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Yayın Reviewing the effects of spatial features on price prediction for real estate market: Istanbul case(IEEE, 2022-09-16) Ecevit, Mert İlhan; Erdem, Zeki; Dağ, HasanIn the real estate market, spatial features play a crucial role in determining property appraisals and prices. When spatial features are considered, classification techniques have been rarely studied compared to regression, which is commonly used for price prediction. This study reviews spatial features' effects on predicting the house price ranges for real estate in Istanbul, Turkey, in the classification context. Spatial features are generated and extracted by geocoding the address information from the original data set. This geocoding and feature extraction is another challenge in this research. The experiments compare the performance of Decision Trees (DT), Random Forests (RF), and Logistic Regression (LR) classifier models on the data set with and without spatial features. The prediction models are evaluated based on classification metrics such as accuracy, precision, recall, and F1-Score. We additionally examine the ROC curve of each classifier. The test results show that the RF model outperforms the DT and LR models. It is observed that spatial features, when incorporated with non-spatial features, significantly improve the prediction performance of the models for the house price ranges. It is considered that the results can contribute to making decisions more accurately for the appraisal in the real estate industry.Yayın Factors encouraging and hindering a wider acceptance and more frequent utilization of mobile payment systems an empirical study among mobile phone subscribers in Turkey(Işık Üniversitesi, 2021-06-21) Coşkun, Ertan; Ferman, Murat; Işık Üniversitesi, Sosyal Bilimler Enstitüsü, Çağdaş İşletme Yönetimi Doktora ProgramıConsidering the technological development in mobile payment technology, and extensive literature of technology adoption models; the current state of the related field needs to be examined in more detail to better understand current situation. Such an investigation may be invaluable to enable further expansion, consumer acceptance, market adoption, and help to improve the existing platforms’ usability. This research deals with determining the factors that affect adoption of mobile payment technology among consumers, in Turkey. It seeks to find any patterns and connections that may be of aid in framing an implementation strategy for facilitating further adoption. It has gathered different definitions of “mobile payment” in literatüre and used a consumer side definition. This study offers a different perspective by grouping constructs from a broader literature and provides a mobile payment acceptance model based on the constructs used in other studies. Previous studies have been performed with small groups of respondents. This study aims to perform the research model in a cosmopolitan city (Istanbul) where all sorts of mobile payment options are available in the market and in the time of a pandemic when remote delivery and online purchases are widely preferred compared to offline alternatives. A survey is conducted among mobile phone subscribers in Istanbul, Turkey for primary data collection phase of this research. Istanbul is the city that holds the biggest population and has the highest amount of mobile phone subscribers in the country. Istanbul’s current population is more than 15.6million and mobile phone subscriptions are more than 22million as of 2019. Survey responses have been analysed with structural equation modeling and results are presented in the corresponding sections. Empirical findings of the research show that factors such as usefulness, security, social influence, ease of use, enjoyment and innovativeness have positive effects on use of mobile payments among consumers. Factors such as attractiveness of alternatives and new technology anxiety have negative effects on use of mobile payments. This study has also discovered that intention to use mobile payments differ among demographic parameters such as education level and gender of respondents.Yayın Emerging technologies and international security: machines, the state, and war(Işık Üniversitesi Yayınları, 2023-10-25) Albasar, İlgi DoğaHalf a century ago, due to rapidly advancing technological developments, one of the most cliché future predictions we saw in scientific magazines was the idea of the sky being filled with flying cars. While the concept of flying cars may not have come to fruition yet, thanks to artificial intelligence, at least we can now listen to Kim Jong-Un singing English Disney songs. Although this may be a humorous example, in a more grim manner, autonomous drones that cause civilian casualties in covert assassination missions can also be given as an example.Yayın Placing STS in and through Turkey(Soc Social Studies Science, 2023-03-02) Alkan, Aybike; Kaşdoğan, Duygu; Maral, ErolWhy and how does it matter to undertake an STS praxis in a country where the field lacks adequate institutional recognition and capacity? This article investigates this question by tracing multiple, fragmented and contingent stories of placing STS in and through Turkey. At first sight, discontinuous stories of STS programs established in universities and unrecognized nature of STS as a discipline by the Council of Higher Education draw attention to the "underdeveloped" nature of the field in this country. This article counters such a perspective by rendering visible the works that support STS ethos as well as loose institutions within which STS is expected to flourish. By following people and artifacts in institutional and more-than institutional places of STS, this article acknowledges the efforts both to translate STS into the particular places of Turkey and to use STS as an intellectual space through which technoscientific knowledge can be questioned and translated into the local contexts of the country. The analysis of these translation efforts reveals that STS can be thought of as a space that enables one to be attuned to the sensibilities and realities of the country and search for ways to democratize the processes of technoscientific knowledge production whether it be in the universities or in public spaces.Yayın Generic BER analysis of VLC channels impaired by 3D user-mobility and imperfect CSI(Institute of Electrical and Electronics Engineers Inc., 2021-07) Reddy Sekhar, K.; Miramirkhani, Farshad; Mitra, Rangeet; Turlapaty, Anish ChandVisible light communications (VLC) has emerged as a high-speed, low-cost, and green supplement for the existing radio frequency (RF) based infrastructures. However, the performance of VLC based systems is found to degrade significantly due to detrimental outages caused by non-negligible variations in the VLC channel-gain, that are jointly induced by radial user-mobility and random photodetector-orientation (together designated as 3D mobility in this letter). In addition to the 3D user-mobility mentioned above, the performance of VLC based systems is further limited by imperfect channel-state information (CSI). Such degradations in the VLC-link caused by the aforementioned factors necessitate the quantification of performance-metrics for further benchmarking/receiver-design. In this work, an analytical expression for bit-error rate (BER) is derived for a single LED indoor VLC system considering the radial user-mobility, random receiver orientation, and imperfect CSI altogether. Further, the derived BER expressions are validated using computer-simulations using typical VLC channel models from the literature. A close agreement between the analytical and the simulated BER is observed, which verifies the accuracy of the presented analysis.Yayın A study on customer perceptions and attitudes towards digital coupons(İzmir Katip Çelebi Üniversitesi, 2021-12-15) Akman, Yasemin; Türkmen, Hediye GamzeDigital coupons, generally considered as a marketing strategy to increase sales and customer loyalty, are important elements in the observation of customer attitudes and perceptions. The main question in the literature is whether these coupons should be redeemed or not, and their effectiveness is discussed depending on their use. However, even if digital coupons are not redeemed after they are acquired in online environments, the way they are obtained or perceived can provide marketers with information about customer attitudes and behaviors. This study aims to determine the effectiveness of digital coupons in digital business models based on consumers' perceptions and attitudes. Attitudes towards digital discount coupons were examined using 10 different dimensions and how these dimensions were influenced by various variables was questioned. The study surveyed 300 participants. As a result of the analysis, it was revealed that the impact of digital coupons on online purchase behavior should be considered from a holistic perspective. Accordingly, other benefits that coupons create for sellers should not be overlooked in addition to coupon redemption.Yayın Motif-oriented characteristics of the Turkish carpets illustrated in English aristocratic portrays of renaissance and effects of the carpets on British carpet production(Ahmet Kara, 2021-08-31) Kalyoncu, HülyaThe Turkish carpets with a great importance in world’s carpet history have their origins in Pazırık Carpet, the world’s oldest and the first knotted carpet which was produced by the Central Asian Turks. Carpet tradition of Turks was kept by the Anatolian Seljuk Empire. It had its golden age with the naturalist carpets woven in Bursa and its vicinity in the 16th century that corresponds to the Ottoman period. The Turkish carpets included in the religion and society-thematic paintings made in Renaissance period by the European painters in various countries were regarded as the expression of wealth and magnificence. The Ottoman-Turkish carpets illustrated in portraits of the English aristocrats as well influenced the English carpet art in addition to adding aesthetic values to the paintings. In this study performed in this context, literature of the portraits of English aristocrats that involve Turkish carpets was reviewed. Besides, painters of the paintings, the aristocrat’s portrayed and motif-oriented characteristics of the Turkish carpets were addressed in detail. It was aimed to reveal the place of the carpets addressed within the discipline of art history, in Turkish cultural history and their effects on the British carpet production. In conclusion, it was turned out that they place premium on Turkish culture and art.Yayın Imlementing digital transformation strategy the case of a local Turkish bank(Işık Üniversitesi, 2022-04-26) Mustafaoglu, Amjad; Akseki, Pınar; Işık Üniversitesi, Lisansüstü Eğitim Enstitüsü, Yöneticiler için İşletme Yönetimi Yüksek Lisans ProgramıBanks' digital transformation process became the most distinctive feature of developed businesses in this millennium, not just a trend or an option to adopt, it became a necessity for growing finance businesses at competitive markets. The goal of this thesis is to focus light upon advantages and effectiveness of digital transformation strategy implementation at one of financial institutions, a “bank” in the republic of Turkey through descriptive qualitative research methodology. When the bank decides to apply digital transformation, all management levels have to collaborate to formulate a strategy roadmap for a long period of years, to shape the right business model in addition to suitable Fintech projects that will follow. Not far away the finance industry and Banks are the most affected sector by digital transformation strategy to keep on with developing their competitive advantages in the global market. “Fintech” is a portmanteau of financial technology, which is an abbreviation for "financial technology." Therefore, Fintech is a term that relates to software and applications for both computer and mobile devices. Efficient Fintech application technology affects both internal and external stakeholders. Internally, all managerial processes and workflow upgraded and reviewed in regard to fit with digital transformation strategy. Externally, satisfying digital customer needs. Therefore, achieving desired effectiveness of bank digital transformation strategy, faced major changes and challenges such as choosing main digital projects for deployment, developing and educating staff, priority of digital fintech projects, analyzing customer-centric problems to commence digital solutions, building internal human resources digital culture, designing digital skills and competencies through training and development, drawing digital customer journey roadmap, redefining bank’s communication framework processes to build future digital customer. Digital transformation strategy of the bank changed the traditional concept of branches, as well as the bank's financial services and relationships with customers, through new projects of fintech Technologies.Yayın Improvement of seismic performance of precast frames with cladding panels fastened by energy dissipative steel cushions(Springer, 2021-09) Özkaynak, Hasan; Khajehdehi, Arastoo; Yüksel, Ercan; Karadoğan, Hüseyin FarukPrecast reinforced concrete panels are commonly used as wall claddings in precast buildings. The cladding panels are generally evaluated as non-structural members and are joined to structural systems via mechanical, welding, and bolted dry connections. Several failures were observed in the last seismic events in Southern Europe, which demonstrate the deficiencies of the cladding connections in terms of strength and ductility. A comprehensive research activity named SAFECLADDING was conducted in Europe to provide knowledge for proper seismic design of precast structures with cladding panels. In this context, energy dissipative steel cushions were developed and evaluated through the extensive experimental and numerical studies. Steel cushions can provide robust interaction of the structural system with the cladding panels. This paper numerically evaluates the effects of cladding panels with steel cushions on the global seismic behaviour of the buildings. An existing representative industrial building is selected to perform intensive nonlinear dynamic analyses. Analyses performed on the bare and hybrid systems showed that the hybrid system has high performance in terms of story drifts, internal forces, and deformations with respect to the bare system. The overall drifts in longitudinal and transversal directions of the building are reduced by about 78 and 54%, respectively. Average residual drifts of cladding panels and steel cushions indicated that the applied steel cushion placement scheme has a promising re-centring capability during seismic action.Yayın A thermo-mechanical model of drill margin-borehole surface interface contact conditions in dry drilling of thick CFRP laminates(Elsevier Ltd, 2020-04-23) Karpat, Yiǧit; Karagüzel, Umut; Bahtiyar, OnurDry drilling of thick carbon fiber reinforced polymer (CFRP) laminates requires careful selection of process parameters in order to obtain acceptable borehole surface quality. Complex contact conditions between the drill margin and the borehole surface determine the integrity of the borehole surface depending on the process parameters and temperature-dependent viscoelastic material properties. Temperature rise during dry drilling reduces the elastic modulus of the CFRP and causes thermal expansion of the drill, resulting in considerable contact length at the drill margin and borehole surface interface. Manufacturers need a better understanding of the interaction among contact pressure, sliding velocity, temperature at the interface, and temperature-dependent material properties to develop predictive models for drilling CFRPs. To examine this complex interaction, this study develops a novel, hybrid model that combines a time-based analytical modeling of drilling process with a finite element-based modeling of temperature rise. Drilling experiments were performed in which thrust force, torque, and temperature were measured as a function of feed, and these measurements were used to identify unknown hybrid model parameters. The results revealed that a significant change in friction conditions occurs when increased temperatures at the margin and borehole surface interface approach and exceed the glass transition temperature of the CFRP laminate at a large feed rate. These findings show the benefit of increasing feed during dry drilling, which is nonetheless limited by the temperature-dependent material properties of the work material.
