Web of Science ve Scopus Atıf Dizinlerindeki Yayınlar
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Web of Science ve Scopus Atıf Dizinlerindeki Yayınlar / Publications in Web of Science and Scopus Citation Indexes
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Öğe Exploration of Soliton Solutions for the Kaup–Newell Model Using Two Integration Schemes in Mathematical Physics(WILEY, 111 RIVER ST, HOBOKEN 07030-5774, NJ, 2025) Kopçasız, Bahadır; Kaya Sağlam, Fatma NurThis research deals with the Kaup–Newell model, a class of nonlinear Schrödinger equations with important applications in plasma physics and nonlinear optics. Soliton solutions are essential for analyzing nonlinear wave behaviors in different physical systems, and the Kaup–Newell model is also significant in this context. The model’s ability to represent subpicosecond pulses makes it a significant tool for the research of nonlinear optics and plasma physics. Overall, the Kaup–Newell model is an important research domain in these areas, with ongoing efforts focused on understanding its various solutions and potential applications. A new version of the generalized exponential rational function method and ( 𝐺′ 𝐺2 ) -expansion function method are utilized to discover diverse soliton solutions. The generalized exponential rational function method facilitates the generation of multiple solution types, including singular, shock, singular periodic, exponential, combo trigonometric, and hyperbolic solutions in mixed forms. Thanks to ( 𝐺′ 𝐺2 ) -expansion function method, we obtain trigonometric, hyperbolic, and rational solutions. The modulation instability of the proposed model is examined, with numerical simulations complementing the analytical results to provide a better understanding of the solutions’ dynamic behavior. These results offer a foundation for future research, making the solutions effective, manageable, and reliable for tackling complex nonlinear problems. The methodologies used in this study are robust, influential, and practicable for diverse nonlinear partial differential equations; to our knowledge, for this equation, these methods of investigation have not been explored before. The accuracy of each solution has been verified using the Maple software program.Öğe Unlocking the high dimensional’ potential: Comparative analysis of qubits and qutrits in variational quantum neural networks(ELSEVIER, RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2025) Acar, Erdi; Yılmaz, İhsanQuantum machine learning is a promising research area with great potential. In particular, Variational quantum neural networks (VQNN) have shown high performance in many applications. However, while qubits, which are 2-level quantum systems, are the standard building blocks of quantum computing, the development of qudits, i.e. d-level quantum systems, has opened up new opportunities in VQNNs thanks to many properties such as robustness to noise and more quantum information processing with fewer quantum resources. In this study, we present a comparative analysis of qubits and qutrits (3-level quantum systems) systems performance in VQNNs while also exploring the effect of encoding strategies and entanglement on classifier performance. Our findings contribute to a better understanding the benefits and limitations of using qutrits in VQNN and pave the way for future developments in this field.Öğe A Monte Carlo-based approach to determine effective atomic numbers of low-Z explosives in landmines(TAYLOR & FRANCIS LTD, 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND, 2025) Özşahin Toker, Melis; Yavaş, Kübra; Toker, Ozan; İçelli, OrhanLandmines pose significant humanitarian and strategic challenges, threatening both civilian populations and military operations worldwide. This study presents a practical simulation method based on Rayleigh and Compton scattering ratios to determine the effective atomic number of low atomic number (low-Z) explosives used in landmines. Utilizing the Monte Carlo N-Particle (MCNP) simulation program, Rayleigh/Compton scattering ratios were obtained using a Ge(Li) detector at a scattering angle of 115° within a simulated geometry. The simulation results were found to be in good agreement with experimental data, confirming the reliability of the method. Pure elements with atomic numbers ranging from 3 to 20 and various explosives were irradiated with photons of 59.54 keV energy to obtain scattering spectra. The effective atomic numbers calculated using Rayleigh/Compton scattering ratios were compared with five different theoretical methods, yielding consistent results. These findings demonstrate that the proposed method can reliably determine the effective atomic number of low-Z elements and explosives containing these elements. Additionally, the study confirms that MCNP simulations can be effectively utilized in various fields such as defense industry, radiation safety, medical applications, and radiation dosimetry.Öğe Thermal and Mechanical Analysis of Wheel Rim in Formula 1 Vehicles(VINCA INST NUCLEAR SCI, MIHAJLA PETROVICA-ALASA 12-14 VINCA, 11037 BELGRADE. POB 522, BELGRADE 11001, SERBIA, 2025) Kepekçi, Haydar İzzettin; Ağca, Mehmet Erdem; Komatina, Mirko S.The wheel rim is a metal or alloy component that holds the tire and connects it to the vehicle. The wheel rims of Formula 1 cars are exposed to thermal stresses during the race and frequent braking at high speeds. In addition to thermal resistance, wheel rims must possess high mechanical durability. Therefore, material selection is crucial, along with the designs of the wheel rims. In the production of wheel rims for Formula 1 vehicles, magnesium, aluminum, and carbon fiber wheel rims are commonly used. Each of these materials has its advantages and limitations. Optimization processes in Formula 1 technology aim to reduce mass while increasing mechanical and thermal properties. Therefore, alloys used in wheel rim production are continuously evolving. In this study, deformation, stress, and temperature values were investigated using the CF) method by exposing Mg AZ80, Al 6061-T6, and carbon fiber to conditions of 300 °C temperature, 1 MPa pressure, and 300 km/h speed. Turbulence modelling was carried out using the k-ε method in numerical analyses, which utilized a mesh file consisting of approximately 2 million grids. As a result, the highest deformation in mechanical pressure analyses was obtained using Mg AZ80 material. In contrast, carbon fiber achieved the lowest deformation value in the analysis. Regarding thermal results, the lowest temperature value of 282.75 °C was obtained from the wheel rim made of carbon fiber, whereas with the use of Mg AZ80 material, this value reached up to 292.03 °C. Considering these values, it was concluded that carbon fiber is the most suitable wheel rim material for Formula 1 race cars.Öğe Exploration of the soliton solutions of the (n+1) dimensional generalized Kadomstev Petviashvili equation using an innovative approach(NATURE PORTFOLIO, HEIDELBERGER PLATZ 3, BERLIN 14197, GERMANY, 2025) Kopçasız, Bahadır; Sağlam, Fatma Nur Kaya; Bulut, Hasan; Radwan, TahaIn this paper, we deal with the (n+1)-dimensional generalized Kadomtsev-Petviashvili equation (dgKPE). This is an important model in nonlinear science, with applications in various fields. Its integrability and rich soliton dynamics continue to attract researchers interested in the field of nonlinear partial differential equations (NLPDEs). We are interested in the new auxiliary equation method (NAEM). We reduce the equation to an ordinary differential equation (ODE) with the help of an appropriate wave transformation and search for different types of soliton solutions. Additionally, we demonstrated the efficacy of the NAEM as a straightforward yet powerful mathematical instrument for handling challenging issues, highlighting its potential to resolve the challenging problems related to the study of nonlinear equations. This technique yields several types of solutions for (n+1)-dgKPE, including trigonometric, hyperbolic, shock wave, singular soliton, exponential, and rational functions. A range of graphs showcasing the results are reviewed, as well as the wave behavior for the solutions in different circumstances. The obtained data provide important information for studying hydrodynamic waves, plasma fluctuations, and optical solitons. They also aid in understanding the behavior of the KPE in different physical situations. We clarify in this article how the (n+1)-dgKPE, when combined with NAEM, can result in better data transmission rates, optimized optical systems, and the advancement of nonlinear optics toward more dependable and efficient communication technologies. The obtained information clarifies the equation and opens up new avenues for investigation. To our knowledge, for this equation, these methods of investigation have not been utilized before. The accuracy of each solution has been verified using the Maple software program.Öğe Artificial intelligence-enhanced intrusion detection systems for drone security: a real-time evaluation of algorithmic efficacy in mitigating wireless vulnerabilities(SPRINGER, ONE NEW YORK PLAZA, SUITE 4600 , NEW YORK, NY 10004, UNITED STATES, 2025) Şentürk, Kenan; Görmüş, Ahmet Faruk; Gönen, Serkan; Barışkan, Mehmet Ali; Durmaz, Ahmet KaanAdvancements in science and technology have provided extensive opportunities and conveniences for mankind. One prime example of these advancements is wireless communication technology. This technology provides users with mobility during communication, initiating a paradigm shift. The convenience of wireless communication technology has initiated the production of versatile devices. Among these technologies developed in recent years for observation and detection purposes in various fields, drones have taken a leading role. Drones, with their versatile applications and access to real-time data, are being used in various operations. With such utilization, humans are increasingly interacting with these systems, leading to natural human-drone interaction. However, in these human-drone interactions, as is the case with many wireless devices, security often becomes an afterthought, leaving many drones vulnerable to cyber attacks. The most effective way to protect against these attackers is to conduct vulnerability analyses of the systems we use against emerging threats and address the detected vulnerabilities. This paper investigates the vulnerabilities of wireless communication regarding remote connectivity usage of a commercial drone, the DJI Ryze Tello, with the aim of examining its weaknesses. In this context, a test environment was created to reveal problems and threats in drone technology through attacks executed on the test environment (DEAUTH ATTACK, Port Scan DOS, DDoS, and MitM). Following the identification of these vulnerabilities, an artificial intelligence-based study was carried out to detect these attacks. In the study, the percentages of attack detection using different algorithms were verified with graphs.Öğe A short-term durability comprehensive study of ceramic waste-doped White Cement composites with hooked-end, basalt and copper-coated fibers(ELSEVIER, RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2025) Al-Sharhanee, Baraa Abduljabbar Badi; Mehmetoğlu, Metin; Aygörmez, Yurdakul; Niş, AnılWhite Cement (WC) mixes are an alternative product to the OPC. However, there are limited studies on the materials used in the production of composite materials as substitutes for the WC. Ceramic waste (CW) is an important alternative material in this regard. In this context, ceramic waste was replaced with White Cement at the rates of 5 %, 10 %, and 15 %, while three different fibers for reinforcement, namely hooked-end (HE) steel fiber, basalt (B) fiber, and copper-coated (CC) steel fiber (0.4 %) were used. The compressive and flexural strength results at 28 and 90 days were examined for the variations of White cement-based mortar properties. After 90 days, durability tests (sulfate effect, high temperature, and freeze-thaw) were applied while mechanical properties and weight losses were measured. SEM, XRD, Micro-CT, and TGA-DTA analyses were also used to see the changes with durability tests. According to the results, the increase in SiO2 and Al2O3 content in the addition of 5 % and 10 % ceramic waste increased the strength while keeping the pozzolanic reaction at a high level. In the case of 15 % substitution, it caused a reduction due to the decrease in the cement’s relative content. The hooked-end steel fiber, which was denser and longer, had the highest performance, while the copper-coated steel fiber showed the lowest performance. With 5 % ceramic powder and hooked-end steel fiber reinforcement, the flexural strength was enhanced by 26 %, while the compressive strength was enhanced by 17 % compared to the 100 % White Cement sample (control sample).Öğe A CMIP6-based drought assessment over Küçük Menderes Basin,Türkiye(SPRINGER WIEN, Prinz-Eugen-Strasse 8-10, A-1040 Vienna, AUSTRIA, 2025) Rotbeei, Farzad; Nuri Balov, Mustafa; Safari, Mir Jafar Sadegh; Vaheddoost, BabakDroughts are the phenomenon of which their magnitude and frequency are forecasted to escalate over time primarily due to the impacts of climate change and global warming. Hence, the potential consequences of the expected drought events are of the great importance in performing efective adaptation and regional mitigation strategies. The objective of the current study is to explore the consequences of climate change on the future droughts in Küçük Menderes Basin in western Türkiye. This objective will be addressed by examining the outputs of four General Circulation Models (GCMs) incorporated within Phase 6 of the Coupled Model Inter-comparison Project (CMIP6), with particular emphasis on two contrasting emission trajectories: SSP2-4.5 and SSP5-8.5. The daily precipitation and temperature projections are then utilized in determination of the so-called Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI) drought indices with consideration to 2015–2039 as near future, 2040–2069 as mid-term future, and 2070–2099 as late future time frames. According to projections based on the SSP2-4.5 and SSP5-8.5 scenarios, the number of dry months is anticipated to escalate by approximately 26.12% and 39.80%, respectively, toward the end of the twenty-frst century (2070–2099), in contrast to the reference period (1985–2014). Results of the current study provide valuable insights for developing adaptation strategies to address future consequences of drought events in the Küçük Menderes Basin amid evolving climate conditions.Öğe Abundant new soliton solutions to the Arshed-Biswas equation via two novel integrating schemes(WORLD SCIENTIFIC PUBL CO PTE LTD, 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE, 2025) Kaya Sağlam, Fatma Nur; Kopçasız, Bahadır; Şenol, MehmetThis paper explores analytical solutions to the Biswas-Arshed equation, a key mathematical model describing soliton propagation in optical fibers. Understanding and solving this equation provide insights into signal stability, dispersion management, and overall improvements in fiber-optic communication technology. To achieve this, we first decompose the equation into real and imaginary components, deriving a system of nonlinear differential equations. We then employ the Kumar-Malik method and the polynomial expansion method - two powerful analytical techniques applied for the first time to this equation - to construct exact solutions. These methods yield soliton solutions in Jacobi elliptic, exponential, hyperbolic, and trigonometric forms, with numerical simulations visualized through 3D, contour, density, and 2D plots. The significance of these findings extends beyond theoretical mathematics. Optical soliton solutions derived from this study can contribute to the development of more efficient optical fiber networks, enhanced data transmission techniques, and improved nonlinear wave applications in photonics. By leveraging advanced analytical methods, this research provides new solution sets that could aid in optimizing real-world optical systems, potentially influencing future advancements in telecommunication infrastructure, high-speed internet technologies, and laser pulse dynamics.Öğe PAFWF-EEGC Net: parallel adaptive feature weight fusion based on EEG-dynamic characteristics using channels neural network for driver drowsiness detection(SPRINGER LONDON LTD, 236 GRAYS INN RD, 6TH FLOOR, LONDON WC1X 8HL, ENGLAND, 2025) Abdulwahhab, Ali Hussein; Myderrizi, Indrit; Yurdakul, Muhammet MustafaDrowsy driving is considered one of the most dangerous causes of road accidents and deaths worldwide. Drivers’ concentration is directly affected by fatigue, which affects their reaction time, reducing their attention and decision-making ability on the road. This can often lead to dangerous situations. With the development of Human Computer Interface systems and the rise of intelligent transportation systems, examining the effects of driver fatigue has become more critical, and research aimed at reducing the risk of fatigue-related accidents has gained importance. For this purpose, this study proposes a Parallel Adaptive Feature Weight Fusion based on EEG-Dynamic Characteristics using Channels Neural Network (PAFWF-EEGC Net) to detect the driver drowsiness condition. Two signal processing techniques are used to extract EEG dynamic features: first, Continuous Wavelet Transform (CWT) to capture the spectral-temporal features by accurately estimating both time and frequency localizations, and second, Fast Fourier Transform (FFT)—Power Spectrum Density (PSD) to convert the signals from the time domain to the frequency domain and show the distribution of signal power over frequency. These extracted dynamic features are passed to Attention channels and Parallel Adaptive Feature Fusion to integrate the most relevant feature channels to detect mental state. Furthermore, three processing dataset scenarios and cross-validation techniques are used to validate the Net. The Net showed excellent performance through ninefold/3rd scenario by achieving 98% detection accuracy, and 84%, 88.75%, 93.8% average detection accuracy through 1st, 2nd, 3rd scenarios respectivelyÖğe Design and Thermodynamic Analysis of Waste Heat-Driven Liquid Metal–Water Binary Vapor Power Plant Onboard Ship(MDPI, ST ALBAN-ANLAGE 66, CH-4052 BASEL, SWITZERLAND, 2024) Kepekçi, Haydar İzzettin; Ezgi, CüneytDay after day, stricter environmental regulations and rising operating costs and fuel prices are forcing the shipping industry to find more effective ways of designing and operating energyefficient ships. One of the ways to produce electricity efficiently is to create a waste heat-driven liquid metal–water binary vapor power plant. The liquid metal Rankine cycle systems could be considered topping cycles. Liquid metal binary cycles share characteristics like those of the steam Rankine power plants. They have the potential for high conversion efficiency, they will likely produce lower-cost power in plants of large capacity rather than small, and they will operate more efficiently at design capacity rather than at partial load. As a result, liquid metal topping cycles may find application primarily as base-load plants onboard ships. In this study, a waste heat-driven liquid metal–water binary vapor power plant onboard a ship is designed and thermodynamically analyzed. The waste heat onboard the vessel is the exhaust gas of the LM2500 marine gas turbine. Mercury and Cesium are selected as liquid metals in the topping cycle, while water is used in the bottoming cycle in binary power plants. Engineering Equation Solver (EES) software (V11.898) is used to perform analyses. For the turbine inlet temperature of 550 ◦C, while the total net work output of the binary cycle system is calculated to be 104.84 kJ/kg liquid metal and 1740.29 kJ/kg liquid metal for mercury and cesium, respectively, the efficiency of the binary cycle system is calculated to be 31.9% and 26.3% for mercury and cesium as liquid metal, respectively. This study shows that the binary cycle has a thermal efficiency of 26.32% and 31.91% for cesium and mercury, respectively, depending on liquid metal condensing pressure, and a binary cycle thermal efficiency of 25.9% and 30.9% for cesium and mercury, respectively, depending on liquid metal turbine inlet temperature, and these are possible with marine engine waste heat-driven liquid metal–water binary vapor cycles.Öğe Thermodynamic Analysis of Marine Diesel Engine Exhaust Heat-Driven Organic and Inorganic Rankine Cycle Onboard Ships(MDPI, ST ALBAN-ANLAGE 66, CH-4052 BASEL, SWITZERLAND, 2024) Ezgi, Cüneyt; Kepekçi, Haydar İzzettinDue to increasing emissions and global warming, in parallel with the increasing world population and energy needs, IMO has introduced severe rules for ships. Energy efficiency on ships can be achieved using the organic and inorganic Rankine cycle (RC) driven by exhaust heat from marine diesel engines. In this study, toluene, R600, isopentane, and n-hexane as dry fluids; R717 and R718 as wet fluids; and R123, R142b, R600a, R245fa, and R141b as isentropic fluids are selected as the working fluid because they are commonly used refrigerants, with favorable thermal properties, zero ODP, low GWP and are good contenders for this application. The cycle and exergy efficiencies, net power, and irreversibility of marine diesel engine exhaust-driven simple RC and RC with a recuperator are calculated. For dry fluids, the most efficient fluid at low turbine inlet temperatures is n-hexane at 39.75%, while at high turbine inlet temperatures, it is toluene at 41.20%. For isentropic fluids, the most efficient fluid at low turbine inlet temperatures is R123 with 23%, while at high turbine inlet temperatures it is R141b with 23%. As an inorganic fluid, R718 is one of the most suitable working fluids at high turbine inlet temperatures of 300 ◦C onboard ships with a safety group classification of A1, ODP of 0, and GWP100 of 0, with a cycle efficiency of 33%. This study contributes to significant improvements in fuel efficiency and reductions in greenhouse gas emissions, leading to more sustainable and cost-effective maritime operations.Öğe Thermodynamic Analysis of a Marine Diesel Engine Waste Heat-Assisted Cogeneration Power Plant Modified with Regeneration Onboard a Ship(MDPI, ST ALBAN-ANLAGE 66, CH-4052 BASEL, SWITZERLAND, 2024) İzzettin Kepekçi, Haydar; Ezgi, CüneytThe objective of this study is to perform a thermodynamic analysis on a marine diesel engine waste heat-assisted cogeneration power plant modified with regeneration onboard a ship. The proposed system utilizes the waste heat from the main engine jacket water and exhaust gases to generate electricity and heat, thereby reducing the fuel consumption and CO2 emissions. The methodology includes varying different turbine inlet pressures, extraction pressures, and fractions of steam extracted from the turbine to evaluate their effects on the efficiency, utilization factor, transformation energy equivalent factor, process heat rate, electrical power output, saved fuel flow rate, saved fuel cost, and reduced CO2 emissions. The analysis demonstrates that the proposed system can achieve an efficiency of 48.18% and utilization factor of 86.36%, savings of up to 57.325 kg/h in fuel, 65.606 USD/h in fuel costs, and 180.576 kg/h in CO2 emissions per unit mass flow rate through a steam turbine onboard a ship.Öğe Gd ve Y İlave Edilmiş AZ31 Magnezyum alaşımına Ekstrüzyon ve Çok Yönlü Dövme Prosesinin Etkisi(GAZI UNIV, CENTER CAMPUS TECHNOLOGY FAC B BLOCK EK BINA, 2ND FL, ANKARA 06500, Turkiye, 2025) Özdamar, Osman; Yetmez, Mehmet; Türen, Yunus; Kocaman, Engin; Özyiğit, Hamdi AlperBu çalışmada AZ31 Magnezyum alaşımına %0,5 ve %1 oranlarında Gadolinyum ile İtriyum Nadir Toprak Elementi kullanılarak yeni bir alaşım oluşturulmuştur. Oluşan bu alaşıma 375oC ekstrüzyon yapıldıktan sonra 400oC kapalı kalıpta çok yönlü dövme işlemi gerçekleştirilmiştir. Alaşım bileşenlerinin mikroyapıdaki değişime etkisi ve bunların mekanik özelliklere etkisi incelenmiştir. Çalışmada iri taneli bir yapıya sahip AZ31 döküm alaşımına ilave edilen nadir toprak elementleri ve uygulanan mekanik işlemlerin mikroyapıda etkili olduğu tespit edilmiştir. Alaşımına ilave edilen Gd ve Y’un mikroyapıda (Mg,Al)3Gd ve Mg24Y5 gibi intermetalik fazların oluşumunu teşvik ederken tane boyutunda önemli bir azalmaya neden olmuştur. Alaşıma kütlece %0.5 Gd ve %0.5Y Nadir Toprak Elementlerinin ilavesiyle elde edilen numunelerin sertlik, akma ve çekme mukavemetlerinin diğer döküm ve %1Gd ve %1Y ilavesiyle elde edilen değerlerden daha yüksek olduğu belirlenmiştir. Öte yandan döküm AZ31 alaşımına uygulanan mekanik işlemlerin tane boyutunu azalttığı ve mekanik özellikleri artırdığı tespit edilmiştir.Öğe Developing machine learning‑based ground motion models to predict peak ground velocity in Turkiye(SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS, 2024) Kuran, Fahrettin; Tanırcan, Gülüm; Pashaei, ElhamThis paper introduces machine learningbased Turkiye-specifc ground motion models for the geometric mean horizontal component of peak ground velocity (PGV). PGV is a signifcant intensity metric to measure and diagnose potential earthquake damage in structures. Reliable prediction of PGV is of essential importance in precise calculations of seismic hazard. The efciencies, reliabilities, and capabilities of various machine learning algorithms, including Random Forest, Support Vector Machine, Linear Regression, Artifcial Neural Network, Gradient Boosting, and Bayesian Ridge Regression, are evaluated and compared. The most recently compiled Turkish strong motion database, which consists of over 950 earthquakes occurring from 1983 to 2023, is used for shaping the models’ ability to learn and make accurate predictions. Three feature selection methodsLeast Absolute Shrinkage and Selection Operator, Recursive Feature Elimination, and Pearson’s Correlation- representing embedded, wrapper, and flter approaches, respectively, are applied to determine the most suitable estimator parameters to predict PGV. Residual analyses and statistical evaluation metrics are employed to measure the performance and efectiveness of the machine learning models. Among the algorithms applied, Gradient Boosting demonstrates exceptional success in predicting PGV, particularly when utilizing all estimator parameters (features) collectively. The Gradient Boosting model exhibits superior predictive capabilities compared to existing ground motion models. It is applicable to shallow crustal strike-slip and normal faulting earthquakes with moment magnitude ranging from 3.5 to 7.8 and Joyner and Boore distance up to 200 km.Öğe A systematic risk assessment approach for urban roadside infrastructure assets(TAYLOR & FRANCIS LTD, 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND, 2024) Yurdabal Apak, Mustafa; Ergün, Murat; Özen, Halit; Yumrutaş, Halil İbrahimRevealing potential risks and the influence of these risks on urban roadside vulnerable/risky zones has been a great deal for the last decades owing to increasing vehicular mobility. This study aimed to develop a risk assessment methodology for urban roadside infrastructure assets. In this context, seven risk parameters that are likely to affect hazardous aboveground assets installed on urban roadsides were determined, and weights of each parameter (order of importance) were presented based on expert surveys and literature information using the Analytic Hierarchy Process (AHP) method. Mathematical models were set up for each risk parameter using real field data, The American Association of State Highway and Transportation Officials (AASHTO), literature, related standards, and expert surveys by linear, nonlinear, and binary logistic regression analyses. Risk groups were created, and precautions were offered. The efficiency of the models was verified based on the 28 accident records and field observations in 172 assets. When considering the assets that undergo traffic accidents, 71% of the total assets are ranked in the critical and high-risk group. This ratio is consistent with the risk group definitions assigned in this study; thus, the model proposed is accurate and can be applied reliably. The verification process of the total risk model was sufficiently successful to be used in practice and can be generalized by considering the road and traffic characteristics, infrastructure facilities, and future requirements of the regions or countries that reflect similar historical and cultural concerns. Practitioners, governmental institutes, and researchers can apply this methodology to provide their own data with high transparency and reliability.Öğe The impact of mental health disorders and job demands on the individual job performance of construction workers(WILEY, 111 RIVER ST, HOBOKEN 07030-5774, NJ, 2024) Kazar, Gökhan; Rahmanzadeh, PouryaObjectives: Understanding the impact of job demands and mental health disorders on individual job performance is crucial to achieving a more productive workforce and should be empirically investigated. Therefore, the main purpose of this study was to assess the impact of job demands and mental health disorders on individual job performance among construction workers. In addition, we examined the interaction effect between job demands and some demographic characteristics (income, marital status, experience, and area of residence) on the job performance of construction workers in 2 dimensions. Methods: For this purpose, a new conceptual model and 3 different hypotheses were introduced. A survey was designed and administered to 513 construction workers. Whereas the measurement items regarding demographic characteristics, job demands, and mental health disorders were addressed to construction workers, the last part related to job performance of construction workers was conducted with site managers of the workers to obtain more objective results. A structural equation modeling approach was adopted to assess the validity of the model and to test the hypotheses. Results: The results of this study show that whereas job demands have a significant and high impact on individual job performance, the effect of mental health disorders on job performance is significant at a moderate level. In addition, the demographic characteristics of marital status and area of residence have a significant interaction effect on job performance when combined with job demands. Conclusion: Providing individualized support systems, resources, and opportunities for construction workers can help mitigate the negative effects of excessive demands and mental disorders on labor productivity.Öğe Sustainability performance of food supply chains with internal and external evaluation perspectives(OXFORD UNIV PRESS, GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND, 2024) Gürül, Binnur; Yılmaz, Dilek; Büyüksaatçı Kiriş, SinemThe challenges of food security, water use, energy consumption and the growing global demand for food raise the importance of ensuring sustainability of the food supply chains (FSCs). Studies in relevant literature discuss the sustainability performances of FSCs generally without distinguishing between the internal and external stakeholders’ concerns or clarifying the existence of greenwashing or bluewashing attempts, jeopardizing true sustainability. This is why modelling towards some holistic treatment of the problem that satisfies those concerns is required. This paper proposes a framework to evaluate the true sustainability performance of FSCs by considering triple bottom line indicators, i.e. economic, environmental and social. In light of the proposed framework, two models have been developed, one calculating the internal and the other an external sustainability score. The presented models can handle interval or ordinal qualitative and quantitative indicators concurrently while considering desirable and undesirable factors. These novel models have been implemented on data from 50 FSCs in Istanbul, using a two-stage imprecise data envelopment analysis with a special multiplier. To facilitate visualization of true sustainability assessment, an internal–external sustainability performance matrix is proposed. Results reveal that the internal sustainability performance of the focal FSCs is better than the external one. The economic dimension predominates in Turkish FSCs’ internal sustainability performance, while the environmental and social dimensions predominate in the external sustainability performance of the FSCs.Öğe Transient analysis of functionally graded axisymmetric plates via finite element method in the Laplace domain(TAYLOR & FRANCIS INC, 530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106, 2024) Doori, Silda Ghazi Mohammed; Noori, Ahmad ReshadThe principal goal of this research article is to examine the forced vibration of Functionally Graded Material (FGM) axisymmetric plates with the aid of the finite element method in the Laplace space. The material properties are assumed to be isotropic, linear viscoelastic, or elastic and vary continuously in the direction of the thickness of the plate. The governing equations of motion are transferred to the Laplace domain and solved for a set of Laplace parameters. Then, a modified Durbin’s inverse Laplace method is employed to retransfer the obtained results back to the time domain. A convergence analysis is conducted to optimize the number of Laplace parameters and time steps. An 8-node quadratic quadrilateral element featuring two degrees of freedom per node is employed to generate the model of the axisymmetric plates. Different loads such as step load, square wave, and sawtooth wave loads are used to observe the impact of load type on the transient response of FGM plates. In viscoelastic analysis, the Kelvin damping model is preferred, and the effect of the damping ratio is investigated. The obtained results are validated with the aid of the available literature and the accuracy of the suggested model is confirmed. It is carried out that the material variation significantly affects the dynamic behavior of the plates, for instance as the material coefficient increases, displacement amplitudes decrease, and periods increase. The novelty of this paper is the employment of the finite element method together with Laplace transformation for addressing the present class of problems for the first time.Öğe Efficient Roof Selection in Rainwater Harvesting: Hybrid Multi-criteria and Experimental Approach(SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS, 2024) Hamidi, Muhammed Nimet; Shitreh, Shayan; Cengiz, Ali Izzet; Özçelik, Kadir; Eryıldız Yesir, Bahriye; Ekmekcioğlu, Ömer; Halat, Oğuzhan Murat; Demirel, Mehmet Cuneyd; Canberk, Berk; Koyuncu, İsmail; Işık, Onur; Güven, Hüseyin; Özgün, Hale; Erşahin, Mustafa EvrenThis study aimed to investigate the effects of different roof configurations on the quality of harvested rainwater (HRW) for sustainable irrigation in agriculture. Three roofing materials (i.e. shingle, galvanized metal, and clay tile) and three roof pitch angles (i.e. 5°, 30°, and 42°) were used at pilot-scale. HRW was characterized in order to determine the roof type and roof slope effect on the HRW quality. HRW from galvanized metal roofs was of higher quality in terms of turbidity and pathogen microorganisms. HRW from shingle and clay tile roofs was treated with a sequential ultrafiltration (UF) membrane and ultraviolet (UV) disinfection system to meet the European Union (EU) water reuse standards for irrigation. The decision-making mechanism was used to select the most appropriate roof configuration. The results showed the significance of financial (21.89%) and environmental (19.75%) aspects. Also, the Escherichia coli (E.coli) content (7%) is the most determinant factor in HRW, followed by the operational cost (6.78%), and reduced runoff (5.73%). Among the roof configurations, galvanized metal roofs, specifically the metal roof with 5°, outperformed others due to their structural, technical, and environmental advances.
