Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2025Scopus SJRQ1/r/bayburt/11026
  Lightweight ASIP Design for Lattice-Based Post-quantum Cryptography Algorithms

  Akçay, Latif; Yalçın, Berna Örs

  Lattice-based cryptography (LBC) algorithms are considered suitable candidates for post-quantum cryptography (PQC), as they dominate the standardization process put forward by the National Institute of Standards and Technology (NIST). Indeed, three of the four key encapsulation mechanism (KEM) algorithms in the third round of the process are based on computationally hard lattice problems. On the other hand, there is an urgent need for processor designs that can run PQC algorithms efficiently, especially for embedded systems. This study presents an application-specific instruction set processor (ASIP) design for the Kyber, Saber, and NewHope algorithms based on transport triggered architecture (TTA). Custom hardware accelerators are added to the baseline processor architecture for computation-intensive steps without applying any software optimization to the reference code. We compared FPGA and ASIC implementations of our design with the prominent RISC-V cores and instruction set extension studies in the literature. According to the results, the proposed design offers greater efficiency, better performance, and lower resource utilization than its competitors in most cases.

  AtıfScopus14·WoS7·OpenAlex17

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• MakaleYalnız künye2024Scopus SJRQ1/r/bayburt/13126
  Dynamic Angular Velocity Load-Based Energy Harvesting Analysis for Different Blade Angles and Polarization Directions of Smart Blades

  Uyar, M.

  Energy consumption and control of electrical devices in flying electric vehicles with propellers such as drones are important for the continuity of the movement process. With this motivation, the piezoelectric energy harvesting performances of the smart drone propeller and smart wind blades are evaluated in order to obtain electrical energy from lead zirconate titanate (PZT) material placed on the propellers. Initially, the effect of smart wind blades with different blade angles on energy harvesting analysis is examined. The energy harvesting performances of the converse (z polarization) and shearing movements (y polarization) of the PZT material placed on the wind blades are compared under different angular rotational velocities. Then, the power outputs obtained depending on the sensor responses of the smart drone propeller with different resistance gains are evaluated according to the polarization directions. The maximum and minimum power output values obtained from the smart drone propeller at 12,000 rpm rotation velocity are measured as about 0.086 and 0.008 W, respectively. The results show that the energy harvesting performance of the z-polarized smart propeller is more effective than the y polarization, and the amount of energy obtained with the increase in the endpoint vibration amplitudes increases as the rotation speed increases.

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  AtıfScopus1·WoS1·OpenAlex1

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• MakaleAçık Erişim2024Scopus SJRQ1/r/bayburt/12942
  A Multi-response Nonlinear Programming Model with an Inscribed Design to Optimize Bioreduction Conditions of (S)-phenyl (pyridin-2-yl)methanol by Leuconostoc pseudomesenteroides N13

  Özdemir, Akın; Şahin, Engin

  Asymmetric bioreductions have the potential to synthesize chiral alcohols when catalyzed by biocatalysts. Nevertheless, the (S)-phenyl (pyridin-2-yl)methanol ((S)-2) analgesic synthesis poses significant challenges concerning unsatisfactory substrate amount and production method. Thus, this study proposes an inscribed design-focused multi-response nonlinear optimization model for the asymmetric reduction of the phenyl(pyridin-2-yl)methanone (1) with Leuconostoc pseudomesenteroides N13 biocatalyst. From the novel inscribed design-focused multi-response nonlinear optimization model, optimization conditions of the reaction, such as pH = 6, temperature = 29 °C, incubation time = 53 h, and agitation speed = 153 rpm, were found. Also, the reaction conversion was predicted to be 99%, and the product of the enantiomeric excess (ee) was 98.4% under the obtained optimization conditions. (S)-2 was obtained with 99% ee, 99% conversion, and 98% yield while performing a validation experiment using the determined optimized conditions. In addition, 1 with the amount of 11.9 g was converted entirely to (S)-2 (11.79 g, 98% isolated yield) on a high gram scale. Also, this study is noted as the first example of the gram-scale production of (S)-2 using an optimization strategy and biocatalyst. Further, the applicability of the inscribed design-focused optimization model in biocatalytic reactions has been demonstrated and provides an effective process for the analgesic synthesis of (S)-2, which is a green, cost-effective method of producing chiral aryl heteroaryl methanol.

  AtıfScopus3·WoS3·OpenAlex3

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• MakaleAçık Erişim2024Scopus SJRQ1/r/bayburt/11910
  Evaluation of Dynamic and Fatigue Behavior of Damaged Steel Beams Strengthened with Different Types of Techniques and a New Strengthening Method Proposal

  Ergün, Mustafa; Ateş, Şevket

  In recent years, the use of carbon fiber-reinforced polymers to strengthen fatigue-damaged steel beams has increased significantly as an alternative to traditional methods due to their easy application to the damaged area, lightweight, durability, and sustainability. In addition to all these positive contributions, there are some disadvantages, such as debonding damage under loading. These disadvantages encourage researchers to produce new materials or apply materials used for other purposes in other fields for fatigue damage. In this paper, an alternative new strengthening technique is mentioned to improve the dynamic and fatigue behavior of fatigue-damaged steel beams. This technique is a strengthening application made using epoxy-based filler and carbon fiber-reinforced polymer fabric. Numerical and experimental studies are carried out on fatigue-damaged steel beams by applying this new technique and using different carbon fiber-reinforced polymers, such as a single and double layer of fabric and a single plate layer. The most significant improvement in dynamic behavior occurred on the specimen, strengthened with this newly proposed technique. In contrast, the lowest increase occurs on the sample strengthened with a single layer of fabric. While the lowest increase arises on the sample strengthened with a single layer of fabric in terms of fatigue life, the most significant progress in fatigue behavior makes on the sample strengthened with a single plate layer. As a result of comparing the results, it is concluded that this new strengthening technique could be an essential alternative to the currently used strengthening methods.

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  AtıfScopus2·WoS2·OpenAlex3

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• MakaleYalnız künye2024Scopus SJRQ1/r/bayburt/11680
  A Novel Fuzzy Cumulative Sum Control Chart with an α-Level Cut Based on Trapezoidal Fuzzy Numbers for a Real Case Application

  Özdemir, Akın; Uçurum, Metin; Serencam, Hüseyin

  Statistical process control (SPC) is widely used to monitor production processes in many industries under certain conditions. When dealing with a quality characteristic for uncertainty, fuzzy numbers are used in the context of the statistical process control (SPC) to monitor a fuzzy production process. The aim of this paper is fourfold. One, a fuzzy X¯-R control chart with an α-level cut is used based on trapezoidal fuzzy numbers (TFNs) for detecting the large shifts in the fuzzy process mean. Second, a fuzzy cumulative sum (FCUSUM) control with an α-level cut based on TFNs is firstly developed for detecting the small shifts in the fuzzy process mean. Third, the fuzzy process capability indices (FPCIs) are presented to measure the fuzzy process performance. Finally, an ultra-fine calcite production process is controlled with both the fuzzy X¯-R control chart and the proposed FCUSUM control chart. The results of the fuzzy X¯-R control charts show that the fuzzy production process is in control, and large shifts in the fuzzy process mean were detected. On the other hand, the results of the FCUSUM charts show that the fuzzy production process is out of control, and small shifts in the fuzzy process mean were detected. FPCIs are also conducted, and the results of fuzzy Cpk indices show that the ultra-fine calcite production process is not capable of meeting specification limits.

  AtıfScopus7·WoS9·OpenAlex9

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• MakaleYalnız künye2023Scopus SJRQ1/r/bayburt/12926
  A New Higher-Order Finite Element for Static Analysis of Two-Directional Functionally Graded Porous Beams

  Turan, Muhittin; Adiyaman, Gokhan

  A new higher-order finite element for the static analysis of two-directional functionally graded (2D FG) porous beams subjected to various boundary conditions based on parabolic shear deformation theory (PSDT) is presented. The main purpose of this study is to predict the deflections and stresses of 2D FG porous and non-porous beams with the help of the proposed finite element. Since a higher-order finite element with a third order polynomial is used, the deflections and stresses can be accurately and rapidly obtained even for short beams. In addition, the new higher-order element is free of shear locking phenomenon without requiring any shear correction factors. Three types of distribution functions were used for porosity in this study. To the author's knowledge, the sinusoidal uneven distribution function (FGP-3) is presented for the first time. The governing equations are derived by Lagrange’s principle using a parabolic shear deformation theory that considers normal and shear deformations. According to a power-law rule, the material change in the beam volume in both directions is defined. The dimensionless maximum transverse deflections, normal stresses, and shear stresses are obtained for various boundary conditions, gradation exponents (px, pz) in the x- and z-directions, porosity coefficient (e), porosity distribution (FGP-1, FGP-2, FGP-3), and the slenderness (L/h). This study's new higher-order finite element gives results compatible with the literature and it can be used to accurately find the deflections and stresses for the 2D FG non-porous or porous beams subjected to various boundary conditions.

  AtıfScopus30·WoS28·OpenAlex26

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• MakaleYalnız künye2023Scopus SJRQ1/r/bayburt/11781
  Electrical, Magnetic, Microstructural, and Characteristic Properties of Zirconium-Substituted Co0.5 Ni0.5 Zrx Fe2− x O4 Spinel Ferrite Nanostructures

  Teber, Ahmet; Sarac, Mehmet F.

  The effect of zirconium (Zr) substitution in nickel–cobalt ferrites, Co0.5Ni0.5ZrxFe2−xO4 (0.0 ≤ x ≤ 1.0) produced by the hydrothermal method on the electrical, magnetic, microstructural and characteristic properties are reported. A secondary phase as tetragonal-ZrO2 phase in the crystal system is detected and have both M-type hexagonal and tetragonal nanocrystallites between 32 and 67 nm. Refined structural parameters using Rietveld analysis are carried out, resulting in lattice parameters, the unit cell volume, parameter ratios, and the crystallite size using the TOPAS refinement program. In addition, residuals for the RBragg factor and goodness of fit (χ2) value for each concentration are represented. The Rietveld analysis determines that the predicted and actual diffraction patterns are in accord. Furthermore, the Zr effect is presented in unit volume as seen by the drop in peak intensity that occurs (with the addition of Zr) due to the lattice tension. Moreover, the morphological analyses indicate that the shape transformed from agglomerated clusters to oval-shaped structures and a reduction in grain size. Fourier transform infrared (FT-IR) analysis in the range of 4000–450 cm−1 correlates with the presence of the hexagonal spinel ferrite structure. The dielectric parameters, such as the relative permittivity, tangent loss, and ac conductivity, are experimentally measured with the oscillation voltage level of 0.05 V in the frequency range of 0.1–10 MHz. The dielectric permittivities and tangent losses of the specimens decreased with an increment in frequency. Magnetic measurements reveal that the values of coercivity (Hc) have the propensity to increase relating to the zirconium concentration.

  AtıfScopus2·WoS3·OpenAlex4

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• MakaleYalnız künye2023Scopus SJRQ1/r/bayburt/11749
  Novel PV Array Reconfiguration and Integration with a Maximum Power Point Tracking Algorithm: RMPPT

  Güngör, Okan; Kahveci, Hakan

  Partial shading significantly impacts the output power of photovoltaic (PV) arrays. This issue can be addressed by reconfiguring connections or positions of modules within the PV array. However, reconfiguration approaches present some drawbacks including the requirements of manual effort, complex algorithms, difficulty in implementation, and switching matrices that increase power losses. To overcome these issues, we present a low-cost and easily implemented reconfiguration method with integration into a maximum power point tracking (MPPT) algorithm for a PV array. We denote our MPPT approach as reconfigurable MPPT (RMPPT), and verify its applicability using a particle swarm optimization (PSO) algorithm, namely the reconfigurable PSO. Consequently, this approach has enhanced the output power of the PV array by at least 7.2% compared to PNO (perturb and observe) and PSO-based MPPT under realistic weather conditions.

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  AtıfScopus6·WoS5·OpenAlex5

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• MakaleAçık Erişim2023Scopus SJRQ1/r/bayburt/10870
  Implementation of Active and Passive Vibration Control of Flexible Smart Composite Manipulators with Genetic Algorithm

  Uyar, M.; Malgaca, L.

  Endpoint vibrations of flexible manipulators (FM) are suppressed using active or passive control techniques. Suppressing vibrations increases the dynamic performance of the FM in engineering applications. In this study, a model extraction approach is proposed for vibration suppression of single-link flexible smart and composite manipulators. Active and passive control (APC) of residual vibrations is studied theoretically and experimentally. The smart manipulator consists of patching a piezoelectric (PZT) actuator to an aluminum and composite link. The finite element (FE) model of smart manipulators, including revolute joint and PZT actuator, is created in ANSYS. The motion profile and actuator voltage are the inputs, the tip displacement is the output. Then, the state-space (SS) mathematical models of the smart manipulators are extracted from the FE models by using the inputs and outputs. The open-loop and closed-loop simulations are performed using the extracted mathematical models in MATLAB. Passive control is achieved by the motion profiles, while active control is achieved by the PZT actuators. The PD controller with the displacement feedback is used to create the actuation voltages. For the optimized APC, the PD gains are optimized with a genetic algorithm by using the integral of the squared error and integral of absolute magnitude of the error fitness functions. Residual vibrations of smart manipulators are successfully reduced by the optimized APC. To verify the simulation results, open-loop and closed-loop experiments are carried out. The SS mathematical model successfully predicts the dynamic performance of FSM for various motion profiles, according to experimental results.

  AtıfScopus12·WoS9·OpenAlex10

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• MakaleAçık Erişim2022Scopus SJRQ1/r/bayburt/13462
  Optimization of Asymmetric Bioreduction Conditions of 2-methyl-1-phenylpropan-1-one by Lactobacillus fermentum BY35 Using I-Optimal Design-Based Model

  Aksuoğlu, Selmani; Özdemir, Akın; Serencam, Hüseyin; Dertli, Enes; Şahin, Engin

  The bioreduction of prochiral ketones offers efficient access to chiral secondary alcohols, which are potentially beneficial precursors for producing many biologically active compounds and natural products. This bioreduction process can be affected by different parameters when whole-cell of biocatalysts such as Lactic Acid Bacteria strains are applied. In this context, this paper proposed an I-optimal design-based model to optimize culture parameters such as temperature, pH, incubation period, and agitation speed for asymmetric bioreduction of 2-methyl-1-phenylpropan-1-one (1) with Lactobacillus fermentum BY35 as a biocatalyst while achieving the highest conversion rate (cr) and enantiomeric excess (ee). The optimum settings of the four culture parameters and the cr and ee values were found using the proposed optimization model as follows: pH = 6.5, temperature = 25 °C, incubation period = 38.5 h, agitation speed = 200 rpm, the ee value = 98.78%, and the cr value = 98.92%. After the validation of the process, the cr and ee values were found to be > 99% and > 99%, respectively, while using the optimum operating conditions from the optimization model. Thus, the results of the optimization model are consistent with the results of the validation experiment. It is also noted that this paper is the first to optimize culture parameters using the proposed I-optimal design-based model for an asymmetric reduction.

  AtıfScopus3·WoS3·OpenAlex3

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