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  • Article
    Citation - WoS: 12
    Citation - Scopus: 12
    Mutual 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, Ziya
    Random 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: 1
    Citation - Scopus: 1
    On the q-moment Determinacy of Probability Distributions
    (Malaysian Mathematical Sciences Soc, 2020) Ostrovska, Sofiya; Turan, Mehmet
    Given 0
  • Article
    Citation - WoS: 1
    Citation - Scopus: 3
    Spectral 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: 4
    Citation - Scopus: 2
    Partner Phubbing and Sleep Quality: Serial Mediation Models With Relationship Satisfaction and Perceived Stress
    (Sage Publications inc, 2024) Dikdere, Busra; Turkarslan, Kutlu Kagan
    The increasing integration of technology into our lives has been affecting our daily routines and even our sleeps. Being a relatively new concept, phubbing refers to the act of overly engaging with one's phone while dismissing those around in the social settings. In this context, partner phubbing involves individuals exhibiting this neglect in the presence of their romantic partners. Evidence suggests that higher partner phubbing may lead to lower relationship satisfaction and higher perceived stress. The aim of the present cross-sectional study was to examine whether relationship satisfaction and perceived stress mediate the relationship between partner phubbing and sleep quality. Four hundred twenty-three individuals (females = 78.5%, M-age = 29.19, SD = 6.87) participated in the study and completed the measures of partner phubbing, relationship satisfaction, perceived stress, and sleep quality. The results of the serial mediation analyses showed that partner phubbing was not a direct predictor of sleep quality. However, the relationship between partner phubbing and sleep quality was mediated by the four indirect paths through relationship satisfaction (beta = 0.04, p < .05), perceived stress (beta = 0.09, p < .05), relationship satisfaction-perceived stress (beta = 0.02, p < .05), and perceived stress-relationship satisfaction (beta = 0.00, p < .05). The findings suggest that partner phubbing may diminish sleep quality by reducing relationship satisfaction and increasing perceived stress levels. Alternatively, perceived stress exacerbated by partner phubbing could reduce relationship satisfaction, which eventually worsens sleep quality. Digital detox programs, group interventions, emotion-focused couple interventions, and stress management training can help overcome the effects of partner phubbing on sleep quality.
  • Article
    Citation - WoS: 9
    Citation - Scopus: 9
    Mixture Representations for Three-State Systems With Three-State Components
    (Ieee-inst Electrical Electronics Engineers inc, 2015) Eryilmaz, Serkan
    This paper is concerned with dynamic reliability modeling of three-state systems consisting of three-state s-independent components. The components and the systems are assumed to be in three states: perfect functioning, partial performance, and complete failure. Survival functions of such systems are studied in different state subsets. It is shown that the survival function of a three-state system with a general structure can be represented as a mixture of the survival functions of the three-state k-out-of-n:G systems. The results are illustrated for the three-state consecutive-k-out-of-n:G systems whose components degrade according to a Markov process.
  • Conference Object
    Citation - WoS: 1
    Citation - Scopus: 1
    Increasing Creativity With Unusual Designs
    (Elsevier Science Bv, 2012) Ergin, Merve Hande; Rouyendegh (Babek Erdebilli), Babak Daneshvar
    Creativity is important in synthesizing new ideas. For the engineering students, there are different methods to increase the level of creativity. Also, the unusual designs stimulate the students' creativity helping them to think innovatively. The assessment tool CEDA (Creative Engineering Design Assessment) is applied with minor modifications (CEDA-modified) to measure creativity in IE 101 Introduction to Engineering course. The CEDA score is modified by using AHP method to decrease the subjectivity of the assessment criteria. The study is applied to 49 industrial engineering students as an exam question. The question asked requires developing five advantages to an unusual design given. Male students developed more ideas compared to female students when they face with unusual design. More designs may be required to discuss through out the term and a proper term project that requires more design may be submitted to increase the success level.
  • Article
    Citation - WoS: 47
    Citation - Scopus: 52
    Biocompatible Electroactive Tetra(aniline)-Conjugated Peptide Nanofibers for Neural Differentiation
    (Amer Chemical Soc, 2018) Arioz, Idil; Erol, Ozlem; Bakan, Gokhan; Dikecoglu, F. Begum; Topal, Ahmet E.; Urel, Mustafa; Guler, Mustafa O.
    Peripheral nerve injuries cause devastating problems for the quality of patients' lives, and regeneration following damage to the peripheral nervous system is limited depending on the degree of the damage. Use of nanobiomaterials can provide therapeutic approaches for the treatment of peripheral nerve injuries. Electroactive biomaterials, in particular, can provide a promising cure for the regeneration of nerve defects. Here, a supramolecular electroactive nanosystem with tetra(aniline) (TA)-containing peptide nanofibers was developed and utilized for nerve regeneration. Self-assembled TA conjugated peptide nanofibers demonstrated electroactive behavior. The electroactive self-assembled peptide nanofibers formed a well-defined three-dimensional nanofiber network mimicking the extracellular matrix of the neuronal cells. Neurite outgrowth was improved on the electroactive TA nanofiber gels. The neural differentiation of PC-12 cells was more advanced on electroactive peptide nanofiber gels, and these biomaterials are promising for further use in therapeutic neural regeneration applications.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 7
    China's Charm Defensive: Image Protection by Acquiring Mass Entertainment
    (Wiley, 2020) Yildirim, Nilgun Elikucuk; Aslan, Mesut
    Focusing on discussion of China's soft power resources, this article argues that China performs two kinds of soft power strategies in developing and developed countries: offensive and defensive, respectively. While China's charm offensive aims to consolidate her comprehensive power through a development model, aid, investment, traditional culture, foreign policy, and international broadcasting in developing countries, the defensive aspect of China's soft power strategy aims to soften the rise of China with traditional culture by introducing appealing parts of Chinese culture through investments and international broadcasting in Western countries. China applies classical soft power tools in developing countries while she endeavors to protect her image in Western countries defensively. China's alternative defensive approach to soft power is mostly implemented through the acquisition of media outlets, and via the entertainment sector and gaming industry by Chinese-owned companies. However, even in the defensive and offensive bifurcation, if charm attacks result in failure, China could turn take a defensive stance in developing countries.
  • Article
    Citation - WoS: 12
    Citation - Scopus: 14
    Numerical Modeling of Visco-Elasto Hygro-Thermal Stresses and the Effects of Operating Conditions on the Mechanical Degradation of Pefc Membranes
    (Elsevier, 2018) Mehrtash, Mehdi; Tari, Ilker; Yesilyurt, Serhat
    Durability of membranes is one of the concerns for widespread commercialization of polymer electrolyte fuel cells. Effects of membrane swelling on the durability pose important challenges for the fabrication of the catalyst-coated membrane. This study provides insight into vulnerable locations of the membrane under hygrothermal loading, mechanical loading due to clamping and realistic conditions where a combination of both of these loadings are imposed. With a half rib-channel model, we simulate a polymer electrolyte fuel cell that operates under varying loads and clamping pressure. Model considers anisotropic diffusion in the gas diffusion layer as well as complex interactions of water transport dynamics between gas diffusion layers and the membrane. Mechanical responses of the membrane subject to conjugate hygro-thermo-mechanical loadings during typical scenarios of fuel cell operation reveal the effects of operating parameters as well as individual contributing factors on the development of local stresses in the membrane.
  • Article
    Citation - WoS: 9
    Citation - Scopus: 9
    Experimental and Modeling Studies of a High-Temperature Electrochemical Hydrogen Compressor
    (Pergamon-elsevier Science Ltd, 2024) Durmus, Gizem Nur Bulanik; Kuzu, Cemil; Devrim, Yilser; Colpan, C. Ozgur
    Some non-technical factors such as economics and logistics prevent hydrogen (H2) tech-nologies from becoming more widespread in daily life. Today, the prevalence of H2 tech-nologies requires new technological developments. Electrochemical hydrogen compressors (ECHC) are of great interest due to their ability to pressurize and purify in one step. In this study, the electrochemical H2 compression performance of high phosphoric acid (PA) doped poly 2,2-m-phenylene-5,5-benzimidazole (PBI) membrane-based HT-ECHC under high temperature and non-humid conditions was investigated through both an experimental and a numerical approach. The H2 compression capacity of HT-ECHC at different operating voltages was examined by performance tests at 160 degrees C, and it was determined that the electrochemical compression performance increased with increasing operating voltage. It was observed that the current density values also increased with increasing voltage, and it was determined that a current density of 61.2 A was obtained at 1 V. As a result of the tests, H2 was successfully compressed from atmospheric pressure to 60 bar by HT-ECHC without any gas leakage. The results of the developed model were compared with the experimental performance test data, and the variation of molar flow, cell voltage, and cell efficiency over time was examined. It has been determined that the back diffusion from the cathode to the anode in the cell increases with the increasing operating voltage of HT-ECHC and therefore the cell efficiency decreases. It has been evaluated that the developed model and experimental results are in good agreement. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.