Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

TÜBİTAK

Discipline
Keyword
Publication Year
Publication

Articles 10441 - 10470 of 12081

Full-Text Articles in Entire DC Network

On 1-Point Gromov-Witten Invariants Of The Hilbert Schemes Of Points On Surfaces, Wei-Ping Li, Zhenbo Qin Jan 2002

On 1-Point Gromov-Witten Invariants Of The Hilbert Schemes Of Points On Surfaces, Wei-Ping Li, Zhenbo Qin

Turkish Journal of Mathematics

We compute certain 1-point genus-0 Gromov-Witten invariants of the Hilbert scheme of points on a simply-connected smooth projective surface.


Evidence For A Conjecture Of Pandharipande, Jim Bryan Jan 2002

Evidence For A Conjecture Of Pandharipande, Jim Bryan

Turkish Journal of Mathematics

In his paper ``Hodge integrals and degenerate contributions'', Pandharipande studied the relationship between the enumerative geometry of certain 3-folds and the Gromov-Witten invariants. In some good cases, enumerative invariants (which are manifestly integers) can be expressed as a rational combination of Gromov-Witten invariants. Pandharipande speculated that the same combination of invariants should yield integers even when they do not have any enumerative significance on the 3-fold. In the case when the 3-fold is the product of a complex surface and an elliptic curve, Pandharipande has computed this combination of invariants on the 3-fold in terms of the Gromov-Witten invariants of …


Variations On Fintushel-Stern Knot Surgery On 4-Manifolds, Selman Akbulut Jan 2002

Variations On Fintushel-Stern Knot Surgery On 4-Manifolds, Selman Akbulut

Turkish Journal of Mathematics

We discuss some consequences Fintushel-Stern `knot surgery' operation coming from its handlebody description. We give some generalizations of this operation and give a counterexample to their conjecture.


Braids And Symplectic Four-Manifolds With Abelian Fundamental Group, Paul Seidel Jan 2002

Braids And Symplectic Four-Manifolds With Abelian Fundamental Group, Paul Seidel

Turkish Journal of Mathematics

We explain how a version of Floer homology can be used as an invariant of symplectic manifolds with b_1>0. As a concrete example, we look at four-manifolds produced from braids by a surgery construction. The outcome shows that the invariant is nontrivial; however, it is an open question whether it is stronger than the known ones.


Low-Dimensional Homology Groups Of Mapping Class Groups: A Survey, Mustafa Korkmaz Jan 2002

Low-Dimensional Homology Groups Of Mapping Class Groups: A Survey, Mustafa Korkmaz

Turkish Journal of Mathematics

In this survey paper, we give a complete list of known results on the first and the second homology groups of surface mapping class groups. Some known results on higher (co) homology are also mentioned.


Gauge Theory And Stein Fillings Of Certain 3-Manifolds, Andras I. Stipsicz Jan 2002

Gauge Theory And Stein Fillings Of Certain 3-Manifolds, Andras I. Stipsicz

Turkish Journal of Mathematics

In the following we show that a Stein filling S of the 3-torus T^3 is homeomorphic to D^2 \times T^2. In the proof we also show that if S is Stein and \partial S is diffeomorphic to the Seifert fibered 3-manifold -\Sigma (2,3,11) then b_1(S)=0 and Q_S=H. Similar results are obtained for the Poincaré homology sphere \pm \Sigma (2,3,5); in studying these fillings we apply recent gauge theoretic results, and prove our theorems by determining certain Seiberg-Witten invariants.


Geology Of The Ören And Surrounding Areas, Sw Anatolia, Ömer Feyzi̇ Gürer, Yücel Yilmaz Jan 2002

Geology Of The Ören And Surrounding Areas, Sw Anatolia, Ömer Feyzi̇ Gürer, Yücel Yilmaz

Turkish Journal of Earth Sciences

On the Lycian Nappes of SW Anatolia, Neogene basins developed along two different trends in different periods. NNE-trending basins formed during the Early-Middle Miocene period as exemplified by the Ören and Yatağan grabens. These graben fills consist of three distinct rock units. At the base are (1) coarse clastics, sourced from elevated areas adjacent to the basin-bounding faults. These are linear river-valley fills. They give way upward to (2) alternating coal-bearing sandstone and limestone as the graben valleys were gradually widened, and the surrounding mountains were reduced by erosion. Finally, lake environment formed, invading the region during the advanced stage …


Upper Cretaceous Stratigraphy Of The Bey Dağları Carbonate Platform, Korkuteli Area (Western Taurides, Turkey), Bi̇lal Sari, Saci̇t Özer Jan 2002

Upper Cretaceous Stratigraphy Of The Bey Dağları Carbonate Platform, Korkuteli Area (Western Taurides, Turkey), Bi̇lal Sari, Saci̇t Özer

Turkish Journal of Earth Sciences

The Upper Cretaceous Korkuteli (Antalya) carbonate sequence of the Bey Dağları autochthonous unit (western Taurides) comprises two formations. The Cenomanian-Santonian Bey Dağları formation lies at the base of this sequence and can be divided into two parts. Neritic part is characterized by platform-type, peritidal limestones and comprises an approximately 600-m-thick sequence that contains two main rudistid horizons corresponding to Cenomanian and early Santonian. The neritic limestones pass gradually upward into the 15-m-thick, middle-upper Santonian massive hemipelagic limestones that form the upper part. The upper Campanian-middle Maastrichtian Akdağ formation consists totally of pelagic limestones that indicate basinal conditions and disconformably overlies …


Obituary, Gülsen Uçarkul, Tuncay Taymaz Jan 2002

Obituary, Gülsen Uçarkul, Tuncay Taymaz

Turkish Journal of Earth Sciences

No abstract provided.


On Summand Sum And Summand Intersection Property Of Modules, Mustafa Alkan, Abdullah Harmanci Jan 2002

On Summand Sum And Summand Intersection Property Of Modules, Mustafa Alkan, Abdullah Harmanci

Turkish Journal of Mathematics

R will be an associative ring with identity and modules M will be unital left R- modules. In this work, extending modules and lifting modules with the SSP (or SIP) are studied. A necessary and sufficient condition for a module M to have the SSP is that for every decomposition M = A\oplus B and f\in Hom(A,B), Im(f) is a direct summand of B. Among others it is shown also that a (C_3) module with the SIP has the SSP, and a (D_3) module with SSP has the SIP.


Asymptotic Formulas For The Eigenvalues Of The Schrodinger Operator, Şi̇ri̇n Atilgan, Sedef Karakiliç, Oktay A. Veliev Jan 2002

Asymptotic Formulas For The Eigenvalues Of The Schrodinger Operator, Şi̇ri̇n Atilgan, Sedef Karakiliç, Oktay A. Veliev

Turkish Journal of Mathematics

In this paper, we obtain asymptotic formulas for the eigenvalues of the d-dimensional Schrodinger operator L=-\Delta +q(x) in d-dimensional parallelepiped F with Dirichlet and Neumann boundary conditions.


Remarks On Bounded Operators In Köthe Spaces, P. B. Djakov, T. Terzi̇oğlu, M. Yurdakul, V. P. Zahariuta Jan 2002

Remarks On Bounded Operators In Köthe Spaces, P. B. Djakov, T. Terzi̇oğlu, M. Yurdakul, V. P. Zahariuta

Turkish Journal of Mathematics

We prove that if \lambda(A),\lambda(B) and \lambda(C) are Köthe spaces such that L(\lambda(A),\lambda(B)) and L(\lambda(C),\lambda(A)) consist of bounded operators then each operator acting on \lambda(A) that factors over \lambda(B)\widehat\otimes_{\pi} \lambda(C) is bounded.


N-Commutator Groups, A. A. Mehrvarz, K. Azizi Jan 2002

N-Commutator Groups, A. A. Mehrvarz, K. Azizi

Turkish Journal of Mathematics

A sufficient condition such that any element of G' (the commutator subgroup of G) can be represented as a product of n commutators, was studied in \cite{GAL62}. In this article we study a necessary and sufficient condition such that any element of G' can be represented as a product of n commutators, Let n be the smallest nature number such that any element of finite group G can be represented as a product of n commutators. A group G with this property will be called an n -commutator group, and n will be denoted by c(G) . Then \frac{\ln( G' …


\Theta-Euclidean L-Fuzzy Ideals Of Rings, Ayten Koç, Erol Balkanay Jan 2002

\Theta-Euclidean L-Fuzzy Ideals Of Rings, Ayten Koç, Erol Balkanay

Turkish Journal of Mathematics

The concept of fuzzy ideals is extended by introducing \theta -Euclidean L-fuzzy ideals in rings. In particular, some structural theorems for a \theta -Euclidean L-fuzzy ideal of R are proved.


Minimality Of Certain Normal Connected Sums, Tian-Jun Li, Andras I. Stipsicz Jan 2002

Minimality Of Certain Normal Connected Sums, Tian-Jun Li, Andras I. Stipsicz

Turkish Journal of Mathematics

We show that the normal connected sum of two minimal symplectic 4-manifolds (neither of them rational or ruled) is a minimal symplectic 4-manifold. In the proof we use a symplectic sum formula for Gromov-Witten invariants.


The Ophiolitic Molasse Unit Of Ikaria Island (Greece), Adonis D. Photiades Jan 2002

The Ophiolitic Molasse Unit Of Ikaria Island (Greece), Adonis D. Photiades

Turkish Journal of Earth Sciences

Ikaria Island can be divided generally into two composite tectonic units, namely the lower and upper. The lower unit comprises paragneiss basement with local orthogneiss bodies that is overlain by a platform-type marble sequence, passing upward into a sequence of intercalated schist and marble that is intruded by Miocene granites. The upper unit has not experienced Alpine high-pressure metamorphism, and is restricted to the central (Kefala unit) and northeastern (Faros area) parts of the island, which host ophiolitic associations similar to those found in the upper unit of several Cycladic islands. The Faros area consists of an Oligocene-Early Miocene age …


Resistivity Distribution In The Gediz Graben And Its Implications For Crustal Structure, Aysan Gürer, Alaatti̇n Pi̇nçe, Ömer Feyzi̇ Gürer, O. Meti̇n İlkişik Jan 2002

Resistivity Distribution In The Gediz Graben And Its Implications For Crustal Structure, Aysan Gürer, Alaatti̇n Pi̇nçe, Ömer Feyzi̇ Gürer, O. Meti̇n İlkişik

Turkish Journal of Earth Sciences

Preliminary results of resistivity distribution in the crust around the Gediz graben by the magnetotelluric (MT) measurements along two 73- and 16-km-long MT profiles (M1 and profile M2) are presented. Bostick depth transformation of the resistivity component of the MT data denoted a conductive zone at a depth of ~ 10 km. This zone may be related to crustal extension and high regional heat flow (50% higher than the world average). Preliminary interpretation based on one dimensional (1D) inversion result show that the thickness of sediments over the resistive basement changes from 950-3800 m along the profile M1. The relations …


Sonar And High Resolution Seismic Studies In The Eastern Black Sea, Günay Çi̇fçi̇, Derman Dondurur, Mustafa Ergün Jan 2002

Sonar And High Resolution Seismic Studies In The Eastern Black Sea, Günay Çi̇fçi̇, Derman Dondurur, Mustafa Ergün

Turkish Journal of Earth Sciences

The Black Sea is one of the largest inland seas in the world. Off the shelf, the water depth quickly plunges to an average depth of 2 km. The Black Sea sediments are rich in calcite and organic carbon, the latter showing a high degree of preservation due to anoxia in the waters below 100-150 m. Slope failures and sediment instability related to immense gas and gas hydrate accumulations are serious problems that can lead to the failure of offshore installations. Marine geophysical surveys have been carried out in the Eastern Black Sea basin using state-of the-art technology to produce …


Tectonostratigraphic Evolution Of The North Anatolian Palaeorift (Napr): Hettangian-Aptian Passive Continental Margin Of The Northern Neo-Tethys, Turkey, Ali̇ Koçyi̇ği̇t, Demi̇r Altiner Jan 2002

Tectonostratigraphic Evolution Of The North Anatolian Palaeorift (Napr): Hettangian-Aptian Passive Continental Margin Of The Northern Neo-Tethys, Turkey, Ali̇ Koçyi̇ği̇t, Demi̇r Altiner

Turkish Journal of Earth Sciences

The Jurassic-Early Cretaceous stratigraphical, sedimentological and structural evolutionary history of the northern branch of Neo-Tethys is recorded and preserved within an average 6-km-thick basin fill. The basin fill is well-exposed as discontinuous inliers of varying size and thickness within, and to the north of, the Late Cretaceous-Early Tertiary İzmir-Ankara-Erzincan Suture throughout northern Turkey. This basin fill unconformably overlies a substratum comprising the deformed rock assemblages of the Triassic Karakaya palaeorift and its Hercynian basement. Detailed studies based on geological mapping at a 1/25,000 scale and stratigraphic sections measured at 14 type localities show that this infill includes stratigraphical and sedimentological …


Numerical Solution And Convergence Speed Of Variational Formulation For Linear Schrödinger Equation, Murat Subaşi, Bünyami̇n Yildiz Jan 2002

Numerical Solution And Convergence Speed Of Variational Formulation For Linear Schrödinger Equation, Murat Subaşi, Bünyami̇n Yildiz

Turkish Journal of Mathematics

This paper presents a numerical solution of an optimal control problem for linear parabolic equations. The estimates for the error of the difference scheme and the speed of convergence have been established. Numerical results are reported on test problems.


Relations For Different Resonators Of Nd:Glass And Nd:Yag Lasers, Erol Taşal, M. Selami̇ Kiliçkaya Jan 2002

Relations For Different Resonators Of Nd:Glass And Nd:Yag Lasers, Erol Taşal, M. Selami̇ Kiliçkaya

Turkish Journal of Physics

Simple relations in terms of effective g parameters are given for linear resonators that contain laser rods with curved endfaces and for symmetrical and asymmetric ring resonators of Nd:Glass and Nd:YAG lasers. The equivalence relationships of thick and thin lenses have been applied.


Cover And Contents Jan 2002

Cover And Contents

Turkish Journal of Biology

No abstract provided.


Cover And Contents Jan 2002

Cover And Contents

Turkish Journal of Biology

No abstract provided.


Cover And Contents Jan 2002

Cover And Contents

Turkish Journal of Biology

No abstract provided.


Asymptotic Analysis Of Singularly Perturbed Abstract Evolution Equations In Banach And Hilbert Spaces, Dialla Konate Jan 2002

Asymptotic Analysis Of Singularly Perturbed Abstract Evolution Equations In Banach And Hilbert Spaces, Dialla Konate

Turkish Journal of Mathematics

In the current paper, we are concerned with the study of abstract linear evolution equations in Banach spaces in which the time derivative term is multiplied by a small parameter, say \epsilon. Such equations arise in the study of radiative transfer and neutron transport in Nuclear Physics. Following works by Krein (cf [9]) and others, Mika (cf [12,13,14,15]) using either the Hilbert method or the Compressed method has shown that the solution of the given singularly perturbed equation may be approximated upto any prescibed order by a sum of two asymptotic expansions that are the outer expansion that is valid …


Cover And Contents Jan 2002

Cover And Contents

Turkish Journal of Agriculture and Forestry

No abstract provided.


Sar Simulations In Wireless Communication And Safety Discussions In The Society, M. O. Özyalçin, Funda Akleman, Levent Sevgi̇ Jan 2002

Sar Simulations In Wireless Communication And Safety Discussions In The Society, M. O. Özyalçin, Funda Akleman, Levent Sevgi̇

Turkish Journal of Electrical Engineering and Computer Sciences

Numerical simulation in cellular phone - human tissue interaction is discussed in this paper. The powerful time domain (TD) techniques, the transmission line matrix (TLM) and the finite-difference time-domain (FDTD) methods, are used to model mutual effects. The purpose is to calculate specific absorption rate (SAR; defined as the power absorbed by the unit mass of the tissue), validate the codes and verify the results. Also, effectiveness of the SAR parameter in determination of the exposure limits for human health and environmental pollution is discussed.


A Macwilliams Type Identity, İrfan Şi̇ap Jan 2002

A Macwilliams Type Identity, İrfan Şi̇ap

Turkish Journal of Mathematics

A MacWilliams identity for a \rho complete weight enumerator of linear spaces of matrices with entries from the ring F_q[u]/(u^r-a), where a \in F_q, endowed with a non-Hamming metric is proved.


Solving Fuzzy Linear Programming Problems With Linear Membership Function, Rafail R. Gasimov, Kürşat Yeni̇lmez Jan 2002

Solving Fuzzy Linear Programming Problems With Linear Membership Function, Rafail R. Gasimov, Kürşat Yeni̇lmez

Turkish Journal of Mathematics

In this paper, we concentrate on two kinds of fuzzy linear programming problems: linear programming problems with only fuzzy technological coefficients and linear programming problems in which both the right-hand side and the technological coefficients are fuzzy numbers. We consider here only the case of fuzzy numbers with linear membership functions. The symmetric method of Bellman and Zadeh [2] is used for a defuzzification of these problems. The crisp problems obtained after the defuzzification are non-linear and even non-convex in general. We propose here the ``modified subgradient method'' and use it for solving these problems. We also compare the new …


Ko-Groups Of Bounded Flag Manifolds, Yusuf Ci̇van Jan 2002

Ko-Groups Of Bounded Flag Manifolds, Yusuf Ci̇van

Turkish Journal of Mathematics

We exhibit an appropriate suspension of bounded flag manifolds as a wedge sum of Thom complexes of associated complex line bundles. We use the existence of such a splitting to assist our computation of real and complex K-groups. Moreover, we compute the Sq^2-homology of bounded flag manifolds to make use of relevant Atiyah-Hirzebruch spectral sequence of KO-theory.