127,618 research outputs found
Evaluation of a prescriptive ventilation standard with regard to 3 different performance indicators
In this paper, the performance of Belgian building code compliant residential ventilation systems is evaluated on multiple performance indicators: occupant exposure to bio-effluents, occupant exposure to other use-related pollutants (odours) and occupant exposure to building material emissions.
The fitness of the proposed criteria in this context is then discussed in a broader context and this information is then used to interpret the fitness of the code prescriptions as design criteria for performant ventilation systems
The influence of Vehicle Dynamics Control System on the Occupant’s Dynamic response during a Vehicle collision
This paper aims to apply a vehicle dynamics control system to mitigate a vehicle collision and to study the effects of this systems on the kinematic behaviour of the vehicle's occupant. A unique three-degree-of-freedom vehicle dynamics-crash mathematical model and a simplified lumped-mass occupant model are developed. The first model is used to define the vehicle body's crash parameters and it integrates a vehicle dynamics model with a model of the vehicle's front-end structure. In this model, the anti-lock braking system and the active suspension control system are co-simulated, and the associated equations of motion are developed. The second model aims to predict the effect of the vehicle dynamics control system on the kinematics of the occupant. The Lagrange equations are used to solve that model owing to the complexity of the obtained equations of motion. It is shown from the numerical simulations that the vehicle dynamics-crash response and occupant behaviour can be captured and analysed quickly and accurately. Furthermore, it is shown that the vehicle dynamics control system can affect the crash characteristics positively and that the occupant's behaviour is improved
Heat metering: socio-technical challenges in district-heated social housing
Individual heat metering and charging (IMC) are seen as promising methods to reduce domestic heating and hot water use through the provision of financial incentives. The heat consumption measured by meters is influenced by both the dwelling characteristics and the behaviour of the occupant, but heating charges would ideally relate to occupant behaviour only. This dilemma can be especially relevant under two circumstances: if the thermal performance of the dwelling is poor and/or if heating costs represent a substantial part of the occupants’ income, i.e. in social housing. The case of a district-heated council block in London is presented where the installation of individual heat meters was planned in 2010 but had to be suspended due to concerns about implications for occupant heating costs in light of the thermal performance of the building. It illustrates a technically and socially complex environment where fairness in allocating heating costs is an important concern. The case also shows how lack of funding or other issues on the infrastructure side can hinder behaviour-orientated measures such as IMC. A holistic energy conservation strategy addressing both physical building properties and occupant behaviour is therefore essential and should be supported by policy
Pediatric Wheelchair Transportation Safety: Transit Manual Wheelchair Design Guidelines and Injury Risk of 6-year-old Children in a Frontal Motor Vehicle Impact
Children with disabilities often cannot be seated in standard child seats or automobile seats because of physical deformities or poor trunk and head control. Therefore, when children with disabilities are transported to schools and developmental facilities, they often remain seated in their wheelchairs in vehicles such as school buses and family vans. Children who must travel seated in their wheelchairs are excluded from the protections dictated by the federal and state laws related to child protection in motor vehicle crashes. This dissertation investigated the safety of children in wheelchairs in transit, mainly using computer simulation software. Three pediatric manual wheelchairs were tested with a Hybrid III 6-year-old ATD in accordance with the ANSI/RESNA WC-19 standard. Using sled test data, a computer model representing a Zippie wheelchair seated with a Hybrid III 6-year-old ATD subjected to a 20g/48kph frontal crash was developed and validated in MADYMO. The injury risks of 6-year-old wheelchair occupants in a frontal impact motor vehicle crash was investigated by analyzing sled test data and by using the pediatric wheelchair computer model. The loads imposed on the wheelchair and occupant restraint system under 20g/48kph frontal impact conditions with varying wheelchair setup conditions was also investigated using the computer model. The study results showed that a 6-year-old wheelchair seated occupant may be subjected to a risk of neck and chest injuries in a frontal impact motor vehicle crash. Results also showed that altering wheelchair settings does have impact on kinematics and injury risk of a 6-year-old wheelchair occupant in a frontal motor vehicle crash. Changing wheelchair settings also had impact on wheelchair kinematics and loads imposed on the wheelchair and occupant restraint system. The study results presented in this dissertation will provide guidelines for manufacturers designing pediatric transit wheelchairs, seating, and occupant restraint system. The pediatric wheelchair model developed in this study will provide a foundation for studying the response of a manual pediatric wheelchair and a child occupant in crashes. Moreover, the model will promote the study of associated injury risks for pediatric wheelchair users in motor vehicle crashes
Behavioural pattern identification and prediction in intelligent environments
In this paper, the application of soft computing techniques in prediction of an occupant's behaviour in an inhabited intelligent environment is addressed. In this research, daily activities of elderly people who live in their own homes suffering from dementia are studied. Occupancy sensors are used to extract the movement patterns of the occupant. The occupancy data is then converted into temporal sequences of activities which are eventually used to predict the occupant behaviour. To build the prediction model, different dynamic recurrent neural networks are investigated. Recurrent neural networks have shown a great ability in finding the temporal relationships of input patterns. The experimental results show that non-linear autoregressive network with exogenous inputs model correctly extracts the long term prediction patterns of the occupant and outperformed the Elman network. The results presented here are validated using data generated from a simulator and real environments
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Single-occupancy simulator for ambient intelligent environment
In this paper, the simulation of an occupant’s behaviour in a single-occupant ambient intelligent environment is addressed. The algorithm of the simulator is designed flexible enough to accept different environmental profiles including the number of areas and the connections between them along with different occupant’s profiles including expected daily occupancy pattern of him/her and the uncertainty of his/her behaviour to follow this occupancy pattern. The generated occupancy signal by the simulator represents the occupancy of areas by assuming a signal level for the occupancy of each area in a single-occupant environment with the resolution of one minute in a whole day activity of the occupant in the environment. The validity of the simulator will be verified by tuning the simulator’s parameters to occupancy data collected by sensory agents from a real equivalent environment. By applying the generated data from this simulator to the data mining techniques, the ability of different techniques will be investigated
Evaluation of Impact Energy Attenuators and Composite Material Designs of a UAM VTOL Concept Vehicle
The development of Vertical Take-off and Landing (VTOL) vehicles for the Urban Air Mobility (UAM) markets presents a need for light weight vehicle structures with effective occupant protection capabilities. The National Aeronautics and Space Administration (NASA) has been working to fill that need, recently developing a cadre of concept vehicles to help characterize UAM design feasibility. This paper describes a study, using these concept vehicles, to evaluate the use of advanced composite structure and energy attenuating designs in the UAM vehicle design space. A finite element model (FEM) of a single passenger quadrotor concept vehicle was developed in LS-Dyna and simulated under nominal and off-nominal vertical impact conditions. A variety of energy attenuating design mechanisms were implemented within this model to quantify their effectiveness in improving occupant safety. The use of carbon composites in both the energy attenuation mechanisms and vehicle structure was evaluated. The results of this study found significant reduction in occupant injury risk with the implementation of energy absorbing composite crush tubes and landing gear within the vehicle design. Additionally the use of a carbon fiber as a structural material was found to provide significant weight reduction while maintaining similar occupant loads to that predicted with an aluminum structure. This work provides a preliminary evaluation of design mechanisms and materials that may be used to optimize occupant protection capabilities within the UAM market
Microcomputer based software for biodynamic simulation
This paper presents a description of a microcomputer based software package, called DYNAMAN, which has been developed to allow an analyst to simulate the dynamics of a system consisting of a number of mass segments linked by joints. One primary application is in predicting the motion of a human occupant in a vehicle under the influence of a variety of external forces, specially those generated during a crash event. Extensive use of a graphical user interface has been made to aid the user in setting up the input data for the simulation and in viewing the results from the simulation. Among its many applications, it has been successfully used in the prototype design of a moving seat that aids in occupant protection during a crash, by aircraft designers in evaluating occupant injury in airplane crashes, and by users in accident reconstruction for reconstructing the motion of the occupant and correlating the impacts with observed injuries
Occupant behaviour in naturally ventilated and hybrid buildings
Adaptive thermal comfort criteria for building occupants are now becoming established. In this paper we illustrate their use in the prediction of occupant behaviour and make a comparison with a non-adaptive temperature threshold approach. A thermal comfort driven adaptive behavioural model for window opening is described and its use within dynamic simulation illustrated for a number of building types. Further development of the adaptive behavioural model is suggested including use of windows, doors, ceiling fans, night cooling, air conditioning and heating, also the setting of opportunities and constraints appropriate to a particular situation. The integration in dynamic simulation of the thermal adaptive behaviours together with non-thermally driven behaviours such as occupancy, lights and blind use is proposed in order to create a more complete model of occupant behaviour. It is further proposed that this behavioural model is implemented in a methodology that includes other uncertainties (e.g. in internal gains) so that a realistic range of occupant behaviours is represented at the design stage to assist in the design of robust, comfortable and low energy buildings
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