This work develops a novel disturbance observer and integral sliding mode technique based fault tolerant attitude control scheme for spacecraft, which is subject to external disturbance torques and ...actuator failures. More specifically, a simple and novel finite-time disturbance observer is first designed to reconstruct the synthetic uncertainty deriving from actuator failures and disturbances, by which the synthetic uncertainty is also compensated or restricted. Then, an integral sliding mode based finite-time fault tolerant attitude stabilisation controller incorporating with an adjusting law is investigated to ensure the closed-loop attitude control system converge to the stable region in finite time. And also the finite-time stability of the closed-loop attitude control system driven by the proposed attitude control scheme is analysed and proved utilising Lyapunov methodology. Finally, a simulation example for a rigid spacecraft model is carried out to verify the effectiveness and superiority of the proposed attitude control approach.
This paper explores consumers' commitment to and conviction about their beliefs in the form of attitude certainty. Based on a review of past research, we present a new framework for understanding ...attitude certainty and how consumers' attitude certainty is shaped by their resisting or yielding to persuasive messages, or even by their reflections on the evidence supporting their attitudes. We propose that attitude certainty is formed and changed largely through an attribution-based reasoning process linked to a finite set of distinct appraisals. Our framework is used to both organize past research and offer guidance for future research endeavors. In addition, we distinguish our framework of appraisal-based attitude certainty from past models in attitudes and persuasion research that have referenced or taken note of the attitude certainty construct. Implications and future directions for the study of consumer behavior are discussed.
Background
Existing studies confirm that some video games can change players' attitudes. However, since we do not know the specific elements responsible for attitude change, the potential of video ...games to achieve desired educational or behavioural outcomes often remains unfulfilled.
Objectives
To fill the research gap, our study examined whether the perspective‐taking game mechanic in the serious game Czechoslovakia 38–89: Borderlands, which had previously been shown to affect attitudes, would have the same effect on another sample of players with different characteristics.
Methods
We have assessed the effect of a historical video game using a perspective‐taking mechanic on players' explicit and implicit attitudes. Explicit attitude changes were measured at a general level, meaning a broad evaluation of a depicted historical event, and at a specific level, meaning a more detailed evaluation of specific aspects of the event. Simultaneously, we measured the effect of players' perceived attitude importance on attitude change. The study used a sample of 137 young adults.
Results and Conclusions
This study's results indicate a significant pretest‐posttest explicit attitude change on the general level and on a specific level in comparison to the control group. Perspective‐taking game mechanics is particularly important for explicit attitude change. No change was found in implicit attitudes. The effect of the perceived attitude importance on attitude change was not confirmed.
Takeaways
As one of the first to focus on the effects of specific game mechanics on attitudes, this study confirmed that perspective‐taking has stable, short‐term effects on attitude change even across different research samples.
Lay Description
What is currently known about the subject matter
It is unclear why some video games can change players' attitudes while others do not.
Several studies confirm video games' effect on explicit, but not on implicit, attitudes.
Research on the effects of game mechanics on attitude changes is in its infancy.
Very few studies focus on what role player characteristics play in their attitude changes.
What our paper adds to this
Perspective‐taking as game mechanics changes explicit attitudes across populations.
Perceived importance of players' attitudes towards topics not necessarily affects attitude changes.
We show that only some facets of attitudes are influenced by the video game.
Implications of study findings for practitioners
Particular game mechanics seem to be essential for attitude changes in players.
Attitude importance and other player characteristics need further research in the video game context.
DIF‐C analysis can provide more detailed information on changes in more complex explicit attitude concepts.
Video games can affect the way we interpret the world around us.
In this paper, for multi-spacecraft systems (MSSs) with a directed complete communication topology and a time-varying virtual leader, an adaptive saturated attitude controller is proposed to achieve ...attitude consensus and attitude tracking under arbitrary initial attitude, mixed attitude constraints, input saturation and external disturbances. Firstly, considering the time-varying desired attitude provided by the virtual leader in a directed complete topology, an MSS attitude error function and an MSS attitude error dynamics based on SO(3) are developed. Next, an effective mixed potential function for the MSS on SO(3) is proposed for the static attitude-forbidden zones, the relative dynamic attitude-forbidden zones and the attitude-mandatory zones. In particular, different from the existing potential functions, the proposed mixed potential function is suitable for arbitrary initial attitude of the spacecraft in MSS, relaxing the restriction on the initial attitude associated with each static and dynamic attitude constraint zones. Then, an adaptive saturated attitude controller is designed to realize attitude consensus and tracking for the MSSs on SO(3) under arbitrary initial attitude, mixed attitude constraints, saturation constraints and external disturbances. Finally, simulation results of an MSS with a time-varying virtual leader are demonstrated to illustrate the efficiency of the proposed attitude controller.
Social cognitive models examining academic and career outcomes emphasize constructs such as attitude, interest, and self-efficacy as key factors affecting students’ pursuit of STEM (science, ...technology, engineering and math) courses and careers. The current research examines another under-researched component of social cognitive models: social support, and the relationship between this component and attitude and self-efficacy in math and science. A large cross-sectional design was used gathering data from 1,552 participants in four adolescent school settings from 5th grade to early college (41 % female, 80 % white). Students completed measures of perceived social support from parents, teachers and friends as well as their perceived ability and attitudes toward math and science. Fifth grade and college students reported higher levels of support from teachers and friends when compared to students at other grade levels. In addition, students who perceived greater social support for math and science from parents, teachers, and friends reported better attitudes and had higher perceptions of their abilities in math and science. Lastly, structural equation modeling revealed that social support had both a direct effect on math and science perceived abilities and an indirect effect mediated through math and science attitudes. Findings suggest that students who perceive greater social support for math and science from parents, teachers, and friends have more positive attitudes toward math and science and a higher sense of their own competence in these subjects.
The study analysed healthcare workers' (HCWs) knowledge, practices, and attitudes regarding coronavirus disease 2019 (COVID-19). A cross-sectional survey was conducted from February 4th to February ...8th, 2020, involving a total of 1357 HCWs across 10 hospitals in Henan, China. Of those surveyed, 89% of HCWs had sufficient knowledge of COVID-19, more than 85% feared self-infection with the virus, and 89.7% followed correct practices regarding COVID-19. In addition to knowledge level, some risk factors including work experience and job category influenced HCWs' attitudes and practice concerning COVID-19. Measures must be taken to protect HCWs from risks linked to job category, work experience, working hours, educational attainment, and frontline HCWs.
Stereotype threat, or the belief that one may be the target of demeaning stereotypes, leads to acute performance decrements and reduced psychological well-being. The current research examined ...stereotype threat among older employees, a group that is the target of many negative stereotypes. Study 1 surveyed older workers in two different organizations regarding their experiences of stereotype threat, their job attitudes and work mental health, and their intentions to resign or retire. Across both samples, feelings of stereotype threat were related to more negative job attitudes and poorer work mental health. In turn, these negative job attitudes were associated with intentions to resign and (possibly) retire. In Study 2, younger and older employees were surveyed. The results indicated that only for older employees were feelings of stereotype threat negatively related to job attitudes, work mental health, and intentions to resign. The implications of these findings for understanding job attitudes and intentions among older workers are discussed.
A naturalistic investigation of New Jersey residents, both before and after they experienced Hurricanes Irene and Sandy, examined support for politicians committed or opposed to policies designed to ...combat climate change. At Time 1, before both hurricanes, participants showed negative implicit attitudes toward a green politician, but at Time 2, after the hurricanes, participants drawn from the same cohort showed a reversed automatic preference. Moreover, those who were significantly affected by Hurricane Sandy were especially likely to implicitly prefer the green politician, and implicit attitudes were the best predictor of voting after the storms, whereas explicit climate-change beliefs was the best predictor before the storms. In concert, the results suggest that direct experience with extreme weather can increase pro-environmentalism, and further support conceptualizing affective experiences as a source of implicit attitudes.
This brief investigates the problem of finite-time output feedback control for spacecraft attitude stabilization without angular velocity measurement. First, two new sufficient conditions for ...finite-time ultimate boundedness and local finite-time stability are derived, which reduce the conservativeness of the traditional conditions. Then, based on the two new sufficient conditions of the finite-time stability, a finite-time observer is proposed to estimate the unknown angular velocity by using the quadratic Lyapunov function method. Next, a finite-time attitude controller is designed based on the estimate of the angular velocity. The finite-time stability of the entire closed-loop system is analyzed through the Lyapunov approach. The rigorous proof shows that the observation errors and the spacecraft attitude will converge to a residual set of zero in finite time. Numerical simulation results illustrate the effectiveness of the proposed strategy.
Objective: Several health behavior theories converge on the hypothesis that attitudes, norms, and self-efficacy are important determinants of intentions and behavior. However, inferences regarding ...the relation between these cognitions and intention or behavior rest largely on correlational data that preclude causal inferences. To determine whether changing attitudes, norms, or self-efficacy leads to changes in intentions and behavior, investigators need to randomly assign participants to a treatment that significantly increases the respective cognition relative to a control condition, and test for differences in subsequent intentions or behavior. The present review analyzed findings from 204 experimental tests that met these criteria. Method: Studies were located using computerized searches and informal sources and meta-analyzed using STATA Version 11. Results: Experimentally induced changes in attitudes, norms, and self-efficacy all led to medium-sized changes in intention (d+ = .48, .49, and .51, respectively), and engendered small to medium-sized changes in behavior (attitudes-d+ = .38, norms-d+ = .36, self-efficacy-d+ = .47). These effect sizes generally were not qualified by the moderator variables examined (e.g., study quality, theoretical basis of the intervention, methodological characteristics, and features of the targeted behavior), although effects were larger for interventions designed to increase (vs. decrease) behavioral performance. Conclusion: The present review lends novel, experimental support for key predictions from health behavior theories, and demonstrates that interventions that modify attitudes, norms, and self-efficacy are effective in promoting health behavior change.
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