377 research outputs found

    Feedback control and its impact on generalist predator–prey system with prey harvesting

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    This article examines the effectiveness of feedback control as a management policy on a generalist predator–prey system with prey harvesting. We discuss the result of implementing feedback control with respect to prey and predator separately. This paper also depicts the effect of exploitations up to maximum sustainable yield (MSY). We observe that with a constant fishing effort MSY policy is a sustainable management policy to protect both the species. However, further increase of fishing effort may cause the extinction of prey species. But considering feedback control of fishing effort may restrict the extinction of prey species. When fishing effort is controlled in terms of prey density, the extinction of prey population can be avoided. In this case, there may be coexistences of prey, predator and fishery or extinction of fishery. But when fishing effort is controlled by predator density, it is difficult to manage the coexistences of prey, predator and fishery. &nbsp

    Impacts of predator–prey interaction on managing maximum sustainable yield and resilience

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    This paper gives a broad outline of some comparative analysis of two ecological services, namely, yield and resilience of a generalist predator–prey system. Although either prey or predator species can be harvested at maximum sustainable yield (MSY) level, yet there is a trade-off between yield and resilience. When both the species are harvested simultaneously, MSY increase by changing catchabilities always increases the system resilience both in prey- and predator-oriented fishery. In particular, a prey-oriented fishery with low prey catchability gives more yield and resilience but in case of predator-oriented fishery with high predator catchability, gives more of these ecological services. Thus to get both the optimum yield and resilience, a balanced harvesting approach is needed between the prey and predator trophic levels. Throughout the analysis, we use both the analytical as well as numerical techniques. &nbsp

    Stability analysis of a prey-predator model incorporating a prey refuge,”

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    Abstract We consider a prey-predator model with Holling type II response function incorporating a prey refuge. The purpose of the work is to offer mathematical analysis of the model and to discuss some significant qualitative results that are expected to arise from the interplay of biological forces. Some numerical simulations are carried out

    An Inventory Model under Space Constraint in Neutrosophic Environment: A Neutrosophic Geometric Programming Approach

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    In this paper, an inventory model is developed without shortages where the production cost is inversely related to the set up cost and production quantity. In addition, the holding cost is considered time dependent. Here impreciseness is introduced in the storage area. The objective and constraint functions are defined by the truth (membership) degree, indeterminacy (hesitation) degree and falsity (non-membership) degree. Likewise, a non-linear programming problem with a constraint is also considered. Then these are solved by Neutrosophic Geometric Programming Technique for linear membership, hesitation and non-membership functions. Also the solution procedure for Neutrosophic Non-linear Programming Problem is proposed by using additive operator and Geometric Programming method. Numerical examples are presented to illustrate the models using the proposed procedure and the results are compared with the results obtained by other optimization techniques

    Global dynamics and optimal control of a nonlinear fractional-order cholera model

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    In this article, a fractional-order epidemic model for cholera is proposed and analyzed. Two transmission routes for cholera are considered to develop the compartmental epidemic model. The basic biological properties of the solutions of the fractional-order model are investigated. The global asymptotic stability of the equilibrium points have been established using appropriate Lyapunov functional. Moreover, a fractional-order control problem is presented, and its analytical solution is derived using Pontryagin’s maximum principle. Also, some graphical visualizations of the theoretical results are provided. It is found that the factional-order derivative only affect the time to reach the stationary states. Sensitivity analysis reveals that by reducing the rates of new recruitment and both the disease transmission rates, it may be possible to reduce the value of the basic reproduction number

    Optimization of EOQ Model with Limited Storage Capacity by Neutrosophic Geometric Programming

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    In this article, we present deterministic single objective economic order quantity model with limited storage capacity in neutrosophic environment. We consider variable limit production cost and time dependent holding cost into account. Here we minimize total average cost of proposed model by applying neutrosophic geometric programming, which is obtained by extending existing fuzzy and intuitionistic fuzzy geometric programming for solving resultant non-linear optimization model. Next we consider numerical application to show that optimal solution obtained by neutrosophic geometric programming is more desirable than that of crisp, fuzzy and intuitionistic fuzzy geometric programming. Also we perform sensitivity analysis of parameters and present key managerial insights

    Parametric optimalization of submerged fermantation conditions for xylanase production Bacillus cereus BSA1 through Taguchi Methodology

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    Extracellular xylanase production of Bacillus cereus BSA1 was optimized under submerged fermentation using Taguchi orthogonal array (OA). An L18 layout of OA was constructed at three-levels of six factors, i.e. temperature, pH, and xylan, Na2HPO4, NH4NO3 and NaCl concentrations, influencing the xylanase synthesis. The enzyme production was studied in 18 parallel batch systems using different levels of each factor. The results were processed with Qualitek-4 software using ‘bigger is better’ quality character, and combination of 35 oC; pH 6.0; and xylan 0.5; NH4NO3 0.5, Na2HPO4, 0.1; NaCl 0.05 concentrations (in w/v %) with a predictive xylanase production of 7.404 U/ml was obtained. Fermentation experiment was performed for further validating the statistical output, and it resulted 10.24% in the xylanase yield (from 6.44 U/ml to 7.10 U/ml) as compared to one variable at a time (OVAT) design. Interaction effects of the factors individually and in combination can be evaluated by using Taguchi method design of experiment

    Clinical Computing in Dentistry

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    Machines can seldom replace dentists in rightly handling the patients with optimistic human insight, considerations, creative planning and the monitoring of psychological acceptance and comfort experienced by any patient with the rehabilitation done. Intelligent computer related armamentarium with software can still help dental practitioners detect typical medical and dental signs and classify them according to certain rules more effectively. Based on image analysis algorithms, CAD systems can be used to look for signs of any tooth pathology that can be spotted in dental X-ray or cone beam computed tomography (CBCT) images. Applying computer vision algorithms to high-resolution CBCT slices helps to a great extent in diagnosing periapical lesions like granulomas, cysts, etc., and can help creating 3-D model of a root canal that reflects its shape with sufficient precision facilitating an optimum endodontic treatment planning. Hence, computer vision systems are already able to speed up the diagnostic process and provide a valuable second opinion in doubtful cases. This can lead a dentist and the patient thoroughly experience an optimistic acceptance and satisfaction of the treatment done

    Forward-central two-particle correlations in p-Pb collisions at root s(NN)=5.02 TeV

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    Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 2GeV/c. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B. V.Peer reviewe

    Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

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    We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe
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