Elektronik ve Haberleşme Mühendisliği Bölümü Yayın Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/260
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Article Citation - WoS: 48Citation - Scopus: 54A Reliable and Competitive Mathematical Analysis of Ebola Epidemic Model(Springer, 2020) Ahmad, Waheed; Abbas, Mujahid; Baleanu, Dumitru; Rafiq, MuhammadThe purpose of this article is to discuss the dynamics of the spread of Ebola virus disease (EVD), a kind of fever commonly known as Ebola hemorrhagic fever. It is rare but severe and is considered to be extremely dangerous. Ebola virus transmits to people through domestic and wild animals, called transmitting agents, and then spreads into the human population through close and direct contact among individuals. To study the dynamics and to illustrate the stability pattern of Ebola virus in human population, we have developed an SEIR type model consisting of coupled nonlinear differential equations. These equations provide a good tool to discuss the mode of impact of Ebola virus on the human population through domestic and wild animals. We first formulate the proposed model and obtain the value of threshold parameter R0 for the model. We then determine both the disease-free equilibrium (DFE) and endemic equilibrium (EE) and discuss the stability of the model. We show that both the equilibrium states are locally asymptotically stable. Employing Lyapunov functions theory, global stabilities at both the levels are carried out. We use the Runge-Kutta method of order 4 (RK4) and a non-standard finite difference (NSFD) scheme for the susceptible-exposed-infected-recovered (SEIR) model. In contrast to RK4, which fails for large time step size, it is found that the NSFD scheme preserves the dynamics of the proposed model for any step size used. Numerical results along with the comparison, using different values of step size h, are provided.Article Citation - WoS: 48Citation - Scopus: 50High-Throughput Screening of Large Volumes of Whole Blood Using Structured Illumination and Fluorescent On-Chip Imaging(Royal Soc Chemistry, 2012) Arpali, Serap Altay; Arpali, Caglar; Coskun, Ahmet F.; Chiang, Hsin-Hao; Ozcan, AydoganUndiluted blood samples are difficult to image in large volumes since blood constitutes a highly absorbing and scattering medium. As a result of this limitation, optical imaging of rare cells (e.g., circulating tumour cells) within unprocessed whole blood remains a challenge, demanding the use of special microfluidic technologies. Here we demonstrate a new fluorescent on-chip imaging modality that can rapidly screen large volumes of absorbing and scattering media, such as undiluted whole blood samples, for detection of fluorescent micro-objects at low concentrations (for example <= 50-100 particles/mL). In this high-throughput imaging modality, a large area microfluidic device (e.g., 7-18 cm(2)), which contains for example similar to 0.3-0.7 mL of undiluted whole blood sample, is directly positioned onto a wide-field opto-electronic sensor-array such that the fluorescent emission within the microchannel can be detected without the use of any imaging lenses. This microfluidic device is then illuminated and laterally scanned with an array of Gaussian excitation spots, which is generated through a spatial light modulator. For each scanning position of this excitation array, a lensfree fluorescent image of the blood sample is captured using the opto-electronic sensor-array, resulting in a sequence of images (e.g., 144 lensfree frames captured in similar to 36 s) for the same sample chip. Digitally merging these lensfree fluorescent images based on a maximum intensity projection (MIP) algorithm enabled us to significantly boost the signal-to-noise ratio (SNR) and contrast of the fluorescent micro-objects within whole blood, which normally remain undetected (i.e., hidden) using conventional uniform excitation schemes, involving plane wave illumination. This high-throughput on-chip imaging platform based on structured excitation could be useful for rare cell research by enabling rapid screening of large volume microfluidic devices that process whole blood and other optically dense media.Article Citation - WoS: 8Citation - Scopus: 10Spectrum-Aware and Energy-Adaptive Reliable Transport for Internet of Sensing Things(Ieee-inst Electrical Electronics Engineers inc, 2018) Bicen, A. Ozan; Ergul, Ozgur; Akan, Ozgur B.; Ozan Bicen, A.Wireless sensors equipped with cognitive radio, i.e., cognitive radio sensor networks (CRSN), can access the spectrum in an opportunistic manner and coexist with licensed users to mitigate the crowded spectrum problem and provide ubiquitous remote event monitoring and tracking for cyber-physical systems. In this paper, a novel transport layer protocol for CRSN, spectrum-aware energy-adaptive reliable transport protocol is presented to enable energy-adaptive collaborative event sensing in spectrum-scarce cyber-physical systems. To the best of our knowledge, this is the first attempt to specifically devise a reliable event transport scheme for CRSN.Article Citation - WoS: 5Citation - Scopus: 5Fringe Waves in an Impedance Half-Plane(Emw Publishing, 2013) Basdemir, Husnu D.The uniform expressions of scalar fringe waves which are based on the physical theory of diffraction (PTD) were obtained for the impedance half plane in terms of the Fresnel integrals. Asymptotic and uniform forms of the fringe fields were compared. The radiated fields of the fringe expressions were analyzed numerically.Article Citation - WoS: 72Citation - Scopus: 85Entropy-Functional Online Adaptive Decision Fusion Framework With Application To Wildfire Detection in Video(Ieee-inst Electrical Electronics Engineers inc, 2012) Toreyin, Behcet Ugur; Kose, Kivanc; Cetin, A. Enis; Gunay, OsmanIn this paper, an entropy-functional-based online adaptive decision fusion (EADF) framework is developed for image analysis and computer vision applications. In this framework, it is assumed that the compound algorithm consists of several subalgorithms, each of which yields its own decision as a real number centered around zero, representing the confidence level of that particular subalgorithm. Decision values are linearly combined with weights that are updated online according to an active fusion method based on performing entropic projections onto convex sets describing subalgorithms. It is assumed that there is an oracle, who is usually a human operator, providing feedback to the decision fusion method. A video-based wildfire detection system was developed to evaluate the performance of the decision fusion algorithm. In this case, image data arrive sequentially, and the oracle is the security guard of the forest lookout tower, verifying the decision of the combined algorithm. The simulation results are presented.Article Citation - WoS: 1Citation - Scopus: 1Multiport Analysis by Pade Approximation(E M W Publishing, 2012) Sener, G.In this paper, a new method to analyze arbitrary shaped microstrip patch antennas is introduced. This method uses the multiport network model (MNM) together with a mathematical approximation called the "Pade approximation" such that the antenna input impedance obtained from the multiport analysis is approximated as a rational function of polynomials. Then, the roots of the denominator of this rational function are used to determine the antenna resonant characteristics. This new method is more time efficient than the standard multiport analysis because the evaluations are made at a single frequency. In the standard method, evaluations are made at multiple frequency values throughout the analysis. Results obtained by the new method are verified using the examples of rectangular and slot loaded compact microstrip patch antennas. Computational efforts for both procedures are presented.Erratum Citation - WoS: 7Citation - Scopus: 7Retracted: a Simple Analytical Eam Model for Some Bcc Metals (Retracted Article. See Vol. 16, Pg. 4547, 2011)(Elsevier, 2010) Dursun, Ibrahim H.; Guvenc, Ziya B.; Kasap, E.An analytical embedded atom method which can treat bcc transition metal iron has been developed. In this model, a new potential was presented and a modified term has been introduced to fit the negative Cauchy pressure P-C = (C-12 - C-44)/2 for Fe element. The new model was applied to calculate thermodynamic properties of binary alloys of the bcc transition metals: Fe, V and Cr. The calculated dilute-solution enthalpies and formation enthalpies of random alloys are in good agreement with the results of first principles calculations and that of the thermodynamic calculations. (C) 2009 Elsevier B.V. All rights reserved.Article Citation - WoS: 74Citation - Scopus: 81Average Intensity and Spreading of Partially Coherent Standard and Elegant Laguerre-Gaussian Beams in Turbulent Atmosphere(Emw Publishing, 2010) Wang, F.; Cai, Y.; Eyyuboglu, H. T.; Baykal, Y.Analytical expressions for the average intensity, mean-squared beam width and angular spread of partially coherent standard and elegant Laguerre-Gaussian (LG) beams propagating in turbulent atmosphere are derived. The properties of the average intensity, spreading and directionality of partially coherent standard and elegant LG beams in turbulent atmosphere are studied numerically and comparatively. It is found that the beam parameters and structure constant of turbulence together determine the properties of the beams in turbulent atmosphere. Partially coherent standard and elegant LG beams with smaller coherence length, larger beam orders and longer wavelength are less affected by the turbulence. A partially coherent elegant LG beam is less affected by turbulence than a partially coherent standard LG beam under the same condition. Furthermore, it is found that there exist equivalent partially coherent standard and elegant LG beams, equivalent fully coherent standard and elegant LG beams, equivalent Gaussian Schell-model beams that may have the same directionality as a fully coherent Gaussian beam both in free space and in turbulent atmosphere. Our results will be useful in long distance free-space optical communications.