Browsing by Author "Bilge, Ayşe Hümeyra"
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The Impact of Dynamic Shocks and Special Days on Time Series Data
This paper includes an examination of a 4-year time series data on retail delivery demand generated by a logistics company based on the dates of creation. The periodic fluctuations observed in the data's normal structure ... -
İkili alım satım yöntemlerinin İstanbul borsası hisse senedi piyasasında uygulanabilirliğinin araştırılması
Memiş, Cansın (Kadir Has Üniversitesi, 2017)İkili hisse alım satımı kantitatif finans alanında, akademisyenler ve profesyonel finans çevrelerinin yıllardır ilgisini çekmiş fakat gerçek veri üzerinde çok az test edilmiş popüler tekniklerden biridir. Bu tezde, ikili ... -
'Level grading' a new graded algebra structure on differential polynomials: application to the classification of scalar evolution equations
Mizrahi, Eti; Bilge, Ayşe Hümeyra (IOP Publishing Ltd, 2013)We define a new grading which we call the 'level grading' on the algebra of polynomials generated by the derivatives u(k+i) over the ring K-(k) of C-infinity functions of x t u u(1) ... u(k) where . This grading has the ... -
Managing natural gas demand for free consumers under uncertainty and limited storage capacity
Aktunç, Esra Ağca; Yükseltan, Ergün; Yücekaya, Ahmet; Bilge, Ayşe Hümeyra (Elsevier, 2020)Demand for energy sources depends on several factors such as population growth, urbanization, industrialization, and climate. Among fundamental energy sources, natural gas is characterized by storage limitations and ... -
A mathematical characterization of the gel point in sol-gel transition
Bilge, Ayşe Hümeyra; Pekcan, Önder (IOP Publishing Ltd, 2015)We model the sol-gel transition in terms of Susceptible-Infected-Removed (SIR) and Susceptible-Exposed-Infected-Removed (SEIR) models and compare with experimental results. We show, numerically, that the "gel point" described ... -
Mathematical Characterization of Thermo-reversible Phase Transitions of Agarose Gels
Öğrenci, Arif Selçuk; Pekcan, Önder; Kara, Selim; Bilge, Ayşe Hümeyra (Taylor & Francis Inc, 2018)The thermal phase transition temperatures of high (HMP) and low melting point (LMP) agarose gels were investigated by using UV-vis spectroscopy techniques. Transmitted light intensities from the gel samples with different ... -
A MATHEMATICAL DESCRIPTION OF THE CRITICAL POINT IN PHASE TRANSITIONS
Bilge, Ayşe Hümeyra; Pekcan, Önder (World Scientific Publ Co Pte Ltd, 2013)Let y(x) be a smooth sigmoidal curve, y((n)) be its nth derivative and {x(m,i)} and {x(a,i)}, i = 1, 2, ... , be the set of points where respectively the derivatives of odd and even order reach their extreme values. We ... -
Mathematical models for phase transitions in biogels
Bilge, Ayşe Hümeyra; Öğrenci, Arif Selçuk; Pekcan, Önder (World Scientific Publ Co Pte Ltd, 2019-03-30)It has been shown that reversible and irreversible phase transitions of biogels can be represented by epidemic models. The irreversible chemical sol-gel transitions are modeled by the Susceptible-Exposed-Infected-Removed ... -
Mathematical models for phase transitions in biogels
Bilge, Ayşe Hümeyra; Öğrenci, Arif Selçuk; Pekcan, Önder (World Scientific Publ Co Pte Ltd, 2019)It has been shown that reversible and irreversible phase transitions of biogels can be represented by epidemic models. The irreversible chemical sol-gel transitions are modeled by the Susceptible-Exposed-Infected-Removed ... -
Maximal linear subspaces of strong self-dual 2-forms and the Bonan 4-form
Bilge, Ayşe Hümeyra; Dereli, Tekin; Koçak, Şahin (Elsevier Science Inc, 2011)The notion of self-duality of 2-forms in 4-dimensions plays an eminent role in many areas of mathematics and physics, but although the 2-forms have a genuine meaning related to curvature and gauge-field-strength in higher ... -
Modeling of Wind Effects on Stratified Flows in Open Channels: A Model for the Istanbul Strait (Bosphorus)
Stratified flows in open channels arise as a result of density or surface level differences. If the channel is connected to a basin at one or both ends, strong winds originating from the basin cause the "wind setup" effect ... -
On the Classification of Fifth Order Quasi-linear Non-constant Separant Scalar Evolution Equations of the KdV-Type
Özkum, Gülcan; Bilge, Ayşe Hümeyra (Physical Soc Japan, 2012)Fifth order, quasi-linear, non-constant separant evolution equations are of the form u(t) = A(partial derivative(5)u/partial derivative x(5)) + (B) over tilde, where A and (B) over tilde are functions of x, t, u and of the ... -
On the classification of scalar evolution equations with non-constant separant
Bilge, Ayşe Hümeyra; Mizrahi, Eti (IOP Publishing Ltd, 2017)The ` separant' of the evolution equation u(t) = F where F is some differentiable function of the derivatives of u up to order m is the partial derivative partial derivative F/partial derivative u(m) where um u(m) = partial ... -
On the Time Shift Phenomena in Epidemic Models
Peker-Dobie, Ayşe; Demirci, Ali; Bilge, Ayşe Hümeyra; Ahmetolan, Semra (Frontiers Media Sa, 2020)In the standard Susceptible-Infected-Removed (SIR) and Susceptible-Exposed-Infected-Removed (SEIR) models, the peak of infected individuals coincides with the inflection point of removed individuals. Nevertheless, a survey ... -
On the uniqueness of epidemic models fitting a normalized curve of removed individuals
Bilge, Ayşe Hümeyra; Samanlıoğlu, Funda; Ergönül, Önder (Springer Heidelberg, 2015)The susceptible-infected-removed (SIR) and the susceptible-exposed-infected-removed (SEIR) epidemic models with constant parameters are adequate for describing the time evolution of seasonal diseases for which available ... -
On the uniqueness of the octonionic instanton solution on conformally flat 8-manifolds
Bilge, Ayşe Hümeyra (IOP Publishing Ltd, 2016)Let M be an 8-manifold and E be an SO(8) bundle on M. In a previous paper [F. Ozdemir and A.H. Bilge, "Self-duality in dimensions 2n > 4: equivalence of various definitions and the derivation of the octonionic instanton ... -
An Overview of the 2009 A(H1N1) Pandemic in Europe: Efficiency of the Vaccination and Healthcare Strategies
Samanlıoğlu, Funda; Bilge, Ayşe Hümeyra (Hindawi Ltd, 2016)2009 A(H1N1) data for 13 European countries obtained from the weekly influenza surveillance overview (WISO) reports of European Centre for Disease Prevention and Control (ECDC) in the form of weekly cumulative fatalities ... -
Sabit oranlı portföy sigortalama stratejisinde sabit çarpanın fiyat
Özer, Özen (Kadir Has Üniversitesi, 2014)Sabit Oranlı Portföy Sigortası temelde riskli ve risksiz varlıktan oluşmaktadır. Portföydeki riskli varlık oranı "Sabit Çarpan" ve "Yastık Tutarı" parametreleri ile belirlenmektedir. Portföy sigortasında yatırımcıya önceden ... -
Sabit oranlı portföy sigortasında modern portföy teorisi ve finansal varlıkları fiyatlama modeli kullanımı önerisi
Büke, Mehmet Ata (Kadir Has Üniversitesi, 2018)Portföy sigortası, yatırımcıları piyasa düşüşlerinden korumak ve piyasa yükselişlerinde portföyün değerini artırmak için dünya çapında kullanılan bir stratejidir. Sabit oranlı portföy sigortası da bu konu başlığı altına ... -
Self-duality in higher dimensions
Bilge, Ayşe Hümeyra; Dereli, Tekin; Koçak, Şahin (IOP Publishing Ltd, 2017)Let w be a 2-form on a 2n dimensional manifold. In previous work, we called w "strong self-dual, if the eigenvalues of its matrix with respect to an orthonormal frame are equal in absolute value. In a series of papers, we ...