Physical Sciences and Mathematics Commons^™

C.P. Modules And Their Applications, Qiongling Liu, Jianlong Chen

Turkish Journal of Mathematics

Let R be a ring. A left R-module M is called a c.p. module if every cyclic submodule of M is projective. This notion is a generalization of left p.p. rings in the general module theoretic setting. The aim of this article is to investigate these modules. Some characterizations and properties are given. As applications, the connections among Baer rings, p.p. rings and von Neumann regular rings are studied.

Scalar Curvature And Symmetry Properties Of Lightlike Submanifolds}, Cyriaque Atindogbe, Oscar Lungiambudila, Joel Tossa

Turkish Journal of Mathematics

In this paper, the induced Ricci tensor and the extrinsic scalar curvature on lightlike submanifolds are obtained. This scalar quantity extend the result given by C. Atindogbe in [1]. An example of extrinsic scalar curvature on one class of 2-degenerate manifolds is provided. We investigate lightlike submanifolds which are locally symmetric, semi-symmetric, Ricci semi-symmetric in indefinite spaces form. In the coisotropic case, we show that, under some conditions, these lightlike submanifolds are totally geodesic.

Gorenstein Transpose With Respect To A Semidualizing Bimodule, Zengfeng Liu, Xiaoguang Yan

Turkish Journal of Mathematics

Let S and R be rings and _SC_R be a semidualizing bimodule. We first give the definitions of C-transpose and n-C-torsionfree and give a criterion for a module A to be G_C-projective by some property of the C-transpose of A. Then we introduce the notion of C-Gorenstein transpose of a module over two-sided Noetherian rings. We prove that a module M in \mod R^{op} is a C-Gorenstein transpose of a module A \in \mod S if and only if M can be embedded into a C-transpose of A with the cokernel G_C-projective. Finally we investigate some homological properties of the …

Blow-Up Phenomena For Nonlocal Inhomogeneous Diffusion Problems, Jianwen Sun, Feiying Yang

Turkish Journal of Mathematics

This paper is concerned with the blow-up of solutions to some nonlocal inhomogeneous dispersal equations subject to homogeneous Neumann boundary conditions. We establish conditions on nonlinearities sufficient to guarantee that solutions exist for all time as well as blow up at some finite time. Moreover, lower bounds for blow-up time of nonlocal problems are obtained.

On Some Results On Ip-Graphs, Roghayeh Hafezieh, Moohammadali Iranmanesh

Turkish Journal of Mathematics

The IP-graph of a naturally valenced association scheme and some of its properties have been studied recently. In this paper we introduce the bipartite version of this graph for a naturally valenced association scheme (X,S), denoted by BIP(S). We also investigate some of its properties.

Algorithm To Solve Certain Ternary Quartic Diophantine Equations, Laszlo Szalay

Turkish Journal of Mathematics

In this paper, we develop an algorithm to solve completely the Diophantine equation F(x,y)=z^2, where the quartic inhomogeneous polynomial F(x,y) with integer coefficients satisfies certain technical conditions. The procedure is an extension of the version of Runge's method given by Poulakis.

Continuous Invariant Averagings, Djavvat Khadjiev, Abdullah Çavuş

Turkish Journal of Mathematics

Main results: For every equicontinuous almost periodic linear representation of a group in a complete locally convex space L with the countability property, there exists the unique invariant averaging; it is continuous and is expressed by using the L-valued invariant mean of Bochner and von-Neumann. An analog of Wiener's approximation theorem for an equicontinuous almost periodic linear representation in a locally convex space with the countability property is proved.

Quasinormability And Diametral Dimension, Ahmet Tosun Terzi̇oğlu

Turkish Journal of Mathematics

Two versions of diametral dimension are shown to coincide for quasinormable Fréchet spaces. The diametral dimension is determined by a single bounded subset in certain cases.

Complete Cotorsion Pairs In The Category Of Complexes, Zhanping Wang, Zhongkui Liu

Turkish Journal of Mathematics

In this paper, we study completeness of cotorsion pairs in the category of complexes of R-modules. Let (A, B) be a cotorsion pair in R-Mod. It is shown that the cotorsion pair (\widetilde{A}, dg\widetilde{B}) and (\overline{A}, \overline{A}^{\perp}) are complete if A is closed under pure submodules and cokernels of pure monomorphisms, where in Gillespie's definitions \widetilde{A} is the class of exact complexes with cycles in A and dg\widetilde{B} is the class of complexes X with components in B such that the complex Hom(A, X) is exact for every complex A \in \widetilde{A}; and \overline{A} is the class of all complexes …

Slant Submersions From Almost Product Riemannian Manifolds, Yilmaz Gündüzalp

Turkish Journal of Mathematics

In this paper, we define the concept of almost product Riemannian submersion between almost product Riemannian manifolds. We introduce slant submersions from almost product Riemannian manifolds onto Riemannian manifolds. We give examples and investigate the geometry of foliations that arise from the definition of a Riemannian submersion. We also find necessary and sufficient conditions for a slant submersion to be totally geodesic.

Factorization Of Composite Polynomials Over Finite Fields, Saeid Mehrabi

Turkish Journal of Mathematics

This paper presents the reducibility of some composite polynomials and explicitly determines the factorization over finite fields. Also families of irreducible polynomials over finite fields are introduced.

A Class Of 3-Dimensional Almost Cosymplectic Manifolds, İrem Küpeli̇ Erken, Cengi̇zhan Murathan

Turkish Journal of Mathematics

The main interest of the present paper is to classify the almost cosymplectic 3-manifolds that satisfy \Vert grad\lambda \Vert = const.(\neq 0) and \bigtriangledown_{\xi} h=2ah\phi.

On The Existence Of Nonzero Injective Covers And Projective Envelopes Of Modules, Xiaoxiang Zhang, Xianmei Song

Turkish Journal of Mathematics

In general, the injective cover (projective envelope) of a simple module can be zero. A ring R is called a weakly left V-ring (strongly left Kasch ring) if every simple left R-module has a nonzero injective cover (projective envelope). It is proven that every nonzero left R-module has a nonzero injective cover if and only if R is a left Artinian weakly left V-ring. Dually, every nonzero left R-module has a nonzero projective envelope if and only if R is a left perfect right coherent strongly left Kasch ring. Some related rings and examples are considered.

Robust Sensorless Predictive Control Of Induction Motors With Sliding Mode Voltage Model Observer, Seyed Alireza Davari, Davood Arab Khaburi, Fengxiang Wang, Ralph Kennel

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a robust sliding mode prediction model is combined with a sliding mode voltage model observer to achieve a sensorless predictive torque control method. In order to compensate the uncertainties of the stator and rotor resistances and the offset of measured current, sliding mode feedbacks were added to the voltage model observer. To reduce the effect of the errors that are injected from the observer to the prediction model in the sensorless application, the prediction model was also reinforced by a sliding mode feedback. The feedback gains for the prediction and observer models are assigned by a robustness …

Intrusive History And Petrogenesis Of The Ash Mountain Complex, Sierra Nevada Batholith, California (Usa), Julie E. Holland, Benjamin E. Surpless, Diane R. Smith, S. L. Loewy, J. S. Lackey

Geosciences Faculty Research

The Ash Mountain Complex (AMC) in the western Sierra Nevada batholith (SNB; California, USA) is an exposure of six compositionally diverse intrusive lithologies with clear crosscutting relationships that permit a focused investigation of magma source characteristics and the relative roles of petrogenetic processes on the evolution of the system. We use new field observations, zircon U-Pb dates, major and trace element data, and Sr-Nd-Pb isotopic data to develop a model that can be applied to similar SNB intrusive suites. Stage 1 units, emplaced ca. 105 Ma, consist of two gabbros, a gabbrodiorite, and a granite. Stage 2 and stage 3 …

Turning Stealth Liposomes Into Cationic Liposomes For Anticancer Drug Delivery, Vijay Gyanani

University of the Pacific Theses and Dissertations

Targeting the anticancer agents selectively to cancer cells is desirable to improve the efficacy and to reduce the side effects of anticancer therapy. Previously reported passive tumor targeting by PEGylated liposomes (stealth liposomes) have resulted in their higher tumor accumulation. However their interaction with cancer cells has been minimal due to the steric hindrance of the PEG coating. This dissertation reports two approaches to enhance the interaction of stealth liposomes with cancer cells. First, we designed a lipid-hydrazone-PEG conjugate that removes the PEG coating at acidic pH as in the tumor interstitium. However, such a conjugate was highly unstable on …

Fracture Density Of Units In The Brushy Canyon Formation, Whitehorse Group And Winchell Formation Of The Permian Basin., Skyler Smith

Earth & Environmental Sciences Theses

This study tests the theoretical equation(Fd Ua)/μ=A v/(1-2v)+B, where Fd equals the fracture density present in a geologic unit under constant strain conditions. The material properties in the equation were measured using acoustic velocities and density from samples taken from outcrops. Fracture density was measured from those same outcrop layers. If the equation is valid the measured data should plot as a straight line. The validity of the equation can be estimated using the correlation coefficient of the straight line graph. Fracture density measurements were made within the Permian age Brushy Canyon formation, Whitehorse Group and Winchell Formation of the …

Critical Research Needs For Successful Food Systems Adaptation To Climate Change, Michelle Miller, Molly Anderson, Charles A. Francis, Chad Kruger, Carol Barford, Jacob Park, Brent H. Mccown

Department of Agronomy and Horticulture: Faculty Publications

There is a growing sense of the fragility of agricultural production in the Global North and South and of increasing risks to food security, as scientific observations confirm significant changes in the Gulf Stream, polar ice, atmospheric CO₂, methane release, and other measures of climate change. This sense is heightened as each of us experiences extreme weather, such as the increasing frequency of droughts, floods, unseasonal temperatures, and erratic seasonality. The central research challenge before us is how global, national, regional, and local food systems may adapt to accelerating climate change stresses and uncertainties to ensure the availability, …

Food Webs And Food Sovereignty: Research Agenda For Sustainability, Charles A. Francis, Michelle Miller, Molly Anderson, Nancy Creamer, Michelle Wander, Jacob Park, Thomas Green, Brent Mccown

Department of Agronomy and Horticulture: Faculty Publications

Future food production will be constrained by the scarcity of fossil fuel and fresh water as well as increasing intensity and unpredictability of weather events and climate changes. The assurance of food security and equity for many consumers is complicated by concentration of ownership of land and other production resources, as well as a global corporate food systems model that is driven by profit at the expense of people and the environment. To assess potential alternatives to the contemporary global food chain, well focused research is needed on local food production and food webs where small- and midscale family farms …

Correcting Heat Flow Data In The United States To Account For Climate Change, Godswill Njoku

Theses and Dissertations

Heat flow measurements may require correction for both recent warming and post-glacial warming signals. Warming during the last century can be detected in borehole temperature profiles. Both climate warming signals during the past century and post-glacial warming signals during the past 10 millennia are greatest near the surface and diminish with depth.

Both atmospheric data and borehole temperature data show that recent warming varies systematically with latitude along a north-south transect in the United States. The systematic increase with latitude from +0.7 oC at 41.6oN to +2.3 oC at 49oN during the last century is consistent with the prediction that …

Gumbos And Nanogumbos: Applications As Photosensitizers In Dye-Sensitized Solar Cells, Atiya Nicole Jordan

LSU Doctoral Dissertations

Renewable energy is a major concern due to increased world energy consumption. In particular, solar energy is a type of renewable energy source that uses devices known as solar cells to convert sunlight to electricity. Specifically, devices referred to as dye-sensitized solar cells (DSSCs) employ dyes to absorb solar energy. Dyes derived from ruthenium complexes have been typically used in DSSCs. Unfortunately, several disadvantages are associated with current ruthenium complex photosensitizers, which can be attributed to limited supply and expense of metals, as well as reduced absorption in the near-infrared region of the electromagnetic spectrum. Accordingly, this dissertation is a …

A Semigroup/Laplace Transform Approach To Approximating Flows, Ladorian Nichele Latin

LSU Doctoral Dissertations

It is well known that all flows in a state space O induce a semigroup of linear operators on an appropriately chosen vector space of functions (observables) from O into a vector space Z (observations). After choosing appropriate continuity assumptions on the flow, the associated semigroup will be strongly continuous and will have a linear, infinitesimal generator A. The purpose of this dissertation is to explore approximation methods for linear semigroups and/or Laplace transform inversion methods in order to reconstruct the flow starting with the linear generator A . In preparing for these investigations, we collect some of the essential …

Super-Aptamer Bio-Imprinted Hydrogels : An Investigation Into The Optimization And Characterization Of Cross-Linked Polymeric Materials Displaying Macromolecular Amplified Responses, Nicholas Alexander Gariano

LSU Doctoral Dissertations

It is becoming more important to detect ultra-low concentrations of analytes for biomedical, environmental, and national security applications. Equally important is that new methods should be easy to use, inexpensive, portable, and if possible allow detection using the naked eye. Detection of low concentrations of analytes generally cannot be achieved directly, but requires signal amplification by catalysts, macromolecules, metal surfaces or supramolecular aggregates. The rapidly progressing field of macromolecular signal amplification has been advanced using conjugated polymers, chirality in polymers, solvating polymers and polymerization/depolymerization strategies. The use of molecularly imprinted polymers is ideal for creation of novel sensors to meet …

Ecosystem Metabolism In Coastal Plain Streams Of Southeast Louisiana : Environmental And Watershed Effects, Jonathan L. West

LSU Doctoral Dissertations

Since its introduction in 1956, the use of open-system, diel dissolved oxygen curves for estimating the components of ecosystem metabolism in the lotic setting have been important in determining the current ecosystem theory of streams, both spatially among multiple systems and longitudinally within the same system, as well as identifying potentially impaired systems, especially when contrasted with streams considered unimpaired. Several factors have been identified as controls on both components of ecosystem metabolism and include light, nutrients, and stable substrates for gross primary production (GPP) and a source of organic matter (OM) for ecosystem respiration (ER). Stream size is important …

Application Of Helmholtz/Hodge Decomposition To Finite Element Methods For Two-Dimensional Maxwell's Equations, Zhe Nan

LSU Doctoral Dissertations

In this work we apply the two-dimensional Helmholtz/Hodge decomposition to develop new finite element schemes for two-dimensional Maxwell's equations. We begin with the introduction of Maxwell's equations and a brief survey of finite element methods for Maxwell's equations. Then we review the related fundamentals in Chapter 2. In Chapter 3, we discuss the related vector function spaces and the Helmholtz/Hodge decomposition which are used in Chapter 4 and 5. The new results in this dissertation are presented in Chapter 4 and Chapter 5. In Chapter 4, we propose a new numerical approach for two-dimensional Maxwell's equations that is based on …

Pattern Detection In Null Model Analysis, Werner Ulrich, Nicholas J. Gotelli

College of Arts and Sciences Faculty Publications

Synthesis The identification of distinctive patterns in species x site presence-absence matrices is important for understanding meta-community organisation. We compared the performance of a suite of null models and metrics that have been proposed to measure patterns of segregation, aggregation, nestedness, coherence, and species turnover. We found that any matrix with segregated species pairs can be re-ordered to highlight aggregated pairs, indicating that these seemingly opposite patterns are closely related. Recently proposed classification schemes failed to correctly classify realistic matrices that included multiple co-occurrence structures. We propose using a combination of metrics and decomposing matrix-wide patterns into those of individual …

Quantifying Temporal Change In Biodiversity: Challenges And Opportunities, Maria Dornelas, Anne E. Magurran, Stephen T. Buckland, Anne Chao, Robin L. Chazdon, Robert K. Colwell, Tom Curtis, Kevin J. Gaston, Nicholas J. Gotelli, Matthew A. Kosnik, Brian Mcgill, Jenny L. Mccune, Hélène Morlon, Peter J. Mumby, Lise Øvreås, Angelika Studeny, Mark Vellend

College of Arts and Sciences Faculty Publications

Growing concern about biodiversity loss underscores the need to quantify and understand temporal change. Here, we review the opportunities presented by biodiversity time series, and address three related issues: (i) recognizing the characteristics of temporal data; (ii) selecting appropriate statistical procedures for analysing temporal data; and (iii) inferring and forecasting biodiversity change. With regard to the first issue, we draw attention to defining characteristics of biodiversity time series-lack of physical boundaries, unidimensionality, autocorrelation and directionality-that inform the choice of analytic methods. Second, we explore methods of quantifying change in biodiversity at different timescales, noting that autocorrelation can be viewed as …

A Time--Memory Trade-Off Approach For The Solution Of Nonlinear Equation Systems, Hüseyi̇n Demi̇rci̇, Mahmut Şami̇l Sağiroğlu, Muhammed Oğuzhan Külekci̇

Turkish Journal of Electrical Engineering and Computer Sciences

We propose a memory-based method for the solution of a specific type of nonlinear equation systems. We observe that when the equations in a system can be separated into 2 parts, where each subset contains fewer parameters than the whole set of equations, the system can be solved faster with a preprocessing phase. We show that reduced rounds of AES produce such a system under a chosen plaintext scenario. This observation enables us to solve that system within a practically applicable complexity of 2^{37} operations where a brute force approach requires 2^{72} trials. The method can be used for the …

End-To-End Transmission Time-Based Opportunistic Routing Protocols For Bus Networks, Luobei Kuang, Zhijun Wang, Ming Xu, Yingwen Cheng

Turkish Journal of Electrical Engineering and Computer Sciences

Single path routing protocols for Internet access in bus networks (composed of traveling city public buses) may not achieve satisfactory performance because of frequent bus mobility. This paper studies the opportunistic routing protocols in bus networks to improve the system throughput and reduce the access delay. In this paper, we first propose an end-to-end transmission time (EET)-based opportunistic routing (OR) framework. We then derive 3 EET-based OR protocols, EETOR (EET-based OR), EETMcOR (EET-based OR with MAC contention consideration), and EETCcOR (EET-based OR with congestion control consideration), which consider 3 different EET metrics. EETOR considers the network layer transmission behavior to …

Simulation Of A Large Electric Distribution System Having Intensive Harmonics In The Industrial Zone Of Konya, Hasan Eroğlu, Musa Aydin

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, measurements were taken at different points of a sample distribution system in order to analyze the levels of harmonics that appear as a day-to-day increasing problem in electrical distribution systems. According to the measurement values, the dominant harmonics have been determined and an electrical model of the system has been prepared using the SimPowerSystems toolbox from MATLAB and Simulink. The accuracy of the electrical model has been verified by the measurement and simulation values. In addition, the transformer connection types' and impedances' simulations have been presented to understand and solve the harmonic problems in electrical distribution systems. …