Current Seat Research Articles

Review on Additive Manufacturing Process in Aircraft Industries

This paper explores the feasibility of implementing 3D printing technology for manufacturing seat buckles in the Airbus A380. While additive manufacturing has gained attention for its versatility, safety-critical components require rigorous testing and certification. Through a comprehensive review of literature and expert interviews, this study analyzes the viability of 3D printing for seat buckle production. The results indicate that traditional manufacturing methods, such as injection molding and forging, remain the preferred choices due to their established reliability and quality control procedures. The aviation industry places the utmost importance on safety and reliability, especially in the manufacturing of safety-critical components like seat buckles. This paper examines the potential integration of 3D printing technology into the production process of seat buckles for the Airbus A380, considering the stringent certification requirements and performance expectations. A literature review encompassing additive manufacturing techniques, aerospace certification processes, and current seat buckle manufacturing practices was conducted. Expert interviews were also conducted to gather insights from industry professionals with expertise in aerospace manufacturing. The analysis revealed that conventional manufacturing methods such as injection molding and forging are currently preferred for seat buckle production in the Airbus A380 and other aircraft parts. These methods have established reliability and quality control procedures, ensuring compliance with rigorous safety standards. Although 3D printing has found success in prototyping and non-critical components, its application in safety-critical components like seat buckles is limited. The decision to favor traditional manufacturing methods for seat buckle production in the Airbus A380 is driven by the need for extensively tested and certified components. Safety-critical parts undergo stringent testing to guarantee their performance under various operating conditions. While 3D printing offers design flexibility and reduced lead times, further research and development is necessary to ensure its viability in safety-critical applications. At present, 3D printing technology is not widely employed for manufacturing seat buckles in the Airbus A380. Traditional methods provide the required reliability and quality control procedures. However, ongoing advancements in additive manufacturing may present future opportunities for incorporating 3D printing technology into safety-critical applications within the aerospace industry. Further research and development are necessary to explore these possibilities.

Seat allocation optimization for railways considering social distancing during the post-pandemic period

IntroductionEnsuring social distance is crucial for protecting public health and reducing the risk of COVID-19 transmission, particularly in enclosed spaces like public transport. However, it implies a reduction in seat occupancy and thereby cuts the revenue of railway operators. In the post-pandemic period, increase revenue while ensuring passenger safety is becoming increasingly important for railway operators. MethodsThis study proposes a group seat allocation method (GSAM) to ensure different social distancing requirements between passenger groups from different risk-level areas. An integer linear programming model is established to maximize the operator’s revenue, and an efficient adaptive large neighborhood search (ALNS) algorithm is developed to solve the large-scale problem of interest. ResultsA set of numerical experiments is conducted to validate the proposed model and assess the computational efficiency of the algorithm. The results obtained from a real-word example demonstrate that the GSAM can improve revenue by a considerable 62.64%, while maintaining public health and safety standards, relative to current seat allocation methods. Furthermore, railway operators can adopt varying levels of social distancing measures in response to different stages of the COVID-19 pandemic, such as implementing more rigorous social distancing requirements during the pre-pandemic period to ensure stringent public health measures. ConclusionsThe findings of this study demonstrate that railway operators can increase revenue while also ensuring passenger safety during an epidemic. These results have practical implications for the railway industry, and the study aspires to provide new insights for operators on how to adapt to the COVID-19 pandemic and similar respiratory virus transmissions in the future.

Reducing pressure with the goal of improving outcomes: a retrospective chart review of cushion evaluations and recommendations at one seating clinic

Purpose To describe the current seating recommendations made by a seating clinic for wheelchair users who presented with a Pressure Injury (PrI) or history of PrI. Methods Retrospective review of electronic medical records of 133 adults who used a wheelchair as their primary means of mobility who had a cushion evaluation during which interface pressure mapping data was documented. Results Clinicians adjusted 71% of participants’ wheelchair cushions, including 49% who received a new cushion, and 37% of participants’ wheelchairs. The most common adjustments besides receiving a new cushion were: addition of an underlay, adjusting the inflation of a cushion, and adjustments to the foot or back support of the wheelchair. Forty-five participants only received adjustments (i.e. no new cushion), while 23 participants only received education and feedback rather than equipment modifications. Those 23 participants had significantly lower Peak Pressure Index (PPI) than those who received equipment modifications (mean [95% CI] 76.7 [59.1, 94.3] versus 111.6 [102.1, 121.2] respectively, p = 0.001). The PPI was reduced by an average of 22.5 mmHg from the initial to final seating system amongst those who received modifications ([13.9–31.0], p<.001). Conclusions The seating clinicians considered interface pressure mapping in their decision-making and effectively reduced interface pressures with their interventions. Cushion replacement is important when someone presents with a PrI. However, adjusting an existing wheelchair cushion and/or seating system provides important additions and alternatives to consider for reducing interface pressure. There is also a role for education about proper use of equipment, weight shifts, and alternate seating surfaces. IMPLICATIONS FOR REHABILITATION A cushion evaluation may involve evaluating more than one cushion configuration and using pressure mapping to compare the best options. To address perceived wheelchair cushion issues, posture and positioning should be evaluated and adjusted as necessary, in addition to evaluating the cushion itself. Common positioning modifications include: modifying/adding cushion underlays or inflation and foot and back supports in response to clients’ changing postural needs and wheelchair components coming out of optimal position due to wear and tear. Adjustments to the wheelchair and cushion aim to distribute body weight over a larger surface area, reduce pressure at high-risk locations, improve posture, and increase function. These adjustments should consider individual’s specific needs and goals, while also being mindful of funding barriers.

Maps of the Roman Catholic Diocese of Poreč and Pula (Dioecesis Parentina et Polensis)

ABSTRACT The paper describes previous maps of the Diocese of Poreč and Pula and creation of a new map of the Diocese made and published after many changes and long-time research at the Faculty of Geodesy, University of Zagreb. The data collection of the general geographic content and the sacral content was the first step for the new map visualization of the Diocese. It also describes different problems for special map contents and observed shortcomings on the previous maps, and how they are solved. The research objective was the creation of the new map of the Diocese based on the collected and verified data, showing the exact borders of the Diocese and current borders of the deaneries with current seats. On the new map (Main Map) at a scale of 1:120 000, the parish borders with the seats and names of parishes are depicted for the first time.

Anthropometric Seat Design for Bus Drivers in Southwestern Nigeria

Most buses used in Nigeria are imported; thus, the anthropometric dimensions of the citizens of the country of manufacture were used for the seat design. Poorly designed seats due to a mismatch in anthropometric measurements may lead to musculoskeletal disorders. Hence, there is a need to design an appropriate seat for particular bus drivers. This study aimed to obtain anthropometric dimensions of Nigerian bus drivers and design an appropriate driver’s seat based on the collected dimensions. Relevant anthropometric variables necessary for the driver’s seat design were obtained from 150 randomly selected male bus drivers from seven towns in Ogun, Oyo and Lagos states. Seat dimensions of 50 urban buses in heavy and medium automobile categories were considered. The means, standard deviations and 5th, 50th and 95th percentiles were calculated. The existing seat dimensions were compared with the required anthropometric measurements of the drivers for the seat design. It was found that the current seat measurements differed from the suggested seat dimensions. The study highlighted that in designing and producing bus seats for Nigerian bus drivers, their anthropometric data should be considered. The study recommended that the dimensions of the driver’s seat should be 46.45-50.45 cm (seat height); 39-48.26 cm (seat depth); 46.83 cm (seat front width); 53 cm (backrest height); 49-58.26 (backrest depth); and 90° to 130° (seat backrest angle).

The effects of a new seat suspension system on whole body vibration exposure and driver low back pain and disability: Results from a randomized controlled trial in truck drivers

Through a randomized controlled trial, we evaluated the effects of an electro-magnetic active seat suspension that reduces exposure of a long-haul truck driver to whole body vibration (WBV) on low back pain (LBP) and disability. Among 276 drivers recruited from six trucking terminals of a major US trucking company, 135 eligible drivers were assigned to either having an Active Seat (Intervention: n = 70) – the BoseRide® electro-magnetic active seat – or Passive Seat (reference: n = 65) – a new version of their current seat (passive air suspension seat) – installed in their truck via block (terminal) randomization. Low back pain (LBP) severity, on a 0–10 scale and the Oswestry LBP Disability Index were collected before and 3-, 6-, 12-, 18-, and 24-months post seat installation. LBP severity and LBP disability scores were significantly lower post seat installation in both groups. At 3 months, LBP severity decreased -1.4 [95% CI: -2.1 to -0.7: n = 46] for drivers in the Active Seat arm, and −1.5 [95% CI: -2.3 to -0.8: n = 41] for drivers in the Passive Seat arm. In a subset of drivers, WBV exposures were collected before and after the seat installation. WBV exposures significantly decreased post seat installation for Active Seat (p < 0.01) but not for Passive Seat (p = 0.15). While the new seat-suspension technology reduced WBV exposures, LBP appeared to be improved by multiple factors. These results were limited by the secondary prevention approach and the longer-term loss to follow up due to large rates of driver turnover typical for the industry.

Ergonomic Perspective: Mismatch between Seat Drivers and Anthropometric Measures of Elderly Taxi Drivers in Malaysia

The ageing community may keep resuming their service even after the pension, which was influenced by their previous work environment. One of the occupations that elderly individuals could engage in is taxi drivers. Feelings of discomfort are generated among drivers when there is a mismatch between the product/device and the user. This study's principal objective is to assess the mismatch between seat drivers and anthropometric measurements among elderly taxi drivers to improve their work environment in term of safety and health. A cross-sectional study was led utilizing a self-administered survey instrument that involved four taxi cars from Proton products on seat measurement. Secondary data applied to obtain anthropometric measurements of elderly taxi drivers, which involved 56 elderly (male) drivers. The anthropometric parameters and seat parameters measured. The mismatch can be determined at any value over 95% or less than 80% of the respondents' total number. The measurements between 80% to 99% are classified as matched to the reference value of the respondents. The cushion width based on the proposed size at 95th percentiles show as much as 91.8% is matched to the width of the hip of the elderly taxi drivers. The backrest width which refers to the proposed measurement at 95th percentiles matched 94.0% the length of elderly taxi drivers' shoulder. The proposed cushion length measurement with knee-length to the buttock of elderly taxi drivers at a 5th percentile is 92.8% matched. The study provides a concrete foundation to identify a mismatch between current seat size with anthropometric of elderly taxi drivers that cause injury or pain due to discomfort while driving in Malaysia. It also helps us initiate the prevention of musculoskeletal disorders (MSDs) in health and safety. The baseline data is believed to benefit the automotive industry before the designing process.

FROM SURVEY TO 3D MODELLING TO DIGITAL FABRICATION. A WORKFLOW AIMED AT DOCUMENTING AND TRANSMITTING BUILT HERITAGE

Abstract. This contribution illustrates the results of research that aims to connect the workflow for knowledge – survey, interpretation, modeling – to the transmission of this knowledge and enhancement of Cultural Heritage by physical models, demonstrating its potential in a “Design for All” perspective. Palazzo Mazzonis, the current seat of the MAO (Museo d’Arte Orientale), is one of the many buildings in the historic city center of Turin characterized by a particular complex vaulted atrium: it has been investigated through TLS survey tools for the production of two-dimensional drawings (for the detailed representation of architectural features) and three-dimensional models (for the interpretation of the design idea through geometry). The last phase of work aims to translate the interpretative digital models into tactile models for Cultural Heritage transmission, through processes of digital fabrication, with obvious impacts on the visit path inside the museum, also with didactic purposes.

Surveying Therapists on Seating Approaches for Patients with Muscular Dystrophy in Japan.

Patients with muscular dystrophy (MD) need fitted wheelchairs. This study aimed to ascertain physiotherapists and occupational therapists’ opinions about the current wheelchair seating process for patients with MD in Japan. We identified 266 academic papers published between August 2014 and July 2019 with the keywords “muscular dystrophy” and either “physiotherapy” or “occupational therapy.” We then sent survey requests to 140 physiotherapists and occupational therapists (who were among the authors of the aforementioned papers), of whom 41 agreed to partake in this study. We found that the time required for each seating was 30–60 min for three types of MD, and the most commonly reported time to trial fitting was 1–3 months. In addition, health insurance reimbursements for seating were considered part of disease-specific rehabilitation in most cases, and most therapists were more or less satisfied with the current seating procedure. Physiotherapists had the highest degree of reflection of their views (wishes) regarding seating, followed by MDs and their families. In Japan, seating has been regarded as a medical practice since 2017. In the future, we would like to investigate the seating concept for individual therapists in detail.

The effects of different seat suspension types on occupants' physiologic responses and task performance: implications for autonomous and conventional vehicles

This study evaluated whole body vibration (WBV), non-driving task performance, muscle activity, and self-reported discomfort and motion sickness between different seat suspension systems in a simulated vehicle environment. In a repeated-measures laboratory experiment where field-measured 6-degree-of-freedom (6-DOF) passenger vehicle vibration was replicated on a 6-DOF motion platform, we measured WBV, non-driving task (pointing, typing, web-browsing, and reading) performance, low back (erector spinae), shoulders (trapezius) and neck (splenius capitis and sternocleido-mastoid) muscle activity, and self-reported discomfort and motion sickness from three different seats: a vertical (z-axis) active suspension, multi-axial active suspension [vertical (z-axis) + lateral (y-axis)], and a static suspension-less seat (current seat type in all passenger cars). Both the vertical and multi-axial active suspension seats significantly reduced the vertical WBV exposure (p < 0.0001). However, no significant differences were found in non-driving task performance (p > 0.30), muscle activity (p > 0.22), self-reported discomfort (p > 0.07), and motion sickness (p = 0.53) across three different seats. These findings indicate that the active suspension seats may have potential to future reduce the vertical and total WBV exposures, respectively. However, none of the suspension seats demonstrate any significant benefits on the non-driving task performance, muscle activity, self-reported discomfort and motion sickness measures in a simulated vehicle environment.

Concept evaluation of a new aircraft passenger privacy bubble using virtual prototyping: A Human-Centered Design framework.

The Human-Centered Design methodology advocates VR prototyping, as an effective tool to evaluate concepts in a cost-efficient, time-saving way. It is the question of whether it works in the development of a product intended to increase privacy while flying. The current study aims at the application of virtual reality on the evaluation of a new privacy bubble called PRIVA for the passenger cabin. An interactive VR was created and aligned with the HTC VIVE headset. 40 participants took part in the experiment as well as in the post-experiment survey. The concept was in overall, desirable as it was perceived to be more private, comfortable, satisfactory, effective, and appealing to participants compared to the current seat experiences. It was also perceived as more satisfactory with regards to the activities. The VR was effective, although there are limitations, the product seems promising and should be developed further.

PRELIMINARY STUDY ON THE ERGONOMIC DESIGN OF MOTORCYCLE SEAT FOR COMFORT USAGE

Motorcycle seats undeniably provides good comfort to motorcyclists but there are some that offers less affirmation on ushering comfort, whilst some even results in harm to users, resulting in back pains, neck, shoulders, and other parts of the body over prolonged riding periods. This research aims to investigate the discomforts faced by motorcyclist and the best seat concept based on an ergonomic design, fit for the masses through a subjective evaluation. A study that includes a survey was conducted to study the subjective assessment against the motorcycle seat comfort. The study is divided into two parts, where in part 1, the anthropometric data were collected from a total of 100 respondents, representing 88 males and 12 females. Mean from the anthropometric data was used for two new seat redesigns, designated Seat A and Seat B. For part 2, sets of questionnaire were distributed to 130 respondents to measure their perception of seat design A and design B. Based on the results produced, 86.2% respondents suffered discomforts while riding a motorcycle. Most suffered discomforts at particular body areas: lower back, buttock and shoulder, while no discomfort reported around leg, feet and thigh. Results also proved that current seat designs needed an improvement with a majority of respondents opting an added backrest and to increase surface around buttock area. Based on the evaluation of designs, Seat B was selected as a better option as compared to seat A in terms of comfort usage.

Relationship between seat surface shape and pressure distribution in school seat models.

Students remain in a sedentary position inside classrooms for 60% to 80% of their school day. As such, research has associated students' prolonged seated posture on school furniture with their discomfort and musculoskeletal pain. The correlation between the shape of the seat surface and the zones of the body making contact with these surfaces constitutes an essential factor in determining comfort-enhancing seat design. This study's primary aim lies in contrasting the standard, current school chair against two seat prototypes, both designed and built from digital models, comparing seat-user pressure distribution and contact area during students' performance of different school tasks. Participants (n = 13), ages 7 to 19, performed school tasks sitting on three different chairs' seat surfaces during the test: the current seat used in schools and two seat prototypes, each designed based on body anatomy. The seats were evaluated through a force-sensing array pressure-mapping system. The measurements from designed seat prototypes provide a better distribution of pressures and greater contact area with the students' anatomical areas (buttocks and thighs) than the seat currently used in the specified schools. The improvement in pressure values and contact area as seen in the second designed seat prototype is due to its inclination angle and contact with students' sacral zone. This research work found that a seat's shape based on human anatomical features (buttocks and thighs), compared to a completely flat seat, creates a higher reduction of body pressures and an increase in the body contact area, with the intent to increase comfort and reduce musculoskeletal pain.

Joining Methods of Analytic Hierarchy Process (AHP), Kano Model and Quality Function Deployment (QFD) to Improve the Tractor’s Seat Design for Tractor Drivers in Bangladesh

Nowadays, many product development projects fail as for not meeting customer’s expectations up to the mark as product development process is conducted very unsystematically and results in waste of resources. Customer requirement and satisfaction measurement is a major challenge which can be achieved through various methods. This paper presents joining methods of Analytic Hierarchy Process (AHP), Kano Model and Quality Function Deployment to improve the Tractor’s Seat design for tractor driver’s in Bangladesh in terms of ergonomic and user’s needs. A survey was done to 50 Tractor drivers to identify problems of the current seat. By analyzing the data identified the customer requirements and ranked it using AHP. With that Kano questionnaires were developed and answered by 50 tractor drivers. After that, with the integration of Kano model, QFD process was carried out to determine the customer requirement weight and the technical requirement weight to develop a modified design. At the end of the study, it was found out that both methods were able to prioritize the modification elements to be implemented into the new ergonomically designed tractor seat. Still there are some limitations. The analysis was performed based on 50 tractor drivers. For more correct results, more than 50 drivers could be taken into account.

Ergonomics assessment of current aircraft passenger seat design against Malaysian anthropometry data

There have been many complaints from aircraft passengers regarding the cabin comfort level during flight. One of the main cabin aspects that influence the level of passenger comfort is identified as the passenger seat. In this study, the representative of the current aircraft seat design is evaluated against anthropometry data of Malaysians. This is done to establish whether there is any mismatch between the seat design and the anthropometry of the Malaysian passengers such that it contributes to the low cabin comfort experiences. Based on the findings, it can be generally concluded that the current aircraft seat needs to be better and more ergonomically designed to match with the Malaysian anthropometry in order to potentially provide more comfortability for the Malaysian aircraft passengers.

Mapping Air Population

Abstract. “Air population” refers to the total number of people flying above the earth at any point in time. The total number of passengers can then be estimated by multiplying the number of seats for each aircraft by the current seat occupancy rate. Using this method, the estimated air population is determined by state for the airspace over the United States. In the interactive, real-time mapping system, maps are provided to show total air population, the density of air population (air population / area of state), and the ratio of air population to ground population.

Air Population over the Great Plains

Early trails through the Great Plains remind us that humans have passed through the area for many years. The area was seen as an impediment; the purpose was simply to get to the other side. The Great Plains are now often referred to as “flyover country,” a disparaging description indicating that most people simply fly over. The “flyoverness” of the Great Plains can be examined through air population, the total number of people flying above the earth at any point in time. The instantaneous location of aircraft can now be tracked through an extensive network of ground aircraft sensors based on ADS-B (Automated Dependent Surveillance-Broadcast) that provides the position of an aircraft along with its identification, aircraft type, altitude, and speed. Air population can then be estimated by multiplying the number of seats for each aircraft by the current seat occupancy rate. This population is further divided by state and county. Maps show the total air population, the density of air population (population/area), and the ratio of air population to ground population. While high ground population areas also have a high air population, “flyover” states have a higher ratio of air population to ground population. The analysis also shows that many counties in the Great Plains regularly have more people above them than live on the ground.

Mapping Air Population

“Air population” is defined as the total number of people flying above the earth at any point in time. It is distinct and separate from the population still physically connected to earth. Real-time air population can be estimated by using an extensive network of ground sensors based on ADS-B (Automatic Dependent Surveillance-Broadcast) that precisely locate the location of aircraft in real time. An aircraft determines its position via GPS and broadcasts it along with its identification, aircraft type, altitude, and speed. The total number of passengers can then be estimated by multiplying the number of seats for each aircraft by the current seat occupancy rate. Using this method, the estimated air population is determined by state and region for the airspace over the USA. In the interactive, real-time mapping system, maps are provided to show total air population, the density of air population (air population/area of state), and the ratio of air population to ground population. Among other things, the analysis shows that while high ground population states also have a high air population, and “flyover” areas have a higher ratio of air population to ground population.

Thirty years of anthropometric changes relevant to the width and depth of transportation seating spaces, present and future

This paper reports the results of an investigation into changes in body shape anthropometry over the past several decades and discusses the impact of those changes on seating in transport, especially airliners. Changes in some body shape dimensions were confirmed in a sample of students at TU Delft; several of the changes, e.g. hip breadth, seated, are relevant to the ongoing design of seating. No change in buttock knee length was observed.The fit between current user anthropometry and current airline seat design, especially regarding seat width, was investigated. A comparison of the average current seat breadth with global anthropometric data suggests that accommodation may be problematic, with less than optimal width for passengers’ shoulder and elbow widths.

The Distribution of Power in the Lebanese Parliament Revisited

The governance structure of the Lebanese Republic is particularly characterized by its confessional nature guaranteeing a pre-defined representation of Christians and Muslims and its sectarian subgroups in parliament. In this sense, the composition of the parliament is based on the allocation of a specific number of seats to each of the two major religious groups and its sectarian subgroups. However, the ratio being used to assign seats to these sectarian subgroups has been an intensively debated controversial issue over decades. Recently, Diss and Zouache (2015) have addressed some aspects of power in the Lebanese Parliament. Applying the Penrose-Banzhaf and Shapley-Shubik indices, they investigate the relative confessional power distributions under the current seat distribution and a proposal for its amendment and revealed some paradoxical effects. Since then a new electoral law has been introduced for the Lebanese Parliament. In this paper, we re-examine the results of Diss and Zouache (2015) applying the Penrose-Banzhaf measure. Furthermore, we take into account the effects of the new electoral law and the seat distribution prior to the current one. This allows us to relate our findings to the general motivations for the electoral reforms underlying all studied seat distributions. Additionally, we address the implications of the existing party blocs in the current parliament from a party and confessional perspective. Currently, their existence is put into question in the public and political discussion. With our analysis, we deliver a theoretical foundation for this debate and demonstrate that in terms of parliamentary power the current bloc formation is a priori disadvantageous.