Scopus İndeksli Yayınlar Koleksiyonu

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https://hdl.handle.net/20.500.14591/6

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Priority based vehicle routing for agile blood transportation between donor / client sites
(IEEE, 2017) Karakoç, Mehmet; Günay, Melih
In this paper, we study Vehicle Routing Problem (VRP) for Blood Transporters (BTs) and propose an efficient vehicle routing scheme for blood transportation between hospitals or Donor/Client Sites (DCSs) within a region that is based on Artificial Intelligence. It is assumed that each BT in a fleet of vehicles starts and completes its route at a blood-bank while visiting a subset of DCSs using the shortest path. However, unlike traditional logistic planning, blood transportation may be time critical. Therefore, in our approach, the vehicle routing is formulated to take into account the urgency of the requests and responses. Consequently, the objective of this study is to minimize the number of BTs while maintaining their minimum traveling lengths considering priority. In this regards, we extended the classical Capacitated VRP (CVRP) and reformulated requests to take into account the priority by assigning weight to each request. A hybrid meta-heuristic algorithm including Genetic Algorithms and Local Search is used to simulate transporting blood requests of DCSs. We challenged our approach with symmetrical CVRP instances taken from literature. In this case study, we observed that both the cost and response time are reduced dramatically for emergency.
Automated diagnosis of Alzheimer's Disease using OCT and OCTA: a systematic review
(IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2024) Turkan, Yasemin; Boray Tek, F.; Arpaci, Fatih; Arslan, Ozan; Toslak, Devrim; Bulut, Mehmet; Yaman, Aylin
Retinal optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) have emerged as promising, non-invasive, and cost-effective modalities for the early diagnosis of Alzheimer's disease (AD). However, a comprehensive review of automated deep learning techniques for diagnosing AD or mild cognitive impairment (MCI) using OCT/OCTA data is lacking. We addressed this gap by conducting a systematic review using the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. We systematically searched databases, including Scopus, PubMed, and Web of Science, and identified 16 important studies from an initial set of 4006 references. We then analyzed these studies through a structured framework, focusing on the key aspects of deep learning workflows for AD/MCI diagnosis using OCT-OCTA. This included dataset curation, model training, and validation methodologies. Our findings indicate a shift towards employing end-to-end deep learning models to directly analyze OCT/OCTA images in diagnosing AD/MCI, moving away from traditional machine learning approaches. However, we identified inconsistencies in the data collection methods across studies, leading to varied outcomes. We emphasize the need for longitudinal studies on early AD and MCI diagnosis, along with further research on interpretability tools to enhance model accuracy and reliability for clinical translation.
Happiness, job stress, job dedication and perceived organizational support: a mediating model
(EMERALD GROUP PUBLISHING LTD, 2023) Akgündüz, Yılmaz; Bardakoğlu, Övünç; Kızılcalıoğlu, Gaye
Purpose - Based on The Conservation of Resources Theory (COR), Spillover Theory and Social Exchange Theory (SET), this study investigates the mediating role of job dedication in the relationships between job stress, happiness and perceived organizational support (POS). Design/methodology/approach - Data were collected from 5-star resort hotel employees in Turkey. 362 valid questionnaires were collected. The research hypotheses were tested using Covariance-Based Structural Equation Modeling (CB-SEM). Findings - The analysis results show that POS is positively related to employee happiness and job dedication. Job stress is negatively related to employee happiness but positively related to job dedication. Job dedication partially mediates the relationships between job stress and happiness, and POS and happiness. Research limitations/implications - The study's findings could be used by hotel managers to improve employees' job dedication, which will lead to increased employee happiness. Together with qualitative and quantitative research methods, future research could be conducted on the predecessors of job dedication and comparatively on employee happiness for different country samples. Practical implications - In order to increase employee happiness, Turkish hotel managers may want to increase POS and decrease perceived job stress of their employees. Although it was found out in this study that job stress increases job dedication, it is also accepted that this unexpected situation arises due to special conditions. Therefore, by reducing job stress, hotel managers may prefer to increase the job dedication of their employees and their happiness indirectly. Originality/value - The current study contributes to the hospitality management literature by investigating the organizational factors behind employee happiness. In addition, it also explored in depth the mediating effect of job dedication on the relationships between POS, job stress and happiness.
Production of a design developed for the assembly filter parts, optimization of welding and field test
(ASSOC MECHANICAL ENGINEERS TECHNICIANS SLOVENIA, 2022) Maden, Hakan; Çetinkaya, Kerim
For the joining of non-removable plastic parts, methods such as friction welding, friction-stir welding, ultra-sonic welding, chemical joining, and hot-plate welding are used. Rotary friction welding is generally used for joining the filter parts of water treatment devices. After the rotating friction welding of the filter parts, semi-melted agglomerations are formed in the inner parts. To prevent semi-melted accumulation, a weld joint profile design was developed in the ABAQUS software in a previous study. In this study, injection moulds had been produced according to weld joint profile design. The taken plastic presses were welded with the friction welding machine and the joint was controlled and compared. It is seen that the semi-melted agglomeration was successfully confined. By performing Taguchi experimental method and ANOVA analysis on friction welding machine parameters, the optimum pressure conditions were determined in order to carry out static and dynamic tests according to NSF standards and field tests by producing 1500 pilot products, and it has been put into use. The lifetime of the developed filter depends on the material which was used in the manufacture. The next study is aimed to improve the lifetime of the developed filters.
Xanthos West Agora III: dynastic nele
(KOC UNIV SUNA & INAN KIRAC RES CTR MEDITERRANEAN CIVILIZATIONS-AKMED, 2023) Dönmez, Aytaç; Erdoğan, Halil Mert
New evidence obtained from excavation of the West Agora of Xanthos indicates that the first functional formation of the area may have taken place around 530-480 BC. This happened just after the founding of the Xanthos Dynasty during the time of the Dynast Kheziga (Kossika) or his son Kuprlli (Kybernis). Our comparisons with the agora of Avsar Tepesi, dated to the Early Classical period, revealed that these areas were a Lycian design. Epigraphic and archaeological evidence suggest that ceremonies for the purpose of ancestor cult, victory celebrations, and worshiping the gods occurred here. In addition, comparisons are made between our results and Oreshko's pairing of acropolis nele, reveals that these two places, called agora and acropolis in Greek inscriptions from the late fifth century BC, may have been identified nele by the Lycians as only one area. It follows that these areas called nele have quite different characteristics from the Greek agora. Therefore, it shows that Lycian nele were only termed agora in translations on the Inscribed Pillar Monument and the Kudalije Sarcophagus. This occurred because of the lack of a more accurate and appropriate synonym for nele in ancient Greek. In addition, considering the early existence of the cult area of agora gods worshiped in the nele, whose sacred and religious function was a priority, it was initially created under the influence of Anatolian culture. However, due to the significant influence of Athens in the Classical period, it became paired with the Greek twelve gods.
An approach to Euler-Mascheroni constant by Bernoulli numbers
(AMER INST PHYSICS, 2020) Aygüneş, Aykut Ahmet
In this paper, we give two different versions of the Euler-Maclaurin summation formula. By using these formulae, we obtain special series including the Bernoulli numbers and Riemann zeta function. Consequently, we show that this series is calculated by Euler-Mascheroni constant.
Convolution formulae related to special case of Euler and Bernoulli polynomials
(AMER INST PHYSICS, 2019) Aygüneş, Aykut Ahmet
In this paper, we give the generating function of the Euler and Bernoulli polynomials.Then, by using the generating function of these polynomials, we obtain two convolution formulae for some special cases of Euler and Bernoulli polynomials.
Convolution identities for new numbers including Euler and Bernoulli numbers
(AMER INST PHYSICS, 2018) Aygüneş, Aykut Ahmet
In this paper, we firstly give the generating functions of the Bernoulli and Euler polynomials. Secondly. for our main result, we define the generating function of number A(n) in terms of Bernoulli and Euler numbers. Then, we obtain an identity for the Bernoulli and Euler numbers.
Diurnal variation of essential oil ratio and composition of some basil genotypes
(BANGLADESH BOTANICAL SOC, 2022) Aygün, Yusuf Ziya; Eren, Yılmaz; Ertekin, Esra Nermin
The change of essential oil ratios and components of five different basil genotypes harvested at different times (00:00, 06:00, 12:00, 18:00) in day was investigated. Plants were grown under the field conditions and essential oils of the plants were extracted by hydro-distillation method. Identification of essential oil components were performed by GC-MS. It was the G5 genotype that had the highest essential oil content in all plant parts, regardless of the time of day. The highest essential oil content (2.8%) was obtained from the dry leaves of the G5 genotype from the sampling made at 18:00. The main components of essential oils were determined as linalool, eucalyptol, trans alpha-bergamotene, methyl cinnamate, alpha-muurolol and eugenol. However, while the ratios of these components differed between genotypes, the changes in time of day were similar for some components. Linalool content tended to increase mostly in the middle of the day. This study indicated that essential oil ratio and components of different basil genotypes significantly differed according to harvesting times in day.
Effect of process parameters on stevioside and rebaudioside a content of stevia extract obtained by decanter centrifuge
(WILEY, 2021) Arslan Kulcan, Aslı; Karhan, Mustafa
The aim of this research is to determine the possibility of decanter extraction for the isolation of steviol glycosides from stevia leaves. Extraction parameters such as temperature, time, and leaf/water ratio were optimized by using Response Surface Methodology. The optimal combination determined as a result of optimization studies was 25 degrees C, 1/27.6 leaf/water ratio, and 105 min extraction time. Under these conditions, experiments were carried out at three different speeds of 4,500, 4,900, and 5,280 rpm (2,264, 2,684, 3,117 g, respectively) in a decanter extraction system to investigate the effect of rotational speed. The amount of stevioside in samples obtained at 4,500, 4,900, and 5,280 rpm was 1080.82, 1919.18, and 2507.35 mg/L, respectively. The amount of rebaudioside A was 761.34, 1417.17, and 1801.93 mg/L, respectively. Results showed that the rotational speed of the decanter had a considerable effect on all the parameters examined. Practical applications Stevia is a product that is widely used in food formulations in the scope of combating obesity and diabetes. In this study, the decanter was applied for the first time to extract stevia leaves and optimum process conditions for decanter extraction of steviol glycosides were determined. It has been observed that stevia extraction can be successfully performed at 25 degrees C with high efficiency using decanter. The yield of the extract increased with increasing decanter rotational speed. The decanter extracted 73% of the total stevioside and rebaudioside A present in the leaves. The results of this study may be used by manufacturers who want to process the stevia plant with more economical and environmentalist approaches.
Exploring the criteria for a green and smart hotel: Insights from hotel managers' perspectives
(EMERALD GROUP PUBLISHING LTD, 2024) Akel, Gökhan; Noyan, Elçin
PurposeThis study aimed to explore the adaptations and perspectives of hotel managers regarding green and smart hotel technologies within the context of sustainability.Design/methodology/approachA comprehensive literature review guided the formulation of this study, followed by face-to-face, semi-structured interviews with hotel managers. A total of 17 prepared questions were finalized after examination by two expert academicians. The responses were analyzed using qualitative research methodology and the results were weighted using the step-wise weight assessment ratio analysis (SWARA) method.FindingsInterviews with sustainability and operational managers yielded insights into environmentally friendly practices and strategies such as reducing energy and water consumption, waste and chemical reduction, supporting local entrepreneurs and adopting smart technologies. These factors are crucial in eco-friendly hotels. According to the SWARA analysis, 'reducing energy consumption' is the most effective criterion.Research limitations/implicationsThis study offers insights into green and smart hotel management by focusing on the perspectives of hotel managers with a small sample. In future studies, research with larger samples on customer perspectives and the effect of hotel selection is recommended.Practical implicationsThis study offers insights to hotel managers on energy conservation and customer satisfaction enhancement through green and technological applications. These technological applications can improve hotel service quality and provide personalized experiences, fostering customer loyalty.Originality/valueThis pioneering study focuses on the intersection of green and smart practices in hospitality. By intertwining the often separately discussed concepts of green and smart, this study presents a novel approach to the sustainability practices in the hospitality industry, holding a key position, especially in Turkey. Implementing these concepts can yield environmental and economic benefits, offering invaluable insights to hotel managers and policymakers into integrating smart technologies with sustainability.
Global land grab and the Balkans: Continuity and changes in a unique historical context
(ROUTLEDGE JOURNALS, TAYLOR & FRANCIS LTD, 2018) Mandacı, Nazif; Tutan, Mehmet Ufuk
Current developments concerning land grabs in the Balkans suggest that the region is re-experiencing in the post-socialist era what happened in the seventeenth and eighteenth centuries due to the decline of the Ottoman land tenure system, under identical conditions involving fundamental socio-political transformations and integration with global capitalism. These changes are emblematic of a transfer of common to individual ownership. Nowadays, small landholders in some parts of the regionmainly the former labourers on socialist agricultural cooperativesare influenced by the accelerating trend of (re)concentrating landownership, which in some cases takes the form of land grabbing similar to that seen in Africa. This study examines the historical continuity between the Ottoman rule over fledgling nation-states and the post-socialist era by referring to widely discussed socio-economic and political developments regarding contemporary land grab processes.
Intimate politics: strategies and practices of female Mukhtars in Turkey
(ROUTLEDGE JOURNALS, TAYLOR & FRANCIS LTD, 2018) Yıldırım, Senem; Uçaray-Mangıtlı, Burcu; Tas, Hakkı
The dualistic separation between the public and private assumes natural and stable boundaries between these spheres. However, a perspective that relies on binaries may deprive certain groups, practices and processes associated with specific spheres from diverse experiences. For instance, women wanting to move from the private sphere and join the political public could not do that due to the domesticated nature of their roles and responsibilities. However, those who do manage to become agents of political activity do so by developing strategies and practices that are context specific. This article examines how the boundaries between the public and private are traversed in Turkish local politics through the mentioned context-specific experiences. It identifies the ways in which female mukhtars in Turkey engage in politics through practices of intimization as a political strategy, which accounts for the strategies and practices of degendering and regendering. The analysis of data from interviews with 20 randomly selected female mukhtars reveals that female mukhtars successfully navigate a versatile strategy of degendering and regendering. In this regard, they may highlight career-defined and gender-neutral attributes or valorize the masculine imperatives of the public domain. They may also affirm and assert their feminine qualities depending on the context.
Relations arising from a family of combinatorial numbers and bernstein type basis functions
(AMER INST PHYSICS, 2018) Küçükoğlu, İrem; Şimşek, Yılmaz
The aim of this paper is to give some combinatorial sums, identities and relations related to a family of combinatorial numbers and the Bernstein type basis functions. With the help of generating functions for the combinatorial numbers from this aforementioned family, we give some functional equations. By using these functional equations, we obtain several relationships including these combinatorial numbers and the Bernstein type basis functions. Moreover, we provide not only some identities, but also applications including combinatorial sums, integrals, the combinatorial numbers, the extended Bersntein basis functions, and the beta function.
Thermal inactivation of airborne SARS-CoV-2 by an electric fan heater in winter and defining conditions to ensure that all the air passes through the fan
(ASME, 2024) Canpolat, Murat; Şakalar, Çağrı; Bozkurt, Serhat; Çoban, Ahmet Yılmaz; Karacaylı, Deniz; Toker, Emre
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is spread, especially in closed environments, by airborne transmission. The study aims to assess the thermal inactivation of airborne SARS-CoV-2 in a 30 m(3) test room as a function of outlet temperature, airflow rate, and operating time of an electric heater, then define a condition to ensure that all air in the room passes through the electric heater. Aerosolized SARS-CoV-2 was delivered to the test room at an ambient temperature of 20 degrees C and 40% humidity. Two electric heaters with different powers and airflow rates were operated respectively in the test room to compare their efficiencies in the inactivation of airborne SARS-CoV-2. The first and second electric heaters had power, airflow rates, and outlet temperatures of 1.5 kW, 44 m(3)/h, 220 degrees C, and 3 kW, 324 m(3)/h, and 150 degrees C, respectively. A fan drew the outside air into the heater. In the first experiment, a 1.5 kW electric heater was operated in the test room for 80 min. In the second experiment, a 3 kW electric heater was used in the test room for 75 min. Airborne SARS-CoV-2 in the test room was inactivated by 99.00% and 99.96% in the first and second experiments, respectively. A condition is defined to ensure that all the air in the room passes at least once through the electric heater fan.
Top quality hotel managers' perspectives on smart technologies: an exploratory study
(EMERALD GROUP PUBLISHING LTD, 2024) Yağmur, Yenal; Demirel, Altan; Kılıç, Gül Damla
PurposeThe main purpose of the study is to reveal the hotel managers' perspectives strategies, and predictions on smart technologies, and their expectations for current staff and potential staff to be employed in the future.Design/methodology/approachA qualitative research approach was used to reveal the internal perspectives of managers to determine their Smart Tourism (ST) perspectives. With the snowball sampling method, face-to-face interviews were conducted with 16 senior hotel managers working in a 5-star hotel in Antalya. The data obtained were carried out with inductive content analysis and descriptive analysis from qualitative research analysis methods.FindingsIn this study, hotel managers' broad perspectives on ST were discussed in depth and presented comprehensively. Managers' perceptions of smart technologies are classified in terms of aggregate dimensions and themes. Among the most important findings, rapidity/quickness, managing/holistic assessment, standardization, harmony/integration-coordination and experience-memory, defined as the crossroads of total dimensions or the heart of smart technologies, were identified as the most important themes. In addition, Stylos et al. (2021), another important finding is the classification of technologies used in top-quality hotels, based on the conceptual framework for smart technologies presented in the literature.Practical implicationsThe effective and efficient use of technology, its internalization and openness to technology provides important advantages in hotels such as increasing revisits and satisfaction, providing loyalty and reducing costs. Thus, the perceptions, practices, strategies and prediction of senior managers working in high-level hotels about ST provide valuable data to other hotels that want to survive in the competition.Originality/valueFrom a theoretical point of view, this study is valuable in that it deals with the ST perceptions of senior managers with an exploratory research approach. Managerially, the research findings offer valuable contribution about the attitudes, trends, forecasts and expectations of senior managers working in high-level hotels towards ST.
Some approximations with hurwitz zeta function
(UNIV NIS, FAC SCI MATH, 2020) Aygüneş, Aykut Ahmet
In this paper, we focus on some approximations with Hurwitz zeta function. By using these approximations, we present some asymptotic formulae related to Hurwitz zeta function. As an application, we give two corollaries related to Bernoulli polynomials.
Utilization of pumice of Burdur region and zeolite of Bigadic-Balikesir region as fine aggregate in construction materials
(MADEN TETKIK VE ARAMA GENEL MUDURLUGU-MTA, 2020) Beycan Tatanoğlu, Özge; Koçkal, Niyazi Uğur
Volcanic originated pumice and zeolite aggregates have low density owing to their considerable porous structure. Porosity is usually correlated with insulation properties. In order to examine the effects of this lightweight aggregates on dead load of structure and insulation properties of standard construction materials, samples were produced by using pumice and zeolite at varying percentages by volume and control samples were manufactured with crushed sand. The samples were exposed to normal (standard) curing, hot water curing and steam curing to observe the effect of different curing regimes on their behavior. Bulk density and thermal conductivity tests were carried out on samples. Both bulk density and thermal conductivity values of the lightweight mortar samples were smaller than those of control sample. Besides, chemical compositions of aggregates and cement, analyses were also performed. Silica content of pumice and zeolite were %54,09 and %75,14 by mass respectively.
Theme park hotel experience, experiential satisfaction and behavioral intention: examination of visitors' experiences
(EMERALD GROUP PUBLISHING LTD, 2023) Akel, Gökhan; Çakır, Engin
PurposeThis research uses the experience economy theory and tourism experiences to explore how different types of experiences in theme parks influence visitors' experiential satisfaction and behavioral intention.Design/methodology/approachThe data were collected from visitors of different nationalities at a theme park hotel. The R program and JASP were used to analyze the data of the multinational sampling. JASP was used for the structural equation modeling (SEM) and the R program for the analysis of the measurement invariance.FindingsThe results highlight the existence of different visitor behavior in the experience economy, tourism experience and experiential satisfaction among visitors of several nationalities. However, the results highlight the existence of common visitor behavior on behavioral intention among visitors of these nationalities. This study reveals that visitors of different nationalities can have both diverse experiential and cultural motivations.Practical implicationsThe results show that managers should apply a plan and strategy according to the differences between the nationalities. By examining visitors from different nationalities, the study was allowed to be interpreted from a wider perspective in terms of academia and industry.Originality/valueThis study makes a difference in the literature in terms of focusing on cross-national differences by examining the experiences of visitors from different nationalities by using experience economy theory and tourism experience elements in the same research model.
Let me make mathematics and music together: A meta-analysis of the causal role of music interventions on mathematics achievement
(ROUTLEDGE JOURNALS, TAYLOR & FRANCIS LTD, 2023) Akın, Ayça
This research aims to conduct a fixed-effects meta-analysis to unpack the causal role of music interventions on mathematics achievement. Findings indicated that music interventions had a small to moderate positive effect on mathematics achievement (N = 77,595, k = 245, g = 0.36, p < 0.01, 95% CI [0.34, 0.38]). Mathematics skills, instructional mathematical content, types of music interventions, and age were significant moderators, whereas development status was not a significant moderator for this meta-analysis. The most crucial result was that studies using music-mathematics integrated intervention produced a large effect size. This study can be considered interesting in terms of revealing that a significantly strong and positive transfer in mathematics learning was only achieved when used mathematics and music together in the learning environment. Consequently, the current research is regarded to have laid some groundwork for further meta-analytic investigations as it provides detailed, up-to-date, and useful evidence on this issue.

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