Research Article
Civil Engineering
Seyed Mahdi Mirkhorsandi; Hossein Khosravi; Alireza Davoodi; Seyed Mojtaba Movahedifar
Abstract
Financially, project portfolios can be completely self-reliant when their required liquidity is merely obtained through reinvesting the profit of the finished projects and the initial capital of the owners. However, the firm can only perform some profitable projects despite maximizing wealth owing to ...
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Financially, project portfolios can be completely self-reliant when their required liquidity is merely obtained through reinvesting the profit of the finished projects and the initial capital of the owners. However, the firm can only perform some profitable projects despite maximizing wealth owing to a shortage of funds. In such cases, projects’ implementation can be phased as a practical solution to satisfy financial deficiencies. Therefore, decision-makers are involved in finding the optimum selection and scheduling of the self-financing phase-able project portfolios. Some projects especially construction projects encompass a multi-stage process of repetitive activities, which pave the way for taking advantage of the economy of scale when organizing for development. This research proposes a mathematical model for the problem of building construction project portfolio with simultaneous consideration of the reinvestment strategy, phasing strategy, and economy of scale at the enterprise level. In this case, an integer programming model to maximize the investment's net present value is presented. The proposed model provides a decition support system for property developers to select and schedule self-financing phase-able building construction project portfolios, in this context, the model's applicability is illustrated in a case example.
Research Article
مهندسی عمران-راه و ترابری
Amirmohammad Esmaeilzadeh Azar; Reza Amin; Ali Khodaii
Abstract
Over the past 10 years, the performance of airlines in the passenger domain has been influenced by various factors. Consequently, numerous studies have been conducted worldwide on the factors affecting the performance of airlines in passenger services, and Iran has also seen significant statistical studies ...
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Over the past 10 years, the performance of airlines in the passenger domain has been influenced by various factors. Consequently, numerous studies have been conducted worldwide on the factors affecting the performance of airlines in passenger services, and Iran has also seen significant statistical studies in this regard. In this research, an attempt has been made to conduct a comparative analysis of the years 2012 to 2022 for Iranian airlines in the passenger domain, using defined statistical indices. The defined indices in this study include passenger density on each flight, the percentage of delayed flights, the percentage of canceled flights, and the number of flights passing through the country's airspace. It was observed that Iran had acceptable performance in three indices until the onset of the COVID-19 pandemic. However, after the pandemic, due to lack of planning and readiness for unforeseen events like COVID-19, the airline performance has been severely impacted. Hence, airlines need effective planning and strategies to prevent the adverse effects of unforeseen events such as the COVID-19 pandemic. Overall, the developments of this decade highlight the need for flexibility and the ability to respond to challenges in the aviation and air transportation industry
Review Article
Civil Engineering
aliasghar Amirkardoust; Omid Tavakoli; davood sedaghat shayegan
Abstract
This article provides a comprehensive review of project planning and elucidates its pivotal role in ensuring success in the complex landscape of civil engineering projects. From various perspectives, the emphasis is placed on the sequential progress of projects, precise planning, resource coordination, ...
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This article provides a comprehensive review of project planning and elucidates its pivotal role in ensuring success in the complex landscape of civil engineering projects. From various perspectives, the emphasis is placed on the sequential progress of projects, precise planning, resource coordination, meticulous control, and the adoption of innovative planning methods as essential components. The consequences of neglecting these fundamental stages, with a focus on cost, time, and project quality factors, are examined. Consequently, the synthesis of these perspectives underscores the linchpin role of planning in construction projects. Sequential progress, coupled with strategic planning and precise control, emerges as a foundational principle. Decision-making based on data and the utilization of mature models enhance project management efficiency. Serving as a comprehensive guide, this article underscores the significance of planning stages as the axis of success in civil engineering projects. With a comprehensive approach, recognition of interdisciplinary nature, and laying the groundwork for informed and strategic decision-making in the dynamic landscape, the article supports the outlook of effective project management in civil engineering.
Review Article
مهندسی عمران-راه و ترابری
Saeid Ghasemi; Reza Amin; Ali Khodaii
Abstract
This article examines the effect of human error in aviation accidents. Aviation accidents are one of the most important factors that threaten security in air transportation, and various factors can play a role in their occurrence. One of these factors is human error, which can lead to an accident from ...
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This article examines the effect of human error in aviation accidents. Aviation accidents are one of the most important factors that threaten security in air transportation, and various factors can play a role in their occurrence. One of these factors is human error, which can lead to an accident from simple to serious and uncorrectable errors, also human error is one of the important factors in plane accidents that can have serious consequences for the health and safety of passengers and aircraft employees. It may occur at any stage of the flight process from design and manufacturing to flight operations and maintenance. In the flight operations phase, this error can include pilot and air traffic control errors, ground logistics errors (such as lack of proper maintenance and repair of aircraft), and flight crew performance errors. It is clear that the detailed investigation of human errors in aviation accidents plays a significant role in increasing the safety of flights and may lead to effective improvements in the fields of pilot training and aircraft systems design. The purpose of this article is to analyze the human error in aviation accidents and the factors affecting its occurrence, which can help improve the safety and performance of airplanes and thus save people's lives in aviation accidents.
