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Commercial Space Technologies
Published in Mohammad Razani, Commercial Space Technologies and Applications, 2018
Once the launch vehicle is fully integrated, it is then joined with its payload. This process is called payload integration. The payload will arrive at the launch site from the manufacturing or checkout site to a specialized facility designed to handle the unique needs of the payload. For example, payloads may require fueling, last-minute integration with components, or final testing and checkout. It is then attached to a payload adapter. The payload adapter is the physical connection between the payload and the launch vehicle, and can be integrated with the launch vehicle either horizontally or vertically depending on the vehicle. Once integrated, the payload fairing is installed. The vehicle and payload then make their way to the launch pad, where the combination continues to be monitored during a technical checklist called a countdown. Fueling of a vehicle using liquid propellants takes place at the pad, usually immediately prior to launch.
Video Game Interfaces and Diegesis: The Impact on Experts and Novices’ Performance and Experience in Virtual Reality
Published in International Journal of Human–Computer Interaction, 2021
Quentin Marre, Loïc Caroux, Jean-Christophe Sakdavong
The experimental task was a classic first-person shooter task. This type of performance-intensive task creates enough pressure to engage attentional processes (McMahan et al., 2012). The participants, who had a fixed position in the middle of the virtual environment, had to shoot at targets (i.e. moving black spheres) continuously appearing, rolling then disappearing after a certain amount of time. They were asked to eliminate the targets as quickly as possible. This temporal pressure was materialized by a countdown timer. The task ended when the countdown reached the end. The targets were not necessarily in the players’ field of vision, so they had to look at the radar and potentially rotate in order to have the target inside their field of vision and then to shoot. They also had to watch the temperature of their weapon that could stop functioning for a few seconds if it turned red (overheating). It was then necessary for the players to shift their attention to various parts of the interface in order to be able to have a good performance. More particularly, they had to monitor effectively the peripheral elements (i.e. the radar to see where are the targets, the overheating indicator to avoid wasting time, the countdown to monitor the remaining time and the score to monitor the quality of the performance) as well as the action scene where targets appeared. Thus, the task has been designed to direct the players’ attention to our characteristics of interest of the interface that are supposed to determine the variations of performance, presence, and enjoyment between the conditions.
Risk-taking during wayfinding is modulated by external stressors and personality traits
Published in Spatial Cognition & Computation, 2019
Tad T. Brunyé, Shaina B. Martis, Breanne Hawes, Holly A. Taylor
On half of the 112 trials (56 buildings), there was no time pressure, making the experience identical to Experiment 1. On the other half of trials, the building-specific time pressure (as previously detailed in the Time Pressure Manipulation section) was introduced. The order of pressured versus non-pressured trials was randomized for each participant. During those trials, a countdown timer appeared on the screen. If the participant navigated from start to the building exit within the time limit, they immediately proceeded to the next trial. If the time limit expired before they reached the building exit, an alert appeared on the screen “Time Out! 5-second Penalty!” Once they exited the building, they would wait for 5 seconds until the next trial began. Because participants are generally eager to complete experiments in a timely manner, this delay introduced a penalty described by the participants as “frustrating” and “annoying.”
Analysis of risk-taking behaviors of electric bicycle riders in response to pedestrian countdown signal devices
Published in Traffic Injury Prevention, 2019
Ruikang Yu, Hui Zhao, Cuiping Zhang, Ziyang Wang
The PCSDs installed at the intersections were clock designed to continuously display the number of seconds remaining for crossing pedestrians. As shown in Figure A1 (see online supplement), countdown timing begins as soon as the red phase ends (Figure A1a) and counts the green time with a digital timer (Figure A1b). In the last 3 s, the countdown timer starts blinking (Figure A1c). As soon as the green timing changes to zero, the non–motor vehicle signals have a 3-s interval with an amber signal and then a 2-s all-red interval. Basically, the PCSD is more intuitive than the traditional flashing display and can assist pedestrians to make wiser decisions on whether to enter the intersection or wait. In addition, PCSDs are expected to alleviate waiting anxiety, reduce the starting loss time, and improve the traffic capacity of the intersection (Pulugurtha et al. 2010). In the surveys, the 2-s green flashing interval is included in the green countdown, because riders can decide whether to enter the intersection by taking advantage of the amber signal.