Yasar University
  • İzmir, Turkey
Recent publications
The study analyzes the asymmetric nexus of coal consumption with environmental quality and economic growth. In this context, the study focuses on 8 leading emerging countries that take place in BRICS, E7, and Fragile Five groups. Also, the study uses yearly data from 1989 to 2021 and performs novel quantile methods, such as Granger Causality-in-Quantiles (GCQ) and Quantile-on-Quantile Regression (QQR). Also, Quantile Regression (QR) is used for robustness check. The results present that (i) there are causalities from coal consumption to both environmental quality and economic growth at 10% significance, whereas quantile and country-based results differ; (ii) effects of coal consumption on environmental quality are much stronger in lower quantiles for Brazil, Indonesia, India, South Africa, and, Turkey, but in higher quantiles for China, Mexico, and Russia; (iii) effects of coal consumption on economic growth are much stronger in lower quantiles for Brazil, Indonesia, India, Russia, South Africa, and Turkey; in higher quantiles for China; lower and middle quantiles for Russia; and all quantiles for Mexico; (iv) the robustness of the QQR results are validated. Hence, empirical outcomes underline the highly crucial effects of coal consumption on environmental quality and economic growth in the countries. The results imply that policymakers should focus on efforts to decrease coal consumption gradually by applying a macro transition plan to increase environmental quality without causing economic decline by considering changing effects of coal consumption at quantiles and countries.
Recent cross-cultural and neuro-hormonal investigations have suggested that love is a near universal phenomenon that has a biological background. Therefore, the remaining important question is not whether love exists worldwide but which cultural, social, or environmental factors influence experiences and expressions of love. In the present study, we explored whether countries’ modernization indexes are related to love experiences measured by three subscales (passion, intimacy, commitment) of the Triangular Love Scale. Analyzing data from 9474 individuals from 45 countries, we tested for relationships with country-level predictors, namely, modernization proxies (i.e., Human Development Index, World Modernization Index, Gender Inequality Index), collectivism, and average annual temperatures. We found that mean levels of love (especially intimacy) were higher in countries with higher modernization proxies, collectivism, and average annual temperatures. In conclusion, our results grant some support to the hypothesis that modernization processes might influence love experiences.
Despite the impact of ideologies on corporate social responsibility (CSR), little is known whether the authenticity of CSR can be assessed in the face of ideological tensions. Following cognitive dissonance and attribution theories, this study investigates the impact of CSR authenticity, which is conceptualized as a function of (1) the ideological fit between company and its CSR initiative and (2) the perceived motive of an ideologically distinct initiative, on organizational attractiveness. Findings of a survey on 253 respondents reveal that while both dimensions of CSR authenticity affect organizational attractiveness, the fit between company and its CSR has a higher effect than does the social motive of CSR. Moreover, positive attitudes toward the CSR initiative as well as the company itself both mediate these relationships. The study shows taking an ideological perspective in authenticity is a relevant approach to understand CSR in the politically polarized contexts of most countries.
Polymer-based dielectric materials exhibiting high permittivity and high dielectric loss can be preferred in electromagnetic interference shielding due to providing lightweight and better corrosion characteristics as compared to heavy metals. In this work, modified carbon black (CB), graphite (GR) and expanded graphite (e-GR) are incorporated with an ionic liquid; 1-Butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) in a polyvinylidene fluoride (PVDF) matrix in form of their binary alloys. Electromagnetic shielding effectiveness (SE) and complex permittivity/permeability characteristics of synthesized materials are investigated and measured both in X and Ku band waveguides. The addition of the [BMIM]BF4 into material is observed to enhance ionic conductivity as well as polarizability of the designed composites. The ionic liquid (IL) comprising and IL-free e-GR based composites are measured to give minimum 32.7 dB and 28.1 dB shielding effectiveness along X-band, and minimum 39.5 dB and 35.5 dB shielding effectiveness along Ku-band frequency ranges for materials having 3.00 mm sample thicknesses, respectively. In comparison with the modified CB and GR, the e-GR exhibits better dispersion and superior SE values in the PVDF matrix. In addition to homogeneity observations obtained from scanning electron microscope (SEM), an electromagnetic approach to check homogeneity of the synthesized composites is proposed to the literature, which compares shielding effectiveness values per unit thickness (dB/mm) calculated from S-parameter measurements with vector network analyzer (VNA) and calculated from permittivity/permeability values being extracted with Nicolson-Ross-Weir (NRW) algorithm. The homogeneity of composites is found sufficient, and more than 9.5 dB/mm and 11.5 dB/mm shielding effectiveness for IL e-GR composite are obtained at X and Ku-bands, respectively.
Sediment transport is a noteworthy task in the design and operation of sewer pipes. Decreasing sewer pipe hydraulic capacity and transport of pollution are the main consequences of continuous sedimentation. Among different design approaches, the non-deposition with deposited bed (NDB) method can be used for the design of large sewer pipes; however, existing models are established on limited data ranges and mostly applied conventional regression methods. The current study improves the NDB sediment transport modeling by utilizing wide data ranges, and furthermore, applying robust machine learning techniques. In the present study, the conventional extreme learning machine (ELM) technique and its advanced versions, namely the online sequential-extreme learning machine (OS-ELM), outlier robust-extreme learning machine (OR-ELM), and parallel layer perceptron-extreme learning machine (PLP-ELM) are used for the modeling. In the studies conducted in the literature, sediment deposited bed thickness (ts) or deposited bed width (Wb) was used in the model structure as a deposited sediment variable, and therefore, different parameters in terms of ts and Wb can be incorporated into the model structure. However, an uncertainty arises in the selection of the appropriate parameter among Wb/Y, ts/Y, Wb/D, and ts/D (Y is flow depth and D circular pipe diameter). In order to define the most appropriate parameter to best describe the impact of deposited sediment at the channel bottom in the modeling procedure, four various scenarios using four different parameters that incorporate deposited sediment variables at their structures as Wb/Y, ts/Y, W/D, and ts/D are considered for model development. It is found that models that incorporate sediment bed thickness (ts) provide better results than those which use deposited bed width (Wb) in their structures. Among four different scenarios, models that utilized ts/D dimensionless parameter, give superior results in contrast to their alternatives. Based on the outcomes, the OR-ELM approach outperformed ELM, OS-ELM, and PLP-ELM techniques. The results obtained from applied methods are compared to their corresponding models in the literature, indicating the superiority of the OR-ELM model. It is figured out that the thickness of the deposited bed is an effective variable in modeling NDB sediment transport in sewer pipes.
For various reasons, it is not always possible to obtain adequate and reliable long-term streamflow records in a river basin. It is known that streamflow records are even shorter when the stations located on tributary channels are of the interest. Hence, it is necessary to develop dependable streamflow estimation models for the tributary streams that play a key role in the micro-hydrology of the basin. In this study, rainfall-runoff models are developed to estimate the daily streamflow in ungauged tributary streams. Precipitation and streamflow in the most similar gauging station on the main channel and lagged values up to three days before on the same tributary station are used as the input variables of the allocated models. To select the most similar gauging station, a similarity index criterion is developed and used in the analysis. Then, two scenarios based on the streamflow or the corresponding set of direct runoff and base-flow in the same station are used. By applying multivariate adaptive regression spline (MARS) and random forest (RF) methods, several rainfall-runoff models are developed and evaluated based on determination coefficient, mean absolute percentage error, root mean square error, relative peak flow, scatter plot and time series plot. Alternatively, the MARS and RF models are combined with a drainage area ratio (DAR) model to produce the DAR-MARS and DAR-RF models. It is concluded that the direct runoff in the mainstream is more effective on the streamflow of the tributary station, while the integration of models with DAR enhanced the capabilities of the models in estimation of extreme values in the streamflow time series.
A guard is defined as an entity capable of observing the terrain or sensing an event on the terrain. By this definition, relay stations, sensors, watchtowers, military units, and similar entities are considered as guards. Terrain Guarding Problem (TGP) is about locating a minimum number of guards on terrain such that points on the terrain are guarded by at least one of the guards. Terrains are generally represented as triangulated irregular networks (TIN), and TINs are also referred to as 2.5 dimensional (2.5D) terrains. TGP on 2.5D terrains is known as 2.5D TGP. 1.5D terrain is a profile of a 2.5D terrain, and the guarding problem on a 1.5D terrain is referred to as 1.5D TGP. This paper presents an example that illustrates that the set of vertices in TIN does not necessarily contain an optimal solution, which implies that an optimal solution is yet to be found for 2.5D TGP. We show that a finite dominating set (FDS) found earlier for 1.5D TGP is optimal in the sense that no other FDS has a smaller cardinality.KeywordsLocation theoryFinite dominating setsTerrain guarding problemSet-covering
With the recent increase in e-commerce, automated warehousing industries seek technology solutions providing high transaction rates with economic investment costs. In this context, the application of smart operational policies towards future smart factories’ concepts becomes a critical issue. With the help of recent IT and technological advancements towards Industry 4.0 developments, we study intelligent autonomous vehicle operation policies where vehicles can make decentralized decisions for their safe and flexible travels between multiple aisles in a warehouse. By that, instead of assigning vehicles within a dedicated zone, we allow vehicles to travel freely between multiple aisles. The advantage of such a travel policy might result in a reduced number of vehicle requirements in a warehouse compared to a dedicated path policy. However, the disadvantage of such a flexible travel policy might be the development of smart collision and deadlock control algorithms, and that travel of vehicles might result in increased travel time during their operation due to deadlock and collision cases. First, we develop a smart travel policy approach for the vehicles using an agent-based simulation modeling approach. Then, we apply a statistical method, analysis of variance (ANOVA), to identify which input design factors significantly affect the system performance. As a result, it is observed that the number of bays is the most significant factor affecting the performance of such a system.KeywordsAutonomous vehicleAgent-based simulationAutomated warehousingCollisionDeadlock
Agile has been invented to improve and overcome the deficiencies of efficient software development. At present, the agile model is used in software development vastly due to its support to both developers and clients resourcefully. Agile methodology increases the interaction between the developer and client to make the software product defect-free. The agile model is getting to be a well-known life cycle model because of its particular features and most owing is to allow changes at any level of the project from the product owner. However, on other hand, this novel feature is a disadvantage of the agile model due to frequent change requests from the client has increased the cost and time. To overcome cost and time estimation issues different cost estimation techniques are being used in agile development but no one is pertinent for accurate estimation. Therefore, this study has proposed a cost estimation technique. The proposed estimation technique is predictions-based and has different categorizations of projects based on user stories complexities and the developer's expertise. We have applied the suggested technique to ongoing projects to find the results and effectiveness. We have used two projects with different sizes and user stories. Both projects have different modules and developers with different expertise. We have used the proposed estimation technique on projects and done a survey session with the teams. This survey session's main objective is to reveal the statistical findings of the proposed solution. We have designed the 12 hypotheses for statistical analysis.
Many different sectors are obliged to implement the 17 goals established by the United Nations General Assembly, both for their own life cycles and for the future of our world. Each goal has its own goals and plans. Although different applications are made for these targets on a sectoral basis, a common language must be developed for each target. In this study, the 7th goal of the Sustainable Development Goals (SDGs), the goal of providing access to economic, sustainable and clean energy for everyone, was emphasized. In the study, the maritime transport sector, which has a large share in the logistics sector in terms of both economic and environmental damage, has been selected. In this context, the sustainability, environment, corporate social responsibility and annual reports of the 33 biggest European ports with a gross weight handling volume were examined in line with the SDG 7 target and a content analysis was made on these reports. According to the results of the analysis, the contribution and approach of Europe’s largest ports to Clean and Affordable Energy, the 7th sustainable development goal of the United Nations, emerged.
Problems such as excessive consumption habits, depletion of natural resources and global climate change keep the concepts of both eco-entrepreneurship and bioeconomy on the agenda. Within the scope of the study, agro-food-oriented bioengineering practices, in which biotechnology is at the center, were examined in the circular economy line. In the review, eco-technological applications under field-specific titles have progressed in the form of examining academic and sectoral studies in the world. Hence, it has been determined that the need for interdisciplinary improvement in biosystems has become an important issue on international scale, especially in recent years. In this way, it has been seen that significant contributions will be made in finding solutions to the productivity and efficiency problems that arise in eco-technological bioengineering applications, especially with the contribution of entrepreneurship ecosystem studies. For this reason, it is essential to carry out studies in which all actors involved in agriculture-food-biotechnology systems can come together. Therefore, existing problem areas in bioengineering applications for sustainable development should be identified and joint solution proposals should be developed for the identified problem areas.
The amount of information that emerges with the rapidly developing technology is increasing daily, revealing the need for knowledge management. Knowledge management updates the ever-increasing information capacity in organizations, makes the information available, defines the processes necessary to reach the required information, and enables the knowledge needed to be shared. Especially in higher education institutions, sustainable knowledge management is essential for developing a long-term sustainable culture. Therefore, this study aims to determine the enablers of sustainable knowledge management in higher education institutions. As a result, fostering sustainable learning is determined as the best criterion for the case of higher education institutors.KeywordsKnowledge ManagementSustainabilityBest Worst Method Sustainable development
This paper studies performance comparison of two shuttle-based storage and retrieval system (SBS/RS) configurations developed on flexible or non-flexible travel policies of shuttles in the system. In the non-flexible SBS/RS, a shuttle is dedicated to a tier so that it cannot travel out of its dedicated aisle and tier. A lifting mechanism is installed in each aisle to provide vertical travel for loads. In flexible SBS/RS, shuttles can travel between tiers by a separate lifting mechanism installed on the other edge point of each aisle. The advantage of that flexible design is that there might be decreased number of shuttles settling in the system compared to the non-flexible design. We simulate the two system configurations and conduct an experimental design for the comparison purpose. Based on the three-performance metrics: total investment cost, throughput rate and energy consumption per transaction, the results show that mainly the flexible system provides better results which might be considered as future system investment for SBS/RS.
This study focuses on fabrication laboratories (fab labs) that provide user-oriented innovative urban spaces to meet advanced technologies and city dwellers who can share their knowledge in solving local problems. The aim is to explore the potential of fab labs as a part of smart city initiatives to develop the fab city by creating a network for collective knowledge and technology-enabled production in collaboration with local communities, companies, NGOs, and institutions. The opted methodology is to examine several fab labs as innovative and creative spaces in İzmir to evaluate their potential role in the development of the fab city. Fab labs might improve the organizational gap between local governments and inhabitants in developing innovative and sustainable solutions. This paper fulfills the lack of systematic research on fab labs; how they relate to smart city initiatives, evolving into fab cities, and obtaining and implementing the know-how of fab cities’ global knowledge.
This paper aims to increase the accuracy measure of the subgraph of a graph and generate new nano topologies on the power set of vertices and edges of a graph. Firstly, we introduce \({\mathcal {E}}_j\)-neighborhoods and \({\mathcal {C}}_j\)-neighborhoods which depend on vertices and edges of a simple directed graph by using j-neighborhoods for \(j\in \{\text {out}, \text {in}, \cap , \cup \}\). Then, we apply these neighborhoods to present the concepts of \({\mathcal {E}}_j\)-approximations and \({\mathcal {C}}_j\)-approximations. We investigate their main properties and relationships among them. Besides, we define the accuracy measures of a subgraph with the help of these approximations and show that \({\mathcal {C}}_j\)-accuracy measures are the highest when we compare these accuracy measures with the previous one. Furthermore, we generate new nano topologies via obtained approximations and illustrate that these topologies may not be comparable. Finally, we give an application in physics to elucidate the current approximations are more general. Throughout the paper, we summarize all comparisons with tables and give counterexamples to support the study.
This article focuses on the effects of different representation modes of architectural heritage in augmented reality (AR) applications on remembering. Deterioration of the tangible evidence of architectural heritage compromises not only its visibility in the heritage site, but also its presence in memory. Converging survived features and digitally produced representations of the heritage, AR applications in mobile devices provide the memory of the site with endurance, however what is remembered immensely depends on how the heritage is digitally represented on screen. Conceived as a case study for the method of analysis derived from classical memorizing technique of the art of memory, the ‘[AR]temis’ project, reported in this article, aimed to get insights into the effects of the representational qualities of augmented architectural heritage on remembering and also into future AR projects developed for architectural heritage sites with its original method of analysis to inform design decisions. The research project involved the development of the method of art of augmented memory, the AR application, as well as questionnaires and interviews with the respondents’ on-site tests of the application. The results of this analysis show that the decisions regarding the digital representation of architectural heritage in AR applications entail not only the visual qualities of the heritage per se, but also how the actual site of memory is visualized on screen.
Windows are the weakest elements due to their high heat transfer coefficient and are responsible for 60% energy heat/gain loss. Healthcare buildings are one of the biggest consumers of energy due to continuous occupation hours and medical requirements, providing comfortable conditions for people in need of care and staff; yet recently less attention was given to healthcare buildings due to their unique operational requirements and advanced medical equipment. Thus, the main purpose of this study was to evaluate energy saving potentials of windows through glazing and shading alternatives over a case study. Within this study, a single patient room in Izmir Turkey has been chosen as a case study, and the room was simulated for sixteen scenarios generated by using four different glazing and shading systems. Each design scenario was simulated using DALEC for their lighting, heating, cooling, and total energy consumption. Results showed that lighting energy consumption constitutes the highest energy demand (up to 52%) and high transmitting glazing usage can reduce lighting loads. Finally, up to 16.3%, energy saving is possible only by changing shading and glazing types. Though there is a great diversity of glazing and shading types, this study’s outputs only reflect the selected four glazing and four shading system types that are offered by DALEC. Healthcare buildings spend a vast amount of energy to provide thermal and visual comfort for various user profiles. Considering the large number of patient rooms in healthcare facilities, only careful consideration of glazing or shadings can significantly contribute to energy savings. This study focuses on shading and glazing alternatives as an energy-saving strategy. For simulation, an underrecognized BES tool DALEC was hyped to show integrated thermal and visual energy consumption. The findings highlight that energy savings of up to 16.3% is possible.
In November 2021, the 26th United Nations Climate Change Conference (COP26) was held in Glasgow, UK, the global leaders from nearly 200 countries stressed taking immediate action on the climate issue and how to ensure global net-zero emissions by 2030. It is possible to accelerate the transition to low-carbon energy systems, the present study seeks to identify and analyse key barriers to Low Carbon Operations (LCO) in emerging economies. A critical literature review was undertaken to recognise the barriers linked to the adoption of LCO. To validate these barriers, an empirical study with a dataset of 127 respondents from the Indian automobile industry was conducted. The validated barriers were analysed using Best Worst Method (BWM) and Decision-Making Trial and Evaluation Laboratory (DEMATEL) techniques. BWM is used to determine the priority ranking of barriers, while the DEMATEL method is employed to elucidate the cause-effect inter-relationships among the listed barriers. The results suggest that ‘Economic’ is the most influential category of barriers followed by ‘Infrastructure’ and ‘Operational’. The results also show that the barriers ‘Economic’, ‘Environmental’, ‘Infrastructure’ and ‘Organizational Governance’ belong to the cause group. Some significant managerial implications are recommended to overcome these barriers and to assist firms in the successful adoption of LCO and achieving net-zero emissions. The work was carried out in the automotive industry in India but provides findings that may have wider applicability in other developing countries and beyond.
This study reviews the role of top management commitment in realizing sustainability goals in interfirm and supply chain relationships. Next, the study employs the resource-based view of the firm to implicate top management commitment as a moderator of influences of green innovation practices on customer cooperation. Using survey design methodology, we collected data from different 181 ISO 14001 certified Turkish manufacturing firms. We tested the proposed hypotheses by using the hierarchical multivariate regression approach. The direct effect of top management commitment on green process innovation is significant, while its effect on green managerial innovation is insignificant. However, the results show that manufacturer-customer relationships support top management commitment as a positive moderator of the relationship between green innovation practices and customer cooperation. Our results underscore the vital role played by top management in the firm’s efforts to accomplish sustainability objectives and enhance interfirm cooperation. Further, the study contributes to the literature by revising the available literature on the different roles of top management commitment in green supply chains and business relationships.
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1,442 members
Mustafa Secmen
  • Electrical and Electronics Engineering
Emre Ozgen
  • Psychology Department
Tuncay Ercan
  • Department of Management Information Systems
Kostadin Kratchanov
  • Software Engineering
Universite Cad. 37, 35100, İzmir, Turkey
Head of institution
Prof. Dr. Cemali Dincer