Emin Kahya

A modified Secant method for unconstrained optimization

Abstract In this study, a modification of the classical Secant method for solving nonlinear, univariate and unconstrained optimization problems based on the development of the cubic approximation is presented. The iteration formula including an approximation of the third derivative of f(x) by using the Taylor series expansion is derived. The performance of the new method is analyzed in terms of the number of iterations in comparison with the Secant methods using six test functions.

A class of exponential quadratically convergent iterative formulae for unconstrained optimization

Abstract For solving nonlinear, univariate and unconstrained optimization problems, Newton method is an important and basic method which converges quadratically. This paper presents a class of exponential iterative formulae. Convergence analyses show that the proposed methods converge quadratically. The efficiencies of the methods are analyzed in terms of the most popular and widely used criterion in comparison with the classical Newton method using five test functions. Numerical results indicate that one of the new exponential iterative formulae is effective and comparable to well-known Newton’s method.

METAL ENDÜSTRİSİNDE ÇEVRESEL KOŞULLARIN ANALİZİ

Cevresel kosullari, her sektorde is sagligi ve verimlilik acisindan yuksek derecede oneme sahiptir. Fakat metal sanayinde yapilan islemler geregi, cevresel kosullarin istenen duzeyde tutulmasi oldukca zordur. Siparis yetistirme vb. baskilar altinda tehlikeli techizatlar ile calisan iscilerin, uygun olmayan cevresel kosullarin da etkisiyle verimlilik degisimlerinin degerlendirilmesi ve cevresel kosullar ile iliskilendirilmesi atilmasi gereken onemli bir adimdir. Bu calismada, Eskisehir’deki metal sanayinin, en onemli cevre faktorleri olan gurultu, sicaklik, nem ve aydinlatma yonuyle duzeylerinin tesbiti amaclanmistir. Verilerin alinmasini saglayacak gozlem kayit formu tasarlanmis ve Eskisehir’de metal endustrisinde faaliyet gosteren ve hidrolik pres, ekzantrik pres, torna, giyotin makas gibi tezgahlarin yer aldigi 8 isletmede, toplam 92 adet olcum alinmistir. Veri analizi sonucunda ele alinan isletmelerdeki sicakligin 16.22-29.74°C (ort. 23.99 °C), nemin %22.69-%54.92 (ort. 36.35), gurultunun 82.3-110.3 dB(A) (ort. 91.88 dB(A)) ve aydinlatma siddetinin 33.2-902.7 luks (ort. 289.34 Lux) oldugu tespit edilmistir.