Search results

1 – 10 of 48
To view the access options for this content please click here
Article
Publication date: 19 March 2021

Selçuk Gürçam, Emrah Konuralp and Selcuk Ekici

This study was carried out in Igdir, where Turkey’s urban air pollution is at the highest level, and the population is among the smallest. Thus, the study aims to…

Abstract

Purpose

This study was carried out in Igdir, where Turkey’s urban air pollution is at the highest level, and the population is among the smallest. Thus, the study aims to determine the effect of air transportation on air pollution in the most polluted city in Turkey.

Design/methodology/approach

The approach includes six stages: choosing the airport, accessing the flight information for the airport, classifying the aircraft that operated at the airport, determining the aircraft engines, calculating the emission amounts, calculating the landing and takeoff-based emissions.

Findings

Rather than devoting the resources disproportionally to the aviation sector within the scope of economic globalization, as a policy recommendation, to realize its production potential, Igdir, which has a great agricultural production capacity, considering its microclimate, fertile soil and arable land, should be urgently integrated into neighboring markets and the national market via railways.

Practical implications

It is inferred from the research that Turkey has to consider implementing the emissions tax policy, while the Turkish aviation sector is to realize new regulations for aircraft-engine matching to take public health and the impacts of the airports on their surroundings into consideration more seriously.

Originality/value

This study is an original one, as it puts the increasing pollution caused by the aircraft into a historical and political-economic perspective. Also, it is an example of an interdisciplinary work that combines environmental science and political science.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 2
Type: Research Article
ISSN: 1748-8842

Keywords

To view the access options for this content please click here
Article
Publication date: 8 February 2021

Emrah Dokur, Cihan Karakuzu, Uğur Yüzgeç and Mehmet Kurban

This paper aims to deal with the optimal choice of a novel extreme learning machine (ELM) architecture based on an ensemble of classic ELM called Meta-ELM structural…

Abstract

Purpose

This paper aims to deal with the optimal choice of a novel extreme learning machine (ELM) architecture based on an ensemble of classic ELM called Meta-ELM structural parameters by using a forecasting process.

Design/methodology/approach

The modelling performance of the Meta-ELM architecture varies depending on the network parameters it contains. The choice of Meta-ELM parameters is important for the accuracy of the models. For this reason, the optimal choice of Meta-ELM parameters is investigated on the problem of wind speed forecasting in this paper. The hourly wind-speed data obtained from Bilecik and Bozcaada stations in Turkey are used. The different number of ELM groups (M) and nodes (Nh) are analysed for determining the best modelling performance of Meta-ELM. Also, the optimal Meta-ELM architecture forecasting results are compared with four different learning algorithms and a hybrid meta-heuristic approach. Finally, the linear model based on correlation between the parameters was given as three dimensions (3D) and calculated.

Findings

It is observed that the analysis has better performance for parameters of Meta-ELM, M = 15 − 20 and Nh = 5 − 10. Also considering the performance metric, the Meta-ELM model provides the best results in all regions and the Levenberg–Marquardt algorithm -feed forward neural network and adaptive neuro fuzzy inference system -particle swarm optimization show competitive results for forecasting process. In addition, the Meta-ELM provides much better results in terms of elapsed time.

Originality/value

The original contribution of the study is to investigate of determination Meta-ELM parameters based on forecasting process.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0332-1649

Keywords

To view the access options for this content please click here
Article
Publication date: 5 March 2021

Emrah Uysal, Mustafa Çakir and Bülent Ekici

Traditional nanocomposite production methods such as in situ polymerization, melt blending and solvent technique, have some deficits. Some of these are non-homogeneous…

Abstract

Purpose

Traditional nanocomposite production methods such as in situ polymerization, melt blending and solvent technique, have some deficits. Some of these are non-homogeneous particle distribution, setup difficulties, time-consuming and costly. On the other hand, three-dimensional printing technology is a quite popular method. Especially, Stereolithography (SLA) printing offers some benefits such as fast printing, easy setup and smooth surface specialties. Furthermore, surface modification of Graphene Oxide (GO) and its effects on polymer nanocomposites are quite important. The purpose of this study is to examine the effect of surface modification of GO nanoparticles on the mechanical properties and morphology of epoxy acrylate (BisGMA/1,6 hexane diol diacrylate) matrix nanocomposites.

Design/methodology/approach

In this study, Ultraviolet (UV) curable end groups of synthesized resin were linked to functional groups of graphene oxide, which are synthesized by the Tour method, which is a kind of modified Hummer method. In addition, synthesized GO nanoparticle’s surfaces were modified by 3-(methacryloyloxy) propyl trimethoxysilane. Significant weight percentages of GO were added into the epoxy acrylate resin. Different Wt.% of modified graphene oxide/acrylate resins was used to print test specimens with SLA type three-dimensional printer.

Findings

Surface modification has a significant effect on tensile strength for graphene oxide nanoparticles contained composites. In addition, a specific trend was not observed for tensile test results of non-modified graphene oxide. The tendency of impact and hardness test finding were similar for both surfaces modified and non-modified nanoparticles. Finally, the distribution of particles was homogeneous.

Originality/value

This paper is unique because of the inclusion of both surface modifications of graphene oxide nanoparticles and SLA production of nanocomposites with its own production of three-dimensional printer and photocurable polymer resin.

Details

Rapid Prototyping Journal, vol. 27 no. 4
Type: Research Article
ISSN: 1355-2546

Keywords

Abstract

Purpose

This paper aims to determine the knowledge and attitudes of the physicians regarding human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS), to emphasize that these patients exist and they will exist in the future and to raise awareness so as to prevent that their rights to treatment are revoked.

Design/methodology/approach

The survey was conducted via a link sent through an online system. Random physicians from 81 cities of the country were invited to the survey. The survey has 41 questions regarding knowledge and attitudes in total, including epidemiological information such as age, gender and title.

Findings

A total of 3,107 physicians has voluntarily participated in the study. In total, 2,195 (70.7%) are internal physicians and 912 (29.3%) are surgical physicians among the participant physicians. In total, 1,452 (46.7%) of the participants are specialist physicians, 608 (19.6%) of the participants are practising physician and the rest of it is physician assistants, academicians and dentists, respectively.

Originality/value

In this study, it has been found out that the physicians have a lack of knowledge on HIV/AIDS and they adopt a discriminatory attitude towards HIV-positive persons. HIV-positive patients who are exposed to discrimination and scared of being uncovered refrain from applying to hospitals for treatment, which puts public health into jeopardy due to the high viral load and these patients are faced with difficulties in coping with both medical and emotional load of the disease.

Details

International Journal of Human Rights in Healthcare, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2056-4902

Keywords

To view the access options for this content please click here
Article
Publication date: 21 March 2019

Abdullahil Mamun, Harun BAL and Emrah Eray AKCA

The study aims to examine the export-led growth (ELG) hypothesis for Bangladesh. The direction of causality between export and output largely determines the success of…

Abstract

Purpose

The study aims to examine the export-led growth (ELG) hypothesis for Bangladesh. The direction of causality between export and output largely determines the success of export-oriented trade policies. A unidirectional causality running from export to output growth is required according to the narrow definition, while bidirectional causality is allowed for the broader definition. The study offers the causality inference, both from narrow and broader senses.

Design/methodology/approach

The study uses the bootstrap version of Toda and Yamamoto-modified causality tests, a recent development in time series econometrics, robust against the regularity conditions such as stationarity, properties of integration and cointegration and constancy of parameters. It uses monthly secondary data for the period of 1990-2014.

Findings

Test results suggest a unidirectional positive causal relationship from exports to output growth, meaning that the policies and strategies supporting exports are promoting output growth and thereby approve the ELG hypothesis for Bangladesh from the narrow sense. However, the absence of bidirectional causality between export and output growth, necessary to support the ELG hypothesis from the broader perspective, discards the conjecture that output growth is reinvigorated through the probable second-round effects of ELG produced from output growth to exports.

Practical implications

Lower investments in infrastructure, technology and education are reasons for the absence of ELG from the broader sense. Therefore, directing returns generated from exports for the development of technology, infrastructure and human capital, with regular and continuous revision of trade-liberalization policies so as to make its exports more competitive in the world market, will help Bangladesh trigger the second-round effect of ELG produced from output growth to exports.

Originality/value

Beyond the conventional approaches, this is the first contemporary time series econometrics causality analysis between export and output growth of Bangladesh, both from narrow and broader senses.

Details

Journal of Asia Business Studies, vol. 13 no. 2
Type: Research Article
ISSN: 1558-7894

Keywords

To view the access options for this content please click here
Article
Publication date: 27 July 2021

Aaron Cohen and Emrah Özsoy

The purpose of this paper is to examine the relationship between dark triad personality (DTP) and organizational and individual counterproductive work behaviors (CWB) and…

Abstract

Purpose

The purpose of this paper is to examine the relationship between dark triad personality (DTP) and organizational and individual counterproductive work behaviors (CWB) and perceived career success among employees in Turkey. Additionally, the study examined the effects of four situational variables: perceived organizational politics, transparency, psychological contract breach, and accountability.

Design/methodology/approach

Data were collected from 156 employees across five service organizations in Sakarya, Turkey, using the survey method.

Findings

The regression analysis findings showed that the three traits of the DTP, Machiavellianism, and psychopathy were significantly related to both organizational and interpersonal dimensions of the CWB. Narcissism was not related to any of the dimensions of CWB. The findings showed no significant relationship between any of the four situational variables and the two forms of CWB. However, three of the situational variables were related to perceived career success, while the three dimensions of DTP were not.

Research limitations/implications

The main limitations of this study are its cross-sectional design and the self-reported measures of the dependent variables. Interestingly, the study showed that having high levels of DTP does not necessarily promote their careers.

Originality/value

This study contributes to examining career success as a dependent variable in addition to CWB. The findings showed that situational variables are related to career success, and DTP is related to CWB. This finding has both conceptual and practical implications.

Details

International Journal of Workplace Health Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1753-8351

Keywords

Content available
Article
Publication date: 8 August 2018

Emrah Bulut, Okan Duru and T.L. Yip

Abstract

Details

Maritime Business Review, vol. 3 no. 2
Type: Research Article
ISSN: 2397-3757

To view the access options for this content please click here
Article
Publication date: 4 February 2021

Vehbi Emrah Atasoy, Ahmet Esat Suzer and Selcuk Ekici

This paper aims to investigate the environmental impact of various pollutant emissions including carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxide (NOx) and…

Abstract

Purpose

This paper aims to investigate the environmental impact of various pollutant emissions including carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxide (NOx) and hydrocarbon (HC) from aircraft exhaust gases during the landing and take-off (LTO) cycles at Eskisehir Hasan Polatkan Airport, Turkey, between 2017 and 2018.

Design/methodology/approach

The methodology approach used to calculate the emissions from aircrafts is based on the ICAO databank and the actual data records taken from Presidency of The Republic of Turkey Directorate of Communications (DoC).

Findings

The maximum amount of total fuel burnt during the two years is 80.898 and 70.168 tons in 2017 and 2018, respectively, while the average fuel burnt per year from 2017 to 2018 is approximately 369.773 tons. The highest CO, CO2, NOx and HC emissions are found to be 248.3 kg in 2017, 261.380 tons, 1.708 tons and 22.15 kg, during the 2018 year, respectively. Average CO, HC, NOx and CO2 emissions amount per year are observed to be 1.392 tons, 135 kg, 6.909 tons and 1,143 tons, respectively. Considering the average of total emission amount as an environmental factor, as expected, CO2 emissions contributed the most to the total emissions while HC emissions contributed the least to the total emissions from the airport.

Practical implications

The study presents the approach in determining the amounts of emissions released into the interannual atmosphere and it explicitly provides researchers and policymakers how to follow emissions from commercial aircraft activities at different airports.

Originality/value

The value of the study lies in the transparent computation of the amounts of pollutants by providing the data directly from the first hand-DoC.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 3
Type: Research Article
ISSN: 1748-8842

Keywords

To view the access options for this content please click here
Article
Publication date: 3 March 2020

Vehbi Emrah Atasoy and Selcuk Ekici

The purpose of this paper is to introduce an approach to evaluate the establishment requirements of an flight training organization (FTO) through indicators that are not…

Abstract

Purpose

The purpose of this paper is to introduce an approach to evaluate the establishment requirements of an flight training organization (FTO) through indicators that are not included in the regulations from the viewpoint of “acquired indicators from FTO experience” (AIs-FTOE).

Design/methodology/approach

Although the establishment requirements of an FTO can be determined through regulations, it was realized that the pilot training process can be achieved in a safe, sustainable and economical manner through indicators that are not included in the regulations. These indicators were obtained through experience in the operation process of the FTOs. In this study, the indicators (obtained from the regulations and experiences) affecting the efficiency of FTOs, that were or would be operational, were determined, and the effects of the indicators on the organization were examined and presented in detail. The case study was carried out in the Department of Flight Training (ETU-P) of Eskişehir Technical University which has an FTO.

Findings

In accordance with the results, the necessity indicators were defined, and the indicators that were not included in the regulations were called as AIs-FTOE. Identified AIs-FTOEs were classified into three main headings: natural and artificial obstacles, meteorological conditions and physical and technological resources. Detailed indicator data results were presented after examinations.

Practical implications

When literature on FTOs was examined, it was seen that there is a need to identify and classify indicators that affect the efficiency of FTOs. To the authors’ knowledge, this study will be the first in the literature that presented information based on an active FTO in detail. Thus, the AIs-FTOEs identified in this study will serve as a roadmap for the FTOs to be established and are to be used as parameters to evaluate efficiency for the established ones.

Originality/value

To the best of authors’ knowledge, this paper will be the first paper in the literature describing the indicators that can be evaluated in terms of efficiency, sustainability and economy of FTOs.

Details

Aircraft Engineering and Aerospace Technology, vol. 92 no. 4
Type: Research Article
ISSN: 1748-8842

Keywords

To view the access options for this content please click here
Article
Publication date: 15 July 2020

Hakan Aygoren and Emrah Balkan

The aim of this study is to investigate the role of efficiency in capital asset pricing. The paper explores the impact of a four-factor model that involves an efficiency…

Abstract

Purpose

The aim of this study is to investigate the role of efficiency in capital asset pricing. The paper explores the impact of a four-factor model that involves an efficiency factor on the returns of Nasdaq technology firms.

Design/methodology/approach

The paper relies on data of 147 firms from July 2007 to June 2017 to examine the impact of efficiency on stock returns. The performances of the capital asset pricing model (CAPM), Fama–French three-factor model and the proposed four-factor model are evaluated based on the time series regression method. The parameters such as the GRS F-statistic and adjusted R² are used to compare the relative performances of all models.

Findings

The results show that all factors of the models are found to be valid in asset pricing. Also, the paper provides evidence that the explanatory power of the proposed four-factor model outperforms the explanatory power of the CAPM and Fama–French three-factor model.

Originality/value

Unlike most asset pricing studies, this paper presents a new asset pricing model by adding the efficiency factor to the Fama–French three-factor model. It is documented that the efficiency factor increases the predictive ability of stock returns. Evidence implies that investors consider efficiency as one of the main factors in pricing their assets.

Details

Managerial Finance, vol. 46 no. 11
Type: Research Article
ISSN: 0307-4358

Keywords

1 – 10 of 48