WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/394
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Article Citation - WoS: 39Citation - Scopus: 51What Are the Key Success Factors for Strategy Formulation and Implementation? Perspectives of Managers in the Hotel Industry(Elsevier Sci Ltd, 2020-08) Koseoglu, Mehmet Ali; Altin, Mehmet; Chan, Eric; Aladag, Omer FarukThis study investigates how hotel managers describe strategy and identify key success factors for its formulation and implementation. The study analyzes qualitative data collected through semi-structured interviews with property level top managers of hotels in Hong Kong. The findings show that hotel managers prioritize competition analysis and macro-environmental conditions over internal characteristics such as teamwork in strategy formulation. In the implementation phase, however, internal considerations such as employee involvement and strategic consensus are given prominence. This study provides a significant contribution by examining how top level practitioners in the industry interpret success factors in their strategic management efforts, and it highlights a largely neglected area in the hospitality and tourism management literature.Article Citation - WoS: 130Citation - Scopus: 157Thermal Conductivity, Compressive Strength and Ultrasonic Wave Velocity of Cementitious Composite Containing Waste PET Lightweight Aggregate (WPLA)(Elsevier Sci Ltd, 2013-02) Akcaozoglu, Semiha; Akcaozoglu, Kubilay; Atis, Cengiz DuranIn this study, the influence of waste PET as lightweight aggregate (WPLA) replacement with conventional aggregate, on thermal conductivity, unit weight and compressive strength properties of concrete composite was investigated. For this purpose, five different mixtures were prepared (the control mixtures and four WPLA mixtures including 30%, 40%, 50%, and 60% waste PET aggregate by volume). Thermal conductivity (TC) coefficients of the specimens were measured with guarded hot plate apparatus according to TS ISO 8302 [1]. The thermal conductivity coefficient, unit weight and compressive strength of specimens decreased as the amount of WPLA increased in concrete. The minimum thermal conductivity value was 0.3924 W/m K, observed at 60% WPLA replacement. From this result, it was concluded that waste PET aggregates replacement with conventional aggregate in the mixture showed better insulation properties (i.e. lower thermal coefficient). Due to the low unit weight and thermal conductivity values of WPLA composites, there is a potential of using WPLA composites in construction applications. (c) 2012 Elsevier Ltd. All rights reserved.Article Citation - WoS: 12Citation - Scopus: 12The Role of Energy Efficiency, Renewable Resources, Green Innovation, and Fiscal Decentralization in Sustainable Development: Evidence From OECD Countries(Elsevier Sci Ltd, 2025-08) Binsaeed, Rima H.; Khan, Zeeshan; Dogan, Eyup; Rahim, SyedEnergy efficiency and renewable resources for sustainable development are novel discussion areas for academics and researchers. Similarly, most developed and emerging countries are experiencing fiscal decentralization to enhance regional development. However, the importance of these sectors in sustainable development is still unclear in the literature. This research investigates the influence of energy efficiency, renewable energy, green innovation, and fiscal decentralization on sustainable development. Using the data for 18 fiscally decentralized OECD countries from 1995 to 2020, the roles of linear and nonlinear green innovation and renewable energy are also considered. This study uses novel moment quantile regression and finds that revenue decentralization, expenditure decentralization, and fiscal decentralization are significant drivers of sustainable development. Additionally, energy efficiency and value-added manufacturing significantly enhance sustainability in the region. However, green innovation and renewables are resources that exhibit a U-shaped association with sustainable development. The robustness of these results is validated via a series of parametric and nonparametric approaches. From the policy perspective, this research suggests improved research and development on renewable energy, green innovation, and energy efficiency could significantly encourage the OECD's journey towards sustainable development. Additionally, subnational governments should be given more fiscal autonomy, which may encourage regional level investments and boost the confidence of clean energy producing sectors to accelerate sustainable regional development.Article Citation - WoS: 108Citation - Scopus: 124Dual Effectiveness of Freezing-Thawing and Sulfate Attack on High-Volume Slag-Incorporated ECC(Elsevier Sci Ltd, 2013-02) Ozbay, Erdogan; Karahan, Okan; Lachemi, Mohamed; Hossain, Khandaker M. A.; Atis, Cengiz DuranThis study investigated the dual effect of freeze-thaw cycles with sodium sulfate solution on the performance of non-air-entrained Engineering Cementitious Composites (ECCs) with high volumes of slag. ECC specimens containing three different levels of slag content as a replacement for cement (55%, 69% and 81% by weight of total cementitious material) were exposed to aggressive sodium sulfate solution under freezing-thawing cycles. The load-deflection response associated with ultimate mid-span deflection and flexural strength/stiffness was determined, along with crack development behavior. For comparison purposes, the freezing-thawing resistance (in water) of control ECC specimens was also evaluated. Modified point count method air-void parameters, compressive strength, porosity, water absorption and sorptivity tests were also conducted on the virgin ECC specimens (those not exposed to freezing-thawing cycles in water or aggressive sodium sulfate solution). The test results for the virgin specimens revealed that increased slag content (S/PC) improved the ductility, hardened air content, water absorption, porosity and sorptivity of ECC, while marginally decreasing the compressive and flexural strengths. Freeze-thaw cycles in water or sodium sulfate solution showed that the ductility of ECC specimens decreased remarkably, irrespective of slag content and applied freezing-thawing process. Reduction in mass loss was at minimal levels and no significant behavior change was monitored between the specimens undergoing freeze-thaw cycling in water and the aggressive sodium sulfate solution. Moreover, the decrease in flexural stiffness was more evident than the reduction of the flexural strength for all ECC mixtures. Crown Copyright (c) 2012 Published by Elsevier Ltd. All rights reserved.Article Citation - WoS: 8Citation - Scopus: 8Characterizing Boron-Enhanced One-Part Alkaline-Activated Mortars: Mechanical Properties, Microstructure and Environmental Impacts(Elsevier Sci Ltd, 2024-05) Orklemez, Ezgi; Ilkentapar, Serhan; Durak, Ugur; Gulcimen, Sedat; Uzal, Nigmet; Uzal, Burak; Atis, Cengiz DuranSince alkali activators negatively effect the environmental impact assessment, it is necessary to develop the alternative activators from natural sources with low environmental impact. Therefore, in this study, the usage of boron refined products colemanite, ulexite and boron pentahydrate as activators in slag-based alkali-activated mortar systems was investigated in detail. Flexural and compressive strength tests, isothermal calorimetry measurement, thermogravimetric and differential thermal analysis, inductively coupled plasma mass spectrometry analysis, field emission scanning electron microscopy, and energy dispersive analysis and elemental mapping and X-ray diffraction analysis were carried out on the samples. In addition, sample production was subjected to life cycle analysis (LCA) with a cradle-to-gate approach using two different transportation scenarios. According to the results obtained, it was determined that colemanite, ulexite and boron penta hydrate, when used in optimum proportions, had a positive effect on strength (up to increase 40% compressive strength by 20% ulexite replacement) and could be used as an activator in slag-based alkali-activated systems. The positive results obtained in strength as a result of using boron-refined products are also supported by other test results conducted within the scope of the study. Furthermore, according to the LCA results, it was observed that there was a significant decrease in global warming potential with the substitution of 20% colemanite, ulexite or boron pentahydrate as activators, not only compared to the reference sample but also traditional cementitious systems.Article Citation - WoS: 22Citation - Scopus: 28Characterization of 3D Fabric Permeability With Skew Terms(Elsevier Sci Ltd, 2017-06) Yun, Minyoung; Sas, Hatice; Simacek, Pavel; Advani, Suresh G.Flow simulations can predict resin flow behavior and void formation locations in a preform. One important parameter for simulation is the preform permeability. For thick parts with distribution media on the surface, resin flow is three dimensional and through the thickness permeability is required for simulation. If the fabric is a 3D preform or unbalanced, the through the thickness (Kzz) and two skew components (Kxz and Kyz) must be characterized. The skew terms influence the flow behavior and hence the void formation. In this study, we present a measurement station that provides all six independent components of the permeability tensor from one experiment. The methodology uses the location data of the flow front with time and then couples it to an optimization algorithm and our flow simulation tool, LIMS (Liquid Injection Molding Simulation). The process is automated and experimental results are superimposed on the simulation results to confirm fidelity of the values determined. (C) 2017 Elsevier Ltd. All rights reserved.Article Citation - WoS: 22Citation - Scopus: 29Automated Quantification of Immunomagnetic Beads and Leukemia Cells from Optical Microscope Images(Elsevier Sci Ltd, 2019-03) Uslu, Fatma; Icoz, Kutay; Tasdemir, Kasim; Yilmaz, BulentQuantification of tumor cells is crucial for early detection and monitoring the progress of cancer. Several methods have been developed for detecting tumor cells. However, automated quantification of cells in the presence of immunomagnetic beads has not been studied. In this study, we developed computer vision based algorithms to quantify the leukemia cells captured and separated by micron size immunomagnetic beads. Color, size based object identification and machine learning based methods were implemented to quantify targets in the images recorded by a bright field microscope. Images acquired by a 40x or a 20x objective were analyzed, the immunomagnetic beads were detected with an error rate of 0.0171 and 0.0384 respectively. Our results reveal that the proposed method attains 91.6% precision for the 40x objective and 79.7% for the 20x objective. This algorithm has the potential to be the signal readout mechanism of a biochip for cell detection. (C) 2019 Elsevier Ltd. All rights reserved.Article Citation - WoS: 35Citation - Scopus: 41Analysis of the Probability of Failure for Open-Grown Trees During Wind Storms(Elsevier Sci Ltd, 2014-07) Ciftci, Cihan; Arwade, Sanjay R.; Kane, Brian; Brena, Sergio F.Although trees convey important environmental, economic, and sociological benefits on humans and society, they can also cause significant economic and societal disruptions, especially when subjected to wind storms in urban environments. Tools for proper assessment of the risk of these disruptions can be of significant benefit to society. In this research an approach to quantifying the failure probability for trees subject to wind storms is presented and illustrated by application to two specific maple trees in Massachusetts, USA. The approach entails four specific steps: (-1) Random wind time history samples were generated using a modified Ochi-Shin spectrum, (2) these wind time histories were used as loading time histories on finite element models of the example trees in both summer (in-leaf) and winter (leafless), (3) maximum bending moments generated by the random wind time histories were compared to the failure (yield) moment of the tree at 1.4 m above ground, (4) the failure/fragility curves of the trees were estimated by Monte Carlo simulation for a range of average wind speeds and for 1000 independent wind time histories at each wind speed. (C) 2014 Elsevier Ltd. All rights reserved.Article Citation - WoS: 53Citation - Scopus: 65Are Clean Energy and Carbon Emission Allowances Caused by Bitcoin? A Novel Time-Varying Method(Elsevier Sci Ltd, 2022) Dogan, Eyup; Majeed, Muhammad Tariq; Luni, TaniaThe bitcoin market has substantially grown in recent years. The researchers are exploring its various repercussions for socioeconomic and political matters; however, the literature still lacks clear evidence on how bitcoin interacts with energy and the environment. This study aims to explore the causal relationship between bitcoin, clean energy, and carbon emissions allowances by applying the novel time-varying Granger causality test on the daily data spanning from Sept 17, 2014, to October 12, 2021. The empirical findings confirm that both clean energy and emission allowances are causally associated with bitcoin. However, this causal relationship varies over time and the duration of causality is longer as suggested by the recursive evolving procedure. The outcome is robust when bitcoin is measured by the volume and the price. Furthermore, the results obtained from robustness analysis conducted through heteroskedastic consistent test also validate the findings that bitcoin causes clean energy and carbon allowance. The findings offer a platform for government officials and policy managers to improve clean energy and carbon allowance markets for sustainable development by managing and using the tools to control and regulate cryptocurrency markets.Conference Object TGF-Β Receptor I/II Signaling at Primary Cilia Membrane Is Regulated by Ceramide to Modulate Cell Migration(Elsevier Sci Ltd, 2016) Gencer, S.; Ogretmen, B.