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Dynamics of a Fractional-Order Predator-Prey Model with Infectious Diseases in Prey Panigoro, Hasan S.; Suryanto, Agus; Kusumahwinahyu, Wuryansari Muharini; Darti, Isnani
Communication in Biomathematical Sciences Vol 2, No 2 (2019)
Publisher : Indonesian Bio-Mathematical Society

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2363.045 KB) | DOI: 10.5614/cbms.2019.2.2.4

Abstract

In this paper, a dynamical analysis of a fractional-order predator-prey model with infectious diseases in prey is performed. First, we prove the existence, uniqueness, non-negativity, and boundedness of the solution. We also show that the model has at most five equilibrium points, namely the origin, the infected prey and predator extinction point, the infected prey extinction point, the predator extinction point, and the co-existence point. For the first four equilibrium points, we show that the local stability properties of the fractional-order system are the same as the first-order system, but for the co-existence point, we have different local stability properties.We also present the global stability of each equilibrium points except for the origin point. We observe an interesting phenomenon, namely the occurrence of Hopf bifurcation around the co-existence equilibrium point driven by the order of fractional derivative. Moreover, we show some numerical simulations based on a predictor-corrector scheme to illustrate the result of our dynamical analysis.
ANALISIS KESTABILAN PADA PERSAMAAN NICHOLSON’S BLOWFLIES DENGAN WAKTU TUNDA Hikmah, Maziyahtul; Suryanto, Agus; Wibowo, Ratno Bagus Edy; Alghofari, Abdul Rouf
Jurnal Mahasiswa Matematika Vol 1, No 1 (2013)
Publisher : Jurnal Mahasiswa Matematika

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Abstract

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Analysis of factors contributing to the dispersal of Casuarina junghuhniana Miq. in a volcanic mountain Brian Rahardi; Serafinah Indriyani; Luchman Hakim; Agus Suryanto
Journal of Degraded and Mining Lands Management Vol 7, No 3 (2020)
Publisher : Brawijaya University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15243/jdmlm.2020.073.2163

Abstract

Casuarina junghuhniana or mountain ru, she oak or cemara is a species from Indonesia which grows in the highland area at an altitude between 2000 - 3000 m above sea level (asl). One of the highland area in Eastern Java (Jawa Timur) of Indonesia is Bromo Tengger Semeru National Park (TNBTS). The study site was on the Tengger Sea of Sands, Eastern Java, Indonesia where it is affected by volcanic activity. This tree, from some references, has not been well studied yet although it has been reported as a tree native to Indonesia. The lack of the study poses problems when there is a program related to planting the tree on a certain location in TNBTS for rehabilitation purposes. This study attempted to construct a Structural Equation Model that mapped some factors observed in the study site related to C. junghuhniana population. Explored factors for their relationship with each other included the number of male and female individuals, growth-related indicators, and environmental factors consisting of altitude and the tree population. Formative factors which consist of parameters related to growth, environmental factors and factor associated with the diffusion of new individuals, may contribute to population growth while population growth was the opposite. The individual growth might not significantly contribute to the population of C. junghuhniana; instead, the population growth was affected by the tree individuals. Generative reproduction contributed the least to the dispersal as it may rely more on vegetative reproduction by adventitious shoots from roots.
Effect of Energy Gain and Loss in Breathing Pattern of Solitary Wave for Nonlinear Equation Nur Shafika Abel Razali; Farah Aini Abdullah; Yahya Abu Hasan; Agus Suryanto
Journal of Natural A Vol 1, No 2 (2014)
Publisher : Fakultas MIPA Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (692.058 KB)

Abstract

Nonlinear phenomena like soliton propagate over long distance in transmit information, without dispersion energy due to the properties of the solitons, which has balanced of the nonlinearity effect and dispersion effect resulted the signal undistorted and symmetric bell shape curve. We study about the properties and breathing pattern of solitary wave of pulses in absence and present of energy loss, by using one dimensional nonlinear equation; cubic-quintic complex Ginzburg-Landau equation (cqCGLE). Breathing pattern of soliton behaviour is constructed with hyperbolic sine and hyperbolic tangent as initial amplitude profile and observed by means of numerical simulation. Resulting in observation of breathing pattern of soliton in term of energy loss and gain while travelling, but it still maintains spatial localization of wave energy in the changing pulses shape through a unique dissipative soliton.Keywords— Soliton, nonlinearity, dispersion, breathing, energy.
A Variational Approach of Creeping Solitons with Hartman-Grobman Theorem in Complex Ginzburg-Landau Equation Nur Izzati Khairudin; Farah Aini Abdullah; Yahya Abu Hassan; Agus Suryanto
Journal of Natural A Vol 1, No 2 (2014)
Publisher : Fakultas MIPA Universitas Brawijaya

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Abstract

The behavior of quintic nonlinear dispersion coefficient of creeping soliton in a spatial domain with hyperbolicity analysis of Hartman-Grobman Theorem by using variational approach is studied. Complex Ginzburg-Landau equation (CGLE) is used in the analysis as we relate the creeping soliton with Hartman- Grobman Theorem. We evaluated our work based on perturbed Jacobian matrix from system of three supercritical ordinary differential Euler-Lagrange equations, in which the eigenvalues of the stability matrix touch the imaginary axis. As a consequence in unfolding the bifurcation of creeping solitons, the equilibrium structure ultimately chaotic at the variation of the coefficient µ away from the critical value, µc . This leads to hyperbolicity loss of Hartman-Grobman Theorem in the dissipative system driven out the oscillatory instability of µ exceeded the criticality parameter corresponding to the Hopf bifurcations as the system is highly complex. This overall approach restrict to numerical investigation of the space time hyperbolic variation of CGLE.Keywords— Dissipative solitons, complex Ginzburg-Landau equation.
Dynamics of a Fractional-Order Predator-Prey Model with Infectious Diseases in Prey Hasan S. Panigoro; Agus Suryanto; Wuryansari Muharini Kusumahwinahyu; Isnani Darti
Communication in Biomathematical Sciences Vol. 2 No. 2 (2019)
Publisher : Indonesian Bio-Mathematical Society

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/cbms.2019.2.2.4

Abstract

In this paper, a dynamical analysis of a fractional-order predator-prey model with infectious diseases in prey is performed. First, we prove the existence, uniqueness, non-negativity, and boundedness of the solution. We also show that the model has at most five equilibrium points, namely the origin, the infected prey and predator extinction point, the infected prey extinction point, the predator extinction point, and the co-existence point. For the first four equilibrium points, we show that the local stability properties of the fractional-order system are the same as the first-order system, but for the co-existence point, we have different local stability properties.We also present the global stability of each equilibrium points except for the origin point. We observe an interesting phenomenon, namely the occurrence of Hopf bifurcation around the co-existence equilibrium point driven by the order of fractional derivative. Moreover, we show some numerical simulations based on a predictor-corrector scheme to illustrate the result of our dynamical analysis.
Forecasting COVID-19 Epidemic in Spain and Italy Using A Generalized Richards Model with Quantified Uncertainty Isnani Darti; Agus Suryanto; Hasan S. Panigoro; Hadi Susanto
Communication in Biomathematical Sciences Vol. 3 No. 2 (2020)
Publisher : Indonesian Bio-Mathematical Society

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/cbms.2020.3.2.1

Abstract

The Richards model and its generalized version are deterministic models that are often implemented to fit and forecast the cumulative number of infective cases in an epidemic outbreak. In this paper we employ a generalized Richards model to predict the cumulative number of COVID-19 cases in Spain and Italy, based on available epidemiological data. To quantify uncertainty in the parameter estimation, we use a parametric bootstrapping approach to construct a 95% confidence interval estimation for the parameter model. Here we assume that the time series data follow a Poisson distribution. It is found that the 95% confidence interval of each parameter becomes narrow with the increasing number of data. All in all, the model predicts daily new cases of COVID-19 reasonably well during calibration periods. However, the model fails to produce good forecasts when the amount of data used for parameter estimations is not sufficient. Based on our parameter estimates, it is found that the early stages of COVID-19 epidemic, both in Spain and in Italy, followed an almost exponentially growth. The epidemic peak in Spain and Italy is respectively on 2 April 2020 and 28 March 2020. The final sizes of cumulative number of COVID-19 cases in Spain and Italy are forecasted to be at 293220 and 237010, respectively.
Dynamics of COVID-19 Epidemic Model with Asymptomatic Infection, Quarantine, Protection and Vaccination Raqqasyi Rahmatullah Musafir; Agus Suryanto; Isnani Darti
Communication in Biomathematical Sciences Vol. 4 No. 2 (2021)
Publisher : Indonesian Bio-Mathematical Society

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/cbms.2021.4.2.3

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We discuss the dynamics of new COVID-19 epidemic model by considering asymptomatic infections and the policies such as quarantine, protection (adherence to health protocols), and vaccination. The proposed model contains nine subpopulations: susceptible (S), exposed (E), symptomatic infected (I), asymptomatic infected (A), recovered (R), death (D), protected (P), quarantined (Q), and vaccinated (V ). We first show the non-negativity and boundedness of solutions. The equilibrium points, basic reproduction number, and stability of equilibrium points, both locally and globally, are also investigated analytically. The proposed model has disease-free equilibrium point and endemic equilibrium point. The disease-free equilibrium point always exists and is globally asymptotically stable if basic reproduction number is less than one. The endemic equilibrium point exists uniquely and is globally asymptotically stable if the basic reproduction number is greater than one. These properties have been confirmed by numerical simulations using the fourth order Runge-Kutta method. Numerical simulations show that the disease transmission rate of asymptomatic infection, quarantine rates, protection rate, and vaccination rates affect the basic reproduction number and hence also influence the stability of equilibrium points.
Kontrol Optimal pada Model Economic Order Quantity (EOQ) dengan Inisiatif Tim Penjualan Abdul Latif Al Fauzi; Isnani Darti; Agus Suryanto
Jurnal Teknik Industri Vol. 19 No. 1 (2017): JUNE 2017
Publisher : Institute of Research and Community Outreach - Petra Christian University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (414.809 KB) | DOI: 10.9744/jti.19.1.21-28

Abstract

Pengendalian  tingkat persediaan stok suatu produk/barang merupakan salah satu kegiatan yang penting dalam kelancaran penjualan, yang juga berakibat pada keuntungan yang akan diperoleh dari penjualan suatu produk/barang.  Model Economic Order Quantity (EOQ) merupakan salah satu model persediaan barang yang sering digunakan untuk pengendalian persedian barang. Pada artikel ini dibahas kontrol optimal pada model EOQ dengan inisiatif tim penjualan tidak hanya pada saat kondisi setimbang saja, tetapi kontrol optimal dengan usaha tim penjualan pada setiap saat. Strategi kontrol optimal dilakukan dengan meminimumkan biaya persediaan, biaya pembelian, biaya penjualan dan biaya usaha tim penjualan. Masalah kontrol optimal diselesaikan menggunakan prinsip maksimum Pontryagin. Solusi optimal yang diperoleh disimulasikan secara numerik menggunakan metode Sweep Maju-Mundur. Berdasarkan hasil simulasi numerik dapat diketahui bahwa semakin besar koefisien tingkat permintaan barang, maka proses persediaan barang akan lebih cepat berkurang. Selain itu semakin besar usaha tim penjualan, maka proses persediaan barang akan lebih sedikit bahkan lebih cepat habis.  
Dynamics of a Fractional Order Eco-Epidemiological Model Kartika Nugraheni; Trisilowati Trisilowati; Agus Suryanto
Journal of Tropical Life Science Vol. 7 No. 3 (2017)
Publisher : Journal of Tropical Life Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11594/jtls.07.03.09

Abstract

In this paper, we propose a fractional order eco-epidemiological model. We considere the existence of time memory in the growth rate of the three populations. We observed the dynamical behaviour by analysing with fractional order and then simulateing using Grünwald-Letnikov approximation to support analytical results. It found that the model has five equilibrium points, namely the origin, the survival of susceptible prey, the predator free equilibria, the infected prey free equilibria, the interior equilibria. Numerical simulations show that the existence of fractional order  is a factor which affects the behaviour of solutions.Â