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2006

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Articles 5071 - 5100 of 5872

Full-Text Articles in Physical Sciences and Mathematics

On Lifts Of Paracomplex Structures, Mehmet Tekkoyun Jan 2006

On Lifts Of Paracomplex Structures, Mehmet Tekkoyun

Turkish Journal of Mathematics

In this paper, we obtain vertical, complete and horizontal lifts of paracomplex geometric structures on paracomplex manifolds to its tangent bundle. Also, we obtain integrability on paracomplex tangent bundle.


On Uniform Hermitian P-Normed Algebras, A. El-Kinani Jan 2006

On Uniform Hermitian P-Normed Algebras, A. El-Kinani

Turkish Journal of Mathematics

We show that the completion of a uniform hermitian p-normed algebra is a commutative C^*-algebra.


On The Power Subgroups Of The Extended Modular Group \Overline{\Gamma} (Corrigendum - Turk. J. Math. 28,143-151, 2004), Recep Şahi̇n, Sebahatti̇n İki̇kardeş, Özden Koruoğlu Jan 2006

On The Power Subgroups Of The Extended Modular Group \Overline{\Gamma} (Corrigendum - Turk. J. Math. 28,143-151, 2004), Recep Şahi̇n, Sebahatti̇n İki̇kardeş, Özden Koruoğlu

Turkish Journal of Mathematics

No abstract provided.


Connectedness In Isotonic Spaces, Eissa D. Habil, Khalid A. Elzenati Jan 2006

Connectedness In Isotonic Spaces, Eissa D. Habil, Khalid A. Elzenati

Turkish Journal of Mathematics

An isotonic space (X,cl) is a set X with isotonic operator cl:P(X) \to P(X) which satisfies cl(\emptyset) = \emptyset and cl(A)\subseteq cl(B) whenever A\subseteq B\subseteq X. Many properties which hold in topological spaces hold in isotonic spaces as well. The notion of connectedness that is familiar from topological spaces generalizes to isotonic spaces. We further extend the notions of Z-connectedness and strong connectedness to isotonic spaces, and we indicate the intimate relationship between these notions.


Existence Of Linear-Quadratic Regulator For Degenerate Diffusions, Md. Azizul Baten Jan 2006

Existence Of Linear-Quadratic Regulator For Degenerate Diffusions, Md. Azizul Baten

Turkish Journal of Mathematics

This paper studies a linear regulatory quadratic control problem for degenerate Hamilton-Jacobi-Bellman (HJB) equation. We establish the existence of a unique viscosity and a classical solution of the degenerate HJB equation associated with this problem by the technique of viscosity solutions, and, hence, derive an optimal control from the optimality conditions in the HJB equation.


Two-Weight Norm Inequalities For Some Anisotropic Sublinear Operators, Yusuf Zeren, V. S. Guliyev Jan 2006

Two-Weight Norm Inequalities For Some Anisotropic Sublinear Operators, Yusuf Zeren, V. S. Guliyev

Turkish Journal of Mathematics

In this paper, we establish several general theorems for the boundedness of the anisotropic sublinear operators on a weighted Lebesgue space. Conditions of these theorems are satisfied by many important operators in analysis. We also give some applications the boundedness of the parabolic singular integral operators, and the maximal operators associated with them from one weighted Lebesgue space to another one. Using this results, we prove weighted embedding theorems for the anisotropic Sobolev spaces W_{\omega_0,\omega_1,...,\omega_n}^{l_1,...,l_n}(\Rn).


On Graded Weakly Prime Ideals, Shahabaddin Ebrahimi Atani Jan 2006

On Graded Weakly Prime Ideals, Shahabaddin Ebrahimi Atani

Turkish Journal of Mathematics

Let G be an arbitrary group with identity e, and let R be a G-graded commutative ring. Weakly prime ideals in a commutative ring with non-zero identity have been introduced and studied in [1]. Here we study the graded weakly prime ideals of a G-graded commutative ring. A number of results concerning graded weakly prime ideals are given. For example, we give some characterizations of graded weakly prime ideals and their homogeneous components.


Some Random Fixed Point Theorems For Non-Self Nonexpansive Random Operators, Poom Kumam, Somyot Plubtieng Jan 2006

Some Random Fixed Point Theorems For Non-Self Nonexpansive Random Operators, Poom Kumam, Somyot Plubtieng

Turkish Journal of Mathematics

Let (\Omega, \Sigma) be a measurable space, with \sum a sigma-algebra of subsets of \Omega, and let E be a nonempty bounded closed convex and separable subset of a Banach space X, whose characteristic of noncompact convexity is less than 1. We prove that a multivalued nonexpansive, non-self operator T: \Omega \times E \rightarrow KC(X) satisfying an inwardness condition and itself being a 1-\chi-contractive nonexpansive mapping has a random fixed point. We also prove that a multivalued nonexpansive, non-self operator T:\Omega\times E\rightarrow KC(X) with a uniformly convex X satisfying an inwardness condition has a random fixed point.


Diagonal Lift In The Tangent Bundle Of Order Two And Its Applications, Fouzi Hathout, H. M. Dida Jan 2006

Diagonal Lift In The Tangent Bundle Of Order Two And Its Applications, Fouzi Hathout, H. M. Dida

Turkish Journal of Mathematics

In this paper we define a diagonal lift ^{D}g of Riemannian metric g of manifold M_n to the tangent bundle of order two denoted by T^{2}M_n of M_n, we associate to ^{D}g its Levi-civita connection of T^2 M and we investigate applications of the diagonal lifts in the killing vectors and geodesics.


Note On Generalized Jordan Derivations Associate With Hochschild 2-Cocycles Of Rings, Atsushi Nakajima Jan 2006

Note On Generalized Jordan Derivations Associate With Hochschild 2-Cocycles Of Rings, Atsushi Nakajima

Turkish Journal of Mathematics

We introduce a new type of generalized derivations associate with Hochschild 2-cocycles and prove that every generalized Jordan derivation of this type is a generalized derivation under certain conditions. This result contains the results of I. N. Herstein [6, Theorem 3.1] and M. Ashraf and N-U. Rehman [1, Theorem].


Weighted Norm Inequalities For A Class Of Rough Maximal Operators, Hussain Al-Qassem Jan 2006

Weighted Norm Inequalities For A Class Of Rough Maximal Operators, Hussain Al-Qassem

Turkish Journal of Mathematics

We consider maximal singular integral operators arising from rough kernels satisfying an H^1-type condition on the unit (n-1)-sphere and prove weighted L^p estimates for certain radial weights. We also prove weighted L^p estimates with A_p-weights where in this case the H^1 -type condition is replaced by an L^q-type condition with q > 1. Some applications of these results are also obtained regarding singular integrals and Marcinkiewicz integrals. Our results are essential extensions and improvements of some known results.


A Note On Kaehlerian Manifolds, Nejmi̇ Cengi̇z, Ö. Tarakçi, A. A. Sali̇mov Jan 2006

A Note On Kaehlerian Manifolds, Nejmi̇ Cengi̇z, Ö. Tarakçi, A. A. Sali̇mov

Turkish Journal of Mathematics

The main purpose of the present paper is to study nearly Kaehlerian manifolds. We give the condition for an almost Hermitian manifold to be nearly Kaehlerian.


Local Fourier Bases And Modulation Spaces, Salti Samarah, Rania Salman Jan 2006

Local Fourier Bases And Modulation Spaces, Salti Samarah, Rania Salman

Turkish Journal of Mathematics

It is shown that local Fourier bases are unconditional bases for modulation spaces. We prove first a version of the Schur test for double sequence with mixed norm and then use it to show boundedness of the analysis operator on the modulation space M_{p,q}^w


Digital Fractional Frequency Synthesizer Based On Counters, Milan Stork Jan 2006

Digital Fractional Frequency Synthesizer Based On Counters, Milan Stork

Turkish Journal of Electrical Engineering and Computer Sciences

This paper describes the architecture of a new pure digital frequency synthesizer based on pulse generators, counters and a register. The technique described here is much simpler than other methods. The synthesizer presented is suitable for the design of VLSI architectures or for programmable large-scale integration circuits.


Modeling Groundwater Denitrification By Ferrous Iron Using Phreeqc, Tedros Tesfay Jan 2006

Modeling Groundwater Denitrification By Ferrous Iron Using Phreeqc, Tedros Tesfay

Theses and Dissertations

Nitrate is one of the most common groundwater contaminants, and ingesting it leads to potential health risks. Denitrification, the only effective process to eliminate nitrate, is limited by the abundance of biologically available electron donors. Thus, understanding the natural denitrification capacity of aquifers, through the analysis of all the major electron donors, is essential.

A better way to estimate groundwater denitrification reactions is to compute the mass balance of the redox sensitive species. The University of North Dakota (UND) denitrification team installed mesocosms (ISMs) to understand the fate of nitrate in field conditions. Accordingly, the team has shown the significant …


Fire Does Not Alter Vegetation In Infertile Prairie, Johannes M.H. Knops Jan 2006

Fire Does Not Alter Vegetation In Infertile Prairie, Johannes M.H. Knops

School of Biological Sciences: Faculty Publications

The paradigm in prairie ecology is that fire is one of the key factors deter-mining vegetation composition. fire can impact grassland ecosystems in various ways, including changing plant species composition and inducing nitro-gen loss. I found that 17 years of different burning frequencies in infertile grassland had only a minor impact on the vegetation composition and diversity. The only major impact from increasing the frequency of fires was a decrease of Poa pratensis abundance. However, other plant species did not r-spond to the change in Poa abundance. This result contrasts with previous studies in savannas and more productive grasslands, where …


Mathematical Modeling Of Smallpox Withoptimal Intervention Policy, Niwas Lawot Jan 2006

Mathematical Modeling Of Smallpox Withoptimal Intervention Policy, Niwas Lawot

Electronic Theses and Dissertations

In this work, two differential equation models for smallpox are numerically solved to find the optimal intervention policy. In each model we look for the range of values of the parameters that give rise to the worst case scenarios. Since the scale of an epidemic is determined by the number of people infected, and eventually dead, as a result of infection, we attempt to quantify the scale of the epidemic and recommend the optimum intervention policy. In the first case study, we mimic a densely populated city with comparatively big tourist population, and heavily used mass transportation system. A mathematical …


Antenna-Coupled Infrared And Millimeter-Wave Detectors: Fabrication, Measurement And Optimization, Charles Middleton Jan 2006

Antenna-Coupled Infrared And Millimeter-Wave Detectors: Fabrication, Measurement And Optimization, Charles Middleton

Electronic Theses and Dissertations

Antenna-coupled detectors provide uncooled, cost-effective solutions for infrared and millimeter-wave imaging. This work describes the design, fabrication, measurement, and optimization of several types of antenna-coupled detectors for LWIR (8 - 12 µm) and 94 GHz radiation. Two types of millimeter-wave antenna-coupled detectors were fabricated and tested: a slot antenna coupled to a bolometer, and a patch antenna coupled to a SiC Schottky diode. Electromagnetic modeling of the antennas helped guide the design of antennas with better impedance matching to the detectors. Schottky diodes are discussed as detectors for millimeter-wave and infrared radiation, with the goal of increasing the cutoff frequency …


Integrated Wavelength Stabilization Of Broad Area Semiconductor Lasers Using A Dual Grating Reflector, Jason O'Daniel Jan 2006

Integrated Wavelength Stabilization Of Broad Area Semiconductor Lasers Using A Dual Grating Reflector, Jason O'Daniel

Electronic Theses and Dissertations

A new fully integrated wavelength stabilization scheme based on grating-coupled surface-emitting lasers is explored. This wavelength stabilization scheme relies on two gratings. The first grating is fabricated on the p-side of the semiconductor laser in close proximity to the laser waveguide such that it couples light out of the guided mode of the waveguide into a propagating mode in the substrate; this grating is known as the grating coupler. The second grating is fabricated on the n-side of the substrate such that for the stabilization wavelength, this second grating operates in the Littrow condition and is known as the feedback …


Utk Geography Newsletter 6 (2006), Department Of Geography Jan 2006

Utk Geography Newsletter 6 (2006), Department Of Geography

UTK Geography Newsletter

No abstract provided.


Aspects Of The Jones Polynomial, Alvin Mendoza Sacdalan Jan 2006

Aspects Of The Jones Polynomial, Alvin Mendoza Sacdalan

Theses Digitization Project

A knot invariant called the Jones polynomial will be defined in two ways, as the Kauffman Bracket polynomial and the Tutte polynomial. Three properties of the Jones polynomial are discussed. We also see how mutant knots share the same Jones polynomial.


Traditional Chinese Medicine On-Line Diagnosis System, Chuan-Ting Chou Jan 2006

Traditional Chinese Medicine On-Line Diagnosis System, Chuan-Ting Chou

Theses Digitization Project

The project developed a web-based application that provides a user-friendly interface to assist practitioners of traditional Chinese medicine in determining the correct diagnosis. Traditional Chinese Medicine On-line Diagnosis System (TCMODS) allows a diagnostician to enter a patient's symptoms using a series of questionnaires to determine health status, which will then be stored in the database as part of the patient's medical records. The database will also differentiate among the patterns of syndromes known in traditional Chinese medicine and search and match these with the patient's data to the known uses of Chinese herbs. TCMODS will then generate that patient's medical …


Cerium(Iii) Ion-Selective Electrodes Based On 1,4,7-Trithiacyclononane, Hamid Reza Pouretedal, Abolfazl Semnani, Mohammad Hossein Keshavarz Jan 2006

Cerium(Iii) Ion-Selective Electrodes Based On 1,4,7-Trithiacyclononane, Hamid Reza Pouretedal, Abolfazl Semnani, Mohammad Hossein Keshavarz

Turkish Journal of Chemistry

Novel plasticized polymeric membrane (PPME) and coated platinum wire (CPWE) electrodes based on 1,4,7-trithiacyclononane and oleic acid, as a good lipophilic additive for highly selective determination of Ce^{3+} ions, have been developed. The electrodes exhibit a Nernstian slope of 19.4 mV/decade (for both electrodes) over a wide Ce^{3+} ion concentration range, from 5.0 \times 10^{-6}-5.0 \times 10^{-2} M and 1.0 \times 10^{-7}-1.0 \times 10^{-2} M for PPME and CPWE, respectively. The limits of detection were 3.5 \times 10^{-6} and 8.0 \times 10^{-8} M for PPME and CPWE, respectively. The electrodes possess a fast response time of 15 s, can be …


The Mechanism And Crystal Structure Of 2-Methoxy-2-Methyl-4-Phenyl-3,4,4a, 10b-Tetrahydro-2h,5h-Pyrano[3,2-C]Chromen-5-One. Acetal Of Warfarin Acid, Saira Shahzadi, Saqib Ali, Irum Asif, Rizwana Ashraf, Guo-Xin Jin Jan 2006

The Mechanism And Crystal Structure Of 2-Methoxy-2-Methyl-4-Phenyl-3,4,4a, 10b-Tetrahydro-2h,5h-Pyrano[3,2-C]Chromen-5-One. Acetal Of Warfarin Acid, Saira Shahzadi, Saqib Ali, Irum Asif, Rizwana Ashraf, Guo-Xin Jin

Turkish Journal of Chemistry

Acetal of warfarin acid has been synthesized via a hemi acetal intermediate and structurally characterized by X-ray diffraction. The crystal structure shows that the title compound was formed by the hydrolysis of warfarin acid in methanol at pH 3, with space group P2_1/n and unit cell parameters a = 5.859 (17), b =16.745 (5), c = 16.402 (5) Å, \alpha = 90.00; \beta = 94.853 (4), and \gamma = 90.00°.


Template Synthesis And Structural Characterization Of Homo Binuclear Chromium(Iii), Manganese(Iii), Iron(Iii), Cobalt(Iii), And Ruthenium(Iii) Complexes With Octaazamacrocyclic Ligands, Vinod K. Sharma, Shipra Srivastava Jan 2006

Template Synthesis And Structural Characterization Of Homo Binuclear Chromium(Iii), Manganese(Iii), Iron(Iii), Cobalt(Iii), And Ruthenium(Iii) Complexes With Octaazamacrocyclic Ligands, Vinod K. Sharma, Shipra Srivastava

Turkish Journal of Chemistry

The Schiff base octaazamacrocyclic ligands derived from primary diamines and 3,6-dimethyl/diphenyl-4,5-diazaocta-3,5-diene-2,7-dione, and their binuclear complexes [M_2LCl_4]Cl_2 [M = Cr(III), Fe(III), Co(III), or Ru(III)] and [Mn_2L(AcO)_4](AcO)_2 were synthesized by template condensation reactions. Attempts to synthesize the corresponding metal-free macrocyclic ligands did not prove successful. The overall geometry and stereochemistry of these complexes were elucidated by elemental analyses, magnetic susceptibilities, electronic spectra, infrared spectra, molar conductance measurements, ^1H NMR, and thermogravimetric analysis. All the trivalent metal ion complexes appear to be 1:2 electrolytes. An octahedral geometry is proposed for all the complexes.


The Effect Of Acid Digestion On The Recoveries Of Trace Elements: Recommended Policies For The Elimination Of Losses, Güler Somer, Arzu Nakişci Ünlü Jan 2006

The Effect Of Acid Digestion On The Recoveries Of Trace Elements: Recommended Policies For The Elimination Of Losses, Güler Somer, Arzu Nakişci Ünlü

Turkish Journal of Chemistry

Digestion of biological materials is very important for trace element determinations. Although the microwave technique is mostly used, there are cases where open wet digestion is needed. This study examined the optimum conditions for the minimum loss of trace elements during the wet digestion of a sample. The effect of acid composition and digestion time for about 21 ions was investigated. The trace element concentrations were determined by differential pulse polarography. For the digestion procedure, a HClO_4-HNO_3 mixture was used for the first step and, after its evaporation (60 min), HCl was added as the second step, since in some …


Hydrothermal And Microwave-Assisted Synthesis Of Boroarsenate, Baso_4, Abdulhadi̇ Baykal, Ayten Evren Jan 2006

Hydrothermal And Microwave-Assisted Synthesis Of Boroarsenate, Baso_4, Abdulhadi̇ Baykal, Ayten Evren

Turkish Journal of Chemistry

BAsO_4 was previously synthesized by solid-state reactions at 800 °C and was characterized by X-ray powder diffraction. Now, we succeeded in preparing BAsO_4 from H_3BO_3 and As_2O_5 using hydrothermal synthesis by heating at 160 °C for 3 days (a single-phase product) and using microwave-assisted synthesis, which takes only 5 min to transform a solid mixture of As_2O_5 and (NH_4)_2B_4O_7.4H_2O into the crystalline titled compound (a single-phase product). The crystallinity of the products is higher than that of the solid-state synthesized product given in the literature. Its X-ray powder diffraction patterns, and both Raman and IR spectra were in good agreement …


Prediction Of Acidity Constants Of Thiazolidine-4-Carboxylic Acid Derivatives Using Ab Initio And Genetic Algorithm-Partial Least Squares, Ali Niazi, Saeed Jameh Bozorghi, Davood Nori Shargh Jan 2006

Prediction Of Acidity Constants Of Thiazolidine-4-Carboxylic Acid Derivatives Using Ab Initio And Genetic Algorithm-Partial Least Squares, Ali Niazi, Saeed Jameh Bozorghi, Davood Nori Shargh

Turkish Journal of Chemistry

A quantitative structure-property relationship study is suggested for the prediction of the acidity constants of some thiazolidine-4-carboxylic acid derivatives in aqueous solution. Ab initio theory was used to calculate some quantum chemical descriptors, including electrostatic potentials and local charges at each atom, highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies, etc. Modeling of the acidity constant of thiazolidine-4-carboxylic acid derivatives as a function of molecular structures was established by means of the partial least squares algorithm. The subset of descriptors, which resulted in a low prediction error, was selected by genetic algorithm. This model was applied …


Synthesis Of 1-Cyclohept-1,2-Dien-1-Yl Benzene From 1-(2-Iodo-, Chlorocyclohept-1-En-1-Yl)Benzene And 1-(2-Iodo-, Chlorocyclohept-2-En-1-Yl)Benzene: Its Trapping With Diphenylisobenzofuran, Mustafa Ceylan, Yakup Budak, Murat Ulukaya, M. Burcu Gürdere, Esra Findik Jan 2006

Synthesis Of 1-Cyclohept-1,2-Dien-1-Yl Benzene From 1-(2-Iodo-, Chlorocyclohept-1-En-1-Yl)Benzene And 1-(2-Iodo-, Chlorocyclohept-2-En-1-Yl)Benzene: Its Trapping With Diphenylisobenzofuran, Mustafa Ceylan, Yakup Budak, Murat Ulukaya, M. Burcu Gürdere, Esra Findik

Turkish Journal of Chemistry

The key compounds vinyl iodides 12a and 13a, for the generation of 1-cyclohept-1,2-dien-1-ylbezene (1), were synthesized from cycloheptanone (5). Bromobenzene was converted to the Grignard reagent, which was condensed with 5. Dehydration of alcohol 6 gave alkene 7. Hydroboration of 7 followed by oxidation with PCC afforded ketone 9, which was converted to hydrazone 10. Treatment of 10 with iodine resulted in the formation of 12a and 13a. The other precursors, 12b and 13b, were synthesized from the reaction of 9 with PCl_5. Reactions of 12a, b and 13a, b with KOtBu in a sealed tube at 185 °C gave …


Home Networking, George K. Thiruvathukal Jan 2006

Home Networking, George K. Thiruvathukal

Computer Science: Faculty Publications and Other Works

My coeditors (Paul Dubois and Konstantin Läufer) and I are among a growing number of individuals who install and maintain a home computer network. When Paul and I first discussed the idea of writing an article about the subject several months ago, my first thought was that you--our cherished readers-might consider this whole notion so trivial as to not be worthy of a column that focuses mostly on scientific programming and software development topics. But based on the realization that we three computer scientists devote a significant part of our time to network and system administration, it almost goes without …