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Koleksiyondaki öğeler
- MakaleYalnız künye2024Scopus SJRQ2Understanding the concept of energy through definitions, drawings, and metaphors
Başkan Takaoğlu, Zeynep
Energy is a concept frequently encountered both in daily life and in various disciplines. Despite such a wide range of scope, conceptualizing it might be challenging at times. This study aims to investigate high school students’ views on the concept of energy through a set of various paper-and-pencil tests. For this purpose, 654 high school students from the ninth, 10th, and 11th grades were asked to explain the concept of energy using definitions, drawings, and metaphors. According to the results, the students had similar misconceptions about their definitions, drawings, and metaphors. However, situations from everyday life were depicted, particularly in drawings and metaphors. Misconceptions decreased considerably in the upper classes, and answers were presented that were close to scientific knowledge, suggesting that, over time, students’ abstract thinking skills improve, the knowledge gained at school contributes to explaining the situations in daily life scientifically, and scientific facts are conceptualized.
AtıfScopus4WoS1OpenAlex3
İncele - MakaleAçık Erişim2023Scopus SJRQ1On the solutions of fractional random ordinary differential equations with the Residual power series method
Merdan, Mehmet; Atasoy, Nihal
In this study, random ordinary differential equations obtained by randomly choosing the coefficients or initial conditions of the ordinary differential equations will be analyzed by the Residual Power Series Method. The initial conditions or coefficients of the equations will be converted to random variables with Normal, Gamma and exponential distribution. Probability characteristics such as expected value, variance and confidence interval of the obtained random ordinary differential equations will be calculated. Obtained results will be drawn with the help of MATLAB (2013a) package program and random results will be interpreted.
AtıfScopus3WoS2İncele - MakaleAçık Erişim2022Scopus SJRQ3Three remarkable Bryophyte species new to Turkey and South–west Asia
Erata, Hüseyin
Turkey, which is surrounded by seas on three sides and consists of three phytogeographic regions, has a very large biological diversity. As a result of extensive bryophyte surveys across the different parts of the Dereli district in Giresun province from Turkey, Dicranum transsylvanicum, Nardia geoscyphus, and Andreaea crassinervia are reported as a new record for Turkey and Southwest Asia. Also, Dicranum transsylvanicum is new to Asia. Descriptions, illustrations, geographic distribution, ecological characteristics, and comparisons with morphologically similar taxa are provided.
AtıfScopus2WoS2OpenAlex10İncele - MakaleAçık Erişim2023The Numerical Solutions of the Conformable Time-Fractional Noyes Field Model via a New Hybrid Method
Öner, Bedir Kaan; Anaç, Halil
This article employs a novel method, namely the conformable q-Sawi homotopy analysis transform method (Cq-SHATM) to investigate the numerical solutions of the nonlinear conformable time-fractional Noyes-Field model. The proposed method, namely Cq-SHATM, is a hybrid approach that integrates the q-homotopy analysis transform method and the Sawi transform using the concept of conformable derivative. 3D graps of the solutions obtained with this method were drawn. Additionally, 2D graphs of the solutions were obtained in the Maple software program. The computer simulations were conducted in order to validate the efficacy and reliability of the proposed method.
AtıfOpenAlex1İncele - MakaleYalnız künye2025Scopus SJRQ1Performance assessment of solar-powered electric vehicles: Importance of maximum power point tracking, range enhancement and charging frequency analysis under various operating and irradiance conditions
Başoğlu, Mustafa Engin
Decarbonizing the transportation sector is becoming a crucial focus in the 21st century. As the popularity of internal combustion engine vehicles declines, the adoption of hybrid and electric vehicles (EVs) is significantly increasing. One of the main challenges for battery-powered vehicles, aside from safety concerns, is the limited driving range and frequent charging requirements. Integrating a photovoltaic (PV) module onto a vehicle's surface enables continuous battery charging during both motion and stationary periods, thereby extending the vehicle's range on a full charge. This study presents two main contributions: a modified 0.8VOC-based maximum power point tracking (MPPT) method for fast-changing irradiance conditions for flat-roof vehicle-integrated PV (VIPV) systems, and a long-term simulation analysis of classical MPPT methods using two new indicators for range extension and vehicle charging frequency variations under different irradiance profiles. The proposed MPPT method yielded superior energy performance, achieving 16–25 % higher energy generation compared to both the incremental conductance (IC) algorithm and the variable step-sized (VSS) perturb and observe (P&O) method. Long-term simulations conducted for three EV models demonstrated a daily driving range extension of 2–7 km with an 185W PV module, along with up to a 19 % reduction in charging frequency, depending on the battery capacity and vehicle models.
AtıfScopus4WoS4OpenAlex4İncele - Kitap BölümüAçık Erişim2024Optimizing customer service with chatbots
Şimşek, Ahmet Bahadir
This chapter explores the intricate domain of enhancing customer service through strategically employing chatbots. It thoroughly investigates diverse optimization techniques, underscoring the vital role of refining chatbot responses and implementing efficiency metrics. The chapter dissects the challenges inherent in chatbot optimization, presenting innovative solutions that highlight the interconnected nature of these challenges. It illuminates the profound impact of well-optimized chatbots on customer service, demonstrating their capability to streamline tasks, improve accessibility, handle routine inquiries, and foster customer loyalty. Looking ahead, the chapter offers insights into upcoming trends and opportunities, such as integrating emotional intelligence and expanding multilingual functionalities. Essentially, this chapter functions as a comprehensive guide for practitioners and researchers, providing a nuanced comprehension of the pivotal role chatbots play in shaping the future landscape of customer service.
AtıfScopus1OpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ1The effect of Augmented Reality (AR) supported geometric shape learning on children’s visual perceptual development in early childhood education
Özel, Özge; Hançer, Buse; Sop, Aylin
This study examined the impact of an Augmented Reality (AR)-based virtual application on preschool children's visual perception development in geometric shape learning. A quasi-experimental research design was employed. The study sample consisted of 26 preschool children, aged 5–6, from a public school in Türkiye. The children in the experimental group engaged with AR-supported materials, allowing them to explore geometric shapes interactively and listen to their properties in a virtual environment. Each child participated individually in the learning application for 50–60 minutes. The Frostig Visual Perception Test was administered as both a pre-test and post-test. Results indicated that the AR-based learning application had a statistically significant positive effect on preschool children's visual perception development.
AtıfScopus2WoS4OpenAlex4İncele - MakaleYalnız künye2024Scopus SJRQ3RULED SURFACES GENERATED BY SALKOWSKI CURVE AND ITS FRENET VECTORS IN EUCLIDEAN 3-SPACE
Çakıl, Ebru; Mazlum, Sümeyye Gür
In present study, we introduce ruled surfaces whose base curve is the Salkowski curve in Euclidean 3-space and whose generating lines consist of the Frenet vectors of this curve (tangent, principal normal and binormal vectors). Then, we produce regular surfaces from a vector with real coefficients, which is a linear com-bination of these vectors, and we examine some special cases for these surfaces. Moreover, we present some geometric properties and graphics of all these surfaces.
AtıfScopus1WoS1İncele - MakaleAçık Erişim2024Scopus SJRQ1Metaverse in tourism education: A mixed method on vision, challenges and extended technology acceptance model
Akyürek, Suat; Genç, Gökhan; Çalık, İsmail; Şengel, Ümit
The metaverse, an emerging educational frontier, presents boundless opportunities and distinct challenges for educators and students alike. This study delves into these aspects within the context of tourism education, employing a mixed-methods approach. It integrates in-depth interviews with 13 tourism academics and a quantitative survey of 268 tourism students. The qualitative data are meticulously coded, and the quantitative data are analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM). This research not only conceptually outlines the future benefits of the metaverse, such as enhanced interactive learning and global classroom experiences but also empirically examines its impact on tourism students' engagement and learning outcomes. Key findings highlight both the empowering potential and the infrastructural and accessibility challenges posed by metaverse technology in tourism education. Ultimately, this study provides a holistic view of metaverse-based education's role in advancing the tourism industry, suggesting practical implications for technological adaptation and pedagogical strategies.
AtıfScopus28WoS22OpenAlex29İncele - MakaleAçık Erişim2025Scopus SJRQ2Investigation of the Effects of Filling Speed, Casting Temperature and Metallurgical Quality on Fluidity of Lamellar Graphite Cast Iron at Different Section Thicknesses
Köse, Sami; Çolak, Murat; Şüküroğlu, Ebru Emine
In this study, the fluidity properties of the alloy were investigated at different casting temperatures, different section thicknesses, and varying casting parameters of lamellar graphite cast iron materials. To achieve our goal, we utilized sand molds that were created with specific parameters including pouring temperature, metallurgical quality, section thickness, and fluidity test model. These molds were used for casting. Thus, the effect of fluidity properties in changing casting conditions and liquid metal advance distances at determined section thicknesses was investigated. Modeling was carried out with FlowCast casting simulation software by determining the liquid metal advance distance depending on the section thickness in the castings made in sand molds under changing casting conditions. The fluidity and advance distance of the liquid metal was determined comparatively with experimental and modeling techniques under the changing casting conditions in the parameters determined in this study. When the outcomes were examined; it was observed that different liquid metal advance distances occur at different cross-section thicknesses depending on the changing conditions.
AtıfScopus8WoS8OpenAlex7İncele - MakaleAçık Erişim2025Scopus SJRQ2Optimal Ratio of Steel and Polyester Fibers on the Mechanical Behavior of Alkali-Activated Concrete Produced by Industrial Waste Minerals
Aksüt, Yavuz Selim; Çullu, Mustafa; Yetgin, Şükrü
Alkali Activation Concretes (AAC) have many superior properties compared to Ordinary Portland Cement Concrete (OPC). However, it shows traditional concrete behavior with its brittleness. In this case, the tensile strength and flexural strength which are weak in addition to ductility is being studied to be increased by using various artificial and natural fibers. In this context, it is inevitable to conduct multifaceted research to improve the behavior of Fiber Alkali Activated Concrete (FAAC). In this study, 13 different mixes were made using steel and polyester fibers in different proportions by volume (0%; 0.25%; 0.50%; 0.75%; 1%) separately and hybrid. The mechanical properties of cubic (150 × 150 × 150 mm), cylindirical (100 × 200 mm) and prismatic (150 × 150 × 600 mm) specimens were determined including compressive strength, modulus of elasticity and poison ratio, splitting tensile strength and flexural strength (toughness-energy absorption capacity and modulus of rupture). crack formation in concrete occurs early and a significant decrease in strength is observed due to the high flexibility and low flow resistance of polyester fibers. Steel fibers with high strength and higher yield strength were used in hybrid form to solve this problem. It was revealed that the blend ratio that contributed the most to the mechanical behavior of the specimens was the case where the fibers were used as hybrid at a ratio of 1% by volume evaluation from both the experimental results and the optimization.
AtıfScopus4OpenAlex6İncele - MakaleAçık Erişim2025Scopus SJRQ4The effect of perceived scarcity of staple goods on stockpiling behaviour and impulse purchase intention and the mediating role of social media
Avci, Ibrahim
The research’s goal in this setting is to uncover the effects of consumers’ perceived scarcity of staple goods on impulse buy intention and stockpiling behaviour, as well as to determine the function of social media posts in mediating these effects. 594 consumers who had recently purchased staple goods from grocery stores participated in the survey. As a result of the structural equation model analysis, it was determined that perceived scarcity of staple goods has a positive effect on impulse purchase intention, stockpiling behaviour and social media. Finally, it was also determined that social media sharing has a mediating role on the effect of perceived scarcity of staple goods on impulse purchase intention and stockpiling behaviour. The findings obtained provide important theoretical and practical contributions.
AtıfScopus2OpenAlex3İncele - Editöre MektupYayıncıda açık erişim2024Scopus SJRQ2The Great Destruction - Turkey in the Earthquake of the Century: A Health Sector Perspective
Ulutaşdemir, Nilgün; Kulakaç, Nurşen
- MakaleAçık Erişim2025Scopus SJRQ1Zircon U-Pb geochronology and Sr-Nd-Pb-Hf-O isotope signatures of Middle Eocene high-K plutons from the Eastern Pontides Orogenic Belt, NE Turkey: implications for parental magma sources and magmatic processes
Kaygusuz, Abdullah; Güloğlu, Zikrullah Samet; Aydınçakır, Emre; Yücel, Cem; Vural, Alaaddin; Saydam Eker, Çiğdem; Cicerali, Derya
The Eastern Pontides Orogenic Belt (EPOB) in northeastern Turkey is a well-preserved continental magmatic arc in the Alpine-Himalayan Orogenic Belt and contains many Eocene I-type high-K plutons. Employing LA-ICP-MS U-Pb zircon geochronology, the crystallization ages of the investigated Yaylalıköy and Taşbaşı plutons were established to be Lutetian (Middle Eocene), ranging from 47 Ma to 46 Ma. These plutons exhibit a compositional spectrum ranging from diorite to granodiorite, characterized by I-type, metaluminous, and high-K geochemical signatures. Notably, they are enriched in large-ion lithophile elements (LILEs) and light rare earth elements (LREEs), displaying pronounced negative Eu anomalies (EuN/Eu* = 0.58–0.96). Isotopic signatures reveal homogeneous and moderately low initial 87 Sr/86 Sr(i) ratios (0.704643–0.705034) and positive εNd(i) values (0.24 to 1.67) for the investigated plutons. These isotopic signatures are consistent with mantle origin, as evidenced by their position within the mantle array on isotope ratio diagrams. Lead isotope compositions exhibit limited variations, with initial ratios of 206 Pb/204 Pb(i) (18.55–18.64), 207 Pb/204 Pb(i) (15.61–15.64), and 208 Pb/204 Pb(i) (38.46–38.75). Zircon εHf(i) values are positive (2.32–6.20), plotting between the depleted mantle and chondritic evolution lines. Additionally, these rocks display low zircon δ18 O values (+4.54 to + 6.53‰), comparable to mantle composition. The petrographic characteristics of the investigated plutons suggest that fractional crystallization with minimal assimilation and/or magma mixing played a dominant role during their solidification. The integration of geochemical and isotopic data, alongside regional geological constraints, advocates for enriched lithospheric mantle as the source for the parental magmas of the studied plutons. These magmas subsequently underwent differentiation within a deep-seated magma chamber, followed by emplacement into the crust.
AtıfScopus5WoS6OpenAlex6İncele - MakaleAçık Erişim2025Scopus SJRQ1Paleolatitudinal movements of the eastern Sakarya Zone from Jurassic to Eocene
Kayın, Sercan; Hisarlı, Z. Mümtaz; İşseven, Turgay; Dokuz, Abdurrahman; Algur, Bahadırhan Sefa
The study area covers a region oriented north-south from the Black Sea coastline in the north to the Kelkit Basin in the south within the eastern Sakarya Zone in northern Türkiye. The objective of this study is to investigate the paleolatitudinal movements of the eastern Sakarya Zone during the Jurassic-Eocene time interval through paleomagnetism. Various volcanic and sedimentary units (e.g., the Şenköy, Berdiga, Mescitli, Çatak, Kızılkaya, and Çağlayan Formations) spanning the time interval from the Early Jurassic to Middle Eocene were identified. A total of 98 locations belonging to Early/Middle Jurassic to Eocene volcanic and sedimentary units were selected for paleomagnetic core sample collection. The samples were subjected to demagnetization through thermal and alternating field methods. Characteristic remanent magnetization directions (ChRM) were obtained. Isothermal remanent magnetization (IRM) and high temperature susceptibility (HTS) measurements were made to identify the minerals responsible for magnetization. To ascertain whether magnetization was acquired through rock formation or as a consequence of subsequent tectonic processes, conglomerate and fold tests were performed. The results showed that magnetization was acquired before folding, i.e., the rocks have primary magnetization. Polarity tests were also conducted using coeval normal and reverse polarity sites. The results indicate that the mean magnetization direction for the Early-Middle Jurassic is 18.1°/55.2° (D/I) and 3.3°/51.5° (D/I) for sedimentary and volcanic rocks, respectively, and 348.7°/46.7° (D/I) for Late Jurassic/Early Cretaceous sedimentary rocks. In the Late Cretaceous period, the mean magnetization direction is 8.0°/49.3° (D/I) and 9.1°/47.0° (D/I) for sedimentary and volcanic rocks, respectively. In the case of the Early/Middle Eocene, the mean magnetization direction is 348.6°/52.7° (D/I) and 5.9°/48.8° (D/I) for sedimentary and volcanic rocks, respectively. In this study, the E/I correction was applied to the Late Jurassic/Early Cretaceous sedimentary rocks, and paleolatitude data obtained from sedimentary rocks were also utilized. Our paleomagnetic results indicate that the eastern Sakarya Zone was situated at latitudes spanning from 27.9° to 35.7° during the Early Jurassic - Middle Eocene time interval. In consequence, the eastern Sakarya Zone constituted a portion of the southern margin of the Eurasian continent during the Late Jurassic and Middle Eocene periods.
- MakaleAçık Erişim2025Scopus SJRQ1The impact of photovoltaic panels on the environment and yield parameters in an open field agrivoltaic system: A case study in Ayaş, Ankara
Senturk, Bilge; Oylek, Yelda; Kanar, Zeynep Sevim; Celik, Ridvan; Kurtulus, Gunes; Ozden, Talat
Agrivoltaic systems represent an innovative approach that integrates energy production and agriculture by installing elevated photovoltaic modules over farmland. In this study, the critical parameters on microclimate and microenvironment conditions — soil moisture and temperature, relative humidity, ambient temperature, photosynthetically active radiation, wind speed — and crop yield amount were monitored and analyzed in a single axis tracking AgriPV system installed in Ankara, Türkiye. Results indicate that under the 35 % coverage AgriPV system, photosynthetically active radiation decreased by 38.55 %. Additionally, soil moisture was found to be higher at 20 cm below under the AgriPV system compared to the reference field during the plant growth period. The yield data showed a considerable difference in crop amount under the AgriPV system across different harvest periods. The results are critically important for developing models in future phases that aim to predict and optimize the agricultural and ecosystem performance of AgriPV systems.
AtıfScopus16WoS14OpenAlex12İncele - MakaleYayıncıda açık erişim2025Scopus SJRQ1Attitude synchronization of chaotic satellites with unknown dynamics using a neural network based fixed time sliding mode controller
Bingöl, Özhan
This study investigates the synchronization and anti-synchronization of both identical and non-identical chaotic satellite systems. A fixed-time sliding mode control framework, based on a radial basis function (RBF) neural network, has been developed to synchronize the chaotic dynamics of master–slave satellite configurations. The proposed control scheme operates under the assumption that the dynamics of the satellites are not entirely known. The proposed control method guarantees that system errors will converge to negligible levels within a fixed time. Furthermore, the controller exhibits robustness in the presence of parametric uncertainties and external disturbances. The stability of the controlled systems is rigorously validated through Lyapunov analysis, and the controller's effectiveness is confirmed through extensive simulation studies. These simulations are conducted on both identical and non-identical satellite models, with performance comparisons made against recent findings reported in the literature.
AtıfScopus9WoS9OpenAlex9İncele - MakaleAçık Erişim2024Scopus SJRQ1Geophysical and numerical approaches to solving the mechanisms of landslides triggered by earthquakes: A case study of Kahramanmaraş (6 February, 2023)
Sari, Mahmut
Many landslides occurred in the 11 Turkish provinces affected by the earthquakes centered in Kahramanmaraş in February 2023, and many people lost their lives due to those landslides. To reduce the risks and hazards brought on by landslides induced by earthquakes, it is essential to identify the mechanisms causing landslides to arise in such situations. In this study, the geological strength index and both seismic refraction tomography and electrical resistivity tomography (ERT) geophysical methods were used to determine the failure mechanism of layered sedimentary units defined as flysch (claystone-siltstone-sandstone-marl). The shear strength reduction finite element method (SSR-FEM) was used with the RS2 computer program for model solutions. One of the geophysical methods, ERT, facilitated an interpretation of the cyclic failure mechanism that occurs in flysch, and it was found to be congruent with numerical models. Landslide slip circle depth, water-saturated layers, and resistivity values were determined with the ERT method. Seismic methods were employed to determine the velocity values (Vp, Vs) of the landslip mass. These velocity data, along with the elasticity modulus and Poisson ratios derived from them, were utilized in our numerical model. In the maximum shear strength and horizontal displacement analyses performed on the section line determined before the landslide, the natural state and the situation under the influence of groundwater were examined and the strength reduction factor (SRF) was determined as 1.35 and 1.24, respectively. In an evaluation conducted under the influence of the maximum horizontal ground acceleration (0.22 g) determined by taking into account the seismicity of the study area, it was concluded that instability occurred in the flysches and the SRF value was 0.72. An important finding of this study is that the results of geophysical methods used to determine the lithological properties of sedimentary rock masses and understand the causes of landslides align closely with those of numerical analysis methods, providing high accuracy. These methods also support new approaches, particularly in identifying landslip boundaries and detecting areas with high water saturation. It has been discovered that earthquakes actively contribute to the instability of these kinds of soils.
AtıfScopus6WoS5OpenAlex6İncele - Kitap BölümüYalnız künye2024Presenteeism: Understanding its impact on workplace productivity and employee well-being
Vural, Selvi
- MakaleAçık Erişim2025Scopus SJRQ3A new class of robust ratio estimators for finite population variance
Zaman, Tolga; Bulut, Hasan
It is a general practice to use robust estimates to improve ratio estimators using functions of the parameters of an auxiliary variable. In this study, a new class of robust estimators based upon the Minimum Covariance Determinant (MCD) and the Minimum Volume Ellipsoid (MVE) robust covariance estimates have been suggested for estimating population variance in the presence of outlier values in the data set for the simple random sampling. The expression for the Mean Square Error (MSE) of the proposed class of estimators is derived from the first degree of approximation. The efficiency of the proposed class of robust estimators is compared with some competing estimators discussed in the literature, and found that proposed estimators are better than other mentioned estimators here. In addition, real data set and simulation studies are performed to present the efficiencies of the estimators. We demonstrate theoretically and numerically that the proposed class of estimators performs better than all other competitor estimators under all situations.
AtıfScopus8WoS14OpenAlex12İncele
