In recent times, COVID-19 pandemic has posed certain challenges to transportation companies due to the restrictions imposed by different countries during the lockdown. These restrictions cause delay and/ or reduction in the number of trips of vehicles, especially, to the regions with higher restrictions. In a pandemic scenario, regions are categorized into different groups based on the levels of restrictions imposed on the movement of vehicles based on the number of active cases (i.e., number of people infected by COVID-19), number of deaths, population, number of COVID-19 hospitals, etc. The aim of this study is to formulate and solve a fixed-charge transportation problem (FCTP) during this pandemic scenario and to obtain transportation scheme with minimum transportation cost in minimum number of trips of vehicles moving between regions with higher levels of restrictions. For this, a penalty is imposed in the objective function based on the category of the region(s) where the origin and destination are situated. However, reduction in the number of trips of vehicles may increase the transportation cost to unrealistic bounds and so, to keep the transportation cost within limits, a constraint is imposed on the proposed model. To solve the problem, the Genetic Algorithm (GA) has been modified accordingly. For this purpose, we have designed a new crossover operator and a new mutation operator to handle multiple trips and capacity constraints of vehicles. For numerical illustration, in this study, we have solved five example problems considering three levels of restrictions, for which the datasets are generated artificially. To show the effectiveness of the constraint imposed for reducing the transportation cost, the same example problems are then solved without the constraint and the results are analyzed. A comparison of results with existing algorithms proves that our algorithm is effective. Finally, some future research directions are discussed.
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http://dx.doi.org/10.1016/j.asoc.2022.109576 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China.
In recent years, aqueous zinc-ion batteries (ZIBs) have shown considerable promise in the energy storage sector, attributed to their inherent high safety and cost-effectiveness. ZnVO(OH)·2HO (ZVO) has emerged as a promising candidate for Zn storage in recent years, owing to its exceptional structural stability that endows it with an excellent cycle life. However, an unsatisfactory rate performance is a limiting factor for its development in ZIBs.
View Article and Find Full Text PDFEur J Phys Rehabil Med
January 2025
Preventive Medicine, Epidemiology and Public Health Area, Department of Biomedical and Diagnostic Sciences, University of Salamanca, Institute for Biomedical Research of Salamanca (IBSAL), Salamanca, Spain -
Background: Neck and back pain pathologies are currently the main cause of absenteeism from work in Spain and in the European Union, and represent a high socio-labor, economic and health cost for the Health Systems.
Aim: To assess the effectiveness of a Back School Program of a Spanish mutual insurance company (risk factors, pain and disability scales) in women workers with low back or neck pain.
Design: We combined a descriptive study of first-session data collected in the total sample and a prospective multicenter intervention study in those participants who completed the second and third check-up at 6 and 9 months.
Chem Sci
January 2025
J. Mike Walker '66 Department of Mechanical Engineering, Texas A&M University College Station TX 77843 USA
This perspective work examines the current advancements in integrated CO capture and electrochemical conversion technologies, comparing the emerging methods of (1) electrochemical reactive capture (eRCC) though amine- and (bi)carbonate-mediated processes and (2) direct (flue gas) adsorptive capture and conversion (ACC) with the conventional approach of sequential carbon capture and conversion (SCCC). We initially identified and discussed a range of cell-level technological bottlenecks inherent to eRCC and ACC including, but not limited to, mass transport limitations of reactive species, limitation of dimerization, impurity effects, inadequate generation of CO to sustain industrially relevant current densities, and catalyst instabilities with respect to some eRCC electrolytes, amongst others. We followed this with stepwise perspectives on whether these are considered intrinsic challenges of the technologies - otherwise recommendations were disclosed where appropriate.
View Article and Find Full Text PDFBackground: In this study, we aimed to determine the effects of the coronavirus disease 2019 (COVID-19) pandemic on in-hospital cardiopulmonary resuscitation (CPR) in patients with out-of-hospital cardiac arrest (OHCA).
Methods And Results: Using the Japanese Diagnosis Procedure Combination inpatient database, we included patients with OHCA who were transported to hospitals between April 2018 and March 2021. Patients were categorized into groups, before and during the COVID-19 pandemic, according to the day of admission (before or after April 1, 2020, respectively).
Biostatistics
December 2024
Department of Biostatistics, Yale University School of Public Health, 60 College Street, New Haven, CT06511, United States.
Evaluating air quality interventions is confronted with the challenge of interference since interventions at a particular pollution source likely impact air quality and health at distant locations, and air quality and health at any given location are likely impacted by interventions at many sources. The structure of interference in this context is dictated by complex atmospheric processes governing how pollution emitted from a particular source is transformed and transported across space and can be cast with a bipartite structure reflecting the two distinct types of units: (i) interventional units on which treatments are applied or withheld to change pollution emissions; and (ii) outcome units on which outcomes of primary interest are measured. We propose new estimands for bipartite causal inference with interference that construe two components of treatment: a "key-associated" (or "individual") treatment and an "upwind" (or "neighborhood") treatment.
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