The Experts below are selected from a list of 240 Experts worldwide ranked by ideXlab platform
Sophia C Alih - One of the best experts on this subject based on the ideXlab platform.
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seismic vulnerability of air traffic Control Towers
Natural Hazards, 2018Co-Authors: Mohammadreza Vafaei, Sophia C AlihAbstract:Airports are one of the critical infrastructures that play an essential role in managing natural disasters through receiving or sending aid and supplies. Air traffic Control (ATC) Towers are an inseparable part of each airport as the performance of airports depends on the functionality of their ATC Towers. Many ATC Towers have been designed and constructed based on older versions of modern seismic codes in which seismic design has followed a force-based design approach. This study addresses the seismic vulnerability of three in-service ATC Towers which have been designed and constructed according to a force-based design concept. The height of the Towers ranges from 24 to 52 m. Fragility curves have been used for the seismic vulnerability study of these Towers. For the derivation of seismic fragility curves, 45 earthquake records were selected and classified into low, medium and high classes based on their ratio of peak ground acceleration (PGA) to peak ground velocity (PGV). It was observed that records with a low PGA/PGV ratio imposed the highest level of damage to the Towers. However, when Towers were subjected to the records with a high PGA/PGV ratio, the damage intensity was not significant. Results indicated that the intensity of seismic-induced damage to the tallest tower was significantly more than that of the shortest tower. It was concluded that only the shortest tower could satisfy the expected seismic performance objectives.
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Assessment of seismic design response factors of air traffic Control Towers
Bulletin of Earthquake Engineering, 2016Co-Authors: Mohammadreza Vafaei, Sophia C AlihAbstract:Air Traffic Control (ATC) Towers are among the most vital structures in each airport. Due to inadequate information regarding the seismic design and assessment of these types of structures, practicing engineers may refer to building codes. However, taking into account the special dynamic behavior of ATC Towers, instructions and recommendations provided in building codes often do not comply with the required seismic performance levels of ATC Towers. In this study, seismic behaviors of three in-service ATC Towers with a dual concrete core lateral load resisting system were studied through pushover and incremental dynamic collapse analysis. Seismic design response factors of the reference Towers were calculated. It was found that seismic design response factors adopted by the design code did not provide a uniform safety margin for all reference ATC Towers. It was also observed that shorter Towers have significantly higher response modification factors compared to taller Towers. For the studied Towers, a structural over-strength factor of 2.4 and a displacement amplification factor of 4 were obtained.
Mohammadreza Vafaei - One of the best experts on this subject based on the ideXlab platform.
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seismic vulnerability of air traffic Control Towers
Natural Hazards, 2018Co-Authors: Mohammadreza Vafaei, Sophia C AlihAbstract:Airports are one of the critical infrastructures that play an essential role in managing natural disasters through receiving or sending aid and supplies. Air traffic Control (ATC) Towers are an inseparable part of each airport as the performance of airports depends on the functionality of their ATC Towers. Many ATC Towers have been designed and constructed based on older versions of modern seismic codes in which seismic design has followed a force-based design approach. This study addresses the seismic vulnerability of three in-service ATC Towers which have been designed and constructed according to a force-based design concept. The height of the Towers ranges from 24 to 52 m. Fragility curves have been used for the seismic vulnerability study of these Towers. For the derivation of seismic fragility curves, 45 earthquake records were selected and classified into low, medium and high classes based on their ratio of peak ground acceleration (PGA) to peak ground velocity (PGV). It was observed that records with a low PGA/PGV ratio imposed the highest level of damage to the Towers. However, when Towers were subjected to the records with a high PGA/PGV ratio, the damage intensity was not significant. Results indicated that the intensity of seismic-induced damage to the tallest tower was significantly more than that of the shortest tower. It was concluded that only the shortest tower could satisfy the expected seismic performance objectives.
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Assessment of seismic design response factors of air traffic Control Towers
Bulletin of Earthquake Engineering, 2016Co-Authors: Mohammadreza Vafaei, Sophia C AlihAbstract:Air Traffic Control (ATC) Towers are among the most vital structures in each airport. Due to inadequate information regarding the seismic design and assessment of these types of structures, practicing engineers may refer to building codes. However, taking into account the special dynamic behavior of ATC Towers, instructions and recommendations provided in building codes often do not comply with the required seismic performance levels of ATC Towers. In this study, seismic behaviors of three in-service ATC Towers with a dual concrete core lateral load resisting system were studied through pushover and incremental dynamic collapse analysis. Seismic design response factors of the reference Towers were calculated. It was found that seismic design response factors adopted by the design code did not provide a uniform safety margin for all reference ATC Towers. It was also observed that shorter Towers have significantly higher response modification factors compared to taller Towers. For the studied Towers, a structural over-strength factor of 2.4 and a displacement amplification factor of 4 were obtained.
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seismic damage detection of tall airport traffic Control Towers using wavelet analysis
Structure and Infrastructure Engineering, 2014Co-Authors: Mohammadreza Vafaei, Azlan AdnanAbstract:In this study, the applicability of continuous wavelet transform (CWT) and discrete wavelet transform (DWT) for seismic damage detection of tall airport traffic Control (ATC) Towers was investigated. Nonlinear finite element (NFE) model of Kuala Lumpur International Airport (KLIA) ATC tower with the height of 120 m was created using discrete moment-curvature hinges. Three different strong ground motions excited the tower and three different damage scenarios were then obtained. Response accelerations at four strategically selected locations were analysed by CWT and DWT to detect the damage scenarios. It was found that CWT successfully detects seismic-induced damage even when the signals are polluted by noises. On the other hand, DWT is quite sensitive to noisy signals and successful damage detection by DWT depends on noise level and sampling interval. Moreover, it was observed that DWT is more sensitive to the change in the stiffness of the tower structural elements than CWT.
Maxime Reynal - One of the best experts on this subject based on the ideXlab platform.
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Non-visual interaction concepts : considering hearing, haptics and kinesthetics for an augmented remote tower environnment
2019Co-Authors: Maxime ReynalAbstract:In an effort to simplify human resource management and reduce operational costs, Control Towers are now increasingly designed to not be implanted directly on the airport but remotely. This concept, known as remote tower, offers a “digital”working context: the view on the runways is broadcast remotely using cameras located on site. Furthermore, this concept could be enhanced to the Control of several airports simultaneously from one remote tower facility, by only one air traffic Controller (multiple remote tower). These concepts offer designers the possibility to develop novel interaction forms. However, the most part of the current augmentations rely on sight, which is largely used and, therefore, is sometimes becoming overloaded. In this Ph.D. work, the design and the evaluation of new interaction techniques that rely onnon-visual human senses have been considered (e.g. hearing, touch and proprioception). Two experimental campaigns have been led to address specific use cases. These use cases have been identified during the design process by involving experts from the field, appearing relevant to Controllers due to the criticality of the situation they define. These situations are a) poor visibility (heavy fog conditions, loss of video signal in remote context), b) unauthorized movements on ground (when pilots move their aircraft without having been previously cleared), c) runway incursion (which occurs when an aircraft crosses the holding point to enter the runway while another one is about to land), and d) how to deal with multiple calls associated to distinct radio frequencies coming from multiple airports. The first experimental campaign aimed at quantifying the contribution of a multimodal interaction technique based on spatial sound, kinaesthetic interaction and vibrotactile feedback to address the first use case of poor visibility conditions. The purpose was to enhance Controllers’ perception and increase overall level of safety, by providing them a novel way to locate aircraft when they are deprived of their sight. 22 Controllers have been involved in a laboratory task within a simulated environment.Objective and subjective results showed significantly higher performance in poor visibility using interactives patial sound coupled with vibrotactile feedback, which gave the participants notably higher accuracy in degraded visibility.Meanwhile, response times were significantly longer while remaining acceptably short considering the temporal aspect of the task. The goal of the second experimental campaign was to evaluate 3 other interaction modalities and feedback addressing 3 other critical situations, namely unauthorized movements on ground, runway incursion and calls from a secondary airport. We considered interactive spatial sound, tactile stimulation and body movements to design3 different interaction techniques and feedback. 16 Controllers’ participated in an ecological experiment in which they were asked to Control 1 or 2 airport(s) (Single Vs. Multiple operations), with augmentations activated or not. Having no neat results regarding the interaction modalities into multiple remote tower operations, behavioural results shown asignificant increase in overall participants’ performance when augmentation modalities were activated in single remoteControl tower operations. The first campaign was the initial step in the development of a novel interaction technique that uses sound as a precise means of location. These two campaigns constituted the first steps for considering non-visual multimodal augmentations into remote tower operations.
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Audio Focus: Interactive spatial sound coupled with haptics to improve sound source location in poor visibility
International Journal of Human-Computer Studies, 2019Co-Authors: Maxime Reynal, Pietro Aricò, Jean-paul Imbert, Gianluca Borghini, Jérôme Toupillier, Christophe HurterAbstract:In an effort to simplify human resource management and reduce costs, Control Towers are now more and more designed to not be implanted directly on the airport but remotely. This concept, known as Remote Control Tower, offers a “digital” working context because the view on the runways is broadcast remotely via cameras, which are located on the physical airport. This offers researchers and engineers the possibility to develop novel interaction techniques. But this technology relies on the sense of sight, which is largely used to give the operator information and interaction, and which is now becoming overloaded. In this paper, we focus on the design and the testing of new interaction forms that rely on the human senses of hearing and touch. More precisely, our study aims at quantifying the contribution of a multimodal interaction technique based on spatial sound and vibrotactile feedback to improve aircraft location. Applied to Remote Tower environment, the final purpose is to enhance Air Traffic Controller's perception and increase safety. Three different interaction modalities have been compared by involving 22 Air Traffic Controllers in a simulated environment. The experimental task consisted in locating aircraft in different airspace positions by using the senses of hearing and touch through two visibility conditions. In the first modality (spatial sound only), the sound sources (e.g. aircraft) had the same amplification factor. In the second modality (called Audio Focus), the amplification factor of the sound sources located along the participant's head sagittal axis was increased, while the intensity of the sound sources located outside this axis was decreased. In the last modality, Audio Focus was coupled with vibrotactile feedback to indicate in addition the vertical positions of aircraft. Behavioral (i.e. accuracy and response times measurements) and subjective (i.e. questionnaires) results showed significantly higher performance in poor visibility when using Audio Focus interaction. In particular, interactive spatial sound gave the participants notably higher accuracy in degraded visibility compared to spatial sound only. This result was even better when coupled with vibrotactile feedback. Meanwhile, response times were significantly longer when using Audio Focus modality (coupled with vibrotactile feedback or not), while remaining acceptably short. This study can be seen as the initial step in the development of a novel interaction technique that uses sound as a means of location when the sense of sight alone is not enough.
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Involving Hearing, Haptics and Kinesthetics into Non-visual Interaction Concepts for an Augmented Remote Tower Environment
2019Co-Authors: Maxime Reynal, Pietro Aricò, Jean-paul Imbert, Christophe Hurter, Gianluca Borghini, Gianluca Di Flumeri, Nicolina Sciaraffa, Antonio Di Florio, Michela Terenzi, Simone PozziAbstract:We investigated the contribution of specific HCI concepts to provide multimodal information to Air Traffic Controlers in the context of Remote Control Towers (i.e. when an airport is Controlled from a distant location). We considered interactive spatial sound, tactile stimulation and body movements to design four different interaction and feedback modalities. Each of these modalities have been designed to provide specific solutions to typical Air Traffic Control identified use cases. Sixteen professional Air Traffic Controllers (ATCos) participated in the experiment, which was structured in four distinct scenarios. ATCos were immersed in an ecological setup, in which they were asked to Control (i) one airport without augmentations modalities, (ii) two airports without augmentations, (iii) one airport with augmentations and (iv) two airports with augmentations. These experimental conditions constituted the four distinct experimental scenarios. Behavioral results shown a significant increase in overall participants’ performance when augmentation modalities were activated in remote Control tower operations for one airport.
Christophe Hurter - One of the best experts on this subject based on the ideXlab platform.
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Audio Focus: Interactive spatial sound coupled with haptics to improve sound source location in poor visibility
International Journal of Human-Computer Studies, 2019Co-Authors: Maxime Reynal, Pietro Aricò, Jean-paul Imbert, Gianluca Borghini, Jérôme Toupillier, Christophe HurterAbstract:In an effort to simplify human resource management and reduce costs, Control Towers are now more and more designed to not be implanted directly on the airport but remotely. This concept, known as Remote Control Tower, offers a “digital” working context because the view on the runways is broadcast remotely via cameras, which are located on the physical airport. This offers researchers and engineers the possibility to develop novel interaction techniques. But this technology relies on the sense of sight, which is largely used to give the operator information and interaction, and which is now becoming overloaded. In this paper, we focus on the design and the testing of new interaction forms that rely on the human senses of hearing and touch. More precisely, our study aims at quantifying the contribution of a multimodal interaction technique based on spatial sound and vibrotactile feedback to improve aircraft location. Applied to Remote Tower environment, the final purpose is to enhance Air Traffic Controller's perception and increase safety. Three different interaction modalities have been compared by involving 22 Air Traffic Controllers in a simulated environment. The experimental task consisted in locating aircraft in different airspace positions by using the senses of hearing and touch through two visibility conditions. In the first modality (spatial sound only), the sound sources (e.g. aircraft) had the same amplification factor. In the second modality (called Audio Focus), the amplification factor of the sound sources located along the participant's head sagittal axis was increased, while the intensity of the sound sources located outside this axis was decreased. In the last modality, Audio Focus was coupled with vibrotactile feedback to indicate in addition the vertical positions of aircraft. Behavioral (i.e. accuracy and response times measurements) and subjective (i.e. questionnaires) results showed significantly higher performance in poor visibility when using Audio Focus interaction. In particular, interactive spatial sound gave the participants notably higher accuracy in degraded visibility compared to spatial sound only. This result was even better when coupled with vibrotactile feedback. Meanwhile, response times were significantly longer when using Audio Focus modality (coupled with vibrotactile feedback or not), while remaining acceptably short. This study can be seen as the initial step in the development of a novel interaction technique that uses sound as a means of location when the sense of sight alone is not enough.
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Involving Hearing, Haptics and Kinesthetics into Non-visual Interaction Concepts for an Augmented Remote Tower Environment
2019Co-Authors: Maxime Reynal, Pietro Aricò, Jean-paul Imbert, Christophe Hurter, Gianluca Borghini, Gianluca Di Flumeri, Nicolina Sciaraffa, Antonio Di Florio, Michela Terenzi, Simone PozziAbstract:We investigated the contribution of specific HCI concepts to provide multimodal information to Air Traffic Controlers in the context of Remote Control Towers (i.e. when an airport is Controlled from a distant location). We considered interactive spatial sound, tactile stimulation and body movements to design four different interaction and feedback modalities. Each of these modalities have been designed to provide specific solutions to typical Air Traffic Control identified use cases. Sixteen professional Air Traffic Controllers (ATCos) participated in the experiment, which was structured in four distinct scenarios. ATCos were immersed in an ecological setup, in which they were asked to Control (i) one airport without augmentations modalities, (ii) two airports without augmentations, (iii) one airport with augmentations and (iv) two airports with augmentations. These experimental conditions constituted the four distinct experimental scenarios. Behavioral results shown a significant increase in overall participants’ performance when augmentation modalities were activated in remote Control tower operations for one airport.
Anna Trzuskawska-grzesińska - One of the best experts on this subject based on the ideXlab platform.
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Control Towers in supply chain management – past and future
Journal of Economics and Management, 2017Co-Authors: Anna Trzuskawska-grzesińskaAbstract:IntroductionThe global economy requires global supply chain management, which engages many partners, processes, resources and a lot of information. In such conditions, competing means implementing and maintaining agile, adaptive and aligned supply chain [Lee 2004]. Dynamic alignment [Gattorna 2008] and agility requires visibility and responsiveness, both driving the need for real time information available to all decision makers with operation's synchronization mechanisms and feedback loops. The visibility and responsiveness could be achieved by implementing supply chain event management (SCEM) consisting of: "[...] monitoring the planned sequence of activities along a supply chain and the subsequent reporting of any divergence from that plan to enable a proactive, even automatic, response to deviations from the plan" [Christopher 2011]. The business reports, IT solutions providers' reports shows that the supply chain event management is delivered by supply chain Control Towers. The author hasn't found any research publications regarding practical applications of Control Towers. Therefore the understanding how the Control tower system delivers the supply chain event management in business practice became the author's research challenge.The goal of the research paper is to identify business examples of different approaches to the supply chain Control tower in the past and initiate a discussion on their future. The author also aims to examine the current state of the supply chain literature in terms of a knowledge gap regarding the Control Towers operations and their future. Through selected case studies and comparative analyses in the high-tech industry this paper brings an update from the market. The results could be used in a further supply chain research and modelling. This paper also delivers to the supply chain managers up-to date practical knowledge regarding possible trends in configuring and developing supply chain Control Towers.The remainder of the paper is organized as follows. The Section 1 contains review of theoretical and practical background for the supply chain and supply chain Control tower. The supply chain Control tower is analyzed in three dimensions: organization, IT solutions and processes.In Section 2 the research methodology is presented. The author selected three companies that operate in the high-tech market and are engaged in aftersales service. The methods used were both case studies and in-depth interviews with management representatives followed by comparative analysis and enriched by literature data directly related to the researched companies.In Section 3 the research results are presented. The past of the researched Control Towers operations and their expected future are characterized. The article finishes with the results discussion and overall conclusions regarding the past and future practices in supply chain Control tower operations.1.Literature reviewAccording to Poirier and Reiter [1996] a supply chain is a system through which organizations deliver their products and services to their customers... a network of the interlinked organizations, that have a common purpose: the best possible means of affecting that delivery. Similar approach was taken by Aitken [1998] followed by Christopher [2011] saying supply chain is a network of connected and interdependent organizations mutually and co-operatively working together to Control, manage and improve the flow of materials and information from suppliers to end users.The supply chain requires management. Following the Council of Supply Chain Management Professionals (CSCM 2016), it could be stated: supply chain management (SCM) encompasses the planning, organizing and Controlling all activities involved in sourcing and procurement, conversion, and all logistics activities. It also includes coordination and collaboration with channel partners, which can be suppliers, intermediaries, third party service providers, and customers. …