phase of services, single and multiple working vacations and customer balking
Abstract:
We analyse a single server balking queueing model with featuring two phases of service in series. During the first phase, customers receive individual service, and in the second phase, they have the option to choose between two distinct services based on their specific needs and receive batch service. To optimise resource utilisation, the server enters a working vacation when there is no customer in the system. We apply the probability generating method to comprehensively analyse the system, considering both single and multiple working vacation. This research underscores the application's adaptability in addressing intricate data processing challenges within the queuing framework. Furthermore, we provide numerical results to demonstrate how the model performs under various conditions.
Journal: Int. J. of Mathematics in Operational Research
Pages: 277-293
Issue: 3
Volume: 32
Year: 2025
Keywords: two phases in series; working vacation; balking; batch service.
File-URL: http://www.inderscience.com/link.php?id=149920
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Handle: RePEc:ids:ijmore:v:32:y:2025:i:3:p:277-293
Template-Type: ReDIF-Article 1.0
Author-Name: Dolagobinda Das
Author-X-Name-First: Dolagobinda
Author-X-Name-Last: Das
Author-Name: Gauranga Charan Samanta
Author-X-Name-First: Gauranga Charan
Author-X-Name-Last: Samanta
Title: A sustainable demand disruption recovery model considering non-zero lead time and advance payment policy during any emergency like COVID-19 pandemic
Abstract:
This study considers three time frames (i.e., before lock-down, during lock-down, and after lock-down) and takes three distinct time-dependent demands that are effective for three time frames. Before lock-down, we use a linear time-dependent demand function; during lock-down, we use a demand function that suddenly drops close to zero due to lock-down restrictions; after a period of time, demand slowly increases to meet customers basic needs, and after the government relaxes lock-down restrictions, demand abruptly increases due to customers panic buying and overstocking nature. Subsequently, non-instantaneous deterioration rate is considered. Due to a significant rise in demand after lock-down, this research permits a shortage that is partially backlogged along with a non-zero lead time and also considers the advance payment policy to reduce the order cancellation rate. Also, green technology is implemented to reduce carbon emissions. Finally, sensitivity experiments are conducted on a few examples to validate the model.
Journal: Int. J. of Mathematics in Operational Research
Pages: 348-389
Issue: 3
Volume: 32
Year: 2025
Keywords: demand disruption; deterioration; advance payment; COVID-19 lock-down; green inventory model; carbon emission.
File-URL: http://www.inderscience.com/link.php?id=149921
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Handle: RePEc:ids:ijmore:v:32:y:2025:i:3:p:348-389
Template-Type: ReDIF-Article 1.0
Author-Name: Fatima Hessas
Author-X-Name-First: Fatima
Author-X-Name-Last: Hessas
Author-Name: Mouloud Goubi
Author-X-Name-First: Mouloud
Author-X-Name-Last: Goubi
Author-Name: Noria Benkhemmou
Author-X-Name-First: Noria
Author-X-Name-Last: Benkhemmou
Title: A new approach for counting patterns in language theory, matchings, and set partitions
Abstract:
The notion of pattern is widely studied in the literature. We focus our attention on patterns appearing in language theory, matchings, and set partitions. We start with some main tools of algebraic generating functions of sequences of numbers. We explain how the Bell, Fibonacci and generalised Fibonacci numbers can be used in the theory of patterns. In particular, we are interested in words containing patterns that are related to arbitrary length so as to provide enumeration formulae, and extract satisfying recurrence relations. Moreover, we revisit the work of Bloom and Elizalde concerning pattern avoidance in matchings and partitions in order to fulfil it with some enumeration formulae.
Journal: Int. J. of Mathematics in Operational Research
Pages: 426-442
Issue: 3
Volume: 32
Year: 2025
Keywords: language theory; patterns; generating functions; matchings; set partitions.
File-URL: http://www.inderscience.com/link.php?id=149922
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Handle: RePEc:ids:ijmore:v:32:y:2025:i:3:p:426-442
Template-Type: ReDIF-Article 1.0
Author-Name: Dibakar Dutta
Author-X-Name-First: Dibakar
Author-X-Name-Last: Dutta
Author-Name: Palash Dutta
Author-X-Name-First: Palash
Author-X-Name-Last: Dutta
Author-Name: Brindaban Gohain
Author-X-Name-First: Brindaban
Author-X-Name-Last: Gohain
Title: Construction of distance measure for Fermatean fuzzy sets and its application in educational assessment and medical diagnosis
Abstract:
Fermatean fuzzy sets (FFSs), an updated, expanded version of intuitionistic fuzzy sets (IFSs), are effective tools for expressing uncertainty and ambiguity in complicated issues. The distance measure is a crucial tool for illustrating the differences between two FFSs while dealing with Fermatean fuzzy information. It is currently unclear how to precisely calculate the distinction between two FFSs. We provide a novel distance measurement method for FFSs in this study. Then, we show that the chosen distance measurement method satisfies the distance function's axiomatic requirements. The presented distance measure is then evidenced with numerical examples to show that it is more accurate and reasonable than the Mizumoto(I) distance measure, Robert(I) distance measure, Robert(II) distance measure, Mizumoto(II) distance measure, Hellinger distance, Euclidean distance (ED) measure and triangle divergence distance measure, which is capable of overcoming the counter-intuitive circumstance. In addition, we successfully use the proposed distance measure approach to handle pattern recognition difficulties, educational assessment issues, and medical diagnosis issues in a fuzzy Fermatean environment. The experimental findings show how effectively the suggested distance measure method can handle real-world applications in a fuzzy Fermatean environment.
Journal: Int. J. of Mathematics in Operational Research
Pages: 294-330
Issue: 3
Volume: 32
Year: 2025
Keywords: Fermatean fuzzy set; FFS; distance measure; educational assessment; medical diagnosis.
File-URL: http://www.inderscience.com/link.php?id=149923
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Handle: RePEc:ids:ijmore:v:32:y:2025:i:3:p:294-330
Template-Type: ReDIF-Article 1.0
Author-Name: Arpita Kabiraj
Author-X-Name-First: Arpita
Author-X-Name-Last: Kabiraj
Author-Name: Swapan Raha
Author-X-Name-First: Swapan
Author-X-Name-Last: Raha
Author-Name: Prasun Kumar Nayak
Author-X-Name-First: Prasun Kumar
Author-X-Name-Last: Nayak
Title: Nonlinear fuzzy programming - a case study
Abstract:
In this article, we would like to attempt finding a convergent near optimal solution of a fuzzy nonlinear programming problem (FNLPP) in which the objective as well as the constraints defining the relationship between variables are so imprecisely stated that it is practically impossible to represent by any existing crisp model. The primary aim of this research is to provide more flexibility to the decision-maker. Accordingly, to solve such a FNLPP, we use approximate reasoning which involves three stages: fuzzification, aggregation and defuzzification. The process is repeated till a convergent near optimal solution is attained. An algorithm is designed for the implementation of the proposal. Artificial examples have been considered to illustrate our approach and existing results are used for comparison. Finally, a case study is undertaken to demonstrate the effectiveness of our proposal.
Journal: Int. J. of Mathematics in Operational Research
Pages: 331-347
Issue: 3
Volume: 32
Year: 2025
Keywords: fuzzy nonlinear programming problem; FNLPP; fuzzification; aggregation; defuzzification.
File-URL: http://www.inderscience.com/link.php?id=149924
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Handle: RePEc:ids:ijmore:v:32:y:2025:i:3:p:331-347
Template-Type: ReDIF-Article 1.0
Author-Name: Santosh Shekhawat
Author-X-Name-First: Santosh
Author-X-Name-Last: Shekhawat
Author-Name: Kalpna Sharma
Author-X-Name-First: Kalpna
Author-X-Name-Last: Sharma
Title: Profit optimisation for deteriorating products with price and stock-based demand with partial credit policy
Abstract:
In this paper, a retailer centred supply chain is studied, and profit models developed under partial credit policy for deteriorating inventories. Two cases are considered for 'upstream and downstream' partial credit period of payments, and these cases are divided into five sub-cases based on cycle length and allowable delay period. Demand is function of price and stock, and holding cost is a nonlinear function of stock level. The cycle length and price are decision variables that maximise profit. Maximum profit has been observed when deadline for payment provided by the first party to the second party is greater than the deadline for payment provided by the second party to third-party. In this case, the second party may earn revenue by banking their earning. Therefore, partial deadline is more beneficial as it provides better cash flow and maximum profit. This study is applicable on supplier-retailer-costumer supply chain with partial trade credit policy and price-stock dependent demand.
Journal: Int. J. of Mathematics in Operational Research
Pages: 390-425
Issue: 3
Volume: 32
Year: 2025
Keywords: deterioration; price-stock based demand; profit-optimisation; credit period.
File-URL: http://www.inderscience.com/link.php?id=149933
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Handle: RePEc:ids:ijmore:v:32:y:2025:i:3:p:390-425