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Article Citation - Scopus: 6Predictive Models for Treated Clayey Soils Using Waste Powdered Glass and Expanded Polystyrene Beads Using Regression Analysis and Artificial Neural Network(Springer Science and Business Media Deutschland GmbH, 2024) Akis,E.; Akış, Ebru; Cigdem,O.Y.; Akış, Ebru; Civil Engineering; Civil EngineeringWaste materials contribute to a wide range of environmental and economic problems. To minimize their effects, a safe strategy for reducing such negative impact is required. Recycling and reusing waste materials have proved to be effective measures in this respect. In this study, an eco-friendly treatment is investigated based on using waste powdered glass (WGP) and EPS beads (EPSb) as mechanical and chemical admixers in soils. For this purpose, Atterberg limit, standard proctor, free swell, and unconfined compression tests are performed on soil samples with different ratios of waste materials at their optimum moisture contents. The obtained test results indicate that adding WGP to cohesive soils increases the unconfined compressive strength (UCS) and reduces free swell (FS). In contrast, using EPSb reduces both FS and UCS of the treated soil samples. An optimum combination of both waste materials is determined for the improvement of the properties of high plasticity clay used in this study. Furthermore, multiple linear regression (MLR) and artificial neural network (ANN) methods are used to predict the FS and UCS of the clayey soils based on the data obtained here and the experimental test results reported in the literature. Once the FS and UCS values of untreated soil and additive percentages are defined as independent variables, both methods are shown to predict the FS and UCS values of the treated soil samples on a satisfactory level with the coefficient of correlation (R2) values greater than 0.926. Additionally, when only the index properties (liquid limit, plastic limit, and plasticity index) of the soil samples with waste materials are used as dependent variables, the R2 values obtained by the ANN method are 0.968 and 0.974 for FS and UCS, respectively. The results of the untreated soil samples' FS and UCS tests are known, and the linear regression and ANN techniques yield similar results. Lastly, the ANN method is used to predict the FS and UCS of the treated samples in accordance to the limited predictors (e.g., only the Atterberg limits of the soil sample). © The Author(s) 2024.Article Citation - WoS: 2Citation - Scopus: 4Optimum Cost Prediction of Reinforced Concrete Cantilever Retaining Walls(Mdpi, 2023) Akis, EbruReinforced concrete cantilever retaining walls (RCCRWs) are widely used in civil engineering projects as a common type of retaining structure. The design of these structures focuses on ensuring safety against various failure scenarios and compliance with standard building code requirements. This research aims to enhance the design process of RCCRWs by developing a specific code and optimizing it through a metaheuristic-based algorithm. In this study, the cost prediction of RCCRWs is also investigated through a parametric study involving key variables such as wall height, seismic zone, backfill material properties, and backfill inclination angle. To achieve this, non-linear regression analysis is employed to establish an empirical correlation, enabling cost estimation for optimized RCCRWs. The resulting prediction equation is simple to use, requiring only limited inputs. Therefore, it can be applied during the initial stages of a project, making a valuable contribution in determining approximate costs for RCCRW projects.Article Citation - WoS: 5Citation - Scopus: 5Improvement of Electrical Characteristics of Snse/Si Heterostructure by Integration of Si Nanowires(Elsevier, 2021) Coskun, E.; Gullu, H. H.; Emir, C.; Parlak, M.In this study, the effects of the nanowire geometry on Si wafer substrate were investigated for the SnSe/Si-nanowire heterojunction device and the obtained results were compared with the one fabricated on planar Si surface. Nanowires on Si surface were produced by metal-assisted etching method and the SnSe film layer was deposited by thermal evaporation technique. On both Si and glass surfaces, deposited film shows polycrystalline and single SnSe phase. From optical transmission measurements, optical band gap of this film was determined as 1.36 eV in a good agreement with the literature. All SnSe/Si heterostructures were found in a p-n diode behavior and the ideality factor and series resistance values were calculated as 2.40, 547 Omega, and 3.71, 1.57 x 10(3) Omega, for SnSe/Si-nanowire and SnSe/Si heterojunctions, respectively. As a result, an improvement in device characteristics concerning the planar Si structure was found by utilizing Si nanowire structure.Article Citation - WoS: 7Citation - Scopus: 6Spectroscopic Ellipsometry Characterization of Pbwo4 Single Crystals(Elsevier, 2022) Delice, S.; Isik, M.; Gasanly, N. M.; Darvishov, N. H.; Bagiev, V. E.Optical characterization of PbWO4 single crystals grown by Czochralski method was achieved in virtue of spectroscopic ellipsometry experiments carried out in the energy region of 1.0-5.6 eV at room temperature. Tetragonal scheelite structure with lattice parameters of a = b = 5.4619 & Aring; and c = 12.0490 & Aring; was determined for the bulk crystal utilizing from XRD analysis. Analyses of the ellipsometry data presented the photon energy dependencies of complex dielectric function of the crystal. The real part of the dielectric function exhibited increasing behavior with energy in the below 4.1 eV and then decreased immediately. Zero frequency refractive index and dielectric constant were determined to be 2.02 and 4.08, respectively, using Wemple and DiDomenico oscillator model. High frequency dielectric constant was calculated as 4.30 by Spitzer-Fan model. Optical band gap of PbWO4 was found to be 3.24 eV from the dielectric relaxation time spectrum. Moreover, existence of two critical points with energies of 3.70 and 4.58 eV was revealed from the analyses of extinction coefficient and second derivative of the dielectric function. These levels were considered to be due to creation of cation exciton (Pb2+ 6s(2) - Pb2+ 6s6p) and transitions in the [WO4](2-) group.Article Citation - WoS: 6Citation - Scopus: 7User-Friendly Locations of Error Messages in Web Forms: an Eye Tracking Study(int Group Eye Movement Research, 2016) Inal, YavuzError messages presented to users are one of the most important elements of Web forms. Error messages are embedded in different parts of the forms available on the Internet and presented in various formats. One of the measures of a user-friendly error message design is the ability to easily capture users' attention and facilitate fast error correction. In this empirical study, I tested four different locations of error messages frequently used in Web forms on 32 participants. In addition, I analysed the participants' interactions with error messages through their eye movements. The results of the study showed that the participants spotted the error message fastest when it was displayed on the right side of the erroneous input field. When error messages displayed further the input field users have less saccades to and fixations on error messages compared to those located near to this field, suggesting that less effort has been spent to understand the given message. However, group mean differences were not statistically significant for form completion time, error recognition time, the number of saccades, and error correction time.Article Citation - WoS: 12Citation - Scopus: 19An Ontology-Based Multi-Agent Virtual Enterprise System (omave): Part 1: Domain Modelling and Rule Management(Taylor & Francis Ltd, 2017) Sadigh, Bahram Lotfi; Unver, Hakki Ozgur; Nikghadam, Shahrzad; Dogdu, Erdogan; Ozbayoglu, A. Murat; Kilic, S. EnginNew advancements in computers and information technologies have yielded novel ideas to create more effective virtual collaboration platforms for multiple enterprises. Virtual enterprise (VE) is a collaboration model between multiple independent business partners in a value chain and is particularly suited to small and medium-sized enterprises (SMEs). The most challenging problem in implementing VE systems is ineffcient and inFLexible data storage and management techniques for VE systems. In this research, an ontology-based multi-agent virtual enterprise (OMAVE) system is proposed to help SMEs shift from the classical trend of manufacturing part pieces to producing high-value-added, high-tech, innovative products. OMAVE targets improvement in the FLexibility of VE business processes in order to enhance integration with available enterprise resource planning (ERP) systems. The architecture of OMAVE supports the requisite FLexibility and enhances the reusability of the data and knowledge created in a VE system. In this article, a detailed description of system features along with the rule-based reasoning and decision support capabilities of OMAVE system are presented. To test and verify the functionality and operation of this system, a sample product was manufactured using OMAVE applications and tools with the contribution of three SMEs.Article Harmanlanmış Hizmet-içi Eğitimin Öğretmen Görüşleri Doğrultusunda Değerlendirilmesi(Atılım Üniversitesi Sosyal Bilimler Dergisi, 2012) Aydın, Cengiz HakanBu çalışma, Türkiye’de Milli Eğitim Bakanlığı bünyesinde uygulanmakta olan harmanlanmış (blended) öğretmen eğitimine ilişkin katılımcı öğretmenlerin görüşlerine dayalı değerlendirme sonuçlarını içermektedir. Milli Eğitim Bakanlığı 2003 yılından bugüne, son yıllarda yaygın kabul gören öğretim stratejilerine derslerinde yer verirken teknolojiden nasıl yararlanabilecekleri konusunda öğretmenlerin bilgi ve becerilerini geliştirmeye yönelik bir hizmet-içi eğitim uygulaması gerçekleştirmektedir. Bu uygulama 2008 yılından itibaren harmanlanmış yapıda gerçekleştirilmeye başlanmıştır. Bu eğitime katılan öğretmenlerin eğitime ilişkin görüşleri anket ve görüşmeler yoluyla toplanmıştır. Elde edilen veriler, öğretmenlerin genel olarak harmanlanmış öğrenmeye ilişkin olumlu düşündüklerini ancak eğitim içeriğinin yoğun olmasından dolayı zorlandıklarını ortaya koymuştur. Bu bulgular doğrultusunda uygulanmakta olan eğitimin geliştirilmesi ve yeni eğitimlere yol göstermesi için bir dizi öneri geliştirilmiştir.Article Citation - WoS: 10Citation - Scopus: 15Increasing Innovative Working Behaviour of Information Technology Employees in Vietnam by Knowledge Management Approach(Mdpi, 2020) Quoc Trung Pham; Anh-Vu Pham-Nguyen; Misra, Sanjay; Damasevicius, Robertas; Pham-nguyen, Anh-vu; Pham, Quoc TrungToday, Knowledge Management (KM) is becoming a popular approach for improving organizational innovation, but whether encouraging knowledge sharing will lead to a better innovative working behaviour of employees is still a question. This study aims to identify the factors of KM affecting the innovative working behaviour of Information Technology (IT) employees in Vietnam. The research model involves three elements: attitude, subjective norm and perceived behavioural control affecting knowledge sharing, and then, on innovative working behaviour. The research method is the quantitative method. The survey was conducted with 202 samples via the five-scale questionnaire. The analysis results show that knowledge sharing has a positive impact on the innovative working behaviour of IT employees in Vietnam. Besides, attitude and perceived behavioural control are confirmed to have a strong positive effect on knowledge sharing, but the subjective norm has no significant impact on knowledge sharing. Based on this result, recommendations to promote knowledge sharing and the innovative work behaviour of IT employees in Vietnam are made.Article Citation - WoS: 7Citation - Scopus: 7Temperature dependent bandgap in NaBi(WO4)2 single crystals(Elsevier Gmbh, 2022) Isik, M.; Gasanly, N. M.; Darvishov, N. H.; Bagiev, V. E.The double tungstates have been an attractive research interest due to their optoelectronic applications. In the present work, NaBi(WO4)(2), one of the members of double tungstates family, was grown by Czochralski method as single crystal form and optically investigated. X-ray diffraction pattern presented three peaks associated with tetragonal scheelite crystalline structure. Optical properties of the crystal were studied by performing temperature-dependent transmission measurements between 10 and 300 K. The shift of the absorption edge to higher energies was observed with decrease of temperature. The analyses indicated that direct band gap energy increases from 3.50 to 3.60 eV when the temperature was decreased from room temperature to 10 K. The temperature dependency of bandgap was studied considering the Varshni model and fitting of the experimental data under the light of model presented the optical parameters of band gap energy at 0 K, rate of band gap change with temperature and Debye temperature as E-g(0) = 3.61 eV, gamma = 8.83 x 10(-4) eV/K and beta = 456 K, respectively. Urbach energies were also determined from the analyses as 122 and 113 meV for 10 and 300 K experimental data, respectively.Article Alasdaır Gray'in “the Fall Of Kelvın Walker” Adlı Romanında Mekân Temsilleri(2021) Çiftcioğlu, Simla Kötüzİskoç Edebiyatı'nın en önemli yazarlarından biri olarak kabul edilen Alasdair Gray,eserlerinde İskoç tarihi, kültürü, kimliği ve edebi geleneğinin sorunlarını politik bir bakışaçısıyla ele alır. Gray'in yazınında politik duruşunu yansıtan en dikkat çekici unsurlardanbiri, eserlerinde genellikle İskoç mekânların, özellikle Glasgow'un, kullanılmasıdır. AncakThe Fall of Kelvin Walker (1985) isimli romanında Gray, kurgu mekânı olarak Londra'yıtercih eder. İskoç başkahramanın Londra algısı ve kimlik arayışının bir parçası olarakkendine Londra'da bir ev kurma süreci anlatının önemli bir parçasını oluşturur. AlasdairGray'in İngiliz-İskoç ilişkilerine yönelik takındığı politik tutumu, bu romanda kentsel vekişisel mekân temsilleri aracılığıyla yansıttığı düşünülmektedir. Bu bağlamda, bu çalışmaThe Fall of Kelvin Walker'daki kentsel mekân olarak Londra'nın kullanımını ve kişiselmekân olarak ev olgusunun temsilini Henri Lefebvre'nin mekânsal üçlü önermesi ışığındaincelemeyi amaçlar. Çalışmada, kentsel mekân olarak Londra ve kişisel mekân olarak ev,mekânsal üçlü önermesinin unsurları olan mekân temsilleri, temsil mekânları vemekânsal pratikler kapsamında incelenecektir.
