Now showing items 1-20 of 27

    • A Certain Class of Harmonic Mappings Related to Functions of Bounded Boundary Rotation 

      Polatoğlu, Yaşar; Yavuz Duman, Emel; Aydoğan, Melike (Eudoxus Press, Llc, 1424 Beaver Trail Drive, Cordova, Tn 38016 Usa, 2014-05)
      Let V(k) be the class of functions with bounded boundary rotation and let S-H be the class of sense-preserving harmonic mappings. In the present paper we investigate a certain class of harmonic mappings related to the ...
    • A Remark on multivalently convex and starlike functions 

      Nunokawa, Mamoru; Owa, Shigeyoshi; Polatoğlu, Yaşar; Yavuz Duman, Emel (2007-01)
      Applying the result for certain analytic functions due to M. Nunokawa [Proc. Japan Acad. 68A, 152–153 (1992; Zbl 0773.30020)], some properties for multivalently convex and starlike functions ar discussed.
    • An investigation on a new class of harmonic mappings 

      Yavuz Duman, Emel; Polatoğlu, Yaşar; Kahramaner, Yasemin (Springer International Publishing Ag, Gewerbestrasse 11, Cham, Ch-6330, Switzerland, 2013)
      In the present paper, we give an extension of the idea which was introduced by Sakaguchi (J. Math. Soc. Jpn. 11:72-75, 1959), and we give some applications of this extended idea for the investigation of the class of harmonic ...
    • Application Of The Subordination Principle To The Harmonic Mappings Convex In One Direction With Shear Construction Method 

      Polatoğlu, Yaşar; Özkan, Hatice Esra; Yavuz Duman, Emel (Hindawi Publishing Corporation, 410 Park Avenue, 15Th Floor, #287 Pmb, New York, Ny 10022 Usa, 2010)
      Any harmonic function in the open unit disc D = {z vertical bar vertical bar z vertical bar < 1} can be written as a sum of an analytic and antianalytic functions f = h(z) + <(g(z))over bar>, where h(z) and g(z) are analytic ...
    • Application of the subordination principle to the multivalent harmonic mappings with shear construction method 

      Polatoğlu, Yaşar; Yavuz Duman, Emel; Özkan, H. Esra (2011-06)
      The harmonic function in the open unit disc D = (z is an element of C vertical bar z vertical bar < 1} can be written as a sum of an analytic and an anti-analytic function. f = h(z) + g(z), where h(z) and g(z) are analytic ...
    • Coefficient Inequality For Perturbed Harmonic Mappings 

      Polatoğlu, Yaşar; Çağlar, Mert; Yavuz Duman, Emel (Pergamon-Elsevier Science Ltd, The Boulevard, Langford Lane, Kidlington, Oxford Ox5 1Gb, England, 2010-08)
      The aim of this work is to give the coefficient inequality for the perturbed harmonic mappings in the open unit disc D. (c) 2010 Elsevier Ltd. All rights reserved.
    • Distortion estimate and radius of starlikeness for generalized p-valent close-to-star functions 

      Özkan, H. Esra; Yavuz Duman, Emel (HIKARI, 2013)
      Let A(p, n), n ≥ 1, p ≥ 1 be the class of all analytic functions in the open unit disc D = {z| |z| < 1} of the form f(z) = zp + anp+1znp+1 + anp+2znp+2 + ··· . Let g(z) be an element of A(p, n) such that g(z) satisfies ...
    • Distortion properties of perturbed m-valent Janowski Starlike log-harmonic functions 

      Polatoğlu, Yaşar; Özkan, H. Esra; Yavuz Duman, Emel (International Conference on Theory and Applications of Mathematics and Informatics, ICTAMI, 2009)
    • Growth and distortion theorems for multivalent Janowski close-to-convex harmonic functions with shear construction method 

      Polatoğlu, Yaşar; Yavuz Duman, Emel; Ozkan, Hatice Esra (Scientific Technical Research Council Turkey-Tubitak, Ataturk Bulvarı No 221, Kavaklıdere, Tr-06100 Ankara, Turkey, 2013)
      In this paper we introduce the class of m-valent Janowski close to convex harmonic functions. Growth and distortion theorems are obtained for this class. Our study is based on the harmonic shear methods for harmonic functions.
    • Growth theorems for perturbated starlike log-harmonic mappings of complex order 

      Polatoğlu, Yaşar; Yavuz Duman, Emel; Özkan, H. Esra (2009)
      Let H(D) be the linear space of all analytic functions defined on the open unit disc D = {z ∈ C : |z| < 1}. A sense-preserving logharmonic mapping is the solution of the non-linear elliptic partial differential equation ...
    • Harmonic mappings for which second dilatation is Janowski functions 

      Yavuz Duman, Emel; Polatoğlu, Yaşar; Kahramaner, Yasemin; Darus, Maslina (2013)
      In the present paper we extend the fundamental property that if h(z) and g(z) are regular functions in the open unit disc D with the properties h(0) = g(0) = 0, h maps D onto many-sheeted region which is starlike with ...
    • New subclasses of certain analytic functions 

      Owa, Shigeyoshi; Polatoğlu, Yaşar; Yavuz Duman, Emel; Aydoğan, S. M. (2010)
      For certain analytic functions fiz) in the open unit disk U, two subclasses 7ia,S;g) and Q(a,(5;g) associated with some analytic function g{z). Some interesting sufficient conditions for fiz) to be in ^(Q,^;^ ) and ...
    • Notes on Certain Harmonic Starlike Mappings 

      Yavuz Duman, Emel; Owa, Shigeyoshi (9th International Symposium on Geometric Function Theory and Applications, GFTA, 2014)
    • Notes on Starlike log-Harmonic Functions of Order alpha 

      Aydoğan, Seher Melike; Yavuz Duman, Emel; Owa, Shigeyoshi (2013)
      For log-harmonic functions f(z) = zh(z)g(z) in the open unit disk U, two subclasses H∗ LH(α) and G∗ LH (α) of S∗ LH(α) consisting of all starlike log-harmonic functions of order α (0 ≤ α < 1) are considered. The object ...
    • On a subclass of harmonic mappings 

      Yavuz Duman, Emel; Kahramaner, Yasemin; Polatoğlu, Yaşar (2013)
      In the present paper we extent the fundamental property that if h(z) and g(z) are regular functions in the open unit disc D with the properties h(0) = g(0) = 0, h(z) maps D onto λ-spiral region and Ren e iλ ...
    • On generalized Janowski starlike logharmonic 

      Mohd, Maisarah Haji; Darus, Maslina; Polatoğlu, Yaşar; Yavuz Duman, Emel (2011)
      In this paper, we consider univalent logharmonic mappings of the form f(z) = zh(z)g(z) defined on the open unit disc with the normalization condition g(0) = 1 and h(0) 6= 0. We investigate the class of generalized ...
    • On subclass of multivalent close-to-convex harmonic functions 

      Polatoğlu, Yaşar; Yavuz Duman, Emel; Özkan, H. Esra (2009)
    • On the improvement of Mocanu's conditions 

      Nunokawa, M.; Owa, Shigeyoshi; Cho, N. E.; Sokół, J.; Yavuz Duman, Emel (Springer International Publishing, 2013-12)
      We estimate |Arg{p(z)}| for functions of the form p(z)=1+a1z+a2z2+a3z3+⋯ in the unit disc D={z:|z|<1} under several assumptions. By using Nunokawa’s lemma, we improve a few of Mocanu’s results obtained by differential ...
    • Partial sums of certain univalent functions 

      Hayami, Toshio; Kuroki, Kazuo; Yavuz Duman, Emel; Owa, Shigeyoshi (2012)
      The partial sums f3(z) of some extermal functions for various classes S∗, K and R of starlike functions, convex functions and functions with positive real part in the open unit disk U, respectively, are discussed. In ...
    • Properties of functions concerned with Caratheodory functions 

      Nunokawa, Mamoru; Yavuz Duman, Emel; Owa, Shigeyoshi (2013)
      Let Pn denote the class of analytic functions p(z) of the form p(z) = 1+ cnzn + cn+1zn+1 + ... in the open unit disc U. Applying the result by S. S. Miller and P. T. Mocanu (J. Math. Anal. Appl. 65 (1978), 289–305), ...