Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8651
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Article Citation - WoS: 7Citation - Scopus: 8Adaptive Modeling of Landslide Susceptibility Using Analytical Hierarchy Process and Multi-Objective Decision Optimization(Elsevier Sci Ltd, 2025) Mao, Yimin; Zhu, Licai; Chen, Junde; Nanehkaran, Yaser A.This study develops a detailed landslide susceptibility map for Kermanshah province, Iran, by analyzing field surveys, historical data, and remote sensing. Fifteen key factors-such as geomorphology, geology, climate, seismicity, and human activities-were identified and ranked using Analytical Hierarchy Process (AHP) and Multi-Objective Decision Optimization (MODO) within a GIS framework. The analysis classifies landslide risk into five categories: very high (18.4%), high (33.98%), moderate (24.19%), low (14.36%), and very low (9.07%). Pixel rate assessment confirmed the map's accuracy, showing that eastern and northeastern regions are particularly prone to landslides, with a substantial portion of the province at moderate to high risk. The study recommends using this map to guide targeted risk mitigation and land-use planning efforts to reduce landslide impacts on vulnerable areas. (c) 2024 COSPAR. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.Article Citation - WoS: 6Citation - Scopus: 7The Hydraulic Investigation of Harmonic Plan Weirs(Elsevier Sci Ltd, 2024) Yildiz, Ali; Marti, Ali Ihsan; Gogus, MustafaExisting dams and reservoirs need to be revised to meet safety standards. For the existing reservoirs where flood control is important and the maximum water level is limited, the best method to increase reservoir capacity is to build a labyrinth weir on the dam. In labyrinth weirs, the collision of two nappe flows produces nappe inter-ference, and this reduces the weir performance. In this study, the semi-circle weirs are placed in an open channel harmonically to increase the efficiency of the labyrinth weirs to make the areas more efficient and increase the flow capacity because of the nappe interference and to ensure the flow moving perpendicular to the weir as possible. In the experimental study of the asymmetrically placed circular weirs, 3 different weir heights (P = 20 cm, 30 cm and 40 cm) and 3 different labyrinth cycle numbers (N = 2, N = 3 and N = 4) were used. As a result of the experiments, although there was a 13 % decrease in the discharge coefficients (Cd) compared to the linear weirs, it provided a 57 % increase in the net crest length (Lnet). Discharge coefficient (Cd) is decreased 3.4 %, as the number of cycles (N) increases. As the weir height (P) decreases, Cd increases 7.5 % due to the vacuum effect.Article Citation - WoS: 13Citation - Scopus: 14A Novel Cfd-Ann Approach for Plunger Valve Optimization: Cost-Effective Performance Enhancement(Elsevier Sci Ltd, 2024) Kaak, Abdul Rahman Sabra; Celebiog, Kutay; Bozkus, Zafer; Ulucak, Oguzhan; Ayli, Ece; Çelebioğlu, KutayThis paper introduces a novel computational fluid dynamics-artificial neural network (CFD-ANN) approach that has been devised to enhance the efficiency of plunger valves. The primary emphasis of this research is to achieve an optimal equilibrium between hydraulic flow and geometric configuration. This study is a novel contribution to the field as it explores the flow dynamics of plunger valves using Computational Fluid Dynamics (CFD) and proposes a unique methodology by incorporating Machine Learning (ML) for performance forecasting. An artificial neural network (ANN) architecture was developed using a thorough comprehension of flow physics and the impact of geometric parameters acquired through computational fluid dynamics (CFD). Using optimization, the primary aspects of the Artificial Neural Network (ANN), including the learning algorithm and the number of hidden layers, have been modified. This refinement has resulted in the development of an architecture exhibiting a remarkably high R2 value of 0.987. This architectural design was employed to optimize the plunger valve. By utilizing Artificial Neural Networks (ANN), a comprehensive analysis comprising 1000 distinct configurations was effectively performed, resulting in a significant reduction in time expenditure compared to relying on Computational Fluid Dynamics (CFD). The result was a refined arrangement that achieved maximum head loss, subsequently verified using computational fluid dynamics (CFD) simulations, resulting in a minimal discrepancy of 2.66%. The efficacy of artificial neural networks (ANN) becomes apparent due to their notable cost-efficiency, along with their capacity to produce outcomes that are arduous and expensive to get through conventional optimization research utilizing computational fluid dynamics (CFD).Article Citation - WoS: 4Citation - Scopus: 5Accurate Method To Calculate Noise Figure in a Low Noise Amplifier: Quantum Theory Analysis(Elsevier Sci Ltd, 2022) Salmanogli, Ahmad; Gecim, H. SelcukIn this study, a low-noise amplifier is quantum-mechanically analyzed to study the behavior of the noise figure. The analysis view has been changed from classic to quantum, because using quantum theory produces some degrees of freedom, which may be ignored when a circuit is analyzed using classical theory. For this purpose, the Lagrangian is initially derived by considering the related nonlinearity of the transistor, and then using the Legendre transformation and canonical quantization procedure, the quantum Hamiltonian is derived. As an interesting point of this study, the low-noise amplifier is deliberately considered as two oscillators connecting to each other to share the photonic modes between them; accordingly, the voltage and current as measurable observations and the noise figure as a critical quantity in a low-noise amplifier are theoretically expressed in terms of the oscillator's mean photon number. The main goal of this work is to study quantities such as the noise figure in a sufficient detail using quantum theory. In addition, as an advantage of this theory, one can control and manipulate the noise figure only by manipulation of the oscillator's mean photon number and coupling it between two oscillators. Finally, the circuit is classically designed and simulated to verify the derived results using quantum theory. The comparison results show that there is a partial consistency between the two approaches; as the frequency increases, the noise figure becomes minimized at a particular frequency.Article Citation - WoS: 13Citation - Scopus: 15Psychometric Adaption of the Impulsive Driver Behavior Scale in a Chinese Sample(Elsevier Sci Ltd, 2020) Qu, Weina; Zhou, Mu; Ozkan, Turker; Bicaksiz, Pinar; Zhang, Kan; Ge, YanImpulsivity plays an important role in aberrant driving behavior and crash involvement. The purpose of this study was to evaluate the reliability and validity of the Impulsive Driver Behavior Scale (IDBS, Bicaksiz & Ozkan, 2016a) with a Chinese sample. Two hundred and ninety-nine drivers completed the Chinese version of the Impulsive Driver Behavior Scale, the Driver Behavior Questionnaire, the Big Five Inventory and some social-demographic and traffic violation items. A confirmatory factor analysis indicated that a four-factor solution with 20 items yielded a better fit to the data than other solutions. The reduced IDBS showed good reliability and a stable structure. Drivers' functional impulsivity was positively correlated with positive driver behavior and some ordinary violations. Meanwhile, the other three dimensions of dysfunctional impulsivity showed negative correlations with positive driver behavior and positive associations with aberrant driving behavior and penalty points and fines. Impulsive driver behavior is also associated with agreeableness and conscientiousness. These results provide evidence supporting the IDBS as a reliable and valuable instrument for measuring driving impulsivity in the Chinese traffic environment. (C) 2019 Elsevier Ltd. All rights reserved.Article Citation - WoS: 3Citation - Scopus: 3Numerical and Experimental Modelling of Flow at Tyrolean Weirs(Elsevier Sci Ltd, 2021) Yildiz, Ali; Marti, Ali Ihsan; Gogus, MustafaIn this study, a small-scaled Tyrolean weir model was constructed in the laboratory environment and a series of experiments were conducted on it, for two different rack inclinations (theta(1) = 18 degrees and theta(2) = 25 degrees) and three different bar spacings (e(1) = 3 mm, e(2) = 6 mm and e(3) = 10 mm) for a range of upstream flow discharges. The flow rates passing through the racks and going downstream over the racks were measured. Empirical equations for the discharge coefficient and water capture capacity of the Tyrolean weirs were determined by applying dimensional analysis to the parameters involved in the phenomenon. The related dimensionless parameters were presented with graphs and empirical equations for discharge coefficients were derived, coefficient of determination R-2 of equations for theta(1) = 18 degrees and theta(2) = 25 degrees are found 0.838 and 0.825 respectively. According to results obtained from experimental data, C-d increases as the Froude number ((F-r)(e)) between bars increases and water capture capacity [(q(w))(i)/(q(w))(T)] of the racks decreases with increasing ((F-r)(e)). Also, a numerical model of the Tyrolean weir was generated by using Flow-3D software and it was shown that the results of the numerical analysis were very consistent with the physical model results at large bar spacing such as e = 10 mm. As the bar spacing (e) reduces, the success of the numerical model giving consistent results with physical model is decreasing.Article Citation - WoS: 205Citation - Scopus: 231Ammonia Removal From Anaerobically Digested Dairy Manure by Struvite Precipitation(Elsevier Sci Ltd, 2005) Uludag-Demirer, S; Demirer, GN; Chen, SAmmonia is one of the most important contaminants impairing the quality of water resources. When this is considered along with the fact that the global demand for nitrogenous fertilizers is in constant rise, the need for recovery as well as removal of nitrogen is well justified. Crystallization of N and P in the form of struvite (MgNH4PO4 center dot 6H(2)O), which is a slow releasing and valuable fertilizer, is one possible technique for this purpose. This study investigated the removal of NR4+ through struvite precipitation from the effluents of one- (R1) and two-phase (R2) anaerobic reactors digesting dairy manure. To force the formation of struvite in the anaerobic reactor effluents, Ma(2+) ion was added by using both Mg(OH)(2) and MgCl2 center dot 6H(2)O. To prevent the effect of different total phosphorus (TP) concentration in the effluents of RI and R2, as well as to not limit the formation of struvite, an excess amount Of PO43- (0.14 M) was added in the form of NaHPO4. Different stoichiometric Mg2+:NH4+:PO43- ratios were tested to determine the required Mg2+ concentrations for maximum NH4+ removal by keeping NH4+:PO43- ratio constant for the effluents of reactors RI and R2. The results revealed that very high NH4+ removal efficiencies (above 95%) were possible by adding Mg 21 ions higher than 0.06 M concentration in the effluents from reactors RI and R2. It was also observed that the initial pH adjustment to 8.50 using NaOH did not result in any significant increase in the removal of NH4+ and the removal of NH4+ in the reactors treated with MgCl2 center dot 6H(2)O was higher than those treated with Mg(OH)(2) for the same Mg2+ concentration. (c) 2005 Published by Elsevier Ltd.Article Citation - WoS: 9Citation - Scopus: 12Implicit Evaluations About Driving Skills Predicting Driving Performance(Elsevier Sci Ltd, 2018) Harma, Mehmet; Dogruyol, Burak; Lajunen, Timo; Ozkan, Turker; Bicaksiz, PinarSelf-reported measures of driving skills have the potential shortcomings of the general self report methodology such as social responding and self-enhancement biases. In the present study, the Implicit Association Test (IAT) procedure was adapted to measure the implicit evaluations of driving skills. The performance of IAT and an explicit, self-report measure of driving skills were compared in predicting driver behaviors and performance. Ninetyone Turkish male drivers participated in the study. The results showed that the implicit test and the self-reported driving skills scale showed different patterns of relationships with the outcome measures in the regression analyses. In addition, the implicit measure of driving skills moderated the relationship between self-reported driving skills and some of the outcome measures used in the current study. These results support the need to use the implicit measures in addition to self-report measures to better understand drivers evaluations of their driving skills, which has the potential to influence their risky driving. (C) 2018 Elsevier Ltd. All rights reserved.Article Citation - WoS: 10Citation - Scopus: 12Impact of Information Bandwidth of In-Vehicle Technologies on Drivers' Attention Maintenance Performance: a Driving Simulator Study(Elsevier Sci Ltd, 2018) Bicaksiz, Pinar; Unverricht, James; Samuel, Siby; Yamani, YusukePrevious research indicates that inexperienced drivers' ability to maintain their attention on the forward roadway during driving is poorer than experienced drivers, leading to more frequent, excessively long, off-road glances that elevate the risk of crashes. However, whether their poorer attention maintenance ability depends on complexities of in vehicle technologies has been underexplored. This study directly manipulated information bandwidth (easy or complex) of an in-vehicle monitor and asked twenty-four drivers aged 18-21 to perform a visual number judgment task with either 5 digits (easy) or 11 digits (complex), during simulated driving. Participants had to verbally respond within 15 s whether each string of presented digits contained more odd or even digits. Eye movements were recorded using an eye tracker. Results show that the drivers produced a greater number of off-road glances and longer summed excess glance durations under a 1.5-s threshold when the in-vehicle task imposed greater information processing demand. In practice, designers of in-vehicle technologies should consider information-processing demands of in-vehicle tasks required by the technologies to minimize the frequency of excessively long off-road glances during driving. (C) 2018 Elsevier Ltd. All rights reserved.Article Citation - WoS: 14Citation - Scopus: 16The Differential Associations of Functional and Dysfunctional Impulsivity With Driving Style: a Simulator Study(Elsevier Sci Ltd, 2019) Ozturk, Ibrahim; Ozkan, Ttirker; Bicaksiz, PinarThe present study investigated the impulsivity and driving style link by measuring driver behaviors on the driving simulator. Previous studies examining this relationship mostly used self-report instruments to measure both impulsivity and driving related outcomes, therefore this study aims to test this association by using a relatively more objective measurement tool than self-report. Moreover, the associations of functional impulsivity dimension with driving style has been investigated, in addition to the dysfunctional impulsivity dimension, which has been predominantly studied in the literature. Finally, both general and driving context specific functional and dysfunctional impulsivity dimensions were included in the analyses of the current study. Eighty (40 women) young drivers (19-25) participated in the present simulator study, and functional and dysfunctional impulsivity dimensions yielded different patterns of associations with driver behavior measures on the simulator. For instance, functional impulsivity yielded significant associations with standard deviation of lateral lane position, while dysfunctional impulsivity was significantly associated with mean velocity. Eye-movements of the participants while driving on the simulator were also recorded and examined as an explorative effort. The findings are discussed with regard to previous research. (C) 2019 Elsevier Ltd. All rights reserved.