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Article
Publication date: 2 March 2022

Emre Aydoğan and Soner Demirel

The purpose of this paper is to create and analyze the effectiveness of a new runway system, which is totally created for the future free route operations.

196

Abstract

Purpose

The purpose of this paper is to create and analyze the effectiveness of a new runway system, which is totally created for the future free route operations.

Design/methodology/approach

This paper researches and analyses the new generated runway concept with the fast time simulation method. Fuel consumption and environmental effect of the new runway system are calculated based on simulation results.

Findings

According to different traffic density analyses the Omnidirectional Runway with Infinite Heading (ORIH) reduced fuel consumption and CO2 emissions up to 46.97%. Also the total emissions of the ORIH concept, for the hydro carbon (HC), carbon monoxide (CO) and nitrogen oxides (NOx) pollutants were lower than the total emissions with the conventional runway up to 83.13, 74.36 and 51.49%, respectively.

Practical implications

Free route airspaces bring many advantages to air traffic management and airline operations. Direct routes become available from airport to airport thanks to free route airspace concept. However, conventional single runway structure does not allow aircraft operations for every direction. The landing and take-off operations of a conventional airport with a single runway must be executed with only two heading direction. This limitation brings a bottleneck direct approach and departure route usage as convenient with free route airspace concept. This paper suggests and analyzes the omnidirectional runway with infinite heading (ORIH) as a solution for free route airspace.

Originality/value

This paper suggests a new and futuristic runway design and operation for the free route operations. This paper has its originality from the suggested and newly created runway system.

Details

Aircraft Engineering and Aerospace Technology, vol. 94 no. 7
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 3 November 2022

Emre Aydoğan and Cem Cetek

The purpose of this paper is to create a flight route optimization for all flights that aims to minimize the total cost consists of fuel cost, ground delay cost and air delay cost…

215

Abstract

Purpose

The purpose of this paper is to create a flight route optimization for all flights that aims to minimize the total cost consists of fuel cost, ground delay cost and air delay cost over the fixed route and free route airspaces.

Design/methodology/approach

Efficient usage of current available airspace capacity becomes more and more important with the increasing flight demands. The efficient capacity usage of an airspace is generally in contradiction to optimum flight efficiency of a single flight. It can only be achieved with the holistic approach that focusing all flights over mixed airspaces and their routes instead of single flight route optimization for a single airspace. In the scope of this paper, optimization methods were developed to find the best route planning for all flights considering the benefits of all flights not only a single flight. This paper is searching for an optimization to reduce the total cost for all flights in mixed airspaces. With the developed optimization models, the determination of conflict-free optimum routes and delay amounts was achieved with airway capacity and separation minimum constraints in mixed airspaces. The mathematical model and the simulated annealing method were developed for these purposes.

Findings

The total cost values for flights were minimized by both developed mathematical model and simulated annealing algorithm. With the mathematical model, a reduction in total route length of 4.13% and a reduction in fuel consumption of 3.95% was achieved in a mixed airspace. The optimization algorithm with simulated annealing has also 3.11% flight distance saving and 3.03% fuel consumption enhancement.

Research limitations/implications

Although the wind condition can change the fuel consumption and flight durations, the paper does not include the wind condition effects. If the wind condition effect is considered, the shortest route may not always cause the least fuel consumption especially under the head wind condition.

Practical implications

The results of this paper show that a flight route optimization as a holistic approach considering the all flight demand information enhances the fuel consumption and flight duration. Because of this reason, the developed optimization model can be effectively used to minimize the fuel consumption and reduce the exhaust emissions of aircraft.

Originality/value

This paper develops the mathematical model and simulated annealing algorithm for the optimization of flight route over the mixed airspaces that compose of fixed and free route airspaces. Each model offers the best available and conflict-free route plan and if necessary required delay amounts for each demanded flight under the airspace capacity, airspace route structure and used separation minimum for each airspace.

Details

Aircraft Engineering and Aerospace Technology, vol. 95 no. 4
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 22 March 2019

Emre Burak Ekmekcioglu and Enver Aydogan

The purpose of this study is to examine the mediating role of organizational identification (OI) on the relationship between organizational justice (OJ) and turnover intention…

893

Abstract

Purpose

The purpose of this study is to examine the mediating role of organizational identification (OI) on the relationship between organizational justice (OJ) and turnover intention (TI), as well as the moderating role of psychological contract fulfillment (PCF) in those relationships.

Design/methodology/approach

Data were collected from 339 employees of a financial institution in Turkey. Regression analyses were conducted to investigate a moderated mediation model.

Findings

This study found that OI was partially mediated the relationship between OJ and TI. The results also indicated that the indirect effect of OJ on TI through OI was moderated by PCF.

Research limitations/implications

The generalizability of the findings is limited. As this study is cross-sectional, causal inferences cannot be inferred regarding the hypothesized relationships.

Practical implications

To reduce TI, organizations should ensure the fair allocation of resources and rewards among employees. Moreover, organizations should pay attention to the expectations of employees and the promises made to them in an attempt to fulfill psychological contract obligations.

Originality/value

This study explores the mediating role of OI in the relationship between OJ and TI. In addition, this research sheds light on the moderating role of PCF in this mediation model.

Details

International Journal of Organizational Analysis, vol. 27 no. 4
Type: Research Article
ISSN: 1934-8835

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Article
Publication date: 8 September 2022

Yildiz Kose, Suleyman Muftuoglu, Emre Cevikcan and Mehmet Bulent Durmusoglu

Autonomous maintenance (AM), one of the pillars of total productive maintenance (TPM), aims to achieve performance toward zero defects and zero breakdowns. AM system equipped with…

1044

Abstract

Purpose

Autonomous maintenance (AM), one of the pillars of total productive maintenance (TPM), aims to achieve performance toward zero defects and zero breakdowns. AM system equipped with comprehensive lean tools provides continuous improvement during the AM activities. Despite its long duration, establishing a lean AM system with a robust guideline would provide significant benefits such as high quality and short lead time. Therefore, AM design approach should be provided in a holistic and detailed manner. This study aims to develop a framework for AM design, including preliminary, reactive, preventive and proactive steps using the axiomatic design (AD).

Design/methodology/approach

Requirements and technical parameters of the AM system are explored with AD. An extensive literature review and a real-life application are presented.

Findings

The proposed design was validated by adapting the proposed roadmap to a textile manufacturing system in Turkey. The application results justify the established AM system design with an average downtime improvement of 69.2% and the average elapsed time between two failures improvement of 65.1% for apparel department.

Originality/value

This study has the novelty of establishing an overall AM system design with all of its stages stepwise. It presents a comprehensive guideline in terms of integration of lean philosophy into AM design by generating maintenance-related use cases for lean tools. The developed approach facilitates creating and analyzing complex systems to improve maintenance implementations while reducing nonvalue-added operations.

Details

International Journal of Lean Six Sigma, vol. 14 no. 3
Type: Research Article
ISSN: 2040-4166

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Article
Publication date: 25 April 2023

Cevahir Uzkurt, Semih Ceyhan, Emre Burak Ekmekcioglu and Musab Talha Akpinar

This paper aims to explore the effect of government support (short work allowances – SWA) on SME employees' job performance and employee motivation perceptions, during the…

746

Abstract

Purpose

This paper aims to explore the effect of government support (short work allowances – SWA) on SME employees' job performance and employee motivation perceptions, during the COVID-19 pandemic in Turkey.

Design/methodology/approach

Survey data were collected from 2,781 employees working in SMEs registered to Small and Medium Enterprises Development Organization (SMEDO) in Turkey. The relationships were assessed through structural equation modeling with bootstrap estimation.

Findings

The results support the proposed framework illustrating the positive effect of government support on employees' perceived motivation and job performance. Findings indicate that employee motivation has exhibited a mediating effect between government support and job performance. Another important finding is that, contrary to the classical understanding of Herzberg's two-factor theory, SWA system was able to perform as a motivating factor during the pandemic by meeting the hygiene needs.

Research limitations/implications

Since this is a cross-sectional research study, causal inferences cannot be derived from the research results.

Originality/value

There is a lack of empirical study on SME employees' perceptions on the government support during the pandemic, especially on the perspectives of emerging economies are infrequent. Turkey's case is unique in terms of providing insights on how perceived employee motivation is increased by the government supports (SWA) in Turkey, and how this motivation mediates the job performance perceptions. Besides, the impacts of government support are mostly studied at the firm or macro-levels, this study's unit of analysis is at individual level. Regarding the criticism from the motivation perspective of two-factor theory, COVID-19 context and its impact on the motivation needs have not been elaborated before. This article starts new discussions on how crisis contexts influence individual motivator factors.

Details

International Journal of Emerging Markets, vol. 20 no. 2
Type: Research Article
ISSN: 1746-8809

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Book part
Publication date: 16 December 2009

Nilufer Narli

The EU harmonisation has created changes in the military's formal and informal influence in the directions of decreased formal and informal military influence in civilian…

Abstract

The EU harmonisation has created changes in the military's formal and informal influence in the directions of decreased formal and informal military influence in civilian politics. The EU reforms have created changes in the mindset of the citizens, by creating changes in the security culture of the citizens and in the civil-military related political culture. The desired level of alignment has not been reached. Therefore, the study examines the areas where further alignment is required. Moving from Rebecca L. Schiff's concordance theory, the article examines the relationship between the Turkish military, the civilian politics and the society before and after the EU harmonisation process. It examines the effects of the EU harmonisation process on the changes in the civil-military balance of power, and on the related security culture and political values. The analysis focuses on: (i) increased civilian control and consequent changes in the policy of accountability; (ii) transparency building in the defence sector; (iii) parliamentary oversight; and (iv) the change in the political culture related to the civil-military issues. It also investigates the extent the EU harmonisation has achieved in building democratic civil-military relations in order to align with the EU standards.

Details

Advances in Military Sociology: Essays in Honor of Charles C. Moskos
Type: Book
ISBN: 978-1-84855-893-9

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Article
Publication date: 1 May 2020

Emre Cevikcan and Mehmet Bulent Durmusoglu

Rabbit chase (RC) is used as one of the most effective techniques in manufacturing systems, as such systems have high level of adaptability and increased productivity in addition…

278

Abstract

Purpose

Rabbit chase (RC) is used as one of the most effective techniques in manufacturing systems, as such systems have high level of adaptability and increased productivity in addition to providing uniform workload balancing and skill improving environment. In assembly systems, RC inspires the development of walking worker assembly line (WWAL). On the other hand, U-type assembly lines (UALs) may provide higher worker utilization, lower space requirement and more convenient internal logistics when compared to straight assembly lines. In this context, this study aims to improve assembly line performance by generating RC cycles on WWAL with respect to task assignment characteristics of UAL within reasonable walking distance and space requirement. Therefore, a novel line configuration, namely, segmented rabbit chase-oriented U-type assembly line (SRCUAL), emerges.

Design/methodology/approach

The mathematical programming approach treats SRCUAL balancing problem in a hierarchical manner to decrease computational burden. Firstly, segments are generated via the first linear programming model in the solution approach for balancing SRCUALs to minimize total number of workers. Then, stations are determined within each segment for forward and backward sections separately using two different pre-emptive goal programming models. Moreover, three heuristics are developed to provide solution quality with computational efficiency.

Findings

The proposed mathematical programming approach is applied to the light-emitting diode (LED) luminaire assembly section of a manufacturing company. The adaptation of SRCUAL decreased the number of workers by 15.4% and the space requirement by 17.7% for LED luminaire assembly system when compared to UAL. Moreover, satisfactory results for the proposed heuristics were obtained in terms of deviation from lower bound, especially for SRCUAL heuristics I and II. Moreover, the results indicate that the integration of RC not only decreased the number of workers in 40.28% (29 instances) of test problems in U-lines, but also yielded less number of buffer points (48.48%) with lower workload deviation (75%) among workers in terms of coefficient of variation.

Practical implications

This study provides convenience for capacity management (assessing capacity and adjusting capacity by changing the number of workers) for industrial SRCUAL applications. Meanwhile, SRCUAL applications give the opportunity to increase the capacity for a product or transfer the saved capacity to the assembly of other products. As it is possible to provide one-piece flow with equal workloads via walking workers, SRCUAL has the potential for quick realization of defects and better lead time performance.

Originality/value

To the best of the authors’ knowledge, forward–backward task assignments in U-type lines have not been adapted to WWALs. Moreover, as workers travel overall the line in WWALs, walking time increases drastically. Addressing this research gap and limitation, the main innovative aspect of this study can be considered as the proposal of a new line design (i.e. SRCUAL) which is sourced from the hybridization of UALs and WWAL as well as the segmentation of the line with RC cycles. The superiority of SRCUAL over WWAL and UAL was also discussed. Moreover, operating systematic for SRCUAL was devised. As for methodical aspect, this study is the first attempt to solve the balancing problem for SRCUAL design.

Details

Assembly Automation, vol. 40 no. 3
Type: Research Article
ISSN: 0144-5154

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