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Some Remarks on Positive Real Functions and Their Circuit Applications

Year 2019, Volume: 8 Issue: 2, 617 - 627, 28.06.2019
https://doi.org/10.17798/bitlisfen.492656
https://izlik.org/JA97US94ZT

Abstract

In this paper, a boundary version of the Schwarz lemma has been considered for driving point impedance functions at s=0 point of the imaginary axis. Accordingly, under Z(0)=0condition, the modulus of the derivative of the Z(s)  function has been considered from below. Here, Z(alfa), c1 and c2 coefficients of the Taylor expansion of the Z(s)=beta+c1(s-alfa)+...  function have been used in the obtained inequalities. The sharpness of these inequalities has also been proved.

References

  • Sharma A., Soni, T. 2017. A Review on Passive Network Synthesis Using Cauer Form, World Journal of Wireless Devices and Engineering, 1 (1): 39–46.
  • Bakshi M., Sule V., Baghini M. S. 2016. Stabilization Theory for Active Multi Port Networks, arXiv preprint (aXiv:1606.03194).
  • Reza F. 1962. A Bound for the Derivative of Positive Real Functions, SIAM Review, 4 (1): 40–42.
  • Richards P. I. 1947. A Special Class of Functions with Positive Real Part in a Half-Plane. Duke Mathematical Journal 1947, 14 (3): 777–786. DOI: 10.1215/S0012-7094-47-01461-0.
  • Osserman R. 2000. A Sharp Schwarz Inequality on the Boundary. Proceedings of the American Mathematical Society, 128 (12): 3513–3517.
  • Dubinin V. 2004. The Schwarz Inequality on the Boundary for Functions Regular in the Disk, Journal of Mathematical Sciences, 122 (6): 3623–3629.
  • Azeroğlu T. A., Örnek B. N. (2013). A Refined Schwarz Inequality on the Boundary, Complex Variables and Elliptic Equations, 58 (4): 571–577.
  • Örnek B. N. 2013. Sharpened Forms of the Schwarz Lemma on the Boundary, Bulletin of the Korean Mathematical Society, 50 (6): 2053–2059.

Pozitif Reel Fonksiyonlar ve Devre Uygulamaları Üzerine Bazı Sonuçlar

Year 2019, Volume: 8 Issue: 2, 617 - 627, 28.06.2019
https://doi.org/10.17798/bitlisfen.492656
https://izlik.org/JA97US94ZT

Abstract



Bu çalışmada, Schwarz lemmasının bir sınır versiyonu,
süren nokta empedans fonksiyonları için sanal eksen üzerindeki s=0
 noktasında
değerlendirilmiştir. Buna göre, Z(0)=0 koşulu altında, Z(s) fonksiyonunun
türevinin modülü aşağıdan değerlendirilmiştir. Burada, elde edilen
eşitsizliklerde, Z(s)=beta+c1(s-alfa)+....  fonksiyonunun Taylor
açılımındaki ,  Z(alfa), c1 ve c2 katsayıları
kullanılmıştır. Aynı zamanda, bu eşitsizliklerin keskinliği ispatlanmıştır.



References

  • Sharma A., Soni, T. 2017. A Review on Passive Network Synthesis Using Cauer Form, World Journal of Wireless Devices and Engineering, 1 (1): 39–46.
  • Bakshi M., Sule V., Baghini M. S. 2016. Stabilization Theory for Active Multi Port Networks, arXiv preprint (aXiv:1606.03194).
  • Reza F. 1962. A Bound for the Derivative of Positive Real Functions, SIAM Review, 4 (1): 40–42.
  • Richards P. I. 1947. A Special Class of Functions with Positive Real Part in a Half-Plane. Duke Mathematical Journal 1947, 14 (3): 777–786. DOI: 10.1215/S0012-7094-47-01461-0.
  • Osserman R. 2000. A Sharp Schwarz Inequality on the Boundary. Proceedings of the American Mathematical Society, 128 (12): 3513–3517.
  • Dubinin V. 2004. The Schwarz Inequality on the Boundary for Functions Regular in the Disk, Journal of Mathematical Sciences, 122 (6): 3623–3629.
  • Azeroğlu T. A., Örnek B. N. (2013). A Refined Schwarz Inequality on the Boundary, Complex Variables and Elliptic Equations, 58 (4): 571–577.
  • Örnek B. N. 2013. Sharpened Forms of the Schwarz Lemma on the Boundary, Bulletin of the Korean Mathematical Society, 50 (6): 2053–2059.
There are 8 citations in total.

Details

Primary Language English
Journal Section Research Article
Authors

Bülent Nafi Örnek 0000-0001-7109-230X

Timur Düzenli 0000-0003-0210-5626

Submission Date December 5, 2018
Acceptance Date May 20, 2019
Publication Date June 28, 2019
DOI https://doi.org/10.17798/bitlisfen.492656
IZ https://izlik.org/JA97US94ZT
Published in Issue Year 2019 Volume: 8 Issue: 2

Cite

IEEE [1]B. N. Örnek and T. Düzenli, “Some Remarks on Positive Real Functions and Their Circuit Applications”, Bitlis Eren Üniversitesi Fen Bilimleri Dergisi, vol. 8, no. 2, pp. 617–627, June 2019, doi: 10.17798/bitlisfen.492656.

Bitlis Eren University
Journal of Science Editor
Bitlis Eren University Graduate Institute
Bes Minare Mah. Ahmet Eren Bulvari, Merkez Kampus, 13000 BITLIS