Yazar "Gumus, Mehmet" seçeneğine göre listele

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    A review on multi-criteria decision-making in passenger transportation: Trends, methods, and future directions
    (Elsevier Science Inc, 2026) Kamber, Eren; Yucel, Buse; Gumus, Mehmet
    This study provides a systematic review of the application of Multi-Criteria Decision-Making (MCDM) methods in passenger transportation. Analyzing 74 studies published between 2009 and 2025, the review classifies research based on transportation modes, methodological approaches, and sustainability dimensions. The findings reveal an increasing preference for fuzzy-based MCDM methods such as Fuzzy-AHP, TOPSIS, VIKOR, and DEMATEL to manage uncertainties in complex decision problems. Although sustainability principles are included in many studies, only a minority treat sustainability as the primary focus. The literature emphasizes service quality evaluation, passenger satisfaction, and system efficiency, with notable gaps in comprehensive sustainabilityfocused models and underexplored domains like maritime passenger safety. Keyword and research area analyses confirm the interdisciplinary nature of the field, linking transportation with engineering, computer science, environmental sciences, and economics. The study concludes with specific future research directions, including user-friendly hybrid MCDM frameworks, real-time data integration, and expanded focus on social and environmental sustainability. These recommendations aim to guide researchers and practitioners toward more inclusive, practical, and sustainable transportation decision-making models.
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    Analysis of national strategic innovation objectives using adapted Porter's diamond model: a comparison of Romania and Türkiye
    (Emerald Group Publishing Ltd, 2025) Militaru, Andreea Maria Gabriela; Kurt, Atil; Gumus, Mehmet
    PurposeNowadays, nations are rapidly changing and evolving, both because of global competitiveness and technological development. The fast change of the economies and the interconnected world has brought a more globalized world than ever. The purpose of this paper is to assess Romania (RO) and T & uuml;rkiye (TR) by using a customized version of Porter's diamond model (PDM), with an emphasis on identifying the key components of their innovation systems.Design/methodology/approachThe paper uses a recognized model to unfold its structure. Based on the PDM, this paper tackles the topic of innovation systems both of RO and TR. Applying the model, a mapping of indicators representing components of the national innovation system is made possible. Besides the traditional four determinants (dimensions) of the model, the authors adapted it and added the technology conditions. Using the five dimensions, a comparison of strategical objectives is made between RO and TR.FindingsThe results show the potential for both countries to develop and embrace the innovation capacity, while there is still room for improvement in this regard. Another point is the map of innovation system components that were used for the comparison. The implications of innovation are analyzed at a strategical level, comparing the mapping with the national strategical objectives.Originality/valueThere are many studies using this model, however a few bring into the light the impact of innovation systems at national level. Hence, a new framework is provided to evaluate innovative systems using a selection of modern indicators. This study uses an existing model in literature, Porter's model mapping indicators, which highlight the innovation capacity.
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    Changes in Water Quality for Sprinkler Irrigation in Selected Lakes of the Poznan Lake District
    (Polish Soc Ecological Engineering-Ptie, 2023) Stachowski, Piotr; Rolbiecki, Stanislaw; Jagosz, Barbara; Krakowiak-Bal, Anna; Rolbiecki, Roman; Figas, Anna; Gumus, Mehmet
    The rapidly changing quality of irrigation water requires urgent attention to understand and predict the long-term effects on soils and food crops, especially in a situation of global freshwater scarcity. The aim of the research was to assess changes in water quality in two selected lakes located in Poland in 2009-2016. The study was carried out in terms of the possibility of using selected reservoirs as sources of water for sprinkler irrigation of agricul-tural crops. The presented analysis was compared with a similar one carried out in 1999-2006 and 2004-2009 to determine the historic and present water quality state. Results indicate, that the source of pollution of the lakes is most often outflows from sewerage systems, the precipitation and surface runoff from the catchment areas of these lakes, which are mainly used as agricultural land. In Lake Niepruszewskie, the oxygen conditions, water transpar-ency, phosphorus content, sestone dry matter and coliform titre increased, while the biological oxygen demand (BOD5), nitrogen, and chlorophyll content decreased. According to present research, in the Strykowskie Lake, the phosphorus content and BOD5 decreased, while the sanitary condition, nitrogen content and oxygen conditions deteriorated. The reduction of mineral fertilization in recent years has reduced the degradation of the lakes and allowed the water quality to remain in Class III of purity. Despite the visible improvement in the general condition of both studied lakes, constant monitoring of their quality is necessary, which is obligatory for the water from these reservoirs to be used for sprinkler irrigation of crops.
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    Dynamic Freight Planning with Hybrid Cross-Docking under Carbon Tax and Bounded Storage Age
    (Sage Publications Inc, 2025) Kurt, Atil; Gumus, Mehmet
    This paper discusses the dynamics of supply chain network optimization, specifically focusing on the role of cross-docking. As experienced by the disruptions of the COVID-19 era, external events can trigger supply chain interruptions, necessitating temporary storage solutions. The study examines a network with diverse suppliers, retailers, products, and hybrid cross-docking (HCD) facilities, wherein both transshipment and short-term inventory with restricted storage-age are permitted. Routing of goods from suppliers to retailers encompasses both direct paths and intermediate HCD points, involving multiple truck types. Importantly, all shipments are subject to a carbon tax, factoring in the imperative of mitigating carbon emissions. A dynamic mixed-integer linear programming model is formulated, alongside a greedy-type heuristic algorithm, to optimize the system's total cost. Various computational experiments are used to evaluate the efficacy and solution quality of these methods. Extensive sensitivity analysis, complemented by statistical tests, dissects the impact of various model parameters within the computational experiments. Findings show that allowing storage at HCD facilities, with limited holding time, does not increase system-wide costs but instead bolsters supply chain flexibility. Moreover, carbon tax requires a shift in truck-type selection and plays an important role in reducing the total load-distance traveled, and, therefore, the total carbon emissions.
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    Location and Capacity Planning of Freight Villages: The Case of Türkiye
    (Mehmet Akif Ersoy Univ, 2024) Gumus, Mehmet; Aydogmus, Hacer Yumurtaci; Ozder, Emir Huseyin
    Freight villages are logistics hubs where distribution and storage related activities meet. Determining their locations and capacities is a strategically important yet a difficult problem due to its complex structure. This paper provides a mixed integer linear programming model for identifying the locations, number, and capacities of freight villages. Objective is to set up a distribution network and minimize its total cost. The proposed model is computationally efficient as the optimal solution can be found within minutes. The model is applied using real life data in Turkey. The application includes major container ports as supply points and all cities as demand points, which are also alternative locations for freight villages. Optimal solution provides a plan and a budget to build the required capacity and number of logistics villages dispersed geographically. Sensitivity analysis is also conducted to investigate the system -wide costs and derive insights when there is a limit on the number of freight villages.
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    Solution for the Problem of Sustainable Staff Scheduling in Semi-Automated Dock Container Terminals in Ports
    (Sage Publications Inc, 2023) Ozder, Emir Huseyin; Gumus, Mehmet
    Port operations in container terminals are as important as container transportation itself. A port has a complex system in which a wide variety of operations take place, and a wide variety of resources are required to interact with each other. The aim of a port operator is to complete the service required in the shortest time and in the most efficient way. The quayside of the port, the equipment used such as cranes and field vehicles, and the operations officer and personnel are factors that directly affect the service provided at a port. The port management aims to maximize efficiency by reaching the maximum number of movements with the least possible cost. Increasing the efficiency and quality of the working personnel is extremely important in achieving this aim. This study provides efficient, fair, and balanced scheduling of field personnel and shift supervisors working in port operations using a real-life case of the semi-automated docks at an international port. A goal-programing model is constructed to manage the workforce needed by the port for a one-week working period and to assign the shift supervisors to the shifts in a balanced way. The personnel's preferences and qualifications, which directly affect productivity, are also considered while planning. Results show an increase in productivity, quality of life, concentration, and employee job satisfaction. The results of the suggested mathematical model in the study show that the demands of the workers facing conflicting constraints were met with the least deviation from goals.
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    Sustainable planning of penal facilities through multi-objective location-allocation modelling and data envelopment analysis
    (Elsevier Science Inc, 2025) Kurt, Atil; Gumus, Mehmet
    The escalating population of inmates necessitates a substantial increase in penal facilities. Consequently, there arises a pressing need for strategic planning to identify the location and capacities of new penal facilities, along with the appropriate allocation of prisoners therein. This study proposes a solution methodology to address this imperative by considering multiple future periods and objectives. Specifically, the study examines three objective functions simultaneously based on the three dimensions of sustainability, delineated along economy, society, and environment. To operationalize this framework, a multi-objective mixed integer linear programming model is developed, and an iterative solution methodology is proposed to generate alternative solutions. The alternative solutions are created for two scenarios: exact and fractional assignment of prisons in cities. Subsequently, the efficacy of these alternatives is assessed through the application of super-efficiency and cross-efficiency data envelopment analysis techniques. In each of these scenarios, the most efficient solution among alternatives is identified as the final solution. The empirical data utilized in the study is sourced from real-world cases in Turkey. Comparative analyses of the solutions under each scenario offer valuable insights into their respective advantages and disadvantages, thereby contributing to a comprehensive understanding of the problem.