WoS İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://gcris.yasar.edu.tr/handle/123456789/11289

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A 2-Dimensional Model of Polynomial Type for Oscillatory ATM-Wip1 Dynamics in p53 Network
(IEEE, 2017) Gokhan Demirkiran; Guleser Kalayc Demir; Cuneyt Guzelis
Under gamma irradiation p53 gene regulatory network is able to exhibit three different modes namely low state oscillations and high state. There are experimental studies demonstrating that oscillatory behaviour of p53 is due to the interaction between upstream mediator of p53 i.e. ATM and a negative feedback loop formed by Wip1 with that upstream. By proposing a canonical model based on ordinary differential equations made up of polynomial type birth and death terms we show mathematically that the simple interaction between ATM and Wip1 is indeed able to exhibit three different behaviours relevant to DNA damage response of p53 network. We further carry out bifurcation analysis on the model with the aim of investigating the mutations such as Wip1 overexpression and ATM deficiency. Based on the proposed canonical model we show that Wip1 is an important target for curing these types of mutations.
A 2-dimensional Reduced Oscillator Model with Rational Nonlinearities for p53 Dynamics
(IEEE, 2017) Gokhan Demirkiran; Guleser Kalayc Demir; Cuneyt Guzelis
p53 tumour suppressor network plays the key role in DNA damage response of the cell. We present a comprehensive 2-dimensional oscillator model for p53 network dynamics. The model is reduced from the known 17-dimensional two-phase model of p53 network which shows temporary oscillatory behaviour under DNA damage type of Double Strand Breaks. The introduced oscillator model shows the same qualitative dynamics of two-phase model of p53 network such as bistability and oscillations when the parameters are adjusted accordingly. With the help of the identified oscillator in p53 network we introduce a new oscillator perspective: p53 network has an oscillator in the centre which other systems in the cell manipulate this oscillator to contribute to cell fate. The introduction of such low dimensional oscillator model will make it possible to study p53 network and the effects of other biological systems in the context of oscillations.
A Comparison of Feature Selection Algorithms for Cancer Classification Through Gene Expression Data: Leukemia Case
(IEEE, 2017) Asli Tasci; Turker Ince; Cuneyt Guzelis
In this study three different feature selection algorithms are compared using Support Vector Machines as classifier for cancer classification through gene expression data. The ability of feature selection algorithms to select an optimal gene subset for a cancer type is evaluated by the classification ability of selected genes. A publicly available micro array dataset is employed for gene expression values. Selected gene subsets were able to classify subtypes of the considered cancer type with high accuracies and showed that these feature selection methods were applicable for bio-marker gene selection.
Citation - WoS: 1
A Numerical Parametric Study of SAR from a Dual-Band PIFA Based Antenna for Mobile Communication
(IEEE, 2017) Serdar Okuyucu; Mustafa Secmen; Korkut Yegin; Basak Ozbakis; Ozbakis, Basak; Secmen, Mustafa; Yegin, Korkut; Ozbakts, Basak; Okuyucu, Serdar
Specific Absorption Rate (SAR) analysis is a vital part of compliance tests for commercial mobile phones performed in accordance with the set of comprehensive standardized practices provided by authoritative bodies. Dependence of SAR on a variety of parameters with the structure of the handset pronounced the most calls for bringing in the SAR analysis of various types of phones into the field of study for reference. This paper focuses on the SAR analysis of a PIFA based mobile phone antenna when operated next to standardized and anatomically correct head models. The effect of averaging method used positioning of the phone frequency of operation and the presence of a homogeneous hand model on SAR is investigated along with the antenna performance in terms of terminal and radiational characteristics.
Citation - Scopus: 1
Effect of Chaotic Mixing on the Rheological Characterization of Mayonnaise
(IEEE, 2017) Seda Genc; Tolga Tugay Izmir; Ruhan Askin Uzel; Gokhan Demirkiran; Savas Sahin; Cuneyt Guzelis; Uzel, Ruhan Askin; Izmir, Tolga Tugay; Demirkiran, Gokhan; Guzelis, Cuneyt; Genc, Seda; Sahin, Savas
In this study a new mixing method for mayonnaise was developed. A chaotic hand mixer was designed. The speed of the mixer rotor was chaotically changed with the proposed method. Performance of the mixed mayonnaise was evaluated by a rheological characterization method. The results showed that the proposed chaotic mixing for mayonnaise has a better performance in terms of energy efficiency than conventional mixed ones indicating potential use in industry or as home appliance.
Citation - WoS: 1
Citation - Scopus: 2
Size-Reduced Printed Log Periodic Dipole Antenna with Single First Order Semi-Circle Iteration and Feed Point Patches
(IEEE, 2017) Mehmet Can Ozgonul; Mustafa Secmen; Seçmen, Mustafa; Özgönül, Mehmet Can
This paper presents the miniaturization and improvement of a printed log periodic dipole antenna (LPDA) by using patches at the feeding point and single first order semicircles. After the design of a conventional printed LPDA on FR4 substrate to cover L-band is performed patches having 12 mm x 5 mm dimensions are placed to the feed point of the antenna. Although this modification gives same antenna size it brings considerable increase in the return-loss bandwidth up to 2.25 GHz and higher gain values up to 2 GHz at the expense of decrease in gain at about 2.4 GHz. Afterwards in order to reduce the total size of the antenna single semicircles are substituted into the dipole arms which results in 14% lateral size reduction. Besides the bandwidth is further improved between 0.9 GHz and 2.4 GHz with better return loss performance higher gain at 2.4 GHz and lower gain variation.

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Browsing WoS İndeksli Yayınlar Koleksiyonu by Journal "10th International Conference on Electrical and Electronics Engineering (ELECO)"