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Now showing 1 - 10 of 764
  • 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: 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: 7
    Citation - Scopus: 10
    Ann-Assisted Forecasting of Adsorption Efficiency To Remove Heavy Metals
    (Tubitak Scientific & Technological Research Council Turkey, 2019) Buaısha, Magdi; Balku, Şaziye; Yaman, Şeniz Özalp
    In wastewater treatment, scientific and practical models utilizing numerical computational techniques suchas artificial neural networks (ANNs) can significantly help to improve the process as a whole through adsorption systems.In the modeling of the adsorption efficiency for heavy metals from wastewater, some kinetic models have been used such as pseudo first-order and second-order. The present work develops an ANN model to forecast the adsorption efficiency of heavy metals such as zinc, nickel, and copper by extracting experimental data from three case studies. To do this, we apply trial-and-error to find the most ideal ANN settings, the efficiency of which is determined by mean square error (MSE) and coefficient of determination (R2). According to the results, the model can forecast adsorption efficiency percent (AE%) with a tangent sigmoid transfer function (tansig) in the hidden layer with 10 neurons and a linear transferfunction (purelin) in the output layer. Furthermore, the Levenberg–Marquardt algorithm is seen to be most ideal for training the algorithm for the case studies, with the lowest MSE and high R2 . In addition, the experimental results and the results predicted by the model with the ANN were found to be highly compatible with each other.
  • Article
    Health Beliefs and Attitudes: a Comparison Between Turkey and Palestine
    (Routledge Journals, Taylor & Francis Ltd, 2018) Menawi, Wafaa Allam; Tengilimoglu, Dilaver; Dziegielewski, Sophia F.
    The purpose of this study is to identify the beliefs and attitudes that influence health-related behavior while comparing two countries that can have different political and economic structures. This study also gathers both Turkish and Palestinian citizens' beliefs and attitudes towards health determinants. To assess and compare citizens' attitudes toward health care and health determinants a total of 4,100 questionnaires were distributed, whereas 2,600 were distributed in Turkey, and another 1,500 questionnaires in the Palestine. According to the research, the individuals surveyed in Turkey noted that smoking, stress, and getting access to a medical institution were noted as the most influential determinants which affect their health; whereas, the people of Palestine thought that income status, and educational levels were the most influential factors in health. In addition, it was found that there were some statistically significant differences between participants' responses in Turkey and Palestine; however, what both samples shared was that economic factors were an important factor affecting health beliefs and attitudes, regardless of where a participant lived. Finally, comparisons and future recommendations are made to improve health-related beliefs, attitudes and behaviors in both countries.
  • Article
    Patient Safety in Healthcare: A Proposal for Ensuring the Use of Regulation-Compliant Safety Devices
    (Springer Heidelberg, 2025) Bayrak, Tuncay
    Medical devices used in health care should fulfill the requirements of the technical regulations to protect patient health. Difficulties in enforcing stricter rules in the new medical device regulations may negatively affect the continuity of care. This study examines the status of manufacturers' compliance with medical device regulations, based on predefined criteria, and proposes a collaborative action plan and an approach to verify regulatory compliance. We conducted a nationwide survey comprising questions grouped by criteria to understand the status of the manufacturers in terms of compliance with the Medical Device Regulation. Four hundred sixty-seven manufacturers participated in the survey. We achieved a Cronbach's alpha of 0.77, which indicates that the survey is statistically reliable. We applied the independent samples t-test to the responses to determine significant features per question and employed factor analysis to investigate the relationships of the questions. The results of independent samples t-tests showed statistically significant differences across groups in replies to several survey items (p < 0.05), indicating that participants' opinions varied based on their demographic characteristics. We applied Exploratory Factor Analysis to introduce the relationships between the questions. The analysis revealed that manufacturers continue to face substantial challenges in acquiring sufficient knowledge and operational capability to meet MDR requirements. In light of these findings, we focused on the person responsible for regulatory compliance, who plays a central role in maintaining regulatory compliance within manufacturing organizations. We proposed an action plan at the macro level to introduce more effective action plans in cooperation with other stakeholders, including healthcare providers, and a verification approach for regulatory compliance to enhance the Person Responsible for Regulatory Compliance's competence. Manufacturers should implement effective postmarketing clinical follow-up plans involving device-oriented parameters for monitoring in the healthcare system, especially in collaboration with health professionals.
  • Review
    Citation - WoS: 16
    Citation - Scopus: 20
    Assessing the Coverage of E-Health Services in Sub-Saharan Africa a Systematic Review and Analysis
    (Georg Thieme verlag Kg, 2017) Adeloye, Davies; Adigun, Taiwo; Misra, Sanjay; Omoregbe, Nicholas
    Background: E-Health has attracted growing interests globally. The relative lack of facilities, skills, funds and information on existing e-Health initiatives has affected progress on e-Health in Africa. Objectives: To review publicly available literature on e-Health in sub-Saharan Africa (sSA) towards providing information on existing and ongoing e-Health initiatives in the region. Methods: Searches of relevant literature were conducted on Medline, EMBASE and Global Health, with search dates set from 1990 to 2016. We included studies on e-Health initiatives (prototypes, designs, or completed projects) targeting population groups in sSA. Results: Our search returned 2322 hits, with 26 studies retained. Included studies were conducted in 14 countries across the four sub-regions in sSA (Central, East, South and West) and spreading over a 12-year period, 2002-2014. Six types of e-Health interventions were reported, with 17 studies (65%) based on telemedicine, followed by mHealth with 5 studies (19%). Other e-Health types include expert system, electronic medical records, e-mails, and online health module. Specific medical specialties covered include dermatology (19%), pathology (12%) and radiology (8%). Successes were 'widely reported' (representing 50% overall acceptance or positive feedbacks in a study) in 10 studies (38%). The prominent challenges reported were technical problems, poor inter net and connectivity, participants' selection biases, contextual issues, and lack of funds. Conclusion: E-Health is evolving in sSA, but with poorly published evidence. While we call for more quality research in the region, it is also important that population-wide policies and on-going e-Health initiatives are contextually feasible, acceptable, and sustainable.
  • Article
    ON A GENERALIZED α-ADMISSIBLE RATIONAL TYPE CONTRACTIVE MAPPING
    (Yokohama Publ, 2016) Erhan, Inci M.; Kir, Mehmet
    Recently, many generalized contractive conditions which involve rational contractive inequalities have been introduced in the context of partially ordered metric spaces. In this paper, we aim to give a generalized rational contractive condition which involves some of these results without need of extra restrictions.
  • Article
    Citation - WoS: 11
    Citation - Scopus: 20
    Reinforcement Learning Using Fully Connected, Attention, and Transformer Models in Knapsack Problem Solving
    (Wiley, 2022) Yildiz, Beytullah; Yıldız, Beytullah; Yıldız, Beytullah
    Knapsack is a combinatorial optimization problem that involves a variety of resource allocation challenges. It is defined as non-deterministic polynomial time (NP) hard and has a wide range of applications. Knapsack problem (KP) has been studied in applied mathematics and computer science for decades. Many algorithms that can be classified as exact or approximate solutions have been proposed. Under the category of exact solutions, algorithms such as branch-and-bound and dynamic programming and the approaches obtained by combining these algorithms can be classified. Due to the fact that exact solutions require a long processing time, many approximate methods have been introduced for knapsack solution. In this research, deep Q-learning using models containing fully connected layers, attention, and transformer as function estimators were used to provide the solution for KP. We observed that deep Q-networks, which continued their training by observing the reward signals provided by the knapsack environment we developed, optimized the total reward gained over time. The results showed that our approaches give near-optimum solutions and work about 40 times faster than an exact algorithm using dynamic programming.
  • Article
    W-Band RCS Prediction of Small Objects: Comparing Two Widely Used Methods with Experimental Validation
    (Gazi University, 2025) Kara, Ali; Aydın, Elif; Yardım, Funda Ergün; Sezgin, Deniz
    This paper compares the accuracy of Shooting and Bouncing Rays and Electric Field Integral Equation methods for Radar Cross Section prediction of small objects at 77-81 GHz band. Existing studies on RCS prediction methods often lack comprehensive comparisons between computational and experimental results, particularly for small objects measured with a 77 GHz radar. This study addresses this gap by presenting an in-depth analysis of both simulation and measurement data. In this work, three targets with varying geometries and materials were measured with a frequency modulated continuous wave radar and simulated using Ansys HFSS and CST Studio Suite. The measurements were performed with a commercial off-the-shelf (COTS) frequency modulated continuous wave radar operating at 77–81 GHz. This study aims to emphasize the importance of considering both efficiency and accuracy when opting for an RCS prediction method. Overall, the outcomes of both methods have largely demonstrated good alignment. It has been noted that, while Shooting and Bouncing Rays method offers promising time-saving advantages, Electric Field Integral Equation method remains a valuable tool for complex geometries where precise results are crucial.
  • Article
    Citation - WoS: 6
    Citation - Scopus: 7
    Construction of Self-Assembled Vertical Nanoflakes on Cztsse Thin Films
    (Iop Publishing Ltd, 2019) Terlemezoglu, M.; Surucu, O. Bayrakli; Colakoglu, T.; Abak, M. K.; Gullu, H. H.; Ercelebi, C.; Parlak, M.
    Cu2ZnSn(S, Se)(4) (CZTSSe) is a promising alternative absorber material to achieve high power conversion efficiencies, besides its property of involving low-cost and earth-abundant elements when compared to Cu(In, Ga) Se-2 (CIGS) and cadmium telluride (CdTe), to be used in solar cell technology. In this study, a novel fabrication technique was developed by utilizing RF sputtering deposition of CZTSSe thin films having a surface decorated with self-assembled nanoflakes. The formation of nanoflakes was investigated by detailed spectroscopic method of analysis in the effect of each stacked layer deposition in an optimized sequence and the size of nanoflakes by an accurate control of sputtering process including film thickness. Moreover, the effects of substrate temperature on the formation of nanoflakes on the film surface were discussed at a fixed deposition route. One of the main advantages arising from the film surface with self-assembled nanoflakes is the efficient light trapping which decreases the surface reflectance. As a result of the detailed production and characterization studies, it was observed that there was a possibility of repeatable and controllable fabrication sequence for the preparation of CZTSSe thin films with self-textured surfaces yielding low surface reflectance.