scholarly journals Intermodal Terminal Planning under Decentralized Management: Optimization Model for Rail-Road Terminals and Application to Portugal

2021 ◽  
Vol 1 (3) ◽  
pp. 533-558
Author(s):  
Erwin Delgado ◽  
Ana Barbosa-Póvoa ◽  
António Antunes

Terminals are key components of intermodal transport networks, as they are the facilities where freight is transferred between transport modes. The efficiency of such facilities crucially depends on their locations (and sizes), which are typically chosen considering two levels of analysis: local/urban and regional/country. Our focus in this presentation is the regional/country level. At this level, the problems involved in the locational (and sizing) decisions at stake are a particular variety of hub locations problems—a class of problems that has been widely studied through optimization approaches. However, they typically assume that decisions are made in a centralized management context: decision-makers not only choose the locations of intermodal terminals (or hubs), but also fully control their utilization (i.e., which terminal each user will patronize). This signifies that such approaches are not applicable when users–potentially, any companies that move freight–behave according to their own individual interests; that is, they are not applicable in a decentralized management context. In this presentation, we describe an ongoing study where (regional) intermodal terminal location problems are dealt with in this type of context considering terminals of different types and respective capacity and operation ranges. In particular, we present the complex optimization model we have developed to handle such problems, and the (sometimes counterintuitive) results it led to when applied to a case study inspired by the Portuguese reality.

Author(s):  
Abbas Al-Refaie ◽  
Mays Judeh ◽  
Ming-Hsien Li

AbstractLittle research has considered fuzzy scheduling and sequencing problem in operating rooms. Multiple-period fuzzy scheduling and sequencing of patients in operating rooms optimization models are proposed in this research taking into consideration patient‘s preference. The objective of the scheduling optimization model is obtaining minimal undertime and overtime and maximum patients' satisfaction about the assigned date. The objective of sequencing the optimization model is both to minimize overtime and to maximize patients' satisfaction about the assigned time. A real-life case study from a hospital that offers comprehensive surgical procedures for all surgical specialties is considered for illustration. Research results showed that the proposed models efficiently scheduled and sequenced patients while considering their preferences and hospitals operating costs. In conclusion, the proposed optimization models may result in improving patient satisfaction, utilizing hospital's resources efficiently, and providing assistance to decision makers and planners in solving effectively fuzzy scheduling and sequencing problems of operating rooms.


2018 ◽  
Vol 45 (9) ◽  
pp. 705-716 ◽  
Author(s):  
Moatassem Abdallah ◽  
Boateng Akyeampong ◽  
Khaled El-Rayes

Existing buildings, especially aging ones, are currently in urgent need of upgrading to improve their performance and potentially achieve green certification. Building owners often need to identify and implement building upgrades that maximize the sustainability of their buildings as well as achieve green certification programs such as the Leadership in Energy and Environmental Design (LEED). This paper presents the development of an optimization model that maximizes the number of earned LEED points for existing buildings within a specified upgrade budget. A case study of an existing building is used to demonstrate the use of the optimization model and illustrate its capabilities. This research presents new methodology for optimizing the selection of building upgrades to maximize the sustainability of existing buildings and achieve green certification within limited budgets. The present model is expected to support decision-makers, building owners and operators, building managers, and contractors to optimize the use of their upgrade budgets and maximize sustainability of their buildings.


2021 ◽  
Vol 13 (3) ◽  
pp. 1514
Author(s):  
Rebecca Peters ◽  
Jürgen Berlekamp ◽  
Ana Lucía ◽  
Vittoria Stefani ◽  
Klement Tockner ◽  
...  

Mitigating climate change, while human population and economy are growing globally, requires a bold shift to renewable energy sources. Among renewables, hydropower is currently the most economic and efficient technique. However, due to a lack of impact assessments at the catchment scale in the planning process, the construction of hydropower plants (HPP) may have unexpected ecological, socioeconomic, and political ramifications in the short and in the long term. The Vjosa River, draining parts of Northern Greece and Albania, is one of the few predominantly free-flowing rivers left in Europe; at the same time its catchment is identified an important resource for future hydropower development. While current hydropower plants are located along tributaries, planned HPP would highly impact the free-flowing main stem. Taking the Vjosa catchment as a case study, the aim of this study was to develop a transferable impact assessment that ranks potential hydropower sites according to their projected impacts on a catchment scale. Therefore, we integrated established ecological, social, and economic indicators for all HPP planned in the river catchment, while considering their capacity, and developed a ranking method based on impact categories. For the Vjosa catchment, ten hydropower sites were ranked as very harmful to the environment as well as to society. A sensitivity analysis revealed that this ranking is dependent upon the selection of indicators. Small HPP showed higher cumulative impacts than large HPP, when normalized to capacity. This study empowers decision-makers to compare both the ranked impacts and the generated energy of planned dam projects at the catchment scale.


Author(s):  
Gabrielle Samuel ◽  
Jenn Chubb ◽  
Gemma Derrick

The governance of ethically acceptable research in higher education institutions has been under scrutiny over the past half a century. Concomitantly, recently, decision makers have required researchers to acknowledge the societal impact of their research, as well as anticipate and respond to ethical dimensions of this societal impact through responsible research and innovation principles. Using artificial intelligence population health research in the United Kingdom and Canada as a case study, we combine a mapping study of journal publications with 18 interviews with researchers to explore how the ethical dimensions associated with this societal impact are incorporated into research agendas. Researchers separated the ethical responsibility of their research with its societal impact. We discuss the implications for both researchers and actors across the Ethics Ecosystem.


2021 ◽  
Vol 13 (5) ◽  
Author(s):  
Viktória Mozgai ◽  
Bernadett Bajnóczi ◽  
Zoltán May ◽  
Zsolt Mráv

AbstractThis study details the non-destructive chemical analysis of composite silver objects (ewers, situlas, amphora and casket) from one of the most significant late Roman finds, the Seuso Treasure. The Seuso Treasure consists of fourteen large silver vessels that were made in the fourth–early fifth centuries AD and used for dining during festive banquets and for washing and beautification. The measurements were systematically performed along a pre-designed grid at several points using handheld X-ray fluorescence analysis. The results demonstrate that all the objects were made from high-quality silver (above 90 wt% Ag), with the exception of the base of the Geometric Ewer B. Copper was added intentionally to improve the mechanical properties of soft silver. The gold and lead content of the objects shows constant values (less than 1 wt% Au and Pb). The chemical composition as well as the Bi/Pb ratio suggests that the parts of the composite objects were manufactured from different silver ingots. The ewers were constructed in two ways: (i) the base and the body were made separately, or (ii) the ewer was raised from a single silver sheet. The composite objects were assembled using three methods: (i) mechanical attachment; (ii) low-temperature, lead-tin soft solders; or (iii) high-temperature, copper-silver hard solders. Additionally, two types of gilding were revealed by the XRF analysis, one with remnants of mercury, i.e. fire-gilding, and another type without remnants of mercury, presumably diffusion bonding.


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