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Full-Text Articles in Physical Sciences and Mathematics

On The Distribution Of Random Dirichlet Series In The Whole Plane, Qiyu Jin, Daochun Sun Jan 2008

On The Distribution Of Random Dirichlet Series In The Whole Plane, Qiyu Jin, Daochun Sun

Turkish Journal of Mathematics

For some random Dirichlet series of order(R) infinite almost surely, every horizontal line is a strong Borel line of order(R) infinite and without exceptional Little functions.


Killing And Geodesic Lightlike Hypersurfaces Of Indefinite Sasakian Manifolds, Fortune Massamba Jan 2008

Killing And Geodesic Lightlike Hypersurfaces Of Indefinite Sasakian Manifolds, Fortune Massamba

Turkish Journal of Mathematics

In this paper, we study a lightlike hypersurface of indefinite Sasakian manifold, tangent to the structure vector field \xi. Theorems on parallel and Killing distributions are obtained. Necessary and sufficient conditions have been given for lightlike hypersurface to be mixed totally geodesic, D-totally geodesic, D\perp-totally geodesic and D'-totally geodesic. We prove that, if the screen distribution of lightlike hypersurface M of indefinite Sasakian manifold is totally umbilical, the D\perp-geodesibility of M is equivalent to the D\perp-parallelism of the distribution T M^\perp of rank 1 (Theorem \ref{Theoscre}). Finally, we give the D\perp-version (Theorem 4.22) of the Theorem 2.2 ([11], page 88).


Dual Quaternions In Spatial Kinematics In An Algebraic Sense, Bedi̇a Akyar Jan 2008

Dual Quaternions In Spatial Kinematics In An Algebraic Sense, Bedi̇a Akyar

Turkish Journal of Mathematics

This paper presents the finite spatial displacements and spatial screw motions by using dual quaternions and Hamilton operators. The representations are considered as 4 \times 4 matrices and the relative motion for three dual spheres is considered in terms of Hamilton operators for a dual quaternion. The relation between Hamilton operators and the transformation matrix has been given in a different way. By considering operations on screw motions, representation of spatial displacements is also given.


Crustal Structure Of The Eastern Part Of Central Anatolia (Turkey), Hüseyi̇n Yilmaz, Sevda Özel Jan 2008

Crustal Structure Of The Eastern Part Of Central Anatolia (Turkey), Hüseyi̇n Yilmaz, Sevda Özel

Turkish Journal of Earth Sciences

This study aims to examine crustal structure in the eastern part of central Anatolia using the magnetotelluric (MT) method. MT data have been collected from 37 stations along a north-south 220 km profile crossing in succession the Tokat Massif (Pontide basement), the Ankara-Erzincan Suture Zone, the Kırşehir Massif, the Pınarbaşı-Divriği Ophiolitic Belt and the Tauride-Anatolide Belt. Data were modelled to derive a geo-electrical model using 2-dimensional inverse techniques. Low resistivity values (981 Ohm.m) coincide with the southern part of the Pontide Magmatic Arc, the Kırşehir Block and the Tauride-Anatolide Belt and are interpreted as upper crust of igneous and metamorphic …


Comparison Of Basic Linear Filters In Extracting Auditory Evoked Potentials, Serap Aydin Jan 2008

Comparison Of Basic Linear Filters In Extracting Auditory Evoked Potentials, Serap Aydin

Turkish Journal of Electrical Engineering and Computer Sciences

In the present study, the performances of two well-known linear filtering techniques are compared for extraction of auditory Evoked Potential (EP) from a relatively small number of sweeps. Both experimental and simulated data are filtered by the two algorithms into two groups. Group A consists of Wiener filtering (WF) applications, where conventional WF and Coherence Weighted WF (CWWF)) have been assessed in combination with the Subspace Method (SM). Group B consists of the well-known adaptive filtering algorithms Least Mean Square (LMS), Recursive Least Square (RLS), and one-step Kalman filtering (KF). Both groups are tested with respect to signal-to-noise ratio (SNR) …


Role Of Artificial Intelligence In The Reliability Evaluation Of Electric Power Systems, Chanan Singh, Lingfeng Wang Jan 2008

Role Of Artificial Intelligence In The Reliability Evaluation Of Electric Power Systems, Chanan Singh, Lingfeng Wang

Turkish Journal of Electrical Engineering and Computer Sciences

Every reliability analysis effort, in some way, involves searching the state space of the system for those states that represent the events of interest, typically failure of the system or a given node to meet the demand. This essentially translates into a search procedure to efficiently identify states to be examined and then using a mechanism to evaluate these states. Traditionally, reliability analysis methods are based either on an implicit or explicit enumeration process or Monte Carlo sampling. More recently, methods based on artificial intelligence have been investigated both as an alternative to Monte Carlo for the search process as …


Detailed Geochemistry And K-Ar Geochronology Of The Metamorphic Sole Rocks And Their Mafic Dykes From The Mersin Ophiolite, Southern Turkey, Ömer Faruk Çeli̇k Jan 2008

Detailed Geochemistry And K-Ar Geochronology Of The Metamorphic Sole Rocks And Their Mafic Dykes From The Mersin Ophiolite, Southern Turkey, Ömer Faruk Çeli̇k

Turkish Journal of Earth Sciences

The metamorphic sole rocks at the base of mantle peridotites from the Mersin ophiolite consist of amphibolites and metasedimentary lithologies. Mineral parageneses in the metamorphic sole rocks exhibit amphibolite and greenschist facies assemblages. Geothermobarometric studies based on mineral assemblages and chemical compositions of minerals indicate that average metamorphic temperature during the metamorphism was 522 ± 15 °C and the pressure was less than 5 kb. Amphibolites from the metamorphic sole rocks exhibit geochemical characteristics of a supra-subduction zone (SSZ) type ophiolite, based on their major, trace and rare earth element (REE) compositions. The Th/Nb ratios of the amphibolites are higher …


On The Origin And Age Of The Arıburnu Beachrock, Gelibolu Peninsula, Turkey, Ahmet Evren Ergi̇nal, Nafi̇ye Kiyak Güneç, Mustafa Bozcu, Ahmet Ertek, Hakan Güngüneş, Ali̇ Sungur, Gülen Türker Jan 2008

On The Origin And Age Of The Arıburnu Beachrock, Gelibolu Peninsula, Turkey, Ahmet Evren Ergi̇nal, Nafi̇ye Kiyak Güneç, Mustafa Bozcu, Ahmet Ertek, Hakan Güngüneş, Ali̇ Sungur, Gülen Türker

Turkish Journal of Earth Sciences

The beachrock formation on the Arıburnu coast situated in the Gelibolu Peninsula has been studied by field observation, thin-section interpretation, physicochemical analyses including ICP-AES and SEM/EDS, and OSL dating. These analyses reveal the presence of different amounts of major (Si, Ca, Mg, K, Fe, Al and Na) and trace elements within the beachrock cement with Si (36.2%) and Ca (32.68%) dominating the overall composition. Beachrocks composed of highly-fractured and friable beds reach a total thickness of 80 cm extending from +60 cm at the uppermost level down to -1 m at their most seaward extent and grade from conglomerate to …


Trace Fossils Of The Upper Eocene-Lower Oligocene Transition Of The Manipur, Indo-Myanmar Ranges (Northeast India), Rajkumar Hemanta Singh, Francisco J. Rodriguez Tovar, Soibam Ibotombi Jan 2008

Trace Fossils Of The Upper Eocene-Lower Oligocene Transition Of The Manipur, Indo-Myanmar Ranges (Northeast India), Rajkumar Hemanta Singh, Francisco J. Rodriguez Tovar, Soibam Ibotombi

Turkish Journal of Earth Sciences

A detailed ichnological analysis, for the first time, has been preformed on Upper Eocene-Lower Oligocene Transition of Manipur, Indo-Myanmar Ranges (Northeast India). Previous trace fossil analyses in India are scarce and usually poorly detailed, especially with respect to Cenozoic materials. Sediments from the Disang and Barail groups contain a relatively abundant and moderately diverse trace fossil assemblage that has been characterized at the ichnogenus and ichnospecies level. ?Arenicolites Salter 1857, Helminthopsis tenuis Ksiazkiewicz 1968, Ophiomorpha nodosa Lundgren 1891, Phycodes palmatus (Hall 1852), Planolites montanus Richter 1937, Rhizocorallium jenense Zenker 1836, Thalassinoides paradoxicus (Woodward 1830) and Skolithos linearis (Haldeman 1840) have …


A Summary Of Recent Developments On Metamaterial-Based And Metamaterial-Inspired Efficient Electrically Small Antennas, Aycan Erentok, Richard W. Ziolkowski Jan 2008

A Summary Of Recent Developments On Metamaterial-Based And Metamaterial-Inspired Efficient Electrically Small Antennas, Aycan Erentok, Richard W. Ziolkowski

Turkish Journal of Electrical Engineering and Computer Sciences

This paper summarizes our recent research efforts to realize efficient electrically small antenna (EESA) systems based on ideal analytical and numerical metamaterial-based antenna systems, and physically realized metamaterial-inspired antenna designs. Our theoretical and numerical studies of the radiation and resonance behaviors of the proposed metamaterial-based EESA systems, as well as our efforts to conceptualize structures which might be used to build them, have led to the discovery of several realizable metamaterial-inspired EESA systems. The measurement results confirm the numerical performance predictions.


A Note On A Problem Of J. Galambos, Lu-Ming Shen, Yue-Hua Liu, Yu-Yuan Zhou Jan 2008

A Note On A Problem Of J. Galambos, Lu-Ming Shen, Yue-Hua Liu, Yu-Yuan Zhou

Turkish Journal of Mathematics

For any x\in (0,1], letx = \frac{1}{d_1} + \frac{a_1}{b_1} \frac{1}{d_2} + ··· + \frac{a_1a_2 ··· a_n}{b_1b_2 ··· b_n} \frac{1}{d_{n+1}} + ··· be the Oppenheim series expansion of x. In this paper, we investigate the Hausdorff dimension of the set B_m={x:1


High Pressure Phase Transition Of Copper Halides, Deoshree Baghmar, Neeraj Kumar Gaur, Sadhna Singh, Dinesh Chandra Gupta Jan 2008

High Pressure Phase Transition Of Copper Halides, Deoshree Baghmar, Neeraj Kumar Gaur, Sadhna Singh, Dinesh Chandra Gupta

Turkish Journal of Physics

The structural changes within copper halides induced by pressure from zinc-blend to rock-salt passing through an intermediate tetragonal structure have been investigated using an effective interionic interaction potential. The values of the phase transition pressures obtained by us for the copper halides are in good agreement with their available experimental data. We have also investigated the equation of state, which shows an appreciable volume collapses at the phase transition pressures.


Cover For Modules And Injective Modules, N. Amiri Jan 2008

Cover For Modules And Injective Modules, N. Amiri

Turkish Journal of Mathematics

Let R be a commutative ring with identity and M be an R-module with Spec(M) \neq \phi. A cover of the R-submodule K of M is a subset C of Spec(M) satisfying that for any x \in K, x \neq 0, there is N \in C such that ann(x) \subset (N:M). If we denote by J = \bigcap_{N \in C} (N:M) and assume that M is finitely generated, then JM=M implies that M=0, M is called C-injective provided each R-homomorphism \phi : (N:M) \rightarrow M with N \in C can be lifted to an R-homomorphism \lambda : R \rightarrow M. …


Cretaceous Pelagic Red Beds And Black Shales (Aptian-Santonian), Nw Turkey: Global Oceanic Anoxic And Oxic Events, İsmai̇l Ömer Yilmaz Jan 2008

Cretaceous Pelagic Red Beds And Black Shales (Aptian-Santonian), Nw Turkey: Global Oceanic Anoxic And Oxic Events, İsmai̇l Ömer Yilmaz

Turkish Journal of Earth Sciences

The study areas located near the towns of Göynük, Mudurnu and Nallıhan in the central northwestern part of Turkey lie on the `Sakarya Continent´, which is one of the tectonic entities of the Cretaceous geology of Turkey. Measured stratigraphic sections comprise the Aptian pelagic carbonates and the overlying Albian-Coniacian turbiditic sequences, which are all capped by a Late Santonian red pelagic succession. Lower and Upper Aptian, Upper Albian and Cenomanian/Turonian marine black shales recognized in the sections are followed by Lower and Upper Aptian, Upper Albian and Turonian marine red beds. The black shales are generally silty, laminated, and include …


Palynostratigraphic, Palaeovegetational And Palaeoclimatic Investigations On The Miocene Deposits In Central Anatolia (Çorum Region And Sivas Basin), Mi̇ne Sezgül Kayseri̇, Funda Akgün Jan 2008

Palynostratigraphic, Palaeovegetational And Palaeoclimatic Investigations On The Miocene Deposits In Central Anatolia (Çorum Region And Sivas Basin), Mi̇ne Sezgül Kayseri̇, Funda Akgün

Turkish Journal of Earth Sciences

Palynostratigraphy of the Neogene coal-bearing sediments in the Çorum region and Sivas Basin has been determined, and three sporomorph associations have been defined. Sporomorph association A is described from the Samsun-Havza region and is of latest Burdigalian age. Sporomorph association B is described from the Çorum region and Sivas Basin and is of early-middle Serravalian age. Sporomorph association C is described from the Sivas-Vasıltepe region and is of earliest Tortonian age. Sporomorph association A indicates warm subtropical climatic conditions and the Coexistence Approach (CA) results are: mean annual temperature (MAT) 19 °C, mean annual coldest month (CMT) 9.75 °C, mean …


In Memoriam Jean Philippe Marcoux, A.M. Celal Şengör Jan 2008

In Memoriam Jean Philippe Marcoux, A.M. Celal Şengör

Turkish Journal of Earth Sciences

No abstract provided.


Linear Connections On Light-Like Manifolds, Teki̇n Dereli̇, Şahi̇n Koçak, Murat Li̇moncu Jan 2008

Linear Connections On Light-Like Manifolds, Teki̇n Dereli̇, Şahi̇n Koçak, Murat Li̇moncu

Turkish Journal of Mathematics

It is well-known that a torsion-free linear connection on a light-like manifold (M,g) compatible with the degenerate metric g exists if and only if Rad(TM) is a Killing distribution. In case of existence, there is an infinitude of connections with none distinguished. We propose a method to single out connections with the help of a special set of 1-forms by the condition that the 1-forms become parallel with respect to this connection. Such sets of 1-forms could be regarded as an additional structure imposed upon the light-like manifold. We consider also connections with torsion and with non-metricity on light-like manifolds.


Calculated Pressure Induced Bcc-Fcc Phase Transitions In Alkali Metals, Hamdi̇ Dağistanli, Riza Haluk Mutlu Jan 2008

Calculated Pressure Induced Bcc-Fcc Phase Transitions In Alkali Metals, Hamdi̇ Dağistanli, Riza Haluk Mutlu

Turkish Journal of Physics

The partial occupation numbers and density of states (DOS), and the total DOS at the Fermi level are calculated as a function of reduced atomic volume for bcc and fcc alkali metals employing the linear-muffin-tin-orbital (LMTO) method. By means of the abrupt changes obtained in the partial and total DOS values at the Fermi level, good agreement with regard to experiment were found in predicting the bcc-fcc transition volumes of the alkali metals.


Nonlinear Process Between Co-Propagating Signal And Control Pulses In Semiconductor Optical Amplifiers, Jianwei Wu, Hai-Bo Bao Jan 2008

Nonlinear Process Between Co-Propagating Signal And Control Pulses In Semiconductor Optical Amplifiers, Jianwei Wu, Hai-Bo Bao

Turkish Journal of Physics

A nonlinear process between co-propagating signal and control pulses has been proposed and demonstrated numerically, based on semiconductor optical amplifiers (SOA). Results show that a Gaussian signal pulse with picosecond duration can be simultaneously amplified and compressed in a SOA by utilizing a co-propagating high-intensity control pulse. To obtain high quality signal pulse with high peak power level and short pulse width, the center carrier wavelengths of two pulses should locate in the gain region of the SOA. The initial delay time between both pulses should be tuned suitably before entering the SOA.


Role Of Substrate Temperature On The Structural And Morphological Properties Of Zno Thin Films Deposited By Ultrasonic Spray Pyrolysis, Abdelkader Djelloul, Khadidja Bouzid, Fahima Guerrab Jan 2008

Role Of Substrate Temperature On The Structural And Morphological Properties Of Zno Thin Films Deposited By Ultrasonic Spray Pyrolysis, Abdelkader Djelloul, Khadidja Bouzid, Fahima Guerrab

Turkish Journal of Physics

Zinc oxide (ZnO) thin films have been prepared by ultrasonic Spray Pyrolysis (USP) technique using zinc acetate dihydrate dissolved in methanol, ethanol and deionized water. A thermodynamic analysis for the growth of ZnO thin films from zinc acetate and water vapor has been made. The evolution of the preferred crystalline orientations in the ZnO films was investigated systematically. The optical measurements reveal that films have a maximum transmittance of about 90% and a direct band gap of 3.26 eV.


Theoretical Analysis Of Acoustic Attenuation And Nonlinearity In Barium Monochalcogenides In B2 Phase, Rajendra Kumar Singh, Rishi Pal Singh, Manish Pratap Singh, Sujeet Kumar Chaurasia Jan 2008

Theoretical Analysis Of Acoustic Attenuation And Nonlinearity In Barium Monochalcogenides In B2 Phase, Rajendra Kumar Singh, Rishi Pal Singh, Manish Pratap Singh, Sujeet Kumar Chaurasia

Turkish Journal of Physics

Temperature dependence of ultrasonic attenuation due to phonon-phonon interaction and thermo-elastic loss have been studied in (CsCl-type) barium monochalcogenides (BaX, X= S, Se, Te), in the temperature range 50-500 K; for longitudinal and shear modes of propagation along , and directions. Second and third order elastic constants have been evaluated using electrostatic and Born repulsive potentials and taking interactions up to next nearest neighbours. Gruneisen parameters, nonlinearity constants, nonlinearity constants ratios and viscous drag due to screw and edge dislocations have also been evaluated for longitudinal and shear waves at 300 K. In the present investigation, it has been found …


Relative Sea-Level Changes Of The Lower Cretaceous Deposits In The Chotts Area Of Southern Tunisia, Lazzez Marzouk, Mohamed Ben Youssef Jan 2008

Relative Sea-Level Changes Of The Lower Cretaceous Deposits In The Chotts Area Of Southern Tunisia, Lazzez Marzouk, Mohamed Ben Youssef

Turkish Journal of Earth Sciences

A transition facies between evaporate and clay, carbonate and siliciclastic deposits occurs within the Lower Cretaceous of Southern Tunisia. The sedimentary deposits comprise four major transgressive-regressive sedimentary sequences with distinctive sabkha, tidal to shallow carbonate marine platform, and mixed siliciclastic ramp environments. Sedimentation rates, as well as thickness and facies changes were controlled by tectonic, climatic and eustatic factors. Transgression pulses encompassing the whole Late Hauterivian-Barremian, Early Aptian and Late Albian have controlled the basin infill. Evaporate and siliciclastic systems pass gradually to carbonate deposition in the Chotts area. Our sedimentation model helps to decipher the roles of tectonics and, …


Evolutionary Algorithms For The Unit Commitment Problem, A. Şi̇ma Uyar, Belgi̇n Türkay Jan 2008

Evolutionary Algorithms For The Unit Commitment Problem, A. Şi̇ma Uyar, Belgi̇n Türkay

Turkish Journal of Electrical Engineering and Computer Sciences

This paper compares three evolutionary computation techniques, namely Steady-State Genetic Algorithms, Evolutionary Strategies and Differential Evolution for the Unit Commitment Problem. The comparison is based on a set of experiments conducted on benchmark datasets as well as on real-world data obtained from the Turkish Interconnected Power System. The results of two state-of-the-art evolutionary approaches, namely a Generational Genetic Algorithm and a Memetic Algorithm for the same benchmark datasets are also included in the paper for comparison. The tests show that Differential Evolution is the best performer among all approaches on the test data used in the paper. The performances of …


A Study On The Reliability Of Polyester Insulators Blended With Borax, Aysel Ersoy, Yasi̇n Özcelep, Ayten Kuntman Jan 2008

A Study On The Reliability Of Polyester Insulators Blended With Borax, Aysel Ersoy, Yasi̇n Özcelep, Ayten Kuntman

Turkish Journal of Electrical Engineering and Computer Sciences

Tracking is the main factor which limits the safe working electric stress of insulation in power system applications. Polymer samples have been tested in laboratory conditions according to ASTM D2303 on accelerated inclined plane tracking test. In this paper, a model based on improved Weibull statistics is proposed for estimating the breakdown time of polymeric insulating materials with borax. The confidence intervals of the Weibull shape parameter and the Weibull scale parameter are determined for the borax concentration values using the Weibull 7++ program.


Best P-Simultaneous Approximation In Some Metric Space, Mona Khandaqji, Wasfi Shatanawi Jan 2008

Best P-Simultaneous Approximation In Some Metric Space, Mona Khandaqji, Wasfi Shatanawi

Turkish Journal of Mathematics

Let X be a Banach space, (I,\mu) be a finite measure space, and \Phi be an increasing subadditive continuous function on [0,+\infty) with \Phi(0)=0. In the present paper, we discuss the best p-simultaneous approximation of L^\Phi(I,G) in L^\Phi(I,X) where G is a closed subspace of X.


On The Regular Elements In Z_N, Osama Alkam, Emad Abu Osba Jan 2008

On The Regular Elements In Z_N, Osama Alkam, Emad Abu Osba

Turkish Journal of Mathematics

All rings are assumed to be finite commutative with identity element. An element a \in R is called a regular element if there exists b \in R such that a=a^2b, the element b is called a von Neumann inverse for a. A characterization is given for regular elements and their inverses in Z_n, the ring of integers modulo n. The arithmetic function V(n), which counts the regular elements in Z_n is studied. The relations between V(n) and Euler's phi-function \varphi (n) are explored.


Mixed Type Of Integral Equation With Potential Kernel, Mohamed Abdella A. Abdou, Gamal Mohamed Abd Al-Kader Jan 2008

Mixed Type Of Integral Equation With Potential Kernel, Mohamed Abdella A. Abdou, Gamal Mohamed Abd Al-Kader

Turkish Journal of Mathematics

This paper presents the solution of an integral equation of a mixed type in three-dimensions in the space L_2 (\Omega) \times C[0,T], where T < \infty, and \Omega is the domain of integration with respect to position. The kernel of position integral term is considered in the potential function form, while the kernel of time is considered as a continuous kernel. A linear system of Fredholm integral equations of the first and second kinds are obtained and solved. Krein's method is used to solve the Fredholm integral equation of the first kind, while the second kind is solved numerically.


Posner´S Second Theorem And An Annihilator Condition With Generalized Derivations, Vincenzo De Filippis Jan 2008

Posner´S Second Theorem And An Annihilator Condition With Generalized Derivations, Vincenzo De Filippis

Turkish Journal of Mathematics

Let R be a prime ring of characteristic different from 2, with extended centroid C, U its two-sided Utumi quotient ring, \delta\neq 0 a non-zero generalized derivation of R, f(x_1,..,x_n) a non-central multilinear polynomial over C in n non-commuting variables, a \in R such that a[\delta(f(r_1,..,r_n)),f(r_1,..,r_n)]=0, for any r_1,..,r_n \in R. Then one of the following holds: 1. a=0; 2. there exists \lambda \in C such that \delta(x)=\lambda x, for all x \in R; 3. there exist q \in U and \lambda \in C such that \delta(x)=(q+\lambda)x+xq, for all x\in R, and f(x_1,..,x_n)^2 is central valued on R.


Diametral Dimension And Köthe Spaces, Tosun Terzi̇oğlu Jan 2008

Diametral Dimension And Köthe Spaces, Tosun Terzi̇oğlu

Turkish Journal of Mathematics

We generalize some well-known results about the diametral dimension of classical Köthe spaces


Lyapunov-Type Inequalities For Certain Nonlinear Systems On Time Scales, Mehmet Ünal, Devri̇m Çakmak Jan 2008

Lyapunov-Type Inequalities For Certain Nonlinear Systems On Time Scales, Mehmet Ünal, Devri̇m Çakmak

Turkish Journal of Mathematics

In this study, we prove Lyapunov-type inequalities for certain nonlinear systems on an arbitrary time scale T by using elementary time scale calculus. These inequalities enable us to obtain a criterion of disconjugacy for such systems. Special cases of our results contain the classical Lyapunov inequality for both differential and difference equations.