A conceptual model for assessing managerial implications of changes in information technologies (Bilişim teknolojilerindeki değişimlerin yönetsel sonuçlarının değerlendirmesi için kavramsal bir model)

Information Technologies and business should be considered together to get the best results in business life. Therefore their integration and reflections on each other are very important in managing institutional change due to changes in the IT world. Change is a very sensitive concept that must be managed very carefully. In this article, a framework for managing IT based changes by protecting the business leverage and through all levels of hierarchy in the company is proposed

A Case of Triple Valve Endocarditis in a Patient on Haemodialysis

A 22 year-old male patient referred to cardiology clinic with complaints of fever, chills and malaise. He had been on haemodialysis for 12 months due to immunoglobulin A nephropathy. On admission his body temperature, pulse rate and blood pressure was 38.6°C, 115 beats/min and 110/70 mmHg, respectively. In the laboratory examination there were leukocyte, C-reactive protein and erythrocyte sedimentation rate elevation. There were vegetations on the mitral, aortic and tricuspid valves. Blood cultures were positive for Enterococcus faecalis which was susceptible to vancomycin. Since the patient did not accept the surgical operation, he died because of multi-organ dysfunction

Neural network consistent empirical physical formula construction for DFT based nonlinear vibrational spectra intensities of N-(2-methylphenyl) and N-(3-methylphenyl) methanesulfonamides

WOS: 000299148200089Vibrational intensities are both experimentally measured and theoretically estimated important physical quantities which are directly related to distributions of the electric charges in a molecule. In this paper, as a novel approach, by a layered feedforward neural network (LFNN), empirical physical formulas (EPFs) were constructed for density functional theory (DFT) vibrational spectra intensities of N-(2-methylphenyl) and N-(3-methylphenyl) methanesulfonamides. The spectral data was obtained from our previous study. Although the DFT spectral data was inherently extremely difficult-to-fit (sparse frequency intervals, highly nonlinear and sharply fluctuating intensities), still the optimally constructed LFFN-EPFs succeeded in fitting this data to medium and higher level of satisfaction. Moreover, LFNN-EPFs test set (i.e. yet-to-be measured experimental data) intensity predictions were also moderate to higher level. This briefly means that the general tendency of the intensity data was consistently estimated by the LFNN to an acceptable degree. In conclusion, provided that vibrational spectral data measured over sufficiently dense frequency intervals are available for any unknown molecule of significant complexity, suitable LFNN-EFFs can be constructed. Then, by various mathematical tools such as differentiation, integration, minimization, these vibrational LFNN-EFFs can be used to estimate the electronic charge distributions of the molecule. Moreover, these estimations can be compared and combined with those of theoretical DFT atomic polar tensor calculations to contribute to the identification of the molecule. (C) 2011 Elsevier B.V. All rights reserved

Electronic, Elastic, Vibrational and Thermodynamic Properties of HfIrX (X = As, Sb and Bi) Compounds: Insights from DFT-Based Computer Simulation

YILDIZ, Yasin Gokturk/0000-0002-1391-1888WOS: 000517222900002Ab-initio calculations were performed to reveal and thoroughly understand the structural, electronic, elastic, thermodynamic and vibrational properties of HfIrX (X = As, Sb and Bi) compounds in the C1(b) phase. Basic physical characteristics, such as bulk modulus, pressure derivative of bulk modulus, anisotropy factor, shear modulus, Poisson's ratio, Cauchy pressure, elastic constants and Young's modulus were obtained and some of them were compared with those in the literature. Electronic band structure, the density of states and phonon dispersion curves were obtained and compared with current theoretical calculations. It was concluded according to current band structure calculations that the HfIrAs and HfIrBi compounds showed semimetal characteristics, while the HfIrSb compound behaves as a semiconductor. It was determined based on phonon calculations that all three compounds were dynamically stable. Various thermodynamic properties, such as heat capacity, thermal expansion coefficient values and Gruneisen parameter were calculated under constant volume and constant pressure by using Gibbs2 code within the Quasi-harmonic approach, and these results are discussed

Neural network consistent empirical physical formula construction for density functional theory based nonlinear vibrational absorbance and intensity of 6-choloronicotinic acid molecule

WOS: 000301913400010PubMed ID: 22306452Being directly related to the electric charge distributions in a molecule, the vibrational spectra intensities are both experimentally and theoretically important physical quantities. However, these intensities are inherently highly nonlinear and of complex pattern. Therefore, in particular for unknown detailed spatial molecular structures, it is difficult to make ab initio intensity calculations to compare with new experimental data. In this respect, we very recently initiated entirely novel layered feedforward neural network (LFNN) approach to construct empirical physical formulas (EPFs) for density functional theory (OFT) vibrational spectra of some molecules. In this paper, as a new and far improved contribution to our novel molecular vibrational spectra LFNN-EPF approach, we constructed LFFN-EPFs for absorbances and intensities of 6-choloronicotinic acid (6-CNA) molecule. The 6-CNA data, borrowed from our previous study, was entirely different and much larger than the vibrational intensity data of our formerly used LFNN-EPF molecules. In line with our another previous work which theoretically proved the LFNN relevance to EPFs, although the 6-CNA DFT absorbance and intensity were inherently highly nonlinear and sharply fluctuating in character, still the optimally constructed train set LFFN-EPFs very successfully fitted the absorbances and intensities. Moreover, test set (i.e. yet-to-be measured experimental data) LFNN-EPFs consistently and successfully predicted the absorbance and intensity data. This simply means that the physical law embedded in the 6-CNA vibrational data was successfully extracted by the LFNN-EPFs. In conclusion, these vibrational LFNN-EPFs are of explicit form. Therefore, by various suitable operations of mathematical analysis, they can be used to estimate the electronic charge distributions of the unknown molecule of the significant complexity. Additionally, these estimations can be combined with those of theoretical OFT atomic polar tensor calculations to contribute to the identification of the molecule. (C) 2012 Elsevier B.V. All rights reserved

Computational investigations of mechanic, electronic and lattice dynamic properties of yttrium based compounds

IYIGOR, Ahmet/0000-0002-5996-6286; YILDIZ, Gokcen DIKICI/0000-0002-5751-0795; YILDIZ, Yasin Gokturk/0000-0002-1391-1888WOS: 000440614900009Electronic, mechanic and lattice dynamic properties of yttrium-based compounds, X3Y, where X = Pd, Pt and Rh were investigated using the density functional theory. The electronic band calculations demonstrated that X3Y compounds are metallic at the cubic crystal structures. The calculated elastic constants using the energy-strain method indicate that the three materials are mechanically stable. The calculated bulk modulus and Young's modulus values suggest that the Pt3Y is stiffer than that of the other two. The type of bonding and ductility in the X3Y compounds were also evaluated based on their B/G ratios, Cauchy pressures (C-12-C-44) and band structure calculations. These compounds were found to be ductile in nature. The density functional perturbation theory was used to derive full phonon frequencies and total and projected phonon density of states. The computed full phonon spectra for X3Y compounds show that these compounds in the L1(2) phase are dynamically stable. Debye temperature and specific heat of these compounds were also calculated and evaluated using quasi harmonic approximation

Evaluation of genetic relationships on single, triple and double cross melon (Cucumis melo var. cantalupensis) hybrids by SSR markers

This study was conducted to determine the quantitative characteristics of 53 hybrid melon genotypes which were obtained by single, triple, double hybridization and to compare the genetic relationship between single, triple and double hybrids and their parental pure lines by SSR markers