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The social distancing imposed by the novel coronavirus, SARS-CoV-2, has affected people’s everyday lives and has resulted in companies changing the way they conduct business. The airline industry has been continually adapting since the novel coronavirus appeared. A series of airlines have changed their airplane boarding and passenger seat allocation process to increase their passengers’ safety. Many suggest a minimum social distance among passengers in the aisle while boarding. Some airlines have reduced their airplanes’ capacities by keeping the middle seats empty. Recent literature indicates that the Reverse Pyramid boarding method provides favorable values for boarding time and passenger health metrics when compared to other boarding methods. This paper analyses the extent to which aisle social distancing, the quantity of carry-on luggage, and an airline’s relative preferences for different performance metrics influence the optimal number of passengers to board the airplane in each of three boarding groups when the Reverse Pyramid method is used and the middle seats are empty. We also investigate the resulting impact on the average boarding time and health risks to boarding passengers. We use an agent-based model and stochastic simulation approach to evaluate various levels of aisle social distancing among passengers and the quantity of luggage carried aboard the airplane. When minimizing boarding time is the primary objective of an airline, for a given value of aisle social distance, decreasing the carry-on luggage volumes increases the optimal number of boarding group 1 passengers and decreases the optimal number of group 2 passengers with aisle seats; for a given volume of luggage, an increase in aisle social distance is associated with more passengers in group 1 and more aisle seat passengers in group 2. When minimizing the health risk to aisle seat passengers or to window seat passengers, the optimal solution results from assigning an equal number of window seat passengers to groups 1 and 2 and an equal number of aisle seat passengers to groups 2 and 3. This solution is robust to changes in luggage volume and the magnitude of aisle social distance. Furthermore, across all luggage and aisle social distancing scenarios, the solution reduces the health risk to aisle seat passengers between 22.76% and 35.31% while increasing average boarding time by less than 3% in each scenario.
Liviu-Adrian Cotfas; R. Milne; Camelia Delcea; Corina Ioanăș. An Investigation of Social Distancing and Quantity of Luggage Impacts on the Three Groups Reverse Pyramid Boarding Method. Symmetry 2021, 13, 544 .
AMA StyleLiviu-Adrian Cotfas, R. Milne, Camelia Delcea, Corina Ioanăș. An Investigation of Social Distancing and Quantity of Luggage Impacts on the Three Groups Reverse Pyramid Boarding Method. Symmetry. 2021; 13 (4):544.
Chicago/Turabian StyleLiviu-Adrian Cotfas; R. Milne; Camelia Delcea; Corina Ioanăș. 2021. "An Investigation of Social Distancing and Quantity of Luggage Impacts on the Three Groups Reverse Pyramid Boarding Method." Symmetry 13, no. 4: 544.
Purpose The airline industry has been significantly hit by the occurrence of the new coronavirus SARS-CoV-2, facing one of its worst crises in history. In this context, the present paper analyses one of the well-known boarding methods used in practice by the airlines before and during the coronavirus outbreak, namely back-to-front and suggests which variations of this method to use when three passenger boarding groups are considered and a jet bridge connects the airport terminal with the airplane. Design/methodology/approach Based on the importance accorded by the airlines to operational performance, health risks, and passengers' comfort, the variations in three passenger groups back-to-front boarding are divided into three clusters using the grey clustering approach offered by the grey systems theory. Findings Having the clusters based on the selected metrics and considering the social distance among the passengers, airlines can better understand how the variations in back-to-front perform in the new conditions imposed by the novel coronavirus and choose the boarding approach that better fits its policy and goals. Originality/value The paper combines the advantages offered by grey clustering and agent-based modelling for offering to determine which are the best configurations that offer a reduced boarding time, while accounting for reduced passengers' health risk, measured through three indicators: aisle risk, seat risk and type-3 seat interferences and for an increased comfort for the passengers manifested through a continuous walking flow while boarding.
Camelia Delcea; Liviu-Adrian Cotfas; R. John Milne; Naiming Xie; Rafał Mierzwiak. Grey clustering of the variations in the back-to-front airplane boarding method considering COVID-19 flying restrictions. Grey Systems: Theory and Application 2021, ahead-of-p, 1 .
AMA StyleCamelia Delcea, Liviu-Adrian Cotfas, R. John Milne, Naiming Xie, Rafał Mierzwiak. Grey clustering of the variations in the back-to-front airplane boarding method considering COVID-19 flying restrictions. Grey Systems: Theory and Application. 2021; ahead-of-p (ahead-of-p):1.
Chicago/Turabian StyleCamelia Delcea; Liviu-Adrian Cotfas; R. John Milne; Naiming Xie; Rafał Mierzwiak. 2021. "Grey clustering of the variations in the back-to-front airplane boarding method considering COVID-19 flying restrictions." Grey Systems: Theory and Application ahead-of-p, no. ahead-of-p: 1.
The coronavirus outbreak has brought unprecedented measures, which forced the authorities to make decisions related to the instauration of lockdowns in the areas most hit by the pandemic. Social media has been an important support for people while passing through this difficult period. On November 9, 2020, when the first vaccine with more than 90% effective rate has been announced, the social media has reacted and people worldwide have started to express their feelings related to the vaccination, which was no longer a hypothesis but closer, each day, to become a reality. The present paper aims to analyze the dynamics of the opinions regarding COVID-19 vaccination by considering the one-month period following the first vaccine announcement, until the first vaccination took place in UK, in which the civil society has manifested a higher interest regarding the vaccination process. Classical machine learning and deep learning algorithms have been compared to select the best performing classifier. 2 349 659 tweets have been collected, analyzed, and put in connection with the events reported by the media. Based on the analysis, it can be observed that most of the tweets have a neutral stance, while the number of in favor tweets overpasses the number of against tweets. As for the news, it has been observed that the occurrence of tweets follows the trend of the events. Even more, the proposed approach can be used for a longer monitoring campaign that can help the governments to create appropriate means of communication and to evaluate them in order to provide clear and adequate information to the general public, which could increase the public trust in a vaccination campaign.
Liviu-Adrian Cotfas; Camelia Delcea; Ioan Roxin; Corina Ioanas; Dana Simona Gherai; Federico Tajariol. The Longest Month: Analyzing COVID-19 Vaccination Opinions Dynamics From Tweets in the Month Following the First Vaccine Announcement. IEEE Access 2021, 9, 33203 -33223.
AMA StyleLiviu-Adrian Cotfas, Camelia Delcea, Ioan Roxin, Corina Ioanas, Dana Simona Gherai, Federico Tajariol. The Longest Month: Analyzing COVID-19 Vaccination Opinions Dynamics From Tweets in the Month Following the First Vaccine Announcement. IEEE Access. 2021; 9 (99):33203-33223.
Chicago/Turabian StyleLiviu-Adrian Cotfas; Camelia Delcea; Ioan Roxin; Corina Ioanas; Dana Simona Gherai; Federico Tajariol. 2021. "The Longest Month: Analyzing COVID-19 Vaccination Opinions Dynamics From Tweets in the Month Following the First Vaccine Announcement." IEEE Access 9, no. 99: 33203-33223.
The onset of the novel coronavirus SARS-CoV2 has changed many aspects of people’s economic and social activities. For many airlines, social distancing has reduced airplane capacity by one third as a result of keeping the middle seats empty. Additionally, social distancing between passengers traversing the aisle slows the boarding process. Recent literature has suggested that the reverse pyramid boarding method provides favorable values for boarding time and passenger health metrics when compared to other boarding methods with social distancing. Assuming reverse pyramid boarding with the middle seats unoccupied, we determined the number of passengers to include in each of three boarding groups. We assumed that passengers use a jet-bridge that connects the airport terminal to the airplane’s front door. We used agent-based modeling and a stochastic simulation to evaluate solutions. A full grid search found an initial good solution, and then local search optimization determined the best solution based upon the airline’s relative preference for minimizing average boarding time and minimizing risks to previously seated passengers from later-boarding, potentially contagious passengers breathing near them. The resulting solution contained the number of passengers to place into each of the three boarding groups. If an airline is most concerned about the health risk to seated passengers from later boarding passengers walking near them, the best three-group reverse pyramid method adapted for social distancing will first board passengers with window seats in the rear half of the airplane, then will board passengers with window seats in the front half of the airplane and those with aisle seats in the rear half of the airplane, and finally will board the passengers with aisle seats in the front half of the airplane. The resulting solution takes about 2% longer to board than the three-group solution that minimizes boarding time while providing a 25% decrease in health risk to aisle seat passengers from later boarding passengers.
Camelia Delcea; R. John Milne; Liviu-Adrian Cotfas. Determining the Number of Passengers for Each of Three Reverse Pyramid Boarding Groups with COVID-19 Flying Restrictions. Symmetry 2020, 12, 2038 .
AMA StyleCamelia Delcea, R. John Milne, Liviu-Adrian Cotfas. Determining the Number of Passengers for Each of Three Reverse Pyramid Boarding Groups with COVID-19 Flying Restrictions. Symmetry. 2020; 12 (12):2038.
Chicago/Turabian StyleCamelia Delcea; R. John Milne; Liviu-Adrian Cotfas. 2020. "Determining the Number of Passengers for Each of Three Reverse Pyramid Boarding Groups with COVID-19 Flying Restrictions." Symmetry 12, no. 12: 2038.
Social distancing resulting from the new coronavirus (SARS-CoV2) has disrupted the airplane boarding process. Social distancing norms reduce airplane capacity by keeping the middle seats unoccupied, while an imposed aisle social distance between boarding passengers slows the boarding. Recent literature suggests the Reverse Pyramid boarding method is a promising way to reduce health risk and keep boarding times low when 10 apron buses (essentially 10 boarding groups) are used to transport passengers from the airport terminal to a two-door airplane. We adapt the Reverse Pyramid method for social distancing when an airplane is boarded using a jet bridge that connects the terminal the airplane’s front door. We vary the number of boarding groups from two to six and use stochastic simulation and agent-based modelling to show the resulting impact on four performance evaluation metrics. Increasing the number of boarding groups from two to six reduces boarding time only up to four groups but continues to reduce infection risk up to six groups. If the passengers carry fewer luggage aboard the airplane, health risks (as well as boarding times) decrease. One adaptation of the Reverse Pyramid (RP) method (RP-Spread) provides slightly faster boarding times than the other (RP-Steep), when luggage volumes are high, while RP-Steep results in less risk to window seat passengers from later-boarding passengers walking by their row. Increasing the minimum aisle social distance from 1 m to 2 m increases boarding times but results in lower health risks to passengers walking down the aisle and to the previously seated passengers they pass.
R. John Milne; Liviu-Adrian Cotfas; Camelia Delcea; Liliana Crăciun; Anca-Gabriela Molănescu. Adapting the reverse pyramid airplane boarding method for social distancing in times of COVID-19. PLoS ONE 2020, 15, e0242131 .
AMA StyleR. John Milne, Liviu-Adrian Cotfas, Camelia Delcea, Liliana Crăciun, Anca-Gabriela Molănescu. Adapting the reverse pyramid airplane boarding method for social distancing in times of COVID-19. PLoS ONE. 2020; 15 (11):e0242131.
Chicago/Turabian StyleR. John Milne; Liviu-Adrian Cotfas; Camelia Delcea; Liliana Crăciun; Anca-Gabriela Molănescu. 2020. "Adapting the reverse pyramid airplane boarding method for social distancing in times of COVID-19." PLoS ONE 15, no. 11: e0242131.
Airlines have recently instituted practices to reduce the risk of their passengers becoming infected with the novel coronavirus (SARS-CoV-2). Some airlines block their airplanes’ middle seats to preserve social distancing among seated passengers. In this context, we present six new boarding methods and compare their performance with that of the two best boarding methods used to date with social distancing. We evaluate the eight boarding methods using three performance metrics related to passenger health and one operational metric (airplane boarding time) for a one-door airplane. The three health metrics reflect the risks of virus spread by passengers through the air and surfaces (e.g. headrests and seat arms) and consider the amount of aisle social distancing between adjacent boarding passengers walking towards their seats. For an airline that highly values the avoidance of window seat risk, the best method to use is one of the new methods: back-to-front by row – WilMA, though it will result in a longer time to complete boarding of the airplane. Airlines placing greater emphasis on fast boarding times— while still providing favorable values for the health metrics—will be best served by using new methods back-to-front by row – WilMA – offset 2 and – offset 3 when aisle social distancing is 1 m and 2 m respectively.
R. John Milne; Camelia Delcea; Liviu-Adrian Cotfas. Airplane boarding methods that reduce risk from COVID-19. Safety Science 2020, 134, 105061 .
AMA StyleR. John Milne, Camelia Delcea, Liviu-Adrian Cotfas. Airplane boarding methods that reduce risk from COVID-19. Safety Science. 2020; 134 ():105061.
Chicago/Turabian StyleR. John Milne; Camelia Delcea; Liviu-Adrian Cotfas. 2020. "Airplane boarding methods that reduce risk from COVID-19." Safety Science 134, no. : 105061.
This paper addresses the airplane passengers’ seat assignment problem while practicing social distancing among passengers. We proposed a mixed integer programming model to assign passengers to seats on an airplane in a manner that will respect two types of social distancing. One type of social distancing refers to passengers being seated far enough away from each other. The metric for this type of social distancing is how many passengers are seated so close to each other as to increase the risk of infection. The other type of social distancing refers to the distance between seat assignments and the aisle. That distance influences the health risk involved in passengers and crew members walking down the aisle. Corresponding metrics for both health risks are included in the objective function. To conduct simulation experiments, we define different scenarios distinguishing between the relative level of significance of each type of social distancing. The results suggest the seating assignments that best serve the intention of the scenarios. We also reformulate the initial model to determine seat assignments that maximize the number of passengers boarding an airplane while practicing social distancing among passengers. In the last part of this study, we compare the proposed scenarios with the recommended middle-seat blocking policy presently used by some airlines to keep social distancing among passengers. The results show that the proposed scenarios can provide social distancing among seated passengers similar to the middle-seat blocking policy, while reducing the number of passengers seated close to the aisle of an airplane.
Mostafa Salari; R. John Milne; Camelia Delcea; Lina Kattan; Liviu-Adrian Cotfas. Social distancing in airplane seat assignments. Journal of Air Transport Management 2020, 89, 101915 -101915.
AMA StyleMostafa Salari, R. John Milne, Camelia Delcea, Lina Kattan, Liviu-Adrian Cotfas. Social distancing in airplane seat assignments. Journal of Air Transport Management. 2020; 89 ():101915-101915.
Chicago/Turabian StyleMostafa Salari; R. John Milne; Camelia Delcea; Lina Kattan; Liviu-Adrian Cotfas. 2020. "Social distancing in airplane seat assignments." Journal of Air Transport Management 89, no. : 101915-101915.
While the literature contains many slightly different definitions for the image of a company, they all put great emphasis on its importance. Many of the messages posted on social media networks nowadays contain strong sentiment and emotion indications regarding almost any topic, therefore turning them into a rich and almost real-time data source for analyzing the public’s opinion on various subjects, including many of the factors that can influence the image of companies. Thus, in this chapter we propose a natural language processing (NLP) approach for monitoring and evaluating the companies’ image by extracting information from social media messages posted on Twitter. The messages are analyzed using a bag-of-words sentiment analysis approach. The results of the analysis are stored as semantically structured data, thus making it possible to fully exploit the possibilities offered by semantic web technologies, such as inference and accessing the vast amount of knowledge in Linked Open Data, for further analysis.
Livu-Adrian Cotfas; Camelia Delcea; Ramona-Mihaela Păun. Companies Image Evaluation Using Social Media and Sentiment Analysis. Financial Environment and Business Development 2020, 277 -286.
AMA StyleLivu-Adrian Cotfas, Camelia Delcea, Ramona-Mihaela Păun. Companies Image Evaluation Using Social Media and Sentiment Analysis. Financial Environment and Business Development. 2020; ():277-286.
Chicago/Turabian StyleLivu-Adrian Cotfas; Camelia Delcea; Ramona-Mihaela Păun. 2020. "Companies Image Evaluation Using Social Media and Sentiment Analysis." Financial Environment and Business Development , no. : 277-286.
Social distancing reduces the risk of people becoming infected with the novel coronavirus (SARS-CoV-2). When passengers are transported from an airport terminal to an airplane using apron buses, safe social distancing during pandemic times reduces the capacity of the apron buses and has led to the practice of airlines keeping the middle seats of the airplanes unoccupied. This paper adapts classical boarding methods so that they may be used with social distancing and apron buses. We conduct stochastic simulation experiments to assess nine adaptations of boarding methods according to four performance metrics. Three of the metrics are related to the risk of the virus spreading to passengers during boarding. The fourth metric is the time to complete boarding of the two-door airplane when apron bus transport passengers to the airplane. Our experiments assume that passengers advancing to their airplane seats are separated by an aisle social distance of 1 m or 2 m. Numerical results indicate that the three variations (adaptations) of the Reverse pyramid method are the best candidates for airlines to consider in this socially distanced context. The particular adaptation to use depends on an airline’s relative preference for having short boarding times versus a reduced risk of later boarding passengers passing (and thereby possibly infecting) previously seated window seat passengers. If an airline considers the latter risk to be unimportant, then the Reverse pyramid – Spread method would be the best choice because it provides the fastest time to board the airplane and is tied for the best values for the other two health risk measures.
R. John Milne; Camelia Delcea; Liviu-Adrian Cotfas; Corina Ioanas. Evaluation of Boarding Methods Adapted for Social Distancing When Using Apron Buses. IEEE Access 2020, 8, 151650 -151667.
AMA StyleR. John Milne, Camelia Delcea, Liviu-Adrian Cotfas, Corina Ioanas. Evaluation of Boarding Methods Adapted for Social Distancing When Using Apron Buses. IEEE Access. 2020; 8 (99):151650-151667.
Chicago/Turabian StyleR. John Milne; Camelia Delcea; Liviu-Adrian Cotfas; Corina Ioanas. 2020. "Evaluation of Boarding Methods Adapted for Social Distancing When Using Apron Buses." IEEE Access 8, no. 99: 151650-151667.
The novel coronavirus (SARS-CoV-2) has imposed the need for a series of social distancing restrictions worldwide to mitigate the scourge of the COVID-19 pandemic. This applies to many domains, including airplane boarding and seat assignments. As airlines are considering their passengers’ safety during the pandemic, boarding methods should be evaluated both in terms of social distancing norms and the resulting efficiency for the airlines. The present paper analyzes the impact of a series of restrictions that have been imposed or mooted worldwide on the boarding methods used by the airlines, featuring the use of jet-bridges and one-door boarding. To compare the efficacy of classical airplane boarding methods with respect to new social distancing norms, five metrics were used to evaluate their performance. One metric is the time to complete the boarding of the airplane. The other four metrics concern passenger health and reflect the potential exposure to the virus from other passengers through the air and surfaces (e.g., headrests and luggage) touched by passengers. We use the simulation platform in NetLogo to test six common boarding methods under various conditions. The back-to-front by row boarding method results in the longest time to complete boarding but has the advantage of providing the lowest health risk for two metrics. Those two metrics are based on passengers potentially infecting those passengers previously seated in the rows they traverse. Interestingly, those two risks are reduced for most boarding methods when the social distance between adjacent passengers advancing down the aisle is increased, thus indicating an unanticipated benefit stemming from this form of social distancing. The modified reverse pyramid by half zone method provides the shortest time to the completing boarding of the airplane and—along with the WilMA boarding method—provides the lowest health risk stemming from potential infection resulting from seat interferences. Airlines have the difficult task of making tradeoffs between economic productivity and the resulting impact on various health risks.
Liviu-Adrian Cotfas; Camelia Delcea; R. John Milne; Mostafa Salari. Evaluating Classical Airplane Boarding Methods Considering COVID-19 Flying Restrictions. Symmetry 2020, 12, 1087 .
AMA StyleLiviu-Adrian Cotfas, Camelia Delcea, R. John Milne, Mostafa Salari. Evaluating Classical Airplane Boarding Methods Considering COVID-19 Flying Restrictions. Symmetry. 2020; 12 (7):1087.
Chicago/Turabian StyleLiviu-Adrian Cotfas; Camelia Delcea; R. John Milne; Mostafa Salari. 2020. "Evaluating Classical Airplane Boarding Methods Considering COVID-19 Flying Restrictions." Symmetry 12, no. 7: 1087.
In the last few years, online social media networks have witnessed an amazing growth in their worldwide usage, with millions of users constantly publishing messages containing opinions on virtually any imaginable topic, including opinions about companies. Accurately understanding these opinions could provide an almost real-time overview of how the company and its actions are perceived by the general public. While existing approaches used for analyzing the opinions expressed in social media messages commonly limit themselves in discovering the polarity of the messages, expressed as a positive, negative, or neutral value, in the present paper, we use semantic web technologies and natural language processing in order to uncover actual feelings, such as happiness, surprise, or disappointment. The emotions are structured in a hierarchy using an ontology, thus offering the possibility to analyze the overall opinion regarding the company at different levels of granularity. The proposed approach is validated by performing an analysis of the public perception towards four well-known technology companies.
Livu-Adrian Cotfas; Camelia Delcea; Ionut Nica. Uncovering Social Media Users’ Emotions Towards Companies Using Semantic Web Technologies. Financial Environment and Business Development 2020, 119 -128.
AMA StyleLivu-Adrian Cotfas, Camelia Delcea, Ionut Nica. Uncovering Social Media Users’ Emotions Towards Companies Using Semantic Web Technologies. Financial Environment and Business Development. 2020; ():119-128.
Chicago/Turabian StyleLivu-Adrian Cotfas; Camelia Delcea; Ionut Nica. 2020. "Uncovering Social Media Users’ Emotions Towards Companies Using Semantic Web Technologies." Financial Environment and Business Development , no. : 119-128.
With the ever-increasing number of social media messages posted daily, millions of users express opinions on various subjects, including opinions concerning the characteristics of products and services that they have already bought or they intend to buy in the near future. Accurately knowing the opinions of such a large number of users in near real time would be invaluable for the companies marketing those products. Thus, in the present paper, we propose an approach based on Semantic Web technologies, natural language processing and machine learning for accurately analysing the social media messages posted on Twitter. Compared to existing approaches, which mainly focus on determining the opinion of the user concerning the entire product, the approach proposed in the present paper offers deeper insights, by taking into consideration the fact that a user might have different and sometimes even contradictory opinions concerning the various characteristics of a single product. We start by creating an ontology for representing the relationships between the products and their characteristics, ontology that is also used for performing named entity recognition, given the fact that various users can employ different terms for referring to the same concept. The ontology is afterwards used in order to filter from the huge number of tweets published every minute only the ones that can prove relevant for the analysis. In the next step, aspect-based sentiment analysis is employed in order to determine the sentiment expressed by the social media user regarding one or several characteristics of the analysed product. The results of the analysis are stored as semantically structured data, thus making it possible to fully exploit the possibilities offered by Semantic Web technologies, such as inference and accessing the vast knowledge in Linked Open Data, for further analysis.
Livu-Adrian Cotfas; Camelia Delcea; Ionut Nica. Analysing Customers’ Opinions Towards Product Characteristics Using Social Media. Financial Environment and Business Development 2020, 129 -138.
AMA StyleLivu-Adrian Cotfas, Camelia Delcea, Ionut Nica. Analysing Customers’ Opinions Towards Product Characteristics Using Social Media. Financial Environment and Business Development. 2020; ():129-138.
Chicago/Turabian StyleLivu-Adrian Cotfas; Camelia Delcea; Ionut Nica. 2020. "Analysing Customers’ Opinions Towards Product Characteristics Using Social Media." Financial Environment and Business Development , no. : 129-138.
As the evacuation problem has attracted and continues to attract a series of researchers due to its high importance both for saving human lives and for reducing the material losses in such situations, the present paper analyses whether the evacuation doors configuration in the case of classrooms and lecture halls matters in reducing the evacuation time. For this aim, eighteen possible doors configurations have been considered along with five possible placements of desks and chairs. The doors configurations have been divided into symmetrical and asymmetrical clusters based on the two doors positions within the room. An agent-based model has been created in NetLogo which allows a fast configuration of the classrooms and lecture halls in terms of size, number of desks and chairs, desks and chair configuration, exits’ size, the presence of fallen objects, type of evacuees and their speed. The model has been used for performing and analyzing various scenarios. Based on these results, it has been observed that, in most cases, the symmetrical doors configurations provide good/optimal results, while only some of the asymmetrical doors configurations provide comparable/better results. The model is configurable and can be used in various scenarios.
Camelia Delcea; Liviu-Adrian Cotfas; Ioana-Alexandra Bradea; Marcel-Ioan Boloș; Gabriella Ferruzzi. Investigating the Exits’ Symmetry Impact on the Evacuation Process of Classrooms and Lecture Halls: An Agent-Based Modeling Approach. Symmetry 2020, 12, 627 .
AMA StyleCamelia Delcea, Liviu-Adrian Cotfas, Ioana-Alexandra Bradea, Marcel-Ioan Boloș, Gabriella Ferruzzi. Investigating the Exits’ Symmetry Impact on the Evacuation Process of Classrooms and Lecture Halls: An Agent-Based Modeling Approach. Symmetry. 2020; 12 (4):627.
Chicago/Turabian StyleCamelia Delcea; Liviu-Adrian Cotfas; Ioana-Alexandra Bradea; Marcel-Ioan Boloș; Gabriella Ferruzzi. 2020. "Investigating the Exits’ Symmetry Impact on the Evacuation Process of Classrooms and Lecture Halls: An Agent-Based Modeling Approach." Symmetry 12, no. 4: 627.
Due to the increase of the amount of electrical and electronical equipment waste (e-waste), the understanding of individual consumers’ main decision triggers represents a key point in increasing the quantity of recycled e-waste. A series of studies from the literature have shown a positive relationship between the consumers’ attitude, awareness, self-efficacy, social norms, and their e-waste recycling intention, as well as the positive influence between the intention and the manifested behavior. Additional to these determinants, in the present study, the influence of social media was analyzed along with the actions taken by the government and nongovernmental organizations, with the purpose to include and to capture, as much as possible, a high amount of determinants in the e-waste recycling process. Nevertheless, the demographic or socio-economic variables, such as age, gender, income, education, number of family members, etc., have shown over time to have a contribution to predicting the consumers’ pro-recycling behavior. As on one side, in the research literature, the opinions related to which of the demographic or socio-economic factors can have an impact on the recycling behavior have been divided and, on another side, a series of researchers believe that the discrepancies in the findings of different studies can be due to culture in various countries, in this paper we conducted such an analysis with reference to the Romania’s case. The results have shown that the demographic variables, such as age and gender, can have a contribution to predicting residents’ pro-e-waste recycling behavior. Based on these findings, the policymakers can gain a better understanding of the e-waste recycling phenomenon and on its main triggers, with results in creating better policies for sustaining a proper e-waste managing system.
Camelia Delcea; Liliana Crăciun; Corina Ioanăș; Gabriella Ferruzzi; Liviu-Adrian Cotfas. Determinants of Individuals’ E-Waste Recycling Decision: A Case Study from Romania. Sustainability 2020, 12, 2753 .
AMA StyleCamelia Delcea, Liliana Crăciun, Corina Ioanăș, Gabriella Ferruzzi, Liviu-Adrian Cotfas. Determinants of Individuals’ E-Waste Recycling Decision: A Case Study from Romania. Sustainability. 2020; 12 (7):2753.
Chicago/Turabian StyleCamelia Delcea; Liliana Crăciun; Corina Ioanăș; Gabriella Ferruzzi; Liviu-Adrian Cotfas. 2020. "Determinants of Individuals’ E-Waste Recycling Decision: A Case Study from Romania." Sustainability 12, no. 7: 2753.
R. John Milne; Liviu-Adrian Cotfas; Camelia Delcea; Mostafa Salari; Liliana Craciun; Anca Gabriela Molanescu. Airplane Boarding Method for Passenger Groups When Using Apron Buses. IEEE Access 2020, 8, 18019 -18035.
AMA StyleR. John Milne, Liviu-Adrian Cotfas, Camelia Delcea, Mostafa Salari, Liliana Craciun, Anca Gabriela Molanescu. Airplane Boarding Method for Passenger Groups When Using Apron Buses. IEEE Access. 2020; 8 ():18019-18035.
Chicago/Turabian StyleR. John Milne; Liviu-Adrian Cotfas; Camelia Delcea; Mostafa Salari; Liliana Craciun; Anca Gabriela Molanescu. 2020. "Airplane Boarding Method for Passenger Groups When Using Apron Buses." IEEE Access 8, no. : 18019-18035.
This paper investigates the time to complete the boarding of a partially occupied two-door airplane when its passengers are transported from the airport terminal to the airplane using two apron buses. We propose a greedy method that assigns each passenger to a particular apron bus based on the passengers’ airplane seat assignments. This greedy approach exploits the airplane’s symmetry by providing essentially the same method for those boarding through the front door of the airplane as those boarding through the rear door of the airplane. The symmetrical properties of window, middle, and aisle seats of each row/side are considered in the proposed method as well. Computer simulation results indicate that, when using the greedy method, the boarding time can be reduced by up to 8.33% compared to the boarding time resulting from the best known practices in the literature, and with up to a 43.72% improvement in boarding time when compared to the boarding method commonly used in many airports. Furthermore, experimental results confirm our hypothesis that when the capacity of the apron buses exceeds the number of passengers to be transported to the airplane, the most time-efficient results of the proposed greedy method occur when an equal number of passengers are assigned to each of the two apron buses.
R. John Milne; Liviu-Adrian Cotfas; Camelia Delcea; Mostafa Salari; Liliana Craciun; Anca Gabriela Molanescu. Greedy Method for Boarding a Partially Occupied Airplane Using Apron Buses. Symmetry 2019, 11, 1221 .
AMA StyleR. John Milne, Liviu-Adrian Cotfas, Camelia Delcea, Mostafa Salari, Liliana Craciun, Anca Gabriela Molanescu. Greedy Method for Boarding a Partially Occupied Airplane Using Apron Buses. Symmetry. 2019; 11 (10):1221.
Chicago/Turabian StyleR. John Milne; Liviu-Adrian Cotfas; Camelia Delcea; Mostafa Salari; Liliana Craciun; Anca Gabriela Molanescu. 2019. "Greedy Method for Boarding a Partially Occupied Airplane Using Apron Buses." Symmetry 11, no. 10: 1221.
Human behavior and the environment’s characteristics have proven to play an important role within the evacuation process as they can facilitate a shorter evacuation time. The collaborative classrooms represent a now-a-days architectural trend as, when compared to the classical classrooms, they provide a friendlier space for learning, allowing students to easily exchange information and knowledge among them and to increase their ability of working as a team in completing the assigned tasks during a class. In this context, the evacuation process from this type of classrooms is discussed. A simulated evacuation has been conducted using 18 students, having ages between 19 and 21 years old, in a classical and in a collaborative classroom, and several aspects related to the evacuation process, such as: speed, dealing with obstacles, ad-hoc guided intervention, have been empirically measured. Considering the observations from the field, an agent-based model has been created, calibrated and used for simulations. The model is highly configurable and be adapted to various classroom configurations. Five types of collaborative classroom configurations have been used and hierarchized base on their evacuation time efficiency when the exit doors’ position is given. The presence of jumped and bypassed obstacles and the volunteer guidance have been analyzed. Their impact on the evacuation time is discussed within the paper, along with the study’s limitations. Based on the simulations, it has been observed that, the evacuation time in the case of the collaborative classroom in the presence of one exit door has been, on average, with 6.02% smaller than in the case of a non-collaborative classroom. Also, the presence of two evacuation doors in a collaborative classroom and a proper desk placement can reduce, on average, the evacuation time with up to 36.51% when compared to one-door evacuation situation.
Camelia Delcea; Liviu-Adrian Cotfas; Liliana Craciun; Anca Gabriela Molanescu. An agent-based modeling approach to collaborative classrooms evacuation process. Safety Science 2019, 121, 414 -429.
AMA StyleCamelia Delcea, Liviu-Adrian Cotfas, Liliana Craciun, Anca Gabriela Molanescu. An agent-based modeling approach to collaborative classrooms evacuation process. Safety Science. 2019; 121 ():414-429.
Chicago/Turabian StyleCamelia Delcea; Liviu-Adrian Cotfas; Liliana Craciun; Anca Gabriela Molanescu. 2019. "An agent-based modeling approach to collaborative classrooms evacuation process." Safety Science 121, no. : 414-429.
The use of apron buses for transporting passengers from the airport terminal to the airplane has become common practice for a series of airports worldwide. Airline companies have become increasingly aware of this practice and have added information to their boarding passes to suggest the airplane door passengers should use while boarding the airplane. In contrast, many of the literature’s methods to reduce boarding time assume the presence of a jet-bridge connecting the airplane to the terminal. These boarding methods are “by seat” and “by group” methods. The use of the apron buses for passengers’ transport limits the usage of these methods because, in most cases now, only two apron buses are needed for transporting the passengers. With two apron buses, boarding control is limited to deciding on which passengers to assign to each of the two buses. We propose 15 new methods that we tested against the previously published Back-to-front method adapted for the apron buses case, by considering 7 luggage situations. An agent-based model in NetLogo is created based on field trials and considerations made in the literature, and we used this model for simulations. Experimental results show that the best performing proposed methods combine aspects of the WilMA and Reverse Pyramid boarding methods adapted for apron buses. The best proposed method can reduce boarding time by up to 39.2% when compared to the benchmark Back-to-front method.
Camelia Delcea; R. John Milne; Liviu-Adrian Cotfas; Liliana Craciun; Anca Gabriela Molanescu. Methods for Accelerating the Airplane Boarding Process in the Presence of Apron Buses. IEEE Access 2019, 7, 134372 -134387.
AMA StyleCamelia Delcea, R. John Milne, Liviu-Adrian Cotfas, Liliana Craciun, Anca Gabriela Molanescu. Methods for Accelerating the Airplane Boarding Process in the Presence of Apron Buses. IEEE Access. 2019; 7 (99):134372-134387.
Chicago/Turabian StyleCamelia Delcea; R. John Milne; Liviu-Adrian Cotfas; Liliana Craciun; Anca Gabriela Molanescu. 2019. "Methods for Accelerating the Airplane Boarding Process in the Presence of Apron Buses." IEEE Access 7, no. 99: 134372-134387.
The use of apron buses has become a common practice at many European airports. Previous studies related to airplane boarding rarely apply when apron buses are used, leaving airlines with no well-researched option except to use the random boarding method. In this paper, we test the time to complete boarding a two-door airplane using various boarding methods with two apron buses. These methods were inspired by the classical outside-in, back-to-front, and reverse-pyramid methods considering the limited number of boarding groups corresponding to the limited number of apron buses used for transporting passengers from the terminal to the aircraft. Unlike earlier publications, we test these methods under partial aircraft occupancy. Furthermore, we test the boarding methods under conditions involving: different passenger occupancy rates, different luggage situations, and with two types of seating assignments—random and based upon passenger seating preferences—by considering the advantages brought by the symmetric layout of the aircraft. Experimental results indicate that the best performing method can reduce the boarding time by up to 38.6% compared to the time resulting from the random boarding method. When the airplane is partially occupied, the best performing methods are reverse pyramid–A, hybrid–A, and hybrid–B, all with similar performances.
Liviu-Adrian Cotfas; Camelia Delcea; R. John Milne; Mostafa Salari; Liliana Crăciun; Anca Gabriela Molănescu. Testing New Methods for Boarding a Partially Occupied Airplane Using Apron Buses. Symmetry 2019, 11, 1044 .
AMA StyleLiviu-Adrian Cotfas, Camelia Delcea, R. John Milne, Mostafa Salari, Liliana Crăciun, Anca Gabriela Molănescu. Testing New Methods for Boarding a Partially Occupied Airplane Using Apron Buses. Symmetry. 2019; 11 (8):1044.
Chicago/Turabian StyleLiviu-Adrian Cotfas; Camelia Delcea; R. John Milne; Mostafa Salari; Liliana Crăciun; Anca Gabriela Molănescu. 2019. "Testing New Methods for Boarding a Partially Occupied Airplane Using Apron Buses." Symmetry 11, no. 8: 1044.
Educational properties have recorded an average of 4980 structure fires between 2011 and 2015 according to US National Fire Protection Association. It has been determined that four out of five fires in schools have occurred between 6 a.m. and 6 p.m., when pupils were around. Even though the percentage of structure fires in educational properties has fallen over the years, there is still place for improvement and knowing how to react in such situations can contribute to reducing pupils’ injuries and also to their lifesaving. Thus, the present paper analysis the possibility of using agent-based simulations in NetLogo for a classroom with two exits in order to increase pupils’ awareness on how to act during an evacuation process caused by a fire. Based on an empirical study, it has been observed that after presenting the NetLogo evacuation simulation, the pupils’ awareness has increased with up to 22.99%, having a direct result on the overall evacuation time and their safety.
Camelia Delcea; Liviu-Adrian Cotfas. Increasing awareness in classroom evacuation situations using agent-based modeling. Physica A: Statistical Mechanics and its Applications 2019, 523, 1400 -1418.
AMA StyleCamelia Delcea, Liviu-Adrian Cotfas. Increasing awareness in classroom evacuation situations using agent-based modeling. Physica A: Statistical Mechanics and its Applications. 2019; 523 ():1400-1418.
Chicago/Turabian StyleCamelia Delcea; Liviu-Adrian Cotfas. 2019. "Increasing awareness in classroom evacuation situations using agent-based modeling." Physica A: Statistical Mechanics and its Applications 523, no. : 1400-1418.