Browse Topic: Reaction and response times
ABSTRACT This study investigated the effect of an innovative chilling device that intends to make subjects more alert and less sleepy. Tests were conducted using a variety of methods including electric-encephalography (EEG) brain tomography. A series of behavioral tests showed an increase in alertness, changes of body temperatures, and performance indicators after usage of this device. The device chills specific areas of the body and disrupts the body’s ability to self-regulate core body temperature. The induced temperature shifts may reduce the body’s capability to go to sleep. Physiological changes and brain wave indicators of alertness were also reviewed in this paper. A full study of alertness indicators in expanded driver simulations is recommended. As for future application of this device to Human Factors aspects, this device may have the potential to enhance alertness in the human dimension of machine operation of manned and unmanned assets with further improvement
ABSTRACT This paper discusses the design and implementation of an interactive mixed reality cockpit that enhances Soldier-vehicle interaction by providing a 360-degree situational awareness system. The cockpit uses indirect vision, where cameras outside the vehicle provide a video feed of the surroundings to the cockpit. The cockpit also includes a virtual information dashboard that displays real-time information about the vehicle, mission, and crew status. The visualization of the dashboard is based on past research in information visualization, allowing Soldiers to quickly assess their operational state. The paper presents the results of a usability study on the effectiveness of the mixed reality cockpit, which compared the Vitreous interface, a Soldier-centered mixed reality head-mounted display, with two other interface and display technologies. The study found that the Vitreous UI resulted in better driving performance and better subjective evaluation of the ability to actively
ABSTRACT In this paper, we propose a new approach to developing advanced simulation environments for use in performing human-subject experiments. We call this approach the mission-based scenario. The mission-based scenario aims to: 1) Situate experiments within a realistic mission context; 2) Incorporate tasks, task loadings, and environmental interactions that are consistent with the mission’s operational context; and 3) Permit multiple sequences of actions/tasks to complete mission objectives. This approach will move us beyond more traditional, tightly-scripted experimental scenarios, and will employ concepts from interactive narrative as well as nonlinear game play approaches to video game design to enhance the richness and realism of Soldier-task-environment interactions. In this paper, we will detail the rationale for adopting such an approach and present a discussion of significant concepts that have guided a proof-of-concept test program of the mission-based scenario, which we
ABSTRACT: Ground vehicle survivability and protection systems and subsystems are increasingly employing sensors to augment and enhance overall platform survivability. These systems sense and measure select attributes of the operational environment and pass this measured “data” to a computational controller which then produces a survivability or protective system response based on that computed data. The data collected is usually narrowly defined for that select system’s purpose and is seldom shared or used by adjacent survivability and protection subsystems. The Army approach toward centralized protection system processing (MAPS Modular APS Controller) provides promise that sensor data will be more judiciously shared between platform protection subsystems in the future. However, this system in its current form, falls short of the full protective potential that could be realized from the cumulative sum of sensor data. Platform protection and survivability can be dramatically enhanced if
ABSTRACT To support customers during product development, General Dynamics Land Systems (GDLS) utilizes a set of Operations Research/Decision Support processes and tools to facilitate all levels of decision-making aimed at achieving a balanced system design. GDLS employs a rigorous Structured Decision (SD) process that allows for large, highly complex or strategic decisions to be made at the system-of-systems, system, and/or subsystem level. Powerful, robust tools -the Advanced Collaborative System Optimization Modeler (ACSOM) and Logical Decisions for Windows (LDW) - are used to make relatively quick assessments and provide recommendations. The latest ACSOM algorithms have increased the response time for trade study analysis by over 2,000 times and future versions will incorporate logistics analysis helping to reduce vehicle Life Cycle Cost
ABSTRACT Military vehicle electrical power systems require quickly responding fault protection to prevent mission failure, vehicle damage, or personnel injury. The electromechanical contactors commonly used for HEV protection have slow response and limited cycle life, factors which could result in fuse activation and disabling of the vehicle, presenting a dangerous situation for the soldier. A protection technology not often considered is Solid State Circuit Breakers (SSCB), which have fast response and good reliability. Challenges of extremely high currents and voltages, high temperatures, and harsh conditions have prevented SSCBs from being effective in high power military vehicle electrical systems. Development of an SSCB for military vehicle power systems would increase electrical power system capacity and expand mission capability. The development of a 1.2 kV/200A Silicon-Carbide MOSFET based SSCB for combat HEVs is presented. The key innovation is packaging that minimizes losses
Severe problem of aerodynamic heating and drag force are inherent with any hypersonic space vehicle like space shuttle, missiles etc. For proper design of vehicle, the drag force measurement become very crucial. Ground based test facilities are employed for these estimates along with any suitable force balance as well as sensors. There are many sensors (Accelerometer, Strain gauge and Piezofilm) reported in the literature that is used for evaluating the actual aerodynamic forces over test model in high speed flow. As per previous study, the piezofilm also become an alternative sensor over the strain gauges due to its simple instrumentation. For current investigation, the piezofilm and strain gauge sensors have mounted on same stress force balance to evaluate the response time as well as accuracy of predicted force at the same instant. However, these force balance need to be calibrated for inverse prediction of the force from recorded responses. A reliable multi point calibration
Abrasion of the Electromechanical brake (EMB) brake pad during the braking process leads to an increase in brake gap, which adversely affects braking performance. Therefore, it is imperative to promptly detect brake pad abrasion and adjust the brake gap accordingly. However, the addition of extra gap adjustment or sensor detection devices will bring extra size and cost to the brake system. In this study, we propose an innovative EMB gap active adjustment strategy by employing modeling and analysis of the braking process. This strategy involves identifying the contact and separation points of the braking process based on the differential current signal. Theoretical analysis and simulation results demonstrate that this gap adjustment strategy can effectively regulate the brake gap, mitigate the adverse effects of brake disk abrasion, and notably reduce the response time of the braking force output. Monitoring is critical to accurately control EMB clamping force. Pressure transducers are
After-treatment sensors are used in the ECU feedback control to calibrate the engine operating parameters. Due to their contact with exhaust gases, especially NOx sensors are prone to soot deposition with a consequent decay of their performance. Several phenomena occur at the same time leading to sensor contamination: thermophoresis, unburnt hydrocarbons condensation and eddy diffusion of submicron particles. Conversely, soot combustion and shear forces may act in reducing soot deposition. This study proposes a predictive 3D-CFD model for the analysis of the development of soot deposition layer on the sensor surfaces. Alongside with the implementation of deposit and removal mechanisms, the effects on both thermal properties and shape of the surfaces are taken in account. The latter leads to obtain a more accurate and complete modelling of the phenomenon influencing the sensor overall performance. The evolution of the fouling thickness is evaluated by means of the implementation of a
This Recommended Practice, Operational Definitions of Driving Performance Measures and Statistics, provides functional definitions of and guidance for performance measures and statistics concerned with driving on roadways. As a consequence, measurements and statistics will be calculated and reported in a consistent manner in SAE and ISO standards, journal articles proceedings papers, technical reports, and presentations so that the procedures and results can be more readily compared. Only measures and statistics pertaining to driver/vehicle responses that affect the lateral and longitudinal positioning of a road vehicle are currently provided in this document. Measures and statistics covering other aspects of driving performance may be included in future editions. For eye glance-related measures and statistics, see SAE J2396 (Society of Automotive Engineers, 2007) and ISO 15007-1 (International Standards Organization, 2002
Motorcyclists are about 29 times more likely than passenger vehicle occupants to die in a motor vehicle crash and are 4 times more likely to be injured. Safe motorcycling takes balance, co-ordination, and good judgement. As per NHTSA, per 100,000 registered vehicles motorcycle fatality and injury rate stand at 58.33 and 975 and that of passenger vehicles stand at 9.42 and 1152. With such rates of fatality and injury of motorcyclists, there is strong need for motorcycle solutions that help to minimize traffic fatalities and improve road safety scenarios. Helmets are estimated to be 37% effective in preventing fatal injuries to motorcycle riders and 41% for motorcycle passengers but there is little to no post-crash assistance available on board the motorcycles. Post-crash emergency response is time sensitive and can be broken down into a subset of activities beginning with discovery of crash, notification, and activation of emergency medical service (EMS), response time, on-scene time
This SAE Aerospace Recommended Practice (ARP) covers the design, construction, performance and testing requirements for hand held aircraft tire inflation pressure gauges with valve stem attachment chuck to be used with all aircraft types. The ground-based gauges in this specification are those which are designed to read the tire inflation pressure from a position adjacent to the tire
Hydrostatic torque modulation is a new, at moment theoretical approach, to developing advanced AWD4WD transmissions. The basic component is a rotational hydrostatic modulator. It is derived from a low-speed high-torque hydrostatic machine. As such, it can be integrated into a standard mechanical AWD4WD transmission as a replacement for the clutch, where torque is controlled through energy dissipation. Controlled by a simple solenoid valve, it provides torque vectoring with a reaction time shorter than 0.5 s, and it provides additional safety features that result in a more robust AWD4WD transmission. As it can modulate torque with energy flow control/transfer, it offers much more than existing systems based on controlled clutches. Specifically, hydrostatic torque modulation, when it is integrated into the AWD4WD transmission, brings CVT or ICT performance. As torque modulation is performed through the control of the energy flow, it provides torque control from 0 km/h without using a
The pleasure boat intended in this paper is an outboard motor boat equipped with an outboard motor operating a propeller thrust and a steering angle. Outboard motor boats have a wide variation in the number of outboard motors to be equipped with depending on the size and a shape of the boat itself, and the environmental disturbances peculiar to a boat such as tidal currents and winds greatly influences the heading control performance. Therefore, it is necessary to realize a robust heading control response to environmental disturbances regardless of the variation of boats. There are two challenges for realizing such heading control response. One challenge is ensuring the stability of the control system in the entire speed region from the low-speed region for fishing applications to the high-speed region for mobile applications to which the autopilot function is applied. The other one is the suppression of the deviation in the response time of the heading control response. In response to
According to research studies, epidemics such as SARS, COVID-19 spread have caused huge negative impacts on population, health and the economy around the globe. The outbreak places a huge burden on international health systems that were already straining to address AIDS, tuberculosis, malaria, and a host of other conditions. Research has proven that incase infected person is not traced timely then the spread of infection in society will take the shape of large-scale community transmission. Most of the infections spread because they got unnoticed by the infected person. One part of the access checker scans is a person’s body temperature by measuring infrared radiation emitted by their skin. Fever screening by infrared thermal imaging has become more widespread following the SARS infection, and particularly during the pandemic H1N1 and COVID-19 outbreak. Skin temperature is measured without contact by monitoring the emitted infrared radiation. The infrared thermal camera that monitors
This study presents a demonstration of generating biodiesel from fish oil utilising microwave with a significant reduction in the amount of catalyst needed during the reaction and the time of reaction. Various factors such as microwave power, catalyst concentration, reaction duration, and molar ratio were tested experimentally. The response surface approach was used to improve the reaction parameters. As reaction parameters, four levels were chosen: molar ratio, catalyst concentration, and reaction time. According to the RSM model results, molar ratio has a crucial role in the transesterification of fish oil to bio diesel. Confirmatory tests were carried out to validate the acquired data, and they proved to be worthwhile
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