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15 records found

Journal article (2026) - Yu Song, Anna S. Reichherzer, Xinhe Yao, Gerbera Vledder, Britta Herbig, Michael Bellmann, Victor Norrefeldt, Peter Vink, Neil Mansfield
Background
A quantitative comfort model will aid in evaluating comfort levels of various target groups before the actual flight of an airplane. However, constructing the model is always a challenge due to the complexity of the phenomenon.

Objectives
In this paper, we present quantitative comfort models to predict the (dis)comfort of passengers flying with turboprops based on objective measures.

Methods
Ninety-seven participants took part in two experiments conducted during real flights, during which forty of them had environmental and personal factors recorded using (self-developed) measurement tools. The collected data were analyzed to model the relations between objective measures and subjective feelings.

Results
Two preliminary models based on gradient boosting regression were developed. The models were able to predict the changes in comfort and discomfort of individual passengers with an accuracy of 0.12±0.01 and 0.21±0.01 regarding normalized comfort and discomfort scores, respectively. Additionally, contributions of different factors were highlighted.

Conclusion
The outcomes of the models show that we took a step forward in modeling the human comfort experience using objective measurements. Anthropometry (including age), seat positions, time duration, and row (noise) emerged as leading factors influencing the feeling of (dis)comfort in turboprop planes. ...
Journal article (2026) - Gerbera Vledder, Xinhe Yao, Yu (Wolf) Song, Peter Vink
Background
Current jet airplanes are not sustainable, and turboprop aircraft can be a more sustainable alternative for regional travels. However, the noise levels in turboprops can range from 83 to 92 dB(A), which is higher than jets and is the largest contributor to discomfort in turboprops.

Objective
The objective of this study was to assess the efficacy of utilizing noise-cancelling headphones or earplugs in mitigating (dis)comfort experienced by passengers aboard turboprop aircraft.

Methods
An experiment was designed in a grounded Boeing 737 cabin with the sound source inside. Twenty-four participants experienced four conditions: jet sound (Boeing 737), turboprop (ATR 72) sound, turboprop sound with active noise-cancelling (ANC) headphones, and turboprop sound with earplugs. The sound level used for all conditions in this test ranged between 84.2 and 86.3 dB(A). Passenger experiences were measured using questionnaires, including a newly developed Ear Local Discomfort questionnaire.

Results
The comfort and discomfort scores for the conditions involving ANC headphones and earplugs are significantly improved compared to the conditions without hearing protection. The impact of noise on discomfort is mitigated in these two conditions, though it remains the most prominent factor. ANC headphones cause more discomfort around the ear, while earplugs cause discomfort inside the ear.

Conclusion
The use of ANC headphones and earplugs in a turboprop airplane might increase the acceptance of these airplanes. ANC headphones are slightly preferred over earplugs, but both solutions have specific limitations. ...
Journal article (2026) - Neil J. Mansfield, Peter Vink, Gerbera Vledder, Xinhe Yao, Britta Herbig, Anna S. Reichherzer, Michael Bellmann
Background
Turboprop aircraft offer the possibility of lower emissions for regional travel in comparison to jets. Future low-carbon aircraft concepts include propeller-generated thrust powered from fuel cells, hydrogen, biofuel, battery or hybrid power. The noise and vibration experienced in a turboprop cabin is different to that experienced in a jet, with signals characterised by tonal components related to the propeller blade pass frequency. These components have been associated with noise and vibration discomfort. There are few published studies of aircraft cabin vibration measured on the seat surface according to ISO2631-1; none report data for the whole flight.

Objective
The objective was to measure and evaluate the vibration experienced by passengers for complete turboprop flights and compare vibration data with standards associated with vibration comfort.

Methods
Vibration data was measured on the surface of three occupied seats during two turboprop aircraft flights. Measurements were made on full flights, and covered the entire duration from gate-to-gate.

Results
Data showed that the vibration is highly tonal, and is affected by position and flight phase. Frequency-weighted vibration showed magnitudes below thresholds for health risk. The highest magnitudes of vibration occurred at the blade pass frequency and its harmonics. These frequencies are rejected by standard comfort assessment methods that use frequency weightings.

Conclusions
Whole-body vibration exposure in the turboprop tested in this study did not approach health risk thresholds using ISO2631-1. Analysis of the vibrational comfort requires use of band-limited vibration assessment methods to include the dominant vibration components in analysis. ...
Conference paper (2024) - P Vink, G. Vledder, X. Yao, Y. Song, Neil Mansfield, britta herbig, Anna Reichherzer, Michael Bellman
Many new future sustainable aircraft concepts have (electric) propeller propulsion. However, the noise and vibration generated by propeller propulsion might create discomfort for passengers. In the Clean Sky 2 project ‘ComfDemo’, all factors influencing comfort and discomfort are studied, with the aim to improve comfort experience for eco airplanes. The results show that noise, vibration and seat are the most mentioned factors influencing discomfort. The flights without passengers showed different noise characteristics, which makes test flights with passengers inevitable. Noise certainly needs attention, but anthropometrics as well as for instance elbow-elbow width is greater than the 18” seat width for many passengers. ...

Registering Walking Foot Shapes Using Attention Enhanced Dynamic-Synchronized Graph Convolutional LSTM Network

Journal article (2024) - Farzam Tajdari, Toon Huysmans, Xinhe Yao, Jun Xu, Maryam Zebarjadi, Yu Song
4D-scans of dynamic deformable human body parts help researchers have a better understanding of spatiotemporal features. However, reconstructing 4D-scans utilizing multiple asynchronous cameras encounters two main challenges: 1) finding dynamic correspondences among different frames captured by each camera at the timestamps of the camera in terms of dynamic feature recognition, and 2) reconstructing 3D-shapes from the combined point clouds captured by different cameras at asynchronous timestamps in terms of multi-view fusion. Here, we introduce a generic framework able to 1) find and align dynamic features in the 3D-scans captured by each camera using the nonrigid-iterative-closest-farthestpoints algorithm; 2) synchronize scans captured by asynchronous cameras through a novel ADGC-LSTMbased-network capable of aligning 3D-scans captured by different cameras to the timeline of a specific camera; and 3) register a high-quality template to synchronized scans at each timestamp to form a highquality 3D-mesh model using a non-rigid registration method. With a newly developed 4D-foot-scanner, we validate the framework and create the first open-access data-set, namely the 4D-feet. It includes 4Dshapes (15 fps) of the right and left feet of 58 participants (116 feet including 5147 3D-frames), covering significant phases of the gait cycle. The results demonstrate the effectiveness of the proposed framework, especially in synchronizing asynchronous 4D-scans. ...
Conference paper (2024) - Anna Reichherzer, britta herbig, P. Vink, Y. Song, G. Vledder, X. Yao, Neil Mansfield, Michael Bellman
Turboprop aircraft are a useful alternative to reduce CO2 emissions, but they have a higher noise and vibration level compared to turbojets. We investigated how passengers perceived noise and vibration during two turboprop flights in an ATR72.In general, noise as assessed as slightly loud and slightly annoying, but became less noisy and more comfortable over time. Subjects evaluated the vibration as rather comfortable, but the perception of vibration varied for different body areas. Discomfort of vibration decreased. If noise sensitivity is added to these analyses, changes over time largely disappeared showing the complex interaction between characteristics of the person and the environment. In summary, the rather negative evaluation of noise and vibration could be the factors why people decide not to fly with turboprop aircrafts. The development of turboprop aircraft with less noise and vibration remains important so that this more sustainable aircraft type is competitive. ...
BACKGROUND: A valid distribution of key anthropometric parameters among participants is often a perquisite of ergonomics research. OBJECTIVE: In this paper, we investigated the accuracy of self-reported stature and body mass of the population in the Netherlands. METHODS: Data from 4 experiments was synthesized where in each experiment, participants self-reported their stature and body mass prior to being measured, of which they were not notified before. RESULTS: Statistical analysis of 249 records indicated that on average, participants overreported their stature by 1.31 cm and underreported their mass by 1.45 kg. This is especially true for people with a BMI ≥ 25. CONCLUSION: Two models were proposed to adjust the self-reported stature and body mass for ergonomic researchers in a survey or recruitment. Limitations in using the models are highlighted as well. ...
Conference paper (2023) - P. Vink, Utkarsh Singh, M. Smulders, G. Vledder, X. Yao, Y. Song
The sleep quality and (dis)comfort sitting upright was studied among 40 participants who took a nap at home. They were asked to take a nap at 17:00h on three consecutive days. The backrest had to be at a different angle every day: upright, reclined and more reclined. They were asked to record the backrest angle of the three positions and report the length of the sleep, the sleep quality, comfort and discomfort and influence of other factors each during each nap. From the 120 cases (3 conditions, 40 participants), the cases where participants were not able to sleep had an average backrest angle of 110˚, which was significantly different from the cases where participants were able to sleep, who had an average backrest angle of 118˚. The scores in the more upright position (<110˚) resulted in significantly more discomfort and a lower sleep quality than in the reclined positions (>123˚). As the conditions were arranged by the participants, there was much variation in outcomes. Therefore, future research under more standardised conditions is recommended. ...

Research Methods and Design

Doctoral thesis (2023) - X. Yao, P. Vink, Y. Song
Comfort, which is defined as “a pleasant state or relaxed feeling of a human being in reaction to its environment”, plays an important role in air travel both for passengers and airlines. However, the combination of strict safety regulations, limited space, and a large variation in passenger body types make aircraft cabins challenging environments to create comfort. The studies presented in this PhD thesis focus on different aspects of comfort experience in air travel and are aimed to be helpful for aircraft interior designers, as well as airlines to have creative design solutions for inflight comfort issues in the future... ...
Wearables are used to recognize human activities in various applications. However, there is limited evidence on the comfort feelings in using wearables, which is crucial for the adoption and long-term engagement of users in those applications. In this paper, we propose the concept of comfort wearables in the context of in-flight posture recognition. A comfort wearable and a tight-fit version, using identical hardware and software architecture, were prototyped and tested by 35 participants in a Boeing 737 cabin. During the usage of each wearable, participants were asked to perform seven frequently observed in-flight sitting postures and report their overall comfort/discomfort afterwards. A multilayer perceptron neural network was used to classify those activities. Experiment results indicated that participants appreciated the comfort wearable, rating it with significantly higher comfort scores and lower discomfort scores. Cross-validation results also revealed that using the comfort wearable achieved even better accuracy (74.8%) than using the tight-fit wearable (65.8%) in posture recognition. Outcomes of the study demonstrate that ergonomic design and technical accuracy are not competing factors in the wearable design and highlight the opportunities for designing and using comfort wearables in broader contexts. ...
Journal article (2022) - Xinhe Yao, Yufei He, Sumalee Udomboonyanupap, Norbert Hessenberger, Yu Song, Peter Vink
Seat pressure maps are often used to evaluate comfort of the users. In this study, we explored the relationships between pressure maps and comfort/discomfort of users in aircraft seats with a focus on a new 6-division method on the pressure maps collected at the bottom of the cushions. An experiment was designed where three cushions with identical shapes but different stiffnesses were prepared. 33 subjects joined the experiment and after sitting on each cushion in 4 postures, they completed comfort questionnaires. Pressure maps on the top as well as the bottom of cushions were collected and analysed. Results indicated that measures on the proposed 6 divisions, especially on the distal posterior thigh regions and regions close to ischial tuberosity of the bottom pressure maps, had larger correlation values to comfort scores compared to other division methods. Practitioner summary: The relations between comfort/discomfort and seat pressure maps collected from the top/bottom of three cushions were studied with 33 subjects in four postures. The distal posterior thigh and ischial tuberosity regions in the proposed 6-division of the bottom pressure maps had larger correlation values to comfort/discomfort compared to other methods. ...
Conference paper (2021) - Y. Ping, X. Yao, J. Xu, Juntian Li, Y. Song, P. Vink
The angle of attack (AOA) of an airplane changes the direction of the gravitational force on passengers and thereby might influence passengers’ flying experience. However, the contribution of the AOA regarding comfort/discomfort is not fully explored. In this paper, we aim to fill this knowledge gap by identifying the relationships between the perceived comfort/ discomfort of passengers and the AOA of the plane during the take-off and climbing phases of a flight. An experiment is conducted in a Boeing 737 fuselage where 10 participants were recruited. Each participant experiences 3 setups of seats with different AOAs (3, 14 and 18 degrees) for 20 minutes, respectively. Participants were asked to complete several sets of questionnaires during each session, and their heart rate and the pressure on the seat and the backrest were recorded as well. Experiment results indicated that participants experienced 14-degree as the most comfortable angle with the lowest discomfort, which might be useful for airlines in setting up the take-off and climbingprocedure. ...
Conference paper (2021) - X. Yao, Y. He, Norbert Hessenberger, Y. Song, P. Vink
During a flight, passengers spend most of their time sitting in their seats. Studying the comfort and discomfort while passengers are sitting is helpful to improve the overall comfort during a flight. Pressure mats are commonly used in studies to collect pressure distribution in order to research sitting comfort. Different from most past studies, in which pressure mats are placed on the top of the cushions, the focus of this paper is to show the potential of placing pressure mat below the seat cushion. Three identical cushions differing in stiffness were prepared. The pressure distribution of 12 sitting postures was collected from 33 subjects both at the top as well as at the bottom of the foam in a randomized order. After sitting on each cushion, the participant was asked to leave the seat and complete a sitting comfort and discomfort questionnaire. The results show that the softest cushion got the highest rank in short-term comfort and lowest rank in short-term discomfort. The recorded pressure distributions both on the top and at the bottom of the foam can influence comfort and discomfort. This indicates the potential to use pressure distributions under the foam to evaluate the perceived comfort and discomfort in sitting, which might reduce the intrusive feeling of theparticipants in comfort studies. ...
Conference paper (2021) - X. Yao, Y. Song, P. Vink
Visual stimulus might influence comfort of passengers in air travel. For a better understanding of the visual comfort, it is crucial to identify the constructs of the visual stimulus in the cabin and the contributions of different elements. A two-step approach was adopted in this study where in the first step, several creative sessions were executed for exploring the effect of different elements in the cabin regarding their impact on visual comfort. To inspire the participants, all creative sessions were held in a Boeing 737 cabin where participants were free to explore and had an immersive experience. All identified elements in the creative session were collected and grouped to different categories, that is use as input for the second step, which is an online survey investigating a possible hierarchy of the impact of those categories of elements on visual comfort. Eight were summarized and the three most influential categories were lighting, colour and the space arrangement. These were significantly different from other categories, namely the seat shape, the pattern, the windows, accessories and existence of advertisements. Regarding the gender and the age of the participants, we did not find significant differences regarding the preferences. ...
Journal article (2021) - Xinhe Yao, Yu Song, Peter Vink
BACKGROUND: Scents may influence the perceived comfort of an environment. There are only a few studies conducted on the relationship between scent and comfort in aircraft cabin. OBJECTIVES: The goal of this research is to explore whether relationships between scents and perceived comfort can be found for passengers in an aircraft cabin. METHODS: 276 participants joined an experiment in a Boeing 737 fuselage. The participants were divided into nine groups and each joined a session for 60 minutes with the exposure to different scents. The effect of the odor was measured by a set of questionnaires at the beginning and at the end of the session. Results of questionnaires were analyzed regarding the effects on the completion time, of the type of scents, of the intensity of the scent and on gender. RESULTS: Significant differences were found at the beginning and at the end of the experiment regarding comfort and emotion, but sometimes no relations could be established. The influence of different scents on comfort/discomfort varied and changed over time. However, in all scenarios, participant' scores on emotion decreased. Additionally, the added scents influenced the linearity between the changes in comfort and discomfort. CONCLUSIONS: Smell could influence the perceived comfort/discomfort of aircraft passengers over time, and different types of smells have different effects on passengers. The preferences on scents are diverse, which highlights the need for personalization in aircraft cabin design. ...