University of the Philippines at Baguio

www.upb.edu.ph
Sigaboy, Philippines

The University of the Philippines Baguio is a public research university in the Philippines. Wikipedia.

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Rabago J.F.T.,University of the Philippines at Baguio
International Journal of Dynamical Systems and Differential Equations | Year: 2017

Various systems of non-linear difference equations, of different forms, were studied in the last two decades or so. In this existing work, two earlier published papers, due, respectively, to Bayram and Das and Elsayed, are revisited. The results exhibited in these previous investigations are re-examined through a new approach, more theoretical and explanative compared to the ones offered in these aforementioned works. Furthermore, the qualitative behaviour of solutions of a system of non-linear difference equations of higher order is investigated through analytical methods. The system, which is considered here, generalises those that are first presented in a paper of Elsayed but are treated differently from this pre-existing work. The results delivered here are important, not only for the reason that they provide theoretical explanations on several earlier results but also because the system being studied can be used to model real-life phenomena exhibiting periodic behaviours. Copyright © 2017 Inderscience Enterprises Ltd.


Rabago J.F.T.,University of the Philippines at Baguio | Bacani J.B.,University of the Philippines at Baguio
AIP Conference Proceedings | Year: 2016

Hensel's lemma is an important result in valuation theory which gives information on finding roots of polynomials. A classical application of this result deals with the problem of finding roots of a p-adic number a in the set of p-adic numbers ℚp. Lately, there are several investigations concerning the problem of finding roots of p-adic numbers using classical root-finding methods from numerical analysis. None of these previous works, however, gave account to the problem of finding roots of a general p-adic polynomial equation in ℤp[x]. Hence, motivated by this observation, we propose an analogue of Steffensen's method in finding roots of a general polynomial equation f (x) = 0 in ℤp[x], thereby providing a generalization of previous investigations regarding root-finding problems in the p-adic setting.


Addawe J.,University of the Philippines at Baguio | Pajimola A.K.,University of the Philippines at Baguio
AIP Conference Proceedings | Year: 2016

In this paper, we proposed to study the dynamics of malaria transmission with periodic birth rate of the vector and an age-structure for the human population. The human population is divided into two compartments: pre-school (0-5 years) and the rest of the human population. We showed the existence of a disease-free equilibrium point. Using published epidemiological parameters, we use numerical simulations to show potential effect of climate change in the dynamics of age-structured malaria transmission. Numerical simulations suggest that there exists an asymptotically attractive solution that is positive and periodic. © 2016 Author(s).


Domogo A.A.,University of the Philippines at Baguio | Collera J.A.,University of the Philippines at Baguio
AIP Conference Proceedings | Year: 2016

We consider a model of a tetrad of semiconductor lasers with unidirectional coupling. This system is described by Lang-Kobayashi (LK) rate equations, which is a system of delay differential equations with one fixed delay. Basic solutions to this system are called compound laser modes (CLMs). We classify the CLMs of this four-laser system according to their symmetry. The symmetric CLMs are identified by looking at the isotropy subgroups of the symmetry group of this system. Numerical continuation in DDE-Biftool generates a branch of symmetric CLMs. We then find steady-state and Hopf bifurcations along the branch of fully symmetric CLMs and identify those that are symmetry-breaking and symmetry-preserving. Finally, we use the Equivariant Branching Lemma and Equivariant Hopf Theorem to establish the existence of emanating branches of solutions from symmetry-breaking bifurcations. © 2016 Author(s).


Bacani J.B.,University of the Philippines at Baguio | Rabago J.F.T.,University of the Philippines at Baguio
AIP Conference Proceedings | Year: 2016

We derive the closed-form solutions of the following difference equations xn+1=xn-3±1+xn-2xn, n=0,1,2,., where x-3, x-2, x-1, x0 (0, ∞). We also investigate the behavior of their respective solutions. Particularly, we study the conver-gence, periodicity character, stability and boundedness of their solutions. © 2016 Author(s).


Collera J.A.,University of the Philippines at Baguio
AIP Conference Proceedings | Year: 2016

We consider a tri-Trophic community module called intraguild predation (IGP) that includes a prey and its predator which share a common basal resource for their sustenance. The growth of the basal resource in the absence of predation follows the Hutchinson's equation where the delay parameter arises, while functional responses in our model are of Lotka-Volterra type. Moreover, the basal resource is harvested for its economic value with a constant harvesting rate. This work generalizes the previous works on the same model with no harvesting and no time delay. We show that the harvesting rate has to be small enough in order for the equilibria to exist. Moreover, we show that by increasing the delay parameter the stability of the equilibrium solutions may change, and periodic solutions may emerge through Hopf bifurcations. In the case of the positive equilibrium solution, multiple stability switches are obtained, and numerical continuation shows that a stable branch of periodic solutions emerges once the positive equilibrium loses its stability at the first Hopf bifurcation point. This result is important because it gives an alternative for the coexistence of all three species, avoiding extinction of one or more species when the positive equilibrium becomes unstable. © 2016 AIP Publishing LLC.


Rabago J.F.T.,University of the Philippines at Baguio
Journal of Physics: Conference Series | Year: 2016

Let (ωn)n∈ℕ be the sequence of k-Fibonacci numbers recursively defined by ω1 = 1, ω2 = 1, ωn+2 = kωn+1 + ωn, ∀n ∈ℕ, and m be a fixed positive integer. In this work we prove that, for almost every x ∈ (0, 1), the pattern k, k, ⋯ k (comprising of m-digits) appears in the continued fraction expansion x = [0, a1, a2; ⋯] with frequency f(k,m) := (-1)m k/log 2 log {φm+1 -1φm -1}, where φm = ωm+1/ωm, i.e., limn→∞ 1/n #{j ∈ Ωn : aj+i = k for all i ∈ Ωm-1 ∪{0}} = f(k,m), where Ωn := {1, 2; ⋯, n}.


Peralta G.,University of the Philippines at Baguio
Zeitschrift fur Angewandte Mathematik und Physik | Year: 2016

A coupled system of partial differential equations modeling the interaction of a fluid and a structure with delay in the feedback is studied. The model describes the dynamics of an elastic body immersed in a fluid that is contained in a vessel, whose boundary is made of a solid wall. The fluid component is modeled by the linearized Navier-Stokes equation, while the solid component is given by the wave equation neglecting transverse elastic force. Spectral properties and exponential or strong stability of the interaction model under appropriate conditions on the damping factor, delay factor and the delay parameter are established using a generalized Lax-Milgram method. © 2016, Springer International Publishing.


Sta Maria C.F.L.,University of the Philippines at Baguio
International Journal of Social Ecology and Sustainable Development | Year: 2014

"Locating ourselves in the center of en masse urbanization⋯." Matnog, Sorsogon, Philippines, primarily a coastal area is not exempted from this socio-cultural shift. And in these changes, people, specifically that of the eight Girls, ages 14 to 18 years old living in the periphery of the coast, begin to question this condition of urbanization that has only created varied and severe strands of poverty in their area. "I look at their photographs and listen to their narrative⋯." Using Alice McIntyre's photovoice, the Girls took photographs of spaces that represent the concepts of poverty and development. I let them speak of these spaces and they begin to talk about "development" and "poverty," focusing on the existence of the Pier, the Coast and that of their lives. "Spatiality of the Pier⋯." Taking the postmodern lens, guided by Edward Soja's notions on spatiality is an attempt to view the unfolding of tensions emanating from urban spaces and their representations. The Pier and that of other spaces become the discursive arena that conjugate non-recognition of positions and conditions between the concepts of "poverty" and "development." With the Pier as the most imposing space emerges ambiguity and blurry vision affect how the Girls perceive, conceive and live in and along these spaces. Development as assumed to be an existing and workable paradigm through urbanization promise alteration of their condition does not exist for them. What happens is that "poverty" becomes the constant wherein time and space are in crisis; and, the spatiality of the Girls becomes fragmented and pulverized. "IT": For urbanization as a development agenda does not fulfill its promise to the Girls of Matnog, Sorsogon and to us. This knowledge as conceptualized for them place them in a position and state where they no longer recognize what development is. In this discourse, development, urbanization and spaces that represent them all becomes (in)visible that have become (un)recognizable and (un)familiar for the Girls and for us. This (non)recognition place all these concepts and spaces as an IT. Copyright © 2014, IGI Global.


Balangcod T.D.,University of the Philippines at Baguio | Balangcod A.K.D.,University of the Philippines at Baguio
Indian Journal of Traditional Knowledge | Year: 2011

Tinoc, Ifugao is located within the Cordillera Central Range, Northern Luzon, Philippines. It is inhabited by the Kalanguya, one of the indigenous societies in the Cordillera, who have a long tradition of using medicinal plants. The paper describes ethnomedicinal importance of 125 plant species, and healthcare practices as cited by 150 informers ranging between 16-90 yrs. Various ailments that are treated by the identified medicinal plants vary from common diseases such as headache, stomachache, toothache, cough and colds, and skin diseases to more serious ailments which includes urinary tract infection, dysentery, and chicken pox. There are different modes of preparation of these medicinal plants. For instance, immediate treatment for cuts was demonstrated by using crushed leaves of Eupatorium adenophorum L. An increased efficacy was noted by creating mixtures from combining certain plants. The medicinal plants are summarized by giving their scientific name, family, vernacular name and utilization.

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