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Article Citation - WoS: 12Citation - Scopus: 12Mutual Correlation of Nist Statistical Randomness Tests and Comparison of Their Sensitivities on Transformed Sequences(Tubitak Scientific & Technological Research Council Turkey, 2017) Doganaksoy, Ali; Sulak, Fatih; Uguz, Muhiddin; Seker, Okan; Akcengiz, ZiyaRandom sequences are widely used in many cryptographic applications and hence their generation is one of the main research areas in cryptography. Statistical randomness tests are introduced to detect the weaknesses or nonrandom characteristics that a sequence under consideration may have. In the literature, there exist various statistical randomness tests and test suites, defined as a collection of tests. An efficient test suite should consist of a number of uncorrelated statistical tests each of which measures randomness from another point of view. `Being uncorrelated' is not a well-defined or well-understood concept in the literature. In this work, we apply Pearson's correlation test to measure the correlation between the tests. In addition, we define five new methods for transforming a sequence. Our motivation is to detect those tests whose results are invariant under a certain transformation. To observe the correlation, we use two methods. One is the direct correlation between the tests and the other is the correlation between the results of a test on the sequence and its transformed form. In light of the observations, we conclude that some of the tests are correlated with each other. Furthermore, we conclude that in designing a reliable and efficient suite we can avoid overpopulating the list of test functions by employing transformations together with a reasonable number of statistical test functions.Article Citation - WoS: 1Citation - Scopus: 3Spectral Approach To Derive the Representation Formulae for Solutions of the Wave Equation(Hindawi Publishing Corporation, 2012) Guseinov, Gusein Sh.Using spectral properties of the Laplace operator and some structural formula for rapidly decreasing functions of the Laplace operator, we offer a novel method to derive explicit formulae for solutions to the Cauchy problem for classical wave equation in arbitrary dimensions. Among them are the well-known d'Alembert, Poisson, and Kirchhoff representation formulae in low space dimensions.Article Citation - WoS: 21Citation - Scopus: 23Best Proximity Points of Generalized Almost Ψ-Geraghty Contractive Non-Self(Springer international Publishing Ag, 2014) Aydi, Hassen; Karapinar, Erdal; Erhan, Inci M.; Salimi, PeymanIn this paper, we introduce the new notion of almost psi-Geraghty contractive mappings and investigate the existence of a best proximity point for such mappings in complete metric spaces via the weak P-property. We provide an example to validate our best proximity point theorem. The obtained results extend, generalize, and complement some known fixed and best proximity point results from the literature.Article Citation - WoS: 37Citation - Scopus: 45Study on the Cytocompatibility, Mechanical and Antimicrobial Properties of 3d Printed Composite Scaffolds Based on Pva/ Gold Nanoparticles (aunp)/ Ampicillin (amp) for Bone Tissue Engineering(Elsevier, 2021) Topsakal, Aysenur; Midha, Swati; Yuca, Esra; Tukay, Ari; Sasmazel, Hilal Turkoglu; Kalaskar, Deepak M.; Gunduz, OguzhanOver the years, gold nanoparticles (AuNP) have been widely used in several biomedical applications related to the diagnosis, drug delivery, bio-imaging, photo-thermal therapy and regenerative medicine, owing to their unique features such as surface plasmon resonance, fluorescence and easy surface functionality. Recent studies showed that gold nanoparticles display positive effect on osteogenic differentiation. In line with this effect, 3-Dimesional (3D) scaffolds that can be used in bone tissue were produced by exploiting the properties of gold nanoparticles that increase biocompatibility and support bone tissue development. In addition, ampicillin was added to the scaffolds containing gold nanoparticles as a model drug to improve its antimicrobial properties. The scaffolds were produced as composites of polyvinyl alcohol (PVA) main matrix as PVA, PVA/AuNP, PVA/Ampicillin (AMP) and PVA/AuNP/AMP. Scanning Electron Microscopy (SEM) Fourier Transform Infrared Spectroscopy (FTIR), tensile measurement tests, and in vitro applications of 3D scaffolds were performed. As depicted by SEM, scaffolds were produced at pore sizes appropriate for bone tissue regeneration. According to FTIR results, there was no modification observed in the AMP, PVA and gold nanoparticles due to mixing in the resultant scaffolds. In vitro results show that 3D printed composite scaffold based on PVA/AuNP/AMP are biocompatible, osteo-inductive and exhibit antimicrobial properties, compared to PVA scaffolds. This study has implications for addressing infections during orthopedic surgeries. The PVA-based gold nanoparticle 3D tissue scaffold study containing ampicillin covers a new study compared to other articles based on gold nanoparticles.Article Citation - WoS: 29Citation - Scopus: 36Massive Mimo Systems for 5g: a Systematic Mapping Study on Antenna Design Challenges and Channel Estimation Open Issues(inst Engineering Technology-iet, 2021) Benzaghta, Mohamed; Rabie, Khaled M.The next generation of mobile networks (5G) is expected to achieve high data rates, reduce latency, as well as improve the spectral and energy efficiency of wireless communication systems. Several technologies are being explored to be used in 5G systems. One of the main promising technologies that is seen to be the enabler of 5G is massive multiple-input multiple-output (mMIMO) systems. Numerous studies have indicated the utility of mMIMO in upcoming wireless networks. However, there are several challenges that needs to be unravelled. In this paper, the latest progress of research on challenges in mMIMO systems is tracked, in the context of mutual coupling, antenna selection, pilot contamination and feedback overhead. The results of a systematic mapping study performed on 63 selected primary studies, published between the year 2017 till the second quarter of 2020, are presented. The main objective of this secondary study is to identify the challenges regarding antenna design and channel estimation, give an overview on the state-of-the-art solutions proposed in the literature, and finally, discuss emerging open research issues that need to be considered before the implementation of mMIMO systems in 5G networks.Article Citation - WoS: 43Coupled Fixed Points for Meir-Keeler Contractions in Ordered Partial Metric Spaces(Hindawi Ltd, 2012) Abdeljawad, Thabet; Aydi, Hassen; Karapinar, ErdalIn this paper, we prove the existence and uniqueness of a new Meir-Keeler type coupled fixed point theorem for two mappings F : X x X -> X and g : X -> X on a partially ordered partial metric space. We present an application to illustrate our obtained results. Further, we remark that the metric case of our results proved recently in Gordji et al. (2012) have gaps. Therefore, our results revise and generalize some of those presented in Gordji et al. (2012)Article Selection of DNA Aptamers Against Parathyroid Hormone for Electrochemical Impedimetric Biosensor System Development(John Wiley and Sons Inc, 2025) Didarian, Reza; Bargh, Saharnaz; Gulerman, Almina; Ozalp, Veli Cengiz; Erel, Ozcan; Yildirim-Tirgil, NimetThis work presents the pioneering development of an aptamer-based electrochemical biosensor for real-time monitoring of parathyroid hormone (PTH) levels, with a focus on intraoperative assessment during parathyroid surgery. It introduces, for the first time, the selection and characterization of aptamers targeting distinct segments of the PTH peptide. The study demonstrates the feasibility and efficacy of the biosensing platform through a precisely designed experimental framework, including SELEX-based aptamer selection, aptamer-peptide interaction analysis, and biosensor fabrication. The SELEX process yields aptamers with notable binding affinities to different fragments of PTH, with the PTH (53-84) aptamer showing particularly sensitive binding to the hormone's C terminus, allowing for precise PTH analysis. Electrochemical characterization reveals significant changes in electrochemical impedance spectroscopy (EIS) signals upon exposure to varying PTH concentrations, highlighting the sensor's sensitivity and selectivity. The increase in charge transfer resistance (Rct) values with rising PTH concentrations underscores the biosensor's capability to detect PTH-induced structural changes, validating its potential for accurate measurement. The biosensor shows remarkable selectivity in the presence of common interferents in serum samples, ensuring precise PTH detection. Stability assessments over a 45-day storage period demonstrate the biosensor's robustness and long-term reliability, affirming its practical suitability. In summary, the developed aptamer-based biosensor represents a promising tool for sensitive and selective PTH detection, with potential applications in biomedical research and clinical diagnostics, particularly for intraoperative PTH analysis during parathyroidectomy. Continued research and optimization efforts hold promise for enhancing its performance and expanding its utility in diverse healthcare settings.Article Citation - WoS: 5Citation - Scopus: 14Existence of a Solution of Integral Equations Via Fixed Point Theorem(Springeropen, 2013) Gulyaz, Selma; Karapinar, Erdal; Rakocevic, Vladimir; Salimi, PeymanIn this paper, we establish a solution to the following integral equation: u(t) = integral(T)(0) G(t, s)f(s, u(s)) ds for all t is an element of [0,T], (1) where T > 0, f : [0, T] x R -> R and G : [0, T] x [0, T] -> [0, infinity) are continuous functions. For this purpose, we also obtain some auxiliary fixed point results which generalize, improve and unify some fixed point theorems in the literature.Article Citation - WoS: 77Citation - Scopus: 81α-admissible mappings and related fixed point theorems(Springeropen, 2013) Hussain, Nawab; Karapinar, Erdal; Salimi, Peyman; Akbar, FarhanaIn this paper, we prove the existence and uniqueness of a fixed point for certain alpha-admissible contraction mappings. Our results generalize and extend some well-known results on the topic in the literature. We consider some examples to illustrate the usability of our results.Publication China-Africa Relations in the 21st Century : Engagement,compromise and Controversy(2009) Uchehara, E.kieranÇin’in Afrika ile ilgili dış politika gündemi, gelişmekte olan ülkeler arasındaki işbirliğini artırma ve yükselen bir süper güç olarak statüsünü gösterme hamlesinin bir parçasını oluşturmaktadır. 2000 Pekin Deklarasyonu ve Çin-Afrika Ekonomik ve Siyasi işbirliği Programı yenilenen ilişkilerin temelini oluşturmaktadır. Çin, Afrika ile tüm karşılıklı ilişki alanlarında Afrika ile farklı ve çeşitli ilişkiler geliştirmiştir. Ancak Çin’in büyüyen sanayisinin ihtiyaç duyduğu Afrika’nın maden ve enerji kaynakları, 21. yüzyılda Çin’in Afrika ile iyi ilişkiler kurmasının ana sebebidir. Çin’in Afrika’daki ticaret ve yatırımındaki hızlı artış, kıtanın kalkınması ile ilgili fırsatlar ve zorlukların yapısına ilişkin ve Batı ile olduğu gibi yeni-sömürgeci tarzı ilişkilerin gelişme ihtimalinin olup olmadığı konusunda akademisyenler ve siyasiler arasındaki uyuşmazlıkları açığa çıkarmıştır. Kısmen ekonomik asimetrilerden kaynaklanan ticari ve yatırım ilişkilerindeki dengesizlik, Çin’in Afrikalı baskıcı yönetimleri kınamaması ve iyi yönetilmeyen ekonomiler; kendisine hizmet eden ve kısa dönem kazanımlardan etkilenen bir dış ekonomik politikayı işaret etmektedir.
