In the present work, we developed a mathematical model for dengue-Chikungunya co-infection to analyze the disease transmission dynamics and interrelationship. We considered the essence of time dependent optimal contro...
详细信息
In this paper, we propose and analyze a three-species predator prey system in the presence of additional food for top predator. It is assumed that the middle predator is acting as a prey as well as a predator and the ...
详细信息
In this paper, we propose and analyze a three-species predator prey system in the presence of additional food for top predator. It is assumed that the middle predator is acting as a prey as well as a predator and the top predator consumes both prey as well as middle predator. It is also considered that a constant amount of additional food for top predator exists in the ecosystem. The effects of harvesting of top predator are investigated. The existence and stability conditions of the equilibria have been discussed analytically. The Hopf bifurcation analysis of the system with respect to predation rate of prey to the top predator and the harvesting effort have been analyzed both analytically and numerically. Pontryagin＇s maximum principle is used to determine the optimal harvesting of top predator population to maximize the discounted net revenue. From our analysis, it is seen that the additional food has a significant impact to prevent the extinction risk of top predator population and also to increase revenue collection. Finally, some numerical results have been given in support of our analytical findings.
This paper deals with a comparison between inventory followed by shortages model and shortages followed by inventory model with variable demand rate. It is assumed that the stock deteriorates over time which follows a...
详细信息
This paper brings in connectivity index of a m-polar fuzzy graph (mPFG) with its boundedness. We investigate how the connectivity index of a mPFG changes when a vertex or an edge is deleted. Some special types of vert...
详细信息
The saturation graph is a well-defined topic. But, saturation in a fuzzy graph was defined recently and investigated many properties. In a fuzzy saturation graph, only one saturation is considered for every vertex. In...
详细信息
In this paper combining the features of swap sequence and swap operation based Particle Swarm Optimization (PSO), Ant Colony Optimization (ACO) and K-Opt operation a hybrid algorithm is proposed to solve well known Tr...
详细信息
The process of unsteady flow of a single-phase liquid in a cylindrical reservoir arising under the elastic mode of reservoir development is considered. To describe this process, a power law of filtration is proposed f...
详细信息
Here, a multi-item, multi-objective inventory model of deteriorating items with stock and time dependent demands is formulated in fuzzy-stochastic environment with finite time horizon. In this model, it is assumed tha...
Here, a multi-item, multi-objective inventory model of deteriorating items with stock and time dependent demands is formulated in fuzzy-stochastic environment with finite time horizon. In this model, it is assumed that setup cost of the items varies directly with the maximum inventory. Also, unit purchase cost is a random parameter represented by Normal distribution and the deterioration rate is imprecise in nature and defined by a trapezoidal fuzzy number. The model is reduced to an equivalent deterministic model using chance constrained and graded mean integration representation techniques. Single objective E- and V-models are solved using generalized reduced gradient (GRG) technique and multi-objective E-V model is solved by Augmented Fuzzy Max-Min Approach. The models are illustrated numerically.
This paper presents a new approach to predict the quality of polypropylene in petrochemical plants. The proposed approach constructs four different models, based on a large number of data collected from a renowned pet...
详细信息
We consider here the inventory problems with infinite rate of replenishment in crisp and fuzzy environments over a finite time horizon for deteriorating multi-items taking time dependent demand and allowing shortages ...
We consider here the inventory problems with infinite rate of replenishment in crisp and fuzzy environments over a finite time horizon for deteriorating multi-items taking time dependent demand and allowing shortages and equal replenishment cycles. Here, the objectives of maximizing the profit and minimizing the replenishment cost are imprecise in nature. Total shortage cost is assumed to be limited but vague and imprecise in non-stochastic sense. The impreciseness in the above objectives’ and constraint’ goals have been expressed by fuzzy linear Membership Functions (MFs). Under these assumptions, a Decision Maker (DM) is confronted with four possibilities depending upon the nature of the first and last cycles and he/she has to choose the best one for maximum profit-ratio (i.e. the ratio of total profit to total cost). Hence, both crisp and fuzzy models with different shortage criteria are developed and solved by the weighted fuzzy non-linear programming (WFNLP) and goal attainment methods (GAM). Fuzzy models have also been solved by an integrated goal attainment and fuzzy non-linear programming technique (GAFNLP). Models are illustrated with numerical examples and the results are compared.
暂无评论