PubMed İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8650

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A zero-crossing technique for the multidetermination of thiamine HCl and pyridoxine HCl in their mixture by using one-dimensional wavelet transform
(Elsevier, 2003) Dinç, E; Baleanu, Dumitru; Baleanu, D; 56389
A new zero-crossing technique based on one-dimensional wavelet transform (WT) was developed and applied on a commercial vitamin product and binary mixtures containing thiamine HCl and pyridoxine HCl in the presence of the interference of the analysed signals. We selected from the data of the UV-Vis absorption spectra a signal consisting of 1150 points corresponding to the concentration range 8-32 mg/ml for both vitamins and we subjected it to one-dimensional continuous WT Mexican (MEXICAN) and Meyer (MEYER). Since the peaks of the transformed signals were bigger than original ones a zero crossing technique was applied to obtain the regression equations. The validity of Beer-Lambert law was assumed for the transformed signals. An appropriate scale setting was choosing to obtain an alternative calibration for each method. The basic concepts about wavelet method were briefly explained and MATLAB 6.5 software was used for one-dimensional wavelet analysis, The obtained results were successfully compared among each other and with those obtained by other literature methods. The developed method is rapid, easy to apply. not expensive and suitable for analysing of the overlapping signals of compounds in their mixtures without any chemical pre-treatment. (C) 2003 Elsevier Science B.V. All rights reserved.
Adaptive fractional-order blood glucose regulator based on high-order sliding mode observer
(inst Engineering Technology-iet, 2019) Delavari, Hadi; Baleanu, Dumitru; Heydarinejad, Hamid; Baleanu, Dumitru; 56389
Type I diabetes is described by the destruction of the insulin-producing beta-cells in the pancreas. Hence, exogenous insulin administration is necessary for Type I diabetes patients. In this study, to estimate the states that are not directly available from the Bergman minimal model a high-order sliding mode observer is proposed. Then fractional calculus is combined with sliding mode control (SMC) for blood glucose regulation to create more robustness performance and make more degree of freedom and flexibility for the proposed method. Then an adaptive fractional-order SMC is proposed. The adaptive SMC protect controller against disturbance and uncertainties while the fractional calculus provides robust performance. Numerical simulation verifies that the proposed controllers have better performance in the presence of disturbance and uncertainties without chattering.
An Efficient Computational Technique for Fractal Vehicular Traffic Flow
(Mdpi, 2018) Kumar, Devendra; Baleanu, Dumitru; Tchier, Fairouz; Singh, Jagdev; Baleanu, Dumitru; 56389
In this work, we examine a fractal vehicular traffic flow problem. The partial differential equations describing a fractal vehicular traffic flow are solved with the aid of the local fractional homotopy perturbation Sumudu transform scheme and the local fractional reduced differential transform method. Some illustrative examples are taken to describe the success of the suggested techniques. The results derived with the aid of the suggested schemes reveal that the present schemes are very efficient for obtaining the non-differentiable solution to fractal vehicular traffic flow problem.
Analysis for Fractional-Order Predator–Prey Model With Uncertainty
(inst Engineering Technology-iet, 2019) Narayanamoorthy, Samayan; Baleanu, Dumitru; Baleanu, Dumitru; Thangapandi, Kalidas; Perera, Shyam Sanjeewa Nishantha; 56389
Here, the authors analyse the fractional-order predator-prey model with uncertainty, due to the vast applications in various ecological systems. The most of the ecological model do not have exact analytic solution, so they proposed a numerical technique for an approximate solution. In the proposed method, they have implemented the higher order term into the fractional Euler method to enhance the precise solution. Further, the present attempt is aimed to discuss the solutions of the FPPM with uncertainty (fuzzy) initial conditions. The initial conditions of the predator-prey model were taken as fuzzy initial conditions due to the fact that the ecological model highly depends on uncertain parameters such as growth/decay rate, climatic conditions, and chemical reactions. Finally, the numerical example manifest that the proposed method is authentic, applicable, easy to use from a computational viewpoint and the acquired outcomes are balanced with the existing method (HPM), which shows the efficiency of the proposed method.
Analysis of reciprocity of cos-Gaussian and cosh-Gaussian laser beams in a turbulent atmosphere
(Optical Soc Amer, 2004) Eyyuboglu, HT; Baykal, Y; 7688; 7812
In a turbulent atmosphere, starting with a cos-Gaussian excitation at the source plane, the average intensity profile at the receiver plane is formulated. This average intensity profile is evaluated against the variations of link lengths, turbulence levels, two frequently used free-space optics wavelengths, and beam displacement parameters. We show that a cos-Gaussian beam, following a natural diffraction, is eventually transformed into a cosh-Gaussian beam. Combining our earlier results with the current findings, we conclude that cos-Gaussian and cosh-Gaussian beams act in a reciprocal manner after propagation in turbulence. The rates (paces) of conversion in the two directions are not the same. Although the conversion of cos-Gaussian beams to cosh-Gaussian beams can happen over a wide range of turbulence levels (low to moderate to high), the conversion of cosh-Gaussian beams to cos-Gaussian beams is pronounced under relatively stronger turbulence conditions. Source and propagation parameters that affect this reciprocity have been analyzed. (C) 2004 Optical Society of America.
Attentional Control is Partially Impaired in Obstructive Sleep Apnea Syndrome
(Wiley, 2013) Tulek, Baykal; Atalay, Nart Bedin; Atalay, Nart Bedin; Kanat, Fikret; Suerdem, Mecit; 102366
Obstructive sleep apnea syndrome is associated with executive cognitive impairment. An important question is whether impairment in executive functioning in obstructive sleep apnea syndrome is independent of dysfunction in attention. Attentional control is a subcomponent of executive functioning that is mediated by frontal lobe processing. In the current study, we investigated whether attentional control is deficient in obstructive sleep apnea syndrome. Attentional control processes were investigated through conflict adaptation and conflict frequency paradigms. These neuropsychological paradigms were assessed by using the Simon, Flanker and Stroop tasks. We additionally analysed post-error slowing data within these tasks. Error processing is another index of cognitive control that is mediated by frontal lobe functioning. Our sample consisted of 14 healthy adults and 24 patients with untreated moderate-severe obstructive sleep apnea syndrome. Results indicated that attentional control is partially dysfunctional among patients with obstructive sleep apnea syndrome. Attentional control processes were deficient when focal attention (Flanker task) processes were involved, but were intact when observed using the Simon and Stroop tasks. A non-significant trend in post-error slowing data suggested that error processing, assessed with the Flanker task, was diminished among patients with obstructive sleep apnea syndrome. These results support the view that obstructive sleep apnea syndrome leads to some amount of frontal lobe dysfunction, and that attentional control and error processing might be particularly affected by obstructive sleep apnea syndrome.
Comparative analysis on wavelet-based detection of finite duration low-amplitude signals related to ventricular late potentials
(Iop Publishing Ltd, 2004) Mousa, A; Yilmaz, A
Ventricular late potentials (VLPs) are considered as a noninvasive marker of patients with myocardial infarction, who are prone to the development of ventricular tachycardia. This paper investigates the effects of variations in physical properties of myocardial infarcts in terms of their effects on the parametric variations in VLP analysis. A sufficiently large set of signals underlining the behavior of physical parameters was employed to represent the effect of physical size, position, orientation and type of infarct. The approximated signals are variations from real electrocardiography signals by adding potentials representing late potentials based on duration, frequency, amplitude and position. The aim is not to exactly model VLP but rather to generate an approximate set of signals to examine the performance of the standard methods for different possibilities in infarct dynamics. We investigate some of the detection approaches together with their related assumptions, and try to pinpoint the drawbacks and inaccuracies of these methods and also their assumptions. The three widely accepted criteria-QRS duration, root-mean-square and duration of the signal at the end of QRS for VLP detection-were used in the investigation. Results from the application of these parameters to the set of signals are presented. In addition we investigate the physical nature of an infarct and list a number of possible reasons that might be the cause of a low success rate for the detection of additive potentials. To improve the performance of the common methods, two more wavelet transform parameters are added to those of the standard methods. The method derived from this analysis is presented as an alternative means for the detection of late signals named as delayed potentials, a more general class that includes VLP as a subset.
Comparative study of the continuous wavelet transform, derivative and partial least squares methods applied to the overlapping spectra for the simultaneous quantitative resolution of ascorbic acid and acetylsalicylic acid in effervescent tablets
(Elsevier Science Bv, 2005) Dinç, E; Baleanu, Dumitru; Ozdemir, A; Baleanu, D; 56389
The simultaneous spectrophotometric determination of ascorbic acid (AA) and acetylsalicylic acid (ASA) in effervescent tablets in the presence of the overlapping spectra was accomplished by the continuous wavelet transform (CWT), derivative spectrophotometry (DS) and partial least squares (PLS) approaches without using any chemical pre-treatment. CWT and DS calibration equations for AA and ASA were obtained by measuring the CWT and DS amplitudes corresponding to zero-crossing points of spectra obtained by plotting continuous wavelet coefficients and first-derivative absorbance values versus the wavelengths, respectively. The PLS calibration was constructed by using the concentration set and its full absorbance data consisting of 850 points from 220 to 305 urn in the range of 210-310 nun. These three methods were tested by analyzing the synthetic mixtures of the above drugs and they were applied to the real samples containing two commercial pharmaceutical preparations of subjected drugs. A comparative study was carried out by using the experimental results obtained from three analytical methodologies and precise and accurate results were obtained. (c) 2004 Published by Elsevier B.V.
Competitive Analysis for Stochastic Influenza Model With Constant Vaccination Strategy
(inst Engineering Technology-iet, 2019) Baleanu, Dumitru; Baleanu, Dumitru; Raza, Ali; Rafiq, Muhammad; Arif, Muhammad Shoaib; Ali, Muhammad Asghar; 56389
This manuscript discusses a competitive analysis of stochastic influenza model with constant vaccination strategy. The stochastic influenza model is comparatively more pragmatic versus the deterministic influenza model. The effect of influenza generation number holds in the stochastic model. If the value of this number is less than one, this situation will help us to control the disease in a population. A greater than one value of this threshold number shows the persistence of disease to become endemic. The proposed structure for the stochastic influenza model as stochastic non-standard finite difference scheme conserve all vital characteristics like positivity, boundedness and dynamical consistency defined by Mickens.
Competitive Numerical Analysis for Stochastic Hıv/Aıds Epidemic Model in A Two-Sex Population
(inst Engineering Technology-iet, 2019) Raza, Ali; Baleanu, Dumitru; Rafiq, Muhammad; Baleanu, Dumitru; Shoaib Arif, Muhammad; Naveed, Muhammad; Ashraf, Kaleem; 56389
This study is an attempt to explain a reliable numerical analysis of a stochastic HIV/AIDS model in a two-sex population considering counselling and antiretroviral therapy (ART). The authors are comparing the solutions of the stochastic and deterministic HIV/AIDS epidemic model. Here, an endeavour has been made to explain the stochastic HIV/AIDS epidemic model is comparatively more pragmatic in contrast with the deterministic HIV/AIDS epidemic model. The effect of threshold number H* holds on the stochastic HIV/AIDS epidemic model. If H* < 1 then condition helps us to control disease in a two-sex human population while H* > 1 explains the persistence of disease in the two-sex human population. Lamentably, numerical methods such as Euler-Maruyama, stochastic Euler, and stochastic Runge-Kutta do not work for large time step sizes. The recommended structure preserving framework of the stochastic non-standard finite difference (SNSFD) scheme conserve all vital characteristics such as positivity, boundedness, and dynamical consistency defined by Mickens. The effectiveness of counselling and ART may control HIV/AIDS in a two-sex population.
Continuous wavelet and derivative transforms for the simultaneous quantitative analysis and dissolution test of levodopa-benserazide tablets
(Elsevier, 2007) Dinc, Erdal; Baleanu, Dumitru; Kaya, Sueha; Doganay, Tanver; Baleanu, Dumitru; 6981; 133597
Simultaneous analyses and dissolution tests of levodopa-benserazide tablets were carried out by continuous wavelet transform (CWT) and classic derivative spectrophotometry (DS) without using any chemical separation step. The developed two spectrophotometric resolutions are based on the transformation of the original UV spectra. The original absorption spectra of levodopa and benserazide in the concentration range of 1-80 mu g/mL and 5-240 mu g/mL in USP simulated gastric juice were registered in the spectral range of 250-310 nm, respectively. Various wavelet families and different spectrophotometric derivative orders were tested to find the optimal signal processing for obtaining desirable calibration graphs and reliable determinations of the investigated drugs. Under the optimized conditions of the methods, symlets wavelet family using a = 128 with sixth order (SYM6-CWT) and the first derivative transform with Delta lambda = 10 nm were identified as optimal signal processing methods for the determinations and dissolution tests. The calibration functions for each drug were obtained by measuring the values of the CWT and derivative amplitudes. The validation of the developed methods was confirmed by analyzing various synthetic mixtures of the investigated drugs. Mean recovery values were found between 99.1% and 104.7% for DS and 100% and 102.9% for CWT, respectively for determination of BEN and LEV in synthetic mixtures. Each developed approaches were successfully applied to the simultaneous determination and dissolution test of levodopa and benserazide in their commercial tablets and a good agreement was observed. (c) 2007 Elsevier B.V. All rights reserved.
Diffraction by a black half plane: Modified theory of physical optics approach
(Optical Soc Amer, 2005) Umul, YZ; Umul, Yusuf Ziya; 42699
The scattered fields from a black half plane which absorbs all the incoming electromagnetic energy are evaluated by defining a new modified theory of physical optics surface current. This current eliminates the reflected fields, coming from the first stationary point of the reflection integral and only creates a reflected diffracted field. The incident scattered fields are found from the same integral, written for the perfectly conducting half plane. The scattered fields are evaluated by using the stationary phase method and edge point technique. The evaluated fields are plotted numerically. (c) 2005 Optical Society of America.
Equivalence of structure constants in non-Kolmogorov and Kolmogorov spectra
(Optical Soc Amer, 2011) Baykal, Yahya; Gercekcioglu, Hamza; 7812
We find the equivalence of the structure constants in non-Kolmogorov and Kolmogorov spectra in a turbulent atmosphere. As the reference point, the spherical wave scintillation index in a non-Kolmogorov medium is used. Relations of the structure constants are found to be functions of the power law of the turbulence spectrum and the Fresnel zone. It will be useful to employ the equivalence of the structure constants in making performance comparisons found with non-Kolmogorov and Kolmogorov spectra. (C) 2011 Optical Society of America
Equivalent functions for the Fresnel integral
(Optical Soc Amer, 2005) Umul, YZ; Umul, Yusuf Ziya; 42699
Fresnel integral is modeled with three equivalent functions. The first function is derived by considering the sum of the first term of the Fresnel integral's asymptotic expansion {(F) over cap (x)} and an exponential function which approaches to infinity at the zero of the Fresnel function's argument and has the properties of a unit step function. The second one is the sum of a unit step function and the transition function defined for the simplified uniform theory of diffraction. The third function considers directly eliminating the infinity coming from (F) over cap (x). The amplitude and the phase of Fresnel integral and its equivalent functions are compared numerically. The result is applied to the modified theory of physical optics solution of the diffraction of edge waves from a half plane problem. (c) 2005 Optical Society of America.
Flat topped beams and their characteristics in turbulent media
(Optical Soc Amer, 2006) Eyyuboglu, Halil Tanyer; Arpali, Caglar; Baykal, Yahya Kemal; 7688; 7812
The source and receiver plane characteristics of flat topped ( FT) beam propagating in turbulent atmosphere are investigated. To this end, source size, beam power and M(2) factor of source plane FT beam are derived. For a turbulent propagation medium, via Huygens Fresnel diffraction integral, the receiver plane intensity is found. Power captured within an area on the receiver plane is calculated. Kurtosis parameter and beam size variation along the propagation axis are formulated. Graphical outputs are provided displaying the variations of the derived source and receiver plane parameters against the order of flatness and propagation length. Analogous to free space behavior, when propagating in turbulence, the FT beam first will form a circular ring in the center. As the propagation length increases, the circumference of this ring will become narrower, giving rise to a downward peak emerging from the center of the beam, eventually turning the intensity profile into a pure Gaussian shape. (c) 2006 Optical Society of America.
Impaired redox homeostasis in the heart left ventricles of aged rats experiencing fast-developing severe hypobaric hypoxia
(Springer, 2019) Agascioglu, Eda; Colak, Ridvan; Demirel, Haydar; Cakatay, Ufuk
Despite its rare occurrence, humans and animals have been prone to getting fast developing severe hypobaric hypoxia. Understanding the redox homeostasis related response of an aging heart to this type of hypoxia are crucially important, since the metabolism of myocardial tissue depends on the redox status of proteins. Rodents can tolerate hypoxic stress better than human subjects. This study was aimed at investigating the effects of fast developing severe hypobaric hypoxia on redox status biomarkers; such as, advanced oxidation protein products (AOPP), lipid hydroperoxides (LHPs), protein carbonyl groups (PCO), protein thiol groups (P-SH), and total thiol groups (T-SH) on the myocardial left ventricles of young and aged Wistar rats. The rats were gradually ascended and exposed to an 8000-meter hypobaric hypoxia. While AOPP levels showed no difference, the TSH and PSH concentrations decreased, and the PCO and LHP increased in both of the hypoxic groups than the controls. The TSH and PSH were lower, and AOPP, PCO and LHP were found to be higher in the elderly hypoxic groups than in the young ones. The significant outcome of the study represents that an 8000-meter hypobaric hypoxia could be considered as a severe hypoxic stress, but not life-treating for the rats and would affect both the young and aged left ventricles similarly in respect to impaired redox status. However, if the percentage increases are taken into consideration, it seems that the higher rate of protein oxidation occurs in young hearts; meanwhile aged hearts are more prone to T-SH oxidation.
Modified theory of physical optics
(Optica Publishing Group, 2004) Umul, YZ; Umul, Yusuf Ziya; 42699
A new procedure for calculating the scattered fields from a perfectly conducting body is introduced. The method is defined by considering three assumptions. The reflection angle is taken as a function of integral variables, a new unit vector, dividing the angle between incident and reflected rays into two equal parts is evaluated and the perfectly conducting (PEC) surface is considered with the aperture part, together. This integral is named as Modified Theory of Physical Optics (MTPO) integral. The method is applied to the reflection and edge diffraction from a perfectly conducting half plane problem. The reflected, reflected diffracted, incident and incident diffracted fields are evaluated by stationary phase method and edge point technique, asymptotically. MTPO integral is compared with the exact solution and PO integral for the problem of scattering from a perfectly conducting half plane, numerically. It is observed that MTPO integral gives the total field that agrees with the exact solution and the result is more reliable than that of classical PO integral. (C) 2004 Optical Society of America.
Modified theory of physical optics approach to wedge diffraction problems
(Optica Publishing Group, 2005) Umul, YZ; Umul, Yusuf Ziya; 42699
The problem of diffraction from a perfectly conducting wedge is examined with the modified theory of physical optics (MTPO). The exact wedge diffraction coefficient is compared with the asymptotic edge waves of MTPO integral and related surface currents are evaluated. The scattered electric fields are expressed by using these current components. The total, incident and reflected diffracted fields are compared with the exact series solution of the wedge problem, numerically. (C) 2005 Optical Society of America.
Modified theory of the physical-optics approach to the impedance wedge problem
(Optical Soc Amer, 2006) Umul, YZ; Umul, Yusuf Ziya; 42699
The problem of a wedge with equal face impedances is examined with a modified theory of physical optics. The surface integral is constructed by use of the impedance boundary condition. The aperture equivalent current is estimated from the behavior of the reflected diffracted field. The integrals obtained are evaluated asymptotically and compared with the exact solution numerically. (c) 2006 Optical Society of America.
Oral Trail Making Task as a Discriminative Tool for Different Levels of Cognitive Impairment and Normal Aging
(Oxford Univ Press, 2013) Bastug, G.; Ozel-Kizil, E. T.; Sakarya, A.; Altintas, O.; Kirici, S.; Altunoz, U.
The Trail Making Test (TMT) is a useful measure of executive dysfunction in elderly subjects. This study aims to investigate the discriminative validity of the oral version of the TMT (OTMT), which can be administered to subjects with visual or motor disabilities, in elderly patients with Mild Cognitive Impairment (MCI; n = 30), Alzheimer's disease (AD; n = 30), and healthy controls (HCs; n = 25). The WAIS-R Digit Span Backwards Subscale, written form of the Trail Making Task, the Clock Drawing Test, the AD Assessment Scale-Cognitive Subscale, and the OTMT were also administered to all participants in order to examine the concurrent validity of the OTMT. The OTMT part B discriminated between patients with MCI, AD, and HC correctly. The OTMT completion time was not correlated with age, but was negatively correlated with education. In conclusion, the OTMT (mostly part B) is a valid and practical measurement tool for different levels of cognitive impairment, especially for patients with visual or motor disabilities for whom the classical written form is not feasible.

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