Ibrahim Yildiz and Hakan Caliskan
The purpose of this study is to evaluate the energy and exergy prices and carbon emission equivalents of the jet kerosene (Jet A-1) fuel considering 12 months data for an air…
Abstract
Purpose
The purpose of this study is to evaluate the energy and exergy prices and carbon emission equivalents of the jet kerosene (Jet A-1) fuel considering 12 months data for an air craft used in the air transport sector in Turkey.
Design/methodology/approach
In the selection of the energy resources, one of the most important factors besides the need is the price of the energy resources. To use and save the energy resources efficiently, the prices should be evaluated in terms of exergy too. In this context, the exergy prices and carbon emission equivalents of the jet kerosene fuel have been examined.
Findings
According to analysis results, after January 2020, a steady decline in energy prices has been obtained until April 2020. In this regard, directly proportional changes have been obtained in exergy prices. The minimum exergy price of the fuel is calculated as 74.36 US cents/kWh for April 2020, while the maximum exergy price of the fuel is calculated as 150.02 US cents/kWh for September 2019. The minimum exergy price based carbon emission equivalents for the jet kerosene fuel is determined as 1,099.98 US cents/kg for April 2020, while the maximum exergy price based carbon emission equivalents for the jet kerosene fuel is found to be 2,219.29 US cents/kg for September 2019.
Originality/value
The new contribution has been made to the open literature by examining the energy and exergy prices of the jet kerosene fuel. In addition, the carbon emission equivalents of the jet kerosene fuel have been determined not only energy but also exergy methods.
Details
Keywords
Metin Vatansever, İbrahim Demir and Ali Hepşen
The main purpose of this study is to detect homogeneous housing market areas among 196 districts of 5 major cities of Turkey in terms of house sale price indices. The second…
Abstract
Purpose
The main purpose of this study is to detect homogeneous housing market areas among 196 districts of 5 major cities of Turkey in terms of house sale price indices. The second purpose is to forecast these 196 house sale price indices.
Design/methodology/approach
In this paper, the authors use the monthly house sale price indices of 196 districts of 5 major cities of Turkey. The authors propose an autoregressive (AR) model-based fuzzy clustering approach to detect homogeneous housing market areas and to forecast house price indices.
Findings
The AR model-based fuzzy clustering approach detects three numbers of homogenous property market areas among 196 districts of 5 major cities of Turkey where house sale price moves together (or with similar house sales dynamic). This approach also provides better forecasting results compared to standard AR models by higher data efficiency and lower model validation and maintenance effort.
Research limitations/implications
In this study, the authors could not use any district-based socioeconomic and consumption behavioral indicators and any discrete geographical and property characteristics because of the data limitation.
Practical implications
The finding of this study would help property investors for establishing more effective property management strategies by taking different geographical location conditions into account.
Social implications
From the government side, knowing future rises, falls and turning points of property prices in different locations can allow the government to monitor the property price changes and control the speculation activities that cause a dramatic change in the market.
Originality/value
There is no previous research paper focusing on neighborhood-based clusters and forecasting house sale price indices in Turkey. At this point, it is the first academic study.
Details
Keywords
Fatih Pinarbasi and Ibrahim Kircova
Today’s business environment has the nature that challenges the decision-making processes of businesses with its many different factors including technological developments and…
Abstract
Today’s business environment has the nature that challenges the decision-making processes of businesses with its many different factors including technological developments and changing consumer structures. Previous research focused on specific contexts of the business environment regarding marketing and innovation issues, however, an integrative approach can be helpful for understanding and taking actions. This study aims to present a comprehensive framework which employs sensemaking from management literature as an approach to evaluate the market environment. Following a conceptual approach for the methodology, a framework consisting of three stages: discovery, sensemaking, and prediction is included in the study. Proposed framework identifies the stages for the sensemaking of consumers and can guide marketing decision-makers for competitiveness in the digital world.
Details
Keywords
Ibrahim Ayaz, Ufuk Sakarya and Ibrahim Hokelek
The purpose of this paper is to present a verification methodology for custom micro coded components designed for Avionics projects. Every electronic hardware which will be…
Abstract
Purpose
The purpose of this paper is to present a verification methodology for custom micro coded components designed for Avionics projects. Every electronic hardware which will be developed for an aircraft must be designed with the compliance of DO-254 processes. Requirements are the key elements of the aviation. All the requirements must be covered by the design to be considered as completed. Therefore, verification of the custom micro coded components against requirements should be comprehensively addressed. The verification using the manual testing approach is less preferable, as humans can possibly make mistakes. Therefore, the most used verification method today is the automated simulation.
Design/methodology/approach
The industry has developed a common methodology for generating automated testbenches by following the standardized guideline. This methodology is named as the universal verification methodology (UVM). In this paper, the verification study of ARINC-429 data bus digital design is presented to describe the DO-254 verification process using the UVM.
Findings
The results are supported with functional coverage and code coverage in addition to the assertions. It is observed that the design worked correctly.
Originality/value
To the best of the authors’ knowledge, this is the first study comprehensively describing the DO-254 verification process and demonstrating it by the UVM application of ARINC-429 on programmable logic devices.
Details
Keywords
Fatih Çelik, Selçuk Yasin Yıldız, Behcet Yalin Ozkara, Mehmet Safa Çam and Blend Ibrahim
The study investigates the antecedents and consequences of digital ad avoidance in the e-commerce industry. This study aims to investigate how digital ad avoidance relates to…
Abstract
Purpose
The study investigates the antecedents and consequences of digital ad avoidance in the e-commerce industry. This study aims to investigate how digital ad avoidance relates to internet usage over time, using a two-wave longitudinal research design. This study also explores how real-world advertising clutter (clutter and non-clutter) affects these relationships.
Design/methodology/approach
The data were collected from 192 online consumers in Türkiye, and a two-wave longitudinal research design and structural equation modeling were conducted to test the hypotheses of the conceptual model.
Findings
The results indicated that perceived goal impediment and prior negative experience had positive effects on affective avoidance in both ad-clutter and non-clutter periods. Further, affective avoidance had a significant positive effect on both cognitive and behavioral avoidance in either period. In addition, ad clutter moderated the effects of cognitive and behavioral avoidance on online purchase intention.
Originality/value
This research provides new evidence of the crucial role perceived goal impediment, prior negative experience and perceived control each play in driving digital ad avoidance. This paper contributes to the body of knowledge in the field by exploring how advertising clutter (both cluttered and non-cluttered settings) moderates these relationships through a two-wave longitudinal study.
Details
Keywords
Ibrahim Yahaya Wuni, Derek Asante Abankwa, Kerim Koc, Bernard Tuffour Atuahene and Abdullahi Saka
Integrated digital delivery (IDD) is the use of digital technologies, data, and platforms to integrate work processes and connect all stakeholders working on the same project…
Abstract
Purpose
Integrated digital delivery (IDD) is the use of digital technologies, data, and platforms to integrate work processes and connect all stakeholders working on the same project throughout the construction and building lifecycle. The benefits of digital technologies are often cited to justify the adoption of IDD in construction projects, but such benefits remain under-researched and unverified. The purpose of the paper is to investigate the performance improvements attributable to the IDD approach in construction projects.
Design/methodology/approach
This study combined questionnaire surveys, statistical analysis, social network analysis, and fuzzy synthetic evaluation to investigate the benefits of IDD in Hong Kong construction projects. The methodology was applied to rank the benefits of IDD, assess the benefit categories of the IDD, and model the relationships between the benefits.
Findings
The results showed twenty-two (22) significant benefits of the IDD approach, grouped into design, cost, collaboration, sustainability, procurement, and productivity benefits. Design and collaboration benefits were ranked at the top and “high quality and faster preparation of designs” and “improved information exchange and management” were the most important benefits in these clusters, respectively. The weighted network model showed that the benefits of IDD are significantly correlated, and “cost savings associated with digital project delivery”, “improved work and project quality”, and “high quality and faster preparation of designs and calculation” were identified as the most influential benefits.
Originality/value
The study outcomes offer the first empirical insights into performance gains achievable with the IDD approach in construction projects. Hence, this study, for the first time, identified and assessed the benefits and benefit categories as well as formulating the relationships between the benefits to suggest the most effective benefit pipeline.
Details
Keywords
Serkan Altuntas, Omer Cinar and Selahattin Kaynak
The purpose of this study is to find the relationships among advanced manufacturing technology (AMT), innovation, export and firm performance by using data obtained from 310…
Abstract
Purpose
The purpose of this study is to find the relationships among advanced manufacturing technology (AMT), innovation, export and firm performance by using data obtained from 310 Turkish manufacturing firms.
Design/methodology/approach
A survey study was performed to obtain data from manufacturing firms. Multiple-item scales were adapted from the literature to conduct the survey in this study. Data were collected from five cities located in the Southeastern Anatolia Region in Turkey (Gaziantep, Adiyaman, Kilis, Diyarbakir and Sanliurfa). Structural equation modeling was utilized to investigate the relationships among AMT, innovation, export and firm performance in Turkish manufacturing firms operating in several industries. The direct and indirect relations between these variables are examined in the proposed conceptual model. In addition, the complex relations including in the proposed model are assessed in detail through the mediation analysis.
Findings
Six of the proposed ten hypotheses related to manufacturers are validated by the empirical evidence from manufacturing companies in Turkey. Significant findings obtained in this study include the following: there are strong positive associations between the use of AMT and innovation and between export and firm performance. In addition, innovation mediates the relationship between AMT and firm performance and between AMT and export. Finally, export mediates the relationship between AMT and firm performance and between innovation and firm performance. It is expected that the results obtained from this empirical analysis will help decision makers and managers to construct a good technology and production management strategy for manufacturing systems.
Originality/value
In this study, a novel conceptual model is proposed to examine the relationships among AMT, innovation, export and firm performance via the use of survey responses from 310 Turkish manufacturing firms. To the authors’ best knowledge, this is the first study that proposes such a conceptual model in the literature.
Details
Keywords
Ibrahim Senol, Metin Demirtas, Sabir Rustemov and Bilal Gumus
The aims of the paper are to improve the dynamic response of an induction motor based position servo system and to remove the chattering problem in the sliding mode control theory…
Abstract
Purpose
The aims of the paper are to improve the dynamic response of an induction motor based position servo system and to remove the chattering problem in the sliding mode control theory by using fuzzy logic principles. The obtained results are also compared with conventional sliding mode controller to show its performance.
Design/methodology/approach
The main method used for the research is to form a thin boundary layer neighboring the switching surface by using fuzzy logic. The sliding mode control law is inherently discontinuous naturally. Therefore, there are some difficulties such as so many switches occurring between the control bounds, which cannot be carried out by real controllers. Therefore, fuzzy logic is used in the thin boundary layer to determine the control signal current. Thus, the chattering is eliminated.
Findings
The results show that the designed controller has superior performance. But, there are also some difficulties. It is difficult to obtain fuzzy rules. The rules can be obtained by using genetic algorithms without expert's knowledge. However, sliding surface slope C can be optimized to increase system's dynamic performance.
Originality/value
A new boundary layer consisting of the fuzzy rules in the sliding mode control is formed.
Details
Keywords
Omer Cinar, Serkan Altuntas and Mehmet Asif Alan
The purpose of this study is to determine the relationships between technology transfer, innovation and firm performance.
Abstract
Purpose
The purpose of this study is to determine the relationships between technology transfer, innovation and firm performance.
Design/methodology/approach
The relationship between technology transfer, innovation and firm performance is examined by using data obtained from 252 Turkish export firms, which are among the top 1,000 firms in terms of export volume in Turkey. To examine these relationships, a theoretical framework is empirically tested using structural equation modeling and tested via an empirical study of Turkish export companies.
Findings
The results of this study can benefit policymakers in government at the national level and company decision-makers at the firm level. Furthermore, an understanding of the relationship between technology transfer, innovation and firm performance may help firms to make correct technology transfer decisions and focus on the correct type of innovation to increase firm performance in practice. The findings indicate the positive effects of technology transfer on innovation and firm performance. In addition, innovation mediates the relationship between technology transfer and firm performance in Turkish export companies. This study suggests that decision-makers should transfer the right technology because well-realized technology transfers lead to the improvement of corporate innovation capacities and improvement of firm performances for export companies.
Originality/value
There is no study that fully examined the relationship between technology transfer, innovation and firm performance. The proposed literature-based theoretical framework in this study is novel for Turkish export companies.