Physical Sciences and Mathematics Commons^™

Portfolio Optimization With Two Quasiconvex Risk Measures, Çağin Ararat

Turkish Journal of Mathematics

We study a static portfolio optimization problem with two risk measures: a principle risk measure in the objective function and a secondary risk measure whose value is controlled in the constraints. This problem is of interest when it is necessary to consider the risk preferences of two parties, such as a portfolio manager and a regulator, at the same time. A special case of this problem where the risk measures are assumed to be coherent (positively homogeneous) is studied recently in a joint work of the author. The present paper extends the analysis to a more general setting by assuming …

A New Implicit-Explicit Local Differential Method For Boundary Value Problems, Hüseyi̇n Tunç, Murat Sari

Turkish Journal of Mathematics

In this study, an effective numerical method based on Taylor expansions is presented for boundary value problems. This method is arbitrary directional and called as implicit-explicit local differential transform method (IELDTM). With the completion of this study, a reliable numerical method is derived by optimizing the required degrees of freedom. It is shown that the order refinement procedure of the IELDTM does not affect the degrees of freedom. A priori error analysis of the current method is constructed and order conditions are presented in a detailed analysis. The theoretical order expectations are verified for nonlinear BVPs. Stability of the IELDTM …

Soft $\Beta$-Rough Sets And Their Application To Determine Covid-19, Mostafa K. El Bably, Abd El Fattah A. El Atik

Turkish Journal of Mathematics

Soft rough set theory has been presented as a basic mathematical model for decision-making for many real-life data. However, soft rough sets are based on a possible fusion of rough sets and soft sets which were proposed by Feng et al. [20]. The main contribution of the present article is to introduce a modification and a generalization for Feng's approximations, namely, soft $\beta$-rough approximations, and some of their properties will be studied. A comparison between the suggested approximations and the previous one [20] will be discussed. Some examples are prepared to display the validness of these proposals. Finally, we put …

Repdigits As Sums Of Two Generalized Lucas Numbers, Sai Gopal Rayaguru, Jhon Jairo Bravo

Turkish Journal of Mathematics

A generalization of the well-known Lucas sequence is the $k$-Lucas sequence with some fixed integer $k \geq 2$. The first $k$ terms of this sequence are $0,\ldots,0,2,1$, and each term afterwards is the sum of the preceding $k$ terms. In this paper, we determine all repdigits, which are expressible as sums of two $k$-Lucas numbers. This work generalizes a prior result of Şiar and Keskin who dealt with the above problem for the particular case of Lucas numbers and a result of Bravo and Luca who searched for repdigits that are $k$-Lucas numbers.

On The Analytical Development Of Incomplete Riemann-Liouville Fractional Calculus, Arran Fernandez, Ceren Ustaoğlu, Mehmet Ali̇ Özarslan

Turkish Journal of Mathematics

The theoretical development of fractional calculus includes the formulation of different definitions, the extension of properties from standard calculus, and the application of fractional operators to special functions. In two recent papers, incomplete versions of classical fractional operators were formulated in connection with special functions. Here, we develop the theory of incomplete fractional calculus more deeply, investigating further properties of these operators and answering some fundamental questions about how they work. By considering appropriate function spaces, we discover that incomplete fractional calculus may be used to analyse a wider class of functions than classical fractional calculus can consider. By using …

Integer-Valued Polynomials Satisfying The Lucas Property, Rattiya Meesa, Vichian Laohakosol, Tuangrat Chaichana

Turkish Journal of Mathematics

The classical theorem of Lucas states that the binomial polynomials, which form a basis for integer-valued polynomials, satisfy a congruence relation related to their integer parameters. We consider here three problems connected with this result in the setting of discrete valued structures. The first problem asks for the shapes of Lagrange-type interpolation polynomials which constitute a basis for integer-valued polynomials and satisfy the Lucas property; the result so obtained extends a 2001 result of Boulanger and Chabert. For the second problem, we show that the Carlitz polynomials, which form a basis for integer-valued polynomials in a function field, satisfy the …

On The Local And Global Stability Of An Sirs Epidemic Model With Logistic Growth And Information Intervention, İrem Çay

Turkish Journal of Mathematics

In this study, we investigate an susceptible-infected-recovered-susceptible (SIRS) epidemic model with logistic growth and information intervention. Firstly, the basic reproduction number $R_0$ is defined and the main results are given in terms of local stability. Then, sufficient conditions for the global stability of endemic equilibrium are obtained. Finally, some numerical simulations are given to validate our theoretical conclusions.

On Hilbert Genus Fields Of Imaginary Cyclic Quartic Fields, Moulay Ahmed Hajjami, Mohamed Mahmoud Chems Eddin

Turkish Journal of Mathematics

Let $p$ be a prime number such that $p=2$ or $p\equiv 1\pmod 4$. Let $\varepsilon_p$ denote the fundamental unit of $\mathbb{Q}(\sqrt{p})$ and let $a$ be a positive square-free integer. The main aim of this paper is to determine explicitly the Hilbert genus field of the imaginary cyclic quartic fields of the form $\mathbb{Q}(\sqrt{-a\varepsilon_p\sqrt{p}})$.

Count Of Genus Zero $J$-Holomorphic Curves In Dimensions Four And Six, Ahmet Beyaz

Turkish Journal of Mathematics

The abstract should provide clear information about the research and the results obtained, and should not exceed 200 words. The abstract should not contain citations. An application of Gromov--Witten invariants is that they distinguish the deformation types of symplectic structures on a smooth manifold. In this manuscript, it is proven that the use of Gromov--Witten invariants in the class of embedded $J$-holomorphic spheres is restricted. This restriction is in the sense that they cannot distinguish the deformation types of symplectic structures on $X_1\times S^2$ and $X_2\times S^2$ for two minimal, simply connected, symplectic $4$-manifolds $X_1$ and $X_2$ with $b_2^+(X_1)>1$ …

A Fourth Order One Step Method For Numerical Solution Of Good Boussinesq Equation, Emre Kirli, Dursun Irk

Turkish Journal of Mathematics

In this paper, we investigate the numerical solution of "good" Boussinesq equation by using the quartic B-spline Galerkin method for space discretization and the fourth order one-step method for time discretization.The proposed numerical scheme is analyzed for truncation error. Four test problems are studied. The accuracy and efficiency are measured by computing error norm $L_{\infty }$ and the order of convergence for the proposed method. The results of numerical experiments confirm that the proposed method has a higher accuracy.

An Application Of Semigroup Theory To The Coagulation-Fragmentation Models, Arijit Das, Nilima Das, Jitraj Saha

Turkish Journal of Mathematics

We present the existence and uniqueness of strong solutions for the continuous coagulation-fragmentation equation with singular fragmentation and essentially bounded coagulation kernel using semigroup theory of operators. Initially, we reformulate the coupled coagulation-fragmentation problem into the semilinear abstract Cauchy problem (ACP) and consider it as the nonlinear perturbation of the linear fragmentation operator. The existence of the substochastic semigroup is proved for the pure fragmentation equation. Using the substochastic semigroup and some related results for the pure fragmentation equation, we prove the existence of global nonnegative, strong solution for the coagulation-fragmentation equation.

On Fractional P-Laplacian Type Equations With General Nonlinearities, Adel Daouas, Mohamed Louchaich

Turkish Journal of Mathematics

In this paper, we study the existence and multiplicity of solutions for a class of quasi-linear elliptic problems driven by a nonlocal integro-differential operator with homogeneous Dirichlet boundary conditions. As a particular case, we study the following problem: \begin{equation*} \left\{ \begin{array}{l} (-\Delta)_p^s u= f(x,u) \quad \hfill \textrm{in} \ \Omega,\\ \quad u=0 \ \hfill \textrm{in} \ R^N \setminus \Omega, \end{array} \right.\\ \end{equation*} where $(-\Delta)_p^s$ is the fractional p-Laplacian operator, $\Omega$ is an open bounded subset of $R^N$ with Lipschitz boundary and $f:\Omega \times R \to R$ is a generic Carath\'eodory function satisfying either a $p-$sublinear or a $p-$superlinear growth condition.

Linear Stability Of Periodic Standing Waves Of The Kgz System, Sevdzhan Ahmedov Hakkaev, Fati̇h Hunutlu

Turkish Journal of Mathematics

In this work we consider the periodic standing wave solutions for a Klein-Gordon-Zakharov system. We find the conditions on the parameters, for which the periodic waves of dnoidal type are linear stable/unstable.

An Exponential Equation Involving $K$-Fibonacci Numbers, Alioune Gueye, Salah Eddine Rihane, Alain Togbe

Turkish Journal of Mathematics

For $k\geq 2$, consider the $k$-Fibonacci sequence $(F_n^{(k)})_{n\geq 2-k}$ having initial conditions $0, \ldots, 0, 1$ ($k$ terms) and each term afterwards is the sum of the preceding $k$ terms. Some well-known sequences are special cases of this generalization. The Fibonacci sequence is a special case of $(F_n^{(k)})_{n\geq 2-k}$ with $k=2$ and Tribonacci sequence is $(F_n^{(k)})_{n\geq 2-k}$ with $k=3$. In this paper, we use Baker's method to show that 4, 16, 64, 208, 976, and 1936 are all $k$-Fibonacci numbers of the form $(3^a\pm 1)(3^b\pm 1)$, where $a$ and $b$ are nonnegative integers.

Applications Of Mass Spectrometry To Forensic Entomology : Calliphoridae Species Determination, Monitoring Of Decomposition Volatiles, And Discovery Of Chemical Cues, Justine Elizabeth Giffen-Lemieux

Legacy Theses & Dissertations (2009 - 2024)

Forensic entomology is the study of insects that colonize human/animal wounds and remains and their development for use in legal contexts. It has numerous facets and applications including: estimation of time since death; investigation of neglect/abuse of children and the elderly; and determination of the presence of toxins and drugs as a potential cause of death. In order for the discovered insects to be of forensic utility, accurate species identification is crucial. Current methodologies for species determination rely on the knowledge and expertise of an entomologist; exhaustive taxonomic keys; and access to adequate equipment and facilities; resources which are often …

Ecology Of Freshwater Turtles And Other Wetland Wildlife In A North-Central West Virginia Watershed, Darien N. Lozon

Graduate Theses, Dissertations, and Problem Reports

The goal of wetland mitigation in the United States is to achieve a no-net-loss of wetlands; however, mitigated wetlands must be monitored to ensure wetland function is comparable to natural wetlands. In this study, relationships between land use practices and freshwater turtle abundance, wetland connectivity, and heavy metal bioaccumulation were investigated. In Chapter 1, a summary of pre-restoration species abundance and diversity is provided for anurans, birds, benthic macroinvertebrates, fishes, small mammals, plants, and turtles in riparian wetlands along Ruby Run, a tributary of Deckers Creek in north-central West Virginia, USA. These data provide a baseline for comparison after mitigation …

Soil Response Of Helicopter Liming In The Monongahela National Forest, Jarrett Douglas Fowler

Graduate Theses, Dissertations, and Problem Reports

Soils in the Monongahela National Forest (MNF) are acidic due to sandstone parent material, acid deposition, uptake of base cations by vegetation, and release of organic acids by organic matter (OM) decomposition. Increases in soil acidity have caused declines in forest health and changed species composition and nutrient status. Liming can neutralize soil acidity, but no large-scale liming projects have been done on acid forest soils in the USA. In anticipation of acquiring funding for a proposed liming project in the MNF, in 2007 and 2009 10 sites were selected to sample and analyze soils before lime was applied. In …

Majorana Nanostructures And Their Electrostatic Environment, Benjamin David Woods

Graduate Theses, Dissertations, and Problem Reports

Majorana zero modes (MZMs) are zero-energy excitations emerging in one- and two-dimensional topological superconductors. These exotic modes have attracted much attention in the last decade due to their topological protection and non-Abelian statistics, which make them possible building blocks for topological quantum computation. In particular, semiconductor-superconductor (SM-SC) nanostructures have attracted the most attention with several measurements being consistent with the presence of MZMs. Debate continues, however, whether MZMs or topologically-trivial Andreev bound states are responsible for such measurements.

In order to interpret experimental results distinguishing MZMs from Andreev bound states and gain a better understanding of what conditions need to …

Development Of Vibrating Sharp-Edge Spray Ionization (Vssi) Methods For Mass Spectrometry Analysis And Imaging, Nandhini Ranganathan

Graduate Theses, Dissertations, and Problem Reports

Mass Spectrometry (MS) is one of the widely used tools for chemical detection down to attomole concentrations for certain proteins. Ionization sources are a critical component for MS analysis. One of the major ionization methods is electrospray ionization (ESI), which remains a gold standard for proteins and peptides. ESI uses voltages up to ~4 kV to produce ions from solubilized molecules. Recently, a novel ionization method termed vibrating sharp-edge spray ionization (VSSI) that nebulizes liquids efficiently at the edge of a vibrating glass slide has been reported. The work in this thesis leverages the capabilities of VSSI for continuous flow-based …

Deep Fingerprint Matching From Contactless To Contact Fingerprints For Increased Interoperability, Alexander James Wilson

Graduate Theses, Dissertations, and Problem Reports

Contactless fingerprint matching is a common form of biometric security today. Most smartphones and associated apps now let users opt into using this form of biometric security. However, it’s difficult to match a finger-photo to a fingerprint because of perspective distortion occurring at the edges of the finger-photo, so direct matching using conventional methods will not be as accurate due to a lack of sufficient matching minutiae points. To address this issue, we propose a deep model, Perspective Distortion Rectification Model (PDRM), to estimate the fingerprint correspondence for finger-photo images in order to recover more minutiae points. Not only do …

Influence Of Mechanical Layering And Natural Fractures On Undercutting And Rapid Headward Erosion (Recession) At Canyon Lake Spillway, Texas, U.S.A, Nathaniel S. Ledbetter Ferrill, David A. Ferrill

Geosciences Faculty Research

This study investigates the role of mechanical layering and fractures on flood-related erosional undercutting and resulting rapid spillway recession. In the summer of 2002, 86 cm of rain fell in an 8-day period across the Guadalupe River drainage basin in central Texas, causing Canyon Lake reservoir to completely fill and overtop the emergency spillway for the first time. The resulting flood incised a gorge into the mechanically layered Glen Rose Formation and caused headward erosion (recession) at the downstream edge of the emergency spillway. Comparison of pre- and post-flood imagery and assessment of flood records indicates that maximum recession localized …

Wildlife-Friendly Fence Policy On Federal Public Lands Managed By The U.S. Forest Service And Bureau Of Land Management, Joshua D. Elliott

Graduate Student Theses, Dissertations, & Professional Papers

Many wildlife species are negatively impacted by the presence of fences on the landscape. Climate change is only exacerbating the problem as home ranges shift and species face heightened levels of stress. In recent decades, wildlife biologists have studied these impacts and devised ways of constructing fences to increase habitat connectivity and significantly reduce fence-related injury and mortality rates. Conservationists attempting to address this issue on a landscape level face significant challenges resulting from complex land ownership patterns, specifically across the western United States.

The two largest landowners in the U.S. are the Bureau of Land Management (BLM) and the …

Petrogenesis And Tectonic Implications Of Cordierite-Orthoamphibole Gneisses (Cog) In The Nw Wyoming Province, Brianna K. Crenshaw Ms

Graduate Student Theses, Dissertations, & Professional Papers

Studying cordierite orthoamphibole gneisses (COG) from five different mountain ranges across the Montana Metasedimentary Terrane (MMT) of the Wyoming Province offers a unique opportunity to elucidate the enigmatic origins and petrogenesis of the lithology in addition to gaining a further understanding of Precambrian crustal assembly processes. Geochemical analyses suggest that COG originates from a basalt that underwent metasomatic alteration, likely via seawater, prior to metamorphism. Moreover, COG is considered to represent oceanic crust that was part of the epicontinental sea adjacent to the Wyoming Province before collision with the Medicine Hat Block. Field observations of associated lithologies such as marbles, …

Investigation Of Emissions And Chemistry Of Formic Acid And Acetic Acid In Wildfire Smoke, Catherine Elizabeth Wielgasz

Graduate Student Theses, Dissertations, & Professional Papers

Formic acid (HCOOH) and acetic acid (CH₃COOH) are two of the most ubiquitous organic acids in the atmosphere. Chemical transport models consistently underestimate HCOOH and CH₃COOH concentrations in environments including fire smoke, implying our incomplete understanding of their global budget. Emissions and secondary production of HCOOH and CH₃COOH within complex mixtures in fire smoke is uncertain.

I used measurements from the NSF/NCAR C-130 aircraft during the Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption, and Nitrogen (WE-CAN) campaign to investigate emissions and photochemical production of HCOOH and CH₃COOH from smoke plumes. First, …

Tolle Lege Works Published In 2021, Mcquade Library

Bibliographies

Compiled Tolle Lege bibliography of works published by members of the Merrimack College Community in 2021. Works include journal articles, books, book chapters, conference presentations and posters, and more.

Reflection Of A Horizon Image On The Surface Of Water, Christopher S. Stuetzle, Steve Warner, John-Paul Mayer

Computer Science Faculty Publications

We have created a piece of software that renders the reflection of a ”landscape” texture on a wavy fluid surface. The fluid is represented by a height field and a quad mesh. Waves are created by using wave particles, non-physical entities that determine the influence a wave has on the fluid around it. The scene is ray traced by sending a ray through each pixel, bouncing it off the water and against the texture backdrop. The color of the texture is quieried and influences the color of the water surface. Surface normals are calulated by interpolating vertex normals across each …

Investigating Biotic Interactions In Deep Time, Danielle Fraser, Laura C. Soul, Anikó B. Tóth, Meghan A. Balk, Jussi T. Eronen, Silvia Pineda-Munoz, Alexandria B. Shupinski, Amelia Villaseñor, W. Andrew Barr, Anna K. Behrensmeyer, Andrew Du, J. Tyler Faith, Nicholas J. Gotelli, Gary R. Graves, Advait M. Jukar, Cindy V. Looy, Joshua H. Miller, Richard Potts, S. Kathleen Lyons

College of Arts and Sciences Faculty Publications

Recent renewed interest in using fossil data to understand how biotic interactions have shaped the evolution of life is challenging the widely held assumption that long-term climate changes are the primary drivers of biodiversity change. New approaches go beyond traditional richness and co-occurrence studies to explicitly model biotic interactions using data on fossil and modern biodiversity. Important developments in three primary areas of research include analysis of (i) macroevolutionary rates, (ii) the impacts of and recovery from extinction events, and (iii) how humans (Homo sapiens) affected interactions among non-human species. We present multiple lines of evidence for an important and …

Body Mass-Related Changes In Mammal Community Assembly Patterns During The Late Quaternary Of North America, Silvia Pineda-Munoz, Advait M. Jukar, Anikó B. Tóth, Danielle Fraser, Andrew Du, W. Andrew Barr, Kathryn L. Amatangelo, Meghan A. Balk, Anna K. Behrensmeyer, Jessica Blois, Matt Davis, Jussi T. Eronen, Nicholas J. Gotelli, Cindy Looy, Joshua H. Miller, Alexandria B. Shupinski, Laura C. Soul, Amelia Villaseñor, Scott Wing, S. Kathleen Lyons

College of Arts and Sciences Faculty Publications

Ecography published by John Wiley & Sons Ltd on behalf of Nordic Society Oikos The late Quaternary of North America was marked by prominent ecological changes, including the end-Pleistocene megafaunal extinction, the spread of human settlements and the rise of agriculture. Here we examine the mechanistic reasons for temporal changes in mammal species association and body size during this time period. Building upon the co-occurrence results from Lyons et al. (2016) – wherein each species pair was classified as spatially aggregated, segregated or random – we examined body mass differences (BMD) between each species pair for each association type and …

Deep-Learning-Based Spraying Area Recognition System Forunmanned-Aerial-Vehicle-Based Sprayers, Shahbaz Khan, Muhammad Tufail, Muhammad Tahir Khan, Zubair Ahmed Khan, Shahzad Anwer

Turkish Journal of Electrical Engineering and Computer Sciences

Unmanned aerial vehicle (UAV)-based spraying system employing machine learning techniques is a recent advancement in precision agriculture for precise spraying, promoting saving chemicals (pesticide/herbicide), and enhancing their effectiveness. This study aims to develop an efficient deep learning system for UAV-based sprayers, which has the capability to accurately recognize spraying areas. A deep learning system is proposed and developed incorporating a faster region-based convolutional neural network (R-CNN) for the imagery collected. In order to develop a classifier for identifying spraying areas from nonspraying areas, four different agriculture croplands and orchards were considered. All the experiments were performed in agriculture fields through …

A Novel Design Of Current Differencing Transconductance Amplifier With Hightransconductance Gain And Enhanced Bandwidth, Shireesh Kumar Rai, Rishikesh Pandey, Bharat Garg, Sujit Patel

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, transconductance gain of current differencing transconductance amplifier (CDTA) has been boosted by using a novel approach. Transconductance is generally varied by two well-known techniques. In the first technique, bias current of differential pair MOSFETs is varied whereas in the second technique, aspect ratios of differential pair MOSFETs are changed. The drawbacks of first technique are limited range of transconductance and higher power dissipation whereas second technique restricts dynamic range, output swing and bandwidth of CDTA. To overcome these drawbacks, 2 new structures of CDTA, namely high transconductance gain CDTAs (HTG-CDTA-I & HTG-CDTA-II) have been proposed. HTG-CDTA-I utilizes …